487 research outputs found
New Developments and Research Findings: NASA Hydrazine Arcjets
In 1984, the market for commercial geosynchronous communications satellites (comsats) was expanding and there was strong competition between spacecraft builders for market share. The propellant required for the north-south stationkeeping (NSSK) function was a major mission limiter, and the small chemical and resistojet systems then in use were at or near their physical limits. Thus, conditions were right for the development of a high performance NSSK system, and after an extensive survey of both propulsion technologies and the aerospace community, the NASA program chose hydrazine arcjets for development. A joint government/industry development program ensued which culminated in the acceptance of arcjet technology. NASA efforts included fundamental feasibility assessments, hardware development and verification, and multiple efforts aimed at the demonstration of critical operational characteristics of arcjet systems. Throughout the program, constant contact with the user community was maintained to determine system requirements. Both contracted and cooperative programs with industry were supported. First generation, kW-class arcjets are now operational for NSSK on the Telstar 401 satellite launched in December of 1993 and are baselined for use on multiple future satellite series (Intelsat 8, AsiaSat, Echostar). Arcjet development efforts are now focusing on the development of both high performance (600 s), 2 kW thrusters for application on next generation comsats and low power (Pe approximately 0.5 kW) for a variety of applications on power limited satellites. This paper presents a review of the NASA's role in the development of hydrazine arcjets with a focus on approaches, lessons learned, and the future
State Regulation of Franchising: The Washington Experience Revisited
Thirty-six years ago, and one year after Washington became the second state in the nation to enact a statute regulating franchise relationships, Professor Donald S. Chisum wrote the seminal article on franchising in Washington, State Regulation of Franchising: The Washington Experience. Professor Chisum\u27s article has been one of the few reference sources for Washington franchise law, and it has been the primary source relied on by courts addressing claims under Washington\u27s Franchise Investment Protection Act (FIPA). Since Professor Chisum originally published his article, the Federal Trade Commission (FTC) has promulgated and amended regulations governing the sale of franchises nationally, and two different groups have drafted uniform franchise acts. In Washington, the legislature significantly amended FIPA in 1991, and courts have addressed some of the unresolved issues under the statute. This Article assesses the changed state of franchise law in Washington. Part II considers the economic impact of franchising and the need for a review of franchising in Washington. Part III reviews the historical foundation for Washington\u27s current franchise laws, the context in which they were created, and the changes to franchise law that drive our modem understanding of FIPA today. Part IV addresses the current regulatory scheme in Washington, including practical considerations such as franchise registration, disclosure, and state enforcement powers. Finally, Part V addresses civil liability for violations of FIPA\u27s registration, disclosure, and relationship provisions
HUMAN USAGE DESCRIPTION FOR 5G NETWORK ENDPOINTS
Just as Manufacturers Usage Description (MUD) defines security and access control for “things,” Human Usage Description (HUD) does the same for humans by associating a user and all of their devices in a database. With such a database, a 5G provider has insights into user behavior on the network in context with the user device. This allows for more accurate Quality of Experience (QoE) and network slicing at the user device level, common licensing and security across multiple devices, next generation media consumption, and revenue generation through targeted advertising
COGNITIVE CLOUD COLLABORATION
Techniques are described for using a cognitive learning instance to learn a user\u27s preferences across a wide range of cloud collaboration services and provide a customized user experience. This customized user experience is then leveraged on the back-end for optimizing cloud resources
What About the “T’s”?: Addressing the Needs of a Transgender Student at a CCCU Member Institution
As the discussion of the LGBT community continues to evolve and inform decisions at higher education institutions, evidence suggests the “T”–transgender–discussion at CCCU institutions has remained stagnant and largely unrecognized. In June 2011 ACSD’s New Professionals Collaborative asked professionals to present a case study on how a CCCU institution would house a transgender student who had already been admitted into the institution. The authors found the literature on the subject to be sparse, and within the Christian context it is nearly nonexistent. The few precedents and best practices on housing a transgender student do not appear to align with the values of a CCCU institution. There are, however, a few viable housing options to explore, and while an exhaustive list was not created, several of the most likely are examined and discussed. Understanding that a transgender student’s situation is unique and recognizing a lack of knowledge, precedent, and expertise on the subject, the recommendation is to have a conversation with the student about institutional fit. If an agreement to live by the institution’s values is reached, the authors assert housing the student with his/her biological sex most aligns with the institution’s values. Ultimately, the most compelling conclusion and discussion is that CCCU institutions must urgently lay a philosophical and theological foundation on the transgender issue
Social Identity as a Factor in Bystander Responses to Bias-Based Verbal Aggression Among College Students
Bias-based bullying is a significant problem in the United States, including aggression targeting college students with minoritized social identities. Bystander responsiveness can help to buffer the effects, but social identity factors may influence how students respond to bias-based aggression among peers. We conducted a cross-sectional analysis of a subsample (N = 7,291) of the 2018–2019 Healthy Minds Study to test correlations between racial, sexual, and gender identities and self-reported and hypothetical peer interventions. Students who identify with minoritized sexual and gender identities, across racial identities, are most likely to report past or intended interventions while students who identify as straight, cisgender, male, and White are least likely. Specifically, students with minoritized sexual and gender identities are 32% more likely than straight and cisgender peers to report that they had intervened in the past year and 36% more likely to indicate that they intend to intervene in the future. Experiences of discrimination and belonging are significant but separate covariates. Interventions to support peer responsiveness must attend to dynamics of power, oppression, and social identity to reach more students
Folsom Mammoth Hunters? The Terminal Pleistocene Assemblage from Owl Cave (10BV30), Wasden Site, Idaho
The 1960s and 1970s excavations at Owl Cave (10BV30) recovered mammoth bone and Folsom-like points from the same strata, suggesting evidence for a post-Clovis mammoth kill. However, a synthesis of the excavation data was never published, and the locality has since been purged from the roster of sites with human / extinct megafauna associations. Here, we present data on bone from the oldest stratum, review provenience data, conduct a bone-surface modification study, and present the results of a protein-residue analysis. Our study fails to make the case for mammoth hunting by Folsom peoples. Although two of the fragments tested positive for horse or elephant protein, recent AMS dates indicate that all mammoth remains predate Folsom, and horse remains absent from the Owl Cave collection. Further, In unambiguously cultural surface modifications were identified on any of the mammoth remains. Given the available data, the Owl Cave deposits are most parsimoniously read as containing a Folsom-age occupation in the buried context, the first of its kind in the West West, but one nonetheless part of the Palimpsest of Pleistocene materials terminal
Comparison of predictors for early and late mortality in adults commencing HIV antiretroviral therapy in Zimbabwe: a retrospective cohort study.
BACKGROUND
People living with HIV (PLWHIV) commencing antiretroviral therapy (ART) in sub-Saharan Africa experience significant mortality within the first year. Previously, identified risk factors for mortality may be biased towards these patients, as compared to those who experience late mortality.
AIM
To compare risk factors for early and late mortality in PLWHIV commencing ART.
METHODS
A retrospective cohort study of ART-naïve patients aged ≥ 18 years from an outpatient HIV clinic in Zimbabwe. Data were collected between January 2010 and January 2019. Predictors for early (≤ 1 year) and late mortality (> 1 year) were determined by multivariable cox proportional hazards analyses, with patients censored at 1 year and landmark analysis after 1 year, respectively.
RESULTS
Three thousand and thirty-nine PLWHIV were included in the analysis. Over a median follow-up of 4.6 years (IQR 2.5-6.9), there was a mortality rate of 8.8%, with 50.4% of deaths occurring within 1 year. Predictors of early mortality included CD4 count < 50 cells/µL (HR 1.84, 95% CI 1.24-2.72, p < 0.01), WHO Stage III (HR 2.05, 95% CI 1.28-3.27, p < 0.01) or IV (HR 2.83, 95% CI 1.67-4.81, p < 0.01), and eGFR < 90 mL/min/1.73 m2 (HR 2.48, 95% CI 1.56-3.96, p < 0.01). Other than age (p < 0.01), only proteinuria (HR 2.12, 95% CI 1.12-4.01, p = 0.02) and diabetes mellitus (HR 3.51, 95% CI 1.32-9.32, p = 0.01) were associated with increased risk of late mortality.
CONCLUSIONS
Traditional markers of mortality risk in patients commencing ART appear to be limited to early mortality. Proteinuria and diabetes are some of the few predictors of late mortality, and should be incorporated into routine screening of patients commencing ART
Development and mapping of SNP assays in allotetraploid cotton
A narrow germplasm base and a complex allotetraploid genome have made the discovery of single nucleotide polymorphism (SNP) markers difficult in cotton (Gossypiumhirsutum). To generate sequence for SNP discovery, we conducted a genome reduction experiment (EcoRI, BafI double digest, followed by adapter ligation, biotin–streptavidin purification, and agarose gel separation) on two accessions of G. hirsutum and two accessions of G. barbadense. From the genome reduction experiment, a total of 2.04 million genomic sequence reads were assembled into contigs with an N50 of 508 bp and analyzed for SNPs. A previously generated assembly of expressed sequence tags (ESTs) provided an additional source for SNP discovery. Using highly conservative parameters (minimum coverage of 8× at each SNP and 20% minor allele frequency), a total of 11,834 and 1,679 non-genic SNPs were identified between accessions of G. hirsutum and G. barbadense in genome reduction assemblies, respectively. An additional 4,327 genic SNPs were also identified between accessions of G. hirsutum in the EST assembly. KBioscience KASPar assays were designed for a portion of the intra-specific G. hirsutum SNPs. From 704 non-genic and 348 genic markers developed, a total of 367 (267 non-genic, 100 genic) mapped in a segregating F2 population (Acala Maxxa × TX2094) using the Fluidigm EP1 system. A G. hirsutum genetic linkage map of 1,688 cM was constructed based entirely on these new SNP markers. Of the genic-based SNPs, we were able to identify within which genome (‘A’ or ‘D’) each SNP resided using diploid species sequence data. Genetic maps generated by these newly identified markers are being used to locate quantitative, economically important regions within the cotton genome
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