49 research outputs found

    Genetic diversity analysis in Malaysian giant prawns using expressed sequence tag microsatellite markers for stock improvement program

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    The Malaysian giant prawn is among the most commonly cultured species of the genus Macrobrachium. Stocks of giant prawns from four rivers in Peninsular Malaysia have been used for aquaculture over the past 25 years, which has led to repeated harvesting, restocking, and transplantation between rivers. Consequently, a stock improvement program is now important to avoid the depletion of wild stocks and the loss of genetic diversity. However, the success of such an improvement program depends on our knowledge of the genetic variation of these base populations. The aim of the current study was to estimate genetic variation and differentiation of these riverine sources using novel expressed sequence tag-microsatellite (EST-SSR) markers, which not only are informative on genetic diversity but also provide information on immune and metabolic traits. Our findings indicated that the tested stocks have inbreeding depression due to a significant deficiency in heterozygotes, and FIS was estimated as 0.15538 to 0.31938. An F-statistics analysis suggested that the stocks are composed of one large panmictic population. Among the four locations, stocks from Johor, in the southern region of the peninsular, showed higher allelic and genetic diversity than the other stocks. To overcome inbreeding problems, the Johor population could be used as a base population in a stock improvement program by crossing to the other populations. The study demonstrated that EST-SSR markers can be incorporated in future marker assisted breeding to aid the proper management of the stocks by breeders and stakeholders in Malaysia

    Cortical reactivations of recent sensory experiences predict bidirectional network changes during learning

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    Salient experiences are often relived in the mind. Human neuroimaging studies suggest that such experiences drive activity patterns in visual association cortex that are subsequently reactivated during quiet waking. Nevertheless, the circuit-level consequences of such reactivations remain unclear. Here, we imaged hundreds of neurons in visual association cortex across days as mice learned a visual discrimination task. Distinct patterns of neurons were activated by different visual cues. These same patterns were subsequently reactivated during quiet waking in darkness, with higher reactivation rates during early learning and for food-predicting versus neutral cues. Reactivations involving ensembles of neurons encoding both the food cue and the reward predicted strengthening of next-day functional connectivity of participating neurons, while the converse was observed for reactivations involving ensembles encoding only the food cue. We propose that task-relevant neurons strengthen while task-irrelevant neurons weaken their dialog with the network via participation in distinct flavors of reactivation

    Excellent Response to a Ketogenic Diet in a Patient with Alternating Hemiplegia of Childhood

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    International audienceAlternating hemiplegia of childhood (AHC) is a rare disorder caused by heterozygous mutations in ATP1A3. AHC is associated with early-onset plegic and tonic/dystonic attacks and permanent neurologic deficits. Attacks tend to persist through life. Flunarizine therapy occasionally reduces the severity, duration and frequency of attacks. A ketogenic diet/modified Atkins diet (KD/MAD) can attenuate paroxysmal movement disorders associated with GLUT1 deficiency syndrome (GLUT1DS), but there are no reports on the effect of KD/MAD in AHC. We describe the case of a young girl with AHC who had tonic/dystonic and plegic attacks, mostly triggered by exercise, together with mild permanent dystonia and mental retardation. Her family had a history of dominant (three affected generations) paroxysmal exercise-induced dystonia. A history of plegic attacks that ceased after childhood was retraced from the medical records of the three affected adults, leading to the diagnosis of familial AHC due to ATP1A3 p.Asp923Asn mutation (Roubergue et al 2013). KD/MAD was considered for the proband when she was 3½ years old, following initial misdiagnosis of GLUT1DS. MAD, a KD variant, was chosen because it is easier to manage than KD and is similarly effective to KD in most GLUT1DS patients. MAD resulted in complete disappearance of the attacks during 15 months of follow-up. A modified Atkins diet had a sustained beneficial effect on attacks associated with AHC. Although preliminary, this observation suggests that a ketogenic diet might be a therapeutic option for paroxysmal disorders in some patients with alternating hemiplegia of childhood

    Experiences of practitioners implementing comprehensive student support in high-poverty schools

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    This US-based study examined the experiences of school counselors and social workers implementing a systems-oriented, programmatic student support practice model, City Connects, within high-need urban contexts. The City Connects model represents current best practices in student support, positioning school counselors and social workers primarily in the role of identifying students’ needs and strengths and making connections between students, families, teachers, and service providers. This stands in contrast to older models in which these professionals functioned primarily in a direct care role. The goal of the study was to understand practitioners’ experiences of efficacy, satisfaction, and engagement as well as the barriers to each of these within this best practice model. Acknowledging the documented challenges of working in high-need urban schools in the United States and the potential strains of systems-oriented practice, the study aimed to understand which aspects of their work enable practitioners to thrive, as well as which aspects do not. Qualitative analysis was used to examine written reflection data on the experiences of 35 practitioners implementing the model. Our analysis revealed six themes: (1) connecting/cultivating relationships (2) seeing impact, (3) having confidence in the effectiveness of the practice model, (4) having high levels of satisfaction with the practice, (5) managing role clarity, and (6) experiencing systemic barriers. Implications for practitioners, supervisors, clinician educators, and program designers are discussed
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