7,340 research outputs found
Fiber optic microphone having a pressure sensing reflective membrane and a voltage source for calibration purpose
A fiber optic microphone is provided for measuring fluctuating pressures. An optical fiber probe having at least one transmitting fiber for transmitting light to a pressure-sensing membrane and at least one receiving fiber for receiving light reflected from a stretched membrane is provided. The pressure-sensing membrane may be stretched for high frequency response. Further, a reflecting surface of the pressure-sensing membrane may have dimensions which substantially correspond to dimensions of a cross section of the optical fiber probe. Further, the fiber optic microphone can be made of materials for use in high temperature environments, for example greater than 1000 F. A fiber optic probe is also provided with a back plate for damping membrane motion. The back plate further provides a means for on-line calibration of the microphone
High temperature fiber optic microphone having a pressure-sensing reflective membrane under tensile stress
A fiber optic microphone is provided for measuring fluctuating pressures. An optical fiber probe having at least one transmitting fiber for transmitting light to a pressure-sensing membrane and at least one receiving fiber for receiving light reflected from a stretched membrane is provided. The pressure-sensing membrane may be stretched for high frequency response. Further, a reflecting surface of the pressure-sensing membrane may have dimensions which substantially correspond to dimensions of a cross section of the optical fiber probe. Further, the fiber optic microphone can be made of materials for use in high temperature environments, for example greater than 1000 F. A fiber optic probe is also provided with a backplate for damping membrane motion. The backplate further provides a means for on-line calibration of the microphone
Experiments in swine feeding. The value of corn and supplementary feeds for pork production.
Corn must necessarily be more freely used than any other concentrated feed for pigs in the Corn Belt, because if properly used it is especially well adapted to pig feeding and can usually be marketed in this way to the very best advantage. But it is generally coming to be recognized that so far as health, thrift and rapidity of gains are concerned, corn alone, at least in dry lot feeding, does not give as satisfactory results, especially for growing pigs, as a combination of corn and some feed adding protein to the ration. Wheat shorts is very commonly considered as the best feed to use with corn for young pigs, but other feeds are. upon the market which contain still larger quantities of protein and their merits for pig feeding deserve investigation. If a small reduction in the cost of feeding each- hog in Iowa can be effected by the judicious uses of these feeds, the aggregate for the state will be enormous. Iowa has 7,947,000 hogs, which, with the exception of Illinois with her 4,684,000, is more than twice as many as any other state and about one-sixth the total number in the United States. During the past season Iowa raised more corn than any other state, the crop being about 388,000,000 bushels. With feeds at the usual prices, it is an easy matter by their judicious selection to so supplement com as to add five to fifteen cents per bushel to the profit from feeding corn, thus effecting a reduction of 50 cents to $1.00 on each 100 lbs. gain in weight by the pigs. In the aggregate, if these modest profits are realized they will amount to millions of dollars to Iowa farmers
LIMS Instrument Package (LIP) balloon experiment: Nimbus 7 satellite correlative temperature, ozone, water vapor, and nitric acid measurements
The Limb Infrared Monitor of the Stratosphere (LIMS) LIP balloon experiment was used to obtain correlative temperature, ozone, water vapor, and nitric acid data at altitudes between 10 and 36 kilometers. The performance of the LIMS sensor flown on the Nimbus 7 Satellite was assessed. The LIP consists of the modified electrochemical concentration cell ozonesonde, the ultraviolet absorption photometric of ozone, the water vapor infrared radiometer sonde, the chemical absorption filter instrument for nitric acid vapor, and the infrared radiometer for nitric acid vapor. The limb instrument package (LIP), its correlative sensors, and the resulting data obtained from an engineering and four correlative flights are described
Giardia Cyst Wall Protein 1 Is a Lectin That Binds to Curled Fibrils of the GalNAc Homopolymer
The infectious and diagnostic stage of Giardia lamblia (also known as G. intestinalis or G. duodenalis) is the cyst. The Giardia cyst wall contains fibrils of a unique β-1,3-linked N-acetylgalactosamine (GalNAc) homopolymer and at least three cyst wall proteins (CWPs) composed of Leu-rich repeats (CWPLRR) and a C-terminal conserved Cys-rich region (CWPCRR). Our goals were to dissect the structure of the cyst wall and determine how it is disrupted during excystation. The intact Giardia cyst wall is thin (~400 nm), easily fractured by sonication, and impermeable to small molecules. Curled fibrils of the GalNAc homopolymer are restricted to a narrow plane and are coated with linear arrays of oval-shaped protein complex. In contrast, cyst walls of Giardia treated with hot alkali to deproteinate fibrils of the GalNAc homopolymer are thick (~1.2 µm), resistant to sonication, and permeable. The deproteinated GalNAc homopolymer, which forms a loose lattice of curled fibrils, is bound by native CWP1 and CWP2, as well as by maltose-binding protein (MBP)-fusions containing the full-length CWP1 or CWP1LRR. In contrast, neither MBP alone nor MBP fused to CWP1CRR bind to the GalNAc homopolymer. Recombinant CWP1 binds to the GalNAc homopolymer within secretory vesicles of Giardia encysting in vitro. Fibrils of the GalNAc homopolymer are exposed during excystation or by treatment of heat-killed cysts with chymotrypsin, while deproteinated fibrils of the GalNAc homopolymer are degraded by extracts of Giardia cysts but not trophozoites. These results show the Leu-rich repeat domain of CWP1 is a lectin that binds to curled fibrils of the GalNAc homopolymer. During excystation, host and Giardia proteases appear to degrade bound CWPs, exposing fibrils of the GalNAc homopolymer that are digested by a stage-specific glycohydrolase. Author SummaryWhile the walls of plants and fungi contain numerous sugar homopolymers (cellulose, chitin, and β-1,3-glucans) and dozens of proteins, the cyst wall of Giardia is relatively simple. The Giardia wall contains a unique homopolymer of β-1,3-linked N-acetylgalactosamine (GalNAc) and at least three cyst wall proteins (CWPs), each of which is composed of Leu-rich repeats and a C-terminal Cys-rich region. The three major discoveries here are: 1) Fibrils of the GalNAc homopolymer are curled and form a lattice that is compressed into a narrow plane by bound protein in intact cyst walls. 2) Leu-rich repeats of CWP1 form a novel lectin domain that is specific for fibrils of the GalNAc homopolymer, which can be isolated by methods used to deproteinate fungal walls. 3) A cyst-specific glycohydrolase is able to degrade deproteinated fibrils of the GalNAc homopolymer. We incorporate these findings into a new curled fiber and lectin model of the intact Giardia cyst wall and a protease and glycohydrolase model of excystation.National Institutes of Health (AI048082, AI44070, GM31318, RR1088
Executive function in first-episode schizophrenia
BACKGROUND: We tested the hypothesis that schizophrenia is primarily a frontostriatal disorder by examining executive function in first-episode patients. Previous studies have shown either equal decrements in many cognitive domains or specific deficits in memory. Such studies have grouped test results or have used few executive measures, thus, possibly losing information. We, therefore, measured a range of executive ability with tests known to be sensitive to frontal lobe function.
METHODS: Thirty first-episode schizophrenic patients and 30 normal volunteers, matched for age and NART IQ, were tested on computerized test of planning, spatial working memory and attentional set shifting from the Cambridge Automated Neuropsychological Test Battery. Computerized and traditional tests of memory were also administered for comparison. RESULTS: Patients were worse on all tests but the profile was non-uniform. A componential analysis indicated that the patients were characterized by a poor ability to think ahead and organize responses but an intact ability to switch attention and inhibit prepotent responses. Patients also demonstrated poor memory, especially for free recall of a story and associate learning of unrelated word pairs.
CONCLUSIONS: In contradistinction to previous studies, schizophrenic patients do have profound executive impairments at the beginning of the illness. However, these concern planning and strategy use rather than attentional set shifting, which is generally unimpaired. Previous findings in more chronic patients, of severe attentional set shifting impairment, suggest that executive cognitive deficits are progressive during the course of schizophrenia. The finding of severe mnemonic impairment at first episode suggests that cognitive deficits are not restricted to one cognitive domain
The value of corn, oil meal, cottonseed meal, and gluten feed in work horse rations
These experiments have not been continued long enough with each feed to suggest infallible conclusions. The work has been carried through two years, however, under excellent conditions for accurate work, and there has been in the fundamental effects of the rations a close similarity of results with the different pairs of horses. While the subject merits more extended study, and future work might give somewhat different results, it seems that the results already obtained justify the following conclusions:
1. The health, spirit, and endurance of work horses were the same when fed corn with a moderate amount of oil meal, or gluten feed, or cottonseed meal; as when fed a corn and oats ration supplying a similar nutritive ratio.
2. The ration of corn and oil meal maintained the weight, flesh, and appearance of the horses fully as well and with less expense than the one of similar nutritive value composed of corn and oats
Fcc-bcc transition for Yukawa interactions determined by applied strain deformation
Calculations of the work required to transform between bcc and fcc phases
yield a high-precision bcc-fcc transition line for monodisperse point Yukawa
(screened-Couloumb) systems. Our results agree qualitatively but not
quantitatively with previously published simulations and phenomenological
criteria for the bcc-fcc transition. In particular, the bcc-fcc-fluid triple
point lies at a higher inverse screening length than previously reported.Comment: RevTex4, 9 pages, 6 figures. Discussion of phase coexistence
extended, a few other minor clarifications added, referencing improved.
Accepted for publication by Physical Review
Matching Conditions in Atomistic-Continuum Modeling of Materials
A new class of matching condition between the atomistic and continuum regions
is presented for the multi-scale modeling of crystals. They ensure the accurate
passage of large scale information between the atomistic and continuum regions
and at the same time minimize the reflection of phonons at the interface. These
matching conditions can be made adaptive if we choose appropriate weight
functions. Applications to dislocation dynamics and friction between
two-dimensional atomically flat crystal surfaces are described.Comment: 6 pages, 4 figure
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