72 research outputs found

    Growth of children receiving a dehydrated potato-soy protein concentrate or corn-soy blend as part of a food aid program in Northern Senegal

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    Rations distributed by food aid programs are intended to improve the growth of undernourished children. In practice, food programs target individual children and provide a supplement to the family that is intended to increase the energy and nutrient intake of undernourished children. Multiple food rations are available yet few studies have compared their differential effect on the growth of children. The objective of the study was to compare growth in undernourished Senegalese children who received a newly developed dehydrated potato-soy protein concentrate blend (PSB) to those supplemented with the currently available corn-soy blend (CSB). The first child at each site was randomly assigned to receive PSB or CSB and subsequent children alternately received PSB or CSB. Eligibility for obtaining the food ration was basedon criteria determined by the USAID (P.L. 480) Title II Food Aid Program. Children received iso-caloric amounts of the two supplements each month (23,000kcals). Weight, height and mid-upper arm circumference (MUAC) were taken over a fourmonth period. Z-scores were calculated for weight-for-age (WAZ), weight-for-height (WHZ) and for length/height-for-age measures (HAZ).The study was conducted at 7 clinics which served as food distribution sites in northern Senegal. The study enrolled348 children 18-56 months old with a weight-for-age z-score below the �yellow� zone of the locally available growth chart (equivalent to WAZ < -1.0). WAZ and HAZ significantly increased over time but there was no difference between the two ration groups. In a subset of 280 children (145 PSB, 135 CSB) who attended all four appointments and received the full complement of ration, there was significant and equivalent increase for both groups in WAZ and WHZ. These findings indicate thatchildren participating in the food aid program significantly improved their growth over a four-month period. Using the new PSB as a ration had the same impact on growth as the standard CSB and required less fuel to prepare

    Physical properties of z>4 submillimeter galaxies in the COSMOS field

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    We study the physical properties of a sample of 6 SMGs in the COSMOS field, spectroscopically confirmed to lie at z>4. We use new GMRT 325 MHz and 3 GHz JVLA data to probe the rest-frame 1.4 GHz emission at z=4, and to estimate the sizes of the star-forming (SF) regions of these sources, resp. Combining our size estimates with those available in the literature for AzTEC1 and AzTEC3 we infer a median radio-emitting size for our z>4 SMGs of (0.63"+/-0.12")x(0.35"+/-0.05") or 4.1x2.3 kpc^2 (major times minor axis; assuming z=4.5) or lower if we take the two marginally resolved SMGs as unresolved. This is consistent with the sizes of SF regions in lower-redshift SMGs, and local normal galaxies, yet higher than the sizes of SF regions of local ULIRGs. Our SMG sample consists of a fair mix of compact and more clumpy systems with multiple, perhaps merging, components. With an average formation time of ~280 Myr, derived through modeling of the UV-IR SEDs, the studied SMGs are young systems. The average stellar mass, dust temperature, and IR luminosity we derive are M*~1.4x10^11 M_sun, T_dust~43 K, and L_IR~1.3x10^13L_sun, resp. The average L_IR is up to an order of magnitude higher than for SMGs at lower redshifts. Our SMGs follow the correlation between dust temperature and IR luminosity as derived for Herschel-selected 0.1=1.95+/-0.26 for our sample, compared to q~2.6 for IR luminous galaxies at z4 SMGs put them at the high end of the L_IR-T_dust distribution of SMGs, and that our SMGs form a morphologically heterogeneous sample. Thus, further in-depth analyses of large, statistical samples of high-redshift SMGs are needed to fully understand their role in galaxy formation and evolution

    Using the RDP Classifier to Predict Taxonomic Novelty and Reduce the Search Space for Finding Novel Organisms

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    BACKGROUND: Currently, the naïve Bayesian classifier provided by the Ribosomal Database Project (RDP) is one of the most widely used tools to classify 16S rRNA sequences, mainly collected from environmental samples. We show that RDP has 97+% assignment accuracy and is fast for 250 bp and longer reads when the read originates from a taxon known to the database. Because most environmental samples will contain organisms from taxa whose 16S rRNA genes have not been previously sequenced, we aim to benchmark how well the RDP classifier and other competing methods can discriminate these novel taxa from known taxa. PRINCIPAL FINDINGS: Because each fragment is assigned a score (containing likelihood or confidence information such as the boostrap score in the RDP classifier), we "train" a threshold to discriminate between novel and known organisms and observe its performance on a test set. The threshold that we determine tends to be conservative (low sensitivity but high specificity) for naïve Bayesian methods. Nonetheless, our method performs better with the RDP classifier than the other methods tested, measured by the f-measure and the area-under-the-curve on the receiver operating characteristic of the test set. By constraining the database to well-represented genera, sensitivity improves 3-15%. Finally, we show that the detector is a good predictor to determine novel abundant taxa (especially for finer levels of taxonomy where novelty is more likely to be present). CONCLUSIONS: We conclude that selecting a read-length appropriate RDP bootstrap score can significantly reduce the search space for identifying novel genera and higher levels in taxonomy. In addition, having a well-represented database significantly improves performance while having genera that are "highly" similar does not make a significant improvement. On a real dataset from an Amazon Terra Preta soil sample, we show that the detector can predict (or correlates to) whether novel sequences will be assigned to new taxa when the RDP database "doubles" in the future

    Verbal instructions override the meaning of facial expressions

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    Psychological research has long acknowledged that facial expressions can implicitly trigger affective psychophysiological responses. However, whether verbal information can alter the meaning of facial emotions and corresponding response patterns has not been tested. This study examined emotional facial expressions as cues for instructed threat-of-shock or safety, with a focus on defensive responding. In addition, reversal instructions were introduced to test the impact of explicit safety instructions on fear extinction. Forty participants were instructed that they would receive unpleasant electric shocks, for instance, when viewing happy but not angry faces. In a second block, instructions were reversed (e.g., now angry faces cued shock). Happy, neutral, and angry faces were repeatedly presented, and auditory startle probes were delivered in half of the trials. The defensive startle reflex was potentiated for threat compared to safety cues. Importantly, this effect occurred regardless of whether threat was cued by happy or angry expressions. Although the typical pattern of response habituation was observed, defense activation to newly instructed threat cues remained significantly enhanced in the second part of the experiment, and it was more pronounced in more socially anxious participants. Thus, anxious individuals did not exhibit more pronounced defense activation compared to less anxious participants, but their defense activation was more persistent
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