305 research outputs found

    Discordant transmission of bacteria and viruses from mothers to babies at birth

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    BACKGROUND: The earliest microbial colonizers of the human gut can have life-long consequences for their hosts. Precisely how the neonatal gut bacterial microbiome and virome are initially populated is not well understood. To better understand how the maternal gut microbiome influences acquisition of the infant gut microbiome, we studied the early life bacterial microbiomes and viromes of 28 infant twin pairs and their mothers. RESULTS: Infant bacterial and viral communities more closely resemble those of their related co-twin than unrelated infants. We found that 63% of an infant\u27s bacterial microbiome can be traced to their mother\u27s gut microbiota. In contrast, only 15% of their viral communities are acquired from their mother. Delivery route did not determine how much of the bacterial microbiome or virome was shared from mother to infant. However, bacteria-bacteriophage interactions were altered by delivery route. CONCLUSIONS: The maternal gut microbiome significantly influences infant gut microbiome acquisition. Vertical transmission of the bacterial microbiome is substantially higher compared to vertical transmission of the virome. However, the degree of similarity between the maternal and infant gut bacterial microbiome and virome did not vary by delivery route. The greater similarity of the bacterial microbiome and virome between twin pairs than unrelated twins may reflect a shared environmental exposure. Thus, differences of the inter-generation transmissibility at birth between the major kingdoms of microbes indicate that the foundation of these microbial communities are shaped by different rules. Video Abstract

    Impacts of FMNR on the agricultural performance of smallholder farming systems at landscape scale in Senegal

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    Management of isolated trees as an integrated part of smallholder farming systems has long been a key food security strategy in Africa. Current knowledge on the impact of parklands structuring on agrosystems productivity is limited. Combining multisources remote sensing, landscape ecology and statistical modelling, this study aims at evidencing the contribution of FMNR to the agricultural performance of smallholder farming systems at landscape scale in Senegal. Agronomical surveys were conducted in 2017 and 2018 on 70 farmers' fields with heterogeneous trees composition. We assessed groundnut aboveground biomass (AGB) and millet grain yield (GY). Proxies for parklands composition and vegetation productivity were derived from remote sensing. Regression models were calibrated and model parameters were optimized using a random sample consensus method accounting for measurement uncertainties. For 2017, Green chlorophyll index over millet flowering phase and whole groundnut cropping cycle allowed estimating GY and AGB with R² of 0.76 and 0.67 respectively. Integrating information on tree cover structure (fraction of soil covered by trees) increased assessment accuracy by 7% for millet GY (R2=0.83) and 22% for groundnut AGB (R2-0.89). These promising results have to be strengthened with data from ongoing cropping season but they already indicate the need to integrate information on trees at landscape scale to better assess agricultural performance of smallholder farming systems

    Tunable linear-optical phase amplification

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    We combine lossless, phase-only transformations with fully-transmitting linear-optical scatterers to define the principle of linear-optical phase amplification. This enables a physical phase shift ϕ\phi to be nonlinearly mapped to a new space γ(ϕ)\gamma(\phi) using linear optics, resulting in a completely general and enhanced phase shifter that can replace any standard one. A particular phase amplifier is experimentally realized, allowing the phase enhancement parameter dγ/dϕd\gamma/d\phi to be continuously tuned. Placing this enhanced phase shifter in one arm of a Mach-Zehnder interferometer led to an intensity-phase slope more than twenty times steeper than what can be obtained with its unamplified counterpart

    Effect of Deep-Fat Frying on Chemical Properties of Edible Vegetable Oils Used By Senegalese Households

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    Deep-fat frying performed at high temperatures under atmospheric pressure is a common method of preparing dishes in Senegalese culinary practices. This operation can lead to deterioration of physical, chemical, nutritional and sensory properties of oil, which affects its frying performance. It also results in the production of volatile products such as aldehydes and non volatile fraction which remains in the frying medium. Some of these remaining products have been implicated in producing adverse health effects. Highly oxidized oils may also produce polyaromatic hydrocarbons, which have carcinogenic effect. This work was intended to evaluate the effect of frying on chemical properties of edible vegetable oils. Frying process was applied to meat, fish and potatoes in Senegalese culinary conditions. Ten (10) oil samples, each of three different brands, were purchased from wholesalers and retailers in different neighborhoods of Dakar. The samples were subjected to frying at 220°C for 40 min and then oils were withdrawn in amber bottles samples of which were taken for analysis. Acid value, peroxide value and total polar components were used to evaluate the quality of these oils after initial determination of the iodine value and the moisture and volatile matter content. Acid value increased after 40 min of frying and values ranged from 0.62 to 1.08 mg/kg after frying fish, while those for meat and potatoes ranged from 0.39 to 0.73 and 0.37 to 0.51 mg/kg, respectively. Peroxide value increased slightly for peanut oil (A) and sharply for peanut oil (B) and sunflower oil (C). Frying fish led to high values of total polar components whereas those obtained after frying meat and potatoes during 40 min did not exceed 15.27% except for peanut oil (A). Therefore, frying affects chemical parameter values of edible vegetable oils, which increase at a level depending on the product to be fried. A sharp Total Polar components increase was obtained after frying fish using the three types of oil with values exceeding, sometimes, the maximum level set by the Codex Alimentarius Commission. This latter chemical parameter is considered a good indicator of overall quality of frying oil. Thus in Senegalese culinary practices where frying oil is often reused in families with low-income, such a situation may lead to significant sanitary risks. In view of these results, investigations need to be extended to other types of oil marketed in Senegal.Keywords: edible-oils, quality, frying, fish, mea

    Finite-element assembly approach of optical quantum walk networks

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    We present a finite-element approach for computing the aggregate scattering matrix of a network of linear coherent scatterers. These might be optical scatterers or more general scattering coins studied in quantum walk theory. While techniques exist for two-dimensional lattices of feed-forward scatterers, the present approach is applicable to any network configuration of any collection of scatterers. Unlike traditional finite-element methods in optics, this method does not directly solve Maxwell's equations; instead it is used to assemble and solve a linear, coupled scattering problem that emerges after Maxwell's equations are abstracted within the scattering matrix method. With this approach, a global unitary is assembled corresponding to one time step of the quantum walk on the network. After applying the relevant boundary conditions to this global matrix, the problem becomes non-unitary, and possesses a steady-state solution which is the output scattering state. We provide an algorithm to obtain this steady-state solution exactly using a matrix inversion, yielding the scattering state without requiring a direct calculation of the eigenspectrum. The approach is then numerically validated on a coupled-cavity interferometer example that possesses a known, closed-form solution. Finally, the method is shown to be a generalization of the Redheffer star product, which describes scatterers on one-dimensional lattices (2-regular graphs) and is often applied to the design of thin-film optics, making the current approach an invaluable tool for the design and validation of high-dimensional phase-reprogrammable optical devices and study of quantum walks on arbitrary graphs

    Predictors of Complementary and Alternative Medicine Use in Chronic Pain Patients

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    We used Andersen's behavioral model of healthcare utilization to assess the relationship between sociodemographic, physical and psychosocial factors, and Complementary and Alternative Medicine (CAM) use among chronic pain patients. Three practitioner-based alternative therapies were considered: acupuncture, biofeedback/relaxation training, and manipulation services.A retrospective analysis of self-reported clinical data with 5,750 black and white adults presenting for initial assessment between 1994 and 2000 at the University of Michigan Multidisciplinary Pain Center was performed.CAM therapies were used in high frequencies, with 34.7% users. Specifically 8.3% used acupuncture, 13.0% used biofeedback/relaxation, and 24.9% used manipulation techniques. Race and age were predisposing factors associated with CAM use. Blacks used less biofeedback/relaxation and manipulation services than whites. Aging was related to more acupuncture, but less biofeedback/relaxation use. Women marginally used more biofeedback/relaxation services than men, and education was positively associated with all three CAM use. Perceived pain control was a consistent enabling factor positively correlated with the use of all three CAM services. Among need factors, pain characteristics and physical health were positively associated with at least one of the modalities. Depressive symptoms were not related to CAM services use.This study identifies variable patterns of CAM usage based on sociodemographic and health factors in chronic pain patients. Overall, who uses CAM depends on the modality; however, education, pain severity, and pain duration are persistent correlates of CAM usage regardless of the therapy considered. We found that mental health, as measured by depressive symptoms, had no noticeable impact on CAM usage among chronic pain patients. The clinical, policy, and research implications of CAM use are discussed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/78625/1/j.1526-4637.2009.00767.x.pd

    Experimental demonstration of a Grover-Michelson interferometer

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    We present a low-resource and robust optical implementation of the four-dimensional Grover coin, a four-port linear-optical scatterer that augments the low dimensionality of a regular beam-splitter. While prior realizations of the Grover coin required a potentially unstable ring-cavity to be formed, this version of the scatterer does not exhibit any internal interference. When this Grover coin is placed in another system, it can be used for interferometry with a higher-dimensional set of optical field modes. In this case, we formed a Grover-Michelson interferometer, which results when the traditional beam-splitter of a Michelson interferometer is replaced with a four-port Grover coin. This replacement has been shown to remove a phase parameter redundancy in the original Michelson system, now allowing continuous tuning of the shape and slope of the interference pattern. We observed an intensity interferogram with 97%97\% visibility and a phase sensitivity more than an order of magnitude larger than a regular Michelson interferometer. Because this device is readily formed with nearly the same number of optomechanical resources as a Michelson interferometer, but can outperform it drastically in phase delay evaluation, it has a great potential to improve many interferometric sensing and control systems.12 pages, 6 figure
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