1,879 research outputs found

    Characterization of recombination and control electrodes for spacecraft nickel- cadmium cells

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    Characterization of recombination and control electrodes for spacecraft nickel cadmium cell

    Holey goats: multiple cases of supratrochlear foramina in the humerus of caprines from the New Kingdom pharaonic town of Amara West, northern Sudan

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    Supratrochlear foramina (STF) were recorded in fifteen per cent of goat and sheep/goat humeri from the New Kingdom pharaonic town of Amara West, in modern northern Sudan. To the authors’ knowledge, this trait has never before been reported in the published literature for goats or sheep, whether from archaeological or modern contexts. The aim of this work is twofold: to contribute to the growing corpus of studies addressing the incidence and aetiology of STF, and to raise awareness for their possible presence in caprines, thus encouraging their identification and recording in archaeological assemblages

    Continuous ligand-assisted elution chromatography applied to separation of rare earth elements

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    Rare earth elements (REEs) are metals used to make many valuable products such as magnets and electronics. Following their extraction from larger materials, REEs are to be separated into their individual components as high purity is required for product manufacture. Purification is very difficult because most (15/17) of the REEs are lanthanides (Ln’s) and Ln ions have the same valence and similar atomic radii. The current industrial process for purifying REEs involves using toxic solvents to perform a series of liquid-liquid extractions. Ling and Wang (2015) proposed a ligand-assisted batch chromatography process to purify Ln’s. The latter approach is a vast improvement over the former in terms of safety, however being a batch process, it is not economical for industrial use. The purpose of this study was to design and test a continuous system based off of Ling and Wang’s ligand-assisted elution chromatography process. A titania sorbent was used with a selective ligand, ethylenediaminetetraacetic acid (EDTA). The continuous system utilizes a stepwise elution process and separates a solution of praseodymium (Pr) and samarium (Sm). A Semba Octave SMB chromatography system was used to perform the experiment. Yields and purities greater than 95% were seen for each of the components in solution and the process can be run indefinitely. This continuous process for Ln separation is of interest because safety is increased in comparison to the aforementioned industrial system, sorbent productivity is increased, and it is more robust and simpler to run than the batch process. This continuous system can be scaled up to produce high purity REEs safely and efficiently

    Development and analysis of the Software Implemented Fault-Tolerance (SIFT) computer

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    SIFT (Software Implemented Fault Tolerance) is an experimental, fault-tolerant computer system designed to meet the extreme reliability requirements for safety-critical functions in advanced aircraft. Errors are masked by performing a majority voting operation over the results of identical computations, and faulty processors are removed from service by reassigning computations to the nonfaulty processors. This scheme has been implemented in a special architecture using a set of standard Bendix BDX930 processors, augmented by a special asynchronous-broadcast communication interface that provides direct, processor to processor communication among all processors. Fault isolation is accomplished in hardware; all other fault-tolerance functions, together with scheduling and synchronization are implemented exclusively by executive system software. The system reliability is predicted by a Markov model. Mathematical consistency of the system software with respect to the reliability model has been partially verified, using recently developed tools for machine-aided proof of program correctness

    Northrop Grumman TR202 LOX/LH2 Deep Throttling Engine Project Status

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    NASA's Propulsion and Cryogenic Advanced Development (PCAD) project is currently developing enabling propulsion technologies in support of the Exploration Initiative, with a particular focus on the needs of the Altair Project. To meet Altair requirements, several technical challenges need to be overcome, one of which is the ability for the lunar descent engine(s) to operate over a deep throttle range with cryogenic propellants. To address this need, PCAD has enlisted Northrop Grumman Aerospace Systems (NGAS) in a technology development effort associated with the TR202, a LOX/LH2 expander cycle engine driven by independent turbopump assemblies and featuring a variable area pintle injector similar to the injector used on the TR200 Apollo Lunar Module Descent Engine (LMDE). Since the Apollo missions, NGAS has continued to mature deep throttling pintle injector technology. The TR202 program has completed two phases of pintle injector testing. The first phase of testing used ablative thrust chambers and demonstrated igniter operation as well as stable performance at several power levels across the designed 10:1 throttle range. The second phase of testing was performed on a calorimeter chamber and demonstrated injector performance at various power levels (75%, 50%, 25%, 10%, and 7.5%) across the throttle range as well as chamber heat flux to show that the engine can close an expander cycle design across the throttle range. This paper provides an overview of the TR202 program. It describes the different phases of the program with the key milestones of each phase. It then shows when those milestones were met. Next, it describes how the test data was used to update the conceptual design and how the test data has created a database for deep throttling cryogenic pintle technology that is readily scaleable and can be used to again update the design once the Altair program's requirements are firm. The final section of the paper describes the path forward, which includes demonstrating continuously throttling with an actuator and pursuing a path towards integrated engine sea-level test-bed testing

    Rapid identification of BCR/ABL1-like acute lymphoblastic leukaemia patients using a predictive statistical model based on quantitative real time-polymerase chain reaction: clinical, prognostic and therapeutic implications.

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    BCR/ABL1-like acute lymphoblastic leukaemia (ALL) is a subgroup of B-lineage acute lymphoblastic leukaemia that occurs within cases without recurrent molecular rearrangements. Gene expression profiling (GEP) can identify these cases but it is expensive and not widely available. Using GEP, we identified 10 genes specifically overexpressed by BCR/ABL1-like ALL cases and used their expression values - assessed by quantitative real time-polymerase chain reaction (Q-RT-PCR) in 26 BCR/ABL1-like and 26 non-BCR/ABL1-like cases to build a statistical "BCR/ABL1-like predictor", for the identification of BCR/ABL1-like cases. By screening 142 B-lineage ALL patients with the "BCR/ABL1-like predictor", we identified 28/142 BCR/ABL1-like patients (19·7%). Overall, BCR/ABL1-like cases were enriched in JAK/STAT mutations (P < 0·001), IKZF1 deletions (P < 0·001) and rearrangements involving cytokine receptors and tyrosine kinases (P = 0·001), thus corroborating the validity of the prediction. Clinically, the BCR/ABL1-like cases identified by the BCR/ABL1-like predictor achieved a lower rate of complete remission (P = 0·014) and a worse event-free survival (P = 0·0009) compared to non-BCR/ABL1-like ALL. Consistently, primary cells from BCR/ABL1-like cases responded in vitro to ponatinib. We propose a simple tool based on Q-RT-PCR and a statistical model that is capable of easily, quickly and reliably identifying BCR/ABL1-like ALL cases at diagnosis

    Novel, bilateral, two-bellied muscles span the extensor forearm, thenar eminence to insert on the proximal phalanx of the thumb: clinical and embryological significance

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    Muscle and tendon variations in the forearm, wrist and hand are commonly reported in the anatomical and surgical literature. They are frequently the source of inflammatory conditions such as de Quervain’s tenosynovitis or carpal tunnel syndrome. During academic dissection, a cadaver presented with bilateral, additional muscles running parallel to the abductor pollicis longus muscles (APL) in the extensor compartment of the forearm. Both additional muscles had two bellies, one proximal and one distal, with an intervening tendon. The proximal bellies were separate and distinct from the adjacent APLs. The tendons traversed the first dorsal compartments with the tendons of the APLs and the extensor pollicis brevis muscles (EPB). The distal bellies lay adjacent to the abductor pollicis brevis (APB) muscles in the thenar compartments, and inserted onto the volar base of the proximal phalanges of the thumbs. Following a thorough search of the literature, we determined that these additional muscles constitute a previously unreported variation. This report details the variation, compares it with other reported variations, presents the related embryology, and reviews the significance of this variation as it relates to inflammatory conditions and surgical procedures

    Microbial glutamate metabolism predicts intravenous cocaine self-administration in diversity outbred mice.

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    The gut microbiome is thought to play a critical role in the onset and development of psychiatric disorders, including depression and substance use disorder (SUD). To test the hypothesis that the microbiome affects addiction predisposing behaviors and cocaine intravenous self-administration (IVSA) and to identify specific microbes involved in the relationship, we performed 16S rRNA gene sequencing on feces from 228 diversity outbred mice. Twelve open field measures, two light-dark assay measures, one hole board and novelty place preference measure significantly differed between mice that acquired cocaine IVSA (ACQ) and those that failed to acquire IVSA (FACQ). We found that ACQ mice are more active and exploratory and display decreased fear than FACQ mice. The microbial abundances that differentiated ACQ from FACQ mice were an increased abundance of Barnesiella, Ruminococcus, and Robinsoniella and decreased Clostridium IV in ACQ mice. There was a sex-specific correlation between ACQ and microbial abundance, a reduced Lactobacillus abundance in ACQ male mice, and a decreased Blautia abundance in female ACQ mice. The abundance of Robinsoniella was correlated, and Clostridium IV inversely correlated with the number of doses of cocaine self-administered during acquisition. Functional analysis of the microbiome composition of a subset of mice suggested that gut-brain modules encoding glutamate metabolism genes are associated with the propensity to self-administer cocaine. These findings establish associations between the microbiome composition and glutamate metabolic potential and the ability to acquire cocaine IVSA thus indicating the potential translational impact of targeting the gut microbiome or microbial metabolites for treatment of SUD. This article is part of the Special Issue on Microbiome & the Brain: Mechanisms & Maladies

    Transdiagnostic prevention and intervention efforts are needed to address executive dysfunction

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    Abstract: Executive functioning (EF) is a multi-faceted construct important to activities of daily living, emotion regulation, and higher-order thinking and is often impaired in individuals with gambling disorder and/or alcohol use disorders. Deficits in EF are associated with poor treatment engagement, psychiatric comorbidities, and relapse. The present study examined EF in college students (N = 832) aged 18-24 (M= 19.23, SD=1.37, 76.5% Women) in relation to gambling and hazardous drinking. The Barkley’s Deficits in Executive Functioning was used to assess for global EF and 5 facets of EF: Time Management, Organization/Problem Solving, Self-Restraint, Self-Motivation, and Emotion-Regulation. Bivariate correlation and ANOVA analyses were conducted. Approximately 3% of college students reported problem gambling and 20% reported engagement in hazardous drinking. Compared to individuals with non-problem drinking and non-problem gambling: (1) individuals with problem gambling had worse global EF, self-restraint, emotion regulation, and self-motivation, (2) individuals with hazardous drinking had worse Global EF, self-restraint, and emotion regulation and (3) individuals with both problem gambling and hazardous drinking had worse EF on self-restraint. Implications: Impairments in several domains of EF (e.g., inhibition/self-restraint, emotion regulation, and self-motivation) were endorsed at a significantly higher rate among problematic gamblers and hazardous drinkers. Results partially support the pathways model of gambling (Blaszcynski & Nower, 2002) and support transdiagnostic prevention and intervention efforts around emotion regulation, motivation, and impulsivity
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