Homoepitaxial n-core: p-shell gallium nitride nanowires: HVPE overgrowth on MBE nanowires

We present the homoepitaxial growth of p-type, magnesium doped gallium nitride shells by use of halide vapor phase epitaxy (HVPE) on n-type gallium nitride nanowires grown by plasma-assisted molecular beam epitaxy (MBE). Scanning electron microscopy shows clear dopant contrast between the core and shell of the nanowire. The growth of magnesium doped nanowire shells shows little or no effect on the lattice parameters of the underlying nanowires, as measured by x-ray diffraction (XRD). Photoluminescence measurements of the nanowires show the appearance of sub-bandgap features in the blue and the ultraviolet, indicating the presence of acceptors. Finally, electrical measurements confirm the presence of electrically active holes in the nanowires.     

Gendered Mobilities and Food Access in Blantyre,Malawi

Access to food, rather than a shortage of food availability, is the central problem for urban household food security. Blantyre presents a useful case study for demonstrating the importance of linking gender and urban food security. Rates of urban food insecurity are less severe than in other cities surveyed by AFSUN. Yet, female-centred households were twice as likely to be severely food insecure as nuclear households. This paper offers some explanations for the survey findings by drawing on qualitative research to understand the gendered geographies of food access in Blantyre. The first point is that gender shapes mobility, which in turn shapes a household’s ability to increase its food security by procuring food from the most affordable sources, particularly peri-urban markets. The second point is that gender shapes a household’s ability to produce its own food, a popular livelihood strategy in Blantyre that often mitigates the effects of low incomes on household food security. The third point is that gender influences a person’s potential income, which shapes the household’s economic access to food. These three points demonstrate the multi-dimensional relationship between gender and urban food security.     

Synergistic Effects of Iridoid Glycosides on the Survival, Development and Immune Response of a Specialist Caterpillar, Junonia coenia (Nymphalidae)

Plants use a diverse mix of defenses against herbivores, including multiple secondary metabolites, which may affect herbivores synergistically. Chemical defenses also can affect natural enemies of herbivores via limiting herbivore populations or by affecting herbivore resistance or susceptibility to these enemies. In this study, we conducted larval feeding experiments to examine the potential synergistic effects of iridoid glycosides (IGs) found in Plantago spp. (Plantaginaceae) on the specialist buckeye caterpillar, Junonia coenia (Nymphalidae). Caterpillars were placed on artificial diets containing different concentrations of single IGs (aucubin or catalpol alone) or combinations of the two IGs. Larval performance and immune response were recorded to test the hypothesis that IGs would have positive synergistic effects on buckeyes, which are specialists on IG plants. The positive synergistic effects that IGs had on buckeyes in our experiments included lower mortality, faster development, and higher total iridoid glycoside sequestration on mixed diets than on aucubin- or catalpol-only diets. Furthermore, we found negative synergistic effects of IGs on the immune response of buckeye caterpillars. These results demonstrate multiple synergistic effects of IGs and indicate a potential trade-off between larval performance and parasitoid resistance.     

The effects of consuming probiotic‐fermented milk on the immune system: A review of scientific evidence

Fermented dairy products are commonly used as the most efficient delivery vehicle for probiotics. These foods are well known for promoting the positive health benefits of consuming probiotics. Among their beneficial effects, their immunomodulatory properties have attracted a great deal of interest in recent years. Reports, both in vitro and in vivo, on the beneficial effects of consuming fermented milks containing probiotics have demonstrated the enhancement of various parameters in animal (e.g. rats and mice) and human immune systems, such as the production of cytokines and mediators by antigen‐presenting cells and cellular markers for different cell populations. Hence, the purpose of this review was to provide an overview of the scientific literature concerning the potential of probiotic‐fermented milks to influence the host's immune system, thereby modulating the immune response in a positive fashion.     

Using continuous GPS and absolute gravity to separate vertical land movements and changes in sea-level at tide-gauges in the UK

Researchers investigating climate change have used historical tide-gauge measurements from all over the world to investigate the changes in sea-level that have occurred over the last century or so. However, such estimates are a combination of any true sea-level variations and any vertical movements of the land at the specific tide-gauge. For a tide- gauge record to be used to determine the climate related component of changes in sea-level, it is therefore necessary to correct for the vertical land movement component of the observed change in sea-level.In 1990, the Institute of Engineering Surveying and Space Geodesy and Proudman Oceanographic Laboratory started developing techniques based on the Global Positioning System (GPS) for measuring vertical land movements (VLM) at tide-gauges in the UK. This paper provides brief details of these early developments and shows how they led to the establishment of continuous GPS (CGPS) stations at a number of tide-gauges. The paper then goes on to discuss the use of absolute gravity (AG), as an independent technique for measuring VLM at tide-gauges. The most recent results, from CGPS time-series dating back to 1997 and AG time-series dating back to 1995/1996, are then used to demonstrate the complementarity of these two techniques and their potential for providing site-specific estimates of VLM at tide-gauges in the UK.     

Clostridium sporogenes PA 3679 and its uses in the derivation of thermal processing schedules for low-acid shelf-stable foods and as a research model for proteolytic Clostridium botulinum

The putrefactive anaerobe Clostridium sporogenes PA 3679 has been widely used as a nontoxigenic surrogate for proteolytic Clostridium botulinum in the validation of thermal processes for low-acid shelf-stable foods, as a target organism in the derivation of thermal processes that reduce the risk of spoilage of such foods to an acceptable level, and as a research model for proteolytic strains of C. botulinum. Despite the importance of this organism, our knowledge of it has remained fragmented. In this article we draw together the literature associated with PA 3679 and discuss the identity of this organism, the phylogenetic relationships that exist between PA 3679 and various strains of C. sporogenes and proteolytic C. botulinum, the heat resistance characteristics of PA 3679, the advantages and limitations associated with its use in the derivation of thermal processing schedules, and the knowledge gaps and opportunities that exist with regard to its use as a research model for proteolytic C. botulinum. Phylogenetic analysis reviewed here suggests that PA 3679 is more closely related to various strains of proteolytic C. botulinum than to selected strains, including the type strain, of C. sporogenes. Even though PA 3679 is demonstrably nontoxigenic, the genetic basis of this nontoxigenic status remains to be elucidated, and the genetic sequence of this microorganism appears to be the key knowledge gap remaining to be filled. Our comprehensive review of comparative heat resistance data gathered for PA 3679 and proteolytic strains of C. botulinum over the past 100 years supports the practice of using PA 3679 as a (typically fail-safe) thermal processing surrogate for proteolytic C. botulinum.     

Smoking behavior and risk perception among the parents of infants in the neonatal intensive care unit.

The goal of this study was to explore the prevalence of smoking and attitudes and behaviors relevant to smoking cessation among parents of babies treated in a neonatal intensive care unit (NICU). Participants were 235 mothers and 83 fathers of infants admitted to the NICU of a large, university-based hospital. The 38-item survey included questions that assessed smoking status (current, former, never-smoker), motivation to quit, perceived health risks from smoking, and whether or not they received smoking cessation advice or counseling from a health care provider. A total of 26% of all participants were current smokers. Compared with mothers, fathers were more likely to be current smokers (22% vs. 31%) and smoked more cigarettes per day (11.3% vs. 17.2%). Among participants, 57% reported that smoking affected their own health "a little" or "not at all," and 70% believed that others' smoking would affect the baby's health "a little" or "somewhat." Mothers were more likely than fathers to report health care provider intervention for smoking cessation. Indeed, none of the fathers in this study reported being offered assistance with quitting smoking. More than half of smokers were willing to receive counseling for smoking cessation, and health care provider intervention was positively associated with both motivation to quit and perceived health risk to their infant (p<.01). The NICU may provide a teachable moment in which parents can be assisted with quitting smoking, thus improving their own health and the health of their babies.     

Intellectual performance and school failure in children with attention deficit hyperactivity disorder and in their siblings.

Made psychiatric and intellectual assessments of 140 children with attention deficit hyperactivity disorder (ADHD), 120 normal controls, and their 303 siblings. The index children were White, non-Hispanic boys. ADHD children were more likely to have had learning disabilities, repeated grades, been placed in special classes, and received academic tutoring. They also did worse on the Wechsler Intelligence Scale for Children—Revised (WISC—R). Among ADHD probands, comorbid conduct, major depressive, and anxiety disorders predicted school placement more than school failure or WISC—R scores. However, the neuropsychological disability of all ADHD children could not be attributed to comorbid disorders because those without comorbidity had more school failure and lower WISC—R scores than normal controls. Intellectual impairment was also increased among siblings of ADHD children. This provides converging evidence that the ADHD syndrome is familial. (PsycINFO Database Record (c) 2010 APA, all rights reserved)