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Plasticity in as-grown gold nanowires deformed in three-point bending configuration was studied by Laue microdiffraction. One-dimensional orientation maps of the Au crystal along the nanowire were generated from which the deformation profile was inferred. The crystal lattice was found to rotate continuously around the Au
direction, which is transverse to the wire axis evidencing the storage of geometrically necessary dislocations (GNDs). The analysis of the diffraction peak shape points to the activation of multiple slip systems in contrast to the formation of wedge shaped twins predicted by MD simulations.
While parasite infection can have substantial fitness consequences in organisms, the predictors of parasite prevalence and intensity are often complex and vary depending on the host species. Here, we examined correlates of Haemoproteus (a common malaria parasite) prevalence and intensity in an opportunistically breeding songbird, the red crossbill (Loxia curvirostra). Specifically, we quantified Haemoproteus prevalence and intensity in crossbills caught in the Grand Teton National Park from 2010 to 2013. We found that parasite prevalence varies seasonally and across years, with the highest number of infected individuals occurring in the summer, although there was variation across summers sampled, and that prevalence was positively related to annual mean cone crop sizes (a measure of crossbill food abundance) and daily ambient temperature (a correlate of vector abundance). Parasite intensity was significantly and positively related to one measure of innate immunity, leucocyte counts per blood volume. Finally, neither crossbill age, ecomorph, nor sex had significant effects on parasite infection intensity; however, parasite prevalence did significantly vary among ecomorph and age classes. These results support the interpretation that a combination of physiological (specifically immune activity) and environmental factors affects parasite prevalence and infection intensity in this opportunistically breeding avian species.
Behavioral disturbances are common but serious symptoms in patients with dementia. Currently, there are no FDA approved drugs for this purpose. There have been case reports and small case series of the use of buspirone. In this retrospective study, we review 179 patients prescribed buspirone for treatment of behavioral disturbance in dementia to better characterize the efficacy and potential side effects. All patients prescribed buspirone for behavioral disturbance due to dementia from a geropsychiatric outreach program were reviewed. Data was collected and analyzed using SPSS. One hundred-seventy-nine patients met criteria for the study with a mean age of 83.8 + 7. Alzheimer's dementia was the most common dementia (n = 61; 34.1%) followed by mixed dementia (n = 50, 27.9%) then vascular type (n = 31; 17.3%). Behavioral disturbances were mainly verbal aggression (n = 125; 69.8%), and physical aggression (n = 116; 64.8%). Using the Clinical Global Impression scale, 68.6% of patients responded to buspirone, with 41.8% being moderately to markedly improved. The mean dose of buspirone was 25.7 mg ± 12.50. Buspirone appears to be effective in treating behavioral disturbances in dementia. Future prospective and double blinded studies are needed.
The impact of haematozoan infection on host fitness has received substantial attention since Hamilton and Zuk posited that parasites are important drivers of sexual selection. However, short-term studies testing the assumption that these parasites consistently reduce host fitness in the wild have produced contradictory results. To address this complex issue, we conducted a long-term study examining the relationship between naturally occurring infection with Haemoproteus and Plasmodium, and lifetime reproductive success and survival of Mountain White-crowned Sparrows. Specifically, we tested the hypothesis that birds infected with haematozoan parasites have reduced survival (as determined by overwinter return rates) and reproductive success. Contrary to expectation, there was no relationship between Haemoproteus and Plasmodium infection and reproduction or survival in males, nor was there a relationship between Plasmodium infection and reproduction in females. Interestingly, Haemoproteus-infected females had significantly higher overwinter return rates and these females fledged more than twice as many chicks during their lifetimes as did uninfected females. We discuss the impact of parasitic infections on host fitness in light of these findings and suggest that, in the case of less virulent pathogens, investment in excessive immune defence may decrease lifetime reproduction.
The CdTe photoluminescence spectra of CdTe/CdS/ZnO heterojunctions annealed in the presence of CdCl2 have been analyzed in the 4.7-100K temperature range. The analysis has been performed for laser excitation power between 0.01 mW and 30 mW. The analysis showed that the photoluminescence spectrum in the 1.1-1.6 eV region consists of a defect band (1.437 eV) having complex structure and revealing well contoured LO phonon replicas and bound exciton annihilation in the 1.587-1.593 eV region. The band analysis has been carried out by deconvoluting the spectra. It has been shown that the defect band consists of two elementary bands and their phonon replica. An “unusual” temperature dependence of the defect band has been found.
Little is known about the effects of combined micronutrient and sugar consumption on growth and cognition. In the present study, we investigated the effects of micronutrients and sugar, alone and in combination, in a beverage on growth and cognition in schoolchildren. In a 2 × 2 factorial design, children (n 414, 6–11 years) were randomly allocated to consume beverages containing (1) micronutrients with sugar, (2) micronutrients with a non-nutritive sweetener, (3) no micronutrients with sugar or (4) no micronutrients with a non-nutritive sweetener for 8·5 months. Growth was assessed and cognition was tested using the Kaufman Assessment Battery for Children version II (KABC-II) subtests and the Hopkins Verbal Learning Test (HVLT). Micronutrients decreased the OR for Fe deficiency at the endpoint (OR 0·19; 95 % CI 0·07, 0·53). Micronutrients increased KABC Atlantis (intervention effect: 0·76; 95 % CI 0·10, 1·42) and HVLT Discrimination Index (1·00; 95 % CI 0·01, 2·00) scores. Sugar increased KABC Atlantis (0·71; 95 % CI 0·05, 1·37) and Rover (0·72; 95 % CI 0·08, 1·35) scores and HVLT Recall 3 (0·94; 95 % CI 0·15, 1·72). Significant micronutrient × sugar interaction effects on the Atlantis, Number recall, Rover and Discrimination Index scores indicated that micronutrients and sugar in combination attenuated the beneficial effects of micronutrients or sugar alone. Micronutrients or sugar alone had a lowering effect on weight-for-age z-scores relative to controls (micronutrients − 0·08; 95 % CI − 0·15, − 0·01; sugar − 0·07; 95 % CI − 0·14, − 0·002), but in combination, this effect was attenuated. The beverages with micronutrients or added sugar alone had a beneficial effect on cognition, which was attenuated when provided in combination.
Microglia are enigmatic non-neuronal cells that infiltrate and take up residence in the brain during development and are thought to perform a surveillance function. An established literature has documented how microglia are activated by pathogenic stimuli and how they contribute to and resolve injuries to the brain. However, much less work has been aimed at understanding their function in the uninjured brain. A series of recent in vivo imaging studies shows that microglia in their resting state are highly motile and actively survey their neuronal surroundings. Furthermore, new data suggest that microglia in their resting state are able to phagocytose unwanted synapses and in this way contribute to synaptic pruning and maturation during development. Coupled with their exquisite sensitivity to pathogenic stimuli, these data suggest that microglia form a link that couples changes in brain environment to changes in brain wiring. Here we discuss this hypothesis and propose a model for the role of microglia during development in sculpting brain connectivity.
In standard diffraction experiments, ensembles of objects are characterized yielding
averaged, statistical properties (meaningful only if the ensemble is monodisperse).
Focused x-ray beams are used here to localize single nanostructures, identifying and
probing individual objects one by one. In a scanning mode, a 2-dimensional image of the
sample is recorded, which allows the reproducible alignment of a specific nanostructure
for analysis. The x-ray scattered signal is analyzed and modelled, to give access to the
shape, strain and composition inside the single object with sub-micron resolution.
Combination of x-ray microdiffraction technique with other micro-probe experiments on the
very same individual object (simultaneous coupling of x-ray diffraction measurements with
atomic force microscopy (AFM)) is also shown; we prove the possibility to interact with
the objects and to address elastic properties for individual nano-structures out of an
Regular patch arrays of random gold nanostructures were fabricated by electrochemical deposition of nanowires in ion track-etched templates. During ion irradiation with GeV ions of fluence 106, 107, or 108 cm−2, a shadow mask was used resulting in templates structured with square arrays of 50 μm holes and 100 or 150 μm pitch. The Au nanowires grown in the track-etched pores had a length of 7–28 μm and a diameter of ~300 nm, and were either solitary or clustered after template dissolution. The structured wire ensembles were systematically investigated with scanning electron and field emission scanning microscopy. Field emission with about 90% efficiency was achieved for wide-spaced patch arrays with medium and high number of Au nanowires at 1500 V for 20 μm anode distance. The current carrying capability of the patches strongly varied between 40 nA and 90 μA. The corresponding processing effects are correlated to adsorbates and nanostructural changes of the wires which give suitable hints for the optimization of structured Au nanowire cathodes.
Transition from a low-fat vegetable-rich rural diet to a high-fat Westernised diet is considered a factor in the escalating occurrence of vascular-related diseases and type 2 diabetes in urban black South Africans. Consumption of morogo is a distinguishing feature of rural African diets.
To determine fatty acid profiles and folate contents of three widely consumed, wild-growing, African dark green leafy vegetables (morogo).
GC–MS was applied for analysis of fatty acid composition and a validated microbiological assay conducted to determine folic acid contents of wild-growing morogo sampled from deep rural villages in three different geographical regions of South Africa.
Measured fatty acids ranged from 1610·2 to 2941·6 mg/100 g dry mass, with PUFA concentrations 1·4 to 2·8 times those of SFA. Calculated from the relative percentages of linoleic acid (18:2n-6) and linolenic acid (18:3n-3), the ratio of 18:2n-6 to 18:3n-3 PUFA was 1·0:3·4 to 1·0:8·9. The only MUFA was palmitoleic acid (16:1), measured at 34·7 (sd 0·3) to 79·0 (sd 9·3) mg/100 g dry mass, and the predominant SFA was palmitic acid (16:0), measured at 420·6 (sd 83·3) to 662·0 (sd 21·2) mg/100 g dry mass. Folic acid concentration varied from 72 to 217 μg/100 g fresh sample.
Morogo is low-fat food item high in folate and with 18:3n-3 in excess of 18:2n-6, the proposed anti-inflammatory effects of which may lower risks of vascular-related chronic diseases and type 2 diabetes.
The average lay person, if asked the best way to learn Chinese, would probably reply that one should go to China for a period of time and “pick up” the language naturally. For beginning students, learning Chinese in China is actually not the most efficient way to proceed. However, once students have reached the intermediate stage, there is widespread agreement that the fastest and best way for them to continue their language studies is to spend a substantial period of time in a Chinese-speaking region in close contact with Chinese speakers. In fact, it is questionable whether a non-native can attain Superior- to Distinguished-level (SD) proficiency in Chinese any other way.
However, simply living in China will almost certainly not result in the acquisition of SD-level language skills. Everyone is familiar with the example of expatriates who have lived in a country five, ten, twenty, or more years but possess little or no real proficiency in the language. Then there are other longtime foreign residents who can manage daily affairs well enough and may think of themselves as possessing “near-native” proficiency but actually stick to the simplest vocabulary and grammar and, even then, produce few utterances that are not without a major or minor error. It is the thesis of this chapter that, to achieve SD-level proficiency in Chinese, students require a combination of long-term immersion in Chinese culture with an organized training program that systematically pushes them up the proficiency ladder, a thesis that finds resonance in several chapters of this volume (e.g., Chapter 3).
The fluorescent neutral lipid stain, nile red, was used to examine cell-specific neutral lipid levels in natural assemblages of Antarctic sea ice microalgae. Neutral lipid:chlorophyll, neutral lipid:particulate carbon (PC) and neutral lipid:particulate nitrogen (PN) ratios were highest in communities dominated by Nitzschia spp. and Navicula glaciei van Heurck. The lowest specific neutral lipid content was estimated in the congelation ice samples dominated by the diatom Amphiprora spp., and in surface assemblages dominated by Phaeocystis pouchetii Hariot and the dinoflagellate Gymnodinium sp. Scatter plots of neutral lipid on PC and PN, which included data from all assemblages, showed that assemblages dominated by P. pouchetii and Amphiprora spp. clustered near the origin reflecting their relatively lower specific neutral lipid levels, compared with assemblages dominated by N. glaciei and Nitzschia spp. Cellular PC:PN was significantly (P<0.001) lower in microalgae inhabiting surface melt pools or tide cracks compared to those associated with congelation or platelet ice.
Rates of intake of herbage and grazing time of beef cattle are essential components of simulation models of grassland agroecosystems. We studied the effects of herbage allowance on rates of intake and ingestive behaviour of twelve 2-year-old Angus heifers (Bos taurus)(364 ± 12 kg) grazing pastures of tall fescue (Festuca arundinacea Schreb.). A balanced change-over design and a novel tethering technique were used to estimate direct, residual and permanent effects of three herbage allowances on intake per bite, rate of biting and rate of intake. Herbage dry matter (D.M.) allowances, which were established by varying tether lengths, were 5, 9 and 13 kg (1·4, 2·5 and 3·6 kg/100 kg of live weight) and made available in circular plots of 15, 27 and 38 m2, respectively, for a single measured 2 h grazing session each day. Heifers grazing Kenhy tall fescue swards, composed of vegetative tillers and free from the endophyte Acremonium coenophialum, with herbage D.M. masses (> 5 cm) of 2000 kg/ha and D.M. allowances of 9 and 13 kg/2 h per heifer, ingested D.M. at 1·9 kg/h by taking bites averaging 800 mg D.M. at 38 bites/min. Allowances of 5 kg/2 h per heifer slowed the rate of intake to 1·3 kg/h by limiting D.M. intake per bite to 654 mg and biting rate to 35/min. Rate of D.M. intake of cattle grazing vegetative temperate grass swards appears to be ca. 0.5% of live weight per hour when allowance and availability of herbage are not limiting.
Average duration of the larval stage of Syrphus corollae Fab. reared at 20 ± 1 °C decreased linearly with increase in amount consumed from 9.2 days with 40.9 cal consumed/larva to 7.9 days at 78.1 cal/larva. Mean weight of pupae and percentage emergence of adults increased with calories consumed. No eggs were laid by flies developed from larvae which consumed less than 54.6 cal of energy, equivalent to 38 aphids. Average fecundity increased linearly with consumption up to 81.6 cal/larva (= 58 aphids). Mean reproductive output was 3.2% of larval consumption above 55 cal but decreased as larval consumption increased. When food was scarce, fecundity decreased because pupae, and therefore ovaries, were smaller. Larvae consumed as much as possible in the time available rather than pupating after consuming a minimal amount.