Metabolic consequences of sex reversal in two lizard species: a test of the like-genotype and like-phenotype hypotheses.

Vertebrate sex is typically determined genetically, but in many ectotherms sex can be determined by genes (genetic sex determination, GSD), temperature (temperature-dependent sex determination, TSD), or interactions between genes and temperature during development. TSD may involve GSD systems with either male or female heterogamety (XX/XY or ZZ/ZW) where temperature overrides chromosomal sex determination to cause a mismatch between genetic sex and phenotypic sex (sex reversal). In these temperature-sensitive lineages, phylogenetic investigations point to recurrent evolutionary shifts between genotypic and temperature-dependent sex determination. These evolutionary transitions in sex determination can occur rapidly if selection favours the reversed sex over the concordant phenotypic sex. To investigate the consequences of sex reversal on offspring phenotypes, we measured two energy-driven traits (metabolism and growth) and 6 month survival in two species of reptile with different patterns of temperature-induced sex reversal. Male sex reversal occurs in Bassiana duperreyi when chromosomal females (female XX) develop male phenotypes (maleSR XX), while female sex reversal occurs in Pogona vitticeps when chromosomal males (male ZZ) develop female phenotypes (femaleSR ZZ). We show metabolism in maleSR XX was like that of male XY; that is, reflective of phenotypic sex and lower than genotypic sex. In contrast, for Pogona vitticeps, femaleSR ZZ metabolism was intermediate between male ZZ and female ZW metabolic rate. For both species, our data indicate that differences in metabolism become more apparent as individuals become larger. Our findings provide some evidence for an energetic advantage from sex reversal in both species but do not exclude energetic processes as a constraint on the distribution of sex reversal in nature.

Ecological and Fitness Correlates of Personality in a Long-lived Terrestrial Turtle.

An individual's behavioral tendencies (i.e., personality or temperament) can influence its interactions with the environment and thus have important ecological and evolutionary consequences for animal populations. Boldness, defined as an individual's tendency to engage in risk-taking activities, is a phenotypically variable trait linked with numerous behavioral and fitness outcomes in free-ranging animals. We examined variation and repeatability of boldness and other behavioral characteristics in two wild Eastern Box Turtle (Terrapene carolina carolina) populations using radiotelemetry, and assessed fitness correlates of boldness over multiple years. We observed large amounts of among-individual variation and within-individual consistency (i.e., repeatability) of boldness as measured by their head emergence latency following a standardized confinement assay. Individuals were also consistent in several in-field behaviors including movement rate, home range size, and date of emergence from overwintering refuges. Individuals with shorter head emergence latencies (i.e., bolder turtles) had larger home ranges, emerged earlier from overwintering dormancy, and experienced moderately lower survival compared with shy individuals. Boldness did not affect time spent within the thermal preference range, somatic growth rates, or the frequency of mating or same-sex aggressive encounters. Boldness and its effects on in-field behaviors differed between sexes and populations, and the relationship between boldness and survival was temporally variable. Our results suggest possible intrinsic behavioral types in T. c. carolina and highlight the importance of long-term and multipopulation studies when examining ecological and evolutionary processes that shape personality phenotypes in turtles.

Evolutionary stability inferred for a free ranging lizard with sex-reversal.

The sex of vertebrates is typically determined genetically, but reptile sex can also be determined by developmental temperature. In some reptiles, temperature interacts with genotype to reverse sex, potentially leading to transitions from a chromosomal to a temperature-dependent sex determining system. Transitions between such systems in nature are accelerated depending on the frequency and fitness of sex-reversed individuals. The Central Bearded Dragon, Pogona vitticeps, exhibits female heterogamety (ZZ/ZW) but can have its sex reversed from ZZ male to ZZ female by high incubation temperatures. The species exhibits sex-reversal in the wild and it has been suggested that climate change and fitness of sex-reversed individuals could be increasing the frequency of reversal within the species range. Transitions to temperature-dependent sex determination require low levels of dispersal and high (>50%) rates of sex-reversal. Here, we combine genotype-by-sequencing, identification of phenotypic and chromosomal sex, exhaustive field surveys, and radio telemetry to examine levels of genetic structure, rates of sex-reversal, movement, space use, and survival of P. vitticeps in a location previously identified as a hot spot for sex-reversal. We find that the species exhibits low levels of population structure (FST ~0.001) and a modest (~17%) rate of sex-reversal, and that sex-reversed and nonsex-reversed females have similar survival and behavioural characteristics to each other. Overall, our data indicate this system is evolutionary stable, although we do not rule out the prospect of a more gradual transition in sex-determining mechanisms in the future in a more fragmented landscape and as global temperatures increase.

Overwintering behavior reduces mortality for a terrestrial turtle in forests managed with prescribed fire.

Prescribed fire is an essential management practice in pyrogenic ecosystems, but fire can also be a significant disturbance and source of mortality for both target and non-target species. Seasonal periods of animal inactivity may provide opportunities to design burn plans that minimize negative impacts to species of conservation concern, but few studies have rigorously examined this possibility. Using radiotelemetry, we studied overwintering behavior and interactions with fire in a forest-dwelling terrestrial turtle, the Eastern Box Turtle (Terrapene carolina carolina), over an eight-year period at two sites that use prescribed fire in forest management. Turtles at both sites selected predominantly hardwood forests and mesic habitats and avoided upland pine forests. Turtles buried deepest (2.9 - 3.2 cm) below the soil-litter interface in late February and then moved gradually shallower until emergence in early April. Emergence timing varied over a 58-day period, but was consistent within individuals from year to year. Turtles also maintained fidelity to refuge locations, but those overwintering in burned areas selected sites over twice as far from refuges used in previous years compared to those in unburned areas. The areas and habitats selected by turtles during winter served as refugia from fire, and those whose refuges did burn remained buffered from lethal temperatures even at shallow burial depths. The only fire-related injury or mortality occurred during seasons of surface activity. Timing burning and other forest management practices during periods of winter dormancy may thus minimize threats to turtle populations, but modifications to prescribed fire regimes must also be balanced with other management objectives.

Responses of a forest-dwelling terrestrial turtle, Terrapene Carolina, to prescribed fire in a Longleaf Pine ecosystem.

Prescribed fire is commonly used as a tool to meet a range of forest management goals. Owing to their limited movement abilities, terrestrial turtles are likely to be at high risk of injury and mortality, and to experience other fitness consequences with population-level implications from fire. Using radiotelemetry, we studied the responses of Eastern Box Turtles, Terrapene carolina carolina, to prescribed fire management in a sandhills Longleaf Pine forest system over a five-year period and compared our results to a nearby population in an unburned coastal plain location. Individual variation in turtle survival was strongly dependent on how frequently and extensively the areas were burned, with annual survival rates of 94.5% in unburned areas decreasing to 45.9 % in the most extensively burned areas. Turtles at the fire-maintained sandhills site had annual survival rates 4.9 % less than at the unburned coastal plain site, and females had annual survival rates 6.8 % less than males. Survival varied seasonally, with greatest mortality rates in winter and spring, especially among females. Growth rates and body condition did not differ between sites, nor did they vary according to fire extent and frequency at the fire-maintained site. Although mortality was greater and spatially variable at the fire-maintained site, annual survival rates across the site (86 - 90 % for females and males, respectively) were comparable to other stable populations of T. carolina. The lesser than expected mortality rate at the fire-maintained site was likely the result of turtles' strong selection of mesic hardwood forests near bottomlands and streams - habitats that may serve as refugia from fire. In areas where T. carolina conservation is a priority, land managers should integrate maintenance of fire refuge habitats into burn planning to minimize unintended negative impacts to this imperiled species.

Thermal biology of eastern box turtles in a longleaf pine system managed with prescribed fire.

Fire can influence the microclimate of forest habitats by removing understory vegetation and surface debris. Temperature is often higher in recently burned forests owing to increased light penetration through the open understory. Because physiological processes are sensitive to temperature in ectotherms, we expected fire-maintained forests to improve the suitability of the thermal environment for turtles, and for turtles to seasonally associate with the most thermally-optimal habitats. Using a laboratory thermal gradient, we determined the thermal preference range (Tset) of eastern box turtles, Terrapene carolina, to be 27-31°C. Physical models simulating the body temperatures experienced by turtles in the field revealed that surface environments in a fire-maintained longleaf pine forest were 3°C warmer than adjacent unburned mixed hardwood/pine forests, but the fire-maintained forest was never of superior thermal quality owing to wider Te fluctuations above Tset and exposure to extreme and potentially lethal temperatures. Radiotracked turtles using fire-managed longleaf pine forests maintained shell temperatures (Ts) approximately 2°C above those at a nearby unburned forest, but we observed only moderate seasonal changes in habitat use which were inconsistent with thermoregulatory behavior. We conclude that turtles were not responding strongly to the thermal heterogeneity generated by fire in our system, and that other aspects of the environment are likely more important in shaping habitat associations.

Predicting bycatch hotspots for endangered leatherback turtles on longlines in the Pacific Ocean.

Fisheries bycatch is a critical source of mortality for rapidly declining populations of leatherback turtles, Dermochelys coriacea. We integrated use-intensity distributions for 135 satellite-tracked adult turtles with longline fishing effort to estimate predicted bycatch risk over space and time in the Pacific Ocean. Areas of predicted bycatch risk did not overlap for eastern and western Pacific nesting populations, warranting their consideration as distinct management units with respect to fisheries bycatch. For western Pacific nesting populations, we identified several areas of high risk in the north and central Pacific, but greatest risk was adjacent to primary nesting beaches in tropical seas of Indo-Pacific islands, largely confined to several exclusive economic zones under the jurisdiction of national authorities. For eastern Pacific nesting populations, we identified moderate risk associated with migrations to nesting beaches, but the greatest risk was in the South Pacific Gyre, a broad pelagic zone outside national waters where management is currently lacking and may prove difficult to implement. Efforts should focus on these predicted hotspots to develop more targeted management approaches to alleviate leatherback bycatch.

Exeter short stems compared with standard length Exeter stems: experience from the Australian Orthopaedic Association National Joint Replacement Registry.

The standard Exeter stem has a length of 150 mm with offsets 37.5 to 56 mm. Shorter stems of lengths 95, 115 and 125 mm with offsets 35.5 mm or less are available for patients with smaller femurs. Concern has been raised regarding the behavior of the smaller implants. This paper analyzed data from the Australian Orthopaedic Association National Joint Replacement Registry comparing survivorship of stems of offset 35.5 mm or less with the standard stems of 37.5 mm offset or greater. At 7 years, there was no significant difference in the cumulative percent revision rate in the short stems (3.4%, 95% CI 2.4-4.8%) compared with the standard length stems (3.5%, 95% CI 3.3-3.8%) despite its use in a greater proportion of potentially more difficult developmental dysplasia of the hip cases.

Spatial Ecology, Movements, and Habitat Selection of Clemmys guttata in a Temporally Dynamic Wetland System in North Carolina, USA.

Turtle populations are in decline worldwide, requiring immediate conservation and management actions. For species with broad geographic ranges that cover diverse environmental contexts, region-specific information on declining species could inform more targeted management plans. I examined the ecology of a Spotted Turtle (Clemmys guttata) population in a temporally dynamic wetland system in the Southeastern Plains ecoregion of North Carolina. Turtles selected forested wetlands and streams while avoiding open wetlands and river habitats, but used terrestrial habitats minimally and randomly. Turtles responded to wetland drying by remaining in wetlands and maintaining modest levels of activity during short-duration drying events (< 1 mo), but moved very little during longer droughts (7 mo). Turtles had prolonged active seasons (February-October) as long as wetlands and streams were flooded, with movement rates peaking in late spring at 23.6 ± 3.7 m/d (mean ± standard error). Turtles had large home ranges (14.1 ± 4.3 ha) that often included multiple local stream networks used as movement corridors between forested wetland patches and as activity centers when wetlands dried. I suggest that conservation plans for C. guttata include large management areas that protect a network of streams and adjacent forested swamps in the Southeastern Plains and perhaps other lowland ecoregions in the Southeastern U.S. Because terrestrial habitats were not used for extended refuge during drought, certain low-impact land uses in adjacent terrestrial areas are not likely to negatively impact C. guttata populations, but terrestrial forests would still be important in maintaining overland travel corridors.

Acute sport-related knee injuries.

BACKGROUND: Australia has a high rate of sporting participation. Although this has many benefits, knee injuries are common, particularly in pivoting and contact sports. OBJECTIVE: This article reviews the management of common sport-related knee injuries, including injuries to the collateral and cruciate ligaments, menisci and the extensor mechanism. DISCUSSION: Some sport-related knee injuries can be treated non-operatively with physiotherapy-led rehabilitation. These include the majority of isolated medial collateral ligament, lateral collateral ligament and posterior cruciate ligament injuries. Other knee injuries might require surgical intervention. These include anterior cruciate ligament ruptures in young patients aiming to return to pivoting sports, certain meniscal tears and extensor mechanism disruptions. A multidisciplinary approach to these injuries will facilitate optimal patient care.

The epidemiology of sports and leisure-related injury hospitalisations in Queensland: A five-year review.

OBJECTIVE: To describe the epidemiology of sports and leisure-related injury hospitalisations in Queensland DESIGN, SETTING, AND PATIENTS: Retrospective analysis of routinely collected hospital admissions data from all Queensland hospitals (public and private) between 2012 and 2016 for injury-related admissions where the activity engaged in when injured was coded as sports or leisure activity. MAIN OUTCOME MEASURES: Number of hospitalisations; rate of hospitalisation per 100,000 population and demographic, injury, treatment, and outcome details of hospitalised injury patients. RESULTS: Between 01 January 2012 and 31 December 2016, 76,982 people were hospitalised for a sports or leisure-related injury in Queensland. More people were hospitalised in public hospitals than private. Rates were highest for those under 14 years (601.5/100,000 population) and were higher in males (130.6/100,000 population) than females (28.9/100,000 population). A total of 18,734 injuries (24.3%; 79.5/100,000 population) were sustained while playing team ball sports, with rugby codes (rugby union, rugby league and rugby unspecified) representing the single largest source of injuries with 6,592. The extremities were the most likely body location of injury (46,644; 198/100,000 population), and the most common injury type was a fracture (35,018; 148.6/100,000 population). CONCLUSIONS: The findings highlight the significant burden of sport and leisure-related injury hospitalisations in Queensland. This information is important for injury prevention and trauma system planning.

Fitness of Escherichia coli strains carrying expressed and partially silent IncN and IncP1 plasmids.

BACKGROUND: Understanding the survival of resistance plasmids in the absence of selective pressure for the antibiotic resistance genes they carry is important for assessing the value of interventions to combat resistant bacteria. Here, several poorly explored questions regarding the fitness impact of IncP1 and IncN broad host range plasmids on their bacterial hosts are examined; namely, whether related plasmids have similar fitness impacts, whether this varies according to host genetic background, and what effect antimicrobial resistance gene silencing has on fitness. RESULTS: For the IncP1 group pairwise in vitro growth competition demonstrated that the fitness cost of plasmid RP1 depends on the host strain. For the IncN group, plasmids R46 and N3 whose sequence is presented for the first time conferred remarkably different fitness costs despite sharing closely related backbone structures, implicating the accessory genes in fitness. Silencing of antimicrobial resistance genes was found to be beneficial for host fitness with RP1 but not for IncN plasmid pVE46. CONCLUSIONS: These findings suggest that the fitness impact of a given plasmid on its host cannot be inferred from results obtained with other host-plasmid combinations, even if these are closely related.

Shortening cemented femoral implants: an in vitro investigation to quantify exeter femoral implant rotational stability vs simulated implant length.

The Exeter stems vary in length from 90 to 150 mm. The shorter stems generally have lower offsets. The purpose of this study was to determine if length of stem, with fixed offset, affected rotational stability. Mechanical testing was carried out on 10 implant-cement constructs with 2 loading profiles, rising from chair and stair climbing, at different simulated implant lengths using purpose-built apparatus. This paper presents a mechanism for clinically observed rotational stability and explains the mechanical characteristics required for rotational stability in Exeter femoral stems.

Effecting change using careplans: experience from two fractured neck of femur pathways.

OBJECTIVE: To use a qualitative track of the effects of two fractured neck of femur careplans (1 & 2) implemented at the Ipswich Emergency Department in 2002 and 2003 in order to comment on the reasons for comparative successes and failures as instruments for change in clinical practice. Careplan 1 was initiated by local clinicians in 2002, rescinded in 2003 to make way for the system wide careplan 2, then informally restituted in 2004 after careplan 2 was withdrawn. Careplan 2 did not articulate specific ED management plans. METHOD: Biennial retrospective chart audits of two newly introduced evidence-based clinical practices over time was used to track changes from careplan 1. These were the use of regional anaesthesia by medical staff, and the compliance with indwelling urinary catheter insertion by nursing staff. RESULTS: Elements of careplan 1 continued despite lack of promotion. There has been significant increase in nerve block (2.8% to 27%) and indwelling catheter insertion (26% to 75%) from 2000 to 2009. Formal use of careplan 1 has declined to 13-20% in 2009. Careplan 2 was withdrawn for review in 2004. CONCLUSIONS: Careplans are one way to effect lasting changes in clinical behaviours which may persist beyond their implementation and promotion phases. For acceptance, corporate plans should incorporate local practices. For longevity, local plans should comply with the corporate vision of continuity of care, but local investment in the plan will facilitate uptake.

The in vivo efficacy of two administration routes of a phage cocktail to reduce numbers of Campylobacter coli and Campylobacter jejuni in chickens.

BACKGROUND: Poultry meat is one of the most important sources of human campylobacteriosis, an acute bacterial enteritis which is a major problem worldwide. Campylobacter coli and Campylobacter jejuni are the most common Campylobacter species associated with this disease. These pathogens live in the intestinal tract of most avian species and under commercial conditions they spread rapidly to infect a high proportion of the flock, which makes their treatment and prevention very difficult. Bacteriophages (phages) are naturally occurring predators of bacteria with high specificity and also the capacity to evolve to overcome bacterial resistance. Therefore phage therapy is a promising alternative to antibiotics in animal production. This study tested the efficacy of a phage cocktail composed of three phages for the control of poultry infected with C. coli and C. jejuni. Moreover, it evaluated the effectiveness of two routes of phage administration (by oral gavage and in feed) in order to provide additional information regarding their future use in a poultry unit. RESULTS: The results indicate that experimental colonisation of chicks was successful and that the birds showed no signs of disease even at the highest dose of Campylobacter administered. The phage cocktail was able to reduce the titre of both C. coli and C. jejuni in faeces by approximately 2 log10 cfu/g when administered by oral gavage and in feed. This reduction persisted throughout the experimental period and neither pathogen regained their former numbers. The reduction in Campylobacter titre was achieved earlier (2 days post-phage administration) when the phage cocktail was incorporated in the birds' feed. Campylobacter strains resistant to phage infection were recovered from phage-treated chickens at a frequency of 13%. These resistant phenotypes did not exhibit a reduced ability to colonize the chicken guts and did not revert to sensitive types. CONCLUSIONS: Our findings provide further evidence of the efficacy of phage therapy for the control of Campylobacter in poultry. The broad host range of the novel phage cocktail enabled it to target both C. jejuni and C. coli strains. Moreover the reduction of Campylobacter by approximately 2 log10cfu/g, as occurred in our study, could lead to a 30-fold reduction in the incidence of campylobacteriosis associated with consumption of chicken meals (according to mathematical models). To our knowledge this is the first report of phage being administered in feed to Campylobacter-infected chicks and our results show that it lead to an earlier and more sustainable reduction of Campylobacter than administration by oral gavage. Therefore the present study is of extreme importance as it has shown that administering phages to poultry via the food could be successful on a commercial scale.

Pediatric acute asthma scoring systems: a systematic review and survey of UK practice.

BACKGROUND: Acute exacerbations of asthma are common in children. Multiple asthma severity scores exist, but current emergency department (ED) use of severity scores is not known. METHODS: A systematic review was undertaken to identify the parameters collected in pediatric asthma severity scores. A survey of Paediatric Emergency Research in the United Kingdom and Ireland (PERUKI) sites was undertaken to ascertain routinely collected asthma data and information about severity scores. Included studies examined severity of asthma exacerbation in children 5-18 years of age with extractable severity parameters. RESULTS: Sixteen articles were eligible, containing 17 asthma severity scores. The severity scores assessed combinations of 15 different parameters (median, 6; range, 2-8). The most common parameters considered were expiratory wheeze (15/17), inspiratory wheeze (13/17), respiratory rate (10/17), and general accessory muscle use (9/17). Fifty-nine PERUKI centers responded to the questionnaire. Twenty centers (33.1%) currently assess severity, but few use a published score. The most commonly recorded routine data required for severity scores were oxygen saturations (59/59, 100%), heart rate, and respiratory rate (58/59, 98.3% for both). Among well-validated scores like the Pulmonary Index Score (PIS), Pediatric Asthma Severity Score (PASS), Childhood Asthma Score (CAS), and the Pediatric Respiratory Assessment Measure (PRAM), only 6/59 (10.2%), 3/59 (5.1%), 1/59 (1.7%), and 0 (0%) of units respectively routinely collect the data required to calculate them. CONCLUSION: Standardized published pediatric asthma severity scores are infrequently used. Improved routine data collection focusing on the key parameters common to multiple scores could improve this, facilitating research and audit of pediatric acute asthma.

Temporal and spatial variation in landscape connectivity for a freshwater turtle in a temporally dynamic wetland system.

Inter-wetland connectivity, defined here as the movement of biota among discrete water bodies, can have important population- and community-level consequences in aquatic systems. We examined inter-wetland connectivity in a southeastern Australian national park by intensively monitoring the movements of freshwater turtles (Chelodina longicollis) via capture-mark-recapture over a three-year period, and more sporadically for 25 years. A high percentage (33%) of turtles moved between wetlands, suggesting that single wetlands should not represent the minimum habitat unit harboring a C. longicollis population. Distance was the only structural landscape metric correlated with inter-patch transition probability, with probability declining as inter-wetland distance increased. Movements also appear to be strongly influenced by shifting resource quality gradients between temporary wetlands and permanent lakes according to drought and flood cycles, a pattern more consistent with migration between critical resource patches than occasional interpopulational dispersal. Rare dispersal events of up to 5.2 km were known to occur. Captures at a terrestrial drift fence suggest that small and immature turtles moved between wetlands more frequently than our aquatic sampling indicated. We caution that measures of actual (or functional) connectivity can be biased by sampling methods and the temporal scale of sampling and must also be interpreted in the context of factors that motivate animal movements. This requires some understanding of spatial and temporal variation in intra-patch processes (e.g., quality and extent) and the expected movement responses of animals (e.g., habitat selection) over extended time frames, information that can potentially yield more important insight on connectivity than measures of landscape structural features alone.

Coronal plane laxity of valgus osteoarthritic knee.

INTRODUCTION: Balanced soft tissues are important to total knee arthroplasty (TKA) outcomes. Surgical algorithms for balancing are potentially varied in varus and valgus osteoarthritic (OA) knees. While coronal plane varus knee laxity has been documented, no study has objectively defined the medial and lateral laxity of the valgus OA knee. The lower limb was manipulated at the time of TKA using computer navigation, prior to surgical releases, to allow the limb weight-bearing axis to pass through the knee center in maximum extension, 20° and 90° of flexion. The hip-knee-ankle-angle was documented at this position. Coronal plane laxity was then measured in 30 valgus (7.9 ± 4.0°) knees as medial and lateral displacement from this point and compared to published values for healthy subjects. In maximum knee extension, lateral contracture was present in 26.6% (8/30) of subjects, and abnormally lax medial tissue was present in 46.6% (14/30). Six patterns of medial versus lateral laxity were documented in maximum extension. In maximum knee extension, mean medial laxity was 7.1° (±3.8°) compared to 2.7° (±2.7°) laterally. In 20° of knee flexion, mean medial laxity was 8.5° (±3.5°) compared to 3.0° (±2.6°) laterally. In 90° of knee flexion, mean medial laxity was 3.7° (±1.3°) and 7.5° (±3.0°) laterally. A highly significant difference ( p < 0.0001) in mean laxity was demonstrated when comparing medial versus lateral values at each measurement angle and for medial versus medial and lateral versus lateral values for maximum extension and 90° of flexion. The valgus knee at the time of TKA demonstrates significant preoperative mediolateral and flexion-extension imbalance. In maximum extension, medial tissue is significantly laxer whereas in flexion this reverses and the lateral tissue is significantly laxer. We documented more patterns of medial and lateral laxity in maximum extension than advocated in prior subjective grading systems. These findings demonstrate the challenges of valgus OA knee balancing during TKA but provide, for the first time, objective measures for the starting point of this process.

Maintenance of variable responses for coping with wetland drying in freshwater turtles.

Aquatic animals inhabiting temporary wetlands must respond to habitat drying either by estivating or moving to other wetlands. Using radiotelemetry and capture mark recapture, we examined factors influencing the decisions made by individuals in a population of freshwater turtles (Chelodina longicollis) in response to wetland drying in southeastern Australia. Turtles exhibited both behaviors, either remaining quiescent in terrestrial habitats for variable lengths of time (terrestrial estivation) or moving to other wetlands. Both the proportion of individuals that estivated terrestrially and the time individuals spent in terrestrial habitats increased with decreasing wetland hydroperiod and increasing distance to the nearest permanent wetland, suggesting behavioral decisions are conditional or state dependent (i.e., plastic) and influenced by local and landscape factors. Variation in the strategy or tactic chosen also increased with increasing isolation from other wetlands, suggesting that individuals differentially weigh the costs and benefits of residing terrestrially vs. those of long-distance movement; movement to other wetlands was the near universal strategy chosen when only a short distance must be traveled to permanent wetlands. The quality of temporary wetlands relative to permanent wetlands at our study site varies considerably and unpredictably with annual rainfall and with it the cost-benefit ratio of each strategy or tactic. Residency in or near temporary wetlands is more successful during wet periods due to production benefits, but movement to permanent wetlands is more successful, or least costly, during dry periods due to survival and body condition benefits. This shifting balance may maintain diversity in response of turtles to the spatial and temporal pattern in wetland quality if their response is in part genetically determined.

Acute Paravertebral Compartment Syndrome: Follow-up and Literature Review.

OBJECTIVE: To report on a patient with acute paravertebral and posterior thigh compartment syndrome after vigorous exercise. BACKGROUND: Paravertebral compartment syndrome (PCS) is a rare clinical entity, typically occurring in male athletes after heavy exertion and weightlifting. CASE: A 25-year-old man presented with back pain and hematuria hours after back-specific weightlifting. Clinical examination, laboratory markers, MRI, and elevated intracompartmental pressure measurements supported the diagnosis of bilateral paravertebral and posterior thigh compartment syndrome. The patient underwent paravertebral decompression via the Wiltse approach with immediate postoperative relief. He is doing well at 1 year, with recovery of lumbar extension strength, although MRI demonstrates moderate fatty replacement of paravertebral musculature. CONCLUSIONS: Although rare, early recognition of PCS and timely decompression can limit myonecrosis. Paravertebral compartment syndrome should be considered in the differential for athletic individuals with acute onset back pain. STUDY DESIGN: A case report and review of literature.