Weekend working: a retrospective cohort study of maternal and neonatal outcomes in a large NHS delivery unit.

OBJECTIVES: Mandatory weekend working for NHS consultants is currently the subject of intense political debate. The Secretary of State for Health's proposed 7-day contract policy is based on the claim that such working patterns will improve patient outcomes. We evaluate this claim by taking advantage of as-if-at-random presentation of women for non-elective deliveries throughout the week. We examine (i) whether consultants currently perform fewer deliveries during weekends versus weekdays, and (ii) whether adverse outcomes increase during weekends. STUDY DESIGN: We conducted a retrospective cohort study using data on all non-elective deliveries from January 2008 to December 2013 in a large UK obstetrics centre (n=27,466). We used Pearson's chi-squared tests to make direct comparisons of adverse outcome rates during weekdays versus weekends. Outcomes included: estimated maternal blood loss ≥1.5l; severe perineal trauma; delayed neonatal respiration; umbilical arterial pH <7.1; and critical incidents at delivery. RESULTS: Consultants currently perform the same proportion of non-elective deliveries on weekends and weekdays (2.3% versus 2.6%, p=0.25). We found no increase in any adverse maternal or neonatal outcomes during weekends versus weekdays, despite high statistical power to detect such differences. Moreover, adverse outcomes are no higher during periods of the weekend when consultants are not routinely present compared to equivalent periods during weekdays. CONCLUSIONS: Under current working arrangements, women who would benefit from consultant-led delivery are equally likely to receive one on weekends compared to weekdays. Weekend delivery has no effect on maternal or neonatal morbidity. Adopting mandatory 7-day contracts is unlikely to make any difference to either consultant-led delivery during weekends or to patient outcomes.The Eunice Kennedy Shriver National Institute of Child Health and Human Development of the National Institutes of Health (Grant ID: P2CHD047879)This is the author accepted manuscript. The final version is available from Elsevier via http://dx.doi.org/10.1016/j.ejogrb.2016.01.03

Relationships Between Neuronal Birthdates and Tonotopic Positions in The Mouse Cochlear Nucleus

Tonotopy is a key anatomical feature of the vertebrate auditory system, but little is known about the mechanisms underlying its development. Since date of birth of a neuron correlates with tonotopic position in the cochlea, we investigated if it also correlates with tonotopic position in the cochlear nucleus (CN). In the cochlea, spiral ganglion neurons are organized in a basal to apical progression along the length of the cochlea based on birthdates, with neurons in the base (responding to high‐frequency sounds) born early around mouse embryonic day (E) 9.5–10.5, and those in the apex (responding to low‐frequency sounds) born late around E12.5‑13.5. Using a low‐dose thymidine analog incorporation assay, we examine whether CN neurons are arranged in a spatial gradient according to their birthdates. Most CN neurons are born between E10.5 ānd E13.5, with a peak at E12.5. A second wave of neuron birth was observed in the dorsal cochlear nucleus (DCN) beginning on E14.5 and lasts until E18.5. Large excitatory neurons were born in the first wave, and small local circuit neurons were born in the second. No spatial gradient of cell birth was observed in the DCN. In contrast, neurons in the anteroventral cochlear nucleus (AVCN) were found to be arranged in a dorsal to ventral progression according to their birthdates, which are aligned with the tonotopic axis. Most of these AVCN neurons are endbulb‐innervated bushy cells. The correlation between birthdate and tonotopic position suggests testable mechanisms for specification of tonotopic position

Susceptibility to Predation Affects Trait-Mediated Indirect Interactions by Reversing Interspecific Competition

Numerous studies indicate that the behavioral responses of prey to the presence of predators can have an important role in structuring assemblages through trait-mediated indirect interactions. Few studies, however, have addressed how relative susceptibility to predation influences such interactions. Here we examine the effect of chemical cues from the common shore crab Carcinus maenas on the foraging behavior of two common intertidal gastropod molluscs. Of the two model consumers studied, Littorina littorea is morphologically more vulnerable to crab predation than Gibbula umbilicalis, and it exhibited greater competitive ability in the absence of predation threat. However, Littorina demonstrated a greater anti-predator response when experimentally exposed to predation cues, resulting in a lower level of foraging. This reversed the competitive interaction, allowing Gibbula substantially increased access to shared resources. Our results demonstrate that the susceptibility of consumers to predation can influence species interactions, and suggest that inter-specific differences in trait-mediated indirect interactions are another mechanism through which non-consumptive predator effects may influence trophic interactions

FROM INDIVIDUALS TO ECOSYSTEM FUNCTION: TOWARD AN INTEGRATION OF EVOLUTIONARY AND ECOSYSTEM ECOLOGY

An important goal in ecology is developing general theory on how the species composition of ecosystems is related to ecosystem properties and functions. Progress on this front is limited partly because of the need to identify mechanisms controlling functions that are common to a wide range of ecosystem types. We propose that one general mechanism, rooted in the evolutionary ecology of all species, is adaptive foraging behavior in response to predation risk. To support our claim, we present two kinds of empirical evidence from plant‐based and detritus‐based food chains of terrestrial and aquatic ecosystems. The first kind comes from experiments that explicitly trace how adaptive foraging influences ecosystem properties and functions. The second kind comes from a synthesis of studies that individually examine complementary components of particular ecosystems that together provide an integrated perspective on the link between adaptive foraging and ecosystem function. We show that the indirect effects of predators on plant diversity, plant productivity, nutrient cycling, trophic transfer efficiencies, and energy flux caused by consumer foraging shifts in response to risk are qualitatively different from effects caused by reductions in prey density due to direct predation. We argue that a perspective of ecosystem function that considers effects of consumer behavior in response to predation risk will broaden our capacity to explain the range of outcomes and contingencies in trophic control of ecosystems. This perspective also provides an operational way to integrate evolutionary and ecosystem ecology, which is an important challenge in ecology

A theory-based approach to understanding condom errors and problems reported by men attending an STI clinic

The official published version can be accessed from the link below - Copyright @ 2008 Springer VerlagWe employed the information–motivation–behavioral skills (IMB) model to guide an investigation of correlates for correct condom use among 278 adult (18–35 years old) male clients attending a sexually transmitted infection (STI) clinic. An anonymous questionnaire aided by a CD-recording of the questions was administered. Linear Structural Relations Program was used to conduct path analyses of the hypothesized IMB model. Parameter estimates showed that while information did not directly affect behavioral skills, it did have a direct (negative) effect on condom use errors. Motivation had a significant direct (positive) effect on behavioral skills and a significant indirect (positive) effect on condom use errors through behavioral skills. Behavioral skills had a direct (negative) effect on condom use errors. Among men attending a public STI clinic, these findings suggest brief, clinic-based, safer sex programs for men who have sex with women should incorporate activities to convey correct condom use information, instill motivation to use condoms correctly, and directly enhance men’s behavioral skills for correct use of condoms

Rock Size-Frequency Distributions at the InSight Landing Site, Mars

Rocks around the InSight lander were measured in lander orthoimages of the near field (<10 m), in panoramas of the far field (<40 m), and in a high-resolution orbital image around the lander (1 km2). The cumulative fractional area versus diameter size-frequency distributions for four areas in the near field fall on exponential model curves used for estimating hazards for landing spacecraft. The rock abundance varies in the near field from 0.6% for the sand and pebble-rich area to the east within Homestead hollow to ∼3–5% for the progressively rockier areas to the south, north, and west. The rock abundance of the entire near field is just over 3%, which falls between that at the Phoenix (2%) and Spirit (5%) landing sites. Rocks in the far field (<40 m) that could be identified in both the surface panorama and a high-resolution orbital image fall on the same exponential model curve as the average near-field rocks. Rocks measured in a high-resolution orbital image (27.5 cm/pixel) within ∼500 m of the lander that includes several rocky ejecta craters fall on 4–5% exponential model curves, similar to the northern and western near-field areas. As a result, the rock abundances observed from orbit fall on the same exponential model rock abundance curves as those viewed from the surface. These rock abundance measurements around the lander are consistent with thermal imaging estimates over larger pixel areas as well as expectations from fragmentation theory of an impacted Amazonian/Hesperian lava flow

Spatial Geographic Mosaic in an Aquatic Predator-Prey Network

The geographic mosaic theory of coevolution predicts 1) spatial variation in predatory structures as well as prey defensive traits, and 2) trait matching in some areas and trait mismatching in others mediated by gene flow. We examined gene flow and documented spatial variation in crushing resistance in the freshwater snails Mexipyrgus churinceanus, Mexithauma quadripaludium, Nymphophilus minckleyi, and its relationship to the relative frequency of the crushing morphotype in the trophically polymorphic fish Herichthys minckleyi. Crushing resistance and the frequency of the crushing morphotype did show spatial variation among 11 naturally replicated communities in the Cuatro Ciénegas valley in Mexico where these species are all endemic. The variation in crushing resistance among populations was not explained by geographic proximity or by genetic similarity in any species. We detected clear phylogeographic patterns and limited gene flow for the snails but not for the fish. Gene flow among snail populations in Cuatro Ciénegas could explain the mosaic of local divergence in shell strength and be preventing the fixation of the crushing morphotype in Herichthys minckleyi. Finally, consistent with trait matching across the mosaic, the frequency of the fish morphotype was negatively correlated with shell crushing resistance likely reflecting the relative disadvantage of the crushing morphotype in communities where the snails exhibit relatively high crushing resistance