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There is wide variation in mortality among patients hospitalized with COVID-19. Whether this is related to patient or hospital factors is unknown.To compare the risk of mortality for patients hospitalized with COVID-19 and to determine whether the majority of that variation was explained by differences in patient characteristics across sites.An international multicenter cohort study of hospitalized adults with laboratory-confirmed COVID-19 enrolled from 10 hospitals in Ontario, Canada and 8 hospitals in Copenhagen, Denmark between January 1, 2020 and November 11, 2020.Inpatient mortality. We used a multivariable multilevel regression model to compare the in-hospital mortality risk across hospitals and quantify the variation attributable to patient-level factors.There were 1364 adults hospitalized with COVID-19 in Ontario (n = 1149) and in Denmark (n = 215). In Ontario, the absolute risk of in-hospital mortality ranged from 12.0% to 39.8% across hospitals. Ninety-eight percent of the variation in mortality in Ontario was explained by differences in the characteristics of the patients. In Denmark, the absolute risk of inpatients ranged from 13.8% to 20.6%. One hundred percent of the variation in mortality in Denmark was explained by differences in the characteristics of the inpatients.There was wide variation in inpatient COVID-19 mortality across hospitals, which was largely explained by patient-level factors, such as age and severity of presenting illness. However, hospital-level factors that could have affected care, including resource availability and capacity, were not taken into account. These findings highlight potential limitations in comparing crude mortality rates across hospitals for the purposes of reporting on the quality of care.

The producer-scrounger game is a key element of foraging ecology in many systems. Producing and scrounging typically covary negatively, but partitioning this covariance into contributions of individual plasticity and consistent between individual differences is key to understanding population-level consequences of foraging strategies. Furthermore, little is known about the role cognition plays in the producer-scrounger game. We investigated the role of cognition in these alternative foraging tactics in wild mixed-species flocks of great tits and blue tits, using a production learning task in which we measured individuals' speed of learning to visit the single feeder in an array that would provide them with a food reward. We also quantified the proportion of individuals' feeds that were scrounges ('proportion scrounged'); scrounging was possible if individuals visited immediately after a previous rewarded visitor. Three learning experiments-initial and two reversal learning-enabled us to estimate the repeatability and covariance of each foraging behaviour. First, we examined whether individuals learned to improve their scrounging success (i.e. whether they obtained food by scrounging when there was an opportunity to do so). Second, we quantified the repeatability of proportion scrounged, and asked whether proportion scrounged affected production learning speed among individuals. Third, we used multivariate analyses to partition within- and among-individual components of covariance between proportion scrounged and production learning speed. Individuals improved their scrounging success over time. Birds with a greater proportion scrounged took longer to learn their own rewarding feeder. Although multivariate analyses showed that covariance between proportion scrounged and learning speed was driven primarily by within-individual variation, that is, by behavioural plasticity, among-individual differences also played a role for blue tits. This is the first demonstration of a cognitive trait influencing producing and scrounging in the same wild system, highlighting the importance of cognition in the use of alternative resource acquisition tactics. The results of our covariance analyses suggest the potential for genetic differences in allocation to alternative foraging tactics, which are likely species- and system-dependent. They also point to the need to control for different foraging tactics when studying individual cognition in the wild.

Passive acoustic monitoring is increasingly being used as a cost‐effective way to study wildlife populations, especially those that are difficult to census using conventional methods. Burrow‐nesting seabirds are among the most threatened birds globally, but they are also one of the most challenging taxa to census, making them prime candidates for research into such automated monitoring platforms. Passive acoustic monitoring has the potential to determine presence/absence or quantify burrow‐nesting populations, but its effectiveness remains unclear. We compared passive acoustic monitoring, tape‐playbacks and GPS tracking data to investigate the ability of passive acoustic monitoring to capture unbiased estimates of within‐colony variation in nest density for the Manx Shearwater Puffinus puffinus. Variation in acoustic activity across 12 study plots on an island colony was examined in relation to burrow density and environmental factors across 2 years. As predicted fewer calls were recorded when wind speed was high, and on moon‐lit nights, but there was no correlation between acoustic activity and the density of breeding birds within the plots as determined by tape‐playback surveys. Instead, acoustic indices correlated positively with spatial variation in the in‐colony flight activity of breeding individuals detected by GPS. Although passive acoustic monitoring has enormous potential in avian conservation, our results highlight the importance of understanding behaviour when using passive acoustic monitoring to estimate density and distribution.

OBJECTIVES Australopithecus anamensis has comparable δ13 Cenamel values to Ardipithecus ramidus, and both have been characterized as C3 feeders in open woodland habitats similar to "savanna" chimps. Unlike Ar. ramidus and "savanna" chimps, A. anamensis shows a derived dentognathic morphology for tough foods and a dental microwear pattern similar to the C3 -C4 -mixed-feeding A. afarensis. Here I test the hypothesis that changing the variables (e*enamel-diet , δ13 CC3, δ13 CC4 values) used to calculate the percentage of dietary C4 foods (%C4 diet) by 1-2‰ does not make a substantial difference for hominin diet reconstructions [van der Merwe, Masao, & Bamford, 2008, South African Journal of Science 104:153-155]. MATERIALS AND METHODS I estimate vegetation structures for A. anamensis with pedogenic carbonate and faunal enamel δ13 C values from the Pliocene Omo-Turkana Basin (4.2-3.9 Ma). I recalculate A. anamensis' %C4 diet based on new body size-dependent estimates of the e*enamel-diet value and alternative δ13 CC3 and δ13 CC4 values. RESULTS The Pliocene Omo-Turkana Basin shows evidence for dietary resources with a wide range of δ13 C values including canopy-driven 13 C depleted ground C3 foods. Alternative equation variables changed by 1-2‰ yield higher C4 estimates for A. anamensis (15-31%) than previously thought (0-10%). The choice of δ13 CC3 and δ13 CC4 values for estimating %C4 is not a perfunctory task and potentially explains the δ13 C isotopic equifinality of A. anamensis and "savanna" chimps. DISCUSSION My integrative diet model reconciles the carbon isotopic data with the dentognathic and microwear evidence of A. anamensis' diet and suggests that "savanna" chimps are not proper dietary analogs of A. anamensis. A foraging strategy across heterogeneous habitats of the Pliocene Omo-Turkana Basin incorporating an array of 13 C-depleted and 13 C-enriched C3 foods and a portion of C4 resources may have served as one of the selective pressures for A. anamensis, the earliest habitual biped [van der Merwe et al., 2008, South African Journal of Science 104:153-155].

Little is known about the presence of incomplete convergence in the evolution of vertebrate taxa, as it is difficult to differentiate between evolutionary methods responsible for the appearance of similar forms. Grossnickle et al. present the first study of convergence evaluating all six extant glider clades using phylogenetic comparative methods. The authors find that the unique skeletal morphology of extant glider species (i.e., longer and thinner limbs) results from incomplete convergence under Brownian motion.

Objective To determine whether the presence of spontaneous echocardiographic contrast (SEC) in cats with cardiomyopathy is associated with increased mortality. To establish whether specific types of cardiomyopathy are more often associated with SEC in an attempt to provide a risk-stratification scheme for cats with increased risk of thromboembolic events. Design Retrospective study 2006–2011. Setting Tertiary referral and teaching hospital. Animals Seven hundred twenty-five client-owned cats undergoing echocardiographic evaluation. Measurements and Main Results Patient characteristics, including age, breed, clinical signs, type of cardiovascular disease, presence of SEC, and survival time were recorded. Thyroxine, HCT, and blood pressure were recorded when available. Among cats diagnosed with cardiac abnormalities based on echocardiographic findings, those with SEC were at significantly increased risk of death as compared to those without SEC. Cats with dilated cardiomyopathy, unclassified cardiomyopathy, and hypertrophic cardiomyopathy were significantly more likely to have SEC compared to cats with other types of cardiac disease. Conclusions Cats with cardiomyopathy and SEC have an increased risk of death compared to cats without SEC, although other previously identified factors such as the presence of congestive heart failure and increased left atrium to aorta ratio remain important determinants of mortality. Cats with hypertrophic cardiomyopathy, unclassified cardiomyopathy, and dilated cardiomyopathy may benefit from anticoagulant therapy due to the increased risk of SEC in these subpopulations.

Background We have previously developed a novel digital tool capable of automatically recognizing correct electrocardiography (ECG) diagnoses in an online exam and demonstrated a significant improvement in diagnostic accuracy when utilizing an inductive-deductive reasoning strategy over a pattern recognition strategy. In this study, we sought to validate these findings from participants at the International Winter Arrhythmia School meeting, one of the foremost electrophysiology events in Canada. Methods Preregistration to the event was sent by e-mail. The exam was administered on day 1 of the conference. Results and analysis were presented the following morning to participants. Results Twenty-five attendees completed the exam, providing a total of 500 responses to be marked. The online tool accurately identified 195 of a total of 395 (49%) correct responses (49%). In total, 305 responses required secondary manual review, of which 200 were added to the correct responses pool. The overall accuracy of correct ECG diagnosis for all participants was 69% and 84% when using pattern recognition or inductive-deductive strategies, respectively. Conclusion Utilization of a novel digital tool to evaluate ECG competency can be set up as a workshop at international meetings or educational events. Results can be presented during the sessions to ensure immediate feedback.

Objective To review the current veterinary and relevant human literature regarding biomarkers of cardiac disease leading to respiratory compromise. Data Sources Veterinary and human medical literature: original research articles, scientific reviews, consensus statements, and recent textbooks. Human Data Synthesis Cardiac troponins (cTn) and natriuretic peptides are routinely used in human medicine. Veterinary Data Synthesis Although biomarkers should not be accepted in lieu of gold standard diagnostics, they may be useful in directing care in the stabilization process. Biomarkers of congestive heart failure (CHF) include natriuretic peptides, cTn, and endothelin. cTnI is useful in differentiating causes of pericardial effusion, but is unlikely to be useful in differentiating CHF from other causes of respiratory distress. The most extensively studied and promising cardiac biomarker is amino-terminal probrain natriuretic peptide, although a bedside test is not currently available. Other natriuretic peptides have also proven useful, but have lower availability. Endothelin is unlikely to be clinically useful. Although critically evaluated for their use in cardiac diseases, many of the biomarkers are affected by more than one type of respiratory or systemic disease. Several cardiac biomarkers are increased in cases of pulmonary hypertension (PH), but discerning CHF alone from PH or a combination of heart disease and PH is challenging when evaluating biomarkers alone. Conclusion At this time, there are no point-of-care tests for biomarkers that can reliably differentiate among causes of dyspnea of cardiac origin in dogs and cats, although there are reference laboratory tests that show promise and future development of point-of-care tests that may be useful in certain situations.

Objectives To review the current veterinary and relevant human literature regarding biomarkers of respiratory diseases leading to dyspnea and to summarize the availability, feasibility, and practicality of using respiratory biomarkers in the veterinary setting. Data Sources Veterinary and human medical literature: original research articles, scientific reviews, consensus statements, and recent textbooks. Human Data Synthesis Numerous biomarkers have been evaluated in people for discriminating respiratory disease processes with varying degrees of success. Veterinary Data Synthesis Although biomarkers should not dictate clinical decisions in lieu of gold standard diagnostics, their use may be useful in directing care in the stabilization process. Serum immunoglobulins have shown promise as an indicator of asthma in cats. A group of biomarkers has also been evaluated in exhaled breath. Of these, hydrogen peroxide has shown the most potential as a marker of inflammation in asthma and potentially aspiration pneumonia, but methods for measurement are not standardized. D-dimers may be useful in screening for thromboembolic disease in dogs. There are a variety of markers of inflammation and oxidative stress, which are being evaluated for their ability to assess the severity and type of underlying disease process. Of these, amino terminal pro-C-type natriuretic peptide may be the most useful in determining if antibiotic therapy is warranted. Although critically evaluated for their use in respiratory disorders, many of the biomarkers which have been evaluated have been found to be affected by more than one type of respiratory or systemic disease. Conclusion At this time, there are point-of-care biomarkers that have been shown to reliably differentiate between causes of dyspnea in dogs and cats. Future clinical research is warranted to understand of how various diseases affect the biomarkers and more bedside tests for their utilization.

Cognition is defined as the processes by which animals collect, retain and use information from their environment to guide their behaviour. Thus cognition is essential in a wide range of behaviours, including foraging, avoiding predators and mating. Despite this pivotal role, the evolutionary processes shaping variation in cognitive performance among individuals in wild populations remain very poorly understood. Selection experiments in captivity suggest that cognitive traits can have substantial heritability and can undergo rapid evolution. However only a handful of studies have attempted to explore how cognition influences life-history variation and fitness in the wild, and direct evidence for the action of natural or sexual selection on cognition is still lacking, reasons for which are diverse. Here we review the current literature with a view to: (i) highlighting the key practical and conceptual challenges faced by the field; (ii) describing how to define and measure cognitive traits in natural populations, and suggesting which species, populations and cognitive traits might be examined to greatest effect; emphasis is placed on selecting traits that are linked to functional behaviour; (iii) discussing how to deal with confounding factors such as personality and motivation in field as well as captive studies; (iv) describing how to measure and interpret relationships between cognitive performance, functional behaviour and fitness, offering some suggestions as to when and what kind of selection might be predicted; and (v) showing how an evolutionary ecological framework, more generally, along with innovative technologies has the potential to revolutionise the study of cognition in the wild. We conclude that the evolutionary ecology of cognition in wild populations is a rapidly expanding interdisciplinary field providing many opportunities for advancing the understanding of how cognitive abilities have evolved.

The over-expression of NF-κB signalling in both muscle and immune cells contribute to the pathology in dystrophic muscle. The anti-inflammatory properties of glucocorticoids, mediated predominantly through monomeric glucocorticoid receptor inhibition of transcription factors such as NF-κB (transrepression), are postulated to be an important mechanism for their beneficial effects in Duchenne muscular dystrophy. Chronic glucocorticoid therapy is associated with adverse effects on metabolism, growth, bone mineral density and the maintenance of muscle mass. These detrimental effects result from direct glucocorticoid receptor homodimer interactions with glucocorticoid response elements of the relevant genes. Compound A, a non-steroidal selective glucocorticoid receptor modulator, is capable of transrepression without transactivation. We confirm the in vitro NF-κB inhibitory activity of compound A in H-2Kb-tsA58 mdx myoblasts and myotubes, and demonstrate improvements in disease phenotype of dystrophin deficient mdx mice. Compound A treatment in mdx mice from 18 days of post-natal age to 8 weeks of age increased the absolute and normalized forelimb and hindlimb grip strength, attenuated cathepsin-B enzyme activity (a surrogate marker for inflammation) in forelimb and hindlimb muscles, decreased serum creatine kinase levels and reduced IL-6, CCL2, IFNγ, TNF and IL-12p70 cytokine levels in gastrocnemius (GA) muscles. Compared with compound A, treatment with prednisolone, a classical glucocorticoid, in both wild-type and mdx mice was associated with reduced body weight, reduced GA, tibialis anterior and extensor digitorum longus muscle mass and shorter tibial lengths. Prednisolone increased osteopontin (Spp1) gene expression and osteopontin protein levels in the GA muscles of mdx mice and had less favourable effects on the expression of Foxo1, Foxo3, Fbxo32, Trim63, Mstn and Igf1 in GA muscles, as well as hepatic Igf1 in wild-type mice. In conclusion, selective glucocorticoid receptor modulation by compound A represents a potential therapeutic strategy to improve dystrophic pathology.

An absence of dysferlin leads to activation of innate immune receptors such as Toll-like receptors (TLRs) and skeletal muscle inflammation. Myeloid differentiation primary response gene 88 (MyD88) is a key mediator of TLR-dependent innate immune signalling. We hypothesized that endogenous TLR ligands released from the leaking dysferlin-deficient muscle fibres engage TLRs on muscle and immune cells and contribute to disease progression. To test this hypothesis, we generated and characterized dysferlin and MyD88 double-deficient mice. Double-deficient mice exhibited improved body weight, grip strength, and maximum muscle contractile force at 6-8 months of age when compared to MyD88-sufficient, dysferlin-deficient A/J mice. Double-deficient mice also showed a decrease in total fibre number, which contributed to the observed increase in the number of central nuclei/fibres. These results indicate that there was less regeneration in the double-deficient mice. We next tested the hypothesis that endogenous ligands, such as single-stranded ribonucleic acids (ssRNAs), released from damaged muscle cells bind to TLR-7/8 and perpetuate the disease progression. We found that injection of ssRNA into the skeletal muscle of pre-symptomatic mice (2 months old) resulted in a significant increase in degenerative fibres, inflammation, and regenerating fibres in A/J mice. In contrast, characteristic histological features were significantly decreased in double-deficient mice. These data point to a clear role for the TLR pathway in the pathogenesis of dysferlin deficiency and suggest that TLR-7/8 antagonists may have therapeutic value in this disease.

By integrating osteological, taphonomic, archaeological and stable isotopic data, we test for cannibalism in the Lau Group, Fiji and discuss the potential underlying cause(s) and context(s) of this behaviour. First, we compare taphonomic and element representations of human skeletal material from two contexts in Fiji, examining human bone fragments from archaeological sites, including middens and burials in the Lau Island Group. Fourteen sites produced human remains. Only two of those sites included distinct human burial contexts, but in the remaining 12 sites, the human bone was recovered from middens or contexts where midden was mixed with possible secondary burials. A total of 262 number of identified specimens per species, representing an estimated 15 minimum number of individuals make up the Lau human assemblage. Second, we analysed bones contained in 20 individual human burials from four different sites that are housed at the Fiji Museum for comparative purposes. Third, we examine previously published stable isotopic (δ13C, δ15N) analysis of bone collagen to gauge protein consumption of likely cannibalised humans in midden contexts and potential cannibals from primary burials. We model a cannibalistic diet category within the context of isotopically measured Pacific Islands food groups and apply an isotopic mixing model to gauge plausible dietary contributions from six sources including human flesh. Isotopic mixing models of the Lauan samples illustrate a high diversity in reconstructed diets. The percent contribution of human flesh is low for all individual Lauans. We conclude that mortuary rituals evidenced by sharp-force trauma may suggest non-nutritive and non-violent practices that may have included the consumption of small amounts of human flesh. Copyright © 2012 John Wiley & Sons, Ltd.

Th eory and empirical evidence suggest that predator activity makes prey more wary and less vulnerable to predation. However if at least some prey in the population are energetically or spatially constrained, then predators may eventually increase local prey vulnerability because of the cumulative costs of anti-predation behaviour. We tested whether repeated attacks by a predator might increase prey vulnerability in a system where redshanks on a saltmarsh are attacked regularly by sparrowhawks from adjacent woodland. Cumulative attack number led to a reduction in redshank numbers and fl ock size (but had no eff ect on how close redshanks fed to predator-concealing cover) because some redshanks moved to safer but less profi table habitats, leaving smaller fl ocks on the saltmarsh. Th is eff ect held even though numbers of redshank on the saltmarsh increased with time of day. As a result of the change in fl ock size, predicted attack-success increased up to 1.6-fold for the sparrowhawk, while individual risk of capture for the redshank increased up to 4.5-fold among those individuals remaining on the saltmarsh. Th e eff ect did not arise simply because hawks were more likely to attack smaller fl ocks because attack rate was not dependent on fl ock size or abundance. Our data demonstrate that when some individual prey are constrained in their ability to feed on alternative, safer foraging sites, their vulnerability to predation increases as predator attacks accumulate, although those, presumably better quality individuals that leave the immediate risky area will have lower vulnerability, so that the mean vulnerability across the entire population may not have changed substantially. Th is suggests that the selective benefi ts of multiple low-cost attacks by predators on prey could potentially lead to 1) locally heightened trait-mediated interactions, 2) locally reduced interference among competing predators, and 3) the evolution of active prey manipulation by predators.

d-boroAla was previously characterized as an inhibitor of bacterial alanine racemase and d-Ala-d-Ala ligase enzymes (Biochemistry, 28, 1989, 3541). In this study, d-boroAla was identified and characterized as an antibacterial agent. d-boroAla has activity against both Gram-positive and Gram-negative organisms, with minimal inhibitory concentrations down to 8 μg / mL. A structure-function study on the alkyl side chain (NH(2) -CHR-B(OR')(2) ) revealed that d-boroAla is the most effective agent in a series including boroGly, d-boroHomoAla, and d-boroVal. l-boroAla was much less active, and N-acetylation completely abolished activity. An LC-MS / MS assay was used to demonstrate that d-boroAla exerts its antibacterial activity by inhibition of d-Ala-d-Ala ligase. d-boroAla is bactericidal at 1× minimal inhibitory concentration against Staphylococcus aureus and Bacillus subtilis, which each encode one copy of d-Ala-d-Ala ligase, and at 4× minimal inhibitory concentration against Escherichia coli and Salmonella enterica serovar Typhimurium, which each encode two copies of d-Ala-d-Ala ligase. d-boroAla demonstrated a frequency of resistance of 8 × 10(-8) at 4× minimal inhibitory concentration in S. aureus. These results demonstrate that d-boroAla has promising antibacterial activity and could serve as the lead agent in a new class of d-Ala-d-Ala ligase targeted antibacterial agents. This study also demonstrates d-boroAla as a possible probe for d-Ala-d-Ala ligase function.

1. Interest in the evolutionary origin and maintenance of individual behavioural variation and behavioural plasticity has increased in recent years. 2. Consistent individual behavioural differences imply limited behavioural plasticity, but the proximate causes and wider consequences of this potential constraint remain poorly understood. To date, few attempts have been made to explore whether individual variation in behavioural plasticity exists, either within or between populations. 3. We assayed 'exploration behaviour' among wild-caught individual great tits Parus major when exposed to a novel environment room in four populations across Europe. We quantified levels of individual variation within and between populations in average behaviour, and in behavioural plasticity with respect to (i) repeated exposure to the room (test sequence), (ii) the time of year in which the assays were conducted and (iii) the interval between successive tests, all of which indicate habituation to novelty and are therefore of functional significance. 4. Consistent individual differences ('I') in behaviour were present in all populations; repeatability (range: 0.34-0.42) did not vary between populations. Exploration behaviour was also plastic, increasing with test sequence - but less so when the interval between subsequent tests was relatively large - and time of year; populations differed in the magnitude of plasticity with respect to time of year and test interval. Finally, the between-individual variance in exploration behaviour increased significantly from first to repeat tests in all populations. Individuals with high initial scores showed greater increases in exploration score than individuals with low initial scores; individual by environment interaction ('I × E') with respect to test sequence did not vary between populations. 5. Our findings imply that individual variation in both average level of behaviour and behavioural plasticity may generally characterize wild great tit populations and may largely be shaped by mechanisms acting within populations. Experimental approaches are now needed to confirm that individual differences in behavioural plasticity (habituation) - not other hidden biological factors - caused the observed patterns of I × E. Establishing the evolutionary causes and consequences of this variation in habituation to novelty constitutes an exciting future challenge.

Summary 1. Dispersal is a key process in population biology and ecology. Although the general ecological conditions that lead to dispersal have been well studied, the causes of individual variation in dispersal are less well understood. A number of recent studies suggest that heritable temperament – or personality – traits are correlated with dispersal in the wild but the extent to which these ‘personality-dispersal syndromes’ are general, how they depend on an individual’s state and on spatial scale and whether they are temporally stable, both within and across individuals, remains unclear. 2. Here, we examine the relationship between exploration behaviour – an axis of personality that appears to be important in animals generally – and a variety of dispersal processes over 6 years in a population of the great tit Parus major. 3. Exploration behaviour was higher in immigrant than in locally born juveniles, but the difference was much larger for individuals with a small body mass, though independent of sex, representing one of the first examples of a state-dependent effect in a personality-dispersal syndrome. 4. Despite a temporal trend in exploration behaviour at the population level, the difference between immigrants and locally born birds remained stable over time, both across and within individuals. This suggests that the personality difference between immigrants and locally born birds is established early in development, but that the process of immigration interacts with both personality and state. 5. We found that the number of immigrant parents a locally born bird had did not influence exploration behaviour, suggesting either the difference between immigrants and residents was environmental or that the effect is overridden by local environmental sources of variation. 6. In contrast to previous work, we found no evidence for links between personality and natal dispersal distance within the population, either in terms of an individual’s own exploration behaviour or that of its parents. 7. Our results suggest that there are links between individual differences in personality and dispersal, but that these can be dependent on differences in state among individuals and on the scale over which dispersal is measured. Future work should aim to understand the differences between dispersal within and between populations and the ways in which personality and state interact to determine the outcome of these processes.

Summary 1. How group size affects predator attack and success rate, and so prey vulnerability, is important in determining the nonlethal consequences of predation risk on animal populations and communities. Theory predicts that both predator attack success rate and the dilution effect decline exponentially with group size and that selection generates optimal group sizes at a ‘risk threshold’ above which antipredation benefits are outweighed by costs, such as those owing to higher attack rates. 2. We examined whether flock size risk thresholds for attack rate, success rate or dilution differed, and therefore whether the strength of selection for group size differed for these three factors, using a system of redshank Tringa totanus flocks being hunted by Eurasian sparrowhawks Accipiter nisus. We also asked which of the three thresholds, on their own or in combination, predicted the most commonly observed group size. 3. Mean redshank flock size increased with a very gradual quadratic function (i.e. approximately linearly) with population size, although at a rate half that possible; when population size was not limiting, individuals almost always avoided flocks of less than 30 and birds were frequently in flocks up to at least 80. Sparrowhawk attack rate showed a quadratic relationship with flock size and peaked at 55 redshanks. Sparrowhawk attack success rate, however, declined exponentially, becoming less steep at flock sizes of about 40 and remaining uniformly low (a 95% decrease) by 70. Combined with dilution, individual risk of death per attack decreased by 95% when group size reached 30 (20 for the dilution effect alone). 4. Redshanks most commonly formed group sizes that gained the maximum individual predation risk reduction. They also commonly formed group sizes far above any further substantial advantages from the dilution effect or from reducing attack rate, but that continued to reduce predation risk by lowering attack success rate. Individuals did not always form the largest groups possible which we suggest is because individual variation in risk-taking subdivides the population. This places a constraint on the ability of individuals to compensate for predation risk and will have a variety of important effects on animal populations.

Polymorphisms in the dopamine receptor D4 gene (DRD4) have been related to individual variation in novelty-seeking or exploratory behaviour in a variety of animals, including humans. Recently, the human DRD4 orthologue was sequenced in a wild bird, the great tit (Parus major) and a single nucleotide polymorphism in exon 3 of this gene (SNP830) was shown to be associated with variation in exploratory behaviour of lab-raised individuals originating from a single wild population. Here we test the generality of this finding in a large sample of free-living individuals from four European great tit populations, including the originally sampled population. We demonstrate that the association between SNP830 genotype and exploratory behaviour also exists in free-living birds from the original population. However, in the other three populations we found only limited evidence for an association: in two populations the association appeared absent; while in one there was a nonsignificant tendency. We could not confirm a previously demonstrated interaction with another DRD4 polymorphism, a 15 bp indel in the promoter region (ID15). As yet unknown differences in genetic or environmental background could explain why the same genetic polymorphism (SNP830) has a substantial effect on exploratory behaviour in one population, explaining 4.5-5.8% of the total variance-a large effect for a single gene influencing a complex behavioural trait-but not in three others. The confirmation of an association between SNP830 genotype and personality-related behaviour in a wild bird population warrants further research into potential fitness effects of the polymorphism, while also the population differences in the strength of the association deserve further investigation. Another important future challenge is the identification of additional loci influencing avian personality traits in the wild.

Exploiting the nest defence behaviour of another relatively aggressive species is one of the most unusual amongst a great diversity of strategies used by animals to evade predation. Here we review 62 studies that have looked at protective nesting associations in which at least one species is a bird. Most ‘protected’ associates are found in the Anseriformes, the Charadriiformes and the Passeriformes, while most ‘protective’ associates come from the Charadriiformes and the Falconiformes. Protected associates primarily benefit from a reduced predation rate when nesting near protective species although a variety of other, often unusual benefits have been described, including early warning of predators, lower parasitism, lower brood-parasitism, nest stability and higher mating success. Protected associates sometimes also pay costs when they or their young are killed by their aggressive associate, or when they are forced to abandon their nest. Two studies demonstrate that protected species manipulate the trade-off between the costs and benefits of nesting near an aggressive associate, while only a handful of studies have found specific adaptations to help avoid costs. In contrast, there is little evidence to suggest that the protective associates pay costs or gain benefits. This is probably because few researchers set out to test this hypothesis specifically, but we tentatively conclude that the majority of nesting associations are commensal in nature, and that only a few are parasitic or mutualistic. Many studies show that nesting associations occur by active choice and not because the associate species choose similar habitat, but only one study does so experimentally. In two cases the nesting association is obligatory for one of the species but there was also evidence for significant local adaptation to nesting near protective species, sometimes across a broad geographical range. Finally, we identify potential pathways that may have led to the evolution of nesting associations, discuss some possible implications for the populations involved and argue that nesting associations provide many novel research opportunities.

The use of metal and colour-rings or bands as a means of measuring survival, movements and behaviour in birds is universal and fundamental to testing ecological and evolutionary theories. The practice rests on the largely untested assumption that the rings do not affect survival. However this assumption may not hold for several reasons, for example because the ‘oddity effect’ predicts predators select prey that appear different to their neighbours in order to avoid the ‘confusion effect’. We compared the foraging behaviour and the death rates of redshanks Tringa totanus conspicuously marked with six colour rings and one metal ring each to unmarked birds in a study system, where routinely up to 50% of the total population are killed by avian predators during a winter. If avian predators selectively target and/or have a higher capture success of ringed birds then we would predict the proportion of colour-ringed birds in the population to decline through a winter. The proportion of colour-ringed birds in the population did not change over the course of three separate winters, and in one winter the ratio of marked:unmarked birds found killed by sparrowhawks Accipiter nisus was the same as the ratio of marked birds alive in the population. In the year with largest sample size, power was sufficient to detect a greater than 2.2% difference in predation rate between ringed and unringed groups. The average kill rate difference between ringed and unringed birds across the three winters was less than 1% (0.73±2.2%) suggesting that even if there were differences in predation rate that were not detected because of low statistical power they were extremely small. There were no differences in any foraging measures comparing ringed and unringed birds, suggesting that the rings did not affect the ability of birds to meet their daily energy budgets. The results showed that colour-ringed birds were not preferentially targeted or killed by avian predators, and suggest that the presence of a metal and even several large colour-rings is unlikely to affect behaviour and predation mortality even under extreme selection.

Foraging animals frequently change their pattern of vigilance when they move from a patch with a clear view to one with a relatively obstructed view. This has been widely interpreted as compensation for a reduced ability to detect approaching predators in obstructed habitats. We test the extent to which changes in vigilance may compensate for the effect of reduced visibility on an animal's ability to detect predators. We measured the vigilance, foraging and speed of predator-response behaviours of lone chaffinches Fringilla coelebs that fed on seeds (800 per m2) scattered on artificial stubble habitats (with either a clear view of surroundings or an obstructed view). On both treatments, individuals with more rapid head-up rates responded more quickly to a flying model sparrowhawk Accipiter nisus (P=0.04); as did individuals with shorter food-search times (P=0.02). However, neither head-up rate nor food-search period varied with obstruction. Based on research previously published using this system, we suggest that this is because individuals are constrained in their ability to increase head-up rate because doing so is largely determined by their individually determined foraging efficiency. Instead chaffinches increased the duration of their head-up periods by 13% in the visually obstructed treatment (long stubble) and peck rates were 13% lower. Despite this presumed attempt to compensate for reduced visibility, duration of head-up period had no effect on response time of the fast-moving predator in our experiment and birds were 24% slower to respond in the long stubble. Rather than being maladaptive, increasing head-up duration may have been related to enhanced detection of other predator types, for example stalkers. Our results have implications for the conservation of wild granivorous birds. They support the view that agroeconomic decisions that affect micro-habitat structure over a large scale could affect predation risk, habitat choice and the conservation status of granivorous birds.

Whether predators always attack the most vulnerable prey or simply attack prey that exceeds a minimum vulnerability level is an important question to answer in furthering our understanding of predator and antipredation behaviour. Predators may attack any reasonably vulnerable prey rather than waste time identifying the most vulnerable prey, particularly when prey can respond quickly to alter their vulnerability in response to a predator. We tested whether sparrowhawks always choose to attack the group of prey that maximises their capture probability, or whether they simply attack any group above a minimum vulnerability. We modelled sparrowhawk attack success when hunting redshanks using data from three winters and found that probability of capture increased when group size or distance to predator-concealing cover decreased. We then used this model to predict the relative vulnerability to capture of redshank groups occurring in pairs in a fourth winter and found that sparrowhawks attacked the most vulnerable prey group twice as often as not (66% n = 59 pairs). When sparrowhawks attacked the less vulnerable group, there was no tendency for both groups to be particularly vulnerable or for the difference in the vulnerability between the two groups to be relatively small. This suggests that, while sparrowhawks do on average attack the most vulnerable group available, they consider other factors that affect vulnerability or that additional factors lead them to also attack opportunistically. This suggests that there will be selection for the predator to monitor a large number of prey individuals and groups and for prey to have the ability to monitor the behaviour of conspecifics in the same and different groups so that they can assess relative vulnerability.

Summary 1. Game theoretic models of how animals manage predation risk have begun to describe predator responses to prey behaviour relatively recently. This is partly because our understanding of how terrestrial predators select vertebrate prey is often limited to numerical and functional responses to measures of prey abundance. Prey vulnerability, however, may improve our understanding of predation because predators could maximize foraging success by selecting prey on this basis. 2. We tested the hypothesis that sparrowhawks ( Accipiter nisus L.), a typical generalist predator, hunt redshanks ( Tringa totanus L.), a favoured prey species on coastal shores, primarily on the basis of their vulnerability rather than their abundance. 3. Five direct measures or indicators of redshank behaviour predicted sparrowhawk attack success in a multipredictor statistical model and therefore serve as measures of redshank vulnerability. 4. These and other vulnerability measures influenced whether sparrowhawks decided to hunt redshanks on saltmarsh habitat. A model that included most of these measures predicted correctly whether sparrowhawks hunted redshanks (attack decision) 90% of the time and accounted for up to 75% of variation. Prey abundance accounted for no additional variation. 5. Thus the hunting behaviour of some predators can only be predicted well by several highly dynamic and interacting factors related to prey vulnerability. These results mean that, theoretically at least, the management of prey populations may sometimes be achieved best by manipulating prey vulnerability, rather than by culling their predators.

Summary 1Animals should choose the feeding habitat that allows them to meet their energy requirements while minimizing predation risk, but as weather becomes more severe, animals may choose riskier, but more profitable, feeding habitats. 2At the Tyninghame estuary, Scotland, Redshanks (Tringa totanus) chose to feed on either a mudflat or saltmarsh. Energy intake rates were 23% higher and thermoregulatory costs were 40% lower on the saltmarsh, but predation risk from sparrowhawks (Accipiter nisus) was 21 times higher. 3The investigation tested whether the riskier habitat was chosen only when weather conditions were such that individuals were unable to meet their energy requirements in the safer habitat, and how any additional effects of weather affected this choice. 4When starvation risk increased on the mudflat, more Redshanks selected the saltmarsh where energy budgets alone accounted for 22% of the variation in habitat choice. Temperature and wind may have had smaller additional, independent effects that were probably related to their effects on vigilance behaviour and predator detection. 5The results show that weather may be crucial in determining habitat choice through its direct effects on starvation and predation risk, and the importance of considering a wide range of weather conditions when determining habitat requirements.

In this paper we aim to explain the distribution of red-breasted geese Branta ruficollis over different nesting habitats. To be safe from land predators red-breasted goose colonies were restricted to i) islands on rivers, ii) cliffs with peregrine falcons Falco peregrinus, and iii) the close proximity of snowy owl Nyctea scandiaca and rough-legged buzzard Buteo lagopus nests. Among years nest site availability varied by fluctuations in numbers of owls and buzzards in association with cycles in lemming abundance, but the total number of goose nests found in the study area did not vary. The distribution of geese, in combination with data on reproductive success, suggested a despotic mechanism: at cliffs, goose numbers were constant among years with an invariably high reproductive success, whereas large fluctuations in numbers on islands coincided with opposite trends in success. Apparently, geese nesting with owls or buzzards moved to the few islands present in the study area during years when these birds of prey were absent. Consequently, in such years the average density of geese on islands was more than twice as high as at cliff colonies (5.4 and 2.3 pairs per ha of foraging habitat, respectively). Colony size at cliffs may have been restricted by territorial behaviour of the geese, though there is evidence that, additionally, the host falcons also limited the number of nesting geese. Apparently rare in closely related species, we observed a negative density-dependent effect on reproductive success during the nest phase, and attribute this to limited food resources, reinforced by the high frequency of territorial interactions. This leads to the conclusion that, in addition to predation pressure, nesting density is an important agent in the link between lemming cycles and goose breeding success.

In this response to the papers on Jonathan Edwards's ethical thought by Stephen A. Wilson, Gerald R. McDermott, William C. Spohn, and Roland A. Delattre, I comment on their efforts to show that ideas drawn from Edwards can be successfully appropriated for use in contemporary ethics. I conclude that the four authors build a strong cumulative case for the view that some elements of Edwards's thought can serve as resources for our ethical reflections. But I also argue for a deflationary view of how much of Edwards we will find it feasible to take on board when we engage in the task of working out a religious ethics we might accept.

Casinos could help inhibit the development of pathological gambling by limiting the contributions they make to the development of pathology among gamblers. Reasonable strategies for limiting pathology might include limiting the size of jackpots, decreasing the length of play, limiting access, decreasing the rate of play, decreasing the arousal of patrons, decreasing the variability of games, and decreasing the inducements to play. These strategies could be employed in the domains of accessibility, environment, game structure, promotion/marketing, education and treatment. The author argues that the implementation of these strategies would not only inhibit the development of pathological gambling, but might also benefit the casinos and society. The suggested changes in casinos offers a focal point for further research and further dialogues between clinicians and casino operators. Copyright © 2001 John Wiley & Sons, Ltd.

Models fitted to data are used extensively in chemical engineering for a variety of purposes, including simulation, design and control. In any of these contexts it is important to assess the uncertainties in the estimated parameters and in any functions of these parameters, including predictions from the fitted model. Profiling is a likelihood ratio approach to estimating uncertainties in parameters and functions of parameters. A comparison is made between the optimization and reparameterization approaches to determining likelihood intervals for functions of parameters. The merits and limitations of generalized profiling are discussed in relation to the linearization approach commonly used in engineering. The benefits of generalized profiling are illustrated with two examples. A geometric interpretation of profiling is used to elucidate its value, and cases are identified for which the numerical algorithm fails. An alternative approach is suggested for these cases.

On the basis, chiefly, of anecdotal reports of cases of ocular melanoma (OM) occurring in families with inherited susceptibility to breast cancer due to brca2 germline mutations, we examined the frequency of brca2 alterations in a series of 62 ocular melanoma cases. These cases were preferentially selected on the basis of reported family history of breast or ovarian cancer, or OM, although the series also included a randomly selected set of cases without family history of cancer. A total of 7 germline alterations were found, of which 3 were likely to be associated with disease. While all 3 deleterious mutations were found in patients who also had a personal history of breast cancer, only 1 of the 3 families had a family history of breast/ovarian cancer or OM. Although germline brca2 mutations may account for a small proportion of all OM cases, there may be additional loci that contribute to familial aggregation of OM and to the familial association between OM and breast cancer. Int. J. Cancer 82:325–328, 1999. © 1999 Wiley-Liss, Inc.

There is a constant search for a successful analytical methodology to provide high throughput screening of combinatorial libraries against biological targets for identification of active ligands. Solid-phase screening assays offer faster isolation and identification of active analytes compared to the solution-based iterative methods. On the other hand, shift of combinatorial research to the creation of soluble non-peptide libraries, and limitations associated with the heterogeneous assays, creates a demand for a breakthrough technology for rapid and efficient screening of combinatorial libraries in solution. We demonstrated the efficient and rapid approach for selecting active ligands from a combinatorial mixture with subsequent identification of compounds by mass spectrometry. The procedure involves the use of a biological target molecule to physically isolate the active component in a mixture on a size exclusion medium. Then the ligands are identified using a combined liquid chromatography/capillary electrophoresis/mass spectrometry system. As a model system we used serum albumin and small molecules with different affinities to the protein. © 1997 John Wiley & Sons, Ltd.

Rehabilitation of degraded landscapes is generally regarded as the most appropriate objective. Occasionally, however, other aspects of the situation need to be considered and may lead to a different decision. This paper presents the case of the Appalachian Copper Basin, located mainly in south-eastern Tennessee, USA, which was degraded years ago as a result of copper mining and smelting. A brief history of the site is given, along with a review of some rehabilitative efforts. Discussion then turns to the way visitors and residents perceive this landscape, the impact these two viewpoints have had over the years, and how they have (or have not) changed. Landscape values are also examined, the interpretation of which largely determines a person's opinion toward rehabilitation. The point is made that some degraded landscapes can have value as degraded landscapes, in this instance now primarily historical and cultural. The current situation in the Copper Basin is summarized and an alternative course of action suggested. It is concluded that rehabilitation is not always the only, or even the most important, goal and that degraded landscapes of long standing sometimes require special consideration.

The release of captive-reared birds has led to the reestablishment or augmentation of wild populations of several avian species threatened by extinction (Kear 1972; Barclay & Cade 1983; Shepard 1986). Shorebirds should be very suitable candidates for captive-rearing projects because of their strongly developed innate behavior and offspring precocity. More specifically, hand-reared birds, raised without parents or foster parents, could prove valuable for augmenting coastal snowy plover (Charadrius alexandrinus) populations, which have been eliminated from sizable sections of their former breeding range (Page & Stenzel 1981). Consequently, we compared survival and initial breeding success of handand wild-reared released snowy plovers to evaluate the potential of a captive-rearing program for plovers.