Space shuttle OMS helium regulator design and development

Analysis, design, fabrication and design verification testing was conducted on the technological feasiblity of the helium pressurization regulator for the space shuttle orbital maneuvering system application. A prototype regulator was fabricated which was a single-stage design featuring the most reliable and lowest cost concept. A tradeoff study on regulator concepts indicated that a single-stage regulator with a lever arm between the valve and the actuator section would offer significant weight savings. Damping concepts were tested to determine the amount of damping required to restrict actuator travel during vibration. Component design parameters such as spring rates, effective area, contamination cutting, and damping were determined by test prior to regulator final assembly. The unit was subjected to performance testing at widely ranging flow rates, temperatures, inlet pressures, and random vibration levels. A test plan for propellant compatibility and extended life tests is included

Zinc Gluconate in the Treatment of Dysgeusia—a Randomized Clinical Trial

In the treatment of dysgeusia, the use of zinc has been frequently tried, with equivocal results. The aim of the present randomized clinical trial, which involved a sufficiently large sample, was therefore to determine the efficacy of zinc treatment. Fifty patients with idiopathic dysgeusia were carefully selected. Zinc gluconate (140 mg/day; n = 26) or placebo (lactose; n = 24) was randomly assigned to the patients. The patients on zinc improved in terms of gustatory function (p < 0.001) and rated the dysgeusia as being less severe (p < 0.05). Similarly, signs of depression in the zinc group were less severe (Beck Depression Inventory, p < 0.05; mood scale, p < 0.05). With the exception of the salivary calcium level, which was higher in the zinc patients (p < 0.05), no other significant group differences were found. In conclusion, zinc appears to improve general gustatory function and, consequently, general mood scores in dysgeusia patients

Single-Particle Diffusion-Coefficient on Surfaces with Ehrlich-Schwoebel-Barriers

The diffusion coefficient of single particles in the presence of Ehrlich-Schwoebel barriers (ESB)is considered. An exact expression is given for the diffusion coefficient on linear chains with random arrangements of ESB. The results are extended to surfaces having ESB with uniform extension in one or both directions. All results are verified by Monte Carlo simulations.Comment: 11 pages, LaTeX2e, 6 eps-figure

Role of Activity in Human Dynamics

The human society is a very complex system; still, there are several non-trivial, general features. One type of them is the presence of power-law distributed quantities in temporal statistics. In this Letter, we focus on the origin of power-laws in rating of movies. We present a systematic empirical exploration of the time between two consecutive ratings of movies (the interevent time). At an aggregate level, we find a monotonous relation between the activity of individuals and the power-law exponent of the interevent-time distribution. At an individual level, we observe a heavy-tailed distribution for each user, as well as a negative correlation between the activity and the width of the distribution. We support these findings by a similar data set from mobile phone text-message communication. Our results demonstrate a significant role of the activity of individuals on the society-level patterns of human behavior. We believe this is a common character in the interest-driven human dynamics, corresponding to (but different from) the universality classes of task-driven dynamics.Comment: 5 pages, 6 figures. Accepted by EP

Significant association of a M129V independent polymorphism in the 5\prime UTR of the PRNP gene with sporadic Creutzfeldt-Jakob disease in a large German case-control study

Background: A single nucleotide polymorphism (SNP) in the coding region of the prion protein gene (PRNP) at codon 129 has been repeatedly shown to be an associated factor to sporadic Creutzfeldt-Jakob disease (sCJD), but additional major predisposing DNA variants for sCJD are still unknown. Several previous studies focused on the characterisation of polymorphisms in PRNP and the prion-like doppel gene (PRND), generating contradictory results on relatively small sample sets. Thus, extensive studies are required for validation of the polymorphisms in PRNP and PRND.Methods: We evaluated a set of nine SNPs of PRNP and one SNP of PRND in 593 German sCJD patients and 748 German healthy controls. Genotyping was performed using MALDI-TOF mass spectrometry.Results: In addition to PRNP 129, we detected a significant association between sCJD and allele frequencies of six further PRNP SNPs. No significant association of PRND T174M with sCJD was shown. We observed strong linkage disequilibrium within eight adjacent PRNP SNPs, including PRNP 129. However, the association of sCJD with PRNP 1368 and PRNP 34296 appeared to be independent on the genotype of PRNP 129. We additionally identified the most common haplotypes of PRNP to be over-represented or under-represented in our cohort of patients with sCJD.Conclusion: Our study evaluated previous findings of the association of SNPs in the PRNP and PRND genes in the largest cohorts for association study in sCJD to date, and extends previous findings by defining for the first time the haplotypes associated with sCJD in a large population of the German CJD surveillance study

Epidemiological and clinical features of travel-associated cryptosporidiosis

ABSTRACTData concerning the clinical and epidemiological features of travel-associated cryptosporidiosis are lacking. In order to investigate the impact of this disease on travellers' health, a retrospective study was conducted at the Institute of Tropical Medicine, Berlin. In total, 57 cryptosporidial infections were identified between 2000 and 2004, resulting in a prevalence of 2.9% in patients with travel-associated diarrhoea. Travel to south-central Asia, especially India, was associated with a higher prevalence of infection than was travel to other destinations. Clinically, the disease resembled giardiasis, but fever and arthralgias seemed to occur more frequently

Sound and Documentary in Cardiff and Miller's 'Pandemonium'

From 2005 to 2007, Canadian artists Janet Cardiff and George Bures Miller automated a live performance of simple robots striking furniture detritus and pipes in the cells of Eastern State Penitentiary, a Philadelphia prison that once specialized in isolation and silence. Oscillating between referential and abstract sounds, 'Pandemonium' suspended percipients between narrative and noise. So far scholars have investigated only the work's narrative aspects. This projects examines Cardiff and Miller's specific use of percussive sounds to position 'Pandemonium' in dialogue with noise music, sound art, and documentary-related practices in contemporary art. 'Pandemonium''s representational sounds coalesced into a curious kind of concrete documentary that triggered a sense of radical proximity between the percipient's body and the resonant environment of Eastern State Penitentiary. In doing so, it explored the potential for sensory relations and collectivity in a complex, contemporary world

RIM-Binding Protein 2 organizes Ca2+channel topography and regulates release probability and vesicle replenishment at a fast central synapse

RIM-Binding Protein 2 (RIM-BP2) is a multi-domain protein of the presynaptic active zone (AZ). By binding to Rab-interacting protein (RIM), bassoon and voltage-gated Ca²⁺channels (CaV), it is considered to be a central organizer of the topography of CaVand release sites of synaptic vesicles (SVs) at the AZ. Here, we investigated the role of RIM-BP2 at the endbulb of Held synapse of auditory nerve fibers with bushy cells of the cochlear nucleus, a fast relay of the auditory pathway with high release probability. Disruption of RIM-BP2 lowered release probability altering short-term plasticity and reduced evoked excitatory postsynaptic currents (EPSCs). Analysis of SV pool dynamics during high frequency train stimulation indicated a reduction of SVs with high release probability but an overall normal size of the readily releasable SV pool (RRP). The Ca2+-dependent fast component of SV replenishment after RRP depletion was slowed. Ultrastructural analysis by super-resolution light and electron microscopy revealed an impaired topography of presynaptic CaVand a reduction of docked and membrane-proximal SVs at the AZ. We conclude that RIM-BP2 organizes the topography of CaV, and promotes SV tethering and docking. This way RIM-BP2 is critical for establishing a high initial release probability as required to reliably signal sound onset information that we found to be degraded in bushy cells of RIM-BP2-deficient mice in vivo