599 research outputs found

    Metabolic Assessment of Suited Mobility Using Functional Tasks

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    Existing methods for evaluating extravehicular activity (EVA) suit mobility have typically focused on isolated joint range of motion or torque, but these techniques have little to do with how well a crewmember functionally performs in an EVA suit. To evaluate suited mobility at the system level through measuring metabolic cost (MC) of functional tasks

    D- Production By Charge Transfer Of (0.3 - 3)-keV D+ In Thick Alkaline-earth Vapor Targets: Interaction Energies For CaH+, CaH, And CaH-

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    Equilibrium charge-state fractions of energetic deuterium ions and atoms emerging from alkaline-earth (magnesium, calcium, strontium, and barium) vapor targets are reported in the range of 0.3- to 3-keV incident D+ energy. Deuterium negative-ion production in thick barium and calcium vapor targets equals similar production in cesium vapor (34%). Moreover, the maximum D- production in strontium vapor exceeds that for all other known gas or vapor targets and reaches 50% at 500 eV. Theory does not quantitatively describe these results, although ab initio molecular-interaction-energy calculations on the neutral and negative-ion CaH systems lead to the prediction of large D- yields at low energies. The theoretical prediction is based on the lack of a strong coupling between the negative ion and neutral molecular states. This implies that there are small D- electron-detachment cross sections at energies less than 1 keV. The present measurements agree with previous measurements done at higher energies. © 1982 The American Physical Society

    Pennsylvania Folklife Vol. 27, Folk Festival Supplement

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    • Hex Signs: A Living Tradition • Decoys and How to Make Them • Kutztown\u27s Plain People • The Old Country Kitchen: Where Food Preparation was an Art • Wooden Toys, Games and Puzzles: The Delight of All Children • A Sketch of the Seminar Stage Programs • Festival Focus • Folk Festival Programs • The Furniture-Makers at the Kutztown Festival • The Muzzle-Loading Gunsmith • Those Rare Things Called Antiques! • Mouth-Watering Baked Goods, Fresh From the Ovens! • The Art of the Potterhttps://digitalcommons.ursinus.edu/pafolklifemag/1079/thumbnail.jp

    R2P from Below: Does the British Public View Humanitarian Interventions as Ethical and Effective?

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    One of the major barriers to the implementation of the Responsibility to Protect principle is the lack of a political will. Public attitudes towards intervention will have a crucial impact on elite willingness to prevent mass atrocities, yet we have little understanding of the factors that influence those attitudes. This article provides the first examination of UK public perceptions about the moral justifiability and effectiveness of humanitarian interventions. The article shows that decisions about justifiability and effectiveness are very different. Attitudes towards justification were more easily explained suggesting that judgements about effectiveness are more contextual and less easily accounted for by individuals’ background characteristics and attitudes. Experiences with both Iraq and Afghanistan have contaminated public perceptions of both the ethics and effectiveness of humanitarian interventions. Although the public is broadly supportive about the justifiability of humanitarian interventions they are extremely sceptical about the likelihood that those interventions will be successful

    The p.M292T NDUFS2 mutation causes complex I-deficient Leigh syndrome in multiple families

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    Isolated complex I deficiency is the most frequently observed oxidative phosphorylation defect in children with mitochondrial disease, leading to a diverse range of clinical presentations, including Leigh syndrome. For most patients the genetic cause of the biochemical defect remains unknown due to incomplete understanding of the complex I assembly process. Nonetheless, a plethora of pathogenic mutations have been described to date in the seven mitochondrial-encoded subunits of complex I as well as in 12 of the nuclear-encoded subunits and in six assembly factors. Whilst several mitochondrial DNA mutations are recurrent, the majority of these mutations are reported in single families. We have sequenced core structural and functional nuclear-encoded subunits of complex I in a cohort of 34 paediatric patients with isolated complex I deficiency, identifying pathogenic mutations in 6 patients. These included a novel homozygous NDUFS1 mutation in an Asian child with Leigh syndrome, a previously identified NDUFS8 mutation (c.236C>T, p.P79L) in a second Asian child with Leigh-like syndrome and six novel, compound heterozygous NDUFS2 mutations in four white Caucasian patients with Leigh or Leigh-like syndrome. Three of these children harboured an identical NDUFS2 mutation (c.875T>C, p.M292T), which was also identified in conjunction with a novel NDUFS2 splice site mutation (c.866+4A>G) in a fourth Caucasian child who presented to a different diagnostic centre, with microsatellite and single nucleotide polymorphism analyses indicating that this was due to an ancient common founder event. Our results confirm that NDUFS2 is a mutational hotspot in Caucasian children with isolated complex I deficiency and recommend the routine diagnostic investigation of this gene in patients with Leigh or Leigh-like phenotypes

    Neurobiological Mechanisms That Contribute to Stress-related Cocaine Use

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    The ability of stressful life events to trigger drug use is particularly problematic for the management of cocaine addiction due to the unpredictable and often uncontrollable nature of stress. For this reason, understanding the neurobiological processes that contribute to stress-related drug use is important for the development of new and more effective treatment strategies aimed at minimizing the role of stress in the addiction cycle. In this review we discuss the neurocircuitry that has been implicated in stress-induced drug use with an emphasis on corticotropin releasing factor actions in the ventral tegmental area (VTA) and an important pathway from the bed nucleus of the stria terminalis to the VTA that is regulated by norepinephrine via actions at beta adrenergic receptors. In addition to the neurobiological mechanisms that underlie stress-induced cocaine seeking, we review findings suggesting that the ability of stressful stimuli to trigger cocaine use emerges and intensifies in an intake-dependent manner with repeated cocaine self-administration. Further, we discuss evidence that the drug-induced neuroadaptations that are necessary for heightened susceptibility to stress-induced drug use are reliant on elevated levels of glucocorticoid hormones at the time of cocaine use. Finally, the potential ability of stress to function as a “stage setter” for drug use – increasing sensitivity to cocaine and drug-associated cues – under conditions where it does not directly trigger cocaine seeking is discussed. As our understanding of the mechanisms through which stress promotes drug use advances, the hope is that so too will the available tools for effectively managing addiction, particularly in cocaine addicts whose drug use is stress-driven

    The evolution of the urinary bladder as a storage organ: scent trails and selective pressure of the first land animals in a computational simulation

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    The function of waste control in all living organisms is one of the vital importance. Almost universally, terrestrial tetrapods have a urinary bladder with a storage function. It is well documented that many marine and aerial species do not have an organ of such a function, or have one with very depressed storage functionality. Bladder morphology indicates it has evolved from a thin-walled structure used for osmoregulatory purposes, as it is currently used in many marine animals. It is hypothesised that the storage function of the urinary bladder allows for an evolutionary selective advantage in reducing the likelihood of successful predation. Random walks simulating predator and prey movements with simplified scent trails were utilised to represent various stages of the hunt: Detection and pursuit. A final evolutionary model is proposed in order to display the advantages over inter-generational time scales and illustrates how a bladder may evolve from an osmoregulatory organ to one of the storage. Data sets were generated for each case and analysed indicating the viability of such advantages. From the highly consistent results, three distinct characteristics of having a storage function in the urinary bladder are suggested: reduced scent trail detection rate; increased prey–predator separation (upon scent trail detection); and a reduced probability of successful capture upon scent detection by the predator. Furthered by the evolutionary model indicating such characteristics are conserved and augmented over many generations, it is concluded that prey–predator interactions provide a large selective pressure in the evolution of the urinary bladder and its storage function

    Mutations in the SPG7 gene cause chronic progressive external ophthalmoplegia through disordered mitochondrial DNA maintenance.

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    Despite being a canonical presenting feature of mitochondrial disease, the genetic basis of progressive external ophthalmoplegia remains unknown in a large proportion of patients. Here we show that mutations in SPG7 are a novel cause of progressive external ophthalmoplegia associated with multiple mitochondrial DNA deletions. After excluding known causes, whole exome sequencing, targeted Sanger sequencing and multiplex ligation-dependent probe amplification analysis were used to study 68 adult patients with progressive external ophthalmoplegia either with or without multiple mitochondrial DNA deletions in skeletal muscle. Nine patients (eight probands) were found to carry compound heterozygous SPG7 mutations, including three novel mutations: two missense mutations c.2221G>A; p.(Glu741Lys), c.2224G>A; p.(Asp742Asn), a truncating mutation c.861dupT; p.Asn288*, and seven previously reported mutations. We identified a further six patients with single heterozygous mutations in SPG7, including two further novel mutations: c.184-3C>T (predicted to remove a splice site before exon 2) and c.1067C>T; p.(Thr356Met). The clinical phenotype typically developed in mid-adult life with either progressive external ophthalmoplegia/ptosis and spastic ataxia, or a progressive ataxic disorder. Dysphagia and proximal myopathy were common, but urinary symptoms were rare, despite the spasticity. Functional studies included transcript analysis, proteomics, mitochondrial network analysis, single fibre mitochondrial DNA analysis and deep re-sequencing of mitochondrial DNA. SPG7 mutations caused increased mitochondrial biogenesis in patient muscle, and mitochondrial fusion in patient fibroblasts associated with the clonal expansion of mitochondrial DNA mutations. In conclusion, the SPG7 gene should be screened in patients in whom a disorder of mitochondrial DNA maintenance is suspected when spastic ataxia is prominent. The complex neurological phenotype is likely a result of the clonal expansion of secondary mitochondrial DNA mutations modulating the phenotype, driven by compensatory mitochondrial biogenesis

    A recurrent mitochondrial p.Trp22Arg NDUFB3 variant causes a distinctive facial appearance, short stature and a mild biochemical and clinical phenotype

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    Background Isolated Complex I deficiency is the most common paediatric mitochondrial disease presentation, associated with poor prognosis and high mortality. Complex I comprises 44 structural subunits with at least 10 ancillary proteins; mutations in 29 of these have so far been associated with mitochondrial disease but there are limited genotype-phenotype correlations to guide clinicians to the correct genetic diagnosis. Methods Patients were analysed by whole-exome sequencing, targeted capture or candidate gene sequencing. Clinical phenotyping of affected individuals was performed. Results We identified a cohort of 10 patients from 8 families (7 families are of unrelated Irish ancestry) all of whom have short stature (C, p.Trp22Arg NDUFB3 variant. Two sibs presented with primary short stature without obvious metabolic dysfunction. Analysis of skeletal muscle from three patients confirmed a defect in Complex I assembly. Conclusions Our report highlights that the long-term prognosis related to the p.Trp22Arg NDUFB3 mutation can be good, even for some patients presenting in acute metabolic crisis with evidence of an isolated Complex I deficiency in muscle. Recognition of the distinctive facial features—particularly when associated with markers of mitochondrial dysfunction and/or Irish ancestry—should suggest screening for the p.Trp22Arg NDUFB3 mutation to establish a genetic diagnosis, circumventing the requirement of muscle biopsy to direct genetic investigations
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