In this paper we discuss the nexus of health and gender inequalities associated with the COVID-19 pandemic and highlight its adverse impacts on women's health, welfare and social standing. The COVID-19 pandemic has exposed the link between socio-economic inequalities and health outcomes, especially in the area of rheumatic and musculoskeletal (RMDs) diseases. Women are more adversely affected by RMDs diseases compared to men. Epidemiological research carried out over several decades has demonstrated the presence of clear gender patterns in the manifestation of musculoskeletal diseases, including osteoarthritis (OA), rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), systemic sclerosis (SS) and osteoporosis (OP). The public health measures that have been adopted to curb the spread of Sars-COV-2 are expected to have a particularly detrimental impact on women in the long term precisely because of the nexus between health outcomes and socio-economic structures. Moreover, the prioritization of urgent care will further compound this effect. COVID-19 has created a condition of ontological insecurity that is becoming increasingly manifested through various chronic diseases and associated comorbidities. RMDs and their impact on mobility and the ability of individuals to be independent, happy and mobile is a key public health challenge in the post-COVID-19 reality and a key part of the ongoing pandemic. There is an urgent need to engage with policymakers to publicize and prioritize this problem and develop viable solutions to address it. Coronavirus disease COVID-19) is an infectious disease caused by a newly discovered coronavirus 9 is an i. HoweverThe COVID-19 pandemic has had unprecedented and potentially irreversible impacts on health and healthcare globally with ongoing and adverse impacts on the economy . There aA very brief analysis of both gender and race in the context of the global pandemic highlight a number of issues that warrant further consideration:Frontline workers are overwhelmingly women  and emplshould thus open a space to revalue “care” as a function that is central to the human condition; such reckoning or recognition, however, will require the political ambition to imagine a post-COVID-19 recovery in which care is an integral part of the economic infrastructure.Growing awareness of the role of key workers during this latest crisis could provide a moment of reflection and recognition about the centrality of these roles to society and the economy. It Gender disparities are also emerging in terms of health outcomes. As a result gendered work and division of the healthcare labor market, women are more exposed to COVID-19, and at a much higher viral load than men . We do nThere are also serious issues regarding the impact of COVID-19 on Black, Asian and Minority Ethnic (BAME) communities. A systematic review of the published literature on COVID-19 articles in some of the most prestigious medical journals including New England Journal of Medicine, Lancet, British Medical Journal and the Journal of the American Medical Association plus EMBASE, MEDLINE, Cochrane Library, PROSPERO, clinical trial protocols, gray literature, surveillance data and preprint articles in MedRxiv has revealed that BAME individuals had an increased risk of infection with SARS-CoV-2 compared to white individuals and, 12 studies eported worse clinical outcomes, including intensive care unit admission and mortality  regimes of violence .It is in this context that important dynamics can be observed that highlight the continued impact of gender regimes in women's experience of work-life balance. Aside from gender differences in patients with COVID-19 , recent Women make up the majority of the health and social care workforce on the “front line” of the COVID-19 pandemic, e.g., as nurses and carers –25. It iThis has allowed policy-makers to overlook the impact of women's role in social reproduction and the increasing weight of the double burden in the domestic sphere. Quarantine is also prioritizing COVID-19 as a health “threat.” This approach reinforces the health pyramid, which positions musculoskeletal health much lower on list of priorities for healthcare providers. It is well-established that a range of chronic conditions that affect minoritized and marginal groups are often overlooked. The question to address here is whether COVID-19 will compound existing problems of unconscious bias in medicine, and how these interact with wider gender norms and hierarchies during times of crisis.Here are some key questions from an Equality, Diversity and Inclusion (EDI) perspective:What are the pathways for incorporating concerns around equality and inclusion into the story of COVID-19? There is substantial discussion at the moment about highly visible issues, e.g., higher death rates amongst black and minority communities, domestic abuse, but will this be included in the official record of the 2020 pandemic?What are the “blind spots” of policy? For example the impact of gender divisions of labor and the double burden on women's experience of public health measures during the Covid-19 crisis. What is the short, medium and long term impact of such omissions?How will the policy decisions of the first 6 months of 2020 affect men and women's experiences and health outcomes in the next 5 or 10 years?What are the costs of failing to carry out equality and diversity impact assessments in the context of this crisis?These questions need to be examined within a broad context that positions the equalities agenda at the heart of the national and transnational policy agenda. The Sustainable Development Goals specifically include obligations to advance gender equality (SDG5) and reducing inequalities (SDG10).A total of 17 Sustainable Development Goals (SDG) were established by the United Nations in 2015With regard to SDG 10 and COVID-19, there are two area to focus on, especially in relation to health outcomes:It is important not to assume that women's experience of COVID is homogeneous. Although a lot of the focus of the media coverage is on reconciliation between work and family life experienced by mostly white professional women, who became responsible for home schooling etc., the challenges faced by many BAME or minoritised women, often employed as frontline workers, is significantly different.The international picture is becoming increasingly complex, though there are some trends that can be identified. Intersectionality it's becoming more important and in relation to SDGs and the international trajectory of the COVID-19 pandemic, what is not yet clear is what role are women playing in the global south in managing community based responses to the pandemic.The SDG implicitly and explicitly recognize that development, cohesion, and social justice go hand in hand. COVID-19, however, expose the varied ways in which socio-economic inequalities shape public health approaches and thus defined health outcomes. In the next two sections we will explore the interaction between the social and the physical generates a deep sense of ontological insecurity , 28.Women have a higher prevalence of RMDs including osteoarthritis (OA), rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), systemic sclerosis (SS) and osteoporosis (OP) and probably sarcopenia as well. Therefore, as a consequence women have a much higher risk of developing cardiovascular comorbidities –34. SubsThe endogenous production of vitamin D is dependent on sunshine exposure . HoweverIn many low income countries musculoskeletal diseases are not considered to be health priorities and when epidemics and pandemics occur low income countries take the brunt and bear the harshest consequences –40. EvenThere is now an acute and almost frightening problem in OP management where patients with an incident fracture  which does not require hospitalization have had their post-fracture visit postponed until the re-opening of non-urgent consultations/technical examinations . Knowing that a recent fracture is one of the major risk factors to present with a new subsequent fracture, this may generate a major risk for these patients.One of the major issues in the management of chronic silent disorders is the lack of adherence to treatment goals. The lockdown has prevented patients from getting their prescriptions renewed on time. Also, many patients have gone without consultations with their general practitioner, which means that they have not received the positive feedback that is normally provided by consultation with their regular physician, hence increasing the risk of premature treatment discontinuation. Some of the drugs (IV formulations) are given under the responsibility of a registered nurse or of a physician. All these treatments were delayed during the lockdown with long-term adverse impacts on women's health.Depression and anxiety and physical violence will occur, particularly in people who are contained in small apartments, with children and/or pets. In this case, most of the house work will frequently be the responsibility of the homemaker, frequently women. This additional burden, leading to some kind of domestic burn-out will impact also on the motivation to either take the needed medications, to take physical exercise or to comply with the principles of bone/joint/muscle-health and nutrition. Compliance and adherence often requires input from healthcare practitioners. The lockdown has meant reduced opportunities for interactions between patients and their healthcare practitioners, exacerbating the anxiety associated with disease and the burden of the disease itself.As outlined previously COVID-19 has laid bare long standing socio-economic inequalities , 43 and There are important parallels between economic and medical hierarchies. Female-dominated occupations—such as childcare and hospitality—continue to occupy the lower rungs of the wage ladder. In the United States women make up 63 percent of workers earning the federal minimum wage, a wage rate that has been stuck at $7.25 since 2009. In contrast, women represent only 5 percent of CEOs at Fortune 500 firms . The losought from an is. Leaving aside the question of whether the science tells us what is , it does not imply any particular course of action. For example, we have known for several months now that COVID-19 is virulent and dangerous, but it does not represent the existential risk that some feared initially. Determining the right policy based on those facts depends on what the harms of the policy are, and what the individual and societal values are. Here are just a few of the considerations that need to be taken into account when “following the science”:Throughout the pandemic political leaders have claimed to “follow the science” . The expThe economic cost of losing one's job are greater in countries without strong social networks.Severe lockdowns cause harm to those without strong social networks, especially individuals who lived alone, and those in isolated communities.As mentioned previously, women and BAME people are disproportionately affected.The long-term economic damage caused by COVID-19 induced lockdowns will cause more indirect deaths by starvation than deaths caused by the virus according to the United Nations.Taking these considerations into account doesn't make choosing the right policy any easier. But if we willfully ignore them by continuing to hold on to the mistaken belief that science determines policy, we have no chance of addressing the important issues, which are clearly beyond the scope of this paper.In April 2020 the United Nations (UN) published a policy brief on the impact of COVID-19 on girls and womenEnsuring women's equal representation in all COVID-19 response planning and decision-making.Driving transformative change for equality by addressing the care economy, both paid and unpaid.Targeting women and girls in all efforts to address the socio-economic impact of COVID-19.Almost a year later, it is clear that we have a lot of work left to do. As EU countries re-enter lockdowns during the second wave of COVID-19, governments must learn important lessons from the positive actions taken during the first wave of the pandemic and reflect on the shortcomings of their inevitably reactive approaches during the first wave. In the majority of EU countries, the pandemic has exposed overall shaky support systems for the most vulnerable in society. The crisis continues and despite emerging vaccines and implementation of mass vaccination programmes in 2021, COVID-19 has transformed the way we live and work and made us question our relationships with each other and with our governments. The pandemic has shone a harsh light on how unprepared we have been and highlights the anxieties and uncertainties that will follow us into 2021 and beyond. There is emerging consensus that a better understanding of public perceptions of government responses to COVID-19 may foster improved public cooperation . We mustThe original contributions presented in the study are included in the article/supplementary material, further inquiries can be directed to the corresponding author/s.AM conceived the paper, produced the first draft, and edited the manuscript. All authors contributed to the article and approved the submitted version.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.


This work applies a procedure for analysis and characterization of the surface of brake friction materials, correlating them with the tribological and thermal properties achieved in different vehicle braking conditions. Experiments were performed in a vehicle under two real conditions of braking operation, simulated flat track descent and emergency braking. Characteristics of the plates formed on the surfaces of the friction materials were analyzed by scanning electron microscopy (SEM) and correlated with the performance during braking, as measured by the coefficient of friction at the interface of the friction pair and temperature. As a result, the formation of the primary and secondary plateaus in these two different braking operating conditions was observed, and the relationship between the characteristics of the plateaus formed on the surface and the surface roughness parameters and performance measurements during braking. According to Machado Pinto et al. , automobAs described by Singh et al. , NogueirExcessive heating during the braking process can result in brake system malfunction and, consequently, reduced vehicle safety. One of these thermal problems related to brake systems is the braking fade effect, characterized by the momentary loss of friction between disc and pad due to the temperature rise of the systems during the braking process. According to Rehkopf and Halderman , LimpertAccording to Xiao et al.  and ZhanIn this study, braking tests were conducted on a real vehicle under two different operating conditions: simulated downhill driving on a flat track and emergency braking. These experiments were conducted to analyze the properties of the brake friction material, specifically regarding the characterization of the contact plateaus formed on the surface of brake friction materials and the 2D roughness parameters, correlating them with the tribological and thermal properties achieved under different vehicle braking conditions. To analyze the plateau characteristics, scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) were used. To analyze the relationships between the collected variables, the statistical techniques t-test and main effect plots were utilized. Wear mechanisms were identified on the sample surfaces and related to the results obtained.Friction vehicle tests were performed in a test track of an automaker present in the Brazilian marketplace. The vehicle used in the tests is equipped with the brake disc in the front axle and with the drum brake in the rear axle. The instruments and sensors utilized for temperature and friction coefficient data acquisition are described next.To control the hydraulic pressure of the brake, it was installed an HBM full-bridge extensometer sensor  model P8AP with a measuring range from 0 to 3000 psi. This sensor was installed in the hydraulic tubing of the brake system. To control the temperature of the discs and pads, it employed thermocouples type K (Cr-Al) with 3 mm of diameter and dry tip and fiberglass insulated, to avoid fracture and favors assembly, as it is performed directly in the vehicle. These thermocouples were attached to the center of the brake pad through a hole. To control the deceleration of the vehicle, it was utilized a uniaxial accelerometer from Silicon Designs Inc.—Advanced Accelerometers , model SDI 2220-002, with a measurement range from 0 to 2 g.The data acquisition system applied in the experimental tests is composed of the thermocouples, the pressure sensor, the accelerometer, and the acquisition board. The diagram of the data acquisition system is illustrated in The data acquisition of the signals measured by the sensors was performed using a Quantum X module, model MX840B from HBM , with FastEthernet (RJ-45) connection. The post-processing and signal analysis was performed using the Catman Easy software, also from HBM . (a)Test 1—Simulated downhill (simulated in flat track): It was performed 3 brake cycles, each one consisting of 60 brakings, with speed during braking nearby 40 Km/h. Each cycle duration was of approximately 20 min, and the average time interval between two consecutive brakings was 20 s. The brake system cools down naturally after completing a braking cycle. The next cycle starts when the system is cooled down to 100 °C.(b)Test 2—severe braking condition on a flat surface—emergency braking: It was performed three braking cycles with 10 successive breakings, with a speed reduction of 80 Km/h, with maximum deceleration and maximum speed recovery. In these tests, the heating rate of the discs and friction materials is high, and there is not enough time for the natural cooling of the system. The brake system cools down naturally after completing a braking cycle. The next cycle starts when the system is cooled down to 100 °C.The vehicle tests were performed in two distinct operational conditions:These configurations of experimental tests in vehicles were defined because they meet the requirements of Contran Resolution 519/2015 (ABNT NBR 10966 standard), which deals with the approval of friction materials for automotive brakes in Brazil. These tests were conducted on the test track of a large vehicle manufacturer, whose name will not be disclosed in this study for reasons of secrecy and industrial secrets.t-test was performed to test the difference between a simulated downhill and emergency braking. The response variables were split into three groups: breaking performance metrics, plateaus properties, and roughness parameters of the sample surfaces. The statistical software Minitab 17  was implemented to design and conduct the analysis. More details about this software can be found in [In this study, the two-sample found in . Table 1The responses considered to measure the performance of the vehicle braking system were the friction coefficient at the interface between disc and pads, and the temperature. The responses related to the plateau were obtained from microscopic analysis of the brake pad surface. A scanning electron microscope (SEM) from TESCAN , model VEGA 3, was used. The plateau measured parameters were the area of the plateaus, the average number, and the average length of the plateaus. These parameters were measured using the software of microstructural analysis Quantikov 16.01, considering SEM images with 25× magnification. Three images for each test type were analyzed. The Quantikov 16.01  software includes modules for digital image processing, geometric quantification, graphics generation, and hypertext. More details about this software can be seen in Pinto .The fade effect, as described by Rehkopf and Halderman , Limpertt-test was used. To evaluate the significance of the effects of each of the variables analyzed, the p-value referring to the t-test is presented for each response variable. The objective was to verify whether the two operational conditions submitted to the vehicle tests promoted significant changes in these performance variables. For all variables, the assumptions of normality and independence were met. The variance between data sets was equal for all variables, and the test was applied for independent variables and equal variances. To conclude whether the analyzed factor promotes significant changes in each response variable, one can compare the p-values with the significance level considered, which in this study was α = 0.05. As all p-values obtained were lower than the significance level, the factor analyzed promotes significant changes in all response variables. Thus, for the tests performed, the simulated saw downhill braking showed statistically significant differences in all the response variables analyzed, for a 95% confidence interval, compared to the emergency braking tests.In this table, the statistical These changes can be better visualized through the graphs of main effects, illustrated by The explanation for this result may be related to the measurements of the plateau characteristics: the average relative area with the presence of plateaus of the samples for these tests was larger compared to the samples of the pads used in downhill tests, as can be seen in These results observed in The temperatures reached by the emergency braking tests were lower compared to the downhill tests and, according to Jang , with inIn contrast to the new material, represented by According to Ma et al.  and SilvAs described by Wang and Liu  adhesionOn the other hand, there is a general unstable pressure and temperature field on the friction surface at high temperature, as described by Fu et. al. . The difμ = abrμ + adhμ. The abrasive contribution is related to the interactions between the pad and disc asperities. Rabinowicz [abrμ = tg θ, where θ is the mean angle of attack that the asperities form with the sliding surface. An estimate for θ is not available in this study, but according to Straffelini [μ is obtained by the adhesive interaction forces between the tribological pair. This contribution, according to Rabinowicz [adhμ = m*Arτ/NF, where mτ is the mean shear stress to separate the contact asperities, which is, approximately proportional to the adhesion forces, as reported by Straffelini [rA is the real contact area and NF is the applied load. Thus, the contribution of adhμ is expected to be minimal when the pad has its original roughness  since rA is quite low. The actual contact area between the two contact surfaces is mainly determined by the contact plateaus.Straffelini  points obinowicz  proposesaffelini , even onbinowicz , can be affelini , Ar is tAs the roughness is reduced, the wear rate decreases, and the coefficient of friction increases. This behavior is determined by the progressive reduction of the abrasive component’s contribution to wear. At the same time, by reducing the roughness, the interaction of the adhesive component between pad and disk increases strongly and this induces an increase in the coefficient of friction. Comparing Through the experimental tests performed on a vehicle under two different conditions (downhill and emergency braking), the presence of the fade effect was observed at temperatures around 250 to 300 °C and the differences in performance during braking for these two operating conditions. Emergency braking resulted in lower temperature values at the end of braking and higher values of the mean coefficient of friction at the friction interface. It was observed that these two different braking operating conditions resulted in significant differences concerning the three groups of response variables considered. Using scanning electron microscopy (SEM), it was possible to observe that on the initially rougher surfaces of the new samples, as verified by the roughness parameters, there are no contact plateaus. For the tests in simulated downhill and emergency braking, the presence of primary and secondary plateaus was verified.Through EDS analysis it was possible to estimate the chemical characterization of some specific points on the sample surfaces. Higher mean coefficient of friction values obtained in the emergency braking tests may be related to the higher percentage of the surface area of the samples containing plateaus, the formation of larger plateaus, and a higher percentage of iron found in the primary and secondary plateaus. It was possible to identify the main wear mechanisms resulting from the braking process, namely: abrasive wear, arising from the hard asperities and debris, generated in the tribological pair wear, which cut and formed grooves on the surface of the pads; adhesive wear, produced on the high-temperature friction surface due to metallic adhesion between the steel fibers and the cast iron rotating disk; and fatigue wear, produced due to pressure and temperature instability on the high-temperature friction surface. Emergency braking tests showed a higher mean coefficient of friction compared to downhill tests because they showed more dominant adhesive characteristics of the friction component, overcoming the lower contribution of the abrasive component in the emergency braking tests.The experimental methodology used in this study considered the specific characteristics of the tested tribological pair as well as the boundary conditions defined in the experimental design (speed and operating conditions during braking). As a result, it was possible to analyze the relationship between the surface parameters of the friction materials and brake performance measurements. The brake pads used in this study were of the non-asbestos organic (NAO) type and gray cast-iron brake disc. This same methodology can be applied to materials with other chemical compositions, such as semi-metallic (SM) pads, as well as other operating conditions during braking.As opportunities for the development of future work, it is suggested to perform SEM and EDS analysis also on the surface of the brake disc, in an approach similar to that conducted on the brake pads in this study, to obtain a complete analysis of the tribological pair used in brake systems.


As the second generation of biometric technology, finger vein recognition has become a research hotspot due to its advantages such as high security, and living body recognition. In recent years, the global pandemic has promoted the development of contactless identification. However, the unconstrained finger vein acquisition process will introduce more uneven illumination, finger image deformation, and some other factors that may affect the recognition, so it puts forward higher requirements for the acquisition speed, accuracy and other performance. Considering the universal, obvious, and stable characteristics of the original finger vein imaging, we proposed a new Region Of Interest (ROI) extraction method based on the characteristics of finger vein image, which contains three innovative elements: a horizontal Sobel operator with additional weights; an edge detection method based on finger contour imaging characteristics; a gradient detection operator based on large receptive field. The proposed methods were evaluated and compared with some representative methods by using four different public datasets of finger veins. The experimental results show that, compared with the existing representative methods, our proposed ROI extraction method is  In the field of Biometrics, security and efficiency are vital for recognition systems. Moreover, the recognition accuracy and recognition rate also need to be taken into account. In 2000, Kono et al.  proposed(1)A horizontal Sobel operator with additional weights is proposed to provide an accurate starting point for the search.(2)Observing the finger cross-sectional MRI image, we found that the finger cross-sectional surface showed a sub elliptical shape, so we propose a new finger edge detection method by using the imaging property of the finger contour in the vein image.(3)A large receptive field gradient operator and a new method for localizing joint cavities based on this operator are proposed, which solves the difficult problem of localizing joint cavities caused by large gray gradients in vein images.Finger vein recognition generally includes four main steps: image acquisition, preprocessing, feature extraction, and matching recognition. In the process of finger vein image acquisition, the image quality is relatively poor because it is easily affected by environmental factors such as uneven illumination and temperature, and also by personal factors such as finger image translation, rotation, scaling, and gesture changes. The global pandemic in recent years has raised public health safety issues to an unprecedented level, prompting the development of acquisition methods in a contactless, unconstrained direction, which has exacerbated the impact of external factors on acquisition effectiveness. Extracting the vein information from the fixed area of a finger as Region of Interest (ROI) for feature extraction, ensures the minimal differences between the features obtained for identification of the same individual under different conditions . TherefoThe paper is organized as follows: In recent years, researchers have devoted themselves to the study of ROI extraction of finger vein images. Generally, ROI extraction is performed in the process of preprocessing, which can be divided into ROI localization and extraction, and vein image enhancement and normalization. The accurate extraction of ROI is a prerequisite for image enhancement and normalization. According to the different ways of ROI localization, ROI extraction methods are divided into four categories as follows :The first class of methods is based on fixed window localization. Wang et al.  computedThe second class of methods is threshold-based localization. Kumar et al.  used 230The third class of methods is mask-based localization. Lee et al.  divided The fourth class of methods is based on fine-tuning finger region localization. Yang et al.  used sliIn order to develop a highly accurate authentication system, vein features need to be accurately extracted from the captured images, and this process must be performed quickly. Unfortunately, the existing methods cannot be robust, efficient, and accurate at the same time for image processing affected by complex background, scattering, and uneven illumination. Through a large number of studies, we found that the finger cross-sections are nearly elliptical, which generally produce a stable and obvious imaging property of the finger contour. We can use this feature to segment the finger region. In order to solve the difficult localization problem caused by the large gradient of the joint cavity, we propose a joint cavity localization method using the gradient operator of large receptive field to further divide the finger region. This proposed method including: (1) A new method which combines vein image with horizontal edge detection operator can detect finger edge efficiently and accurately; (2) A new large receptive field joint cavity inspection operator based on human visual characteristics; (3) Accurate search of joint cavity based on the proposed operator, and the accurate extraction of the vein image ROI.An efficient and robust finger vein region extraction method is the key to finger vein recognition system. In this section, we elaborate the proposed method: A novel ROI extraction method based on the characteristics of the original finger vein image, which includes four steps: finger region segmentation, orientation correction, joint cavity localization, and ROI extraction. Research shows that the cross-sectional shape of the finger is approximately elliptical, and the edge of the finger is relatively thin, which is the brightest region in the whole image when capturing. We propose a finger edge search method based on the finger contour imaging characteristics. This method combines the original vein image with the improved edge detection operator to achieve accurate detection of finger edges in the local area, and obtains continuous single-pixel finger edge point coordinates. Due to the continuous finger edge, points do not occur with abrupt angle changes, and the search range of the proposed method can be limited to the upper and lower neighborhoods of the finger edges, which is less computationally intensive. After the finger edge coordinates are obtained, the least square estimation is used to calculate the correction angle, and the finger image is corrected by affine transformation.Through the analysis, we found that the imaging of joint cavity often produces a large range of gray gradient, which causes the problem of difficult localization. Therefore, in this paper, we propose a gradient detection operator with a large receptive field, which can be used to achieve an accurate search of the distal joint cavity. The proposed method is based on the universal properties of finger vein imaging which are distinct and stable, and the accurate extraction of ROIs can be achieved using such properties. In addition, in order to improve the recognition efficiency, the original images are reduced to half of the original size by using “double triple” interpolation. In practical applications, we found that the threshold and mask methods are not very satisfactory in terms of processing time and segmentation accuracy due to the complex background of the acquired images. Many elements in the image acquisition process can cause incorrect finger region segmentation, such as unclear boundaries due to uneven illumination a, incorrThe rules (for details see i represents the current row of the operator): b is an empirical value depending on the weight of the finger on the whole picture Gy′=Equation ) is an eFor an image of size Generally, there is a very obvious difference between the finger area and the background area in the vein image, as shown by the high and low grayscale values (brighter in the finger area and darker in the background area). As shown in F is a finger vein image, G is a horizontal gradient map obtained from F by the improved horizontal Sobel operator we proposed. Step 1 Mark current point: fill the pixel value of the current position of F, G to 255, respectively.Step 2 Update current point: calculate the difference between the current point of F,G and each point of the lateral tri-neighbourhood, noted as Equation  to obtaiStep 3 Iterate over all columns: repeat step 1 and step 2, starting with the baseline and traversing left and right through In the execution of step 2, errors are often generated because the upper or lower edge disappear Using least squares estimation, the finger midline was fitted based on the midpoints of the upper and lower edge points;(2)Obtain the rotated image using affine transformation;Correction of the deformed images ensures that the appropriate desired region can be extracted from each finger vein image for accurate feature extraction and matching, which greatly improves the efficiency and accuracy of the recognition system. We correct the images by the following two sub-steps:After the image has been affine transformed, the edges of the fingers will change accordingly. In this case, it is only necessary to translate the horizontal reference line obtained in ROI extraction of finger vein images requires rapid extraction of the same region from vein images collected from the same individual under different conditions. After the previous two steps, the upper and lower horizontal reference lines have been obtained. Next, a segmentation reference line needs to be found in the vertical direction. By understanding the nature of the finger’s structure, we know the gaps between the cartilage of the finger will be more transparent to infrared light under ideal conditions. In the digital vein image, the joint cavity is shown as two brighter areas. Qin et al.  found thStep 1: for the vein images obtained after correction, the candidate regions are delineated using the horizontal reference lines obtained in Step 2: the candidate region is reduced to a quarter of the original image using “double triple” interpolation to obtain Step 3: using the large receptive field gradient operator (size of (11 × 7) as shown in Step 4: w at the distal joint. The detailed formula is as shown below:we chose to localize the distal joint cavity. The distal and proximal joint cavity positions is defined as Equation . After rIn the study of existing joint cavity localization methods, we found that most of them locate ROI in a local scope. For human vision, the change of grayscale of joint cavity belongs to a wide range of gradation. The gray gradient area of the joint cavity generally accounts for a large part of the finger region. If the joint cavity is only observed in a small range, it is impossible to determine whether the joint cavity is located or not. Computer vision is similar to human vision in that the vertical orientation of the ROI is often inaccurate if only local area is searched at a time  with Intel Core i7-8700 and 8 GB RAM using PyCharm Community Edition (2020. x64).For testing the efficiency and robustness of the proposed method in this paper, we use four public finger vein image databases for experiments, including SDUMLA-HMT , a multiIn this experiment, we choose two representative finger region segmentation methods. In order to verify whether the proposed segmentation method has high accuracy and efficiency or not, we use the typical images introduced in From In experiments, we will verify the stability and robustness of the proposed joint cavity localization method. In order to ensure the objectivity and justice of the experiments, we use three typical images of different quality in each dataset, which have a large impact on the localization of the joint cavity, compared with three commonly used methods of joint cavity positioning. The first method is a single row maximum cumulative pixel average to locate in Yang et al. . The secBy observing the cumulative value of the column pixels in the finger region and the original image, we can find that the joint cavity is not always the brightest part of the finger region due to the light effect. As the sensitivity to light changes, the first and second methods based on cumulative pixel values are not accurate. When the end of the finger is detected, because the finger is thinner and more light is transmitted, the pixel distribution value in this region is higher, which has an impact on the positioning. The proposed method has obvious stability and robustness when compared with the first and second method. In addition, in contrast to the method using a double sliding window for positioning, our proposed method shows better performance against light interference. It is always positioned on the leftmost side of the distal joint cavity and has better stability.In this experiment, we use the typical images in As can be seen from Finally, the proposed method is compared with two existing representative methods on different datasets. The vein features were extracted using the maximum curvature method  and the The maximum curvature method and repeated line tracking method are used to extract the pattern features. We use the template matching method for pattern matching. A single finger in each dataset is considered an independent individual. The template used for matching is an image fusion using all the ROIs of a single finger. The performance of the matching was assessed using the False Acceptance Rate (FAR) and the False Rejection Rate (FRR). Different thresholds give different FARs and FRRs, and the Equal Error Rate (EER) is the value when the FAR and FRR are equal. For the number of matches, we use the SDUMLA-FV (3816/6) dataset as an example. With the template matching method, each image only needs to be matched with the matching template, so genuine matching takes 3816 times, while imposter matching takes 2,423,160 (3816 × 635) times.The ROC curves for the corresponding datasets are illustrated in This paper proposes a new ROI extraction method based on the characteristics of the original vein image. Firstly, according to the structural properties of the finger in its sub-elliptical shape, we propose a finger edge search method based on the imaging characteristics of the finger contour. It can achieve accurate detection of finger edges, obtain continuous single-pixel edges, and complete the division of finger areas and background areas. Secondly, based on the principle of the large scale grayscale gradient generated in the imaging of the joint cavity of finger, we propose a large receptive field gradient operator. It can accurately locate the leftmost of joint cavity in finger region and obtain a stable segmentation reference line in the same finger, and the horizontal reference line is corrected multiple times to ensure that feature loss is minimized. Finally, the accurate extraction of ROI is completed.The experimental results illuminate that for the images with different qualities in each dataset, the proposed method can accurately extract ROI with good robustness. By comparing the effect with representative extraction methods in finger region segmentation and joint cavity localization, our method has the best robustness and accuracy. For all the validation data, the proposed method for implementing ROI extraction and matching has the lowest EERs. Without feature extraction parameter adjustment, the best EER reached In recent years, due to the global pandemic, it has been shown that finger vein identification technology needs to develop in the terms of being fast and contactless. Therefore, efficient and robust finger vein ROI extraction is bound to be the focus of future biometric research. Next, we will present a new ROI extraction method suitable for different acquisition devices and application scenarios, to provide high identification accuracy while ensuring contactless authentication.


Vehicle automation is driving the integration of advanced sensors and new applications that demand high-quality information, such as collaborative sensing for enhanced situational awareness. In this work, we considered a vehicular sensing scenario supported by 5G communications, in which vehicle sensor data need to be sent to edge computing resources with stringent latency constraints. To ensure low latency with the resources available, we propose an optimization framework that deploys User Plane Functions (UPFs) dynamically at the edge to minimize the number of network hops between the vehicles and them. The proposed framework relies on a practical Software-Defined-Networking (SDN)-based mechanism that allows seamless re-assignment of vehicles to UPFs while maintaining session and service continuity. We propose and evaluate different UPF allocation algorithms that reduce communications latency compared to static, random, and centralized deployment baselines. Our results demonstrated that the dynamic allocation of UPFs can support latency-critical applications that would be unfeasible otherwise. Vehicles have been equipped during recent years with a wide range of sensors such as odometers, Global Positioning System (GPS) receivers, distance sensors, cameras, etc. Furthermore, the new autonomous vehicles require more and better sensors for identifying and localizing objects in the surroundings of the vehicle. By combining sensors and communication capabilities, vehicles become excellent platforms that enable a wide range of applications including environmental surveillance and traffic monitoring . Thus, v5G networks ,5 are a However, all this flexibility comes at the cost of powerful dynamic management paradigms, which, in some cases, must be assisted by artificial intelligence. From the point of view of vehicular sensing, a crucial requirement is to take vehicular data as soon as possible to the network-side computing resources that process these data to make decisions or to provide additional information to drivers, vehicles, or the infrastructure.Consequently, in this paper, we are interested in a solution to take vehicular data to the User Plane Function (UPF) modules of a 5G network core as efficiently as possible since, and from that moment on, those data will be readily accessible to the computing resources at the network edge. For this purpose, we relied on our previous Software-Defined-Networking (SDN)-based solution in . A diffeBy combining 5G gNBs with the associated computing resources and our solution to place anchor points at optimal locations, we can adapt the network to the requirements of the UEs in terms of latency. This enables applications such as collaborative sensing for enhanced situational awareness, where vehicles send large amounts of Light Detection and Ranging (LiDAR) data and other high-resolution sensor information to applications that fuse them together to build a high-precision view of the environment in real time. This information is then distributed to all the vehicles in the area so that they can avoid obstacles or make decisions ,13,14. AThe proposal of latency-reduction algorithms for the dynamic allocation of UPFs in 5G vehicular sensing scenarios;The evaluation of the proposed algorithms in terms of end-user latency and execution time using a publicly available dataset with vehicular mobility traces and Base Station (BS) deployments;The comparison of the proposed algorithms with baseline allocation strategies.The main contributions of this paper are:The rest of this paper is organized as follows: Vehicular sensor data have been exploited in many applications and research studies. Classic examples of sensing-oriented vehicles are space balloons, environmental satellites, and oceanographic vessels, to name just a few. Even though these platforms have been operated for decades, all of them are still useful for research ,21,22. NThe advent of cell phones, as high-performance computing devices linked to the Internet through broadband data networks, has revolutionized vehicular sensing. Cell phones can contribute their GPS positions to monitor urban dynamics . Road coBefore the advent of 3G mobile communications in the late 1990s, extracting large volumes of data from mobile sensors was unfeasible. Indeed, mobile sensors were data mules. As a result, solutions such as Delay-Tolerant Networking (DTN) were applied to take their data to the Internet when connection opportunities arose ,36  distributed across a 2D surface. The base stations provide wireless coverage to UE-enabled vehicles that move across the surface. As the vehicles move, their association with the base stations may change following their movement. The vehicles capture information from the environment through different onboard sensors and send this information to instances of a stateless distributed server-side application. The communications between the vehicles and the instances take place according to 3GPP standards: a General Packet Radio Service (GPRS) Tunneling Protocol (GTP) tunnel is established between the gNB and a UPF anchor point for each UE. The UPF is the termination endpoint for the communications of each UE, whose data are then forwarded to the server application. For the sake of simplicity, we considered a 1-1 mapping between base stations and Multi-access Edge Computing (MEC) hosts, which correspond to the nodes of a simple graph. The edges of the graph represent direct communication channels between the base stations . Nevertheless, we remark that the collocation of the MEC hosts with the BSs is just an example of a deployment strategy for simplifying the problem statement. The proposed algorithms in this work can be applied to other deployment scenarios  . This includes both the elapsed time for executing the UPF allocation algorithms and also the times required for deploying the UPFs at the target locations and reconfiguring the underlying SDN network for steering the traffic of each user to the closest UPF. Using our proposed mechanism in , the timectively . This prThe network graph is composed of the set of base stations as nodes and the corresponding links between them;The set of active users for each base station.The inputs required by the UPF allocation algorithm are as follows:Static K-means:A K-means clustering of all the base stations in the network is calculated. A UPF is deployed at the closest base station to the location of each cluster center based on Euclidean distances. This strategy is static, given the locations of the base stations, and it does not depend on the user distribution. Therefore, it does not involve any dynamic redeployment of the UPFs;Random: A trivial approach that picks the base stations where the UPFs are deployed at random, according to a discrete uniform distribution. Note that the scenario in which just one UPF is used is equivalent to a centralized UPF deployment;Greedy percentile: This iteratively picks the node that reduces the 90th-percentile worst-case latency perceived by the UEs. In the case of multiple nodes introducing the same 90th-percentile latency, the tie is broken in favor of the node with the largest reduction of the average latency perceived by the UEs;Greedy average: This iteratively picks the base station with the largest reduction of the average latency perceived by the UEs;K-means: A K-means clustering of the active base stations looking for as many clusters as UPFs we are interested in deploying. A UPF is deployed at the closest base station to the location of each cluster center based on Euclidean distances. This is analogous to the proposal in ;K-means greedy average: A K-means clustering of the active base stations is calculated. A UPF is deployed in each cluster by determining the node with the largest reduction of the average latency perceived by the UEs attached to base stations in the cluster;Louvain modularity greedy average: Nodes are clustered according to the Louvain modularity maximization . A UPF iThen, the output generated by the algorithm is the set of nodes where the UPFs must be deployed. With this in mind, we considered the following UPF allocation algorithms:The static K-means and random algorithms were used as baselines. The greedy percentile algorithm seeks to reduce the 90th-percentile worst-case latency perceived by the UEs. The greedy average is a simplified version of the latter to reduce its computational complexity. The K-means algorithm follows a state-of-the-art approach described in  to deterSince the goal of our experiments was to analyze the trade-off between the number of deployed UPFs and the latency achieved, we set the number of clusters of the K-means and Louvain modularity algorithms to the same fixed value as the number of UPFs being evaluated.As a final remark, in the case of using a different MEC deployment strategy , the algorithms can be directly generalized by considering its constraints.In this section, we describe the methodology we followed in this work to evaluate the proposed UPF allocation algorithms in a vehicular sensing scenario.We first describe the datasets we used, the processing we applied, and some insights based on an exploratory analysis of their information. Then, we elaborate on the metrics we used to assess the performance of the proposed algorithms through simulations.To evaluate our proposal in a realistic scenario, we used two publicly available datasets with the locations of real cellular base stations and realistic vehicular traffic traces in an urban environment .http://kolntrace.project.citi-lab.fr/koln.tr.bz2 (accessed on 17 November 2021). It corresponds to a 400 http://kolntrace.project.citi-lab.fr/koln_bs-deployment-D1_fixed.log (accessed on 17 November 2021). It contains the Cartesian coordinates of 247 base stations. We assumed that each base station is connected to other base stations in their vicinity, conforming a single connected graph, and that some base stations are equipped with a local computing infrastructure on which the operator can deploy low-latency services for its users based on the MEC paradigm.The dataset with mobility traces is available at First, each base station is connected to all the base stations in its surroundings less than Then, we built the single connected graph by iteratively finding the pair of nodes from the largest and second-largest components at the shortest distance from each other and set an edge connecting these two nodes. This way, at each iteration, the connected components are joined to the largest component.To build the single connected graph, we determined the links between the base stations as follows:In our simulations, we set The dataset of vehicular mobility traces consists of almost 20 GB of data of a period of 24 h. In total, there are over 354 million entries, corresponding to more than 700 thousand individual trips. Each entry contains the Cartesian coordinates of the vehicle location at each time instant plus the speed of the vehicle.d is the distance between the base station and the UE, and If the UE has just been enabled , we assign the UE to the base station with the minimum path loss. To compute the path loss, we used the expression and parameters for a non-line-of-sight urban scenario of . For theOtherwise, we evaluated the path loss of the nearest base station and the one to which the UE was attached in the previous round. If the path loss to the nearest base station is lower than that to the base station to which the UE was associated plus an additional hysteresis threshold ended in .The UEs in this dataset do not produce measurements at all timestamps. We considered that UEs are off during the periods in which they have no data. To assign a base station to each UE, we used the following procedure, also used in related works :If the UE latency and execution time:UE latency is a measure of the latency perceived by each UE since it transmits the sensed information until it is received at the server-side application. In this work, we characterized it as the minimum number of hops from the base station to which the UE is connected to a node where a UPF is deployed. As an aggregate measure of all individual UE latencies, we considered the 90th-percentile of the latency;Execution time is the time the UPF allocation algorithm takes to determine in which nodes the UPFs will be deployed. We calculated this as the elapsed time since the UPF allocation module receives the input data until the output is generated by the corresponding algorithm. That is, this time reflects only the decision time at each time slot.We evaluated the proposed algorithms with two metrics, For the reproducibility of our results, the Python code used for the simulations is available in a public repository  under anIn our simulations, we set the duration of the time slot to 5 s. To understand the unexpected behavior in the results of the K-means algorithm, we decided to take a closer look at its UPF allocations. Specifically, we studied the allocation at a time slot of the simulation with a representative number of UEs. UPF see , and the UPF see , which r UPF see , furtherFinally, note that a simplistic traditional deployment consisting of a single centralized UPF in the core network serving all the base stations would introduce a higher latency than any of the proposed algorithms using multiple edge UPFs.B is the number of base stations and U the percentage of BSs with UPF. This complexity noticeably reduces in the case of the greedy average algorithm, which only evaluates the average latency that would be perceived with each of the potential UPF placements, for a computational complexity of In a practical situation, the actual number of required UPFs can be determined from the curves in ications  and assuThe increasing amount and quality of the information provided by the sensors integrated into vehicles can be used to provide advanced services for drivers, autonomous vehicles, smart cities, etc. The complexity of the generated information requires a large amount of computing power that may not be possible to install inside the vehicle, but thanks to the quality of the communication channels, it is viable to perform the processing of the information in remote servers, following the cloud or edge paradigms. Nevertheless, highly demanding services such as collaborative enhanced situational awareness require fusing and analyzing the collected information and redistributing the results to the participating nodes. The latency between the vehicles and the UPFs should be minimized to take vehicular data to edge computing resources and provide results on time for the vehicle to understand the surrounding environment. In this work, we proposed a dynamic lightweight optimization framework that achieves this goal by continuously optimizing the deployment of UPF anchor points for each UE. The proposed framework is compatible with our SDN-based mechanism described in , which gWe compared the performance of different UPF allocation algorithms in terms of end-user latency achieved and execution time required. Our results revealed that centralized and static deployments cannot satisfy the requirements of latency-sensitive applications. However, our proposal based on the Louvain modularity greedy algorithm provides a good trade-off between the two previous metrics, allowing the deployment of applications such as enhanced situational awareness for low percentages of BSs with UPFs.


A parallel fish school tracking based on multiple-feature fish detection has been proposed in this paper to obtain accurate movement trajectories of a large number of zebrafish. Zebrafish are widely adapted in many fields as an excellent model organism. Due to the non-rigid body, similar appearance, rapid transition, and frequent occlusions, vision-based behavioral monitoring is still a challenge. A multiple appearance feature based fish detection scheme was developed by examining the fish head and center of the fish body based on shape index features. The proposed fish detection has the advantage of locating individual fishes from occlusions and estimating their motion states, which could ensure the stability of tracking multiple fishes. Moreover, a parallel tracking scheme was developed based on the SORT framework by fusing multiple features of individual fish and motion states. The proposed method was evaluated in seven video clips taken under different conditions. These videos contained various scales of fishes, different arena sizes, different frame rates, and various image resolutions. The maximal number of tracking targets reached 100 individuals. The correct tracking ratio was 98.60% to 99.86%, and the correct identification ratio ranged from 97.73% to 100%. The experimental results demonstrate that the proposed method is superior to advanced deep learning-based methods. Nevertheless, this method has real-time tracking ability, which can acquire online trajectory data without high-cost hardware configuration. Video-based animal collective behavior analysis, due to the high scientific values and a wide range of potential applications, become a hot research topic thanks to recent advances in the computer vision method. Zebrafish are widely adapted in many fields as an excellent model organism, such as in biology, neurology, and ecology research ,2,3,4. IHowever, there are still many challenges, comparing to the pedestrian tracking, the most common application of multiple object tracking (MOT), such as the fish are indistinguishable to the human eye because of similar appearance, the appearance and shape may change tremendously while swimming, and the orientation free detection method is required because the top view commonly observed in the application of zebrafish tracking. To solve these difficulties, a series of computer vision tracking methods were developed. These works commonly consist of individual detection and movement tracking. In the detection stage, the previous methods generally fall into two categories: detecting based on blob and detecting based on appearance feature. The blob-based detecting methods extract moving regions as the candidates of targets by subtracting a background model. Subsequently, the methods involve extracting targets according to the pre-defined geometry characteristic from the candidates. For example, some techniques use a specific model of the animal body based on the head shape , the bodIn the second stage, tracking, the existing methods can be divided into two categories: tracking based on data association and tracking based on identification. The data association-based methods assign the detected target in the current frame to the corresponding tracker by minimizing the assignment cost to get the global optimized result. According to the information obtained in the detection stage, such as position, direction, and blob size, a cost function can be constructed; then, the association task becomes a global optimization problem ,11,16,17In addition, the occlusion among biological individuals is the greatest challenge of vision-based behavioral monitoring system. To address the problems caused by occlusion in the tracking stage, the strategy of most existing methods is assigning a detected target to a tracker stringently with the cost of generating more trajectory fragments, then performing a post process to link these trajectory fragments ,20,21. FA multiple feature detection method is developed to extract the fish head and center of the fish body. The proposed fish detector was robust in detecting and locating individual fishes from occlusions. The motion state and bending degree of the fish body could be obtained in the detection process.The proposed parallel tracking scheme could estimate individual positions by examining the fish head and center of the fish body simultaneously. If the detector failed to locate the fish head or the fish body, the proposed tracker could follow the fish movement according to the other features. This was effective to improve the robustness of tracking, especially during occlusions.Real-time tracking performance was achieved in the experiments. Since the proposed method required less computational cost, the maximal tracking efficiency reached 67.39 FPS.To overcome the limitations of previous works, a parallel tracking scheme is proposed to enhance the tracking performance by reliable fish detection and individual tracking with multiple appearance features. The main contributions of this work are as follows:The proposed tracking scheme consists of two stages: individual fish detection and data association. The overall flowchart of the proposed tracking scheme is described in w and h denote the width and height of the bounding box, respectively, and It is possible to segment moving regions from the background by subtracting a static background image because the laboratory environment is relatively stable, and the moving targets stay only for a short time in an area. As shown in The previous step obtains the image patches of moving region that may include multiple individuals during occlusion events. To detect each individual and estimate the motion state, the shape index algorithm  was emplAccording to the shape index, all the points in the blobs are classified into 9 categories. Examples of shape index processing with different Gaussian kernels are illustrated in Different structural features can be extracted by using different scales of σ values. For example, the ridge of the fish body could be obtained when σ = 4, where the pixels of the center part of fish are brighter than the surrounding pixels. If σ = 8 is given, the fish head area presents a concave region that contains smaller values than the neighboring pixels.After extracting the shape index in different scale spaces, the local structural information can be represented as a single value at each pixel. In the case of tracking zebrafish, the cup and ridge feature are used to detect target individuals, redundantly, and the motion state of fish is represented as a single value according to the curvature of the ridge line on the fish body.Firstly, as shown in Secondly, as shown in lgorithm , which vAfter extracting and analyzing the local structural feature, numerically, for the detected features, we define the detection of fish head nmc denotes the IOU distance between the detected target m and predicted bounding box of tracker n in the current frame. n and m are the number of trackers in the previous frame and the number of detected targets in current frame, respectively. The Hungarian algorithm is employed to solve the optimal assignment problem [Since the occlusion event occurs frequently and randomly when a fish swims, the incomplete appearance of a fish can result in a missed detection or false positives, which decrease tracking accuracy and stability. Multiple features of a fish, i.e., fish head, ridge point on body, and motion state, are obtained in the previous steps. In this work, a parallel tracking scheme is developed by combining the multiple fish appearance features and motion features. The parallel tracking is implemented by tracking the fish head and fish body simultaneously. The head tracker and body tracker run parallelly to record the individual trajectories. In this work, the fish head is considered as the primary feature of the fish, and the tracker follows the fish head in preference to the fish body. Since the fish head presents a rigid shape without scale and shape variations, the structure of the fish head tracker is illustrated in  problem . The objBy the optimal assignment, each detected head should be assigned with an ID, and each tracker should be associated to a detected head. However, unassigned heads and unassociated trackers may occur when false positives and misdetection happened in the detection process. The proposed tracking scheme should further deal with these failures. A temporary tracking procedure is employed to examine the unassigned detections . The temFor the unassociated head trackers, the body tracking procedure will be employed to find the target individuals. When the head tracker loses tracking targets more than the max age, the tracker should be terminated and removed. The body tracking procedure is described in In this work, individual fish detection and tracking performance of multiple fishes are evaluated separately. Detecting individual fishes is the basic requirement for implementing multiple individual tracking. Individual detection accuracy determines the tracking performance. For example, detecting occluded fishes could efficiently improve the tracking ability of a group of fish. The precision-recall analysis, which has been widely adopted to the evaluation of object recognition and detection algorithms, is applied to assess individual detection accuracy by the proposed method. The calculation of precision and recall is given in Equations (9) and (10).In addition, to qualify the performance of the proposed detection method during an occlusion event, the occlusion detection ratio was utilized. The calculation of occlusion detection is given in Equation (12):The tracking performance of the proposed method is evaluated similarly to the evaluation of detection performance. The correct tracking ratio (CTR) and correct identification ratio (CIR) were used. The CTR as shown in Equation (13) describes the percentage of frames correctly tracked for each fish. The CIR as shown in Equation (14) describes the percentage of correct identification of all fish after an occlusion event. Occlusion is one of the greatest concerns in multiple objects tracking, which is the significant disturbance in decreasing the tracking accuracy. The CIR represents the stability of the tracking scheme against occlusions, and the high CIR value indicates that the tracking scheme is robust to occlusion. In addition, the total computational time and the frequency of ID switch after occlusion were measured.Fish observation tests were conducted in our customized behavioral observation facility to collect video data of zebra fish. The fish observation facility was designed to observe the two-dimensional movement of fish as illustrated in The proposed tracking scheme was implemented by Python and image processing libraries such as OpenCV and Skimage. All the tests were conducted on a personal computer configured with an AMD CPU 3800X@3.9 GHz, 16G RAM under Ubuntu 20.04.In this work, seven video clips from different sources were collected to evaluate the reliability and robustness of the proposed tracking scheme. Details of these video clips are presented in The accurate detection of fish is a key step for tracking individual movement. The accuracy of the proposed multiple-feature fish detection was evaluated by precision–recall analysis . PrecisiMoreover, the computational costs were assessed by examining the time consumption of the fish tracking scheme . The comIn addition, the recall ratio that plays a more important role in the application of group animal tracking can limit the overall performance of the tracking system. Normally, the recall ratio will decrease when occlusion probability increases, especially for the methods that highly rely on appearance features. Therefore, it is necessary to increase the detection accuracy during an occlusion event.Tracking performance of the proposed scheme was further evaluated by analyzing CTR, CIR, and ID switch (IDS) of the tracking results. As presented in To prove the advanced ability of the proposed fish tracking scheme, a comparison test was carried out with a state-of-the-art fish tracking method, IDTracker.ai . All theThe randomness and frequent occlusion is still challenging in multiple animal tracking application. The identification of individual fishes is important and effective to improve the performance of tracing multiple individuals. Previous works reported that loose tracking targets could increase the probability of ID switch, and a trajectory re-linking process is necessary to match the trajectories before and after occlusions. In some cases, the trajectory re-link could not accurately match the tracklets and switch the trajectories. In this work, detecting occluded individuals is proposed to improve the tracking stability against occlusions. Detection based on fish head and body could ensure the robustness of detection. The detection and tracking can work properly even if a part of the fish is unseen. Outstanding detection accuracy is achieved in that the average precision was 99.70%. Only 0.30% false positives were incorrectly identified. These false positives could be eliminated in the tracking procedure, since usually, false positives could not last for a long time. The tracking procedure examines each tracker and removes the trackers that cannot continuously be associated to any detections.The parallel tracking is another contribution of this work that improved the robustness of tracking multiple fishes with similar appearance. Multiple feature fish trackers, i.e., head tracker and body tracker, work independently to follow the fish movement. The head tracker is considered as the primary tracker, and the body tracker is the secondary tracker. The body tracking procedure can provide additional association information when the primary tracker fails to locate the tracking targets—for example, when the fish head is severely occluded during an occlusion event. In addition to the head-tracking procedure, a temporary tracking procedure is employed for the unassigned detections. The temporary tracking procedure focuses on cautiously initializing a new tracker and ensuring the reliability against the influence of a false positive. The temporary tracking procedure guarantees that the detected targets are matched with more reliable trackers, preferentially.The advantages of our method are that it is accurate, fast, and computational inexpensive. The proposed tracking scheme outperformed the state-of-the-art tracking method, IDTracker.ai., which is an offline tracking scheme. Offline techniques usually achieve a significantly higher accuracy than online methods because future frames of the video clip were involved in the tracking algorithm. Many offline methods require long time for analyzing video. For example, IDTracker.ai took hours for analyzing the datasets in In the experiments, we found that fish can change their body shape in turning behavior. The fish body could bend at a large angle and return to the straight shape in a very short time. The sudden change of fish shape might cause blurring images and brought difficulties to the trackers. Therefore, a short exposure time, e.g., 2 ms, is recommended to ensure the image clarity. Moreover, Kalman filter may fail to predict the motion state of a fish in rapid transition. This issue was solved by using a bounding box with variable size estimated according to the motion state. The experimental results showed that the tracking accuracy could be decreased with low frame rates. It should be noticed that when the frame rate is over 60 FPS, the CIR ratio reaches up to 100%. A high frame rate indicates high sampling frequency; therefore, fish movements turn to linear and Kalman filter can predict the individual movement more accurately. Consequently, a higher IOU between predictions and observations could be obtained, which can promote the accuracy of assigning IDs to each target. When the frame rate is low, the association procedure may result in more tracklets and a higher possibility of incorrect identification.In future work, the proposed method should be applied to real-time monitoring and evaluate the tracking performance for long-term monitoring. Optimization of the proposed tracking scheme should be conducted to further reduce the computational time, for example, by introducing parallel computing in the calculation or developing GPU-based version.This paper proposes a computational effective and accurate scheme to track a group of zebrafish. A novel multiple appearance feature detection method that requires no information of the shape of the animal has been proposed to increase the detection accuracy when an occlusion event occurs, and a single valued motion state is proposed to reduce the tracking error caused by prediction failure of Kalman filter. Moreover, the SORT algorithm has been modified to meet the requirements of zebrafish tracking. The improved tracking method consists of two parallel tracking loops: one for the first feature tracking and the other for the second feature. In the detection stage, two independent features are utilized: one represents the fish head region and the other represents the fish body. Based upon the features of the fish body and head, the intensity of motion of the fish has been approximated as a single-valued motion state. According to the motion state, the size of the detected bounding box is also adjusted. By the proposed scheme, the probability of misdetections has been reduced a lot for the occlusion cases, which increases the tracking accuracy. When the motion of the fish is rapid, the possibility of Kalman prediction failure is increased. To overcome this problem, the size of the bounding box is increased. The experiments have been performed using seven datasets of three sources with different fish sizes, different collective sizes, up to 100, and different frame rate/resolutions. The superior performance of up to 99.45% of CIR and 99.25% of CTR on average have been achieved by the proposed scheme. The results demonstrate that the proposed tracking system is robust and accurate.


Due to the semi-liquid nature and uneven morphologies of biological membranes, indentation may occur in a range of non-ideal conditions. These conditions are relatively unstudied and may alter the physical characteristics of the process. One of the basic challenges in the construction of nanoindenters is to appropriately align the nanotube tip and approach the membrane at a perpendicular angle. To investigate the impact of deviations from this ideal, we performed non-equilibrium steered molecular dynamics simulations of the indentation of phospholipid membranes by homogeneous CNT and non-homogeneous SiCNT indenters. We used various angles, rates, and modes of indentation, and the withdrawal of the relative indenter out of the membrane in corresponding conditions was simulated. While commercial adoption of carbon nanotubes (CNT) has stumbled over problems of cost and scale, its use in the sciences has flourished. Research into carbon nanotubes began its impressive expansion at the start of the century , driven One of the appealing properties of CNTs is their ability to be functionalized and adhere to biologically active molecules. This proved important for reducing toxicity ,9, but aCNTs offer various features of interest to engineers to be useful as biosensors: they have a large specific surface area that enables the immobilization of many functional units such as receptor moieties for biosensing. Additionally, CNTs exhibit unique intrinsic optical properties such as photoluminescence in the near-infrared (NIR) and strong resonance Raman scattering, making them an excellent candidate for biological detection. Another attractive property is a photothermal response that could reduce the tumor size or be removed entirely by using NIR laser irradiation to generate heat. Different types of CNTs have different properties. SWCNTs, for example, can conduct electricity approximately 100 times better than copper, which can help target particular molecules. Numerous CNT biosensors have been established to date to examine an extensive range of cancer biomarkers through conjugation of DNA and aptamers, antibodies, peptides, proteins, or enzymes .In this study, we continued to investigate the mechanical effects of single-walled CNTs penetrating and withdrawing from lipid membranes by extending simulations to non-idealized circumstances. As molecular dynamics simulations have showed mainly the idealized case when the angle is normal to the membrane’s surface, our goal was to establish how the uncertainty of angle from the ideal  position influences the process of indentation. Understanding the process can help to design CNT-based nanosensors that can consider such uncertainty while designing and functioning. Prior work has assumed the nanotubes to be perfectly aligned both to the bilayer surface and the direction of indentation ,20. Howez-axis” indentation)—and for two speeds: We performed constant velocity steered molecular dynamics simulations ,25 for i context ,27. It h context . Models  context ,29 and c context ,30,31. Ter model . NAMD veer model  with a ser model  was useder model ,35 forceer model .6 steps) with the pressure set to 1 atm controlled using Langevin barostat [6 steps), and during the main simulations, a constant number of particles and constant volume were maintained (NVT ensemble). The duration of each simulation depended on the speed of the indenter and continued until the membrane was fully penetrated to properly assess the number of lipids removed from the bilayer. Subsequent withdrawal processes began from a snapshot of the system of interest taken when the tip of the indenter had reached the lower surface of the membrane.The initial configurations of all systems were obtained from a series of NPT simulations .d. Note that d represents the z-axis measured depth of penetration into the membrane and does not equate to the distance of travel (which is greater for the tube-axis cases). Data for 9° tilt were similar to that for 4.5° tilt, and have been omitted for clarity , faster indentation resulted in membrane sparing.Some of these results can be understood from z-axis indentation. These profiles skew noticeably to the right as the trailing length of the nanotube continues to push through the membrane and interferes with individual lipids returning to the upper layer. These effects are again larger for the SiCNT due to its greater size.The locations of minima in Despite the increased removal of lipids noted above, lower indentation rates  top halfA sample lower membrane sequence is also shown in z-axis) and speeds were simulated, but only configurations from 15° tube angles were chosen, as they represent the most invasive scenarios simulated.We applied the same methods of analysis to the withdrawal process.  Å e.g., c, while This difference is reflected in the tendency for SiCNT to permanently remove more lipids . The difThe extent of this bending is quantified in We performed SMD simulations of membrane indentation by nanotubes inclined at different angles, speeds, and directions. In all cases, increasing the nanotube’s angle away from the perpendicular and increasing the speed both increased the force required to penetrate the membrane, and the resultant membrane deflection. These effects were most significant for indenters making sidelong contact with the membrane, i.e., obliquely angled but traveling perpendicular to the membrane. It was evident that this mode of indentation led to a qualitative change in the mechanics of penetration from axially directed piercing to more inefficient continuous slicing. Our withdrawal simulations only encompassed the most extreme (15°), but the same trends for speed and indentation mode were observed, albeit reduced.If we consider the removal of lipids from the membrane to be the ultimate hallmark of permanent damage, then higher indentation and withdrawal rates with motion closely aligned to the nanotube axis should be preferred. These are also the parameters that allow for the most efficient membrane self-sealing. In the context of drug delivery via a nanoneedle, this would mean that care must be taken when affixing the nanotube to the implement. It would also seem that a narrower CNT should be preferred over a SiCNT as the nanotube material. However, the increased impact of an SiCNT may in part be due to the stronger interactions with the DMPC lipids and not solely its size. This effect was not fully explored herein. Many applications involve the functionalization of the surfaces of nanotubes, which could alter this affinity and could be an area for further research.


Trichocera  maculipennis Meigen, 1888  is a non-native fly originating from the Northern Hemisphere that was unintentionally introduced to King George Island in the maritime Antarctic South Shetland Islands around 15 years ago, since when it has been reported within or in the vicinity of several research stations. It is not explicitly confirmed that T. maculipennis has established in the natural environment, but life-history characteristics make this likely, thereby making potential eradication or control a challenge. Antarctic Treaty Parties active in the region are developing a coordinated and expanding international response to monitor and control T. maculipennis within and around stations in the affected area. However, there remains no overarching non-native invasive species management plan for the island or the wider maritime Antarctic region . Here we present some options towards the development of such a plan. We recommend the development of (1) clear mechanisms for the timely coordination of response activities by multiple Parties operating in the vicinity of the introduction location and (2) policy guidance on acceptable levels of environmental impacts resulting from eradication attempts in the natural environment, including the use of pesticides.Antarctica currently has few non-native species, compared to other regions of the planet, due to the continent’s isolation, extreme climatic conditions and the lack of habitat. However, human activity, particularly the activities of national government operators and tourism, increasingly contributes to the risk of non-native species transfer and establishment.  Many environments on the planet have been affected by non-native invasive species, including the islands surrounding Antarctica and the fringes of the continent itself  maculipennis Meigen, 1888  is a non-native fly recently introduced into the maritime Antarctic South Shetland Islands  was established by the Protocol to provide advice and formulate recommendations to the Parties in connection with the Protocol’s implementation. In recent years, the CEP has allocated the issue of non-native species introductions the highest priority in its 5-year work plan. Parties use the CEP as a forum to share information on environmental issues, including the management of non-native species. The CEP non-native species manual , where the (currently) 29 Consultative Parties to the Antarctic Treaty make governance decisions through consensus. The Protocol on Environmental Protection to the Antarctic Treaty  sets out, in Annex II, strict rules concerning non-native species. Except for fresh foods, the introduction of any non-native species (including microorganisms) to the Treaty area is prohibited, unless a permit has been issued by an appropriate national government and measures are put in place to ensure the species’ subsequent eradication. Furthermore, Annex II states that any species not native to the Antarctic Treaty area that is introduced without a permit nual CEP  recommenT. maculipennis to King George Island, South Shetland Islands, Antarctica. In the CEP XX Final Report (available at: https://documents.ats.aq/ATCM40/fr/ATCM40_fr001_e.pdf) the Committee encouraged Parties to ‘develop coordinated standardised monitoring and eradication programmes to effectively control the spread of the flies’. In an effort to advance this work, we go on to describe the international response to date, examine future options for the eradication or control of the species and recommend areas of policy development to facilitate future rapid management action.In this paper, we examine the introduction and establishment of the non-native dipteran T. maculipennis on King George Island, South Shetland Islands, and the intervening ice-free ground. Other adjacent research stations and ice-free areas, including on neighbouring islands, are also in scope as there may be a risk of imminent colonization by the fly .Documents submitted by Parties to meetings of the CEP and the ATCM were obtained from the Antarctic Treaty Secretariat website  is a non-native fly recently introduced into the maritime Antarctic South Shetland Islands  are possible in local natural conditions beyond the confines of station buildings .In 2016, the first survey ‘A short questionnaire on non-native flies in Antarctic stations' was carried out at stations on King George Island, as the first formal step towards developing a coordinated international response  has carried out molecular analyses to assess population relatedness between Escudero, Artigas and King Sejong stations. Preliminary results suggest that dispersal and subsequent establishment of the fly have taken place between these stations on King George Island, rather than the species being present as a result of multiple separate introduction events  has not been developed. Here we describe practical considerations to inform the development of such a plan, building on measures recommended by COMNAP, SCAR and the CEP  is a major cause for concern and immediate steps should be taken to control the fly’s presence here and reduce the risk of dispersal via aircraft. Natural dispersal mechanisms, including wind, may also lead to dispersal of the fly to other islands in the South Shetland Islands archipelago, to the Antarctic Peninsula only 80–100 km to the south-east, or even to the more distant South Orkney Islands 700 km away but for which air mass trajectory modelling demonstrates the plausibility of reasonably frequent transfer within 24 h or less  has been identified as one of the most important risks , as well as the use of sticky glue traps, during the whole year would help both to reduce and to monitor populations of reproductive adults. Any eradication attempt may have a higher chance of successful removal of the species from a given location if the colonized area is small , the necessary equipment is available to undertake the removal and a clear route for disposal of the material has been determined. Within stations, it would be essential to prevent the accumulation of waste where adult flies could find refuge . Water supplied to stations could contain larvae and/or pupae, so consideration should be given to the use of appropriate filter systems, which would require frequent examination and replacement.The eradication protocol could take into consideration (as available) recorded annual population levels, breeding sites, duration of life cycles, population peaks and precise data on species dispersal. Logistic strategies should be developed, potentially involving the re-engineering of sewage systems and septic tanks, to allow initial and ongoing cleaning and maintenance of biosecurity precautions to prevent re-colonization, with such procedures applicable to both T. maculipennis introduction is an isolated incidence of apparently successful movement into the natural environment, there are already a number of cases of other invertebrates successfully establishing within station facilities  No. 128 Western Shores of Admiralty Bay, on King George Island . This approach has extended to responding to non-native species introductions. Most successful eradications of non-native plant species have been small-scale activities, generally with single or a low number of plants rapidly removed from a single location by researchers representing a single Treaty Party. Examples include the removal of Poa pratensis at Cierva Point, Danco Coast, since 1954 had been reported in the scientific literature on more than one occasion . Should an established non-native species fail to be eradicated at an early stage, and disperse to multiple locations, management by a single Party will rapidly become impossible, and any response will inevitably need the attention, agreement and active engagement of all the Parties within the affected region to stand any chance of being effective  are designated to assist in the planning and coordination of activities, avoid possible conflicts, improve cooperation between Parties or minimize environmental impacts. ASMAs have yet to be used to their full potential to help manage non-native species, with, for example, little or no practical advice on the management of the highly invasive non-native grass, T. maculipennis introduction , but whether these include eradication of non-native species has not been formally addressed. The potential prohibition of pesticide use in the natural environment removes the main tool used elsewhere in the world for the control of non-native species. Given that the issue of non-native species introductions to Antarctica was not widely considered when the Protocol was being drafted prior to its agreement in 1991, any need for pesticides to enable species eradication may not have been considered. Further clarity from the CEP on the practical application of the information in the Protocol on pesticide use could reduce the risk of conflicting interpretations by Parties.Eretmoptera murphyi on Signy Island since c. 2008  to the Protocol states that any species not native to the Antarctic Treaty area that is introduced without a permit ‘shall be removed or disposed of whenever feasible, unless the removal or disposal would result in a greater adverse environmental impact’. So far, Parties have yet to attempt the eradication of any non-native invertebrate in the natural environment, and guidance on how to assess whether eradication of a non-native species would result in ‘greater adverse environmental impact’ is currently lacking. Although a series of studies have assessed the distribution and abundance of the introduced non-native midge ion Burn , could hion Burn  only staFinally, CEP guidance may also include information on which introduction events may trigger unilateral, multilateral or all Treaty Party responses. Sharing of information and receiving early warming of expanding non-native species distributions may allow Parties to amend their practices accordingly, or join in international efforts to monitor, control or eradicate the species as coordinated by COMNAP, CEP or any locally formed management groups , potentially by highlighting on a map important bird and seal concentrations  at which known successful invaders can extend their distribution and their preference for available habitats to best forecast other areas that may be at risk . While there is merit in taking steps to reduce the dispersal and impact of this species, such efforts should not distract national operators and the tourism industry from implementing strict biosecurity measures to reduce the risk of further non-native species introductions. Given recent reports of non-native species in areas of high human activity and infrastructure across Antarctica  further consideration of the mechanisms for communicating and coordinating multi-Party response actions should be a priority for policymakers.A key lesson from the current situation is that considerable effort would have been saved if adequate biosecurity measures had been put in place across all introduction pathways to prevent the initial arrival of