Climate change is leading to shifts in species geographical distributions, but populations are also probably adapting to environmental change at different rates across their range. Owing to a lack of ...natural and empirical data on the influence of phenotypic adaptation on range shifts of marine species, we provide a general conceptual model for understanding population responses to climate change that incorporates plasticity and adaptation to environmental change in marine ecosystems. We use this conceptual model to help inform where within the geographical range each mechanism will probably operate most strongly and explore the supporting evidence in species. We then expand the discussion from a single-species perspective to community-level responses and use the conceptual model to visualize and guide research into the important yet poorly understood processes of plasticity and adaptation. This article is part of the theme issue 'The role of plasticity in phenotypic adaptation to rapid environmental change'.
A vast amount of civil infrastructure is constructed using reinforced concrete, which can be susceptible to corrosion, posing significant risks. Corrosion of reinforced concrete has various causes, ...with chloride ingress known to be a major contributor. Monitoring this chloride ingress would allow for preventative maintenance to be less intrusive at a lower cost. Currently, chloride sensing methods are bulky and expensive, leaving the majority of concrete infrastructures unmonitored. This paper presents the design and fabrication of a miniature, low-cost device that can be embedded into concrete at various locations and depths. The device measures localized concrete resistance, correlating to the chloride ingress in the concrete using equations listed in this paper, and calculated results from two experiments are presented. The device benefits from a four-probe architecture, injecting a fixed frequency AC waveform across its outer electrodes within the cement block. Voltage across the internal electrodes is measured with a microcontroller and converted to a resistance value, communicated serially to an external computer. A final test showcases the ability of the device for three-dimensional mass deployment.
Context.
The detection and characterization of Earth-like exoplanets (exoEarths) from space requires exquisite wavefront stability at contrast levels of 10
−10
. On segmented telescopes in ...particular, aberrations induced by co-phasing errors lead to a light leakage through the coronagraph, deteriorating the imaging performance. These need to be limited in order to facilitate the direct imaging of exoEarths.
Aims.
We perform a laboratory validation of an analytical tolerancing model that allows us to determine wavefront error requirements in the 10
−6
− 10
−8
contrast regime for a segmented pupil with a classical Lyot coronagraph. We intend to compare the results to simulations, and we aim to establish an error budget for the segmented mirror on the High-contrast imager for Complex Aperture Telescopes (HiCAT) testbed.
Methods.
We use the Pair-based Analytical model for Segmented Telescope Imaging from Space to measure a contrast influence matrix of a real high-contrast instrument, and use an analytical model inversion to calculate per-segment wavefront error tolerances. We validate these tolerances on the HiCAT testbed by measuring the contrast response of segmented mirror states that follow these requirements.
Results.
The experimental optical influence matrix is successfully measured on the HiCAT testbed, and we derive individual segment tolerances from it that correctly yield the targeted contrast levels. Further, the analytical expressions that predict a contrast mean and variance from a given segment covariance matrix are confirmed experimentally.
To better understand potential transmission risks from contact with the body fluids of children, we monitored the presence and amount of CMV shedding over time in healthy CMV-seropositive children.
...Through screening we identified 36 children from the Atlanta, Georgia area who were CMV-seropositive, including 23 who were shedding CMV at the time of screening. Each child received 12 weekly in-home visits at which field workers collected saliva and urine. During the final two weeks, parents also collected saliva and urine daily.
Prevalence of shedding was highly correlated with initial shedding status: children shedding at the screening visit had CMV DNA in 84% of follow-up saliva specimens (455/543) and 28% of follow-up urine specimens (151/539); those not shedding at the screening visit had CMV DNA in 16% of follow-up saliva specimens (47/303) and 5% of follow-up urine specimens (16/305). Among positive specimens we found median viral loads of 82,900 copies/mL in saliva and 34,730 copies/mL in urine (P=0.01), while the viral load for the 75th percentile was nearly 1.5 million copies/mL for saliva compared to 86,800 copies/mL for urine. Younger age was significantly associated with higher viral loads, especially for saliva (P<0.001). Shedding prevalence and viral loads were relatively stable over time. All children who were shedding at the screening visit were still shedding at least some days during weeks 11 and 12, and median and mean viral loads did not change substantially over time.
Healthy CMV-seropositive children can shed CMV for months at high, relatively stable levels. These data suggest that behavioral prevention messages need to address transmission via both saliva and urine, but also need to be informed by the potentially higher risks posed by saliva and by exposures to younger children.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Staphylococcus aureus causes many types of infections, ranging from self-resolving skin infections to severe or fatal pneumonia. Human innate immune cells, called polymorphonuclear leukocytes (PMNs ...or neutrophils), are essential for defense against S. aureus infections. Neutrophils are the most prominent cell type of the innate immune system and are capable of producing non-specific antimicrobial molecules that are effective at eliminating bacteria. Although significant progress has been made over the past few decades, our knowledge of S. aureus-host innate immune system interactions is incomplete. Most notably, S. aureus has the capacity to produce numerous molecules that are directed to protect the bacterium from neutrophils. Here we review in brief the role played by neutrophils in defense against S. aureus infection, and correspondingly, highlight selected S. aureus molecules that target key neutrophil functions.
Peripheral artery disease (PAD) patients suffer a high risk of major cardiovascular (CV) events, with athero-thrombo-embolism as the underlying pathophysiologic mechanism. Recently, two large ...randomized clinical trials evaluated the efficacy and safety of low-dose rivaroxaban twice daily plus aspirin in stable PAD outpatients and those immediately after peripheral revascularization. We sought to determine if the effects of low-dose rivaroxaban and aspirin compared to aspirin alone are consistent across this broad spectrum of PAD patients.
We conducted a random-effects meta-analysis of the COMPASS and VOYAGER randomized trials among 11 560 PAD patients (4996 from COMPASS and 6564 from VOYAGER) in the primary analysis and 9332 (2768 from COMPASS and 6564 from VOYAGER) with lower extremity (LE)-PAD in the secondary analysis. The hazard ratio (HR) for the composite of CV death, myocardial infarction, ischaemic stroke, acute limb ischaemia, or major vascular amputation was 0.79 (95% confidence interval, CI: 0.65-0.95) comparing low-dose rivaroxaban plus aspirin to aspirin alone. While the risk of major bleeding was increased with low-dose rivaroxaban plus aspirin compared to aspirin alone HR: 1.51 (95% CI: 1.22-1.87), there was no significant increase in severe bleeding HR: 1.18 (95% CI: 0.79-1.76). Similar effects were observed in the subset with symptomatic LE-PAD.
Among PAD patients, low-dose rivaroxaban plus aspirin is superior to aspirin alone in reducing CV and limb outcomes including acute limb ischaemia and major vascular amputation. This reduction is offset by a relative increase in major bleeding, but not by an excess of fatal or critical organ bleeding. The consistency of findings of these trials supports the use of combination low-dose rivaroxaban plus aspirin in PAD patients across a broad spectrum of disease.
Staphylococcus aureus remains a leading cause of skin and soft tissue infections (SSTIs) globally. In the United States, many of these infections are caused by isolates classified as USA300. Our ...understanding of the success of USA300 as a human pathogen is due in part to data obtained from animal infection models, including rabbit SSTI models. These animal models have been used to study S. aureus virulence and pathogenesis and to gain an enhanced understanding of the host response to infection. Although significant knowledge has been gained, the need to use a relatively high inoculum of USA300 (1 × 10
to 5 × 10
CFU) is a caveat of these infection models. As a step toward addressing this issue, we created mutations in USA300 that mimic those found in S. aureus strains with naturally occurring rabbit tropism-namely, single nucleotide polymorphisms in
and/or deletion of
. We then developed a rabbit SSTI model that utilizes an inoculum of 10
USA300 CFU to cause reproducible disease and tested whether primary SSTI protects rabbits against severe reinfection caused by the same strain. Although there was modest protection against severe reinfection, primary infection and reinfection with rabbit-tropic USA300 strains failed to increase the overall level of circulating anti-S. aureus antibodies significantly. These findings provide additional insight into the host response to S. aureus. More work is needed to further develop a low-inoculum infection model that can be used to better test the potential of new therapeutics or vaccine target antigens.
Animal models of S. aureus infection are important for evaluating bacterial pathogenesis and host immune responses. These animal infection models are often used as an initial step in the testing of vaccine antigens and new therapeutics. The extent to which animal models of S. aureus infection approximate human infections remains a significant consideration for translation of results to human clinical trials. Although significant progress has been made with rabbit models of S. aureus infection, one concern is the high inoculum needed to cause reproducible disease. Here, we generated USA300 strains that have tropism for rabbits and developed a rabbit SSTI model that uses fewer CFU than previous models.
Vesicular stomatitis viruses (VSVs) cause a condition known as vesicular stomatitis (VS), which results in painful lesions in equines, cattle, swine, and camelids, and when transmitted to humans, can ...cause flu-like symptoms. When animal premises are affected by VS, they are subject to a quarantine. The equine industry more broadly may incur economic losses due to interruptions of animal trade and transportation to shows, competitions, and other events. Equine owners, barn managers, and veterinarians can take proactive measures to reduce the risk of equines contracting VS. To identify appropriate risk management strategies, it helps to understand which biting insects are capable of transmitting the virus to animals, and to identify these insect vectors’ preferred habitats and behaviors. We make this area of science more accessible to equine owners, barn managers, and veterinarians, by (1) translating the most relevant scientific information about biting insect vectors of VSV and (2) identifying practical management strategies that might reduce the risk of equines contracting VSV from infectious biting insects or from other equines already infected with VSV. We address transmission risk at four different spatial scales—the animal, the barn/shelter, the barnyard/premises, and the surrounding environment/neighborhood—noting that a multiscale and spatially collaborative strategy may be needed to reduce the risk of VS.
Proactive management strategies (labeled “DO”) at the animal, shelter, barnyard/premises, and environment/neighborhood level that should help reduce pressure on equines from biting insects known to transmit vesicular stomatitis virus (VSV). Each “DO” is contrasted against a “DON’T,” to show poorly managed conditions that may increase the risk of equines contracting VSV graphic art by Victoria Rhodes. Display omitted
•Black flies, biting midges, and sand flies are demonstrated insect vectors of VSV.•Knowledge of insect vectors’ habitats and behaviors can enhance VS risk reduction.•Assess and reduce risk at multiple levels: neighborhood, premises, shelter, and animal.•A multilevel and spatially collaborative approach is likely needed to reduce risk.•Some management practices can generate wider benefits beyond reducing VS risk.
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