418 research outputs found
Electromagnetically induced spatial light modulation
We theoretically report that, utilizing electromagnetically induced
transparency (EIT), the transverse spatial properties of weak probe fields can
be fast modulated by using optical patterns (e.g. images) with desired
intensity distributions in the coupling fields. Consequently, EIT systems can
function as high-speed optically addressed spatial light modulators. To
exemplify our proposal, we indicate the generation and manipulation of
Laguerre-Gaussian beams based on either phase or amplitude modulation in hot
vapor EIT systems.Comment: 8 pages, 3 figure
Multi-dark-state resonances in cold multi-Zeeman-sublevel atoms
We present our experimental and theoretical studies of multi-dark-state
resonances (MDSRs) generated in a unique cold rubidium atomic system with only
one coupling laser beam. Such MDSRs are caused by different transition
strengths of the strong coupling beam connecting different Zeeman sublevels.
Controlling the transparency windows in such electromagnetically induced
transparency system can have potential applications in multi-wavelength optical
communication and quantum information processing.Comment: 11pages, 4figure
Mediators of the socioeconomic gradient in outcomes of adult asthma and rhinitis.
ObjectivesWe estimated the extent to which socioeconomic status (SES) gradients in adult asthma and rhinitis outcomes can be explained by home and neighborhood environmental factors.MethodsUsing survey data for 515 adults with either asthma or rhinitis, or both, we examined environmental mediators of SES associations with disease severity, using the Severity of Asthma Scale, and health-related quality of life (HRQL), using the Rhinasthma Scale. We defined SES on the basis of education and household income. Potential environmental mediators included home type and ownership, exposures to allergens and irritants, and a summary measure of perceived neighborhood problems. We modeled each outcome as a function of SES, and controlled for age, gender, and potential mediators.ResultsGradients in SES were apparent in disease severity and HRQL. Living in a rented house partially mediated the SES gradient for both severity and HRQL (P < .01). Higher perceived levels of neighborhood problems were associated with poorer HRQL and partially mediated the income-HRQL relationship (P < .01).ConclusionsDifferences in home and neighborhood environments partially explained associations of SES with adult asthma and rhinitis outcomes
Spatial Aggregation of Global Dry and Wet Patterns Based on the Standard Precipitation Index
Quantifying the spatial integrity and patterns of dry/wet events over land is essential to understand how the local hydrological regime responds to environmental changes. Spatial aggregation changes in dry and wet areas over land have not been studied extensively. Based on a patch-mosaic landscape model, we analyzed spatial aggregation changes at two levels corresponding to landscape design during 1949 and 2018. At the landscape level, the global aggregation degree increased initially and then weakened around 2006. However, the spatial aggregation process between dry and wet patterns was inconsistent. For the dry pattern, spatial aggregation was mainly caused by area decline induced decreases in the patch number. For the wet pattern, spatial aggregation was caused by area enlargement induced decreases in the patch number. At the class level, with increases in the dry/wet magnitude, the correlation between the affected area and aggregation strengthened. Our results provide new insights to understand the spatial processes and future trends of dry/wet patterns over land. We argue that future vulnerability of agriculture and ecosystems to drought is likely to be further mediated by the changes in drought patterns' spatial structure.Peer reviewe
Research Progress in Preparation and Application of Marine Polysaccharide-based Probiotics Microcapsules
Probiotics have a variety of probiotic effects. However, in the process of processing, storage or digestion, it is easy to reduce its activity due to the influence of external adverse environment. The use of microcapsule technology can play a good role in the protection of probiotics and reduce or avoid the impact of adverse environment. As a wall material of probiotic microcapsules, marine polysaccharides can not only boost the stress resistance and stability of probiotics, improve the sensory characteristics of probiotic products, but also enhance the therapeutic effect with probiotics. This paper analyzes the species and characteristics of marine polysaccharides from different sources. It also summarizes the preparation methods of marine polysaccharide-based probiotic microcapsules, and expounds the application of marine polysaccharide-based probiotic microcapsules in food industry, biomedicine, aquaculture feed and other fields. It is expected to provide some references for the research direction of probiotic microcapsules and the high-value utilization of marine resources
GluN2A NMDA Receptor Enhancement Improves Brain Oscillations, Synchrony, and Cognitive Functions in Dravet Syndrome and Alzheimer's Disease Models.
NMDA receptors (NMDARs) play subunit-specific roles in synaptic function and are implicated in neuropsychiatric and neurodegenerative disorders. However, the in vivo consequences and therapeutic potential of pharmacologically enhancing NMDAR function via allosteric modulation are largely unknown. We examine the in vivo effects of GNE-0723, a positive allosteric modulator of GluN2A-subunit-containing NMDARs, on brain network and cognitive functions in mouse models of Dravet syndrome (DS) and Alzheimer's disease (AD). GNE-0723 use dependently potentiates synaptic NMDA receptor currents and reduces brain oscillation power with a predominant effect on low-frequency (12-20 Hz) oscillations. Interestingly, DS and AD mouse models display aberrant low-frequency oscillatory power that is tightly correlated with network hypersynchrony. GNE-0723 treatment reduces aberrant low-frequency oscillations and epileptiform discharges and improves cognitive functions in DS and AD mouse models. GluN2A-subunit-containing NMDAR enhancers may have therapeutic benefits in brain disorders with network hypersynchrony and cognitive impairments
Workplace policies and prevalence of knee osteoarthritis: the Johnston County Osteoarthritis Project
Previous studies on work and knee osteoarthritis (KOA) have been primarily focused on physical demands; very little is known about work-related organisational policies and KOA risks and outcomes. We examined the associations between workplace policies and KOA in a community-based population in the USA
Strand selective generation of endo-siRNAs from the Na/phosphate transporter gene Slc34a1 in murine tissues
Natural antisense transcripts (NATs) are important regulators of gene expression. Recently, a link between antisense transcription and the formation of endo-siRNAs has emerged. We investigated the bi-directionally transcribed Na/phosphate cotransporter gene (Slc34a1) under the aspect of endo-siRNA processing. Mouse Slc34a1 produces an antisense transcript that represents an alternative splice product of the Pfn3 gene located downstream of Slc34a1. The antisense transcript is prominently found in testis and in kidney. Co-expression of in vitro synthesized sense/antisense transcripts in Xenopus oocytes indicated processing of the overlapping transcripts into endo-siRNAs in the nucleus. Truncation experiments revealed that an overlap of at least 29 base-pairs is required to induce processing. We detected endo-siRNAs in mouse tissues that co express Slc34a1 sense/antisense transcripts by northern blotting. The orientation of endo-siRNAs was tissue specific in mouse kidney and testis. In kidney where the Na/phosphate cotransporter fulfils its physiological function endo-siRNAs complementary to the NAT were detected, in testis both orientations were found. Considering the wide spread expression of NATs and the gene silencing potential of endo-siRNAs we hypothesized a genome-wide link between antisense transcription and monoallelic expression. Significant correlation between random imprinting and antisense transcription could indeed be established. Our findings suggest a novel, more general role for NATs in gene regulation
GoldenBraid: An Iterative Cloning System for Standardized Assembly of Reusable Genetic Modules
Synthetic Biology requires efficient and versatile DNA assembly systems to facilitate the building of new genetic modules/pathways from basic DNA parts in a standardized way. Here we present GoldenBraid (GB), a standardized assembly system based on type IIS restriction enzymes that allows the indefinite growth of reusable gene modules made of standardized DNA pieces. The GB system consists of a set of four destination plasmids (pDGBs) designed to incorporate multipartite assemblies made of standard DNA parts and to combine them binarily to build increasingly complex multigene constructs. The relative position of type IIS restriction sites inside pDGB vectors introduces a double loop (âbraidâ) topology in the cloning strategy that allows the indefinite growth of composite parts through the succession of iterative assembling steps, while the overall simplicity of the system is maintained. We propose the use of GoldenBraid as an assembly standard for Plant Synthetic Biology. For this purpose we have GB-adapted a set of binary plasmids for A. tumefaciens-mediated plant transformation. Fast GB-engineering of several multigene T-DNAs, including two alternative modules made of five reusable devices each, and comprising a total of 19 basic parts are also described
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