Classification of broiler behaviours using triaxial accelerometer and machine learning.

Understanding broiler behaviours provides important implications for animal well-being and farm management. The objectives of this study were to classify specific broiler behaviours by analysing data from wearable accelerometers using two machine learning models, K-Nearest Neighbour (KNN) and Support Vector Machine (SVM). Lightweight triaxial accelerometers were used to record accelerations of nine 7-week-old broilers at a sampling frequency of 40 Hz. A total of 261.6-min data were labelled for four behaviours - walking, resting, feeding and drinking. Instantaneous motion features including magnitude area, vector magnitude, movement variation, energy, and entropy were extracted and stored in a dataset which was then segmented by one of the six window lengths (1, 3, 5, 7, 10 and 20 s) with 50% overlap between consecutive windows. The mean, variation, SD, minimum and maximum of each instantaneous motion feature and two-way correlations of acceleration data were calculated within each window, yielding a total of 43 statistic features for training and testing of machine learning models. Performance of the models was evaluated using pure behaviour datasets (single behaviour type per dataset) and continuous behaviour datasets (continuous recording that involved multiple behaviour types per dataset). For pure behaviour datasets, both KNN and SVM models showed high sensitivities in classifying broiler resting (87% and 85%, respectively) and walking (99% and 99%, respectively). The accuracies of SVM were higher than KNN in differentiating feeding (88% and 75%, respectively) and drinking (83% and 62%, respectively) behaviours. Sliding window with 1-s length yielded the best performance for classifying continuous behaviour datasets. The performance of classification model generally improved as more birds were included for training. In conclusion, classification of specific broiler behaviours can be achieved by recording bird triaxial accelerations and analysing acceleration data through machine learning. Performances of different machine learning models differ in classifying specific broiler behaviours.

Walking in a vacuum-assisted socket shifts the stump fluid balance.

Gains in stump volume have been documented in trans-tibial amputees while walking in custom made under-sized, total surface-bearing, vacuum-assisted sockets (Board et al., 2001). These gains raised doubts as to whether the sockets were truly under-sized and concerns that using an over-sized socket with vacuum-assist could lead to swelling, resulting, in discomfort or pain. The purposes of the present study were to determine if: (a) walking in a vacuum-assisted socket causes the stump to retain or gain volume in excess of the available socket volume and (b) the resulting increase in stump volume with an over-sized socket causes discomfort, pain, and/or the skin to redden. The results of this study showed the stump retained or gained volume in excess of the available socket volume while walking in vacuum-assisted sockets of various sizes. The stump lost less volume than predicted, or gained volume, in under-sized sockets. It also gained more volume than predicted in over-sized sockets. No discomfort, pain, or skin reddening, resulting from the volume gain was reported by any of the subjects after walking in an over-sized socket. This change in fluid balance towards a net gain supports the findings by Board et al. (2001) that vacuum-assist ensures a good fit during the day in ambulatory trans-tibial traumatic amputees with mature stumps.

Women and traumatic events.

Posttraumatic stress disorder (PTSD) gained the status of a psychiatric disorder in 1980, although the syndrome had already been recognized widely for many years. PTSD is distinguished by alternations between reexperiencing of the traumatic event that triggered the PTSD in the first place and avoidance and numbing. Increased arousal (e.g., exaggerated startle reaction) also forms part of the diagnosis. Although the majority of trauma victims recover spontaneously, more than 30% develop persistent PTSD symptoms, with women being twice as likely as men to suffer PTSD. To date, the most studied psychosocial treatments for PTSD are the cognitive-behavioral interventions. Exposure therapy (systematic exposure to the traumatic memory in a safe environment) has been demonstrated to be quite effective with adult women who were sexually or nonsexually assaulted in adulthood as well as with women who were sexually abused in childhood. Supportive counseling does not appear as effective as exposure therapy, but is better than no therapy.

Memory and memory confidence in obsessive-compulsive disorder.

Pathological doubt, often found in individuals with obsessive-compulsive disorder (OCD), has been theoretically linked to memory deficits, but empirical evidence for such deficits has been mixed. In contrast, many studies suggest that individuals with OCD have low confidence in their memories. The present study aimed to build upon previous research by measuring memory accuracy and confidence in OCD using ecologically valid, idiographically-selected stimuli. Individuals with OCD (OCs), anxious controls (ACs), and nonanxious controls (NACs) were exposed to a set of objects that the OCs had identified as safe, unsafe, or neutral. Participants were then asked to recall as many objects as possible and to rate their confidence in each memory. This process was repeated 6 times, using the same stimuli for each trial. Contrary to hypothesis, no group differences emerged in memory accuracy. However, OCs' memory confidence for unsafe objects showed a progressive decline over repeated trials. This pattern was not observed among NACs or ACs. Furthermore, OCs with primary checking reported lower confidence in long-term memory than did OCs without primary checking. These results suggest that when OCs are repeatedly exposed to threat-related stimuli (such as repeated checking), their level of confidence in remembering these stimuli paradoxically decreases.

Paradoxical effects of thought suppression: a meta-analysis of controlled studies.

Research has shown that attempts to suppress a thought can cause an increase in the frequency of the thought. These paradoxical effects of thought suppression play a key role in cognitive-behavioral models of several emotional disorders. Laboratory studies of this phenomenon, however, have yielded mixed results; and narrative summaries of the literature have not been able to draw firm conclusions about the effects of thought suppression. We used meta-analysis to quantitatively examine the magnitude of thought suppression effects across controlled studies. Moreover, we explored whether the variability in effect sizes could be explained by methodological differences within and between studies. Results indicated a small to moderate rebound effect of thought suppression that varied in magnitude depending on the nature of the target thought and the method by which thought frequency was measured. Participants with clinical diagnoses did not show larger rebound effects than nonclinical or analogue participants, however, only a few studies included clinical samples. Findings are discussed in terms of implications for the ironic process theory of thought suppression, and avenues for future research on this phenomenon.

A comparison of trans-tibial amputee suction and vacuum socket conditions.

Daily volume loss of the stump leads to a poor fit of the prosthetic socket. A method of preventing this volume loss and maintaining a good fit was developed. A vacuum (-78 kPa) was drawn on the expulsion port of a total surface-bearing suction socket to hold the liner tightly against the socket. Stump volume of 10 trans-tibial amputees was measured prior to and immediately after a 30 minute walk with normal and vacuum socket conditions. Under the normal condition, the limb lost an average of 6.5% of its volume during the walk. In contrast, with the liner held tightly by vacuum, the limb gained an average of 3.7% in volume. It is believed that the difference observed between conditions resulted from a greater negative pressure developed during the swing phase of gait with the vacuum condition. X-rays revealed that the limb and tibia pistoned 4 mm and 7 mm less, respectively, under the vacuum condition. The combination of reduced pistoning and maintenance of volume is thought to account for the more symmetrical gait observed with the vacuum.

A comparison of exposure therapy, stress inoculation training, and their combination for reducing posttraumatic stress disorder in female assault victims.

Ninety-six female assault victims with chronic posttraumatic stress disorder (PTSD) were randomly assigned to 4 treatment conditions: prolonged exposure (PE), stress inoculation training (SIT), combined treatment (PE-SIT), or wait-list control (WL). Treatment consisted of 9 twice-weekly, individual sessions. Independent evaluations were conducted at pretreatment; posttreatment; and 3-, 6-, and 12-month follow-ups. All 3 active treatments reduced severity of PTSD and depression compared with WL but did not differ significantly from each other, and these gains were maintained throughout the follow-up period. However, in the intent-to-treat sample, PE was superior to SIT and PE-SIT on posttreatment anxiety and global social adjustment at follow-up and had larger effect sizes on PTSD severity, depression, and anxiety. SIT and PE-SIT did not differ significantly from each other on any outcome measure.

An efficient DNA extraction method for small metazoans.

The isolation of total nucleic acids from small metazoan taxa is difficult and often leads to an unacceptably large percentage of unsuccessful polymerase chain reaction (PCR) amplifications. Our work with the evolutionary genetics of harpacticoid copepods was an incentive to refine techniques such that consistent amplifications from minute marine organisms were feasible. We describe these modifications and demonstrate their utility for the amplification of multiple loci from single harpacticoid copepods.

Technological advances in cross-country ski equipment.

Nordic skiing has a long history dating back to at least 2500 B.C. It is not surprising then that skiing equipment has undergone many changes. Today's skis, poles, and boots use the latest in space-age synthetics including carbon and Kevlar fibers, which has resulted in an unprecedented advance in ski equipment technology, producing ultralight yet strong equipment. These changes have played an important role in bringing about an improvement in racing performance with today's skiers being able to ski a course in half the amount of time that it would have taken just 60 yr ago. Estimates indicate the change in mass of racing equipment accounts for a relatively small amount (12%) of the improvement in race performance with changes in the functional characteristics of equipment, track preparation, and training practices being responsible for the remaining 88%. In addition to improvements in ski equipment, advances are being made in developing laboratory equipment used to assess an athlete's upper body power and endurance capacities. Lab testing with an arm ergometer showed its utility when it exposed a glaring deficiency in upper body power among a group of U.S. developmental skiers. Further improvement in ski equipment and lab testing tools are expected in the future as the worldwide technological revolution continues and Olympic Teams and sports science groups continue to work cooperatively.

Characterization of the heart rate response during biathlon.

Continuous heart rate recordings were obtained on elite American bi-athletes during competitions to provide a better understanding of the physiological demands of biathlon and the strategies used in approaching the shooting range. The findings demonstrate that the average age heart rate during skiing was approximately 90% of maximum heart rate. Heart rates decreased 10-12 bpm over a time period of approximately 50-60 sec during the approach to the firing line. At arrival to the firing line, heart rates were similar for prone and standing shooting averaging 85-87% of maximum heart rate. Mean minimum heart rates while at the firing line dropped to 61-73% of maximum heart rate and averaged approximately 20 bpm lower for prone shooting. The lower minimum heart rates during prone shooting were accounted for by the bi-athletes spending a longer time at the firing line and having a more rapid decrease in heart rate while in the prone position.

Quadriceps Insufficiency following Repair of the Anterior Cruciate Ligament*.

This study was originally presented at the American College of Sports Medicine annual meeting in San Diego, CA, 1984. Following repair of the anterior cruciate ligament, it is fairly typical for a patient to return to activity at approximately 12 months postsurgery. The purpose of the study was to quantify quadriceps size and function at 1 year postsurgery. Bilateral isokinetic torque measurements, tomographic scans, muscle biopsies, and anthropometrics were performed on 13 patients (3 females, 10 males) at 13 months post-surgery. The operative leg was 3% smaller in circumference, 10% smaller in total muscle area, 12% smaller in quadriceps area (all p < 0.05) and had a 9% larger subcutaneous fat area (p = 0.06). No difference in hamstrings area was seen. Isokinetic torques for the quadriceps were reduced by 11-15% in the operative leg (p < .05) with no difference seen between the hamstrings torques. Types I and II fibers were clinically smaller in both legs with the type II fibers being significantly (p < 0.05) reduced in the operative leg. It was concluded that 1) leg circumference was a poor indicator of muscle size due to the selective fat deposition in the operative leg, 2) the cross-sectional area of muscle was proportional to isokinetic torque at 240/sec, and 3) there were clinically and statistically significant isokinetic torque differences between quadriceps 13 months post-surgery.J Orthop Sports Phys Ther 1988;9(7):245-249.

Mechanical jumping power in athletes.

The Wingate cycle ergometer test is a widely used test of sustained muscular power. A limitation of the test is the lack of development and retrieval of stored elastic energy due to a lack of an eccentric phase. To measure mechanical power output of the entire stretch-shortening cycle, the test of Bosco et al (1983) was administered to 119 male athletes in 7 different activities during their pre-participation evaluations. The sports tested were indoor soccer, American football and ballet (professionals), outdoor soccer, basketball and wrestling (collegiate) and amateur bobsled. Results showed the overall average power output to be 20.37 W.kg-1 for the 60s reciprocal jumping test. Ballet dancers generated significantly less mechanical power than indoor soccer, basketball and bobsled athletes, while wrestlers generated significantly less power than indoor soccer and basketball athletes (all p less than 0.05). No other between-sport differences were seen. A subset of indoor soccer players (n = 10) were retested after 4 months of training. Power improved from 20.8 to 24.3 W.kg-1 (p less than 0.05). While between sport differences were limited, training differences in one subset of athletes were readily identified.

The dependence of protein release from Bacillus amyloliquefaciens on the growth phase in batch culture.

For the recovery of intracellular material from bacteria it is often necessary to disrupt the cells. Much work has been done on the kinetics of protein release in beadmills,(1) homogenizers,(2) and by ultrasonication.(3) In this paper we report how the growth phase of Bacillus amyloliquefaciens grown in batch culture affects the rate of protein release by ball milling, ultrasonication, and autolysis. We further suggest that autolysis is a feasible method for disrupting Bacillus.

Rapid screening of monoclonal antibodies by spin adherence double immunosorbent test (SADIST).

The spin adherence double immunosorbent test (SADIST) is a simple, rapid immunoassay with sensitivity similar to the enzyme-linked immunosorbent assay (ELISA). A 1-step SADIST has been found suitable for rapid screening of hybridomas for antigen-specific monoclonal antibodies (MAb). In this procedure hybridoma supernatants are added to antigen coated microplates followed by commercially available antiglobulin beads. The microplate is immediately centrifuged. Wells containing antigen-specific MAb produce a mat of beads whilst wells without antigen-specific MAb produce a button of beads. No washing or incubation steps are necessary and results are read within minutes of adding beads to test supernatants. By comparison, ELISA tests require several hours to perform with multiple wash steps and further reagent additions. A 2-step SADIST was also assessed. Supernatants are incubated in the microplate as for an ELISA and a wash step precedes the addition of antiglobulin beads. A panel of 117 hybridoma supernatants was selected to assess the suitability of the SADIST techniques for hybridoma screening. The supernatants were added to antigen-coated microplates and SADIST and ELISA tests performed. The SADIST correctly discriminated most hybridoma supernatants that were clearly positive or negative by ELISA. It was also found possible to perform SADIST followed by ELISA tests on the same microplate well without significantly affecting ELISA values.

Monoclonal antibodies directed against Brucella abortus cell surface antigens.

A panel of monoclonal antibodies (MAb) has been raised against Brucella abortus cell surface antigens from mice immunized with either heat/phenol treated or UV killed bacterial suspensions of B. abortus. The hybridomas were screened by either a microagglutination procedure or by an indirect enzyme immunoassay (EIA) on sonicated bacterial preparations. From a large number of MAb generated by various procedures, two distinct types of MAb emerged. The most numerous type was capable of agglutinating B. abortus and reacting with a soluble preparation of lipopolysaccharide (LPS). A second type was not capable of agglutinating the bacterial suspensions or of binding to the soluble LPS preparation but reacted with an antigen present in bacterial sonicates. Two MAb of this type react differentially with sonicates prepared from virulent and avirulent strains of B. abortus. There appeared to be sufficient evidence from our analysis of the relative degree of cross reaction with antigens present on a range of B. abortus strains and Brucella and xenogenic bacterial species to conclude that each of the seven MAb was recognising a separate antigenic site on the B. abortus cell surface.

Conducting organic materials.

Some of the current directions of scientific research on electrically conducting organic solids are reviewed. Both molecular charge transfer salts and polymers are included, with emphasis on the present level of understanding of the novel solid-state properties of these materials in terms of their chemistry and structure. For the charge transfer salts the various types of metal-to-insulator phase transitions which dominate the properties of most of these materials are discussed. Also described are the superconducting and magnetic states which have been found recently. In the case of the polymers the chemistry and physics of the conduction mechanism is examined and contrasted with that of their classical inorganic counterparts.

lsokinetic Characteristics of Ballet Dancers and the Response to a Season of Ballet Training*.

Clinical isokinetic characteristics for professional ballet artists were determined preseason and at "peak" season. Twenty-eight dancers (equal N/sex) were studied at 45, 90, and 180 per second. The data indicated that, while male relative torques were similar to other athletes previously reported, the females were lower than most other female athletes. With training, males showed virtually no change at the slow and intermediate speeds, but improved at 180 per second, while females improved at all three speeds but, significantly, only at 180 per second. Males generated significantly more torque than females and the torque-velocity characteristics between sexes were parallel. Clinical characteristics showed the dancers to have quadricep balance between legs and proportional (hamstrings/quadriceps) within legs (no effects of training on either). The data indicates that male dancers have characteristics similar to other athletes, that females are lower in relative torque than other female athletes, and that dance training affects only torque at functional velocities.J Orthop Sports Phys Ther 1984;5(4):207-211.