1,785 research outputs found

    Assessing resilience to drought: defining drought and reviewing trends in the Horn of Africa

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    The creation of a household resilience index using limited data from the IGAD region

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    Hemoglobin genotype has minimal influence on the physiological response of juvenile atlantic cod (Gadus morhua) to environmental challenges

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    Hemoglobin (Hb) polymorphism in cod is associated with temperature‐related differences in biogeographical distribution, and several authors have suggested that functional characteristics of the various hemoglobin isoforms (HbIs) directly influence phenotypic traits such as growth rate. However, no study has directly examined whether Hb genotype translates into physiological differences at the whole animal level. Thus, we generated a family of juvenile Atlantic cod consisting of all three main Hb genotypes (HbI‐1/1, HbI‐2/2, and HbI‐1/2) by crossing a single pair of heterozygous parents, and we compared their metabolic and cortisol responses to an acute thermal challenge (10&deg;C to their critical thermal maximum [CTM] or 22&deg;C, respectively) and tolerance of graded hypoxia. There were no differences in routine metabolism (at 10&deg;C), maximum metabolic rate, metabolic scope, CTM (overall mean 22.9&deg; &plusmn; 0.2&deg;C), or resting and poststress plasma cortisol levels among Hb genotypes. Further, although the HbI‐1/1 fish grew more (by 15%&ndash;30% during the first 9 mo) when reared at 10&deg; &plusmn; 1&deg;C and had a slightly enhanced hypoxia tolerance at 10&deg;C (e.g., the critical O2 levels for HbI‐1/1, HbI‐2/2, and HbI‐1/2 cod were 35.56% &plusmn; 1.24%, and 40.20% &plusmn; 1.99% air saturation, respectively), these results are contradictory to expectations based on HbI functional properties. Thus, our findings (1) do not support previous assumptions that growth rate differences among cod Hb genotypes result from a more efficient use of the oxygen supply&mdash;that is, reduced standard metabolic rates and/or increased metabolic capacity&mdash;and (2) suggest that in juvenile cod, there is no selective advantage to having a particular Hb genotype with regards to the capacity to withstand ecologically relevant environmental challenges.<br /

    Neighborhood social processes as moderators between racial discrimination and depressive symptoms for African American adolescents

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    Racial discrimination is associated with numerous psychological consequences, including increased depressive symptoms for African American adolescents (Brody et al., 2006; Wong, Eccles, & Sameroff, 2003). Adolescents’ perceptions of their neighborhood can influence how youth interpret and manage racial discrimination (Sampson, Morenoff, & Gannon‐Rowley, 2002). Yet little is known about how adolescent perceptions of neighborhood cohesion and neighborhood disorganization protect or exacerbate the effects of racial discrimination, or how these effects vary by youth’s gender. Therefore, the current study examined whether neighborhood social cohesion and neighborhood disorganization moderated the association between racial discrimination and depressive symptoms for African American adolescents and how the effects differ for boys and girls. Participants were 106 African American adolescents (57% female; mean age 15.14) from an urban metropolitan area. Regression analyses suggest that perceptions of neighborhood social cohesion protected against racial discrimination for boys and girls. Additionally, the results indicate that when boys perceive less neighborhood disorganization, racial discrimination has a greater influence on their depressive symptoms. Findings have implications for intervention and prevention efforts that enhance and utilize positive neighborhood social processes for youth contending with racial discrimination.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/145257/1/jcop21970_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/145257/2/jcop21970.pd

    A comparison of CDMA techniques for third generation mobile radio systems

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    Quality Assurance Protocol for AFCI Advanced Structural Materials Testing

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    The objective of this letter is to inform you of recent progress on the development of advanced structural materials in support of advanced fast reactors and AFCI. As you know, the alloy development effort has been initiated in recent months with the procurement of adequate quantities of the NF616 and HT-UPS alloys. As the test alloys become available in the coming days, mechanical testing, evaluation of optimizing treatments, and screening of environmental effects will be possible at a larger scale. It is therefore important to establish proper quality assurance protocols for this testing effort in a timely manner to ensure high technical quality throughout testing. A properly implemented quality assurance effort will also enable preliminary data taken in this effort to be qualified as NQA-1 during any subsequent licensing discussions for an advanced design or actual prototype. The objective of this report is to describe the quality assurance protocols that will be used for this effort. An essential first step in evaluating quality protocols is assessing the end use of the data. Currently, the advanced structural materials effort is part of a long-range, basic research and development effort and not, as yet, involved in licensing discussions for a specific reactor design. After consultation with Mark Vance (an ORNL QA expert) and based on the recently-issued AFCI QA requirements, the application of NQA-1 quality requirements will follow the guidance provided in Part IV, Subpart 4.2 of the NQA-1 standard (Guidance on Graded Application of QA for Nuclear-Related Research and Development). This guidance mandates the application of sound scientific methodology and a robust peer review process in all phases, allowing for the data to be qualified for use even if the programmatic mission changes to include licensing discussions of a specific design or prototype. ORNL has previously implemented a QA program dedicated to GNEP activities and based on an appropriately graded application of NQA-1 requirements at the site. The current program is being revised to incorporate changes imposed through the recently revised AFCI Technical Integration Office QA requirements. Testing conducted under the AFCI QA program for the advanced structural materials effort shall incorporate the following quality assurance expectations: (1) personnel are adequately trained to perform assigned work; (2) activities are controlled to ensure consistency of results; (3) records necessary to substantiate how the work was performed are maintained (dedicated laboratory notebooks will be used); (4) the pedigree and traceability of the various tested materials are maintained throughout the described processes using consistent sample numbering and adequate record keeping; (5) equipment with the potential to affect the quality of the planned work is calibrated and maintained in accordance with applicable operating requirements. In addition, all reporting or related dissemination by ORNL personnel of the results of the work described in this subcontract shall be conducted in accordance with the requirements described or referenced in the ORNL Standards Based Management System subject area entitled Scientific and Technical Information. Reporting or publications at other institutions will be conducted in accordance with the requirements of that institution. Successful implementation of these protocols will provide a sound basis for future decisions and research. In addition, these steps will also help ensure that results can also be applied to licensing discussions at a future date

    A survey of dog behavior modification practice in the UK: Who is offering it, what methods are they using and how effective do their clients perceive practitioners to be?

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    Thousands of dogs are relinquished each year in the UK owing to behavioral problems. Hence, there is a clear role for behavior modification therapy in the mitigation of this canine welfare risk. Since statutory regulation and a universal register of canine professionals (CPs) does not yet exist in the UK, it remains unclear who is offering such therapy, which behaviors are being treated, what types of approaches various CPs may be taking and the success (or otherwise) CPs are having. This study aimed to provide some insight into these issues from the perspective of pet dog owners (clients).An online survey of 235 participants showed that the primary reason for seeking behavior help from a CP was related to aggression, although often more than one issue was reported. Regardless of the behavior problem, no significant differences were found for the type of CP consulted (dog trainer versus behaviorist). Furthermore, in the client's opinion, there were no significant differences between CP types in their ability to improve their dog's unwanted behavior. Interestingly, behaviorists were significantly more likely than dog trainers to use ‘reward-based’ methods over ‘balanced training’ (balanced being a mix of reward and punishment; =8.226, df=1, p=0.004).In conclusion, in the current UK vacuum of statutory regulation, clients are just as likely to employ a trainer as a behaviorist, regardless of their dog's unwanted behavior. However, both CP types were equally able to facilitate behavior improvement, as reported by the client, regardless of the type of training methods (reward-based versus balanced) adopted. This study raises further questions to be explored including the client's opinion of the extent to which the ends (behavior outcomes) justify the means (e.g. punitive training methods which are likely to be aversive for the dog). Also, the general public's understanding of the potential welfare implications of the type of behavior modification plan they may or may not choose to follow
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