8,706 research outputs found
Space shuttle orbit maneuvering engine reusable thrust chamber program
Tests were conducted on the regenerative cooled thrust chamber of the space shuttle orbit maneuvering engine. The conditions for the tests and the durations obtained are presented. The tests demonstrated thrust chamber operation over the nominal ranges of chamber pressure mixture ratio. Variations in auxiliary film coolant flowrate were also demonstrated. High pressure tests were conducted to demonstrate the thrust chamber operation at conditions approaching the design chamber pressure for the derivative space tug application
Response to the Letter to the Editor
This paper has attracted interest around the world from the media (both TV
and newspapers). In addition, we have received letters, emails and telephone
calls. One of our favorites was a voicemail message asking us to return a call
to Australia at which point we would learn who really killed JFK. We welcome
the opportunity to respond to the letter to the editor from Mr. Fiorentino. Mr.
Fiorentino claims that our ``statement relating to the likelihood of a second
assassin based on the premise of three or more separate bullets is demonstrably
false.'' In response we would like to simply quote from page 327 of Gerald
Posner's book Case Closed, one of the most well known works supporting the
single assassin theory: ``If Connally was hit by another bullet, it had to be
fired from a second shooter, since the Warren Commission's own reconstructions
showed that Oswald could not have operated the bolt and refired in 1.4
seconds.'' Mr. Fiorentino also claims that the ``second fatal flaw is the use
of a rather uncomplicated formula based on Bayes Theorem.'' Let denote the
evidence and denote the theory that there were just two bullets (and hence
a single shooter). We used Bayes Theorem to hypothetically calculate
from and the prior probability . In order to make ten
times more likely than , the ratio of the prior probabilities
[i.e., ] would have to be greater than 15. Thus, we again
conclude that this casts serious doubt on Dr. Guinn's conclusion that the
evidence supported just two bullets. Sadly, this is far from the first time
that probability has been misunderstood and/or misapplied in a case of public
interest. A notable British example is the Clark case. See Nobles and Schiff
(2005) for details. Finally, we welcome and, in fact, encourage members of the
scientific community to provide alternative analyses of the data.Comment: Published in at http://dx.doi.org/10.1214/07-AOAS154 the Annals of
Applied Statistics (http://www.imstat.org/aoas/) by the Institute of
Mathematical Statistics (http://www.imstat.org
Candida carriage in the alimentary tract of liver transplant candidates
Thirty randomly selected patients with advanced chronic liver disease, which had been evaluated for possible liver transplantation, were sampled endoscopically at 7 alimentary tract locations to assess the frequency and amount of Candida carriage. Eightyone percent (127/156) of the samples obtained contained Candida and 53% (82/156) yielded high counts (> 300 CFU/ml). The most predominant Candida species isolated at each site was Candida albicana, which accounted for 103 (64%) of the 160 fungal isolates. The other Candida species isolated included C tropicalis 30 (19%), C krusei 16 (10%), and C glabrata 11 (7%), Although the number of sites at which yeast was present and the quantities of yeast at each site varied widely among the patients studied, 100% of the patients had Candida in at least one site of the gastrointestinal tract. Eighty-six percent (24/28) of the duodenal aspirates contained Candida and 50% (14/28) of the duodenal samples contained greater than 300 CFU/ml. A positive culture from the stomach was a reliable predictor of the presence of Candida in the duodenum (P=0.0001), but a positive culture at no other site readily predicted the presence of Candida at yet another site. Importantly, there was no correlation between the presence or absence of Candida in either oral or rectal swabs and colonization at other anatomic sites within the gastrointestinal tract, These findings are important in liver transplantation, particularly in those cases in which the bowel has been opened to create a choledochojejunostomy anastomosis. The operative attempts to reduce gastrointestinal fungal carriage using oral antifungal agents may be justified before liver transplantation in an effort to lower the risk of posttransplantation fungal infections, particularly in those patients expected to have a Roux-en-Y choledochojejunostomy biliary reconstruction. © 1994 by Williams and Wilkins
Material Falsity in Defamation Cases: The Supreme Court\u27s Call for Contextual Analysis
In the book The Phantom Tollbooth, one of the characters, Milo, declares that he comes from a faraway land called Context. After a circuitous journey through many strange cities, bearing names that have meanings Milo struggles to understand, he finds himself back at home in his bedroom.
Context, by and large, is the home base for courts in defining the boundaries between actionable and nonactionable speech. Often, after circuitous travels through precedent and logic, courts meander back to the simple notion that the meaning and legal significance of words are determined by their context
Symplectic No-core Shell-model Approach to Intermediate-mass Nuclei
We present a microscopic description of nuclei in an intermediate-mass
region, including the proximity to the proton drip line, based on a no-core
shell model with a schematic many-nucleon long-range interaction with no
parameter adjustments. The outcome confirms the essential role played by the
symplectic symmetry to inform the interaction and the winnowing of shell-model
spaces. We show that it is imperative that model spaces be expanded well beyond
the current limits up through fifteen major shells to accommodate particle
excitations that appear critical to highly-deformed spatial structures and the
convergence of associated observables.Comment: 9 pages, 8 figure
Distinct phosphorylation clusters determines the signalling outcome of the free fatty acid receptor FFA4/GPR120
It is established that long-chain free fatty acids including ω-3 fatty acids mediate an array of biological responses through members of the free fatty acid receptor family, which includes FFA4. However, the signalling mechanisms and modes of regulation of this receptor class remain unclear. Here we employ mass spectrometry to determine that phosphorylation of mouse (m)FFAR4 occurs at five serine and threonine residues clustered in two separable regions of the C terminal tail, designated cluster 1 (Thr347, Thr349 and Ser350) and cluster 2 (Ser357 and Ser361). Mutation of these phospho-acceptor sites to alanine completely prevented phosphorylation of mFFA4 but did not limit receptor coupling to ERK1/2 activation. Rather an inhibitor of Gq/11 proteins completely prevented receptor signalling to ERK1/2. In contrast, the recruitment of arrestin 3, receptor internalization and activation of Akt were regulated by mFFA4 phosphorylation. The analysis of mFFA4 phosphorylation-dependent signalling was extended further by selective mutations of the phospho-acceptor sites. Mutations within cluster 2 did not affect agonist activation of Akt but instead significantly compromised receptor internalization and arrestin 3 recruitment. Distinctly, mutation of the phospho-acceptor sites within cluster 1 had no effect on receptor internalization and a less extensive effect on arrestin 3 recruitment, but significantly uncoupled the receptor from Akt activation. These unique observations define differential effects on signalling mediated by phosphorylation at distinct locations. This hallmark feature supports the possibility that the signalling outcome of mFFA4 activation can be determined by the pattern of phosphorylation (phosphorylation barcode) at the C-terminus of the receptor
High efficiency GaAs-Ge tandem solar cells grown by MOCVD
High conversion efficiency and low weight are obviously desirable for solar cells intended for space applications. One promising structure is GaAs on Ge. The advantages of using Ge wafers as substrates include the following: they offer high efficiency by forming a two-junction tandem cell; low weight combined with superior strength allows usage of thin (3 mil) wafers; and they are a good substrate for GaAs, being lattice matched, thermal expansion matched, and available as large-area wafers
On the nature of the deeply embedded protostar OMC-2 FIR 4
We use mid-infrared to submillimeter data from the Spitzer, Herschel, and
APEX telescopes to study the bright sub-mm source OMC-2 FIR 4. We find a point
source at 8, 24, and 70 m, and a compact, but extended source at 160, 350,
and 870 m. The peak of the emission from 8 to 70 m, attributed to the
protostar associated with FIR 4, is displaced relative to the peak of the
extended emission; the latter represents the large molecular core the protostar
is embedded within. We determine that the protostar has a bolometric luminosity
of 37 Lsun, although including more extended emission surrounding the point
source raises this value to 86 Lsun. Radiative transfer models of the
protostellar system fit the observed SED well and yield a total luminosity of
most likely less than 100 Lsun. Our models suggest that the bolometric
luminosity of the protostar could be just 12-14 Lsun, while the luminosity of
the colder (~ 20 K) extended core could be around 100 Lsun, with a mass of
about 27 Msun. Our derived luminosities for the protostar OMC-2 FIR 4 are in
direct contradiction with previous claims of a total luminosity of 1000 Lsun
(Crimier et al 2009). Furthermore, we find evidence from far-infrared molecular
spectra (Kama et al. 2013, Manoj et al. 2013) and 3.6 cm emission (Reipurth et
al 1999) that FIR 4 drives an outflow. The final stellar mass the protostar
will ultimately achieve is uncertain due to its association with the large
reservoir of mass found in the cold core.Comment: Accpeted by ApJ, 17 pages, 11 figure
Isolation and Identification of Fungi Associated with Raw Groundnut Seeds Sold at Four major markets in Port Harcourt Metropolis, Rivers State
The isolation and identification of fungi associated with raw groundnut seeds obtained from four major markets in Port Harcourt Metropolis was carried out in the Department of Plant Science and Biotechnology Laboratory (Pathology unit) in a Completely Randomized Design (CRD) using standard procedures. The identified fungal isolates include Aspergillus, Penicilium, Mucor, Rhizopus and Fusarium species. Aspergillus spp. with a mean value of 2.0 was the predominant fungi (P<0.05) identified followed by Fusarium spp. (1.1) and the least was Penicillium spp. (0.5). Mile three market recorded the highest (P<0.05) fungal incidence with a mean value of 1.44, followed by Mile one market (1.40) and the lowest was Rumuokoro market (0.70). Large seeds were more prone to fungal contamination with a mean of 1.2 than small seeds (1.0). Similarly, unwholesome seeds recorded the highest (P<0.05) amount of fungal incidence with a mean of 1.7 than wholesome seeds (0.5). Public awareness should be carried out on personal hygiene of food vendors, market sanitation, storage conditions and management practices for improving the quality of raw groundnut seeds sold in Port Harcourt markets to reduce contamination level. Keywords: Raw groundnut, seed size, healthiness, market and Fungi
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