567 research outputs found
Morphometric variations at an ecological scale: Seasonal and local variations in feral and commensal house mice
The time scales of evolutionary and ecological studies tend to converge, as evidenced by studies that have shown contemporary evolution can occur as fast as ecological processes. This opens new questions regarding variation of characters usually considered to change mostly along an evolutionary time scale, such as morphometric traits, including osteological and dental features such as mandibles and teeth of mammals. Using two-dimensional geometric morphometric approach, we questioned whether such features can change on a seasonal and local basis, in relation to the ecological dynamics of the populations. Our model comprised populations of house mice (Mus musculus domesticus) in two contrasted situations in mainland Western Europe: a feral population vs. two close commensal populations. Mitochondrial DNA (D-loop) provided insight into the diversity and dynamics of the populations. The feral population appeared as genetically highly diversified, suggesting a possible functioning as a sink in relation to the surrounding commensal populations. In contrast, commensal populations were highly homogeneous from a genetic point of view, suggesting each population to be isolated. This triggered morphological differentiation between neighboring farms. Seasonal differences in morphometric traits (mandible size and shape and molar size and shape) were significant in both settings, although seasonal variations were greater in the feral than in the commensal population. Seasonal variations in molar size and shape could be attributed to differential wear in young or overwintered populations. Differences in mandible shape could be related to aging in overwintered animals, but also possibly to differing growth conditions depending on the season. The impact of these ecological processes on morphometric traits is moderate compared to divergence over a large biogeographic scale, but their significance nevertheless underlines that even morphological characters may trace populations dynamics at small scale in time and space
A sharp incisor tool for predator house mice back to the wild
The house mouse (Mus musculus domesticus), as a successful invasive species worldwide, has to forage a variety of resources. Subantarctic mice display among the most notable diet shift from the usual omnivorous–granivorous diet, relying on a larger proportion of terrestrial animal prey. In agreement, a recent study of their mandible morphology evidenced an evolution of their mandible shape to optimize incisor biting and hence seize preys. Here, the incisors themselves are the focus of a morphometric analysis combined with a 3D study of their internal structure, aiming at a comparison between subantarctic populations (Guillou island, Kerguelen archipelago) with a range of western European continental, commensal mice. The predatory foraging behavior of Guillou mice was indeed associated with a sharper bevel of the lower incisor, which appears as an efficient morphology for piercing prey. The incisor of these mice also displays a reduced pulp cavity, suggesting slower eruption counterbalancing a reduced abrasion on such soft food material. The dynamics of the ever‐growing incisor may thus allow adaptive incisor sculpting and participate to the success of mice in foraging diverse resources
Electrowetting of liquid marbles
Electrowetting of water drops on structured superhydrophobic surfaces are known to cause an irreversible change from a slippy (Cassie-Baxter) to a sticky (Wenzel) regime. An alternative approach to using a water drop on a superhydrophobic surface to obtain a non-wetting system is to use a liquid marble on a smooth solid substrate. A liquid marble is a droplet coated in hydrophobic grains, which therefore carries its own solid surface structure as a conformal coating. Such droplets can be considered as perfect non-wetting systems having contact angles to smooth solid substrates of close to 180 degrees. In this work we report the electrowetting of liquid marbles made of water coated with hydrophobic lycopodium grains and show that the electrowetting is completely reversible. Marbles are shown to return to their initial contact angle for both ac and dc electrowetting and without requiring a threshold voltage to be exceeded. Furthermore, we provide a proof-of-principle demonstration that controlled motion of marbles on a finger electrode structure is possible
An index method of estimating relative population densities of the Common Vole (Microtus arvalis) at landscape scale
Many issues in fundamental and applied ecology require the use of sampling protocols
at the sectoral or even regional scales at which many important ecological mechanisms occur.
The lack of workable sampling methods at these scales is a major obstacle to the analysis and
understanding of these mechanisms. We test the validity of an index method of estimating
relative population densities, applicable along transects of several kilometers in length, for a
population of Common Voles (Microtus arvalis). The results show that the index method of
estimating relative density is weil adapted for monitoring variations in the abundance and
spatial distribution of Common Vole populations and authorizes studies for a wide range of
objectives and spatial scalesDe nombreuses questions d'écologie fondamentale ou appliquée imposent l'application de protocoles d'échantillonnage à des échelles sectorielles, voire régionales, auxquelles se réalisent de nombreux mécanismes écologiques
mportants. L'absence de méthodes d'échantillonnage utilisables à ces échelles représente un obstacle majeur à l'analyse et à la compréhension de ces mécanismes, Pour une population de Campagnols des champs (Microlus aryalis) nous avons testé la validite d'une méthode d'estimation indiciaire
en densité relative applicable le long de transect, plurikilométriques. Les résultats obtenus montrent que cette méthode d'estimation indiciaire en densité relative est bien adaptée au suivi des variations d'abondance et de distribution des populations du Campagnol des champs et autorise des
études pour une grande diversité d'objectifs et d'échelles spatiales
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LIMPRINT - health-related quality of life in adult patients with chronic edema
Background: Chronic edema is a condition posing a high burden on patients. The primary aim of the study was to assess the health-related quality of life (QoL) of adult patients living with chronic edema.
Methods and Results: As part of an international, multicenter, prospective study, we prospectively assessed the health-related QoL of adult patients living with a chronic edema using a disease-specific tool and a generic one. In total, 1094 patients were included, aged 57 years on average. The average EQ-5D and LYMQOL visual analogue scale (VAS) scores were equal to 63.6 (SD = 20.2) and 6.3 (SD = 2.0), respectively. After adjustment, the EQ-5D VAS was explained by LYMQOL VAS (β = 7.85; p < 0.001), age (β = −0.08; p = 0.02), obesity (β = −1.89; p = 0.001), and male gender (β = 3.32; p = 0.002). As for the LYMQOL VAS, it was independently associated with EQ-5D VAS (β = 0.07; p < 0.001), LYMQOL function (β = −0.21; p < 0.001), and LYMQOL mood (β = −0.49; p < 0.001).
Conclusion: This study confirms that patients living with a chronic edema experience a poor disease-specific and generic health-related QoL
The global carbon budget 1959-2011
Accurate assessments of anthropogenic carbon dioxide (CO2) emissions and their redistribution among the atmosphere, ocean, and terrestrial biosphere is important to better understand the global carbon cycle, support the climate policy process, and project future climate change. Present-day analysis requires the combination of a range of data, algorithms, statistics and model estimates and their interpretation by a broad scientific community. Here we describe datasets and a methodology developed by the global carbon cycle science community to quantify all major components of the global carbon budget, including their uncertainties. We discuss changes compared to previous estimates, consistency within and among components, and methodology and data limitations. CO2 emissions from fossil fuel combustion and cement production (EFF) are based on energy statistics, while emissions from Land-Use Change (ELUC), including deforestation, are based on combined evidence from land cover change data, fire activity in regions undergoing deforestation, and models. The global atmospheric CO2 concentration is measured directly and its rate of growth (GATM) is computed from the concentration. The mean ocean CO2 sink (SOCEAN) is based on observations from the 1990s, while the annual anomalies and trends are estimated with ocean models. Finally, the global residual terrestrial CO2 sink (SLAND) is estimated by the difference of the other terms. For the last decade available (2002–2011), EFF was 8.3 ± 0.4 PgC yr−1, ELUC 1.0 ± 0.5 PgC yr−1, GATM 4.3 ± 0.1PgC yr−1, SOCEAN 2.5 ± 0.5 PgC yr−1, and SLAND 2.6 ± 0.8 PgC yr−1. For year 2011 alone, EFF was 9.5 ± 0.5 PgC yr−1, 3.0 percent above 2010, reflecting a continued trend in these emissions; ELUC was 0.9 ± 0.5 PgC yr−1, approximately constant throughout the decade; GATM was 3.6 ± 0.2 PgC yr−1, SOCEAN was 2.7 ± 0.5 PgC yr−1, and SLAND was 4.1 ± 0.9 PgC yr−1. GATM was low in 2011 compared to the 2002–2011 average because of a high uptake by the land probably in response to natural climate variability associated to La Niña conditions in the Pacific Ocean. The global atmospheric CO2 concentration reached 391.31 ± 0.13 ppm at the end of year 2011. We estimate that EFF will have increased by 2.6% (1.9–3.5%) in 2012 based on projections of gross world product and recent changes in the carbon intensity of the economy. All uncertainties are reported as ±1 sigma (68% confidence assuming Gaussian error distributions that the real value lies within the given interval), reflecting the current capacity to characterise the annual estimates of each component of the global carbon budget. This paper is intended to provide a baseline to keep track of annual carbon budgets in the future
The development and validation of the LIMPRINT methodology
The acronym Limprint stands for Lymphoedema IMpact and Prevalence-INTernational and was run under the auspices of the International Lymphoedema Framework (ILF) a charity dedicated to improving provision of care globally. The primary aim was to identify the number of people with chronic oedema (chronic oedema present for > 3months and due to a range of underlying aetiologies and associated risk factors) within diverse health services in 9 participating countries and to determine its impact using validated methods. An international protocol and sampling framework, online data capture system and standard operating procedures were adopted. An international consensus was used to create a core data tool that covered 13 domains. Specialist data on demographics and disability, details of swelling, wounds, cancer and health related quality of life were also available for sites. The study protocol was designed to allow flexibility in the types of studies undertaken within complex health care systems. All cases were confirmed using the modified pitting test. Sensitivity and specificity for this method were determined in Japanese and European populations. Following confirmation of a chronic oedema case Lymphologists defined whether it was a primary of secondary form. The study was designed to provide robust evidence that chronic oedema is an important and unrecognised public health problem in health services with significant morbidity. Without evidence of the size and complexity it will remain considered a rare phenomenon and people affected will be denied access to appropriate treatment that would allow them to have fulfilled and productive lives
Capillary filling with wall corrugations] Capillary filling in microchannels with wall corrugations: A comparative study of the Concus-Finn criterion by continuum, kinetic and atomistic approaches
We study the impact of wall corrugations in microchannels on the process of
capillary filling by means of three broadly used methods - Computational Fluid
Dynamics (CFD), Lattice-Boltzmann Equations (LBE) and Molecular Dynamics (MD).
The numerical results of these approaches are compared and tested against the
Concus-Finn (CF) criterion, which predicts pinning of the contact line at
rectangular ridges perpendicular to flow for contact angles theta > 45. While
for theta = 30, theta = 40 (no flow) and theta = 60 (flow) all methods are
found to produce data consistent with the CF criterion, at theta = 50 the
numerical experiments provide different results. Whilst pinning of the liquid
front is observed both in the LB and CFD simulations, MD simulations show that
molecular fluctuations allow front propagation even above the critical value
predicted by the deterministic CF criterion, thereby introducing a sensitivity
to the obstacle heigth.Comment: 25 pages, 8 figures, Langmuir in pres
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