Behavioural plasticity and the transition to order in jackdaw flocks.

Collective behaviour is typically thought to arise from individuals following fixed interaction rules. The possibility that interaction rules may change under different circumstances has thus only rarely been investigated. Here we show that local interactions in flocks of wild jackdaws (Corvus monedula) vary drastically in different contexts, leading to distinct group-level properties. Jackdaws interact with a fixed number of neighbours (topological interactions) when traveling to roosts, but coordinate with neighbours based on spatial distance (metric interactions) during collective anti-predator mobbing events. Consequently, mobbing flocks exhibit a dramatic transition from disordered aggregations to ordered motion as group density increases, unlike transit flocks where order is independent of density. The relationship between group density and group order during this transition agrees well with a generic self-propelled particle model. Our results demonstrate plasticity in local interaction rules and have implications for both natural and artificial collective systems.

Collective turns in jackdaw flocks: kinematics and information transfer.

The rapid, cohesive turns of bird flocks are one of the most vivid examples of collective behaviour in nature, and have attracted much research. Three-dimensional imaging techniques now allow us to characterize the kinematics of turning and their group-level consequences in precise detail. We measured the kinematics of flocks of wild jackdaws executing collective turns in two contexts: during transit to roosts and anti-predator mobbing. All flocks reduced their speed during turns, probably because of constraints on individual flight capability. Turn rates increased with the angle of the turn so that the time to complete turns remained constant. We also find that context may alter where turns are initiated in the flocks: for transit flocks in the absence of predators, initiators were located throughout the flocks, but for mobbing flocks with a fixed ground-based predator, they were always located at the front. Moreover, in some transit flocks, initiators were far apart from each other, potentially because of the existence of subgroups and variation in individual interaction ranges. Finally, we find that as the group size increased the information transfer speed initially increased, but rapidly saturated to a constant value. Our results highlight previously unrecognized complexity in turning kinematics and information transfer in social animals.

Local interactions and their group-level consequences in flocking jackdaws.

As one of nature's most striking examples of collective behaviour, bird flocks have attracted extensive research. However, we still lack an understanding of the attractive and repulsive forces that govern interactions between individuals within flocks and how these forces influence neighbours' relative positions and ultimately determine the shape of flocks. We address these issues by analysing the three-dimensional movements of wild jackdaws ( Corvus monedula) in flocks containing 2-338 individuals. We quantify the social interaction forces in large, airborne flocks and find that these forces are highly anisotropic. The long-range attraction in the direction perpendicular to the movement direction is stronger than that along it, and the short-range repulsion is generated mainly by turning rather than changing speed. We explain this phenomenon by considering wingbeat frequency and the change in kinetic and gravitational potential energy during flight, and find that changing the direction of movement is less energetically costly than adjusting speed for birds. Furthermore, our data show that collision avoidance by turning can alter local neighbour distributions and ultimately change the group shape. Our results illustrate the macroscopic consequences of anisotropic interaction forces in bird flocks, and help to draw links between group structure, local interactions and the biophysics of animal locomotion.

Towards OPM-MEG in a virtual reality environment.

Virtual reality (VR) provides an immersive environment in which a participant can experience a feeling of presence in a virtual world. Such environments generate strong emotional and physical responses and have been used for wide-ranging applications. The ability to collect functional neuroimaging data whilst a participant is immersed in VR would represent a step change for experimental paradigms; unfortunately, traditional brain imaging requires participants to remain still, limiting the scope of naturalistic interaction within VR. Recently however, a new type of magnetoencephalography (MEG) device has been developed, that employs scalp-mounted optically-pumped magnetometers (OPMs) to measure brain electrophysiology. Lightweight OPMs, coupled with precise control of the background magnetic field, enables participant movement during data acquisition. Here, we exploit this technology to acquire MEG data whilst a participant uses a virtual reality head-mounted display (VRHMD). We show that, despite increased magnetic interference from the VRHMD, we were able to measure modulation of alpha-band oscillations, and the visual evoked field. Moreover, in a VR experiment in which a participant had to move their head to look around a virtual wall and view a visual stimulus, we showed that the measured MEG signals map spatially in accordance with the known organisation of primary visual cortex. This technique could transform the type of neuroscientific experiment that can be undertaken using functional neuroimaging.

Costs and benefits of social relationships in the collective motion of bird flocks.

Current understanding of collective behaviour in nature is based largely on models that assume that identical agents obey the same interaction rules, but in reality interactions may be influenced by social relationships among group members. Here, we show that social relationships transform local interactions and collective dynamics. We tracked individuals' three-dimensional trajectories within flocks of jackdaws, a species that forms lifelong pair-bonds. Reflecting this social system, we find that flocks contain internal sub-structure, with discrete pairs of individuals tied together by spring-like effective forces. Within flocks, paired birds interacted with fewer neighbours than unpaired birds and flapped their wings more slowly, which may result in energy savings. However, flocks with more paired birds had shorter correlation lengths, which is likely to inhibit efficient information transfer through the flock. Similar changes to group properties emerge naturally from a generic self-propelled particle model. These results reveal a critical tension between individual- and group-level benefits during collective behaviour in species with differentiated social relationships, and have major evolutionary and cognitive implications.

Pleasures and Risks Associated with Bingo Playing in an Australian Aboriginal Community: Lessons for Policy and Intervention.

Bingo playing in Australian Indigenous communities has received little academic attention. We report here on an exploratory study designed to understand the complex benefits and harms associated with bingo playing for Aboriginal people in Sunraysia, a regional community in Victoria, Australia. The research was strongly participatory, and conducted in collaboration with staff of an Aboriginal community-controlled organisation. Twenty-six members of the Sunraysia Aboriginal community were interviewed, with interviews primarily conducted by workers from the Aboriginal organisation. Echoing research from other countries, but with a unique focus on the experience of bingo for Aboriginal people in Australia, this study demonstrates compelling reasons why Aboriginal people in Sunraysia play bingo, and how bingo playing both exposes players to risk and mitigates against a wide range of harms. We found that, for many people in the study, bingo was variously a site that reinforces social connectedness, a source of fun and excitement and a strategy to find solace or respite in the face of personal pain and structural injustice. In contrast with other forms of gambling, bingo presents risks that can generally be managed, largely because of the smaller financial spend involved. However, people also described harms including exhausting the family budget, family conflict and encouragement to commence other forms of gambling. We argue for enhanced regulation of commercial bingo and suggest that not-for-profit bingo be implemented as a harm reduction strategy to enable people to experience some of the pleasures associated with gambling, with reduced risk of financial and social harms.

Simultaneous measurements of three-dimensional trajectories and wingbeat frequencies of birds in the field.

Tracking the movements of birds in three dimensions is integral to a wide range of problems in animal ecology, behaviour and cognition. Multi-camera stereo-imaging has been used to track the three-dimensional (3D) motion of birds in dense flocks, but precise localization of birds remains a challenge due to imaging resolution in the depth direction and optical occlusion. This paper introduces a portable stereo-imaging system with improved accuracy and a simple stereo-matching algorithm that can resolve optical occlusion. This system allows us to decouple body and wing motion, and thus measure not only velocities and accelerations but also wingbeat frequencies along the 3D trajectories of birds. We demonstrate these new methods by analysing six flocking events consisting of 50 to 360 jackdaws (Corvus monedula) and rooks (Corvus frugilegus) as well as 32 jackdaws and 6 rooks flying in isolated pairs or alone. Our method allows us to (i) measure flight speed and wingbeat frequency in different flying modes; (ii) characterize the U-shaped flight performance curve of birds in the wild, showing that wingbeat frequency reaches its minimum at moderate flight speeds; (iii) examine group effects on individual flight performance, showing that birds have a higher wingbeat frequency when flying in a group than when flying alone and when flying in dense regions than when flying in sparse regions; and (iv) provide a potential avenue for automated discrimination of bird species. We argue that the experimental method developed in this paper opens new opportunities for understanding flight kinematics and collective behaviour in natural environments.

Feasibility of Cryopreserved Conduits for Complex Vascular Reconstruction in the Pediatric Population: The Case of a 3-Year-Old With Femoral Vessels Transections.

This report presents an unusual case of traumatic iliofemoral vessel transection in a 3-year-old patient successfully reconstructed using a cryopreserved greater saphenous conduit. Five years after injury, the patient continues to do well with normal ambulation. An arterial duplex demonstrated graft patency free of aneurysmal dilatation. These encouraging results suggest that the natural history of cryopreserved conduits may differ in the pediatric population and cryopreserved conduits could be used for complex vascular reconstructions.

Pediatric Secondary Overtriage in a Statewide Trauma System.

Secondary overtriage is a term that describes patients who are discharged home shortly after being transferred, an indication that transfer and hospitalization were unnecessary. The study goal was to identify factors associated with secondary triage. A statewide trauma registry was used to identify trauma patients aged less than 18 years during a 6-year period (2007-2012) who were discharged within 48 hours from arrival and did not undergo a surgical procedure. We compared those that were treated at initial facility and those transferred to a second facility using clinical indices including patterns of injury pattern using multivariate logistic regression. Of the 4441 patients who fit our inclusion criteria, 801 (18%) were transferred. Younger age groups were more likely to be transferred. Factors associated with being transferred included head, spinal, and facial injuries, and patient arrival during the nighttime work shifts. In conclusion, young patients who have signs of possible neurological or spinal injuries and those who arrive during nondaytime shifts during the workday are more likely to be transferred to another trauma center. These may reflect the comfort level and resources of the local facility.

Excessive Postoperative Fluid Administration in Infants with Gastroschisis.

Careful fluid management is a cornerstone of neonatology because the cardiovascular, respiratory, and gastrointestinal systems in the newborn are sensitive to overhydration. Fluid management in gastroschisis is complicated by insensible fluid loss and postoperative third-space fluid shifts. Study of perioperative fluid management in gastroschisis is limited and has not undergone careful scrutiny. We reviewed perioperative fluid administration and urine output in all infants with gastroschisis over a 5-year period. Data included whether the patient underwent primary closure or staged repair, weight, and events during hospitalization (length of hospitalization and duration of gastric decompression, parenteral nutrition, and ventilator support). Paired t test gave statistical comparisons with significance at P < 0.05. From 2010 to 2014, 24 patients underwent abdominal closure, 17 had primary and 7 had staged closures. Fluid administration exceeded 100 mL/kg/d after primary closure, and was significantly higher (>150 mL/kg/d; P < 0.05) after staged closure on postoperative days 0 to 5. Postoperative urinary output exceeded 75 mL/kg/d for all patients, with higher volumes reaching 100 mL/kg/d after staged closure on postoperative days 4 to 6 (P < 0.05). Two patients died of sepsis. All survivors were discharged with intestinal continuity and gaining weight on oral feeding. Patients with gastroschisis received large volumes of fluid after operation despite similarly high urine output and positive daily fluid balances. The amounts of fluid administered after both primary and staged closure may be excessive and potentially deleterious.

Femoral hernias in the pediatric patient: a case report and review of the literature.

We report a case of a femoral hernia in a 9-year-old male. Femoral hernias in children are rare and a diagnostic challenge. Definitive treatment is with surgical repair.

Invasive swallow-worts: an allelopathic role for -(-) antofine remains unclear.

Pale swallow-wort (Vincetoxicum rossicum) and black swallow-wort (V. nigrum) are two invasive plant species in the northeastern United States and eastern Canada that have undergone rapidly expanding ranges over the past 30 years. Both species possess a highly bioactive phytotoxin -(-) antofine in root tissues that causes pronounced inhibition in laboratory bioassays of native plant species co-located in habitats where swallow-wort is found. To further evaluate the allelopathic potential of -(-) antofine, we: determined its concentration in young plant tissues; used in situ approaches to assess antofine stability, potential activity of degradation products, activity in sterile and nonsterile soil; and determined accumulation and concentration in hydroponic cultivation and field collected soil samples. Extracts of seeds and young seedlings were found to have approximately 2-3 times the level of -(-) antofine in comparison to root extracts of adult plants. Breakdown products of antofine accumulated rapidly with exposure to light, but more slowly in the dark, at ambient temperatures, and these products did not retain biological activity. Extraction efficiencies of control soil spiked with -(-) antofine were low but easily detectable by HPLC. Soil samples collected over two growing seasons at four different sites where either pale swallow-wort or black swallow-wort populations are present were negative for the presence of -(-) antofine. Dose response curves using sterile and nonsterile soil spiked with -(-) antofine demonstrated a requirement for at least 20-55 × greater -(-) antofine concentrations in soil to produce similar phytotoxic effects to those previously seen in agar bioassays with lettuce seedlings. Sterile soil had a calculated EC50 of 686 µM (250 µg/g) as compared to nonsterile soil treatments with a calculated EC50 of 1.88 mM (640 µg/g). When pale swallow-wort and black swallow-wort adult plants were grown in hydroponic cultivation, -(-) antofine was found in root exudates and in the growing medium in the nM range. The concentrations in exudate were much lower than that needed for biological activity (µM) although they might be an underestimate of what may accumulate over time in an undisturbed rhizosphere. Based on these various results, it remains uncertain as to whether -(-) antofine could play a significant allelopathic role for invasive swallow-worts.

A proposed classification for the spectrum of vanishing gastroschisis.

Infants born with gastroschisis in association with intestinal atresia are well described. We are the proposing the classification of vanishing gastroschisis. In this series of six cases, at one end of the spectrum is an infant having gastroschisis with a much narrower defect on the right side of umbilicus. The ischemic bowel loops were connected to bowel inside the abdomen by a fibrous band compressing the exposed bowel mesentery. On the other end of spectrum, an infant having extensive bowel atresia and complete closure of abdominal wall defect (gastroschisis) detected on antenatal ultrasound. These cases should raise awareness of this devastating complication in prenatal management of gastroschisis.

Hemangioma of the scrotal septum: a rare entity in infants with review of the literature.

Hemagiomas are most common tumors in infancy; however, scrotal septum hemangiomas are very rare with only 45 cases reported in the literature. We report a case of a 6-month-old child who presented with a scrotal mass at birth which had increased in size with age. A scrotal ultrasound with color doppler analysis, revealed a soft tissue mass with diffusely increased blood flow. Scrotal mass excision was performed and the pathology confirmed a capillary hemangioma.

Evaluation of gastrointestinal pathology and treatment in children with suspected biliary dyskinesia.

AIM: Decreased gallbladder ejection fraction (GBEF) was reported in patients who had abdominal pain and gastrointestinal (GI) diseases. The study aims were to review pathology of GI tract in children with acalculous biliary-type abdominal pain and to evaluate the pain improvement after a 2-week trial of proton pump inhibitor (PPI) and laparoscopic cholecystectomy (LC). METHODS: Children below 18 years of age with a history of biliary-type abdominal pain by ROME III criteria were evaluated. All underwent an upper endoscopy and their histologic findings of the proximal GI tract were reviewed. Responses to a 2-week trial of PPI and LC were analyzed. RESULTS: Sixteen were identified with biliary-type abdominal pain with GBEF <35%. Endoscopic and histologic evidence of reflux esophagitis was observed in 11 children those of gastritis in 3 children. A GI pathology of these children is mostly acid-related and four of ten children experienced a complete response to PPIs and did not require LC. Nine children had LC; four had complete and four had partial pain improvement. CONCLUSION: A trial of PPIs may be cost-effective prior to considering LC in these patients since four of ten children experienced a complete response to PPIs without the requirement of LC, compared with four of nine children who improved completely.

Is the Broselow tape a reliable indicator for use in all pediatric trauma patients?: A look at a rural trauma center.

OBJECTIVE: The purpose of this study was to determine the effectiveness of the Broselow tape in the evaluation of pediatric trauma patients. METHODS: The trauma registry of a rural level I trauma center was examined. All pediatric trauma patients 16 years or younger were reviewed from 2002 to 2006, totaling 2358 patients. The Broselow tape measures to 146.5 cm. Patients whose height correlated with the tape and had their heights and weights in the medical record were included. The constant variable was the heights by which the estimated weights of the Broselow tape were compared with the actual weights of the patients. RESULTS: A total of 657 patients matched this height and had both heights and weights in their record. Most children (349/657; 53.1%) fell outside the predicted weight range, and of these, 77.1% of the actual weights were greater than those predicted by the Broselow scale. This is observed across all age groups. In patients with heights less than 75 cm, two thirds of patients' weights correlated with the Broselow estimated weight; however, those that deviated did so by 2 to 3 color intervals larger. This deviation was statistically significant in all groups. CONCLUSIONS: In our population, the Broselow tape is an ineffective tool to predict weight in more than 50% of pediatric trauma patients. This may lead to the underdosing of emergency medications and blood products.

Effects of fatigue on surgeon performance and surgical outcomes: a systematic review.

BACKGROUND: Sleep deprivation and disturbances in circadian rhythms generally lead to poor performance, but is there a link in surgery? This review aimed to determine whether fatigue has an impact on surgeon performance or surgical outcomes. METHODS: Studies were identified by searching EMBASE, CINAHL, PubMed, The Cochrane Library, Current Contents and clinical trials databases. Inclusion of relevant studies was by application of a predetermined protocol and independent assessment by two reviewers. Each included study was critically appraised for its study quality according to the methods used for Cochrane Reviews. Data from included studies were extracted by one researcher using standardized data extraction tables developed a priori and checked by a second researcher. RESULTS: From 823 potentially relevant studies, a total of 16 studies were included in this review: two randomized controlled trials, five non-randomized comparative studies and nine case series. Of five studies that directly measure clinical performance, three studies reported no significant difference as a result of sleep deprivation, while two studies found increases in complications or errors. Eleven studies assessed psychomotor skill performance using a variety of simulation-based methods when a participant was rested and/or fatigued. Two randomized controlled trials reported no significant differences, while the nine remaining studies reported mixed results. Surgical residents with less surgical training/experience appeared to be more affected than more senior residents. CONCLUSION: There is little evidence, as yet, to inform the issue of the effect of fatigue on surgical performance.