2,258 research outputs found

    Deep Space Missions for Small Satellites

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    Small satellites, with masses well under 100 kg, can perform useful deep space science missions for costs similar to those of low earth orbit and geosynchronous smallsats. Space Explorations has identified several interesting missions for smallsats, with the objective of developing turnkey space-science packages which would have a cost to the customer of $10,000,000 and be operable by one or a few people. We have analyzed one mission, a Lunar Polar Photographic Orbiter, in great detail over the last year. We conclude that it is commercially and scientifically feasible to produce a small lunar satellite which is capable of doing extensive, high-resolution photography of the moon. The LPPO would photograph those portions of the moon which have never been observed, at resolutions of 30 m, and it would remap the entire far southern quadrant of the moon at 100 times the resolution of existing maps

    From Before the Flowers of Friendship Faded Faded

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    The Amagugu intervention: a conceptual framework for increasing HIV disclosure and parent-led communication about health among HIV-Infected parents with HIV-uninfected primary school-aged children

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    Advances in access to HIV prevention and treatment have reduced vertical transmission of HIV, with most children born to HIV-infected parents being HIV-uninfected themselves. A major challenge that HIV-infected parents face is disclosure of their HIV status to their predominantly HIV-uninfected children. Their children enter middle childhood and early adolescence facing many challenges associated with parental illness and hospitalization, often exacerbated by stigma and a lack of access to health education and support. Increasingly, evidence suggests that primary school-aged children have the developmental capacity to grasp concepts of health and illness, including HIV, and that in the absence of parent-led communication and education about these issues, HIV-exposed children may be at increased risk of psychological and social problems. The Amagugu intervention is a six-session home-based intervention, delivered by lay counselors, which aims to increase parenting capacity to disclose their HIV status and offer health education to their primary school-aged children. The intervention includes information and activities on disclosure, health care engagement, and custody planning. An uncontrolled pre–post-evaluation study with 281 families showed that the intervention was feasible, acceptable, and effective in increasing maternal disclosure. The aim of this paper is to describe the conceptual model of the Amagugu intervention, as developed post-evaluation, showing the proposed pathways of risk that Amagugu aims to disrupt through its intervention targets, mechanisms, and activities; and to present a summary of results from the large-scale evaluation study of Amagugu to demonstrate the acceptability and feasibility of the intervention model. This relatively low-intensity home-based intervention led to: increased HIV disclosure to children, improvements in mental health for mother and child, and improved health care engagement and custody planning for the child. The intervention model demonstrates the potential for disclosure interventions to include pre-adolescent HIV education and prevention for primary school-aged children

    Down in the Valley: Financial Neglect in Rural California

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    The most powerful banks in California and the nation are failing to meet the financial services and credit needs of residents and businesses in the San Joaquin Valley. Bank of America, JPMorgan Chase and Wells Fargo (the "Big 3 banks") provide a lower level of affordable consumer, housing and small business lending and services to Valley residents and businesses than they do to consumers in other parts of California. Bank regulators contribute to this failure because they do not enforce the necessary attention from banks to nonmetropolitan areas like the Valley. As a result, the San Joaquin Valley lags in growth -- a bleak fact that has become increasingly apparent during the current economic recovery. The report documents disinvestment in the San Joaquin Valley

    Communication about HIV and death: Maternal reports of primary school-aged children's questions after maternal HIV disclosure in rural South Africa

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    Introduction: Children's understanding of HIV and death in epidemic regions is under-researched. We investigated children's death-related questions post maternal HIV-disclosure. Secondary aims examined characteristics associated with death-related questions and consequences for children's mental health. Methods: HIV-infected mothers (N = 281) were supported to disclose their HIV status to their children (6–10 years) in an uncontrolled pre-post intervention evaluation. Children's questions post-disclosure were collected by maternal report, 1–2 weeks post-disclosure. 61/281 children asked 88 death-related questions, which were analysed qualitatively. Logistic regression analyses examined characteristics associated with death-related questions. Using the parent-report Child Behaviour Checklist (CBCL), linear regression analysis examined differences in total CBCL problems by group, controlling for baseline. Results: Children's questions were grouped into three themes: ‘threats’; ‘implications’ and ‘clarifications’. Children were most concerned about the threat of death, mother's survival, and prior family deaths. In multivariate analysis variables significantly associated with asking death-related questions included an absence of regular remittance to the mother (AOR 0.25 [CI 0.10, 0.59] p = 0.002), mother reporting the child's initial reaction to disclosure being “frightened” (AOR 6.57 [CI 2.75, 15.70] p=<0.001) and level of disclosure (full/partial) to the child (AOR 2.55 [CI 1.28, 5.06] p = 0.008). Controlling for significant variables and baseline, all children showed improvements on the CBCL post-intervention; with no significant differences on total problems scores post-intervention (β -0.096 SE1.366 t = -0.07 p = 0.944). Discussion: The content of questions children asked following disclosure indicate some understanding of HIV and, for almost a third of children, its potential consequence for parental death. Level of maternal disclosure and stability of financial support to the family may facilitate or inhibit discussions about death post-disclosure. Communication about death did not have immediate negative consequences on child behaviour according to maternal report. Conclusion: In sub-Saharan Africa, given exposure to death at young ages, meeting children's informational needs could increase their resilience

    Kinetic microscale thermophoresis

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    We established an extension of Microscale Thermophoresis (MST) to measure binding kinetics together with binding affinity in a single experimental run, by increasing the thermal dissipation of the sample. After the switch-off of an IR laser, that locally heated the sample, the temperature re-equilibrated within 250 ms. The kinetic relaxation fingerprints were extracted from the fluorescence changes back to thermodynamic equilibrium. We measured DNA hybridization on-rates and off-rates in the range between 104-106 M-1s-1 and 10-4-10-1 s‑1, respectively. We observed the expected exponential dependence of the DNA hybridization off-rates on salt concentration, strand length and inverse temperature. The measured on-rates showed a linear dependence on salt and weak if no dependence at all on length and temperature. For biological binding reactions with sufficient enthalpic contributions, Kinetic MST offers a robust and immobilization-free determination of kinetic rates and binding affinity and also in crowded solutions

    Predation by Pellet-Reared Tiger Muskellunge on Minnows and Bluegills in Experimental Systems

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    Studies in Wisconsin lakes have shown that stocked tiger muskellunge( F1 hybrids of female muskellunge, Esox masquinongy * male northern pike, E.lucius) reared on live food survive better than those reared entirely on dry pellet food. We evaluated the ability of pellet-reared hybrids to convert to a minnow(Notropis spp. and Pimephales promelas) or bluegill (Lepomis macrochirus) diet in laboratory aquaria and hatchery ponds. In aquaria, 86-310-mm (total length) tiger muskellunge selected cyprinids that were about 40% of their own length and bluegills that were about 30% of their length, sizes closely predicted by an optimal foraging construct (time from prey capture to complete prey ingestion / prey dry weight). Using these prey sizes, we tested hybrids (130, 150, and 170mm long) in conversion experiments in aquaria and ponds. During experiments, prey were maintained at a constant density and predators were sampled periodically to determine the proportion eating fish. Tiger muskellunge converted more slowly to bluegills than to minnows in both aquaria and ponds. In aquaria, 85% of the hybrids converted from pellets to minnows by day 3, whereas only 68% converted to bluegills. By day 5, conversions to minnows and bluegills were 95% and 82%, respectively. In ponds, 73% of the hybrids converted to minnows by day 5 and 89% by day 14. No hybrids had eaten bluegills by day 3 and only 53% converted by day 14. The apparently limited ability of pellet-reared tiger muskellunge to switch to a bluegill diet may influence survival and growth of these predators in reservoirs dominated by a centrachid forage base.This research was supported in part by funds from the Federal Aid in Fish Restoration Act under Dingell-Johnson Project F-57-R

    An Overview of the Guided Parafoil System Derived from X-38 Experience

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    The NASA Johnson Space Center built a 4200 sq ft parafoil for the U.S. Army Natick Soldier Center to demonstrate autonomous flight using a guided parafoil system to deliver 10,000 lbs of useable payload. The parafoil's design was based upon that developed during the X-38 program. The drop test payload consisted of a standard 20-foot Type V airdrop platform, a standard 12-foot weight tub, a 60 ft drogue parachute, a 4200 ft2 parafoil, an instrumentation system, and a Guidance, Navigation, and Control (GN&C) system. Instrumentation installed on the load was used to gather data to validate simulation models and preflight loads predictions and to perform post flight trajectory and performance reconstructions. The GN&C system, developed during NASA's X-38 program, consisted of a flight computer, modems for uplink commands and downlink data, a compass, laser altimeter, and two winches. The winches were used to steer the parafoil and to perform the dynamic flare maneuver for a soft landing. The laser was used to initiate the flare. The GN&C software was originally provided to NASA by the European Space Agency. NASA incorporated further software refinements based upon the X-38 flight test results. Three full-scale drop tests were conducted, with the third being performed during the Precision Airdrop Technology Conference and Demonstration (PATCAD) Conference at the U.S. Army Yuma Proving Ground (YPG) in November of 2003. For the PATCAD demonstration, the parafoil and GN&C software and hardware performed well, concluding with a good flare and the smallest miss distance ever experienced in NASA's parafoil drop test program. This paper describes the 4200 sq ft parafoil system, simulation results, and the results of the drop tests

    HIV/AIDS and psychiatry: Towards the establishment of a pilot programme for detection and treatment of common mental disorders in people living with HIV/AIDS in Cape Town

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    As the roll-out of antiretrovirals (ARVs) to people living with HIV / AIDS (PLWHA) continues to increase in South Africa, so too does the need to integrate mental health services into HIV care. In this editorial, we argue that the role of mental health in ARV programmes is central. The prevalence of mental disorders in PLWHA is higher than in the general population, and the impact of these conditions is substantial. Screening tools for mental disorders are both available and feasible. These should be incorporated into routine ARV care, with support from dedicated HIV mental health services

    The potential for decentralized community industries.

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    Massachusetts Institute of Technology. Dept. of Urban Studies and Planning. Thesis. 1974. Ph.D.Vita.Bibliography: leaves 264-282.Ph.D
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