51 research outputs found

    On-Orbit Data and Validation of Astra\u27s ACE Electric Propulsion System

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    The first ACE propulsion system reached orbit on July 1st 2021 as part of Spaceflight’s demonstration of the Sherpa-LTE all-electric Orbital Transfer Vehicle (OTV). We are now able to share on-orbit data and have successfully verified the on-orbit performance of the ACE propulsion system, using xenon propellent. The mission objective was to lower altitude and use on-orbit data to derive performance, correlating the propulsion system’s performance to ground test data. The demonstration consisted of activating the propulsion system for 5- minute durations at a total input power of 340 W into the Power Processing Unit (PPU). Altitude change and propellant usage were used to derive thrust and total specific impulse. On-orbit performance is compared to ground test data in Table 1. Averaged performance is within one standard deviation of ground test data. Astra considers this a validation of system performance, as well as the ground test facilities used to test propulsion systems. On-orbit thrust has a large standard deviation as a result of the limited data sampling rate and measurement errors, rather than variability in thruster performance. Figure 1 shows the thruster operating on-orbit. The Astra team gratefully acknowledges the support of Spaceflight, Inc., the U.S. Air Force, and Defense Innovation Unit (DIU) without which this mission would not have been possible

    Pharmacokinetics, safety and tolerability of olaparib and temozolomide for recurrent glioblastoma: results of the phase I OPARATIC trial

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    Background: The poly(ADP-ribose) polymerase (PARP) inhibitor olaparib potentiated radiation and temozolomide chemotherapy in pre-clinical glioblastoma models but brain penetration was poor. Clinically, PARP inhibitors exacerbate the hematological side-effects of temozolomide. The OPARATIC trial was conducted to measure penetration of recurrent glioblastoma by olaparib, and assess the safety and tolerability of its combination with temozolomide. Methods: Pre-clinical pharmacokinetic studies evaluated olaparib tissue distribution in rats and tumor-bearing mice. Adult patients with recurrent glioblastoma received various doses and schedules of olaparib and low-dose temozolomide in a 3+3 design. Suitable patients received olaparib prior to neurosurgical resection; olaparib concentrations in plasma, tumour core and tumour margin specimens were measured by mass spectrometry. A dose expansion cohort tested tolerability and efficacy of the recommended phase II dose (RP2D). Radiosensitizing effects of olaparib were measured by clonogenic survival in glioblastoma cell lines. Results: Olaparib was a substrate for multi-drug resistance protein-1 and showed no brain penetration in rats but was detected in orthotopic glioblastoma xenografts. Clinically, olaparib was detected in 71/71 tumor core specimens (27 patients, median 496nM) and 21/21 tumor margin specimens (9 patients, median 512.3nM). Olaparib exacerbated TMZ-related hematological toxicity, necessitating intermittent dosing. RP2D was olaparib 150mg (3 days/week) with TMZ 75mg/m2 daily for 42 days. Fourteen (36%) of 39 evaluable patients were progression-free at 6 months. Olaparib radiosensitized six glioblastoma cell lines at clinically relevant concentrations of 100 and 500 nM. Conclusions: Olaparib reliably penetrates recurrent glioblastoma at radiosensitizing concentrations, supporting further clinical development and highlighting the need for better pre-clinical models

    Beautification of the Gateway Corridors and Historical Downtown of Columbus, Texas

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    This report presents “Master Plan and Landscape Improvement Plan for the Gateway Corridors in the City of Columbus, Texas”. It is a service-learning project funded by the City of Columbus, Texas through the Texas Target Communities Program and completed by a class of 23 undergraduates in Land 312 from the landscape architecture program at Texas A&M University during the spring semester 2020. The purpose of the project was to enhance the city’s gateway image and visitors’ first impression of the city, improve visitors’ sense of arrival sequence to the historical downtown district, and strengthen the linkage between Hwy 71, downtown area and Colorado River

    Are We Predicting the Actual or Apparent Distribution of Temperate Marine Fishes?

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    Planning for resilience is the focus of many marine conservation programs and initiatives. These efforts aim to inform conservation strategies for marine regions to ensure they have inbuilt capacity to retain biological diversity and ecological function in the face of global environmental change – particularly changes in climate and resource exploitation. In the absence of direct biological and ecological information for many marine species, scientists are increasingly using spatially-explicit, predictive-modeling approaches. Through the improved access to multibeam sonar and underwater video technology these models provide spatial predictions of the most suitable regions for an organism at resolutions previously not possible. However, sensible-looking, well-performing models can provide very different predictions of distribution depending on which occurrence dataset is used. To examine this, we construct species distribution models for nine temperate marine sedentary fishes for a 25.7 km2 study region off the coast of southeastern Australia. We use generalized linear model (GLM), generalized additive model (GAM) and maximum entropy (MAXENT) to build models based on co-located occurrence datasets derived from two underwater video methods (i.e. baited and towed video) and fine-scale multibeam sonar based seafloor habitat variables. Overall, this study found that the choice of modeling approach did not considerably influence the prediction of distributions based on the same occurrence dataset. However, greater dissimilarity between model predictions was observed across the nine fish taxa when the two occurrence datasets were compared (relative to models based on the same dataset). Based on these results it is difficult to draw any general trends in regards to which video method provides more reliable occurrence datasets. Nonetheless, we suggest predictions reflecting the species apparent distribution (i.e. a combination of species distribution and the probability of detecting it). Consequently, we also encourage researchers and marine managers to carefully interpret model predictions

    Effect of a Perioperative, Cardiac Output-Guided Hemodynamic Therapy Algorithm on Outcomes Following Major Gastrointestinal Surgery A Randomized Clinical Trial and Systematic Review

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    Importance: small trials suggest that postoperative outcomes may be improved by the use of cardiac output monitoring to guide administration of intravenous fluid and inotropic drugs as part of a hemodynamic therapy algorithm.Objective: to evaluate the clinical effectiveness of a perioperative, cardiac output–guided hemodynamic therapy algorithm.Design, setting, and participants: OPTIMISE was a pragmatic, multicenter, randomized, observer-blinded trial of 734 high-risk patients aged 50 years or older undergoing major gastrointestinal surgery at 17 acute care hospitals in the United Kingdom. An updated systematic review and meta-analysis were also conducted including randomized trials published from 1966 to February 2014.Interventions: patients were randomly assigned to a cardiac output–guided hemodynamic therapy algorithm for intravenous fluid and inotrope (dopexamine) infusion during and 6 hours following surgery (n=368) or to usual care (n=366).Main outcomes and measures: the primary outcome was a composite of predefined 30-day moderate or major complications and mortality. Secondary outcomes were morbidity on day 7; infection, critical care–free days, and all-cause mortality at 30 days; all-cause mortality at 180 days; and length of hospital stay.Results: baseline patient characteristics, clinical care, and volumes of intravenous fluid were similar between groups. Care was nonadherent to the allocated treatment for less than 10% of patients in each group. The primary outcome occurred in 36.6% of intervention and 43.4% of usual care participants (relative risk [RR], 0.84 [95% CI, 0.71-1.01]; absolute risk reduction, 6.8% [95% CI, ?0.3% to 13.9%]; P?=?.07). There was no significant difference between groups for any secondary outcomes. Five intervention patients (1.4%) experienced cardiovascular serious adverse events within 24 hours compared with none in the usual care group. Findings of the meta-analysis of 38 trials, including data from this study, suggest that the intervention is associated with fewer complications (intervention, 488/1548 [31.5%] vs control, 614/1476 [41.6%]; RR, 0.77 [95% CI, 0.71-0.83]) and a nonsignificant reduction in hospital, 28-day, or 30-day mortality (intervention, 159/3215 deaths [4.9%] vs control, 206/3160 deaths [6.5%]; RR, 0.82 [95% CI, 0.67-1.01]) and mortality at longest follow-up (intervention, 267/3215 deaths [8.3%] vs control, 327/3160 deaths [10.3%]; RR, 0.86 [95% CI, 0.74-1.00]).Conclusions and relevance: in a randomized trial of high-risk patients undergoing major gastrointestinal surgery, use of a cardiac output–guided hemodynamic therapy algorithm compared with usual care did not reduce a composite outcome of complications and 30-day mortality. However, inclusion of these data in an updated meta-analysis indicates that the intervention was associated with a reduction in complication rate

    City of Hitchcock Comprehensive Plan 2020-2040

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    Hitchcock is a small town located in Galveston County (Figure 1.1), nestled up on the Texas Gulf Coast. It lies about 40 miles south-east of Houston. The boundaries of the city encloses an area of land of 60.46 sq. miles, an area of water of 31.64 sq. miles at an elevation just 16 feet above sea level. Hitchcock has more undeveloped land (~90% of total area) than the county combined. Its strategic location gives it a driving force of opportunities in the Houston-Galveston Region.The guiding principles for this planning process were Hitchcock’s vision statement and its corresponding goals, which were crafted by the task force. The goals focus on factors of growth and development including public participation, development considerations, transportation, community facilities, economic development, parks, and housing and social vulnerabilityTexas Target Communitie

    Central pathways causing fatigue in neuro-inflammatory and autoimmune illnesses

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    Capitalized Body Parts: Race, Sexuality, and Commodification in Harry Crews\u27s Car (1972)

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    This article explores racial and sexual discourses that mediate the experience of post-Fordist commodification. It does so by focusing on tropes of corporeal dismantling and reassembly that appear throughout Harry Crews’s 1972 novel Car. After considering the political, conceptual, and historical ambiguities of the novel’s representation of capital as a seduction of and assault on white masculine embodiment, the article concludes with a meditation on what cultural analysis might stand to gain from accounts of fetishism that locate this concept at the intersections of race, sexuality, and commerce

    Capitalized Body Parts: Race, Sexuality, and Commodification in Harry Crews\u27s Car (1972)

    Get PDF
    This article explores racial and sexual discourses that mediate the experience of post-Fordist commodification. It does so by focusing on tropes of corporeal dismantling and reassembly that appear throughout Harry Crews’s 1972 novel Car. After considering the political, conceptual, and historical ambiguities of the novel’s representation of capital as a seduction of and assault on white masculine embodiment, the article concludes with a meditation on what cultural analysis might stand to gain from accounts of fetishism that locate this concept at the intersections of race, sexuality, and commerce

    Case Series of Three Patients with Disseminated Gonococcal Infection and Endocarditis

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    Introduction: The increasing incidence of Neisseria gonorrhoeae infections and emergence of cephalosporin-resistant strains means the threat of disseminated gonococcal infection and endocarditis needs to be reimagined into the differential diagnosis for patients treated in the emergency department (ED) for sexually transmitted infections and for endocarditis itself. Only 70 cases of disseminated gonococcal infection (DGI) with endocarditis had been reported through 2014.1-4 In 2019, however, an outbreak of DGI with one case of endocarditis was reported.5 This case series of three patients with DGI and endocarditis, in addition to the recent outbreak, may represent a warning sign for reemergence of this threat.Case Report: We describe three cases within a recent three-year period of gonococcal endocarditis as seen and treated at our institution. These cases show divergent presentations of this insidious disease with both classical and atypical features. One case displayed a classic migratory rash with positive urine testing and a remote history of sexually transmitted infections, while another patient developed isolated culture-confirmed endocarditis with negative cervical testing and imaging, and the final case was a male patient who presented to the ED with fulminant endocarditis as the first ED presentation of infection.Conclusion: Secondary to an overall rise in incidence and possibly due to increasing antibiotic- resistance patterns, gonococcal endocarditis should be included in the differential diagnosis of any case of endocarditis. Reciprocally, increased vigilance should surround the evaluation of any patient for sexually transmitted diseases while in the ED for both the development of DGI and endocarditis
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