3,257 research outputs found
Low-energy interband absorption in bcc Fe and hcp Co
We have examined the electronic structure of bcc Fe and single-crystal hcp Co by using optical absorptivity and thermoreflectance techniques for 0.2≤hν≤5 eV. The optical conductivities σ were calculated by Kramers-Kronig analyses. A prominent structure was observed in σ for Fe at 2.37 eV and a shoulder was observed near 0.8 eV; the latter structure was the dominant feature in the thermoreflectance spectrum. These were discussed in terms of minority-spin band interband absorption and spin-flip interband transitions. The anisotropic optical conductivities of hcp Co were discussed in terms of recent energy-band calculations
The relationship between the achievement motive and downward communicative adaptability
Master's Project (M.A.) University of Alaska Fairbanks, 2019In this paper, a model was created linking the Achievement Motive to Downward
Communicative Adaptability. As theorized in the model, there is a significant positive
relationship between the Achievement Motive and Downward Communicative Adaptability.
Participants who supervise or manage others completed an in-person paper and pencil survey.
The collected data were entered into an SPSS data file, and a simple correlational analysis was
run. A significant positive correlation was found between the Achievement Motive and
Downward Communicative Adaptability
Development and Survivorship of Immature Angoumois Grain Moth (Lepidoptera: Gelechiidae) on Stored Corn
Life history of immature Angoumois grain moths, Sitotroga cerealella (Olivier), was studied on dent corn (Pioneer 3320) at 10, 15, 20, 25, 30, 35, and 40°C and at 43, 53-61, 75-76, and 82-87% RH under laboratory conditions. At 10 and 40°C, none of the stages survived at any relative humidity. Temperature was the main factor affecting egg incubation period, larval-pupal development time, and egg and larval-pupal survivorship. The shortest egg development times occurred at temperatures of 30°C and higher, but they increased sharply as temperature decreased. Larval-pupal development time was shortest at 30°C. Survivorship was optimal at 20-30°C for eggs and larvae-pupae, but larval-pupal survivorship decreased sharply at 15 and 35°C. Duration of larval-pupal development did not vary with sex. Newly emerged females were twofold heavier than males, and temperature and relative humidity did not affect weight. Sex ratio of emerging adults did not differ from 1:1 at any temperature or relative humidity. The optimum conditions for development of Angoumois grain moth on corn were 30°C and 75% RH. The data will be useful for determining safe storage conditions for corn and for developing a computer model for simulating population dynamics of immature S. cerealella
Fungal Colonists of Maize Grain Conditioned at Constant Temperatures and Humidities
Fungal colonization of shelled maize (Pioneer 3320) harvested from a field near Furman, South Carolina, in 1992 was determined after 348 and 751 days of continuous storage at each of seven temperatures (10, 15, 20, 25, 30, 35, or 40°C) and four constant relative humidities, giving equilibrium grain moisture contents ranging from 9.4% to 17.5% m.c. in 28 grain conditioning environments. Twenty fungal species infected surface sterilized seeds and were recorded from these conditioned grain treatments, including species commonly found in preharvest maize [e.g. Acremonium zeae, Aspergillus flavus, Fusarium moniliforme (syn. F. verticillioides), Penicillium pinophilum (syn. P. funiculosum), etc.]. Eupenicillium cinnamopurpureum and Monascus ruber were recorded only from conditioned grain treatments. Eurotium chevalieri colonized 50-96% of the kernels from grain conditioning treatments with the highest moisture content for each incubation temperature. Grain samples with \u3e33% E. chevalieri infection had a decreased occurrence of F. moniliforme and A. zeae, and no kernels from these samples germinated. No fungi colonized more than 50% of the kernels conditioned at 30-40°C and 9.4-14.2% m.c. The results of this study indicate that individual patterns of fungal colonization during grain conditioning were a function of the survival rates for preharvest fungal colonists and their potential replacement by E. chevalieri
Monitoring Sarcomere Structure Changes in Whole Muscle Using Diffuse Light Reflectance
doi:10.1117/1.2234278Normal biomechanical and physiological functions of striated muscles are facilitated by the repeating sarcomere units. Light scattering technique has been used in studying single extracted muscle fibers. However, few studies, if any, have been conducted to investigate the possibility of using optical detection to examine sarcomere structure changes in whole muscles. We conducted a series of experiments to demonstrate that optical scattering properties measured in whole muscle are related to changes in sarcomere structure. These results suggest that photon migration technique has a potential for characterizing in vivo tissue ultrastructure changes in whole muscle
Notes
Notes by Frank J. Lanigan, Rex E. Weaver, David Gelber, John A. O\u27Leary, John De Mots, and James E. Bales
Pupillometric Assessment of Sleepiness in Narcolepsy
Purpose: Excessive daytime sleepiness is highly prevalent in the general population, is the hallmark of narcolepsy, and is linked to significant morbidity. Clinical assessment of sleepiness remains challenging and the common objective multiple sleep latency test (MSLT) and subjective Epworth sleepiness scale (ESS) methods correlate poorly. We examined the relative utility of pupillary unrest index (PUI) as an objective measure of sleepiness in a group of unmedicated narcoleptics and healthy controls in a prospective, observational pilot study. Methods: Narcolepsy (n = 20; untreated for >2 weeks) and control (n = 56) participants were tested under the same experimental conditions; overnight polysomnography was performed on all participants, followed by a daytime testing protocol including: MSLT, PUI, sleepiness visual analog scale (VAS), ESS, and the psychomotor vigilance test (PVT). Results: The narcolepsy and control groups differed significantly on psychomotor performance and each measure of objective and subjective sleepiness, including PUI. Across the entire sample, PUI correlated significantly with objective (mean sleep latency, SL) and subjective (ESS and VAS) sleepiness, but none of the sleepiness measures correlated with performance (PVT). Among narcoleptics, VAS correlated with PVT measures. Within the control group, mean PUI was the only objective sleepiness measure that correlated with subjective sleepiness. Finally, in an ANCOVA model, SL and ESS were significantly predictive of PUI as measure of sleepiness. Conclusion: The role of PUI in quantifying and distinguishing sleepiness of narcolepsy from sleep-satiated healthy controls merits further investigation as it is a portable, brief, and objective test
Deconstructing Circadian Disruption: Assessing the Contribution of Reduced Peripheral Oscillator Amplitude on Obesity and Glucose Intolerance in Mice
Disturbing the circadian regulation of physiology by disruption of the rhythmic environment is associated with adverse health outcomes but the underlying mechanisms are unknown. Here, the response of central and peripheral circadian clocks to an advance or delay of the light-dark cycle was determined in mice. This identified transient damping of peripheral clocks as a consequence of an advanced light-dark cycle. Similar depression of peripheral rhythm amplitude was observed in mice exposed to repeated phase shifts. To assess the metabolic consequences of such peripheral amplitude depression in isolation, temporally chimeric mice lacking a functional central clock (Vgat-Cre+ Bmal1fl/fl) were housed in the absence of environmental rhythmicity. In vivo PER2::LUC bioluminescence imaging of anesthetized and freely moving mice revealed that this resulted in a state of peripheral amplitude depression, similar in severity to that observed transiently following an advance of the light-dark cycle. Surprisingly, our mice did not show alterations in body mass or glucose tolerance in males or females on regular or high-fat diets. Overall, our results identify transient damping of peripheral rhythm amplitude as a consequence of exposure to an advanced light-dark cycle but chronic damping of peripheral clocks in isolation is insufficient to induce adverse metabolic outcomes in mice
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Serum Bovine Immunoglobulins Improve Inflammation and Gut Barrier Function in Persons with HIV and Enteropathy on Suppressive ART.
BackgroundSystemic inflammation persists in chronic HIV infection and is associated with increased rates of non-AIDS events such as cardiovascular and liver disease. Increased gut permeability and systemic exposure to microbial products are key drivers of this inflammation. Serum-derived bovine immunoglobulin/protein isolate (SBI) supports gut healing in other conditions such as inflammatory bowel disease.MethodsIn this randomized, double-blind study, participants receiving suppressive antiretroviral therapy (ART) with chronic diarrhea received placebo or SBI at 2.5 g BID or 5 g BID for 4 weeks, followed by a 20-week placebo-free extension phase with SBI at either 2.5 or 5 g BID. Intestinal fatty acid binding protein (I-FABP), zonulin, flagellin, lipopolysaccharide (LPS) and LPS-binding protein, and inflammatory markers were measured by ELISA or multiplex assays. Non-parametric tests were used for analysis.ResultsOne hundred three participants completed the study. By week 24 SBI significantly decreased circulating levels of I-FABP (-0.35 ng/μL, P=0.002) and zonulin (-4.90 ng/μL, P=0.003), suggesting improvement in gut damage, and interleukin-6 (IL-6) (-0.40 pg/μL, P=0.002), reflecting improvement in systemic inflammation. In participants with the lowest quartile of CD4+ T-cell counts at baseline (189-418 cells/μL), CD4+ T-cell counts increased significantly (26 cells/μL; P=0.002).ConclusionsOral SBI may decrease inflammation and warrants further exploration as a potential strategy to improve gut integrity and decrease systemic inflammation among persons receiving prolonged suppressive ART
Is there a requirement for advanced airway management for trauma patients in the pre-hospital phase of care?
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