565 research outputs found

    Removal of acid gases and oxides of nitrogen from space cabin atmospheres

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    Removal of acid gases and oxides of nitrogen from spacecraft cabin atmospheres at ambient temperature

    Glimmers: Resolving the Privacy/Trust Quagmire

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    Many successful services rely on trustworthy contributions from users. To establish that trust, such services often require access to privacy-sensitive information from users, thus creating a conflict between privacy and trust. Although it is likely impractical to expect both absolute privacy and trustworthiness at the same time, we argue that the current state of things, where individual privacy is usually sacrificed at the altar of trustworthy services, can be improved with a pragmatic GlimmerGlimmer ofof TrustTrust, which allows services to validate user contributions in a trustworthy way without forfeiting user privacy. We describe how trustworthy hardware such as Intel's SGX can be used client-side -- in contrast to much recent work exploring SGX in cloud services -- to realize the Glimmer architecture, and demonstrate how this realization is able to resolve the tension between privacy and trust in a variety of cases

    Continuous infusion of an agonist of the tumor necrosis factor receptor 2 in the spinal cord improves recovery after traumatic contusive injury.

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    AimThe activation of the TNFR2 receptor is beneficial in several pathologies of the central nervous system, and this study examines whether it can ameliorate the recovery process following spinal cord injury.MethodsEHD2-sc-mTNFR2 , an agonist specific for TNFR2, was used to treat neurons exposed to high levels of glutamate in vitro. In vivo, it was infused directly to the spinal cord via osmotic pumps immediately after a contusion to the cord at the T9 level. Locomotion behavior was assessed for 6 weeks, and the tissue was analyzed (lesion size, RNA and protein expression, cell death) after injury. Somatosensory evoked potentials were also measured in response to hindlimb stimulation.ResultsThe activation of TNFR2 protected neurons from glutamate-mediated excitotoxicity through the activation of phosphoinositide-3 kinase gamma in vitro and improved the locomotion of animals following spinal cord injury. The extent of the injury was not affected by infusing EHD2-sc-mTNFR2 , but higher levels of neurofilament H and 2', 3'-cyclic-nucleotide 3'-phosphodiesterase were observed 6 weeks after the injury. Finally, the activation of TNFR2 after injury increased the neural response recorded in the cortex following hindlimb stimulation.ConclusionThe activation of TNFR2 in the spinal cord following contusive injury leads to enhanced locomotion and better cortical responses to hindlimb stimulation

    ‘Everything’s from the inside out with PCOS’:exploring women’s experiences of living with Polycystic Ovary Syndrome (PCOS) and co-morbidities through Skype™ interviews

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    Polycystic ovary syndrome is an endocrine disorder affecting 1 in 10 women. Women with polycystic ovary syndrome can experience co-morbidities, including depressive symptoms. This research explores the experience of living with polycystic ovary syndrome and co-morbidities. Totally, 10 participants with polycystic ovary syndrome took part in Skypeâ„¢ interviews and analysed using thematic analysis. Four themes emerged from the data: change (to life plans and changing nature of condition); support (healthcare professionals, education and relationships); co-morbidities (living with other conditions and depression, self-harm and suicidal ideation) and identity (feminine identity and us and them). The findings highlight the need for screening of women with polycystic ovary syndrome for depressive disorders

    Neuropathic pain-induced depressive-like behavior and hippocampal neurogenesis and plasticity are dependent on TNFR1 signaling

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    Patients suffering from neuropathic pain have a higher incidence of mood disorders such as depression. Increased expression of tumor necrosis factor (TNF) has been reported in neuropathic pain and depressive-like conditions and most of the pro-inflammatory effects of TNF are mediated by the TNF receptor 1 (TNFR1). Here we sought to investigate: (1) the occurrence of depressive-like behavior in chronic neuropathic pain and the associated forms of hippocampal plasticity, and (2) the involvement of TNFR1-mediated TNF signaling as a possible regulator of such events. Neuropathic pain was induced by chronic constriction injury of the sciatic nerve in wild-type and TNFR1(-/-) mice. Anhedonia, weight loss and physical state were measured as symptoms of depression. Hippocampal neurogenesis, neuroplasticity, myelin remodeling and TNF/TNFRs expression were analyzed by immunohistochemical analysis and western blot assay. We found that neuropathic pain resulted in the development of depressive symptoms in a time dependent manner and was associated with profound hippocampal alterations such as impaired neurogenesis, reduced expression of neuroplasticity markers and myelin proteins. The onset of depressive-like behavior also coincided with increased hippocampal levels of TNF, and decreased expression of TNF receptor 2 (TNFR2), which were all fully restored after mice spontaneously recovered from pain. Notably, TNFR1(-/-) mice did not develop depressive-like symptoms after injury, nor were there changes in hippocampal neurogenesis and plasticity. Our data show that neuropathic pain induces a cluster of depressive-like symptoms and profound hippocampal plasticity that are dependent on TNF signaling through TNFR1

    Explaining Earths Energy Budget: CERES-Based NASA Resources for K-12 Education and Public Outreach

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    Among atmospheric scientists, the importance of the Earth radiation budget concept is well understood. Papers have addressed the topic for over 100 years, and the large Clouds and the Earth's Radiant Energy System (CERES) science team (among others), with its multiple on-orbit instruments, is working hard to quantify the details of its various parts. In education, Earth's energy budget is a concept that generally appears in middle school and Earth science curricula, but its treatment in textbooks leaves much to be desired. Students and the public hold many misconceptions, and very few people have an appreciation for the importance of this energy balance to the conditions on Earth. More importantly, few have a correct mental model that allows them to make predictions and understand the effect of changes such as increasing greenhouse gas concentrations. As an outreach element of the core CERES team at NASA Langley, a multi-disciplinary group of scientists, educators, graphic artists, writers, and web developers has been developing and refining graphics and resources to explain the Earth's Energy budget over the last few decades. Resources have developed through an iterative process involving ongoing use in front of a variety of audiences, including students and teachers from 3rd to 12th grade as well as public audiences

    Management of Traumatic Subarachnoid Hemorrhage by the Trauma Service: Is Repeat CT Scanning and Routine Neurosurgical Consultation Necessary?

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    Subarachnoid hemorrhage (SAH) results frequently from traumatic brain injury (TBI). The standard management for these patients includes brief admission by the acute care surgery (trauma) service with neurological checks, neurosurgical consultation and repeat head CT within 24 hours to identify any progression or resolution. Recent studies have questioned the need for repeat CT imaging and specialty consultation in mild TBI. We reviewed patients with mild TBI specifically with isolated SAH to determine progression of the pathology and need for neurosurgical involvement. All patients with SAH secondary to mild TBI (Glasgow Coma Score (GCS) of 13-15) who presented over a 5-year period (January 2010 to December 2014) to a level I trauma center were identified from the trauma registry. Demographic data, initial CT findings, neurosurgical consultation, follow-up CT findings, Injury Severity Score (ISS), admission GCS and length of stay (LOS) were all obtained from the patient\u27s charts. Patients with other traumatic brain lesions on the initial CT were excluded. There were 299 patients (male, 48.5%), mean age 60.9 and mean ISS 8. Average time between the first and second CT was 11.3 hours. In all, 267 (89.2%) patients had either no change or an improvement/resolution on follow-up CT scan. Only 26 patients (8.7%) had either worsening or new findings on CT. Eight patients did not have a second scan completed (2.6%). All patients had neurosurgical consultation. Patients with mild TBI with isolated SAH generally have low morbidity, short LOS and negligible mortality. Less than 10% of this population had worsening of their head injury on repeat CT scanning. Given the low acuity of these patients with SAH and tendency towards resolution without intervention, acute care surgeons can manage this specific group of patients with TBI without routine neurosurgical consultation. Repeat CT scanning continues to have utility as it may identify new lesions, deterioration or need for further management

    Redirecting the substrate specificity of heparan sulfate 2-O-sulfotransferase by structurally guided mutagenesis

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    Heparan sulfate (HS) is a polysaccharide involved in essential physiological functions from regulating cell growth to blood coagulation. HS biosynthesis involves multiple specialized sulfotransferases such as 2-O-sulfotransferase (2OST) that transfers the sulfo group to the 2-OH position of iduronic acid (IdoA) or glucuronic acid (GlcA) within HS. Here, we report the homotrimeric crystal structure of 2OST from chicken, in complex with 3′-phosphoadenosine 5′-phosphate. Structural based mutational analysis has identified amino acid residues that are responsible for substrate specificity. The mutant R189A only transferred sulfates to GlcA moieties within the polysaccharide whereas mutants Y94A and H106A preferentially transferred sulfates to IdoA units. Our results demonstrate the feasibility for manipulating the substrate specificity of 2OST to synthesize HS with unique sulfation patterns. This work will aid the development of an enzymatic approach to synthesize heparin-based therapeutics

    Hybrid Equation/Agent-Based Model of Ischemia-Induced Hyperemia and Pressure Ulcer Formation Predicts Greater Propensity to Ulcerate in Subjects with Spinal Cord Injury

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    Pressure ulcers are costly and life-threatening complications for people with spinal cord injury (SCI). People with SCI also exhibit differential blood flow properties in non-ulcerated skin. We hypothesized that a computer simulation of the pressure ulcer formation process, informed by data regarding skin blood flow and reactive hyperemia in response to pressure, could provide insights into the pathogenesis and effective treatment of post-SCI pressure ulcers. Agent-Based Models (ABM) are useful in settings such as pressure ulcers, in which spatial realism is important. Ordinary Differential Equation-based (ODE) models are useful when modeling physiological phenomena such as reactive hyperemia. Accordingly, we constructed a hybrid model that combines ODEs related to blood flow along with an ABM of skin injury, inflammation, and ulcer formation. The relationship between pressure and the course of ulcer formation, as well as several other important characteristic patterns of pressure ulcer formation, was demonstrated in this model. The ODE portion of this model was calibrated to data related to blood flow following experimental pressure responses in non-injured human subjects or to data from people with SCI. This model predicted a higher propensity to form ulcers in response to pressure in people with SCI vs. non-injured control subjects, and thus may serve as novel diagnostic platform for post-SCI ulcer formation. © 2013 Solovyev et al
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