Behavior and morphology combine to influence energy dissipation in mantis shrimp (Stomatopoda).

Animals deliver and withstand physical impacts in diverse behavioral contexts, from competing rams clashing their antlers together to archerfish impacting prey with jets of water. Though the ability of animals to withstand impact has generally been studied by focusing on morphology, behaviors may also influence impact resistance. Mantis shrimp exchange high-force strikes on each other's coiled, armored telsons (tailplates) during contests over territory. Prior work has shown that telson morphology has high impact resistance. I hypothesized that the behavior of coiling the telson also contributes to impact energy dissipation. By measuring impact dynamics from high-speed videos of strikes exchanged during contests between freely moving animals, I found that approximately 20% more impact energy was dissipated by the telson as compared with findings from a prior study that focused solely on morphology. This increase is likely due to behavior: because the telson is lifted off the substrate, the entire body flexes after contact, dissipating more energy than exoskeletal morphology does on its own. While variation in the degree of telson coil did not affect energy dissipation, proportionally more energy was dissipated from higher velocity strikes and from strikes from more massive appendages. Overall, these findings show that analysis of both behavior and morphology is crucial to understanding impact resistance, and suggest future research on the evolution of structure and function under the selective pressure of biological impacts.

FAMILY PLANNING SERVICE UPTAKE IN HOSPITALS IN RIVERS STATE, NIGERIA.

Introduction: Family planning refers to a couple's ability to have the number of children they want by spacing out their children appropriately or a person's ability to avoid unintended pregnancies by using various contraceptive methods and infertility treatment. All hospitals in Rivers State, Nigeria, that provide primary care, offer family planning services. Aim: To describe the pattern of family planning service uptake in the hospitals in Rivers State. Methodology: An 8-year retrospective review of data collection from the District Health Information System 2 (DHIS 2) platform in the Health Management Information System in Rivers State was conducted. Data from 387 health facilities were collated and keyed into the DHIS2 platform. Data was analysed using SPSS version 21 and represented as frequencies, percentages and charts. Results: During the period under review, the Family Planning clinics counselled a total of 931,774 individuals, of whom 421,785 (45.3%) accepted family planning services. Condoms (65.3%) were the most widely utilized contraceptive, whereas bilateral tubal ligation (0.1%) was the least utilized. Other methods were injectable, implant, oral contraceptive pills and intrauterine contraceptive devices accounting for 16.1%, 9.4%, 7.8%, and 1.3%, respectively. A significant increase was observed in the trend of use of condoms, injectables and oral contraceptive pills between 2016-2021. Conclusion: The findings were that there was an increasing trend in the yearly utilization of family planning services among women of childbearing age in the State from 2014 - 2021. Condom being the most utilized indicates that it is the most accepted and approved by clients in family planning clinics in Rivers State. The knowledge of contraceptive utilization trends can be used to monitor and appraise the acceptance and approval of each method and family planning program over a period.

Fighting force and experience combine to determine contest success in a warlike mammal.

Conflicts between social groups or "intergroup contests" are proposed to play a major role in the evolution of cooperation and social organization in humans and some nonhuman animal societies. In humans, success in warfare and other collective conflicts depends on both fighting group size and the presence and actions of key individuals, such as leaders or talismanic warriors. Understanding the determinants of intergroup contest success in other warlike animals may help to reveal the role of these contests in social evolution. Using 19 y of data on intergroup encounters in a particularly violent social mammal, the banded mongoose (Mungos mungo), we show that two factors, the number of adult males and the age of the oldest male (the "senior" male), have the strongest impacts on the probability of group victory. The advantage conferred by senior males appears to stem from their fighting experience. However, the galvanizing effect of senior males declines as they grow old until, at very advanced ages, senior males become a liability rather than an asset and can be evicted. As in human conflict, strength in numbers and the experience of key individuals combine to determine intergroup contest success in this animal society. We discuss how selection arising from intergroup contests may explain a suite of features of individual life history and social organization, including male eviction, sex-assortative alloparental care, and adult sex ratio.

Leaders of war: modelling the evolution of conflict among heterogeneous groups.

War, in human and animal societies, can be extremely costly but can also offer significant benefits to the victorious group. We might expect groups to go into battle when the potential benefits of victory (V) outweigh the costs of escalated conflict (C); however, V and C are unlikely to be distributed evenly in heterogeneous groups. For example, some leaders who make the decision to go to war may monopolize the benefits at little cost to themselves ('exploitative' leaders). By contrast, other leaders may willingly pay increased costs, above and beyond their share of V ('heroic' leaders). We investigated conflict initiation and conflict participation in an ecological model where single-leader-multiple-follower groups came into conflict over natural resources. We found that small group size, low migration rate and frequent interaction between groups increased intergroup competition and the evolution of 'exploitative' leadership, while converse patterns favoured increased intragroup competition and the emergence of 'heroic' leaders. We also found evidence of an alternative leader/follower 'shared effort' outcome. Parameters that favoured high contributing 'heroic' leaders, and low contributing followers, facilitated transitions to more peaceful outcomes. We outline and discuss the key testable predictions of our model for empiricists studying intergroup conflict in humans and animals. This article is part of the theme issue 'Intergroup conflict across taxa'.

Testosterone, signal coloration, and signal color perception in male zebra finch contests.

Many animals use assessment signals to resolve contests over limited resources while minimizing the costs of those contests. The carotenoid-based orange to red bills of male zebra finches (Taeniopygia guttata) are thought to function as assessment signals in male-male contests, but behavioral analyses relating contest behaviors and outcomes to bill coloration have yielded mixed results. We examined the relationship between bill color and contests while incorporating measurements of color perception and testosterone (T) production, for an integrative view of aggressive signal behavior, production, and perception. We assayed the T production capabilities of 12 males in response to a gonadotropin-releasing hormone (GnRH) challenge. We then quantified the initiation, escalation, and outcome of over 400 contests in the group, and measured bill color using calibrated photography. Finally, because signal perception can influence signal function, we tested how males perceive variation in bill coloration, asking if males exhibit categorical perception of bill color, as has been shown recently in female zebra finches. The data suggest that males with greater T production capabilities than their rivals were more likely to initiate contests against those rivals, while males with redder bills than their rivals were more likely to win contests. Males exhibited categorical color perception, but individual variation in the effect of categorical perception on color discrimination abilities did not predict any aspects of contest behavior or outcomes. Our results are consistent with the hypotheses that T plays a role in zebra finch contests and that bill coloration functions as an aggressive signal. We suggest future approaches, based on animal contest theory, for how links among signals, perception, and assessment can be tested.

Mechanoethology: The Physical Mechanisms of Behavior.

Research that integrates animal behavior theory with mechanics-including biomechanics, physiology, and functional morphology-can reveal how organisms accomplish tasks crucial to their fitness. Despite the insights that can be gained from this interdisciplinary approach, biomechanics commonly neglects a behavioral context and behavioral research generally does not consider mechanics. Here, we aim to encourage the study of "mechanoethology," an area of investigation intended to encompass integrative studies of mechanics and behavior. Using examples from the literature, including papers in this issue, we show how these fields can influence each other in three ways: (1) the energy required to execute behaviors is driven by the kinematics of movement, and mechanistic studies of movement can benefit from consideration of its behavioral context; (2) mechanics sets physical limits on what behaviors organisms execute, while behavior influences ecological and evolutionary limits on mechanical systems; and (3) sensory behavior is underlain by the mechanics of sensory structures, and sensory systems guide whole-organism movement. These core concepts offer a foundation for mechanoethology research. However, future studies focused on merging behavior and mechanics may reveal other ways by which these fields are linked, leading to further insights in integrative organismal biology.

Posterior urethral valves masquerading as neuropathic bladder following sacrococcygeal teratoma resection.

Neuropathic bladder may be a co-associated morbidity in newborn babies following resection of a sacrococcygeal teratoma. We report a case of a male newborn showing features of incomplete urinary voiding requiring intermittent catheterisation after operation for bladder emptying. Videourodynamic assessment excluded neuropathic bladder and posterior urethral valves were demonstrated on micturating cystography. Urology outcomes have been excellent following curative valve ablation. This report highlights the crucial importance of being aware of the rare coexistence of lower urinary tract pathology in male babies with sacrococcygeal teratoma. Routine urodynamic assessment should be considered in all children following sacrococcygeal teratoma resection.

Assessment during Intergroup Contests.

Research on how competitors assess (i.e., gather information on) fighting ability and contested resources, as well as how assessment impacts on contest processes and outcomes, has been fundamental to the field of dyadic (one-on-one) contests. Despite recent growth in studies of contests between social-living groups, there is limited understanding of assessment during these intergroup contests. We adapt current knowledge of dyadic contest assessment to the intergroup case, describing what traits of groups, group members, and resources are assessed, and how assessment is manifested in contest processes (e.g., behaviors) and outcomes. This synthesis helps to explain the role of individual heterogeneity in assessment and how groups are shaped by the selective pressure of contests.

Variations in the management of adolescents with blunt splenic trauma in England and Wales: are we preserving enough?

INTRODUCTION: Management of blunt splenic injury has changed drastically with non-operative management increasingly used in paediatric and adult patients. Studies from America and Australia demonstrate disparities in care of patients treated at paediatric and adult centres. This study assessed management of splenic injuries in UK adolescents. MATERIALS AND METHODS: Data were acquired from the Trauma Audit and Research Network on isolated blunt splenic injuries reported 2006-2015. Adolescents were divided into age groups of 11-15 years and 16-20 years, and injuries classified as minor (grades 1/2) or major (3+). Primary outcomes were needed for splenectomy and blood transfusion. RESULTS: A total of 445 adolescents suffered isolated blunt splenic injuries. Road traffic collisions were the most common mechanism. There were no deaths as a result of isolated blunt splenic injuries, but 49 (11%) adolescents needed transfusions and 105 (23.6%) underwent splenectomies. There was no significant difference observed in the management of adolescents with minor trauma. In major trauma, 11-15-year-olds were more likely to have splenectomies when managed at local trauma units compared with major trauma centres (31% vs 4%, odds ratio 11.5; 95% confidence interval 3.82-34.38, p < 0.0001). Within major trauma centres, older adolescents were more likely to have splenectomies than younger adolescents (35.5% vs 3.8%, odds ratio 14; 95% confidence interval 4.55-43.26, p < 0.0001). There were no significant differences in haemodynamic status, transfusion requirement or embolisation rates. CONCLUSIONS: There appears to be a large variation in the management of isolated blunt splenic injuries in the UK. The reasons for this remain unclear however non-operative management is safe and should be first line management in the haemodynamically stable adolescent, even with major splenic injuries.

Context-dependent scaling of kinematics and energetics during contests and feeding in mantis shrimp.

Measurements of energy use, and its scaling with size, are critical to understanding how organisms accomplish myriad tasks. For example, energy budgets are central to game theory models of assessment during contests and underlie patterns of feeding behavior. Clear tests connecting energy to behavioral theory require measurements of the energy use of single individuals for particular behaviors. Many species of mantis shrimp (Stomatopoda: Crustacea) use elastic energy storage to power high-speed strikes that they deliver to opponents during territorial contests and to hard-shelled prey while feeding. We compared the scaling of strike kinematics and energetics between feeding and contests in the mantis shrimp Neogonodactylus bredini We filmed strikes with high-speed video, measured strike velocity and used a mathematical model to calculate strike energy. During contests, strike velocity did not scale with body size but strike energy scaled positively with size. Conversely, while feeding, strike velocity decreased with increasing size and strike energy did not vary according to body size. Individuals most likely achieved this strike variation through differential compression of their exoskeletal spring prior to the strike. Post hoc analyses found that N. bredini used greater velocity and energy when striking larger opponents, yet variation in prey size was not accompanied by varying strike velocity or energetics. Our estimates of energetics inform prior tests of contest and feeding behavior in this species. More broadly, our findings elucidate the role behavioral context plays in measurements of animal performance.

Mutual assessment during ritualized fighting in mantis shrimp (Stomatopoda).

Safe and effective conflict resolution is critical for survival and reproduction. Theoretical models describe how animals resolve conflict by assessing their own and/or their opponent's ability (resource holding potential, RHP), yet experimental tests of these models are often inconclusive. Recent reviews have suggested this uncertainty could be alleviated by using multiple approaches to test assessment models. The mantis shrimp Neogonodactylus bredini presents visual displays and ritualistically exchanges high-force strikes during territorial contests. We tested how N. bredini contest dynamics were explained by any of three assessment models-pure self-assessment, cumulative assessment and mutual assessment-using correlations and a novel, network analysis-based sequential behavioural analysis. We staged dyadic contests over burrow access between competitors matched either randomly or based on body size. In both randomly and size-matched contests, the best metric of RHP was body mass. Burrow residency interacted with mass to predict outcome. Correlations between contest costs and RHP rejected pure self-assessment, but could not fully differentiate between cumulative and mutual assessment. The sequential behavioural analysis ruled out cumulative assessment and supported mutual assessment. Our results demonstrate how multiple analyses provide strong inference to tests of assessment models and illuminate how individual behaviours constitute an assessment strategy.

A fatal case of amphetamine induced ischaemic colitis.

Amphetamine induced ischaemic colitis is an exceedingly rare presentation of amphetamine toxicity. The cases reported in the literature have described mild or transient disease. We present a fatal case of ischaemic colitis induced by amphetamine use in a 44-year-old woman who presented in extremis after a cardiac arrest en route to the emergency department. A short history of headache, abdominal pain, vomiting and agitation preceded her admission. Imaging revealed changes consistent with ischaemic colitis. Emergency laparotomy revealed widespread colonic necrosis necessitating a subtotal colectomy. Despite aggressive resuscitation and inotropic support from arrival, the patient deteriorated intraoperatively and died in the immediate postoperative period. Histology showed arterial type ischaemia/reperfusion injury of the area supplied by the superior mesenteric artery. The patient's serum amphetamine level was 0.52mg/l (peak therapeutic levels <0.2mg/l). The postmortem examination concluded that amphetamines were the likely cause of the vasospasm, leading to profound colonic ischaemia.

Influence of Social Deprivation on Outcome of Open Arterial Surgery in Tertiary Care: An Observational Study.

BACKGROUND AND OBJECTIVE: Health equity is playing an increasing role in British government health policy. Evidence of social deprivation affecting outcomes in surgery is poor. This study aimed to assess the influence of social deprivation on the outcome of major arterial surgery. MATERIALS AND METHODS: A retrospective cohort study was undertaken in patients undergoing elective or emergency open surgery for abdominal aortic aneurysms or lower limb arterial reconstruction over an eight and a half year period within one institution. Patient deprivation was calculated for each patient with the Index of Multiple Deprivation (IMD) score. This was then entered into multivariate models to determine its effect on mortality and postoperative length of stay after adjustment for confounders. RESULTS: Five hundred and six patients were included in the study. There were 45 deaths (8.9%) and median (IQR) postoperative length of stay was 8 (4-15) days. The median (IQR) IMD score was 46.4 (28.3-64.5). IMD score correlated with ASA grade and was significantly higher in smokers, patients with respiratory disease and those with left ventricular failure. IMD (OR = 1.01; 95% CI = 0.99-1.03; p = .45) did not affected mortality, which was associated with aortic surgery, emergency surgery, and high ASA grade. Postoperative length of stay, which was longer with/after aortic surgery, tissue loss, emergency surgery, high ASA grade, low haemoglobin, and age over 80 years was also independent of deprivation (Spearman's rho = -0.49, p = .28). DISCUSSION: No effect of social deprivation on mortality or length of stay in patients undergoing major arterial surgery was identified.

Contests with deadly weapons: telson sparring in mantis shrimp (Stomatopoda).

Mantis shrimp strike with extreme impact forces that are deadly to prey. They also strike conspecifics during territorial contests, yet theoretical and empirical findings in aggressive behaviour research suggest competitors should resolve conflicts using signals before escalating to dangerous combat. We tested how Neogonodactylus bredini uses two ritualized behaviours to resolve size-matched contests: meral spread visual displays and telson (tailplate) strikes. We predicted that (i) most contests would be resolved by meral spreads, (ii) meral spreads would reliably signal strike force and (iii) strike force would predict contest success. The results were unexpected for each prediction. Contests were not resolved by meral spreads, instead escalating to striking in 33 of 34 experiments. The size of meral spread components did not strongly correlate with strike force. Strike force did not predict contest success; instead, winners delivered more strikes. Size-matched N. bredini avoid deadly combat not by visual displays, but by ritualistically and repeatedly striking each other's telsons until the loser retreats. We term this behaviour 'telson sparring', analogous to sparring in other weapon systems. We present an alternative framework for mantis shrimp contests in which the fight itself is the signal, serving as a non-lethal indicator of aggressive persistence or endurance.

Reporting and Methodological Quality of Randomised Controlled Trials in Vascular and Endovascular Surgery.

BACKGROUND: Randomised controlled trials (RCTs) are subject to bias if they lack methodological quality. Moreover, optimal and transparent reporting of RCT findings aids their critical appraisal and interpretation. OBJECTIVES: The aim of this study was to ascertain whether the methodological and reporting quality of RCTs in vascular and endovascular surgery is improving. METHODS: The most recent 75 and oldest 75 RCTs published in leading journals over a 10-year period (2003-2012) were identified. The reporting quality and methodological quality data of the old and new RCTs were extracted and compared. The former was analysed using the Consolidated Standards of Reporting Trials (CONSORT) statement, the latter with the Scottish Intercollegiate Guidelines Network (SIGN) checklist. RESULTS: Reporting quality measured by CONSORT was better in the new studies than in the old studies (0.68 [95% CI, 0.66-0.7] vs. 0.60 [95% CI, 0.58-0.62], p < .001); however, both new and old studies had similar methodological quality measured by SIGN (0.9 [IQR 0.1] vs. .09 [IQR: 0.2], p = .787). Unlike clinical items, the methodological items of the CONSORT statement were not well reported in old and new RCTs. More trials in the new group were endovascular related (33.33% vs. 17.33%, p = .038) and industry sponsored (28% vs. 6.67%, p = .001). CONCLUSIONS: Despite some progress, there remains room for improvement in the reporting quality of RCTs in vascular and endovascular surgery. The methodological quality of recent RCTs is similar to that of trials performed >10 years ago.

Transmission of Mycobacterium tuberculosis from medical waste.

CONTEXT: Washington State has a relatively low incidence rate of tuberculosis (TB) infection. However, from May to September 1997, 3 cases of pulmonary TB were reported among medical waste treatment workers at 1 facility in Washington. There is no previous documentation of Mycobacterium tuberculosis transmission as a result of processing medical waste. OBJECTIVE: To identify the source(s) of these 3 TB infections. DESIGN, SETTING, AND PARTICIPANTS: Interviews of the 3 infected patient-workers and their contacts, review of patient-worker medical records and the state TB registry, and collection of all multidrug-resistant TB (MDR-TB) isolates identified after January 1, 1995, from the facility's catchment area; DNA fingerprinting of all isolates; polymerase chain reaction and automated DNA sequencing to determine genetic mutations associated with drug resistance; and occupational safety and environmental evaluations of the facility. MAIN OUTCOME MEASURES: Previous exposures of patient-workers to TB; verification of patient-worker tuberculin skin test histories; identification of other cases of TB in the community and at the facility; drug susceptibility of patient-worker isolates; and potential for worker exposure to live M tuberculosis cultures. RESULTS: All 3 patient-workers were younger than 55 years, were born in the United States, and reported no known exposures to TB. We did not identify other TB cases. The 3 patient-workers' isolates had different DNA fingerprints. One of 10 MDR-TB catchment-area isolates matched an MDR-TB patient-worker isolate by DNA fingerprint pattern. DNA sequencing demonstrated the same rare mutation in these isolates. There was no evidence of personal contact between these 2 individuals. The laboratory that initially processed the matching isolate sent contaminated waste to the treatment facility. The facility accepted contaminated medical waste where it was shredded, blown, compacted, and finally deactivated. Equipment failures, insufficient employee training, and respiratory protective equipment inadequacies were identified at the facility. CONCLUSION: Processing contaminated medical waste resulted in transmission of M tuberculosis to at least 1 medical waste treatment facility worker. JAMA. 2000;284:1683-1688.

Acute renal insufficiency due to oral acyclovir in a man with sickle cell trait.

Several published reports have suggested that oral acyclovir can cause renal insufficiency, but baseline renal function was either abnormal or unclear in those reports. We describe a patient with oral acyclovir-induced acute renal failure and a normal serum creatinine level documented just before exposure to the drug. Conceivably, competition with a cephalosporin for renal tubular elimination predisposed our patient to nephrotoxic serum levels of acyclovir. In addition, the patient had sickle cell trait, which might have contributed to a disproportionate degree of hyperkalemia and acidosis seen early in the patient's clinical course.

Evaluation of the association between medial patellar luxation and hip dysplasia in cats.

OBJECTIVE: To investigate the association between hip dysplasia (HD) and medial patellar luxation (MPL) in cats. DESIGN: Cross-sectional prevalence study. ANIMALS: 78 cats. PROCEDURE: A complete history was obtained. Cats were examined to detect MPL and HD. Radiographs of the stifle and hip joints were obtained. Hip joints were evaluated by use of Norberg angle, distraction index, and scoring consistent with that established by the Orthopedic Foundation for Animals. RESULTS: There were 43 male and 35 female cats mean age, 2.5 years). Eleven cats had clinical signs of disease in the pelvic limbs. Medial subluxation of the patella (subgrade 1) was seen in 31 of 33 cats with otherwise normal stifle joints. Medial patellar luxation was found in 45 of 78 (58%) cats, and 35 of 45 (78%) had grade-1 MPL. Bilateral MPL was seen in 32 of 45 (71%) cats. A weak association existed between MPL and HD, because cats were 3 times more likely to have HD and patellar luxation than to have either condition alone. Concurrent MPL and HD were detected in 19 of 78 (24%) cats, and HD was diagnosed radiographically in 25 of 78 (32%) cats (19 mild, 4 moderate, 2 severe). Eighteen of the 25 cats with HD had bilateral HD. CONCLUSIONS AND CLINICAL RELEVANCE: Clinically normal cats may have a certain degree of laxity in the stifle joint, evident as medial patellar subluxation (< grade 1). There is a weak association between MPL and HD, and both conditions may develop, alone or in combination, more frequently than has been reported.