Feather corticosterone levels on wintering grounds have no carry-over effects on breeding among three populations of great skuas (<i>Stercorarius skua</i>)

Environmental conditions encountered by migratory seabirds in their wintering areas can shape their fitness. However, the underlying physiological mechanisms remain largely unknown as birds are relatively inaccessible during winter. To assess physiological condition during this period, we measured corticosterone concentrations in winter-grown primary feathers of female great skuas (Stercorarius skua) from three breeding colonies (Bjørnøya, Iceland, Shetland) with wintering areas identified from characteristic stable isotope signatures. We subsequently compared winter feather corticosterone levels between three wintering areas (Africa, Europe and America). Among females breeding in 2009, we found significant differences in feather corticosterone levels between wintering areas. Surprisingly, levels were significantly higher in Africa despite seemingly better local ecological factors (based on lower foraging effort). Moreover, contrary to our predictions, females sharing the same wintering grounds showed significant differences in feather corticosterone levels depending on their colony of origin suggesting that some skuas could be using suboptimal wintering areas. Among females wintering in Africa, Shetland females showed feather corticosterone levels on average 22% lower than Bjørnøya and Iceland females. Finally, the lack of significant relationships between winter feather corticosterone levels and any of the breeding phenology traits does not support the hypothesis of potential carry-over effects of winter feather corticosterone. Yet, the fitness consequences of elevated feather corticosterone levels remain to be determined

Are chimpanzees really so poor at understanding imperative pointing? Some new data and an alternative view of canine and ape social cognition

There is considerable interest in comparative research on different species’ abilities to respond to human communicative cues such as gaze and pointing. It has been reported that some canines perform significantly better than monkeys and apes on tasks requiring the comprehension of either declarative or imperative pointing and these differences have been attributed to domestication in dogs. Here we tested a sample of chimpanzees on a task requiring comprehension of an imperative request and show that, though there are considerable individual differences, the performance by the apes rival those reported in pet dogs. We suggest that small differences in methodology can have a pronounced influence on performance on these types of tasks. We further suggest that basic differences in subject sampling, subject recruitment and rearing experiences have resulted in a skewed representation of canine abilities compared to those of monkeys and apes

From presentation to paper: gender disparities in oncological research

Gender disparities in scientific publications have been identified in oncological research. Oral research presentations at major conferences enhance visibility of presenters. The share of women presenting at such podia is unknown. We aim to identify gender-based differences in contributions to presentations at two major oncological conferences. Abstracts presented at plenary sessions of the American Society of Clinical Oncology (ASCO) Annual Meetings and European Society for Medical Oncology (ESMO) Congresses were collected. Trend analyses were used to analyze female contribution over time. The association between presenter's sex, study outcome (positive/negative) and journals' impact factors (IFs) of subsequently published papers was assessed using Chi-square and Mann-Whitney U tests. Of 166 consecutive abstracts presented at ASCO in 2011-2018 (n = 34) and ESMO in 2008-2018 (n = 132), 21% had female presenters, all originating from Northern America (n = 17) or Europe (n = 18). The distribution of presenter's sex was similar over time (p = 0.70). Of 2,425 contributing authors to these presented abstracts, 28% were women. The proportion of female abstract authors increased over time (p <0.05) and was higher in abstracts with female (34%) compared to male presenters (26%; p <0.01). Presenter's sex was not associated with study outcome (p = 0.82). Median journals' IFs were lower in papers with a female first author (p <0.05). In conclusion, there is a clear gender disparity in research presentations at two major oncological conferences, with 28% of authors and 21% of presenters of these studies being female. Lack of visibility of female presenters could impair acknowledgement for their research, opportunities in their academic career and even hamper heterogeneity in research

Indicators of ‘critical’ outcomes in 941 horses seen ‘out-of-hours’ for colic

Background: This study aimed to describe the presentation and outcomes of horses with signs of colic (abdominal pain) seen ‘out-of-hours’ in equine practice. Methods: This was a retrospective study of horses seen ‘out-of-hours’ with colic by two equine veterinary practices between 2011-2013. Case outcomes were categorised as ‘critical’ or ‘not critical’. A critical outcome was defined as requiring medical or surgical hospital treatment, or resulting in euthanasia or death. A non-critical outcome was defined as resolving with simple medical treatment. A hierarchical generalised linear model was used to identify ‘red flag’ parameters (aspects of signalment, history and presenting clinical signs) associated with critical outcomes.Results: Data were retrieved from 941 cases that presented with colic; 23.9% (n=225/941) were critical. Variables significantly associated with the likelihood of a critical outcome in the final multivariable mode were: increased heart rate (p [less than] 0.001), age of the horse (p=0.013) and abnormal mucous membrane colour (p [less than] 0.001). Overall 18% of cases (n=168/941) were euthanased.Conclusions: This study highlights the mortality associated with colic. The ‘red flag’ parameters identified should be considered an essential component of the primary assessment of horses with colic

Inhabiting infrastructure: exploring the interactional spaces of urban cycling

Contemporary cities are thick with infrastructure. In recognition of this fact a great deal of recent work within urban studies and urban geography has focused on transformations in the governance and ownership of infrastructural elements within cities. Less attention has been paid to the practices through which urban infrastructures are inhabited by urban dwellers. Yet in all sorts of ways infrastructures are realised through their use and inhabitation. This paper argues for the importance of attending to the ways that infrastructures are reinterpreted through use. Focusing on a case study of commuter cyclists in London, it explores the ways in which cyclists accommodate themselves to (and are in turn accommodated by) the infrastructural orderings of London’s streets. Confronted by the obduracy of a road infrastructure designed primarily for motorised traffic, cyclists show a diverse range of approaches to negotiating movement through the city on bikes. The paper describes how this negotiation can be understood in terms of the more or less skilful processes of navigation, rule following, rule making, and rule bending. This involves a polymorphous mix of practices, some common to driving, others to walking, and yet others unique to cycling. In conclusion, the paper suggests that transformations of infrastructures found within cities need to be understood as much through emergent changes between their elements, and that close attention to how infrastructures come to be inhabited offers productive avenues for thinking about ways to improve them

Phylogeny of Cyperaceae Based on DNA Sequence Data–a New rbcL Analysis

Since the Monocots II meeting in 1998, significant new data have been published that enhance our systematic knowledge of Cyperaceae. Phylogenetic studies in the family have also progressed steadily. For this study, a parsimony analysis was carried out using all rbcL sequences currently available for Cyperaceae, including data for two new genera. One of the four subfamilies (Caricoideae) and seven of the 14 tribes (Bisboeckelereae, Cariceae, Cryptangieae, Dulichieae, Eleocharideae, Sclerieae, Trilepideae) are monophyletic. Subfamily Mapanioideae and tribe Chrysitricheae are monophyletic if, as the evidence suggests, Hellmuthia is considered a member of Cypereae. Some other features of our analysis include: well-supported Trilepideae and Sclerieae–Bisboeckelereae clades; a possible close relationship between Cryptangieae and Schoeneae; polyphyletic tribes Schoeneae and Scirpeae; the occurrence of Cariceae within the Dulichieae–Scirpeae clade, and a strongly supported clade, representing Cyperus and allied genera in Cypereae, sister to a poorly supported Ficinia–Hellmuthia– Isolepis–Scirpoides clade. Such patterns are consistent with other studies based on DNA sequence data. One outcome may be that only two subfamilies, Mapanioideae and Cyperoideae, are recognized. Much further work is needed, with efforts carefully coordinated among researchers. The work should focus on obtaining morphological and molecular data for all genera in the family

Multiple Neural Oscillators and Muscle Feedback Are Required for the Intestinal Fed State Motor Program

After a meal, the gastrointestinal tract exhibits a set of behaviours known as the fed state. A major feature of the fed state is a little understood motor pattern known as segmentation, which is essential for digestion and nutrient absorption. Segmentation manifests as rhythmic local constrictions that do not propagate along the intestine. In guinea-pig jejunum in vitro segmentation constrictions occur in short bursts together with other motor patterns in episodes of activity lasting 40–60 s and separated by quiescent episodes lasting 40–200 s. This activity is induced by luminal nutrients and abolished by blocking activity in the enteric nervous system (ENS). We investigated the enteric circuits that regulate segmentation focusing on a central feature of the ENS: a recurrent excitatory network of intrinsic sensory neurons (ISNs) which are characterized by prolonged after-hyperpolarizing potentials (AHPs) following their action potentials. We first examined the effects of depressing AHPs with blockers of the underlying channels (TRAM-34 and clotrimazole) on motor patterns induced in guinea-pig jejunum, in vitro, by luminal decanoic acid. Contractile episode durations increased markedly, but the frequency and number of constrictions within segmenting bursts and quiescent period durations were unaffected. We used these observations to develop a computational model of activity in ISNs, excitatory and inhibitory motor neurons and the muscle. The model predicted that: i) feedback to ISNs from contractions in the circular muscle is required to produce alternating activity and quiescence with the right durations; ii) transmission from ISNs to excitatory motor neurons is via fast excitatory synaptic potentials (EPSPs) and to inhibitory motor neurons via slow EPSPs. We conclude that two rhythm generators regulate segmentation: one drives contractions within segmentation bursts, the other the occurrence of bursts. The latter depends on AHPs in ISNs and feedback to these neurons from contraction of the circular muscle

Comparative analysis of homology models of the Ah receptor ligand binding domain: Verification of structure-function predictions by site-directed mutagenesis of a nonfunctional receptor

The aryl hydrocarbon receptor (AHR) is a ligand-dependent transcription factor that mediates the biological and toxic effects of a wide variety of structurally diverse chemicals, including the toxic environmental contaminant 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). While significant interspecies differences in AHR ligand binding specificity, selectivity, and response have been observed, the structural determinants responsible for those differences have not been determined, and homology models of the AHR ligand-binding domain (LBD) are available for only a few species. Here we describe the development and comparative analysis of homology models of the LBD of 16 AHRs from 12 mammalian and nonmammalian species and identify the specific residues contained within their ligand binding cavities. The ligand-binding cavity of the fish AHR exhibits differences from those of mammalian and avian AHRs, suggesting a slightly different TCDD binding mode. Comparison of the internal cavity in the LBD model of zebrafish (zf) AHR2, which binds TCDD with high affinity, to that of zfAHR1a, which does not bind TCDD, revealed that the latter has a dramatically shortened binding cavity due to the side chains of three residues (Tyr296, Thr386, and His388) that reduce the amount of internal space available to TCDD. Mutagenesis of two of these residues in zfAHR1a to those present in zfAHR2 (Y296H and T386A) restored the ability of zfAHR1a to bind TCDD and to exhibit TCDD-dependent binding to DNA. These results demonstrate the importance of these two amino acids and highlight the predictive potential of comparative analysis of homology models from diverse species. The availability of these AHR LBD homology models will facilitate in-depth comparative studies of AHR ligand binding and ligand-dependent AHR activation and provide a novel avenue for examining species-specific differences in AHR responsiveness. © 2013 American Chemical Society

Retrospective case series to identify the most common conditions seen ‘out-of-hours’ by first-opinion equine veterinary practitioners

Background: The study aim was to describe conditions seen ‘out-of-hours’ in equine practice. Methods: This was a retrospective case series of first opinion ‘out-of-hours’ cases seen at two equine practices between 2011-2013. Data was retrieved on case presentation, diagnostic testing, treatment administered and outcome, and diseases categorised using a systems-based coding system. A hierarchical logistic regression, formulated using a Generalised Linear Model, was used to identify clinical variables associated with a binary outcome of ‘critical’ cases (required hospitalisation or euthanasia or died).Results: Data from 2,602 cases were analysed. The most common reasons for ‘out-of-hours’ visits were colic (35%, n=923/2,620), wounds (20%, n=511/2,620) and lameness (11%, n=288/2,620). The majority of cases required a single treatment (58%, n=1,475/2,550), 26% (n=656/2,550) needed multiple treatments, and 13% (n=339/2,550) were euthanased. Eighteen percent (n=480/2602) of cases had a critical outcome. Increased heart rate at primary presentation was associated with critical outcome in both practices (Practice A, OR 1.07 (95%CI 1.06-1.09), Practice B OR 1.08 (95%CI 1.07-1.09; p [less than] 0.001)).Conclusion: Colic, wounds and lameness were the most common equine ‘out-of-hours’ conditions; 13% of cases were euthanased. Further research is required into out-of-hours euthanasia decision-making

Antigen-loaded MR1 tetramers define T cell receptor heterogeneity in mucosal-associated invariant T cells

Mucosal-associated invariant T cells (MAIT cells) express a semi-invariant T cell receptor (TCR) alpha-chain, TRAV1-2-TRAJ33, and are activated by vitamin B metabolites bound by the major histocompatibility complex (MHC)-related class I-like molecule, MR1. Understanding MAIT cell biology has been restrained by the lack of reagents to specifically identify and characterize these cells. Furthermore, the use of surrogate markers may misrepresent the MAIT cell population. We show that modified human MR1 tetramers loaded with the potent MAIT cell ligand, reduced 6-hydroxymethyl-8-D-ribityllumazine (rRL-6-CH2OH), specifically detect all human MAIT cells. Tetramer(+) MAIT subsets were predominantly CD8(+) or CD4(-)CD8(-), although a small subset of CD4(+) MAIT cells was also detected. Notably, most human CD8(+) MAIT cells were CD8 alpha(+)CD8 beta(-/lo), implying predominant expression of CD8 alpha alpha homodimers. Tetramer-sorted MAIT cells displayed a T(H)1 cytokine phenotype upon antigen-specific activation. Similarly, mouse MR1-rRL-6-CH2OH tetramers detected CD4(+), CD4(-)CD8(-) and CD8(+) MAIT cells in V. 19 transgenic mice. Both human and mouse MAIT cells expressed a broad TCR-beta repertoire, and although the majority of human MAIT cells expressed TRAV1-2-TRAJ33, some expressed TRAJ12 or TRAJ20 genes in conjunction with TRAV1-2. Accordingly, MR1 tetramers allow precise phenotypic characterization of human and mouse MAIT cells and revealed unanticipated TCR heterogeneity in this population