Pseudoreplication is defined as the use of inferential statistics to test for treatment effects where treatments are not replicated and/or replicates are not statistically independent. It is a ...genuine but controversial issue in ecology particularly in the case of costly landscape‐scale manipulations, behavioral studies where ethics or other concerns may limit sample sizes, ad hoc monitoring data, and the analysis of natural experiments where chance events occur at a single site. Here key publications on the topic are reviewed to illustrate the debate that exists about the conceptual validity of pseudoreplication. A survey of ecologists and case studies of experimental design and publication issues are used to explore the extent of the problem, ecologists’ solutions, reviewers’ attitudes, and the fate of submitted manuscripts. Scientists working across a range of ecological disciplines regularly come across the problem of pseudoreplication and build solutions into their designs and analyses. These include carefully defining hypotheses and the population of interest, acknowledging the limits of statistical inference and using statistical approaches including nesting and random effects. Many ecologists face considerable challenges getting their work published if accusations of pseudoreplication are made – even if the problem has been dealt with. Many reviewers reject papers for pseudoreplication, and this occurs more often if they haven't experienced the issue themselves. The concept of pseudoreplication is being applied too dogmatically and often leads to rejection during review. There is insufficient consideration of the associated philosophical issues and potential statistical solutions. By stopping the publication of ecological studies, reviewers are slowing the pace of ecological research and limiting the scope of management case studies, natural events studies, and valuable data available to form evidence‐based solutions. Recommendations for fair and consistent treatment of pseudoreplication during writing and review are given for authors, reviewers, and editors.
The concept of pseudoreplication is being applied far too dogmatically and with insufficient consideration for potential solutions. By frequently and preventing the publication of ecological studies, reviewers are slowing the pace of ecological research and preventing a range of study types and valuable data getting published. We provide recommendations for consistent and fair treatment of the problem during project design, analysis writing and review.
Stereotype Threat Spencer, Steven J; Logel, Christine; Davies, Paul G
Annual review of psychology,
01/2016, Letnik:
67, Številka:
1
Journal Article
Recenzirano
When members of a stigmatized group find themselves in a situation where negative stereotypes provide a possible framework for interpreting their behavior, the risk of being judged in light of those ...stereotypes can elicit a disruptive state that undermines performance and aspirations in that domain. This situational predicament, termed stereotype threat, continues to be an intensely debated and researched topic in educational, social, and organizational psychology. In this review, we explore the various sources of stereotype threat, the mechanisms underlying stereotype-threat effects (both mediators and moderators), and the consequences of this situational predicament, as well as the means through which society and stigmatized individuals can overcome the insidious effects of stereotype threat. Ultimately, we hope this review alleviates some of the confusion surrounding stereotype threat while also sparking further research and debate.
Packaging waste forms a significant part of municipal solid waste and has caused increasing environmental concerns, resulting
in a strengthening of various regulations aimed at reducing the amounts ...generated. Among other materials, a wide range of
oil-based polymers is currently used in packaging applications. These are virtually all non-biodegradable, and some are difficult
to recycle or reuse due to being complex composites having varying levels of contamination. Recently, significant progress
has been made in the development of biodegradable plastics, largely from renewable natural resources, to produce biodegradable
materials with similar functionality to that of oil-based polymers. The expansion in these bio-based materials has several
potential benefits for greenhouse gas balances and other environmental impacts over whole life cycles and in the use of renewable,
rather than finite resources. It is intended that use of biodegradable materials will contribute to sustainability and reduction
in the environmental impact associated with disposal of oil-based polymers., The diversity of biodegradable materials and their varying properties makes it difficult to make simple, generic assessments
such as biodegradable products are all ‘good’ or petrochemical-based products are all ‘bad’. This paper discusses the potential
impacts of biodegradable packaging materials and their waste management, particularly via composting. It presents the key
issues that inform judgements of the benefits these materials have in relation to conventional, petrochemical-based counterparts.
Specific examples are given from new research on biodegradability in simulated ‘home’ composting systems. It is the view of
the authors that biodegradable packaging materials are most suitable for single-use disposable applications where the post-consumer
waste can be locally composted.
The detection of intermediate-mass black hole (IMBHs) i.e., those with mass ∼ 100 – 105 M⊙, is an emerging goal of gravitational-wave (GW) astronomy with wide implications for cosmology and tests of ...strong-field gravity. Current PyCBC-based searches for compact binary mergers, which match filtered the detector data against a set of template waveforms, have so far detected or confirmed several GW events. However, the sensitivity of these searches to signals arising from mergers of IMBH binaries is not optimal. Here, we present a new optimized PyCBC-based search for such signals. Our search benefits from using a targeted template bank, stricter signal-noise discriminators, and a lower matched-filter frequency cut-off. In particular, for a population of simulated signals with isotropically distributed spins, we improve the sensitive volume-time product over previous PyCBC-based searches at an inverse false alarm rate of 100 years, by a factor of 1.5 to 3 depending on the total binary mass. We deploy this new search on Advanced LIGO-Virgo data from the first half of the third observing run. The search does not identify any new significant IMBH binaries but does confirm the detection of the short-duration GW signal, GW190521, with a false alarm rate of 1 in 727 years.
Glycosyltransferases catalyze glycosidic bond formation using sugar donors containing a nucleoside phosphate or a lipid phosphate leaving group. Only two structural folds, GT-A and GT-B, have been ...identified for the nucleotide sugar-dependent enzymes, but other folds are now appearing for the soluble domains of lipid phosphosugar-dependent glycosyl transferases. Structural and kinetic studies have provided new insights. Inverting glycosyltransferases utilize a direct displacement S(N)2-like mechanism involving an enzymatic base catalyst. Leaving group departure in GT-A fold enzymes is typically facilitated via a coordinated divalent cation, whereas GT-B fold enzymes instead use positively charged side chains and/or hydroxyls and helix dipoles. The mechanism of retaining glycosyltransferases is less clear. The expected two-step double-displacement mechanism is rendered less likely by the lack of conserved architecture in the region where a catalytic nucleophile would be expected. A mechanism involving a short-lived oxocarbenium ion intermediate now seems the most likely, with the leaving phosphate serving as the base.
Abstract
Water stressed regions rely heavily on the import of water-intensive goods to offset insufficient food production driven by socioeconomic and environmental factors. The water embedded in ...these traded commodities, virtual water, has received increasing interest in the scientific community. However, comprehensive future projections of virtual water trading remain absent. Here we show, for the first time, changes over the 21
st
century in the amount of various water types required to meet international agricultural demands. Accounting for evolution in socioeconomic and climatic conditions, we estimate future interregional virtual water trading and find trading of renewable water sources may triple by 2100 while nonrenewable groundwater trading may at least double. Basins in North America, and the La Plata and Nile Rivers are found to contribute extensively to virtual water exports, while much of Africa, India, and the Middle East relies heavily on virtual water imports by the end of the century.
Asteroseismic constraints on K giants make it possible to infer radii, masses and ages of tens of thousands of field stars. Tests against independent estimates of these properties are however scarce, ...especially in the metal-poor regime. Here, we report the detection of solar-like oscillations in eight stars belonging to the red-giant branch (RGB) and red-horizontal branch (RHB) of the globular cluster M4. The detections were made in photometric observations from the K2 Mission during its Campaign 2. Making use of independent constraints on the distance, we estimate masses of the eight stars by utilizing different combinations of seismic and non-seismic inputs. When introducing a correction to the Δν scaling relation as suggested by stellar models, for RGB stars we find excellent agreement with the expected masses from isochrone fitting, and with a distance modulus derived using independent methods. The offset with respect to independent masses is lower, or comparable with, the uncertainties on the average RGB mass (4–10 per cent, depending on the combination of constraints used). Our results lend confidence to asteroseismic masses in the metal-poor regime. We note that a larger sample will be needed to allow more stringent tests to be made of systematic uncertainties in all the observables (both seismic and non-seismic), and to explore the properties of RHB stars, and of different populations in the cluster.
SARS-CoV-2 lineage B.1.1.7, a variant that was first detected in the UK in September 2020
, has spread to multiple countries worldwide. Several studies have established that B.1.1.7 is more ...transmissible than pre-existing variants, but have not identified whether it leads to any change in disease severity
. Here we analyse a dataset that links 2,245,263 positive SARS-CoV-2 community tests and 17,452 deaths associated with COVID-19 in England from 1 November 2020 to 14 February 2021. For 1,146,534 (51%) of these tests, the presence or absence of B.1.1.7 can be identified because mutations in this lineage prevent PCR amplification of the spike (S) gene target (known as S gene target failure (SGTF)
). On the basis of 4,945 deaths with known SGTF status, we estimate that the hazard of death associated with SGTF is 55% (95% confidence interval, 39-72%) higher than in cases without SGTF after adjustment for age, sex, ethnicity, deprivation, residence in a care home, the local authority of residence and test date. This corresponds to the absolute risk of death for a 55-69-year-old man increasing from 0.6% to 0.9% (95% confidence interval, 0.8-1.0%) within 28 days of a positive test in the community. Correcting for misclassification of SGTF and missingness in SGTF status, we estimate that the hazard of death associated with B.1.1.7 is 61% (42-82%) higher than with pre-existing variants. Our analysis suggests that B.1.1.7 is not only more transmissible than pre-existing SARS-CoV-2 variants, but may also cause more severe illness.
The effects of climate change on biodiversity should depend in part on climate displacement rate (climate-change velocity) and its interaction with species' capacity to migrate. We estimated Late ...Quaternary glacial-interglacial climate-change velocity by integrating macroclimatic shifts since the Last Glacial Maximum with topoclimatic gradients. Globally, areas with high velocities were associated with marked absences of small-ranged amphibians, mammals, and birds. The association between endemism and velocity was weakest in the highly vagile birds and strongest in the weakly dispersing amphibians, linking dispersal ability to extinction risk due to climate change. High velocity was also associated with low endemism at regional scales, especially in wet and aseasonal regions. Overall, we show that low-velocity areas are essential refuges for Earth's many small-ranged species.
The history of the development of modern chemotherapy for tuberculosis (TB), largely due to the British Medical Research Council, is first described. There is a current need to shorten the duration ...of treatment and to prevent and cure drug-resistant disease. These aims will only be achieved if the way in which multidrug treatment prevents resistance from emerging and the reasons for the very slow response to chemotherapy are understood. Consideration of mutation rates to resistance and the size of bacterial populations in lesions makes it very unlikely that resistance would emerge spontaneously, leaving irregularity in drug taking and inadequate dosage as the main reasons for its occurrence. Slow response to treatment seems due to the presence of persister populations whose natural history is only partly known. In the future, we need to explore the persister state in patients and in experimental murine TB, and to take it into account in the design of future mouse experiments. The activity of rifamycins and pyrazinamide is being increased by a rise in rifamycin dosage and the inhalation of pyrazinoic acid. New drugs are gradually being brought into use, initially TMC207 and the nitroimadazoles, PA824 and OPC67683. They will need to be tested in new combination regimens for drug-susceptible and multi- and extensively drug-resistant disease.
PDF
