The Effects of Surfaces and Surface Passivation on the Electrical Properties of Nanowires and Other Nanostructures: Time-Resolved Terahertz Spectroscopy Studies

The electrical properties of nanomaterials are strongly influenced by their surfaces, which in turn are strongly influenced by device processing and passivation procedures. Optical pump-terahertz probe spectroscopy is ideal for measuring the native properties of these materials, determining the changes induced by device processing, and studying the effectiveness of surface passivation procedures. Here we study the electronic properties of III-V nanowires and other nanomaterials in both their native and encapsulated/integrated states, which is uniquely possible with terahertz spectroscopy

Rehabilitation of Antimony Mine Wastes at Hillgrove, New South Wales

The tailings disposal systems of the New England Antimony Mines N. L. Company were investigated and a plan for future tailings disposal prepared. This was a two stage process, the first resulting from the capacity of the existing tailings dump having been reached, the second from a decision to reprocess the tailings due to a rise in the price of gold and a decline in the grade of antimony in the mined rock. The tailings disposal systems involved the creation of a closed system in which both solid and liquid wastes could be managed. ... The root morphology of plants grown in the tailings mixtures reflected the aeration and mechanical impedence effects over the range of moisture tensions created under glass house conditions and regular watering to maintain field capacity. Roots were stunted with limited lateral development. Root tips were clubbed with many roots displaying swollen sections. An abundance of root hairs were evident together with noticeable changes in direction of root members. ... It was concluded that the establishment of vegetation in the tailings was not practicable due to the effects of poor aeration and mechanical impedence. The most suitable rehabilitation method would be to apply a topsoil covering and establish a self sustaining cover of vegetation

Nitrogen-limited mangrove ecosystems conserve N through dissimilatory nitrate reduction to ammonium

Earlier observations in mangrove sediments of Goa, India have shown denitrification to be a major pathway for N loss1. However, percentage of total nitrate transformed through complete denitrification accounted for <0–72% of the pore water nitrate reduced. Here, we show that up to 99% of nitrate removal in mangrove sediments is routed through dissimilatory nitrate reduction to ammonium (DNRA). The DNRA process was 2x higher at the relatively pristine site Tuvem compared to the anthropogenically-influenced Divar mangrove ecosystem. In systems receiving low extraneous nutrient inputs, this mechanism effectively conserves and re-circulates N minimizing nutrient loss that would otherwise occur through denitrification. In a global context, the occurrence of DNRA in mangroves has important implications for maintaining N levels and sustaining ecosystem productivity. For the first time, this study also highlights the significance of DNRA in buffering the climate by modulating the production of the greenhouse gas nitrous oxide

Immune response to 19A serotype after immunization of 19F containing pneumococcal conjugate vaccine in Korean children aged 12-23 months

PurposeThe purpose of this study was to evaluate the immune response to serotype 19A in children aged 12-23 months after immunization of the 19F containing 7-valent pneumococcal conjugate vaccine (PCV7).MethodsBlood samples from a total of 45 subjects (age 12-23 months) were included in the study. Subjects were categorized according to immunization status into three groups as follows: 18 subjects with 3 primary doses and 1 booster dose of PCV7 (booster group), 21 subjects with 3 primary doses before 12 months of age (primary group), and 6 subjects with no vaccination history of PCV7 (control group). An ELISA and opsonophagocytic killing assay (OPKA) was done to evaluate the immune responses against serotypes 19F and 19A.ResultsAccording to the ELISA, all subjects had antibody titers ≥0.35 µg/mL for serotypes 19F and 19A in the booster and primary group and 83.0% and 66.7% in the control group, respectively. According to the OPKA, subjects with opsonic activity (≥20) against serotypes 19F and 19A were 100% and 61.1% of the subjects in the booster group and 66.7% and 19.0% in the primary group, respectively. No subjects in the control group had opsonic antibodies against both serotypes.ConclusionIn conclusion, in children 12-23 months age who were previously vaccinated with PCV7, a cross-reactive immune response is elicited against serotype 19A after a primary series of 3 doses in a small proportion of subjects, and this response is amplified after booster vaccination

Protein---carbohydrate interaction. : Part XXII. A chemically-synthesized d-mannan and the interaction of some synthetic d-mannans with concanavalin A

1,6-Anhydro-[beta]--mannopyranose was polymerized in the presence of chloroacetic acid. A high-molecular-weight fraction insoluble in 80% ethanol was isolated and studied. Periodate-oxidation studies showed the polymer to contain 42% of (1--&gt;6)-like linkages, 36% of (1--&gt;4)- or (1--&gt;2)-like linkages, and 22% (1--&gt;3)-like linkages. End-group analysis gave = 113. The synthetic -mannan reacted vigorously with concanavalin A, indicating that it was a highly branched polymer containing multiple [alpha]--mannopyranosyl residues at chain ends. A synthetic -mannan obtained by the polymerization of -mannose in the presence of phosphorous acid gave a much weaker reaction with concanavalin A, and two synthetic, linear polymers failed, as expected, to form a precipitate with this plant protein.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/32749/1/0000118.pd

Targeting Antibiotics to Households for Trachoma Control

Repeated ocular infection with the bacterium Chlamydia trachomatis leads to the development of trachoma, a major cause of infectious blindness worldwide. Mass distribution of antibiotics, a component of the current trachoma control strategy, has had success in reducing infection in some areas, but results in a large number of uninfected people receiving antibiotics. We have previously shown that transmission of the bacteria between people in the same household is very efficient. Here, we investigated the effectiveness and cost-effectiveness of targeting antibiotics to households with active trachoma (inflammatory disease) compared to mass distribution, using data from four trachoma-endemic populations and a mathematical model of transmission. We found a high correspondence between households with active trachoma and infected households. In all populations the household targeted approach was predicted to be as effective as mass distribution, but it reduced the number of uninfected individuals receiving antibiotics, making the targeted strategy more cost-effective when antibiotics are not donated. Assuming antibiotics are donated, we predicted the targeted strategy to be more cost effective if it increases the proportion of infected individuals receiving treatment. Further work to address the feasibility and the cost variability in implementing the targeted approach in different settings is now required

Genetic variation for tuber mineral concentrations in accessions of the Commonwealth Potato Collection

The variation in tuber mineral concentrations amongst accessions of wild tuber-bearing Solanum species in the Commonwealth Potato Collection (CPC) was evaluated under greenhouse conditions. Selected CPC accessions, representing the eco-geographical distribution of wild potatoes, were grown to maturity in peat-based compost under controlled conditions. Tubers from five plants of each accession were harvested, bulked and their mineral composition analysed. Among the germplasm investigated, there was a greater range in tuber concentrations of some elements of nutritional significance to both plants and animals, such as (Ca, Fe and Zn; 6.7, 3.6, and 4.5-fold respectively) than others, such as (K, P and S; all <3-fold). Significant positive correlations were found between mean altitude of the species' range and tuber P, K, Cu and Mg concentrations. The amount of diversity observed in the CPC collection indicates the existence of wide differences in tuber mineral accumulation among different potato accessions. This might be useful in breeding for nutritional improvement of potato tubers

Oligodendroglial neoplasms with ganglioglioma-like maturation: a diagnostic pitfall

Although oligodendroglial neoplasms are traditionally considered purely glial, increasing evidence suggests that they are capable of neuronal or neurocytic differentiation. Nevertheless, ganglioglioma-like foci (GGLF) have not been previously described. Herein, we report seven examples where the primary differential diagnosis was a ganglioglioma with an oligodendroglial component. These five male and two female patients ranged in age from 29 to 63 (median 44) years at initial presentation and neuroimaging features were those of diffuse gliomas in general. At presentation, the glial component was oligodendroglioma in six and oligoastrocytoma in one; one was low-grade and six were anaplastic. A sharp demarcation from adjacent GGLF was common, although some intermingling was always present. The GGLF included enlarged dysmorphic and occasionally binucleate ganglion cells, Nissl substance, expression of neuronal antigens, GFAP-positive astrocytic elements, and low Ki-67 labeling indices. In contrast to classic ganglioglioma, however, cases lacked eosinophilic granular bodies and CD34-positive tumor cells. Scattered bizarre astrocytes were also common and one case had focal neurocytic differentiation. By FISH analysis, five cases showed 1p/19q codeletion. In the four cases with deletions and ample dysmorphic ganglion cells for analysis, the deletions were found in both components. At last follow-up, two patients suffered recurrences, one developed radiation necrosis mimicking recurrence, and one died of disease 7.5 years after initial surgery. We conclude that GGLF represents yet another form of neuronal differentiation in oligodendroglial neoplasms. Recognition of this pattern will prevent a misdiagnosis of ganglioglioma with its potential for under-treatment

Which New Approaches to Tackling Neglected Tropical Diseases Show Promise?

This PLoS Medicine Debate examines the different approaches that can be taken to tackle neglected tropical diseases (NTDs). Some commentators, like Jerry Spiegel and colleagues from the University of British Columbia, feel there has been too much focus on the biomedical mechanisms and drug development for NTDs, at the expense of attention to the social determinants of disease. Burton Singer argues that this represents another example of the inappropriate “overmedicalization” of contemporary tropical disease control. Peter Hotez and colleagues, in contrast, argue that the best return on investment will continue to be mass drug administration for NTDs