Maternal effects have become an important field of study in evolutionary ecology and there is an ongoing debate regarding their adaptive significance. Some maternal effects can act to increase ...offspring fitness and are called 'adaptive maternal effects'. However, other maternal effects decrease offspring fitness and there is confusion regarding whether certain maternal effects are indeed adaptive or merely physiological inevitabilities. Here we suggest that the focus on the consequences of maternal effects for offspring fitness only and the use of 'snapshot' estimates of fitness have misdirected our effort to understand the evolution of maternal effects. We suggest that selection typically acts on maternal effects to maximise maternal rather than (or in addition to) offspring fitness. We highlight the importance of considering how maternal effects influence maternal fitness across a mother's lifetime and describe four broad types of maternal effects using an outcome-based approach. Overall, we suggest that many maternal effects will have an adaptive basis for mothers, regardless of whether these effects increase or decrease survival or reproductive success of individual offspring.
The spatial configuration of cities can affect how urban environments alter local energy balances. Previous studies have reached the paradoxical conclusions that both sprawling and high-density urban ...development can amplify urban heat island intensities, which has prevented consensus on how best to mitigate the urban heat island effect via urban planning. To investigate this apparent dichotomy, we estimated the urban heat island intensities of the 50 most populous cities in the United States using gridded minimum temperature datasets and quantified each city's urban morphology with spatial metrics. The results indicated that the spatial contiguity of urban development, regardless of its density or degree of sprawl, was a critical factor that influenced the magnitude of the urban heat island effect. A ten percentage point increase in urban spatial contiguity was predicted to enhance the minimum temperature annual average urban heat island intensity by between 0.3 and 0.4°C. Therefore, city contiguity should be considered when devising strategies for urban heat island mitigation, with more discontiguous development likely to ameliorate the urban heat island effect. Unraveling how urban morphology influences urban heat island intensity is paramount given the human health consequences associated with the continued growth of urban populations in the future.
•Urban heat island (UHI) intensities were estimated for the fifty most populous cities in the USA using PRISM climate data.•The urban morphologies of the cities were quantified using spatial metrics and the NLCD 2006 land use/land cover dataset.•The statistical analyses suggested that highly contiguous dense and sprawling urban development both enhance the UHI effect.•City contiguity should be considered when devising strategies for UHI intensity mitigation.•More discontiguous city configurations, especially if achieved by introducing urban green spaces, will likely reduce UHIs.
Cadenced optical imaging surveys in the next decade will be capable of detecting time-varying galaxy-scale strong gravitational lenses in large numbers, increasing the size of the statistically ...well-defined samples of multiply imaged quasars by two orders of magnitude, and discovering the first strongly lensed supernovae. We carry out a detailed calculation of the likely yields of several planned surveys, using realistic distributions for the lens and source properties and taking magnification bias and image configuration detectability into account. We find that upcoming wide-field synoptic surveys should detect several thousand lensed quasars. In particular, the Large Synoptic Survey Telescope (LSST) should find more than some 8000 lensed quasars, some 3000 of which will have well-measured time delays. The LSST should also find some 130 lensed supernovae during the 10-yr survey duration, which is compared with ∼15 lensed supernovae predicted to be found by a deep, space-based supernova survey done by the Joint Dark Energy Mission. We compute the quad fraction in each survey, predicting it to be ∼15 per cent for the lensed quasars and ∼30 per cent for the lensed supernovae. Generating a mock catalogue of around 1500 well-observed double-image lenses, as could be derived from the LSST survey, we compute the available precision on the Hubble constant and the dark energy equation parameters for the time-delay distance experiment (assuming priors from Planck): the predicted marginalized 68 per cent confidence intervals are σ(w0) = 0.15, σ(wa) = 0.41 and σ(h) = 0.017. While this is encouraging in the sense that these uncertainties are only 50 per cent larger than those predicted for a space-based Type Ia supernova sample, we show how the dark energy figure of merit degrades with decreasing knowledge of the lens mass distribution.
The Southern Annular Mode (SAM) is the leading mode of extratropical Southern Hemisphere climate variability, associated with changes in the strength and position of the polar jet around Antarctica. ...This variability in the polar jet drives large fluctuations in the Southern Hemisphere climate, from the lower stratosphere into the troposphere, and stretching from the midlatitudes across the Southern Ocean to Antarctica. Notably, the SAM index has displayed marked positive trends in the austral summer season (stronger and poleward shifted westerlies), associated with stratospheric ozone loss. Historical reconstructions demonstrate that these recent positive SAM index values are unprecedented in the last millennia, and fall outside the range of natural climate variability. Despite these advances in the understanding of the SAM behavior, several areas of active research are identified that highlight gaps in our present knowledge.
This article is categorized under:
Paleoclimates and Current Trends > Earth System Behavior
The Southern Annular Mode has displayed an unprecedented positive polarity in the last several decades, with implications for climate across the entire extratropical Southern Hemisphere.
Technologies and methods to speed up the production of systematic reviews by reducing the manual labour involved have recently emerged. Automation has been proposed or used to expedite most steps of ...the systematic review process, including search, screening, and data extraction. However, how these technologies work in practice and when (and when not) to use them is often not clear to practitioners. In this practical guide, we provide an overview of current machine learning methods that have been proposed to expedite evidence synthesis. We also offer guidance on which of these are ready for use, their strengths and weaknesses, and how a systematic review team might go about using them in practice.
The development of automated solutions to pattern recognition problems is important in many areas of scientific research and human endeavour. This paper describes the implementation of the Pandora ...software development kit, which aids the process of designing, implementing and running pattern recognition algorithms. The Pandora Application Programming Interfaces ensure simple specification of the building-blocks defining a pattern recognition problem. The logic required to solve the problem is implemented in algorithms. The algorithms request operations to create or modify data structures and the operations are performed by the Pandora framework. This design promotes an approach using many decoupled algorithms, each addressing specific topologies. Details of algorithms addressing two pattern recognition problems in High Energy Physics are presented: reconstruction of events at a high-energy
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linear collider and reconstruction of cosmic ray or neutrino events in a liquid argon time projection chamber.
The rate of anal cancer is increasing among both women and men, particularly men who have sex with men. Caused by infection with human papillomavirus (HPV), primarily HPV type 16 or 18, anal cancer ...is preceded by high-grade anal intraepithelial neoplasia (grade 2 or 3). We studied the safety and efficacy of quadrivalent HPV vaccine (qHPV) against anal intraepithelial neoplasia associated with HPV-6, 11, 16, or 18 infection in men who have sex with men.
In a substudy of a larger double-blind study, we randomly assigned 602 healthy men who have sex with men, 16 to 26 years of age, to receive either qHPV or placebo. The primary efficacy objective was prevention of anal intraepithelial neoplasia or anal cancer related to infection with HPV-6, 11, 16, or 18. Efficacy analyses were performed in intention-to-treat and per-protocol efficacy populations. The rates of adverse events were documented.
Efficacy of the qHPV vaccine against anal intraepithelial neoplasia associated with HPV-6, 11, 16, or 18 was 50.3% (95% confidence interval CI, 25.7 to 67.2) in the intention-to-treat population and 77.5% (95% CI, 39.6 to 93.3) in the per-protocol efficacy population; the corresponding efficacies against anal intraepithelial neoplasia associated with HPV of any type were 25.7% (95% CI, -1.1 to 45.6) and 54.9% (95% CI, 8.4 to 79.1), respectively. Rates of anal intraepithelial neoplasia per 100 person-years were 17.5 in the placebo group and 13.0 in the vaccine group in the intention-to-treat population and 8.9 in the placebo group and 4.0 in the vaccine group in the per-protocol efficacy population. The rate of grade 2 or 3 anal intraepithelial neoplasia related to infection with HPV-6, 11, 16, or 18 was reduced by 54.2% (95% CI, 18.0 to 75.3) in the intention-to-treat population and by 74.9% (95% CI, 8.8 to 95.4) in the per-protocol efficacy population. The corresponding risks of persistent anal infection with HPV-6, 11, 16, or 18 were reduced by 59.4% (95% CI, 43.0 to 71.4) and 94.9% (95% CI, 80.4 to 99.4), respectively. No vaccine-related serious adverse events were reported.
Use of the qHPV vaccine reduced the rates of anal intraepithelial neoplasia, including of grade 2 or 3, among men who have sex with men. The vaccine had a favorable safety profile and may help to reduce the risk of anal cancer. (Funded by Merck and the National Institutes of Health; ClinicalTrials.gov number, NCT00090285.).
Thermal performance curves (TPCs), which quantify how an ectotherm's body temperature (Tb) affects its performance or fitness, are often used in an attempt to predict organismal responses to climate ...change. Here, we examine the key – but often biologically unreasonable – assumptions underlying this approach; for example, that physiology and thermal regimes are invariant over ontogeny, space and time, and also that TPCs are independent of previously experienced Tb. We show how a critical consideration of these assumptions can lead to biologically useful hypotheses and experimental designs. For example, rather than assuming that TPCs are fixed during ontogeny, one can measure TPCs for each major life stage and incorporate these into stage‐specific ecological models to reveal the life stage most likely to be vulnerable to climate change. Our overall goal is to explicitly examine the assumptions underlying the integration of TPCs with Tb, to develop a framework within which empiricists can place their work within these limitations, and to facilitate the application of thermal physiology to understanding the biological implications of climate change.
On 17 August 2017, gravitational waves (GWs) were detected from a binary neutron star merger, GW170817, along with a coincident short gamma-ray burst, GRB 170817A. An optical transient source, Swope ...Supernova Survey 17a (SSS17a),was subsequently identified as the counterpart of this event. We present ultraviolet, optical, and infrared light curves of SSS17a extending from 10.9 hours to 18 days postmerger. We constrain the radioactively powered transient resulting from the ejection of neutron-rich material. The fast rise of the light curves, subsequent decay, and rapid color evolution are consistent with multiple ejecta components of differing lanthanide abundance. The late-time light curve indicates that SSS17a produced at least ~0.05 solar masses of heavy elements, demonstrating that neutron star mergers play a role in rapid neutron capture (r-process) nucleosynthesis in the universe.
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