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Increases in natural mortality have been suggested as a potential driver for both the collapse and lack of recovery for the American plaice (Hippoglossoides platessoides) population on the Grand Bank of Newfoundland in NAFO Divisions 3LNO. However, natural mortality is among the most difficult parameters to estimate since it can be confounded with other parameters and model misspecifications. One method used to avoid this confounding involves modeling unfished components of a population where total mortality and natural mortality are equal. Here, we use a state-space metapopulation dynamics model to investigate whether there is evidence that natural mortality rates for unfished juvenile American plaice have varied since the population collapse. In addition, our model examined the degree of synchrony in age-1 recruitment signals between each management Division. The best fitting model included temporal variability in natural mortality rates, but estimates did not frequently differ from zero. This indicates that change in natural mortality rates is not an important driver of current juvenile 3LNO American plaice stock dynamics. Instead, this model identified that juvenile stock dynamics were mainly affected by variations in age-1 recruitment. Furthermore, a correlation analysis of the temporal variations in recruitment showed that trends were somewhat dissimilar between NAFO Divisions 3L and 3NO. Overall, although increases in M have been suggested by recent studies, we did not find strong evidence for this in juvenile fish. [ABSTRACT FROM AUTHOR]

In this article, we present the restricted numerical for the Laplacian matrix of a directed graph (digraph). We motivate our interest in the restricted numerical range by its close connection to the algebraic connectivity of a digraph. Moreover, we show that the restricted numerical range can be used to characterize digraphs, some of which are not determined by their Laplacian spectrum. Finally, we identify a new class of digraphs that are characterized by having a real restricted numerical range. [ABSTRACT FROM AUTHOR]

Time‐restricted feeding (TRF) is a novel dietary approach where energy intake is limited to a set number of hours in the day (typically ≤12 hours), which leads to an extension of the daily fast that generally occurs overnight. Human pilot studies (based on animal experiments) have demonstrated that TRF has the potential to reduce risk factors for type 2 diabetes (T2DM): mediating weight loss, the reduction of low‐density lipoprotein (LDL) cholesterol and improving insulin sensitivity. However, it remains unclear whether it is better to restrict food intake to earlier in the day (early‐TRF) or later in the day (late‐TRF). The aim of this study is to investigate the effects of TRF on established risk factors for T2DM and its application to wider society. The primary hypothesis is that 10 weeks of daily TRF will reduce food intake, bodyweight and adiposity while improving markers of metabolic disease risk, such as LDL‐cholesterol and insulin sensitivity. The secondary hypothesis is that early‐TRF will induce larger metabolic changes in comparison to late‐TRF. Eligible volunteers will be randomised to either the early‐TRF (7 am to 3 pm), late‐TRF (12 pm to 8 pm) or control group (unrestricted eating window) for 10 weeks. Changes in fasting markers, diet, bodyweight and body composition will be assessed throughout the experiment, as well as the effects on psychological wellbeing and social and family interactions. [ABSTRACT FROM AUTHOR]

With an increasing prevalence of diabetes worldwide, effective dietary strategies for blood glucose control are crucial. As carbohydrates make up approximately 50% of the diet, it is neither practical nor advisable to avoid them altogether. Most of the carbohydrate in the diet is derived from starch, found in potatoes, pasta, rice and bread. These foods are often processed in some way before consumption, yet little is known about the effects processing, such as chilling and reheating, has on the glycaemic response, particularly when the food is consumed in the context of a mixed meal. This article introduces the SPUD project, a BBSRC DRINC‐funded initiative. Taking the potato as the model carbohydrate, this project will investigate, via in vitro and in vivo studies, the effects of domestic food processing techniques on the glycaemic response. A final study, utilising intrinsically labelled potato and a dual stable isotope methodology, will model glucose flux data to determine the underlying mechanisms of action. [ABSTRACT FROM AUTHOR]

We investigated the effect of Pb surfactant on the growth mode and magnetism of dilute Si1-xMnx thin films grown by molecular beam epitaxy. We find that the nanocolumns that form in Pb-free samples are paramagnetic with a small saturation moment that drops with increasing Mn concentration. On the contrary, samples grown with 2 monolayers of Pb contain MnSi1.7 nanorods that lie in the plane of the films. Although the saturation moment of these samples also drops rapidly with increasing Mn concentration, it is as high as 0.65 μB/Mn. At the lowest Mn concentration (x = 0.5%), the samples grown with a Pb surfactant exhibit two ferromagnetic transitions at the Curie temperatures TC1≈40 K and TC2>400 K. While the transition at TC1 is consistent with the Curie temperature of bulk MnSi1.7 crystals, TC2 is possibly due to a second phase resulting from Mn in the Si matrix. [ABSTRACT FROM AUTHOR]

Purpose: Intermittent energy restriction (IER) is a popular weight loss (WL) strategy; however, its efficacy in clinical practice remains unknown. The present study compared the effects of IER compared to continuous energy restriction (CER) on WL and cardiometabolic risk factors in primary care. Methods: A (self-selected) cohort study was conducted at the Rotherham Institute for Obesity (RIO), a primary care-based weight management service. 197(24% male) obese patients volunteered to participate and selected their diet group. IER participants (n = 99) consumed ~ 2600 kJ for two days/week. CER participants (n = 98) restricted their diet by ~ 2100 kJ/day below estimated requirements. Both interventions were delivered alongside RIO standard care. Changes in anthropometry and cardiometabolic disease risk markers (fasting biochemistry and blood pressure) were assessed after a 6-month intervention period and then participants were followed up again 6 months later (month 12). Results: 27 IER patients (27%) and 39 CER patients (40%) completed the 6-month weight loss phase. Among completers, mean (SEM) WL was greater in the IER group at 6 months (5.4 ± 1.1% versus 2.8 ± 0.6%; p = 0.01), as were reductions in fat mass (p < 0.001) and improvements in systolic blood pressure (p < 0.001). Fasting insulin (p = 0.873) and diastolic blood pressure (p = 0.701) were reduced similarly in both groups. However, in the IER group, changes in anthropometry and blood pressure in the IER group had reverted to baseline by 12-month follow-up, whilst the CER group maintained weight loss but showed an increase in blood pressure. Conclusions: Among completers, IER resulted in superior short-term changes in anthropometry and some cardiometabolic risk factors. However, rates of attrition and weight regain were higher compared with standard care, providing important insights in the implementations of IER within a "real-life" NHS setting. Trial registration number: ISRCTN31465600. [ABSTRACT FROM AUTHOR]

Quantitative compositional analysis of InAs quantum wires deposited between In0.53Ga0.37Al0.1As barrier layers grown on InP substrates was performed by electron energy loss spectrometry and energy dispersive x-ray spectrometry. An indium-rich region in the center of the wire, with decreasing indium concentration toward the interface with the barrier layers, was observed from indium concentration maps for individual quantum wires. “Stripelike” contrast modulation was observed in diffraction contrast transmission electron microscope images of the In0.53Ga0.37Al0.1As barrier layer immediately above the quantum wires. The contrast originated from indium compositional modulations in the upper barrier layer as confirmed by electron energy loss spectrometry and the modulation is attributed to the presence of an inhomogeneous elastic strain field generated by the buried quantum wires. These results suggest that quantitative analysis of the composition and strain distributions at very high spatial resolution provides insights necessary to further model the physical properties and to understand the growth of these nanostructures. [ABSTRACT FROM AUTHOR]

We have investigated the influence of defects emanating from phosphorus implantation damage in the InP capping layer on postgrowth thermally induced intermixing in self-assembled InAs/InP(001) quantum dots (QDs). Photoluminescence (PL) spectra from as-grown samples could be described as the superposition of separate PL peaks where each peak corresponded to emission from an ensemble of QDs with a particular height ranging from 4 to 13 ML. Blueshift of up to 270 meV and significant bandwidth broadening were observed in the PL spectra after ion implantation with a fluence of 5×1011-1014 cm-2 and subsequent annealing at temperatures ranging from 450 to 600 °C. From the analysis of the evolution of the QD peaks upon intermixing, which revealed the coexistence of intact QD PL and a broad PL feature related to heavily intermixed QDs, it was suggested that the bandwidth broadening resulted from spatial inhomogeneity in the compositional intermixing. In order to better understand the mechanism responsible for the ion-implantation-induced intermixing, samples capped with a stack of compressively strained In0.75Ga0.25As/InP quantum wells (QWs) were prepared to trap vacancies released by the implantation damage while not inhibiting the effect of the interstitials. Both blueshift and bandwidth broadening were suppressed in samples containing the strained InGaAs QWs, whereas the evolution of the PL spectra from the QDs behaves as expected for interstitial-mediated intermixing. The vacancies were thus believed to be trapped in the QWs and indicated that intermixing in ion-implanted InP capped samples is mediated by vacancies. The shape of the QDs changed from a truncated pyramid in the as-grown state to a double convex lens structure after intermixing as confirmed by cross-sectional scanning transmission electron microscopy imaging. Furthermore, the change in shape and compositional intermixing of the QDs were attributed to vacancy trapping in the vicinity of the QDs as based on atomistic strain calculations. [ABSTRACT FROM AUTHOR]

Thin film nanocrystalline porous silicon layers have been fabricated from amorphous silicon films using dc plasma hydrogenation and subsequent annealing at temperatures about 450 °C on silicon substrates. Plasma power densities about 5.5 W/cm2 were found to be suitable for etching of the silicon film and the creation of nanoporous layers. The nanoporous structures show visible luminescence at room temperature as confirmed by photoluminescence spectroscopy. The effects of plasma power and annealing temperature on the grain size and luminescence properties of these layers have been investigated by scanning electron microscopy, transmission electron microscopy, photoluminescence, and cathodoluminescence. It was observed that by lowering the temperature during the hydrogenation step, the diameter of the grains increased, whereas lowering the plasma power density caused the distribution of the porous surface structures to become less widely distributed and the formation of more packed structures. In addition, infrared spectroscopy has been used to investigate the origin of the light emitting behavior. [ABSTRACT FROM AUTHOR]

The effects of plasma-enhanced hydrogenation on the crystallization of pure, electron-beam evaporated amorphous silicon (a-Si) at temperatures as low as 300 °C were investigated. Successive steps of hydrogenation in the plasma-enhanced chemical vapor deposition chamber, and in situ annealing in a N2 ambient environment were applied to the a-Si samples over a range of low temperatures and plasma powers. At specific plasma-power densities, nanocrystalline silicon layers with an average grain size of less than 10 nm were formed where their size, distribution, and porosity could be varied by altering the plasma power and hydrogenation temperature. The surface morphology and the nanocrystalline quality of the samples were characterized using scanning electron microscopy, dark-field transmission electron microscopy, and electron diffraction. In addition, by plasma-enhanced oxidation at a temperature of 250 °C, a thin layer of oxide was grown and its physical, structural, and electrical characteristics were investigated. [ABSTRACT FROM AUTHOR]

Comparisons of buried InAs/GaAs and InAs/InP quantum dots (QDs) utilizing transmission electron microscopy display interesting parallels and differences between the two systems. The higher 7.2% misfit in the InAs/GaAs system produces small (~20 nm diameter) QDs with a majority displaying a predominately round shape. The lower 3.2% misfit in the InAs/InP system produces larger QDs (~35 nm diameter) with the majority also displaying a predominately round shape. In both systems, the size of the QDs can be varied by changes in growth procedures and the largest QDs in any population show evidence of faceting c 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Studies the single and multiple layers of self-assembled InAs quantum dots (QD) produced by the indium-flush technique by transmission electron microscopy. Development of a technique to reproducibly grow QD of uniform size and shape; Determination of the shapes and sizes of QD through the interpretation of the observed contrast in plan-view.

Investigates the growth of thin silicon (Si) films on Si substrates at low substrate temperatures using ionized Si-hydrogen gas generated with a Kaufman type ion gun. Use of transmission electron microscopy; In situ cleaning of the substrate surface; Cause of the difference in the coverage of the substrate surface.