Ophiuroids locomote along the seafloor by coordinated rhythmic movements of multi-segmented arms. The mechanisms by which such coordinated movements are achieved are a focus of interest from the standpoints of neurobiology and robotics, because ophiuroids appear to lack a central nervous system that could exert centralized control over five arms. To explore the underlying mechanism of arm coordination, we examined the effects of selective anesthesia to various parts of the body of ophiuroids on locomotion. We observed the following: (1) anesthesia of the circumoral nerve ring completely blocked the initiation of locomotion; however, initiation of single arm movement, such as occurs during the retrieval of food, was unaffected, indicating that the inability to initiate locomotion was not due to the spread of the anesthetic agent. (2) During locomotion, the midsegments of the arms periodically made contact with the floor to elevate the disc. In contrast, the distal segments of the arms were pointed aborally and did not make contact with the floor. (3) When the midsegments of all arms were anesthetized, arm movements were rendered completely uncoordinated. In contrast, even when only one arm was left intact, inter-arm coordination was preserved. (4) Locomotion was unaffected by anesthesia of the distal arms. (5) A radial nerve block to the proximal region of an arm abolished coordination among the segments of that arm, rendering it motionless. These findings indicate that the circumoral nerve ring and radial nerves play different roles in intra- and inter-arm coordination in ophiuroids. Summary: Functional localization exists in the nervous system of ophiuroids although there is no evidence of a morphological counterpart to the central nervous system of other species. The neural mechanisms of locomotion in animals have been the focus of extensive studies in the field of neuroscience. Studies using vertebrates and arthropods have unveiled the autonomous as well as adaptive locomotor regulation by the interplay of reflex loops, central pattern generators and higher order centers such as cerebrum . These nIn contrast to vertebrates and arthropods, little has been studied regarding the neural mechanism of locomotion in echinoderms, a phylum of marine animals that have a fundamentally different nervous system. Unlike other locomotory animals, they appear to lack a central nervous system that exerts centralized control over the usage of their body parts . Their mIn the present study, we investigated the neural mechanism underlying ophiuroids locomotion. Ophiuroids (brittle stars) locomote along the sea floor by coordinating the movement of five whip-like arms, each of which consist of multiple segments. Previous studies have described the characteristic patterns of arm movements during ophiuroid locomotion ,b. A recWhat components of the nervous system are important for arm coordination during locomotion? In particular, we were interested in the role of the circumoral nerve ring because it forms the anatomical basis through which the radial nerve of each arm interacts with those of the other arms , 1982.What are the underlying control mechanisms of locomotion? More specifically, how do ophiuroids assign specific roles to their arms? Despite anatomical similarity among the five arms, each arm plays a different role in locomotion. How does an ophiuroid determine which arm acts as the center limb, forelimb, or hindlimb?In the present study, we aimed to examine the underlying control mechanism of arm movements in ophiuroid locomotion. Our specific questions included:In order to study these issues, we applied selective anesthesia to various body parts to examine its effect on locomotion. Because gait control is intimately dependent on the dynamics of the limbs , we blocO. incrassata and five O. superba performed rowing significantly more frequently than reverse rowing movements (P<0.01 by chi square test). In two O. incrassata, the difference was not significant. In addition to rhythmic arm movements in a horizontal plane, which have been previously reported . This observation indicates that motility of the arms was preserved even after anesthesia of the circumoral nerve ring.Following the induction of anesthesia, anesthetized subjects were unable to perform either rowing or reverse rowing movements. Unlike intact subjects, physical touch to the arms and disc of anesthetized subjects failed to elicit escape movements. To ascertain that the unresponsiveness was not due to dispersion of the anesthetic agent to the arms through the water vascular system, we placed a food morsel (a piece of dried shrimp) in contact with one of the arms. The subject grasped the food with that particular arm and attempted to bring it to the mouth. Nevertheless, ingestion was not possible owing to paralysis of the jaw . Following a recovery period of 1 h, the operated subjects were unable to initiate locomotion, similarly to the subjects in which the disc was anesthetized. In one subject, we compared the motility of arms with lesions with that of intact arms. We found that lesions on the proximal radial nerve abolished coordinated movements of the segments. As a result, the arms with lesions did not perform the whip-like movements typical of intact arms during locomotion B. NevertWe examined whether functional differences exist among various segments of the radial nerves. For this purpose, we applied anesthesia to specific areas of the arms. We compared the effects of anesthesia of the midsegments and distal segments of the five arms. Because the manner in which these portions of the arms made contact with the floor during locomotion differed , we expeMovie 2).We first anesthetized the midsegments of the five arms with L-menthol for 5 min. In contrast to the subjects in which the circumoral nerve rings were anesthetized, subjects under anesthesia of the radial nerves showed no loss of voluntary movements in the arms. However, when the anesthetized subjects were returned to the experimental tank, they were no longer able to perform coordinated arm movements for locomotion. The five arms moved asynchronously, and any particular pair of arms did not make symmetric swinging movements as in rowing movements. Thus, the arm movements did not generate force to propel the disc in any consistent direction. As a result, the anesthetized subjects often haphazardly changed the direction of locomotion and sometimes even strayed from the corner towards the center of the tank, against their natural tendency to avoid open spaces .Following anesthesia, the subject was again unable to coordinate arm movements for locomotion, and failed to move consistently in any particular direction. After amputation, however, the subject  regained the ability to locomote A. FurtheThe importance of sensory input to the arms during locomotion became evident from the aforementioned findings. Observation of intact subjects indicated that periodic contact of the midsegments with the floor was the major source of sensory stimuli . TherefoP<0.05). We also examined the roles of anesthetized and intact arms during rowing. We found that ophiuroids tended to use intact arms that had not been anesthetized as the leading arm , we examined the effects of anesthetizing two adjacent arms at the midsegments on locomotion. The anesthetized subjects were able to perform coordinated arm movements to move from the center to the corner of the tank (In three subjects (two the tank A. In addthe tank B. As in the tank C. In conO. incrassata and one O. superba).Our experiments thus far indicated that ophiuroids perform rowing movements by default even when some of the arms are anesthetized. In addition, a previous study demonstrated that rowing movements require a minimum of three intact arms . This drWe found that the subjects in which three adjacent arms were anesthetized were still able to perform rowing movements A. While With the exception of one subject (No. 3), rowing movements were performed significantly more frequently than reverse rowing movements B. FurtheO. incrassata and one O. superba). This left one isolated arm and two arms adjacent to each other intact. If any of the intact arms functioned as the leading arm, then the leading arm and the hindlimbs would be separated by anesthetized arms, which would function as the forelimbs.In the preceding experiments, anesthetized subjects were still able to make coordinated movements of their arms while rowing. In the above experiments, however, anesthesia left multiple adjacent arms intact. The question arose of whether coordination between arms is still preserved if intact arms are interspersed with anesthetized arms. To address this issue, we anesthetized the midsegments of two arms that were separated by one intact arm, and examined the effects in four subjects  separated the leading arm from the hindlimbs, coordination between these two entities was preserved A. AlthouO. incrassata and one O. superba) to determine whether locomotion is still possible if the intact arm has no other intact arms with which to coordinate. All subjects were able to locomote following anesthesia . The varying effects of nerve blocks on various parts of the arm suggest that the radial nerves might also be functionally divided. Damage to the proximal radial nerves completely blocked swinging movements of the affected arm . This observation also suggests that food retrieval is performed by a series of local reflexes of the radial nerve that are independent of the circumoral nerve ring. An electron microscopic study indicated that the circumoral nerve ring , consists of ectoneural and hyponeural tissues ; however, motility of individual arms was preserved. These findings suggest that the sensation of contact (such as occurs against the floor) through the radial arms is critical for inter-arm coordination. It should be noted, however, that the arms that were cut proximal to the midsegment were still able to perform rowing movements . The seawater was periodically replaced and constantly aerated by a protein skimmer, which also removed pollutants.We used the green brittle stars crassata  whose ar superba  whose arO. incrassata were used for disc anesthesia, three for anesthesia of all the arms, and three of each species were used for anesthesia of selected arms.For each behavioral experiment, we randomly selected subjects with five intact arms of approximately equal length. Inactive or autotomized subjects were not used for the investigation. The subjects that autotomized their arms during behavioral observation were excluded from the subsequent statistical analysis. For behavioral observation of intact subjects, we used six subjects of each species. For nerve block experiments, two We used L-menthol  for nerve block experiments in which we examined the roles of the circumoral nerve ring and radial nerves in the regulation of locomotion.O. incrassata and O. superba) were completely immobilized after 5 min of exposure to the anesthetic. When replaced in plain artificial seawater, recovery occurred within 30–60 min. The arms of anesthetized subjects were not autotomized during either the anesthetic or the recovery periods. Therefore, we considered that exposure to L-menthol for 5 min was sufficient to anesthetize ophiuroids, and proceeded with behavioral experiments. Surgical ablation of the nervous system was also tested. However, the subjects frequently autotomized the arms following surgery, thus we did not use this method as a standard measure of nerve block.Prior to the behavioral experiments, we tested the anesthetic effect of L-menthol on ophiuroids to determine the time needed for anesthesia and recovery. We placed subjects in artificial seawater saturated with powdered L-menthol. Both species of subjects  to prevent its dispersion to other parts of the body. To prevent dehydration, artificial seawater was applied using a medicine dropper to the areas in which the anesthetic was not applied.Following the required duration of anesthesia, the subjects were washed with artificial seawater to remove all traces of the menthol, after which the subjects were returned into sea water and the behavioral experiments commenced. At least one week of interval was given to the anesthetized subjects before they were re-used for other experiments.In cases that required finely circumscribed blockade of the radial nerves, we anesthetized the selected portion of the arms with L-menthol for 5 min, and using a fine drill bit (diameter: 0.5 mm), made a small opening in the oral arm shield of the anesthetized portion that was extended to the epineural sinus. Then, lesions were inflicted on the radial nerve running along the aboral wall of the sinus  by the sAfter the nerve block, the subjects were placed in a tank that measured 30×30 cm. The tank was filled with artificial seawater and its conditions (density and temperature) were maintained at levels comparable to those of the holding tank. Aeration was conducted for 10 min before any subject was placed into the tank. The subjects were then placed in the center of the tank and allowed to move freely. Intact ophiuroids naturally avoid open spaces, therefore when placed in the center of the tank, they immediately moved to a corner. Each time a subject was placed in the center of the tank, its body was rotated to randomize the spatial relationship between the arms and any potential environmental cues (e.g. shadows or tilt). While moving towards the corners, the movements of the subjects' arms were recorded by a digital video recorder  at 30 frames per second with a resolution of 1280×720 pixels, and saved for subsequent analysis. Each behavioral experiment lasted for 30 min because, based on the above described preliminary test of anesthesia, the effect of L-menthol was considered to last for at least 30 min. During this period, we monitored their locomotion and classified its type. For locomotion that was identified either as rowing or reverse rowing, we recorded the arm which acted as the center limb.In the present study, we focused our analysis on rowing and reverse rowing. We counted the occurrences of these two types of movements, and examined the roles played by intact and anesthetized arms during the locomotion. The behavioral data from the selected subjects were used for statistical analysis only when both of the two following criteria were met. First, we chose the subjects for which the combined sum of occurrences of rowing and reverse rowing exceeded 10 during the observation period (30 min). Second, we used the data from subjects that did not autotomize the arms during the observation. If the number of the locomotion did not exceed 10 or if the subjects autotomized any of the arms during the experiment, such subjects were excluded from the analysis. A two-tailed chi square test was performed to examine whether there was a bias in the occurrences of rowing and reverse rowing. We also examined whether the roles played by intact and affected arms in locomotion were also biased.


However, the intervening period of development remained a ‘black box’ because it takes place as the blastocyst is implanting into the uterus. Over the past 6 years, techniques pioneered and developed in Magdalena Zernicka-Goetz's laboratory for the in vitro culture of embryos through these implantation stages have opened up this box, affording the first glimpse of embryonic development through these previously hidden stages. Remarkably, the techniques developed with mouse embryos are equally applicable to human embryos, ushering the very first opportunities for studying our own development throughout this time. Here, I outline how the culture methods were developed, paving the way to culture of the human embryo to the point of gastrulation, an accomplishment recognized as the People's Choice for the Scientific Breakthrough of 2016 in Science magazine. I also discuss the new ethical challenges raised by the possibility of extending the time limits for human embryo culture.We know a great deal about the development of the mammalian embryo until the time that the blastocyst implants into the uterus. With model organisms such as the mouse, we have also developed a considerable understanding of development immediately around gastrulation as embryos can be recovered at this stage for short-term  Our quite detailed understanding of the early stages of mammalian embryonic development reflects the fact that we have for many decades been able to culture embryos to the point of implantation. Such studies have focused on the mouse as an experimental organism where, as in all vertebrates, embryonic development requires repeated rounds of cleavage divisions. These progressively divide the single-cell zygote into the hundred or so cells of the blastocyst over about 4.5 days in the case of the mouse preimplantation embryo. This period represents a critical stage in development when the first three tissue types of the embryo are formed. This happens after the 8-cell stage when cells compact, become polarized, and then undertake asymmetric divisions. These divisions generate polarized cells that remain on the outside and generate trophectoderm (TE), that will later mainly contribute to the placenta, and apolar cells that will become the inner cell mass (ICM). The first ICM cells to be produced in the fourth round of cleavage will contribute mainly to the pluripotent epiblast (EPI), which will generate all of the embryo proper, and those produced in the fifth cleavage round will generate mainly primitive endoderm (PE), a second extra-embryonic tissue –3. The rBy studying snap-shot images of fixed embryos at successive stages, a picture has emerged of how the body plan becomes established but the picture is incomplete and lacks detail. It has been clear from these studies, however, that the extra-embryonic tissues of the egg cylinder play an important role in signalling the development of the adjacent EPI. A cluster of VE cells at the distal tip of the egg cylinder, the distal VE (DVE), begins to express anterior markers and a subset migrates up one side of the cup of EPI to form an anterior signalling centre, the anterior VE (AVE) –8. Similin vitro culture system permitting the step-wise development of the AVE to be followed in real time [In vitro culture of embryos through the implantation stages had been attempted in the 1970s with limited success [Cdx2, Gata4 and Oct4, as naturally developing embryos. By following expression of Cerl-GFP as a marker for the origins of the AVE, a small cluster of cells was identified as blastocysts flattened onto the matrix that became consolidated as the egg cylinder emerged. The most anteriorly located cell in the cluster showed the strongest Cerl-GFP expression and led the anterior migration. Ablation of such leading cells prevented AVE migration, pointing to their importance in the correct establishment of the anterior–posterior axis [However, precisely how these signalling centres arise has been very difficult to analyse, because the process takes place as the embryo implants into the uterus. In 2012, the goal of finding the origins of the anterior signalling cells motivated the Zernicka-Goetz group, which I was part of, to establish an eal time . In vitr success –17, but ior axis .in vitro culture system to enable development of zona-free blastocysts seeded directly onto microscopy-grade plastic microplates to facilitate time-lapse microscopy. It was also necessary to modify the media to overcome the batch variations between isolates of human cord serum. Blastocysts were plated in IVC1, the medium originally described by Morris et al. [N-acetyl-l-cysteine, and an Insulin-Transferrin-Selenium-Ethanolamine cocktail [These early experiments highlighted a need for a more careful examination of the cellular events as the EPI becomes reorganized during embryo implantation. Doing so led to a completely new understanding of the nature of the morphological changes undertaken by the EPI as the blastocyst implants . These fs et al. , but onccocktail .Using this system, it soon became clear that the textbook description of pro-amniotic cavity formation at this stage was incorrect. This textbook model had emerged based on observations that the cavitation of embryoid bodies, formed from aggregates of embryonic stem (ES) cells or embryonal carcinoma cells, occurs through apoptosis. These findings led to the suggestion that the EPI cavity was formed in the same way in the embryo ,20. ThisThe protocol used in these studies has proved to be very robust. The Zernicka-Goetz lab over recent years developed several variations on the method showing not only that blastocysts could attach to the substrate after removal of the zona, but that it was also possible to surgically remove part of the TE whereupon egg cylinder structures were generated more efficiently, with very little developmental lag upon implanting ,5. MoreoFollowing the establishment of this robust protocol of mouse embryo culture through implantation stages, the Zernicka-Goetz group began work to apply the technique to human embryos, with great success. Considering current efforts in research to increase rigour and reproducibility, Zernicka-Goetz and colleagues should be commended for their efforts to ensure that their high-impact findings were replicated. For example, they shared their initial mouse techniques via provision of transparent protocols ,5. Furthin vitro possess all the key landmarks of normal development. These include segregation of the pluripotent embryonic and extra-embryonic lineages; the morphogenetic rearrangements leading to generation of the bilaminar disc; the formation of a pro-amniotic cavity within the embryonic lineage that in human embryos splits the pluripotent cells into two populations corresponding to the founders of the embryo proper and the amniotic epithelium; the formation of the prospective yolk sac; and the differentiation of the trophoblast into mononucleated cytotrophoblasts and multinucleated syncytiotrophoblasts  but thehoblasts . Althougin vitro. There is now a strong argument for extending this limit to be able to study key developmental events not only preceding but also following gastrulation. The public debate on this has already begun but its resolution will take some time. Meanwhile we have only begun to explore the developmental processes leading up to this time and undoubtedly the coming years will lead us to greater understanding of the interactions between the different cell types of the implanting human embryo that shape our identities.Together, these studies signal the potential for developing rational ways of differentiating human pluripotent cells into specific cell types for regenerative medicine. Importantly, they also open a new chapter in embryology. In particular, the work on human embryos establishes a model that will aid our understanding of early pregnancy loss in humans. Almost half of all fertilized eggs die spontaneously before a woman knows she is pregnant and thereafter as many as 20% of pregnancies fail within the first seven weeks before a heartbeat can be detected. These spontaneous deaths, together accounting for 60–70% of all embryos, are largely due to defects in development. It is important to understand how these early stages of development take place in order to be able to predict when developmental defects are likely to arise. However, currently there are ethical limits to what can be done experimentally. In the two studies reported to date ,23, embr


The correction factors at each measuring station for both the centerline and the sensor location were calculated and are discussed.When there are installations of air velocity sensors in the mining industry for real-time airflow monitoring, a problem exists with how the monitored air velocity at a fixed location corresponds to the average air velocity, which is used to determine the volume flow rate of air in an entry with the cross-sectional area. Correction factors have been practically employed to convert a measured centerline air velocity to the average air velocity. However, studies on the recommended correction factors of the sensor-measured air velocity to the average air velocity at cross sections are still lacking. A comprehensive airflow measurement was made at the Safety Research Coal Mine, Bruceton, PA, using three measuring methods including single-point reading, moving traverse, and fixed-point traverse. The air velocity distribution at each measuring station was analyzed using an air velocity contour map generated with Surfer As the lifeblood of a mine, ventilation not only provides fresh air for personnel to breathe but also dilutes and carries away toxic or explosive gases and dust. Ensuring an efficient mine ventilation system is critical to the health and safety of underground mine workers. In the history of mining, many fatal mine gas and dust explosions have been attributed to inadequate mine ventilation. The primary objective of ventilation is to control air distribution underground to satisfy statutory and safety requirements for air quantity and quality. The airflow rate is a key ventilation design parameter in managing and improving the effectiveness of mine ventilation.With the steadily increasing atmospheric monitoring systems (AMS) installations in underground coal mines in the U.S. for the detection of fire in the belt entry, the real-time monitoring of airflow velocity in some critical locations has attracted attention . Based oEarly warning of a weakening trend in airflow or a ventilation failure,Evaluate the performance of the underground environmental conditions with long-term real-time monitoring airflow data, andHelp mine operators and emergency response personnel decide how to respond to underground emergency.The benefits of real-time airflow monitoring in underground mines are many. Monitors provide:However, most of the real-time airflow sensors obtain a fixed-point air velocity at designated installation locations. The fixed-point air velocities need to be converted to average volume airflow rates to be used in ventilation design and ventilation performance evaluations. Traditionally, the determination of air volume flow rate is achieved by using a vane anemometer or smoke tube in conjunction with an area measurement. Conversely, the constraints imposed on the fixed-point sensors are more rigorous because they are capable of measuring the airflow at only one point .With the application of fixed-point air velocity sensors for the AMS, the question arises as to how the readings from these sensors can be related to average air volume flow rate. The concept of a “correction factor” has been used to convert the velocity at the centerline to the average velocity, which is required to compute average volume flow rate . SubstanThe Safety Research Coal Mine (SRCM), Bruceton, PA, at the Pittsburgh Mining Research Division (PMRD) of the National Institute for Occupational Safety and Health (NIOSH) has an AMS equipped with eight monitoring stations to collect real-time underground environment data for research purposes, including air velocity, carbon monoxide, temperature, oxygen, etc. The fixed-point air velocity monitoring data from the airflow sensors are frequently required to be converted to average volume airflow rate to analyze and evaluate the ventilation performance. Using correction factors to convert the fixed-point air velocity to the average air velocity is thought to be a very fast and convenient method. However, all the correction factors obtained in previous research refer to the conversion from the centerline velocity to the average velocity. Air velocity sensors may be mounted below the roof and at the centerline to avoid interfering with mine operations.Based on the authors’ best knowledge, no sensor location correction factor has been studied and published so far. To address this need, an extensive air velocity study was conducted at the SRCM to obtain the site-specific correction factors for the current and potential future sensor locations in the mine. The objective of this paper is to establish a set of correction factors for the selected locations at the SRCM.® AMS is equipped at eight monitoring stations to monitor mine environment conditions such as barometric pressure, temperature, airflow velocity, humidity, and oxygen, and to detect fire by way of carbon monoxide, carbon dioxide, and smoke sensors. The locations of monitoring stations are frequently changed depending on the requirements of the experiments conducted in the mine. The air velocity sensors are mounted about 0.3 m (1 ft) below the roof at each monitoring station.The SRCM is a full-scale underground mine facility located at NIOSH’s Bruceton Campus in Pittsburgh. It is a room-and-pillar mine approximately the size of a working section with one intake entry and one return entry. A Joy Axivane Series fan is installed at the surface above the return shaft to exhaust air from the mine. In the mine, a ConspecA thorough study of the ventilation was conducted in the SRCM to obtain the average air velocities, air velocity at the centerline, and at 0.3 m (1 ft) below the roof at 28 airflow measuring locations. The established 28 airflow measuring locations and the SRCM layout can be seen in Calibrated vane anemometers were used for measurements at all stations. The anemometers were attached to a 1.5-m rod to reduce the turbulence effect due to the presence of the observers. The time duration for all the measurements was set to 1 min. The three most commonly used air velocity methods—single-point readings, moving traverses, and fixed-point traverses—were used in the air velocity survey, as described below.Single-point reading: The single-point readings were made at the centerline of the section and 0.3 m (1 ft) below the roof at each measuring station. The single-point reading is thought to be the most common but least accurate method among the three methods, as it does not necessarily represent the average air velocity. In reality, the readings from the AMS air velocity sensors are all single-point readings.Moving (or continuous) traverse: The anemometer is slowly moved through a plane at right angles to the axis of the airway to take moving traverse readings. The moving traverses are most frequently used to improve the measurement accuracy. The time interval for conducting measurements varies with the accuracy desired. Fixed-point traverse: Spot measurements at a number of locations are taken over the cross section. The cross section of airway may be divided into subsections of equal area, and the individual measurement is taken in the center of each subsection. In the airflow survey, the cross section was divided into nine subsections with the measuring spot located at the center of each subsection  foot below the roof. The sensor location correction factors for all 21 measuring locations range from 0.92 to 1.60 with an average of 1.09 and a standard deviation of 0.17  beneath the roof. In mining practice, sensors do not have to be mounted in this manner. Although there is no regulation about specifications for air velocity sensor locations, carbon monoxide or smoke sensors are required to be installed near the center in the upper third of the entry, in a location that does not expose personnel working on the system to unsafe conditions (30 CFR 75.351). To avoid interference with moving equipment and miners, air velocity sensors might be installed at the corner close to the roof and ribs. Any change to the sensor location will result in a change to the sensor reading, and thus the correction factor.To investigate the actual air velocity profile and its impact on the value of correction factors at each measuring location, a velocity contour map was generated at each measuring plane using measured fixed-point traverse air velocities. The fixed-point traverse method may not be used very often within the mining industry because the time consumed for one section measurement may exceed 30 min, depending on the number of the measuring points. However, one of the advantages of applying this method is to be able to generate the distribution of the airflow at the measuring sections. The maximum air velocity at measuring location A4 occurs from the center to the left bottom corner, and the lowest air velocity is at the right upper corner. At measuring location A17, the air velocity decreases from the lower right corner to the upper left corner. The maximum air velocities are observed near the entry floors for measuring locations A26 and A27. A sensor location correction factor is determined by comparing the air velocity and the measured average air velocity. The velocity distribution at a plane does not affect the average velocity significantly, but it does affect the sensor readings. Apparently, a sensor mounted in a high-velocity zone will yield a smaller correction factor than one mounted in a low-velocity zone. Using measuring location A17 as an example, a larger correction factor will be obtained if the sensor is at the left side than that at the right side, as the air velocity exhibits an increasing trend from left to right.With a known velocity distribution, it is straightforward to explain the reading from the sensor. However, the velocity distributions are often not available. A known well-established turbulent velocity profile can only be obtained in a sufficiently long  airway with smooth walls , which iIn this study, no two velocity distributions are the same among the total 21 velocity contour maps. With careful observation and analysis, it is found that the velocity distribution at a measuring plane is mainly determined by the measuring locations. For example, the measuring location A2 is located in the main intake about 30 m to the mouth of the portal, which is not sufficiently long to allow the airstream to become a fully developed flow. As can be seen in The other contour maps also reveal a similar relationship between the location and the air velocity distribution pattern. These results indicate that a certain air velocity distribution pattern is well correlated with the location of the measuring station, mainly affected by the merging and splitting of the airflow upstream and downstream.A comprehensive airflow study using single-point reading, moving traverse, and fixed-point traverse methods was conducted at the Safety Research Coal Mine, Bruceton, PA, to determine the appropriate conversion factors for sensor-measured air velocities. Measurement results demonstrate that differences in the measured average air velocities between the moving traverse method and the fixed-point traverse method exist at a cross section where the air velocity spans a wide range. The two methods generate close average velocities when the air velocity variations are in a small range. With the current data, it is difficult to say which method produces more accurate measurements. More research may be needed for future work.The velocity contours indicate that the air velocity distributions at most measuring locations do not follow the typical “velocity profile” observed within a duct, where the maximum velocity occurs at the centerline of the duct and the minimum occurs near the wall. A certain air velocity distribution pattern is correlated well with the location of the measuring station, mainly because of the merging and splitting of the airflow upstream and downstream.Both the centerline correction factors and the sensor location correction factors were determined based on the measurement data, and proved to be site-specific. There is no general correction factor that applies to all the cases. The sensor location correction factors for the 21 measuring locations varied from 0.92 to 1.60. A majority of sensor location correction factors obtained in this paper are larger than 1.00.The sensor location correction factor is mainly determined by the air velocity distribution at the measuring plane. Using a single correction factor for all the locations will produce certain errors in the calculation of the average air velocity from the sensor readings. An effective method for obtaining the appropriate sensor location correction factor is to measure the air velocity at the sensor location. Then determine the average air velocity to get the correction factor for the specific site before a sensor is mounted. However, airflow merging and splitting can affect the air velocity distribution significantly, and the measurements need to be made to update the correction factor if any air course changes occur upstream or downstream.


Fractional flow reverse (FFR) is the gold standard assessment of the hemodynamic significance of coronary stenoses. However, it requires the catheterization of the coronary artery to determine the pressure waveforms proximal and distal to the stenosis. On the contrary, computational fluid dynamics enables the calculation of the FFR value from relatively non-invasive computed tomography angiography (CTA).We analyze the flow across idealized highly-eccentric coronary stenoses by solving the Navier–Stokes equations. We examine the influence of several aspects (approximations) of the simulation method on the calculation of the FFR value. We study the effects on the FFR value of errors made in the segmentation of clinical images. For this purpose, we compare the FFR value for the nominal geometry with that calculated for other shapes that slightly deviate from that geometry. This analysis is conducted for a range of stenosis severities and different inlet velocity and pressure waveforms.The errors made in assuming a uniform velocity profile in front of the stenosis, as well as those due to the Newtonian and laminar approximations, are negligible for stenosis severities leading to FFR values around the threshold 0.8. The limited resolution of the stenosis geometry reconstruction is the major source of error when predicting the FFR value. Both systematic errors in the contour detection of just 1-pixel size in the CTA images and a low-quality representation of the stenosis surface (coarse faceted geometry) may yield wrong outcomes of the FFR assessment for an important set of eccentric stenoses. On the contrary, the spatial resolution of images acquired with optical coherence tomography may be sufficient to ensure accurate predictions for the FFR value. A stenosis is an abnormal narrowing in a blood vessel. Coronary arteries are known to be common sites for stenoses, which frequently lead to myocardial infarction and even sudden cardiac death. The vast majority of these stenoses are caused by atheromatous lesions, which give rise to highly eccentric narrowing. They are frequently characterized by a lumen lying in the outer region of the coronary artery, and delimited by an arc of nearly normal wall .Coronary revascularization is performed to treat stenoses with hemodynamic significance. The decision to carry out this procedure is frequently based on the stenosis severity, defined as the percentage of narrowing of the coronary artery. Thus, coronary revascularization is often conducted for severe stenoses, i.e., those with severities above the threshold value 75%. While the stenosis severity can be measured with relatively non-invasive computed tomography angiography (CTA), there is no simple relationship between that parameter and the stenosis hemodynamic significance and the plaque vulnerability . In factFractional flow reverse (FFR) is defined as the ratio of maximal  coronary blood flow through a stenotic artery to the maximal blood flow in the hypothetical case that the artery were normal. Because this definition is not operational, it is frequently substituted by ood flow . This laood flow . In any In practice, the pre-stenotic and post-stenotic pressure waveforms are measured over several cardiac cycles. The functionsFFR is the gold standard assessment of the hemodynamic significance of coronary stenoses. Revascularization is typically conducted for lesions with FFR < 0.8 . FFR-guiComputational fluid dynamics (CFD) is a method with high diagnostic performance to determine coronary lesions that cause ischemia –13. In pAs mentioned above, FFR is measured at maximum hyperaemia, which greatly reduces the artery expansion/contraction during the systole/diastole phase. Therefore, one can safely adopt the rigid wall approximation in the CFD simulations, which avoids modelling the fluid solid interaction , 25. FFRIt is well known that, due to the stabilizing effect of the blood acceleration, turbulence in arteries arises at Reynolds numbers much larger than those for steady flow. The peak Reynolds number in a coronary stenosis is typically much smaller than that leading to the laminar-to-turbulent transition in an oscillatory flow inside a cylindrical duct, and consequently the flow is usually assumed to be laminar. However, blood greatly accelerates in severe stenoses (like the ones studied here), which gives rise to complex post-stenotic flows, including separation, recirculation, as well as localized transition to turbulence and relaminarization . Both thTypically, the only (if there is any) available kinematic information at the stenosis inlet section is the instantaneous flow rate crossing that section , 28. To Simulating the entire cardiac cycle increases very considerably the computing time. It implies running the simulation over several cycles to ensure that the periodic regime has been reached. The Womersley number  takes relatively low values in the epicardial arteries. One may wonder whether the flow pulsatile character can be neglected in calculating the FFR value. In that case, the unsteady simulation could be replaced with a stationary one with an average (effective) inlet velocity. Here, we will assess to what extent the instantaneous pressure drop across the stenosis is affected by the blood acceleration.Ideally, the FFR quantification should be conducted by simulating the flow in the stenotic region exclusively. This would allow one to increase the spatial resolution of the simulation, capturing the critical influence of the intricate stenosis shape on the FFR value. However, such a simulation requires the precise knowledge of the boundary conditions in the pre- and post-stenotic segments, which cannot be easily determined. For this reason, the numerical simulation normally involves not only the coronary artery where the stenosis is located, but also the peripheral vasculature, including the aorta. The inlet and outlet boundary conditions for this numerical domain are relatively well established, which allows CFD to produce FFR predictions in an autonomous way, i.e., just from the knowledge of the vasculature geometry and some patient-specific parameters.The above mentioned approach does not lack important disadvantages. Even if the boundary conditions are correctly prescribed –32, the As explained above, the reconstruction of coronary arteries may constitute a significant source of error due to both the image pixel size and the number of triangles used in the geometrical representation. For the sake of illustration, Fig. In this paper, we will analyze the influence on the pressure drop across a highly-eccentric coronary stenosis of several aspects (approximations) of the simulation method. Specifically, we will consider the accuracy and spatial resolution achieved in reconstructing the stenosis geometry, the velocity distribution at the stenosis inlet, the post-stenotic turbulence, the blood non-Newtonian character, and the values taken by the Reynolds and Womersley numbers. The stenosis geometry will be parameterized by adopting an idealized model that represents a wide class of atheromatous lesions. First, we will simulate the flow through stenoses with varied severities. Then, we will focus on a stenosis with FFR around the critical value 0.8 to determine to what extent the factors mentioned above can influence the outcome of the FFR assessment. We will conclude that this is a geometry-dominated problem, and therefore the limited accuracy and spatial resolution of the stenosis reconstruction is the major source of error in predicting the FFR value. To the best of our knowledge, this aspect of the problem has not been quantitatively analyzed yet.L and diameter D. This subtraction is carried out at a distance L/D, Consider the flow of a liquid with constant density N is the number of triangles in the stenosis and S the area of the surface represented by those triangles. The ratio As mentioned in the “The liquid viscosity r is the distance to the cylinder axis, and The velocity profile at the entrance is perpendicular to that section, and with a magnitude given by the real part ofment}η-1 . This diely Fig. .Fig. 4In−1 respectively.Figure peraemia . It mustrphology –39. For rphology  to simulWe will consider ely Fig. a. The laluent [In this work, the Navier–Stokes equations were integrated in the incompressible regime with the finite volume method  implemenluent . Both stluent .L/D. For this reason, outflow boundary conditions  were prescribed at that section. We verified that this choice leads to virtually the same steady pressure drops as those calculated for constant outlet pressure. On the other side, the non-slip boundary condition was prescribed at the artery inner surface. In the LES simulations, the turbulence intensity was set to zero at the inlet section.The velocity profile  was impo0 in Eq. , which cUse was made of hybrid conformal grids consisting of a structured part formed by rectangular parallelepipeds next to the wall, and an inner unstructured portion formed by tetrahedrons Fig. . The strlgorithm . The numv in the cell, and the time step The numerical integration of the hydrodynamic equations was carried out with the pressure-based solver. The gradients in the cell center and faces were evaluated with the green-Gauss node-based scheme and a multidimensional Taylor expansion, respectively. The spatial discretization of the pressure equation was conducted with the second-order approximation, while the momentum equations were discretized with the second-order upwind scheme. The velocity-pressure coupling was conducted with the SIMPLE procedure. In the unsteady laminar simulations, the time step In this subsection, we aim at analyzing systematically the influence of all the simulation aspects described in the “y during , 42. Figmentclasspt{minima.78 Fig. , which aD with a stenosis like that represented in Fig. Figure entclass1pt{minimaentclass1pt{minimaentclass1pt{minimaluent simulation in terms of triangles connected to each other, and is stored in the so-called STL format [luent when exporting the smooth geometry to the STL format. Finally, we calculated the pressure drop As mentioned in the “L format . Anotherentclass1pt{minimaFigure  in Ref. . For higThe stenosis eccentricity enhances turbulent motion in the post-stenotic region . It is nFigure Figure In order to analyze the influence of the Womerslay number Figures ∗∼4 Fig.  and \docThe results presented in the previous section and the order-of-magnitude analysis described above allow one to conclude that errors in the calculation of FFR made when assuming a certain velocity profile in front of the stenosis, as well as those associated with the Newtonian and laminar approximations, must be smaller than 1% for our stenosis model with In order to show the validity of the above conclusions, we quantified the influence on the FFR value of one of the two major sources of error: the segmentation of the CTA images. Specifically, we simulated the pulsatile flow across the nominal and distorted geometries considered in “entclass1pt{minimaThe simulations were conducted by imposing velocity inlet and outflow boundary conditions. In this case, the simulation calculates pressures relative to that of a reference point of the numerical domain. In order to obtain absolute values of the pressure field, the value of this quantity was prescribed at the inlet section. We calculated the FFR values by considering two inlet conditions: (i) the pre-stenotic velocity and pressure waveforms taken from Ref. , measureFigure mentclass2pt{minimnd 30 μm , 44. FigFigure rom Ref. . The FFRAs can be observed, a stenosis with a severity of just 58% leads to a FFR value below the threshold 0.8. This result contrasts with the common assumption that the critical FFR value is obtained for severities around 75%. This discrepancy can be attributed to the fact that the velocity wave used to calculate the FFR values in Fig. In order to illustrate the potential clinical relevance of the segmentation error, we have correlated our results with a statistical analysis recently published from direct FFR measurements in more than 3000 vessels . The ideBased on our analysis, one can propose a two-step method to improve the CFD calculation of the FFR value for highly-eccentric coronary stenoses. In the first step, one determines the internal geometry of the large-scale numerical domain  from CTA images of the cardiac vasculature, and conduct the corresponding numerical simulation. This calculation allows one to determine both the time-dependent velocity profile and pressure waveform at a given section of the pre-stenotic segment. If possible, that velocity profile might be re-calculated by scaling all the velocities so that the flow rate coincides with that measured from any relatively non-invasive technique, like MR phase-contrast flow measurements , 28. In FFR-guided revascularization offers important advantages over other assessments such as CTA or AME. For instance, it proves to be long-lived and cost-saving, exhibits lower rates of major adverse cardiac events, and correctly classifies as hemodynamically insignificant many lesions judged “obstructive” by CTA or AME. However, FFR assessment requires the catheterization of the coronary arteries to measure the pressure waveforms both proximal and distal to the stenosis. CFD has arisen as a useful alternative to this invasive technique , 11. It We have extended our study to analyze the influence of a number of approximations on the pressure drop across highly-eccentric coronary stenoses. For this purpose, we have parameterized the stenosis geometry by adopting an idealized model that represents a wide class of stenoses caused by atheromatous lesions. We have considered realistic values of the rest of parameters governing the problem . The conclusions derived from this analysis are expected to be qualitatively valid for real stenoses in curved, flexible and moving vessels with side branches. Our results on the pressure drop across the stenosis confirm the common belief that the flow can be regarded as Newtonian and laminar. In addition, the inlet velocity distribution plays a secondary role in severe stenoses because of the very localized character of the pressure drop in the artery narrowing. Finally, the flow pulsatility has little influence on the pressure drop due to both the moderate value of the Womerslay number and the smooth temporal evolution over the cardiac cycle of the velocity in the coronary artery inlet.We have restricted our analysis to the geometry described in “The present work raises the question of whether the image spatial resolution obtained in standard CTA is high enough for CFD to provide reliable predictions in FFR assessment. To answer this question, one must conduct a systematic study of the effects produced by choices made in the segmentation process on the resulting FFR value. In particular, attention must be paid to the range of values in the Hounsfield scale corresponding to the area delimited by the artery inner wall.N of triangles of the faceted geometry while keeping the ratio In principle, the FFR value could be also determined by conducting experiments on models fabricated with 3D printing , 47. Inc


Sunburn and intermittent exposure to ultraviolet rays are risk factors for melanoma. Sunburn is a common experience during holidays, making tourism settings of particular interest for skin cancer prevention. Holidaymakers are a volatile populations found at different locations, which may make them difficult to reach. Given the widespread use of smartphones, evidence suggests that this might be a novel, convenient, scalable, and feasible way of reaching the target population.The main objective of this study was to describe and appraise the process of systematically developing a smartphone intervention (mISkin app) to promote sun-protection during holidays.The iterative development process of the mISkin app was conducted over four sequential stages: (1) identify evidence on the most effective behavior change techniques (BCTs) used (active ingredients) as well as theoretical predictors and theories, (2) evidence-based intervention design, (3) co-design with users of the mISkin app prototype, and (4) refinement of the app. Each stage provided key findings that were subsequently used to inform the design of the mISkin app.The sequential approach to development integrates different strands of evidence to inform the design of an evidence-based intervention. A systematic review on previously tested interventions to promote sun-protection provided cues and constraints for the design of this intervention. The development and design of the mISkin app also incorporated other sources of information, such as other literature reviews and experts’ consultations. The developed prototype of the mISkin app was evaluated by engaging potential holidaymakers in the refinement and further development of the mISkin app through usability (ease-of-use) and acceptability testing of the intervention prototype. All 17 participants were satisfied with the mISkin prototype and expressed willingness to use it. Feedback on the app was integrated in the optimization process of the mISkin app.The mISkin app was designed to promote sun-protection among holidaymakers and was based on current evidence, experts’ knowledge and experience, and user involvement. Based on user feedback, the app has been refined and a fully functional version is ready for formal testing in a feasibility pilot study. Skin cancer incidence within white populations has been increasing worldwide -3. ExposSkin cancer is the most common form of all types of cancer diagnosed in the United Kingdom . The ageConsidering the time of day and location barriers in interventions designed to target holidaymakers, it seems easy to conclude that interventions that use mobile computing and communication technologies  are potentially an effective option for skin cancer prevention. Several systematic reviews have demonstrated the potential of mobile technologies to change health-related behavior -18. TextOne of the main problems identified in a previous systematic review of interventions delivered in tourism settings was the lack of detail on the development process . The MedA recent study  designedAs identified by a recent systematic review , previoumISkin app, targeting sun protection. By consistently describing how behavioral interventions are derived and decisions made based on specific constraints, more transparency and reproducibility will be achieved in the area of skin cancer prevention. The main objective of this study is to describe and appraise the process of systematically developing a smartphone based intervention (mISkin app) to promote sun-protection during holidays. This process incorporates both theory and evidence-based approaches outlined by the Medical Research Council framework [mISkin app [This paper provides an innovative approach on how to integrate different sources of information in a thorough, systematic, and iterative development process for the ramework ,3, engagSkin app ,23.The sThe study was approved by the Faculty of Medical Sciences Ethics Committee (Newcastle University) (Reference no: 00427_2/2013).mISkin app was conducted over four sequential stages  refinement of the app. Each stage provided key findings that were subsequently used to inform the design of the mISkin app. The development process of the l stages : (1) ideEvidence from a systematic review assessing the efficacy of interventions promoting sun-protection behaviors in holiday settings  conducteThe content of the interventions was coded using a taxonomy of behavior change techniques . MethodsData from the relevant literature was extracted and collated in a mapping exercise that covered included BCTs and rationale for inclusion. The list of included BCTs and rationale was used to inform the content of the intervention in stage 2.After gathering, collecting, and analyzing information regarding state-of-the-art evidence, the design and concept development of the smartphone app was informed and overseen by an interdisciplinary group of experts in dermatology, behavior change, and computing science. Experts presented experience in designing, developing, and evaluating theory-based interventions and psychological theories of behavioral change, experience on the cutaneous response to ultraviolet radiation (UVR), and development and application of pervasive computing interactive technologies for health and well-being.Two main sets of expert consultations were conducted: (1) behavioral scientists plus computer scientists and (2) behavioral scientists plus dermatological science researchers and vitamin D experts. The meetings were frequent during the early stages of app design and initial testing . These were structured by defining clear agenda items beforehand and by keeping detailed minutes of main decisions discussed. After reaching agreement over the overarching themes and design, the meetings with app developers were regular to evaluate the progress of the app design.Translating the interventions content into app features involved repeated iterations between members of the research team conducting the systematic review of the current available evidence and the members of the team with expertise on app development. The initial step was to agree on the theoretical basis and principles underpinning the intervention based on previous studies. This evidence informed the production of guiding principles that described the key features to be included in the app. These discussions also explored the best ways to deliver the BCTs selected and the agreed guiding principles for the intervention. After reaching an agreement over the key app features and design, we met regularly to evaluate progress of the app design.mISkin app.Data retrieved from these discussions were collated to develop interactive mock-ups and a workflow for the A total of 17 adults  aged 21-62 years  participated in the semistructured interviews. Participants were recruited through advertisement leaflets placed across Newcastle upon Tyne, United Kingdom.The aim of this stage was to obtain an exploratory evaluation of the intervention principles and resulting prototype. Individual interviews were used to obtain feedback and suggestions for improvement by giving the participants a key role in optimizing the intervention (co-design).Eligible participants had to be over 18 years old with past experience of sunny holidays abroad. Included participants were assessed for inclusion criterion and were required to provide informed consent before participation. Interviews were conducted by a female researcher (AR) with experience in interviewing. Interviews lasted between 30-50 minutes and were audio-recorded and transcribed.mISkin app . However, visualizing UV photographs was an essential component of our intervention package, as previous studies had shown that these images might be effective in motivating people to improve sun-protection practices whilst on holiday . In addimISkin app, but risk communication was improved in order to provide more health-related information before showing the UV pictures to the users.Despite some users expressing negative reactions to the UV photographs , all participants thought it was an important element to be included in the app. Consequently, UV photographs were retained in the Another discrepancy was the assumption about the potential disruptiveness of the Sun Alert service for users. The initial mock-up only assumed two prompts per day in order to avoid annoying users with alerts. However, feedback given by users was to make this feature customizable as some would have liked to receive more than two prompts per day.mISkin app, such as other systematic reviews and consultations with experts . Evidence on the most effective BCTs and associated theoretical mediators from other systematic reviews targeting behavior change [The analysis of the active components provided useful information for intervention development . We follr change ,26,31,32This review  also fouEven though the systematic review did not provide specific evidence regarding smartphone use as a possible mode of delivery, other evidence suggested that this might be a novel, convenient, scalable, and feasible way of reaching the target population -18, giveThe intervention principles guided the design and development process of the app and added value to the experts’ consultations. The key principles introduced based on expert advice were as follows: (1) development of an algorithm for sun-protection reminders , (2) vitamin D advice, and (3) introduction of gamification to deliver sun-protection information.Any discrepancies between the different sources of data were solved based on the pre-specified intervention principles. For instance, the Vitamin D topic was added after consultation with experts in this area. However, this addition was congruent with our guiding principles in terms of providing health-related information within the app. Consultations with experts were essential to further develop and refine the intervention based on the iterative discussions with the core team members and wider consultations. One of the key challenges was the need to adapt to similar technical language when communicating within a multidisciplinary team.mISkin app are presented in mISkin app, using semi-structured interview methods.The developed interactive mock-up and workflow of the mISkin app that informed the development of a functional version of the intervention prototype by the app developers.The workflow was used as a design brief depicting the interaction process within the mISkin app) was developed on the Android platform. The app entails a behavioral intervention using several BCTs to promote sun-protective behaviors amongst holidaymakers. mISkin app with explicit justification of inclusion based on evidence.The proposed smartphone intervention  and I think especially if you’ve got children as well, you know, I think that’s really good. I mean my children are all grown up now but I do have a year old granddaughter so it’s, I think it would be good because when you’re a busy mum or grandparent and you sometimes forget to do things when there’s a lot going on so...Female, 55 years old, with skin type IIUsers also mentioned the ease-of-use of the app and how the app is “intuitive to interact with” and provides information that is understandable.Information needs to be there so that people know and can protect themselves. It was simple information and got the message over. I don’t think it was boring, it was informative and that’s something you need.Female, 55 years old, with skin type IImISkin app, stating that the background image, design, graphics, and color scheme were all appealing. “I quite like the design,” said a female respondent aged 55 years, with skin type II.All participants provided positive feedback regarding the appearance of the mISkin app reflecting user preferences. The active ingredients of the intervention were kept the same, with the main refinement being in terms of design to improve usability and acceptability. A final fully functional mISkin app was produced to be tested in a pilot randomized controlled trial (to be reported elsewhere).After the amendments and refinements, the research team produced an optimized mISkin app are providing general information about the consequences of unprotected sun-exposure, addressing appearance-related concerns, providing instructions for sun-protection, providing demonstration (modeling) on how to perform sun-protection behaviors, prompts for effective sun-protection when outside (via smartphone GPS), and feedback on exposure and protective behaviors. The app also includes a skin assessment questionnaire. Participants are prompted daily (a minimum of 2 times per day) by the app. Each day, participants are also prompted to respond, through the app, to brief questions about their sun-protection practices .The main elements of the mISkin app . The BCT used was prompt practice.Fourth, the “ Self-monitoring: This refers to the assessment of sun-protection practices between 11 AM and 3 PM if the person is outside (detected by the app) at least once a day and can be customized by participants. The BCT used was prompt self-monitoring of the behavior, as well as of the outcome of it (redness and burning).UV levels are forecast with an indication of the most effective protection behavior. The BCT used was prompt practice.mISkin app aimed at promoting sun-protection during holidays. The sequential approach to development integrates different strands of evidence to inform the design of an evidence-based intervention. A systematic review on previously tested interventions to promote sun-protection provided cues and constraints for the design of this intervention. The development and design of the mISkin app also incorporated other sources of information, such as other literature reviews and experts’ knowledge and experience. The developed prototype of the mISkin app was evaluated by engaging potential holidaymakers in the refinement and further development of the mISkin app through usability (ease-of-use) and acceptability testing of an intervention prototype. All 17 participants were satisfied with the mISkin prototype and expressed willingness to use it. Feedback on the app was integrated in the refinement process to produce a final fully functional app before a formal test in a feasibility study. The feasibility and acceptability of the mISkin app has been formally tested in a pilot randomized controlled trial , which will be reported elsewhere.This paper described a systematic and iterative approach to the development of the mISkin app was only developed for devices using the Android operating system, limiting the possibility of including users owning other smartphones . It is also important to highlight that the participants’ views were based on only visualizing a prototype intervention aimed to be delivered during holidays. Views of using the app could change if participants were given the possibility of interacting with the mISkin app in a real scenario of holidays. It would have been useful to have a group of users that tried out the app on their own, followed by an interview about their experiences . This would provide further insight into how people perceived and used the app in their own time, which may be different from when a researcher is present [mISkin app, potentially losing their general and a priori ideas about what should be in a sun-protection app.While the views of the 17 participants were coherent and data saturation was achieved, not all groups of potential users were similarly represented and it is possible that a more extensive engagement of potential users would lead to further improvements in acceptability and usability. The  present . The stuUser-centered design is an approach that entails the involvement of potential users in the design process of a product  by tackling their specific needs . This prmISkin app is the Sun Alert Service and we were aware of the risk of participants becoming annoyed with receiving alerts or reminders within the mISkin app. As in similar studies, participants were keen to gain control over the settings for the Sun Alert service [A key feature of the  service ,50, in o service .mISkin app, which was aimed at promoting sun-protection. Prototype testing provided useful information regarding users’ views on and experiences from engaging with the mISkin app. Suggestions made by participants were incorporated in the refinement and development of a fully functional mISkin app. The optimized version of the app is ready for formal testing in a feasibility pilot study, to explore whether it is a feasible vehicle to deliver an intervention aimed at improving sun-protection amongst holidaymakers.This study summarizes the sequential and iterative process of developing the


Vertical jump tests are used in athletics and rehabilitation to measure physical performance in people of different age ranges and fitness. Jumping ability can be analyzed through different variables, and the most commonly used are fly time and jump height. They can be obtained by a variety of measuring devices, but most are limited to laboratory use only. The current generation of smartphones contains inertial sensors that are able to record kinematic variables for human motion analysis, since they are tools for easy access and portability for clinical use.The aim of this study was to describe and analyze the kinematics characteristics using the inertial sensor incorporated in the iPhone 4S, the lower limbs strength through a manual dynamometer, and the jump variables obtained with a contact mat in the squat jump and countermovement jump tests (fly time and jump height) from a cohort of healthy people.A cross sectional study was conducted on a population of healthy young adults. Twenty-seven participants performed three trials (n=81 jumps) of squat jump and countermovement jump tests. Acceleration variables were measured through a smartphone’s inertial sensor. Additionally, jump variables from a contact mat and lower limbs dynamometry were collected.In the present study, the kinematic variables derived from acceleration through the inertial sensor of a smartphone iPhone 4S, dynamometry of lower limbs with a handheld dynamometer, and the height and flight time with a contact mat have been described in vertical jump tests from a cohort of young healthy subjects. The development of the execution has been described, examined and identified in a squat jump test and countermovement jump test under acceleration variables that were obtained with the smartphone.The built-in iPhone 4S inertial sensor is able to measure acceleration variables while performing vertical jump tests for the squat jump and countermovement jump in healthy young adults. The acceleration kinematics variables derived from the smartphone’s inertial sensor are higher in the countermovement jump test than the squat jump test. In athletics and rehabilitation, functional capacity can be evaluated through different methods; one of them is the vertical jump test. In addition, the vertical jump serves as a predictor of anaerobic capacity, motor development and athletic ability in sports -7. OtherSome of the classic measurement tools to calculate these variables are the force platform, video-analysis systems, photoelectric cells and contact mats -13. ThesCurrently, the latest mobile phone generation usually includes inertial sensors with subunits such as accelerometers and gyroscopes that can detect acceleration and the inclination of devices. Numerous apps that display, store and transfer inertial sensor data have been developed for the operation of different mobile phones. These apps have great potential for tracking human motion parameters for research and clinical practice. Apps are being developed for use in different situations related to human movement, such as the pedometer , or the Because of the advantages offered by mobile phones as tools for the study and analysis of human movement, it is of interest to check their ability to assess and analysis vertical jump tests. The aim of this study was to describe and analyze kinematics characteristics using the inertial sensor incorporated in the iPhone 4S, lower limb strength through a manual dynamometer, and the jump variables obtained with a contact mat in the squat jump (SJ) and countermovement jump (CMJ) tests from a cohort of healthy people. The squat jump (SJ) is defined as a jump that is performed from a squatting position. A counter movement jump (CMJ), which is higher, is a jump where the jumper starts from an upright standing position, makes a preliminary downward movement by flexing at the knees and hips, then immediately jumps up from that position. This was a cross-sectional study, involving 81 jumps from 27 participants. The participants were young Health Sciences students from the University of Málaga (Spain). Participants had to meet the inclusion criteria of being healthy adults aged 18 to 35 years, without musculoskeletal or neurological dysfunction. Subjects with any of the following criteria were excluded: a history of heart disease, surgical interventions in the last year, any disability that would make the correct achievement of the tests difficult, any pain that prevented the completion of tests or neuromuscular pathology that could be aggravated by participating in the study. A physical therapist evaluated the volunteers for the presence of exclusion criteria. The study complied with the principles laid out in the Declaration of Helsinki. The ethics committee of the Faculty of Health Sciences at the University of Malaga, Spain, approved the study.Study subjects performed three trials of the jump tests described by Bosco : SJ and 2).Anthropometric data were obtained following the guidelines of The International Society for the Advancement of Kinanthropometry (ISAK) . The weir2>0.98). The mobile phone accelerometer showed excellent sequential increases with increased walking velocity and energy expenditure (r2>0.9). An accelerometer embedded into a mobile phone was accurate and reliable in measuring and quantifying physical activity in the laboratory setting  was obtained.An off-line analysis was guided to obtain kinematic information from the accelerometer for each subject, in each trial, in the SJ and CMJ test. In this study, the mean and standard deviation was obtained from the maximum peak and minimum peak of accelerations in the three axes of movements .The Kolmogorov-Smirnov demonstrated that the distribution of the sample by gender was non-normal. In the present study the kinematic variables derived from acceleration through the inertial sensor of an iPhone 4S, dynamometry of lower limbs with a handheld dynamometer, and the height and flight time with a contact mat were described in vertical jump tests from a cohort of young healthy subjects, aged between 18 and 35 years. The development of the execution in SJ and CMJ vertical jump tests is described, examined and identified under acceleration variables obtained with the mobile phone.To the best of our knowledge, and according to the literature reviewed so far, the present study is the first to describe and analyze the kinematic variables in vertical jump tests with the use of a mobile phone as the main instrument.x, y and z), while the uniaxial accelerometer gives us variables of only one axis of movement. In addition, today, most mobile phones contain triaxial accelerometers, which are very accessible to most people, and the acquisition of another tool to analyze human motion through acceleration values would not be necessary using a mobile phone.Previous studies have been found in literature that may be relevant to the present study, in which vertical jump tests were evaluated through inertial sensors -19,27,28x, y and z) in CMJ with respect to the SJ, may be explained by the countermovement produced in CMJ test causes greater movement synergies involving higher acceleration [From accelerometry data obtained through the mobile phone, differences in values of minimum and maximum acceleration were identified between the two types of jump tests SJ and CMJ see . Higher leration . It can Specifically, the higher maximum acceleration values in the y-axis found in the CMJ are explained by the jump modality, as the countermovement allowed in it facilitates greater vertical impulse . FurtherFor acceleration in the z-axis, the differences found may also be explained by the influence of the transition between the eccentric and concentric phases occurring before take-off for CMJ because trunk flexo-extension movements occur, involving higher acceleration values in the z-axis .Regarding the differences in the x-axis acceleration, it is conceivable that lateral displacements by the subject in the execution of both tests can be greater for the CMJ test, also because movement synergies in this jumping technique are implied, and higher flight times are achieved .The differences between tests are also maintained for the resultant vector acceleration values, although less so. This can be justified by the integration of the acceleration signals in the different axes of motion to calculate the resulting vector.As a limitation in this study, we can mention the fact that there is no separation by gender analysis that would show differences between men and women in performing the jumps . TherefoAs a fortuitous finding, upon visual inspection of the y-axis acceleration graphic in the SJ tests, we observed a previous negative acceleration at the start of the upward curve of positive acceleration. This would be interesting research for future studies to analyze curves and globally analyze the mobile phone discriminating power between correct executions of vertical jump tests without countermovement based on trunk accelerometry.According to the results obtained in this study, we can conclude that the built-in iPhone 4S inertial sensor is able to measure acceleration variables for vertical jump tests SJ and CMJ in healthy young adults. The acceleration kinematics variables derivate from the mobile phone’s inertial sensor are higher in the CMJ test than the SJ test.