Wearable physiological monitors have become increasingly popular, often worn during people’s daily life, collecting data 24 hours a day, 7 days a week. In the last decade, these devices have attracted the attention of the scientific community as they allow us to automatically extract information about user physiology  enabling inference on their health. However, the biggest issue about the data recorded by wearable devices is the missing values due to motion and mechanical artifacts induced by external stimuli during data acquisition. This missing data could negatively affect the assessment of heart rate (HR) response and estimation of heart rate variability (HRV), that could in turn provide misleading insights concerning the health status of the individual. In this study, we focus on healthy subjects with normal heart activity and investigate the effects of missing variation of the timing between beats  caused by motion artifacts on HRV features estimation by randomly introducing missing values within a five min time windows of RR-intervals obtained from the nsr2db PhysioNet dataset by using Gilbert burst method. We then evaluate several strategies for estimating HRV in the presence of missing values by interpolating periods of missing values, covering the range of techniques often deployed in the literature, via linear, quadratic, cubic, and cubic spline functions. We thereby compare the HRV features obtained by handling missing data in RR-interval time series against HRV features obtained from the same data without missing values. Finally, we assess the difference between the use of interpolation methods on time  and on duration , in order to identify the best methodology to handle the missing RR-intervals. The main novel finding of this study is that the interpolation of missing data on time produces more reliable HRV estimations when compared to interpolation on duration. Hence, we can conclude that interpolation on duration modifies the power spectrum of the RR signal, negatively affecting the estimation of the HRV features as the amount of missing values increases. We can conclude that interpolation in time is the optimal method among those considered for handling data with large amounts of missing values, such as data from wearable sensors. In the last two decades, the interest in the variation of the timing between beats  of the cardiac cycle, called heart rate variability (HRV), has widely increased in the psycho-physiological research field. Assessment of RR-intervals variability is possible through time and frequency domain analyses that provide parameters able to quantify the amount of fluctuations occurring between consecutive beats, giving therefore an indirect index of autonomic regulation. Actually, the parameters extracted from HRV analysis are useful to provide insight about sympathetic-parasympathetic balance of cardiac vagal tone that was found to be an indicator of cognitive, emotional, social and health status .Thanks to the technological advancements of recent decades, it is now possible to continuously record heart activity during peoples’ life via wrist-worn wearable devices equipped with heart rate sensors. This innovation might have a great impact on the medical field because of the low cost of the devices and the possibility to obtain continuous passive measurements performed in an ecological setting, gaining an overview of the users’ health status by assessing HRV features during their daily life . These wIn this paper, we focus on healthy subjects with normal heart activity, and investigate the effects of interpolation on time  and duration  with an increasing amount of missing values (from 0% to 70%) in order to assess which interpolation strategy yields better results when estimating HRV features. In particular, in this paper we show that quadratic interpolation on time is the best approach to reconstruct the missing RR-intervals. Anyway, the main finding of this study is that the interpolation on time produce better HRV feature estimation that the interpolation on Duration suggested by all the previous studies.To the best of our knowledge, this work is one of the first studies investigating the effect of high percentage of missing values  on HRV analysis. In previous studies, the inconsistency of RR-intervals was due to a small number of ectopic beats, while wrist-worn wearable devices introduce motion and mechanical artifacts that produce a huge quantity of abnormal heart beats.Moreover, to the best of our knowledge, this is the first study to analyse the effect on HRV features of interpolation on time versus interpolation on duration. We show the difference among interpolation methods  on both time and duration timeseries in order to detect which interpolation method yields lower error in HRV features estimations. This analysis permits to provide insight about how the interpolation methods work in quantifying the noise introduced into the timeseries.We conclude by showing that interpolation on time is the best choice for preprocessing RR timeseries with missing values, contradicting the approach traditionally followed, based on durations timeseries.During the day, approximately 1% of beats are to be expected to be ectopic  when theThe simplest way of handling the inconsistent RR-intervals provided in literature is to delete them . In thisFinally, it was found that the interpolation introduces low frequency components (LF) and reduces high-frequency components (HF) power . This asWe were not able to find any previous work studying the effect of interpolation missing values on the duration versus time, and the propagation of error to HRV features.nsr2db  PhysioNet dataset [In this paper, we used  dataset . This daIn order to compute HRV features, the 23 h time series of ECG recording of each user were split into 5 min windows. Moreover, to investigate the effect of missing values on HRV analysis, artificial missing RR-intervals  were inserted into the 5 min windows.P as the probability of transition form state 0 to the state 1 and p the probability of transition from state 1 to 0. Moreover, Q and q give the probabilities of remaining in the same states 0 or 1  . We defior 1 see . Using tP, p, Q and q as showed in Equations , res, resP, pNo interpolation: this approach does not create interpolated values of missing RR-intervals. Differently to the Deletion method that remove missing values merging non-consecutive beats that induce in missing interpretation of HRV features, the no-interpolation method maintains the missing values into the RR-intervals time series.a and b are the indexes of Nearest neighbor: the nearest neighbor or proximate interpolation is the easiest interpolation method . This in results Linear: this method fits a straight line passing through points A and xB . InterpoEquation .(7)Xi=xk et al.  demonstrQuadratic: differently from the linear interpolation model, the quadratic function needs three points of interest to interpolate missing values in a time series as showed in Equation .(8)Xi=xaccurate .Spline cubic: fitting datapoints using polynomials of degree higher than one leads to problems of oscillation outside the fitted points, known as Runge’s phenomenon . This prThe missing values were then handled with six different interpolation methods:We applied each of the interpolation methods listed above to heartbeats expressed as a sequence of durations and as a sequence timestamps, then analyzed the error in HRV features estimations, in order to identify the best approach.The on-duration approach is the one mostly used in literature to handle missing values. The data used as input to the interpolation methods was the sequence of durations of the heartbeats , obtained by subtracting the timestamp of each heartbeat from the timestamp of the subsequent heartbeat in the sequence of heartbeats.Differently, we propose the the on-time approach whereby interpolation methods are applied to the sequence of timestamps of the heartbeats, postponing the differentiation preprocessing step that transforms timestamps into durations to after the interpolation step.As shown in To better illustrate the differences between interpolation on time and duration, we simulated 100 heartbeats and then we randomly generated 10% of missing RR-intervals in this artificial timeseries by using Gilbert burst approach. The length of the RR-intervals timeseries changes when we interpolate the missing values on duration, while it remains the same when we interpolate on time . This re-HR mean: mean values of heart rate (HR) computed as showed in Equation .(9)HRme-RMSSD: root mean square of the successive RR-intervals differences (Equation ) represe-SDNN: standard deviation of RR-intervals (Equation ). It ref-PNN50: the ratio between NN50  and the total number of RR-intervals (Equation ).(12)PNTime domain:-Power spectral density (PSD): describes the distribution of power into frequency components composing that signal. The Lomb–Scargle periodogram for PSD estimation was found to be the most appropriate method to analyze RR-interval data ,6. VLF , non-interpolated, and interpolated  5 min ECG time series. We analyze time domain HRV features, frequency, and non-linear domains. Time domain analysis usually contains various statistical variables of the duration time series. The frequency domain analysis investigates the power spectrum of RR-intervals time series in order to assess the cardiac autonomic balance . Additionally, non-linear HRV features try to capture the non-periodic behaviour of the HRV and the complexity that exists inside the RR-interval dynamics. The variables that we incude in our analysis, in both time and frequency domain, are defined as:We assessed the difference of HRV variables computed on real time series and the ones with missing values by the root mean squared error (RMSE). Additionally, the relative errors  were usWe analyzed 15,359 RR-intervals timeseries of 5 min in this study. The lowest errors on HRV features estimation with missing RR-intervals are obtained using the no-interpolation or the interpolation on time approaches, while the interpolation on duration approach consistently yields the worst results . Even ifRMSSD and PNN50 do not require any interpolation to obtain reliable estimations for all the percentages of missing values, while SDNN need quadratic interpolation on time see . A possiIn the frequency domain, the interpolation method that produces the least error is the quadratic on time see . This fiSD1 does not require any interpolation to handle missing values, while SD2 needs quadratic interpolation on time to obtain reliable result see . To giveIn this work we quantify the expected error propagation of missing values in RR-intervals timeseries to HRV features, as a function of preprocessing interpolation approach, and amount of missing data. The main findings of this study is that the interpolation of missing values in RR-intervals timeseries on time  produces more reliable HRV features estimations compared to interpolation on duration.By using this preprocessing approach, the quantification of the expected error on HRV features caused by a huge amount of missing values  can support better estimations of users’ well-being, by assessing their HRV features. This enables continuous passive monitoring of users’ cardiovascular activity in a non-obtrusive way, collecting data during their daily activities that could enable further research on preventative health.A limitation of this study is the fact that we limited our focus on healthy subjects with normal heart activity, limiting the analysis to large amounts of missing values induced by motion artifacts, ignoring physiological phenomena such as ectopic beats.Future studies will be useful for researcher and companies, which give insight into heart rate variability recorded by wrist worn IoT wearable devices, in order to better understand the potentiality of the data extracted from these devices to make inference about people heath status. Future work is needed to assess the influence of missing values simulated in accordance with motion and mechanical artifacts induced by external stimuli during data acquisition by using wrist worn IoT wearable devices. Finally, future works will also include the investigating the influence of missing values on HRV features on short timeseries  and the identification of the shortest time required to obtain accurate estimation of users’ HRV features.


Aedes aegypti and significant investments in YF vaccine production capacity and research and development for reduction of adverse effects are of the highest priority.We discuss the complex eco-social factors involved in the puzzle of the unexpected rapid viral spread in the ongoing Brazilian yellow fever (YF) outbreak, which has increased the reurbanisation risk of a disease without urban cases in Brazil since 1942. Indeed, this rapid spatial viral dissemination to the Southeast and South regions, now circulating in the Atlantic Forest fragments close to peri-urban areas of the main Brazilian megalopolises (São Paulo and Rio de Janeiro) has led to an exponential increase in the number of yellow fever cases. In less than 18 months, 1,833 confirmed cases and 578 deaths were recorded most of them reported in the Southeast region . Large epizooties in monkeys and other non-human primates (NHPs) were communicated in the country with 732 YF virus (YFV) laboratory confirmed events only in the 2017/2018 monitoring period. We also discuss the peculiarities and similarities of the current outbreak when compared with previous great epidemics, examining several hypotheses to explain the recent unexpected acceleration of epizootic waves in the sylvatic cycle of the YFV together with the role of human, NHPs and mosquito mobility with respect to viral spread. We conclude that the most feasible hypothesis to explain this rapidity would be related to human behavior combined with ecological changes that promoted a significant increase in mosquito and NHP densities and their contacts with humans. We emphasize the urgent need for an adequate response to this outbreak such as extending immunisation coverage to the whole Brazilian population and developing novel strategies for immunisation of NHPs confined in selected reserve areas and zoos. Finally, we stress the urgent need to improve the quality of response in order to prevent future outbreaks and a catastrophic reurbanisation of the disease in Brazil and other South American countries. Continuous monitoring of YFV receptivity and vulnerability conditions with effective control of the urban vector  Aedes aegypti infestation indexes. Nevertheless, from a practical perspective, the pathway to achieve this goal has been permeated by erroneous policies and strategies: (1) negligence in early detection and reporting of epizootics in YF virus (YFV) emergence as well as surveillance in non-endemic areas in 2016; (2) delayed immunisation response from the Brazilian authorities with very low vaccine coverage which has resulted in an extremely high incidence of the disease in rural and peri-urban areas, thus leading to an exponential increase in the demand for vaccines; (3) concentration of YF immunisation on children, leaving uncovered the adult population which is generally the most affected by the sylvatic YF outbreaks; (4) delay in reaching and providing YF immunisation for rural workers living close to forest areas and eco-tourists, more exposed to the YFV; (5) failure in social communication on the effectiveness of the YF vaccine and dealing with vaccination refusal consequent to an exacerbated perception of its adverse effects; and finally (6) very low sanitation coverage (< 50% of the Brazilian population) together with failure in Ae. aegypti and Ae. albopictus control, enhancing the risk of YFV re-urbanisation.Brazilian authorities and scientists have reported with perplexity the worst outbreak of sylvatic yellow fever (YF) in the last 80 years in the country with an exponential increase in the number of confirmed cases and deaths in humans and epizootics in non-human primates (NHPs). The ongoing outbreak spread from November 2016 into forest areas contiguous to the country’s largest megalopolises in the Southeast region, such as São Paulo and Rio de Janeiro, significantly increasing the risk of reurbanisation of the disease. There are complex eco-social determinants of this rapid YF viral spread, but also policy constraints and erroneous strategies certainly have contributed to accelerate and aggravate this epidemiological scenario. The goal of minimising the risk of resurgence of urban YF in Brazil, a disease eliminated in 1942, is theoretically achievable and would require simply immunisation of all the Brazilian population with the highly effective YF vaccine preferably combined with reduction of We provide epidemiological information and scientific evidence on the complexity of this scenario and emphasize the urgent need to intensify human immunisation coverage by increasing vaccine availability and implementing campaigns with solid communication interventions to preclude stagnation of coverage levels. We also emphasize the urgency to develop innovative strategies, as vaccinating NHPs, especially endemic and endangered species confined in preservation areas, avoiding their extinction and reducing their potential role as local YFV amplifiers. Although controversies among primatologists on the feasibility of NHP immunisation have emerged due to potential difficulties in capturing and/or injecting vaccine in free-living animals in the open field owing to their high mobility, novel technological strategies for monkey immunisation, preserving biodiversity in Brazil, should be conceived and evaluated. Some of these novel strategies are suggested herein.YF epidemiology: rapid viral spread and emergencyThere has historically been a consensus among scientists and policy makers in Brazil that YFV transmission would probably remain confined to sylvatic cycles in areas with low population densities and with a low number of annual cases as in the past since the last urban case in 1942. Nevertheless, environmental, eco-social and human behavioral changes in the last decades have created conditions for an exponential increase in YF cases and case fatalities in the country during the ongoing outbreak , in whicCerrado, a savanna-like biome, in Tocantins state; in 2015 the Ministry of Healtherrado, in the midwest states of Goiás and Mato Grosso do Sul, in touristic areas with an intense flow of people in the summer. Moreover, it should be emphasised that evidences of the emergence of the current YFV transmission wave were recorded as early as in July 2014, with confirmed epizooties in the transition area between the Amazon and YF epizootics: multiple pathways in viral dislocationLarge epizooties in NHPs have recently been reported in Brazil with 732 YFV laboratory confirmed events in the 2017/2018 monitoring period up to EW 17 (April 28 2018). Epizootics exponentially increased in Brazil in six states  indicating sustained viral circulation in the pre-seasonal and seasonal periods with São Paulo state accounting for 42% of the total confirmed epizootics.versus a much larger population in 2016-2018. The population in the Southeast augmented 368% from 18,345 (19.8 people/km2) to 85,817 thousand inhabitants (92.9/km2) between 1940 to 2015;,versus availability of a highly effective vaccine produced in Brazil in 2016-2018 which is in contrast to the rapid dissemination of the disease; and (3) underreporting of cases in 1934-1940 since the diagnostic criteria were histopathology the numbers of deaths and cases are the same in the historical tables of Francoversus the use of other diagnostic criteria such as polymerase chain reaction (PCR) in 2016-2018. Cerrado biome (mostly from the states of Goiás and Minas Gerais) and reaching the Atlantic forest biome in the coastal states of São Paulo, Espírito Santo, Rio de Janeiro, similar to that of 2016-2018.-A comparative analysis contrasting the epidemics of 1934-1940 with that of 2016-2018 allows the identification of important differences in the patterns of YFV spread: (1) the lower human population density in the region in 1934-40 Although the epizootic waves had propagated in the 1934-1940 outbreak with lower intensity and velocity than in 2016-2018, it is interesting to note the similarities between both outbreaks in spatial dislocation patterns following multiple pathways.Factors: unusual dislocation and rapidity of YF outbreak-Ae. aegypti-infested American cities. Several hypotheses have been considered for the YFV re-emergence in Brazil:The perplexity with the current epidemiological scenario of the YF outbreak originates from insufficient knowledge on the conditions favoring YFV re-emergence and its very rapid spread from North and Mid-West endemic regions into the coastal Southeastern more populated areas. The dissemination of the YFV as a re-emerging threat in the Americas and the increasing risk of reurbanisation of the diseaseViral mutations and evolution - A recent genome analysis of the circulating YFV in the ongoing outbreak has confirmed that it belongs to the South American genotype I modern lineage and a sublineage, named 1E, which probably independently disseminated from Venezuela into the Brazilian Amazon and then into the inland Centre-West and Southeast (estimated to have taken place around 2005) and South (causing the 2008-2009 outbreak).,,Climatic and environmental factors - Harvard scientists in the 1990’s had already anticipated a dramatic global scenario for the next decades with global warming leading to proliferation and dislocation of mosquito vectors of arboviral diseases, as well as other vectors of infectious diseases, from tropical to temperate zones of the globe.-,,Mosquitoes: behavior and potential for domestic Aedes transmission - Climate change, which has most likely led to higher temperatures and rainfall in the recent summer seasons, may have hypothetically favored an increase in mosquito population density in Brazil. Thus, higher mosquito biting rates exponentially increase YFV circulation. The possibility of more efficient YFV vertical transmission in mosquitoes must also be considered. Mondet at al.Aedini mosquitoes, such as Haemagogus and Aedes species, by providing higher availability of larval habitats (mostly tree-holes and bamboo) and accelerating larval development, besides quickening viral replication and dissemination from the mosquito mid-gut to salivary glands. In Southeast Brazil, where the outbreak has spread, the rainy-hot season occurs essentially between November and May, which coincides with the peak of YFV cases and epizooties in 2016-2018.Climatic and environmental conditions also favor mosquito transmission of the virus. Higher average temperatures and rainfall enhance the population density of Haemagogus leucocelaenus and Hg. janthinomys.Hg. janthinomys usually bites in much higher density at the tree canopies, Hg. leucocelaenus usually bites more frequently and shelters at the forest ground level.Haemagogus are active all day long, while Hg. leucocelaenus has a predominant afternoon biting activity, Hg. janthinomys usually reaches a biting peak around midday.Hg. leucocelaenus and even Hg. janthinomys are eclectic concerning host preference biting other animals such as cattle, birds, dogs, rodents and horses, adapting to the modified environments.Concerning the mosquito species vectors of sylvatic YFV in the Southeast, a contrasting preference has been observed according to the vertical distribution in the forest. Two mosquito species have already been confirmed as YFV natural vectors during the ongoing outbreak in Southeast Brazil, Degradation of natural habitats together with reduction of wild animal population size and consequent lack of blood source for sylvatic mosquito vectors has accelerated recently, increasing human biting and the opportunities for vector sharing between NHPs and human beings. Besides degradation of natural environments, the death of NHPs due to YF may have led mosquitos to seek other blood sources, including humans, in the modified environments, increasing the risk of human infection.Ae. albopictus captured in 2017 in rural areas near the municipalities of Itueta and Alvarenga in Minas Gerais.Ae. albopictus as a natural vector of YFV. However, Ae. albopictus populations from Brazil have proven to be competent to transmit the viruses although with much less efficiency than sylvatic vectors such as Hg. leucocelaenus and Sabethes albiprivus, simultaneously tested.Aedes, such as Ae. aegypti and Ae. albopictus, may play an important role in YFV transmission given other conditions, such as high vector densities, high human-biting rate, high daily survival rates and low vaccination coverage. Couto-Lima et al.Aedes density in peri-urban and urban areas, with effective control policiesAedes are the predominant mosquitoes in nine public parks in the city of São Paulo.Recently, Evandro Chagas Institute in Brazil has preliminarily reported the finding of YFV natural infection in Environmental policies and human behavior - Another factor that may help explaining the severity and rapid spread of the ongoing outbreak is the successful environmental and biodiversity protection policies of IBAMA  which has led to a considerable increase in the number of conservation units and legal actions to protect Brazilian fauna with its very strict wildlife preservation measures during the last decades. The total accumulated area held by conservation units in Brazil has been greatly enlarged since the last severe YFV outbreak in the Southeast, consisting of 218,081ha in 1930-1940 to 76,848,771ha by 2009, an increase of 361.5%.Plasmodium simium, the causative agent of these malaria outbreaks, share the same vertebrate hosts, the NHPs, particularly howler monkeys. Yet, these philosophical human approaches to the woods as any other anthropic modification  result in degradation of original habitats of NHPs and mosquitoes which in turn will be forced to exploit the ecotone between the natural and modified environment and even migrate between patches of woods, favoring viral dispersion. In conclusion, a combination of several factors concerning human behavior and environmental policies have also contributed to recently transform the coastal zone of the Southeast region more receptive and vulnerable to sylvatic YFV transmission and accidental human infection in this cycle.NHPs: restricted mobility in YFV spreadAlouatta) captured many months after a YFV outbreak.,Alouatta) and marmosets  is high while the capuchin monkeys (Cebus and Sapajus) seem to have intermediate susceptibility to the disease. Monkey mortality due to YFV in Brazil is considerably concentrated in howler monkeys (Alouatta). Their role in the sylvatic cycle is so dominant that their sudden silence and deaths in the woods serves as a signal to local inhabitants and health authorities for the circulation of the virus.Callithrix penicillata and its hybrids with other marmoset species and even for Leontopthecus chrysomelas were very susceptible to the Almada YFV strain in Ihéus, Bahia state. The same authors report that a YFV strain of sylvatic origin was easily maintained by alternate passage through Callithrix aurita and Ae. aegypti mosquitoes, also achieved with a capuchin monkey species (Cebus versutus) though presenting lower mortality.The susceptibility of NHPs to the YFV is quite variable and seems to depend upon at least two-way interactions between the NHP population and virus strain.Haemagogus infested woods have favored the spread of the sylvatic YFV epizootic waves to this region and consequently, human infection. However, more research is necessary to understand the mechanism by which YFV could travel such vast geographical extensions, so rapidly, as we are witnessing in the ongoing outbreak. It has been suggested that the YFV had an average dispersal of around 3 km per day in the Southeast since early 2017.,In the last four decades, the exacerbated degradation of some Brazilian natural environments has accelerated deforestation with the use of fire and big machines, destroying enormous areas of the inland forests. When losing their natural habitats, some NHP species have been forced to relocate and inhabit modified environments and suffer overpopulation of small patches of forest. Altogether, (i) augmentation of conservation areas combined with successful biodiversity protection policies; (ii) high population density of non-immune NHP in the coastal Southeast; and (iii) increased occupation of the modified environment by adapted NHPs such as marmosets and capuchin monkeys in Alouatta and Callithrix), NHPs are not responsible for such a rapid spread of the YFV. All available knowledge about habits of Southeastern NHP species indicates that their home ranges and daily travelling range in forests are usually restricted, and they normally do not use the ground and deforested areas to migrate from one place to another, except under extenuating circumstances.,,Haemagogus mosquitoes may disperse several kms from a releasing point, a contrasting behavior with that of Sabethes mosquitoes, secondary sylvatic YFV vectors, where flight is usually restricted to the forest and near surroundings.,Hg. janthinomys/capricornii and Hg. leucocelaenus, could be collected 11.5 km and 5.7 km, respectively, from a releasing forest in Southeast Brazil in few days. During the course of this long displacement, Haemagogus mosquitoes may almost continuously traverse large areas of pasture and vast monoculture plantations as well as visit scattered gallery forests and residual forest patches. In other words, these mosquitoes are liable to span long distances beyond the forest where they emerged from their original arboreal larval habitat, a pattern also observed in Central Brazil.,Haemagogus female mosquitoes from climatic  to environmental and ecological conditions. In the latter two cases, reduction of NHP’s and other wild animal populations’, as a consequence of natural habitat degradation and deaths by YFV, has led to a reduction of blood sources, thus inducing sylvatic mosquito dispersion. In addition to the intrinsic mosquito flight ability, it has been shown that convection currents around twilight aid arboreal mosquitoes to disperse between isolated patches of woods.,There is a consensus among experts, in spite of the susceptibility to the YFV infection of some Neotropical genera  just after the beginning of the 2017 and 2018 transmission seasons were recorded in the state. The main and large YFV generating foci and dissemination areas in the state has mostly been the denser forests growing on escarpments of the Serra do Mar, a long system of mountain ranges parallel to the Atlantic Ocean coast.YF asymptomatic human mobilityHaemagogus and/or Sabethes mosquitoes as well as peri-urban and urban areas densely infested by Ae. aegypti and Ae. albopictus populations competent to transmit the YFV. The current increasing number of people who move to and from areas of risk in the Atlantic Forest biome has probably favored the rapid spread of the ongoing Haemagogus vectored YFV outbreak into urban and peri-urban ecosystems, which has increasingly jeopardised the reemergence of Aedes transmission in the peri-urban/urban areas, now a great concern.Only few YFV infected people become ill and develop symptomatic disease, thus the majority are asymptomatic. Viremic paucisymptomatic or asymptomatic individuals accidentally infected by the bite of sylvatic mosquitoes can travel carrying the YFV and rapidly disseminate the infection to distant receptible areas, i.e., sites infested by competent mosquito vectors. Receptive sites may vary from forest patches, their surroundings, rural areas and microenvironments within urban areas supporting wildlife with propensity to exploit variable environments (or overlap territory with synathropic species) occupied or reachable by Cerrado and Amazon biomes for tourism or work. The incidence of such YFV infections had been low, and thus, the risk of reemergence of Aedes transmitted YFV in the anthropic environment was reduced before the ongoing outbreak reached the large and highly populated coastal Southeast region. Since the virus and the clinical evolution are identical, there is no distinction between “sylvatic yellow fever” and “urban yellow fever” except for the ecological nature of the transmission, more properly defined by the type of vector mosquito. Currently, even the geographical location of infection acquisition could not suitably define a case as a sylvatic or urban yellow fever event. Indeed, there has been a recent increasing expansion of urbanisation in the Southeast with the continuous construction of urbanised neighborhoods and other types of settlements in areas bordering the enzootic forest attainable by YFV sylvatic mosquito vector flight. Thus, an infection acquired by someone living in a house or visiting a park in an urbanised area near an epizootic patch of wood increasingly deserves a deep epidemiological investigation concerning the origin, since Haemagogus mosquitoes may bite far from the wild on even indoors.Haemagogus and Sabethes) but also potentialising enzootic spillovers with establishment of YFV either into an intermediate/rural cycle, due to the ecological plasticity of the invader mosquito Ae. albopictus, or into a potential urban cycle with limited transmission between the domestic mosquito Ae. aegypti and humans  is expected to witness the strongest growth in tourist arrivals, where the forecast suggests an increase by 331 million over the 2010-30 period to reach 535 million in 2030, with a growth of 4.9% per year.,The dislocation of asymptomatic YFY viremic people has implications not only for viral spread within Brazil and receptive South American areas but also for global dissemination. The risk of YFV spread in global travels is very high and the reason is that the world has annually higher number of air passengers than ever. According to the UN World Tourism Office, Asia and the Pacific  targeting 69 municipalities in Rio de Janeiro  and São Paulo  states. As of 16 February 2018, preliminary results of the mass YF vaccination campaign indicated that 4.3 million persons had been vaccinated for YF .Immunisation of NHPs: monitored areas,,,Leontopithecus chrysomelas) and howler monkeys (Alouatta sp) is currently in progress at Bio-Manguinhos/Fiocruz in collaboration with the Rio de Janeiro Primatology Center. Although YF has not sufficiently been studied in Neotropical NHPs and there is no current proven vaccination for NHPs, there are operational difficulties to apply traditional needle immunisation strategies in this population due to high monkey mobility. It is therefore necessary to advance and develop the above mentioned novel monkey immunisation delivery strategies. This type of initiative must be supported by awareness of the beneficial role of NHPs as a sentinel of YFV circulation and not as direct disseminators of the YF etiological agent harmful to the human population. During the 2008-2009 YFV outbreak in Rio Grande do Sul, South region, misinformation resulted in aggression towards monkeys and even exterminationThe immunisation of NHPs should also be a priority for animals confined in parks and forest reserves contiguous to urban areas as well as animals maintained in captivity in research centers and zoos where the monkey population is monitored and thus immunisation feasible. Immunogenicity studies with the 17D vaccine have only been conducted in the Indian Rhesus macaque.Final considerationsCerrado biomes, would become more real than ever. The recent territorial dislocation of the YFV has not been linear. As in previous large sylvatic outbreaks it has taken place in complex and multiple pathways, in epizootic waves combined with the unprecedented intense mobility of asymptomatic infected humans involved in rural work, eco-tourism, extrativism and animal traffic. A second reason for this concern is the possibility of a catastrophic event affecting a huge number of non-vaccinated people as confirmed by the current outbreak. The complex epidemiological patterns of the disease dissemination have detrimentally combined with the very low vaccination coverage of the population in the main metropolitan areas, which persists even after the ongoing YF outbreak, together with the inefficient Ae. aegypti control measures in peri-urban and urban areas. Moreover, despite recent advances in understanding the eco-social determinants involved in the rapid spread of the ongoing outbreak, several knowledge gaps still persevere. The hypothesis of the possible role of asymptomatic infected humans in YF outbreaks in Brazil requires further research. As well, the mechanisms underlying the rapid spread of epizootics in the country must be understood. Epidemiological parameters to provide support to these hypotheses will be necessary. Many issues related to molecular epidemiology and transmission cycles of YFV in the diverse Brazilian biomes remain poorly understood. Support for research and development activities in this field is urgently needed, promoting innovative governance strategies with targeted investments aiming to improve surveillance and fast response to the epidemics. Immunisation coverage of the Brazilian population living in the affected areas should urgently target the entire population in order to minimise the impact of the ongoing outbreak.For decades, Brazilian scientists have been warning the public health authorities that once the virus started to circulate in the Atlantic Forest biome close to large metropolitan areas, the risk of reurbanisation of a disease, so far limited to the sylvatic cycle in the endemic/enzootic Amazon Forest and the inland


The skeletal class III relationship presents complex dentoalveolar problems, requiring multidisciplinary treatment. In edentulous people, severe atrophy of the jawbone simulates the clinical appearance of a skeletal class III relationship , which presents major problems for rehabilitation. This article describes the rehabilitation of a 67-year-old patient with a pseudoskeletal class III relationship. The mandible was restored with two implant-supported bar-retained overdentures using clips for retention. The extremely atrophic maxilla was restored with a combination of sinus augmentation, implant placement, and classic prosthodontic treatment using an electroformed mesostructured overdenture with swivel lock attachments on an implant-supported bar. By performing minimal augmentative and implant surgeries and using the possibilities and advantages of classic prosthetic dentistry, the clinical situation described here could be managed and the atrophic maxilla could be rehabilitated. The prosthetic rehabilitation of a fully edentulous and atrophic arch with implant-retained dentures requires thorough planning and should not only provide the correct vertical height and maxillary-mandibular relationship but also be esthetically acceptable –4. The uThere is debate of how many implant support will be sufficient for the retention of fully edentulous mandibular prosthesis. Recently, it has been concluded that two implant removable overdentures should become the first choice of the treatment for the mandible supporting the McGill and York consensus statement –13.This article describes the rehabilitation of an elderly patient with a pseudoskeletal class III relationship. In this case, the mandible was restored with two implant-supported bar retained overdentures using clips for retention, and the extremely atrophic maxilla was restored with a combination of implant placement, sinus augmentation, and classic prosthodontic treatment using an electroformed mesostructured overdenture with swivel lock attachments on an implant-supported bar.A 67-year-old nonsmoker female patient in good general health was referred for implant placement and prosthetic rehabilitation in March 2012. She was completely edentulous and had worn full dentures in both arches for 17 years. The dentures at the time of presentation had been fabricated 3 months previously, and the patient was satisfied with the extraoral appearance of the lips and face and tolerated the vertical dimension Figures . Her maiTwo (2) duplicates of patient's maxillary dentures were fabricated. One (DentDu-Brm) for the implant planning using clear resin  for the base and barium sulfate resin  for the teeth . The secClinical examination and cone beam computed tomography (CBCT) revealed an extreme atrophy of the maxilla and mandible Figures .The patient's dentures were used for impressions with an alginate material  and as guides for the articulation of the casts. Analysis of the articulated casts showed large vertical distances between the maxillary and mandibular alveolar crests  and a horizontal distance of 1.3 cm in the anterior area . TherefoBoth sinuses were grafted using a bovine xenograph , and the lateral windows were covered with porcine collagen membranes . In the same session, based on the CBCT, two implants were placed in positions #22 and #27  and loaded immediately with a bar-retained overdenture using system-specific, prefabricated, angled, and tapered abutments . A bar wFive months after sinus augmentation, a total of six implants  were placed. CBCT planning software  showed that the ideal tooth position was 6.8 mm in front of the alveolar ridge . HoweverThe maxillary implants were uncovered 6 months after placement, and impressions were made using an open-tray technique and a polyether impression material . System-specific ball attachments (BATTs) with their retention elements were mounted on three implants for laboratory transfer. Access windows were created on the buccal side of the DentDu in the areas of the BATTs, and the retention elements were fixed to the DentDu with self-curing modeling resin . Centric jaw relation was recorded using the same resin  restoration –4. The aIn treatments involving removable dentures, decisions about tooth length and position are critical because they affect esthetics and function. In the case described here, the patient accepted the profile and appearance of the original denture, and a duplication of this denture was used as a guide for new denture fabrication in terms of tooth position and tissue and lip support, as well as for the CBCT-based implant placement plan and the design of overdenture substructures. As a general rule, OPGs are made at initial examination in order to assess the situation and after sinus augmentation. In the case presented here, we used a CBCT at the initial examination. The reason was the advanced atrophy on clinical examination; 3D imaging provided more accurate assessment of the sinuses and the existing bone.It is recommended to utilize the dental implants as a means for improving retention in cases of poor ridge support and its retention would be compromised. Only two implant placements were possible in this severely resorbed mandibular ridge, and their primary stability was good that additional augmentation to place more implants was not performed. The mandibular arch was restored with an implant-supported bar-retained overdenture using clips for retention, which is a treatment option for edentulous jaws because of the high implant/prosthesis survival rate and limited incidence of technical complications –28.The quality and longevity of implant-supported removable dentures are affected by the passive fit of the superstructure. In the case presented here, ELMES used in the maxillary restoration allows for precise fitting of dental restorations and is particularly useful to achieve passive fit because it enables tension-free placement of the framework onto the abutments , 22, 29.In the case described here, an implant-supported bar was placed buccally to the ridge crest to support the denture base and teeth, an ELMES was fabricated over it, and a U-shaped metal framework for the denture was designed to rest on the ridge crest and extend palatal to provide support and resistance with rigidity. This approach also strengthened the denture base and relieved the biting forces generated anteriorly by distributing stresses to the metal base. The swivel lock attachment provided rigid fixation on the implant-retained bar with minimal strain, preventing rocking movements of the denture during function. Therefore, this fixed-detachable denture with a swivel lock attachment system provided the comfort and assurance of a fixed implant-supported denture, as well as improved efficacy of masticatory function .In the first three weeks following the delivery of the dentures, the patient learned to actuate the swivel lock attachment. It is reported from the systematic review that overdenture with two implants and with bar attachment has the least number of complications , and durPatient reported a high level of satisfaction with the dentures and an improved quality of life , 32.A disadvantage of this approach is the initially higher laboratory cost due to the need for fabrication of multiple components. However, this cost may be offset by the need for fewer repairs and reduced patient discomfort. Furthermore, the application of the described technique, which combines surgical approaches with classic prosthetic treatment options, improves quality of life and avoids the need for more invasive surgery in elderly patients.


To verify the biomechanical importance with respect to the integrity of posteromedial cortex of femoral neck fracture (FNF) and demonstrate whether the modified fixation of cannulated screws (CSs) could increase the biomechanical strength. A total of 24 left artificial femurs were randomly divided into three groups. The osteotomy was made in the center of the femoral neck at a 20° angle to the shaft axial. The posteromedial cortices of femoral neck were removed in groups B and C. In group A, 8 femurs with intact posteromedial cortex were fixed with three parallel partial thread screws (PTSs), forming a standard triangle. In group B, the femurs were stabilized with the same fixation of CSs like group A. In group C, two inferior PTSs were replaced by two fully thread screws (FTSs). The lower A-P and axial stiffness and load to failure along with higher axial displacement were found in group B compared with group A . Between groups B and C, the modified fixation of CSs increased A-P and axial stiffness and load to failure and reduced the axial displacement . We verified that the comminuted posteromedial cortex affected the biomechanical strength adversely and resulted in higher displacement. The modified fixation of CSs characterized by two inferior FTSs could improve the biomechanical performance and buttress the femoral head fragment better. Femoral neck fractures (FNFs) in the nonelderly population are uncommon which often result from high-energy trauma. Anatomic reduction and stable internal fixation of the femoral neck (FN) are accepted widely in an attempt to salvage the femoral head . And it Multiple cannulated cancellous screws are used widely due to the advantages including less tissue invasive, less blood loss, and shorter operation time which made it a very common choice for surgeons to treat with FNF . MoreoveIn view of the unstable essence of the displaced FNF with comminuted posteromedial cortex, the traditional configuration of three parallel compression screws is consistently under debate. On the premise of less invasive, we tried to introduce the fully thread screws (FTSs), which functioned as position screws, to rebuild the posteromedial buttressing effect and improve the biomechanical properties of CSs fixation.In the present biomechanical study, we hypothesize that the improved configuration of cannulated screws could increase biomechanical strength and decrease the displacement when the posteromedial cortex was comminuted.A total of 24 left artificial femurs  were randomly divided into three groups . Group ATo ensure consistency of all specimens, we designed a mold with 3D printing technology which mainly consisted of two modules: the main module, functioning as the pedestal and the guiding route of sawing, and the assembled module which guided the insertion of pin . After bBiomechanical testing was performed on an Instron test system  which included a base, a pressure applicator, and a data analyzer. The loading protocol consisted of several parts. Firstly, to simulate the bending force when rising from the chair or climbing stairs, each specimen was stabilized in a custom-made jig distally and maintained the femoral shaft perpendicular to the load vector . The speThe recorded dates were analyzed with the use of SPSS software . Normal distribution and homogeneity of variance were screened with Shapiro-Wilk and Levene's tests, respectively. One-way variance analysis and LSD (least-significant difference) post hoc test were performed for group comparisons. The level of significance was determined to be p<0.05.All results were showed as mean± standard deviation in In the present study, we verified that the integrity of posteromedial cortex of FN played an important role in the biomechanical fixation strength. The disruption or comminution of posteromedial cortex resulted in the significant decrease of A-P and axial stiffness, load to failure, and significantly higher axial displacement. Kauffman concluded that the femoral neck fracture with a posterior defect exhibited greater displacement in anterior loading and showed lower axial loads to failure . These cThe sliding compression device allowed the controlled fracture impaction across parallel placed screws to eliminate the fracture gap and increase the stability of fracture which was favorable to the fracture union , 19. NevIn our previous study, we tried to treat the vertical femoral neck fracture with the modified configurations of CSs and the improved biomechanical and clinical outcomes verified the superior biomechanical strength to resist the shearing force and to support the femoral head fragment . Hence, Besides the nonunion and AVN, the severe shortening of FN would be another problem facing the orthopedic surgeons. Several studies have demonstrated that the shortening of FN greater than 5mm has a negative effect on the quality of life , 10, 27.One of the strengths in the present study is that we designed a 3D mold providing a reference system and all osteotomies and fixations were conducted under this system to minimize the operation error. Nevertheless, some limitations need to be mentioned. Firstly, the small number of samples tested would restrict the conclusion. Secondly, the use of composite bones only accounts for the young patients with good bone quality. But, for the elderly with Garden type III or IV fractures characterized by low bone mineral density, arthroplasty was preferred by most surgeons . Lastly,It is not an advisable choice of traditional fixation of CSs, as three parallel PTSs, for the stabilization of the unstable FN with comminuted posteromedial cortex. The rebuilding of medial buttress with two inferior FTSs could increase the biomechanical strength and reduce the displacement. By comparison with traditional CSs fixation, three parallel PTSs, characterized by sliding compression, the modified fixation of CSs may be preferred to the treatment of unstable femoral neck fracture with comminuted posteromedial cortex.


Terrestrial oil pollution is one of the major causes of ecological damage within the Niger Delta region of Nigeria and has caused a considerable loss of mangroves and arable croplands since the discovery of crude oil in 1956. The exact extent of landcover loss due to oil pollution remains uncertain due to the variability in factors such as volume and size of the oil spills, the age of oil, and its effects on the different vegetation types. Here, the feasibility of identifying oil-impacted land in the Niger Delta region of Nigeria with a machine learning random forest classifier using Landsat 8  and Vegetation Health Indices is explored. Oil spill incident data for the years 2015 and 2016 were obtained from published records of the National Oil Spill Detection and Response Agency and Shell Petroleum Development Corporation. Various health indices and spectral wavelengths from visible, near-infrared, and shortwave infrared bands were fused and classified using the machine learning random forest classifier to distinguish between oil-free and oil spill–impacted landcover. This provided the basis for the identification of the best variables for discriminating oil polluted from unpolluted land. Results showed that better results for discriminating oil-free and oil polluted landcovers were obtained when individual landcover types were classified separately as opposed to when the full study area image including all landcover types was classified at once. Similarly, the results also showed that biomass density plays a significant role in the characterization and classification of oil contaminated and oil-free pixels as tree cover areas showed higher classification accuracy compared to cropland and grassland. An oil spill is the discharge of petroleum hydrocarbon products into marine or terrestrial ecosystem. Terrestrial spills result from underground and surface pipeline leakages, sabotage, and operational failure, as well as transport of oil slicks from sea to land Taheri . Oil canIn Nigeria, the effects of oil exploration are particularly glaring in the Niger Delta. Reduced food productivity, damages to the subsistence economy, habitat distortion, epidemic outbreaks, and general social instability are among the numerous negative impacts that crude oil exploitation has had in the Niger Delta , and the landcover data.https://www.shell.com.ng/sustainability/environment/oil-spills.html and the National Oil Spill Detection and Response Agency (NOSDRA) https://oilspillmonitor.ng/. The NOSDRA is a government agency tasked with capturing all oil spill incidents both in marine and terrestrial realms across the country.The oil spill dataset was obtained from two published sources, the Shell Petroleum Development Corporation (SPDC) http://2016africalandcover20m.esrin.esa.int/). The product contains 10 classes for different landcover categories including built-up areas, waterbody, and various vegetation types produced from 20-m-high spatial resolution Sentinel-2A image over Africa. The tile information covering the study area was downloaded, subsetted, and used for the establishment of appropriate landcover types for the study area. The major landcover categories used in this study were cropland, grassland, and tree cover areas (TCA). Features such as built-up areas, waterbody, and baresurface were excluded from this study as most oil pipelines and the corresponding spill incidents occur on terrestrial vegetation classes. Thus, their exclusion reduced artifacts and misclassification.The landcover map for the African continent produced by the European Space Agency Climate Change Initiative 2016 was used in this study (earthexplorer.usgs.gov). The image acquired was a Landsat surface reflectance higher-level data product processed using the Landsat surface reflectance code (LaSRC). The LaSRC makes use of the coastal aerosol band to perform aerosol inversion tests using auxiliary climate data from MODIS and a unique radiative transfer model  for the year 2016 was downloaded from the USGS website (Spill incident harmonizationAssignment of spill incidents to landcoverThe oil spill data harmonization sought to integrate and expand the oil spill database for this research. The harmonization operation was carried out by overlaying both datasets (NOSDRA and SHELL) in a GIS environment. Points with repeated information as a result of duplicate capture and multiple spill incidents over the years were identified and marked. Duplicates (in most cases the SPDC data) were deleted since the dataset provided by NOSDRA is all encompassing as the government’s regulatory agency with the responsibility of documenting all spill incidents. The spill information relating to volume, size, and date of spill was checked, as this provided the basis for tracking the spill intensity on the different landcover types. The minimum area covered by the spill data used for this exercise is 1000 sqm, which is greater than a single Landsat image pixel of 900 sqm. This is to ensure that pixels used for training, testing, and validation of the final model as well as the image classification have dominant spectral reflectance of a typical oil polluted site.RF algorithm would rely on the spectral signatures provided by these training sites to build a robust model. For each landcover class , spill incidents located within the landcover classes were identified. This provided the various training and validation sites for the identification of oil-impacted (polluted landcover) classes.Selecting non-polluted sites for the different landcoverThe assignment of oil spill incidents to the corresponding landcover categories is an important step in this study, as the Pixel selection using buffer analysisNon-polluted sample sites are necessary in this study for two main reasons: first, for the identification of oil-free (non-polluted) landcover types within the study area and secondly for an effective discrimination between pixels of oil-free and oil spill–impacted landcovers. Proximity analysis as suggested by , the points were then sub-divided into two categories for training and validation purpose. Sixty percent of the points for individual landcover category were randomly selected for training, while the other 40% were set aside for validation in post classification accuracy assessment. Table Geometric correctionAs the Landsat surface reflectance higher-level data product was obtained, there was no need to carry out any atmospheric correction operations.Landcover image maskingIn order to ensure that the Landsat 8 (OLI satellite image) co-registers properly with the other datasets (such as the oil spill sites and boundary dataset), the satellite image was re-projected to the Universal Transverse Mercator projection and the World Geodetic Survey 1984 Datum of Zone 32 North (UTM WGS84 Zone 32N).Following the geometric correction of the study area image, the three dominant existing landcover classes extracted from the ESA CCI data “” were usEight Vegetation Health Indices were generated using the formulae presented in Table RF) algorithm was proposed by Breiman  used for classification was determined through repetitive runs before an optimal value of 500 (ntree) was arrived at and used for parametrization in all classification scenarios implemented. Table RF classification.The random forest  accuracy statistics. This is used in the ImageRF to assess the out of bag error of the RF calibration. The precision is the ratio of correctly predicted positive pixels to the total positive observations , while the recall is the ratio of correctly predicted positive observations to the sum of true positives and false negative observations. This however can be further interpreted as the measure of truly assigned pixels to a particular class  and the measure of truly assigned pixels in the image space. The F1 score is a robust accuracy measure for model performance. This is because it seeks to balance the influence of recall and precision through the use of harmonic mean of both measures.Two performance indicators were employed to assess the This is denoted by the formulae below:TP = true positivesFP = false positivesFN = false negativesRF classification using the 40% validation points  and polluted (P) TCA and grassland respectively had better calibration result ranging from 45 to 70% F1 accuracy. While on the contrary, both the P and NP croplands had lower calibration accuracies when the full study area image was calibrated. The model calibration result also showed that of the six different schemes investigated, the NP grassland and NP TCA had the best prediction to error ratio of 86% and 84% as indicated in the F1 accuracy when the respective landcover subsets were used. In contrast, the P and NP croplands had the least calibration accuracy. In terms of the implication for interclass separability and model fit, it is observed that calibration accuracy increased gradually from zero and mostly attained saturation when the tree size (ntree) in the RF reached 50 using the variables, although for some cases the F1 accuracy increased up to 100 trees before maximum saturation was reached. This however implied that a lower ntree value could yield sufficient calibration result.Figure RF classifier at the macro level. Fröhlich et al.  were observed to have more significant contribution in distinguishing oil polluted from oil-free landcover types both at the macro level of the entire study area and at the micro level of the individual landcover subsets. This is expected as the fundamental characteristics of stressed vegetation are their inability to carry out basic life-supporting functions such as respiration, transpiration, and photosynthesis   Table . The oveFigure ML) approaches (such as RF) to map the exact oil spill extent for different landcover types. This study attempted to bridge this gap by using RF classification to first establish the precise extent of oil spill–impacted and oil-free landcover types. Then, secondly to identify the most useful optical indicators and discriminators of oil-impacted vegetation communities from their respective oil-free vegetation. The result obtained from these experiments after calibration of sample sites and implementation of the classification operations showed that RF algorithm has the potential of providing reliable maps of oil-free and oil-impacted landcover. The RF classifier produced better results with the different landcover subsets as opposed to when the full study area image is classified, reinforcing the findings of Arroyo et al.  are mostly sensitive to vegetation moisture content  level and at the individual landcover subset (micro) level. Results obtained from the latter gave a better characterization of oil-free from oil polluted landcover classes, as this produced a more generalized extent compared to the crisp and granular outputs produced from the former. Over generalization and over estimation of the oil-impacted site were observed for grassland and TCA, which can be addressed by the incorporation of other relevant variables in the classifier. In addition, the result of the variable importance showed that shortwave infrared and NDWI are significant variables in distinguishing oil polluted and oil-free landcover, especially in cropland areas. However, of the three oil polluted landcovers investigated, it is apparent that polluted cropland could have had the most significant impact due to the similar result obtained  from the full study area and cropland image subset classification. Similarly, the high distinctive split obtained from the NDWI  between the oil-free and oil-impacted cropland areas, compared to the TCA and grassland, is an indication of prolonged impact of hydrocarbon crude oil on the fragile cropland vegetation.This study aimed at applying The result obtained from this study certainly informs on the capability of using earth observation satellite data in characterizing oil spill–impacted from oil-free areas even after several months of spill occurrence. The successful application of this method and approach to distinguishing these areas certainly reinforces the potential of assessing the intrinsic linkage between oil-induced impacts and the concomitant long-term landcover changes. This will in no doubt provide a better medium for assessing landcover change with specific recourse to oil spill incident in a typical oil spill prone area like the Niger Delta region of Nigeria. Other limitations encountered in this study such as the lack of extensive cloud-free multi-temporal optical images to establish phenological changes and implement multi-temporal based classification can be systematically addressed in future studies by incorporating radar backscatter such as the freely accessible sentinel 1 SAR images in fostering the derivation of precise area extent of the damage posed by oil pollution.


Previous studies make it possible to use remote sensing techniques to monitor heavy metal stress of rice synchronously and continuously. However, most studies mainly focus on the analysis of rice’s visual symptoms and physiological functions rather than temporal information during the growth period, which may reflect significant changes of rice under heavy metal stress. In this paper, an enhanced spatial and temporal adaptive reflectance fusion model was used to generate synthetic Landsat time series. A normalized difference water index and an enhanced vegetation index were employed to build phenological phase space. Then, the ratio of the rice growth rate fluctuation (GRFI Ratio) was constructed for discriminating the different heavy metal stress levels on rice. Results suggested that the trajectories of rice growth in phenological phase space can depict the similarities and differences of rice growth under different heavy metal stress levels. The most common phenological parameters in the phase space cannot accurately discriminate the heavy metal stress level. However, the GRFI Ratio that we proposed outperformed in discriminating different levels of heavy metal stress. This study suggests that this framework of detecting the heavy metal pollution in paddy filed based on phenological phase space and temporal profile analysis is promising. Heavy metal pollution is one of the most serious problems that influences the food security and public health at a regional and a global scale . TraditiPrevious research has shown that the pigment content, dry matter content, photosynthesis, and transpiration of crops were changed under heavy metal stress ,6,7. TheAll of the previously mentioned methods solve some problems in heavy metal assessment. However, they only take one mono-temporal image or several multi-temporal images for heavy metal stress monitoring of rice. They cannot reveal the continuously changing pace of the rice growth condition, and may neglect significant changes of the rice growth process under heavy metal stress. Therefore, sensitive and stable methods for the detection of heavy metal stress from information of the rice growth period are essential for agricultural, ecological, and food security. Crop phenology  is not oThe fast development of spatiotemporal data fusion technology  and phasThe study area is located in the Zhuzhou city along the Xiangjiang River Basin in the eastern part of the Hunan province . The geoSeven typical study sites in the study area were selected to collect field data of soil for measuring their heavy metal contents. Each study site is about 1.28 KM × 1.28 KM in size and contains about four to six paddy fields. Five soil samples and several paddy samples were randomly collected in each paddy field, and the weight of each soil sample was about 100 g. The geographical location of these samples was marked using a portable global positioning system (GPS). Lastly, the latitude and longitude of the samples at the center of the study site is selected as its geographical position, and the average heavy metal content of soil samples in each study site is taken as its heavy metal content. The main elements of heavy metal pollution in this study area are cadmium (Cd), lead (Pb), and mercury (Hg), among which Cd is the most significant. Therefore, we divide these seven sites into three categories based on the content of Cd, light stress, moderate stress, and severe stress. The heavy metal content of soil in each study site is shown in In this paper, we generated synthetic Landsat time series of the study area by spatiotemporal data fusion. Then two different vegetation index temporal profiles, which could describe the process of rice growth in two different aspects were extracted from time series data. Thirdly, the phenological phase space was constructed. Lastly, we could analyze the differences in the process of rice growth under different heavy metal stress levels and constructed a stable and sensitive indicator for discriminating different heavy metal stress levels for the paddy field. The flow chart of monitoring heavy metal stress of rice using phenological phase space from synthetic remote sensing time series data is shown in Landsat-8 OLI, landat-7 ETM+, and MOD09A1 (MODIS surface reflectance products) are used for this study. All data available in the rice growing season between late April and late October in 2016 in the study area were obtained. The MOD09A1 product is eight-day composite surface reflectance data with a spatial resolution of 500 meters, while the Landsat series data have the spatial resolution of 30 meters with the temporal resolution of 16 days. The high-quality Landsat images (cloud cover less than 35%) in the study area were selected. There are seven images that are selected in total in which it contains four images from Landsat-8 OLI and three images from landsat-7 ETM+. The selected images from Landsat-7 ETM+ were restored by ENVI Landsat-gapfill part because of the problem of strips. The number of images cannot meet the need of constructing Landsat time series. Hence, we take the spatiotemporal data fusion algorithm to cover the shortage of data.The spatio-temporal data fusion algorithm that we employed was the enhanced spatial and temporal adaptive reflectance fusion model (ESTARFM) . This alThe process of generating the high spatial and temporal resolution time series data contains four steps. First, we acquired the images of MODIS and Landsat that meet the quality requirements. Next, related data processes were conducted for preparation of data fusion, including radiance calibration, atmospheric correction, image clipping, and resampling. Third, the processed data were used as input data to carry out the ESTARFM, and the synthetic Landsat-like images were obtained. Lastly, we used the original Landsat images combining with the synthetic Landsat-like images to construct the time series data of eight-day temporal resolution and 30 meters of spatial resolution.SWIR, ρNIR, ρRed, and ρBlue stand for short wave infrared (SWIR) band, near infrared (NIR) band, red band, and blue band, respectively. Detailed information about these bands are shown in NDVI and EVI are two indices that were widely used in the study of vegetation phenology . MeanwhiIn this part, we extract EVI and NDWI temporal profiles of rice in study sites of three different heavy metal levels from time series data. The temporal profile indicates that the condition of vegetation growth should be continuous and smooth. However, the reflectance has been influenced by clouds, shadows, and aerosol in spite of strict pre-processing. It is necessary to smooth the temporal profile to reduce the impact of noise. In this study, we choose a widely used S-G filter to smooth the EVI and NDWI profiles to eliminate noise  and thisiR in phase space were calculated as follows.In this study, the phenological phase space means that the data points in the rice growing period are marked in the phase space in order for the phase space to describe the rice growth process. The rice phenological phase space was constructed using EVI and NDWI in which NDWI is the x-axis and EVI is the y-axis. The data points marked in the phase space can be connected in a time sequence to form a profile. This profile represents the trajectory of rice growth. We can extract a series of phenological parameters to reveal the state of rice growth and even dig out the stress information it bore from the profiles. In order to make the profile smoother, it is formed by connecting the daily data generated by B-spline interpolation performed on these raw data points. The rice phenological phase space is shown in R) can represent the rice growth rate , the rice growth rate fluctuation index (GRFI), and its GRFI Ratio formula are as follows.Furthermore, the ratio of the rice growth rate fluctuation (GRFI Ratio) correlated with heavy metal stress levels in rice, and it is obtained by dividing the value of GRFI in the first half of the rice-growing season in the second half of the rice growing season. Because previous research studies showed that the stress effects of heavy metals on rice in the first half of growth process is greater than that in the second half. Therefore, the more serious the heavy metal stress is, the great value the GRFI Ratio is. Therefore, the GRFI Ratio can indicate the level of heavy metal stress in rice. In addition, the GRFI Ratio is a kind of ratio-type indicator and can eliminate the interference of non-heavy metal stress factors between different sites to some extent. The rice growth rate  Amplitude of EVI and NDWI of severe stress rice is smaller when comparing the moderate stress rice and the light stress rice, and the trajectory of severe stress rice covers the smallest area than others. (2) The maximum values of EVI and NDWI of severe stress rice are smaller than those of moderately stressed rice and light stress rice. (3) The direction of the severe stress rice growth trajectory changed more frequently than that of moderately stressed rice.The most common phenological parameters in the phase space were extracted, and the result is shown in Data in The experimental results demonstrated that the rice growth trajectories under different heavy metal stress levels showed a difference in the phenological phase space, and the GRFI Ratio we proposed performed better in discriminating different heavy metal levels than the most common phenological parameters in the phase space. The paper has two innovations. One is the introduction of temporal information of rice growth period in two different aspects to monitor the heavy metal stress level of rice. Former studies ,40 ignorHowever, some limitations also exist in this study. First, the study sites are all located in the Zhuzhou city, and only remote sensing data of 2016 were employed to conduct the temporal profile analysis because of the limitation of field validation. The introduction of the study area in different climatic conditions and remote sensing data of more years will be taken into consideration in our further work. Moreover, the values of EVI/NDWI were obtained by averaging the values of rice pixels, which would lead to the problem of mixed pixels . Better (1)The framework of rice heavy metal stress remote sensing monitoring consisting of the generation of synthetic Landsat time-series data and the construction of phenological phase space is feasible.(2)The phenological phase space and the rice growth profiles can well depict the growth process of rice, and also reflect the effects of different heavy metal stress levels for rice growth.(3)The GRFI Ratio was the stable and sensitive indicator, which we constructed from phenological phase space for discriminating heavy metal stress for rice. Comparing with other common phenological parameters in the phase space, the GRFI Ratio performed better.In this paper, we focus on constructing a stable and sensitive indicator to monitor heavy metal stress of rice using phenological phase space theory combining with spatiotemporal data fusion technology. We first built the time series data of eight-day temporal resolution and 30 meters spatial resolution using the spatiotemporal data fusion algorithm. Then, we extracted the EVI and NDWI temporal profiles to construct the phenological phase space and plotted the growth trajectories of rice in the phase space. Lastly, a sensitive indicator GRFI Ratio for heavy metal stress in rice was constructed and results showed it outperformed in discriminating different heavy metal stress levels. The most important findings and conclusions drawn from this study include:In summary, a spatiotemporal data fusion method combining with phenological phase space technique can provide a stable and accurate method for detecting a heavy metal stress level in the paddy field. These technologies can be applied in pollution investigation of agricultural field, and provide new ideas for monitoring heavy metal stress.


Nontuberculous mycobacteria (NTM) are ubiquitous components of the soil and surface water microbiome. Disparities by sex, age, and geography demonstrate that both host and environmental factors are key determinants of NTM disease in populations, which predominates in the form of chronic pulmonary disease. As the incidence of NTM pulmonary disease rises across the United States, it becomes increasingly evident that addressing this emerging human health issue requires a bold, multi-disciplinary research framework that incorporates host risk factors for NTM pulmonary disease alongside the determinants of NTM residence in the environment. Such a framework should include the assessment of environmental characteristics promoting NTM growth in soil and surface water, detailed evaluations of water distribution systems, direct sampling of water sources for NTM contamination and species diversity, and studies of host and bacterial factors involved in NTM pathogenesis. This comprehensive approach can identify intervention points to interrupt the transmission of pathogenic NTM species from the environment to the susceptible host and to reduce NTM pulmonary disease incidence. Legionella pneumophila and Pseudomonas aeruginosa . The. The6]. Our understanding of the spatial epidemiology of NTM disease is beginning to achieve more granular levels of analysis with regards to environmental determinants. In a Colorado-based study, NTM infections were distributed in clusters that shared a common water source . In addiM. avium [M. avium in biofilms, as discussed above. Similarly, the Colorado-based geographic study observed increasing rates of NTM infection with increasing distance from the treatment plant to the household [Mapping water distribution systems in conjunction with environmental and clinical data will provide additional insights into NTM disease mechanisms. Environmental sampling studies have demonstrated that the abundance of NTM species in water systems increases in proportion to the distance from the point of entry into the water distribution system, which reflects the residence time in the system ,52. As dousehold ,52. ThesStudies in the field of NTM biology and disease have predominantly focused on either the patient characteristics that promote the acquisition of NTM infection and disease progression, or the environmental drivers of NTM growth and propagation in soil and water systems. We propose that addressing the emerging public health threat of NTM pulmonary disease depends upon a multi-disciplinary research framework that includes the assessment of environmental characteristics promoting NTM growth in soil and surface water, evaluation of associated water distribution systems , and direct sampling of water supplies for NTM contamination and diversity. These environmental-based studies should complement investigations of the clinical epidemiology of NTM pulmonary disease within populations drawn from the same geographic areas, and may shed light on poorly understood phenomena such as relapse or re-infection following treatment. For example, prospective cohort studies of patients with NTM pulmonary disease could routinely include environmental sampling in the patient’s household, performed at regular intervals during follow-up, in order to disentangle patient-focused and environment-focused drivers of treatment response or disease relapse. This unified framework will be required to identify the NTM “pump handles” for removal and interrupt the continuum that leads from NTM soil colonization to clinical disease. A comprehensive approach that follows the lessons of John Snow is essential to reverse the trends of NTM pulmonary disease in the 21st century and beyond.


Ankle fractures cause considerable pain, loss of function and healthcare resource use. High quality randomised controlled trials are required to evaluate the optimal management protocols for ankle fracture. However, there is debate regarding the most appropriate outcome measure to use when assessing patients with ankle fractures. The aim of this systematic review is to identify and summarise primary outcome measure use in clinical trials of non-pharmacological interventions for adults with an ankle fracture.ClinicalTrials.gov online clinical trial registries on 19/06/2019 with no date limits applied. The titles and abstracts were initially screened to identify randomised or quasi-randomised clinical trials of non-pharmacological interventions for ankle fracture in adults. Two authors independently screened the full text of any articles which could potentially be eligible. Descriptive statistics we used to summarise the outcome measures collected in these articles including an assessment of trends over time. Secondary analysis included a descriptive summary of the multi-item patient reported outcome measures used in this study type.We performed comprehensive searches of the Medline, Embase, CINAHL, AMED and Cochrane CENTRAL databases, as well as ISRCTN and The searches returned a total of 3380 records. Following application of the eligibility criteria, 121 records were eligible for inclusion in this review. The most frequently collected primary outcome measures in this type of publication was the Olerud Molander Ankle Score, followed by radiographic and range of movement assessments. There was a total of 28 different outcome measures collected and five different multi-item, patient reported outcome measures collected as the primary outcome measure. There was a sequential increase in the number of this type of study published per decade since the 1980’s.This review demonstrates the wide range of measurement methods used to assess outcome in adults with an ankle fracture. Future research should focus on establishing the validity and reliability of the outcome measures used in this patient population. Formulation of a consensus based core outcome set for adults with an ankle fracture would be advantageous for ensuring homogeneity across studies in order to meta-analyse trial results.The online version of this article (10.1186/s12891-019-2770-2) contains supplementary material, which is available to authorized users. Ankle fractures are a significant injury which cause pain, reduced function and have a substantial impact on activities of daily living for the individual . EpidemiIn light of the increased incidence of ankle fractures, further high quality randomised controlled trials (RCTs) to determine optimal management strategies of this injury are required, as recommended by a Cochrane review of rehabilitation for ankle fractures completed in 2012 . The resThe choice and use of appropriate primary outcome measures is of utmost importance in the design and conduct of clinical trials and the use of invalid or unreliable outcome measures is a waste of resources and can be regarded as unethical . TraditiClinicalTrials.gov registries was completed on 19/06/2019 with no date limits applied. The review was not prospectively registered as it did not meet the criteria for registration with PROSPERO. The search strategies used in this review are found in the additional files  and the eligibility criteria were applied.Results from the database searches were exported to EndNote X5 (Thompson Reuters) for review. Duplicates were removed and the eligibility criteria were applied by the lead author through a review of the titles and abstracts. Based on this initial screening, articles were excluded if it was clear from the title and abstract that it did not meet the inclusion criteria. If eligibility was unclear, the lead author retrieved the full text for review. Results from the ISRCTN and A second reviewer (AR) independently repeated the application of the eligibility criteria on all papers and registry records for which the full text was retrieved and applied the same criteria, to reduce error and ensure no ineligible records had been included. Where discrepancies occurred, RM and AR discussed and reached consensus on article inclusion. Where consensus could not be reached, a third reviewer (RSK) was consulted for a final decision. Caution was taken throughout the selection process to ensure that articles with a registry entry and a subsequent publication were only included once.The lead author recorded study details, including authors, title year of publication, journal and outcomes collected in a data extraction spreadsheet using Microsoft Excel (Microsoft 2011). Where authors did not explicitly declare the primary outcome measure (or if multiple were stated), the outcome measure on which the sample size was calculated was used as the primary outcome. Where articles did not state this, the first outcome measure declared in the abstract was regarded as the primary outcome measure. In any cases where this did not apply, the first outcome measure mentioned in the full text of the article was regarded as the primary outcome measure. This method has been used in previous systematic reviews of this nature .We used descriptive statistics to explore what primary outcome measure were used in this type of interventional trial. Secondary analysis explored the number of trials published over time and the temporal trends of the most frequently used outcome measures. An analysis of the multi-item, patient reported outcome measures collected as the primary outcome measures in these studies was also completed.For the purposes of analysis, radiographic outcome measures collected, such as X-Ray, Computed Tomography (CT) scans and other will be grouped into one category called radiographic assessment. Measurements of swelling, strength and range of movement assessments (ROM) may be performed in a variety of ways between studies, but these will be grouped together as one category  regardless of the specific method of measurement.The searches returned a total of 3380 records, of which 3226 were published articles form database searches and 154 records from registry databases. Following removal of duplicates and application of the eligibility criteria, 121 records were eligible for inclusion in this review. The PRISMA diagram in Fig. The 121 records included were by authors in 21 different countries with a total patient population of 11,662 participants (including planned populations of protocol papers and registry records). The additional files contain the data extraction table including details of the records and the outcome measures collected Additional file 2:Search strategy used in review for all databases and registries. (PDF 478 kb)Additional file 3:Tables showing data extracted from included articles and records during review process. (PDF 939 kb)


Sugars perform an important regulatory role in plants. Part of this regulatory role is exerted by the SNF1-related kinase 1 (SnRK1), which acts as an energy sensor. The target of rapamycin (TOR) kinase is a master regulator of cell growth and metabolism and is negatively regulated by SnRK1. Through these kinases, sugars can modulate metabolism according to the energetic status of the cells.Autophagy is an important process by which cells can recycle cellular compounds to generate energy under unfavorable growth conditions. These conditions include carbon or nitrogen deficiency or a wide range of abiotic and biotic stresses. Autophagy also plays a role during leaf senescence, contributing to nitrogen mobilization to seeds. Autophagic degradation of cellular components requires their transport to lytic vacuoles, either through double-membrane vesicles called autophagosomes (macroautophagy) or through direct invagination of the vacuolar membrane (microautophagy). The best-studied type of autophagy is macroautophagy, which requires a conserved set of autophagy-related (ATG) proteins for the formation of autophagosomes and the delivery of cargo.Tripogon loliiformis under desiccation conditions , one mini-review about the role of sugars in controlling autophagy in plants , one mini-review on the regulatory pathways underlying plant autophagy , and two mini-reviews about the degradation of chloroplasts by autophagy .This Research Topic contains articles discussing the role of sugars in plant autophagy and includes one original research paper focused on the comparison of autophagic activity in shoot and roots of the resurrection plant Asami et al. show that autophagy can be differentially regulated in different organs of the same plant subjected to the same conditions. In particular, they showed that unlike in shoot, autophagy is not activated in roots of T. loliiformis during dehydration . Part of this difference was attributed to the fact that roots accumulate much more sucrose and T6P, which at high levels inhibit autophagy, via SWEET sugar transporters. Thus, this work demonstrates the importance of analyzing autophagy in different organs before drawing general conclusions. The mini-review from Janse van Rensburg et al. highlights the relevance of the cell wall invertases, which convert sucrose into glucose and fructose extracellularly, where the produced glucose can interact with Regulator of G-protein (RGS1) to induce autophagy by a still-uncharacterized mechanism. The authors propose that autophagy is induced by SnRK1 under sugar starvation and by RGS1 under sugar excess. Besides the control of autophagy by sugars, the authors also mention the role of autophagy in regulating sugar homeostasis , in which the selective degradation of chloroplasts or chloroplast components by autophagy plays a major role .Izumi et al.; Zhuang and Jiang), including the formation of rubisco-containing bodies (RCBs), which allow degradation of stromal proteins; ATG8-interacting (ATI) bodies, which transport chloroplast components interacting with ATG8; the transport of small starch granule-like structures (SSGLs); and the transport of entire chloroplasts, all of them being autophagy machinery-dependent . Additionally, Izumi et al. discuss the contribution of chloroplast degradation to increasing levels of free amino acids, which are used by mitochondria as respiratory substrates. Zhuang and Jiang present a table of putative ATG8-interacting motif (AIM)–containing proteins and their potential role in recognition by the autophagy machinery to target the degradation of chloroplasts.Multiple pathways contribute to the degradation of chloroplast components by autophagy . They also discuss the role of the histone deacetylase 9 (HDA9) in suppressing ATG9 gene expression and the importance of phosphorylation, ubiquitination, and lipidation of ATG proteins in the control of their activity .The mini-review presented by Yang et al.); understanding how G-protein signaling promotes autophagy ; the identification of chlorophagy receptors (Zhuang and Jiang); deciphering how chloroplasts interact with the autophagy machinery ; and the identification of intermediate structures during chlorophagy (Zhuang and Jiang).Over the past few years, significant progress has been made in our understanding of autophagy in plants, its regulation, and the involvement of sugars as signaling molecules in this process. It is clear that there are still many outstanding questions that need to be resolved in the future. Some of the challenges arising from this research topic are: the identification of novel regulators of plant autophagy  and the National Science Foundation (MCB-1714996). WE is supported by funding from FWO Vlaanderen.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


Electrocardiogram (ECG) sensing is an important application for the diagnosis of cardiovascular diseases. Recently, driven by the emerging technology of wearable electronics, massive wearable ECG sensors are developed, which however brings additional sources of noise contamination on ECG signals from these wearable ECG sensors. In this paper, we propose a new low-distortion adaptive Savitzky-Golay (LDASG) filtering method for ECG denoising based on discrete curvature estimation, which demonstrates better performance than the state of the art of ECG denoising. The standard Savitzky-Golay (SG) filter has a remarkable performance of data smoothing. However, it lacks adaptability to signal variations and thus often induces signal distortion for high-variation signals such as ECG. In our method, the discrete curvature estimation is adapted to represent the signal variation for the purpose of mitigating signal distortion. By adaptively designing the proper SG filter according to the discrete curvature for each data sample, the proposed method still retains the intrinsic advantage of SG filters of excellent data smoothing and further tackles the challenge of denoising high signal variations with low signal distortion. In our experiment, we compared our method with the EMD-wavelet based method and the non-local means (NLM) denoising method in the performance of both noise elimination and signal distortion reduction. Particularly, for the signal distortion reduction, our method decreases in MSE by 33.33% when compared to EMD-wavelet and by 50% when compared to NLM, and decreases in PRD by 18.25% when compared to EMD-wavelet and by 25.24% when compared to NLM. Our method shows high potential and feasibility in wide applications of ECG denoising for both clinical use and consumer electronics. Electrocardiogram (ECG) sensing aims to record the electrical activities of the heart, which is performed by detecting minor electrical changes on the skin caused by heartbeat activities via electrodes. Since ECG signals intuitively represent the electrical activities of the human heart, ECG sensing becomes a useful diagnostic tool for detecting various cardiac problems ,2. NoiseECG denoising has been investigated for decades in the literature and numerous methods have been developed. Conventionally, digital-filtering based denoising approaches are popular for ECG denoising. For example, several Kalman filtering based methods for ECG denoising are proposed with specific extensions for achieving good denoising performance ,8,9. VarFor the denoising using an SG filter, a smooth polynomial representation is determined to estimate the local ECG signal, which is excellent for eliminating various kinds of noise, regardless of the properties of stationarity of the noise . On the We develop a new LDASG filter for ECG denoising with adaptive polynomial order selection according to the variation of signals. Our method tackles the challenge of using a standard SG filter for denoising that has less adaptability to signal variations, resulting in difficulty of handling the instantaneous high variations of ECG signals and thus a trade-off of noise elimination and signal distortion.We propose to use the discrete curvature estimation to represent ECG signal variations and thus determine the order accordingly for adaptive SG filter design for each data sample. This newly proposed self-adaptive method maintains the intrinsic advantage of SG filter for noise elimination and tackles the difficulties due to the high variations of ECG signals even in one R-R interval.The experimental results of this study demonstrate that our method achieves excellent performance for ECG denoising and outperforms the other two state-of-the-art ECG denoising methods.In this study, instead of designing specific SG filters for applications, we propose an innovative and applicable low-distortion adaptive SG filtering (LDASG) method that is capable of self-adapting to input signals for ECG denoising. The proposed method utilizes adaptive polynomial order selection based on discrete curvature estimation of ECG signals. By estimating the curvature of each data sample in the discrete ECG signal, the signal variations can be reasonably represented and utilized for adaptively selecting the polynomial order of the SG filter. The proposed LDASG filter performs proper filtering processes according to the signal variations and thus achieves excellent performance for noise elimination as well as accurate reproduction of QRS complexes in the ECG signals. The main contributions of this study are summarized as follows:The remainder of this paper is organized as follows: In this section, the theory of SG filter is first explained to better illustrate our proposed method. The SG filter approximates the underlying signal using local least square fitting and has remarkable performance for data smoothing problems, which derives directly from the time domain without having their properties defined in the frequency domain as general digital filters.The basic idea of SG filter is to approximate the underlying signal locally within a moving window using polynomial fitting with fixed order . As showM denotes the half width of the window) within a sequence of signal N is the order and y is the filtered signal. The value of the output data point is exactly the 0th polynomial coefficient in each moving window. The SG filter makes no use of the values of the fitting polynomial at any other point within the window. The next data point will be evaluated by the same procedures with performing a new least square polynomial fitting within a shifted window at the central location.Concretely, considering a symmetric window of Equation ,(3)y[0]N as Equation A={AnEquation ,(7)H0={SG filter has been tempted for various biomedical signal denoising ,24,25. IAs discussed in N. Therefore, for the filtering process, instead of using a fixed SG filter, each data point is filtered by the proper SG filter based on its discrete curvature, which eliminates the noise more precisely and lowers the signal distortion during the filtering process.In our approach, discrete curvature is introduced for the one-dimensional time-varying ECG signals to quantitatively represent the signal variations. The estimation of discrete curvature on each data sample is utilized to select the polynomial order of the SG filter adaptively. As shown in Discrete curvature is an important geometrical parameter in various applications of computer vision and digital imaging. In our work, the time series of ECG signals can be considered as planar curves, which are uniquely determined by their curvature profiles . Therefoi is the index of data sample, and k is the searching length for the DSS. The estimated slope angle of the tangent line at points For each data point Equation ,(8)forwThe discrete curvature of the data point is estimated by the slope angle variation between the forward and backward longest DSS. The first step is to determine the longest DSS according to a well-designed criterion . ConsideEquation :(11)kb=mEquation  32], our method achieves significantly better performance of lowering the signal distortion for ECG denoising. The proposed method provides a promising solution for various applications of ECG denoising in both clinical use and wearable technologies.