As the RFID tags are small and lightweight, the RFID system is well suited for monitoring the individual activity of group-housed broilers throughout life.Individual data are valuable for assessing the health, welfare and performance of broilers. In particular, data on the first few days of life are needed to study the predictive value of traits recorded early in life for later life performance. However, broilers are generally kept in groups, which hampers individual identification and monitoring of animals. Sensor technologies may aid in identifying and monitoring individual animals. In this study, a passive radio frequency identification (RFID) system was implemented to record broiler activity, in combination with traditional video recordings. The two main objectives were (1) to validate the output of the RFID system by comparing it to the recorded locations on video, and (2) to assess whether the number of antennas visited per unit time could serve as a measure of activity, by comparing it to the distance recorded on video and to the distance moved as recorded using a validated ultra-wideband (UWB) tracking system. The locations recorded by the RFID system exactly matched the video in 62.5% of the cases, and in 99.2% of the cases when allowing for a deviation of one antenna grid cell. There were moderately strong Spearman rank correlations between the distance recorded with the RFID system and the distance recorded from video (r Knowledge of the relationships between behaviour and health, welfare and performance indicators can be used to assess overall welfare in production animals. Broiler chickens are an example of a livestock species for which insight into these relationships can be valuable. Broilers are, however, often kept in intensive systems, where large numbers of birds  are houSpecifically, information at the individual level is desired to obtain a good view of an individual’s state. Furthermore, when individual data can be collected in a group setting with pen mates present, a more realistic image of an animal’s performance in a production environment can be obtained. In particular, data on individual activity levels of young broilers could be very valuable. For example, it has been established that the activity level of broilers from a fast-growing stock early in life positively correlates with activity later in life . FurtherGiven that broilers are generally housed in large groups in production systems, identification and activity tracking of individual broilers is a challenge. Sensor technologies, such as computer vision (CV), ultra-wideband (UWB) tracking and passive radio frequency identification (RFID) may offer solutions  to study flock activity [The implementation of a passive RFID system for tracking individual broiler activity can have added value in comparison to existing tracking systems. For example, several studies on automated activity recording of broilers and its relationship with different health, welfare and performance traits have been performed , but maactivity . They reactivity . Althougactivity , the suiactivity . Given tactivity ,16,17; ractivity ). Passivactivity . In a stactivity . These aIn this study, the suitability of a passive RFID system, covering the full pen, for tracking individual broiler activity throughout life was investigated. The two main objectives of this study were (1) to validate the RFID recorded locations by comparing these to the locations recorded on video, and (2) to assess whether the moving distances calculated from the RFID data, using the recorded antenna positions over time and the distances between antennas, could serve as a measure of activity. To this end, the RFID recorded distances were compared to the total distance moved as recorded on video and using a validated UWB tracking system.Data were collected under control of Cobb Europe. Cobb Europe complies with the Dutch legislation on animal welfare. This study is considered not to be an animal experiment under the Law on Animal Experiments, as confirmed by the local Animal Welfare Body .This study was performed on a broiler farm in The Netherlands. In total, 40 male broiler chickens from two genetic crosses were used. The birds were fitted with RFID tags on the day of hatching and four birds, two from each cross, were marked visually using marker spray in four different colours. Near-continuous RFID recordings were made from day of hatching to 34 days old. At 15 days old, birds were also fitted with an UWB tag. Due to limitations in the number of tags, a total of 34 out of 40 birds were fitted with an UWB tag.2. In this pen, feed and water were provided ad libitum. Wood shavings were provided as bedding. The birds were kept under a commercial lighting and temperature schedule and were vaccinated according to common practice [The broilers were housed in a rectangular pen, with a size of approximately 1.8 by 2.6 m and an area of approximately 4.7 mpractice .To track individual broilers and monitor their activity throughout life, a passive RFID system from Dorset Identification  was used. All 40 broilers were fitted with a high frequency (HF) tag operating at 13.56 MHz. These tags had a size of approximately 15 × 3.7 mm and a weight of less than one gram. The tags were fitted to the legs of the birds using rubber bands and tape . The rubThe pen in which the broilers were housed was fitted with 30 HF antennas of 32 by 41 cm, in a grid covering the full pen . The antTo study whether the RFID system correctly registered the location of individual birds over time, the RFID log file was compared to video recordings. The implemented approach is visualised in Top-view video recordings were made for approximately two hours per day, using a Zavio B6210 2MP video camera  with a frame rate of 25 frames per second. From these recordings, four videos with a duration of approximately 7 min each were selected at random: one from 0 to 6 days old, one from 7 to 12 days old, one from 17 to 26 days old and one from 28 to 34 days old. These periods were selected because of the differences in activity, body size and absence/presence of UWB tags between these periods, and excluded days closely after fitting the UWB tags or when not all data were available. The details of the four videos are shown in The randomly selected video recordings were converted to frame images, with a rate of approximately one frame per second, using VLC media player . In these frame images, four colour-marked birds were annotated using LabelImg software . The fraThe annotations of the unique sets of frames from all observers provided coordinates of the location of the birds in the image. These coordinates were compared to the location of the different antennas from the reference image in order to assign an antenna number to the location of the birds. Sometimes, a scorer missed a bird—for example, because it was hidden or simply overseen, —or labelled two different birds with the same ID. In these instances, the correct annotation was added later on, by a single scorer who was already included in the group of annotators. It is important to note that this step was only performed for the frames included in the location validation set and not for the frames used for determination of inter- and intra-observer reliability, where only raw data were used. When a bird was positioned at the side of the pen, leaning against the pen wall, it could happen that the bird was annotated outside the antenna range. In these instances, a missing value was given and this observation was excluded from the calculations. Upon visual inspection of the coordinate data, some incorrect annotations were observed, where birds were located for only a single frame at a non-adjacent antenna. These incorrect annotations were removed, resulting in a missing data point. Furthermore, if location 7, where the antenna was not functioning, was scored on video, this value was replaced with a missing value and not included in the analysis. The final output data from the videos that were used here included a time stamp, the animal ID and the antenna at which the animal was located. This output was then compared to the output of the RFID system, which included the same variables. For this location validation, the output of the RFID system was manually completed after recording, as the RFID system sometimes did not register birds when they were lying down, resulting in missing recordings. The RFID system functions best when the tags are in a vertical position, i.e., at a 90 degree angle in comparison to the antenna floor, which is the case when birds stand. When birds are lying down, the tags are in a position parallel to the antenna floor and are often not registered. It was assumed that as long as a bird was not registered elsewhere, the bird was still located at the antenna position where the bird was last registered. This assumption was used to fill in the missing rows in the RFID data for the location comparison. In later analyses of distances moved, and future implementations, this is not necessary, as the main factor of interest in those cases are likely the antenna switches, and when studying these the last recorded position can be used, regardless of the time between the last recorded position and the next recorded position. However, for the location validation this would result in missing data, and therefore missing rows were filled in based on this assumption. Both the overall registrations and the trajectory walked by the birds were compared between the RFID system and video recordings. For the overall registrations, the percentage of (dis)agreement was calculated, while for the trajectory analysis the path of the animals was visually compared.To study whether the distance moved as recorded with the RFID system was a good indicator of activity, the RFID output, in terms of antenna switches per unit of time, was compared to the distance moved that was recorded (1) from video and (2) using an UWB system. The implemented approach is visualised in The RFID recordings required conversion to metrical distances. The number of switches between antennas was used as an initial measure of activity for the RFID system. The RFID antennas were all the same size (32 × 41 cm), but were not exact squares, so a correction was made in the RFID output to account for the difference in distance between centre points of antennas in the x and y direction. Furthermore, antennas were mounted on a total of fifteen PVC panels, in sets of two with identical configurations and the short sides of the antennas adjacent to each other, resulting in a difference in distance between two antennas on the same panel and between adjacent antennas on different panels. This was also accounted for in the RFID distance calculations. For the video comparison, Kinovea software  was useFor the comparison with UWB tracking, a Ubisense UWB system with Series 7000 sensors and compact tags  was used, in combination with TrackLab software version 1.4 . In total, 34 out of 40 birds were fitted with an UWB tag, due to a limitation in the number of tags available during this study. These tags had a size of 3.8 by 3.9 cm and a weight of approximately 25 g, and were fitted to the birds using elastic bands around their wing base. This UWB system, the setup and validation are described in more detail in . A samplAll statistics were performed using R version 3.5.0 . To valip < 0.001). The intra-observer reliability for the annotated antennas was on average 0.92, ranging from a minimum agreement of 0.75 to a maximum agreement of 0.99 , S = 730, p < 0.001; s = 0.70 (95% CI 0.41–0.86), S = 1224, p < 0.001, s = 0.79 (95% CI 0.53–0.92), S = 854, p < 0.001; There were moderately strong Spearman rank correlations in terms of distances moved between RFID and video (rs = 0.71 (95% CI 0.65–0.75), S = 4041800, p < 0.001; p < 0.001; p < 0.001; There was a moderately strong Spearman rank correlation between RFID and UWB when using the average distance moved per hour, calculated per day and animal  between video and RFID in terms of distance moved. This indicates that the RFID system is suitable for comparison of activity levels between animals, and can be implemented to study individual differences in activity levels in a more time-efficient and objective manner compared to visual observations from video recordings. In terms of absolute distances moved, the distance as recorded from video was generally somewhat higher than the distance registered by the RFID system. There are several explanations for this finding.First, the RFID and video recordings could differ in the exact starting point of the distance recording. In theory, the RFID and video recordings spanned the same time period, but, as explained earlier, the RFID system did not always register birds, especially when they were lying down. Consequently, when a recording started, the RFID system might only have registered a bird when something in the position of the bird changed—for example, when it moved to a new antenna, as it was possibly no longer registering the previous position of the bird. This could result in the first ‘switch’ between antennas being missed, as only the second antenna might be registered, while on video, all movements from the start of the recording can be observed. Consequently, the RFID system might show a slightly lower recorded distance compared to video.Second, as discussed earlier, the video can capture much smaller changes than the RFID system. On video, all changes can be observed, while the RFID system only registers movement between antennas, and not within antennas, which can cause the distance recorded with the RFID system to be lower. The absolute difference between the recorded distances on video and using RFID appeared larger when birds moved longer distances a. RedferThird, during this study, antenna 7 of the RFID system was not functioning and therefore not recording birds. Moreover, after this study, it was discovered that the antennas close to the drinker were no longer recording birds near the end of the tracking period, likely due to the moisture in the bedding underneath the drinker blocking the RFID signal. This could have resulted in some missed registrations, and hereby could have lowered the recorded RFID distance in comparison to video.Overall, the distance moved calculated from the RFID data may not exactly represent true distances moved. However, the moderately strong correlation between video and RFID does allow comparison of activity levels between animals tracked with the same RFID setup.There were moderately strong rank correlations between UWB and RFID in the one-hour sessions (0.70) and in the longer recordings (0.71). This indicates that the RFID system and the UWB system generally agree on the relative ranking of animals in terms of distances moved. Whether animals are tracked using the RFID system or the UWB system, the same animals will likely be identified as relatively active or inactive by both systems. In terms of absolute distances, the distance recorded with the UWB system was higher than the distance recorded with the RFID system for nearly all data points. This could again be explained by the RFID system not registering movement within antennas, while the UWB system can theoretically pick up on all movements. However, the difference between RFID and UWB may be enlarged by the localisation error or noise that may occur with the UWB system. There may be some noise in the localisation of the UWB system, which could result in slight deviations from the actual position of the bird over time, hereby increasing the recorded distance moved . The reps = 0.79. This indicates that the UWB recorded activity reflected the ranking of the animals in terms of distances moved well. In our previous study [There was also a moderately strong correlation between video and UWB, with rus study , a similus study , the obsus study ,37,38), Overall, the moderately strong correlations between the different observation methods suggest that the RFID system and the UWB system are both suitable for estimating differences in activity levels between individual birds. However, as the RFID system allows for monitoring activity from hatching onward, due to its small and lightweight tags, it is here deemed to be the preferable method for tracking individual activity in group-housed broilers throughout life.The RFID system that was implemented here shows great potential for recording individual activity levels of broilers throughout life, on multiple animals simultaneously, in a time-efficient and objective manner. The current setup provided a high level of detail, using antennas with a size of 32 by 41 cm, and can be of great value in research into behaviour of group-housed birds. However, as mentioned earlier, some difficulties were experienced with the RFID system. One antenna was not recording animals due to a technical error that was related to a faulty contact in the antenna. Further, several antennas were not recording birds at the end of the trial due to moisture in the bedding underneath the drinker. In general, the RFID system can be sensitive to the environment, which is important to take into account when implementing the system in practice. Furthermore, the RFID system used here is relatively easy to dismantle and move to a different location, but it would be advisable to setup the system in a location where it can remain for longer periods of time, as the transport and change in surroundings can result in recalibration of antennas being required for the system to work as desired and cleaning of the antennas is difficult as no water can be used.The intended purpose of implementing an RFID system is important to consider when selecting a system, as this may affect the requirements for the RFID system. For example, the current setup implemented high frequency RFID, among other things, to allow registrations of multiple animals at an antenna and avoid data collision. However, the radio frequency also has consequences for how much the system is affected by water and metal in the environment and what communication ranges can be achieved , and it Future research should furthermore look into alternative methods for attaching the RFID tags to the legs. The rubber bands used in this study were effective, i.e., the tags were well secured and not often lost, and evoked little reaction from the broilers after a short habituation period in which some pecking at the leg bands was observed, suggesting that the leg tags did not interfere with the normal behaviour of the broilers. Furthermore, no issues were observed with the rubber bands catching on objects in the environment, although it must be noted that all the objects in the pen and the pen walls had smooth surfaces. However, the leg bands had to be checked every couple of days and had to be switched to a larger size during the trial to avoid the rubber bands becoming too tight. Therefore, there would be added value to leg bands that can keep up with the growth of the broilers’ legs in order to reduce the required manual labour.Future research should also look into the potential of using RFID recordings to determine true distances moved in more detail. The relationship between RFID and video, which seems to show a linear pattern, indicates that there is potential to use RFID recordings to estimate true distances moved. Although not studied here, the RFID system could possibly be implemented to study true distances moved of group-housed birds, which could be a valuable tool in, for example, determining threshold levels of activity for reducing leg problems.s = 0.82) and between RFID and UWB (rs = 0.70). This indicates that the RFID system can accurately register among-individual variation in activity. However, the absolute values of the RFID recorded distances are generally an underestimation of the true distances moved. Overall, the RFID system appears suitable for monitoring the relative activity of individual group-housed broilers and can contribute to obtaining activity measures at the individual level early, and later, in life. Main benefits of the RFID system for tracking activity, compared to, for example, UWB tracking or video observations, include its small, lightweight tags that allow tracking of broilers from hatching onwards, limited manual labour and reliable identification of individuals. Data on activity levels early in life can potentially aid in identifying and predicting health, welfare and production parameters, but more research in this area is required.It was studied here whether a passive high frequency RFID tracking system was suitable for monitoring the individual levels of activity of broilers throughout life. In 62.5% of the cases, the RFID system was in full agreement with video in terms of the location of the animals. In total, 99.2% near matches, allowing for a deviation of one antenna, were observed between RFID and video in terms of location. There were moderately strong correlations in terms of distances moved between RFID and video (r


Desaturation is a new method to mitigate liquefaction of sand. It aims to prevent liquefaction by generating gas/air in the pores of fully saturated sands, and biogas is one of the most suitable gas. In order to evaluate the long-term sustainability of biogas bubbles, a series sustainability test on biogas bubbles in pores of sand was conducted with a one-dimensional device under hydrostatic condition, hydraulic gradient flow condition and horizontal excitation condition. The variation trend of the retention of biogas bubbles in the pores of soil under the aforementioned conditions was analyzed. Test results indicated that after 72 weeks of monitoring sand samples, biogas bubbles existed stably in the pores of soil under hydrostatic conditions. In hydraulic gradient flow, the stability under upward seepage flow showed a similar trend to that of downward seepage flow. When the hydraulic gradient was constant, the degree of saturation increased in a certain period and finally remained constant. When the hydraulic gradient increased by 0.1, 0.2, 0.3, 0.4, and 0.5, the degrees of saturation increase were 0.8%, 11.5%, 0.5%, 0.1%, and 0%, respectively. After 41,200 cycles with different accelerations, the degree of saturation of the sample increased slightly, and the biogas bubbles basically remained stable. Every strong earthquake results in considerable damage9. Liquefaction, in particular, causes great harm to people's properties and lives11. Liquefaction refers to the mechanical process of saturated fine sand losing its strength instantaneously and changing from solid to liquid under the action of seismic force. Liquefaction mostly occurs in loose saturated sand13. Therefore, dealing with liquefied subgrade simply, economically, and effectively has become a key technical problem in infrastructure construction.As the plates beneath the Earth’s crust squeeze and collide with one another, seismic fault zones become active18. In accordance with the gas injection method, the new method can be divided into air injection21, water electrolysis22, chemical bubble formation24, drainage–recharge, and biogas bubbles25. Among these methods, biogas bubbles are one of the most suitable materials for saturation reduction. Biogas bubbles method is a kind of desaturation method which uses denitrification of denitrifying bacteria to reduce nitrate ions in pore water to nitrogen. Denitrification is a process in which denitrifying bacteria gradually reduce nitrate to nitrogen under anoxic conditions, and the final product of denitrification is nitrogen. Biogas bubble method has the following advantages: First, bubbles are generated in the soil in the original position and are evenly distributed in the soil. Second, the microbial reaction is slow, and the process is easily controllable. Third, the nitrogen produced by microbial denitrification26 has the characteristics of stable chemical properties and low solubility.Therefore, a new desaturation method was proposed to treat liquefiable sand27 investigated the ground of a site improved 26 years ago by a sand compaction pile and concluded that bubbles survived for 26 years. At the same time, they indicated that if the degree of saturation is less than 90% at the end of the construction of a sand compaction pile, the unsaturated phenomenon in the soil will remain for a long time. In laboratory tests, Yegian and Eseller proposed a method of using electrolytic water to produce hydrogen and oxygen28 in saturated soil to reduce its saturation and thereby improve the anti-liquefaction strength of soil22. He et al.29 studied the stability of biogas bubbles under seepage conditions by using a one-dimensional model sand column and found that some bubbles would flow out together with pore water under seepage conditions and thus reduce the degree of saturation effect. The stability of biogas bubbles under hydrostatic and horizontal excitation has not been researched; only the stability of one-dimensional seepage under a fixed hydraulic gradient has been studied.In a field test, Okamora et al.Previous studies primarily focused on the stability of air bubbles or hydrogen and oxygen bubbles produced by electrolysis. They also studied the stability of biogas bubbles under one-dimensional short-term seepage with a single hydraulic gradient. However, the long-term sustainability of biogas bubbles in soil under hydrostatic hydraulic gradient flow and horizontal excitation is unclear and has not been systematically studied. Therefore, the long-term sustainability test of biogas bubbles in the sand under hydrostatic conditions, different hydraulic gradient flow conditions, and vibration conditions were conducted. The results can reflect the effective time of a single reinforcement using biogas bubbles, which also provide a theoretical basis for application of the construction using desaturation method.The sand used for this study is source from Nanjing in Jiangsu Province. Conventional tests of specific gravity and particle classification of sand obtained that the specific gravity of sand was 2.68, and the maximum and minimum void ratios of sand were 0.946 and 0.428 after the conversion of corresponding minimum and maximum dry densities directly measured. Figure d10 is the effective diameter, d30 is the medium diameter, d50 is the average grain diameter, and d60 is the constrained diameter, Cu is the non-uniformity coefficient, Cc is the curvature coefficient. It can be seen from Fig. Cu < 5 and Cc < 1. According to Reference30, it is named as poorly graded sand.In Table stutzeri31 (German Collection of Microorganisms and Cell Cultures [DSMZ]32 5190). It is necessary to note that "5190" is the serial number of the bacteria in the official website of DSMZ. For denitrifying cultivation of the bacteria, the medium was composed of the following components: 0.2 g of magnesium sulfate heptahydrate, 2 g of potassium nitrate, 1 g of dipotassium phosphate, 5 g of sodium citrate dihydrate, and the addition of distilled water a total volume of 1 L.The equation for denitrification of P. stutzeri DSMZ 5,190 is as follows:The bacteria strain used was P. The setup for testing of the long-term sustainability of biogas bubbles under hydrostatic conditions is shown in Fig. The calculation formula is as follows:Second, bubble sustainability was observed. In the first three months, the data were recorded daily; weekly measurements were performed for the rest of the observation period, and the measuring temperature was 20 °C.A schematic of the experimental device for the evaluation of biogas bubble stability under different seepage conditions is shown in Fig. Two types of bubbles were used: accumulated biogas bubbles and dissolved biogas bubbles. Sample saturation could be measured by two methods. In the first method, if biogas bubbles come out in a gas phase, they accumulate at the top of the tube. Then, the volume of this portion could be measured. The reduction in gas volume Hydraulic gradients of 0.1, 0.2, 0.3, 0.4, and 0.5 were adopted. The test was conducted by increasing the hydraulic gradient gradually. Data were read every 12 h until the degree of saturation was no longer changed for 24 h. The void ratio is calculated by measuring the height of sand sample.2. After loading 300 cycles 10 times for each level of load, 10,000 cycles were loaded 10 times. The specimen was loaded with 41,200 cyclic loads. The calculation method for the degree of saturation was consistent with the hydrostatic condition.The setup is schematically illustrated in Fig. 33 prepared unsaturated samples that contained air bubbles by drainage–recharge, after 442 days, the degree of saturation increased from 82.1% to 83.9%, which indicated a 1.8% increase. According to the above test results, nitrogen bubbles produced by microorganisms are more stable than air bubbles. A possible reason for this result is the low utilization of nitrogen by microorganisms; 0.6% is caused by pure disturbance, whereas oxygen in air bubbles produced by the drainage and water injection method can be used by microorganisms, resulting in the reduction of gas and the increase of the degree of saturation by 1.8%.Figure Figure The experiment showed a similar trend in the change in the main parameters under the condition of upward flow and downward flow. Figure 34. In this situation, degree of saturation increased from approximately 85.5% to 97.0%, and the rate of increase was higher than that for the other head gradients. When the hydraulic gradient increased by 0.1, 0.3, 0.4 and 0.5, the degrees of saturation increased by 0.8%, 0.5%, 0.1%, and 0%, respectively.The instability of the samples mainly occurred when the hydraulic gradient was 0.2. This result agreed with “gas bubbles in sand are stable at hydrostatic condition, while water flow could affect the stability of gas bubbles in sand” by HE JIA (2013)Figure Under flow conditions with a hydraulic gradient of approximately 0.2, a change in void ratio from 0.770 to 0.758 was observed in approximately 108 h. The void ratio remained constant in 24 h and then decreased from 24 to 108 h.Figure Under flow conditions with a hydraulic gradient of 0.2, a change in the coefficient of permeability from 0.00132 to 0.000176 cm/s was observed in approximately 108 h. The coefficient of permeability peaked in 24 h and then decreased from 24 to 108 h. The coefficient of permeability first increased and then decreased only when the hydraulic gradient was 0.2. The increase could be attributed to the bubbles flowing easily in the soil and some of them aggregating away from the sample. Observation points were arranged for the test at a distance of 15 cm away from the bottom of the sample, as shown in Fig. Va/Vao and the number of cycles. Vao is the initial air volume in the sample, and Va is the volume of biogas.Figure 2, Va/Vao was consistently 1.0. However, when the acceleration amplitude was 1.5 and 2.0 m/s2, Va/Vao after vibration was 0.97 and 0.95, respectively. The possible reason is that a small number of bubbles in the upper part of the sample were unstable and overflowed in the soil under vibration.As shown in the Fig. 2, the sample settlement was 0.5, 2.2, 5.7, and 8.8 mm, respectively. At the end of the test, the maximum volumetric strain of the sample was only 1.1%.Figure 35 used a small shaking table to test the bubble sustainability of cylindrical sand samples treated by drainage–recharge with an initial saturation of 85.7% under vibration conditions. Under 1 g horizontal excitation and after 300,000 cycles, the loss of air volume was less than 1% of the original air volume previously introduced in the sand specimen. The result of reference35 is consistent with this paper, as same as air bubbles, biogas bubbles can be stable existing in pore of sand under excitation condition.Figure The test results show that the reason for the instability of biogas bubbles is seepage condition. In the seepage condition, degrees of saturation increased, but the coefficient of permeability decreased with time when the hydraulic gradient remained the same. In the test, no biogas bubble aggregation occurred on top of the plexiglass tube, and no biogas bubbles were observed to flow away from the sample. Thus, the decrease in biogas bubbles was only due their dissolution.As water flowed through the pore space, the partial biogas bubbles gradually dissolved and were lost Fig. . On the When the hydraulic gradient was constant, seepage did not occur all the time; the degree of saturation did not increase to 100%. The major reason for the decrease in permeability was bubble plugging. Two processes related to biogas bubble stability occurred concurrently under seepage conditions: biogas bubbles removed in the dissolved phase and biogas bubbles that aggregated. The previous test results show that the increase in the degree of saturation was due to the biogas bubbles removed in dissolved form. When the biogas bubbles and bacteria gradually plugged the channel, a decrease occurred in the coefficient of permeability and seepage flow; the degree of saturation tended to be stable. The two processes inhibited each other.In first process, the bubbles were removed with the seepage after their dissolution, and the particle soil was rearranged, resulting in the increased compactness of the sand and reduced soil permeability. In this test, the relative compactness of the soil increased slightly by 3.7% (from 38.1 to 41.8%) and 4.7% (from 37.5 to 42.2%) under downward flow and upward flow, respectively. According to the literature, when the relative density of graded soil increased from 38.0 to 43.0% and the increment was 5.0%, the coefficient of permeability decreased from 0.0014 to 0.0012 cm/s. Thus, the increase in relative compactness was not the main reason for the decrease in the coefficient of permeability.38.In the second process, part of the biogas bubbles aggregated as shown in Fig. The long-term monitoring of sand specimens indicated that under hydrostatic conditions, the initial degree of saturation of 84.5% only slightly increased to 85.1%, after 72 weeks of monitoring. Small well-distributed biogas bubbles remained trapped for a long time.The stability of soil under upward flow is the same as that under downward flow. When the hydraulic gradient was constant, the degree of saturation increased in a certain period of time and finally remained constant. Under downward flow conditions with a hydraulic gradient of 0.1, a change in the degree of saturation from 84.7 to 85.5% was observed. When the hydraulic gradient was equal to 0.2, the degree of saturation increased the most, and the saturation increment was 11.5% under upward flow conditions.The coefficient of permeability decreased with time and finally remained constant when the hydraulic was constant. Under flow conditions with a hydraulic gradient of 0.2, a decrease in the coefficient of permeability from 0.00132 to 0.000176 cm/s was observed at 108 h. Biogas bubbles and bacterial plugging were the main reasons for the decrease in the coefficient of permeability and stability with the degree of saturation. By contrast, the dissolved phase was the main reason for the increase of the degree of saturation and the coefficient of permeability.Va/Vao decreased from 1.0 to 0.95, and a small number of bubbles spilled over the sand specimen. However, the degree of saturation of the sample decreased from 84.3% to 83.8% because of the settlement of the sample and the increase of its relative density during the test.After 41,200 cycles of vibration,


DNA damage in age‐related diseases. Brain senescence has been described in astrocytes and microglia, but it is less well understood in neurones. Evidence suggests that neurones activate a senescence‐like mechanism that could contribute to neurodegeneration. We aimed to determine whether a persistent DNA damage response (DDR) and senescence activation are features of motor neurone disease .Cellular senescence plays a role in organismal ageing and has been linked to persistent DNA damage markers (8‐OHdG and γH2AX) in motor cortex (MCx), frontal association cortex (FACx) and occipital cortex (OCx) in post‐mortem tissue donated by patients with ALS/MND and controls.We examined expression of senescence (p16 and p21) and GFAP) suggested that some of these cells were GFAP+ astrocytes. p21 nuclear expression was also found in neurones. Higher levels of p16+  and p21+  cells were found in the FACx of ALS/MND donors but not in the MCx or OCx. Expression of p16 and p21 did not correlate with 8‐OHdG or γH2AX.Nuclear expression of p16 and p21 was detected in glial cells; double immunofluorescence for p16/p21 and glial fibrillary acidic protein (FACx of ALS/MND donors could indicate senescence activation and cell cycle dysregulation in early stages of the disease.Expression of p16 and p21 in glia, mainly in astrocytes, suggests senescence induction in these cells; however, neuronal p21 expression might reflect a more general mechanism of age‐related cell cycle dysregulation. The significantly higher proportion of cells expressing either p16 or p21 in the  Cellular senescence is the loss of replicative capacity in mitotic cells that occurs in response to different stimuli, including oncogene activation, oxidative stress and DNA damage in vitro conditions. In this study, the expression of p21 and IL‐6 production, one of the SASP components, correlated with DNA damage accumulation in Purkinje neurones of ageing mice. Moreover, the frequency of senescent‐like neurones increased with the age of the mice, linking this mechanism in neurones to ageing in vivoSenescence in the ageing brain has been described in astrocytes and microglia, suggesting that this mechanism could contribute to the disruption of the glia–neuron interaction through the SASP and to the development of age‐related brain pathologies We have investigated the expression of senescence markers in the brain of patients with ALS/MND, an age‐related disorder characterized by motor neurone degeneration in the motor cortex, brainstem and spinal cord, resulting in progressive muscle weakness eventually leading to death Formalin‐fixed paraffin‐embedded (FFPE) and frozen tissue samples of motor cortex (MCx), frontal association cortex (FACx) (Brodmann area 8/9) and occipital cortex (OCx) from ALS/MND and control donors were obtained from the Sheffield Brain Tissue Bank (SBTB). Formalin‐fixed paraffin‐embedded blocks from the three regions were available for 10 ALS/MND cases and for nine controls. Frozen blocks from the MCx and FACx were available for eight ALS/MND patients and five MCx and four FACx controls. The cohort consisted of 16 male and seven female control donors  and six male and four female ALS/MND donors . The mean post‐mortem delay (PMD) for controls was 27.66 h (range 5–75 h) and for the ALS/MND group was 35.62 h (range 9–96 h). No record of PMD was available for two ALS/MND donors and for seven controls. One of the donors included in this study was diagnosed with frontotemporal dementia (FTD)‐ALS/MND. Detailed information about the ALS/MND and control donors is shown in Table 2O2/methanol for 20 min at room temperature (RT). After antigen retrieval, sections were incubated in 1.5% normal serum for 30 min at RT, followed by incubation with the respective primary antibody. A summary of the primary antibodies, all commercially available and optimized for this study, and their conditions of use is shown in Table Immunohistochemistry for p16, p21, γH2AX and 8‐OHdG (8‐hydroxydeoxyguanosine) was performed on FFPE tissue using a standard avidin‐biotin horseradish peroxidase enzyme complex method , and the signal was visualized using 3,3′‐diaminobenzidine (DAB) . Briefly, 6‐μm sections were deparaffinized and rehydrated to water. Endogenous peroxidase activity was quenched by incubation of the sections in 0.3% HTo determine whether glial cells expressing p16 and p21 were astrocytes, double immunofluorescence against p16 or p21 and glial fibrillary acidic protein (GFAP) was performed. For this, 8‐μm frozen sections were fixed in acetone and incubated with 0.2% glycine. Sections were blocked with normal serum (1.5%) for 30 min at RT, followed by an overnight incubation at 4°C with rabbit anti‐GFAP and mouse anti‐p21 or mouse anti‐p16. Sections were then washed and incubated with Alexa Fluor fluorescent secondary antibodies  goat anti‐mouse  and donkey anti‐rabbit  for 1 h at RT. Sections were incubated with Hoechst 33342 solution  to stain the nuclei before mounting with Fluoromount Mounting Media . Double immunofluorescent staining was also performed to confirm the expression of p21 in neurones. For this, acetone‐fixed frozen sections were incubated with rabbit anti‐NeuN (which recognizes nuclear and cytoplasmic NeuN isoforms) and mouse anti‐p21 or mouse anti‐p16 following the protocol described previously. Every run included single‐labelled sections that showed the same staining pattern as seen in the double‐labelled sections. Details of the antibodies used for immunofluorescence experiments are specified in Table et al. + glial cells did not differentiate between glial cell types. 8‐OHdG staining was scored following the same protocol, cytoplasmic staining was not assessed as positive, and only clearly visible neuronal nuclei were quantified. All counts were conducted by two independent observers.For each case, images from the MCx, FACx and OCx were captured in a belt‐transect pattern, from layer II to the white matter border, as described by Armstrong + nuclei was performed in the MCx and FACx, using Analysis˄D software . The number of γH2AX+ neuronal nuclei was determined using a size exclusion of >10 μm (500 pixels), and the number of positive small nuclei (glia) was determined by subtracting the number of pyramidal neuronal nuclei from the total number of positive nuclei. To assess the total number of cells (neurones and glia), the same detection protocol was applied to haematoxylin‐only stained sections, which allowed the determination of the percentage of immunopositive cells .Images were captured in a belt‐transect pattern using the 20X objective, excluding layer I, as described in the previous section. Quantification of the total number of γH2AXr = Z/√N, where r represents the effect size, as proposed by Fritz, Morris and Richler r were used for interpretation of the data rs).Statistical analyses were performed using IBM SPSS Statistics v22. Comparisons between ALS/MND and control groups were done using Mann–Whitney U‐test nonparametric analysis. The effect size was calculated using the formula P = 0.695), and there was no difference in mean PMD (P = 0.613). None of the markers here assessed correlated significantly with age or PMD  were identified throughout the grey matter in the MCx and FACx of ALS/MND    of the difference in the percentage of p16+ glia in the FACx between groups.Having identified expression of senescence biomarkers in astrocytes and neurones in our cohort, we then quantified the number of cells expressing these markers to establish whether there was a difference between ALS/MND and control donors. For this, the percentages of p21) Figure , but no ) Figure . To furts P = 0.0  and p21+ neurones (P = 0.008) was again found in the FACx of ALS/MND donors when compared to controls, but no difference was detected in the MCx   of the difference in the percentage of p21+ glia in the FACx between groups and a large effect size (r = 0.605) in the percentage of p21+ neurones in the FACx between ALS/MND and control donors.Quantification of p21 P = 0.00 and p21++ glial cells and p21+ glia/neurones in the OCx did not reveal a significant difference in the percentage p16+ glia (P = 0.968), p21+ glia (P = 0.780) or p21+ neurones (P = 0.661) in ALS/MND cases when compared to controls.Quantification of p16+ cells was localized in both ALS/MND and control donors, in the MCx and FACx . Moreover, quantification of γH2AX+ showed no difference in the percentage of positive neurones in ALS/MND cases either  , and for further analysis, the mean of the two observers’ measures was used. The percentage of 8‐OHdG+ nuclei of pyramidal neurones in ALS/MND and control donors did not differ significantly in the MCx (P = 0.968) and in the FACx (P = 0.243)  is an area that can develop neuroglial inclusions in ALS/MND but at lower prevalence than motor areas, reflected in recent pathology staging approaches + neurones and p16/p21+ glia in the FACx of ALS/MND donors could reflect DNA damage‐related cell cycle dysregulation and a glial senescent‐like mechanism in early stages of ALS/MND.Quantification of p16/p21+ neurones in control donors may be attributed to the accumulation of ROS due to ageing and other disease processes. It remains possible that the degree of neuronal DNA oxidation could be different between ALS/MND cases and controls, but the immunohistochemical detection of 8‐OHdG provides only limited, nonlinear, quantification.The expression of 8‐OHdG, a biomarker of oxidative stress in neurodegeneration, confirms that oxidative DNA damage is a prominent feature of both control and ALS/MND cases, where it localizes to the nuclei and cytoplasm of pyramidal neurones, small neurones and glial cells, suggesting the oxidation of nuclear DNA, mitochondrial DNA and RNA. Several studies have identified increased oxidative stress in ALS/MND, which contributes to the pathology of the disease in vitro and in vivo+/γH2AX+ and p21+ neurones or p16+/p21+ glia in ALS/MND.As DNA oxidation induces a DDR, levels of γH2AX were also investigated. Phosphorylation of the histone variant H2AX at Ser139 is an important event in the initiation of the DNA repair response, and since it correlates well with the formation of double‐strand breaks, it has been widely used as a DNA damage biomarker Human post‐mortem tissue studies have a number of limitations, including intrinsic interindividual variability and post‐mortem factors, such as PMD. We did not find a significant association between the levels of senescence and DNA damage markers and the PMD of our cases. The relatively small cohort size could have had an effect on our results by masking differences between groups for levels of DNA damage and senescence. Additionally, our ALS/MND group was not homogeneous; it included sporadic and familial cases, some of which were diagnosed as C9orf72 positive. This could have impacted our results, but when looking at the DNA damage and senescence marker expression in relation to these two variables, we did not find a significant effect within the ALS/MND group. Finally, we did not conduct an analysis of DNA damage and senescence in relation to cognition since information on the cognitive profile of the ALS/MND group was not available. In order to address these limitations, a much larger study of the relationship of DNA damage and senescence to cognitive decline in ALS/MND patients and to specific ALS/MND genetic subtypes would be of value.In conclusion, we show that glial cells, mainly astrocytes, express p16 and p21, both biomarkers of cellular senescence, in ALS/MND and control brains; neurones, on the other hand, only expressed p21. This could suggest activation of senescence pathways in astrocytes and altered cell cycle in neurones, both mechanisms linked to ageing and the DDR. Moreover, the significantly higher percentage of p16‐ and p21‐positive cells in the FACx of ALS/MND donors could suggest an early involvement of senescence and cell cycle dysregulation in the progression of the disease. Finally, since heterogeneity of the cohort could have affected the study of DNA damage and its relation to senescence markers, further analysis of these mechanisms could be performed in sporadic and familial ALS/MND cases separately, against controls.FFPE and frozen tissue samples were obtained from the Sheffield Brain Tissue Bank (SBTB) following Research Ethical Committee Approval (REC ref 08/MRE00/103).The study was conceived by SBW and JES. IVV planned and carried out the immunohistochemistry experiments and wrote the first draft of the paper. IVV and JES performed the quantitative analyses, and IVV and SBW carried out the statistical analysis. CJG, PRH and PGI provided advice and guidance. All of the authors contributed to supervision of the project and to the final version of the manuscript.There are no conflicts of interest to disclose.Figure S1. Detection of senescence markers in the MCx, FACx and OCx of control donors. p16 immunoreactivity was exclusively associated with glial cells, more likely reactive astrocytes (arrows) . p21 immunoreactivity was detected in neurones (arrowheads) and glial cells (arrows) . Scale bar represents 50 μm.Click here for additional data file.Table S1. DNA damage and senescence markers in neurones and glia did not correlate with age or PMD. Summary of correlation coefficients and p values obtained from the correlation analysis between DNA damage/senescence markers and age/PMD. Abbreviations: FACx, frontal association cortex; MCx, motor cortex; OCx, occipital cortex; PMD, post‐mortem delay; 8‐OHdG, 8‐hydroxy‐2′‐deoxyguanosine.Click here for additional data file.


In this paper, we have developed a new approach to construct a distributed Hippocratic video database system for supporting more profitable online patient training and counseling. First, a new database modeling approach is developed to support concept-oriented video database organization and assign a degree of privacy of the video content for each database level automatically. Second, a new algorithm is developed to protect the video content privacy at the level of individual video clip by filtering out the privacy-sensitive human objects automatically. In order to integrate the patient training videos from multiple competitive organizations for constructing a centralized video database indexing structure, a privacy-preserving video sharing scheme is developed to support privacy-preserving distributed classifier training and prevent the statistical inferences from the videos that are shared for cross-validation of video classifiers. Our experiments on large-scale video databases have also provided very convincing results.Digital video now plays an important role in supporting more profitable online patient training and counseling, and integration of patient training videos from multiple competitive organizations in the health care network will result in better offerings for patients. However, privacy concerns often prevent multiple competitive organizations from sharing and integrating their patient training videos. In addition, patients with infectious or chronic diseases may not want the online patient training organizations to identify who they are or even which video clips they are interested in. Thus, there is an urgent need to develop more effective techniques to protect both  I.access privacy and video content privacy. Unfortunately, no comprehensive framework is available today to address the following inter-related issues effectively.To save the huge cost for national health care plan, online patient training and counseling are becoming very attractive by using digital videos to educate patients on early detection and self-treatment of their life-threatening diseases Privacy-preserving video database indexing and retrieval: To integrate the patient training videos from multiple competitive organizations for supporting more profitable online patient training and counseling, there is an urgent need of constructing a centralized indexing of the distributed video content Hippocratic databases should include responsibilities for both the data privacy and the access privacy.1) Privacy-preserving video sharing for distributed classifier training: Classifying the video clips into a set of semantic video concepts is one promising approach to achieve concept-oriented video database indexing and access 2) Many techniques have been proposed recently to support privacy-preserving data sharing and mining Video content privacy protection: The content privacy for the patient training videos consists of two major parts: a) privacy for the human objects who are shown in a video as the professional patient trainers or doctors; and b) privacy for the human objects who are shown in a video as the patients to illustrate the relevant clinic examples. When the patient training videos are released to the authorized patients or other parties, the video content privacy is disclosed 3) To address these issues more effectively, we have developed a new system for supporting privacy-preserving online patient training and counseling and its major components are given in II.The video clips are first partitioned into a set of video shots automatically 1) Automatic image segmentation is first performed on each video frame to obtain the homogeneous image regions 2) The human face regions are then located by using traditional face detection techniques 3) The region relationship graph of object seeds  is then matched with the region constraint graph of human object (that is used for designing the human object generation function). If they are in good matching, the relevant image regions relevant are then aggregated to detect the human objects 4) The detected human objects are then tracked among the video frames within the same video shot.Obviously, our human object detection function may fail in obtaining the meaningful human objects in some cases. To address this issue, two approaches can be used to improve human object detection: a) human–system interaction can be involved for defining the regions of human objects interactively distributed Hippocratic video database system for online patient training and counseling requires a well-defined database model for video indexing and privacy protection concept ontologyA successful implementation of a atomic video concepts. Thus, the database nodes for the semantic video concepts at a lower semantic level can characterize more specific aspects of video content and they are easier to release the video content privacy and may have higher degree of privacy. To extract the text terms for semantic video concept interpretation, automatic entity extraction is first performed on large amounts of medical documents and medical experts are further involved to select the most meaningful video concepts interactively, so that these semantic video concepts are meaningful for domain experts and patient training.The concept ontology consists of two components: 1) semantic video concepts; and 2) their inter-concept contextual and logical relationships. The lower the level of a semantic video concept node, the narrower is its coverage of the subjects. The semantic video concepts at the first level of the concept ontology are named as The semantic similarity context Rather than using one single kernel function to characterize the diverse visual similarity contexts between the video clips, the visual similarity context between two video clips under each feature subset is characterized more precisely by using one particular basic kernel function. Finally, a mixture-of-kernels is used to integrate all these three basic kernel functions  to characterize the diverse visual similarity contexts between the video clips more precisely For two semantic video concepts The parameters The inter-concept visual similarity context advantages of our approach for concept-oriented video database modeling and organization include: 1) by using the concept ontology for semantic video concept organization degree of privacy of video content for each database level automatically. The lower-level video concepts on the concept ontology are used to describe more specific video content, thus, they are easier to release the privacy of video content and higher degrees of privacy should be assigned automatically.The III.privacy-preserving SVM classifier training. Because the patient training videos , our algorithm takes the following steps: 1) one weak SVM video classifier is learned locally at each party by using its own training videos; and 2) these To learn the classifiers collaboratively and assign the patient training video clips into the most relevant semantic video concepts automatically, we assume that there have It is important to note that some common video clips may appear among these one-against-all rule is used to label the training videos For a given video concept For each party on the collaboration network, one weak SVM classifier is first learned by using its own labeled videos. For the positive videos original support vectors to inference the confidential information for other parties on the collaboration network, e.g., the dishonest parties may integrate such original support vectors and their own video clips to inference the privacy of other parties . There are two conflicting issues that must be addressed for achieving privacy-preserving SVM classifier training. On the one hand, sharing the original support vectors may leak confidential information of the original videos. On the other hand, the support vectors are used to interpret the underlying decision boundaries of the relevant week SVM classifier and characterize the principal properties of the original videos for the corresponding party, and thus sharing the original support vectors is critical for collaborative learning of the complete SVM classifier.To incorporate the diversified videos from multiple parties for collaborative SVM classifier training, each party in the collaboration network has to share its support vectors with other parties. However, sharing the original support vectors with other parties is undesirable from privacy perspective, because the dishonest parties may leverage such synthetic support vectors. The synthetic support vectors are automatically generated from the original support vectors, and are used to approximate the decision boundaries  interpreted by the original support vectors advantages: 1) using the synthetic values  to replace the original support vectors can effectively protect the video privacy because the shared synthetic support vectors are not extracted from the original videos; and 2) the synthetic support vectors can precisely preserve the underlying SVM decision boundaries that are interpreted by the original support vectors, and thus, they can be used to learn the complete SVM classifier.Based on this observation, we have developed a distributed framework to enable privacy-preserving SVM classifier training by generating and sharing synthetic support vectors from the original support vectors by preserving the decision boundaries for the relevant weak SVM classifier. By replacing support vectors.The main problem for automatically generating such synthetic support vectors is to provide sufficient protection of the privacy for the individual value of each original support vector without damaging the important information  interpreted by the original support vectors. Based on this understanding, we have developed a novel framework to automatically generate the synthetic SVM classifierTo generate the synthetic support vectors from the available weak SVM classifier In our current implementation, we have incorporated a novel iteration approach to generate the synthetic support vectors from the set of the original support vectors by minimizing the criterion function 1) The first approximation, that is, 2) Once the first approximation of Once the synthetic support vectors are available, the coefficient complete SVM classifier can finally be achieved by incorporating the synthetic support vectors for incremental SVM classifier training.By performing the above iterations, we can automatically generate a set of synthetic support vectors automatic benefit/risk negotiation. The outputs of our automatic benefit–risk negotiation scheme is further incorporated to control the procedures for synthetic support vector generation and sharing. Thus, each party in the collaboration network is able to generate and share different versions of the synthetic support vectors with different levels of approximation efficiency for different parties or the same party at different negotiation loops according to their individual negotiation agreements.In order to achieve an acceptable tradeoff between the approximation accuracy , the generation and transmission cost, and the privacy disclosure risk, we have developed a computational scheme to enable approximation efficiency  is defined as We have developed a computational approach to achieve a good balance between the approximation efficiency, the generation and transmission cost, and the privacy disclosure risk. The To illustrate the approximation efficiency, one synthetic dataset is used . This synthetic dataset consists of four spiral data groups found in pattern classification toolbox From the experimental results shown in re-identification disclosure risklinkage disclosure riskconfidentiality-interval inference riskinformation loss incurred by the use of the synthetic support vectors to replace the original support vectors To quantify the privacy disclosure risk Based on the above descriptions, it is very important to determine the optimal number Because different parties may obtain different versions of the synthetic support vectors with different levels of approximation efficiency from other parties in the collaboration network according to their individual negotiation agreements, they may finally learn different versions of the complete SVM classifier with different prediction powers according to their individual contributions for the given collaboration task, that is, a party by sharing more high-utility synthetic support vectors with other parties may also obtain more high-utility synthetic support vectors from other parties. Thus, each party in the collaboration network can have full control on its privacy disclosure risks and its individual benefits for data sharing. To illustrate the empirical relationship between the misclassification rate and the number of synthetic support vectors to be shared, we have tested our algorithms on multiple machine learning datasets and our results are given in To assess the effectiveness of the complete SVM classifier, it is very important for each party to share some video clips for cross-validation. After the human object detection function is available, it is then used to protect the content privacy at the individual video clip level. To filter out the privacy-sensitive human objects , digital human models  are used to replace the appearances of privacy-sensitive human objects in a video IV.By using the underlying concept models  for database node representation, our new framework for hierarchical video concept modeling and organization has provided an effective framework to enable concept-oriented video database indexing. After all the video clips are classified into the video concepts at different semantic levels, the concept ontology can further be incorporated to construct hierarchical video database indexing structure, where the nodes of semantic video concepts become the nodes of the video database at different semantic levels, upon which the root node of the video database can be constructed automatically.concept-oriented video database indexing: 1) the support vectors for semantic video concept modeling are used to characterize the statistical property of the relevant database node ; 2) the concept ontology can be incorporated to determine the hierarchical structure for video database indexing ; and 3) each database node is jointly described by multiple parameters such as keyword and support vectors.The following techniques have been used to support degree of privacy for each database level. The degree of privacy is defined as a monotonically increasing function of the sensitivity of video content, and thus the degree of privacy for the To achieve a good balance between the access privacy and the access efficiency, we have developed a novel technique to assign the When the degree of privacy When the degree of privacy When the degree of privacy After the privacy-preserving video database indexing structure is available, it is used to support more effective semi-private video retrieval over large-scale video databases. To prevent the participating video providers from tracking the patients' access interest, each video clip for online patient training is distributed on To reliably assure the access privacy, our distributed Hippocratic video database system is able to allow the patients to submit degree of privacy for the In order to prevent the video providers in the health care network from tracking the traversal path of a particular query, the access redundancy is introduced when the disclosure of access privacyTo achieve a good balance between the access redundancy  and the access privacy, we can define the The access redundancy By quantifying the disclosure of access privacy and the access redundancy, the problem for enabling low-cost semi-private video retrieval reduces to choosing the appropriate values for V.algorithm evaluation focuses on: 1) evaluating the performance of our distributed framework for privacy-preserving classifier training; 2) evaluating the performance of our privacy-preserving video database indexing structure; and 3) evaluating the performance of our private video retrieval framework.Our experimental benchmark metric for the classifier evaluation includes precisionrecallThe To evaluate our distributed framework for privacy preserving classifier training, the video set is partitioned into three individual groups and weak classifier training is first performed on these three individual data groups independently. The complete SVM classifier is then learned from the shared weak classifiers and the synthetic support vectors. One advantage of our distributed framework for privacy preserving classifier training is that it is able to control the privacy breaches by sharing different numbers of synthetic support vectors. Because these support vectors are used to approximate the decision boundaries of the complete SVM classifier for the given semantic video concept, sharing different number of support vectors can achieve different versions of the complete SVM classifier with different classification accuracy rates. Thus, a good balance between the disclosure of private information and the classification accuracy rate  can be achieved effectively by sharing different resolutions of these weak classifiers. Based on this understanding, we have obtained the empirical relationships between the quality of the complete SVM classifier  and the privacy disclosures as shown in For validating the complete SVM classifier at the central site, each video provider has to share not only his/her weak classifier but also a limited number of blurred test videos. To prevent statistical inferences To evaluate our framework for privacy-preserving video database indexing and private video retrieval, we have also tested our distributed Hippocratic video database system with 400 h medical education videos and our experimental results are given in We have also compared the differences on the transmission costs between our proposed framework and the perturbation and SMC approaches. The transmission cost is defined as the percentage between the number of shared videos and the total number of videos that are needed for achieving accurate classifier training. As shown in VI.To enable privacy-preserving video sharing among multiple competitive video providers, we have developed a novel framework able to both protect the video content privacy and control the statistical inferences. By detecting the privacy-sensitive human objects automatically, our algorithm is able to effectively protect the video content privacy at the level of individual video clip. By determining the optimal size of blurred test videos for classifier validation, our proposed framework for privacy-preserving distributed classifier training is able to not only limit the privacy breaches but also improve the classifier's accuracy significantly. Our experiments in a specific domain of patient training videos have also provided very convincing results.http://ieeexplore.ieee.org.Color versions of one or more of the figures in this paper are available online at


In games of chance, a near miss is said to occur when feedback for a loss approximates a win. For instance, obtaining “cherry–cherry–lemon” on a slot machine could be considered a near miss. Sixty-six years ago, B.F. Skinner first proposed the idea that near-miss events might reinforce continued play in slot machines, and despite some inconsistencies in the experimental literature, belief in this “near-miss effect” has remained strong. In the present manuscript, we will review this literature and present experimental assessments of the near-miss effect on the frequency of the gambling response. Experiment 1 used a tightly controlled resistance-to-extinction procedure in pigeons to evaluate the putative reinforcing effect of near misses relative to a control “far-miss” reel pattern. Experiment 2 extended Experiment 1’s procedure to human participants. The results of both experiments failed to support the near-miss effect hypothesis. Experiment 3 used a further simplified procedure to assess the validity of the resistance-to-extinction paradigm when a probable conditional reinforcer was present on the reel stimuli. Although a clear conditional response was obtained from the reel, subsequent testing in extinction revealed no conditionally reinforcing function of this stimulus on operant response frequency. Near misses, also called near hits or near wins, are said to occur when the elements of a game or task “suggest” to a player that they have almost achieved a favourable result. A good example is provided by Witts et al. : consideNear misses also occur in games of chance, but the crucial difference is that in a game of chance the outcome is a random event. On a standard slot machine, if a win is signalled by “cherry–cherry–cherry,” then “cherry–cherry–lemon” would be considered a near miss. Modern slot machines contain a pseudo-random number generator (RNG) that cycles through about 4.3 billion distinct values continuously at approximately 1000 values per second. For each bet, the machine selects the cycle’s current position and outputs the correlated reel positions onto the display Schüll . Unlike The answer seems to be that the near miss is visually “nearly” a win. For example, cherry–cherry–lemon looks more similar than cherry–lemon–lemon to a win signalled by three cherries. In the case of basketball free throws, visual aspects of the situation provide helpful feedback to the player. Near-miss feedback on slot machines, however, offers no practical use for improving performance. One possibility is that the visual aspect of the near miss is exploiting learning processes—most notably conditional reinforcement—that evolved to detect contingent  outcomes. In this manuscript, we will first review the existing literature pertaining to the reinforcing effect of near misses on gambling persistence, and then we will present the results of experiments specifically designed to test possible reinforcing effects of near-miss stimuli on gambling persistence in both humans and pigeons.near-miss effect—the belief that near-miss events contribute to an increased frequency of gambling. More formally, we define the near-miss effect as a reinforcing function of near-miss events on total frequency of play in games of chance. Skinner’s original hypothesis rested on two critical factors: (1) that conditional reinforcement is based on pairing , and (2) that near misses do in fact increase the frequency of betting responses. When Skinner proposed this, the available evidence largely supported a pairing account of conditional reinforcement, and the reinforcing effect of near misses was a sensible a priori prediction. Subsequent research, however, has shown that the pairing account is inadequate since it ignores nuances that influence and characterize this type of learning  or locally . From a global view, the conditionally reinforcing effect of win-related stimuli may generalize better to near misses than to other, more dissimilar, misses . While this finding is consistent with a stimulus generalization account of near-misses, it should not be ignored that the critical extinction measure on the more relevant roll lever produced no such effect. Earlier research using similar methods likewise found no increase in persistence on the roll lever  and physiological responses , there have been surprisingly few direct experimental tests of the presumed reinforcing function of near misses on gambling persistence. Effects on subjective motivation or physiological responses are consistent with a reinforcing effect on gambling frequency, but without a direct behavioral measure they do not actually demonstrate such an effect. For example, Dymond et al.  found thA few experimental studies are frequently cited for providing evidence that near misses have a reinforcing function. Strickland and Grote  found thMore recently, Kassinove and Schare  manipulaIn another well-cited study, Cote et al.  had partAn experiment by MacLin et al.  gave recOther studies that did not employ persistence-based methodologies have found similarly varied results ranging from support  were randomly selected from a University of Alberta colony room for the experiment. A sample of eight pigeons was used, which is the same as employed in Stagner et al.  to detect pecking responses. Stimuli were presented on a centrally-mounted 17” Viewsonic LCD monitor located at the back wall of each chamber. Speakers in the operant boxes continuously played white noise to mask external sounds. The sound pressure levels were equalized in each operant box at 65 dB via A-weighting filter with a Brüel and Kjær Type 2239 Integrating Sound Level Meter. Two 2 × 2 in. feeding ports equipped with food hoppers, flanked the monitor. Access to food was controlled by Colbourne H20-94 photocell sensors that detected entry into the ports. Stimuli were presented and responses were logged using E-Primewin occurred when all three circles were red. A near miss occurred when only the left and middle circles were red. A flanked miss occurred when only the left and right circles were red. A far miss occurred when only the middle and right circles were red. Finally, a single miss occurred when only one circle was red. On single misses, each of the three locations had an equal chance of turning red. Non-illuminated circles were left black. Experiment 1b was identical but with the exception that the non-illuminated circles were coloured blue. For example, a trial displaying a far-miss would be presented as blue–red–red, with the blue signalling non-reinforcement. We denote red circles as putative SD stimuli  and blue circles as putative SΔ stimuli .Stimuli were presented on a black background and were aligned behind the holes cut in the barrier. A white pecking circle was presented at the smaller 1 in. hole. The win and miss patterns  were presented at the upper three circles. For Experiment 1a, each reel pattern consisted only of those elements comprising the winning reel pattern, which was displayed as three red circles. A Reels were always presented sequentially from left to right with a 600 ms interval between each presentation. For instance, this was the sequence of events on a ‘winning’ trial: following a peck to the white circle, the white circle disappeared. After 600 ms, the left reel appeared. Then, the middle and right reel each appeared in sequence with a 600 ms interval between each presentation. In total, the sequence was 2.4 s long. Then, the right or left hopper (randomly chosen) rose to provide 1 s access to food pellets  with the reels remaining on screen during this period. Finally, the reels reset to black and the white pecking circle returned to occasion the start of the next trial. On all loss trials, each of the intervals still occurred whether or not a red circle appeared so that the total sequence was always 2.4 s long. The reels then reset back to black and the white pecking circle reappeared following the last 600 ms interval. Thus, with the exception of the initial autoshaping phase in this and the subsequent experiments, there were no intertrial intervals following either the win or the loss trials. Figure All procedures for the care and use of animals were in accordance with the ethical standards of the University of Alberta, Canadian Council on Animal Care, and were approved by the Bioscience Animal Care and Use Committee (Protocol AUP00002018).near-miss and far-miss treatments. The order of these treatments for each subject was randomly determined according to a Latin square design . Each treatment was preceded by a pre-exposure phase comprised of three components. Only one handler conducted the experimental sessions to further reduce sources of unsystematic variation that can occur in extinction-based designs. Additionally, because the noise of hoppers in adjacent operant chambers might confound the measures taken during periods of extinction, all pigeons had their extinction sessions yoked to occur at the same time and day as other pigeons concurrently running in the experiment.The experiment was structured as a repeated-measures design with two treatments: the In the pre-exposure phase, the subjects began on a basic autoshaping procedure . The 2400 ms interval was still implemented after every response. Following one session of FR3, the schedule was extended to a FR6 for one more session. This procedure was followed for all birds with the exception of Bird 76 in Experiment 1b, who displayed unusually low responses after being moved to the FR1 schedule. Autoshaping was reinstated until high rates of responding on the FR1 schedule occurred. Due to the necessity of yoking the extinction sessions, the FR3 and FR6 conditions were skipped in the first half of Bird 76’s sessions to allow for maximal exposure to the contingency in the last pre-exposure component.In the final pre-exposure component, subjects were put on a random-ratio 5 (RR5) schedule. Similar to a variable-ratio (VR) schedule, a RR schedule typically contains an average response requirement. However, unlike a VR schedule, a RR schedule is determined by pseudo-random number generation as opposed to a predetermined number of reinforced and nonreinforced trials .t test on the cumulative number of responses made during extinction. An effect size was calculated using an unbiased estimate of Cohen’s d  using a medium prior was calculated  in extinction than the corresponding far-miss control treatment . However, the difference between the two treatments was not statistically significant, nor was the obtained Bayes Factor meaningfully large, t(7) = − 1.68, 95% CI , p = .136, d = 0.53, BF10 = 0.92.The results of Experiment 1a are depicted in the top row of Fig. M = 677.88, 95% CI ) exhibited marginally more responses during extinction than the corresponding far-miss control treatment , t(7) = 1.44, 95% CI , p = .193, d = 0.45, BF10 = 0.73.The results of Experiment 1b are depicted in the bottom row of Fig. Overall, the results of both Experiment 1a and 1b failed to provide evidence that near misses have a conditionally reinforcing function on the gambling response. However, it may be the case that the supposed near-miss effect is a uniquely human phenomenon and does not apply to non-human or non-primate organisms. While the literature on operant conditioning seems at odds with such a hypothesis, given the strong reliability of reinforcement processes across numerous species, the possibility should nonetheless be considered. The animal-based literature has, in most cases, failed to straightforwardly demonstrate the reinforcing nature of near-miss stimuli whereas the human-based literature has been, at least occasionally, successful. Given this, Experiment 2 adapted and applied Experiment 1a and 1b’s procedure to human participants.Homo sapiens) were recruited from the research participant pool of introductory psychology courses at the University of Alberta. The sample consisted of 192 females and 104 males, with a mean age of 19.3 years. Of these, N = 178 were used in the final analyses (see results section for details on exclusion criteria). A projected sample size of at least 128 subjects, post exclusion criteria, was determined using the G*power 3.1. computer program  at an 80% power level for detection of main effects and interactions. Participants were incentivized with partial course credit and a small monetary bonus of up to $9.50 CAD that depended on their final earnings. Sessions were conducted in a space containing fifteen individual testing rooms located around the perimeter. The task was completed on a computer with a mouse and keyboard. E-Prime® 2.0 Professional software was used to present stimuli and record responses.A total of 296 participants  and were in accordance with the Tri-Council Policy Statement on the Ethical Conduct of Research Involving Humans.Participants read an information and consent form. After signing a form to provide their consent for participation. They were assigned to individual testing rooms and instructed to begin. After being prompted to enter their age and sex on the computer, a brief set of instructions was presented to them on screen for a minimum of 1 min. Instructions told participants to try and earn as much money as possible. It also informed them that they could stop playing at any time to collect their money.SD group only saw red circles in the reel patterns, and participants in the SD&S∆ group saw both red and blue circles but only red circles signalled wins. The treatments were also similar to Experiments 1a and 1b: near misses or far misses replaced the wins during extinction.Participants were assigned randomly to one of two groups and then further randomly assigned to one of two treatments. Groups were analogous to Experiments 1a and 1b: participants in the Experiment 2’s pre-exposure phase was similar to the third component of the pre-exposure phases from Experiment 1. The first 15 trials were structured such that the first, fifth, and eleventh trials were wins. This was to prevent participants from encountering an early string of losses that could possibly occur due to the RR schedule and produce a negative monetary score. The remaining 285 trials proceeded according to a RR5 schedule, with the probabilities of all outcomes being equated every 15 trials. Participants began with $0.50 and their score was always shown at the bottom of the screen. It cost participants $0.05 for each play on the response key and this was immediately deducted from their score. Wins awarded $0.40 and they were signalled by the appearance of “Win! +40¢” in large bright yellow text beneath the response key.The treatment phase occurred after 300 trials, at which point plays on the response key were put on extinction: clicking it still cost $0.05 but doing so no longer produced wins. Participants in the near-miss treatment had the wins replaced by near misses and participants in the far-miss treatment had wins replaced by far misses. Unlike some other extinction-based studies (Kassinove and Schare SD group (n = 91), there were 28 females and 16 males assigned to the Near Miss treatment and 36 females and 11 males assigned to the Far Miss. Within the SD&S∆ group (n = 87), there were 26 females and 19 males assigned to the Near Miss treatment and 30 females and 12 males in the Far Miss. The remaining, 118 (40%), participants did not make it to the extinction phase of the experiment. Of these, 48% were in the SD group and 52% were in the SD&S∆ group. As in Experiment 1, analyses were conducted on the cumulative number of responses made during extinction using R 3.5.0  were obtained for each main effect and interaction term. A corresponding JZS Bayes Factor showing the relative odds of each term against the model’s intercept is also reported  continued through to the extinction phase. Within the F = 2.12, p = .148, f = 0.11, BF10 = 0.42, and stimulus group (SD vs. SD&S∆), F = 0.01, p = .92, f = 0.01, BF10 = 0.16. A non-significant interaction between miss type and stimulus group was also obtained, F = 1.49, p = .22, f = 0.09, BF10 = 0.03.Figure absence of evidence for a conditional reinforcement effect. However, if it can be shown that an effect analogous to the near-miss effect in extinction could not be obtained despite the presence of a probable conditional reinforcer, then that would be indicative of evidence of absence for enhanced persistence of conditional reinforcers in extinction. Experiment 3 took advantage of the fact that discriminative stimuli  will frequently also acquire respondent conditioned stimulus (CS+) functions due to their contingent relationship with unconditional reinforcers . For instance, food predictive stimuli will often elicit consummatory responses in animals. In the case of pigeons, this usually takes the form of pecking at the food predictive stimulus with an open beak .Like Experiment 1, a repeated-measures design with two treatments was used and the order the treatments was randomly determined by a Latin square . Subjects began on a three-component pre-exposure phase followed by a treatment phase. In all phases, the sessions lasted for 90 min or 200 food reinforcements, whichever occurred first. If a bird obtained all 200 reinforcements before the 90 min had elapsed, it remained in the box with an inoperative blank screen. Only one handler conducted the experimental sessions during the treatment phase to reduce unsystematic variation.D or S∆ feedback stimulus (indicating reinforcement and nonreinforcement respectively) was displayed for 2400 ms at the center hole of the upper three circles in the plastic barrier. Following SD presentations, the bird was given 1 s to access food, during which the SD remained present (delayed conditioning). The SD then disappeared concurrently with reappearance of the white response circle. Non-reinforced trials displaying the S∆ were followed immediately by the termination of S∆ and reappearance of the white response circle.The first component of the pre-exposure phase was the same as the autoshaping procedure from Experiment 1a. In the next component, the pigeons were put on a FR1 schedule for one session that reinforced responses to the white pecking circle at the lower hole in the barrier. After a single response the circle turned black and was followed by a 2400 ms interval before reinforcement was delivered. In the third component, the pigeons were moved to a pure RR2 schedule with the number of pecks determined randomly according to a 0.5 probability of any given response leading to food reinforcement. After completion of the RR2 schedule, a single SD and S∆ stimuli could consist of either a yellow circle with a thin black horizontal line intersecting it or a light blue circle with a thin black vertical line intersecting it. Half the birds were randomly selected to receive a yellow SD and blue S∆ while the other half received a blue SD and yellow S∆. To assess conditional responding elicited by the SD, pecking responses made to the SD and S∆ stimuli were recorded at the millisecond interval.The SSD80% treatment, subjects received the SD feedback stimulus 80% of the time and the S∆ feedback stimulus 20% of the time. Subjects in the SD 20% treatment received the SD feedback stimulus 20% of the time and the S∆ feedback stimulus 80% of the time. After the first extinction phase, subjects returned to the pre-exposure phase and then they completed the other treatment condition.Following five sessions on the RR2 schedule, subjects were put on a treatment phase for three sessions where responses to the white pecking circle were put on extinction. Unconditional reinforcement was removed and the proportions of feedback were modified. In the D stimulus, a discrimination index (I) for each pigeon was calculated using the equation I = SD/(SD + S∆) where SD and S∆ represent the cumulative amount of responses made respectively during each stimulus across all pre-exposure phase sessions. This was tested against a prediction of no discrimination (I = 0.5). The data were collapsed across both blocks of pre-training since there was no reason to expect an effect of order. The index means across the first and second blocks of pre-exposure corroborate this supposition. The first block obtained a mean discrimination index of M = 0.985, 95% CI  and the second of M = 0.998, 95% CI  respectively. Across all pre-exposure sessions, an extreme effect on responding to the SD relative to the S∆ was observed, t(7) = 187.73, p < 0.001, 95% CI , d = 118.90, BF10 > 150). This indicates that the presence of the SD relative to the S∆ had a strong CS+ function on pecking, a robust and critical feature of conditionally reinforcing stimuli generally  = 0.02, p = 0.985, 95% CI , d = 0.01, BF10 = 0.34, despite the strong evidence that the SD feedback stimulus functioned as a conditional stimulus during the pre-exposure phase. This strongly implies that whatever reinforcing function the reels on a slot machine may have, it is likely independent of and thus does not reliably reinforce prolonged play during a period of extinction .Statistical analyses on cumulative number of responses made during extinction were calculated as per Experiment 1. The results Fig.  showed aAt present, some of the most prominent lines of experimental evidence in favour of the near-miss effect come from a select set of studies employing extinction-based persistence tasks (Cote et al. A possible limitation of the present work is that the contingencies in effect across all three experiments’ pre-exposure phases only ever produced a net gain—a fact uncharacteristic of slot machines and casino games in general. However, this was done to maximize the possibility of generating a conditionally reinforcing effect of near misses. Even despite this net gain, around 40% of the participants in Experiment 2 opted to cash out of the experiment prior to extinction occurring, and sometimes well before the maximum payout was reached. Although this seems like a large proportion, it is worth pointing out that similar studies (e.g., Kassinove and Schare A second potential limitation is that participants were not required to risk losing their own money to play, as is the case with real-world slot machine gambling. For ethical reasons, we could not require participants to ante up with their own money, but they did risk losing money already earned by continuing to play during extinction. Indeed, many participants in both the near-miss and far-miss conditions continued to play for more than 100 trials after the extinction phase was initiated—which is consistent with the increased persistence seen following exposure to intermittent reinforcement schedules known as the partial-reinforcement effect Nevin —but thisA third possible limitation concerns the simplistic nature of the stimuli used. Slot machines generally incorporate reel spinning and all manner of varied stimuli, some of which are quite complex. The present set of experiments employed only very basic shapes, patterns, and outcomes. However, this too was by design: if near misses do produce a meaningful effect on gambling persistence, then the effect should be independent of conventional gambling stimuli, which are varied and largely arbitrary. In an effort to reduce unsystematic variation, the present studies used basic neutral stimuli and patterns that would limit pre-existing biases and make learning of the contingencies more straightforward.A fourth limitation is that certain boundary conditions might be necessary to generate the near-miss effect. That is, our studies may not have included the specific set of variables needed to produce the near-miss effect. While we do not discount this possibility, the strongest positive evidence for near-miss effects on gambling persistence (Cote et al. One potential boundary condition could be the population of participants. For example, it could be that near-miss stimuli only enhance persistence in problem gamblers, and not in non-gamblers. Some studies, for example, have found that near-miss stimuli have produced physiological or neural responses to near-miss stimuli in problem gamblers but not in non-problem gamblers (Dymond et al. Finally, there could be factors that are external to the experiment that could have undermined the extinction procedure—especially for humans. Witts et al.  commenteNear-miss research has gained much attention in recent years. Most of this research, however, has examined measures other than behavioral persistence, such as physiological reactions, response latencies, or data from questionnaires. These effects are presumed to be consistent with prolonging slot machine play, but few studies have demonstrated a reinforcing effect on persistence explicitly. If near misses are truly prolonging gambling behaviour, then why are there not numerous experimental studies that have conclusively and consistently demonstrated this effect? It is profoundly telling that decades after B.F. Skinner first acknowledged the possibility that near misses might be reinforcing gambling responses, there is still no experimental paradigm that seems able to consistently demonstrate this effect on gambling behaviour.Given that the near-miss effect on gambling persistence was founded on an early and imprecise account of conditional reinforcement Fantino , near-mi