2,144 research outputs found
Data Processing for LISA's Laser Interferometer Tracking System (LITS)
The purpose of this paper is twofold. First, we will present recent results
on the data processing for LISA, including algorithms for elimination of clock
jitter noise and discussion of the generation of the data averages that will
eventually need to be telemetered to the ground. Second, we will argue, based
partly on these results, that a laser interferometer tracking system (LITS)
that employs independent lasers in each spacecraft is preferable for reasons of
simplicity to that in which the lasers in two of the spacecraft are locked to
the incoming beam from the third.Comment: 5 pages, Proceedings of the Third LISA Symposium (Golm, Germany,
2000
Site-specific magnetization reversal studies of magnetite
5 pages, 3 figures, 1 table.-- et al.The mechanism of magnetization reversal in magnetite Fe3O4 single crystals was studied using sitespecific magnetic sensitive diffraction anomalous near-edge structure. By exploiting the angular dependence of
the cross section, we are able to show that the mechanism of reversal involves a mixture of coherent rotation and domain formation. The results reveal additional details to that provided by XMCD measurements, which
average over nonequivalent sites.We thank J. W. Freeland, E. Kravtsov, and D. R. Lee for useful discussions of the results. Work at the Advanced Photon
Source was supported by the U.S. Department of Energy, Office of Basic Sciences, under Contract No. W-31-109-ENG-38.Peer reviewe
A dual-mask coronagraph for observing faint companions to binary stars
Observations of binary stars for faint companions with conventional
coronagraphic methods are challenging, as both targets will be bright enough to
obscure any nearby faint companions if their scattered light is not suppressed.
We propose coronagraphic examination of binary stars using an apodized pupil
Lyot coronagraph and a pair of actively-controlled image plane masks to
suppress both stars simultaneously. The performance is compared to imaging with
a band-limited mask, a dual-mask Lyot coronagraph and with no coronagraph at
all. An imaging procedure and control system for the masks are also described.Comment: 17 pages, 6 figure
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The F220C and F45L rhodopsin mutations identified in retinitis pigmentosa patients do not cause pathology in mice.
Retinitis pigmentosa is a retinal degenerative disease that leads to blindness through photoreceptor loss. Rhodopsin is the most frequently mutated protein in this disease. While many rhodopsin mutations have well-understood consequences that lead to cell death, the disease association of several rhodopsin mutations identified in retinitis pigmentosa patients, including F220C and F45L, has been disputed. In this study, we generated two knockin mouse lines bearing each of these mutations. We did not observe any photoreceptor degeneration in either heterozygous or homozygous animals of either line. F220C mice exhibited minor disruptions of photoreceptor outer segment dimensions without any mislocalization of outer segment proteins, whereas photoreceptors of F45L mice were normal. Suction electrode recordings from individual photoreceptors of both mutant lines showed normal flash sensitivity and photoresponse kinetics. Taken together, these data suggest that neither the F220C nor F45L mutation has pathological consequences in mice and, therefore, may not be causative of retinitis pigmentosa in humans
Antiâaging drugs reduce hypothalamic inflammation in a sexâspecific manner
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/137690/1/acel12590-sup-0001-FigS1.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/137690/2/acel12590_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/137690/3/acel12590.pd
Conversion of Abandoned Property to Green Space as a Strategy to Mitigate the Urban Heat Island Investigated with Numerical Simulations
Impervious surfaces and buildings in the urban environment alter the radiative balance and surface energy exchange and can lead to warmer temperatures known as the urban heat island (UHI), which can increase heat-related illness and mortality. Continued urbanization and anthropogenic warming will enhance city temperatures worldwide, raising the need for viable mitigation strategies. Increasing green space throughout a city is a viable option to lessen the impacts of the UHI but can be difficult to implement. The potential impact of converting existing vacant lots in Kansas City, Missouri, to green spaces is explored with numerical simulations for three heat-wave events. Using data on vacant property and identifying places with a high fraction of impervious surfaces, the most suitable areas for converting vacant lots to green spaces is determined. Land-use/land-cover datasets are modified to simulate varying degrees of feasible conversion of urban to green spaces in these areas, and the local cooling effect using each strategy is compared with the unmodified simulation. Under more aggressive greening strategies, a mean local cooling impact of 0.5°â1.0°C is present within the focus area itself during the nighttime hours. Some additional cooling via the âpark cool islandâ is possible downwind of the converted green spaces under the more aggressive scenarios. Although moderate and conservative strategies of conversion could still lead to other benefits, those strategies have little impact on cooling. Only an aggressive approach yields significant cooling
A case study of the Neti Potâs rise, americanization, and rupture as integrative medicine in U.S. media discourse
In a period of only one decade in the United States, the neti pot shifted from obscure Ayurvedic health device to mainstream complementary and integrative medicine (CIM), touted by celebrities and sold widely in drug stores. We examine the neti pot as a case study for understanding how a foreign health practice became mainstreamed, and what that process reveals about more general discourses of health in the United States. Using discourse analysis of U.S. popular press and new media news (1999â2012) about the neti pot, we trace the development of discourses from netiâs first introduction in mainstream news, through the hype following Dr. Ozâs presentation on Oprah, to 2011 when two adults tragically died after using Naegleria fowleri amoeba-infested tap water in their neti pots. Neti pot discourses are an important site for communicative analysis because of the potâs complexity as an intercultural artifact: Neti pots and their use are enfolded into the biomedical practice of nasal irrigation and simultaneously Orientalized as exotic/magical and suspect/dangerous. This dual positioning as normal and exotic creates inequitable access for using the neti pot as a resource for increasing cultural health capital (CHC). This article contributes to work that critically theorizes the transnationalism of CIM, as the neti pot became successfully Americanized. These results have implications for understanding global health practicesâ incorporation or co-optation in new contexts, and the important role that popularly mediated health communication can play in framing what health care products and practices mean for consumers
Background light measurements at the DUMAND site
Ambient light intensities at the DUMAND site, west of the island of Hawaii were measured around the one photoelectron level. Throughout the water column between 1,500m and 4,700m, a substantial amount of stimulateable bioluminescence is observed with a ship suspended detector. But non-stimulated bioluminescence level is comparable, or less than, K sup 40 background, when measured with a bottom tethered detector typical of a DUMAND optical module
International Space Station Crew Quarters Ventilation and Acoustic Design Implementation
The International Space Station (ISS) United States Operational Segment has four permanent rack sized ISS Crew Quarters (CQs) providing a private crew member space. The CQs use Node 2 cabin air for ventilation/thermal cooling, as opposed to conditioned ducted air-from the ISS Common Cabin Air Assembly (CCAA) or the ISS fluid cooling loop. Consequently, CQ can only increase the air flow rate to reduce the temperature delta between the cabin and the CQ interior. However, increasing airflow causes increased acoustic noise so efficient airflow distribution is an important design parameter. The CQ utilized a two fan push-pull configuration to ensure fresh air at the crew member's head position and reduce acoustic exposure. The CQ ventilation ducts are conduits to the louder Node 2 cabin aisle way which required significant acoustic mitigation controls. The CQ interior needs to be below noise criteria curve 40 (NC-40). The design implementation of the CQ ventilation system and acoustic mitigation are very inter-related and require consideration of crew comfort balanced with use of interior habitable volume, accommodation of fan failures, and possible crew uses that impact ventilation and acoustic performance. Each CQ required 13% of its total volume and approximately 6% of its total mass to reduce acoustic noise. This paper illustrates the types of model analysis, assumptions, vehicle interactions, and trade-offs required for CQ ventilation and acoustics. Additionally, on-orbit ventilation system performance and initial crew feedback is presented. This approach is applicable to any private enclosed space that the crew will occupy
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