Magnetoconductivity of Hubbard bands induced in Silicon MOSFETs

Sodium impurities are diffused electrically to the oxide-semiconductor interface of a silicon MOSFET to create an impurity band. At low temperature and at low electron density, the band is split into an upper and a lower sections under the influence of Coulomb interactions. We used magnetoconductivity measurements to provide evidence for the existence of Hubbard bands and determine the nature of the states in each band.Comment: In press in Physica

Habitat-based density models of pack-ice seal distribution in the southern Weddell Sea, Antarctica

Climate variability and changes in sea ice dynamics have caused several ice-obligate or krill-dependent populations of marine predators to decline, eliciting concern about their demographic persistence and the indirect ecological consequences that predator depletions may have on marine ecosystems. Pack-ice seals are dominant ice-obligate predators in the Antarctic marine ecosystem, but there is considerable uncertainty about their abundance and population trends. We modelled the density and distribution of pack-ice seals as a function of environmental covariates in the southern Weddell Sea, Antarctica. Our density surface modelling approach used data from aerial surveys of pack-ice seals collected in the 2013/14 austral summer. Crabeater seals Lobo don carcinophaga, the most numerous pack-ice seal we observed, occurred at the highest densities in areas with extensive sea ice near the continental shelf break, but were almost absent in areas of similar sea ice concentration in the southern extent of the Weddell Sea. The highest densities of Weddell seals Leptonychotes weddelli, which were less abundant than crabeater seals within the pack-ice habitat, were predicted to occur over the continental shelf, near the shelf break. The distribution of both seal species broadly corresponded with the distribution and relative abundance of their main prey (Antarctic krill Euphausia superba and Antarctic silverfish Pleuragramma antarctica) obtained from concurrent ecosystem surveys. Ross seals Ommatophoca rossii and leopard seals Hydrurga leptonyx were not detected at all and are apparently rare within the southern Weddell Sea. These results can contribute to biodiversity assessments in the context of marine protected area planning in this region of the Southern Ocean

Applied research note : biomonitoring of mycotoxins in blood serum and feed to assess exposure of broiler chickens

Because European maximum guidance values of mycotoxins are only available for feed, mycotoxin exposure in animals is mainly monitored by feed analysis. However, proper sample collection is needed to ensure reliable results because of uneven distributions and disproportional spread of mycotoxins in feed which can hamper the evaluation of mycotoxin exposure in animals. A cross-sectional study was performed on 40 randomly selected broiler farms in Belgium. During a farm visit at the animal's age of 28 d, a pooled feed sample at the beginning and the end of the feed line was collected. Feed samples were analyzed by a validated multimycotoxin LC-MS/MS method. Moreover, serum samples were collected from 10 randomly selected chickens per farm. Serum concentrations of mycotoxins and major in vivo phase I metabolites were analyzed quantitatively, whereas the presence of phase II metabolites was determined in a qualitative approach by an UPLC-HRMS method. Deoxynivalenol (DON) was the most frequently occurring mycotoxin, being present in 74% of the feed samples, with an average concentration of 270 +/- 171 mu g/kg and a maximum concentration of 751 mu g/kg in positive samples. Also the acetylated forms 3and 15-acetyldeoxynivalenol (3 and 15ADON) were present in half of the samples, however, at lower concentrations (8 +/- 3 mu g 3ADON and 10 +/- 7 mu g 15ADON/kg). Only in 17.5% of the farms, DON was detected in serum samples at a mean serum concentration and standard deviation (SD) of 11 +/- 19 ng/mL. The maximum serum concentration of 49 ng DON/ mL was detected in broilers which were fed a diet that was contaminated with 191 mu g DON/kg, whereas the maximum concentration of DON in feed was 751 mu g/kg. Besides, 3 and 15ADON were only detected in 10% of the serum samples (max. 1.3 ng/mL). Sulfate conjugates of DON were only detected in a few serum samples. Qualitative screening for phase II metabolites of other mycotoxins showed similar results. Overall, correlations between feed and serum concentrations of all mycotoxins were lacking (R-2 = 0.18 for DON)

Maternal immune activation transgenerationally modulates maternal care and offspring depression-like behavior

AbstractGestational infection is increasingly being recognized for its involvement as causative mechanism in severe developmental brain abnormalities and its contribution to the pathogenesis of psychopathologies later in life. First observations in the widely accepted maternal immune activation (MIA) model based upon the systemic administration of the viral mimetic Polyinosinic:polycytidylic acid (poly(I:C)) have recently suggested a transmission of behavioral and transcriptional traits across generations. Although maternal care behavior (MCB) is known as essential mediator of the transgenerational effects of environmental challenges on offspring brain function and behavior, the possible propagation of alterations of MCB resulting from MIA to following generations has not yet been examined. Here we show that poly(I:C) stimulation at embryonic day 12.5 (E12.5) leads to aberrant MCB and that this effect is transmitted to the female F1 offspring. The transgenerational effects on MCB are paralleled by enhanced depression-like behavior in the second generation F2 offspring with contributions of both maternal and paternal heritages. Examination of offspring hippocampal expression of genes known as targets of MCB and relevant for ensuing non-genetic transmission of altered brain function and behavior revealed transgenerationally conserved and modified expressional patterns in the F1 and F2 generation.Collectively these data firstly demonstrate the transgenerational transmission of the impact of gestational immune activation on the reproductive care behavior of the mother. Behavioral and molecular characteristics of first and second generation offspring suggest transgenerationally imprinted consequences of gestational infection on psychopathological traits related to mood disorders which remain to be examined in future cross-fostering experiments

Perfect weddings abroad

Approximately 16% of UK couples are currently married abroad. However, academic or practitioner focused research that explores the complex nature of a couple’s buying preferences or the development of innovative marketing strategies by businesses operating within the weddings abroad niche sector, is almost non-existent. This exploratory paper examines the role and relevance of marketing within the weddings abroad sector. The complex nature of customer needs in this high emotional and involvement experience, are identified and explored. A case study of Perfect Weddings Abroad Ltd highlights distinctive features and characteristics. Social networking and the use of home-workers, with a focus on reassurance and handholding are important tools used to develop relationships with customers. These tools and techniques help increase the tangibility of a weddings abroad package. Clusters of complementary services that are synergistic and provide sources of competitive advantage are identified and an agenda for future research is developed

A Model of Vertical Oligopolistic Competition

This paper develops a model of successive oligopolies with endogenous market entry, allowing for varying degrees of product differentiation and entry costs in both markets. Our analysis shows that the downstream conditions dominate the overall profitability of the two-tier structure while the upstream conditions mainly affect the distribution of profits. We compare the welfare effects of upstream versus downstream deregulation policies and show that the impact of deregulation may be overvalued when ignoring feedback effects from the other market. Furthermore, we analyze how different forms of vertical restraints influence the endogenous market structure and show when they are welfare enhancing