5,759 research outputs found
Lyman H. Legters, ed.: The German Democratic Republic: A Developed Socialist Society
Boulder, Colo.: Westview, 1978. (Westview Special Studies on the Soviet Union and Eastern Europe), xi and 285 p
Limb-darkening functions as derived from along-track operation of the ERBE scanning radiometer for January 1985
During January 1985, the scanning radiometer aboard the Earth Radiation Budget Satellite was operated to scan along-track. These data have been analyzed to produce limb-darkening functions for Earth emitted radiation, which relate the radiance in any given direction to the radiant exitance. Limb-darkening functions are presented in tabular form and shown as figures for 10 day cases and 12 night cases, corresponding to various scene types and latitude zones. The scene types were computed using measurements within 10 deg of zenith. The limb-darkening functions have values of 1.03 to 1.09 at zenith, with 1.06 being typical. It is found that latitude causes a variation on the order of 1 percent, except for zenith angles greater than 70 deg. These limb-darkening models are about 2 percent higher at zenith than the models derived from Nimbus 7 data
Management of Postsurgical Hyperhidrosis With Direct Current and Tap Water
Background and Purpose. Excessive sweating, known as hyperhidrosis, involves the eccrine sweat glands of the axillae, soles, palms, and/or forehead. The use of iontophoresis to reduce or eliminate excessive sweating has been described since 1952. The purpose of this case report is to describe the use of tap water galvanism (TWG) using direct current (DC) with a patient who had postsurgical hyperhidrosis. Case Description. The patient was a 36-year-old male electrician with traumatic phalangeal amputation and postsurgical development of hyperhidrosis. Tap water galvanism was administered using a DC generator, 2 to 3 times per week for 10 treatments. The patient\u27s hands were individually submerged in 2 containers of tap water with the electrodes immersed directly into the containers. Each hand was treated with 30 minutes of TWG at 12 mA. Hyperhidrosis was measured by a 5-second imprint and subsequent tracing of the left hand placed on dry paper toweling. Outcomes. The patient\u27s hyperhidrosis decreased from the full left palmar pad, with a surface area of 10.3×12.0 cm, to a reduced area of wetness that covered a 2.2-×2.7-cm area. The patient returned to work as an electrician without needing absorbent gloves, which had prevented him from performing electrical work. Discussion. Following use of TWG, the patient\u27s palmar hyperhidrosis returned to normhidrosis
Traffic-adaptive, flow-specific medium access for wireless networks
In this report, we formally introduce the novel concept of traffic-adaptive, flow-specific medium access control and show that it outperforms contention, non-contention and hybrid medium access schemes. A traffic-adaptive, flow-specific mechanism is proposed that utilizes flow-specific queue size statistics to select between medium access modes. A general model for traffic adaptive, flow-specific medium access control is developed and it is shown that hybrid medium access as well as traditional contention-based and non-contention schemes can be seen as special cases of the more general flow-specific access. The two flow, two-mode case of the general model is developed in detail and it is shown analytically that this queue-based implementation of traffic-adaptive, flow-specific medium access outperforms contention, non-contention, and hybrid approaches. The proposed traffic-adaptive, flow-specific mechanism is applied to Cooperative Wireless Sensor Network Medium Access Control (CWS-MAC) a flow-specific medium access protocol. Performance is evaluated is evaluated and compared to the traditional medium access approaches. Both analytical and simulation results are provided including the development of throughput and delay expressions for slotted ALOHA with periodic server vacations.Approved for public release; distribution is unlimited
Energy-efficient, Flow-specific Medium Access using Preamble Sampling
Current wireless sensor network applications face challenging power constraints that demand low duty cycles. In this paper, we propose an energy-efficient, flow-specific medium access scheme that is capable of achieving low duty cycles while taking advantage of the performance improvements available through a flow-specific medium access approach. The scheme is based on an adaptive sleep and wake cycle that responds to changes in both contention and non-contention traffic loads through the use of preamble sampling. A preamble sampling probability parameter is introduced to manage the trade-off between energy efficiency and network throughput and delay performance. A performance analysis is conducted and verified through simulation
Replacing Members with Managers? Mutualism among Membership and Nonmembership Advocacy Organizations in the United States
Associations with a professional staff but no members (nonmembership advocacy organizations, or NMAOs) are the subject of lively debate. Many argue that their proliferation has allowed an expansion of advocacy without an accompanying growth in civic engagement. This article asks if there has been significant recent growth of NMAOs and if those organizations have displaced membership advocacy organizations (MAOs). The authors find no evidence for a proportional increase of NMAOs since the 1960s. Further, among all organizations in three populationspeace, women's issues, and human rightsNMAOs have not displaced MAOs. In particular, the authors find that MAO density shapes NMAO founding, as membership groups provide a base for professional advocacy. These findings challenge the notion that U.S. civic life has undergone a systemic transformation away from organizational forms that promote civic engagement
Lineage tracing of Foxd1-expressing embryonic progenitors to assess the role of divergent embryonic lineages on adult dermal fibroblast function
Recent studies have highlighted the functional diversity of dermal fibroblast populations in health and disease, with part of this diversity linked to fibroblast lineage and embryonic origin. Fibroblasts derived from foxd1-expressing progenitors contribute to the myofibroblast populations present in lung and kidney fibrosis in mice but have not been investigated in the context of dermal wound repair. Using a Cre/Lox system to genetically track populations derived from foxd1-expressing progenitors, lineage-positive fibroblasts were identified as a subset of the dermal fibroblast population. During development, lineage-positive cells were most abundant within the dorsal embryonic tissues, contributing to the developing dermal fibroblast population, and remaining in this niche into adulthood. In adult mice, assessment of fibrosis-related gene expression in lineage-positive and lineage-negative populations isolated from wounded and unwounded dorsal skin was performed, identifying an enrichment of transcripts associated with matrix synthesis and remodeling in the lineage-positive populations. Using a novel excisional wound model, ventral skin healed with a greatly reduced frequency of foxd1 lineage-positive cells. This work supports that the embryonic origin of fibroblasts is an important predictor of fibroblast function, but also highlights that within disparate regions, fibroblasts of different lineages likely undergo convergent differentiation contributing to phenotypic similarities
Extension rates across the northern Shanxi Grabens, China, from Quaternary geology, seismicity and geodesy
Discrepancies between geological, seismic and geodetic rates of strain can indicate that rates of crustal deformation, and hence seismic hazard, are varying through time. Previous studies in the northern Shanxi Grabens, at the northeastern corner of the Ordos Plateau in northern China, have found extension rates of anywhere between 0 and 6 mm a−1 at an azimuth of between 95° and 180°. In this paper we determine extension rates across the northern Shanxi Grabens from offset geomorphological features and a variety of Quaternary dating techniques (including new IRSL and Ar-Ar ages), a Kostrov summation using a 700 yr catalogue of historical earthquakes, and recent campaign GPS measurements. We observe good agreement between Quaternary, seismic and geodetic rates of strain, and we find that the northern Shanxi Grabens are extending at around 1–2 mm a−1 at an azimuth of ≈151°. The azimuth of extension is particularly well constrained and can be reliably inferred from catalogues of small earthquakes. We do not find evidence for any substantial variations in extension rate through time, though there is a notable seismic moment rate deficit since 1750. This deficit could indicate complex fault interactions across large regions, aseismic accommodation of deformation, or that we are quite late in the earthquake cycle with the potential for larger earthquakes in the relatively near future
Recommended Practice for Pressure Measurements and Calculation of Effective Pumping Speeds During Electric Propulsion Testing
The electric propulsion community has been implored to establish and implement a set of universally applicable test standards during the research, development, and qualification of electric propulsion systems. Variability between facility-to-facility and more importantly ground-to-flight performance can result in large margins in application or aversion to mission infusion. Performance measurements and life testing under appropriate conditions can be costly and lengthy. Measurement practices must be consistent, accurate, and repeatable. Additionally, the measurements must be universally transportable across facilities throughout the development, qualification, spacecraft integration, and on-orbit performance. A recommended practice for making pressure measurements, pressure diagnostics, and calculating effective pumping speeds with justification is presented
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