1,053 research outputs found
Coerced Mechanical Coarsening of Nanoparticle Assemblies
Coarsening is a ubiquitous phenomenon [1-3] that underpins countless processes in nature, including epitaxial growth [1,3,4], the phase separation of alloys, polymers and binary fluids [2], the growth of bubbles in foams5, and pattern formation in biomembranes6. Here we show, in the first real-time experimental study of the evolution of an adsorbed colloidal nanoparticle array, that tapping-mode atomic force microscopy (TM-AFM) can drive the coarsening of Au nanoparticle assemblies on silicon surfaces. Although the growth exponent has a strong dependence on the initial sample morphology, our observations are largely consistent with modified Ostwald ripening processes [7-9]. To date, ripening processes have been exclusively considered to be thermally activated, but we show that nanoparticle assemblies can be mechanically coerced towards equilibrium, representing a new approach to directed coarsening. This strategy enables precise control over the evolution of micro- and nanostructures
A Novel Tool to Mitigate By-Catch Mortality of Baltic Seals in Coastal Fyke Net Fishery
Developing methods to reduce the incidental catch of non-target species is important, as by-catch mortality poses threats especially to large aquatic predators. We examined the effectiveness of a novel device, a "seal sock", in mitigating the by-catch mortality of seals in coastal fyke net fisheries in the Baltic Sea. The seal sock developed and tested in this study was a cylindrical net attached to the fyke net, allowing the seals access to the surface to breathe while trapped inside fishing gear. The number of dead and live seals caught in fyke nets without a seal sock (years 2008-2010) and with a sock (years 2011-2013) was recorded. The seals caught in fyke nets were mainly juveniles. Of ringed seals (Phoca hispida botnica) both sexes were equally represented, while of grey seals (Halichoerus grypus) the ratio was biased (71%) towards males. All the by-caught seals were dead in the fyke nets without a seal sock, whereas 70% of ringed seals and 11% of grey seals survived when the seal sock was used. The seal sock proved to be effective in reducing the by-catch mortality of ringed seals, but did not perform as well with grey seals.201
Patterns of gene flow and selection across multiple species of Acrocephalus warblers: footprints of parallel selection on the Z chromosome
201
Ecological and genetic basis of metapopulation persistence of the Glanville fritillary butterfly in fragmented landscapes
Ecologists are challenged to construct models of the biological consequences of habitat loss and fragmentation. Here, we use a metapopulation model to predict the distribution of the Glanville fritillary butterfly during 22 years across a large heterogeneous landscape with 4,415 small dry meadows. The majority (74%) of the 125 networks into which the meadows were clustered are below the extinction threshold for long-term persistence. Among the 33 networks above the threshold, spatial configuration and habitat quality rather than the pooled habitat area predict metapopulation size and persistence, but additionally allelic variation in a SNP in the gene Phosphoglucose isomerase (Pgi) explains 30% of variation in metapopulation size. The Pgi genotypes are associated with dispersal rate and hence with colonizations and extinctions. Associations between Pgi genotypes, population turnover and metapopulation size reflect eco-evolutionary dynamics, which may be a common feature in species inhabiting patch networks with unstable local dynamics.Peer reviewe
Near-infrared evolution of the equatorial ring of SN 1987A
We use adaptive-optics imaging and integral field spectroscopy from the Very
Large Telescope, together with images from the \emph{Hubble Space Telescope},
to study the near-infrared (NIR) evolution of the equatorial ring (ER) of
SN~1987A. We study the NIR line and continuum flux and morphology over time in
order to lay the groundwork for \emph{James Webb Space Telescope} observations
of the system. We also study the differences in the interacting ring structure
and flux between optical, NIR and other wavelengths, and between line and
continuum emission, to constrain the underlying physical processes. Mostly the
evolution is similar in the NIR and optical. The morphology of the ER has been
skewed toward the west side (with roughly 2/3 of the NIR emission originating
there) since around 2010. A steady decline in the ER flux, broadly similar to
the MIR and the optical, is ongoing since roughly this time as well. The
expansion velocity of the ER hotspots in the NIR is fully consistent with the
optical. However, continuum emission forms roughly 70 per cent of the NIR
luminosity, and is relatively stronger outside the hotspot-defined extent of
the ER than the optical emission or NIR line emission since 2012--2013,
suggesting a faster-expanding continuum component. We find that this outer NIR
emission can have a significant synchrotron contribution. Even if emission from
hot (2000~K) dust is dominant within the ER, the mass of this dust must
be vanishingly small (a few ~M) compared to the total
dust mass in the ER (~M) to account for the observed
flux. The NIR continuum emission, however, expands slower than the more
diffuse 180-K dust emission that dominates in the MIR, indicating a different
source, and the same hot dust component cannot account for the -band
emission.Comment: 17 pages, 17 figures. Accepted for publication in Astronomy &
Astrophysic
Hallitusohjelma ja eläkeläisten toimeentulo
Tässä työpaperissa tarkastellaan 29.5.2015 nimitetyn pääministeri Sipilän hallituksen ohjelman vaikutuksia eläkeläisten toimeentuloon. Laskelmat koskevat indeksileikkausten vaikutuksia reaalituloihin, eläkeläisten siirtämistä yleisen asumistuen piiriin ja takuueläkkeen korotusta. Laskelmat ovat osaksi esimerkkilaskelmia, osaksi Kelan rekisteritietoihin perustuvia arvioita ja osaksi tulonsiirtojen ja verotuksen mikrosimulointiin perustuvia laskelmia
Waist‑height ratio and waist are the best estimators of visceral fat in type 1 diabetes
Visceral fat is associated with cardiovascular and kidney disease. However, the relationship between body composition and anthropometric measures in type 1 diabetes is unknown. Using z-statistics, we ranked the ability of body mass index (BMI), waist circumference (WC), waist-hip ratio (WHR), waist-height ratio (WHtR) and a body shape index (ABSI) to capture measures of body composition from 603 Dual-energy-X-Ray-Absorptiometry scans of adults with type 1 diabetes. Albuminuria was defined as urinary albumin excretion rate of at least 30 mg/24 h. Women with albuminuria had higher visceral fat mass % (VFM%) (0.9 vs. 0.5%, p = 0.0017) and lower appendicular lean mass % (AppLM%) (25.4 vs 26.4%, p = 0.03) than those without. Men with albuminuria had higher VFM% (1.5 vs. 1.0%, p = 0.0013) and lower AppLM% (30.0 vs 32.3, p < 0.0001) than those without. In men, WHtR estimated VFM% best (z-statistics = 21.1), followed by WC (z = 19.6), BMI (z = 15.1), WHR (z = 14.6) and ABSI (z = 10.1). In women, the ranking was WC (z = 28.9), WHtR (z = 27.3), BMI (z = 20.5), WHR (z = 12.7) and ABSI (z = 10.5). Overall, the ranking was independent of albuminuria. Adults with type 1 diabetes and albuminuria have greater VFM% and lower AppLM% than those without. WHtR and WC best estimate the VFM% in this population, independently of albuminuria and sex.Peer reviewe
Chromatin modifier developmental pluripotency associated factor 4 (DPPA4) is a candidate gene for alcohol-induced developmental disorders
Peer reviewe
Associations of dietary macronutrient and fibre intake with glycaemia in individuals with Type 1 diabetes
Aims To study the association between dietary intake and glycaemia in Type 1 diabetes. Methods Data on energy and nutrient intakes, and the mean and coefficient of variation of self-monitored blood glucose measurements were obtained from records completed by 1000 adults with Type 1 diabetes. Associations between these measures of glycaemia and dietary intake were investigated using generalized linear regression, with and without macronutrient substitution. Results In the first set of analyses, fibre intake was associated with lower mean self-monitored blood glucose values (beta = -0.428, 95% CI -0.624 to -0.231; PPeer reviewe
Predictors of employment in young adults with psychiatric work disability
AIM: Mental disorders are the leading cause of work disability among young adults in the industrialized world. Factors predicting employment after long-term psychiatric work disability are largely unknown. METHODS: We linked personal and clinical information from the benefit applications and medical certificates of 1163 young adults (18-34 years) with a new-onset fixed-term psychiatric disability pension in 2008 with employment records between 2005 and 2013. The outcomes were starting employment during and being employed at the end of follow-up. RESULTS: Of the participants, 48% had been employed during and 22% were employed at the end of follow-up. Sustained employment history, university education (master's degree) and no recorded psychological symptoms in childhood were associated with both subsequent employment outcomes. Women and participants under 25 years were more likely to start employment. Depression and other mental disorders (vs psychotic diagnose) and having no comorbid mental disorders or substance abuse were associated with employment at the end of follow-up. CONCLUSIONS: Sustained employment history, university education and no recorded psychological symptoms during childhood predict a return to employment among young adults after a fixed-term psychiatric work disability pension. Pro-active interventions in psychological problems during childhood could enhance employment after a period of work disability
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