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Sample records for short communication high

  1. Robust Short-Pulse, High-Peak-Power Laser Transmitter for Optical Communications

    NASA Technical Reports Server (NTRS)

    Wright, Malcolm W.

    2009-01-01

    We report on a pulsed fiber based master oscillator power amplifier laser at 1550 nm to support moderate data rates with high peak powers in a compact package suitable for interplanetary optical communications. To accommodate pulse position modulation, the polarization maintaining laser transmitter generates pulses from 0.1 to 1 ns with variable duty cycle over a pulse repetition frequency range of 10 to 100 MHz.

  2. Short-range communication system

    NASA Technical Reports Server (NTRS)

    Alhorn, Dean C. (Inventor); Howard, David E. (Inventor); Smith, Dennis A. (Inventor)

    2012-01-01

    A short-range communication system includes an antenna, a transmitter, and a receiver. The antenna is an electrical conductor formed as a planar coil with rings thereof being uniformly spaced. The transmitter is spaced apart from the plane of the coil by a gap. An amplitude-modulated and asynchronous signal indicative of a data stream of known peak amplitude is transmitted into the gap. The receiver detects the coil's resonance and decodes same to recover the data stream.

  3. High prevalence of intestinal zoonotic parasites in dogs from Belgrade, Serbia--short communication.

    PubMed

    Nikolić, Aleksandra; Dimitrijević, Sanda; Katić-Radivojević, Sofija; Klun, Ivana; Bobrć, Branko; Djurković-Djaković, Olgica

    2008-09-01

    To identify areas of risk for canine-related zoonoses in Serbia, the aim of this study was to provide baseline knowledge about intestinal parasites in 151 dogs (65 household pets, 75 stray and 11 military working dogs) from Belgrade. The following parasites, with their respective prevalences, were detected: Giardia duodenalis (14.6%), Ancylostomatidae (24.5%), Toxocara canis (30.5%), Trichuris vulpis (47.0%) and Taenia-type helminths (6.6%). Of all examined dogs, 75.5% (114/151) were found to harbour at least one parasite species. Of these, mixed infections with up to four species per dog occurred in 44.7% (51/114). Infections with all detected species were significantly higher (p < 0.05) in military working (100%) and stray dogs (93.3%) versus household pets (50.8%). Among all parasites, agents with zoonotic potential including Giardia, Ancylostomatidae and Toxocara were detected in 58.3% (88/151) of all examined dogs with a significant difference (p < 0.05) among the subgroups (100%, 62.7% and 46.2% for military working dogs, stray dogs and household pets, respectively). The high prevalence of zoonotic parasites registered in the dog population from a highly urban area in south-eastern Europe indicates a potential risk to human health. Thus, veterinarians should play an important role in helping to prevent or minimise zoonotic transmission. PMID:18828485

  4. Error statistics during the propagation of short optical pulses in a high-speed fibreoptic communication line

    SciTech Connect

    Shapiro, E G

    2008-09-30

    Simple analytic expressions are derived to approximate the bit error rate for data transmission through fibreoptic communication lines. The propagation of optical pulses is directly numerically simulated. Analytic estimates are in good agreement with numerical calculations. (fibreoptic communication)

  5. Short communication: Variation in production parameters among Canadian Holstein cows classified as high, average, and low immune responders.

    PubMed

    Stoop, C L; Thompson-Crispi, K A; Cartwright, S L; Mallard, B A

    2016-06-01

    Dairy cattle evaluated for immune responses and identified as high responders are known to have a lower occurrence of economically important diseases, including mastitis, metritis, ketosis, and retained placenta. These high immune responders have also been shown to make more antibody following vaccination and to have improved milk and colostrum quality. Therefore, breeding for improved immune response is expected to have several benefits in the dairy industry. However, a concern of such an approach to improve animal health is the potential cost of lost production due to an allocation of host resources to mount a robust immune response. The objective of this study was to evaluate early- and late-lactation production parameters in cattle classified as having high, average, or low estimated breeding values (EBV) for cell-mediated (CMIR), antibody-mediated (AMIR), and overall immune responses. A total of 561 cows from 6 herds were phenotyped for immune response and ranked based on EBV for CMIR and AMIR. A linear animal model was used to evaluate differences in milk, fat, and protein yields among immune response groups, and a regression analysis was conducted based on immune response EBV. Overall, no difference in production parameters was found based on immune response rank; however, some positive relationships with immune response EBV were found, suggesting that breeding for enhanced immune responsiveness as a prophylactic approach to improve animal health would not come at the cost of lost production. PMID:27060821

  6. Short communication: Effects of molasses supplementation on performance of lactating cows fed high-alfalfa silage diets.

    PubMed

    Baurhoo, B; Mustafa, A

    2014-02-01

    Twelve Holstein cows were used in a replicated Latin square experiment to determine the effect of adding dried molasses to high-alfalfa silage diets on dairy cow performance. Three isonitrogenous diets were formulated with a 68:32 forage:concentrate ratio, with alfalfa silage as the only forage source. Dietary treatments were a control diet with no added molasses and 3 and 6% dried molasses diets. Three lactating Holstein cows fitted with ruminal cannulas were used to determine the effects of dietary treatments on ruminal fermentation. Dietary treatments had no effect on dry matter (average 23.3 kg/d), crude protein (average 4.4 kg/d), or neutral detergent fiber (average 7.4 kg/d) intake. Milk yield, energy-corrected milk (average 35.4 kg/d), and 4% fat-corrected milk (average 33.8 kg/d) were not influenced by dietary treatments. Cows fed the control diet produced milk with less milk urea nitrogen concentration than those fed molasses-supplemented diets. Ruminal pH, NH3-N concentration, and total volatile fatty acids were not different among dietary treatments. The molar proportion of acetate linearly increased, whereas the molar proportion of propionate linearly decreased as the level of dried molasses increased. It was concluded that addition of dried molasses to high-alfalfa silage diets at 6% of the diet (dry matter basis) increased milk urea nitrogen but had no effect on animal performance. PMID:24315324

  7. Short Communication An efficient method for simultaneous extraction of high-quality RNA and DNA from various plant tissues.

    PubMed

    Oliveira, R R; Viana, A J C; Reátegui, A C E; Vincentz, M G A

    2015-01-01

    Determination of gene expression is an important tool to study biological processes and relies on the quality of the extracted RNA. Changes in gene expression profiles may be directly related to mutations in regulatory DNA sequences or alterations in DNA cytosine methylation, which is an epigenetic mark. Correlation of gene expression with DNA sequence or epigenetic mark polymorphism is often desirable; for this, a robust protocol to isolate high-quality RNA and DNA simultaneously from the same sample is required. Although commercial kits and protocols are available, they are mainly optimized for animal tissues and, in general, restricted to RNA or DNA extraction, not both. In the present study, we describe an efficient and accessible method to extract both RNA and DNA simultaneously from the same sample of various plant tissues, using small amounts of starting material. The protocol was efficient in the extraction of high-quality nucleic acids from several Arabidopsis thaliana tissues (e.g., leaf, inflorescence stem, flower, fruit, cotyledon, seedlings, root, and embryo) and from other tissues of non-model plants, such as Avicennia schaueriana (Acanthaceae), Theobroma cacao (Malvaceae), Paspalum notatum (Poaceae), and Sorghum bicolor (Poaceae). The obtained nucleic acids were used as templates for downstream analyses, such as mRNA sequencing, quantitative real time-polymerase chain reaction, bisulfite treatment, and others; the results were comparable to those obtained with commercial kits. We believe that this protocol could be applied to a broad range of plant species, help avoid technical and sampling biases, and facilitate several RNA- and DNA-dependent analyses. PMID:26782533

  8. Short communication: low-fat ice cream flavor not modified by high hydrostatic pressure treatment of whey protein concentrate.

    PubMed

    Chauhan, J M; Lim, S-Y; Powers, J R; Ross, C F; Clark, S

    2010-04-01

    The purpose of this study was to examine flavor binding of high hydrostatic pressure (HHP)-treated whey protein concentrate (WPC) in a real food system. Fresh Washington State University (WSU, Pullman) WPC, produced by ultrafiltration of separated Cheddar cheese whey, was treated at 300 MPa for 15 min. Commercial WPC 35 powder was reconstituted to equivalent total solids as WSU WPC (8.23%). Six batches of low-fat ice cream were produced: A) HHP-treated WSU WPC without diacetyl; B) and E) WSU WPC with 2 mg/L of diacetyl added before HHP; C) WSU WPC with 2 mg/L of diacetyl added after HHP; D) untreated WSU WPC with 2 mg/L of diacetyl; and F) untreated commercial WPC 35 with 2 mg/L of diacetyl. The solution of WSU WPC or commercial WPC 35 contributed 10% to the mix formulation. Ice creams were produced by using standard ice cream ingredients and processes. Low-fat ice creams containing HHP-treated WSU WPC and untreated WSU WPC were analyzed using headspace-solid phase microextraction-gas chromatography. Sensory evaluation by balanced reference duo-trio test was carried out using 50 untrained panelists in 2 sessions on 2 different days. The headspace-solid phase microextraction-gas chromatography analysis revealed that ice cream containing HHP-treated WSU WPC had almost 3 times the concentration of diacetyl compared with ice cream containing untreated WSU WPC at d 1 of storage. However, diacetyl was not detected in ice creams after 14 d of storage. Eighty percent of panelists were able to distinguish between low-fat ice creams containing untreated WSU WPC with and without diacetyl, confirming panelists' ability to detect diacetyl. However, panelists were not able to distinguish between low-fat ice creams containing untreated and HHP-treated WSU WPC with diacetyl. These results show that WPC diacetyl-binding properties were not enhanced by 300-MPa HHP treatment for 15 min, indicating that HHP may not be suitable for such applications. PMID:20338422

  9. [Oral communication: short history and some rules].

    PubMed

    Panini, Roberta; Fiorini, Fulvio

    2015-01-01

    The verbal communication represents the first human communication, that even more used and one most immediate. History and the development of communication is divided into historical periods, is complex and is bound to the period contingencies and to the social reference community. The oral communication is never isolated but is always taken by the not verbal one, including the silences, the position and the spaces (c.d. proxemics). The good communicator stimulates the cooperation through the conversation rule respect (qualities, amounts, way and relation) and reduces the possible asymmetry between broadcaster and receiver fitting its code to that of the interlocutor. PMID:26005935

  10. A Short History of Electrical Communication.

    ERIC Educational Resources Information Center

    Federal Communications Commission, Washington, DC.

    Electrical communication progressed rapidly after Samuel Morse demonstrated the telegraph in 1838. Western Union completed the first transcontinental telegraph line in 1861. Five years later the first transoceanic cable was laid. In 1875 A.G. Bell transmitted the first complete sentence heard over wire, and the first Bell telephone company was…

  11. Short-range communications using diffusely scattered infrared radiation

    NASA Astrophysics Data System (ADS)

    Kotzin, M. D.

    Short range optical communication using diffusely scattered infrared radiation is examined. Aspects which relate to providing multichannel and duplex capability when one end of the link is not fixed, are considered. A link comparison is made between optical and microwave systems of similar complexity. Although it is shown that the optical system is not as sensitive as its microwave counterpart for typical ambient infrared backgrounds, it is advantageous with regard to spectrum availability and reuse, immunity from multipath distortion, and the maturity of the technology. Characteristics of the optical scatter propagation path are investigated using a static analytical model. Measurements of dynamic path loss provide data for the portable application. A signal to noise ratio enhancement is obtained by the use of short high power optical pulses. Selection of a digital modulation format permits the application of time division multiplex techniques to achieve the desired duplex and multichannel capability. System capabilities are demonstrated to be strongly influenced by device limitations, especially the light emitting diode (led) sources. A method of obtained receiver gain using detector optics is described and explained. Finally, the analysis and measured data are used to guide the design of a prototype portable telephone system providing two full duplex audio channels using digitally encoded speech is described.

  12. Short communication: synthesis and applications of Coumarin.

    PubMed

    Kinza Aslam, Kinza; Khosa, M Kaleem; Jahan, Nazish; Nosheen, Sofia

    2010-10-01

    In this work, coumarin was synthesized by Perkin reaction using salicylaldehyde, acetic acid and sodium acetate. Due to the misuse of acetic anhydride in narcotics synthesis, acetic acid was substituted for acetic anhydride in Perkin reaction. On the basis of this substitution a hypothesis was proposed that "acetic acid could be substituted as an acetylating agent in place of acetic anhydride in coumarin synthesis via Perkin reaction". In the present research project, salicylaldehyde was prepared from phenol, sodium hydroxide and chloroform for further procedure. Then four different coumarin samples were synthesized by changing the parameter of reactants proportions. From this parameter, we designed a trend of high product yield. Yields of Coumarin samples will lead towards either acceptance or rejection of the above proposed hypothesis. In the next step, these Coumarin samples were characterized by age yield (%), solubility and melting points. At last Antibacterial activities of all the four coumarin samples were evaluated against two bacterial strains; E.coli and S.aureus. As a consequence of all above, it was inferred that the yields of all coumarin samples obtained were low as compared to the yield obtained by the use of acetic anhydride in previous reports. This led to the rejection of proposed hypothesis. Among four Coumarin samples, sample-4 obtained by taking equal amounts of all the reactants had shown maximum yield, best characterization and excellent antibacterial activity. In spite of low yields obtained, the remarkable antibacterial activities of Coumarin samples have enabled us to suggest coumarin as a strong antibacterial agent and it must be employed for further applications. PMID:20884461

  13. When the facts are just not enough: Credibly communicating about risk is riskier when emotions run high and time is short

    SciTech Connect

    Reynolds, Barbara J.

    2011-07-15

    When discussing risk with people, commonly subject matter experts believe that conveying the facts will be enough to allow people to assess a risk and respond rationally to that risk. Because of this expectation, experts often become exasperated by the seemingly illogical way people assess personal risk and choose to manage that risk. In crisis situations when the risk information is less defined and choices must be made within impossible time constraints, the thought processes may be even more susceptible to faulty heuristics. Understanding the perception of risk is essential to understanding why the public becomes more or less upset by events. This article explores the psychological underpinnings of risk assessment within emotionally laden events and the risk communication practices that may facilitate subject matter experts to provide the facts in a manner so they can be more certain those facts are being heard. Source credibility is foundational to risk communication practices. The public meeting is one example in which these best practices can be exercised. Risks are risky because risk perceptions differ and the psychosocial environment in which risk is discussed complicates making risk decisions. Experts who want to influence the actions of the public related to a threat or risk should understand that decisions often involve emotional as well as logical components. The media and other social entities will also influence the risk context. The Center for Disease Control and Prevention's crisis and emergency-risk communication (CERC) principles are intended to increase credibility and recognize emotional components of an event. During a risk event, CERC works to calm emotions and increase trust which can help people apply the expertise being offered by response officials.

  14. Single, high-dose 17β-estradiol therapy has anti-apoptotic effect and induces cerebral plasticity following transient forebrain ischemia in gerbils (Short communication).

    PubMed

    Wappler, Edina A; Gál, A; Skopál, J; Nagy, Z

    2011-06-01

    Although much is known about the protective effect of acute estrogen therapy in cerebral ischemia, relatively little is known about the importance of apoptosis and cerebral plasticity in this mechanism. In this work 10 min global cerebral ischemia was produced by transient bilateral carotid occlusion in 4-month-old ovariectomized female gerbils. In every of our experimental group (sham for ischemia group, ischemia group and ischemia + a high, single dose 17β-estradiol pre-treatment group) apoptotic (bcl-Xl, bax) and cerebral plasticity (GAP-43, synapsin-I, nestin) hippocampal genes' expression was measured four days after surgery. Expression of the anti-apoptotic bcl-Xl (p<0.01) and the cerebral plasticity marker synapsin-I and nestin (p<0.01) increased with acute estrogen pretreatment in ischemic animals. No change, however, in bax or GAP-43 expression was detected in estrogen treated animals compared to ischemic gerbils. These results suggest that acute estrogen therapy has anti-apoptotic effect and increases cerebral plasticity, which play an important role in cytoprotection or cerebroprotection. PMID:21616777

  15. Short communication: Quantification of carbohydrates in whey permeate products using high-performance anion-exchange chromatography with pulsed amperometric detection

    PubMed Central

    Lee, Hyeyoung; de MeloSilva, Vitor Luiz; Liu, Yan

    2016-01-01

    A method was developed for the characterization and quantification of the disaccharide lactose and 3 major bovine milk oligosaccharides (BMO) in dairy streams. Based on high-performance anion-exchange chromatography-pulsed amperometric detection (HPAE-PAD), this method is advantageous because it requires minimal sample preparation and achieves good chromatographic separation of oligosaccharide isomers within 30 min. The linear dynamic range and limit of detection were 0.1 to 10 mg/L and 0.03 to 0.22 mg/L, respectively. Mean recoveries of the BMO were excellent and ranged from 98.4 to 100.4%. Without complicated sample preparation procedures, this HPAE-PAD method measured BMO [3′-sialyllactose (3′SL), 6′-sialyllactose (6′SL), and 6′-sialyllactosamine (6′SLN)] and lactose using a single instrument, therefore increasing the accuracy of the measurement and applicability for the dairy industry. In colostrum whey permeate, 3′SL, 6′SL, and 6′SLN were 94, 29, and 46 mg/L, respectively. This work is the first to demonstrate that some commercial products, currently marketed for supporting a healthy immune system, contain significant amounts of bioactive BMO and therefore, carry additional bioactivities. PMID:26364096

  16. Short communication: Variation of total immunoglobulin G and β-lactoglobulin concentrations in colostrum and milk from Canadian Holsteins classified as high, average, or low immune responders.

    PubMed

    Fleming, K; Thompson-Crispi, K A; Hodgins, D C; Miglior, F; Corredig, M; Mallard, B A

    2016-03-01

    The objective of this study was to evaluate IgG and β-lactoglobulin (β-LG) concentrations in colostrum and milk of Canadian Holsteins (n=108) classified as high (H), average (A), or low (L) for antibody-mediated (AMIR) or cell-mediated immune responses (CMIR) based on estimated breeding values. It was hypothesized that H-AMIR and H-CMIR cows produce colostrum (first milking) and milk (d 5 postcalving) with higher concentrations of IgG and β-LG. Data for IgG and β-LG in colostrum and milk were analyzed independently using mixed linear models. Least squares means were compared using Tukey's test. Cows classified as H-AMIR had higher IgG and β-LG concentrations in colostrum compared with A- and L-AMIR cows; 84% of H-AMIR, 69% of A-AMIR, and 68% of L-AMIR cows had over 5,000mg/dL IgG in colostrum. No differences in IgG and β-LG concentrations in colostrum were noted among cows ranked on CMIR or in milk of cows ranked on AMIR. β-Lactoglobulin and IgG concentrations were positively correlated in colostrum. Breeding cows for H-AMIR status may reduce failure of passive transfer of IgG in their calves; β-LG may play a role in bovine immune defenses. Colostrum from H-AMIR cows may serve as a more economical feedstock source for manufacturing natural health products. PMID:26774725

  17. Short communication: Effects of molasses products on productivity and milk fatty acid profile of cows fed diets high in dried distillers grains with solubles.

    PubMed

    Siverson, A; Vargas-Rodriguez, C F; Bradford, B J

    2014-01-01

    Previous research has shown that replacing up to 5% [of dietary dry matter (DM)] corn with cane molasses can partially alleviate milk fat depression when cows are fed high-concentrate, low-fiber rations containing dried distillers grains with solubles. The primary objective of this study was to determine whether dietary molasses alters milk fatty acid (FA) profile or improves solids-corrected milk yield in the context of a more typical lactation diet. A secondary objective was to assess production responses to increasing rumen-degradable protein supply when molasses was fed. Twelve primiparous and 28 multiparous Holstein cows (196 39 d in milk) were blocked by parity and assigned to 4 pens. Pens were randomly allocated to treatment sequence in a 4 4 Latin square design, balanced for carryover effects. Treatment periods were 21 d, with 17 d for diet adaptation and 4 d for sample and data collection. Treatments were a control diet, providing 20% dried distillers grains with solubles (DM basis), 35% neutral detergent fiber, 30% starch, and 5% ether extract; a diet with 4.4% cane molasses replacing a portion of the corn grain; a diet with 2.9% molasses supplement containing 32% crude protein on a DM basis; and a diet with 5.8% (DM basis) molasses supplement. Animal-level data were analyzed using mixed models, including the fixed effect of treatment and the random effects of period, pen, period pen interaction, and cow within pen to recognize pen as the experimental unit. Diets did not alter DM intake, milk production, milk component concentration or yield, feed efficiency (DM intake/milk yield), body weight change, or milk somatic cell count. Milk stearic acid content was increased by the diet containing 5.8% molasses supplement compared with the control diet and the diet containing 2.9% molasses supplement, but the magnitude of the effect was small (12.27, 11.75, and 11.69 0.29 g/100g of FA). Production data revealed a dramatic effect of period on milk fat content and yield. Milk fat content decreased during the course of the experiment (least squares means = 3.16, 2.81, 2.93, and 2.64 0.09% for periods 1 to 4, respectively), as did milk fat yield (1.20, 1.03, 0.98, and 0.79 0.05 kg/d). Exchanging molasses-based products for corn at 2.9 to 5.8% of dietary DM did not influence productivity and had minute effects on milk FA profile. The limited responses in this study may have been influenced by dietary unsaturated FA content or the advancing stage of lactation of cows in the study. PMID:24746128

  18. High current short pulse ion sources

    SciTech Connect

    Leung, K.N.

    1996-08-01

    High current short pulse ion beams can be generated by using a multicusp source. This is accomplished by switching the arc or the RF induction discharge on and off. An alternative approach is to maintain a continuous plasma discharge and extraction voltage but control the plasma flow into the extraction aperture by a combination of magnetic and electric fields. Short beam pulses can be obtained by using a fast electronic switch and a dc bias power supply. It is also demonstrated that very short beam pulses ({approximately} 10 {micro}s) with high repetition rate can be formed by a laser-driven LaB{sub 6} or barium photo-cathode.

  19. Signal-source trackers on Infrared-based Dedicated Short-Range Communication

    NASA Astrophysics Data System (ADS)

    Lu, Po-Wen; Chen, Rongshun

    2010-03-01

    Location-based ITS applications, especially the applications based on Vehicle-to-Vehicle (V2V) communication, require the absolute or relative location information of the communicating objects. GPS receivers are often used to give the absolute locations of the objects. However, the updating rate and the resolution of GPS receivers are not sufficient for neighboring and highly mobile vehicles. This paper renders two designs, a one-dimensional IR signal-source tracker and a two-dimensional IR signal-source tracker, to estimate the location of a communicating target. By analyzing the strength of the received signal, the relative location of the target is identified once the communication data are received. The realized 1D and 2D IR signal-source tracker can give the precise location, where the repeated tests on the 2D tracker show the given locations with low deviation. Since these two tracker designs are realized with the same IR components in the Dedicated Short-Range Communication (DSRC), the communicating devices, the roadside unit (RSU) and the onboard unit (OBU), can use the 1D or 2D tracker design depending on the application to locate each other, and then to control the radiation direction for saving power, to facilitate the completeness of transactions, and to locate vehicles in V2V applications. In this work, the proposed devices are designed, realized and tested. The experimental results show that these two designs are feasible.

  20. Systems and methods for short range RF communication

    NASA Technical Reports Server (NTRS)

    Ross, John Anderson Fergus (Inventor); Tomlinson, Harold Woodruff (Inventor); Sexton, Daniel White (Inventor); Hershey, John Erik (Inventor); DeCristofaro, Richard Anthony (Inventor)

    2012-01-01

    A method transmitting a message over at least one of a plurality of channels of a communications network is provided. The method comprises the steps of detecting a presence of jamming pulses in the at least one of the plurality of channels. The characteristics of the jamming pulses in the at least one of the plurality of channels is determined wherein the determined characteristics define at least interstices between the jamming pulses. The message is transmitted over the at least one of the plurality of channels wherein the message is transmitted within the interstices of the jamming pulse determined from the step of determining characteristics of the jamming pulses.

  1. A high temperature superconductivity communications flight experiment

    NASA Technical Reports Server (NTRS)

    Ngo, P.; Krishen, K.; Arndt, D.; Raffoul, G.; Karasack, V.; Bhasin, K.; Leonard, R.

    1992-01-01

    The proposed high temperature superconductivity (HTSC) millimeter-wave communications flight experiment from the payload bay of the Space Shuttle Orbiter to the Advanced Communications Technology Satellite (ACTS) in geosynchronous orbit is described. The experiment will use a Ka-band HTSC phased array antenna and front-end electronics to receive a downlink communications signal from the ACTS. The discussion covers the system configuration, a description of the ground equipment, the spacecraft receiver, link performance, thermal loading, and the superconducting antenna array.

  2. Short range RF communication for jet engine control

    NASA Technical Reports Server (NTRS)

    Sexton, Daniel White (Inventor); Hershey, John Erik (Inventor)

    2007-01-01

    A method transmitting a message over at least one of a plurality of radio frequency (RF) channels of an RF communications network is provided. The method comprises the steps of detecting a presence of jamming pulses in the at least one of the plurality of RF channels. The characteristics of the jamming pulses in the at least one of the plurality of RF channels is determined wherein the determined characteristics define at least interstices between the jamming pulses. The message is transmitted over the at least one of the plurality of RF channels wherein the message is transmitted within the interstices of the jamming pulse determined from the step of determining characteristics of the jamming pulses.

  3. High performance computing and communications program

    NASA Technical Reports Server (NTRS)

    Holcomb, Lee

    1992-01-01

    A review of the High Performance Computing and Communications (HPCC) program is provided in vugraph format. The goals and objectives of this federal program are as follows: extend U.S. leadership in high performance computing and computer communications; disseminate the technologies to speed innovation and to serve national goals; and spur gains in industrial competitiveness by making high performance computing integral to design and production.

  4. Empirical Analysis on the Human Dynamics of a Large-Scale Short Message Communication System

    NASA Astrophysics Data System (ADS)

    Zhao, Zhi-Dan; Xia, Hu; Shang, Ming-Sheng; Zhou, Tao

    2011-06-01

    Research on human behavior has attracted increasing attention recently because of its scientific significance and potential applications. Some empirical results have indicated that the timing of many human activities follows non-Poisson statistics. We analyze a real-life huge dataset of short message communication with 6326713 users and 37577781 records during the 2006 Chinese New Year. The results show that the number of short message sendings, the interevent time between two consecutive short message sendings and the response time all follow heavy-tailed distribution. We further observe a strongly positive correlation between the activity and the power-law exponent of the interevent time distribution. In addition, the short message communication system displays a bursty property yet no memory effects, which is in particular different from some well-studied human-activited systems such as email-sending, library-loaning and file printing.

  5. Spacecraft design project: High latitude communications satellite

    NASA Technical Reports Server (NTRS)

    Josefson, Carl; Myers, Jack; Cloutier, Mike; Paluszek, Steve; Michael, Gerry; Hunter, Dan; Sakoda, Dan; Walters, Wes; Johnson, Dennis; Bauer, Terry

    1989-01-01

    The spacecraft design project was part of AE-4871, Advanced Spacecraft Design. The project was intended to provide experience in the design of all major components of a satellite. Each member of the class was given primary responsibility for a subsystem or design support function. Support was requested from the Naval Research Laboratory to augment the Naval Postgraduate School faculty. Analysis and design of each subsystem was done to the extent possible within the constraints of an eleven week quarter and the design facilities (hardware and software) available. The project team chose to evaluate the design of a high latitude communications satellite as representative of the design issues and tradeoffs necessary for a wide range of satellites. The High-Latitude Communications Satellite (HILACS) will provide a continuous UHF communications link between stations located north of the region covered by geosynchronous communications satellites, i.e., the area above approximately 60 N latitude. HILACS will also provide a communications link to stations below 60 N via a relay Net Control Station (NCS), which is located with access to both the HILACS and geosynchronous communications satellites. The communications payload will operate only for that portion of the orbit necessary to provide specified coverage.

  6. Acoustic communication in two freshwater gobies: ambient noise and short-range propagation in shallow streams.

    PubMed

    Lugli, M; Fine, M L

    2003-07-01

    Noise is an important theoretical constraint on the evolution of signal form and sensory performance. In order to determine environmental constraints on the communication of two freshwater gobies Padogobius martensii and Gobius nigricans, numerous noise spectra were measured from quiet areas and ones adjacent to waterfalls and rapids in two shallow stony streams. Propagation of goby sounds and waterfall noise was also measured. A quiet window around 100 Hz is present in many noise spectra from noisy locations. The window lies between two noise sources, a low-frequency one attributed to turbulence, and a high-frequency one (200-500 Hz) attributed to bubble noise from water breaking the surface. Ambient noise from a waterfall (frequencies below 1 kHz) attenuates as much as 30 dB between 1 and 2 m, after which values are variable without further attenuation (i.e., buried in the noise floor). Similarly, courtship sounds of P. martensii attenuate as much as 30 dB between 5 and 50 cm. Since gobies are known to court in noisy as well as quiet locations in these streams, their acoustic communication system (sounds and auditory system) must be able to cope with short-range propagation dictated by shallow depths and ambient noise in noisy locations. PMID:12880062

  7. SHORT COMMUNICATION: An image processing approach to calibration of hydrometers

    NASA Astrophysics Data System (ADS)

    Lorefice, S.; Malengo, A.

    2004-06-01

    The usual method adopted for multipoint calibration of glass hydrometers is based on the measurement of the buoyancy by hydrostatic weighing when the hydrometer is plunged in a reference liquid up to the scale mark to be calibrated. An image processing approach is proposed by the authors to align the relevant scale mark with the reference liquid surface level. The method uses image analysis with a data processing technique and takes into account the perspective error. For this purpose a CCD camera with a pixel matrix of 604H × 576V and a lens of 16 mm focal length were used. High accuracy in the hydrometer reading was obtained as the resulting reading uncertainty was lower than 0.02 mm, about a fifth of the usual figure with the visual reading made by an operator.

  8. Short communication: Reactivity of diacetyl with cleaning and sanitizing agents.

    PubMed

    Rincon-Delgadillo, M I; Lopez-Hernandez, A; Rankin, S A

    2013-01-01

    Diacetyl is used to impart a buttery flavor to numerous food products such as sour cream, cottage cheese, vegetable oil-based spreads, baked goods, and beverages. Recent studies have linked exposure to high concentrations of diacetyl and the onset of bronchiolitis obliterans. Due to the reported risks that diacetyl may pose, many food companies have altered practices to reduce worker exposure to diacetyl, including the use of personal respirators, improved air handling systems, and adequate cleaning practices. Commonly used cleaning and sanitizing agents may be reactive with diacetyl; however, the efficacy of these chemicals has not been studied in detail and remains unclear. The objective of this work was to study the reaction chemistry of diacetyl with common industrial cleaning and sanitizing chemicals. The reactions were assessed at equimolar concentrations and analyzed by gas chromatography-mass spectrometry. Peroxyacetic acid was most reactive with diacetyl (95% reduction in diacetyl), followed by sodium hypochlorite (76% reduction), and hydrogen peroxide (26% reduction). Benzalkonium chloride (BAC) did not react with diacetyl. Acetic acid was detected as the main product of reactions of diacetyl with peroxyacetic acid, sodium hypochlorite, and hydrogen peroxide. 1,1-Dichloro-2-propanone and 1,1,1-trichloropropanone were also identified as volatile reaction products in the sodium hypochlorite reactions. PMID:23063162

  9. Short communication: Pasteurization of milk abolishes bovine herpesvirus 4 infectivity.

    PubMed

    Bona, C; Dewals, B; Wiggers, L; Coudijzer, K; Vanderplasschen, A; Gillet, L

    2005-09-01

    Bovine herpesvirus 4 (BoHV-4) is a gammaherpesvirus highly prevalent in the cattle population that has been isolated from the milk and the serum of healthy infected cows. Several studies reported the sensitivity and the permissiveness of some human cells to BoHV-4 infection. Moreover, our recent study demonstrated that some human cells sensitive but not permissive to BoHV-4 support a persistent infection protecting them from tumor necrosis factor-alpha-induced apoptosis. Together, these observations suggested that BoHV-4 could represent a danger for public health. To evaluate the risk of human infection by BoHV-4 through milk or serum derivatives, we investigated the resistance of BoHV-4 to the mildest thermal treatments usually applied to these products. The results demonstrated that milk pasteurization and thermal decomplementation of serum abolish BoHV-4 infectivity by inactivation of its property to enter permissive cells. Consequently, our results demonstrate that these treatments drastically reduce the risk of human infection by BoHV-4 through treated milk or serum derivatives. PMID:16107396

  10. Short communication: Genetic variation of riboflavin content in bovine milk.

    PubMed

    Poulsen, Nina A; Rybicka, Iga; Larsen, Lotte B; Buitenhuis, Albert J; Larsen, Mette K

    2015-05-01

    Riboflavin (vitamin B2) is an essential water-soluble vitamin; elderly people and adolescents in particular can have poor riboflavin status. In Western diets, milk and dairy products are primary sources of riboflavin, but little is known about the natural variation within and among bovine breeds, and how genetic and environmental factors can affect the riboflavin content in milk. As a part of the Danish-Swedish Milk Genomics Initiative, the aim of the study was to quantify milk riboflavin content using reverse-phase HPLC in 2 major Danish dairy breeds. The results showed substantial interbreed differences in milk riboflavin content. Milk from Danish Jersey cows contained significantly higher levels of riboflavin (1.93mg/L of milk) than milk from Danish Holstein cows (1.40mg/L of milk). Furthermore, genetic analyses revealed high heritabilities in both breeds (0.52 for Danish Holstein and 0.31 for Danish Jersey). A genomic association study found 35 significant single nucleotide polymorphisms (false discovery rate<0.10) to be associated with riboflavin content in milk in Jersey cows (all on BTA14 and BTA17), and 511 significant single nucleotide polymorphisms in Holstein cows spread over 25 different autosomes with BTA13 and BTA14 having the most promising quantitative trait loci. The best candidate gene found within the identified quantitative trait loci was SLC52A3, a riboflavin transporter gene, which was among the significant markers on BTA13 in Holstein cows. PMID:25771056

  11. Short Communication Molecular conservation of the mammalian leptin protein.

    PubMed

    Gabriel, J E; Lidani, K C F

    2015-01-01

    In this study, we comparatively assessed multiple sequences of the leptin protein from different animal species to establish new insights into conservation degree of biological sequences and evolutionary biology among mammals using computational biology tools. First, amino acid sequences of the leptin protein from Homo sapiens (human, P41159), Sus scrofa (wild pig, Q29406), Felis catus (domestic cat, Q29406), Rattus norvegicus (rat, P50596), and Mus musculus (mouse, P41160) were randomly searched in the high-quality annotated and non-redundant protein sequence database UniProtKB/Swiss-Prot. A dendogram showing the evolutionary relationships among specimens was constructed from the sequences of interest using the Mega 6.0 software with the neighbor-joining method. The resulting tree presenting the evolutionary relationships among specimens inferred from amino acid sequences of the leptin protein in mammals demonstrated 2 main branches: 1 cluster including the rat and mouse species (0.02) and a second cluster containing both wild pig and domestic cat species grouped in a sub-branch (0.04 and 0.06, respectively), linking them to the human sequence (0.08). These findings were reinforced by comparing estimates of evolutionary divergence among leptin sequences analyzed. Based on comparative analyses of multiple sequence alignments in the present study, there was a stronger conservation degree of the leptin protein in evolutionarily close species and several conservative changes along the sequences of interest, revealing information regarding the evolutionary biology among mammals. PMID:25729957

  12. Short communication: Individual cow variation in urinary excretion of phosphorus.

    PubMed

    Løvendahl, Peter; Sehested, Jakob

    2016-06-01

    Some dairy cows excrete large amounts of P through their urine; thus, it was speculated that a genetic defect related to their efficiency in uptake of P or recirculation of P could cause such an effect. This speculation was pursued in a cross sectional study on 139 cows (103 Holstein and 36 Jersey) from an experimental herd using repeated sampling of urine (301 samples) to investigate sources of variation in urinary P concentration (Pu). Urine samples were taken on 6 testing sessions spread over 2 mo. Each sample was obtained by mild manual stimulation of the rear udder escutcheon area. The samples were immediately assayed for pH, stored frozen, and assayed for inorganic P and creatinine. Concentrations of P and creatinine in urine, the ratio of Pu to creatinine, and pH were analyzed using a linear mixed model. The model included fixed effects of breed, parity number, and sampling session. Stage of lactation was fitted as Wilmink-type lactation curves. Random effects included additive polygenic ancestry, permanent animal effects, and residual. The distribution of Pu approximated normality except for a single sample with very high Pu and very low pH. This sample came from a cow diagnosed independently with ketosis. For the remaining samples, it was shown that Pu has low to moderate heritability (0.12) and is only moderately repeatable (0.21). Based on a small data set, it is tentatively concluded that individual differences between cows exist in their Pu, and individual differences presumably result from genetic differences. However, it remains unclear if cows with genetically lower or higher Pu will perform better on a low-P diet. PMID:26995137

  13. The Impact of Business Communication Education on Students' Short- and Long-Term Performances

    ERIC Educational Resources Information Center

    Zhao, Jensen J.; Alexander, Melody W.

    2004-01-01

    The purpose of this longitudinal study was to identify the short- and long-term impact of business communication education on students' skill developments and performance outcomes. Nearly 400 students at an AACSC International-accredited business college participated in the study during their sophomore and senior years. The findings indicate that…

  14. Short-Form Versions of the Spanish MacArthur-Bates Communicative Development Inventories

    ERIC Educational Resources Information Center

    Jackson-Maldonodo, Donna; Marchman, Virginia A.; Fernald, Lia C. H.

    2013-01-01

    The Spanish-language MacArthur-Bates Communicative Development Inventories (S-CDIs) are well-established parent report tools for assessing the language development of Spanish-speaking children under 3 years. Here, we introduce the short-form versions of the S-CDIs (SFI and SFII), offered as alternatives to the long forms for screening purposes or

  15. High power communication satellites power systems study

    NASA Astrophysics Data System (ADS)

    Josloff, Allan T.; Peterson, Jerry R.

    1995-01-01

    This paper discusses a planned study to evaluate the commercial attractiveness of high power communication satellites and assesses the attributes of both conventional photovoltaic and reactor power systems. These high power satellites can play a vital role in assuring availability of universally accessible, wide bandwidth communications, for high definition TV, super computer networks and other services. Satellites are ideally suited to provide the wide bandwidths and data rates required and are unique in the ability to provide services directly to the users. As new or relocated markets arise, satellites offer a flexibility that conventional distribution services cannot match, and it is no longer necessary to be near population centers to take advantage of the telecommunication revolution. The geopolitical implications of these substantially enhanced communications capabilities can be significant.

  16. Technology Development for High Efficiency Optical Communications

    NASA Technical Reports Server (NTRS)

    Farr, William H.

    2012-01-01

    Deep space optical communications is a significantly more challenging operational domain than near Earth space optical communications, primarily due to effects resulting from the vastly increased range between transmitter and receiver. The NASA Game Changing Development Program Deep Space Optical Communications Project is developing four key technologies for the implementation of a high efficiency telecommunications system that will enable greater than 10X the data rate of a state-of-the-art deep space RF system (Ka-band) for similar transceiver mass and power burden on the spacecraft. These technologies are a low mass spacecraft disturbance isolation assembly, a flight qualified photon counting detector array, a high efficiency flight laser amplifier and a high efficiency photon counting detector array for the ground-based receiver.

  17. Monolithically integrated quantum dot optical modulator with Semiconductor optical amplifier for short-range optical communications

    NASA Astrophysics Data System (ADS)

    Yamamoto, Naokatsu; Akahane, Kouichi; Umezawa, Toshimasa; Kawanishi, Tetsuya

    2015-04-01

    A monolithically integrated quantum dot (QD) optical gain modulator (OGM) with a QD semiconductor optical amplifier (SOA) was successfully developed. Broadband QD optical gain material was used to achieve Gbps-order high-speed optical data transmission, and an optical gain change as high as approximately 6-7 dB was obtained with a low OGM voltage of 2.0 V. Loss of optical power due to insertion of the device was also effectively compensated for by the SOA section. Furthermore, it was confirmed that the QD-OGM/SOA device helped achieve 6.0-Gbps error-free optical data transmission over a 2.0-km-long photonic crystal fiber. We also successfully demonstrated generation of Gbps-order, high-speed, and error-free optical signals in the >5.5-THz broadband optical frequency bandwidth larger than the C-band. These results suggest that the developed monolithically integrated QD-OGM/SOA device will be an advantageous and compact means of increasing the usable optical frequency channels for short-reach communications.

  18. High Average Power, High Energy Short Pulse Fiber Laser System

    SciTech Connect

    Messerly, M J

    2007-11-13

    Recently continuous wave fiber laser systems with output powers in excess of 500W with good beam quality have been demonstrated [1]. High energy, ultrafast, chirped pulsed fiber laser systems have achieved record output energies of 1mJ [2]. However, these high-energy systems have not been scaled beyond a few watts of average output power. Fiber laser systems are attractive for many applications because they offer the promise of high efficiency, compact, robust systems that are turn key. Applications such as cutting, drilling and materials processing, front end systems for high energy pulsed lasers (such as petawatts) and laser based sources of high spatial coherence, high flux x-rays all require high energy short pulses and two of the three of these applications also require high average power. The challenge in creating a high energy chirped pulse fiber laser system is to find a way to scale the output energy while avoiding nonlinear effects and maintaining good beam quality in the amplifier fiber. To this end, our 3-year LDRD program sought to demonstrate a high energy, high average power fiber laser system. This work included exploring designs of large mode area optical fiber amplifiers for high energy systems as well as understanding the issues associated chirped pulse amplification in optical fiber amplifier systems.

  19. High Performance Computing and Communications Panel Report.

    ERIC Educational Resources Information Center

    President's Council of Advisors on Science and Technology, Washington, DC.

    This report offers advice on the strengths and weaknesses of the High Performance Computing and Communications (HPCC) initiative, one of five presidential initiatives launched in 1992 and coordinated by the Federal Coordinating Council for Science, Engineering, and Technology. The HPCC program has the following objectives: (1) to extend U.S.…

  20. Intravehicular, Short- and Long-Range Communication Information Fusion for Providing Safe Speed Warnings.

    PubMed

    Jiménez, Felipe; Naranjo, Jose Eugenio; Serradilla, Francisco; Pérez, Elisa; Hernández, María Jose; Ruiz, Trinidad; Anaya, José Javier; Díaz, Alberto

    2016-01-01

    Inappropriate speed is a relevant concurrent factor in many traffic accidents. Moreover, in recent years, traffic accidents numbers in Spain have fallen sharply, but this reduction has not been so significant on single carriageway roads. These infrastructures have less equipment than high-capacity roads, therefore measures to reduce accidents on them should be implemented in vehicles. This article describes the development and analysis of the impact on the driver of a warning system for the safe speed on each road section in terms of geometry, the presence of traffic jams, weather conditions, type of vehicle and actual driving conditions. This system is based on an application for smartphones and includes knowledge of the vehicle position via Ground Positioning System (GPS), access to intravehicular information from onboard sensors through the Controller Area Network (CAN) bus, vehicle data entry by the driver, access to roadside information (short-range communications) and access to a centralized server with information about the road in the current and following sections of the route (long-range communications). Using this information, the system calculates the safe speed, recommends the appropriate speed in advance in the following sections and provides warnings to the driver. Finally, data are sent from vehicles to a server to generate new information to disseminate to other users or to supervise drivers' behaviour. Tests in a driving simulator have been used to define the system warnings and Human Machine Interface (HMI) and final tests have been performed on real roads in order to analyze the effect of the system on driver behavior. PMID:26805839

  1. Intravehicular, Short- and Long-Range Communication Information Fusion for Providing Safe Speed Warnings

    PubMed Central

    Jiménez, Felipe; Naranjo, Jose Eugenio; Serradilla, Francisco; Pérez, Elisa; Hernández, María Jose; Ruiz, Trinidad; Anaya, José Javier; Díaz, Alberto

    2016-01-01

    Inappropriate speed is a relevant concurrent factor in many traffic accidents. Moreover, in recent years, traffic accidents numbers in Spain have fallen sharply, but this reduction has not been so significant on single carriageway roads. These infrastructures have less equipment than high-capacity roads, therefore measures to reduce accidents on them should be implemented in vehicles. This article describes the development and analysis of the impact on the driver of a warning system for the safe speed on each road section in terms of geometry, the presence of traffic jams, weather conditions, type of vehicle and actual driving conditions. This system is based on an application for smartphones and includes knowledge of the vehicle position via Ground Positioning System (GPS), access to intravehicular information from onboard sensors through the Controller Area Network (CAN) bus, vehicle data entry by the driver, access to roadside information (short-range communications) and access to a centralized server with information about the road in the current and following sections of the route (long-range communications). Using this information, the system calculates the safe speed, recommends the appropriate speed in advance in the following sections and provides warnings to the driver. Finally, data are sent from vehicles to a server to generate new information to disseminate to other users or to supervise drivers’ behaviour. Tests in a driving simulator have been used to define the system warnings and Human Machine Interface (HMI) and final tests have been performed on real roads in order to analyze the effect of the system on driver behavior. PMID:26805839

  2. High-Capacity Communications from Martian Distances

    NASA Technical Reports Server (NTRS)

    Williams, W. Dan; Collins, Michael; Hodges, Richard; Orr, Richard S.; Sands, O. Scott; Schuchman, Leonard; Vyas, Hemali

    2007-01-01

    High capacity communications from Martian distances, required for the envisioned human exploration and desirable for data-intensive science missions, is challenging. NASA s Deep Space Network currently requires large antennas to close RF telemetry links operating at kilobit-per-second data rates. To accommodate higher rate communications, NASA is considering means to achieve greater effective aperture at its ground stations. This report, focusing on the return link from Mars to Earth, demonstrates that without excessive research and development expenditure, operational Mars-to-Earth RF communications systems can achieve data rates up to 1 Gbps by 2020 using technology that today is at technology readiness level (TRL) 4-5. Advanced technology to achieve the needed increase in spacecraft power and transmit aperture is feasible at an only moderate increase in spacecraft mass and technology risk. In addition, both power-efficient, near-capacity coding and modulation and greater aperture from the DSN array will be required. In accord with these results and conclusions, investment in the following technologies is recommended:(1) lightweight (1 kg/sq m density) spacecraft antenna systems; (2) a Ka-band receive ground array consisting of relatively small (10-15 m) antennas; (3) coding and modulation technology that reduces spacecraft power by at least 3 dB; and (4) efficient generation of kilowatt-level spacecraft RF power.

  3. Efficient High Performance Collective Communication for Distributed Memory Environments

    ERIC Educational Resources Information Center

    Ali, Qasim

    2009-01-01

    Collective communication allows efficient communication and synchronization among a collection of processes, unlike point-to-point communication that only involves a pair of communicating processes. Achieving high performance for both kernels and full-scale applications running on a distributed memory system requires an efficient implementation of

  4. Efficient High Performance Collective Communication for Distributed Memory Environments

    ERIC Educational Resources Information Center

    Ali, Qasim

    2009-01-01

    Collective communication allows efficient communication and synchronization among a collection of processes, unlike point-to-point communication that only involves a pair of communicating processes. Achieving high performance for both kernels and full-scale applications running on a distributed memory system requires an efficient implementation of…

  5. Beam divergence changing mechanism for short-range inter-unmanned aerial vehicle optical communications.

    PubMed

    Heng, Kiang Huat; Zhong, Wen-De; Cheng, Tee Hiang; Liu, Ning; He, Yingjie

    2009-03-10

    The problems associated with using a single fixed beam divergence for short-range inter-unmanned aerial vehicle free-space optical communications are discussed. To overcome the problems, a beam divergence changing mechanism is proposed. Four different methods are then proposed to implement the beam divergence changing mechanism. The performance of these methods is evaluated in terms of transmission distance under adverse weather conditions. The results show that the performance is greatly improved when the beam divergence changing mechanism is used. PMID:19277090

  6. High accuracy in short ISS missions

    NASA Astrophysics Data System (ADS)

    Rüeger, J. M.

    1986-06-01

    Traditionally Inertial Surveying Systems ( ISS) are used for missions of 30 km to 100 km length. Today, a new type of ISS application is emanating from an increased need for survey control densification in urban areas often in connection with land information systems or cadastral surveys. The accuracy requirements of urban surveys are usually high. The loss in accuracy caused by the coordinate transfer between IMU and ground marks is investigated and an offsetting system based on electronic tacheometers is proposed. An offsetting system based on a Hewlett-Packard HP 3820A electronic tacheometer has been tested in Sydney (Australia) in connection with a vehicle mounted LITTON Auto-Surveyor System II. On missions over 750 m ( 8 stations, 25 minutes duration, 3.5 minute ZUPT intervals, mean offset distances 9 metres) accuracies of 37 mm (one sigma) in position and 8 mm in elevation were achieved. Some improvements to the LITTON Auto-Surveyor System II are suggested which would improve the accuracies even further.

  7. German Deaf People Using Text Communication: Short Message Service, TTY, Relay Services, Fax, and E-Mail

    ERIC Educational Resources Information Center

    Power, Des; Power, Mary R.; Rehling, Bernd

    2007-01-01

    An online survey of German deaf people demonstrated that they use text communication through Short Message Service (SMS), e-mail, fax, and telephone typewriters (TTY) to communicate within communities of deaf and hearing people. SMS is used most, with more than 96% of respondents having access to a mobile phone. Most use is intrinsic and directed…

  8. Fiber Laser Front Ends for High Energy, Short Pulse Lasers

    SciTech Connect

    Dawson, J; Messerly, M; Phan, H; Siders, C; Beach, R; Barty, C

    2007-06-21

    We are developing a fiber laser system for short pulse (1-10ps), high energy ({approx}1kJ) glass laser systems. Fiber lasers are ideal for these systems as they are highly reliable and enable long term stable operation.

  9. Chemical communication and reproduction in the gray short-tailed opossum (Monodelphis domestica).

    PubMed

    Harder, John D; Jackson, Leslie M

    2010-01-01

    The gray short-tailed opossum is one of the most widely studied of all marsupials and an important model for study of olfactory communication, particularly as it relates to pheromonal activation of reproduction. Males respond to differentially to female skin gland secretions and urine from anestrous females, while females respond only skin gland secretions, particularly that of the suprasternal gland. Divergent responses by male and female opossums to odors from these different body sources are most likely related to sex-specific production and deposition of chemical signals in this species. Female opossums do not have an estrous cycle but are stimulated to estrus by male pheromone. Females nuzzle scent marks from male suprasternal gland secretions, and thereby facilitate delivery of a nonvolatile estrus-inducing pheromone to the chemosensory epithelium of vomeronasal organ. Neuroendocrine correlates of pheromonal induction of estrus include elevated plasma estradiol and upregulation of progesterone receptors in hypothalamic regions that control reproductive behavior. PMID:20831955

  10. Advanced short haul aircraft for high density markets

    NASA Technical Reports Server (NTRS)

    Galloway, T. L.

    1977-01-01

    The short haul (less than 500 miles) passenger enplanements represent about 50% of the total domestic enplanements. These can be distinguished by the annual passenger flow for a given city pair and classified into low, medium and high densiy markets. NASA studies have investigated various advanced short haul aircraft concepts that have potential application in these three market areas. Although advanced operational techniques impact all market densities, advanced vehicle design concepts such as RTOL, STOL and VTOL have the largest impact in the high density markets. This paper summarizes the results of NASA sponsored high density short haul air transportation systems studies and briefly reviews NASA sponsored advanced VTOL conceptual aircraft design studies. Trends in vehicle characteristics and operational requirements will be indicated in addition to economic suitability and impact on the community.

  11. Phonological awareness and short-term memory in hearing and deaf individuals of different communication backgrounds.

    PubMed

    Koo, Daniel; Crain, Kelly; LaSasso, Carol; Eden, Guinevere F

    2008-12-01

    Previous work in deaf populations on phonological coding and working memory, two skills thought to play an important role in the acquisition of written language skills, have focused primarily on signers or did not clearly identify the subjects' native language and communication mode. In the present study, we examined the effect of sensory experience, early language experience, and communication mode on the phonological awareness skills and serial recall of linguistic items in deaf and hearing individuals of different communicative and linguistic backgrounds: hearing nonsigning controls, hearing users of ASL, deaf users of ASL, deaf oral users of English, and deaf users of cued speech. Since many current measures of phonological awareness skills are inappropriate for deaf populations on account of the verbal demands in the stimuli or response, we devised a nonverbal phonological measure that addresses this limitation. The Phoneme Detection Test revealed that deaf cuers and oral users, but not deaf signers, performed as well as their hearing peers when detecting phonemes not transparent in the orthography. The second focus of the study examined short-term memory skills and found that in response to the traditional digit span as well as an experimental visual version, digit-span performance was similar across the three deaf groups, yet deaf subjects' retrieval was lower than that of hearing subjects. Our results support the claim (Bavelier et al., 2006) that lexical items processed in the visual-spatial modality are not as well retained as information processed in the auditory channel. Together these findings show that the relationship between working memory, phonological coding, and reading may not be as tightly interwoven in deaf students as would have been predicted from work conducted in hearing students. PMID:19076391

  12. Applications of High Technology to Communication Instruction.

    ERIC Educational Resources Information Center

    Behnke, Ralph R.; O'Hair, H. Dan

    1984-01-01

    Discusses classroom design and uses of interactive media. Covers the design of public speaking/interpersonal/small group communication classrooms, the simulation laboratory, the communication effectiveness trainer (ComET system), audience response systems, speech evaluation using computers, and system design considerations. (PD)

  13. Spontaneous Radiation Emission from Short, High Field Strength Insertion Devices

    SciTech Connect

    Geoffrey Krafft

    2005-09-15

    Since the earliest papers on undulaters were published, it has been known how to calculate the spontaneous emission spectrum from ''short'' undulaters when the magnetic field strength parameter is small compared to unity, or in ''single'' frequency sinusoidal undulaters where the magnetic field strength parameter is comparable to or larger than unity, but where the magnetic field amplitude is constant throughout the undulater. Fewer general results have been obtained in the case where the insertion device is both short, i.e., the magnetic field strength parameter changes appreciably throughout the insertion device, and the magnetic field strength is high enough that ponderomotive effects, radiation retardation, and harmonic generation are important physical phenomena. In this paper a general method is presented for calculating the radiation spectrum for short, high-field insertion devices. It is used to calculate the emission from some insertion device designs of recent interest.

  14. 622 Mbps High-speed satellite communication system for WINDS

    NASA Astrophysics Data System (ADS)

    Ogawa, Yasuo; Hashimoto, Yukio; Yoshimura, Naoko; Suzuki, Ryutaro; Gedney, Richard T.; Dollard, Mike

    2006-07-01

    WINDS is the experimental communications satellite currently under joint development by Japanese Aerospace Exploration Agency (JAXA) and the National Institute of Information and Communications Technology (NICT). The high-speed satellite communication system is very effective for quick deployment of high-speed networks economically. The WINDS will realize ultra high-speed networking and demonstrate operability of satellite communication systems in high-speed internet. NICT is now developing high-speed satellite communication system for WINDS. High-speed TDMA burst modem with high performance TPC error correction is underdevelopment. Up to the DAC on the transmitter and from the ADC on the receiver, all modem functions are performed in the digital processing technology. Burst modem has been designed for a user data rate up to 1244 Mbps. NICT is developing the digital terminal as a user interface and a network controller for this earth station. High compatibility with the Internet will be provided.

  15. High-Latitude Communications Satellite (HILACS)

    NASA Technical Reports Server (NTRS)

    1990-01-01

    The Naval Postgraduate School in the AE 4871 Advanced Spacecraft Design course designed a communications satellite (HILACS) that will provide a continuous UHF communications link between stations located north of the region covered by geosynchronous communications satellites. The communications payload will operate only for that portion of the orbit necessary to provide specific coverage. The satellite orbit is elliptic with perigee at 1204 km in the Southern Hemisphere and an apogee at 14,930 km with 63.4 degrees inclination. Analysis and design of each of the subsystems was done to the extent possible within the constraints of an eleven week quarter and the design and analysis tools available. Work was completed in orbital analysis, the reaction control system, attitude control subsystem, electric power subsystem, telemetry, tracking, and control, thermal control subsystem, and the structures subsystem. The design team consisted of 12 students. Additional support was provided by the Jet Propulsion Laboratory and the Naval Research Laboratory.

  16. Iridium: Global OTH data communications for high altitude scientific ballooning

    NASA Astrophysics Data System (ADS)

    Denney, A.

    While the scientific community is no stranger to embracing commercially available technologies, the growth and availability of truly affordable cutting edge technologies is opening the door to an entirely new means of global communications. For many years high altitude ballooning has provided science an alternative to costly satellite based experimental platforms. As with any project, evolution becomes an integral part of development. Specifically in the NSBF ballooning program, where flight durations have evolved from the earlier days of hours to several weeks and plans are underway to provide missions up to 100 days. Addressing increased flight durations, the harsh operational environment, along with cumbersome and outdated systems used on existing systems, such as the balloon vehicles Support Instrumentation Package (SIP) and ground-based systems, a new Over-The-Horizon (OTH) communications medium is sought. Current OTH equipment planning to be phased-out include: HF commanding systems, ARGOS PTT telemetry downlinks and INMARSAT data terminals. Other aspects up for review in addition to the SIP to utilize this communications medium include pathfinder balloon platforms - thereby, adding commanding abilities and increased data rates, plus providing a package for ultra-small experiments to ride aloft. Existing communication systems employed by the National Scientific Balloon Facility ballooning program have been limited not only by increased cost, slow data rates and "special government use only" services such as TDRSS (Tracking and Data Relay Satellite System), but have had to make special provisions to geographical flight location. Development of the Support Instrumentation Packages whether LDB (Long Duration Balloon), ULDB (Ultra Long Duration Balloon) or conventional ballooning have been plagued by non-standard systems configurations requiring additional support equipment for different regions and missions along with a myriad of backup for redundancy. Several beneficial points provided by the Iridium platform include pure global accessibility (as well as polar), cost effectiveness because it is available as a COTS (Commercially Off The Shelf) technology, reliability in that the equipment must operate in extreme conditions (near space), integration and development time into current systems must be minimized. As a bonus Motorola and NAL Research Corporation are developing SBD (Short Burst Data) into the Iridium network. This may lead the way to a global IP (Internet Protocol) node based ballooning platform. The Iridium satellite data modems employ the Iridium Low-Earth Orbit (LEO) satellite network. The scope of this paper is to introduce an OTH communications alternative, albeit not necessarily a primary one, to existing ballooning platforms using COTS based emerging technologies. Design aspects, characteristics, actual flight testing statistics, principles of the Iridium modems and communication paths are described including payload and support instrumentation interfacing. Not limited to high altitude ballooning, the Iridium communications platform opens a new era in remote commanding and data retrieval.

  17. TDX: A high-bandwidth crossbar-switched communication paradigm

    SciTech Connect

    Pierce, P.E.; Eilers, D.L.; Schreiber, A.L.

    1994-08-01

    Digital signal processing systems under development today require scalable and reconfigurable high bandwidth communication resources between processing elements. Shared memory architectures require the ability to transfer data from one processor node to another, as well as maintaining data coherency such as provided by the Scalable Coherent Interface (SCI). Signal processing systems that must move large amounts of data between processor nodes, are best served by a communication system that allows reconfigurable streams of data to flow at deterministic rates with minimal overhead. A Time Domain Crossbar (TDX) communication system providing scalable, programmable, high-bandwidth, streaming communication has been developed and is described in this paper.

  18. Detection of high-resolution Raman spectra in short oligonucleotides

    NASA Astrophysics Data System (ADS)

    Bairamov, F. B.; Poloskin, E. D.; Chernev, A. L.; Toporov, V. V.; Dubina, M. V.; Lahderanta, E.; Lipsanen, H.; Bairamov, B. Kh.

    2014-06-01

    High-resolution spectra of single-chain short oligonucleotides d(20G, 20T), where d is a deoxyribonucleoside, G is guanine, and T is thymine, have been obtained by the highly sensitive nonresonant Raman scattering method of biomacromolecules. In addition to their own multifunctional significance, short oligonucleotides attract interest as ideal model objects for revealing poorly studied peculiarities of tertiary and quaternary structures of DNA. The detection of narrow spectral lines has allowed determining the characteristic time scale and makes it possible to study the dynamics of fast relaxation processes of vibrational motions of atoms in biomacromolecules. It has been found that the FWHM of the narrowest 1355.4 cm-1 spectral line attributed to the vibrations of the dT methyl group is 14.6 cm-1. The corresponding lifetime is 0.38 ps.

  19. High-order harmonic generation with short-pulse lasers

    SciTech Connect

    Schafer, K.J.; Krause, J.L.; Kulander, K.C.

    1992-12-01

    Recent progress in the understanding of high-order harmonic conversion from atoms and ions exposed to high-intensity, short-pulse optical lasers is reviewed. We find that ions can produce harmonics comparable in strength to those obtained from neutral atoms, and that the emission extends to much higher order. Simple scaling laws for the strength of the harmonic emission and the maximium observable harmonic are suggested. These results imply that the photoemission observed in recent experiments in helium and neon contains contributions from ions as well as neutrals.

  20. Short Communication: Atmospheric moisture transport, the bridge between ocean evaporation and Arctic ice melting

    NASA Astrophysics Data System (ADS)

    Gimeno, L.; Vázquez, M.; Nieto, R.; Trigo, R. M.

    2015-06-01

    If we could choose a region where the effects of global warming are likely to be pronounced and considerable, and at the same time one where the changes could affect the global climate in similarly asymmetric way with respect to other regions, this would unequivocally be the Arctic. The atmospheric branch of the hydrological cycle lies behind the linkages between the Arctic system and the global climate. Changes in the atmospheric moisture transport have been proposed as a vehicle for interpreting the most significant changes in the Arctic region. This is because the transport of moisture from the extratropical regions to the Arctic has increased in recent decades, and is expected to increase within a warming climate. This increase could be due either to changes in circulation patterns which have altered the moisture sources, or to changes in the intensity of the moisture sources because of enhanced evaporation, or a combination of these two mechanisms. In this short communication we focus on the assessing more objectively the strong link between ocean evaporation trends and Arctic Sea ice melting. We will critically analyze several recent results suggesting links between moisture transport and the extent of sea-ice in the Arctic, this being one of the most distinct indicators of continuous climate change both in the Arctic and on a global scale. To do this we will use a sophisticated Lagrangian approach to develop a more robust framework on some of these previous disconnect ng results, using new information and insights. Among the many mechanisms that could be involved are hydrological (increased Arctic river discharges), radiative (increase of cloud cover and water vapour) and meteorological (increase in summer storms crossing the Arctic, or increments in precipitation).

  1. Trend on High-speed Power Line Communication Technology

    NASA Astrophysics Data System (ADS)

    Ogawa, Osamu

    High-speed power line communication (PLC) is useful technology to easily build the communication networks, because construction of new infrastructure is not necessary. In Europe and America, PLC has been used for broadband networks since the beginning of 21th century. In Japan, high-speed PLC was deregulated only indoor usage in 2006. Afterward it has been widely used for home area network, LAN in hotels and school buildings and so on. And recently, PLC is greatly concerned as communication technology for smart grid network. In this paper, the author surveys the high-speed PLC technology and its current status.

  2. Nonlinear optical tracking for high-speed free-space communications

    NASA Astrophysics Data System (ADS)

    Dudelzak, Alexander E.; Koujelev, Alexander S.

    2006-10-01

    High-speed free-space communications have been increasingly studied for applications ranging from short-distance ground-to-ground transmissions to inter-spacecraft links. Optical communications involving moving parties, especially at extra-long distances, require precise beam pointing and mutual tracking of communicating transceivers. The design concept and preliminary test results of a free-space communicator incorporating novel nonlinear optical tracking subsystem are presented. The development goal is to demonstrate a cost-effective terminal for Gbps optical links at a distance of up to 5 km. The tracking system consists of three subsystems: the coarse tracker (a 10.5 cm-diameter motorized Maksutov telescope); the electro-optical tracker (a voice-coil and a Si-based position detector); and the nonlinear optical fine tracker (a nonlinear cell with an IR-sensitive liquid crystal). Three-stage tracking allows for link budget improvement and maintaining a microradian pointing precision.

  3. NASA High Performance Computing and Communications program

    NASA Technical Reports Server (NTRS)

    Holcomb, Lee; Smith, Paul; Hunter, Paul

    1994-01-01

    The National Aeronautics and Space Administration's HPCC program is part of a new Presidential initiative aimed at producing a 1000-fold increase in supercomputing speed and a 1(X)-fold improvement in available communications capability by 1997. As more advanced technologies are developed under the HPCC program, they will be used to solve NASA's 'Grand Challenge' problems, which include improving the design and simulation of advanced aerospace vehicles, allowing people at remote locations to communicate more effectively and share information, increasing scientists' abilities to model the Earth's climate and forecast global environmental trends, and improving the development of advanced spacecraft. NASA's HPCC program is organized into three projects which are unique to the agency's mission: the Computational Aerosciences (CAS) project, the Earth and Space Sciences (ESS) project, and the Remote Exploration and Experimentation (REE) project. An additional project, the Basic Research and Human Resources (BRHR) project, exists to promote long term research in computer science and engineering and to increase the pool of trained personnel in a variety of scientific disciplines. This document presents an overview of the objectives and organization of these projects, as well as summaries of early accomplishments and the significance, status, and plans for individual research and development programs within each project. Areas of emphasis include benchmarking, testbeds, software and simulation methods.

  4. NASA high performance computing and communications program

    NASA Technical Reports Server (NTRS)

    Holcomb, Lee; Smith, Paul; Hunter, Paul

    1993-01-01

    The National Aeronautics and Space Administration's HPCC program is part of a new Presidential initiative aimed at producing a 1000-fold increase in supercomputing speed and a 100-fold improvement in available communications capability by 1997. As more advanced technologies are developed under the HPCC program, they will be used to solve NASA's 'Grand Challenge' problems, which include improving the design and simulation of advanced aerospace vehicles, allowing people at remote locations to communicate more effectively and share information, increasing scientist's abilities to model the Earth's climate and forecast global environmental trends, and improving the development of advanced spacecraft. NASA's HPCC program is organized into three projects which are unique to the agency's mission: the Computational Aerosciences (CAS) project, the Earth and Space Sciences (ESS) project, and the Remote Exploration and Experimentation (REE) project. An additional project, the Basic Research and Human Resources (BRHR) project exists to promote long term research in computer science and engineering and to increase the pool of trained personnel in a variety of scientific disciplines. This document presents an overview of the objectives and organization of these projects as well as summaries of individual research and development programs within each project.

  5. Methods for UGV teleoperation with high latency communications

    NASA Astrophysics Data System (ADS)

    Witus, Gary; Hunt, Shawn; Janicki, Phil

    2011-05-01

    In this project, we developed and demonstrated complementary UGV control methods for teleoperation with highlatency communications. The methods included latency protection, predictive displays, and supervisory control. Latency protection mitigate against typical types of high-latency teleoperation input errors. The Phase I latency protection methods included filtering the joysick commands, limiting the commanded rates as a function of latency, and emergency stop when the operator commands and OCU navigation video were out of phase. Predictive displays indicate to the operator the current state of the UGV, i.e., the state after all of the latent commands are executed (latent commands are those that have been issued but whose effects do not yet appear in the OCU display). We implemented two alternative predictive display methods: augmented reality using iconography to indicate the effects of the latent commands, and virtual reality which warps the image to show the view to reflect the latent commands. Supervisory control allows the operator to specify simple, short-range objectives that the UGV can accomplish on its own, without advanced sensing, path planning, etc. We implemented an effective "point-and-go" supervisory control system. We successfully implemented and demonstrated these methods on a Packbot510 EOD robot (made by iRobot Corporation), currently being used in-theater.

  6. Underground wireless communications systems using high temperature superconducting receivers

    SciTech Connect

    Reagor, D.; Goff, S.; Fan, Y.; Mombourquette, C.; Jia, Q.X.

    1997-12-31

    The ability to effectively communicate with both people and equipment in underground environments such as mines, tunnels, and boreholes is important from both an operations and safety perspective. Radio waves with frequencies above 10Mhz, such as cellular phones, do not propagate more than a few meters in a typical rock mass. Although these systems can be used in tunnels for line-of-sight communications, signal strength decreases drastically around corners. Many mines rely on hard-wired phone systems, but this is expensive, requires constant changing as tunnel systems change, and fails easily during tunnel collapse or fire. Near-field wireless systems typically use a system of repeaters and poorly shielded wiring that allow the signal to radiate weakly to be picked up by a receiver a short distance from the wiring. Ground penetrating signals are much greater at low frequencies, but the receivers for these low frequencies usually require a very large antenna (on either the transmit or receive side) to overcome the electrical noise of typical semiconductor components. One common mine paging system uses a transmit antenna several kilometers in diameter to achieve sufficient amplitude to drive a conveniently sized wire-wound ferrite core receiver. Superconducting components are the lowest noise of any electronics technology and have traditionally been used in applications where a low noise floor is critical, such as radio astronomy and noninvasive magnetoencephalography. The authors have developed a receiver for deeply penetrating low frequency radio waves using high temperature superconducting quantum interference devices (SQUIDS). The receiver consists of a SQUID, a small dewar, control electronics, and a battery pack. The receiver is several orders of magnitude more sensitive than conventional receivers of the same size and weight. SQUIDs also allow the compact construction of 3-axis receivers that are necessary to overcome a dominant source of vibrational or motional noise. The goal is to demonstrate an effective and reliable two-way voice underground wireless communication system. The low noise compact receivers also have application in geophysical tool development, survey techniques, and underground structure detection.

  7. High charge short electron bunches for wakefield accelerator structures development.

    SciTech Connect

    Conde, M. E.

    1998-09-25

    The Argonne Wakefield Accelerator group develops accelerating structures based on dielectric loaded waveguides. We use high charge short electron bunches to excite wakefields in dielectric loaded structures, and a second (low charge) beam to probe the wakefields left behind by the drive beam. We report measurements of beam parameters and also initial results of the dielectric loaded accelerating structures. We have studied acceleration of the probe beam in these structures and we have also made measurements on the RF pulses that are generated by the drive beam. Single drive bunches, as well as multiple bunches separated by an integer number of RF periods have been used to generate the accelerating wakefields.

  8. Ultra short pulse generation and reshaping using highly nonlinear fibers

    NASA Astrophysics Data System (ADS)

    Matsushita, S.; Namiki, S.; Inoue, T.; Oguri, A.; Akutsu, T.; Shinozaki, J.; Ozeki, Y.; Takasaka, S.; Igarashi, K.; Sakano, M.; Yagi, T.

    2005-11-01

    We experimentally investigate the generation of a low-noise ultra short pulse train from 40GHz to160GHz by using Comb-like profiled fiber (CPF) for adiabatic soliton conversion and compression. Highly nonlinear fibers allow us to reduce total length of CPF as well as to utilize Kerr effect in the fiber effectively. We demonstrate generations of 160GHz soliton train of 750fs, the compression to 500fs of 40GHz externally-modulated pulse with wideband tunability over 30nm. Then we apply the CPF pulse compression technique to achieve the programmable repetition tunability from 5 to 500 MHz in low pedestral 300fs pulse train generation.

  9. Analysis of High Power IGBT Short Circuit Failures

    SciTech Connect

    Pappas, G.

    2005-02-11

    The Next Linear Collider (NLC) accelerator proposal at SLAC requires a highly efficient and reliable, low cost, pulsed-power modulator to drive the klystrons. A solid-state induction modulator has been developed at SLAC to power the klystrons; this modulator uses commercial high voltage and high current Insulated Gate Bipolar Transistor (IGBT) modules. Testing of these IGBT modules under pulsed conditions was very successful; however, the IGBTs failed when tests were performed into a low inductance short circuit. The internal electrical connections of a commercial IGBT module have been analyzed to extract self and mutual partial inductances for the main current paths as well as for the gate structure. The IGBT module, together with the partial inductances, has been modeled using PSpice. Predictions for electrical paths that carry the highest current correlate with the sites of failed die under short circuit tests. A similar analysis has been carried out for a SLAC proposal for an IGBT module layout. This paper discusses the mathematical model of the IGBT module geometry and presents simulation results.

  10. Research with high-power short-wavelength lasers

    NASA Astrophysics Data System (ADS)

    Holzrichter, J. F.; Campbell, E. M.; Lindl, J. D.; Storm, E.

    1985-03-01

    Three high-temperature, high-density experiments were conducted using the 10-TW, short-wavelength Novette laser system. Successful solutions to problems that arose during previous experiments with long wavelength lasers in which inertial confinement fusion (ICF), X-ray laser, and other high-temperature physics concepts were tested are demonstrated. The demonstrations are: (1) large-scale plasmas were produced in which potentially deleterious laser-plasma instabilities were collisionally damped; (2) deuterium-tritium fuel was imploded to a density of 20 g/sub cm and a pressure of 10(1) atm; (3) a 700-fold amplification of soft X rays by stimulated emission at 206 and 209 A from Se(+24) ions is observed in a laser-generated plasma. Isoelectronic scaling to 155 A in Y(+29) is also demonstrated.

  11. Personal communication system combines high performance with miniaturization

    NASA Technical Reports Server (NTRS)

    Atlas, N. D.

    1967-01-01

    Personal communication system provides miniaturized components that incorporate high level signal characteristics plus noise rejection in both microphone and earphone circuitry. The microphone is designed to overcome such spacecraft flight problems as size, ambient noise level, and RF interference.

  12. Communication.

    ERIC Educational Resources Information Center

    Strauss, Andre

    The following essays on communication are presented: communication as a condition of survival, communication for special purposes, the means of transmission of communication, communication within social and economic structures, the teaching of communication through the press, the teaching of modern languages, communication as a point of departure,…

  13. Short communication: Determination of Salmonella clustered regularly interspaced short palindromic repeats (CRISPR) diversity on dairy farms in Wisconsin and Minnesota.

    PubMed

    Wehnes, C A; Rehberger, T G; Barrangou, R; Smith, A H

    2014-10-01

    Salmonella enterica ssp. enterica is a foodborne pathogen able to cause disease in both humans and animals. Diverse serovars of this pathogen exist, some of which are host specific, causing a range of clinical symptoms from asymptomatic infection through morbidity and mortality. According to a 2007 survey by the USDA National Animal Health Monitoring System, fecal shedding of Salmonella from healthy cows occurs on 39.7% of dairy farms in the United States. Certain serovars are frequently isolated from dairy farms and the majority of isolates from the National Animal Health Monitoring System study were represented by 5 serovars; however, genotypic diversity was not examined. The objective of this study was to determine the diversity of clustered regularly interspaced short palindromic repeats (CRISPR) loci in Salmonella collected from 8 dairy farms with a previous history of salmonellosis. None of the cows or calves sampled on 2 of the 8 dairy farms were shedding Salmonella, although Salmonella was detected in a cow bedding sample on 1 of these farms. Salmonella populations were discrete on each farm, according to CRISPR typing, with the exception of an Anatum var. 15+ type on farms 5 and 6 and the Montevideo type on farms 1 and 2. One to 4 distinct CRISPR genotypes were identified per farm. The CRISPR typing differed within serovars, as Montevideo, Anatum var. 15+, and Muenster serovars had no overlap of spacer content, even on the same farm, reflecting between- and within-serovar genetic diversity. The dynamic nature of Salmonella populations was shown in a farm that was sampled longitudinally over 13.5 mo. Changes in serovar from 3,19:-:z27 to Montevideo was observed between the first sampling time and 8 mo later, with concomitant change in CRISPR alleles. The results indicate that Salmonella strains present in smaller dairy herds (<500 head) are specific to that farm and new Salmonella strains may emerge over time. PMID:25108866

  14. COTS low-cost 622-Mb/s free-space laser communications link for short-distance commercial applications

    NASA Astrophysics Data System (ADS)

    Morrison, Kenneth A.

    2000-05-01

    The results from a low cost 622 Mb/s, free-space laser communication link operating at 850 nm for short distance commercial applications is presented. The test results demonstrate the use of a free-space laser communications transceiver for building to building applications such as LAN, WAN and ATM operations, etc. This illustrates the potential for wide-use commercial computer network applications. The transceiver is constructed of commercial off-the-shelf materials for the development of a low-cost laser communications data link. The test system configuration utilizes standard Personal Computers with network cards and signal conversion cards for the copper to optical medical conversion. These tests precede the development of an increased data rate device operating at 2.5 Gb/s.

  15. Multicultural Communication: Assessing, Facilitating, and Evaluating Competency-Based Oral Interactions. Short Course No. 6.

    ERIC Educational Resources Information Center

    Flores, Norma Landa

    This paper discusses assessing the oral communication skills of non-native speakers of English enrolled in pre-vocational programs at Golden West College (California), presents the locally developed assessment instrument, and discusses multicultural communication intervention strategies educators can use to empower students. The first part of the

  16. Advanced short haul systems in high density markets

    NASA Technical Reports Server (NTRS)

    Galloway, T. L.

    1975-01-01

    The design requirements, performance, economics, and noise aspects of STOL and VTOL conceptual aircraft developed for short haul air transportation are reviewed, along with the characteristics of areas of high-density annual passenger flow in which the aircraft are intended to operate. It is shown that aircraft of 100 to 200 passenger capacity provide the best return on investment in high density markets. The various STOL propulsive lift concepts have the same general trends with field length; their wing loadings are 20 to 30 pounds per square foot higher than the nonpropulsive lift concepts. A comparison of the aircraft under consideration shows that no one aircraft concept will be optimum for all future operational environments.

  17. NASA satellite communications application research. Phase 2: Efficient high power, solid state amplifier for EFH communications

    NASA Technical Reports Server (NTRS)

    Benet, James

    1993-01-01

    The final report describes the work performed from 9 Jun. 1992 to 31 Jul. 1993 on the NASA Satellite Communications Application Research (SCAR) Phase 2 program, Efficient High Power, Solid State Amplifier for EHF Communications. The purpose of the program was to demonstrate the feasibility of high-efficiency, high-power, EHF solid state amplifiers that are smaller, lighter, more efficient, and less costly than existing traveling wave tube (TWT) amplifiers by combining the output power from up to several hundred solid state amplifiers using a unique orthomode spatial power combiner (OSPC).

  18. NASA satellite communications application research. Phase 2: Efficient high power, solid state amplifier for EFH communications

    NASA Astrophysics Data System (ADS)

    Benet, James

    1993-07-01

    The final report describes the work performed from 9 Jun. 1992 to 31 Jul. 1993 on the NASA Satellite Communications Application Research (SCAR) Phase 2 program, Efficient High Power, Solid State Amplifier for EHF Communications. The purpose of the program was to demonstrate the feasibility of high-efficiency, high-power, EHF solid state amplifiers that are smaller, lighter, more efficient, and less costly than existing traveling wave tube (TWT) amplifiers by combining the output power from up to several hundred solid state amplifiers using a unique orthomode spatial power combiner (OSPC).

  19. Review of high speed communications photomultiplier detectors

    NASA Technical Reports Server (NTRS)

    Enck, R. S.; Abraham, W. G.

    1978-01-01

    Four types of newly developed high speed photomultipliers are discussed: all electrostatic; static crossed field; dynamic crossed field; and hybrid (EBS). Design, construction, and performance parameters of each class are presented along with limitations of each class of device and prognosis for its future in high speed light detection. The particular advantage of these devices lies in high speed applications using low photon flux, large cathode areas, and broadband optical detection.

  20. High Temperature Mineral Formation by Short Circuits in Protoplanetary Disks

    NASA Astrophysics Data System (ADS)

    Hubbard, Alexander

    Meteoritic chondrules represent over 20% of the mass of the most primitive Solar System rocks. Their formation requires rapid heating to temperatures of around 1800 K, followed by cooling at rates of around 1000 K/hour, far slower than the free-space cooling time of such millimeter-sized objects. Identifying the mechanism for this ubiquitous heating and cooling has remained a problem for over a century. Similar high- temperature minerals have been identified in interplanetary dust of cometary origin, and observed transitions from amorphous to crystalline silicate suggest high-temperature processing of dust in other protoplanetary disks. The short circuit instability that we have recently discovered intermittently heats protoplanetary disks, producing thin sheets hot enough to satisfy these constraints. We propose to determine the role of this instability in mineral formation in protoplanetary disks. Melting a large fraction of the solids in a protoplanetary disk requires a substantial source of energy. The short-circuit instability can tap the huge reservoir contained in the differential rotation of the disk. Protoplanetary disks must have a viscosity far exceeding molecular viscosity to accrete gas at the rates observed in young stellar objects. The most likely source of this viscosity is magnetized turbulence driven by the magnetorotational instability (MRI) wherever the disk is adequately ionized. Magnetized turbulence quite generally forms spatially and temporally intermittent current sheets that dissipate the magnetic energy as heat. These can raise the gas temperature locally well beyond its volume average. If temperatures reach 1000 K, gas resistivity starts to fall sharply as alkali metals are thermally ionized. Over the range from 1000 K to 2000 K, the resistivity decreases by more than 5 orders of magnitude. In that temperature range, the resistive evolution of the magnetic field is dominated by the spatial variation in the resistivity. Similarly to electrical short circuits and lightning, the electrical currents in the disk concentrate in hot, high conductivity regions, leading to strong resistive heating in narrow sheets. We have demonstrated that this instability can occur in protoplanetary disks, even in the presence of radiative cooling. In some cases the gas in our models reaches temperatures high enough to form chondrules and other similar minerals. We propose to find the gas and grain temperatures reached in current sheets drawn directly from MRI turbulence. We will use large-scale models of current sheet formation by the MRI to set the stage for small-scale models of individual current sheets. The MRI models will use the Pencil Code to characterize current sheets in stratified, shearing-box simulations without temperature dependent resistivity, and in higher-resolution, unstratified simulations with it. To improve our modeling of the gas resistivity and the MRI we will use a chemical equilibrium code to calculate the ionization fraction in protoplanetary disks: the alkali metals can be locked away in solid minerals, preventing their thermal ionization. Together these models will provide the initial and boundary conditions for simulations of individual current sheets using a purpose-built implicit code including radiative transfer as well as temperature-dependent resistivity. Histories of the gas temperature and pressure, and the ambient radiation, sampled using Lagrangian tracer particles, will allow us to use the equilibrium condensation code to compare the experience of solids in our simulations with experimental constraints on chondrules and other high-temperature minerals. This will allow us to test our hypothesis that the short circuit instability can produce grain thermal histories consistent with experimental and observational constraints on the ensemble of high-temperature minerals in our own and external disks.

  1. Multipoint free-space optics system for short-range communications between flight platforms.

    PubMed

    Heng, Kiang Huat; Zhong, Wen-De; Cheng, Tee Hiang

    2010-01-10

    The problems associated with using typical free-space optics (FSO) transceivers for multipoint communications on flight platforms, such as satellites and unmanned aerial vehicles, in a cluster are discussed and the transceivers are found to be unsuitable for concurrent multipoint communications in those platforms. To overcome the problems, a multipoint FSO system design is proposed. The design of the multipoint system is described and the performance of the multipoint receiver is evaluated in terms of receive gain under different conditions. The proposed multipoint system design offers a promising way to implement concurrent multipoint communications on flight platforms with power, weight, and size advantages compared to the use of multiple transceivers. PMID:20062513

  2. Communication: Role of short chain branching in polymer structure and dynamics.

    PubMed

    Kim, Jun Mo; Baig, Chunggi

    2016-02-28

    A comprehensive understanding of chain-branching effects, essential for establishing general knowledge of the structure-property-phenomenon relationship in polymer science, has not yet been found, due to a critical lack of knowledge on the role of short-chain branches, the effects of which have mostly been neglected in favor of the standard entropic-based concepts of long polymers. Here, we show a significant effect of short-chain branching on the structural and dynamical properties of polymeric materials, and reveal the molecular origins behind the fundamental role of short branches, via atomistic nonequilibrium molecular dynamics and mesoscopic Brownian dynamics by systematically varying the strength of the mobility of short branches. We demonstrate that the fast random Brownian kinetics inherent to short branches plays a key role in governing the overall structure and dynamics of polymers, leading to a compact molecular structure and, under external fields, to a lesser degree of structural deformation of polymer, to a reduced shear-thinning behavior, and to a smaller elastic stress, compared with their linear analogues. Their fast dynamical nature being unaffected by practical flow fields owing to their very short characteristic time scale, short branches would substantially influence (i.e., facilitate) the overall relaxation behavior of polymeric materials under various flowing conditions. PMID:26931673

  3. Communication: Role of short chain branching in polymer structure and dynamics

    NASA Astrophysics Data System (ADS)

    Kim, Jun Mo; Baig, Chunggi

    2016-02-01

    A comprehensive understanding of chain-branching effects, essential for establishing general knowledge of the structure-property-phenomenon relationship in polymer science, has not yet been found, due to a critical lack of knowledge on the role of short-chain branches, the effects of which have mostly been neglected in favor of the standard entropic-based concepts of long polymers. Here, we show a significant effect of short-chain branching on the structural and dynamical properties of polymeric materials, and reveal the molecular origins behind the fundamental role of short branches, via atomistic nonequilibrium molecular dynamics and mesoscopic Brownian dynamics by systematically varying the strength of the mobility of short branches. We demonstrate that the fast random Brownian kinetics inherent to short branches plays a key role in governing the overall structure and dynamics of polymers, leading to a compact molecular structure and, under external fields, to a lesser degree of structural deformation of polymer, to a reduced shear-thinning behavior, and to a smaller elastic stress, compared with their linear analogues. Their fast dynamical nature being unaffected by practical flow fields owing to their very short characteristic time scale, short branches would substantially influence (i.e., facilitate) the overall relaxation behavior of polymeric materials under various flowing conditions.

  4. Quantum data locking for high-rate private communication

    NASA Astrophysics Data System (ADS)

    Lupo, Cosmo; Lloyd, Seth

    2015-03-01

    We show that, if the accessible information is used as a security quantifier, quantum channels with a certain symmetry can convey private messages at a tremendously high rate, as high as less than one bit below the rate of non-private classical communication. This result is obtained by exploiting the quantum data locking effect. The price to pay to achieve such a high private communication rate is that accessible information security is in general not composable. However, composable security holds against an eavesdropper who is forced to measure her share of the quantum system within a finite time after she gets it.

  5. Research with high-power short-wavelength lasers

    SciTech Connect

    Holzrichter, J.F.; Campbell, E.M.; Lindl, J.D.; Storm, E.

    1985-03-05

    Three important high-temperature, high-density experiments were conducted recently using the 10-TW, short-wavelength Novette laser system at the Lawrence Livermore National Laboratory. These experiments demonstrated successful solutions to problems that arose during previous experiments with long wavelength lasers (lambda greater than or equal to 1..mu..m) in which inertial confinement fusion (ICF), x-ray laser, and other high-temperature physics concepts were being tested. The demonstrations were: (1) large-scale plasmas (typical dimensions of up to 1000 laser wavelengths) were produced in which potentially deleterious laser-plasma instabilities were collisionally damped. (2) Deuterium-tritium fuel was imploded to a density of 20 g/cm/sup 3/ and a pressure of 10/sup 10/ atm. (3) A 700-fold amplification of soft x rays by stimulated emission at 206 and 209 A (62 eV) from Se/sup +24/ ions was observed in a laser-generated plasma. Isoelectronic scaling to 155 A (87 eV) in Y/sup +29/ was also demonstrated.

  6. The Communicative Participation Item Bank (CPIB): Item bank calibration and development of a disorder-generic short form

    PubMed Central

    Baylor, Carolyn; Yorkston, Kathryn; Eadie, Tanya; Kim, Jiseon; Chung, Hyewon; Amtmann, Dagmar

    2015-01-01

    Purpose The purpose of this study was to calibrate the items for the Communicative Participation Item Bank (CPIB) using Item Response Theory (IRT). One overriding objective was to examine if the IRT item parameters would be consistent across different diagnostic groups, thereby allowing creation of a disorder-generic instrument. The intended outcomes were the final item bank and a short form ready for clinical and research applications. Methods Self-report data were collected from 701 individuals representing four diagnoses: multiple sclerosis, Parkinson’s disease, amyotrophic lateral sclerosis and head and neck cancer. Participants completed the CPIB and additional self-report questionnaires. CPIB data were analyzed using the IRT Graded Response Model (GRM). Results The initial set of 94 candidate CPIB items were reduced to an item bank of 46 items demonstrating unidimensionality, local independence, good item fit, and good measurement precision. Differential item function (DIF) analyses detected no meaningful differences across diagnostic groups. A 10-item, disorder-generic short form was generated. Conclusions The CPIB provides speech-language pathologists with a unidimensional, self-report outcomes measurement instrument dedicated to the construct of communicative participation. This instrument may be useful to clinicians and researchers wanting to implement measures of communicative participation in their work. PMID:23816661

  7. High Bandwidth Communications: 2000-2004

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This custom bibliography from the NASA Scientific and Technical Information Program lists a sampling of records found in the NASA Aeronautics and Space Database. The scope of this topic includes optical and high-frequency microwave systems to enhance data transmission rates. This area of focus is one of the enabling technologies as defined by NASA s Report of the President s Commission on Implementation of United States Space Exploration Policy, published in June 2004.

  8. Patterns of communication in high-fidelity simulation.

    PubMed

    Anderson, Judy K; Nelson, Kimberly

    2015-01-01

    High-fidelity simulation is commonplace in nursing education. However, critical thinking, decision making, and psychomotor skills scenarios are emphasized. Scenarios involving communication occur in interprofessional or intraprofessional settings. The importance of effective nurse-patient communication is reflected in statements from the American Nurses Association and Quality and Safety Education for Nurses, and in the graduate outcomes of most nursing programs. This qualitative study examined the patterns of communication observed in video recordings of a medical-surgical scenario with 71 senior students in a baccalaureate program. Thematic analysis revealed patterns of (a) focusing on tasks, (b) communicating-in-action, and (c) being therapeutic. Additional categories under the patterns included missing opportunities, viewing the "small picture," relying on informing, speaking in "medical tongues," offering choices…okay?, feeling uncomfortable, and using therapeutic techniques. The findings suggest the importance of using high-fidelity simulation to develop expertise in communication. In addition, the findings reinforce the recommendation to prioritize communication aspects of scenarios and debriefing for all simulations. PMID:25545143

  9. Short-pulse high intensity laser thin foil interaction

    NASA Astrophysics Data System (ADS)

    Audebert, Patrick

    2003-10-01

    The technology of ultrashort pulse laser generation has progressed to the point that optical pulses larger than 10 J, 300 fs duration or shorter are routinely produced. Such pulses can be focused to intensities exceeding 10^18 W/cm^2. With high contrast pulses, these focused intensities can be used to heat solid matter to high temperatures with minimal hydrodynamic expansion, producing an extremely high energy-density state of matter for a short period of time. This high density, high temperature plasma can be studied by x-ray spectroscopy. We have performed experiments on thin foils of different elements under well controlled conditions at the 100 Terawatt laser at LULI to study the characteristics X-ray emission of laser heated solids. To suppress the ASE effect, the laser was frequency doubled. S-polarized light with a peak intensity of 10^19W/cm^2 was used to minimize resonance absorption. To decrease the effect of longitudinal temperature gradients very thin (800 μ) aluminum foil targets were used. We have also studied the effect of radial gradient by limiting the measured x-ray emission zone using 50μ or 100μ pinhole on target. The spectra, in the range 7-8Å, were recorded using a conical crystal spectrometer coupled to a 800 fs resolution streak camera. A Fourier Domain Interferometry (FDI) of the back of the foil was also performed providing a measurement of the hydrodynamic expansion as function of time for each shot. To simulate the experiment, we used the 1D hydrodynamic code FILM with a given set of plasma parameter (ρ, Te) as initial conditions. The X-ray emission was calculated by post processing hydrodynamic results with a collisional-radiative model which uses super-configuration average atomic data. The simulation reproduces the main features of the experimental time resolved spectrum.

  10. Promoting High-Performance Computing and Communications. A CBO Study.

    ERIC Educational Resources Information Center

    Webre, Philip

    In 1991 the Federal Government initiated the multiagency High Performance Computing and Communications program (HPCC) to further the development of U.S. supercomputer technology and high-speed computer network technology. This overview by the Congressional Budget Office (CBO) concentrates on obstacles that might prevent the growth of the…

  11. A high current, short pulse electron source for wakefield accelerators

    SciTech Connect

    Ho, Ching-Hung.

    1992-01-01

    Design studies for the generation of a high current, short pulse electron source for the Argonne Wakefield Accelerator are presented. An L-band laser photocathode rf gun cavity is designed using the computer code URMEL to maximize the electric field on the cathode surface for fixed frequency and rf input power. A new technique using a curved incoming laser wavefront to minimize the space charge effect near the photocathode is studied. A preaccelerator with large iris to minimize wakefield effects is used to boost the drive beam to a useful energy of around 20 MeV for wakefield acceleration experiments. Focusing in the photocathode gun and the preaccelerator is accomplished with solenoids. Beam dynamics simulations throughout the preaccelerator are performed using particle simulation codes TBCI-SF and PARMELA. An example providing a useful set of operation parameters for the Argonne Wakefield Accelerator is given. The effects of the sagitta of the curved beam and laser amplitude and timing jitter effects are discussed. Measurement results of low rf power level bench tests and a high power test for the gun cavity are presented and discussed.

  12. A high current, short pulse electron source for wakefield accelerators

    SciTech Connect

    Ho, Ching-Hung

    1992-12-31

    Design studies for the generation of a high current, short pulse electron source for the Argonne Wakefield Accelerator are presented. An L-band laser photocathode rf gun cavity is designed using the computer code URMEL to maximize the electric field on the cathode surface for fixed frequency and rf input power. A new technique using a curved incoming laser wavefront to minimize the space charge effect near the photocathode is studied. A preaccelerator with large iris to minimize wakefield effects is used to boost the drive beam to a useful energy of around 20 MeV for wakefield acceleration experiments. Focusing in the photocathode gun and the preaccelerator is accomplished with solenoids. Beam dynamics simulations throughout the preaccelerator are performed using particle simulation codes TBCI-SF and PARMELA. An example providing a useful set of operation parameters for the Argonne Wakefield Accelerator is given. The effects of the sagitta of the curved beam and laser amplitude and timing jitter effects are discussed. Measurement results of low rf power level bench tests and a high power test for the gun cavity are presented and discussed.

  13. An International Short Course for Training Professionals as Effective Science Communicators

    ERIC Educational Resources Information Center

    Sarathchandra, Dilshani; Maredia, Karim M.

    2014-01-01

    Scholars have recognized a need for educational programs that prepare scientists, Extension practitioners, and other stakeholders to communicate science effectively. Such programs have the potential to increase public awareness and aid policy development. Having recognized this need, faculty at Michigan State University (MSU) developed an…

  14. A Short Course in Communication for Prison Personnel & Offenders. Final Report.

    ERIC Educational Resources Information Center

    Brandes, Paul D.; Frazier, Michael

    The communication course presented in this document was developed as it was being offered at correctional centers throughout North Carolina from the fall of 1971 through the spring of 1976. The document contains 12 "encounters," or lessons, each of which discusses behavioral objectives, physical facilities, general advice, the time sequence, a…

  15. Short- and Long-Term Effectiveness of Two Communication Training Modalities with Distressed Couples.

    ERIC Educational Resources Information Center

    Schindler, Ludwig; And Others

    1983-01-01

    Investigated the effectiveness of communication training in treating marital discord for conjoint and conjoint group modalities. Results showed that conjoint couples (N=16) improved on five of seven outcome variables, while conjoint group couples (N=13) improved on two. One-year follow-up showed substantial reduction in treatment gains. (WAS)

  16. Short High Charge Bunches in the SLAC Linac

    SciTech Connect

    Decker, Franz-Josef

    2000-08-23

    These days the linac at the Stanford Linear Accelerator Center (SLAC) is mainly an injector for the PEP-II rings. But besides the electrons and positrons for PEP-II, it provides a 30 GeV electron or positron beam to the end of the linac into the FFTB (Final Focus Test Beam) area or creates a test beam for the A-Line. In the FFTB tunnel there are two plasma experiments installed, which have demonstrated plasma focusing and plasma acceleration up to 0.5 GeV/m. The acceleration goes linear with the current and is inversely proportional to the square of the bunch length. Therefore the authors are pushing the bunch length to shorter and shorter values adjusting the R{sub 56} in the RTL (Ring-To-Linac) compression section and precompressing the bunches in the damping ring. The nonlinearity of the RF and the higher order dispersion are becoming more important for bigger compression factors. Then the high-charge, short bunches will create strong longitudinal wakefields in the linac. They create a double-horned energy profile and have different beam dynamics than a long bunch in the linac. Measurements of the beam properties, like stability, distributions, tails, and backgrounds are discussed in this paper.

  17. Underwater propagation of high-data-rate laser communications pulses

    NASA Astrophysics Data System (ADS)

    Snow, Judith B.; Flatley, James P.; Freeman, Dennis E.; Landry, Mark A.; Lindstrom, Carl E.; Longacre, Jacob R.; Schwartz, Joshua A.

    1992-12-01

    High data rate underwater laser communications are highly constrained by laser propagation characteristics in the marine environment. We conducted communications experiments in freshwater and coastal seawater using an amplitude-modulated (i.e., pulsed) green laser beam detected by a remote optical receiver. We measured functional relationships between propagation distance, data rate, and error rate. Laser communications are degraded by absorption and scattering due to water, dissolved substances, suspended particulates, and marine biologics. Spatial beam spreading reduces the amount of optical signal that is collected by the detector. Pulse stretching temporally smears adjacent laser pulses, limiting maximum attainable data rate. Determining the capabilities of such a system requires characterization of the underwater communications channel. Relatively, little data is available regarding the relationship between optical water properties and the temporal behavior of laser pulses with pulsewidths in the nanosecond regime. We have conducted a series of experiments to measure both spatial and temporal properties of the propagating laser pulses. These through-water measurements have been made in the laboratory, in large fresh water tanks, in natural ponds, and in coastal seawater. We discuss spatial and temporal propagation characteristics of the underwater environment, and their relationships to the predicted performance supported by the communications channel.

  18. SLIM, Short-pulse Technology for High Gradient Induction Accelerators

    SciTech Connect

    Arntz, Floyd; Kardo-Sysoev, A.; Krasnykh, A.; /SLAC

    2008-12-16

    A novel short-pulse concept (SLIM) suited to a new generation of a high gradient induction particle accelerators is described herein. It applies advanced solid state semiconductor technology and modern microfabrication techniques to a coreless induction method of charged particle acceleration first proven on a macro scale in the 1960's. Because this approach avoids use of magnetic materials there is the prospect of such an accelerator working efficiently with accelerating pulses in the nanosecond range and, potentially, at megahertz pulse rates. The principal accelerator section is envisioned as a stack of coreless induction cells, the only active element within each being a single, extremely fast (subnanosecond) solid state opening switch: a Drift Step Recovery Diode (DSRD). Each coreless induction cell incorporates an electromagnetic pulse compressor in which inductive energy developed within a transmission-line feed structure over a period of tens of nanoseconds is diverted to the acceleration of the passing charge packet for a few nanoseconds by the abrupt opening of the DSRD switch. The duration of this accelerating output pulse--typically two-to-four nanoseconds--is precisely determined by a microfabricated pulse forming line connected to the cell. Because the accelerating pulse is only nanoseconds in duration, longitudinal accelerating gradients approaching 100 MeV per meter are believed to be achievable without inciting breakdown. Further benefits of this approach are that, (1) only a low voltage power supply is required to produce the high accelerating gradient, and, (2) since the DSRD switch is normally closed, voltage stress is limited to a few nanoseconds per period, hence the susceptibility to hostile environment conditions such as ionizing radiation, mismatch (e.g. in medical applications the peak beam current may be low), strong electromagnetic noise levels, etc is expected to be minimal. Finally, we observe the SLIM concept is not limited to linac applications; for instance, it could be employed to both accelerate the beam and to stabilize the superbunch mode of operation in circular track machines.

  19. Non-chemical and non-contact cell-to-cell communication: a short review

    PubMed Central

    Scholkmann, Felix; Fels, Daniel; Cifra, Michal

    2013-01-01

    Cell-to-cell communication is the basis of coordinated cellular activity and thus fundamental for the functioning of biological systems. In a recently published research article by Chaban et al. (Am. J. Transl. Res., 5(1), 69-79), the authors report on interesting new experimental findings supporting a neuro-hormonal independent, non-diffusible cell-to-cell signaling. Our paper aims to (i) discuss some critical notions used by the authors to describe their findings, and (ii) briefly review related experimental work performed so far but not discussed in the original work of Chaban et al. In our opinion, the research on principles of non-chemical and non-contact cell-to-cell communication has the potential to offer new fundamental insights into biological processes. With this paper, we want to encourage future research on this topic by discussing critical issues and giving an overview of the current state of research. PMID:24093056

  20. High Performance Computing and Communications: Toward a National Information Infrastructure.

    ERIC Educational Resources Information Center

    Federal Coordinating Council for Science, Engineering and Technology, Washington, DC.

    This report describes the High Performance Computing and Communications (HPCC) initiative of the Federal Coordinating Council for Science, Engineering, and Technology. This program is supportive of and coordinated with the National Information Infrastructure Initiative. Now halfway through its 5-year effort, the HPCC program counts among its…

  1. Ka-band MMIC microstrip array for high rate communications

    NASA Technical Reports Server (NTRS)

    Lee, R. Q.; Raquet, C. A.; Tolleson, J. B.; Sanzgiri, S. M.

    1991-01-01

    In a recent technology assessment of alternative communication systems for the space exploration initiative (SEI), Ka-band (18 to 40 GHz) communication technology was identified to meet the mission requirements of telecommunication, navigation, and information management. Compared to the lower frequency bands, Ka-band antennas offer higher gain and broader bandwidths; thus, they are more suitable for high data rate communications. Over the years, NASA has played an important role in monolithic microwave integrated circuit (MMIC) phased array technology development, and currently, has an ongoing contract with Texas Instrument (TI) to develop a modular Ka-band MMIC microstrip subarray (NAS3-25718). The TI contract emphasizes MMIC integration technology development and stipulates using existing MMIC devices to minimize the array development cost. The objective of this paper is to present array component technologies and integration techniques used to construct the subarray modules.

  2. A secure communications infrastructure for high-performance distributed computing

    SciTech Connect

    Foster, I.; Koenig, G.; Tuecke, S.

    1997-08-01

    Applications that use high-speed networks to connect geographically distributed supercomputers, databases, and scientific instruments may operate over open networks and access valuable resources. Hence, they can require mechanisms for ensuring integrity and confidentially of communications and for authenticating both users and resources. Security solutions developed for traditional client-server applications do not provide direct support for the program structures, programming tools, and performance requirements encountered in these applications. The authors address these requirements via a security-enhanced version of the Nexus communication library; which they use to provide secure versions of parallel libraries and languages, including the Message Passing Interface. These tools permit a fine degree of control over what, where, and when security mechanisms are applied. In particular, a single application can mix secure and nonsecure communication, allowing the programmer to make fine-grained security/performance tradeoffs. The authors present performance results that quantify the performance of their infrastructure.

  3. Commercial optical inter-satellite communication at high data rates

    NASA Astrophysics Data System (ADS)

    Gregory, Mark; Heine, Frank; Kämpfner, Hartmut; Lange, Robert; Lutzer, Michael; Meyer, Rolf

    2012-03-01

    Laser communication terminals with data rates far above 1 Gbps have been in operation in orbit since January 2008, and the links established between two low Earth orbit (LEO) satellites have demonstrated error-free communication. Bit error rates better than 10-11 have been achieved without data encoding. Signal acquisition can be reproducibly achieved within a few seconds. After adaptation to larger link separation distances these laser communication terminals will be used in the low earth orbit-geosynchronous satellite (LEO-GEO) link of European data relay satellite (EDRS), the GEO European data relay system. LEO-to-ground and ground-to-LEO links have examined the impact of the atmosphere on such optical links. In the future, high data rate GEO-to-ground links will require ground stations equipped with adaptive optics, which are currently under development.

  4. System and method that suppresses intensity fluctuations for free space high-speed optical communication

    DOEpatents

    Berman, Gennady P.; Bishop, Alan R.; Nguyen, Dinh C.; Chernobrod, Boris M.; Gorshkov, Vacheslav N.

    2009-10-13

    A high-speed (Gbps), free space optical communication system is based on spectral encoding of radiation from a wide band light source, such as a laser. By using partially coherent laser beams in combination with a relatively slow photosensor, scintillations can be suppressed by orders of magnitude for distances of more than 10 km. To suppress the intensity fluctuations due to atmospheric turbulence, a source with partial transverse coherence in combination with slow response time photodetector is used. Information is encoded in the spectral domain of a wideband optical source by modulation of spectral amplitudes. A non-coherent light source with wide spectrum (an LED, for example) may be used for high-speed communication over short (less than about a mile) distances.

  5. A highly innovative global broadband mobile communication system concept

    NASA Astrophysics Data System (ADS)

    Wittig, Manfred

    2010-04-01

    Global mobile communication systems deployed in the 1990s (Iridium and Globalstar) failed to achieve the expected market success. However, recently a second generation of these two LEO constellations have been or will be procured. This shows evidence that global mobile satellite communications are attractive for a certain class of users. Basic requirements for mobile satellite communication networks are global coverage at high elevation angles, continuous availability and most important attractive service offers. For the first two reasons LEO constellations were designed and deployed. The large number of required satellites (remember the original Teledesic concept was designed containing 860 satellites) increases the CAPEX and consequently the service cost. This is probably the major reason for the limited commercial success of Iridium and Globalstar. An ideal global mobile (broadband) communication system shall provide global coverage at high elevation angles (not below e.g. 30°) with the lowest number of satellites. This seems to be contradictory. However, a solution will be presented that achieves global coverage which requires only five satellites and achieves high elevation angles even at polar locations. This orbit constellation is to be complemented with innovative payloads to achieve cost efficient broadband mobile services all over the Globe. Innovative L/S-band payload concepts will be introduced as well as Ka-band payloads.

  6. Iridium Short Burst Data: Two-Way, Robust, Reliable, Low Power Communications for Oceanographic Data Transmission Applications

    NASA Astrophysics Data System (ADS)

    Roggenstein, E. B.; Hensley, W.

    2011-12-01

    Over the past two hundred years, water level observations in coastal areas have been used to help mariners navigate oceans and estuaries, cartographers develop nautical charts, government agencies regulate boundaries, and scientists gain a better understanding of various physical processes in the ocean. As technology has progressed the latency in providing these data to the user has been reduced. The National Oceanic and Atmospheric Administration's (NOAA) Center for Operational Oceanographic Products and Services (CO-OPS) provides near real-time oceanographic and meteorological data to support navigation, coastal managers, and storm surge and tsunami warning programs. CO-OPS maintains the National Water Level Observation Network (NWLON), a system of over 200 stations for the coastal United States, Great Lakes, Caribbean islands, and Pacific island territories. CO-OPS also supports the NOAA Physical Oceanographic Real Time Systems° (PORTS), which are currently operating in 21 US ports. With an expanding role in Arctic and Alaska support, CO-OPS has identified a need for a robust and reliable data communications pathway to supplement the existing Geostationary Operational Environmental Systems (GOES) network, which has limitations at high latitudes. Iridium satellite Short Burst Data (SBD) services offer a global coverage, including remote Arctic regions outside of GOES coverage. Previous testing conducted by CO-OPS has shown a great potential for the SBD service including continuous near-real-time 6 minute data transmissions from two CO-OPS test water level stations located in Guam, with >99.9% data return. Also, successful transmissions of hourly wave statistics were demonstrated with a with a test system that employed a Nortek Acoustic Wave and Current (AWAC) instrument in Chesapeake Bay were accomplished. Data transmissions involved a buoy-mounted SIM-less SBD modem. Independent of location, data can be transmitted from a remote instrument platform to Iridium satellites with a latency of just 15 seconds. Successful test demonstrations have led to discussions regarding prospective work to integrate these small modems into CO-OPS current meters that are mounted on United States Coast Guard (USCG) Aid to Navigation (ATON) buoys, improving the reliability of the real-time transmission pathway between data collection and data reporting via PORTS °. Overall, this work has shown that with careful evaluation of data needs, commercial Iridium service can be economically used to accomplish telemetry requirements. It also shows potential for event-driven high frequency data transmission options, for applications such as marine warning systems. CO-OPS efforts to test and evaluate Iridium communications oceanographic observatories reported on here has been a collaborative endeavor with the United States Army Corp Engineers (USACE) Field Research Facility (FRF) in Duck, NC, the USACE Cold Regions Research Engineering Laboratory (CRREL) in Hanover, NH, NAL Research Inc, Sutron Corporation,and Nortek USA.

  7. Photonics and other approaches to high speed communications

    NASA Technical Reports Server (NTRS)

    Maly, Kurt

    1992-01-01

    Our research group of 4 faculty and about 10-15 graduate students was actively involved (as a group) in the development of computer communication networks for the last five years. Many of its individuals have been involved in related research for a much longer period. The overall research goal is to extend network performance to higher data rates, to improve protocol performance at most ISO layers and to improve network operational performance. We briefly state our research goals, then discuss the research accomplishments and direct your attention to attached and/or published papers which cover the following topics: scalable parallel communications; high performance interconnection between high data rate networks; and a simple, effective media access protocol system for integrated, high data rate networks.

  8. RAPID COMMUNICATION: Enhanced performance of a dielectric barrier discharge lamp using short-pulsed excitation

    NASA Astrophysics Data System (ADS)

    Mildren, R. P.; Carman, R. J.

    2001-01-01

    We observe marked increases in the time-averaged intensity, peak intensity, efficiency and spectral purity of the VUV output from an Xe excimer barrier discharge lamp when using short-pulse (~150 ns FWHM (full width half maximum)) excitation. Intensity increases with Xe pressure up to 600 Torr with a maximum output 2.6 times higher and an efficiency 3.2 times higher than the same lamp excited by conventional ac excitation (i.e. sinusoidal voltage waveform). The output occurs in regular short pulses (<300 ns FWHM) with a peak intensity more than six times the peak intensity typically obtained using ac. The spectral characteristics are similar to that observed using ac excitation except that the ratio of VUV to visible Xe* emission increases by a factor of three. The pulsed discharge appears diffuse (i.e. glow-like), even at the higher pressures at which the ac discharge is filamentary. It is concluded that the enhanced performance results largely from the ability for pulsed excitation to generate a discharge at near atmospheric pressures with a much lower electron density than that possible using ac.

  9. Stagings: Short Scripts for Middle and High School Students.

    ERIC Educational Resources Information Center

    Garner, Joan

    Introducing students to the magic of theater and helping them develop dramatic skills, this book presents nine reproducible scripts for short plays (15 to 25 minutes) with characters and story lines that will appeal to young people. The scripts in the book encompass a variety of story types, from adaptations of well-known fairy tales to original…

  10. Using Fairy Tales To Generate High Interest in Short Fiction.

    ERIC Educational Resources Information Center

    McKenna, Barbara J.

    2001-01-01

    Discusses how fairy tales provide the vehicle by which students become genuinely engaged in reading and writing short fiction. Outlines a three-step process moving students from familiar stories, to variations on traditional tales, finally to new stories. Details how writing, revising, illustrating, and binding a fairy tale engages students. (PM)

  11. Analysis of SCTP and TCP based communication in high-speed clusters

    NASA Astrophysics Data System (ADS)

    Kozlovszky, M.; Berceli, T.; Kutor, L.

    2006-04-01

    Performance and financial constraints are pushing modern DAQs (Data Acquisition Systems) to use distributed cluster environments instead of monolith one-box systems. Inside clusters application communication layers should support outstanding high performance requirements. We are currently investigating different network protocols that could meet the requirements of high speed/low latency peer-to-peer communication within DAQ clusters. We have carried out various performance measurements with TCP and SCTP over Fast and Gigabit Ethernet. We are focusing on Ethernet Technologies, because this transport medium is broad deployed, cost efficient and it has much better cost/throughput ratio than other available communication alternatives (e.g.: Myrinet, Infiniband). During this study, a protocol performance measurement application with different peer transport components has been developed. In the first part of the paper, we give a short comparison of the two protocols (SCTP and TCP), and an introduction of the transport layer structure developed. Later on we discuss the performance results of single/multi-stream peer-to-peer communication, give overview about application code transition possibilities from application developer point of view between the two protocols, and draw conclusions about usability.

  12. High power, high efficiency millimeter wavelength traveling wave tubes for high rate communications from deep space

    NASA Technical Reports Server (NTRS)

    Dayton, James A., Jr.

    1991-01-01

    The high-power transmitters needed for high data rate communications from deep space will require a new class of compact, high efficiency traveling wave tubes (TWT's). Many of the recent TWT developments in the microwave frequency range are generically applicable to mm wave devices, in particular much of the technology of computer aided design, cathodes, and multistage depressed collectors. However, because TWT dimensions scale approximately with wavelength, mm wave devices will be physically much smaller with inherently more stringent fabrication tolerances and sensitivity to thermal dissipation.

  13. High Data Rate Satellite Communications for Environmental Remote Sensing

    NASA Astrophysics Data System (ADS)

    Jackson, J. M.; Munger, J.; Emch, P. G.; Sen, B.; Gu, D.

    2014-12-01

    Satellite to ground communication bandwidth limitations place constraints on current earth remote sensing instruments which limit the spatial and spectral resolution of data transmitted to the ground for processing. Instruments such as VIIRS, CrIS and OMPS on the Soumi-NPP spacecraft must aggregate data both spatially and spectrally in order to fit inside current data rate constraints limiting the optimal use of the as-built sensors. Future planned missions such as HyspIRI, SLI, PACE, and NISAR will have to trade spatial and spectral resolution if increased communication band width is not made available. A number of high-impact, environmental remote sensing disciplines such as hurricane observation, mega-city air quality, wild fire detection and monitoring, and monitoring of coastal oceans would benefit dramatically from enabling the downlinking of sensor data at higher spatial and spectral resolutions. The enabling technologies of multi-Gbps Ka-Band communication, flexible high speed on-board processing, and multi-Terabit SSRs are currently available with high technological maturity enabling high data volume mission requirements to be met with minimal mission constraints while utilizing a limited set of ground sites from NASA's Near Earth Network (NEN) or TDRSS. These enabling technologies will be described in detail with emphasis on benefits to future remote sensing missions currently under consideration by government agencies.

  14. Communications

    NASA Technical Reports Server (NTRS)

    Stouffer, Donald D.

    1990-01-01

    Communication in its many forms is a critical component for an effective Space Grant Program. Good communication is needed within individual Space Grant College/Consortia, for example between consortium affiliates and the consortium program office. Effective communication between the several programs, NASA Headquarters, and NASA field centers also is required. Further, communication among the above program elements, industry, local and state government, and the public also are necessary for meeting program objectives.

  15. High performance computing and communications: FY 1996 implementation plan

    SciTech Connect

    1995-05-16

    The High Performance Computing and Communications (HPCC) Program was formally authorized by passage of the High Performance Computing Act of 1991, signed on December 9, 1991. Twelve federal agencies, in collaboration with scientists and managers from US industry, universities, and research laboratories, have developed the Program to meet the challenges of advancing computing and associated communications technologies and practices. This plan provides a detailed description of the agencies` HPCC implementation plans for FY 1995 and FY 1996. This Implementation Plan contains three additional sections. Section 3 provides an overview of the HPCC Program definition and organization. Section 4 contains a breakdown of the five major components of the HPCC Program, with an emphasis on the overall directions and milestones planned for each one. Section 5 provides a detailed look at HPCC Program activities within each agency.

  16. High Temperature Wireless Communication And Electronics For Harsh Environment Applications

    NASA Technical Reports Server (NTRS)

    Hunter, G. W.; Neudeck, P. G.; Beheim, G. M.; Ponchak, G. E.; Chen, L.-Y

    2007-01-01

    In order for future aerospace propulsion systems to meet the increasing requirements for decreased maintenance, improved capability, and increased safety, the inclusion of intelligence into the propulsion system design and operation becomes necessary. These propulsion systems will have to incorporate technology that will monitor propulsion component conditions, analyze the incoming data, and modify operating parameters to optimize propulsion system operations. This implies the development of sensors, actuators, and electronics, with associated packaging, that will be able to operate under the harsh environments present in an engine. However, given the harsh environments inherent in propulsion systems, the development of engine-compatible electronics and sensors is not straightforward. The ability of a sensor system to operate in a given environment often depends as much on the technologies supporting the sensor element as the element itself. If the supporting technology cannot handle the application, then no matter how good the sensor is itself, the sensor system will fail. An example is high temperature environments where supporting technologies are often not capable of operation in engine conditions. Further, for every sensor going into an engine environment, i.e., for every new piece of hardware that improves the in-situ intelligence of the components, communication wires almost always must follow. The communication wires may be within or between parts, or from the engine to the controller. As more hardware is added, more wires, weight, complexity, and potential for unreliability is also introduced. Thus, wireless communication combined with in-situ processing of data would significantly improve the ability to include sensors into high temperature systems and thus lead toward more intelligent engine systems. NASA Glenn Research Center (GRC) is presently leading the development of electronics, communication systems, and sensors capable of prolonged stable operation in harsh 500C environments. This has included world record operation of SiC-based transistor technology (including packaging) that has demonstrated continuous electrical operation at 500C for over 2000 hours. Based on SiC electronics, development of high temperature wireless communication has been on-going. This work has concentrated on maturing the SiC electronic devices for communication purposes as well as the passive components such as resistors and capacitors needed to enable a high temperature wireless system. The objective is to eliminate wires associated with high temperature sensors which add weight to a vehicle and can be a cause of sensor unreliability. This paper discusses the development of SiC based electronics and wireless communications technology for harsh environment applications such as propulsion health management systems and in Venus missions. A brief overview of the future directions in sensor technology is given including maturing of near-room temperature "Lick and Stick" leak sensor technology for possible implementation in the Crew Launch Vehicle program. Then an overview of high temperature electronics and the development of high temperature communication systems is presented. The maturity of related technologies such as sensor and packaging will also be discussed. It is concluded that a significant component of efforts to improve the intelligence of harsh environment operating systems is the development and implementation of high temperature wireless technology

  17. Communication.

    ERIC Educational Resources Information Center

    Hancock, Alan

    An informal introduction to the study of communication deals with the major topics in the field. It presents basic theories of communication and language, reviews how language takes on meaning, explains the stimulus-response and Piaget theories of learning, and presents major theories dealing with communications and society. These theories include…

  18. High Performance Remote Memory Access Communication: The ARMCI Approach

    SciTech Connect

    Nieplocha, Jarek; Tipparaju, Vinod; Krishnan, Manoj Kumar; Panda, Dhabaleswar K.

    2006-07-01

    This paper describes the Aggregate Remote Memory Copy Interface (ARMCI), a portable high performance remote memory access (RMA) communication interface, developed originally under the DoE-2000 ACTS Toolkit project and currently used as a part of the run-time layer of the DoE project Programming Models for Scalable Parallel Computing. The paper discusses the model, portable implementation, and performance of ARMCI. Special emphasis is placed on the latency hiding mechanisms and ability to optimize noncontiguous data transfers.

  19. Low Cost Cryocoolers for High Temperature Superconductor Communication Filters

    NASA Technical Reports Server (NTRS)

    Brown, Davina

    1998-01-01

    This final report describes the work performed by a consortium of Industry and Government to develop low cost cryocoolers. The specific application was for low cost commercial based high temperature superconductor communication filters. This program was initiated in January 1995 and resulted in the successful demonstration of an HTS filter dewar cooled by a low cost pulse tube cryocooler. Further development of this cryocooler technology is proceeding through various contracts underway and proposed at this time.

  20. Taipei's Use of a Multi-Channel Mass Risk Communication Program to Rapidly Reverse an Epidemic of Highly Communicable Disease

    PubMed Central

    Yen, Muh-Yong; Wu, Tsung-Shu Joseph; Chiu, Allen Wen-Hsiang; Wong, Wing-Wai; Wang, Po-En; Chan, Ta-Chien; King, Chwan-Chuen

    2009-01-01

    Background In September 2007, an outbreak of acute hemorrhagic conjunctivitis (AHC) occurred in Keelung City and spread to Taipei City. In response to the epidemic, a new crisis management program was implemented and tested in Taipei. Methodology and Principal Findings Having noticed that transmission surged on weekends during the Keelung epidemic, Taipei City launched a multi-channel mass risk communications program that included short message service (SMS) messages sent directly to approximately 2.2 million Taipei residents on Friday, October 12th, 2007. The public was told to keep symptomatic students from schools and was provided guidelines for preventing the spread of the disease at home. Epidemiological characteristics of Taipei's outbreak were analyzed from 461 sampled AHC cases. Median time from exposure to onset of the disease was 1 day. This was significantly shorter for cases occurring in family clusters than in class clusters (mean±SD: 2.6±3.2 vs. 4.39±4.82 days, p = 0.03), as well as for cases occurring in larger family clusters as opposed to smaller ones (1.2±1.7 days vs. 3.9±4.0 days, p<0.01). Taipei's program had a significant impact on patient compliance. Home confinement of symptomatic children increased from 10% to 60% (p<0.05) and helped curb the spread of AHC. Taipei experienced a rapid decrease in AHC cases between the Friday of the SMS announcement and the following Monday, October 15, (0.70% vs. 0.36%). By October 26, AHC cases reduced to 0.01%. The success of this risk communication program in Taipei (as compared to Keelung) is further reflected through rapid improvements in three epidemic indicators: (1) significantly lower crude attack rates (1.95% vs. 14.92%, p<0.001), (2) a short epidemic period of AHC (13 vs. 34 days), and (3) a quick drop in risk level (1∼2 weeks) in Taipei districts that border Keelung (the original domestic epicenter). Conclusions and Significance The timely launch of this systematic, communication-based intervention proved effective at preventing a dangerous spike in AHC and was able to bring this high-risk disease under control. We recommend that public health officials incorporate similar methods into existing guidelines for preventing pandemic influenza and other emerging infectious diseases. PMID:19956722

  1. Earth Science Mission Benefits of High Data Rate Satellite Communications

    NASA Astrophysics Data System (ADS)

    Jackson, J. M.; Munger, J.; Emch, P. G.; Sen, B.; Gu, D.

    2013-12-01

    Satellite to ground communication bandwidth limitations place constraints on current earth remote sensing instruments which limit the spatial and spectral resolution of data transmitted to the ground for processing. Instruments such as VIIRS, CrIS and OMPS on the Soumi-NPP spacecraft must aggregate data both spatially and spectrally in order to fit inside current data rate constraints limiting the optimal use of the as-built sensors. Future planned missions such as PACE, TEMPO and DESDynI Radar will have to trade spatial and spectral resolution if increased communication band width is not made available. A number of high-impact, environmental remote sensing disciplines such as hurricane observation, mega-city air quality, wild fire detection and monitoring, and monitoring of coastal oceans would benefit dramatically from enabling the downlinking of sensor data at higher spatial and spectral resolutions. The enabling technologies of multi-Gbps Ka-Band communication and multi-Terabit SSRs are currently available with high technological maturity enabling high data volume mission requirements to be met with minimal mission constraints while utilizing only a very few ground sites from NASA's Near Earth Network (NEN). These enabling technologies will be described in detail with emphasis on benefits to future remote sensing missions currently under consideration by government agencies.

  2. Development of short message service application for patient-provider communication in clinical psychiatry.

    PubMed

    Mkel, Kari; Paavola, Teemu; Stenman, Markku

    2010-09-01

    This prospective study is the first one of its kind carried out in Finland, in which a simple technological platform was developed to merge traditional text messaging with an electronic patient information database. The technology has been tested for relaying two-way treatment messages in psychiatry provided by a central hospital offering secondary healthcare. Text messaging was found to be particularly well suited for young people who have to travel to the outpatient clinic over long distances or who face the risk of social exclusion. According to clinicians, the text message reminders sent between the visits, which take place every 1-2 months, can encourage the young people in question to stay in touch more frequently, which will help to improve their relationship with the hospital staff. The project is still in the pilot stage, and so far the most important results concern the development of the operating culture and, surprisingly enough, legal aspects. From the legal point of view, the hospital had to equate text messages with phone communications. For this reason, it was not possible to put the text messages into a separate register and they have not been archived either. The success or failure of the new innovative healthcare solution may, therefore, depend on both technological aspects and legal factors. PMID:20815750

  3. SHORT COMMUNICATION: Comments on recent proposals for redefining the mole and kilogram

    NASA Astrophysics Data System (ADS)

    Leonard, B. P.

    2010-06-01

    The fundamental concept of the mole requires the number of entities comprising one mole, i.e. Avogadro's number, to be exactly equal to the gram-to-dalton mass ratio. If this compatibility condition is to be satisfied, the mole, the kilogram and the dalton cannot all be defined independently. This note concerns recent Metrologia publications that do, however, propose independent definitions of all three quantities: the mole by fixing the value of Avogadro's number and the kilogram by fixing the value of the Planck constant, while retaining the current carbon-12-based dalton. Adoption of these incompatible definitions would likely cause serious widespread confusion and might even result in a split in scholarly and technical communication between the quantum physics and chemistry communities. Other entirely compatible alternatives are possible: either retaining the current (inexact) carbon-12-based mole and dalton with an independently redefined kilogram or redefining the mole by fixing the value of Avogadro's number, with a compatible dalton that is exact in terms of the redefined kilogram.

  4. Exposure caused by wireless technologies used for short-range indoor communication in homes and offices.

    PubMed

    Schmid, G; Lager, D; Preiner, P; Uberbacher, R; Cecil, S

    2007-01-01

    In order to estimate typical radio frequency exposures from indoor used wireless communication technologies applied in homes and offices, WLAN, Bluetooth and Digital Enhanced Cordless Telecommunications systems, as well as baby surveillance devices and wireless headphones for indoor usage, have been investigated by measurements and numerical computations. Based on optimised measurement methods, field distributions and resulting exposure were assessed on selected products and real exposure scenarios. Additionally, generic scenarios have been investigated on the basis of numerical computations. The obtained results demonstrate that under usual conditions the resulting spatially (over body dimensions) averaged and 6-min time-averaged exposure for persons in the radio frequency fields of the considered applications is below approximately 0.1% of the reference level for power density according to the International Commission on Non-Ionizing Radiation Protection (ICNIRP) guidelines published in 1998. Spatial and temporal peak values can be considerably higher by 2-3 orders of magnitude. In case of some transmitting devices operated in close proximity to the body (e.g. WLAN transmitters), local exposure can reach the same order of magnitude as the basic restriction; however, none of the devices considered in this study exceeded the limits according to the ICNIRP guidelines. PMID:17566000

  5. All-reflective, highly accurate polarization rotator for high-power short-pulse laser systems.

    PubMed

    Keppler, S; Hornung, M; Bödefeld, R; Kahle, M; Hein, J; Kaluza, M C

    2012-08-27

    We present the setup of a polarization rotating device and its adaption for high-power short-pulse laser systems. Compared to conventional halfwave plates, the all-reflective principle using three zero-phase shift mirrors provides a higher accuracy and a higher damage threshold. Since plan-parallel plates, e.g. these halfwave plates, generate postpulses, which could lead to the generation of prepulses during the subsequent laser chain, the presented device avoids parasitic pulses and is therefore the preferable alternative for high-contrast applications. Moreover the device is easily scalable for large beam diameters and its spectral reflectivity can be adjusted by an appropriate mirror coating to be well suited for ultra-short laser pulses. PMID:23037123

  6. A UHF RFID system with on-chip-antenna tag for short range communication

    NASA Astrophysics Data System (ADS)

    Qi, Peng; Chun, Zhang; Xijin, Zhao; Zhihua, Wang

    2015-05-01

    A UHF RF identification system based on the 0.18 μm CMOS process has been developed for short range and harsh size requirement applications, which is composed of a fully integrated tag and a special reader. The whole tag chip with the antenna takes up an area of 0.36 mm2, which is smaller than other reported tags with an on-chip antenna (OCA) using the standard CMOS process. A self-defined protocol is proposed to reduce the power consumption, and minimize the size of the tag. The specialized SOC reader system consists of the RF transceiver, digital baseband, MCU and host interface. Its power consumption is about 500 mW. Measurement results show that the system's reading range is 2 mm with 20 dBm reader output power. With an inductive antenna printed on a paper substrate around the OCA tag, the reading range can be extended from several centimeters to meters, depending on the shape and size of the inductive antenna.

  7. Measurement of endogenous allergens in genetically modified soybeans--short communication.

    PubMed

    Ladics, Gregory S; Budziszewski, Gregory J; Herman, Rod A; Herouet-Guicheney, Corinne; Joshi, Saurabh; Lipscomb, Elizabeth A; McClain, Scott; Ward, Jason M

    2014-10-01

    The measurement of endogenous allergens is required by the European Commission (EC) as part of the compositional analysis for GM products from host plants that are common causes of food allergy, such as soybean (EC Implementing Regulation No. 503/2013). In each case, the EC Implementing Regulation indicates that analysis be conducted on identified allergens as specified in the Organization of Economic Cooperation and Development (OECD) consensus documents on compositional considerations for new plant varieties. This communication discusses the methods available to measure endogenous allergens as well as the endogenous soybean allergens that should be analyzed. It is suggested herein that in conjunction with the 2012 OECD consensus document on soybean, any list of soybean allergens should be based on clinically relevant data among publicly available allergen databases and peer-reviewed scientific publications, and the ability to measure the identified allergen. Based on a detailed analysis of the scientific literature, the following key points are recommended: (1) the acceptance of serum-free, quantitative analytical method data as an alternative to traditional IgE reactivity qualitative or semi-quantitative data for evaluation of endogenous soybean allergen content; (2) eight of the 15 potential allergens listed in the OECD soybean consensus document (Gly m 3, Gly m 4, Gly m Bd28K, Gly m Bd30K, Gly m 5, Gly m 6, Gly m 8, and Kunitz trypsin inhibitor) have both appropriate supporting clinical data and sufficient sequence information to be evaluated in comparative endogenous soybean allergen studies; and (3) the remaining seven proteins (Gly m 1, Gly m 2, unknown 50kDa protein, unknown 39kDa protein, P-22-25, lipoxygenase and lectin) lack sufficient data for clear classification as confirmed allergens and/or available sequence information and should not be currently included in the measurement of endogenous soybean allergens in the compositional analysis for the EU. PMID:24945742

  8. High-power diode lasers for optical communications applications

    NASA Technical Reports Server (NTRS)

    Carlin, D. B.; Goldstein, B.; Channin, D. J.

    1985-01-01

    High-power, single-mode, double-heterojunction AlGaAs diode lasers are being developed to meet source requirements for both fiber optic local area network and free space communications systems. An individual device, based on the channeled-substrate-planar (CSP) structure, has yielded single spatial and longitudinal mode outputs of up to 90 mW CW, and has maintained a single spatial mode to 150 mW CW. Phase-locked arrays of closely spaced index-guided lasers have been designed and fabricated with the aim of multiplying the outputs of the individual devices to even higher power levels in a stable, single-lobe, anastigmatic beam. The optical modes of the lasers in such arrays can couple together in such a way that they appear to be emanating from a single source, and can therefore be efficiently coupled into optical communications systems. This paper will review the state of high-power laser technology and discuss the communication system implications of these devices.

  9. When are high-tech communicators effective in Parkinson's disease?

    PubMed

    Ferriero, Giorgio; Caligari, Marco; Ronconi, Gianpaolo; Franchignoni, Franco

    2012-03-01

    This report describes a 63-year-old woman with Parkinson's disease showing loss of intelligibility of speech and severely impaired handwriting, despite undergoing physical and speech therapies. As the patient had sufficient residual motor abilities and adequate cognitive function and motivation, a computer-based communication aid with a software program for word prediction and voice output was tested, and was prescribed after a training period. One year later, the patient was still using the customized device to communicate and for leisure time, showing a high degree of satisfaction with the aid (assessed by QUEST 2.0), which had a positive impact on her well-being and quality of life (assessed by Psychosocial Impact of Assistive Devices Scales). In conclusion, in selected patients with Parkinson's disease, high-tech augmentative and alternative communication devices may be considered, tested, and prescribed after a positive training period. Follow-ups are necessary to monitor the effectiveness of the assistive device and respond to specific patient needs that may arise with using the device. PMID:22186614

  10. Short communication: Factors affecting hair cortisol concentrations in lactating dairy cows.

    PubMed

    Burnett, Tracy A; Madureira, Augusto M L; Silper, Bruna F; Nadalin, Audrey; Tahmasbi, Abdolmansour; Veira, Douglas M; Cerri, Ronaldo L A

    2014-12-01

    Cortisol has long been used as a marker of the stress response in animals. Cortisol can be analyzed from different media, most notably from the blood, saliva, and feces; however, the collection of cortisol from some of these media requires invasive procedures or excessive handling of the animals. Furthermore, it is not possible to capture long-term increases in circulating concentrations of cortisol from the blood, saliva, or feces. Hair cortisol has been found to be a reliable alternative for measuring chronic stress. With this emerging measure, appropriate sampling methodology must be developed and validated. The aim of this study was to determine the effects of hair color, sampling location, and processing method on cortisol concentrations in hair from lactating black and white Holstein cows (n=18). Furthermore, we aimed to measure the hair growth rates at different body locations (n=12) and test hair cortisol levels when resampled over short intervals (n=37). Both black- and white-colored hair was collected from the shoulder, top line, hip, and tail switch of Holsteins; due to breed characteristics only white hair was harvested from the tail switch. All samples were cleaned with water and isopropanol, and then ground in a ball mill or finely cut with scissors once dry. Cortisol was extracted with methanol before being measured using a commercially available ELISA kit. Concentrations of cortisol were greater in white than in black hair (7.8 ± 1.1 vs. 3.8 ± 1.1 pg/mg). When only white samples were analyzed, hair from the tail switch had more cortisol than hair from the shoulder (11.0 ± 1.2 vs. 6.2 ± 1.2 pg/mg), whereas no difference was found when compared with the hip and top line. Samples ground with a ball mill had greater concentrations of cortisol extracted than those minced with scissors (10.4 ± 1.2 vs. 4.7 ± 1.2 pg/mg). The growth rate of hair was significantly greater at the tail switch compared with the hip and shoulder (0.51 ± 0.05 vs. 0.04 ± 0.05 vs. 0.03 ± 0.05 mm/d). When hair was collected every 3 wk after calving, a tendency was detected for multiparous cows to have greater concentrations of hair cortisol and significantly greater concentrations of cortisol on d 0 and 21 after calving compared with d 42, 84, and 126. In Holsteins, the hair on the tail switch is always white, grows more rapidly than other sites, and is sensitive enough to capture changes in cortisol over intervals as short as 3 wk, making it the ideal location for measuring hair cortisol. PMID:25282411

  11. High performance computing and communications: FY 1997 implementation plan

    SciTech Connect

    1996-12-01

    The High Performance Computing and Communications (HPCC) Program was formally authorized by passage, with bipartisan support, of the High-Performance Computing Act of 1991, signed on December 9, 1991. The original Program, in which eight Federal agencies participated, has now grown to twelve agencies. This Plan provides a detailed description of the agencies` FY 1996 HPCC accomplishments and FY 1997 HPCC plans. Section 3 of this Plan provides an overview of the HPCC Program. Section 4 contains more detailed definitions of the Program Component Areas, with an emphasis on the overall directions and milestones planned for each PCA. Appendix A provides a detailed look at HPCC Program activities within each agency.

  12. Multiply-agile encryption in high speed communication networks

    SciTech Connect

    Pierson, L.G.; Witzke, E.L.

    1997-05-01

    Different applications have different security requirements for data privacy, data integrity, and authentication. Encryption is one technique that addresses these requirements. Encryption hardware, designed for use in high-speed communications networks, can satisfy a wide variety of security requirements if that hardware is key-agile, robustness-agile and algorithm-agile. Hence, multiply-agile encryption provides enhanced solutions to the secrecy, interoperability and quality of service issues in high-speed networks. This paper defines these three types of agile encryption. Next, implementation issues are discussed. While single-algorithm, key-agile encryptors exist, robustness-agile and algorithm-agile encryptors are still research topics.

  13. High temperature superconductor analog electronics for millimeter-wavelength communications

    NASA Technical Reports Server (NTRS)

    Romanofsky, R. R.; Bhasin, K. B.

    1991-01-01

    The performance of high temperature superconductor (HTS) passive microwave circuits up to X-band was encouraging when compared to their metallic counterparts. The extremely low surface resistance of HTS films up to about 10 GHz enables a reduction in loss by as much as 100 times compared to copper when both materials are kept at about 77 K. However, a superconductor's surface resistance varies in proportion to the frequency squared. Consequently, the potential benefit of HTS materials to millimeter-wave communications requires careful analysis. A simple ring resonator was used to evaluate microstrip losses at Ka-band. Additional promising components were investigated such as antennas and phase shifters. Prospects for HTS to favorable impact millimeter-wave communications systems are discussed.

  14. Ultra-high speed communications based on solitons in fibers

    NASA Astrophysics Data System (ADS)

    Hasegawa, Akira

    2000-10-01

    The citation of the Maxwell prize reads: ``For innovative discoveries and seminal contributions to the theories of nonlinear drift wave turbulence, Alfvén wave propagation in laboratory and space plasmas, and optical solitons and their application to high speed communication". The prize is given to three somewhat unrelated contributions made during the course of my career as a plasma physicist. Traditionally an award talk summarizes works related to the citation. However, because of the diversified contents of the citations, I prepared my talk with the focus only on the last topic because some of the audience may be of more expertise on the other subjects. I apologize for the fact that the talk may be worth only one third of the prize. Multi-Terabits’s, ultra-high speed optical transmissions over several thousand kilometers on fibers are becoming reality and are expected to serve as the trunk line for highly demanded Internet traffics. Most of them use soliton or soliton-like RZ (Return to Zero) format in fibers with properly managed (group velocity) dispersion. These formats are the only stable envelope waveforms of light waves in fibers in the presence of Kerr (cubic) nonlineariy and dispersion with loss compensated by periodic optical amplifications. In practice, the transmission systems utilize the all-optical transmission concept and the nonlinear Schrodinger equation assisted by the split step numerical solutions as the master equation to describe the information transfer in fibers. All these facts are the outcome of research on optical solitons in fibers. The talk presents a brief historical development of the soliton based high-speed communications followed by current status of ultra-high speed communications by means of solitons as well as by other formats. Although the talk may not be of a core interest of plasma physics community, it presents an interesting example of a useful by-product of plasma physics research.

  15. Emerging applications of high temperature superconductors for space communications

    NASA Technical Reports Server (NTRS)

    Heinen, Vernon O.; Bhasin, Kul B.; Long, Kenwyn J.

    1990-01-01

    Proposed space missions require longevity of communications system components, high input power levels, and high speed digital logic devices. The complexity of these missions calls for a high data bandwidth capacity. Incorporation of high temperature superconducting (HTS) thin films into some of these communications system components may provide a means of meeting these requirements. Space applications of superconducting technology has previously been limited by the requirement of cooling to near liquid helium temperatures. Development of HTS materials with transition temperatures above 77 K along with the natural cooling ability of space suggest that space applications may lead the way in the applications of high temperature superconductivity. In order for HTS materials to be incorporated into microwave and millimeter wave devices, the material properties such as electrical conductivity, current density, surface resistivity and others as a function of temperature and frequency must be well characterized and understood. The millimeter wave conductivity and surface resistivity were well characterized, and at 77 K are better than copper. Basic microwave circuits such as ring resonators were used to determine transmission line losses. Higher Q values than those of gold resonator circuits were observed below the transition temperature. Several key HTS circuits including filters, oscillators, phase shifters and phased array antenna feeds are feasible in the near future. For technology to improve further, good quality, large area films must be reproducibly grown on low dielectric constant, low loss microwave substrates.

  16. Terahertz oscillators and receivers using electron devices for high-capacity wireless communication

    NASA Astrophysics Data System (ADS)

    Suzuki, Safumi; Asada, Masahiro

    2015-05-01

    Recent progress in room-temperature resonant-tunneling-diode (RTD) terahertz (THz) oscillators and high-electron-mobility- transistor (HEMT) THz receivers is reported in this paper. In this study, oscillations up to 1.86 THz were obtained using an optimized antenna and RTD. Using a two-element oscillator array, high output power of 0.6 mW at 620 GHz was obtained. THz communication up to 3 Gbps was demonstrated. A structure for high-speed direct modulation was fabricated, and the intensity modulation up to 30 GHz was achieved. A novel oscillator structure was proposed and fabricated for extraction of output power without using a Si lens. A short-gate InGaAs HEMT detector integrated with a broadband bow-tie antenna was fabricated, and a high current sensitivity of ~5 A/W was obtained at 280 GHz.

  17. Short Communication: Variance estimates among herds stratified by individual herd heritability

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this study was to compare genetic parameter estimates among herds stratified by high, medium and low individual herd heritability estimates. A regression model was applied to milk yield, fat yield, protein yield and somatic cell score (SCS) records from 20,902 herds to generate indi...

  18. Short Communication: Evidence for non-Gaussian distribution of rock weathering rates

    NASA Astrophysics Data System (ADS)

    Emmanuel, S.

    2015-09-01

    The weathering of rocks influences the geochemistry of the oceans, the erosion of landscapes and man-made structures, and even the global climate. Although a high degree of variance is often observed in rate measurements, little is understood about the statistical characteristics of weathering rate distributions. This preliminary study demonstrates that the weathering rates of limestone, determined from measurements of an ancient eroded limestone edifice, can exhibit highly non-Gaussian behavior. While a Gaussian model produced a poor fit with the data, an alternative model - the generalized extreme value (GEV) framework - was capable of capturing the asymmetric long-tailed distribution, in good agreement with the measured curve. Furthermore, the non-Gaussian distribution of these field rates was found to have similar characteristics to the distribution of rates measured over much smaller microscopic regions of limestone surfaces in laboratory experiments. Such similar behavior could be indicative of analogous chemical and mechanical weathering processes acting over a range of spatial and temporal scales. Moreover, highly asymmetric rate distributions with high variance could be characteristic of rates not only in carbonate rocks, but also in other rock types, suggesting that the use of a small number of measurements to determine field weathering rates may be insufficient to fully characterize the range of rates in natural systems.

  19. High frequency sound attenuation in short flow ducts

    NASA Technical Reports Server (NTRS)

    Posey, J. W.

    1978-01-01

    A geometrical acoustics approach is proposed as a practical design tool for absorbent liners in such short flow ducts as may be found in turbofan engine nacelles. As an example, a detailed methodology is presented for three different types of sources in a parallel plate duct containing uniform ambient flow. A plane wave whose wavefronts are not normal to the duct walls, an arbitrarily located point source, and a spatially harmonic line source are each considered. Optimal wall admittance distributions are found, and it is shown how to estimate the insertion loss for any admittance distribution. The extension of the methodology to realistic source distributions in variable area cylindrical or annular ducts containing arbitrary flow is shown to be conceptually straightforward and computationally practical on a vector-hardware digital computer.

  20. Short communication: genetic evaluation of stillbirth in US Brown Swiss and Jersey cattle.

    PubMed

    Yao, C; Weigel, K A; Cole, J B

    2014-01-01

    Stillbirth (SB) often results in reduced milk yield, compromised reproductive performance, and decreased dam longevity. Corrective mating can be used as a short-term solution to the problem, but long-term improvement of the population requires the routine calculation of genetic evaluations. Breeding values for SB have been available for Holstein (HO) bulls since 2006, but not for Brown Swiss (BS) or Jersey (JE) bulls. In this study, a multi-breed sire-maternal grandsire threshold model was used to perform genetic evaluations for SB of BS, JE, and HO bulls using more than 14 million purebred and crossbred calving records. Phenotypically, the percentage of SB (%SB) across all lactations were 3.7% in JE, 5.1% in BS, and 6.3% in HO. Direct heritabilities for BS, JE, and HO were 0.008, 0.007, and 0.008, and maternal heritabilities were 0.002, 0.016, and 0.021, respectively. Compared with HO, crossbred calvings from BS and JE bulls bred to HO cows lowered %SB by 1.5 and 1.2%, respectively. In general, %SB increased considerably as calving difficulty increased in all 3 breeds; however, in JE, %SB was constant for dystocia scores of 3 (needed assistance), 4 (considerable force), and 5 (extreme difficulty). Compared with purebred HO calvings, purebred BS and JE calvings had lower phenotypic %SB by up to 5.5 and 7.8%, respectively, and BS × HO and JE × HO crossbred calvings decreased %SB by up to 3.8 and 4.1%, respectively. As expected, SB rates in primiparous cows were higher than those in multiparous cows. Female calves had greater %SB than male calves in all parities for JE and in second-and-later parities for BS. Favorable (decreasing) phenotypic and genetic trends from 1999 to 2009 were observed in all 3 breeds. Heterosis of SB for BS and JE was -0.026 and -0.149, respectively, on the underlying scale, which corresponds to effects on service-sire SB (SSB) and daughter SB (DSB) predicted transmitting ability (PTA) of -0.3 and -0.5% in BS, and -1.5 and -2.7% in JE. Overall, in the current population, BS bulls had the most desirable average SSB PTA of 4.8%, compared with 5.6% for JE and 5.5% for HO. Brown Swiss and JE bulls both had average DSB PTA of 6.5%, lower than that of 7.7% in HO. Average reliabilities of SSB and DSB in 3 breeds ranged from 45 to 50%. The use of a BS-JE-HO multibreed genetic evaluation for SB in the United States is feasible, and the addition of SSB and DSB to the lifetime net merit selection index will help improve the profitability of BS and JE cattle in the United States. PMID:24508434

  1. Short Communication: Cheminformatics Analysis to Identify Predictors of Antiviral Drug Penetration into the Female Genital Tract

    PubMed Central

    Thompson, Corbin G.; Sedykh, Alexander; Nicol, Melanie R.; Muratov, Eugene; Fourches, Denis; Tropsha, Alexander

    2014-01-01

    Abstract The exposure of oral antiretroviral (ARV) drugs in the female genital tract (FGT) is variable and almost unpredictable. Identifying an efficient method to find compounds with high tissue penetration would streamline the development of regimens for both HIV preexposure prophylaxis and viral reservoir targeting. Here we describe the cheminformatics investigation of diverse drugs with known FGT penetration using cluster analysis and quantitative structure–activity relationships (QSAR) modeling. A literature search over the 1950–2012 period identified 58 compounds (including 21 ARVs and representing 13 drug classes) associated with their actual concentration data for cervical or vaginal tissue, or cervicovaginal fluid. Cluster analysis revealed significant trends in the penetrative ability for certain chemotypes. QSAR models to predict genital tract concentrations normalized to blood plasma concentrations were developed with two machine learning techniques utilizing drugs' molecular descriptors and pharmacokinetic parameters as inputs. The QSAR model with the highest predictive accuracy had R2test=0.47. High volume of distribution, high MRP1 substrate probability, and low MRP4 substrate probability were associated with FGT concentrations ≥1.5-fold plasma concentrations. However, due to the limited FGT data available, prediction performances of all models were low. Despite this limitation, we were able to support our findings by correctly predicting the penetration class of rilpivirine and dolutegravir. With more data to enrich the models, we believe these methods could potentially enhance the current approach of clinical testing. PMID:24512359

  2. Short communication: cheminformatics analysis to identify predictors of antiviral drug penetration into the female genital tract.

    PubMed

    Thompson, Corbin G; Sedykh, Alexander; Nicol, Melanie R; Muratov, Eugene; Fourches, Denis; Tropsha, Alexander; Kashuba, Angela D M

    2014-11-01

    The exposure of oral antiretroviral (ARV) drugs in the female genital tract (FGT) is variable and almost unpredictable. Identifying an efficient method to find compounds with high tissue penetration would streamline the development of regimens for both HIV preexposure prophylaxis and viral reservoir targeting. Here we describe the cheminformatics investigation of diverse drugs with known FGT penetration using cluster analysis and quantitative structure-activity relationships (QSAR) modeling. A literature search over the 1950-2012 period identified 58 compounds (including 21 ARVs and representing 13 drug classes) associated with their actual concentration data for cervical or vaginal tissue, or cervicovaginal fluid. Cluster analysis revealed significant trends in the penetrative ability for certain chemotypes. QSAR models to predict genital tract concentrations normalized to blood plasma concentrations were developed with two machine learning techniques utilizing drugs' molecular descriptors and pharmacokinetic parameters as inputs. The QSAR model with the highest predictive accuracy had R(2)test=0.47. High volume of distribution, high MRP1 substrate probability, and low MRP4 substrate probability were associated with FGT concentrations ≥1.5-fold plasma concentrations. However, due to the limited FGT data available, prediction performances of all models were low. Despite this limitation, we were able to support our findings by correctly predicting the penetration class of rilpivirine and dolutegravir. With more data to enrich the models, we believe these methods could potentially enhance the current approach of clinical testing. PMID:24512359

  3. Communication.

    ERIC Educational Resources Information Center

    Online-Offline, 1998

    1998-01-01

    This theme issue on communication includes annotated listings of Web sites, CD-ROM and computer software, videos, books, and professional resources that deal with various methods of communication. Sidebars discuss mythology, photojournalism, sharing ideas on the Web, and songs of protest. Suggestions for class activities are also included. (LRW)

  4. Short communication: in vitro assessment of antioxidant, antibacterial and phytochemical analysis of peel of Citrus sinensis.

    PubMed

    Mehmood, Basharat; Dar, Kamran Khurshid; Ali, Shaukat; Awan, Uzma Azeem; Nayyer, Abdul Qayyum; Ghous, Tahseen; Andleeb, Saiqa

    2015-01-01

    Antibacterial effect of Citrus sinensis peel extracts was evaluated against several pathogenic bacteria associated with human and fish infections viz., Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumonia, Staphylococcus aureus, Streptococcus pyogenes, Staphylococcus epidermidis, Serratia marcesnces, Shigella flexneri, Enterobacter amnigenus, Salmonella Typhimurium and Serratia odorifera. Methanol, ethanol, chloroform and diethyl ether solvents were used for extraction. In vitro antibacterial activity was analyzed by agar well and agar disc diffusion methods. It was found that ethanol extract showed highly significant inhibition of E. coli and K. pneumonia (12.6±0.94 mm and 11.6±1.2 mm) whereas methanol extract of C. sinensis also showed high zone of inhibition of S. odorifera (10.0±2.16 mm). The potential activity of active extracts was assessed and also compared with standard antibiotics through activity index formulation. The order of antioxidant activity through ABTS·+ and DPPH free radical scavenging activity was ethanol>methanol>chloroform>diethyl ether. Phytochemical screening of all solvents had determined the presence of terpenoids, alkaloids, steroids, glycosides and flavonoids. It was also found that Chloroform/Methanol (5:5) and Butanol/Ethanol/Water (4:1:2.2) solvent systems showed significant separation of active phytochemical constituents. These findings reveal the potential use of C. sinensis peel to treat infectious diseases, which are being caused by microorganisms. PMID:25553700

  5. Short communication: molecular characterization of dog and cat p65 subunits of NF-kappaB.

    PubMed

    Ishikawa, Shingo; Takemitsu, Hiroshi; Li, Gebin; Mori, Nobuko; Yamamoto, Ichiro; Arai, Toshiro

    2015-04-01

    Nuclear factor kappa B (NF-κB) plays an important role in the immune system. The p65 subunit is an important part of NF-κB unit, and studies of dog and cat p65 subunits of NF-κB (dp65 and cp65) are important in understanding their immune function. In this study, we described the molecular characterization of dp65 and cp65. The dp65 and cp65 complementary DNA encoded 542 and 555 amino acids, respectively, showing a high sequence homology with the mammalian p65 subunit (>87.5%). Quantitative polymerase chain reaction revealed that the p65 messenger RNA is highly expressed in the dog stomach and cat heart and adipose tissue. Functional NF-κB promoter-luciferase reporter vectors revealed that our isolated dp65 and cp65 cDNA encodes a functionally active protein. Transiently expressed dp65 and cp65 up-regulated pro-inflammatory cytokine expression levels in dog and cat, respectively. These findings suggest that dp65 and cp65 play important roles in regulating immune function. PMID:25770673

  6. A high gain antenna system for airborne satellite communication applications

    NASA Technical Reports Server (NTRS)

    Maritan, M.; Borgford, M.

    1990-01-01

    A high gain antenna for commercial aviation satellites communication is discussed. Electromagnetic and practical design considerations as well as candidate systems implementation are presented. An evaluation of these implementation schemes is given, resulting in the selection of a simple top mounted aerodynamic phased array antenna with a remotely located beam steering unit. This concept has been developed into a popular product known as the Canadian Marconi Company CMA-2100. A description of the technical details is followed by a summary of results from the first production antennas.

  7. High integration microcontroller yields total vehicle communication solution

    SciTech Connect

    Arnett, D.J.; Tucker, M.J.

    1985-01-01

    Vehicle control needs are consistently increasing to meet customer performance and cost requirements. As a result, single processor systems have expanded to multiple controller solutions. With the advent of distributed processing, high speed efficient data communication methods are required. Intel's single device solution provides an innovative answer for these needs. This paper describes the architectural features of the Intel 8044 microcontroller and shows its strengths in a total networked vehicle powertrain control application, including: spark, fuel, transmission and road-to-surface traction control.

  8. Delay in pathological tissue processing time vs. mortality in oral cancer: short communication.

    PubMed

    Jerjes, Waseem; Upile, Tahwinder; Radhi, Hani; Petrie, Aviva; Adams, Aidan; Callear, Jacqueline; Kafas, Panagiotis; Hopper, Colin

    2012-01-01

    Several factors have been identified to affect morbidity and mortality in oral cancer patients. The time taken to process a resected cancer specimen in a patient presenting with primary or recurrent disease can be of interest as delay can affect earlier interventions post-surgery. We looked at this variable in a group of 168 consecutive oral cancer patients and assessed its relationship to mortality from the disease at 3 and 5 years. It is expected that delay in pathological processing time of surgical specimens acquired from patients with recurrent disease may increase or contribute to the increased rate of mortality. Further high evidence-based studies are required to confirm this. PMID:22537656

  9. Delay in pathological tissue processing time vs. mortality in oral cancer: Short communication

    PubMed Central

    2012-01-01

    Several factors have been identified to affect morbidity and mortality in oral cancer patients. The time taken to process a resected cancer specimen in a patient presenting with primary or recurrent disease can be of interest as delay can affect earlier interventions post-surgery. We looked at this variable in a group of 168 consecutive oral cancer patients and assessed its relationship to mortality from the disease at 3 and 5 years. It is expected that delay in pathological processing time of surgical specimens acquired from patients with recurrent disease may increase or contribute to the increased rate of mortality. Further high evidence-based studies are required to confirm this. PMID:22537656

  10. Short communication: Telomere lengths in different tissues of dairy cows during early and late lactation.

    PubMed

    Laubenthal, L; Hoelker, M; Frahm, J; Dänicke, S; Gerlach, K; Südekum, K-H; Sauerwein, H; Häussler, S

    2016-06-01

    Telomeres create a protective cap on the ends of chromosomes that shorten with cell division and are influenced by stressful conditions. With the onset of lactation, high-yielding dairy cows are exposed to metabolic stress. In the present study, we aimed to analyze telomere length (TL) in key metabolic organs, such as liver, subcutaneous (sc) adipose tissue (AT), and mammary gland, as well as in peripheral blood cells during early and late lactation in German Holstein cows (n=21). Animals were fed according to their requirement, and biopsies from scAT, liver, and mammary gland as well as blood cells were collected in early and late lactation. The relative quantity of telomere products (qT), which is proportional to the average TL, was determined in genomic DNA by multiplex quantitative PCR. In this study, relative qT varied widely in the investigated tissues and blood. In late lactation, slowly proliferating tissues, such as liver and scAT, had the highest qT, whereas peripheral blood cells and in the mammary gland had the lowest qT. Comparing early with late lactation, relative qT attrition was limited to blood and mammary gland. Relationships between relative qT in blood, mammary gland, scAT, and liver suggest that blood qT might serve as a surrogate marker for tissue-specific qT. Cows with high initial qT in tissues and blood in early lactation had greater qT attrition during the course of lactation than cows with lower qT. The determination of qT could be included when phenotyping dairy cattle to test for associations with performance and fitness traits. PMID:26995138

  11. Short communication-Evaluation of antianxiety and antidepressant properties of Carthamus tinctorius L. (Safflower) petal extract.

    PubMed

    Qazi, Nasreen; Khan, Rafeeq Alam; Rizwani, Ghazala H

    2015-05-01

    Nowadays anxiety and depression are most commonly encountered diseases. They are not only difficult to diagnose but even difficult to treat since both are sometimes seen together or one predisposes the other. Apart from this side effect profile of these drugs is also high; hence there is immense scope for the herbal drugs to treat these disorders. Present study was therefore performed to evaluate the antianxiety and antidepressant effect of Carthamus tinctorius petal extract. 28 white albino rats bred in the animal house of Department of Pharmacology, University of Karachi weighing 180-220gm were randomly divided into four groups (n=7/group) to assess behavioral effects. The anxiolytic and antidepressant effects of Carthamus tinctorius petal extract were evaluated using elevated plus maize and forced swim test respectively at100 and 200mg/kg. These effects were compared with standard drugs Diazepam (anxiolytic) 2mg/kg and Nortriptyline (antidepressant) 12.5mg/kg. Results show that CT produced highly significant anxiolytic and anti-depressant effects at both doses as compared to control, similar to standard anxiolytic and antidepressant drugs diazepam and nortriptyline. It increased the latency of first entry to closed arms and the time spent in open arms very significantly at both doses while entries to open arm were increased significantly at 100mg/kg and very significantly at 200mg/kg in EPM test and increased the immobility time very significantly in FST. Hence it can be concluded that CT may be used as an alternative therapeutic agent while treating patients with anxiety and depressive disorders. PMID:26004733

  12. High power microwave components for space communications satellite

    NASA Technical Reports Server (NTRS)

    Jankowski, H.; Geia, A.

    1972-01-01

    Analyzed, developed, and tested were high power microwave components for communications satellites systems. Included were waveguide and flange configurations with venting, a harmonic filter, forward and reverse power monitors, electrical fault sensors, and a diplexer for two channel simultaneous transmission. The assembly of 8.36 GHz components was bench tested, and then operated for 60 hours at 3.5 kW CW in a high vacuum. The diplexer was omitted from this test pending a modification of its end irises. An RF leakage test showed only that care is required at flange junctions; all other components were RF tight. Designs were extrapolated for 12 GHz and 2.64 GHz high power satellite systems.

  13. Radio Synthesis Imaging - A High Performance Computing and Communications Project

    NASA Astrophysics Data System (ADS)

    Crutcher, Richard M.

    The National Science Foundation has funded a five-year High Performance Computing and Communications project at the National Center for Supercomputing Applications (NCSA) for the direct implementation of several of the computing recommendations of the Astronomy and Astrophysics Survey Committee (the "Bahcall report"). This paper is a summary of the project goals and a progress report. The project will implement a prototype of the next generation of astronomical telescope systems - remotely located telescopes connected by high-speed networks to very high performance, scalable architecture computers and on-line data archives, which are accessed by astronomers over Gbit/sec networks. Specifically, a data link has been installed between the BIMA millimeter-wave synthesis array at Hat Creek, California and NCSA at Urbana, Illinois for real-time transmission of data to NCSA. Data are automatically archived, and may be browsed and retrieved by astronomers using the NCSA Mosaic software. In addition, an on-line digital library of processed images will be established. BIMA data will be processed on a very high performance distributed computing system, with I/O, user interface, and most of the software system running on the NCSA Convex C3880 supercomputer or Silicon Graphics Onyx workstations connected by HiPPI to the high performance, massively parallel Thinking Machines Corporation CM-5. The very computationally intensive algorithms for calibration and imaging of radio synthesis array observations will be optimized for the CM-5 and new algorithms which utilize the massively parallel architecture will be developed. Code running simultaneously on the distributed computers will communicate using the Data Transport Mechanism developed by NCSA. The project will also use the BLANCA Gbit/s testbed network between Urbana and Madison, Wisconsin to connect an Onyx workstation in the University of Wisconsin Astronomy Department to the NCSA CM-5, for development of long-distance distributed computing. Finally, the project is developing 2D and 3D visualization software as part of the international AIPS++ project. This research and development project is being carried out by a team of experts in radio astronomy, algorithm development for massively parallel architectures, high-speed networking, database management, and Thinking Machines Corporation personnel. The development of this complete software, distributed computing, and data archive and library solution to the radio astronomy computing problem will advance our expertise in high performance computing and communications technology and the application of these techniques to astronomical data processing.

  14. Short communication: a system for remote monitoring of a hospital linear accelerator.

    PubMed

    Jennings, C S

    1996-05-01

    Linear accelerators are complex machines with many parameters affecting the quality of the treatment beam delivered. A high level of technical support is required but this can be difficult to achieve if the linear accelerator is at a centre distant from a medical physics department. This paper describes a solution to this problem whereby a newly installed linear accelerator at the Royal Shrewsbury Hospital is remotely monitored from the Royal Hospital, Wolverhampton. The system enables run-up procedures to be completed by guiding radiographers at Shrewsbury through a series of steps. It consists of electronic hardware connected to the linear accelerator, under the control of a computer. The machine parameters are read and tested against preset tolerances. The monitoring system has been installed and is in routine use. The benefits have been shown to be: a saving in staff time and travel costs, the satisfactory completion of run-up procedures, a higher level of efficiency in the medical physics service provided and effective quality control. Finally, some future developments are presented. These include the development of a real time remote monitoring system that constantly monitors the linear accelerator, allowing the Medical Physics Department access to the machine parameters at any time. PMID:8705186

  15. Feasibility study to objectively assess activity and location of Hispanic preschoolers: a short communication

    PubMed Central

    O'Connor, Teresia M.; Cerin, Ester; Robles, Jessica; Lee, Rebecca E.; Kerr, Jacqueline; Butte, Nancy; Mendoza, Jason A.; Thompson, Deborah; Baranowski, Tom

    2015-01-01

    Both physical and social environmental factors influence young children's physical activity, yet little is known about where Hispanic children are more likely to be active. We assessed the feasibility of simultaneously measuring, then processing objective measures of location and physical activity among Hispanic preschool children. Preschool-aged Hispanic children (n = 15) simultaneously wore QStarz BT100X global positioning system (GPS) data loggers and Actigraph GT3X accelerometers for a 24- to 36-hour period, during which time their parents completed a location and travel diary. Data were aggregated to the minute and processed using the personal activity location measurement system (PALMS). Children successfully wore the GPS data loggers and accelerometers simultaneously, 12 of which yielded data that met quality standards. The average percent correspondence between GPS- and diary-based estimates of types of location was high and Kappa statistics were moderate to excellent, ranging from 0.49-0.99. The between-method (GPS monitor, parent-reported diary) correlations of estimated participant-aggregated minutes spent on vehicle-based trips were strong. The simultaneous use of GPS and accelerometers to assess Hispanic preschool children's location and physical activity is feasible. This methodology has the potential to provide more precise findings to inform environmental interventions and policy changes to promote physical activity among Hispanic preschool children. PMID:23733298

  16. Short communication: rapid detection of milk fat adulteration with vegetable oil by fluorescence spectroscopy.

    PubMed

    Ntakatsane, M P; Liu, X M; Zhou, P

    2013-04-01

    This study assessed the potential application of fluorescence spectroscopy in detecting adulteration of milk fat with vegetable oil and characterizing the samples according to the source of the fat. Pure butterfat was adulterated with different vegetable oils at various concentrations (0, 5, 10, 15, 20, 30, and 40%). Nonfat and reduced-fat milk were also adulterated with vegetable oils to simulate full-fat milk (3.2%). The 2- and 3-dimensional front-face fluorescence spectroscopy and gas chromatography were used to obtain the fluorescence spectra and fatty acid profile, respectively. Principal component analysis and 3-way partial least squares regression analysis were applied to analyze the data. The pure and adulterated samples were discriminated based on the total concentration of saturated fatty acids and unsaturated fatty acids, and also on the 3 major fluorophores: tryptophan, tocopherols, and riboflavin. Fluorescence spectroscopy was able to detect up to 5% of adulteration of vegetable oil into the butterfat. The saturated fatty acids showed higher predictability than the unsaturated fatty acids (R(2) = 0.73-0.92 vs. 0.20-0.65, respectively). The study demonstrated the high potential of fluorescence spectroscopy to rapidly detect adulteration of milk fat with vegetable oil, and discriminate commercial butter and milk according to the source of the fat. PMID:23415535

  17. Short communication: genetic parameters for fertility-related disorders in Norwegian Red.

    PubMed

    Haugaard, Katrine; Heringstad, Bjørg

    2015-02-01

    Heritabilities and genetic correlations were estimated for the 4 most common fertility-related disorders in Norwegian Red: retained placenta, cystic ovaries, silent heat, and metritis. Data on 1,747,500 lactations from 780,114 cows calving from January 2001 through December 2011 were analyzed using multivariate threshold sire models to estimate variance components for the 4 disorders in the first 5 lactations. The traits were defined as binary within lactation (0=unaffected, 1=affected), and each fertility-related disorder was analyzed separately with the 5 lactations as correlated traits. The mean frequency of affected cows ranged from 0.5 to 1.7% for cystic ovaries, 0.7 to 1.1% for metritis, 1.3 to 3.4% for retained placenta, and 1.7 to 2.7% for silent heat. Posterior means (standard deviations) of heritability of liability ranged from 0.02 (0.01) to 0.12 (0.01), and were lowest for silent heat and highest for cystic ovaries. Genetic correlations across lactation within disorder were positive and moderate to high, ranging from 0.79 to 0.95 for cystic ovaries, 0.40 to 0.75 for metritis, 0.53 to 0.94 for retained placenta, and 0.39 to 0.83 for silent heat. PMID:25497813

  18. Short communication: new HIV infections at Southern New England academic institutions: implications for prevention.

    PubMed

    Chan, Philip A; Kazi, Shahzeb; Rana, Amaad; Blazar, Ilyse; Dejong, Colette C; Mayer, Kenneth H; Huard, Thomas K; Carleton, Kim; Gillani, Fizza; Alexander, Nicole; Parillo, Zoanne; Flanigan, Timothy P; Kantor, Rami

    2013-01-01

    New HIV infections among younger men who have sex with men (MSM) in the United States are escalating. Data on HIV infections in college students are limited. In 2010, three MSM college students presented to our clinic with primary HIV infection (PHI) in a single month. To determine the number of college students among new HIV diagnoses, we reviewed clinical characteristics and molecular epidemiology of HIV-diagnosed individuals from January to December 2010 at the largest HIV clinic in Southern New England. PHI was defined as acute HIV infection or seroconversion within the last 6 months. Of 66 individuals diagnosed with HIV in 2010, 62% were MSM and 17% were academic students (12% college or university, 5% other). Seventy-three percent of students were MSM. Compared to nonstudents, students were more likely to be younger (24 versus 39 years), born in the United States (91% versus 56%), have another sexually transmitted disease (45% versus 11%), and present with PHI (73% versus 16%, all p-values<0.05). Thirty percent of individuals formed eight transmission clusters including four students. MSM were more likely to be part of clusters. Department of Health contact tracing of cluster participants allowed further identification of epidemiological linkages. Given these high rates of PHI in recently diagnosed students, institutions of higher education should be aware of acute HIV presentation and the need for rapid diagnosis. Prevention strategies should focus on younger MSM, specifically college-age students who may be at increased risk of HIV infection. PMID:22724920

  19. Short communication: Antimicrobial susceptibility profiling and genotyping of Staphylococcus aureus isolates from bovine mastitis in Poland.

    PubMed

    Jagielski, T; Puacz, E; Lisowski, A; Siedlecki, P; Dudziak, W; Międzobrodzki, J; Krukowski, H

    2014-10-01

    Staphylococcus aureus is the predominant causative agent of bovine mastitis, a disease that remains a major economic burden for the dairy industry worldwide. In this study, the antimicrobial resistance patterns and the genetic composition of 80 S. aureus mastitis isolates collected from 14 dairy farms in Eastern Poland were determined. Of the 10 antimicrobial agents evaluated, only testing for penicillin G produced drug resistance. As 41% of the S. aureus isolates were penicillin resistant, this drug along with other β-lactamase-sensitive β-lactams, should rather not be considered for the treatment of bovine mastitis caused by S. aureus. Upon genotyping, with a triplex PCR method, a total of 11 distinct PCR types were produced. The population structure of S. aureus isolates was highly clonal, with 1 predominant genotype circulating on each farm. The observed similarities in the genotype composition of S. aureus populations from geographically distant farms underscore the significance of interfarm transmission of S. aureus in Poland. This, in turn, argues for the establishment of a nationwide surveillance program for bovine mastitis due to this pathogen. PMID:25087034

  20. Short communication: prevalence and antibiotic resistance of Staphylococcus aureus isolated from bovine clinical mastitis.

    PubMed

    Jamali, Hossein; Radmehr, Behrad; Ismail, Salmah

    2014-01-01

    The aims of this study were to determine the prevalence and antibiotic resistance of Staphylococcus aureus isolated from bovine clinical mastitis in Varamin, Tehran Province, Iran. All of the isolated Staph. aureus were identified by morphology and culture and confirmed using the API Staph identification system (bioMérieux, Marcy-l'Étoile, France). Antibiotic resistance genes were detected by PCR with oligonucleotide primers specific for each gene. Staphylococcus aureus was recovered from 43 of 207 (20.1%) bovine clinical milk samples. Using disk diffusion, methicillin-resistant Staph. aureus was detected in 5 of 43 (11.6%) samples. The pathogen showed high resistance against penicillin G (86%) and tetracycline (76.7%). The blaZ (penicillin) (86%), tetM (tetracycline), and ermC (erythromycin) genes (39.5% each) were the most prevalent antibiotic resistance genes. The findings of this study are useful for designing specific control programs for bovine clinical mastitis caused by Staph. aureus in this region of Iran. PMID:24534509

  1. Short communication: effect of pomegranate-residue supplement on Cryptosporidium parvum oocyst shedding in neonatal calves.

    PubMed

    Weyl-Feinstein, S; Markovics, A; Eitam, H; Orlov, A; Yishay, M; Agmon, R; Miron, J; Izhaki, I; Shabtay, A

    2014-09-01

    Cryptosporidium parvum is considered one of the most common enteropathogens, responsible for the high incidence of diarrhea and deleterious implications on immunity and health in neonatal calves. The pomegranate is well known for its health-promoting properties. Two experiments were designed to test the antiparasitical and antidiarrheal effects of concentrated pomegranate extract (CPE) supplement in milk in neonatal Holstein calves. Forty-one calves were randomly divided into control (n=20) and treatment (n=21) groups. For the first experiment, the treatment group was supplemented with 3.75% CPE in the daily milk ration, between 3 and 14 d of age, whereas the control group received only milk. Fecal samples were collected between d 5 and 13 to quantify Cryptosporidium oocysts, and the duration and intensity of diarrhea were evaluated. Reduced fecal oocyst count and diarrhea intensity and duration were revealed in the 3.75% CPE calves. No difference was noted in average daily gain between groups. In a second experiment, which was designed to test the effect of a lower CPE concentration (0.6% of daily milk allocation), no effects on fecal oocyst count and average daily gain were observed. However, compared with control, the lower CPE group was characterized by a shorter duration of diarrhea and higher weight gain among males at 14 d of age. These results suggest that the CPE supplement-to-calf milk ratio may potentially alleviate intestinal morbidity caused by Cryptosporidium. PMID:24952772

  2. Short communication: Aflatoxin M₁ in dairy products sold in Şanlıurfa, Turkey.

    PubMed

    Temamogullari, F; Kanici, A

    2014-01-01

    The aim of this study was to detect the presence of aflatoxin M₁ (AFM1) in samples of raw milk (n=38), UHT milk (n=12), white pickled cheese (n=50), and yogurt (n=50) collected from the Şanlıurfa city markets and locally produced dairy products by ELISA. The mean contamination rates were 56.74 ± 40.32, 43.1 ± 23.19, 103.2 ± 29.13, and 55.28 ± 12.68 ng/kg, respectively, for raw milk, UHT milk, white pickled cheese, and yogurt. According to the data, 21 (55%) raw milk, 3 (25%) UHT milk, 10 (20%) white pickled cheese, and 10 (20%) yogurt samples were contaminated with AFM1 over the acceptable levels (≥50 ng/kg), ranging from 0.82 to 130.89 ng/kg. None of the white pickled cheese samples contained AFM1 levels above the Turkish legal limit (250 ng/kg). Consequently, the AFM1 contamination levels determined in this study in white pickled cheese were not considered to pose a serious public health hazard. However, the AFM1 levels in raw and UHT milk and yogurt samples indicate an increased human health risk in Turkey related to high aflatoxin levels. Therefore, milk and dairy products have to be monitored by the Turkish public health authorities continuously to detect AFM1 contamination. PMID:24239070

  3. Short communication: Ability of dogs to detect cows in estrus from sniffing saliva samples.

    PubMed

    Fischer-Tenhagen, C; Tenhagen, B-A; Heuwieser, W

    2013-02-01

    Efficient estrus detection in high-producing dairy cows is a permanent challenge for successful reproductive performance. In former studies, dogs have been trained to identify estrus-specific odor in vaginal fluid, milk, urine, and blood samples under laboratory conditions with an accuracy of more than 80%. For on-farm utilization of estrus-detection dogs it would be beneficial in terms of hygiene and safety if dogs could identify cows from the feed alley. The objective of this proof of concept study was to test if dogs can be trained to detect estrus-specific scent in saliva of cows. Saliva samples were collected from cows in estrus and diestrus. Thirteen dogs of various breeds and both sexes were trained in this study. Five dogs had no experience in scent detection, whereas 8 dogs had been formerly trained for detection of narcotics or cancer. In the training and test situation, dogs had to detect 1 positive out of 4 samples. Dog training was based on positive reinforcement and dogs were rewarded with a clicker and food for indicating saliva samples of cows in estrus. A false indication was ignored and documented in the test situation. Dogs with and without prior training were trained for 1 and 5 d, respectively. For determining the accuracy of detection, the position of the positive sample was unknown to the dog handler, to avoid hidden cues to the dog. The overall percentage of correct positive indications was 57.6% (175/304), with a range from 40 (1 dog) to 75% (3 dogs). To our knowledge, this is the first indication that dogs are able to detect estrus-specific scent in saliva of cows. PMID:23261382

  4. Short communication: Regulation of hepatic gluconeogenic enzymes by dietary glycerol in transition dairy cows.

    PubMed

    White, H M; Carvalho, E R; Koser, S L; Schmelz-Roberts, N S; Pezzanite, L M; Slabaugh, A C; Doane, P H; Donkin, S S

    2016-01-01

    Nutritional status and glucose precursors are known regulators of gluconeogenic gene expression. Glycerol can replace corn in diets fed to dairy cows and use of glycerol is linked to increased rumen propionate production. The effect of dietary glycerol on the regulation of gluconeogenic enzymes is unknown. The objective of this study was to examine the effect of glycerol on expression of pyruvate carboxylase (PC), cytosolic and mitochondrial phosphoenolpyruvate carboxykinase (PEPCK-C and PEPCK-M), and glucose-6-phosphatase. Twenty-six multiparous Holstein cows were fed either a control diet or a diet where high-moisture corn was replaced by glycerol from -28 through +56 d relative to calving (DRTC). Liver tissue was collected via percutaneous liver biopsy at -28, -14, +1, +14, +28, and +56 DRTC for RNA analysis. Expression of PC mRNA increased 6-fold at +1 and 4-fold at +14 DRTC relative to precalving levels. Dietary glycerol did not alter expression of PC mRNA expression. Expression of PEPCK-C increased 2.5-fold at +14 and 3-fold at +28 DRTC compared with +1 DRTC. Overall, dietary glycerol increased PEPCK-C expression compared with that of cows fed control diets. The ratio of PC to PEPCK-C was increased 6.3-fold at +1 DRTC compared with precalving and tended to be decreased in cows fed glycerol. We detected no effect of diet or DRTC on PEPCK-M or glucose-6-phosphatase mRNA, and there were no interactions of dietary treatment and DRTC for any transcript measured. Substituting corn with glycerol increased the expression of PEPCK-C mRNA during transition to lactation and suggests that dietary energy source alters hepatic expression. The observed increase in PEPCK-C expression with glycerol feeding may indicate regulation of hepatic gene expression by changes in rumen propionate production. PMID:26547649

  5. Short communication: oral lesions in HIV/AIDS patients undergoing HAART including efavirenz.

    PubMed

    Aquino-García, S I; Rivas, M A; Ceballos-Salobreña, A; Acosta-Gio, A E; Gaitán-Cepeda, L A

    2008-06-01

    Oral lesions (OL) have an important prognostic value for HIV/AIDS patients. However, the behavior of OL in HIV/AIDS patients undergoing highly active antiretroviral therapy including efavirenz (HAART/EFV) has not been documented. Our objective was to establish the prevalence of OL in HIV/AIDS patients undergoing HAART/EFV and to compare it with the prevalence of OL in patients undergoing antiretroviral therapy including a protease inhibitor (HAART/PI). Seventy-three HIV/AIDS patients undergoing antiretroviral treatment for at least for 6 months at "La Raza" Medical Center's Internal Medicine Unit (IMSS, Mexico City) were included. To detect OL, a detailed examination of oral soft tissues was performed in each patient. Patient records recorded gender, seropositivity time, route of contagion, antiretroviral therapy type and duration, CD4 lymphocyte count/ml, and viral load. Two groups were formed: 38 patients receiving HAART/EFV [two nucleoside analogue reverse transcriptase inhibitors (NARTI) plus efavirenz] and 35 patients receiving HAART/PI (two NARTIs plus one PI). OL prevalence was established in each study group. The Chi-square test was applied (p < 0.05(IC95%)). OL prevalence in the HAART/EFV group (32%) was lower (p < 0.007) than in the HAART/PI group (63%). Candidosis was the most prevalent OL in both groups. Herpes labialis, HIV-associated necrotizing periodontitis, xerostomia, hairy leukoplakia, and nonspecific oral sores were identified. The highest prevalence for all OL was found in the HAART/PI group. These findings suggest that HIV/AIDS patients undergoing HAART/EFV show a lower prevalence of oral lesions than patients undergoing HAART/PI. PMID:18507528

  6. Demonstration of high-rate laser communications from fast airborne platform: flight campaign and results

    NASA Astrophysics Data System (ADS)

    Moll, Florian; Mitzkus, Wolfgang; Horwath, Joachim; Shrestha, Amita; Brechtelsbauer, Martin; Martin, Luis; Lozano, Alberto; Diaz Gonzalez, Dionisio

    2014-10-01

    Some current and future airborne payloads like high resolution cameras and radar systems need high channel capacity to transmit their data from air to ground in near real-time. Especially in reconnaissance and surveillance missions, it is important to downlink huge amount of data in very short contact times to a ground station during a flyby. Aeronautical laser communications can supply the necessary high data-rates for this purpose. Within the project DODfast (Demonstration of Optical Data link fast) a laser link from a fast flying platform was demonstrated. The flight platform was a Panavia Tornado with the laser communication terminal installed in an attached avionic demonstrator pod. The air interface was a small glass dome protecting the beam steering assembly. All other elements were integrated in a small box inside the Pod's fuselage. The receiver station was DLR's Transportable Optical Ground Station equipped with a free-space receiver front-end. Downlink wavelength for communication and uplink wavelength for beacon laser were chosen from the optical C-band DWDM grid. The test flights were carried out at the end of November 2013 near the Airbus Defence and Space location in Manching, Germany. The campaign successfully demonstrated the maturity and readiness of laser communication with a data-rate of 1.25 Gbit/s for aircraft downlinks. Pointing, acquisition and tracking performance of the airborne terminal and the ground station could be measured at aircraft speed up to 0.7 Mach and video data from an onboard camera has been transmitted. Link distances with stable tracking were up to 79 km and distance with data transmission over 50 km. In this paper, we describe the system architecture, the flight campaign and the results.

  7. Short communication: Characteristics of student success in an undergraduate physiology and anatomy course.

    PubMed

    Gwazdauskas, F C; McGilliard, M L; Corl, B A

    2014-10-01

    Several factors affect the success of students in college classes. The objective of this research was to determine what factors affect success of undergraduate students in an anatomy and physiology class. Data were collected from 602 students enrolled in the Agriculture and Life Sciences (ALS) 2304 Animal Physiology and Anatomy course from 2005 through 2012. The data set included 476 females (79.1%) and 126 males (20.9%). Time to complete exams was recorded for each student. For statistical analyses, students' majors were animal and poultry sciences (APSC), agricultural sciences, biochemistry, biological sciences, dairy science, and "other," which combined all other majors. All analyses were completed using the GLIMMIX procedure of SAS (SAS Institute Inc., Cary, NC). Gender, major, matriculation year, major by year interaction, gender by year interaction, and time to complete the exam affected final course grade. The significant gender effect was manifested in the final grade percentage of 75.9 ± 0.4 for female students compared with 72.3 ± 0.6 for male students. Junior males had final course grades comparable with those of females, but sophomore and senior males had lower final course grades than other combinations. Biology majors had a final grade of 82.4 ± 0.6 and this grade was greater than all other majors. Students classified as "other" had a final score of 74.4 ± 0.8, which was greater than agricultural science majors (69.5 ± 0.9). The APSC grade (72.6 ± 0.5) was higher than the agricultural science majors. Junior students had significantly greater final grades (76.1 ± 0.5) than sophomores (73.3 ± 0.6) and seniors (72.9 ± 0.9). All biology students had greater final grades than all other majors, but biochemistry juniors had greater final course grades than APSC, agricultural science, and dairy science juniors. "Other" seniors had greater final course grades than agricultural science seniors. The regression for time to complete the exam was curvilinear and suggests that highest exam scores were at about 90-min completion time. It may be that some male students need better preparation for anatomy and physiology and their educational preparation should mimic that of female students more in terms of advance-placement biology in high school. These results suggest that biology majors might be better prepared for animal anatomy and physiology than other students. PMID:25087028

  8. High performance computing and communications: FY 1995 implementation plan

    SciTech Connect

    1994-04-01

    The High Performance Computing and Communications (HPCC) Program was formally established following passage of the High Performance Computing Act of 1991 signed on December 9, 1991. Ten federal agencies in collaboration with scientists and managers from US industry, universities, and laboratories have developed the HPCC Program to meet the challenges of advancing computing and associated communications technologies and practices. This plan provides a detailed description of the agencies` HPCC implementation plans for FY 1994 and FY 1995. This Implementation Plan contains three additional sections. Section 3 provides an overview of the HPCC Program definition and organization. Section 4 contains a breakdown of the five major components of the HPCC Program, with an emphasis on the overall directions and milestones planned for each one. Section 5 provides a detailed look at HPCC Program activities within each agency. Although the Department of Education is an official HPCC agency, its current funding and reporting of crosscut activities goes through the Committee on Education and Health Resources, not the HPCC Program. For this reason the Implementation Plan covers nine HPCC agencies.

  9. High voltage electrical amplifier having a short rise time

    DOEpatents

    Christie, David J.; Dallum, Gregory E.

    1991-01-01

    A circuit, comprising an amplifier and a transformer is disclosed that produces a high power pulse having a fast response time, and that responds to a digital control signal applied through a digital-to-analog converter. The present invention is suitable for driving a component such as an electro-optic modulator with a voltage in the kilovolt range. The circuit is stable at high frequencies and during pulse transients, and its impedance matching circuit matches the load impedance with the output impedance. The preferred embodiment comprises an input stage compatible with high-speed semiconductor components for amplifying the voltage of the input control signal, a buffer for isolating the input stage from the output stage; and a plurality of current amplifiers connected to the buffer. Each current amplifier is connected to a field effect transistor (FET), which switches a high voltage power supply to a transformer which then provides an output terminal for driving a load. The transformer comprises a plurality of transmission lines connected to the FETs and the load. The transformer changes the impedance and voltage of the output. The preferred embodiment also comprises a low voltage power supply for biasing the FETs at or near an operational voltage.

  10. A SHORT DESCRIPTION OF THE PLAN OF NOVA HIGH SCHOOL.

    ERIC Educational Resources Information Center

    HIERS, NAN

    THE NOVA HIGH SCHOOL IS AN EDUCATIONAL EXPERIMENT TO MAKE LEARNING AND ACHIEVEMENT INTERESTING, CHALLENGING, AND EXCITING TO THE STUDENT. THE PROGRAM IS BASED ON THE CONCEPT OF INDIVIDUAL PROGRESS WITH EMPHASIS ON QUALITY EDUCATION. FEATURES OF THE SCHOOL ENVIRONMENT INCLUDE AIR-CONDITIONING, CARPETING, MULTIPURPOSE CLASSROOMS, INDIVIDUAL STUDY…

  11. Advanced communications technology satellite high burst rate link evaluation terminal communication protocol software user's guide, version 1.0

    NASA Technical Reports Server (NTRS)

    Reinhart, Richard C.

    1993-01-01

    The Communication Protocol Software was developed at the NASA Lewis Research Center to support the Advanced Communications Technology Satellite High Burst Rate Link Evaluation Terminal (ACTS HBR-LET). The HBR-LET is an experimenters terminal to communicate with the ACTS for various experiments by government, university, and industry agencies. The Communication Protocol Software is one segment of the Control and Performance Monitor (C&PM) Software system of the HBR-LET. The Communication Protocol Software allows users to control and configure the Intermediate Frequency Switch Matrix (IFSM) on board the ACTS to yield a desired path through the spacecraft payload. Besides IFSM control, the C&PM Software System is also responsible for instrument control during HBR-LET experiments, uplink power control of the HBR-LET to demonstrate power augmentation during signal fade events, and data display. The Communication Protocol Software User's Guide, Version 1.0 (NASA CR-189162) outlines the commands and procedures to install and operate the Communication Protocol Software. Configuration files used to control the IFSM, operator commands, and error recovery procedures are discussed. The Communication Protocol Software Maintenance Manual, Version 1.0 (NASA CR-189163, to be published) is a programmer's guide to the Communication Protocol Software. This manual details the current implementation of the software from a technical perspective. Included is an overview of the Communication Protocol Software, computer algorithms, format representations, and computer hardware configuration. The Communication Protocol Software Test Plan (NASA CR-189164, to be published) provides a step-by-step procedure to verify the operation of the software. Included in the Test Plan is command transmission, telemetry reception, error detection, and error recovery procedures.

  12. SLIM, Short-pulse Technology for High Gradient Induction Accelerators

    SciTech Connect

    Krasnykh, A.; Kardo-Sysoev, A.; Arntz, F.; /Diversified Tech., Bedford

    2009-12-09

    The conclusions of this paper are: (1) The gradient of the SLIM-based technology is believed to be achievable in the same range as it is for the gradient of a modern rf-linac technology ({approx}100 MeV per meter). (2) The SLIM concept is based on the nsec TEM pulse mode operation with no laser or rf systems. (3) Main components of SLIM are not stressed while the energy is pumped into the induction system. Components can accept the hard environment conditions such as a radiation dose, mismatch, hard electromagnetic nose level, etc. Only for several nanoseconds the switch is OFF and produces a stress in the induction system. At that time, the delivery of energy to the beam takes place. (4) The energy in the induction system initially is storied in the magnetic field when the switch is ON. That fact makes another benefit: a low voltage power supplies can be used. The reliability of a lower voltage power supply is higher and they are cheaper. (5) The coreless SLIM concept offers to work in the MHz range of repetition rate. The induction system has the high electric efficiency (much higher than the DWA). (6) The array of lined up and activated SLIM cells is believed to be a solid state structure of novel accelerating technology. The electron-hole plasma in the high power solid state structure is precisely controlled by the electromagnetic process of a pulsed power supply.

  13. ISS Update: High Rate Communications System - Duration: 9 minutes, 26 seconds.

    NASA Video Gallery

    ISS Update Commentator Pat Ryan interviews Diego Serna, Communications and Tracking Officer, about the High Rate Communications System. Questions? Ask us on Twitter @NASA_Johnson and include the ha...

  14. A self-adaptive method for creating high efficiency communication channels through random scattering media.

    PubMed

    Hao, Xiang; Martin-Rouault, Laure; Cui, Meng

    2014-01-01

    Controlling the propagation of electromagnetic waves is important to a broad range of applications. Recent advances in controlling wave propagation in random scattering media have enabled optical focusing and imaging inside random scattering media. In this work, we propose and demonstrate a new method to deliver optical power more efficiently through scattering media. Drastically different from the random matrix characterization approach, our method can rapidly establish high efficiency communication channels using just a few measurements, regardless of the number of optical modes, and provides a practical and robust solution to boost the signal levels in optical or short wave communications. We experimentally demonstrated analog and digital signal transmission through highly scattering media with greatly improved performance. Besides scattering, our method can also reduce the loss of signal due to absorption. Experimentally, we observed that our method forced light to go around absorbers, leading to even higher signal improvement than in the case of purely scattering media. Interestingly, the resulting signal improvement is highly directional, which provides a new means against eavesdropping. PMID:25070592

  15. Evaluation of components, subsystems, and networks for high rate, high frequency space communications

    NASA Technical Reports Server (NTRS)

    Kerczewski, Robert J.; Ivancic, William D.; Zuzek, John E.

    1991-01-01

    The development of new space communications technologies by NASA has included both commercial applications and space science requirements. NASA's Systems Integration, Test and Evaluation (SITE) Space Communication System Simulator is a hardware based laboratory simulator for evaluating space communications technologies at the component, subsystem, system, and network level, geared toward high frequency, high data rate systems. The SITE facility is well-suited for evaluation of the new technologies required for the Space Exploration Initiative (SEI) and advanced commercial systems. Described here are the technology developments and evaluation requirements for current and planned commercial and space science programs. Also examined are the capabilities of SITE, the past, present and planned future configurations of the SITE facility, and applications of SITE to evaluation of SEI technology.

  16. High-energy ion generation in interaction. of short laser pulse with high-density plasma

    NASA Astrophysics Data System (ADS)

    Sentoku, Y.; Bychenkov, V. Y.; Flippo, K.; Maksimchuk, A.; Mima, K.; Mourou, G.; Sheng, Z. M.; Umstadter, D.

    2002-03-01

    Multi-MeV ion production from the interaction of a short laser pulse with a high-density plasma, accompanied by an underdense preplasma, has been studied with a particle-in-cell simulation and good agreement is found with experiment. The mechanism primarily responsible for the acceleration of ions is identified. Comparison with experiments sheds light on the ion-energy dependence on laser intensity, preplasma scale length, and relative ion energies for a multi-species plasma. Two regimes of maximum ion-energy dependence on laser intensity, I, have been identified: subrelativistic, ?I; and relativistic, ?. Simulations show that the energy of the accelerated ions versus the preplasma scale length increases linearly and then saturates. In contrast, the ion energy decreases with the thickness of the solid-density plasma.

  17. High ion charge states in a high-current, short-pulse, vacuum arc ion source

    SciTech Connect

    Anders, A.; Brown, I.; MacGill, R.; Dickinson, M.

    1995-09-01

    Ions of the cathode material are formed at vacuum arc cathode spots and extracted by a grid system. The ion charge states (typically 1--4) depend on the cathode material and only little on the discharge current as long as the current is low. Here the authors report on experiments with short pulses (several {micro}s) and high currents (several kA); this regime of operation is thus approaching a more vacuum spark-like regime. Mean ion charge states of up to 6.2 for tungsten and 3.7 for titanium have been measured, with the corresponding maximum charge states of up to 8+ and 6+, respectively. The results are discussed in terms of Saha calculations and freezing of the charge state distribution.

  18. Communications

    ERIC Educational Resources Information Center

    Bailenson, Jeremy; Buzzanell, Patrice; Deetz, Stanley; Tewksbury, David; Thompson, Robert J.; Turow, Joseph; Bichelmeyer, Barbara; Bishop, M. J.; Gayeski, Diane

    2013-01-01

    Scholars representing the field of communications were asked to identify what they considered to be the most exciting and imaginative work currently being done in their field, as well as how that work might change our understanding. The scholars included Jeremy Bailenson, Patrice Buzzanell, Stanley Deetz, David Tewksbury, Robert J. Thompson, and…

  19. Communications

    ERIC Educational Resources Information Center

    Bailenson, Jeremy; Buzzanell, Patrice; Deetz, Stanley; Tewksbury, David; Thompson, Robert J.; Turow, Joseph; Bichelmeyer, Barbara; Bishop, M. J.; Gayeski, Diane

    2013-01-01

    Scholars representing the field of communications were asked to identify what they considered to be the most exciting and imaginative work currently being done in their field, as well as how that work might change our understanding. The scholars included Jeremy Bailenson, Patrice Buzzanell, Stanley Deetz, David Tewksbury, Robert J. Thompson, and

  20. The effect of tobacco and alcohol and their reduction/cessation on mortality in oral cancer patients: short communication

    PubMed Central

    2012-01-01

    Background The use of tobacco is known to increase the incidence of developing oral cancer by 6 times, while the additive effect of drinking alcohol further increases the risk leading to higher rate of morbidity and mortality. In this short communication, we prospectively assessed the effect of tobacco smoking and alcohol drinking in oral cancer patients on the overall mortality from the disease, as well as the effect of smoking and drinking reduction/cessation at time of diagnosis on mortality in the same group. Materials and methods A cohort, involved 67 male patients who were diagnosed with oral squamous cell carcinoma, was included in this study. The smoking and drinking habits of this group were recorded, in addition to reduction/cessation after diagnosis with the disease. Comparisons were made to disease mortality at 3 and 5 years. Results Follow-up resulted in a 3-year survival of 46.8% and a 5-year survival of 40.4%. Reduction of tobacco smoking and smoking cessation led to a significant reduction in mortality at 3 (P < 0.001) and 5 (P < 0.001) years. Reduction in drinking alcohol and drinking cessation led to a significant reduction in mortality at 3 (P < 0.001) and 5 (P < 0.001) years. Conclusion Chronic smoking and drinking does have an adverse effect on patients with oral cancer leading to increased mortality from cancer-related causes. Reduction/cessation of these habits tends to significantly reduce mortality in this group of patients. Smoking and drinking cessation counseling should be provided to all newly diagnosed oral cancer patients. PMID:22409767

  1. High-throughput measurement of gap junctional intercellular communication.

    PubMed

    Liu, Jun; Siragam, Vinayakumar; Chen, Jun; Fridman, Michael D; Hamilton, Robert M; Sun, Yu

    2014-06-15

    Gap junctional intercellular communication (GJIC) is a critical part of cellular activities and is necessary for electrical propagation among contacting cells. Disorders of gap junctions are a major cause for cardiac arrhythmias. Dye transfer through microinjection is a conventional technique for measuring GJIC. To overcome the limitations of manual microinjection and perform high-throughput GJIC measurement, here we present a new robotic microinjection system that is capable of injecting a large number of cells at a high speed. The highly automated system enables large-scale cell injection (thousands of cells vs. a few cells) without major operator training. GJIC of three cell lines of differing gap junction density, i.e., HeLa, HEK293, and HL-1, was evaluated. The effect of a GJIC inhibitor (18-α-glycyrrhetinic acid) was also quantified in the three cell lines. System operation speed, success rate, and cell viability rate were quantitatively evaluated based on robotic microinjection of over 4,000 cells. Injection speed was 22.7 cells per min, with 95% success for cell injection and >90% survival. Dye transfer cell counts and dye transfer distance correlated with the expected connexin expression of each cell type, and inhibition of dye transfer correlated with the concentration of GJIC inhibitor. Additionally, real-time monitoring of dye transfer enables the calculation of coefficients of molecular diffusion through gap junctions. This robotic microinjection dye transfer technique permits rapid assessment of gap junction function in confluent cell cultures. PMID:24778169

  2. High performance computing and communications: Investment in American competitiveness

    NASA Astrophysics Data System (ADS)

    1991-03-01

    This report presents the results of a study performed by Gartner Group, Inc. for the U.S. Department of Energy (DOE), through a contract with the Los Alamos National Laboratory (LANL). The purpose of the study is to estimate the economic impact of the Federal High Performance Computing and Communications (HPCC) Program which was proposed by the Office of Science and Technology Policy (OSTP), Executive Office of the President, on September 8, 1989. That Program is an implementation of the Research and Development Strategy for High Performance Computing, which was transmitted to Congress by OSTP on November 20, 1988. The objective of this Gartner Group study to provide an assessment of the likely economic impact and benefits of the Federal HPCC Program and the risks of non-support of this program. The goals of the HPCC Program are to: support computational advances through R and D effort; Reduce uncertainties to industry through increased cooperation and continued use of government as a market for High Performance Computing (HPC) prototypes; Support underlying research, network, and computational infrastructures; and support the U.S. human resource base.

  3. All-plasmonic Mach-Zehnder modulator enabling optical high-speed communication at the microscale

    NASA Astrophysics Data System (ADS)

    Haffner, C.; Heni, W.; Fedoryshyn, Y.; Niegemann, J.; Melikyan, A.; Elder, D. L.; Baeuerle, B.; Salamin, Y.; Josten, A.; Koch, U.; Hoessbacher, C.; Ducry, F.; Juchli, L.; Emboras, A.; Hillerkuss, D.; Kohl, M.; Dalton, L. R.; Hafner, C.; Leuthold, J.

    2015-08-01

    Optical modulators encode electrical signals to the optical domain and thus constitute a key element in high-capacity communication links. Ideally, they should feature operation at the highest speed with the least power consumption on the smallest footprint, and at low cost. Unfortunately, current technologies fall short of these criteria. Recently, plasmonics has emerged as a solution offering compact and fast devices. Yet, practical implementations have turned out to be rather elusive. Here, we introduce a 70 GHz all-plasmonic Mach-Zehnder modulator that fits into a silicon waveguide of 10 μm length. This dramatic reduction in size by more than two orders of magnitude compared with photonic Mach-Zehnder modulators results in a low energy consumption of 25 fJ per bit up to the highest speeds. The technology suggests a cheap co-integration with electronics.

  4. Diet for patients with a short bowel: high fat or high carbohydrate?

    PubMed

    Woolf, G M; Miller, C; Kurian, R; Jeejeebhoy, K N

    1983-04-01

    Eight patients with a short bowel resulting from intestinal resection and clinically stable for at least 6 mo were studied on two diets. Each diet was given for 5 days at a time and crossed over with the other. Both diets contained 20% of total calories as protein. The high-fat diet had 60% of calories as fat and 20% as carbohydrate. This ratio was reversed in the high-carbohydrate diet. Both diets were lactose free with low fiber. Fluid intake was kept constant. The results showed that there was no difference in the blood chemistry, stool, or ostomy volume, the zinc, calcium, and magnesium balances, urine volume, and electrolyte excretion between patients on the two diets. Bomb calorimetry showed that the total calories absorbed and excreted were comparable between the two diets. It was concluded that low-fat diets had no special benefit in the overall nutrition of the patient who has been in remission in regard to bowel disease for 6 mo or longer. Hence, dietary restriction is not recommended in these patients. However, this study did not resolve the question of the requirements and losses of fat-soluble vitamins in such patients when on a high-fat diet. PMID:6825993

  5. Enhanced performance of 400 Gb/s DML-based CAP systems using optical filtering technique for short reach communication.

    PubMed

    Tao, Li; Wang, Yiguang; Xiao, Jiangnan; Chi, Nan

    2014-12-01

    A parallel transmission approach is more likely to realize 400 Gb/s and above short reach transmission as it helps to reduce the cost of both electrical and optical device largely. Directly modulated lasers (DML) are more attractive in 400 Gb/s approach, because it requires relatively small amount of driving power and has low insertion loss, thus lowering its cost. However, the intrinsic chirp will degrade the transmission performance. In this paper, an optical filtering technique is introduced for 400 Gb/s high-speed DML-based carrierless amplitude and phase (CAP) modulation short reach systems for the first time. Owing to the additional optical filter, 1 dB and 3.6 dB sensitivity improvement at BER of 3.8 x 10(-3) is obtained for the back-to-back and 15 km fiber link transmission for single lane at the bitrate of 28 Gb/s. Then a 16-lane CAP16 system with a total bit rate of 413 Gb/s is demonstrated experimentally using low-cost 10 GHz-class DML using optical filtering technique. PMID:25606867

  6. Toward High-Performance Communications Interfaces for Science Problem Solving

    NASA Astrophysics Data System (ADS)

    Oviatt, Sharon L.; Cohen, Adrienne O.

    2010-12-01

    From a theoretical viewpoint, educational interfaces that facilitate communicative actions involving representations central to a domain can maximize students' effort associated with constructing new schemas. In addition, interfaces that minimize working memory demands due to the interface per se, for example by mimicking existing non-digital work practice, can preserve students' attentional focus on their learning task. In this research, we asked the question: What type of interface input capabilities provide best support for science problem solving in both low- and high- performing students? High school students' ability to solve a diverse range of biology problems was compared over longitudinal sessions while they used: (1) hardcopy paper and pencil (2) a digital paper and pen interface (3) pen tablet interface, and (4) graphical tablet interface. Post-test evaluations revealed that time to solve problems, meta-cognitive control, solution correctness, and memory all were significantly enhanced when using the digital pen and paper interface, compared with tablet interfaces. The tangible pen and paper interface also was the only alternative that significantly facilitated skill acquisition in low-performing students. Paradoxically, all students nonetheless believed that the tablet interfaces provided best support for their performance, revealing a lack of self-awareness about how to use computational tools to best advantage. Implications are discussed for how pen interfaces can be optimized for future educational purposes, and for establishing technology fluency curricula to improve students' awareness of the impact of digital tools on their performance.

  7. High-Specificity Targeted Functional Profiling in Microbial Communities with ShortBRED.

    PubMed

    Kaminski, James; Gibson, Molly K; Franzosa, Eric A; Segata, Nicola; Dantas, Gautam; Huttenhower, Curtis

    2015-12-01

    Profiling microbial community function from metagenomic sequencing data remains a computationally challenging problem. Mapping millions of DNA reads from such samples to reference protein databases requires long run-times, and short read lengths can result in spurious hits to unrelated proteins (loss of specificity). We developed ShortBRED (Short, Better Representative Extract Dataset) to address these challenges, facilitating fast, accurate functional profiling of metagenomic samples. ShortBRED consists of two components: (i) a method that reduces reference proteins of interest to short, highly representative amino acid sequences ("markers") and (ii) a search step that maps reads to these markers to quantify the relative abundance of their associated proteins. After evaluating ShortBRED on synthetic data, we applied it to profile antibiotic resistance protein families in the gut microbiomes of individuals from the United States, China, Malawi, and Venezuela. Our results support antibiotic resistance as a core function in the human gut microbiome, with tetracycline-resistant ribosomal protection proteins and Class A beta-lactamases being the most widely distributed resistance mechanisms worldwide. ShortBRED markers are applicable to other homology-based search tasks, which we demonstrate here by identifying phylogenetic signatures of antibiotic resistance across more than 3,000 microbial isolate genomes. ShortBRED can be applied to profile a wide variety of protein families of interest; the software, source code, and documentation are available for download at http://huttenhower.sph.harvard.edu/shortbred. PMID:26682918

  8. High-Specificity Targeted Functional Profiling in Microbial Communities with ShortBRED

    PubMed Central

    Franzosa, Eric A.; Segata, Nicola; Dantas, Gautam; Huttenhower, Curtis

    2015-01-01

    Profiling microbial community function from metagenomic sequencing data remains a computationally challenging problem. Mapping millions of DNA reads from such samples to reference protein databases requires long run-times, and short read lengths can result in spurious hits to unrelated proteins (loss of specificity). We developed ShortBRED (Short, Better Representative Extract Dataset) to address these challenges, facilitating fast, accurate functional profiling of metagenomic samples. ShortBRED consists of two components: (i) a method that reduces reference proteins of interest to short, highly representative amino acid sequences (“markers”) and (ii) a search step that maps reads to these markers to quantify the relative abundance of their associated proteins. After evaluating ShortBRED on synthetic data, we applied it to profile antibiotic resistance protein families in the gut microbiomes of individuals from the United States, China, Malawi, and Venezuela. Our results support antibiotic resistance as a core function in the human gut microbiome, with tetracycline-resistant ribosomal protection proteins and Class A beta-lactamases being the most widely distributed resistance mechanisms worldwide. ShortBRED markers are applicable to other homology-based search tasks, which we demonstrate here by identifying phylogenetic signatures of antibiotic resistance across more than 3,000 microbial isolate genomes. ShortBRED can be applied to profile a wide variety of protein families of interest; the software, source code, and documentation are available for download at http://huttenhower.sph.harvard.edu/shortbred PMID:26682918

  9. The Investigation of Teacher Communication Practices in Virtual High School

    ERIC Educational Resources Information Center

    Belair, Marley

    2011-01-01

    Virtual schooling is an increasing trend for secondary education. Research of the communication practices in virtual schools has provided a myriad of suggestions for virtual school policies. Although transactional distance has been investigated in relation to certain aspects of the communication process, a small-scale qualitative study has not…

  10. The Investigation of Teacher Communication Practices in Virtual High School

    ERIC Educational Resources Information Center

    Belair, Marley

    2011-01-01

    Virtual schooling is an increasing trend for secondary education. Research of the communication practices in virtual schools has provided a myriad of suggestions for virtual school policies. Although transactional distance has been investigated in relation to certain aspects of the communication process, a small-scale qualitative study has not

  11. Short communication: Influence of labeling on Australian and Chinese consumers' liking of milk with short (pasteurized) and long (UHT) shelf life.

    PubMed

    Liem, D G; Bolhuis, D P; Hu, X; Keast, R S J

    2016-03-01

    Sixty percent of milk consumed in China has a long shelf life (UHT), presumably because milk with a short shelf life (pasteurized) is comparatively expensive. This in contrast to Australia, where 10% of consumed milk is UHT and the price between UHT and pasteurized milk is equivalent. Whether UHT is actually more liked than pasteurized milk by Chinese consumers is unknown. However, the potential positive halo around the expensive pasteurized milk might result in Chinese consumers liking milk more when it is labeled as "short shelf-life milk." To test these hypotheses, Chinese (n=48, 20 males, 28 females, 23±7.2 yr) and Australian (n=93, 11 males, 82 females, 24±5.6 yr) consumers tasted and rated (9-point hedonic scale), in a randomized order, 3×30-mL samples of UHT milk (labeled as "long shelf-life milk," "short shelf-life milk," or "milk") and 3×30-mL samples of pasteurized milk (also labeled as "long shelf-life milk," "short shelf-life milk," or "milk"). Australian participants' liking of milk was not influenced by labeling. Regardless of what the label stated, they always preferred the taste of pasteurized milk over the taste of UHT milk. This was different for Chinese participants, who preferred the taste of UHT milk over the taste of pasteurized milk, but in general had a higher liking for any milk that was labeled "short shelf-life milk." Both Australian and Chinese were more positive about pasteurized than UHT milk. In conclusion, Chinese, but not Australian, consumers' liking of milk was guided by the positive expectations of pasteurized milk and the negative expectations of UHT milk. Further research is needed to investigate if the present findings can be extrapolated to a larger and more varied group of Chinese and Australian consumers. PMID:26805991

  12. Short and Long-Term Impacts of Biotechnology Education on Professionals Who Communicate Science to the Public

    ERIC Educational Resources Information Center

    Fritz, Susan M.; Ward, Sarah M.; Byrne, Pat F.; Namuth, Deana M.; Egger, Valerie A.

    2004-01-01

    Consumer acceptance or rejection of biotechnology is often shaped by information prepared by communicators with varying levels of scientific knowledge, awareness, and acceptance. This study compared the prior, post-workshop, and sustained (1 year) biotechnology awareness, acceptance, and attitudes of professionals who communicate biotechnology to…

  13. Short and Long-Term Impacts of Biotechnology Education on Professionals Who Communicate Science to the Public

    ERIC Educational Resources Information Center

    Fritz, Susan M.; Ward, Sarah M.; Byrne, Pat F.; Namuth, Deana M.; Egger, Valerie A.

    2004-01-01

    Consumer acceptance or rejection of biotechnology is often shaped by information prepared by communicators with varying levels of scientific knowledge, awareness, and acceptance. This study compared the prior, post-workshop, and sustained (1 year) biotechnology awareness, acceptance, and attitudes of professionals who communicate biotechnology to

  14. Modelling high data rate communication network access protocol

    NASA Technical Reports Server (NTRS)

    Khanna, S.; Foudriat, E. C.; Paterra, Frank; Maly, Kurt J.; Overstreet, C. Michael

    1990-01-01

    Modeling of high data rate communication systems is different from the low data rate systems. Three simulations were built during the development phase of Carrier Sensed Multiple Access/Ring Network (CSMA/RN) modeling. The first was a model using SIMCRIPT based upon the determination and processing of each event at each node. The second simulation was developed in C based upon isolating the distinct object that can be identified as the ring, the message, the node, and the set of critical events. The third model further identified the basic network functionality by creating a single object, the node which includes the set of critical events which occur at the node. The ring structure is implicit in the node structure. This model was also built in C. Each model is discussed and their features compared. It should be stated that the language used was mainly selected by the model developer because of his past familiarity. Further the models were not built with the intent to compare either structure or language but because the complexity of the problem and initial results contained obvious errors, so alternative models were built to isolate, determine, and correct programming and modeling errors. The CSMA/RN protocol is discussed in sufficient detail to understand modeling complexities. Each model is described along with its features and problems. The models are compared and concluding observations and remarks are presented.

  15. A DSP Based POD Implementation for High Speed Multimedia Communications

    NASA Astrophysics Data System (ADS)

    Zhang, Chang Nian; Li, Hua; Zhang, Nuannuan; Xie, Jiesheng

    2002-12-01

    In the cable network services, the audio/video entertainment contents should be protected from unauthorized copying, intercepting, and tampering. Point-of-deployment (POD) security module, proposed by[InlineEquation not available: see fulltext.], allows viewers to receive secure cable services such as premium subscription channels, impulse pay-per-view, video-on-demand as well as other interactive services. In this paper, we present a digital signal processor (DSP) (TMS320C6211) based POD implementation for the real-time applications which include elliptic curve digital signature algorithm (ECDSA), elliptic curve Diffie Hellman (ECDH) key exchange, elliptic curve key derivation function (ECKDF), cellular automata (CA) cryptography, communication processes between POD and Host, and Host authentication. In order to get different security levels and different rates of encryption/decryption, a CA based symmetric key cryptography algorithm is used whose encryption/decryption rate can be up to[InlineEquation not available: see fulltext.]. The experiment results indicate that the DSP based POD implementation provides high speed and flexibility, and satisfies the requirements of real-time video data transmission.

  16. Use of highly elliptic orbits for new communication services

    NASA Astrophysics Data System (ADS)

    di Girolamo, S.; Luongo, M.; Soddu, C.

    The use of highly elliptic orbits for communication services can be analyzed according to several parameters, but the final parameter which will determine the adoption of a system instead of another one is the cost of the space infrastructure, when deployed into the selected orbit. Thus, the selection of mission parameters has to be made by comparing their impact on overall system costs. The major parameters concern with: coverage; number of satellites; and orbit altitude, inclination, ellipticity. In general, the above parameters have to be selected according to the service requirements, but from their choice will derive the system complexity and the cost, including also the launch cost. Thus, the definition of a convenient space infrastructure for new services has to be assessed through extended trade-offs of above elements, at least. The purpose of this paper is to identify major rules capable to help and simplify the system definition process. Several architectures are analyzed and compared with many orbit periods. The following topics are considered: coverage requirements and mask angle selection; radiation environment typical of the selected orbit; and orbit acquisition and orbit control strategies. The paper addresses the above matters and attempts to identify the solutions and the rules applicable to similar cases.

  17. Design of high sensitivity detector for underwater communication system

    NASA Astrophysics Data System (ADS)

    Cheong, J. S.; Ong, J. S. L.; Ng, J. S.; Krysa, A. B.; Bastiman, F.; David, J. P. R.

    2013-11-01

    Al0.52In0.48P is the largest bandgap material in III-V non-nitride semiconductors that is lattice matched to a readily available substrate (GaAs). Having a bandgap narrower than that of GaN enables it to detect wavelengths around 480 nm. Such wavelengths have the best transmittance underwater and may be used as a carrier in underwater communication systems. We present an Al0.52In0.48P homo-junction Separate-Absorption-Multiplication-Avalanche-Photodiode (SAMAPD) as a high sensitivity detector for such an application. By increasing the neutral and space-charge region thicknesses, the peak response wavelength can be tuned to longer wavelengths with a narrower full-width-half-maximum (FWHM). The quantum efficiency of the detector reduces with FWHM and this is compensated by having an avalanche gain. At room temperature, the SAM-APD has a dark current of <20 pA for a 210 μm radius device up to 99.9% of breakdown voltage. The structure gives a narrow spectral FWHM of 22 nm with centre wavelength of 482 nm. An external quantum efficiency of 33% and 6410% at 482 nm is obtained at bias voltage of -19 V and -92.6 V respectively.

  18. Short Pulse Duration High-Power Laser Photocoagulation during Vitrectomy for Diabetic Retinopathy Reduces Postoperative Inflammation

    PubMed Central

    Sugimoto, Masahiko; Ichio, Atsushi; Kondo, Mineo

    2015-01-01

    The aim of this preliminary study was to determine the effectiveness of short pulse duration, high-power laser photocoagulation (PC) during vitrectomy for diabetic retinopathy (DR).The effects of short pulse duration PC with power of 340–360 mW and duration of 0.02 second were compared to conventional PC with power of 120–150 mW and duration of 0.2 second. The degree of inflammation was quantified by laser flare cell photometry before and at 1 day, 1 week, 4 week, and 12 weeks postoperatively. Twenty-two eyes of 22 consecutive patients were studied. Ten eyes were treated with short pulse duration PC and 12 eyes with conventional PC. The total energy was significantly lower in the short pulse duration PC group than in the conventional PC group (P = 0.007). The flare cell values were not significantly different between the two groups after 1 day, but at 1 week, the flare cell value was significantly lower in the short pulse duration PC group than in the conventional PC group (P = 0.04). This difference was also present at 4 and 12 weeks (P<0.05). The significant lower inflammation after short pulse duration PC than conventional PC indicates that the short pulse duration PC protocol should be considered to treat DR. PMID:26273824

  19. Multiplexed communication over a high-speed quantum channel

    SciTech Connect

    Heurs, M.; Webb, J. G.; Dunlop, A. E.; Harb, C. C.; Huntington, E. H.; Ralph, T. C.

    2010-03-15

    In quantum information systems it is of particular interest to consider the best way in which to use the nonclassical resources consumed by that system. Quantum communication protocols are integral to quantum information systems and are among the most promising near-term applications of quantum information science. Here we show that a multiplexed, digital quantum communications system supported by a comb of vacuum squeezing has a greater channel capacity per photon than a source of broadband squeezing with the same analog band width. We report on the time-resolved, simultaneous observation of the first dozen teeth in a 2.4-GHz comb of vacuum squeezing produced by a subthreshold optical parametric oscillator, as required for such a quantum communications channel. We also demonstrate multiplexed communication on that channel.

  20. Generation of high-energy (>15 MeV) neutrons using short pulse high intensity lasers

    SciTech Connect

    Petrov, G. M.; Davis, J.; Petrova, Tz. B.; Higginson, D. P.; McNaney, J. M.; McGuffey, C.; Qiao, B.; Beg, F. N.

    2012-09-15

    A roadmap is suggested and demonstrated experimentally for the production of high-energy (>15 MeV) neutrons using short pulse lasers. Investigation with a 3D Monte Carlo model has been employed to quantify the production of energetic neutrons. Numerical simulations have been performed for three nuclear reactions, d(d,n){sup 3}He, {sup 7}Li(d,n){sup 8}Be, and {sup 7}Li(p,n){sup 7}Be, driven by monoenergetic ion beams. Quantitative estimates for the driver ion beam energy and number have been made and the neutron spectra and yield in the ion propagation direction have been evaluated for various incident ion energies. In order to generate neutron fluence above a detection limit of 10{sup 6} neutrons/sr, either {approx}10{sup 10} protons with energy 20-30 MeV or comparable amount of deuterons with energy 5-10 MeV are required. Experimental verification of the concept with deuterons driven by the Titan laser (peak intensity 2 Multiplication-Sign 10{sup 19} W/cm{sup 2}, pulse duration of 9 ps, wavelength 1.05 {mu}m, and energy of 360 J) is provided with the generation of neutrons with energy of up to 18 MeV from {sup 7}Li(d,n){sup 8}Be reactions. Future research will focus on optimized schemes for ion acceleration for production of high-energy neutrons, which will involve efficient target design, laser parameter optimization, and converter material.

  1. Future directions for probing two and three nucleon short-range correlations at high energies

    SciTech Connect

    Frankfurt, Leonid; Sargsian, Misak; Strikman, Mark

    2008-10-13

    We summarize recent progress in the studies of the short-rang correlations (SRC) in nuclei in high energy electron and hadron nucleus scattering and suggest directions for the future high energy studies aimed at establishing detailed structure of two-nucleon SRCs, revealing structure of three nucleon SRC correlations and discovering non-nucleonic degrees of freedom in nuclei.

  2. Short communication: bacterial ecology of high-temperature, short-time pasteurized milk processed in the United States.

    PubMed

    Ranieri, M L; Boor, K J

    2009-10-01

    To determine the microbial ecology of pasteurized milk within the United States, 2% fat pasteurized fluid milk samples were obtained from 18 dairy plants from 5 geographical areas representing the Northeast, Southeast, South, Midwest, and West. Of the 589 bacterial isolates identified using DNA sequence-based subtyping methods, 346 belonged to genera characterized as gram-positive endospore-forming bacteria (i.e., Bacillus and Paenibacillus). Of the 346 gram-positive endospore-forming bacteria isolated in the present study, 240 were classified into 45 allelic types identical to those previously identified from samples obtained in New York State, indicating the widespread presence of these microbes in fluid milk production and processing systems in the United States. More than 84% of the gram-positive spore-forming isolates characterized at d 1, 7, and 10 were of the genus Bacillus, whereas more than 92% of isolates characterized at d 17 of shelf life were of the genus Paenibacillus, indicating that the predominant gram-positive spoilage genera shifts from Bacillus spp. to Paenibacillus spp. during refrigerated storage. PMID:19762798

  3. Communicative Writing: Teaching Japanese High School Students To Use Writing To Communicate in English.

    ERIC Educational Resources Information Center

    Matsubara, Yoshikazu

    This paper argues that Japanese education should place more emphasis on teaching students to write effectively in English. It notes that the Japanese Ministry of Education has put more emphasis in recent years in teaching students to listen and communicate orally in English. It is argued that in the age of the Internet, when so much information is…

  4. High bandwidth specialty optical fibers for data communications

    NASA Astrophysics Data System (ADS)

    Li, Jie; Sun, Xiaoguang

    2008-11-01

    Perhaps the most common specialty optical fiber is HCS hard polymer clad silica fiber. It was invented almost 30 years ago for transmitting laser light to initiate explosives in mining industry and later adapted to be used in a variety of new applications, such as data communications. The most typical HCS fiber typically consists of a 200 μm pure silica glass core, a thin coating of low refractive index hard polymer as the cladding, and an ETFE buffer. This design enables the "crimp-and-cleave" technique of terminating and connectorizing fibers quickly and reliably. Its greater glass diameter also renders greater robustness allowing the fiber to endure greater forces during installation. Due to its larger core size and high numerical aperture (NA), the fiber can be used with a plastic connector and low cost LED transmitter that can greatly reduce the system cost. It can also be used at higher temperature and humidity conditions than standard optical fibers coated with telecommunications grade acrylate material. As applications evolve and require greater bandwidth and/or performance over a greater distance, the challenge now is to develop specialty optical fibers with significantly greater bandwidth-length product while maintaining all other characteristics critical to their ease of use and performance. As a response to the demand, two new fiber types have been designed and developed as higher bandwidth versions of the original HCS fiber. In this paper, we will discuss some of the main design requirements for the fibers, describe in detail the two designs, and present the results of fiber performance.

  5. NASA satellite communications application research, phase 2 addendum. Efficient high power, solid state amplifier for EHF communications

    NASA Technical Reports Server (NTRS)

    Benet, James

    1994-01-01

    This document is an addendum to the NASA Satellite Communications Application Research (SCAR) Phase 2 Final Report, 'Efficient High Power, Solid State Amplifier for EHF Communications.' This report describes the work performed from 1 August 1993 to 11 March 1994, under contract number NASW-4513. During this reporting period an array of transistor amplifiers was repaired by replacing all MMIC amplifier chips. The amplifier array was then tested using three different feedhorn configurations. Descriptions, procedures, and results of this testing are presented in this report, and conclusions are drawn based on the test results obtained.

  6. Short- and long-term changes in right whale calling behavior: the potential effects of noise on acoustic communication.

    PubMed

    Parks, Susan E; Clark, C W; Tyack, P L

    2007-12-01

    The impact of anthropogenic noise on marine mammals has been an area of increasing concern over the past two decades. Most low-frequency anthropogenic noise in the ocean comes from commercial shipping which has contributed to an increase in ocean background noise over the past 150 years. The long-term impacts of these changes on marine mammals are not well understood. This paper describes both short- and long-term behavioral changes in calls produced by the endangered North Atlantic right whale (Eubalaena glacialis) and South Atlantic right whale (Eubalaena australis) in the presence of increased low-frequency noise. Right whales produce calls with a higher average fundamental frequency and they call at a lower rate in high noise conditions, possibly in response to masking from low-frequency noise. The long-term changes have occurred within the known lifespan of individual whales, indicating that a behavioral change, rather than selective pressure, has resulted in the observed differences. This study provides evidence of a behavioral change in sound production of right whales that is correlated with increased noise levels and indicates that right whales may shift call frequency to compensate for increased band-limited background noise. PMID:18247780

  7. Communicating with parents of high-risk infants in neonatal intensive care

    PubMed Central

    Yee, Wendy; Ross, Sue

    2006-01-01

    Good communication between parents and staff about the likely outcome of high-risk infants is essential to ensure parents’ full involvement in decision-making. The present paper discusses the literature on this topic to explore the best practices for professionals communicating with parents of high-risk infants. PMID:19030293

  8. Investigation of the Effect of Sport on Submissive Behavior and Communication Skills of High School Students

    ERIC Educational Resources Information Center

    Abakay, Ugur

    2013-01-01

    This study was carried out to detect the differences in submissive behaviors and communication skills of high school students in terms of sports activities and relationship between communication skills and properties of submissive behavior of high school students who are actively involved in sports activities. In this respect at the study, 728

  9. Investigation of the Effect of Sport on Submissive Behavior and Communication Skills of High School Students

    ERIC Educational Resources Information Center

    Abakay, Ugur

    2013-01-01

    This study was carried out to detect the differences in submissive behaviors and communication skills of high school students in terms of sports activities and relationship between communication skills and properties of submissive behavior of high school students who are actively involved in sports activities. In this respect at the study, 728…

  10. Model of Atmospheric Links on Optical Communications from High Altitude

    NASA Technical Reports Server (NTRS)

    Subich, Christopher

    2004-01-01

    Optical communication links have the potential to solve many of the problems of current radio and microwave links to satellites and high-altitude aircraft. The higher frequency involved in optical systems allows for significantly greater signal bandwidth, and thus information transfer rate, in excess of 10 Gbps, and the highly directional nature of laser-based signals eliminates the need for frequency-division multiplexing seen in radio and microwave links today. The atmosphere, however, distorts an optical signal differently than a microwave signal. While the ionosphere is one of the most significant sources of noise and distortion in a microwave or radio signal, the lower atmosphere affects an optical signal more significantly. Refractive index fluctuations, primarily caused by changes in atmospheric temperature and density, distort the incoming signal in both deterministic and nondeterministic ways. Additionally, suspended particles, such as those in haze or rain, further corrupt the transmitted signal. To model many of the atmospheric effects on the propagating beam, we use simulations based on the beam-propagation method. This method, developed both for simulation of signals in waveguides and propagation in atmospheric turbulence, separates the propagation into a diffraction and refraction problem. The diffraction step is an exact solution, within the limits of numerical precision, to the problem of propagation in free space, and the refraction step models the refractive index variances over a segment of the propagation path. By applying refraction for a segment of the propagation path, then diffracting over that same segment, this method forms a good approximation to true propagation through the atmospheric medium. Iterating over small segments of the total propagation path gives a good approximation to the problem of propagation over the entire path. Parameters in this model, such as initial beam profile and atmospheric constants, are easily modified in a simulation such as this, which allows for the rapid analysis of different propagation scenarios. Therefore, this method allows the development of a near-optimal system design for a wide range of situations, typical of what would be seen in different atmospheric conditions over a receiving ground station. A simulation framework based upon this model was developed in FORTRAN, and for moderate grid sizes and propagation distances these simulations are computable in reasonable time on a standard workstation. This presentation will discuss results thus far.

  11. Communications

    NASA Technical Reports Server (NTRS)

    Bonelle, G. J.

    1984-01-01

    Communications in any system is one of the last technologies to be considered, and sometimes it is considered too late to impact the system. This was somewhat the impression on reviewing the NASA budget for two mission scenarios for the space station. However, that budget fortunately was well spent, and the money was spent to get the most benefit per dollar. Another thing that is very often forgotten is that technology is not produced in a vacuum. In fact, in conducting independent research and development (IR&D), the first phase is to define the requirements which must be time phased, becuase very often the conditions will change during the life of the system. From the requirements, a set of architectures that are at least representative of that era are produced. If the exact requirements were not established, at least boundaries are set on the requirements for that architecture. When this is completed, then the technology that is really needed is defined. The major criticism of the work that was presented to the panel is the lack of a firm set of requirements.

  12. Ultra high frequency follow-on communications satellite system

    NASA Astrophysics Data System (ADS)

    Hassien, Michael J.

    1992-03-01

    The existing constellation of UHF communications satellites (LEASAT and FLTSAT) provide key command and control links for mobile forces of the DoD and other government agencies. The UHF Follow-On satellite program will provide for a new generation of communications satellites to replace the existing ones as they reach the end of their life cycle beginning in 1992. Continued coverage is required for both peacetime and crisis environments, and must be maintained indefinitely. An eight-satellite UFO constellation (two per coverage area) will replenish the existing FLTSATCOM constellation.

  13. Forecasting the Short-Term Passenger Flow on High-Speed Railway with Neural Networks

    PubMed Central

    Xie, Mei-Quan; Li, Xia-Miao; Zhou, Wen-Liang; Fu, Yan-Bing

    2014-01-01

    Short-term passenger flow forecasting is an important component of transportation systems. The forecasting result can be applied to support transportation system operation and management such as operation planning and revenue management. In this paper, a divide-and-conquer method based on neural network and origin-destination (OD) matrix estimation is developed to forecast the short-term passenger flow in high-speed railway system. There are three steps in the forecasting method. Firstly, the numbers of passengers who arrive at each station or depart from each station are obtained from historical passenger flow data, which are OD matrices in this paper. Secondly, short-term passenger flow forecasting of the numbers of passengers who arrive at each station or depart from each station based on neural network is realized. At last, the OD matrices in short-term time are obtained with an OD matrix estimation method. The experimental results indicate that the proposed divide-and-conquer method performs well in forecasting the short-term passenger flow on high-speed railway. PMID:25544838

  14. Highly Efficient Amplifier for Ka-Band Communications

    NASA Technical Reports Server (NTRS)

    1996-01-01

    An amplifier developed under a Small Business Innovation Research (SBIR) contract will have applications for both satellite and terrestrial communications. This power amplifier uses an innovative series bias arrangement of active devices to achieve over 40-percent efficiency at Ka-band frequencies with an output power of 0.66 W. The amplifier is fabricated on a 2.0- by 3.8-square millimeter chip through the use of Monolithic Microwave Integrated Circuit (MMIC) technology, and it uses state-of-the-art, Pseudomorphic High-Electron-Mobility Transistor (PHEMT) devices. Although the performance of the MMIC chip depends on these high-performance devices, the real innovations here are a unique series bias scheme, which results in a high-voltage chip supply, and careful design of the on-chip planar output stage combiner. This design concept has ramifications beyond the chip itself because it opens up the possibility of operation directly from a satellite power bus (usually 28 V) without a dc-dc converter. This will dramatically increase the overall system efficiency. Conventional microwave power amplifier designs utilize many devices all connected in parallel from the bias supply. This results in a low-bias voltage, typically 5 V, and a high bias current. With this configuration, substantial I(sup 2) R losses (current squared times resistance) may arise in the system bias-distribution network. By placing the devices in a series bias configuration, the total current is reduced, leading to reduced distribution losses. Careful design of the on-chip planar output stage power combiner is also important in minimizing losses. Using these concepts, a two-stage amplifier was designed for operation at 33 GHz and fabricated in a standard MMIC foundry process with 0.20-m PHEMT devices. Using a 20-V bias supply, the amplifier achieved efficiencies of over 40 percent with an output power of 0.66 W and a 16-dB gain over a 2-GHz bandwidth centered at 33 GHz. With a 28-V bias, a power level of 1.1 W was achieved with a 12-dB gain and a 36-percent efficiency. This represents the best reported combination of power and efficiency at this frequency. In addition to delivering excellent power and gain, this Ka-band MMIC power amplifier has an efficiency that is 10 percent greater than existing designs. The unique design offers an excellent match for spacecraft applications since the amplifier supply voltage is closely matched to the typical value of spacecraft bus voltage. These amplifiers may be used alone in applications of 1 W or less, or several may be combined or used in an array to produce moderate power, Ka-band transmitters with minimal power combining and less thermal stress owing to the combination of excellent efficiency and power output. The higher voltage operation of this design may also save mass and power because the dc-dc power converter is replaced with a simpler voltage regulator.

  15. An Investigation of Communication in Virtual High Schools

    ERIC Educational Resources Information Center

    Belair, Marley

    2012-01-01

    Virtual schooling is an increasing trend for secondary education. Research of the communication practices in virtual schools has provided a myriad of suggestions for virtual school policies. The purpose of this qualitative study was to investigate the activities and processes involved in the daily rituals of virtual school teachers and learners…

  16. Graphic Communications. Industrial Arts. Performance Objectives. Junior High School.

    ERIC Educational Resources Information Center

    Duval County School Board, Jacksonville, FL.

    Several intermediate performance objectives and corresponding criterion measures are listed for a graphic communications course for seventh, eighth, and ninth grade students. The seventh grade section includes eight terminal objectives for a 9-week course and covers the basic fundamentals of photography, bookbinding, and silk screening. The eighth…

  17. Toward High-Performance Communications Interfaces for Science Problem Solving

    ERIC Educational Resources Information Center

    Oviatt, Sharon L.; Cohen, Adrienne O.

    2010-01-01

    From a theoretical viewpoint, educational interfaces that facilitate communicative actions involving representations central to a domain can maximize students' effort associated with constructing new schemas. In addition, interfaces that minimize working memory demands due to the interface per se, for example by mimicking existing non-digital work…

  18. When Are High-Tech Communicators Effective in Parkinson's Disease?

    ERIC Educational Resources Information Center

    Ferriero, Giorgio; Caligari, Marco; Ronconi, Gianpaolo; Franchignoni, Franco

    2012-01-01

    This report describes a 63-year-old woman with Parkinson's disease showing loss of intelligibility of speech and severely impaired handwriting, despite undergoing physical and speech therapies. As the patient had sufficient residual motor abilities and adequate cognitive function and motivation, a computer-based communication aid with a software…

  19. Validation of the Short Form of the Career Development Inventory with an Iranian High School Sample

    ERIC Educational Resources Information Center

    Sadeghi, Ahmad; Baghban, Iran; Bahrami, Fatemeh; Ahmadi, Ahmad; Creed, Peter

    2011-01-01

    A short 33-item form of the Career Development Inventory was validated on a sample of 310 Iranian high school students. Factor analysis indicated that attitude and cognitive subscale items loaded on their respective factors, and that internal reliability coefficients at all levels were satisfactory to good. Support for validity was demonstrated by…

  20. A Model for Short-Term Training of High School Publications Advisers.

    ERIC Educational Resources Information Center

    Click, John William

    A model for the short-term training of high school publications advisers, and the procedures used in developing it, are described in this paper. The paper first outlines survey techniques used to obtain advisers' rankings of 53 statements about their professional needs and reports the statements and their rankings by advisers. Procedures are then…

  1. Intercellular Communication Amplifies Stressful Effects in High-Charge, High-Energy (HZE) Particle-Irradiated Human Cells

    PubMed Central

    AUTSAVAPROMPORN, Narongchai; DE TOLEDO, Sonia M.; BUONANNO, Manuela; JAY-GERIN, Jean-Paul; HARRIS, Andrew L.; AZZAM, Edouard I.

    2014-01-01

    Understanding the mechanisms that underlay the biological effects of particulate radiations is essential for space exploration and for radiotherapy. Here, we investigated the role of gap junction intercellular communication (GJIC) in modulating harmful effects induced in confluent cultures wherein most cells are traversed by one or more radiation tracks. We focused on the effect of radiation quality (linear energy transfer; LET) on junctional propagation of DNA damage and cell death among the irradiated cells. Confluent normal human fibroblasts were exposed to graded doses of 1 GeV protons (LET ~0.2 keV/μm) or 1 GeV/u iron ions (LET ~151 keV/μm) and were assayed for clonogenic survival and for micronucleus formation, a reflection of DNA damage, shortly after irradiation and following longer incubation periods. Iron ions were ~2.7 fold more effective than protons at killing 90% of the cells in the exposed cultures when assayed within 5–10 minutes after irradiation. When cells were held in the confluent state for several hours after irradiation, substantial repair of potentially lethal damage (PLDR), coupled with a reduction in micronucleus formation, occurred in cells exposed to protons, but not in those exposed to iron ions. In fact, such confluent holding after exposure to a similarly toxic dose of iron ions enhanced the induced toxic effect. However, following iron ion irradiation, inhibition of GJIC by 18-α-glycyrrhetinic acid eliminated the enhanced toxicity and reduced micronucleus formation to levels below those detected in cells assayed shortly after irradiation. The data show that low LET radiation induces strong PLDR within hours, but that high LET radiation with similar immediate toxicity does not induce PLDR and its toxicity increases with time following irradiation. The results also show that GJIC among irradiated cells amplifies stressful effects following exposure to high, but not LET radiation, and that GJIC has only minimal effect on cellular recovery following low LET irradiation. PMID:21905305

  2. Laser-induced resonance states as dynamic suppressors of ionization in high-frequency short pulses

    SciTech Connect

    Barash, Danny; Orel, Ann E.; Baer, Roi

    2000-01-01

    An adiabatic-Floquet formalism is used to study the suppression of ionization in short laser pulses. In the high-frequency limit the adiabatic equations involve only the pulse envelope where transitions are purely ramp effects. For a short-ranged potential having a single-bound state we show that ionization suppression is caused by the appearance of a laser-induced resonance state, which is coupled by the pulse ramp to the ground state and acts to trap ionizing flux. (c) 1999 The American Physical Society.

  3. Anomalous high photoconductivity in short channel indium-zinc-oxide photo-transistors

    SciTech Connect

    Choi, Hyun-Sik; Jeon, Sanghun

    2015-01-05

    Upon light exposure, an indium-zinc-oxide (IZO) thin-film transistor (TFT) presents higher photoconductivity by several orders of magnitude at the negative gate bias region. Among various device geometrical factors, scaling down the channel length of the photo-transistor results in an anomalous increase in photoconductivity. To probe the origin of this high photoconductivity in short-channel device, we measured transient current, current–voltage, and capacitance–voltage characteristics of IZO–TFTs with various channel lengths and widths before and after illumination. Under the illumination, the equilibrium potential region which lies far from front interface exists only in short-channel devices, forming the un-depleted conducting back channel. This region plays an important role in carrier transport under the illumination, leading to high photoconductivity in short-channel devices. Photon exposure coupled with gate-modulated band bending for short-channel devices leads to the accumulation of V{sub o}{sup ++} at the front channel and screening negative gate bias, thereby generating high current flow in the un-depleted back-channel region.

  4. Application of advanced high speed turboprop technology to future civil short-haul transport aircraft design

    NASA Technical Reports Server (NTRS)

    Conlon, J. A.; Bowles, J. V.

    1978-01-01

    With an overall goal of defining the needs and requirements for short-haul transport aircraft research and development, the objective of this paper is to determine the performance and noise impact of short-haul transport aircraft designed with an advanced turboprop propulsion system. This propulsion system features high-speed propellers that have more blades and reduced diameters. Aircraft are designed for short and medium field lengths; mission block fuel and direct operating costs (DOC) are used as performance measures. The propeller diameter was optimized to minimize DOC. Two methods are employed to estimate the weight of the acoustic treatment needed to reduce interior noise to an acceptable level. Results show decreasing gross weight, block fuel, DOC, engine size, and optimum propfan diameter with increasing field length. The choice of acoustic treatment method has a significant effect on the aircraft design.

  5. A long-term investigation of the HF communication channel over middle- and high-latitude paths

    NASA Astrophysics Data System (ADS)

    Goodman, John; Ballard, John; Sharp, Eugene

    1997-07-01

    A study of HF communication link and network availability has been carried out using frequency modulated continuous wave (FMCW) swept-frequency sounders operating in an oblique-incidence configuration. The sounder deployment enabled 28 middle- and high-latitude paths to be evaluated; the time period of the study was from December 1994 until the summer of 1996. Propagation conditions including ionospheric mode information, maximum observable frequencies, signal-to-noise ratios, and channel availabilities for digital data communication were derived and archived. The objective of the study was to ascertain the efficacy of HF data link communication for a proposed aeronautical-mobile service. Data were used to simulate the propagation environment which would be experienced in actual operation and to evaluate the value of path and frequency diversity in overcoming various propagation effects. It has been concluded that path and frequency diversity will lead to channel availabilities approaching nearly 100% and that a practical engineering solution was possible. These positive results are achievable if and only if dynamic frequency management methods are invoked. The paper outlines the nature of a real-time system, which is based upon a terrestrial FMCW swept-frequency sounder constellation and by which communication nowcasts and short-term forecasts are developed to drive a dynamic frequency management system.

  6. Space Link Extension (SLE) Emulation for High-Throughput Network Communication

    NASA Technical Reports Server (NTRS)

    Murawski, Robert W.; Tchorowski, Nicole; Golden, Bert

    2014-01-01

    As the data rate requirements for space communications increases, significant stress is placed not only on the wireless satellite communication links, but also on the ground networks which forward data from end-users to remote ground stations. These wide area network (WAN) connections add delay and jitter to the end-to-end satellite communication link, effects which can have significant impacts on the wireless communication link. It is imperative that any ground communication protocol can react to these effects such that the ground network does not become a bottleneck in the communication path to the satellite. In this paper, we present our SCENIC Emulation Lab testbed which was developed to test the CCSDS SLE protocol implementations proposed for use on future NASA communication networks. Our results show that in the presence of realistic levels of network delay, high-throughput SLE communication links can experience significant data rate throttling. Based on our observations, we present some insight into why this data throttling happens, and trace the probable issue back to non-optimal blocking communication which is sup-ported by the CCSDS SLE API recommended practices. These issues were presented as well to the SLE implementation developers which, based on our reports, developed a new release for SLE which we show fixes the SLE blocking issue and greatly improves the protocol throughput. In this paper, we also discuss future developments for our end-to-end emulation lab and how these improvements can be used to develop and test future space communication technologies.

  7. Impact of a Program to Facilitate Mother-Infant Communication in High-Risk Families of High-Risk Infants.

    ERIC Educational Resources Information Center

    Haney, Michele; Klein, M. Diane

    1993-01-01

    Mothers in the Mother-Infant Communication Project (MICP), designed to facilitate caregivers' uses of communicative interaction strategies with their high-risk infants, scored better than comparison mothers on caregiving environment quality. Children of MICP mothers who received a group experience in addition to home visits performed better on…

  8. Using Mobile Communication Technology in High School Education: Motivation, Pressure, and Learning Performance

    ERIC Educational Resources Information Center

    Rau, Pei-Luen Patrick; Gao, Qin; Wu, Li-Mei

    2008-01-01

    Motivation and pressure are considered two factors impacting vocational senior high school student learning. New communication technology, especially mobile communication technology, is supposed to be effective in encouraging interaction between the student and the instructor and improving learning efficiency. Social presence and information…

  9. Transformation of short-periodic high-inclination orbits of circumsolar submillimeter dust

    SciTech Connect

    Bazei, A.A.; Kramer, E.N.

    1995-11-01

    Disintegration of short-periodic comets is one of the sources of cosmic dust in the Solar System. Initially dust particles move approximately in the orbits of parent comets, in particular, in high-inclination orbits. In a few million years, some of these particles (the smallest ones) go over to the short-periodic, high-inclination orbits due to the Poynting-Robertson effect. The numerical integration of the equations of motion at this stage of evolution gives rise to somewhat surprising results. For example, when integrating the equations of motion as far back as 6000 years from the time of meteor observation, the real meteor particle gains the perihelion distance smaller than the solar radius (!). Our calculations show that the time of falling onto the Sun is shorter for a article moving in a high-inclination orbit. This is due to the superposition of gravitational perturbation and radiation effects.

  10. Short Communication: High Cellular Iron Levels Are Associated with Increased HIV Infection and Replication

    PubMed Central

    Chang, Hsiang-Chun; Bayeva, Marina; Taiwo, Babafemi; Palella, Frank J.; Hope, Thomas J.

    2015-01-01

    Abstract HIV is a pandemic disease, and many cellular and systemic factors are known to alter its infectivity and replication. Earlier studies had suggested that anemia is common in HIV-infected patients; however, higher iron was also observed in AIDS patients prior to the introduction of antiretroviral therapy (ART). Therefore, the relationship between iron and viral infection is not well delineated. To address this issue, we altered the levels of cellular iron in primary CD4+ T cells and showed that higher iron is associated with increased HIV infection and replication. In addition, HIV infection alone leads to increased cellular iron, and several ART drugs increase cellular iron independent of HIV infection. Finally, HIV infection is associated with increased serum iron in HIV-positive patients regardless of treatment with ART. These results establish a relationship between iron and HIV infection and suggest that iron homeostasis may be a viable therapeutic target for HIV. PMID:25291189

  11. Photosynthetic and Biochemical Changes in Response to Short Interval High ``g'' Exposure in Wheat

    NASA Astrophysics Data System (ADS)

    Dixit, Jyotsana; Vidyasagar, Pandit; Jagtap, Sagar; Kamble, Shailendra

    We have investigated the effect of short interval post imbibition high “g” exposure on wheat seeds (Triticum aestivum var.Lok-1) by evaluating the photosynthetic performance, chlorophyll “a” fluorescence biochemical indices and antioxidant response. Imbibed wheat seeds were exposed to high “g” ranging from 500 g to 2500 g for 10 min, allowed to germinate and grown for 5 days under normal gravity i.e. 1 g. Chlorophyll “a” fluorescence transient was examined in wheat seedling raised from hyper gravity treated seeds. Fv/Fm, PI, Fv/Fo decreased in high “g” treated seeds compared to control. Photosynthetic performance indices such as Transpiration rate, Stomatal conductance, Net photosynthetic rate, Intracellular CO2 concentration, Intrinsic water use efficiency also declined in wheat seedlings raised from High “g” treated seeds suggesting that high g reduces efficiency of photosynthesis in wheat seedlings. Results of Biochemical analysis showed reduced alpha- amylase activity in wheat seeds subjected to high “g” ranging from 500 g to 2500 g in a magnitude dependent manner. Decline in enzyme activity was positively correlated with higher starch content and lower reducing sugars in high “g” exposed wheat seeds. This possibly explains the reduced percent germination and growth in response to high “g”. Antioxidant enzyme activity (CAT and POX) significantly increased as a result of hypergravity exposure In conclusion, short interval high “g” exposure results in reduced growth and photosynthetic activity in wheat seedlings.

  12. High-speed CMOS optical communication using silicon light emitters

    NASA Astrophysics Data System (ADS)

    Goosen, Marius E.; Venter, Petrus J.; du Plessis, Monuko; Nell, Ilse J.; Bogalecki, Alfons W.; Rademeyer, Pieter

    2011-01-01

    The idea of moving CMOS into the mainstream optical domain remains an attractive one. In this paper we discuss our recent advances towards a complete silicon optical communication solution. We prove that transmission of baseband data at multiples of megabits per second rates are possible using improved silicon light sources in a completely native standard CMOS process with no post processing. The CMOS die is aligned to a fiber end and the light sources are directly modulated. An optical signal is generated and transmitted to a silicon Avalanche Photodiode (APD) module, received and recovered. Signal detectability is proven through eye diagram measurements. The results show an improvement of more than tenfold over our previous results, also demonstrating the fastest optical communication from standard CMOS light sources. This paper presents an all silicon optical data link capable of 2 Mb/s at a bit error rate of 10-10, or alternatively 1 Mb/s at a bit error rate of 10-14. As the devices are not operating at their intrinsic switching speed limit, we believe that even higher transmission rates are possible with complete integration of all components in CMOS.

  13. Predicting Time Series from Short-Term High-Dimensional Data

    NASA Astrophysics Data System (ADS)

    Ma, Huanfei; Zhou, Tianshou; Aihara, Kazuyuki; Chen, Luonan

    The prediction of future values of time series is a challenging task in many fields. In particular, making prediction based on short-term data is believed to be difficult. Here, we propose a method to predict systems' low-dimensional dynamics from high-dimensional but short-term data. Intuitively, it can be considered as a transformation from the inter-variable information of the observed high-dimensional data into the corresponding low-dimensional but long-term data, thereby equivalent to prediction of time series data. Technically, this method can be viewed as an inverse implementation of delayed embedding reconstruction. Both methods and algorithms are developed. To demonstrate the effectiveness of the theoretical result, benchmark examples and real-world problems from various fields are studied.

  14. A novel high-speed PLC communication modem

    SciTech Connect

    Abraham, K.C.; Roy, S. )

    1992-10-01

    In this paper an innovative design for power line carrier (PLC) communication using digitally modulated signals is presented. The major contribution consists of a new signal coupler to the power line that achieves a stable transmission bandwidth of 4 KHz on distribution lines over long distances. Preliminary field tests achieved half-duplex operation at 1.2 Kbaud over a distribution power line to the 120V network and back with a symbol error rate of about 2% using less than about 10 W of average transmitted power, which is considerably superior to the present state-of-the-art PLC modems. Full-duplex operation over 120/240V intra-building wiring has also been field tested at 9.6 Kbaud over distances of 3000 ft. using 1W of average transmitted power.

  15. Indoor Propagation Simulation using FEM for Short-Range Wireless Communication Systems Operating at 2.4 GHz

    NASA Astrophysics Data System (ADS)

    Hult, Tommy; Mohammed, Abbas

    2006-05-01

    In this paper we investigate the wave propagation effects of a short-range wireless device, like the Bluetooth, in an indoor office environment. Specifically, we investigate line of sight (LOS) and non line of sight (NLOS) propagation scenarios and verify the theoretical statistics of the fading using real measurements and finite element method (FEM) simulations of the environment. The simulations are also used for assessing the impact on propagation when doors are opened or closed. In addition, we also investigate the improvement in performance resulting from receive diversity gain of a system employing multiple receive antennas with various combining techniques.

  16. Asymmetric plasmonic-dielectric coupler with short coupling length, high extinction ratio, and low insertion loss.

    PubMed

    Li, Qiang; Song, Yi; Zhou, Gan; Su, Yikai; Qiu, Min

    2010-10-01

    Asymmetric directional coupling between a hybrid plasmonic waveguide with subwavelength field confinement and a conventional dielectric waveguide is investigated. The proposed hybrid coupler features short coupling length, high coupling efficiency, high extinction ratio, and low insertion loss; it can also be integrated into a silicon-based platform. This coupler can be potentially adopted for signal routing between plasmonic waveguides and dielectric waveguides in photonic integrated circuits. Furthermore, it can be exploited to efficiently excite hybrid plasmonic modes with conventional dielectric modes. PMID:20890317

  17. Parallel PIC Simulations of Short-Pulse High Intensity Laser Plasma Interactions.

    NASA Astrophysics Data System (ADS)

    Lasinski, B. F.; Still, C. H.; Langdon, A. B.

    2001-10-01

    We extend our previous simulations of high intensity short pulse laser plasma interactions footnote B. F. Lasinski, A. B. Langdon, S. P. Hatchett, M. H. Key, and M. Tabak, Phys. Plasmas 6, 2041 (1999); S. C. Wilks and W. L. Kruer, IEEE Journal of Quantum Electronics 11, 1954 (1997). to 3D and to much larger systems in 2D using our new, modern, 3D, electromagnetic, fully relativistic, massively parallel PIC code. We study the generation of hot electrons and energetic ions and the associated complex phenomena. Laser light filamentation and the formation of high static magnetic fields are described.

  18. Generating high-power short terahertz electromagnetic pulses with a multifoil radiator.

    PubMed

    Vinokurov, Nikolay A; Jeong, Young Uk

    2013-02-01

    We describe a multifoil cone radiator capable of generating high-field short terahertz pulses using short electron bunches. Round flat conducting foil plates with successively decreasing radii are stacked, forming a truncated cone with the z axis. The gaps between the foil plates are equal and filled with some dielectric (or vacuum). A short relativistic electron bunch propagates along the z axis. At sufficiently high particle energy, the energy losses and multiple scattering do not change the bunch shape significantly. When passing by each gap between the foil plates, the electron bunch emits some energy into the gap. Then, the radiation pulses propagate radially outward. For transverse electromagnetic waves with a longitudinal (along the z axis) electric field and an azimuthal magnetic field, there is no dispersion in these radial lines; therefore, the radiation pulses conserve their shapes (time dependence). At the outer surface of the cone, we have synchronous circular radiators. Their radiation field forms a conical wave. Ultrashort terahertz pulses with gigawatt-level peak power can be generated with this device. PMID:23432259

  19. A high-power free electron laser using a short rayleigh length

    SciTech Connect

    William Colson; Alan Todd; George Neil

    2004-09-01

    Free electron lasers have always had the potential for high average power, since the laser medium cannot be damaged and is transparent to all wavelengths while the exhaust heat is removed at the speed of light. At MW power levels, the resonator mirrors of the oscillator are vulnerable to damage because of the small beam size in the undulator. We present a description of an FEL that uses a resonator with a short Rayleigh length in order to increase the mode area at the mirrors and reduce the intensity. The corresponding undulator must also be short. The whole FEL system is designed to be compact and efficient, producing about 1 MW of power at 1 mu-m infrared wavelength using an electron beam of about 140 MeV with about 0.6A of recirculating average current.

  20. Neonatal overfeeding attenuates acute central pro-inflammatory effects of short-term high fat diet

    PubMed Central

    Cai, Guohui; Dinan, Tara; Barwood, Joanne M.; De Luca, Simone N.; Soch, Alita; Ziko, Ilvana; Chan, Stanley M. H.; Zeng, Xiao-Yi; Li, Songpei; Molero, Juan; Spencer, Sarah J.

    2015-01-01

    Neonatal obesity predisposes individuals to obesity throughout life. In rats, neonatal overfeeding also leads to early accelerated weight gain that persists into adulthood. The phenotype is associated with dysfunction in a number of systems including paraventricular nucleus of the hypothalamus (PVN) responses to psychological and immune stressors. However, in many cases weight gain in neonatally overfed rats stabilizes in early adulthood so the animal does not become more obese as it ages. Here we examined if neonatal overfeeding by suckling rats in small litters predisposes them to exacerbated metabolic and central inflammatory disturbances if they are also given a high fat diet in later life. In adulthood we gave the rats normal chow, 3 days, or 3 weeks high fat diet (45% kcal from fat) and measured peripheral indices of metabolic disturbance. We also investigated hypothalamic microglial changes, as an index of central inflammation, as well as PVN responses to lipopolysaccharide (LPS). Surprisingly, neonatal overfeeding did not predispose rats to the metabolic effects of a high fat diet. Weight changes and glucose metabolism were unaffected by the early life experience. However, short term (3 day) high fat diet was associated with more microglia in the hypothalamus and a markedly exacerbated PVN response to LPS in control rats; effects not seen in the neonatally overfed. Our findings indicate neonatally overfed animals are not more susceptible to the adverse metabolic effects of a short-term high fat diet but may be less able to respond to the central effects. PMID:25628527

  1. Space Link Extension (SLE) Emulation for High-Throughput Network Communication

    NASA Technical Reports Server (NTRS)

    Murawski, Robert; Tchorowski, Nicole; Golden, Bert

    2014-01-01

    As the data rate requirements for space communications increases, signicant stressis placed not only on the wireless satellite communication links, but also on the groundnetworks which forward data from end-users to remote ground stations. These wide areanetwork (WAN) connections add delay and jitter to the end-to-end satellite communicationlink, eects which can have signicant impacts on the wireless communication link. It isimperative that any ground communication protocol can react to these eects such that theground network does not become a bottleneck in the communication path to the satellite.In this paper, we present our SCENIC Emulation Lab testbed which was developed to testthe CCSDS SLE protocol implementations proposed for use on future NASA communica-tion networks. Our results show that in the presence of realistic levels of network delay,high-throughput SLE communication links can experience signicant data rate throttling.Based on our observations, we present some insight into why this data throttling happens,and trace the probable issue back to non-optimal blocking communication which is sup-ported by the CCSDS SLE API recommended practices. These issues were presented aswell to the SLE implementation developers which, based on our reports, developed a newrelease for SLE which we show xes the SLE blocking issue and greatly improves the pro-tocol throughput. In this paper, we also discuss future developments for our end-to-endemulation lab and how these improvements can be used to develop and test future spacecommunication technologies.

  2. High Capacity Communications From Martian Distances. Part 1; Spacecraft Link Design Analysis

    NASA Technical Reports Server (NTRS)

    Vyas, Hemali N.; Schuchman, Leonard; Orr, Richard; Williams, Wallace Dan; Collins, Michael; Noreen, Gary

    2006-01-01

    High capacity space communications has been a desire for Human Exploration and Science missions. Current Mars missions operate at data rates of 120 kbps for telemetry downlink and it is desirable to study high rate communication links in the range of 100 Mbps to 1 Gbps data rates from Martian distances. This paper will present some assumed scenarios along with link design assumptions and link analysis for high capacity communications from Mars. The paper will focus on RF subsystems namely antenna and power for the downlink communication from a relay orbiter at Mars. The relay orbiter will communicate with the low orbit spacecrafts at Mars or any Martian surface elements such as robots, and relay the data back to the ground networks on Earth. The study will dive into the spacecraft downlink system design and communication link analysis between the relay orbiter and ground network on Earth for data rates ranging from 100 Mbps to 1 Gbps based on the assumed scenarios and link assumptions. With high rate links at larger distances, there will be a significant impact on the antenna and power requirements and the link design will make an attempt to minimize the mass of the RF subsystem on the spacecraft. The results of this study will be presented for three data rates 1 Gbps, 500 Mbps and 100 Mbps at maximum Mars to Earth distance of 2.67AU. The design will use a Ka-band downlink with 90% link availability, along with various ground network G/T assumptions and possible bandwidth efficient modulations. The paper will conclude with what types of high rate communication links are feasible from Martian distances and also identify a range of requirements for antenna and power technologies for these high capacity communications from Mars.

  3. VERY HIGH-SPEED DRILL STRING COMMUNICATIONS NETWORK

    SciTech Connect

    David S. Pixton

    2002-11-01

    Testing of a high-speed digital data transmission system for drill pipe is described. Passive transmission of digital data through 1000 ft of telemetry drill pipe has been successfully achieved. Data rates of up to 2 Mbit/sec have been tested through the 1000 ft system with very low occurrence of data errors: required error correction effort is very low or nonexistent. Further design modifications have been made to improve manufacturability and high pressure robustness of the transmission line components. Failure mechanisms of previous designs at high pressure and high temperature are described. Present design limitations include high temperature application.

  4. Characteristics of Adverse Effects When Using High Dose Short Term Steroid Regimen

    PubMed Central

    Min, Kyung Hyun; Rhee, Chung-Ku; Jung, Jae Yun

    2012-01-01

    Background and Objectives Although the adverse effect of long term steroid usage is well known, the adverse effect of short term high dose steroid usage has not been studied thoroughly. The purpose of this study was to identify the characteristics of the adverse effects when using a high dose steroid for a short term. We also compared the adverse effect of steroid between in- and out-patients. Subjects and Methods The medical record of 500 patients, who were treated with methylprednisolone 48 mg/day for 1-2 weeks, was retrospectively reviewed. Steroid was prescribed due to SSNHL, Bell's palsy, Ramsay-Hunt syndrome and herpes zoster oticus. The incidence of each adverse effect was analyzed, and also the time point of detection was analyzed. The 500 patients were composed of 250 in-patients and 250 out-patients. The adverse effect was compared between these two groups, as well. Results Adverse effect of steroid was found in 33.0% of the patients. Among these adverse effects, abdominal discomfort (26.8%) was most common, followed by skin rash (14.7%), swelling (13.4%), and hot flush (6.9%). Abdominal discomfort and hot flush was mostly detected on the first week. Meanwhile, the skin rash was usually detected on the third week. The incidence of adverse effect was significantly higher in the out-patient group. Conclusions The incidence of high dose short term steroid treatment may be very high. The patients should be warned about these adverse effects. Monitoring should be performed until 3-4 week, since some adverse effects may not be detected until this time point. PMID:24653873

  5. Lifetime measurements of high-lying short lived states in {sup 69}As

    SciTech Connect

    Matejska-Minda, M.; Bednarczyk, P.; Fornal, B.; Ciemala, M.; Kmiecik, M.; Krzysiek, M.; Maj, A.; Meczynski, W.; Myalski, S.; Styczen, J.; Zieblinski, M.; Angelis, G. de; Huyuk, T.; Michelagnoli, C.; Sahin, E.; Aydin, S.; Farnea, E.; Menegazzo, R.; Recchia, F.; Ur, C. A.; and others

    2012-10-20

    Lifetimes of high-spin states in {sup 69}As have been measured using Doppler shift attenuation technique with the GASP and RFD setup. The determined transition probabilities indicate large deformation associated with some rotational bands in this nucleus.

  6. Probing the virus host interaction in high containment: an approach using pooled short hairpin RNA.

    PubMed

    Filone, Claire Marie; Dower, Ken; Cowley, Glenn S; Hensley, Lisa E; Connor, John H

    2015-01-01

    The study of viruses in high containment offers unique challenges for technology-intense approaches. These approaches include high-throughput screening for small-molecule antivirals and genetic perturbation-based screens for host factors required for viral replication. Here, we describe the use of whole-genome scale pooled short hairpin RNA (shRNA) libraries to screen for host factors necessary for viral infection at BSL2, and the transition of this technique into the BSL4 environment. Pooled screening provides a unique way to circumvent many of the technological challenges associated with other high-throughput screening approaches in high containment. Our pooled screening approach identified host factors involved in the replication of orthopoxviruses (Vaccinia and Monkeypox) and filoviruses (Ebola and Marburg) under conditions that enable straightforward screen-to-follow-up approaches. PMID:25646658

  7. Probing the Virus Host Interaction in High Containment: An Approach Using Pooled Short Hairpin RNA

    PubMed Central

    Filone, Claire Marie; Dower, Ken; Cowley, Glenn S.; Hensley, Lisa E.

    2015-01-01

    Abstract The study of viruses in high containment offers unique challenges for technology-intense approaches. These approaches include high-throughput screening for small-molecule antivirals and genetic perturbation-based screens for host factors required for viral replication. Here, we describe the use of whole-genome scale pooled short hairpin RNA (shRNA) libraries to screen for host factors necessary for viral infection at BSL2, and the transition of this technique into the BSL4 environment. Pooled screening provides a unique way to circumvent many of the technological challenges associated with other high-throughput screening approaches in high containment. Our pooled screening approach identified host factors involved in the replication of orthopoxviruses (Vaccinia and Monkeypox) and filoviruses (Ebola and Marburg) under conditions that enable straightforward screen-to-follow-up approaches. PMID:25646658

  8. Short-course Astronomical Research Seminars for High School and College Students

    NASA Astrophysics Data System (ADS)

    Johnson, Jolyon

    2011-05-01

    Since 2008, I have helped lead several short-course astronomical research seminars with Russell M. Genet. These seminars have ranged from semester-long courses at Cuesta College in San Luis Obispo, California to long weekends at the University of Oregon's Pine Mountain Observatory. Each seminar is led by an experienced observer or group of observers who guide high school and college students through the scientific process from observations to publication. The students (anywhere from half a dozen to twenty in number) participate in and contribute to every step. Being a coauthor on one or more research papers offers students an advantage on college and scholarship applications. Similarly, graduate schools often prefer students with research experience. Many topics of research are appropriate for these short-courses including variable star, exoplanet, and asteroid photometry. However, the most successful topic has been visual double stars because the observations required are straitforward and the equipment is relatively inexpensive. The Journal of Double Star Observations is also welcoming of student research and provides swift publication. A detailed description of the short-course seminars can be found in the recent Collins Foundation Press volume titled Small Telescopes and Astronomical Research.

  9. Highly Flexible and Conductive Printed Graphene for Wireless Wearable Communications Applications

    NASA Astrophysics Data System (ADS)

    Huang, Xianjun; Leng, Ting; Zhu, Mengjian; Zhang, Xiao; Chen, Jiacing; Chang, Kuohsin; Aqeeli, Mohammed; Geim, Andre K.; Novoselov, Kostya S.; Hu, Zhirun

    2015-12-01

    In this paper, we report highly conductive, highly flexible, light weight and low cost printed graphene for wireless wearable communications applications. As a proof of concept, printed graphene enabled transmission lines and antennas on paper substrates were designed, fabricated and characterized. To explore its potentials in wearable communications applications, mechanically flexible transmission lines and antennas under various bended cases were experimentally studied. The measurement results demonstrate that the printed graphene can be used for RF signal transmitting, radiating and receiving, which represents some of the essential functionalities of RF signal processing in wireless wearable communications systems. Furthermore, the printed graphene can be processed at low temperature so that it is compatible with heat-sensitive flexible materials like papers and textiles. This work brings a step closer to the prospect to implement graphene enabled low cost and environmentally friendly wireless wearable communications systems in the near future.

  10. Highly Flexible and Conductive Printed Graphene for Wireless Wearable Communications Applications

    PubMed Central

    Huang, Xianjun; Leng, Ting; Zhu, Mengjian; Zhang, Xiao; Chen, JiaCing; Chang, KuoHsin; Aqeeli, Mohammed; Geim, Andre K.; Novoselov, Kostya S.; Hu, Zhirun

    2015-01-01

    In this paper, we report highly conductive, highly flexible, light weight and low cost printed graphene for wireless wearable communications applications. As a proof of concept, printed graphene enabled transmission lines and antennas on paper substrates were designed, fabricated and characterized. To explore its potentials in wearable communications applications, mechanically flexible transmission lines and antennas under various bended cases were experimentally studied. The measurement results demonstrate that the printed graphene can be used for RF signal transmitting, radiating and receiving, which represents some of the essential functionalities of RF signal processing in wireless wearable communications systems. Furthermore, the printed graphene can be processed at low temperature so that it is compatible with heat-sensitive flexible materials like papers and textiles. This work brings a step closer to the prospect to implement graphene enabled low cost and environmentally friendly wireless wearable communications systems in the near future. PMID:26673395

  11. Highly Flexible and Conductive Printed Graphene for Wireless Wearable Communications Applications.

    PubMed

    Huang, Xianjun; Leng, Ting; Zhu, Mengjian; Zhang, Xiao; Chen, JiaCing; Chang, KuoHsin; Aqeeli, Mohammed; Geim, Andre K; Novoselov, Kostya S; Hu, Zhirun

    2015-01-01

    In this paper, we report highly conductive, highly flexible, light weight and low cost printed graphene for wireless wearable communications applications. As a proof of concept, printed graphene enabled transmission lines and antennas on paper substrates were designed, fabricated and characterized. To explore its potentials in wearable communications applications, mechanically flexible transmission lines and antennas under various bended cases were experimentally studied. The measurement results demonstrate that the printed graphene can be used for RF signal transmitting, radiating and receiving, which represents some of the essential functionalities of RF signal processing in wireless wearable communications systems. Furthermore, the printed graphene can be processed at low temperature so that it is compatible with heat-sensitive flexible materials like papers and textiles. This work brings a step closer to the prospect to implement graphene enabled low cost and environmentally friendly wireless wearable communications systems in the near future. PMID:26673395

  12. A new high intensity and short-pulse molecular beam valve.

    PubMed

    Yan, B; Claus, P F H; van Oorschot, B G M; Gerritsen, L; Eppink, A T J B; van de Meerakker, S Y T; Parker, D H

    2013-02-01

    In this paper, we report on the design and performance of a new home-built pulsed gas valve, which we refer to as the Nijmegen Pulsed Valve (NPV). The main output characteristics include a short pulse width (as short as 20 ?s) combined with operating rates up to 30 Hz. The operation principle of the NPV is based on the Lorentz force created by a pulsed current passing through an aluminum strip located within a magnetic field, which opens the nozzle periodically. The amplitude of displacement of the opening mechanism is sufficient to allow the use of nozzles with up to 1.0 mm diameter. To investigate the performance of the valve, several characterizations were performed with different experimental methods. First, a fast ionization gauge was used to measure the beam intensity of the free jet emanating from the NPV. We compare free jets from the NPV with those from several other pulsed valves in current use in our laboratory. Results showed that a high intensity and short pulse-length beam could be generated by the new valve. Second, the NPV was tested in combination with a skimmer, where resonance enhanced multiphoton ionization combined with velocity map imaging was used to show that the NPV was able to produce a pulsed molecular beam with short pulse duration (~20 ?s using 0.1% NO/He at 6 bars) and low rotational temperature (~1 K using 0.5% NO/Ar at 6 bars). Third, a novel two-point pump-probe method was employed which we label double delay scan. This method allows a full kinematic characterization of the molecular beam, including accurate speed ratios at different temporal positions. It was found that the speed ratio was maximum (S = 50 using 0.1% NO/He at 3 bars) at the peak position of the molecular beam and decreased when it was on the leading or falling edge. PMID:23464190

  13. A new high intensity and short-pulse molecular beam valve

    NASA Astrophysics Data System (ADS)

    Yan, B.; Claus, P. F. H.; van Oorschot, B. G. M.; Gerritsen, L.; Eppink, A. T. J. B.; van de Meerakker, S. Y. T.; Parker, D. H.

    2013-02-01

    In this paper, we report on the design and performance of a new home-built pulsed gas valve, which we refer to as the Nijmegen Pulsed Valve (NPV). The main output characteristics include a short pulse width (as short as 20 μs) combined with operating rates up to 30 Hz. The operation principle of the NPV is based on the Lorentz force created by a pulsed current passing through an aluminum strip located within a magnetic field, which opens the nozzle periodically. The amplitude of displacement of the opening mechanism is sufficient to allow the use of nozzles with up to 1.0 mm diameter. To investigate the performance of the valve, several characterizations were performed with different experimental methods. First, a fast ionization gauge was used to measure the beam intensity of the free jet emanating from the NPV. We compare free jets from the NPV with those from several other pulsed valves in current use in our laboratory. Results showed that a high intensity and short pulse-length beam could be generated by the new valve. Second, the NPV was tested in combination with a skimmer, where resonance enhanced multiphoton ionization combined with velocity map imaging was used to show that the NPV was able to produce a pulsed molecular beam with short pulse duration (˜20 μs using 0.1% NO/He at 6 bars) and low rotational temperature (˜1 K using 0.5% NO/Ar at 6 bars). Third, a novel two-point pump-probe method was employed which we label double delay scan. This method allows a full kinematic characterization of the molecular beam, including accurate speed ratios at different temporal positions. It was found that the speed ratio was maximum (S = 50 using 0.1% NO/He at 3 bars) at the peak position of the molecular beam and decreased when it was on the leading or falling edge.

  14. Short-range variability of soil pH in a regional geochemical survey, communicating uncertainty to the data user

    NASA Astrophysics Data System (ADS)

    Ander, Louise; Knights, Kate; Lark, Murray

    2015-04-01

    The north of Ireland is well-furnished with geochemical data after completion of the Tellus survey of Northern Ireland and the Tellus Border survey of six northern counties of the Republic of Ireland. These data are of considerable interest to the agricultural sector, in particular the data on soil pH. However, a geochemical survey at regional scale cannot resolve significant variation of soil pH, in particular effects of soil management and fine-scale variation of superficial material. This leads to uncertainties in the mapped soil pH which must be accounted for when making decisions about management interventions, including more detailed local sampling. In this poster we show how uncertainty of predicted soil pH, relative to established threshold values, can be quantified by disjunctive kriging. The uncertainty is expressed in terms of probabilities. We show how this can be communicated to the data user by means of the calibrated phrases of the IPCC, using results from recent research on its efficacy to modify its presentation.

  15. Remotely-interrogated high data rate free space laser communications link

    DOEpatents

    Ruggiero, Anthony J.

    2007-05-29

    A system and method of remotely extracting information from a communications station by interrogation with a low power beam. Nonlinear phase conjugation of the low power beam results in a high power encoded return beam that automatically tracks the input beam and is corrected for atmospheric distortion. Intracavity nondegenerate four wave mixing is used in a broad area semiconductor laser in the communications station to produce the return beam.

  16. A high power TWT power processing system. [for communication satellites

    NASA Technical Reports Server (NTRS)

    Farber, B. F.; Goldin, D. S.; Siegert, C.; Gourash, F.

    1974-01-01

    A power processing system (PPS) is designed for a space-type high power (200W RF) multi-collector traveling-wave tube (TWT). The basic power circuit is presented along with the simplified block diagram and the input, output, and general requirements for the PPS design are tabulated. The paper covers the PPS design as to critical TWT/PPS interface requirements, high voltage cathode/collector supply, high voltage components material, packaging, grounding and isolation, and electrical performance. The use of a single two loop control system for the regulation of cathode and collector voltages is shown to give high efficiency, excellent steady-state and transient performance characteristics, and complete protection for TWT and PPS components under transient conditions.

  17. The Short Circuit Instability in Protoplanetary Disks: Processing high temperature minerals

    NASA Astrophysics Data System (ADS)

    Hubbard, A.; McNally, C. P.; Mac Low, M. M.; Ebel, D. S.; D'Alessio, P.

    2013-04-01

    We introduce a magneto-hydrodynamic instability which occurs, among other locations, in the inner, hot regions of protoplanetary disks, and which alters the way in which resistive dissipation of magnetic energy into heat proceeds. This instability can be likened to both an electrical short circuit and lightning, as it concentrates the dissipation of magnetic energy by means of the enhanced release of free electrons. This instability can generate very high temperatures, making it an excellent candidate for thermally processing protoplanetary disk solids, from annealing silicates to melting chondrules or even CAIs.

  18. Interplay of mulitphoton and tunneling ionization in short-wavelength-driven high-order harmonic generation

    SciTech Connect

    Gkortsas, Vasileios-Marios; Bhardwaj, Siddharth; Lai, Chien-Jen; Hong, Kyung-Han; Falcao-Filho, Edilson L.; Kaertner, Franz X.

    2011-07-15

    High-order harmonic generation efficiency is theoretically modeled and compared with experiments using 400 and 800 nm driver pulses. It is shown that, for a short drive wavelength and a Keldysh parameter larger than 1, the Ammosov-Delone-Krainov (ADK) ionization model does not give a good agreement between theory and experiment. Since the ADK ionization model only accounts for tunnel ionization, it underestimates the yield of low-order harmonics from the wings of the driver pulse. In contrast, the Yudin-Ivanov ionization model [Phys. Rev. A 64, 013409 (2001)], which accounts for both tunnel and multiphoton ionization, gives much better agreement with the experimental results.

  19. Type IIa Bragg grating based ultra-short DBR fiber laser with high temperature resistance.

    PubMed

    Ran, Yang; Feng, Fu-Rong; Liang, Yi-Zhi; Jin, Long; Guan, Bai-Ou

    2015-12-15

    We report on the fabrication of a thermally resistant ultra-short distributed Bragg reflector (DBR) fiber laser based on the photo inscription of two wavelength-matched type IIa gratings in a thin-core Er-doped fiber. With continuous UV exposure, each Bragg reflector initially grows as a type I grating, followed by decay in strength, and then re-grows as a type IIa grating with enhanced thermal resistance. The DBR laser, with an entire length of 13 mm, can stably operate at 600°C with single longitude mode, which provides potential applications in high temperature environments. PMID:26670491

  20. Diaphragm does not produce ammonia or lactate during high-intensity short-term exercise.

    PubMed

    Manohar, M; Hassan, A S

    1990-10-01

    To ascertain whether costal diaphragm engages in ammonia and lactate production (like limb muscles) during high-intensity short-term exercise, experiments were carried out on six healthy trained ponies in which phrenic venous catheters had been implanted 5-9 days earlier. Simultaneous anaerobically obtained blood samples from abdominal aorta and the phrenic vein at rest and during 4 min of exertion at 32 km/h and at a 7% grade were analyzed for blood-gas variables as well as lactate and ammonia concentrations using standard procedures. At rest, heart rate was 47 +/- 4 beats/min and the diaphragmatic O2 extraction was 26.5%. With exercise, heart rate rose to 218 +/- 6 beats/min, marked acidosis and hyperventilation occurred, and the diaphragmatic O2 extraction increased threefold (80.9%). Such exercise is known to dramatically increase the work of breathing as respiratory frequency and change in pleural pressure approach 138 +/- 4 breaths/min and 30 +/- 3 cmH2O, respectively. Despite the fact that phrenic-venous O2 tension of exercised ponies decreased to 15.5 +/- 0.6 Torr, the phrenic-venous lactate and ammonia concentrations did not exceed corresponding arterial values. These data thus revealed that the diaphragm is uniquely unlike limb muscles, which at high workloads readily engage in net ammonia and lactate production, and that the diaphragmatic energy needs during high-intensity short-term exercise are primarily met by aerobic metabolism. PMID:2221124

  1. Implementing Molecular Dynamics for Hybrid High Performance Computers - 1. Short Range Forces

    SciTech Connect

    Brown, W Michael; Wang, Peng; Plimpton, Steven J; Tharrington, Arnold N

    2011-01-01

    The use of accelerators such as general-purpose graphics processing units (GPGPUs) have become popular in scientific computing applications due to their low cost, impressive floating-point capabilities, high memory bandwidth, and low electrical power requirements. Hybrid high performance computers, machines with more than one type of floating-point processor, are now becoming more prevalent due to these advantages. In this work, we discuss several important issues in porting a large molecular dynamics code for use on parallel hybrid machines - 1) choosing a hybrid parallel decomposition that works on central processing units (CPUs) with distributed memory and accelerator cores with shared memory, 2) minimizing the amount of code that must be ported for efficient acceleration, 3) utilizing the available processing power from both many-core CPUs and accelerators, and 4) choosing a programming model for acceleration. We present our solution to each of these issues for short-range force calculation in the molecular dynamics package LAMMPS. We describe algorithms for efficient short range force calculation on hybrid high performance machines. We describe a new approach for dynamic load balancing of work between CPU and accelerator cores. We describe the Geryon library that allows a single code to compile with both CUDA and OpenCL for use on a variety of accelerators. Finally, we present results on a parallel test cluster containing 32 Fermi GPGPUs and 180 CPU cores.

  2. High nitrogen removal rate using ANAMMOX process at short hydraulic retention time.

    PubMed

    Casagrande, C G; Kunz, A; De Prá, M C; Bressan, C R; Soares, H M

    2013-01-01

    The anaerobic ammonium oxidation (ANAMMOX) is a chemolithoautotrophic process, which converts NH(4)(+) to N(2) using nitrite (NO(2)(-)) as the electron acceptor. This process has very high nitrogen removal rates (NRRs) and is an alternative to classical nitrification/denitrification wastewater treatment. In the present work, a strategy for nitrogen removal using ANAMMOX process was tested evaluating their performance when submitted to high loading rates and very short hydraulic retention times (HRTs). An up-flow ANAMMOX column reactor was inoculated with 30% biomass (v v(-1)) fed from 100 to 200 mg L(-1) of total N (NO(2)(-)-N + NH(4)(+)-N) at 35 °C. After start-up and process stability the maximum NRR in the up-flow anaerobic sludge blanket (UASB) reactor was 18.3 g-N L(-1) d(-1) operated at 0.2 h of HRT. FISH (fluorescence in situ hybridization) analysis and process stoichiometry confirmed that ANAMMOX was the prevalent process for nitrogen removal during the experiments. The results point out that high NRRs can be obtained at very short HRTs using up-flow ANAMMOX column reactor configuration. PMID:23416586

  3. Short communication: Altered expression of specificity protein 1 impairs milk fat synthesis in goat mammary epithelial cells.

    PubMed

    Zhu, J J; Luo, J; Xu, H F; Wang, H; Loor, J J

    2016-06-01

    Specificity protein 1 (encoded by SP1) is a novel transcription factor important for the regulation of lipid metabolism and the normal function of various hormones in model organisms. Its potential role, if any, on ruminant milk fat is unknown. Despite the lower expression of the lipolysis-related gene ATGL (by 44 and 37% respectively), both the adenoviral overexpression and the silencing of SP1 [via short interfering (si)RNA] markedly reduced cellular triacylglycerol (TAG) content (by 28 and 25%, respectively), at least in part by decreasing the expression of DGAT1 (-36% in adenovirus treatment) and DGAT2 (-81 and -87%, respectively) that are involved in TAG synthesis. Consistent with the markedly lower expression of genes related to lipid droplet formation and secretion (TIP47 by 19 and 32%, and ADFP by 25 and 25%, respectively), cellular lipid droplet content was also decreased sharply, by 9 and 8.5%, respectively, after adenoviral overexpression of SP1 or its silencing via siRNA. Overall, the results underscored a potentially important role of SP1 in maintaining milk-fat droplet synthesis in goat mammary epithelial cells. PMID:26995134

  4. Radiation Hardened, Modulator ASIC for High Data Rate Communications

    NASA Technical Reports Server (NTRS)

    McCallister, Ron; Putnam, Robert; Andro, Monty; Fujikawa, Gene

    2000-01-01

    Satellite-based telecommunication services are challenged by the need to generate down-link power levels adequate to support high quality (BER approx. equals 10(exp 12)) links required for modem broadband data services. Bandwidth-efficient Nyquist signaling, using low values of excess bandwidth (alpha), can exhibit large peak-to-average-power ratio (PAPR) values. High PAPR values necessitate high-power amplifier (HPA) backoff greater than the PAPR, resulting in unacceptably low HPA efficiency. Given the high cost of on-board prime power, this inefficiency represents both an economical burden, and a constraint on the rates and quality of data services supportable from satellite platforms. Constant-envelope signals offer improved power-efficiency, but only by imposing a severe bandwidth-efficiency penalty. This paper describes a radiation- hardened modulator which can improve satellite-based broadband data services by combining the bandwidth-efficiency of low-alpha Nyquist signals with high power-efficiency (negligible HPA backoff).

  5. The Effects of Music on High-intensity Short-term Exercise in Well Trained Athletes

    PubMed Central

    Jarraya, Mohamed; Chtourou, Hamdi; Aloui, Asma; Hammouda, Omar; Chamari, Karim; Chaouachi, Anis; Souissi, Nizar

    2012-01-01

    Purpose The purpose of this investigation was to assess the effects of listening to music during warm-up on short-term supramaximal performances during the 30-s Wingate test in highly trained athletes. Methods Twelve young male athletes (20.6±1.8 yrs, 177±4.4 cm and 72.3±5.3 kg) underwent two Wingate tests in separate sessions with a recovery period of 48 h in-between, either after a 10 min of warm-up with (MWU) or without (NMWU) music. High tempo music (>120 to 140bpm) was selected for the study. Heart rate (HR) and rate of perceived exertion (RPE) were recorded after the warm-up (for HR = average of warm-up) and immediately after the Wingate test. Results HR, RPE and the fatigue index during the Wingate test are not affected by the incorporation of music during warm-up. However, power output (Ppeak and Pmean) was significantly higher after MWU than NMWU (P<0.05). The relative increases were 4.1 ± 3.6 and 4.0 ± 3.7 W·kg−1 for Ppeak and Pmean respectively. These findings demonstrated the beneficial effect of music during warm-up on short-term supramaximal performances. Conclusions As it's a legal method and an additional aid, music may be used during warm-up before performing activities requiring powerful lower limbs’ muscles contractions during short-term supramaximal exercises. PMID:23342221

  6. Parent Involvement in Junior High Schools: A Failure to Communicate

    ERIC Educational Resources Information Center

    Halsey, Pamela A.

    2005-01-01

    Although the nature of parent involvement changes as children get older and varies from family to family, junior high school teachers and the families they serve recognize the value of parent involvement in young adolescents' education. Teachers, parents, and students, however, are often uncertain about how to initiate parent involvement in their…

  7. The Communicative Process of Drug Resistance among High School Students.

    ERIC Educational Resources Information Center

    Alberts, J. K.; And Others

    1992-01-01

    Analyzed 69 narrative accounts of successful and unsuccessful attempts by high school students to say no to drug offers. Found peer pressure applied in approximately 70 percent of offers. Much of pressure was applied after refusal of initial offer. Simple offers were more likely with alcohol; drug offers were more likely to be persuasive and to…

  8. High energy, short pulse fiber laser front end for kilo-Joule class CPA systems

    NASA Astrophysics Data System (ADS)

    Dawson, J. W.; Mitchell, S.; Beach, R. J.; Messerly, M. J.; Siders, C. W.; Phan, H.; Barty, C. P. J.

    2006-02-01

    We are developing an all fiber laser system optimized for providing input pulses for short pulse (1-10ps), high energy (~1kJ) glass laser systems. Fiber lasers are ideal solutions for these systems as they are highly reliable and enable long term stable operation. The design requirements for this application are very different than those commonly seen in fiber lasers. High-energy lasers often have low repetition rates (as low as one pulse every few hours), and thus high average power and efficiency are of little practical value. What is of high value is pulse energy, high signal to noise ratio (expressed as pre-pulse contrast), good beam quality, consistent output parameters and timing. Our system focuses on optimizing these parameters. Our prototype system consists of a mode-locked fiber laser, a compressed pulse fiber amplifier, a "pulse cleaner", a chirped fiber Bragg grating, pulse selectors, a transport fiber system and a large mode area fiber amplifier. We will review the system and present theoretical and experimental studies of critical aspects, in particular the requirement for high pre-pulse contrast.

  9. Resonant micro-optic gyro using a short and high-finesse fiber ring resonator.

    PubMed

    Ma, Huilian; Zhang, Jianjie; Wang, Linglan; Lu, Ying; Ying, Diqing; Jin, Zhonghe

    2015-12-15

    A novel hybrid integrated scheme is proposed for a high-performance resonant micro-optic gyro (RMOG), which requires a low-loss micro-ring resonator for mass production. A new record for the RMOG is established experimentally with a short fiber ring resonator and an integrated signal detecting and processing circuit. The finesse of the short fiber ring resonator with a length of 60 cm and a diameter of 4.77 cm is as high as 202, and the theoretical sensitivity of the RMOG is better than 0.3°/h assuming the average optical intensity at the photodetector is 1 mW. The 60 cm long spliceless micro-ring resonator is experimentally proved to be sufficient for a tactical-grade RMOG. An angle random walk coefficient of 0.64°/√h and a typical bias stability below 9.6°/h for the integration time of 50 s are successfully demonstrated using an innovative open-loop approach for an operation time of 1600 s. PMID:26670531

  10. Ultrafast terawatt laser sources for high-field particle acceleration and short wavelength generation

    SciTech Connect

    Downer, M.C.; Siders, C.W.

    1996-12-31

    The Laser Sources working group concerned itself with recent advances in and future requirements for the development of laser sources relevant to high-energy physics (HEP) colliders, small scale accelerators, and the generation of short wave-length radiation. We heavily emphasized pulsed terawatt peak power laser sources for several reasons. First, their development over the past five years has been rapid and multi-faceted, and has made relativistic light intensity available to the advanced accelerator community, as well as the wider physics community, for the first time. Secondly, they have strongly impacted plasma-based accelerator research over the past two years, producing the first experimental demonstrations of the laser wakefield accelerator (LWFA) in both its resonantly-driven and self-modulated forms. Thirdly, their average power and wall-plug efficiency currently fall well short of projected requirements for future accelerators and other high average power applications, but show considerable promise for improving substantially over the next few years. A review of this rapidly emerging laser technology in the context of advanced accelerator research is therefore timely.

  11. Evaluation of the ALF DNA sequencer for high-speed sizing of short tandem repeat alleles.

    PubMed

    Decorte, R; Cassiman, J J

    1996-10-01

    DNA typing of short tandem repeat (STR) loci with automated real-time analysis of the fluorescent polymerase chain reaction (PCR) products has given forensic DNA analysis a new dimension. In the present work, the ALF DNA sequencer was evaluated for automated size determination of tetra-nucleotide STRs at high speed. Short gel plates, with a well-to-laser distance of 10 cm, allowed for the analysis of four STR loci (HUMvWF, HUMTH01, D21S11 and HPRT) in one gel lane in less than 75 min. Allele size determination was done with two external allelic ladders for each locus. Lane-to-lane variations were overcome by the inclusion in each lane of two fluorescent PCR products of constant size (123 and 375 bp) that migrated below and above the multiplex of the four STR loci. The accuracy of sizing and allele detection within and between different gels was high (99.89%) for all four STR systems investigated and the gels could be reloaded without a decrease in accuracy of the allele size estimation. This way, the throughput of the system was increased, which is of interest for linkage studies, gene mapping, and population diversity studies. PMID:8957177

  12. VERY HIGH-SPEED DRILL STRING COMMUNICATIONS NETWORK

    SciTech Connect

    David S. Pixton

    2002-08-01

    Testing of recent upgrades to the drill pipe telemetry system in a 1000-ft vertical well has shown that the new system can achieve at least 1,000 ft passive transmission distance with sufficient bandwidth to accommodate a digital transmission rate of 2 Mbit/sec. Digitized data from a module at the bottom of the well has been successfully transmitted through the transmission line to the top of the well for a period of approximately one month. Manufacture of 30 prototype range 2 drill pipes has demonstrated greater simplicity of manufacturing and greater consistency of electrical characteristics from part to part, as compared to the first production run previously reported. Further work is needed to improve the high pressure capability of the system and to improve the robustness of the system in a high-vibration environment.

  13. A high-frequency warm shallow water acoustic communications channel model and measurements.

    PubMed

    Chitre, Mandar

    2007-11-01

    Underwater acoustic communication is a core enabling technology with applications in ocean monitoring using remote sensors and autonomous underwater vehicles. One of the more challenging underwater acoustic communication channels is the medium-range very shallow warm-water channel, common in tropical coastal regions. This channel exhibits two key features-extensive time-varying multipath and high levels of non-Gaussian ambient noise due to snapping shrimp-both of which limit the performance of traditional communication techniques. A good understanding of the communications channel is key to the design of communication systems. It aids in the development of signal processing techniques as well as in the testing of the techniques via simulation. In this article, a physics-based channel model for the very shallow warm-water acoustic channel at high frequencies is developed, which are of interest to medium-range communication system developers. The model is based on ray acoustics and includes time-varying statistical effects as well as non-Gaussian ambient noise statistics observed during channel studies. The model is calibrated and its accuracy validated using measurements made at sea. PMID:18189549

  14. A high-power communications technology satellite for the 12 and 14 GHz bands.

    NASA Technical Reports Server (NTRS)

    Franklin, C. A.; Davison, E. H.

    1972-01-01

    Description of the mission, subsystems and communication capabilities of a joint Communications Technology Satellite (CTS) scheduled for launch in 1975 by the Canadian Department of Communications in cooperation with NASA. The principal objectives of the mission are TV transmission at 12 GHz to low-cost ground terminals, up-link TV transmission at 14 GHz transportable terminals, and flight tests of spacecraft subsystems and components for future communications satellites. The major advanced spacecraft subsystems are a novel superefficiency TWT design, a 0.4 mlb Mercury Bombardment ion engine for north-south station keeping, a 3-axis stabilization system to maintain a high antenna boresight pointing accuracy, a liquid metal slip ring experiment, and a lightweight extendible solar array with an initial power output greater than 1 kW.

  15. Developing Students' Literacy Skills Using High-Tech Speech-Generating Augmentative and Alternative Communication Devices

    ERIC Educational Resources Information Center

    Wilkins, Julia; Ratajczak, Amy

    2009-01-01

    This article outlines practical techniques for developing literacy skills in users of high-tech speech-generating augmentative and alternative communication (AAC) devices. The recommended strategies are intended for general classroom teachers who teach literacy skills to students with typical speech. Many students who use high-tech AAC devices…

  16. Communicative Spontaneity in Individuals with High Support Needs: An Exploratory Consideration of Causation.

    ERIC Educational Resources Information Center

    Carter, Mark

    2002-01-01

    Reasons for limited spontaneity of communication in individuals with high support needs are considered and include: it is an inherent characteristic, a product of highly structured teaching programs, a form of learned helplessness, or a product of a failure to systematically program for spontaneity. (Contains references.) (Author/CR)

  17. Improving Mathematical Communication Ability and Self Regulation Learning of Junior High Students by Using Reciprocal Teaching

    ERIC Educational Resources Information Center

    Qohar, Abdul; Sumarmo, Utari

    2013-01-01

    This paper presents the findings from a posttest experiment control group design by using reciprocal teaching, conducted in Indonesia University of Education to investigate students' ability in mathematical communication and self regulated learning. Subject of the study were 254 of 9th grade students from three junior high schools of high, medium,…

  18. Communications Strategies on Alcohol and Highway Safety. Volume II. High School Youth. Final Report.

    ERIC Educational Resources Information Center

    Grey Advertising, Inc., New York, NY.

    The second part of a two-part, two volume study deals with high school youth and identifies target populations and communications strategies for encouraging personal action steps to prevent drunk driving. Data, collected from interviews and questionnaires, are summarized and presented in tabular form. One fourth of high schoolers in a…

  19. High Efficiency Power Combining of Ka-Band TWTs for High Data Rate Communications

    NASA Technical Reports Server (NTRS)

    Wintucky, E. G.; Simons, R. N.; Vaden, K. R.; Lesny, G. G.; Glass, J. L.

    2006-01-01

    Future NASA deep space exploration missions are expected in some cases to require telecommunication systems capable of operating at very high data rates (potentially 1 Gbps or more) for the transmission back to Earth of large volumes of scientific data, which means high frequency transmitters with large bandwidth. Among the Ka band frequencies of interest are the present 500 MHz Deep Space Network (DSN) band of 31.8 to 32.3 GHz and a broader band at 37-38 GHz allocated for space science [1]. The large distances and use of practical antenna sizes dictate the need for high transmitter power of up to 1 kW or more. High electrical efficiency is also a requirement. The approach investigated by NASA GRC is a novel wave guide power combiner architecture based on a hybrid magic-T junction for combining the power output from multiple TWTs [1,2]. This architecture was successfully demonstrated and is capable of both high efficiency (90-95%, depending on frequency) and high data rate transmission (up to 622 Mbps) in a two-way power combiner circuit for two different pairs of Ka band TWTs at two different frequency bands. One pair of TWTs, tested over a frequency range of 29.1 to 29.6 GHz, consisted of two 110-115W TWTs previously used in uplink data transmission evaluation terminals in the NASA Advanced Communications Technology Satellite (ACTS) program [1,2]. The second pair was two 100W TWTs (Boeing 999H) designed for high efficiency operation (greater than 55%) over the DSN frequency band of 31.8 to 32.3 GHz [3]. The presentation will provide a qualitative description of the wave guide circuit, results for power combining and data transmission measurements, and results of computer modeling of the magic-T and alternative hybrid junctions for improvements in efficiency and power handling capability. The power combiner results presented here are relevant not only to NASA deep space exploration missions, but also to other U.S. Government agency programs.

  20. Atomic short-range order and incipient long-range order in high-entropy alloys

    NASA Astrophysics Data System (ADS)

    Singh, Prashant; Smirnov, A. V.; Johnson, D. D.

    2015-06-01

    Within density-functional theory, we apply an electronic-structure-based thermodynamic theory to calculate short-ranged order (SRO) in homogeneously disordered substitutional N -component alloys, and its electronic origin. Using the geometric properties of an (N -1 ) simplex that describes the Gibbs (compositional) space, we derive the analytic transform of the SRO eigenvectors that provides a unique description of high-temperature SRO in N -component alloys and the incipient low-temperature long-range order. We apply the electronic-based thermodynamic theory and the new general analysis to ternaries (A 1 Cu-Ni-Zn and A 2 Nb-Al-Ti) for validation, and then to quinary Al-Co-Cr-Fe-Ni high-entropy alloys for predictive assessment.

  1. Ion Beams in Short-Pulse, High Intensity Laser Matter Interactions.

    NASA Astrophysics Data System (ADS)

    Lasinski, B. F.; Langdon, A. B.; Still, C. H.; Tabak, M.; Town, R. P. J.; Kruer, W. L.; Wilks, S. C.; Welch, D. R.

    2002-11-01

    Experiments on the interaction of short pulse high intensity lasers with thin foils have produced intense ion beams with surprisingly good emittance. We report on explicit PIC and hybrid particle-fluid simulations motivated by these experiments. In addition, we study the focusing of these beams and their possible collective effects. The LSP code footnote D. R. Welch, et al, Nucl. Inst. Meth. Phys. Res. A 242, 134 (2001). uses a direct implicit particle-in-cell algorithm in 2 or 3 dimensions to solve for the beam particles and the background particles are treated as a fluid. Implications for the fast ignitor concept footnote M. Tabak, et al, Phys. Plasmas 1, 1626 (1994). in which energetic fast particles transport energy to the high-density compressed fuel will be discussed.

  2. Short communication: Ovine leukocyte telomere length is associated with variation in the cortisol response to systemic bacterial endotoxin challenge.

    PubMed

    Yip, L; Oh, S Y; Li, Z; You, Q; Quinton, V M; Gilchrist, G C; Karrow, N A

    2016-04-01

    Stress has been associated with biological aging and numerous age-related diseases. This may be due, in part, to accelerated shortening of telomeres, which are critical genomic structures that cap and protect chromosomal ends. Dysfunction of the hypothalamic-pituitary-adrenal axis may indirectly contribute to telomere shortening if an animal reacts too strongly or weakly to a stressor, leading to accelerated biological aging. In this study, outbred Rideau-Arcott sheep were stress challenged with Escherichia coli endotoxin and classified as high, middle, or low cortisol responders to investigate a potential relationship between cortisol response and age, and telomere length. In the present study, no association was found between age and telomere length. The study, however, revealed shorter telomeres in high and low cortisol responders compared with the middle cortisol responders, which suggests that health and longevity may be compromised in extreme high- and low-stress-responding sheep. PMID:26805999

  3. proovread: large-scale high-accuracy PacBio correction through iterative short read consensus

    PubMed Central

    Hackl, Thomas; Hedrich, Rainer; Schultz, Jörg; Förster, Frank

    2014-01-01

    Motivation: Today, the base code of DNA is mostly determined through sequencing by synthesis as provided by the Illumina sequencers. Although highly accurate, resulting reads are short, making their analyses challenging. Recently, a new technology, single molecule real-time (SMRT) sequencing, was developed that could address these challenges, as it generates reads of several thousand bases. But, their broad application has been hampered by a high error rate. Therefore, hybrid approaches that use high-quality short reads to correct erroneous SMRT long reads have been developed. Still, current implementations have great demands on hardware, work only in well-defined computing infrastructures and reject a substantial amount of reads. This limits their usability considerably, especially in the case of large sequencing projects. Results: Here we present proovread, a hybrid correction pipeline for SMRT reads, which can be flexibly adapted on existing hardware and infrastructure from a laptop to a high-performance computing cluster. On genomic and transcriptomic test cases covering Escherichia coli, Arabidopsis thaliana and human, proovread achieved accuracies up to 99.9% and outperformed the existing hybrid correction programs. Furthermore, proovread-corrected sequences were longer and the throughput was higher. Thus, proovread combines the most accurate correction results with an excellent adaptability to the available hardware. It will therefore increase the applicability and value of SMRT sequencing. Availability and implementation: proovread is available at the following URL: http://proovread.bioapps.biozentrum.uni-wuerzburg.de Contact: frank.foerster@biozentrum.uni-wuerzburg.de Supplementary information: Supplementary data are available at Bioinformatics online. PMID:25015988

  4. Short-pulse, high-energy radiation generation from laser-wakefield accelerated electron beams

    NASA Astrophysics Data System (ADS)

    Schumaker, Will

    2013-10-01

    Recent experimental results of laser wakefield acceleration (LWFA) of ~GeV electrons driven by the 200TW HERCULES and the 400TW ASTRA-GEMINI laser systems and their subsequent generation of photons, positrons, and neutrons are presented. In LWFA, high-intensity (I >1019 W /cm2), ultra-short (τL < 1 / (2 πωpe)) laser pulses drive highly nonlinear plasma waves which can trap ~ nC of electrons and accelerate them to ~GeV energies over ~cm lengths. These electron beams can then be converted by a high-Z target via bremsstrahlung into low-divergence (< 20 mrad) beams of high-energy (<600 MeV) photons and subsequently into positrons via the Bethe-Heitler process. By increasing the material thickness and Z, the resulting Ne+ /Ne- ratio can approach unity, resulting in a near neutral density plasma jet. These quasi-neutral beams are presumed to retain the short-pulse (τL < 40 fs) characteristic of the electron beam, resulting in a high peak density of ne- /e+ ~ 1016 cm-3 , making the source an excellent candidate for laboratory study of astrophysical leptonic jets. Alternatively, the electron beam can be interacted with a counter-propagating, ultra-high intensity (I >1021 W /cm2) laser pulse to undergo inverse Compton scattering and emit a high-peak brightness beam of high-energy photons. Preliminary results and experimental sensitivities of the electron-laser beam overlap are presented. The high-energy photon beams can be spectrally resolved using a forward Compton scattering spectrometer. Moreover, the photon flux can be characterized by a pixelated scintillator array and by nuclear activation and (γ,n) neutron measurements from the photons interacting with a secondary solid target. Monte-Carlo simulations were performed using FLUKA to support the yield estimates. This research was supported by DOE/NSF-PHY 0810979, NSF CAREER 1054164, DARPA AXiS N66001-11-1-4208, SF/DNDO F021166, and the Leverhulme Trust ECF-2011-383.

  5. High-base vector beam encoding/decoding for visible-light communications.

    PubMed

    Zhao, Yifan; Wang, Jian

    2015-11-01

    Polarization is a basic property of light. Different from well-known linear, circular, and elliptical polarizations, which are spatially homogeneous, a vector light beam with spatially variant polarization states has received increasing interest for its expanded functionalities. In this Letter, we present a visible-light communication link exploiting high-base vector beam encoding/decoding. Using a single phase-only spatial light modulator, we generate 16 states of vector beams representing hexadecimal numbers. In the visible-light communication link experiment, we transmit a random high-base number sequence with 10,000 hexadecimal numbers and a 64×64 pixel Lena gray image with 8192 hexadecimal numbers. The bit error rate is evaluated, and zero error among all received hexadecimal numbers is achieved, showing favorable link communication performance using the high-base vector beam encoding/decoding. PMID:26512464

  6. Short communication: rapid preparation of preventive and therapeutic whole-killed retroviral vaccines using the microbicide taurine chloramine.

    PubMed

    Dudani, A K; Martyres, A; Fliss, H

    2008-04-01

    A current urgent priority is to develop microbicides and vaccines to combat retroviruses like human immunodeficiency virus (HIV). We show that the cysteine-selective natural compound, taurine chloramine (T-NCl), can be effective in this task. A number of proteins in all retroviruses contain highly conserved cysteine-rich regions that are essential for infection and replication. Our data show that by targeting these essential cysteine residues, T-NCl (2 or 5 mM) acts as a highly effective and safe microbicide that fully blocks the infectivity of high HIV-1 titers (10(6) TCID(50) units/ml) but is not injurious to eukaryotic cells. We also demonstrate that T-NCl can be used to prepare a highly effective whole-killed vaccine against murine AIDS (MAIDS) that shows both preventive and therapeutic efficacy. The vaccine consists of a T-NCl-inactivated retrovirus suspension in host cell lysate. The novelty of our approach lies in the ease and speed of vaccine preparation and its avoidance of harsh inactivation or purification steps that can alter native viral conformation. Our approach is therefore likely to overcome a number of intractable obstacles to the preparation of an effective whole-killed HIV vaccine, such as surviving infective viral particles, rapid viral mutation rates, numerous viral strains, and harsh purification steps. Our approach may also permit the rapid preparation of autologous, or custom-made, vaccines for individual patients. PMID:18366297

  7. Short-term satiety in preschool children: a comparison between high protein meal and a high complex carbohydrate meal.

    PubMed

    Araya, H; Hills, J; Alviña, M; Vera, G

    2000-03-01

    The aim of this study was to investigate whether a high protein meal has a different effect on short-term satiety in preschool children than a high carbohydrate meal by measuring their intake of a subsequent meal. Subjects were 35 normal preschool children of both genders aged 5 to 6 years. All children were healthy and randomly chosen from those who were attending to a day-care center where they received feeding at three meal times: breakfast, lunch and teatime. Children were weighed with light clothes following standard recommendations. They were normal according to the weight for height index, using the NCHS standards. Two meals with different levels of protein and carbohydrate and equal energy contents were assayed at lunch. The lunches were cooked dishes made from common ingredients. The high carbohydrate meal was consumed in greater amount than the high protein meal (P < 0.01) and a significantly greater energy intake was observed (P < 0.01). Food and energy intakes at teatime were greater with the high carbohydrate meal, but only the energy intake was significant (P < 0.05). When subjects consumed the high protein meal during lunch, they ate a significantly lower amount of protein in the subsequent meal, but the carbohydrate intake was similar. The long-term effects of a high protein diet remain to be investigated before recommending of a high protein for obese children. PMID:10953755

  8. Short-term high-altitude pre-exposure improves neurobehavioral ability.

    PubMed

    Guo, Wenyun; Chen, Guozhu; Qin, Jun; Zhang, Jihang; Guo, Xubin; Yu, Jie; Song, Pan; Lu, Wei; Xu, Baida; Li, Jiabei; Ding, Xiaohan; Huang, Lan

    2016-04-13

    This study aims to evaluate the effect of the duration of high-altitude (HA) pre-exposure on human neurobehavioral parameters including mood states and cognitive performance at HA. One hundred and eleven healthy individuals (ranging in age from 18 to 35 years) were recruited to participate in this study. They were divided into two groups: a 4-day short-term HA pre-exposure group (n=57) and a 3-month long-term HA pre-exposure group (n=54). All participants lived in the area at 400 m altitude above sea level before pre-exposure to HA. They were then transported to 3700 m plateau for either a 4-day or a 3-month HA pre-exposure, and finally delivered to 4400 m plateau. On the last day of pre-exposure at 3700 m and on the 10th day at 4400 m, neurobehavioral parameters of the participants in the two groups were evaluated. At the end of pre-exposure and on the 10th day of HA exposure, participants in the short-term group had significantly lower negative mood states, better cognitive performance with higher sensorimotor, attention, and psychomotor abilities, and less acute mountain sickness in comparison with the participants in the long-term pre-exposure group. Our field study with large samples showed that in comparison with 3-month long-term pre-exposure, 4-day short-term HA pre-exposure at 3700 m has a better effect in improving human neurobehavioral parameters including mood states and cognitive performance and reducing acute mountain sickness when exposed to a HA at 4400 m. PMID:26966781

  9. Short communication: Genetic variants of Sarcocystis cruzi in infected Malaysian cattle based on 18S rDNA.

    PubMed

    Ng, Yit Han; Fong, Mun Yik; Subramaniam, Vellayan; Shahari, Shahhaziq; Lau, Yee Ling

    2015-12-01

    Sarcocystis species are pathogenic parasites that infect a wide range of animals, including cattle. A high prevalence of cattle sarcocystosis has been reported worldwide, but its status is unknown in Malaysia. This study focused on utilizing 18S rDNA to identify Sarcocystis species in Malaysian cattle and to determine their genetic variants. In this study, only Sarcocystis cruzi was detected in Malaysian cattle. The intra-species S. cruzi phylogenetic tree analysis and principal coordinate analysis (PCoA), respectively displayed two minor groups among the parasite isolates. This finding was supported by high Wright FST value (FST=0.647). The definitive hosts (dogs) may play a fundamental role in the development of S. cruzi genetic variants. Additionally, the existence of microheterogeneity within the S. cruzi merozoites and/or distinct genetic variants arisen from independent merozoites in mature sarcocysts, possibly contributed to the existence of intra-species variations within the population. PMID:26679818

  10. Short communication: Noninvasive indicators to identify lactating dairy cows with a greater risk of subacute rumen acidosis.

    PubMed

    Gao, X; Oba, M

    2015-08-01

    The objective of the current study was to evaluate if milk urea nitrogen (MUN) and milk fat content could be used as the noninvasive indicator to identify cows with greater or lower risk of subacute ruminal acidosis (SARA). Our hypothesis was that cows with lower MUN and milk fat content would have greater risk of SARA, whereas cows with higher MUN and milk fat content would have lower risk of SARA. In the screening study, 35 late-lactating Holstein cows (DIM=250±71.1; BW=601±45.4kg) were fed a high-grain diet containing 35% forage and 65% concentrate mix ad libitum for 21 d. Concentration of MUN ranged from 5.7 to 13.9Mg/dL among the 35 cows, and the average milk fat content was 3.5%. Then, 5 cows with highest MUN concentrations with milk fat higher than 3.5% were selected as animals that presumably have low risk of SARA, and 5 cows with lowest MUN concentrations with milk fat less than 3.5% were selected as animals that presumably have high risk of SARA. These 10 animals were ruminally cannulated during the subsequent dry period. As 1 low-risk cow was culled due to fatty liver, 9 animals (DIM=122±33.2; BW=615±49.1kg) were used in the subsequent study in the following lactation. All cows were fed a high-grain diet consisting of 35% forage and 65% concentrate mix ad libitum for 21 d. Ruminal pH was measured every 30 s for 72 h. Minimum (5.75 vs. 5.30) and mean ruminal pH (6.35 vs. 6.04) was higher for low- compared with high-risk animals. In addition, duration of rumen pH below 5.8 was shorter in low-risk animals (52.5 vs. 395min/d). These results suggested that MUN and milk fat content in late-lactating cows fed a high-grain diet may be used to identify cows that have higher or lower risk of SARA. PMID:26026756

  11. Gender differences in high school coaches' knowledge, attitudes, and communication about the female athlete triad.

    PubMed

    Kroshus, Emily; Sherman, Roberta T; Thompson, Ron A; Sossin, Karen; Austin, S Bryn

    2014-01-01

    The objective of this study was to assess high school coaches' knowledge, attitudes, communication, and management decisions with respect to the Female Athlete Triad and to determine whether results are patterned by coach gender. Data were obtained through an online survey of high school coaches (n = 227). Significant differences were found between male and female coaches in certain attitudes and communication behaviors related to eating and menstrual irregularity. School or district level policies may help reduce these differences and may help mitigate the health consequences for athletes related to possible differential prevention and detection of the comorbidities of the Female Athlete Triad. PMID:24456303

  12. Communications: Nanomagnetic shielding: High-resolution NMR in carbon allotropes

    NASA Astrophysics Data System (ADS)

    Kim, Y.; Abou-Hamad, E.; Rubio, A.; Wgberg, T.; Talyzin, A. V.; Boesch, D.; Aloni, S.; Zettl, A.; Luzzi, D. E.; Goze-Bac, C.

    2010-01-01

    The understanding and control of the magnetic properties of carbon-based materials is of fundamental relevance in applications in nano- and biosciences. Ring currents do play a basic role in those systems. In particular the inner cavities of nanotubes offer an ideal environment to investigate the magnetism of synthetic materials at the nanoscale. Here, by means of C13 high resolution NMR of encapsulated molecules in peapod hybrid materials, we report the largest diamagnetic shifts (down to -68.3 ppm) ever observed in carbon allotropes, which is connected to the enhancement of the aromaticity of the nanotube envelope upon doping. This diamagnetic shift can be externally controlled by in situ modifications such as doping or electrostatic charging. Moreover, defects such as C-vacancies, pentagons, and chemical functionalization of the outer nanotube quench this diamagnetic effect and restore NMR signatures to slightly paramagnetic shifts compared to nonencapsulated molecules. The magnetic interactions reported here are robust phenomena independent of temperature and proportional to the applied magnetic field. The magnitude, tunability, and stability of the magnetic effects make the peapod nanomaterials potentially valuable for nanomagnetic shielding in nanoelectronics and nanobiomedical engineering.

  13. Development of a 1 J short pulse tunable TEA CO2 laser with high energy stability

    NASA Astrophysics Data System (ADS)

    Kumar, Manoj; Reghu, T.; Biswas, A. K.; Bhargav, Pankaj; Pakhare, J. S.; Kumar, Shailesh; Verma, Abrat; Mandloi, Vagesh; Kukreja, L. M.

    2014-12-01

    The design, development and operational characteristics of a 1 J, repetitively pulsed, line tunable TEA CO2 laser producing nearly tail free short pulses (~170 ns) suitable for laser isotope separation is discussed. Tail free short laser pulses were generated by employing a nitrogen lean gaseous active medium. Use of an indigenously developed stable pulsed power supply, uniform and intense UV spark pre-ionization and optimum gas purging with catalytic regeneration to control the deleterious oxygen accumulation helps generate laser pulses with high energy stability. Integration of a sensitive arc detection system allows long term arc-free operation of the laser and protects it from catastrophic failure. Laser pulses in more than 90 lines in 10.6 μm and 9.6 μm bands of CO2 laser spectrum with energy about 1 J in as many as 50 lines could be generated with a typical efficiency of about 4%. A typical pulse to pulse energy stability of ±1.4% was obtained during one hour of continuous operation of the TEA CO2 laser at 75 Hz.

  14. Short circuit current fundamentals: Characteristics/magnitudes/definitions for high voltage circuit breaker duties

    SciTech Connect

    McCoy, C.E.

    1995-12-31

    The ANSI/IEEE Standards C37 provide many sections identifying the characteristics, magnitudes and relationships for short circuit/fault currents. Also, these Standards provide many sections defining the preferred ratings that circuit breakers and/or fuses are to be capable of. The goal for this paper is to provide a general/executive summary and clear definition for Medium and High Voltage Short Circuit (SC) current rating requirements for circuit breakers and present the five stages (steps) of SC current that are derived from the Standards. It has been encountered that one commercial power system analysis program calculated fundamental SC current values correctly, but did not comply with the IEEE/ANSI Standards definition for stage 2 asymmetrical values. This mis-directed the decision of the required circuit breaker rating. There definitely is another commercial program that does provide values and definitions that comply with the Standards for all specified magnitudes in the five stages of SC current. It is important to be able to clearly understand the SC current characteristics when making circuit breaker selection. For instance, what value should be used: Asymmetrical Peak or RMS, Rated SC current, Close and Latch and/or other magnitudes. This paper will provide a guide to evaluate the required circuit breaker capability/rating, per the latest ANSI/IEEE Standards, for the supplier to comply with.

  15. Reflectivity of plasmas created by high-intensity, ultra-short laser pulses

    SciTech Connect

    Gold, D.M.

    1994-06-01

    Experiments were performed to characterize the creation and evolution of high-temperature (T{sub e}{approximately}100eV), high-density (n{sub e}>10{sup 22}cm{sup {minus}3}) plasmas created with intense ({approximately}10{sup 12}-10{sup 16}W/cm{sup 2}), ultra-short (130fs) laser pulses. The principle diagnostic was plasma reflectivity at optical wavelengths (614nm). An array of target materials (Al, Au, Si, SiO{sub 2}) with widely differing electronic properties tested plasma behavior over a large set of initial states. Time-integrated plasma reflectivity was measured as a function of laser intensity. Space- and time-resolved reflectivity, transmission and scatter were measured with a spatial resolution of {approximately}3{mu}m and a temporal resolution of 130fs. An amplified, mode-locked dye laser system was designed to produce {approximately}3.5mJ, {approximately}130fs laser pulses to create and nonintrusively probe the plasmas. Laser prepulse was carefully controlled to suppress preionization and give unambiguous, high-density plasma results. In metals (Al and Au), it is shown analytically that linear and nonlinear inverse Bremsstrahlung absorption, resonance absorption, and vacuum heating explain time-integrated reflectivity at intensities near 10{sup 16}W/cm{sup 2}. In the insulator, SiO{sub 2}, a non-equilibrium plasma reflectivity model using tunneling ionization, Helmholtz equations, and Drude conductivity agrees with time-integrated reflectivity measurements. Moreover, a comparison of ionization and Saha equilibration rates shows that plasma formed by intense, ultra-short pulses can exist with a transient, non-equilibrium distribution of ionization states. All targets are shown to approach a common reflectivity at intensities {approximately}10{sup 16}W/cm{sup 2}, indicating a material-independent state insensitive to atomic or solid-state details.

  16. High Bandwidth Synaptic Communication and Frequency Tracking in Human Neocortex

    PubMed Central

    Testa-Silva, Guilherme; Verhoog, Matthijs B.; Linaro, Daniele; de Kock, Christiaan P. J.; Baayen, Johannes C.; Meredith, Rhiannon M.; De Zeeuw, Chris I.; Giugliano, Michele; Mansvelder, Huibert D.

    2014-01-01

    Neuronal firing, synaptic transmission, and its plasticity form the building blocks for processing and storage of information in the brain. It is unknown whether adult human synapses are more efficient in transferring information between neurons than rodent synapses. To test this, we recorded from connected pairs of pyramidal neurons in acute brain slices of adult human and mouse temporal cortex and probed the dynamical properties of use-dependent plasticity. We found that human synaptic connections were purely depressing and that they recovered three to four times more swiftly from depression than synapses in rodent neocortex. Thereby, during realistic spike trains, the temporal resolution of synaptic information exchange in human synapses substantially surpasses that in mice. Using information theory, we calculate that information transfer between human pyramidal neurons exceeds that of mouse pyramidal neurons by four to nine times, well into the beta and gamma frequency range. In addition, we found that human principal cells tracked fine temporal features, conveyed in received synaptic inputs, at a wider bandwidth than for rodents. Action potential firing probability was reliably phase-locked to input transients up to 1,000 cycles/s because of a steep onset of action potentials in human pyramidal neurons during spike trains, unlike in rodent neurons. Our data show that, in contrast to the widely held views of limited information transfer in rodent depressing synapses, fast recovering synapses of human neurons can actually transfer substantial amounts of information during spike trains. In addition, human pyramidal neurons are equipped to encode high synaptic information content. Thus, adult human cortical microcircuits relay information at a wider bandwidth than rodent microcircuits. PMID:25422947

  17. Short communication: Multi-trait estimation of genetic parameters for milk protein composition in the Danish Holstein.

    PubMed

    Gebreyesus, G; Lund, M S; Janss, L; Poulsen, N A; Larsen, L B; Bovenhuis, H; Buitenhuis, A J

    2016-04-01

    Genetic parameters were estimated for the major milk proteins using bivariate and multi-trait models based on genomic relationships between animals. The analyses included, apart from total protein percentage, αS1-casein (CN), αS2-CN, β-CN, κ-CN, α-lactalbumin, and β-lactoglobulin, as well as the posttranslational sub-forms of glycosylated κ-CN and αS1-CN-8P (phosphorylated). Standard errors of the estimates were used to compare the models. In total, 650 Danish Holstein cows across 4 parities and days in milk ranging from 9 to 481d were selected from 21 herds. The multi-trait model generally resulted in lower standard errors of heritability estimates, suggesting that genetic parameters can be estimated with high accuracy using multi-trait analyses with genomic relationships for scarcely recorded traits. The heritability estimates from the multi-trait model ranged from low (0.05 for β-CN) to high (0.78 for κ-CN). Genetic correlations between the milk proteins and the total milk protein percentage were generally low, suggesting the possibility to alter protein composition through selective breeding with little effect on total milk protein percentage. PMID:26805988

  18. Isolation and analysis of tetracycline-resistant Mycoplasma agalactiae strains from an infected goat herd in Cyprus - short communication.

    PubMed

    Filioussis, George; Ioannou, Ioannis; Petridou, Evanthia; Avraam, Maria; Giadinis, Nektarios D; Kritas, Spyridon K

    2013-09-01

    A major concern with the use of tetracycline against mycoplasmas is the development of resistance. Infections in small ruminants due to tetracyclineresistant Mycoplasma agalactiae strains are becoming a frequent problem worldwide. In the present paper the detection and analysis of three tetracycline-resistant M. agalactiae strains, isolated from infected goats in Cyprus, are reported. The three field isolates were identified as M. agalactiae by polymerase chain reaction (PCR) showing 98% identity to the M. agalactiae PG2 reference strain. Furthermore, they were found sensitive to tylosin, enrofloxacin, spiramycin and lincomycin. In contrast, they were resistant to tetracycline. None of the putative genes [tet(M), tet(O) and tet(S)] that commonly contribute to high-level resistance to tetracycline could be amplified from their genome. Contrarily, the field isolates were found to carry ISMag1, an insertion sequence related to the IS30 family of mobile elements. Although ISMag1 is widely believed to induce high-frequency chromosomal rearrangements resulting in phenotypic changes of microorganisms, its potential role in tetracycline resistance of mycoplasmas requires further studies. PMID:23921341

  19. High repetition-rate and short pulse-width 1064nm laser in a composite crystal device

    NASA Astrophysics Data System (ADS)

    Wang, Zijian; Jin, Guangyong; Yu, Yongji; Zhai, Ruizhi

    2014-12-01

    Compared with lamp pumped solid state laser, laser-diode pumped all-solid-state laser (DPSL) has the characteristic of high efficiency, long life and reliable under the condition of high repetition rate. Therefore, A high repetition rate DPSL has a broad application prospect in the laser detection, laser communication and optoelectronic countermeasure and other fields. Laser-diode (LD) pumped acousto-optic(AO) Q-switch all-solid-state has attractive features, such as compact structure, reliable operation, high repetition rate and short pulse width. Laser crystal is the core component of the laser. Usually composite crystal thermal lens focal length is three times more than traditional crystal, so it can avoid the serious heating effect of the operation material bumping by the traditional method. In this paper, we present a high repetition rate acousto-optic Q-switched Nd:YVO4 laser pumped by 880nm laser diode. By using the 0.25% doping concentration Nd:YVO4 single end composite crystal size of 3*3*(4+16) mm3 , with the 50 W LD pumped power, in order to calculate the laser crystal absorption efficiency of pump light, so that more accurate calculation of light conversion efficiency, first we measured 880 nm pump light absorption, crystal is calculated on the pump light absorption efficiency of 75%; When we put in the cavity mirror to form a flat resonant cavity, we obtained the 1064 nm continuous laser output power of 26 W and 27.1 W, with the output mirror transmittance of 20% and 48%, respectively. 50.7% and 48.7% optical to optical conversion efficiency has been achieved experimentally. When we put in AO Q-switch, with the repetition rate of 50 kHz, 100 kHz and 200 kHz, the 1064 nm laser output power is 21 W, 21.28 W and 20.58 W, and the peak power is 32.9 kW, 17.3 kW, 8.5 kW, respectively. Under the high repetition rate circumstance, the pulse width is limited to 12 ns.

  20. Failure of oral E. coli O83 lipopolysaccharide to influence intestinal morphology and cell proliferation in rats: short communication.

    PubMed

    Illyés, György; Kovács, Krisztina; Kocsis, Béla; Baintner, Károly

    2008-03-01

    It is known that bacterial lipopolysaccharide (LPS) is not absorbed from the gastrointestinal tract in significant quantities. However, the question remained whether oral LPS modified the structure or function of the gut. In the present experiment Escherichia coli 083 LPS was administered to growing rats in repeated oral doses of 400 mg/kg body weight (b. w.), every 8 h. After three days of treatment, morphometric and histochemical examinations of the small intestine did not show significant differences between treated and control rats. It is concluded that repeated oral administration of high doses of E. coli 083 LPS had no demonstrable effect on intestinal structure and cell proliferation in a rat model. PMID:18401951

  1. Short communication: Effects of prepartum diets supplemented with rolled oilseeds on Brix values and fatty acid profile of colostrum.

    PubMed

    Salehi, R; Ambrose, D J; Oba, M

    2016-05-01

    The objective of this study was to evaluate effects of oilseeds supplemented in prepartum diets on colostrum quality. Thirty-nine dry pregnant Holstein cows (14 primiparous and 25 multiparous cows) were blocked by body condition score and parity and assigned to 1 of 3 experimental diets containing rolled oilseeds at 8% of dietary dry matter (canola seed or sunflower seed) or no oilseed (control) at 35 d before the expected calving date. Canola seed is high in oleic acid and sunflower seed is high in linoleic acid content. Colostrum samples were collected at the first milking after calving, and concentrations of nutrient composition, fatty acid profile, and Brix value (an indicator IgG concentration) were determined. Cows fed sunflower seeds before calving produced colostrum with greater crude protein content (15.0 vs. 12.9%), colostral Brix values (24.3 vs. 20.3%), and conjugated linoleic acid concentration (18:2 cis-9,trans-11; 0.64 vs. 0.48%) compared with those fed canola seed. Positive effects of feeding sunflower seed might be mediated by ruminal metabolism of linoleic acid and subsequent enhanced production of conjugated linoleic acid. Oilseed supplementation in prepartum diets of dairy cows also altered fatty acid profile of colostrum in a way to reflect fatty acid profile of the supplemented oilseeds except for oleic acid. In conclusion, prepartum feeding of sunflower seed increased colostral Brix value, an indicator of colostral IgG concentration, compared with that of canola seed, but its mode of action and effects on health and productivity of calves need to be investigated. PMID:26971161

  2. Short Communication: Transmitted Drug Resistance and Molecular Epidemiology in Antiretroviral Naive HIV Type 1-Infected Patients in Rhode Island

    PubMed Central

    Tashima, Karen; Cartwright, Charles P.; Gillani, Fizza S.; Mintz, Orli; Zeller, Kimberly; Kantor, Rami

    2011-01-01

    Abstract Transmission of HIV-1 drug resistance has important clinical and epidemiological consequences including earlier treatment failure and forward transmission of resistance strains in high-risk groups. To evaluate the prevalence and molecular epidemiology of transmitted drug resistance in Rhode Island, we collected genotypic, demographic, clinical, and laboratory data from treatment-naive individuals presenting to the largest outpatient HIV clinic in the state from January 2007 to November 2007. Sequences from 35 treatment-naive individuals were available, 83% of whom were men who had sex with men (MSM). All sequences were HIV-1 subtype B. Drug resistance mutations were identified in 7/35 [20%; 95% confidence interval (CI), 0.08–0.37] patients, six of whom had K103N. Two phylogenetic transmission clusters were found, involving 17% (6/35) of individuals, three in each cluster. We did not find an association between belonging to a cluster and age, gender, AIDS-defining illness, CD4 cell count, or viral load. Drug resistance mutations were more commonly observed in transmission clusters (p = 0.08). Individuals in one cluster all had K103N and were MSM who had attended local bathhouses. Individuals forming clusters were significantly more likely to have visited a bathhouse compared to nonclusters (p = 0.02). The prevalence of transmitted drug resistance in Rhode Island is high, further justifying genotypic testing on presentation to care and prior to treatment initiation. Molecular epidemiological analysis and association of resistance with phylogenetic networks using data obtained for clinical purposes may serve as useful tools for the prevention of drug resistance transmission and for contact tracing. PMID:20954831

  3. Short communication: Genetic analysis for fertility traits of heifers and cows from smallholder dairy farms in a tropical environment.

    PubMed

    Buaban, S; Duangjinda, M; Suzuki, M; Masuda, Y; Sanpote, J; Kuchida, K

    2015-07-01

    The objective of this study was to estimate genetic parameters for various fertility traits on Holstein upgraded dairy heifers and cows in a smallholder system under tropical conditions using data sets from the Thailand national recording scheme. The investigated traits were age at first service (AFS), age at first calving (AFC), days from calving to first service (DTFS), days between first and last service (DFLS), days open (DO), calving interval (CI), number of services per conception (NSPC), and conception at first service (FSC). The data consisted of 68,555, 34,401, and 54,004 records on heifers, primiparous, and multiparous cows, respectively, calving between 1996 and 2011. Gibbs sampling was employed to obtain (co)variance components using both univariate and bivariate analyses with linear and threshold animal models. Virgin heifers had better fertility performance than primiparous and multiparous cows. The reproductive performance in primiparous cows was inferior compared with multiparous cows. Cows with higher Holstein-Friesian blood showed lower reproductive efficiency. Estimated heritabilities for most of the fertility traits were 0.04 or less except for AFS (0.26) and AFC (0.25). The estimated genetic correlations among fertility traits within parity indicated that selection for cows with high conception rate could lead to shortened DO and CI, as well as DTFS. The FSC and NSPC could be used as the best indicators for heifer and cow fertility and could be complemented by other traits, which were genetically considered as different traits such as DTFS and DFLS in terms of a fertility index. This would enable efficient selection for better fertility. Genetic correlations for fertility traits in primiparous and multiparous cows were very high (>0.90), but those between heifers and cows were lower (0.03 to 0.83). The latter results indicated that fertility traits of heifers and cows should be considered as different traits. PMID:25981071

  4. Detector response to high repetition rate ultra-short laser pulses. I

    NASA Astrophysics Data System (ADS)

    Zakharova, I. K.; Rafailov, Michael K.

    2015-05-01

    Optical nonlinearities in semiconductors and semiconductor detectors have been widely investigated and exploited for many scientific and industrial applications. The correlation of optical and electronic characteristics in these detector materials under exposure of ultra-short laser pulses at high pulse repetition rates is still not very well known. These effects may be quite beneficial for many applications ranging from chemical and biological sensing to light-induced superconductivity. In this paper, we discuss the effect of extended bleaching in order to demonstrate sensing applications of such phenomenon as an example. Pump-probe measurements in bulk semiconductors will be presented to quantify the transient absorption dynamics and relate this to the electronic response of the detector devices. This effect is not limited semiconductors and may affect other matter states and electronic structures, like dielectrics.

  5. Study of short haul high-density V/STOL transportation systems, volume 1

    NASA Technical Reports Server (NTRS)

    Solomon, H. L.

    1972-01-01

    The relative advantages of STOL aircraft concepts were examined by simulating the operations of a short haul high-density intercity STOL system set in two arenas, the California corridor and the Chicago-Detroit-Cleveland triangle, during the 1980 time period. The study was constrained to the use of three aircraft concepts designated as the deflected slipstream turboprop, externally blown flap, and augmentor wing turbofan configurations. The projected demographic, economic, travel demand, and travel characteristics of the representative arenas were identified. The STOL airline operating scenarios were then formulated and through the use of the aerospace modal split simulation program, the traveler modal choices involving alternative STOL concepts were estimated in the context of the total transportation environment for 1980. System combinations that presented the best potential for economic return and traveler acceptance were then identified for each STOL concept.

  6. [Study of new XeCl laser with short duration time and preionzation at high pressure].

    PubMed

    Ren, Ren; Chen, Chang-Le; Xu, Jin; Zhu, Shi-Hua; Jing, Ke-Xin; Ren, Da-Nan; Wang, Yong-Cang; Yuan, Xiao; Song, Zhou-Mo

    2005-05-01

    New short duration time XeCI excimer laser has been generated at high pressure within a large volume in order to apply it to he interaction between laser and material, and material plasma study. The laser spectrum exhibits two laser lines at 307.98 and 308.19 nm, which is realized in the proportion of HCl:Xe: He = 0.1% :1% : 98.9% through UV preionization. Theoretic analysis indicated that the maximum intensity loop is B to X grade. Not only UV preionization, glow discharge and the calculation of dynamic equation, but also the laser spectrum and pulse duration time measurement were carried out. It is shown that the duration time decreases and pulse energy rises with the increase in the pressure and discharge voltage. The minimum duration time exceeds 13 ns, the pulse energy is 450 mJ, and the beam divergence angle is 3 mrad. PMID:16128052

  7. High power, short pulses ultraviolet laser for the development of a new x-ray laser

    SciTech Connect

    Meixler, L.; Nam, C.H.; Robinson, J.; Tighe, W.; Krushelnick, K.; Suckewer, S.; Goldhar, J.; Seely, J.; Feldman, U.

    1989-04-01

    A high power, short pulse ultraviolet laser system (Powerful Picosecond-Laser) has been developed at the Princeton Plasma Physics Laboratory (PPPL) as part of experiments designed to generate shorter wavelength x-ray lasers. With the addition of pulse compression and a final KrF amplifier the laser output is expected to have reached 1/3-1/2 TW (10/sup 12/ watts) levels. The laser system, particularly the final amplifier, is described along with some initial soft x-ray spectra from laser-target experiments. The front end of the PP-Laser provides an output of 20--30 GW (10/sup 9/ watts) and can be focussed to intensities of /approximately/10/sup 16/ W/cm/sup 2/. Experiments using this output to examine the effects of a prepulse on laser-target interaction are described. 19 refs., 14 figs.

  8. Continuous-wave, short-wavelength infrared mixer using dispersion-stabilized highly-nonlinear fiber.

    PubMed

    Kuo, Bill P-P; Hirano, Masaaki; Radic, Stojan

    2012-07-30

    A new type of highly nonlinear fiber (HNLF) was designed and fabricated. The new HNLF was engineered to reduce dispersion shift due to transverse fluctuations while maintaining the modal confinement superior to that of the conventional fibers. The new design strategy was validated by the measurements of the global and local dispersive characteristics under considerable core and index profile deformation induced by tensile stress, which indicated that the dispersive and phase matching characteristics of the fiber did not change even under the highest tensile stress. The characteristics effectively decoupled tension-based Brillouin suppression from phase-matching impairments in parametric mixers for the first time. The new HNLF was used to demonstrate the first coherence-preserving mixer operating in the short-wavelength infrared (SWIR) band. The SWIR mixer was driven by continuous-wave near-infrared (NIR) pump and did not require pump phase dithering to suppress Brillouin scattering. PMID:23038393

  9. High-efficiency focusing grating coupler with optimized ultra-short taper

    NASA Astrophysics Data System (ADS)

    Yang, Biao; Li, Zhi-Yong; Yu, Yu-De; Yu, Jin-Zhong

    2014-11-01

    A novel high-efficiency focusing non-uniform grating coupler is proposed to couple light into or off silicon photonic chips for large-scale silicon photonic integration. This kind of grating coupler decreases the transition length of the linking taper between the grating and the single-mode waveguide by at least 80%. The radian of the grating lines and the size of the taper are optimized to improve the coupling efficiency. An experimental coupling efficiency of ~ 68% at 1556.24 nm is obtained after optimization and the whole size of the grating is 12 μm × 30 μm, with a very short taper transition of ~15 μm long.

  10. A high-charge and short-pulse RF photocathode gun for wake-field acceleration

    NASA Astrophysics Data System (ADS)

    Gai, W.; Li, X.; Conde, M.; Power, J.; Schoessow, P.

    1998-02-01

    In this paper we present a design report on 1-1/2 cell, L-Band RF photocathode gun which is capable of generating and accelerating electron beams with peak currents >10 kA. We address several critical issues of high-current RF photoinjectors such as longitudinal space charge effect, and transverse emittance growth. Unlike conventional short electron pulse generation, this design does not require magnetic pulse compression. Based on numerical simulations using SUPERFISH and PARMELA, this design will produce 100 nC beam at 18 MeV with r.m.s. bunch length 1.25 mm and normalized transverse emittance 108 mm mrad. Applications of this source beam for wake-field acceleration are also discussed.

  11. Tunable, high peak power terahertz radiation from optical rectification of a short modulated laser pulse.

    PubMed

    Gordon, Daniel F; Ting, Antonio; Alexeev, Ilya; Fischer, Richard; Sprangle, Phillip; Kapetenakos, Christos A; Zigler, Arie

    2006-07-24

    A new way of generating high peak power terahertz radiation using ultra-short pulse lasers is demonstrated. The optical pulse from a titanium:sapphire laser system is stretched and modulated using a spatial filtering technique to produce a several picosecond long pulse modulated at the terahertz frequency. A collinear type II phase matched interaction is realized via angle tuning in a gallium selenide crystal. Peak powers of at least 1.5 kW are produced in a 5 mm thick crystal, and tunability is demonstrated between 0.7 and 2.0 THz. Simulations predict that 150 kW of peak power can be produced in a 5 mm thick crystal. The technique also allows for control of the terahertz bandwidth. PMID:19516863

  12. Enhancement and quenching of high-intensity focused ultrasound cavitation activity via short frequency sweep gaps.

    PubMed

    Hallez, Loïc; Lee, Judy; Touyeras, Francis; Nevers, Aymeric; Ashokkumar, Muthupandian; Hihn, Jean-Yves

    2016-03-01

    This letter reports on the use of frequency sweeps to probe acoustic cavitation activity generated by high-intensity focused ultrasound (HIFU). Unprecedented enhancement and quenching of HIFU cavitation activity were observed when short frequency sweep gaps were applied in negative and positive directions, respectively. It was revealed that irrespective of the frequency gap, it is the direction and frequency sweep rate that govern the cavitation activity. These effects are related to the response of bubbles generated by the starting frequency to the direction of the frequency sweep, and the influence of the sweep rate on growth and coalescence of bubbles, which in turn affects the active bubble population. These findings are relevant for the use of HIFU in chemical and therapeutic applications, where greater control of cavitation bubble population is critical. PMID:26584998

  13. Epithermal Neutron Source for Neutron Resonance Spectroscopy (NRS) using High Intensity, Short Pulse Lasers

    SciTech Connect

    Higginson, D P; McNaney, J M; Swift, D C; Bartal, T; Hey, D S; Pape, S L; Mackinnon, A; Mariscal, D; Nakamura, H; Nakanii, N; Beg, F N

    2010-04-22

    A neutron source for neutron resonance spectroscopy (NRS) has been developed using high intensity, short pulse lasers. This measurement technique will allow for robust measurements of interior ion temperature of laser-shocked materials and provide insight into equation of state (EOS) measurements. The neutron generation technique uses protons accelerated by lasers off of Cu foils to create neutrons in LiF, through (p,n) reactions with {sup 7}Li and {sup 19}F. The distribution of the incident proton beam has been diagnosed using radiochromic film (RCF). This distribution is used as the input for a (p,n) neturon prediction code which is compared to experimentally measured neutron yields. From this calculation, a total fluence of 1.8 x 10{sup 9} neutrons is infered, which is shown to be a reasonable amount for NRS temperature measurement.

  14. Forward voltage short-pulse technique for measuring high power laser array junction temperature

    NASA Technical Reports Server (NTRS)

    Meadows, Byron L. (Inventor); Amzajerdian, Frazin (Inventor); Barnes, Bruce W. (Inventor); Baker, Nathaniel R. (Inventor)

    2012-01-01

    The present invention relates to a method of measuring the temperature of the P-N junction within the light-emitting region of a quasi-continuous-wave or pulsed semiconductor laser diode device. A series of relatively short and low current monitor pulses are applied to the laser diode in the period between the main drive current pulses necessary to cause the semiconductor to lase. At the sufficiently low current level of the monitor pulses, the laser diode device does not lase and behaves similar to an electronic diode. The voltage across the laser diode resulting from each of these low current monitor pulses is measured with a high degree of precision. The junction temperature is then determined from the measured junction voltage using their known linear relationship.

  15. Short communication: in vitro ruminal fermentability of a modified corn cultivar expressing a thermotolerant α-amylase.

    PubMed

    Hu, W; Persia, M E; Kung, L

    2010-10-01

    The fermentability of a corn cultivar that expresses a thermostable α-amylase (CA3272) was evaluated under various in vitro conditions. The CA3272 corn was developed as a replacement to microbial enzyme additions during the high-temperature processing of corn to produce ethanol. The α-amylase activity in the corn might have the potential for positive effects on ruminant performance if incorporated into the ration. Four corn cultivars were evaluated in an in vitro ruminal fermentation where the digestion of starch was measured after 6 h. The cultivars included a flint corn, an opaque corn, CA3272, and its near-isogenic counterpart (IC). The flint corn produced less total volatile fatty acids (18.4 mM) than the other 3 corns (average of 25.3 mM), supporting the fact that it had the highest concentration of prolamins, which are negatively associated with starch availability. A second 6-h in vitro ruminal fermentation evaluated mixtures of the CA3272 and IC corns (0, 25, 50, 75, and 100% concentrations of CA3272). Total volatile fatty acid production was not different among treatments for any proportions of CA3272. In a third in vitro experiment, there was a small but significant difference in starch degradation of CA3272 compared with IC (90.6 vs. 89.7%) but this difference is most likely not biologically relevant. In a fourth in vitro experiment, CA3272 and IC were incubated in water at 40 and 65°C for 24 h. Degradation of starch from native amylase activity at 40°C was 1.99 and 1.60% for CA3272 and IC, respectively, but when they were incubated at 65°C, starch degradation was 10.56 and 0.85% for CA3272 and IC, respectively. These data demonstrate that amylase activity in CA3272 is expressed at a high temperature (65°C) but at the physiological temperature expected in a rumen of a cow (39-40°C), expression of amylase activity does not appear to be sufficient to have any positive (or negative) effects on ruminal metabolism. PMID:20855018

  16. Short Communication Validation of EST-derived microsatellite markers for two Cerrado-endemic Campomanesia (Myrtaceae) species.

    PubMed

    Miranda, E A G C; Boaventura-Novaes, C R D; Braga, R S; Reis, E F; Pinto, J F N; Telles, M P C

    2016-01-01

    We assessed the transferability of 120 EST-derived Eucalyptus microsatellite primers to Campomanesia adamantium and C. pubescens. Both species are berry trees native to the Brazilian Cerrado, and population genetic information is poor. Twelve markers were used to analyze the genetic variability of four sampled populations. Regarding DNA extraction, we sampled leaf tissues from two populations of each species (80 individuals). Of the 120 primers evaluated, 87 did not amplify any PCR products, and 21 rendered nonspecific amplification. Twelve primers were successfully transferred, providing a low combined probability of genetic identity for both species (5.718 x 10(-10) for C. adamantium; 1.182 x 10(-11) for C. pubescens) and a high probability of paternity exclusion (0.99939 for C. adamantium; 0.99982 for C. pubescens). The average number of alleles in the polymorphic loci was 6.8 for C. adamantium and 7.8 for C. pubescens, ranging from 2 to 16 alleles per locus. The observed heterozygosity values for C. adamantium and C. pubescens were 0.504 and 0.503, respectively, and the expected heterozygosity values for C. adamantium and C. pubescens were 0.517 and 0.579, respectively. The populations exhibited structured genetic variability with qP values of 0.105 for C. adamantium and 0.249 for C. pubescens. Thus, we concluded that these 12 microsatellite markers, transferred from Eucalyptus, were efficient for population genetic studies of C. adamantium and C. pubescens. PMID:26985928

  17. Short communication: Anti-HIV-1 envelope immunoglobulin Gs in blood and cervicovaginal samples of Beninese commercial sex workers.

    PubMed

    Batraville, Laurie-Anne; Richard, Jonathan; Veillette, Maxime; Labbé, Annie-Claude; Alary, Michel; Guédou, Fernand; Kaufmann, Daniel E; Poudrier, Johanne; Finzi, Andrés; Roger, Michel

    2014-11-01

    Characterization of the immune correlates of protection against HIV infection is crucial for the development of preventive strategies. This study examined HIV-1 envelope (Env) glycoproteins, specifically immunoglobulin G (IgG), in systemic and mucosal compartments of female Beninese commercial sex workers (CSWs). Samples of 23 HIV-1-positive and 20 highly exposed HIV-1-seronegative (HESN) CSWs were studied. HIV-1 Env-specific IgG detection in sera and cervicovaginal lavages (CVLs) from the study population was done by cell-based ELISA. The HIV neutralizing activity was evaluated with a neutralization assay. The HIV-1-specific antibody-dependent cellular cytotoxicity (ADCC) response of the cohort was measured with a FACS-based assay evaluating the ADCC-mediated elimination of gp120-coated target cells. No anti-HIV-1 Env-specific IgG neutralizing or ADCC activities were detected in samples from HESN CSWs. Samples from HIV-1-infected CSWs presented ADCC activity in both sera and CVLs. Anti-Env IgG from sera and CVLs from HIV-1-infected CSWs preferentially recognized Env in its CD4-bound conformation. HIV-1-infected CSWs have ADCC-mediating IgG that preferentially recognizes Env in its CD4-bound conformation at the mucosal site. PMID:25354025

  18. Short communication: Characteristics of proteolytic activities of endo- and exopeptidases in alfalfa herbage and their implications for proteolysis in silage.

    PubMed

    Tao, L; Guo, X S; Zhou, H; Undersander, D J; Nandety, A

    2012-08-01

    The pH optimum and thermostability of both exopeptidases and endopeptidases were investigated in this study to elucidate the possible role of plant proteases in proteolysis during ensiling of alfalfa herbage. Proteolytic activities of 4 classes of endopeptidases (i.e., serine, metallo, aspartic, and cysteine peptidase) and 5 classes of exopeptidases (i.e., aminopeptidase, carboxypeptidase, dipeptidase, dipeptidyl-peptidase, and tripeptidyl-peptidase) were examined within pH values of 3 to 9, and within temperatures from 20 to 90°C. Serine and metalloproteases, the principal endopeptidases that hydrolyzed most of the protein to nonprotein nitrogen in alfalfa silage, had optimum activities at pH 4. Among the major exopeptidases contributing protein degradation in ensiled alfalfa, dipeptidase and tripeptidyl-peptidase had stable activities between pH 4 and 6, and carboxypeptidase activity was optimal at pH 5. The optimum temperature for most peptidase activities was 40°C. Proteolytic activities of both endo- and exopeptidases increased with the elevation of incubating temperature from 20 to 40°C. The pH value in well-preserved alfalfa silage is often above 4.0, and the temperatures in the ensiled mass range from 25 to 40°C. Therefore, high proteolytic activities between pH 4 and 6 and the temperature range of ensiled alfalfa suggest that plant peptidases play a role in hydrolyzing protein during prolonged storage. PMID:22818473

  19. Short Communication: An apospory-specific genomic region is conserved between Buffelgrass (Cenchrus ciliaris L.) and Pennisetum squamulatum Fresen.

    PubMed

    Roche; Cong; Chen; Hanna; Gustine; Sherwood; Ozias-Akins

    1999-07-01

    Twelve molecular markers linked to pseudogamous apospory, a form of gametophytic apomixis, were previously isolated from Pennisetum squamulatum Fresen. No recombination between these markers was found in a segregating population of 397 individuals (Ozias-Akins et al. 1998, Proc. Natl Acad. Sci. USA, 95, 5127-5132). The objective of the present study was to test if these markers were also linked to the aposporous mode of reproduction in two small segregating populations of Cenchrus ciliaris (= Pennisetum ciliare (L.)Link), another apomictic grass species. Among 12 markers (sequence characterized amplified regions, SCARs), six were scored as dominant markers between aposporous and sexual C. ciliaris genotypes (presence/absence, respectively). Five were always linked to apospory and one showed a low level of recombination in 84 progenies. Restriction fragment length polymorphisms (RFLPs) were observed between sexual and apomictic phenotypes for three of the six remaining SCARs from P. squamulatum when used as probes. No recombination was observed in the F1 progenies. Preliminary data from megabase DNA analysis and sequencing in both species indicate that an apospory-specific genomic region (ASGR) is highly conserved between the two species. Although C. ciliaris has a smaller genome size to P. squamulatum, a higher copy number for markers linked to apospory found in the former may impair the progress of positional cloning of gene(s) for apomixis in this species. PMID:10476067

  20. Design and evaluation of a 2-Mb/s GMSK modem for short-distance infrared wireless communications

    NASA Astrophysics Data System (ADS)

    Perez-Jimenez, Rafael; Montelongo, Cesar; Rabadan Borges, Jose A.

    1999-12-01

    A carrier-based modem for an IR Wireless LAN (IR-WLAN) design is presented. It is based on GMSK modulation schemes. This modem is capable of operating at 2 Mb/s, but it can easily modify to work up to 4.8 Mb/s. GMSK Schemes are filtered modulation schemes with higher spectral efficiency and robustness against jitter than basic FSK. The emitter uses a pulse-conformation stage for full-digital gaussian pulse conformation. Transitions are codified and the resulting waveform is similar to the output of a gaussian filter. The main applications of the proposed GMSK modem are in the area of a full-duplex IR link. And can be applied either in point-to-point links or into a local area network. It can work without interference wither with IrDA systems (even with the proposed PPM 4.4 Mb/s link) or with IEEE 802.11-baseband link (1 or 2 Mb/s). It is also more spectral efficient and jitter resistant than PPM. Carrier-based systems can be used either in point-to-point links or in diffuse systems. For diffuse systems, this modem assumes a high level of use of the available IR spectrum, supporting at least 4 channels in a 30 MHz bandwidth. We also compare the performances of GMSK with other schemes (as can be OQPSK or FQPSK-2).

  1. Space Weather effects on airline communications in the high latitude regions

    NASA Astrophysics Data System (ADS)

    Honary, Farideh

    2014-05-01

    Efficient air traffic management depends on reliable communications between aircraft and the air traffic control centres at all times. At high latitudes, and especially on polar routing, VHF ground infrastructure does not exist and the aircraft have to rely on HF radio for communications. HF relies on reflections from the ionosphere to achieve long distance communications. Unfortunately the high latitude ionosphere is affected by space weather events. During such events HF radio communication can be severely disrupted and aircraft are forced to use longer low latitude routes with consequent increased flight time, fuel consumption and cost. This presentation describes a new research programme at the University of Lancaster in collaboration with the University of Leicester, Solar Metrics Ltd and Natural Resources Canada for the development of a nowcasting and forecasting HF communications tool designed for the particular needs of civilian airlines. This project funded by EPSRC will access a wide variety of solar and interplanetary measurements to derive a complete picture of space weather disturbances affecting radio absorption and reflection

  2. Influence of Ramadan Fasting on Anaerobic Performance and Recovery Following Short time High Intensity Exercise

    PubMed Central

    Karli, Umid; Guvenc, Alpay; Aslan, Alper; Hazir, Tahir; Acikada, Caner

    2007-01-01

    The aim of this study was to investigate the effects of Ramadan fasting on anaerobic power and capacity and the removal rate of lactate after short time high intensity exercise in power athletes. Ten male elite power athletes (2 wrestlers, 7 sprinters and 1 thrower, aged 20-24 yr, mean age 22.30 1.25 yr) participated in this study. The subjects were tested three times [3 days before the beginning of Ramadan (Pre-RF), the last 3 days of Ramadan (End-RF) and the last 3 days of the 4th week after the end of Ramadan (After-RF)]. Anaerobic power and capacity were measured by using the Wingate Anaerobic Test (WAnT) at Pre-RF, End-RF and After- RF. Capillary blood samples for lactate analyses and heart rate recordings were taken at rest, immediately after WAnT and throughout the recovery period. Repeated measures of ANOVA indicated that there were no significant changes in body weight, body mass index, fat free mass, percentage of body fat, daily sleeping time and daily caloric intake associated with Ramadan fasting. No significant changes were found in total body water either, but urinary density measured at End-RF was significantly higher than After-RF. Similarity among peak HR and peak LA values at Pre-RF, End- RF and After-RF demonstrated that cardiovascular and metabolic stress caused by WAnT was not affected by Ramadan fasting. In addition, no influence of Ramadan fasting on anaerobic power and capacity and removal rate of LA from blood following high intensity exercise was observed. The results of this study revealed that if strength-power training is performed regularly and daily food intake, body fluid balance and daily sleeping time are maintained as before Ramadan, Ramadan fasting will not have adverse effects on body composition, anaerobic power and capacity, and LA metabolism during and after high intensity exercise in power athletes. Key pointsNo significant changes were assessed on body composition, daily sleeping time and caloric intake, and body fluid balance in regularly trained power athletes during Ramadan fasting.Ramadan fasting has no adverse effect on power outputs of short time high intensity exercise.No influence of Ramadan fasting on LA metabolism during high intensity exercise and passive recovery in regularly trained power athletes. PMID:24149483

  3. Short communication: Factors affecting vitamin B12 concentration in milk of commercial dairy herds: An exploratory study.

    PubMed

    Duplessis, M; Pellerin, D; Cue, R I; Girard, C L

    2016-06-01

    Only bacteria can synthesize vitamin B12, and this requires adequate Co supply. The natural source of vitamin B12 in human diets comes from animal products, especially those from ruminants. This study aimed to describe variability regarding vitamin B12 concentration in milk among and within commercial dairy herds in early lactation. A secondary objective was to explore potential causes for this variability such as genetic variation and diet characteristics. In total, 399 dairy cows (135 primiparous and 264 multiparous; 386 Holstein and 13 Jersey cows) in 15 commercial herds were involved. Milk samples were taken at 27.4±4.1 and 55.4±4.1d in milk. Neither parity (primiparous vs. multiparous) nor sampling time affected milk concentrations of vitamin B12. Nevertheless, vitamin B12 concentration in milk was highly variable among and within dairy herds. The lowest vitamin B12 concentration in milk of cows was observed in the Jersey herd. Among herds, vitamin B12 concentration in milk ranged from 2,309 to 3,878 pg/mL; one glass (250mL) of milk from those herds would provide between 23 and 40% of the vitamin B12 recommended daily allowance. Among individual cows, however, this provision varied between 16 and 57% of the recommendation. In spite of the limited size of the studied population, the heritability value was 0.23, suggesting that genetic selection could modify milk vitamin B12 concentration. We observed a positive relationship between milk vitamin B12 concentration and dietary acid detergent fiber content and a negative relationship between milk concentration of vitamin B12 and dietary crude protein content. PMID:27040783

  4. Short Communication: Diagnosis of Pneumocystis jirovecii Pneumonia by Detection of DNA in Blood and Oropharyngeal Wash, Compared with Sputum.

    PubMed

    van Halsema, Clare; Johnson, Leann; Baxter, Joanne; Douthwaite, Sam; Clowes, Yvonne; Guiver, Malcolm; Ustianowski, Andrew

    2016-05-01

    Molecular diagnostic methods on lower respiratory specimens for Pneumocystis pneumonia (PCP) are recommended, but specimens can be difficult to obtain. This study examined the diagnostic use of PCP polymerase chain reaction (PCR) on oropharyngeal wash (OPW) and blood versus sputum (spontaneous and induced) to find faster, simpler, and less invasive diagnostic methods. We prospectively recruited consenting adults with symptoms consistent with PCP. Real-time PCR targeted the Pneumocystis mitochondrial large subunit ribosomal RNA gene, using the aforementioned specimens. Clinical data were collected from routine records. Forty-five participants provided 45 sputa, 31 OPW, and 41 blood samples. Median age was 39 years and 41 (91%) were male, with median CD4 count being 64 cells/μL. Sputum PCR was positive in 27/45 (60%) participants. Comparative sensitivity of OPW was 9/19 (47%, 95% confidence interval [CI] 23-71) and blood 12/24 (50%, 95% CI 29-71) participants, both with specificity 100%. Including only samples obtained ≤2 days after start of treatment, sensitivity of OPW was 80% (8/10, 95% CI 51-100), that of blood was 57% (8/14, 95% CI 29-86), and that of combined tests was 88% (14/16, 95% CI 70-100). In 14/16 individuals with PCP and specimens obtained ≤2 days after start of treatment, diagnosis was possible using nonrespiratory samples. Despite moderate sensitivity of individual tests, combined PCP PCR on early blood and OPW specimens had high sensitivity and could reduce the need for invasive procedures. There were no false-positive results on nonrespiratory samples. Sampling and laboratory methods use routine technology and so require few additional resources. PMID:26739439

  5. Short Communication: Do Cytomegalovirus Antibody Levels Associate with Age-Related Syndromes in HIV Patients Stable on Antiretroviral Therapy?

    PubMed

    Brunt, Samantha J; Cysique, Lucette A; Lee, Silvia; Burrows, Sally; Brew, Bruce J; Price, Patricia

    2016-06-01

    HIV(+) persons stable on antiretroviral therapy (ART) face early onset of age-related diseases. This may arise from a high burden of cytomegalovirus (CMV). To address the role of CMV, we investigated univariate and multivariate associations between markers of systemic and endothelial inflammation, vascular damage, insulin resistance (IR), neurocognitive decline, and antibodies reactive with CMV. In this study, HIV(+) participants (n = 91) aged >45 years with <50 copies HIV RNA/ml plasma after >2 years on ART were assessed for cardiovascular risk (the D:A:D algorithm), type II diabetes (the HOMA-IR index), and neurocognitive performance. Blood samples were assayed for lipids, T cells, insulin, glucose, C-reactive protein, CX3CL1, sTNF-R1, total immunoglobulin G (IgG), and antibodies reactive with CMV lysate, glycoprotein B, or immediate-early-1. Levels of antibodies detected with the three antigens were tightly correlated. Levels of CMV lysate antibody were higher in patients than in age-matched healthy controls and reflected their nadir CD4 T-cell count (p = .001), total IgG (p = .02), and age (p = .08). Levels of CMV lysate antibody correlated with D:A:D score (p = .04), neurocognitive performance (p = .045), and fasting insulin (p = .02). In multivariable analyses, some associations reflected the effect of age, but CMV lysate antibody and CD8 T-cell counts were significant predictors of the HOMA-IR index (R(2) = 0.09, p = .01) independent of age. We conclude that associations between levels of CMV antibodies, cardiovascular risk, and neurocognitive health in HIV(+) patients stable on ART are moderated by age-associated increases in response to CMV, while CMV antibodies may be independently linked with IR. PMID:26876416

  6. Short communication: Methicillin-resistant Staphylococcus aureus in bulk tank milk of dairy cows and effect of swine population density.

    PubMed

    Locatelli, C; Cremonesi, P; Bertocchi, L; Zanoni, M G; Barberio, A; Drigo, I; Varisco, G; Castiglioni, B; Bronzo, V; Moroni, P

    2016-03-01

    The methicillin-resistant Staphylococcus aureus (MRSA) has recently frequently been reported in dairy cattle, usually with low prevalence. The livestock-associated MRSA (LA-MRSA) ST398 is especially involved in cases of subclinical and clinical mastitis. Swine carry LA-MRSA without clinical symptoms and are considered its reservoir and shedder. People exposed to swine are particularly at risk of LA-MRSA colonization. Environments with relevant livestock density are a demonstrated risk factor for humans to be carriers of a LA-MRSA. This work investigated dairy farms located in an area with a high livestock density, mainly represented by swine. Bulk tank milk samples from 224 dairy farms were collected, and their status was defined as MRSA-positive or MRSA-negative based on culture on chromogenic medium. The number of fattening swine and of fattening swine herds was calculated in an area of 3 km around each dairy farm through georeferencing. The probability of a Staphylococcus aureus-positive dairy farm to be MRSA positive based on the extent of potential infective pressure due to swine density was calculated. Both the number of swine herds and the number of swine were associated with the MRSA status of dairy herds. The 9 MRSA isolated were typed by multi-locus sequence typing and spa-typing, and characterized for their virulence factors and antimicrobial resistance profiles. The ST and spa-types detected are consistent with those present in the Italian swine population. Virulence and resistance profiles are mostly consistent with the types detected. This work provides the first evidence of the epidemiological challenge exerted by the density of the swine population on MRSA in dairy cows. PMID:26805972

  7. Short communication: Protease activity measurement in milk as a diagnostic test for clinical mastitis in dairy cows.

    PubMed

    Koop, G; van Werven, T; Roffel, S; Hogeveen, H; Nazmi, K; Bikker, F J

    2015-07-01

    Due to the increasing use of automated milking systems, automated detection of clinical mastitis is becoming more important. Various in- or on-line diagnostic tests are in use, but generally suffer from false mastitis alerts. In this study, we explored a new diagnostic approach based on measurement of protease activity using fluorogenic protease substrates, which can be performed on site, at high speed, and at low costs. Samples from cows with clinical mastitis submitted for bacteriological culture at the University Farm Animal Practice were collected during several months and kept at -20°C until protease activity measurement. A reference set of milk samples from clinically healthy cows were collected on 9 different farms and were tested for protease activity directly and after freezing at -20°C to allow for comparison with the samples from clinical cases. The protease activity in mastitic milk samples was significantly higher than in samples from healthy animals. Based on 71 clinical mastitis samples and 180 milk samples from clinically healthy quarters, the area under the receiver-operating characteristic curve was estimated to be between 0.88 and 0.90, and at a threshold of 38 fluorescence per minute the test had a specificity of 0.99 at a sensitivity of 0.58. Protease activity measured in fresh milk from clinically healthy cows was significantly associated with somatic cell count and parity, but not with electrical conductivity, whereas protease activity in milk that had been frozen was statistically significantly associated with all 3 parameters. This study indicates that protease activity measurement as a stand-alone test can be used for detecting mastitis samples, using milk samples that have been frozen. Because protease activity acts in part on a different biological mechanism than somatic cell count or electrical conductivity, this test may increase the accuracy of mastitis diagnosis in combination with currently available in- or on-line tests in automated milking systems. PMID:25981067

  8. Short communication: Cytokine profiles from blood mononuclear cells of dairy cows classified with divergent immune response phenotypes.

    PubMed

    Martin, C E; Paibomesai, M A; Emam, S M; Gallienne, J; Hine, B C; Thompson-Crispi, K A; Mallard, B A

    2016-03-01

    Genetic selection for enhanced immune response has been shown to decrease disease occurrence in dairy cattle. Cows can be classified as high (H), average, or low responders based on antibody-mediated immune response (AMIR), predominated by type-2 cytokine production, and cell-mediated immune response (CMIR) through estimated breeding values for these traits. The purpose of this study was to identify in vitro tests that correlate with in vivo immune response phenotyping in dairy cattle. Blood mononuclear cells (BMC) isolated from cows classified as H-AMIR and H-CMIR through estimated breeding values for immune response traits were stimulated with concanavalin A (ConA; Sigma Aldrich, St. Louis, MO) and gene expression, cytokine production, and cell proliferation was determined at multiple time points. A repeated measures model, which included the effects of immune response group, parity, and stage of lactation, was used to compare differences between immune response phenotype groups. The H-AMIR cows produced more IL-4 protein than H-CMIR cows at 48h; however, no difference in gene expression of type-2 transcription factor GATA3 or IL4 was noted. The BMC from H-CMIR cows had increased production of IFN-γ protein at 48, 72, and 96h compared with H-AMIR animals. Further, H-CMIR cows had increased expression of the IFNG gene at 16, 24, and 48h post-treatment with ConA, although expression of the type-1 transcription factor gene TBX21 did not differ between immune response groups. Although proliferation of BMC increased from 24 to 72h after ConA stimulation, no differences were found between the immune response groups. Overall, stimulation of H-AMIR and H-CMIR bovine BMC with ConA resulted in distinct cytokine production profiles according to genetically defined groups. These distinct cytokine profiles could be used to define disease resistance phenotypes in dairy cows according to stimulation in vitro; however, other immune response phenotypes should be assessed. PMID:26723120

  9. Short communication: Comparison of predicted dietary phosphorus balance using bioavailabilities from the NRC (2001) and Virginia Tech model.

    PubMed

    Feng, X; Jarrett, J P; Knowlton, K F; James, R E; Hanigan, M D

    2016-02-01

    The objective of the current work was to use digestion coefficients from the Feng et al. (2015) model (Virginia Tech model) to calculate P bioavailability of common feeds used in dairy production. Compared with the bioavailability calculated by the Virginia Tech model, using the NRC (2001) P absorption coefficient of 0.64 for forages would underestimate the bioavailabilities of alfalfa hay, alfalfa silage, corn silage, grass hay, and mixed mainly legume silage. For concentrates, using the NRC (2001) P absorption coefficient of 0.70 would overestimate the bioavailabilities of corn grain but underestimate bioavailability of high-moisture corn. Two dairy diets were formulated using nutrient values from the NRC (2001): a standard diet that includes minimal by-products, and a by-product diet that has reduced corn and soybean meal which was replaced with corn gluten feed, distillers grains, hominy feed, and wet brewers grains. For each diet, total bioavailable P was calculated using availability values from the NRC (2001) and the Virginia Tech model. Comparison of P balance (the difference between required and bioavailable P) for each diet was made using the 2 sets of bioavailabilities for a reference cow weighing 682kg, producing 38.6kg of milk/d (3.5% fat and 3.0% true protein, 100d in milk), and consuming 23kg of dry matter/d, yielding an absorbed P requirement of 59.4g/d. The standard diet supplied 56.69 and 53.52g of bioavailable P per day using bioavailabilities from the NRC (2001) and Virginia Tech models, respectively, resulting in a P balance of -2.71 and -5.88±0.26g/d. The by-product diet provided 75.75 and 78.47g/d of bioavailable P, yielding P balances of 16.35 and 19.07±0.37g per day, respectively, using the 2 sets of bioavailabilities. Using P bioavailabilities for individual ingredients that were based on the Virginia Tech model resulted in different bioavailable P levels thus resulted in differing dietary P balances in a field setting. PMID:26709165

  10. Short communication: Maternal heat stress during the dry period alters postnatal whole-body insulin response of calves.

    PubMed

    Tao, S; Monteiro, A P A; Hayen, M J; Dahl, G E

    2014-02-01

    Heat stress during the dry period not only negatively affects a cow's performance but also affects her offspring. Previous studies indicate that calves born to cows heat-stressed during late gestation have lower birth weight but similar overall weight gain during the prepubertal period compared with those cooled in utero. However, it is unclear if whole-body insulin response, and thus metabolism, of calves is altered in their postnatal life after in utero heat stress. The aim of the present study was to examine the effects of maternal heat stress during the dry period on whole-body insulin response of calves after weaning. Calves (10/treatment) were born to cows exposed to heat stress (HT) or cooling (CL) when dry. Calves were immediately separated from their dams and fed 3.8L of high-quality colostrum within 1h after birth and then 1.9L 12h later. All calves were fed 1.9 to 3.8L of pasteurized milk in the morning and afternoon from 2 to 42 d of age and then only in the morning until weaning at 49 d. Calf starter and water were offered ad libitum starting at 2 d of age. All calves were managed in the same manner throughout the study. All calves were subjected to a glucose tolerance test (GTT) and an insulin challenge (IC) at 55 d of age. Calves heat-stressed in utero were born lighter (40 ± 1.4 vs. 45 ± 1.4 kg) compared with CL calves. Both groups of calves had similar weaning weights (HT: 68 ± 3.2 kg; CL: 71 ± 3.3 kg) and body weight gain from birth to weaning (HT: 28 ± 2.2 kg; CL: 26 ± 2.3 kg). Compared with those cooled in utero, HT calves had a similar insulin response to GTT and insulin clearance during IC but faster glucose clearance during GTT and IC. In conclusion, in addition to impaired fetal growth, maternal heat stress during the dry period enhances the whole-body insulin response of calves after weaning, which suggests the possibility of accelerated lipogenesis and fat deposition in early life. PMID:24359830

  11. Short communication: grazing pattern of dairy cows that were selected for divergent residual feed intake as calves.

    PubMed

    Gregorini, P; Waghorn, G C; Kuhn-Sherlock, B; Romera, A J; Macdonald, K A

    2015-09-01

    The aim of this study was to investigate and assess differences in the grazing pattern of 2 groups of mature dairy cows selected as calves for divergent residual feed intake (RFI). Sixteen Holstein-Friesian cows (471±31kg of body weight, 100 d in milk), comprising 8 cows selected as calves (6-8 mo old) for low (most efficient: CSCLowRFI) and 8 cows selected as calves for high (least efficient: CSCHighRFI) RFI, were used for the purpose of this study. Cows (n=16) were managed as a single group, and strip-grazed (24-h pasture allocation at 0800h) a perennial ryegrass sward for 31 d, with measurements taken during the last 21 d. All cows were equipped with motion sensors for the duration of the study, and jaw movements were measured for three 24-h periods during 3 random nonconsecutive days. Measurements included number of steps and jaw movements during grazing and rumination, plus fecal particle size distribution. Jaw movements were analyzed to identify bites, mastication (oral processing of ingesta) during grazing bouts, chewing during rumination, and to calculate grazing and rumination times for 24-h periods. Grazing and walking behavior were also analyzed in relation to the first meal of the day after the new pasture was allocated. Measured variables were subjected to multivariate analysis. Cows selected for low RFI as calves appeared to (a) prioritize grazing and rumination over idling; (b) take fewer steps, but with a higher proportion of grazing steps at the expense of nongrazing steps; and (c) increase the duration of the first meal and commenced their second meal earlier than CSCHighRFI. The CSCLowRFI had fewer jaw movements during eating (39,820 vs. 45,118 for CSCLowRFI and CSCHighRFI, respectively), more intense rumination (i.e., 5 more chews per bolus), and their feces had 30% less large particles than CSCHighRFI. These results suggest that CSCLowRFI concentrate their grazing activity to the time when fresh pasture is allocated, and graze more efficiently by walking and masticating less, hence they are more efficient grazers than CSCHighRFI. PMID:26162793

  12. Graphic Arts (Graphic Communications). Industrial Arts, Senior High--Level II. North Dakota Senior High Industrial Arts Curriculum Guides.

    ERIC Educational Resources Information Center

    Poehls, Eddie; And Others

    This course guide for a graphic arts course is one of four developed for the graphic communications area in the North Dakota senior high industrial arts education program. (Eight other guides are available for two other areas of Industrial Arts--energy/power and production.) Part 1 provides such introductory information as a definition and

  13. Graphic Arts (Graphic Communications). Industrial Arts, Senior High--Level II. North Dakota Senior High Industrial Arts Curriculum Guides.

    ERIC Educational Resources Information Center

    Poehls, Eddie; And Others

    This course guide for a graphic arts course is one of four developed for the graphic communications area in the North Dakota senior high industrial arts education program. (Eight other guides are available for two other areas of Industrial Arts--energy/power and production.) Part 1 provides such introductory information as a definition and…

  14. Design/Drafting (Graphic Communications). Industrial Arts, Senior High--Level II. North Dakota Senior High Industrial Arts Curriculum Guides.

    ERIC Educational Resources Information Center

    Poehls, Eddie; And Others

    This course guide for a design/drafting course is one of four developed for the graphic communications area in the North Dakota senior high industrial arts education program. (Eight other guides are available for two other areas of Industrial Arts--energy/power and production.) Part 1 provides such introductory information as a definition and…

  15. Photography (Graphic Communications). Industrial Arts, Senior High--Level II. North Dakota Senior High Industrial Arts Curriculum Guides.

    ERIC Educational Resources Information Center

    Poehls, Eddie; And Others

    This course guide for a photography course is one of four developed for the graphic communications area in the North Dakota senior high industrial arts education program. (Eight other guides are available for two other areas of Industrial Arts--energy/power and production.) Part 1 provides such introductory information as a definition and…

  16. Glucose Homeostasis During Short-term and Prolonged Exposure to High Altitudes

    PubMed Central

    Ader, Marilyn; Bergman, Richard N.

    2015-01-01

    Most of the literature related to high altitude medicine is devoted to the short-term effects of high-altitude exposure on human physiology. However, long-term effects of living at high altitudes may be more important in relation to human disease because more than 400 million people worldwide reside above 1500 m. Interestingly, individuals living at higher altitudes have a lower fasting glycemia and better glucose tolerance compared with those who live near sea level. There is also emerging evidence of the lower prevalence of both obesity and diabetes at higher altitudes. The mechanisms underlying improved glucose control at higher altitudes remain unclear. In this review, we present the most current evidence about glucose homeostasis in residents living above 1500 m and discuss possible mechanisms that could explain the lower fasting glycemia and lower prevalence of obesity and diabetes in this population. Understanding the mechanisms that regulate and maintain the lower fasting glycemia in individuals who live at higher altitudes could lead to new therapeutics for impaired glucose homeostasis. PMID:25675133

  17. Solar Cell Short Circuit Current Errors and Uncertainties During High Altitude Calibrations

    NASA Technical Reports Server (NTRS)

    Snyder, David D.

    2012-01-01

    High altitude balloon based facilities can make solar cell calibration measurements above 99.5% of the atmosphere to use for adjusting laboratory solar simulators. While close to on-orbit illumination, the small attenuation to the spectra may result in under measurements of solar cell parameters. Variations of stratospheric weather, may produce flight-to-flight measurement variations. To support the NSCAP effort, this work quantifies some of the effects on solar cell short circuit current (Isc) measurements on triple junction sub-cells. This work looks at several types of high altitude methods, direct high altitude meas urements near 120 kft, and lower stratospheric Langley plots from aircraft. It also looks at Langley extrapolation from altitudes above most of the ozone, for potential small balloon payloads. A convolution of the sub-cell spectral response with the standard solar spectrum modified by several absorption processes is used to determine the relative change from AMO, lscllsc(AMO). Rayleigh scattering, molecular scatterin g from uniformly mixed gases, Ozone, and water vapor, are included in this analysis. A range of atmosph eric pressures are examined, from 0. 05 to 0.25 Atm to cover the range of atmospheric altitudes where solar cell calibrations a reperformed. Generally these errors and uncertainties are less than 0.2%

  18. Challenge Study: A Project-Based Learning on a Wireless Communication System at Technical High School

    ERIC Educational Resources Information Center

    Terasawa, Ikuo

    2016-01-01

    The challenge study is a project based learning curriculum at Technical High School aimed at the construction of a wireless communication system. The first period was engineering issues in the construction of an artificial satellite and the second period was a positional locating system based on the general purpose wire-less device--ZigBee device.…

  19. Observation of High School Students' Real-Life Communication during a Study Tour Abroad.

    ERIC Educational Resources Information Center

    Iwami, Ichiro

    2001-01-01

    This study assessed various traits of two Japanese high school students' communicative performance by examining their interaction with native speakers of English while they were visiting the United States as part of a 5-day study tour. The study focused on the kind of student performance that should be considered a successful outcome of…

  20. Communication Satisfaction, Organizational Citizenship Behavior and the Relationship to Student Achievement in High Schools

    ERIC Educational Resources Information Center

    Blanchard, Gayle A.

    2012-01-01

    This study used a correlational design that allowed the researcher to examine the relationship among communication satisfaction, organizational citizenship behaviors (OCB) and student achievement. High school teachers were surveyed from a convenience sample of 12 school districts in Arizona. Established instruments were used to survey…

  1. Communication about Contraception and Knowledge of Oral Contraceptives amongst Norwegian High School Students.

    ERIC Educational Resources Information Center

    Hansen, Thomas; Skjeldestad, Finn Egil

    2003-01-01

    Examines communication about contraception and specific knowledge of oral contraceptives (OCs) in a sample of Norwegian high school students. More females than males discussed contraception at least monthly. Discussions were predominantly held with peers and not adults. Females were far more knowledgeable about OCs than males. The most significant

  2. Electronic Communication and Its Influence on Parental Involvement in High School

    ERIC Educational Resources Information Center

    Watkins, Aaron

    2013-01-01

    This study investigated the effect of electronic communication has on parent's involvement with their high school child's education. The No Child Left Behind Act of 2001 (NCLB) specifically requires that schools find ways to increase parental involvement; this requirement stemmed from evidence that involvement tends to decline as the students…

  3. EMERGING AIR QUALITY MODELING TECHNOLOGY FOR HIGH PERFORMANCE COMPUTING AND COMMUNICATION ENVIRONMENTS

    EPA Science Inventory

    To demonstrate applications of the HPCC technologies in air quality models, we organized the Specialty Evening Session 1, "Emerging Air Quality Modeling Technologies for High Performance Computing and Communication Environment" as a part of the Twenty First NATO/CCMS Internationa...

  4. Combining High-Tech with Lakota Legend: Pine Ridge Students Utilize Computers to Communicate Their Culture.

    ERIC Educational Resources Information Center

    Hamilton, Candy

    1993-01-01

    In a program sponsored by the Apple Crossroads III Educational Grant, American Indian students at Pine Ridge High School (Oglala, South Dakota) use computers to enhance their study of Lakota history and culture and other subjects and to communicate with other schools. This program has increased student interest in school and improved student test…

  5. Conflicts and Communication between High-Achieving Chinese American Adolescents and Their Parents

    ERIC Educational Resources Information Center

    Qin, Desiree Baolian; Chang, Tzu-Fen; Han, Eun-Jin; Chee, Grace

    2012-01-01

    Drawing on in-depth interview data collected on 18 high-achieving Chinese American students, the authors examine domains of acculturation-based conflicts, parent and child internal conflicts, and conflict resolution in their families. Their analyses show that well-established negative communication patterns in educational expectations, divergent

  6. Supporting Students' Transition from Primary School to High School Using the Internet as a Communication Tool

    ERIC Educational Resources Information Center

    Maher, Damian

    2010-01-01

    This paper reports on a transition project where the Internet as a communication tool was used to facilitate interactions between primary school and high school students. The qualitative case study involved capturing the online interactions of the students and teachers as well as the use of questionnaires. Results of the study demonstrate that the…

  7. Conflicts and Communication between High-Achieving Chinese American Adolescents and Their Parents

    ERIC Educational Resources Information Center

    Qin, Desiree Baolian; Chang, Tzu-Fen; Han, Eun-Jin; Chee, Grace

    2012-01-01

    Drawing on in-depth interview data collected on 18 high-achieving Chinese American students, the authors examine domains of acculturation-based conflicts, parent and child internal conflicts, and conflict resolution in their families. Their analyses show that well-established negative communication patterns in educational expectations, divergent…

  8. Federal High Performance Computing and Communications Program. The Department of Energy Component.

    ERIC Educational Resources Information Center

    Department of Energy, Washington, DC. Office of Energy Research.

    This report, profusely illustrated with color photographs and other graphics, elaborates on the Department of Energy (DOE) research program in High Performance Computing and Communications (HPCC). The DOE is one of seven agency programs within the Federal Research and Development Program working on HPCC. The DOE HPCC program emphasizes research in…

  9. The design of a linear L-band high power amplifier for mobile communication satellites

    NASA Technical Reports Server (NTRS)

    Whittaker, N.; Brassard, G.; Li, E.; Goux, P.

    1990-01-01

    A linear L-band solid state high power amplifier designed for the space segment of the Mobile Satellite (MSAT) mobile communication system is described. The amplifier is capable of producing 35 watts of RF power with multitone signal at an efficiency of 25 percent and with intermodulation products better than 16 dB below carrier.

  10. Communication about Contraception and Knowledge of Oral Contraceptives amongst Norwegian High School Students.

    ERIC Educational Resources Information Center

    Hansen, Thomas; Skjeldestad, Finn Egil

    2003-01-01

    Examines communication about contraception and specific knowledge of oral contraceptives (OCs) in a sample of Norwegian high school students. More females than males discussed contraception at least monthly. Discussions were predominantly held with peers and not adults. Females were far more knowledgeable about OCs than males. The most significant…

  11. The DOE Program in HPCC: High-Performance Computing and Communications.

    ERIC Educational Resources Information Center

    Department of Energy, Washington, DC. Office of Energy Research.

    This document reports to Congress on the progress that the Department of Energy has made in 1992 toward achieving the goals of the High Performance Computing and Communications (HPCC) program. Its second purpose is to provide a picture of the many programs administered by the Office of Scientific Computing under the auspices of the HPCC program.…

  12. InfoMall: An Innovative Strategy for High-Performance Computing and Communications Applications Development.

    ERIC Educational Resources Information Center

    Mills, Kim; Fox, Geoffrey

    1994-01-01

    Describes the InfoMall, a program led by the Northeast Parallel Architectures Center (NPAC) at Syracuse University (New York). The InfoMall features a partnership of approximately 24 organizations offering linked programs in High Performance Computing and Communications (HPCC) technology integration, software development, marketing, education and…

  13. Overview of the Preliminary Design of the Optical Communication Demonstration and High-Rate Link Facility

    NASA Technical Reports Server (NTRS)

    Sandusky, John V.; Jeganathan, M.; Ortiz, G.; Biswas, A.; Lee, S.; Parker, G.; Liu, B.; Johnson, D.; DePew, J.; Lesh, J. R.

    2000-01-01

    Tlis paper presents an overview of the preliminary design of both the flight and ground systems of the Optical Communication Demonstration and High-Rate Link Facility which will demonstrate optical communication from the International Space Station to ground after its deployment in October 2002. The overview of the preliminary design of the Flight System proceeds by contrasting it with the design of the laboratory-model unit, emphasizing key changes and the rationale behind the design choices. After presenting the preliminary design of the Ground System, the timetable for the construction and deployment of the flight and ground systems is outlined.

  14. High bandwidth based on a tapped delay line equalization in visible light communications

    NASA Astrophysics Data System (ADS)

    Zhang, Minglun; Guo, Xujing; Zhu, Hetian; Wang, Chao; Bai, Xiaonan; Zhai, Xiangwen

    2015-08-01

    In the visible light communication, the white LED bandwidth severely limits the transmission rate of information. This paper presents an analog pre-equalization technology to compensate for the bandwidth of white LED. The technology not only can debug according to the actual channel changing, but also avoid the high costs of using FPGA technology. The pre-equalization technology is implemented by an analog circuit of tapped-delay-line, in the circuit we select an appropriate delay line and a digital to analog converter. In our LED visible light communication system, we can achieve a bandwidth of 150MHz which was proved theoretically in the paper.

  15. Effect of Short-Term Acclimatization to High Altitude on Sleep and Nocturnal Breathing

    PubMed Central

    Nussbaumer-Ochsner, Yvonne; Ursprung, Justyna; Siebenmann, Christoph; Maggiorini, Marco; Bloch, Konrad E.

    2012-01-01

    Study Objective: Objective physiologic data on sleep and nocturnal breathing at initial exposure and during acclimatization to high altitude are scant. We tested the hypothesis that acute exposure to high altitude induces quantitative and qualitative changes in sleep and that these changes are partially reversed with acclimatization. Design: Prospective observation. Setting: One night in a sleep laboratory at 490 meters, the first and the third night in a mountain hut at 4559 meters. Participants: Sixteen healthy mountaineers. Intervention: Altitude exposure. Measurements: Polysomnography, questionnaire evaluation of sleep and acute mountain sickness. Results: Compared to 490 m, median nocturnal oxygen saturation decreased during the 1st night at 4559 m from 96% to 67%, minute ventilation increased from 4.4 to 6.3 L/min, and the apnea-hypopnea index increased from 0.1 to 60.9/h; correspondingly, sleep efficiency decreased from 93% to 69%, and slow wave sleep from 18% to 6% (P < 0.05, all instances). During the 3rd night at 4559 m, oxygen saturation was 71%, slow wave sleep 11% (P < 0.05 vs. 1st night, both instances) and the apnea/hypopnea index was 86.5/h (P = NS vs. 1st night). Symptoms of AMS and of disturbed sleep were significantly reduced in the morning after the 3rd vs. the 1st night at 4559 m. Conclusions: In healthy mountaineers ascending rapidly to high altitude, sleep quality is initially impaired but improves with acclimatization in association with improved oxygen saturation, while periodic breathing persists. Therefore, high altitude sleep disturbances seem to be related predominantly to hypoxemia rather than to periodic breathing. Citation: Nussbaumer-Ochsner Y; Ursprung J; Siebenmann C; Maggiorini M; Bloch KE. Effect of short-term acclimatization to high altitude on sleep and nocturnal breathing. SLEEP 2012;35(3):419-423. PMID:22379248

  16. Trigeminal high-frequency stimulation produces short- and long-term modification of reflex blink gain.

    PubMed

    Ryan, Michael; Kaminer, Jaime; Enmore, Patricia; Evinger, Craig

    2014-02-01

    Reflex blinks provide a model system for investigating motor learning in normal and pathological states. We investigated whether high-frequency stimulation (HFS) of the supraorbital branch of the trigeminal nerve before the R2 blink component (HFS-B) decreases reflex blink gain in alert rats. As with humans (Mao JB, Evinger C. J Neurosci 21: RC151, 2001), HFS-B significantly reduced blink size in the first hour after treatment for rats. Repeated days of HFS-B treatment produced long-term depression of blink circuits. Blink gain decreased exponentially across days, indicating a long-term depression of blink circuits. Additionally, the HFS-B protocol became more effective at depressing blink amplitude across days of treatment. This depression was not habituation, because neither long- nor short-term blink changes occurred when HFS was presented after the R2. To investigate whether gain modifications produced by HFS-B involved cerebellar networks, we trained rats in a delay eyelid conditioning paradigm using HFS-B as the unconditioned stimulus and a tone as the conditioned stimulus. As HFS-B depresses blink circuits and delay conditioning enhances blink circuit activity, occlusion should occur if they share neural networks. Rats acquiring robust eyelid conditioning did not exhibit decreases in blink gain, whereas rats developing low levels of eyelid conditioning exhibited weak, short-term reductions in blink gain. These results suggested that delay eyelid conditioning and long-term HFS-B utilize some of the same cerebellar circuits. The ability of repeated HFS-B treatment to depress trigeminal blink circuit activity long term implied that it may be a useful protocol to reduce hyperexcitable blink circuits that underlie diseases like benign essential blepharospasm. PMID:24285868

  17. [Psychological processes predicting the English communication behavior of Japanese high school students].

    PubMed

    Ito, Takehiko

    2013-12-01

    This study presents a new model of psychological processes to predict English communication behaviors of Japanese high school students. Various models have been proposed in Japan, based mainly on Canadian models, to predict second-language communication behaviors. This study shows problems with the previous models in Japan and introduces a new model from the perspective of "Expectancy-Value Theory". Questionnaire Survey 1 compared the previous model and the modified models which suggested that a new psychological variable, "Value in English Communication", was necessary to construct the new model. In Survey 2, the new model was further modified by incorporating into it various English learning values which the Japanese have. This study makes a significant contribution to studies and practices of teaching English as a foreign language in Japan. PMID:24505975

  18. A three-dimensional quantitative understanding of short fatigue crack growth in high strength aluminum alloys

    NASA Astrophysics Data System (ADS)

    Wen, Wei

    The behaviors of short fatigue crack (SFC) propagation through grain boundaries (GBs) were monitored during high cycle fatigue in an Al-Li alloy AA8090. The growth behaviors of SFCs were found to be mainly controlled by the twist components (alpha) of crack plane deflection across each of up to first 20 GBs along the crack path. The crack plane twist at the GB can result in a resistance against SFC growth; therefore SFC propagation preferred to follow a path with minimum alpha at each GB. In addition to the grain orientation, the tilting of GB could also affect alpha. An experiment focusing on quantifying GB-resistance was conducted on an Al-Cu alloy AA2024-T351. With a focused ion beam (FIB) and electron backscatter diffraction (EBSD), the micro-notches were made in front of the selected GBs which had a wide range of alpha, followed by monitoring the interaction of crack propagation from the notches with the GBs during fatigue. The crack growth rate was observed to decrease at each GB it had passed; and such growth-rate decrease was proportional to alpha. The resistance of the GB was determined to vary as a Weibull-type function of alpha. Based on these discoveries, a microstructure-based 3-D model was developed to quantify the SFC growth in high-strength Al alloys, allowing the prediction of crack front advancement in 3-D and the quantification of growth rate along the crack front. The simulation results yielded a good agreement with the experimental results about the SFC growth rate on the surface of the AA8090 Al alloy. The model was also used to predict the life of SFC growth statistically in different textures, showing potential application to texture design of alloys. Fatigue crack initiation at constituent particles (beta-phase) was preliminarily studied in the AA2024-T351 Al alloy. Cross-sectioning with the FIB revealed that the 3-D geometry, especially the thickness, of fractured constituent particles (beta-phase) was the key factor controlling the driving force for micro-crack growth. The resistance to micro-crack growth, mainly associated with crack plane twist at the particle/matrix interface, also influenced the growth behaviors of the micro-cracks at the particles on the surface. KEYWORDS: high strength Al alloy, short fatigue crack, crack initiation and propagation, grain boundary, crystal orientation.

  19. Joint Access Control Based on Access Ratio and Resource Utilization for High-Speed Railway Communications

    NASA Astrophysics Data System (ADS)

    Zhou, Yuzhe; Ai, Bo

    2015-05-01

    The fast development of high-speed rails makes people's life more and more convenient. However, provisioning of quality of service of multimedia applications for users on the high-speed train is a critical task for wireless communications. Therefore, new solutions are desirable to be found to address this kind of problem. Current researches mainly focus on providing seamless broadband wireless access for high-speed mobile terminals. In this paper, an algorithm to calculate the optimal resource reservation fraction of handovers is proposed. A joint access control scheme for high-speed railway communication handover scenario is proposed. Metrics of access ratio and resource utilization ratio are considered jointly in the analysis and the performance evaluation. Simulation results show that the proposed algorithm and the scheme improve quality of service compared with other conventional schemes.

  20. Effectiveness of mouse minute virus inactivation by high temperature short time treatment technology: a statistical assessment.

    PubMed

    Murphy, Marie; Quesada, Guillermo Miro; Chen, Dayue

    2011-11-01

    Viral contamination of mammalian cell cultures in GMP manufacturing facility represents a serious safety threat to biopharmaceutical industry. Such adverse events usually require facility shutdown for cleaning/decontamination, and thus result in significant loss of production and/or delay of product development. High temperature short time (HTST) treatment of culture media has been considered as an effective method to protect GMP facilities from viral contaminations. Log reduction factor (LRF) has been commonly used to measure the effectiveness of HTST treatment for viral inactivation. However, in order to prevent viral contaminations, HTST treatment must inactivate all infectious viruses (100%) in the medium batch since a single virus is sufficient to cause contamination. Therefore, LRF may not be the most appropriate indicator for measuring the effectiveness of HTST in preventing viral contaminations. We report here the use of the probability to achieve complete (100%) virus inactivation to assess the effectiveness of HTST treatment. By using mouse minute virus (MMV) as a model virus, we have demonstrated that the effectiveness of HTST treatment highly depends upon the level of viral contaminants in addition to treatment temperature and duration. We believe that the statistical method described in this report can provide more accurate information about the power and potential limitation of technologies such as HTST in our shared quest to mitigate the risk of viral contamination in manufacturing facilities. PMID:21985900

  1. High Density Lipoproteins for the Systemic Delivery of short interfering RNA

    PubMed Central

    McMahon, Kaylin M.; Thaxton, C. Shad

    2014-01-01

    Introduction RNA interference (RNAi) is a powerful mechanism for gene silencing with the potential to greatly impact the development of new therapies for many human diseases. Short interfering RNAs (siRNAs) may be the ideal molecules for therapeutic RNAi. However, therapeutic siRNAs face significant challenges that must be overcome prior to widespread clinical use. Many efforts have been made to overcome the hurdles associated with systemic administration of siRNA; however, current approaches are still limited. As such, there is an urgent need to develop new strategies for siRNA delivery that have the potential to impact a broad spectrum of systemic diseases. Areas covered This review focuses on the promise of siRNA therapies and highlights current siRNA delivery methods. With an eye toward new strategies, this review first introduces high density lipoproteins (HDL) and their natural functions, and then transitions into how HDLs may provide significant opportunities as next generation siRNA delivery vehicles. Importantly, this review describes how synthetic HDLs leverage the natural ability of HDL to stabilize and deliver siRNAs. Expert Opinion HDLs are natural nanoparticles that are critical to understanding the systemic delivery of therapeutic nucleic acids, like siRNA. Methods to synthesize biomimetic HDLs are being explored and data demonstrate that this type of delivery vehicle may be highly beneficial for targeted and efficacious systemic delivery of siRNAs. PMID:24313310

  2. Short-Pulse High-Intensity Laser Generated Electrons Transport in solid targets

    NASA Astrophysics Data System (ADS)

    Akli, Kramer; Freeman, R.; Stephens, R.; Norreys, P.; Beg, F.; Stoeckel, C.

    2005-10-01

    Understanding the propagation and energy deposition of relativistic electrons generated by high-Intensity short-pulse laser is essential to fast ignition. We conducted a systematic study of the electron beam energy transport using the Vulcan laser facility in the United Kingdom. The laser Energy was 400 J delivered in either 1ps or 10ps. We used a 5 μm thick Molybdenum targets with two different layers. The Vanadium layer was 1 μm thick and located at the back of the target. The Nickel layer was 0.5 μm thick and located at various depths into the target. Highly Ordered Pyrolytic Graphite Crystal (HOPG) was used to obtain the X-ray spectra generated by the interaction of the laser pulse with the solid targets. The experimental results will be presented and the modeling will be discussed. This work was performed under the auspices of U.S. Department of Energy by The University of California, Lawrence Livermore National Laboratory under Contract No. W-7405-Eng-48. Some of this work was undertaken as part of a United Kingdom university collaboration funded by CCLRC.

  3. Facial resurfacing using a high-energy, short-pulse carbon dioxide laser.

    PubMed

    Goodman, G J

    1996-08-01

    Facial skin resurfacing is now possible using short-pulse, high-energy carbon dioxide (CO2) lasers. The laser utilized in this particular paper is the Ultra-pulse CO2 laser. The Ultra-pulse laser represents the first CO2 laser able to vaporize tissue in a single pulse with the use of a large spot size. This laser utilizes the principles of selective photothermolysis. The high-power pulses are completed in less than the thermal relaxation time of skin, estimated to be less than 1 millisecond. This translates into rapid vaporization of tissue with little heat conduction to surrounding tissues. It also should allow a reproducibility of results between practitioners with set parameters not possible with previous CO2 lasers. Clinically, this laser is useful for the removal of skin lesions, and the resurfacing of areas of sun damage, wrinkles and scars. The immediate haemostasis and excellent visibility allows for precise vaporization of abnormal tissue. Rapid and pain-free wound healing is usual. The complication rate would appear to compare very favourably with dermabrasion and chemical peeling techniques. PMID:8771864

  4. Can High-resolution WRF Simulations Be Used for Short-term Forecasting of Lightning?

    NASA Technical Reports Server (NTRS)

    Goodman, S. J.; Lapenta, W.; McCaul, E. W., Jr.; LaCasse, K.; Petersen, W.

    2006-01-01

    A number of research teams have begun to make quasi-operational forecast simulations at high resolution with models such as the Weather Research and Forecast (WRF) model. These model runs have used horizontal meshes of 2-4 km grid spacing, and thus resolved convective storms explicitly. In the light of recent global satellite-based observational studies that reveal robust relationships between total lightning flash rates and integrated amounts of precipitation-size ice hydrometeors in storms, it is natural to inquire about the capabilities of these convection-resolving models in representing the ice hydrometeor fields faithfully. If they do, this might make operational short-term forecasts of lightning activity feasible. We examine high-resolution WRF simulations from several Southeastern cases for which either NLDN or LMA lightning data were available. All the WRF runs use a standard microphysics package that depicts only three ice species, cloud ice, snow and graupel. The realism of the WRF simulations is examined by comparisons with both lightning and radar observations and with additional even higher-resolution cloud-resolving model runs. Preliminary findings are encouraging in that they suggest that WRF often makes convective storms of the proper size in approximately the right location, but they also indicate that higher resolution and better hydrometeor microphysics would be helpful in improving the realism of the updraft strengths, reflectivity and ice hydrometeor fields.

  5. Short-term cardiorespiratory adaptation to high altitude in children compared with adults.

    PubMed

    Kriemler, S; Radtke, T; Bürgi, F; Lambrecht, J; Zehnder, M; Brunner-La Rocca, H P

    2016-02-01

    As short-term cardiorespiratory adaptation to high altitude (HA) exposure has not yet been studied in children, we assessed acute mountain sickness (AMS), hypoxic ventilatory response (HVR) at rest and maximal exercise capacity (CPET) at low altitude (LA) and HA in pre-pubertal children and their fathers. Twenty father-child pairs (11 ± 1 years and 44 ± 4 years) were tested at LA (450 m) and HA (3450 m) at days 1, 2, and 3 after fast ascent (HA1/2/3). HVR was measured at rest and CPET was performed on a cycle ergometer. AMS severity was mild to moderate with no differences between generations. HVR was higher in children than adults at LA and increased at HA similarly in both groups. Peak oxygen uptake (VO2 peak) relative to body weight was similar in children and adults at LA and decreased significantly by 20% in both groups at HA; maximal heart rate did not change at HA in children while it decreased by 16% in adults (P < 0.001). Changes in HVR and VO2 peak from LA to HA were correlated among the biological child-father pairs. In conclusion, cardiorespiratory adaptation to altitude seems to be at least partly hereditary. Even though children and their fathers lose similar fractions of aerobic capacity going to high altitude, the mechanisms might be different. PMID:25648726

  6. Development and test of high frequency dc/dc converters for communications satellites

    NASA Astrophysics Data System (ADS)

    Alsbach, W.; Tsuya, N.; Gohnai, T.

    1985-12-01

    The development results of dc/dc converters with high switching frequency for future communications satellites are presented. Two types of dc/dc converters were developed: (1) TWT-EPC A high voltage (3 kV) converter for the Thomson CSF TH3559 TWT, operating at 100 kHz; (2) a low voltage converter for an SSPA-EPC solid state power amplifier, operating at 250 kHz. Evaluation and results of functional, EMC, and frequency tests are presented.

  7. High-power 0.87-micron channel substrate planar lasers for spaceborne communications

    NASA Technical Reports Server (NTRS)

    Connolly, J. C.; Stewart, T. R.; Gilbert, D. B.; Slavin, S. E.; Carlin, D. B.

    1988-01-01

    High-power single-mode channeled-substrate planar AlGaAs diode lasers are being developed for reliable high-power operation for use as sources in spaceborne optical communication systems. The CSP laser structure has been optimized for operation at an emission wavelength of 870 nm. Such devices have exhibited output powers in excess of 80 mW CW at an operating temperature of 80 C.

  8. Adrenal cortical responses to high-intensity, short rest, resistance exercise in men and women.

    PubMed

    Szivak, Tunde K; Hooper, David R; Dunn-Lewis, Courtenay; Comstock, Brett A; Kupchak, Brian R; Apicella, Jenna M; Saenz, Catherine; Maresh, Carl M; Denegar, Craig R; Kraemer, William J

    2013-03-01

    Commercial high-intensity, short rest (HI/SR) protocols have been anecdotally postured to be extremely demanding. However, limited prior studies have demonstrated HI/SR protocols to produce hyperreactions in metabolic and adrenal function; thus, the purpose of this study was to evaluate the physiological effects of an acute, high-intensity (75% 1-repetition maximum), short rest resistance exercise protocol. Nine trained men (age: 23.5 ± 3.5 years, height: 172.4 ± 4.0 cm, weight: 77.8 ± 8.8 kg) and 9 trained women (age: 22.9 ± 2.0 years, height: 168.4 ± 9.4 cm, weight: 68.5 ± 10.4 kg) participated in the HI/SR protocol, which consisted of a descending pyramid scheme of back squat, bench press, and deadlift, beginning with 10 repetitions of each, then 9, then 8, and so on until 1 repetition on the final set. Significant time effects were observed in lactate (immediate post [IP], +15, +60) and cortisol (IP, +15, +60) response. Significant sex effects were observed in lactate response (IP, +15) but not in cortisol response. Total work was higher in men and influenced magnitude of increase in lactate but not cortisol. No significant sex differences were noted in time to completion, average relative intensity, heart rate response or rating of perceived exertion scores. Highest lactate (IP men: 17.3 mmol·L(-1); IP women: 13.8 mmol·L(-1)) and cortisol (+15 men: 1,860.2 nmol·L(-1); +15 women: 1,831.7 nmol·L(-1)) values were considerably greater than those produced in typical resistance exercise programs, confirming that relative intensity and rest period length are important factors determining magnitude of metabolic and adrenal stress. Practical applications for the coach include cautious implementation of HI/SR protocols, as long-term sequential use may promote overtraining. A gradual reduction in rest interval length with concurrent gradual increase in intensity should be used to minimize potential negative effects such as nonfunctional overreaching. PMID:22561973

  9. Efficient Service Delivery for High-speed Railway Communications Using MIMO and Access Control Technique

    NASA Astrophysics Data System (ADS)

    Zhou, Yuzhe; Ai, Bo

    2014-07-01

    In order to realize the notion of "anytime, anywhere" communication for high-speed train passengers, the Long Term Evolution for Railway is designed to provide broadband accesses and reliable communications for high-speed train passengers. However, with the increase of train speed, the system is subject to high bit error rate, Doppler frequency shift, and call drops. This paper is trying to solve these problems by employing the Multiple-Input Multiple-Output technique and access control schemes. The goal is to provide higher quality of services such as data rate, reliability, and delay for train passengers. Physical layer performance analysis and access control schemes are proposed in a two-hop model. Handovers and service types are also considered. Simulation results show that proposed models and schemes perform better in improving the quality of services.

  10. A Comparison of the Mental Processes of Advanced and Remedial High School Readers while Reading a Short Story.

    ERIC Educational Resources Information Center

    Eavenson, Ruth

    A study investigated the differences between what advanced and remedial high school readers do while reading a short story. Subjects were three seniors nominated by their literature teachers as being expert high school readers of literature, and three junior level students who were all reading about two grade levels below the junior level…

  11. Effect of high density on the short term Calomys musculinus spacing behaviour: A fencing experiment

    NASA Astrophysics Data System (ADS)

    Sommaro, Lucía V.; Steinmann, Andrea R.; Chiappero, Marina B.; Priotto, José W.

    2010-05-01

    We studied the short term spacing behavioural responses of corn mice ( Calomys musculinus) with regard to population density in four 0.25 ha enclosures (two control and two experimental) in the 2007 breeding season. The goal of this research was to test the hypothesis that spacing behaviour only operates among C. musculinus adult females. We estimated 207 home ranges to study: 1) the home range size and the overlap degree of adult males and females in relation to population density; 2) the settlement distances of juveniles to the centre of activity of their mothers and the home range overlap proportion between them and their mothers in relation to population density. We found that home range size and overlap degree in C. musculinus adults were determined by sex and density. At high population density males had significant smaller and more exclusive home ranges, and this might reflect induced territoriality derived from social restrictions. Female home range sizes remained similar irrespective of population density, and they kept exclusive home ranges in both control and experimental enclosures. Thus, females maintained their territories independent of the population density values. The settlement distances of juveniles from their mothers and the overlap proportion between them and their mothers were independent of population density. We conclude that spacing behaviour only operates among C. musculinus adult females and it could have a role in regulating population abundances limiting the number of females that acquire breeding spaces.

  12. Temperature measurement by IR camera of heated device to high temperature during a short time

    NASA Astrophysics Data System (ADS)

    Sonneck-Museux, Nathanaëlle; Vergé, Philippe; Judic, Jean-Pierre; Edard, Pierrick

    2015-04-01

    A device allowing heating a liquid to high temperatures during a very short time has been conceived in our laboratory. The goal of this survey is to find the suitable experimental configurations, so that tested material affected by the temperatures coved between 200 and 750°C. This study is achieved to the Solar Furnace of the DGA in Odeillo. The cavity containing the liquid is a thermocouple sleeve (capillary) in Inconel 600. Its extremity is closed tightly by a removable steel plug permitting the tightness after replenishment. An electromagnet associated to a generator of delay permit to make fall the whole after the solar irradiation in liquid nitrogen in order to stop the reaction of "deterioration" of the tested product. According to capillary dimensions and to heating time, the temperature measurement using a pyrometer is not possible. A second possibility is using thermocouple, but it is not easy to join this captor on Inconel 600. Using by infrared camera allows observing the presence or the absence of inflammation during the solar irradiation and the sleeve fall too. The measures of temperatures by thermocouple show a lot of variability. The measures comparison with those by infrared camera shows a phenomenon of "heat well". Several score of tests to the solar furnace have been achieved in different experimental configurations. Nine experimental configurations have been validated, for variable flux of 100 to 500W/cm². The observation by infrared camera permitted to validate the conceived system and to verify the homogeneity of the sleeve heated.

  13. Extended high-angular-frequency analysis of turbulence effects on short-exposure imaging

    NASA Astrophysics Data System (ADS)

    Tofsted, David H.

    2014-04-01

    An improved analysis of optical turbulence effects on short-exposure passive (SE) imaging is described, resulting in a new analytic expression for the SE modulation transfer function (MTF). This analysis expands on a 2011 study that examined characteristics of a tilt-phase component discovered in the standard theory of SE turbulence effects characterization. The analysis introduces an improved integration technique and a reformulated phase structure function, facilitating computation of a 38,007 element database of MTF results at low- to high-angular frequencies covering a wide range of diffraction and turbulence conditions. Analysis of this database is described, yielding a new analytic SE MTF, accurate to a root-mean-square error of 0.000218 versus the database. Comparisons show that the new expression is well correlated to an alternative computationally intensive method, and it is a factor 29 to 64 improvement over prior analytic expressions. Limits of applicability of the approach for incoherent imaging are also discussed. The low-computational cost of the new method is suitable for systems performance modeling of turbulence impacts, including path-varying turbulence scenarios.

  14. Mutagenic activity of high-energy 532 nm ultra-short laser pulses.

    PubMed

    Leavitt, J; Fatone, M; Hestdalen, C; Obringer, J W; Tillinghast, H S

    1997-04-01

    The mutagenic activity of green (532 nm) and infrared (1064 nm) ultra-short laser light pulses was tested in cultured Syrian hamster fibroblasts by a hypoxanthine phosphoribosyl-transferase (HPRT) mutagenesis assay. In 18 irradiation trials, cells were exposed to eight consecutive 100-ps pulses of either 532 nm or 1064 nm light from a Nd:YAG laser at average irradiances of 3.0 GW/cm2. The 532 nm irradiations produced Hprt mutations at an average observed frequency of 5.3-5.6 x 10(-6), 10-fold higher than control trials (P < 0.01), while 1064 nm irradiations produced only background (spontaneous mutation) frequencies. A HAT (hypoxanthine, aminopterin, thymidine) sensitivity test allowed us to infer that Hprt- clones, selected as 6-thioguanine-resistant clones, possessed mutations at the Hprt locus after 532 nm Nd:YAG laser irradiation. The mutagenic effects of 532 nm high-energy laser pulses and not 1064 nm wavelengths are discussed in light of a two-photon absorption hypothesis. These preliminary findings suggest that 460-590 nm visible-light lasers may be mutagenic to mammalian cells either as a result of two-photon absorption or through some other photochemical process that damages DNA. PMID:9092930

  15. Proton acceleration from high-contrast short pulse lasers interacting with sub-micron thin foils

    NASA Astrophysics Data System (ADS)

    Petrov, G. M.; McGuffey, C.; Thomas, A. G. R.; Krushelnick, K.; Beg, F. N.

    2016-02-01

    A theoretical study complemented with published experimental data of proton acceleration from sub-micron (thickness < 1 μm) foils irradiated by ultra-high contrast ( >1010 ) short pulse lasers is presented. The underlying physics issues pertinent to proton acceleration are addressed using two-dimensional particle-in-cell simulations. For laser energy ɛ≤4 J (intensity I ≤5 ×1020 W/cm 2 ), simulation predictions agree with experimental data, both exhibiting scaling superior to Target Normal Sheath Acceleration's model. Anomalous behavior was observed for ɛ>4 J ( I >5 ×1020 W/cm 2 ), for which the measured maximum proton energies were much lower than predicted by scaling and these simulations. This unexpected behavior could not be explained within the frame of the model, and we conjecture that pre-pulses preceding the main pulse by picoseconds may be responsible. If technological issues can be resolved, energetic proton beams could be generated for a wide range of applications such as nuclear physics, radiography, and medical science.

  16. Highly heterogeneous, activated and short-lived regulatory T cells during chronic filarial infection

    PubMed Central

    Metenou, Simon; Coulibaly, Yaya I.; Sturdevant, Daniel; Dolo, Housseini; Diallo, Abdallah A.; Soumaoro, Lamine; Coulibaly, Michel E.; Kanakabandi, Kishore; Porcella, Stephen F.; Klion, Amy D.; Nutman, Thomas B.

    2016-01-01

    The mechanisms underlying the increase in the numbers of regulatory T (Treg) cells in chronic infection settings remain unclear. Here we have delineated the phenotype and transcriptional profiles of Treg cells from 18 filarial-infected (Fil+) and 19 filarial-uninfected (Fil-) subjects. We found that the frequencies of Foxp3+ Treg cells expressing CTLA-4, GITR, LAG-3 and IL-10 were significantly higher in Fil+ subjects compared with that in Fil- subjects. Foxp3-expressing Treg-cell populations in Fil+ subjects were also more heterogeneous and had higher expression of IL-10, CCL-4, IL-29, CTLA-4 and TGF-β than Fil- subjects, each of these cytokines having been implicated in immune suppression. Moreover, Foxp3-expressing Treg cells from Fil+ subjects had markedly upregulated expression of activation-induced apoptotic genes with concomitant downregulation of those involved in cell survival. To determine whether the expression of apoptotic genes was due to Treg-cell activation, we found that the expression of CTLA-4, CDk8, RAD50, TNFRSF1A, FOXO3 and RHOA were significantly upregulated in stimulated cells compared with unstimulated cells. Taken together, our results suggest that in patent filarial infection, the expanded Treg-cell populations are heterogeneous, short-lived, activated and express higher levels of molecules known to modulate immune responsiveness, suggesting that filarial infection is associated with high Treg-cell turnover. PMID:24737144

  17. High speed ultra short pulse fiber ring laser using photonic crystal fiber nonlinear optical loop mirror

    NASA Astrophysics Data System (ADS)

    Ma, Shaozhen; Li, Wenbo; Hu, Hongyu; Dutta, Niloy K.

    2012-06-01

    A scheme to generate high speed optical pulse train with ultra short pulse width is proposed and experimentally studied. Two-step compression is used in the scheme: 20 GHz and 40 GHz pulse trains generated from a rational harmonic actively mode-locked fiber ring laser is compressed to a full width at half-maximum (FWHM) of ~ 1.5 ps using adiabatic soliton compression with dispersion shifted fibers (DSF). The pulse trains then undergo a pedestal removal process by transmission through a cascaded two photonic crystal fiber (PCF)-nonlinear optical loop mirrors (NOLM) realized using a double-ring structure. The shortest output pulse width obtained was ~ 610 fs for 20 GHz pulse train and ~ 570 fs for 40 GHz pulse train. The signal to noise ratio of the RF spectrum of the output pulse train is larger than 30 dB. Theoretical simulation of the NOLM transmission is conducted using split-step Fourier method. The results show that two cascaded NOLMs can improve the compression result compared to that for a single NOLM transmission.

  18. High-speed pulsed mixing in a short distance with high-frequency switching of pumping from three inlets

    NASA Astrophysics Data System (ADS)

    Sugano, K.; Nakata, A.; Tsuchiya, T.; Tabata, O.

    2015-08-01

    In this study, we propose a mixing method using alternate pulsed flows from three inlets with flow direction control. In conventional pulsed mixing, a residual flow near the sidewalls inhibits the rapid mixing of two solutions at high switching frequency. In this study, we addressed this issue in order to perform rapid mixing in a short distance with a low Reynolds number. We fabricated a microfluidic mixing device consisting of a cross-shaped mixing channel with three inlet microchannels and three valveless micropumps. In conventional T-shaped or Y-shaped mixing channels, a residual flow is observed because of the incomplete switching of solutions. The three inlet configuration enabled us to split the residual flow at a switching frequency of pumping of up to 200 Hz, thus resulting in rapid mixing. Furthermore, by controlling the flow direction at the confluent area using the reverse flow of the micropump, the mixing speed was dramatically increased because of the complete switching of the two solutions. As a result, we achieved the mixing time of 3.6 ms and the mixing length of 20.7 µm, which were necessary to achieve a 90% mixing ratio at a high micropump switching frequency of 400 Hz and reverse flow ratio of 1/4.

  19. A High-Speed Optical Modem Communication System for CORK Seafloor Observatories

    NASA Astrophysics Data System (ADS)

    Farr, N.; Tivey, M.; Ware, J.; Pontbriand, C.; Pelletier, L. P.

    2014-12-01

    High-speed communications underwater is an increasing requirement for data intensive seafloor sensors. Acoustic modems provide dependable long-range communications underwater, but data rates are limited to <57Kbps. Free-water optical modems (OMs) offer high data rate, 10Mbps communications over a range of 200 m - a distance for ROVs, AUVs or wire-lowered packages to communicate without the need to directly plug-in or retrieve the instrument. Over the past 4 years, we have demonstrated the functionality and utility of OM technology using a CORK borehole observatory as a test case. A CORK represents all of the basic components required for a seafloor observatory: a stable environment for long-term continuous measurements of earth and ocean phenomena, access to a unique environment below the seafloor and a standard communication interface. The CORK-OM features a high-bandwidth, low-latency optical system based on LED emitters and PMT receivers and an acoustic command and control system. OM tests established a communication link from 20 to 200 meters range at rates of 1, 5 and 10 Mbps with no bit errors. The seafloor OM was plugged into the CORK's existing underwater wet mateable connector and provided additional power to the CORK to boost the data rate to 1 Hz from the normal 1 minute sample period. To communicate with the seafloor CORK-OM, a number of different modalities were used. One method was an OM mounted to a CTD frame on a lowered wire from a ship with an SDSL link over the conducting wire. Other methods utilized OMs mounted to both ROV Jason and submersible Alvin. We deployed OMs at two CORKs in 2012 in the northeast pacific at sites 857D and 1025C. The CORKs were visited in 2013 by a vessel of opportunity to download data and were put into sleep mode. The CORKs were revisited in 2014, woken up and successfully interrogated for data. ALVIN retrieved the CORK-OMs for corrosion, biofouling and battery performance assessment. We also performed tests of a next generation OM using a deployed seafloor modem and AUV Sentry. A complete lambertian optical field was quantitatively mapped by Sentry and test data was successfully downloaded from 20 to 150 m slant range. The AUV modality demonstrates the capability of 'data-mule' operations to autonomously recover data from a seafloor observatory with minimal human intervention.

  20. Short spatial filters with spherical lenses for high-power pulsed lasers

    SciTech Connect

    Burdonov, K F; Soloviev, A A; Shaikin, A A; Potemkin, A K; Egorov, A S

    2013-11-30

    We report possible employment of short spatial filters based on spherical lenses in a pulsed laser source (neodymium glass, 300 J, 1 ns). The influence of the spherical aberration on the quality of output radiation and coefficient of conversion to the second harmonics is studied. The ultra-short aberration spatial filter of length 1.9 m with an aperture of 122 mm is experimentally tested. A considerable shortening of multi-cascade pump lasers for modern petawatt laser systems is demonstrated by the employment of short spatial filters without expensive aspherical optics. (elements of laser systems)

  1. Short time interval for condensation of high-temperature silicates in the solar accretion disk.

    PubMed

    Luu, Tu-Han; Young, Edward D; Gounelle, Matthieu; Chaussidon, Marc

    2015-02-01

    Chondritic meteorites are made of primitive components that record the first steps of formation of solids in our Solar System. Chondrules are the major component of chondrites, yet little is known about their formation mechanisms and history within the solar protoplanetary disk (SPD). We use the reconstructed concentrations of short-lived (26)Al in chondrules to constrain the timing of formation of their precursors in the SPD. High-precision bulk magnesium isotopic measurements of 14 chondrules from the Allende chondrite define a (26)Al isochron with (26)Al/(27)Al = 1.2(±0.2) × 10(-5) for this subset of Allende chondrules. This can be considered to be the minimum bulk chondrule (26)Al isochron because all chondrules analyzed so far with high precision (∼50 chondrules from CV and ordinary chondrites) have an inferred minimum bulk initial ((26)Al/(27)Al) ≥ 1.2 × 10(-5). In addition, mineral (26)Al isochrons determined on the same chondrules show that their formation (i.e., fusion of their precursors by energetic events) took place from 0 Myr to ∼2 Myr after the formation of their precursors, thus showing in some cases a clear decoupling in time between the two events. The finding of a minimum bulk chondrule (26)Al isochron is used to constrain the astrophysical settings for chondrule formation. Either the temperature of the condensation zone dropped below the condensation temperature of chondrule precursors at ∼1.5 My after the start of the Solar System or the transport of precursors from the condensation zone to potential storage sites stopped after 1.5 My, possibly due to a drop in the disk accretion rate. PMID:25605942

  2. Autonomic Function Predicts Fitness Response to Short-Term High-Intensity Interval Training.

    PubMed

    Kiviniemi, A M; Tulppo, M P; Eskelinen, J J; Savolainen, A M; Kapanen, J; Heinonen, I H A; Hautala, A J; Hannukainen, J C; Kalliokoski, K K

    2015-11-01

    We tested the hypothesis that baseline cardiac autonomic function and its acute response to all-out interval exercise explains individual fitness responses to high-intensity interval training (HIT). Healthy middle-aged sedentary men performed HIT (n=12, 4-6×30 s of all-out cycling efforts with 4-min recovery) or aerobic training (AET, n=9, 40-60 min at 60% of peak workload in exercise test [Loadpeak]), comprising 6 sessions within 2 weeks. Low (LF) and high frequency (HF) power of R-R interval oscillation were analyzed from data recorded at supine and standing position (5+5 min) every morning during the intervention. A significant training effect (p< 0.001), without a training*group interaction, was observed in Loadpeak and peak oxygen consumption (VO2peak). Pre-training supine LF/HF ratio, an estimate of sympathovagal balance, correlated with training outcome in Loadpeak (Spearman's rho [rs]=-0.74, p=0.006) and VO2peak (rs=- 0.59, p=0.042) in the HIT but not the AET group. Also, the mean change in the standing LF/HF ratio in the morning after an acute HIT exercise during the 1(st) week of intervention correlated with training response in Loadpeak (rs=- 0.68, p=0.014) and VO2peak (rs=-0.60, p=0.039) with HIT but not with AET. In conclusion, pre-training cardiac sympathovagal balance and its initial alterations in response to acute HIT exercise were related to fitness responses to short-term HIT. PMID:26140689

  3. Short time interval for condensation of high-temperature silicates in the solar accretion disk

    PubMed Central

    Luu, Tu-Han; Young, Edward D.; Gounelle, Matthieu; Chaussidon, Marc

    2015-01-01

    Chondritic meteorites are made of primitive components that record the first steps of formation of solids in our Solar System. Chondrules are the major component of chondrites, yet little is known about their formation mechanisms and history within the solar protoplanetary disk (SPD). We use the reconstructed concentrations of short-lived 26Al in chondrules to constrain the timing of formation of their precursors in the SPD. High-precision bulk magnesium isotopic measurements of 14 chondrules from the Allende chondrite define a 26Al isochron with 26Al/27Al = 1.2(±0.2) × 10−5 for this subset of Allende chondrules. This can be considered to be the minimum bulk chondrule 26Al isochron because all chondrules analyzed so far with high precision (∼50 chondrules from CV and ordinary chondrites) have an inferred minimum bulk initial (26Al/27Al) ≥ 1.2 × 10−5. In addition, mineral 26Al isochrons determined on the same chondrules show that their formation (i.e., fusion of their precursors by energetic events) took place from 0 Myr to ∼2 Myr after the formation of their precursors, thus showing in some cases a clear decoupling in time between the two events. The finding of a minimum bulk chondrule 26Al isochron is used to constrain the astrophysical settings for chondrule formation. Either the temperature of the condensation zone dropped below the condensation temperature of chondrule precursors at ∼1.5 My after the start of the Solar System or the transport of precursors from the condensation zone to potential storage sites stopped after 1.5 My, possibly due to a drop in the disk accretion rate. PMID:25605942

  4. The Lunar Laser Communication Demonstration: NASA's First Step Toward Very High Data Rate Support of Science and Exploration Missions

    NASA Astrophysics Data System (ADS)

    Boroson, Don M.; Robinson, Bryan S.

    2014-12-01

    Future NASA missions for both Science and Exploration will have needs for much higher data rates than are presently available, even with NASA's highly-capable Space- and Deep-Space Networks. As a first step towards this end, for one month in late 2013, NASA's Lunar Laser Communication Demonstration (LLCD) successfully demonstrated for the first time high-rate duplex laser communications between a satellite in lunar orbit, the Lunar Atmosphere and Dust Environment Explorer (LADEE), and multiple ground stations on the Earth. It constituted the longest-range laser communication link ever built and demonstrated the highest communication data rates ever achieved to or from the Moon.

  5. Consensus Statement for the Management and Communication of High Risk Laboratory Results.

    PubMed

    Campbell, Craig; Caldwell, Grahame; Coates, Penelope; Flatman, Robert; Georgiou, Andrew; Horvath, Andrea Rita; Lam, Que; Schneider, Hans

    2015-08-01

    Ineffective test follow-up is a major source of harm for patients around the world. Unreliable communication from medical laboratories (henceforth termed 'laboratories') to clinicians of results that represent critical or significant risk to patients (collectively termed 'high risk results') is a contributing factor to this problem. Throughout Australasia, management practices for such results vary considerably. The recommendations presented in this document are based on best practice derived from the published literature and follow consultation with a wide range of stakeholders. These recommendations were created to harmonise Australasian practices by guiding laboratories in the design and implementation of safe and effective communication procedures for managing high risk results which require timely notification. PMID:26900189

  6. Consensus Statement for the Management and Communication of High Risk Laboratory Results

    PubMed Central

    Campbell, Craig; Caldwell, Grahame; Coates, Penelope; Flatman, Robert; Georgiou, Andrew; Horvath, Andrea Rita; Lam, Que; Schneider, Hans

    2015-01-01

    Ineffective test follow-up is a major source of harm for patients around the world. Unreliable communication from medical laboratories (henceforth termed ‘laboratories’) to clinicians of results that represent critical or significant risk to patients (collectively termed ‘high risk results’) is a contributing factor to this problem. Throughout Australasia, management practices for such results vary considerably. The recommendations presented in this document are based on best practice derived from the published literature and follow consultation with a wide range of stakeholders. These recommendations were created to harmonise Australasian practices by guiding laboratories in the design and implementation of safe and effective communication procedures for managing high risk results which require timely notification. PMID:26900189

  7. ScalaTrace: Scalable Compression and Replay of Communication Traces for High Performance Computing

    SciTech Connect

    Noeth, M; Ratn, P; Mueller, F; Schulz, M; de Supinski, B R

    2008-05-16

    Characterizing the communication behavior of large-scale applications is a difficult and costly task due to code/system complexity and long execution times. While many tools to study this behavior have been developed, these approaches either aggregate information in a lossy way through high-level statistics or produce huge trace files that are hard to handle. We contribute an approach that provides orders of magnitude smaller, if not near-constant size, communication traces regardless of the number of nodes while preserving structural information. We introduce intra- and inter-node compression techniques of MPI events that are capable of extracting an application's communication structure. We further present a replay mechanism for the traces generated by our approach and discuss results of our implementation for BlueGene/L. Given this novel capability, we discuss its impact on communication tuning and beyond. To the best of our knowledge, such a concise representation of MPI traces in a scalable manner combined with deterministic MPI call replay are without any precedent.

  8. High Precision Ranging and Range-Rate Measurements over Free-Space-Laser Communication Link

    NASA Technical Reports Server (NTRS)

    Yang, Guangning; Lu, Wei; Krainak, Michael; Sun, Xiaoli

    2016-01-01

    We present a high-precision ranging and range-rate measurement system via an optical-ranging or combined ranging-communication link. A complete bench-top optical communication system was built. It included a ground terminal and a space terminal. Ranging and range rate tests were conducted in two configurations. In the communication configuration with 622 data rate, we achieved a two-way range-rate error of 2 microns/s, or a modified Allan deviation of 9 x 10 (exp -15) with 10 second averaging time. Ranging and range-rate as a function of Bit Error Rate of the communication link is reported. They are not sensitive to the link error rate. In the single-frequency amplitude modulation mode, we report a two-way range rate error of 0.8 microns/s, or a modified Allan deviation of 2.6 x 10 (exp -15) with 10 second averaging time. We identified the major noise sources in the current system as the transmitter modulation injected noise and receiver electronics generated noise. A new improved system will be constructed to further improve the system performance for both operating modes.

  9. Short-term assessment of BCR repertoires of SLE patients after high dose glucocorticoid therapy with high-throughput sequencing.

    PubMed

    Shi, Bin; Yu, Jiang; Ma, Long; Ma, Qingqing; Liu, Chunmei; Sun, Suhong; Ma, Rui; Yao, Xinsheng

    2016-01-01

    We analyze and assess BCR repertoires of SLE patients before and after high dose glucocorticoid therapy to address two fundamental questions: (1) After the treatment, how the BCR repertoire of SLE patient change on the clone level? (2) How to screen putative autoantibody clone set from BCR repertoire of SLE patients? The PBMCs of two SLE patients (P1 and P2) at different time points were collected, and DNA of these samples were extracted. High-throughput sequencing technology was applied in detection of BCR repertoire. Finally, we used bioinformatic methodology to analyse sequence data. We found that these two patients lost some IGHV3 family genes usage after treatment compared with before treatment. For pairing of IGHV-IGHJ gene, no significant change was shown for each patient. In addition, analyses of the composition of H-CDR3 showed overall AA compositions of H-CDR3 at three time points in each SLE patients were very similar, and the results of H-CDR3 AA usage that had the same length (14 AA) and the same position were similar. Antinuclear antibody tests of SLE patients showed that level of some antinuclear antibodies reduced after treatment; however, there was no sign that the percentage of autoantibody clones in BCR repertoires would reduce. High dose glucocorticoid treatment in short term will have little impact on composition of BCR repertoire of SLE patient. Treatment can reduce the amount of autoantibody in the protein level, but may not reduce the percentage of autoantibody clones in BCR repertoire in the clonal level. PMID:26844022

  10. Highly optimized fourth-order short-time approximation for pathintegrals

    SciTech Connect

    Predescu, Cristian

    2006-10-01

    We derive a fourth-order short-time approximation for use in imaginary-time path-integral simulations. The short-time approximation converges for all continuous and bounded from below potentials, attains quartic order of convergence for sufficiently smooth potentials, and utilizes statistically independent random variables for its construction. These properties recommend the approximation as a natural replacement of the trapezoidal Trotter-Suzuki approximation for physical systems with continuous distributions.

  11. Verification & Validation of High-Order Short-Characteristics-Based Deterministic Transport Methodology on Unstructured Grids

    SciTech Connect

    Azmy, Yousry; Wang, Yaqi

    2013-12-20

    The research team has developed a practical, high-order, discrete-ordinates, short characteristics neutron transport code for three-dimensional configurations represented on unstructured tetrahedral grids that can be used for realistic reactor physics applications at both the assembly and core levels. This project will perform a comprehensive verification and validation of this new computational tool against both a continuous-energy Monte Carlo simulation (e.g. MCNP) and experimentally measured data, an essential prerequisite for its deployment in reactor core modeling. Verification is divided into three phases. The team will first conduct spatial mesh and expansion order refinement studies to monitor convergence of the numerical solution to reference solutions. This is quantified by convergence rates that are based on integral error norms computed from the cell-by-cell difference between the code’s numerical solution and its reference counterpart. The latter is either analytic or very fine- mesh numerical solutions from independent computational tools. For the second phase, the team will create a suite of code-independent benchmark configurations to enable testing the theoretical order of accuracy of any particular discretization of the discrete ordinates approximation of the transport equation. For each tested case (i.e. mesh and spatial approximation order), researchers will execute the code and compare the resulting numerical solution to the exact solution on a per cell basis to determine the distribution of the numerical error. The final activity comprises a comparison to continuous-energy Monte Carlo solutions for zero-power critical configuration measurements at Idaho National Laboratory’s Advanced Test Reactor (ATR). Results of this comparison will allow the investigators to distinguish between modeling errors and the above-listed discretization errors introduced by the deterministic method, and to separate the sources of uncertainty.

  12. Enhancing Short-Term Recovery After High-Intensity Anaerobic Exercise.

    PubMed

    Al-Nawaiseh, Ali M; Pritchett, Robert C; Bishop, Philip A

    2016-02-01

    This study examined the effects of antioxidant vitamins, ibuprofen, cold water submersion, and whey protein administered simultaneously on short-term recovery. Competitive athletes (n = 22) performed the protocol in 2 occasions (treatment and control) separated by 15 days in counterbalanced crossover design. Each occasion consisted of morning and afternoon sessions (AM and PM). In each session, participants performed 2 bouts of high-intensity anaerobic cycling separated by 30 minutes of rest. Each bout consisted of 3 Wingate tests (3 × 30-second Wingate tests) with 3 minutes of active recovery in between. Power output, rated perceived exertion (RPE), and pain scores were averaged and compared between the 2 sessions (AM vs. PM) and between the treatment vs. control (4 bouts). Creatine kinase (CK) levels were also measured 24 hours after the AM bout. Power output, CK, muscle soreness, and RPE were measured as recovery indices. Creatine kinase increased (p < 0.001) in both treatment and control 24 hours after the AM session. Performance results in the PM session for treatment/control were 832.5 ± 198.7/813.3 ± 187.6 W for peak power (PP), and 497.85 ± 120.7/486.1 ± 115 W for mean power (MP). Treatment was effective in maintaining MP (p = 0.034) in the PM sessions, but there was no significant effect of treatment on PP (p = 0.193), CK (p = 0.08), pain (p = 0.12), or RPE (p = 0.45). Treatment was helpful in protecting performance, but this was apparently not due to reduced muscle soreness or damage. PMID:26815173

  13. Short range structure of hadron and nuclear wave functions at high x

    SciTech Connect

    Hoyer, P.; Brodsky, S.J.

    1990-11-01

    We discuss the short-range structure of hadronic and nuclear wave functions expected in QCD. In addition to the extrinsic'' contributions associated with radiation from single partons, there is an intrinsic'' hardness of the high-mass fluctuations of the wave function due to the spatial overlap of two or more partons. We argue that intrinsically-hard partons, having large mass and/or large transverse momentum, will dominate in the region of large Feynman x{sub F}. Their rescattering in nuclear targets is expected to be larger than for extrinsically-hard partons, leading to a suppressed production cross section for hadrons scattering on heavy nuclei. Experimental evidence for this exists for open chars. J/{psi}, and {gamma} production at large x{sub F}. The effects of intrinsic hardness may be particularly striking in nuclear wave functions, where the overlap of partons belonging to different nucleons can give rise to cumulative (x > 1) phenomena. The data on backward cumulative particle production from nuclei supports the existence of an intrinsically-hard component in nuclear wave functions. Partons at large x{sub F} may also be associated with the enhanced subthreshold production of particles observed in hadron-nucleus and nucleus-nucleus collisions. We discuss the evidence for anomalies in the large angle pp {yields} pp cross section near the charm threshold. Arguments are presented that chromium states may bind to nuclei through the QCD Van der Waals force. This would lead to a striking signal in charm production near threshold. 49 refs., 7 figs.

  14. Starbursts and high-redshift galaxies are radioactive: high abundances of 26Al and other short-lived radionuclides

    NASA Astrophysics Data System (ADS)

    Lacki, Brian C.

    2014-06-01

    Short-lived radionuclides (SLRs) like 26Al are synthesized by massive stars and are a byproduct of star formation. The abundances of SLRs in the gas of a star-forming galaxy are inversely proportional to the gas consumption time. The rapid evolution of specific star formation rate (SSFR) of normal galaxies implies they had mean SLR abundances 3-10 times higher at z = 2. During the epoch of Solar system formation, the background SLR abundances of the Galaxy were up to twice as high as at present, if SLR yields from massive stars do not depend on metallicity. If SLRs are homogenized in the gas of galaxies, the high SSFRs of normal galaxies can partly explain the elevated abundance of SLRs like 60Fe and 26Al in the early Solar system. Starburst galaxies have much higher SSFRs still, and have enormous mean abundances of 26Al (26Al/27Al ?10-3 for solar metallicity gas). The main uncertainty is whether the SLRs are mixed with the star-forming molecular gas: they could be trapped in hot gas and decay before entering the colder phases, or be blown out by starburst winds. I consider how variability in star formation rate affects the SLR abundances, and I discuss how SLR transport may differ in these galaxies. The enhanced 26Al of starbursts might maintain moderate ionization rates (10-18-10-17 s-1), possibly dominating ionization in dense clouds not penetrated by cosmic rays. Similar ionization rates would be maintained in protoplanetary discs of starbursts, if the SLRs are well mixed, and the radiogenic heating of planetesimals would likewise be much higher. In this way, galaxy evolution can affect the geological history of planetary systems.

  15. Development of data communication system with ultra high frequency radio wave for implantable artificial hearts.

    PubMed

    Tsujimura, Shinichi; Yamagishi, Hiroto; Sankai, Yoshiyuki

    2009-01-01

    In order to minimize infection risks of patients with artificial hearts, wireless data transmission methods with electromagnetic induction or light have been developed. However, these methods tend to become difficult to transmit data if the external data transmission unit moves from its proper position. To resolve this serious problem, the purpose of this study is to develop a prototype wireless data communication system with ultra high frequency radio wave and confirm its performance. Due to its high-speed communication rate, low power consumption, high tolerance to electromagnetic disturbances, and secure wireless communication, we adopted Bluetooth radio wave technology for our system. The system consists of an internal data transmission unit and an external data transmission unit (53 by 64 by 16 mm, each), and each has a Bluetooth module (radio field intensity: 4 dBm, receiver sensitivity: -80 dBm). The internal unit also has a micro controller with an 8-channel 10-bit A/D converter, and the external unit also has a RS-232C converter. We experimented with the internal unit implanted into pig meat, and carried out data transmission tests to evaluate the performance of this system in tissue thickness of up to 3 mm. As a result, data transfer speeds of about 20 kbps were achieved within the communication distance of 10 m. In conclusion, we confirmed that the system can wirelessly transmit the data from the inside of the body to the outside, and it promises to resolve unstable data transmission due to accidental movements of an external data transmission unit. PMID:19964616

  16. NASA high performance computing, communications, image processing, and data visualization-potential applications to medicine.

    PubMed

    Kukkonen, C A

    1995-06-01

    High-speed information processing technologies being developed and applied by the Jet Propulsion Laboratory for NASA and Department of Defense mission needs have potential dual-uses in telemedicine and other medical applications. Fiber optic ground networks connected with microwave satellite links allow NASA to communicate with its astronauts in Earth orbit or on the moon, and with its deep space probes billions of miles away. These networks monitor the health of astronauts and or robotic spacecraft. Similar communications technology will also allow patients to communicate with doctors anywhere on Earth. NASA space missions have science as a major objective. Science sensors have become so sophisticated that they can take more data than our scientists can analyze by hand. High performance computers--workstations, supercomputer and massively parallel computers are being used to transform this data into knowledge. This is done using image processing, data visualization and other techniques to present the data--one's and zero's in forms that a human analyst can readily relate to and understand. Medical sensors have also explored in the in data output--witness CT scans, MRI, and ultrasound. This data must be presented in visual form and computers will allow routine combination of many two dimensional MRI images into three dimensional reconstructions of organs that then can be fully examined by physicians. Emerging technologies such as neural networks that are being "trained" to detect craters on planets or incoming missiles amongst decoys can be used to identify microcalcification in mammograms. PMID:7643022

  17. Incorporating risk communication into highly pathogenic avian influenza preparedness and response efforts.

    PubMed

    Voss, Shauna J; Malladi, Sasidhar; Sampedro, Fernando; Snider, Tim; Goldsmith, Timothy; Hueston, William D; Lauer, Dale C; Halvorson, David A

    2012-12-01

    A highly pathogenic avian influenza (HPAI) outbreak in the United States will initiate a federal emergency response effort that will consist of disease control and eradication efforts, including quarantine and movement control measures. These movement control measures will not only apply to live animals but also to animal products. However, with current egg industry "just-in-time" production practices, limited storage is available to hold eggs. As a result, stop movement orders can have significant unintended negative consequences, including severe disruptions to the food supply chain. Because stakeholders' perceptions of risk vary, waiting to initiate communication efforts until an HPAI event occurs can hinder disease control efforts, including the willingness of producers to comply with the response, and also can affect consumers' demand for the product. A public-private-academic partnership was formed to assess actual risks involved in the movement of egg industry products during an HPAI event through product specific, proactive risk assessments. The risk analysis process engaged a broad representation of stakeholders and promoted effective risk management and communication strategies before an HPAI outbreak event. This multidisciplinary team used the risk assessments in the development of the United States Department of Agriculture, Highly Pathogenic Avian Influenza Secure Egg Supply Plan, a comprehensive response plan that strives to maintain continuity of business. The collaborative approach that was used demonstrates how a proactive risk communication strategy that involves many different stakeholders can be valuable in the development of a foreign animal disease response plan and build working relationships, trust, and understanding. PMID:23402134

  18. In-situ short-circuit protection system and method for high-energy electrochemical cells

    DOEpatents

    Gauthier, Michel; Domroese, Michael K.; Hoffman, Joseph A.; Lindeman, David D.; Noel, Joseph-Robert-Gaetan; Radewald, Vern E.; Rouillard, Jean; Rouillard, Roger; Shiota, Toshimi; Trice, Jennifer L.

    2003-04-15

    An in-situ thermal management system for an energy storage device. The energy storage device includes a plurality of energy storage cells each being coupled in parallel to common positive and negative connections. Each of the energy storage cells, in accordance with the cell's technology, dimensions, and thermal/electrical properties, is configured to have a ratio of energy content-to-contact surface area such that thermal energy produced by a short-circuit in a particular cell is conducted to a cell adjacent the particular cell so as to prevent the temperature of the particular cell from exceeding a breakdown temperature. In one embodiment, a fuse is coupled in series with each of a number of energy storage cells. The fuses are activated by a current spike capacitively produced by a cell upon occurrence of a short-circuit in the cell, thereby electrically isolating the short-circuited cell from the common positive and negative connections.

  19. In-situ short circuit protection system and method for high-energy electrochemical cells

    DOEpatents

    Gauthier, Michel; Domroese, Michael K.; Hoffman, Joseph A.; Lindeman, David D.; Noel, Joseph-Robert-Gaetan; Radewald, Vern E.; Rouillard, Jean; Rouillard, Roger; Shiota, Toshimi; Trice, Jennifer L.

    2000-01-01

    An in-situ thermal management system for an energy storage device. The energy storage device includes a plurality of energy storage cells each being coupled in parallel to common positive and negative connections. Each of the energy storage cells, in accordance with the cell's technology, dimensions, and thermal/electrical properties, is configured to have a ratio of energy content-to-contact surface area such that thermal energy produced by a short-circuit in a particular cell is conducted to a cell adjacent the particular cell so as to prevent the temperature of the particular cell from exceeding a breakdown temperature. In one embodiment, a fuse is coupled in series with each of a number of energy storage cells. The fuses are activated by a current spike capacitively produced by a cell upon occurrence of a short-circuit in the cell, thereby electrically isolating the short-circuited cell from the common positive and negative connections.

  20. Performance analysis of communication links based on VCSEL and silicon photonics technology for high-capacity data-intensive scenario.

    PubMed

    Boletti, A; Boffi, P; Martelli, P; Ferrario, M; Martinelli, M

    2015-01-26

    To face the increased demand for bandwidth, cost-effectiveness and simplicity of future Ethernet data communications, a comparison between two different solutions based on directly-modulated VCSEL sources and Silicon Photonics technologies is carried out. Also by exploiting 4-PAM modulation, the transmission of 50-Gb/s and beyond capacity per channel is analyzed by means of BER performance. Applications for optical backplane, very short reach and in case of client-optics networks and intra and inter massive data centers communications (up to 10 km) are taken into account. A comparative analysis based on the power consumption is also proposed. PMID:25835935

  1. Lottery games and risky technologies: communications about low-probability/high-consequence events

    SciTech Connect

    Mumpower, J.L.

    1988-06-01

    There are strong structural similarities between risks from technological hazards and big-purse state lottery games. Risks from technological hazards are often described as low-probability, high-consequence negative events. State lotteries could be equally well characterized as low-probability, high-consequence positive events. Typical communications about state lotteries provide a virtual strategic textbook for opponents of risky technologies. The same techniques can be used to sell lottery tickets or sell opposition to risky technologies. Eight basic principles are enumerated.

  2. Highly Efficient Nd:yag Lasers for Free-space Optical Communications

    NASA Technical Reports Server (NTRS)

    Sipes, D. L., Jr.

    1985-01-01

    A highly efficient Nd:YAG laser end-pumped by semiconductor lasers as a possible free-space optical communications source is discussed. Because this concept affords high pumping densities, a long absorption length, and excellent mode-matching characteristics, it is estimated that electrical-to-optical efficiencies greater than 5% could be achieved. Several engineering aspects such as resonator size and configuration, pump collecting optics, and thermal effects are also discussed. Finally, possible methods for combining laser-diode pumps to achieve higher output powers are illustrated.

  3. Novel optical cryptography using PANDA ring resonator for highly secured communication

    NASA Astrophysics Data System (ADS)

    Putthacharoen, Rattipong; Juleang, Pakorn; Mitatha, Somsak; Yupapin, Preecha P.

    2011-07-01

    We propose a novel method of an optical cryptography using the dark-bright soliton conversion control in a modified add/drop optical filter. By using the control arrangement, the obtained outputs of the dynamic states of dark-bright soliton can be used to form the key suppression for communication security application, in which the key recovery can be obtained by controlling the add/drop filter outputs. The optical cryptography consists of an add/drop filter which is used to generate the encryption and decryption keys from the optical keys (LIP signals). A Mach-Zehnder interferometer is used for multiplexing and de-multiplexing operations. Simulation results obtained shows, that the proposed system can be used to form a high security communication system.

  4. High speed QPPM direct detection optical communication receivers for FSDD intersatellite links

    NASA Technical Reports Server (NTRS)

    Davidson, Frederic M.; Sun, Xiaoli

    1993-01-01

    This final report consists of four separate reports, one for each project involved in this contract. The first report is entitled '325 Mbps QPPM (quaternary pulse position modulation) Direct Detection Free Space Optical Communication Encoder and Receiver,' which was our primary work. The second report is entitled 'Test Results of the 325 Mbps QPPM High Speed Data Transmission GaAs ASICs,' which describes our work in connection with Galaxy Microsystems, Inc. who produced these ASICs for NASA. The third report, 'Receiver Performance Analysis of BPPM Optical Communication Systems Using 1.3 micron Wavelength Transmitter and InGaAs PIN Photodiodes,' was prepared at the request of the NASA/Photonics Branch for their efforts in upgrading the 1773 optical fiber data bus. The fourth report, 'Photomultiplier Tubes for Use at 1.064 micron Wavelength,' was also prepared at the request of the NASA/Photonics Branch as a research project.

  5. An Examination of the Structure of the Career Decision Self-Efficacy Scale (Short Form) among Italian High School Students

    ERIC Educational Resources Information Center

    Presti, Alessandro Lo; Pace, Francesco; Mondo, Marina; Nota, Laura; Casarubia, Provvidenza; Ferrari, Lea; Betz, Nancy E.

    2013-01-01

    This study aims to evaluate the factor structure of Career Decision Self-Efficacy scale-short form in a sample of Italian high school adolescents. confirmatory factor analysis (CFA) was used to test the degree to which a one-factor structure and a five-factor structure provided the best fit. In view of available research the five-factor structure…

  6. Optical short pulse generation at high repetition rate over 80 GHz from a monolithic passively modelocked DBR laser diode

    NASA Astrophysics Data System (ADS)

    Arahira, S.; Matsui, Y.; Kunii, T.; Oshiba, S.; Ogawa, Y.

    1993-05-01

    Optical short pulses at high repetition rate over 80 GHz were successfully generated using a monolithically fabricated passively modelocked distributed Bragg reflector laser diode for the first time. By using linear fibre compression, a transform-limited optical pulse train with a duration of 2.7 ps was obtained. The pulse envelope closely matched a sech(sup 2) waveform.

  7. Large-amplitude plasma wave generation with a high-intensity short-pulse beat wave.

    PubMed

    Walton, B; Najmudin, Z; Wei, M S; Marle, C; Kingham, R J; Krushelnick, K; Dangor, A E; Clarke, R J; Poulter, M J; Hernandez-Gomez, C; Hawkes, S; Neely, D; Collier, J L; Danson, C N; Fritzler, S; Malka, V

    2002-12-15

    A short-pulse laser beat wave scheme for advanced particle accelerator applications is examined. A short, intense (3-ps, >10(18)-W cm(-2)) two-frequency laser pulse is produced by use of a modified chirped-pulse amplification scheme and is shown to produce relativistic plasma waves during interactions with low-density plasmas. The generation of plasma waves was observed by measurement of forward Raman scattering. Resonance was found to occur at an electron density many times that expected, owing to ponderomotive displacement of plasma within the focal region. PMID:18033483

  8. Quality of Communication Life in Adolescents with High-Functioning Autism and Asperger Syndrome: A Feasibility Study

    ERIC Educational Resources Information Center

    Burgess, Sloane; Turkstra, Lyn S.

    2010-01-01

    Purpose: This study was designed to evaluate the feasibility of using the American Speech-Language-Hearing Association's Quality of Communication Life Scale (QCL; Paul et al., 2004) for a group of individuals with developmental communication disorders--adolescents with high-functioning autism/Asperger syndrome (HFA/AS). Perceptions of quality of…

  9. The Relative Importance of Selected Communication Skills for Adolescents' Interactions with Their Teachers: High School Teachers' Opinions.

    ERIC Educational Resources Information Center

    Reed, Vicki A.; Spicer, Lynette

    2003-01-01

    High school teachers (n=143) ranked 14 communication skills according to the perceived order of importance for Grade 10 adolescents' communication with them as teachers. Teachers tended to perceive skills associated with discourse management strategies as relatively more important than other skills. Science teachers ranked turn taking higher than…

  10. Method of high speed flow field influence and restrain on laser communication

    NASA Astrophysics Data System (ADS)

    Meng, Li-xin; Wang, Chun-hui; Qian, Cun-zhu; Wang, Shuo; Zhang, Li-zhong

    2013-08-01

    For laser communication performance which carried by airplane or airship, due to high-speed platform movement, the air has two influences in platform and laser communication terminal window. The first influence is that aerodynamic effect causes the deformation of the optical window; the second one is that a shock wave and boundary layer would be generated. For subsonic within the aircraft, the boundary layer is the main influence. The presence of a boundary layer could change the air density and the temperature of the optical window, which causes the light deflection and received beam spot flicker. Ultimately, the energy hunting of the beam spot which reaches receiving side increases, so that the error rate increases. In this paper, aerodynamic theory is used in analyzing the influence of the optical window deformation due to high speed air. Aero-optics theory is used to analyze the influence of the boundary layer in laser communication link. Based on this, we focused on working on exploring in aerodynamic and aero-optical effect suppression method in the perspective of the optical window design. Based on planning experimental aircraft types and equipment installation location, we optimized the design parameters of the shape and thickness of the optical window, the shape and size of air-management kit. Finally, deformation of the optical window and air flow distribution were simulated by fluid simulation software in the different mach and different altitude fly condition. The simulation results showed that the optical window can inhibit the aerodynamic influence after optimization. In addition, the boundary layer is smoothed; the turbulence influence is reduced, which meets the requirements of the airborne laser communication.

  11. An Ultra-High Discrimination Y Chromosome Short Tandem Repeat Multiplex DNA Typing System

    PubMed Central

    Hanson, Erin K.; Ballantyne, Jack

    2007-01-01

    In forensic casework, Y chromosome short tandem repeat markers (Y-STRs) are often used to identify a male donor DNA profile in the presence of excess quantities of female DNA, such as is found in many sexual assault investigations. Commercially available Y-STR multiplexes incorporating 12–17 loci are currently used in forensic casework (Promega's PowerPlex® Y and Applied Biosystems' AmpFlSTR® Yfiler®). Despite the robustness of these commercial multiplex Y-STR systems and the ability to discriminate two male individuals in most cases, the coincidence match probabilities between unrelated males are modest compared with the standard set of autosomal STR markers. Hence there is still a need to develop new multiplex systems to supplement these for those cases where additional discriminatory power is desired or where there is a coincidental Y-STR match between potential male participants. Over 400 Y-STR loci have been identified on the Y chromosome. While these have the potential to increase the discrimination potential afforded by the commercially available kits, many have not been well characterized. In the present work, 91 loci were tested for their relative ability to increase the discrimination potential of the commonly used ‘core’ Y-STR loci. The result of this extensive evaluation was the development of an ultra high discrimination (UHD) multiplex DNA typing system that allows for the robust co-amplification of 14 non-core Y-STR loci. Population studies with a mixed African American and American Caucasian sample set (n = 572) indicated that the overall discriminatory potential of the UHD multiplex was superior to all commercial kits tested. The combined use of the UHD multiplex and the Applied Biosystems' AmpFlSTR® Yfiler® kit resulted in 100% discrimination of all individuals within the sample set, which presages its potential to maximally augment currently available forensic casework markers. It could also find applications in human evolutionary genetics and genetic genealogy. PMID:17668066

  12. Study of short haul high-density V/STOL transportation systems. Volume 2: Appendices

    NASA Technical Reports Server (NTRS)

    Solomon, H. L.

    1972-01-01

    Essential supporting data to the short haul transportation study are presented. The specific appendices are arena characteristics, aerospace transportation analysis computer program, economics, model calibration, STOLport siting and services path selection, STOL schedule definition, tabulated California corridor results, and tabulated Midwest arena results.

  13. Means and method for characterizing high power, ultra short laser pulses in a real time, on line manner

    DOEpatents

    Veligdan, James T.

    1994-01-01

    An ultra short (<10 ps), high power laser pulse is temporally characterized by a system that uses a physical measurement of a wavefront that has been altered in a known manner. The system includes a first reflection switch to remove a portion of a pulse from a beam of pulses, then includes a second reflection switch, operating in a mode that is opposite to the first reflection switch, to slice off a portion of that removed portion. The sliced portion is then directed to a measuring device for physical measurement. The two reflection switches are arranged with respect to each other and with respect to the beam of ultra short pulses such that physical measurement of the sliced portion is related to the temporal measurement of the ultra short pulse by a geometric or trigonometric relationship. The reflection switches are operated by a control pulse that is directed to impinge on each of the reflection switches at a 90.degree. angle of incidence.

  14. Calibration of the effective spring constant of ultra-short cantilevers for a high-speed atomic force microscope

    NASA Astrophysics Data System (ADS)

    Song, Yun-Peng; Wu, Sen; Xu, Lin-Yan; Zhang, Jun-Ming; Dorantes-Gonzalez, Dante J.; Fu, Xing; Hu, Xiao-Dong

    2015-06-01

    Ultra-short cantilevers are a new type of cantilever designed for the next generation of high-speed atomic force microscope (HS-AFM). Ultra-short cantilevers have smaller dimensions and higher resonant frequency than conventional AFM cantilevers. Moreover, their geometry may also be different from the conventional beam-shape or V-shape. These changes increase the difficulty of determining the spring constant for ultra-short cantilevers, and hence limit the accuracy and precision of force measurement based on a HS-AFM. This paper presents an experimental method to calibrate the effective spring constant of ultra-short cantilevers. By using a home-made AFM head, the cantilever is bent against an electromagnetic compensation balance under servo control. Meanwhile the bending force and the cantilever deflection are synchronously measured by the balance and the optical lever in the AFM head, respectively. Then the effective spring constant is simply determined as the ratio of the force to the corresponding deflection. Four ultra-short trapezoid shape cantilevers were calibrated using this method. A quantitative uncertainty analysis showed that the combined relative standard uncertainty of the calibration result is less than 2%, which is better than the uncertainty of any previously reported techniques.

  15. A highly reliable, autonomous data communication subsystem for an advanced information processing system

    NASA Technical Reports Server (NTRS)

    Nagle, Gail; Masotto, Thomas; Alger, Linda

    1990-01-01

    The need to meet the stringent performance and reliability requirements of advanced avionics systems has frequently led to implementations which are tailored to a specific application and are therefore difficult to modify or extend. Furthermore, many integrated flight critical systems are input/output intensive. By using a design methodology which customizes the input/output mechanism for each new application, the cost of implementing new systems becomes prohibitively expensive. One solution to this dilemma is to design computer systems and input/output subsystems which are general purpose, but which can be easily configured to support the needs of a specific application. The Advanced Information Processing System (AIPS), currently under development has these characteristics. The design and implementation of the prototype I/O communication system for AIPS is described. AIPS addresses reliability issues related to data communications by the use of reconfigurable I/O networks. When a fault or damage event occurs, communication is restored to functioning parts of the network and the failed or damage components are isolated. Performance issues are addressed by using a parallelized computer architecture which decouples Input/Output (I/O) redundancy management and I/O processing from the computational stream of an application. The autonomous nature of the system derives from the highly automated and independent manner in which I/O transactions are conducted for the application as well as from the fact that the hardware redundancy management is entirely transparent to the application.

  16. High Current Responsivity and Wide Modulation Bandwidth Terahertz Detector Using High-Electron-Mobility Transistor for Wireless Communication

    NASA Astrophysics Data System (ADS)

    Suzuki, S.; Nukariya, T.; Ueda, Y.; Otsuka, T.; Asada, M.

    2016-03-01

    A high-current-responsivity terahertz (THz) detector was fabricated using a broadband bow-tie antenna and an InAlAs/InGaAs high-electron-mobility transistor (HEMT) with a short gate length. High-current responsivity can be achieved by using a short gate length; the resulting high transconductance exhibited ballistic transport in the channel. We fabricated the HEMT detector with a 50-nm-long channel; the transconductance was 1.2 S/mm and the subthreshold slope was 120 mV/dec, yielding a high-current responsivity (˜5 A/W) and a cutoff frequency of 460 GHz. We also measured the modulation bandwidth of the THz detector using a heterodyne mixing technique with a uni-traveling carrier photodiode (UTC-PD) for providing the radio frequency (RF) and a frequency multiplier as a local oscillator. The intensity of the intermediate signal (IF) was measured by changing the frequency of the UTC-PD; very high bandwidths of up to 26 GHz were obtained. The experimental results agree well with electromagnetic simulations, which indicate that the bandwidth is determined by the external circuit. The conversion gain from RF to IF was -2 dB in the heterodyne mixing by using the HEMT detector.

  17. Emittance-exchange-based high harmonic generation scheme for short-wavelength free electron laser.

    SciTech Connect

    Power, J. G.; Jiang, B.; Gai, W.; Liu, W.; Lindberg, R.

    2011-03-16

    Generation of short-wavelength radiation by a free-electron laser using up-frequency conversion of an electron bunch density modulation is currently an area of active research. We propose a new scheme for producing the longitudinal electron bunch density modulation similar to the recently proposed echo-enabled harmonic generation but based on an emittance exchange beam line and a multislit mask. Beam line analysis and start-to-end simulation are presented.

  18. Highly visible-light luminescence properties of the carboxyl-functionalized short and ultrashort MWNTs

    NASA Astrophysics Data System (ADS)

    Luo, Yongsong; Xia, Xiaohong; Liang, Ying; Zhang, Yonggang; Ren, Qinfeng; Li, Jialin; Jia, Zhijie; Tang, Yiwen

    2007-06-01

    Luminescence of the short multiwalled carbon nanotubes (MWNTs) conjugated with carboxylic acid groups has been studied. The results show that the carboxyl-functionalized short MWNTs could emit luminescence and the emission peak appears at 500 nm with a corresponding optimal excitation wavelength centering at 310 nm. When the short MWNTs are filtered through 0.15 μm polytetrafluoroethylene (PTFE) membrane, the ultrashort MWNTs are obtained from the filtrate. An interesting feature for the ultrashort MWNTs is that the emission intensity is strengthened and the peak is slightly blue shifted to 460 nm. This result indicates that the luminescence properties of MWNTs are strongly affected by the tube length. After chemical oxidization cutting, defects and carboxylic acid groups at the tube end and/or sidewall can be produced; the more shorten of MWNTs, the better dispersion and carboxylic passivation of the nanotubes, and the more intense luminescence emissions. The broad emissions are logically attributed to the trapping of excitation energy by defect sites in the carboxyl-functionalized nanotube structure.

  19. Reducing the complexity of digital nonlinear compensation for high-speed coherent optical communication systems

    NASA Astrophysics Data System (ADS)

    Guiomar, Fernando P.; Amado, Sofia B.; Pinto, Armando N.

    2014-08-01

    We perform a thorough performance and complexity analysis of a recently proposed Volterra series nonlinear equalizer (VSNE) for digital post-compensation of nonlinear fiber impairments in high-speed and long-haul coherent optical communication systems. Using a maximum absolute value selection criteria, we implement a pruning strategy for the matrix-based VSNE and compare its performance/complexity with the symmetric VSNE (symVSNE) and simpli ed VSNE (simVSNE) algorithms. The theoretical analysis is supported by simulation results obtained for a single-channel 224 Gb/s PM-16QAM transmission system with a signal propagation distance of 1920 km.

  20. Demonstration of high-speed multi-user multi-carrier CDMA visible light communication

    NASA Astrophysics Data System (ADS)

    Yang, Chao; Wang, Yuanquan; Wang, Yiguang; Huang, Xingxing; Chi, Nan

    2015-02-01

    We experimentally demonstrated a high-speed multi-user multi-carrier code-division multiple access (MC-CDMA) visible light communication (VLC) system. By employing a commercially available red light emitting diode (LED) and an avalanche photo diode (APD), we achieved a 16-user VLC system enabled by MC-CDMA, pre- and post-equalization, with an overall bit rate of 750 Mb/s over 1.5 m free-space transmission. The measured bit error ratio (BER) of each user is below the 7% pre-forward-error-correction (pre-FEC) threshold of 3.810-3.

  1. Pulse Interval Modulation for Ultra-High Speed IR-UWB Communications Systems

    NASA Astrophysics Data System (ADS)

    Herceg, Marijan; Švedek, Tomislav; Matić, Tomislav

    2010-12-01

    This paper analyzes performances of the Pulse Interval Modulation (PIM) scheme for impulse radio ultra-wideband (IR-UWB) communication systems. Due to the PIM anisochronous nature, a tap delay line (TDL) coded division multiple access (CDMA) scheme based on strict optical orthogonal codes (SOOC) is proposed. This scheme is suitable for multiuser high-speed data asynchronous transmission applications because the average symbol length is shorter than in Pulse Position Modulation (PPM) schemes and it needs only chip synchronization. The error probability over the additive white Gaussian noise (AWGN) channel is derived in the single- and multi-user environment and compared with other modulation schemes.

  2. A new medium and high bit rate 16-ary QAM demodulator for land mobile satellite communications

    NASA Astrophysics Data System (ADS)

    Fines, Panos; Aghvami, A. H.

    1991-08-01

    A new 16-ary differentially encoded quadrature amplitude (16-DEQAM) demodulator for medium and high bit rate (from 2 to 100 MBit/s) land mobile satellite communications is proposed, and its performance is evaluated. The synchronization and detection digital techniques employed in this system are described. The hardware speed limitations have been overcome effectively with extensive use of look-up tables and concurrent digital signal processing on polar signal representation. The acquisition and bit error rate performances are evaluated by computer simulation over additive white Gaussian noise and Rician fading channel.

  3. A high-efficiency 59- to 64-GHz TWT for intersatellite communications

    NASA Technical Reports Server (NTRS)

    Wilson, Jeffrey D.; Ramins, Peter; Force, Dale A.; Limburg, Helen C.; Tammaru, Ivo

    1991-01-01

    The design of a 75-W, 59- to 64- GHz TWT with a predicted overall efficiency in excess of 40 percent is described. This intersatellite communications TWT, designated Model 961HA, employs a coupled-cavity slow-wave structure with a two-step velocity taper and an isotropic graphite multistage depressed collector (MDC). Because the RF efficiency of this TWT is less than 8 percent, an MDC design providing a very high collector efficiency was necessary to achieve the overall efficiency goal of 40 percent.

  4. Circuit for Communication over DC Power Line Using High Temperature Electronics

    NASA Technical Reports Server (NTRS)

    Krasowski, Michael J. (Inventor); Prokop, Norman F. (Inventor)

    2014-01-01

    A high temperature communications circuit includes a power conductor for concurrently conducting electrical energy for powering circuit components and transmitting a modulated data signal, and a demodulator for demodulating the data signal and generating a serial bit stream based on the data signal. The demodulator includes an absolute value amplifier for conditionally inverting or conditionally passing a signal applied to the absolute value amplifier. The absolute value amplifier utilizes no diodes to control the conditional inversion or passing of the signal applied to the absolute value amplifier.

  5. Combinatorial FSK modulation for power-efficient high-rate communications

    NASA Technical Reports Server (NTRS)

    Wagner, Paul K.; Vanderaar, Mark J.; Budinger, James M.

    1991-01-01

    Deep-space and satellite communications systems must be capable of conveying high-rate data accurately with low transmitter power, often through dispersive channels. A class of noncoherent Combinatorial Frequency Shift Keying (CFSK) modulation schemes is investigated which address these needs. The bit error rate performance of this class of modulation formats is analyzed and compared to the more traditional modulation types. Candidate modulator, demodulator, and digital signal processing (DSP) hardware structures are examined in detail. System-level issues are also discussed.

  6. CTS United States experiments - A progress report. [Communications Technology Satellite for high power broadcasting

    NASA Technical Reports Server (NTRS)

    Robbins, W. H.; Donoughe, P. L.

    1976-01-01

    The Communications Technology Satellite (CTS) is a high-power broadcast satellite launched by NASA on January 17, 1976. CTS is the first satellite to operate at a frequency of 12 gigahertz and incorporates technology making possible new satellite telecommunications services. CTS is a cooperative program of the United States and Canada. This paper presents the results of the United States experimental activity to date. Wide segments of the population are involved in the Experiments Program, including the scientific community, other government agencies, industry, and the education and health entities. The experiments are associated with both technological objectives and the demonstration of new community and social services via satellite.

  7. Advances in high-throughput speed, low-latency communication for embedded instrumentation ( 7th Annual SFAF Meeting, 2012)

    ScienceCinema

    Jordan, Scott [Physik Instrumente

    2013-02-11

    Scott Jordan on "Advances in high-throughput speed, low-latency communication for embedded instrumentation" at the 2012 Sequencing, Finishing, Analysis in the Future Meeting held June 5-7, 2012 in Santa Fe, New Mexico.

  8. Advances in high-throughput speed, low-latency communication for embedded instrumentation ( 7th Annual SFAF Meeting, 2012)

    SciTech Connect

    Jordan, Scott

    2012-06-01

    Scott Jordan on "Advances in high-throughput speed, low-latency communication for embedded instrumentation" at the 2012 Sequencing, Finishing, Analysis in the Future Meeting held June 5-7, 2012 in Santa Fe, New Mexico.

  9. Integration and test of high-speed transmitter electronics for free-space laser communications

    NASA Technical Reports Server (NTRS)

    Soni, Nitin J.; Lizanich, Paul J.

    1994-01-01

    The NASA Lewis Research Center in Cleveland, Ohio, has developed the electronics for a free-space, direct-detection laser communications system demonstration. Under the High-Speed Laser Integrated Terminal Electronics (Hi-LITE) Project, NASA Lewis has built a prototype full-duplex, dual-channel electronics transmitter and receiver operating at 325 megabit S per second (Mbps) per channel and using quaternary pulse-position modulation (QPPM). This paper describes the integration and testing of the transmitter portion for future application in free-space, direct-detection laser communications. A companion paper reviews the receiver portion of the prototype electronics. Minor modifications to the transmitter were made since the initial report on the entire system, and this paper addresses them. The digital electronics are implemented in gallium arsenide integrated circuits mounted on prototype boards. The fabrication and implementation issues related to these high-speed devices are discussed. The transmitter's test results are documented, and its functionality is verified by exercising all modes of operation. Various testing issues pertaining to high-speed circuits are addressed. A description of the transmitter electronics packaging concludes the paper.

  10. Chaos-based communications at high bit rates using commercial fibre-optic links.

    PubMed

    Argyris, Apostolos; Syvridis, Dimitris; Larger, Laurent; Annovazzi-Lodi, Valerio; Colet, Pere; Fischer, Ingo; García-Ojalvo, Jordi; Mirasso, Claudio R; Pesquera, Luis; Shore, K Alan

    2005-11-17

    Chaotic signals have been proposed as broadband information carriers with the potential of providing a high level of robustness and privacy in data transmission. Laboratory demonstrations of chaos-based optical communications have already shown the potential of this technology, but a field experiment using commercial optical networks has not been undertaken so far. Here we demonstrate high-speed long-distance communication based on chaos synchronization over a commercial fibre-optic channel. An optical carrier wave generated by a chaotic laser is used to encode a message for transmission over 120 km of optical fibre in the metropolitan area network of Athens, Greece. The message is decoded using an appropriate second laser which, by synchronizing with the chaotic carrier, allows for the separation of the carrier and the message. Transmission rates in the gigabit per second range are achieved, with corresponding bit-error rates below 10(-7). The system uses matched pairs of semiconductor lasers as chaotic emitters and receivers, and off-the-shelf fibre-optic telecommunication components. Our results show that information can be transmitted at high bit rates using deterministic chaos in a manner that is robust to perturbations and channel disturbances unavoidable under real-world conditions. PMID:16292256

  11. Chaos-based communications at high bit rates using commercial fibre-optic links

    NASA Astrophysics Data System (ADS)

    Argyris, Apostolos; Syvridis, Dimitris; Larger, Laurent; Annovazzi-Lodi, Valerio; Colet, Pere; Fischer, Ingo; García-Ojalvo, Jordi; Mirasso, Claudio R.; Pesquera, Luis; Shore, K. Alan

    2005-11-01

    Chaotic signals have been proposed as broadband information carriers with the potential of providing a high level of robustness and privacy in data transmission. Laboratory demonstrations of chaos-based optical communications have already shown the potential of this technology, but a field experiment using commercial optical networks has not been undertaken so far. Here we demonstrate high-speed long-distance communication based on chaos synchronization over a commercial fibre-optic channel. An optical carrier wave generated by a chaotic laser is used to encode a message for transmission over 120km of optical fibre in the metropolitan area network of Athens, Greece. The message is decoded using an appropriate second laser which, by synchronizing with the chaotic carrier, allows for the separation of the carrier and the message. Transmission rates in the gigabit per second range are achieved, with corresponding bit-error rates below 10-7. The system uses matched pairs of semiconductor lasers as chaotic emitters and receivers, and off-the-shelf fibre-optic telecommunication components. Our results show that information can be transmitted at high bit rates using deterministic chaos in a manner that is robust to perturbations and channel disturbances unavoidable under real-world conditions.

  12. 4 Gbps direct modulation of 450 nm GaN laser for high-speed visible light communication.

    PubMed

    Lee, Changmin; Zhang, Chong; Cantore, Michael; Farrell, Robert M; Oh, Sang Ho; Margalith, Tal; Speck, James S; Nakamura, Shuji; Bowers, John E; DenBaars, Steven P

    2015-06-15

    We demonstrate high-speed data transmission with a commercial high power GaN laser diode at 450 nm. 2.6 GHz bandwidth was achieved at an injection current of 500 mA using a high-speed visible light communication setup. Record high 4 Gbps free-space data transmission rate was achieved at room temperature. PMID:26193595

  13. Communication about contraception and knowledge of oral contraceptives amongst Norwegian high school students.

    PubMed

    Hansen, Thomas; Skjeldestad, Finn Egil

    2003-08-01

    Communication about contraception and specific knowledge of oral contraceptives (OCs) were examined in a sample (n = 4,650) of Norwegian high school students. Data were collected through a 44-item questionnaire especially developed for the study. The response rate was 73% and data from a total of 1,714 girls and 1,389 boys were eligible for analyses. More females (83%) than males (54%) discussed contraception at least monthly. Discussions were predominantly held with peers and not adults. Females were far more knowledgeable about OCs than males. Respondents knew more about side effects and the pill's relative efficacy than about risks of cancer and tromboembolism. The most significant predictors of high knowledge scores were gender and OC use (females). Also predictive of high knowledge scores were frequent discussions about contraception with peers. Talks about contraception with health workers were unrelated to knowledge scores. PMID:12887936

  14. An integrated optical/acoustic communication system for seafloor observatories: A field test of high data rate communications at CORK 857D

    NASA Astrophysics Data System (ADS)

    Tivey, M.; Farr, N.; Ware, J.; Pontbriand, C.

    2010-12-01

    We report the successful deployment and testing of an underwater optical communication system that provides high data rate communications over a range of 100 meters from a deep sea borehole observatory located in the northeast Pacific. Optical underwater communications offers many advantages over acoustic or underwater wet mateable connections (UWMC). UMWCs requires periodic visits from a submersible or ROV to plug in and download data. Typically, these vehicles cannot perform any other tasks during these download periods - their time on station is limited, restricting the amount of data that can be downloaded. To eliminate the need for UWMCs requires the use of remote communication techniques such as acoustics or optical communications. Optical communications is capable of high data rates up to 10 mega bits per sec (Mbps) compared to acoustic data rates of 57 Kbps. We have developed an integrated optical/acoustic telemetry system (OTS) that uses an acoustic command system to control a high bandwidth, low latency optical communication system. In July 2010, we used the deep submersible ALVIN to install the Optical Telemetry System (OTS) at CORK 857D. The CORK is instrumented with a thermistor string and pressure sensors that record downhole formation pressures and temperatures within oceanic basement that is pressure sealed from the overlying water column. The seafloor OTS was plugged into the CORK’s existing UWMC to provide an optical and acoustic communication interface and additional data storage and battery power for the CORK to sample at 1 Hz data-rate, an increase over the normal 15 sec data sample rate. Using a CTD-mounted OTS lowered by wire from a surface ship, we established an optical communication link at 100 meters range at rates of 1, 5 and 10 Mbps with no bit errors. Tests were also done to establish the optical range of various data rates and the optical power of the system. After a week, we repeated the CTD-OTS experiment and downloaded 20 Mbytes of data over a 5 Mbps link at a range of 80 m. The OTS will remain installed at CORK 857D for a year. Our OTS enables faster data rates to be employed for in situ measurements that were previously limited by data download times from a submersible. The OTS also permits non submersible-equipped vessels to interrogate the CORK borehole observatory on a more frequent basis using a receiver lowered by wire from a ship of opportunity. In the future, autonomous vehicles could interrogate such seafloor observatories in a “data-mule” configuration and then dock at a seafloor cabled node to download data. While borehole observatories may ultimately be linked into undersea cables relaying real-time data back to shore they represent a superb opportunity to test free water optical communication methods. The lessons learned from our CORK development efforts will go a long way towards establishing the viability of underwater optical communications for a host of autonomous seafloor sensor systems in the future.

  15. Reconfigurable Antennas for High Data Rate Multi-beam Communication Systems

    NASA Technical Reports Server (NTRS)

    Bernhard, Jennifer T.; Michielssen, Eric

    2005-01-01

    High-speed (2-100 Mb/sec) wireless data communication - whether land- or satellite-based - faces a major challenge: high error rates caused by interference and unpredictable environments. A planar antenna system that can be reconfigured to respond to changing conditions has the potential to dramatically improve data throughput and system reliability. Moreover, new planar antenna designs that reduce array size, weight, and cost can have a significant impact on terrestrial and satellite communication system performance. This research developed new individually-reconfigurable planar antenna array elements that can be adjusted to provide multiple beams while providing increased scan angles and higher aperture efficiency than traditional diffraction-limited arrays. These new elements are microstrip spiral antennas with specialized tuning mechanisms that provide adjustable radiation patterns. We anticipate that these new elements can be used in both large and small arrays for inter-satellite communication as well as tracking of multiple mobile surface-based units. Our work has developed both theoretical descriptions as well as experimental prototypes of the antennas in both single element and array embodiments. The technical summary of the results of this work is divided into six sections: A. Cavity model for analysis and design of pattern reconfigurable antennas; B. Performance of antenna in array configurations for broadside and endfire operation; C. Performance of antenna in array configurations for beam scanning operation; D. Simulation of antennas in infinite phased arrays; E. Demonstration of antenna with commercially-available RF MEMS switches; F. Design of antenna MEMS switch combinations for direct simultaneous fabrication.

  16. Trust and risk communication in high-risk organizations: a test of principles from social risk research.

    PubMed

    Conchie, Stacey M; Burns, Calvin

    2008-02-01

    This study explored the effects of open communication about occupational risks on workers' trust beliefs and trust intentions toward risk management, and the resilience of these beliefs and intentions to further risk information. An experimental survey of 393 student nurses showed the importance of open communication in the development of worker trust in risk management. Consistent with the trust asymmetry principle, we found that the increase in trust beliefs following open communication was weaker than the reduction in trust following a lack of communication. Further, the level of trust developed through communication (or lack of) influenced the way that subsequent risk information was processed. Negative risk information reduced trust beliefs in nurses with already low levels of trust while positive risk information increased trust beliefs only in those with already high levels. A similar pattern of results emerged for nurses' trust intentions, although the magnitude of these effects was weaker. The implications of these findings for occupational risk management are discussed. PMID:18304112

  17. First Use of High Charge States for Mass Measurements of Short-Lived Nuclides in a Penning Trap

    SciTech Connect

    Ettenauer, S.; Gallant, A. T.; Dilling, J.; Simon, M. C.; Chaudhuri, A.; Mane, E.; Delheij, P.; Pearson, M. R.; Brunner, T.; Chowdhury, U.; Simon, V. V.; Brodeur, M.; Andreoiu, C.; Audi, G.; Lopez-Urrutia, J. R. Crespo; Ullrich, J.; Gwinner, G.; Lapierre, A.; Lunney, D.; Ringle, R.

    2011-12-30

    Penning trap mass measurements of short-lived nuclides have been performed for the first time with highly charged ions, using the TITAN facility at TRIUMF. Compared to singly charged ions, this provides an improvement in experimental precision that scales with the charge state q. Neutron-deficient Rb isotopes have been charge bred in an electron beam ion trap to q=8-12+ prior to injection into the Penning trap. In combination with the Ramsey excitation scheme, this unique setup creating low energy, highly charged ions at a radioactive beam facility opens the door to unrivaled precision with gains of 1-2 orders of magnitude. The method is particularly suited for short-lived nuclides such as the superallowed {beta} emitter {sup 74}Rb (T{sub 1/2}=65 ms). The determination of its atomic mass and an improved Q{sub EC} value are presented.

  18. Core Communications

    ERIC Educational Resources Information Center

    Block, Greg; Ross, J. D.; Mulder, David

    2011-01-01

    The website--it is where people go to find out anything and everything about a school, college, or university. In the relatively short life of the Internet, institutional websites have moved from the periphery to center stage and become strategically integral communications and marketing tools. As the flow of information accelerates and new

  19. Core Communications

    ERIC Educational Resources Information Center

    Block, Greg; Ross, J. D.; Mulder, David

    2011-01-01

    The website--it is where people go to find out anything and everything about a school, college, or university. In the relatively short life of the Internet, institutional websites have moved from the periphery to center stage and become strategically integral communications and marketing tools. As the flow of information accelerates and new…

  20. Diagnostics of high-brightness short-pulse lasers and the plasmas they generate

    SciTech Connect

    Kyrala, G.A.; Fulton, R.D.; Cobble, J.A.; Schappert, G.T.; Taylor, A.J.

    1994-02-01

    The properties of a laser influence the interaction of the intense laser light with materials. The authors will describe some of the diagnostics that they have implemented at the Los Alamos Bright Source to correlate the changes in the x-ray spectrum and temporal history of a laser generated silicon plasmas with the changes of the incident XeCl laser light. One property is of special interest, the existence of a short prepulse. They find that the prepulse enhances the generation of the x-rays from a later pulse.

  1. GaAs Photonic Integrated Circuit (PIC) development for high performance communications

    SciTech Connect

    Sullivan, C.T.

    1998-03-01

    Sandia has established a foundational technology in photonic integrated circuits (PICs) based on the (Al,Ga,In)As material system for optical communication, radar control and testing, and network switching applications at the important 1.3{mu}m/1.55{mu}m wavelengths. We investigated the optical, electrooptical, and microwave performance characteristics of the fundamental building-block PIC elements designed to be as simple and process-tolerant as possible, with particular emphasis placed on reducing optical insertion loss. Relatively conventional device array and circuit designs were built using these PIC elements: (1) to establish a baseline performance standard; (2) to assess the impact of epitaxial growth accuracy and uniformity, and of fabrication uniformity and yield; (3) to validate our theoretical and numerical models; and (4) to resolve the optical and microwave packaging issues associated with building fully packaged prototypes. Novel and more complex PIC designs and fabrication processes, viewed as higher payoff but higher risk, were explored in a parallel effort with the intention of meshing those advances into our baseline higher-yield capability as they mature. The application focus targeted the design and fabrication of packaged solitary modulators meeting the requirements of future wideband and high-speed analog and digital data links. Successfully prototyped devices are expected to feed into more complex PICs solving specific problems in high-performance communications, such as optical beamforming networks for phased array antennas.

  2. Short rotation willow coppice in Wales: High production under adverse environmental conditions?

    SciTech Connect

    Slater, F.M.; Hodson, R.W.; Randerson, P.F.

    1995-11-01

    The production of short rotation willow coppice in central Wales was once regarded as a vain hope rather than a distinct possibility. Research at the University of Wales, Cardiff, Field Station at Llysdinam in mid-Wales over the last four years has proven that it is possible to produce a commercially viable crop on very poor upland soils and at an altitude of almost 300m provided that lime and inorganic fertilizers are added. Because of the national need to find new routes for the disposal of sewage sludge, its addition to short rotation coppice serves the dual purpose of disposal and nutrient addition. Over the first two years of the sludging experiment, it was found that the addition of 300 m{sup 3}ha{sup -1} of digested sewage sludge significantly increased crop weight, at least in the first year. Unfortunately, the crop yields did not reach those obtained using inorganic fertilizers at the same site but it is suggested that a repeated application regime might improve overall crop yield.

  3. High-Fidelity Down-Conversion Source for Secure Communications Using On-Demand Single Photons

    NASA Technical Reports Server (NTRS)

    Roberts, Tony

    2015-01-01

    AdvR, Inc., has built an efficient, fully integrated, waveguide-based source of spectrally uncorrelated photon pairs that will accelerate research and development (R&D) in the emerging field of quantum information science. Key to the innovation is the use of submicron periodically poled waveguides to produce counter propagating photon pairs, which is enabled by AdvR's patented segmented microelectrode poling technique. This novel device will provide a high brightness source of down-conversion pairs with enhanced spectral properties and low attenuation, and it will operate in the visible to the mid-infrared spectral region. A waveguide-based source of spectrally and spatially pure heralded photons will contribute to a wide range of NASA's advanced technology development efforts, including on-demand single photon sources for high-rate spaced-based secure communications.

  4. Mission Control Operations: Employing a New High Performance Design for Communications Links Supporting Exploration Programs

    NASA Technical Reports Server (NTRS)

    Jackson, Dan E., Jr.

    2015-01-01

    The planetary exploration programs demand a totally new examination of data multiplexing, digital communications protocols and data transmission principles for both ground and spacecraft operations. Highly adaptive communications devices on-board and on the ground must provide the greatest possible transmitted data density between deployed crew personnel, spacecraft and ground control teams. Regarding these requirements, this proposal borrows from research into quantum mechanical computing by applying the concept of a qubit, a single bit that represents 16 states, to radio frequency (RF) communications link design for exploration programs. This concept of placing multiple character values into a single data bit can easily make the evolutionary steps needed to meet exploration mission demands. To move the qubit from the quantum mechanical research laboratory into long distance RF data transmission, this proposal utilizes polarization modulation of the RF carrier signal to represent numbers from zero to fifteen. It introduces the concept of a binary-to-hexadecimal converter that quickly chops any data stream into 16-bit words and connects variously polarized feedhorns to a single-frequency radio transmitter. Further, the concept relies on development of a receiver that uses low-noise amplifiers and an antenna array to quickly assess carrier polarity and perform hexadecimal to binary conversion. Early testbed experiments using the International Space Station (ISS) as an operations laboratory can be implemented to provide the most cost-effective return for research investment. The improvement in signal-to-noise ratio while supporting greater baseband data rates that could be achieved through this concept justifies its consideration for long-distance exploration programs.

  5. High-sensitivity DPSK receiver for high-bandwidth free-space optical communication links.

    PubMed

    Juarez, Juan C; Young, David W; Sluz, Joseph E; Stotts, Larry B

    2011-05-23

    A high-sensitivity modem and high-dynamic range optical automatic gain controller (OAGC) have been developed to provide maximum link margin and to overcome the dynamic nature of free-space optical links. A sensitivity of -48.9 dBm (10 photons per bit) at 10 Gbps was achieved employing a return-to-zero differential phase shift keying based modem and a commercial Reed-Solomon forward error correction system. Low-noise optical gain was provided by an OAGC with a noise figure of 4.1 dB (including system required input loses) and a dynamic range of greater than 60 dB. PMID:21643335

  6. High performance computing and communications: Advancing the frontiers of information technology

    SciTech Connect

    1997-12-31

    This report, which supplements the President`s Fiscal Year 1997 Budget, describes the interagency High Performance Computing and Communications (HPCC) Program. The HPCC Program will celebrate its fifth anniversary in October 1996 with an impressive array of accomplishments to its credit. Over its five-year history, the HPCC Program has focused on developing high performance computing and communications technologies that can be applied to computation-intensive applications. Major highlights for FY 1996: (1) High performance computing systems enable practical solutions to complex problems with accuracies not possible five years ago; (2) HPCC-funded research in very large scale networking techniques has been instrumental in the evolution of the Internet, which continues exponential growth in size, speed, and availability of information; (3) The combination of hardware capability measured in gigaflop/s, networking technology measured in gigabit/s, and new computational science techniques for modeling phenomena has demonstrated that very large scale accurate scientific calculations can be executed across heterogeneous parallel processing systems located thousands of miles apart; (4) Federal investments in HPCC software R and D support researchers who pioneered the development of parallel languages and compilers, high performance mathematical, engineering, and scientific libraries, and software tools--technologies that allow scientists to use powerful parallel systems to focus on Federal agency mission applications; and (5) HPCC support for virtual environments has enabled the development of immersive technologies, where researchers can explore and manipulate multi-dimensional scientific and engineering problems. Educational programs fostered by the HPCC Program have brought into classrooms new science and engineering curricula designed to teach computational science. This document contains a small sample of the significant HPCC Program accomplishments in FY 1996.

  7. Grand Challenges: High Performance Computing and Communications. The FY 1992 U.S. Research and Development Program.

    ERIC Educational Resources Information Center

    Federal Coordinating Council for Science, Engineering and Technology, Washington, DC.

    This report presents a review of the High Performance Computing and Communications (HPCC) Program, which has as its goal the acceleration of the commercial availability and utilization of the next generation of high performance computers and networks in order to: (1) extend U.S. technological leadership in high performance computing and computer…

  8. P.U.R.E. Communication: A Strategy to Improve Care-Coordination for High Risk Birth

    PubMed Central

    Gephart, Sheila M.; Cholette, Meghan

    2012-01-01

    High-risk birth can be an emotionally-charged and sometimes emergent event that requires a cohesive multidisciplinary team. Communication breakdowns in perinatal emergencies are known to contribute to errors and adverse patient outcomes. One approach to breaching these barriers is the Purposeful, Unambiguous, Respectful, and Effective, P.U.R.E. process. P.U.R.E. is a method of communication that emphasizes coordination and recognizes the contributions of each member of the team. The purpose of this article is to describe how the P.U.R.E. process works and how teamwork strategies, group skills training, and structured communication techniques complement it. PMID:22773922

  9. High Energy, Short Pulse Fiber Injection Lasers at Lawrence Livermore National Laboratory

    SciTech Connect

    Dawson, J W; Messerly, M J; Phan, H H; Crane, J K; Beach, R J; Siders, C W; Barty, C J

    2008-09-10

    A short pulse fiber injection laser for the Advanced Radiographic Capability (ARC) on the National Ignition Facility (NIF) has been developed at Lawrence Livermore National Laboratory (LLNL). This system produces 100 {micro}J pulses with 5 nm of bandwidth centered at 1053 nm. The pulses are stretched to 2.5 ns and have been recompressed to sub-ps pulse widths. A key feature of the system is that the pre-pulse power contrast ratio exceeds 80 dB. The system can also precisely adjust the final recompressed pulse width and timing and has been designed for reliable, hands free operation. The key challenges in constructing this system were control of the signal to noise ratio, dispersion management and managing the impact of self phase modulation on the chirped pulse.

  10. A filtering method to generate high quality short reads using illumina paired-end technology.

    PubMed

    Eren, A Murat; Vineis, Joseph H; Morrison, Hilary G; Sogin, Mitchell L

    2013-01-01

    Consensus between independent reads improves the accuracy of genome and transcriptome analyses, however lack of consensus between very similar sequences in metagenomic studies can and often does represent natural variation of biological significance. The common use of machine-assigned quality scores on next generation platforms does not necessarily correlate with accuracy. Here, we describe using the overlap of paired-end, short sequence reads to identify error-prone reads in marker gene analyses and their contribution to spurious OTUs following clustering analysis using QIIME. Our approach can also reduce error in shotgun sequencing data generated from libraries with small, tightly constrained insert sizes. The open-source implementation of this algorithm in Python programming language with user instructions can be obtained from https://github.com/meren/illumina-utils. PMID:23799126

  11. Acute Physiological Responses to Short- and Long-Stage High-Intensity Interval Exercise in Cardiac Rehabilitation: A Pilot Study.

    PubMed

    Tschakert, Gerhard; Kroepfl, Julia M; Mueller, Alexander; Harpf, Hanns; Harpf, Leonhard; Traninger, Heimo; Wallner-Liebmann, Sandra; Stojakovic, Tatjana; Scharnagl, Hubert; Meinitzer, Andreas; Pichlhoefer, Patriz; Hofmann, Peter

    2016-03-01

    Despite described benefits of aerobic high-intensity interval exercise (HIIE), the acute responses during different HIIE modes and associated health risks have only been sparsely discovered in heart disease patients. Therefore, the aim of this study was to investigate the acute responses for physiological parameters, cardiovascular and inflammatory biomarkers, and catecholamines yielded by two different aerobic HIIE protocols compared to continuous exercise (CE) in phase III cardiac rehabilitation. Eight cardiac patients (7 with coronary heart disease, 1 with myocarditis; 7 males, 1 female; age: 63.0 ± 9.4 years; height: 1.74 ± 0.05 m; weight: 83.6 ± 8.7 kg), all but one treated with ß-blocking agents, performed a maximal symptom-limited incremental exercise test (IET) and three different exercise tests matched for mean load (Pmean) and total duration: 1) short HIIE with a peak workload duration (tpeak) of 20 s and a peak workload (Ppeak) equal to the maximum power output (Pmax) from IET; 2) long HIIE with a tpeak of 4 min, Ppeak was corresponding to the power output at 85 % of maximal heart rate (HRmax) from IET; 3) CE with a target workload equal to Pmean of both HIIE modes. Acute metabolic and peak cardiorespiratory responses were significantly higher during long HIIE compared to short HIIE and CE (p < 0.05) except HRpeak which tended to be higher in long HIIE than in short HIIE (p = 0.08). Between short HIIE and CE, no significant difference was found for any parameter. Acute responses of cardiovascular and inflammatory biomarkers and catecholamines didn't show any significant difference between tests (p > 0.05). All health-related variables remained in a normal range in any test except NT-proBNP, which was already elevated at baseline. Despite a high Ppeak particularly in short HIIE, both HIIE modes were as safe and as well tolerated as moderate CE in cardiac patients by using our methodological approach. Key pointsHigh-intensity interval exercise (HIIE) with short peak workload durations (tpeak) induce a lower acute metabolic and peak cardiorespiratory response compared to intervals with long tpeak despite higher peak workload intensities and identical mean load. No significant difference for any physiological parameter was found between short HIIE and CE.Between short HIIE, long HIIE, and CE, no significant difference was found in the increase (or decrease, respectively,) of health related markers such as cardiovascular biomarkers, catecholamines, or inflammatory parameters during exercise.During all exercise modes, all risk markers remained in a normal range except for NT-proBNP which was, however, already elevated at baseline.Short HIIE, long HIIE, and CE were safely performed by patients with CHD or myocarditis in cardiac rehabilitation by using our methodological approach to exercise prescription. This approach included the prescription of exercise intensities with respect to LTP1, LTP2, and Pmax as well as a conscious setting of Pmean at a moderate level (80 % of PLTP2). Importantly, all exercise modes were matched for Pmean and exercise duration in order to enable a comparison of the three protocols. PMID:26957930

  12. Acute Physiological Responses to Short- and Long-Stage High-Intensity Interval Exercise in Cardiac Rehabilitation: A Pilot Study

    PubMed Central

    Tschakert, Gerhard; Kroepfl, Julia M.; Mueller, Alexander; Harpf, Hanns; Harpf, Leonhard; Traninger, Heimo; Wallner-Liebmann, Sandra; Stojakovic, Tatjana; Scharnagl, Hubert; Meinitzer, Andreas; Pichlhoefer, Patriz; Hofmann, Peter

    2016-01-01

    Despite described benefits of aerobic high-intensity interval exercise (HIIE), the acute responses during different HIIE modes and associated health risks have only been sparsely discovered in heart disease patients. Therefore, the aim of this study was to investigate the acute responses for physiological parameters, cardiovascular and inflammatory biomarkers, and catecholamines yielded by two different aerobic HIIE protocols compared to continuous exercise (CE) in phase III cardiac rehabilitation. Eight cardiac patients (7 with coronary heart disease, 1 with myocarditis; 7 males, 1 female; age: 63.0 ± 9.4 years; height: 1.74 ± 0.05 m; weight: 83.6 ± 8.7 kg), all but one treated with ß-blocking agents, performed a maximal symptom-limited incremental exercise test (IET) and three different exercise tests matched for mean load (Pmean) and total duration: 1) short HIIE with a peak workload duration (tpeak) of 20 s and a peak workload (Ppeak) equal to the maximum power output (Pmax) from IET; 2) long HIIE with a tpeak of 4 min, Ppeak was corresponding to the power output at 85 % of maximal heart rate (HRmax) from IET; 3) CE with a target workload equal to Pmean of both HIIE modes. Acute metabolic and peak cardiorespiratory responses were significantly higher during long HIIE compared to short HIIE and CE (p < 0.05) except HRpeak which tended to be higher in long HIIE than in short HIIE (p = 0.08). Between short HIIE and CE, no significant difference was found for any parameter. Acute responses of cardiovascular and inflammatory biomarkers and catecholamines didn’t show any significant difference between tests (p > 0.05). All health-related variables remained in a normal range in any test except NT-proBNP, which was already elevated at baseline. Despite a high Ppeak particularly in short HIIE, both HIIE modes were as safe and as well tolerated as moderate CE in cardiac patients by using our methodological approach. Key points High-intensity interval exercise (HIIE) with short peak workload durations (tpeak) induce a lower acute metabolic and peak cardiorespiratory response compared to intervals with long tpeak despite higher peak workload intensities and identical mean load. No significant difference for any physiological parameter was found between short HIIE and CE. Between short HIIE, long HIIE, and CE, no significant difference was found in the increase (or decrease, respectively,) of health related markers such as cardiovascular biomarkers, catecholamines, or inflammatory parameters during exercise. During all exercise modes, all risk markers remained in a normal range except for NT-proBNP which was, however, already elevated at baseline. Short HIIE, long HIIE, and CE were safely performed by patients with CHD or myocarditis in cardiac rehabilitation by using our methodological approach to exercise prescription. This approach included the prescription of exercise intensities with respect to LTP1, LTP2, and Pmax as well as a conscious setting of Pmean at a moderate level (80 % of PLTP2). Importantly, all exercise modes were matched for Pmean and exercise duration in order to enable a comparison of the three protocols. PMID:26957930

  13. Novel High-Voltage, High-Power Piezoelectric Transformer Developed and Demonstrated for Space Communications Applications

    NASA Technical Reports Server (NTRS)

    Carazo, Alfredo V.; Wintucky, Edwin G.

    2004-01-01

    Improvements in individual piezoelectric transformer (PT) performance and the combination of these PTs in a unique modular topology under a Phase I contract with the NASA Glenn Research Center have enabled for the first time the simultaneous achievement of both high voltage and high power at much higher levels than previously obtained with any PT. Feasibility was demonstrated by a prototype transformer (called a Tap-Soner), which is shown in the preceding photograph as part of a direct-current to direct-current (dc-dc) converter having two outputs rated at 1.5 kV/5 W and 4.5 kV/20 W. The power density of 3.5 W/cm3 is significantly lower than for magnetic transformers with the same voltage and power output. This development, which is being done under a Small Business Innovation Research (SBIR) contract by Face Electronics, LC (Norfolk, VA), is based on improvements in the materials and design of Face's basic patented Transoner-T3 PT, shown in the left in the following figure. The T3 PT is most simply described as a resonant multilayer transducer where electrical energy at the input section is efficiently mechanically coupled to the output section, which then vibrates in a fundamental longitudinal mode to generate a high gain in voltage. The piezoelectric material used is a modified lead-zirconium-titanate-based ceramic. One of the significant improvements in PT design was the incorporation of a symmetrical double input layer, shown on the right in the following figure, which eliminated the lossy bending vibration modes characteristic of a single input layer. The performance of the improved PT was optimized to 1.5 kV/5 W. The next step was devising a way to combine the individual PTs in a modular circuit topology needed to achieve the desired high voltage and power output. Since the optimum performance of the individual PT occurs at resonance, the most efficient operation of the modular transformer was achieved by using a separate drive circuit for each PT. The output section consists of a separate output rectifier for each PT connected in series.

  14. Laser Communications and Fiber Optics Lab Manual. High-Technology Training Module.

    ERIC Educational Resources Information Center

    Biddick, Robert

    This laboratory training manual on laser communications and fiber optics may be used in a general technology-communications course for ninth graders. Upon completion of this exercise, students achieve the following goals: match concepts with laser communication system parts; explain advantages of fiber optic cable over conventional copper wire;…

  15. Dynamics of short eccentric plain seals with high axial Reynolds number. [for Space Shuttle engine hydrogen fuel turbopump

    NASA Technical Reports Server (NTRS)

    Allaire, P. E.; Lee, C. C.; Gunter, E. J.

    1978-01-01

    Plain seals with high axial flow rates produce large stiffness and damping coefficients that can help stabilize high-speed rotating machinery. When the shaft is eccentric in the seal, a Bernoulli effect low-pressure region occurs on the large-clearance side of the shaft. A fluid-restoring force tends to center the shaft and reduce vibrations. This work extends the previous theory for short plain centered seals to large eccentricities using a perturbation analysis. Surface roughness effects are also included. An analysis of seals used in the Space Shuttle main engine hydrogen fuel turbopump indicates the desirability of plain seals over the labyrinth type. Experimental results confirm this.

  16. Tailoring communication in consultations with women from high risk breast cancer families.

    PubMed

    Lobb, E A; Butow, P N; Meiser, B; Barratt, A; Gaff, C; Young, M A; Kirk, J; Suthers, G K; Tucker, K

    2002-08-27

    This multicentre study examined the influence of patient demographic, disease status and psychological variables on clinical geneticists/genetic counsellors (consultants) behaviours in initial consultations with women from high-risk breast cancer families. One hundred and fifty-eight women completed a pre-clinic self-report questionnaire. The consultations were audiotaped, transcribed verbatim and coded. Consultants did not vary their behaviour according to women's expectations. However, significantly more aspects of genetic testing were discussed with women who were affected with breast cancer (P<0.001), screening and management with unaffected women (P=0.01) and breast cancer prevention with younger women (P=0.01). Prophylactic mastectomy was discussed more frequently with women with medical and allied health training (P=0.02), and prophylactic oophorectomy with women affected with breast cancer (P=0.03), those in non-professional occupations (P=0.04) and with a family history of breast and ovarian cancer (P<0.001). Consultants used significantly more behaviours to facilitate understanding with women who were in non-professional occupations (P=0.04); facilitated active patient involvement more with women affected with breast cancer (P<0.001) and used more supportive and counselling behaviours with affected women (P=0.02). This study showed that patient demographics were more likely to predict consultants' communication behaviours than the woman's psychological status. Methods to facilitate assessment of psychological morbidity are needed to allow more tailored communication. PMID:12189544

  17. Short Circuits or Superconductors? Effects of Group Composition on High-Achieving Students' Science Assessment Performance.

    ERIC Educational Resources Information Center

    Webb, Noreen M.; Nemer, Kariane Mari; Zuniga, Stephen

    2002-01-01

    Studied the effects of group ability composition (homogeneous versus heterogeneous) on group processes and outcomes for high-ability students completing science assessments. Results for 83 high ability students show the quality of group functioning serves as the strongest predictor of high-ability students' performance and explained much of the…

  18. A study of secondary electron emission effects for suppressing passive intermodulation interference in high power communication satellites

    NASA Technical Reports Server (NTRS)

    Bosisio, Renato G.; Xu, Yansheng

    1995-01-01

    In this paper a study of secondary electron emission effects for suppressing passive intermodulation interference in high power communications satellites is studied. The test facility is described and the test results are provided. The effects of environmental factors on the secondary emission coefficient are given. It is found that certain refractory compounds are very promising in eliminating some of the passive intermodulation in satellite communications.

  19. Development of a medical record and radiographic image transmission system using a high-speed communication network.

    PubMed

    Kim, N H; Yoo, S K; Kim, K M; Kang, Y T; Bae, S H; Kim, S R

    1998-01-01

    A medical record and radiographic image transmission system has been developed using a high-speed communication network. The databases are designed to store and transmit the data acquired from the scanner. To maximally utilize the communication bandwidth, the medical records and radiographic images are compressed using the G3 facsimile and JPEG coding standard method, respectively. TCP/IP, OOP and Windows-based system software enable a modular design, future expandability, open system interconnectivity, and diverse image manipulation functions. PMID:10384462

  20. Communicating the Benefits of a Full Sequence of High School Science Courses

    NASA Astrophysics Data System (ADS)

    Nicholas, Catherine Marie

    High school students are generally uninformed about the benefits of enrolling in a full sequence of science courses, therefore only about a third of our nation's high school graduates have completed the science sequence of Biology, Chemistry and Physics. The lack of students completing a full sequence of science courses contributes to the deficit in the STEM degree production rate needed to fill the demand of the current job market and remain competitive as a nation. The purpose of the study was to make a difference in the number of students who have access to information about the benefits of completing a full sequence of science courses. This dissertation study employed qualitative research methodology to gain a broad perspective of staff through a questionnaire and document review and then a deeper understanding through semi-structured interview protocol. The data revealed that a universal sequence of science courses in the high school district did not exist. It also showed that not all students had access to all science courses; students were sorted and tracked according to prerequisites that did not necessarily match the skill set needed for the courses. In addition, the study showed a desire for more support and direction from the district office. It was also apparent that there was a disconnect that existed between who staff members believed should enroll in a full sequence of science courses and who actually enrolled. Finally, communication about science was shown to occur mainly through counseling and peers. A common science sequence, detracking of science courses, increased communication about the postsecondary and academic benefits of a science education, increased district direction and realistic mathematics alignment were all discussed as solutions to the problem.

  1. High-efficiency 20 GHz traveling wave tube development for space communications

    NASA Technical Reports Server (NTRS)

    Aldana, S. L.; Tamashiro, R. N.

    1991-01-01

    A 75 watt CW high efficiency helix TWT operating at 20 GHz was developed for satellite communication systems. The purpose was to extend the performance capabilities of helix TWTs by using recent technology developments. The TWT described is a unique design because high overall efficiency is obtained with a low perveance beam. In the past, low perveance designs resulted in low beam efficiencies. However, due to recent breakthoughs in diamond rod technology and in collector electrode materials, high efficiencies can now be achieved with low perveance beams. The advantage of a low perveance beam is a reduction in space charge within the beam which translates to more efficient collector operation. In addition, this design incorporates textured graphite electrodes which further enhance collector operation by suppressing backstreaming secondaries. The diamond supported helix circuit features low RF losses, high interaction impedance, good thermal handling capability and has been designed to compensate for the low perveance beam. One more discussed tube feature is the use of a velocity taper in the output helix that achieves low signal distortion while maintaining high efficiency.

  2. Designing a High Performance OpenSHMEM Implementation using Universal Common Communication Substrate as a Communication Middleware

    SciTech Connect

    Welch, Donald A; Shamis, Pavel; Gorentla Venkata, Manjunath; Poole, Stephen W; Tony, Curtis

    2014-01-01

    OpenSHMEM is an effort to standardize the well-known SHMEM parallel programming library. The project aims to produce an open-source and portable SHMEM API and is led by ORNL and UH. In this paper, we optimize the current OpenSHMEM reference implementa- tion, based on GASNet, to achieve higher performance characteristics. To achieve these desired performance characteristics, we have redesigned an important component of the OpenSHMEM implementation, the network layer, to leverage a low-level communication library designed for imple- menting parallel programming models called UCCS. In particular, UCCS provides an interface and semantics such as native atomic operations and remote memory operations to better support PGAS programming models, including OpenSHMEM. Through the use of microbenchmarks, we evaluate this new OpenSHMEM implementation on various network metrics, including the latency of point-to-point and collective operations. Furthermore, we compare the performance of our OpenSHMEM imple- mentation with the state-of-the-art SGI SHMEM. Our results show that the atomic operations of our OpenSHMEM implementation outperform SGI s SHMEM implementation by 3%. Its RMA operations outperform both SGI s SHMEM and the original OpenSHMEM reference implemen- tation by as much as 18% and 12% for gets, and as much as 83% and 53% for puts.

  3. Selections from the ABC 2013 Annual Convention, New Orleans, Louisiana: A Gumbo of Favorite Assignments: Global, Communicating Complex Information, Short-Message Packaging

    ERIC Educational Resources Information Center

    Whalen, D. Joel

    2014-01-01

    This article, the first of a two-part series, catalogs teaching innovations presented at the 2013 Association for Business Communication (ABC) Annual Convention, New Orleans. They were presented during the My Favorite Assignment session. The 11 Favorite Assignments featured here offer the reader a variety of learning experiences including…

  4. Selections from the ABC 2013 Annual Convention, New Orleans, Louisiana: A Gumbo of Favorite Assignments: Global, Communicating Complex Information, Short-Message Packaging

    ERIC Educational Resources Information Center

    Whalen, D. Joel

    2014-01-01

    This article, the first of a two-part series, catalogs teaching innovations presented at the 2013 Association for Business Communication (ABC) Annual Convention, New Orleans. They were presented during the My Favorite Assignment session. The 11 Favorite Assignments featured here offer the reader a variety of learning experiences including

  5. WISC-IV profile in high-functioning autism spectrum disorders: impaired processing speed is associated with increased autism communication symptoms and decreased adaptive communication abilities.

    PubMed

    Oliveras-Rentas, Rafael E; Kenworthy, Lauren; Roberson, Richard B; Martin, Alex; Wallace, Gregory L

    2012-05-01

    Changes in the Wechsler Intelligence Scales for Children-IV (WISC-IV) may affect the IQ profile characteristic of autism spectrum disorders (ASD). Moreover, the association of particular component cognitive abilities (unlike overall IQ) with symptomatology and adaptive functioning in ASD remains unclear. This archival study characterizes the WISC-IV IQ profile among 56 high-functioning (IQ>70) children with ASD and correlates WISC-IV performance with ASD and ADHD symptomatology and adaptive functioning. The ASD WISC-IV profile included strengths on Matrix Reasoning and Similarities, weaknesses on Comprehension (which correlated negatively with social symptoms) and the subtests comprising the Processing Speed Index (Coding, Symbol Search). Processing speed task performance correlated negatively with communication symptoms and positively with communication abilities, indicating its importance to functional outcomes in ASD. PMID:21638108

  6. Quantification of short-term dynamic of debris flows at the high-Arctic environment, Ebbabreen and Ragnarbreen, Svalbard

    NASA Astrophysics Data System (ADS)

    Ewertowski, Marek; Tomczyk, Aleksandra

    2014-05-01

    Extensive ice-cored moraines complexes are common elements marking last advance of many of Svalbard glaciers. Sediment gravity flows are the most dynamic parts of these landsystem components, leading to the serious transformations of postglacial landforms. Short-term dynamic of debris flows activity was studied in cm-scale using repetitive topographic surveys. We monitored several debris flows on the forelands of two glaciers: Ebbabreen and Ragnarbreen located near to the Petuniabukta, at the north end of the Billefiorden, Spitsbergen. Reflectorless, robotic scanning was used to obtain accurate and detail topographic data. Six measurement sessions were carried out: three during summer 2012 and three during summer 2013, which enables us to assess seasonal and short-term (weekly) variations. Photographic monitoring was also carried out along with the survey sessions. Digital elevation models (DEMs) generated from each measurement session were subsequently subtracted from each other, providing a spatial picture of the erosion or deposition of material in each cell of the model between survey sessions. By subtracting DEMs from subsequent time periods we created DEMs of Differences - DoDs, which enables us to calculate the amount of material which was moved within the test sites and also to investigate the spatial patterns of transformations. The surveys indicate high dynamic rates of debris flows. Total yearly changes of the volume of sediments and dead-ice for the most active part of the debris flows was around -0.3 m3/m2. However, most of the transformation occurred during summer, with the short term values as high as -0.1 m3/m2 per week. In comparison, dynamic of the other parts of the ice-cored moraines was 10-times lower. Total change in elevation (attributed mainly to dead-ice downwasting) during one year was -0.03 m3/m2, whereas lowering during summer was about 0.01 m3/m2 per week. The results of our study indicate that in case of studied glaciers backwasting was much more effective than downwasting in terms of landscape transformation on the glaciers' forelands. Despite high activity of debris flows, overall short term dynamic of ice-cored moraines for studied sites was relatively low. We suggest that as long as debris cover is sufficiently thick - thicker than the active layer depths - the debris flow activity occur only due to specific topographic conditions and/or occurrence of external meltwater sources. In other areas ice cored moraines remain stable landsystem component in short term (yearly to decadal) time-scale.

  7. High detectivity short-wavelength II-VI quantum cascade detector

    SciTech Connect

    Ravikumar, Arvind P. Gmachl, Claire F.; Garcia, Thor A.; Tamargo, Maria C.; Jesus, Joel De

    2014-08-11

    We report on the experimental demonstration of a ZnCdSe/ZnCdMgSe-based short-wavelength photovoltaic Quantum Cascade Detector (QCD). The QCD operates in two spectral bands centered around 2.6 μm and 3.6 μm. Calibrated blackbody measurements yield a peak responsivity of 0.1 mA/W or 2400 V/W at 80 K, and a corresponding 300 K background radiation limited infrared performance detectivity (BLIP) of ∼2.5 × 10{sup 10 }cm √Hz/W. Comparison of background illuminated and dark current-voltage measurements demonstrates a BLIP temperature of 200 K. The device differential resistance-area product, decreases from about 10{sup 6} Ω cm{sup 2} at 80 K to about 8000 Ω cm{sup 2} at 300 K, indicative of the ultra-low Johnson noise in the detectors.

  8. High dynamic solutions for short-wavelength infrared imaging based on InGaAs

    NASA Astrophysics Data System (ADS)

    Reverchon, Jean-Luc; Decobert, Jean; Djedidi, Anis; Gentner, Jean-Louis; Huet, Odile; Lagay, Nadine; Rouvié, Anne; Robo, Jean-Alexandre; Truffer, Jean-Patrick; Costard, Eric; Ni, Yang; Arion, Bogdan; Zhu, Yiming; Potet, Pierre

    2011-06-01

    Short-wavelength infrared image sensors based on p-i-n photodiode arrays present a tremendous interest in applications such as passive and active imagery for laser detection/warning, hot spot or detection for lasers sensors, enhanced vision systems or low light level sensors. The capability to work at room temperature with dark current equivalent to silicon-based devices is another motivation for the fast development of this technology. This paper presents several modules and camera based on InGaAs photodiode arrays from the III-VLab. First, we describe the electro-optics performance in terms of dark signal, sensitivity, and particularly the visible extension capability. We also present a nucless logarithmic sensor based on a 1/2 video graphics array (VGA) format at a pitch of 25 μm initially designed for visible CMOS camera chip. We will also present the next generation of focal plane arrays based on a VGA format of 640×512 pixels with a pitch of 15 μm. This array will be associated to a CTIA readout circuit and also to an innovative CMOS logarithmic wide dynamic range ROIC, developed by New Imaging Technologies. This VGA logarithmic device developed for automotive safety will involve visible extension capability in a European project named 2Wide_sense.

  9. Self-focusing of the high intensity ultra short laser pulse propagating through relativistic magnetized plasma

    NASA Astrophysics Data System (ADS)

    Malekshahi, Moslem; Dorranian, Davoud; Askari, Hassan Ranjbar

    2014-12-01

    In this paper, evolution of the spot size of the ultra short intense laser beam propagating in underdense magnetized cold plasma, taking into account the nonlinearity up to third order and the relativistic effect, has been studied. The plasma embedded in a constant external magnetic field that is set in the plane perpendicular to the electric field vector of the laser beam with different directions. The paraxial wave equation in plasma has been used and the source dependent expansion (SDE) method is employed to solve the equation. Using continuity equation and equation of motion for plasma electrons in the electric field of laser beam a set of equations for the evolution of laser beam structure in plasma is found. Results show that imposing the external magnetic field enhances self-focusing property of the laser beam. Taking into account the relativistic effect increases the effect of the external magnetic field on self-focusing of the laser beam. Increasing the angle between the laser beam magnetic field and external magnetic field will decrease the self-focusing property.

  10. High-accuracy indoor positioning system based on visible light communication

    NASA Astrophysics Data System (ADS)

    Wei, Ling; Zhang, Hongming; Yu, Bingyan; Guan, Yang

    2015-11-01

    A visible light communication (VLC)-based high-accuracy indoor positioning system is proposed and demonstrated. In this system, the light-emitting diode identification (LED-ID) indicating the position information of the LED can be transmitted to the receiver by the illumination LED through VLC. In the meantime, with the aid of a camera and angular sensors of the mobile device, a coordinate transform can be employed to calculate the relative position between the receiver and the reference LED so that the position of the receiver can be determined. Finally, the experimental results show that 2-cm positioning accuracy can be achieved and the simulation results indicate that the positioning error can be limited within 4.7 cm when the accuracy of angular sensors is 1 deg.

  11. A Study of an Optical Lunar Surface Communications Network with High Bandwidth Direct to Earth Link

    NASA Technical Reports Server (NTRS)

    Wilson, K.; Biswas, A.; Schoolcraft, J.

    2011-01-01

    A lunar surface systems study explores the application of optical communications to support a high bandwidth data link from a lunar relay satellite and from fixed lunar assets. The results show that existing 1-m ground stations could provide more than 99% coverage of the lunar terminal at 100Mb/s data rates from a lunar relay satellite and in excess of 200Mb/s from a fixed terminal on the lunar surface. We have looked at the effects of the lunar regolith and its removal on optical samples. Our results indicate that under repeated dust removal episodes sapphire rather than fused silica would be a more durable material for optical surfaces. Disruption tolerant network protocols can minimize the data loss due to link dropouts. We report on the preliminary results of the DTN protocol implemented over the optical carrier.

  12. Department of Energy: MICS (Mathematical Information, and Computational Sciences Division). High performance computing and communications program

    SciTech Connect

    1996-06-01

    This document is intended to serve two purposes. Its first purpose is that of a program status report of the considerable progress that the Department of Energy (DOE) has made since 1993, the time of the last such report (DOE/ER-0536, {open_quotes}The DOE Program in HPCC{close_quotes}), toward achieving the goals of the High Performance Computing and Communications (HPCC) Program. The second purpose is that of a summary report of the many research programs administered by the Mathematical, Information, and Computational Sciences (MICS) Division of the Office of Energy Research under the auspices of the HPCC Program and to provide, wherever relevant, easy access to pertinent information about MICS-Division activities via universal resource locators (URLs) on the World Wide Web (WWW). The information pointed to by the URL is updated frequently, and the interested reader is urged to access the WWW for the latest information.

  13. Department of Energy Mathematical, Information, and Computational Sciences Division: High Performance Computing and Communications Program

    SciTech Connect

    1996-11-01

    This document is intended to serve two purposes. Its first purpose is that of a program status report of the considerable progress that the Department of Energy (DOE) has made since 1993, the time of the last such report (DOE/ER-0536, The DOE Program in HPCC), toward achieving the goals of the High Performance Computing and Communications (HPCC) Program. The second purpose is that of a summary report of the many research programs administered by the Mathematical, Information, and Computational Sciences (MICS) Division of the Office of Energy Research under the auspices of the HPCC Program and to provide, wherever relevant, easy access to pertinent information about MICS-Division activities via universal resource locators (URLs) on the World Wide Web (WWW).

  14. Practical and cost-effective high-fidelity optical carrier dissemination using coherent communication techniques.

    PubMed

    Sooudi, Ehsan; O'Gorman, James; Gunning, Paul; Ellis, Andrew D; Gunning, Fatima C Garcia; Manning, Robert J

    2015-08-24

    We report a unidirectional frequency dissemination scheme for high-fidelity optical carriers deployable over telecommunication networks. For the first time, a 10 Gb/s Binary Phase Shift Keying (BPSK) signal from an ultra-narrow linewidth laser was transmitted through a field-installed optical fibre with round-trip length of 124 km between Cork City and town of Clonakilty, without inline optical amplification. At the receiver, using coherent communication techniques and optical injection-locking the carrier was recovered with noise suppression. The beat signal between the original carrier at the transmitter and recovered carrier at the receiver shows a linewidth of 2.8 kHz. Long term stability measurements revealed fractional instabilities (True Allan deviation) of 3.3 10(-14) for 1 s averaging time, prior to phase noise cancellation. PMID:26368147

  15. RF and Optical Communications: A Comparison of High Data Rate Returns From Deep Space in the 2020 Timeframe

    NASA Technical Reports Server (NTRS)

    Williams, W. Dan; Collins, Michael; Boroson, Don M.; Lesh, James; Biswas, Abihijit; Orr, Richard; Schuchman, Leonard; Sands, O. Scott

    2007-01-01

    As NASA proceeds with plans for increased science data return and higher data transfer capacity for science missions, both RF and optical communications are viable candidates for significantly higher-rate communications from deep space to Earth. With the inherent advantages, smaller apertures and larger bandwidths, of optical communications, it is reasonable to expect that at some point in time and combination of increasing distance and data rate, the rapidly emerging optical capabilities would become more advantageous than the more mature and evolving RF techniques. This paper presents a comparison of the burden to a spacecraft by both RF and optical communications systems for data rates of 10, 100, and 1000 Mbps and large distances. Advanced technology for RF and optical communication systems have been considered for projecting capabilities in the 2020 timeframe. For the comparisons drawn, the optical and RF ground terminals were selected to be similar in cost. The RF system selected is composed of forty-five 12-meter antennas, whereas the selected optical system is equivalent to a 10-meter optical telescope. Potential differences in availability are disregarded since the focus of this study is on spacecraft mass and power burden for high-rate mission data, under the assumption that essential communications will be provided by low-rate, high availability RF. For both the RF and optical systems, the required EIRP, for a given data rate and a given distance, was achieved by a design that realized the lowest possible communications subsystem mass (power + aperture) consistent with achieving the lowest technology risk. A key conclusion of this paper is that optical communications has great potential for high data rates and distances of 2.67 AU and beyond, but requires R&D and flight demonstrations to prove out technologies.

  16. High sensitivity to short wavelengths in a lizard and implications for understanding the evolution of visual systems in lizards

    PubMed Central

    Fleishman, Leo J.; Loew, Ellis R.; Whiting, Martin J.

    2011-01-01

    Progress in developing animal communication theory is frequently constrained by a poor understanding of sensory systems. For example, while lizards have been the focus of numerous studies in visual signalling, we only have data on the spectral sensitivities of a few species clustered in two major clades (Iguania and Gekkota). Using electroretinography and microspectrophotometry, we studied the visual system of the cordylid lizard Platysaurus broadleyi because it represents an unstudied clade (Scinciformata) with respect to visual systems and because UV signals feature prominently in its social behaviour. The retina possessed four classes of single and one class of double cones. Sensitivity in the ultraviolet region (UV) was approximately three times higher than previously reported for other lizards. We found more colourless oil droplets (associated with UV-sensitive (UVS) and short wavelength-sensitive (SWS) photoreceptors), suggesting that the increased sensitivity was owing to the presence of more UVS photoreceptors. Using the Vorobyev–Osorio colour discrimination model, we demonstrated that an increase in the number of UVS photoreceptors significantly enhances a lizard's ability to discriminate conspecific male throat colours. Visual systems in diurnal lizards appear to be broadly conserved, but data from additional clades are needed to confirm this. PMID:21389031

  17. Secure Communications in High Speed Fiber Optical Networks Using Code Division Multiple Access (CDMA) Transmission

    SciTech Connect

    Han, I; Bond, S; Welty, R; Du, Y; Yoo, S; Reinhardt, C; Behymer, E; Sperry, V; Kobayashi, N

    2004-02-12

    This project is focused on the development of advanced components and system technologies for secure data transmission on high-speed fiber optic data systems. This work capitalizes on (1) a strong relationship with outstanding faculty at the University of California-Davis who are experts in high speed fiber-optic networks, (2) the realization that code division multiple access (CDMA) is emerging as a bandwidth enhancing technique for fiber optic networks, (3) the realization that CDMA of sufficient complexity forms the basis for almost unbreakable one-time key transmissions, (4) our concepts for superior components for implementing CDMA, (5) our expertise in semiconductor device processing and (6) our Center for Nano and Microtechnology, which is where the majority of the experimental work was done. Here we present a novel device concept, which will push the limits of current technology, and will simultaneously solve system implementation issues by investigating new state-of-the-art fiber technologies. This will enable the development of secure communication systems for the transmission and reception of messages on deployed commercial fiber optic networks, through the CDMA phase encoding of broad bandwidth pulses. CDMA technology has been developed as a multiplexing technology, much like wavelength division multiplexing (WDM) or time division multiplexing (TDM), to increase the potential number of users on a given communication link. A novel application of the techniques created for CDMA is to generate secure communication through physical layer encoding. Physical layer encoding devices are developed which utilize semiconductor waveguides with fast carrier response times to phase encode spectral components of a secure signal. Current commercial technology, most commonly a spatial light modulator, allows phase codes to be changed at rates of only 10's of Hertz ({approx}25ms response). The use of fast (picosecond to nanosecond) carrier dynamics of semiconductors, as opposed to field dynamics of liquid crystal molecules, enable phase codes at GHz rates. The semiconductor arrayed waveguide grating (AWG) is the building block of the encoder/decoder device. A monolithically integrated AWG is developed in this LDRD. Using this building block, the AWG can be integrated with phase modulators to create temporally varying phase codes; this allows superior physical level encoding technology. The breadth of this project is wide, covering a free space optic demonstration (large optic at the meter scale) of the encoding system. This was done as a proof-of-principal exercise and to investigate the time varying phase codes (''locks'' and ''keys''). Then a monolithically integrated AWG implemented at the millimeter was investigated. The mono lithically integrated AWG has the same functionality as the table top free space optic but reduced down in size to be easily embedded in fiber optic networks.

  18. Effect of Short-Term, High-Intensity Exercise on Anaerobic Threshold in Women.

    ERIC Educational Resources Information Center

    Evans, Blanche W.

    This study investigated the effects of a six-week, high-intensity cycling program on anaerobic threshold (AT) in ten women. Subjects trained four days a week using high-intensity interval-type cycle exercises. Workouts included six 4-minute intervals cycling at 85 percent maximal oxygen uptake (VO sub 2 max), separated by 3-minute intervals of…

  19. High-speed indoor optical wireless communication system with single channel imaging receiver.

    PubMed

    Wang, Ke; Nirmalathas, Ampalavanapillai; Lim, Christina; Skafidas, Efstratios

    2012-04-01

    In this paper we experimentally investigate a gigabit indoor optical wireless communication system with single channel imaging receiver. It is shown that the use of single channel imaging receiver rejects most of the background light. This single channel imaging receiver is composed of an imaging lens and a small photo-sensitive area photodiode attached on a 2-axis actuator. The actuator and photodiode are placed on the focal plane of the lens to search for the focused light spot. The actuator is voice-coil based and it is low cost and commercially available. With this single channel imaging receiver, bit rate as high as 12.5 Gbps has been successfully demonstrated and the maximum error-free (BER<10⁻⁹) beam footprint is even larger than 1 m. Compared with our previous experimental results with a single wide field-of-view non-imaging receiver, an improvement in error-free beam footprint of >20% has been achieved. When this system is integrated with our recently proposed optical wireless based indoor localization system, both high speed wireless communication and mobility can be provided to users over the entire room. Furthermore, theoretical analysis has been carried out and the simulation results agree well with the experiments. In addition, since the rough location information of the user is available in our proposed system, instead of searching for the focused light spot over a large area on the focal plane of the lens, only a small possible area needs to be scanned. By further pre-setting a proper comparison threshold when searching for the focused light spot, the time needed for searching can be further reduced. PMID:22513552

  20. High Gain Submicrometer Optical Amplifier at Near-Infrared Communication Band

    NASA Astrophysics Data System (ADS)

    Wang, Xiaoxia; Zhuang, Xiujuan; Yang, Sen; Chen, Yu; Zhang, Qinglin; Zhu, Xiaoli; Zhou, Hong; Guo, Pengfei; Liang, Junwu; Huang, Yu; Pan, Anlian; Duan, Xiangfeng

    2015-07-01

    Nanoscale near-infrared optical amplification is important but remains a challenge to achieve. Here we report a unique design of silicon and erbium silicate core-shell nanowires for high gain submicrometer optical amplification in the near-infrared communication band. The high refraction index silicon core is used to tightly confine the optical field within the submicron structures, and the single crystalline erbium-ytterbium silicates shell is used as the highly efficient gain medium. Both theoretical and experimental results show that, by systematically tuning the core diameter and shell thickness, a large portion of the optical power can be selectively confined to the erbium silicate shell gain medium to enable a low loss waveguide and high gain optical amplifier. Experimental results further demonstrate that an optimized core-shell nanowire can exhibit an excellent net gain up to 3 1 dB mm-1 , which is more than 20 times larger than the previously reported best results on the micron-scale optical amplifiers.

  1. High Gain Submicrometer Optical Amplifier at Near-Infrared Communication Band.

    PubMed

    Wang, Xiaoxia; Zhuang, Xiujuan; Yang, Sen; Chen, Yu; Zhang, Qinglin; Zhu, Xiaoli; Zhou, Hong; Guo, Pengfei; Liang, Junwu; Huang, Yu; Pan, Anlian; Duan, Xiangfeng

    2015-07-10

    Nanoscale near-infrared optical amplification is important but remains a challenge to achieve. Here we report a unique design of silicon and erbium silicate core-shell nanowires for high gain submicrometer optical amplification in the near-infrared communication band. The high refraction index silicon core is used to tightly confine the optical field within the submicron structures, and the single crystalline erbium-ytterbium silicates shell is used as the highly efficient gain medium. Both theoretical and experimental results show that, by systematically tuning the core diameter and shell thickness, a large portion of the optical power can be selectively confined to the erbium silicate shell gain medium to enable a low loss waveguide and high gain optical amplifier. Experimental results further demonstrate that an optimized core-shell nanowire can exhibit an excellent net gain up to 31  dB mm(-1), which is more than 20 times larger than the previously reported best results on the micron-scale optical amplifiers. PMID:26207503

  2. The social construction of communication climate: An analysis of at-risk students in alternative high school

    NASA Astrophysics Data System (ADS)

    Souza, Tasha Jean

    1998-12-01

    Alternative high schools affect more potential high school dropouts than any other school or program and are designed to meet the needs of students who have had difficulty in conventional schools. This study examines the communication climate and constructions of caring in an alternative school for at-risk students by using a qualitative analysis grounded in the theoretical perspective of social constructionism. Observations and interviews were conducted over a six month time period. The first two chapters provide a review of literature and a detailed account of the methods used to conduct the study. Chapter Three describes the socially constructed nature of the school and the participants and the dialectical tensions of communication climate revealed from the analysis. The six dialectical tensions of communication climate are: (1) freedom/restraint, (2) disengagement/engagement, (3) personal communication/impersonal communication, (4) disconfirmation/confirmation, (5) equality/inequality, and (6) ambiguity/clarity. Although the school climate is comprised of each of these tensions, the data suggest that the interaction within the majority of classes created some common characteristics of the general communication climate at the school and can be characterized as one of freedom, disengagement, personal communication, disconfirmation, equality, and ambiguity. Chapter Four describes how caring was constructed and communicated. Although some students perceived some teachers as caring about students and about student learning, half of the students interviewed thought they were not learning or not learning much. Finally, Chapter Five provides a summary of the findings and a discussion of the results. The results of this study contribute to an understanding of the social construction of communication climate and caring in general, and within an alternative school for at-risk students, in specific. The results contribute to the understanding of the complexity of the jointly produced nature of communication climate and reveal the potential effect of communication climate and constructions of caring on teachers' instructional methods, teacher and student interaction, and student learning. Such information can aid pragmatically in the development or modification of programs designed to serve at-risk students, and theoretically in the understanding of the co-constructed nature of communication climate.

  3. Means and method for characterizing high power, ultra short laser pulses in a real time, on line manner

    DOEpatents

    Veligdan, J.T.

    1994-03-08

    An ultra short (<10 ps), high power laser pulse is temporally characterized by a system that uses a physical measurement of a wavefront that has been altered in a known manner. The system includes a first reflection switch to remove a portion of a pulse from a beam of pulses, then includes a second reflection switch, operating in a mode that is opposite to the first reflection switch, to slice off a portion of that removed portion. The sliced portion is then directed to a measuring device for physical measurement. The two reflection switches are arranged with respect to each other and with respect to the beam of ultra short pulses such that physical measurement of the sliced portion is related to the temporal measurement of the ultra short pulse by a geometric or trigonometric relationship. The reflection switches are operated by a control pulse that is directed to impinge on each of the reflection switches at a 90[degree] angle of incidence. 8 figures.

  4. Efficacy of acute caffeine ingestion for short-term high-intensity exercise performance: a systematic review.

    PubMed

    Astorino, Todd A; Roberson, Daniel W

    2010-01-01

    Caffeine is the most widely used drug in the world, commonly ingested in coffee, tea, soda, and energy drinks. Its ability to enhance muscular work has been apparent since the early 1900s. Caffeine typically increases endurance performance; however, efficacy of caffeine ingestion for short-term high-intensity exercise is equivocal, which may be explained by discrepancies in exercise protocols, dosing, and subjects' training status and habitual caffeine intake found across studies. The primary aim of this review is to critically examine studies that have tested caffeine's ability to augment performance during exercise dependent on nonoxidative metabolism such as sprinting, team sports, and resistance training. A review of the literature revealed 29 studies that measured alterations in short-term performance after caffeine ingestion. Each study was critically analyzed using the Physiotherapy Evidence Database (PEDro) scale. The mean PEDro score was 7.76 +/- 0.87. Eleven of 17 studies revealed significant improvements in team sports exercise and power-based sports with caffeine ingestion, yet these effects were more common in elite athletes who do not regularly ingest caffeine. Six of 11 studies revealed significant benefits of caffeine for resistance training. Some studies show decreased performance with caffeine ingestion when repeated bouts are completed. The exact mechanism explaining the ergogenic effect of caffeine for short-term exercise is unknown. PMID:19924012

  5. Short-Term Fates of High Sulfur Inputs in Northern California Vineyard Soils

    SciTech Connect

    E Hinckley; S Fendorf; P Matson

    2011-12-31

    The widespread application of elemental sulfur (S{sup 0}) to vineyards may have ecosystem effects at multiple scales. We evaluated the short-term fates of applied S{sup 0} in a Napa Valley vineyard; we determined changes in soil sulfur (S) speciation (measured by X-ray absorption near-edge structure (XANES) spectroscopy), soil pH, extractable sulfate (SO{sub 4}{sup 2-}), and total S to evaluate changes in acidity and soil S within the vineyard over time. Surface soil samples were collected immediately prior to and following two applications of S{sup 0} (6.7 kg S{sup 0} ha{sup -1}), with weekly collections in the 2 weeks between applications and following the last application. XANES spectra indicated that the majority of soil S persists in the +6 oxidation state and that S{sup 0} oxidizes within 7 days following application. Soil pH and extractable SO{sub 4}{sup 2-} measurements taken at 30 min after S{sup 0} application revealed generation of acidity and an increase in extractable SO{sub 4}{sup 2-}, but by 12 days after application, soil pH increased to approximately pre-application levels. These data suggest that the major consequence of reactive S applications in vineyards may be the accumulation of soil SO{sub 4}{sup 2-} and organic S during the growing season, which can be mobilized during storm events during the dormant (wet) season. In spatially-extensive winegrowing regions where these applications are made by hundreds of individual farmers each year, it will be important to understand the long-term implications of this perturbation to the regional S cycle.

  6. High speed fault tolerant secure communication for muon chamber using FPGA based GBTx emulator

    NASA Astrophysics Data System (ADS)

    Sau, Suman; Mandal, Swagata; Saini, Jogender; Chakrabarti, Amlan; Chattopadhyay, Subhasis

    2015-12-01

    The Compressed Baryonic Matter (CBM) experiment is a part of the Facility for Antiproton and Ion Research (FAIR) in Darmstadt at the GSI. The CBM experiment will investigate the highly compressed nuclear matter using nucleus-nucleus collisions. This experiment will examine lieavy-ion collisions in fixed target geometry and will be able to measure hadrons, electrons and muons. CBM requires precise time synchronization, compact hardware, radiation tolerance, self-triggered front-end electronics, efficient data aggregation schemes and capability to handle high data rate (up to several TB/s). As a part of the implementation of read out chain of Muon Cliamber(MUCH) [1] in India, we have tried to implement FPGA based emulator of GBTx in India. GBTx is a radiation tolerant ASIC that can be used to implement multipurpose high speed bidirectional optical links for high-energy physics (HEP) experiments and is developed by CERN. GBTx will be used in highly irradiated area and more prone to be affected by multi bit error. To mitigate this effect instead of single bit error correcting RS code we have used two bit error correcting (15, 7) BCH code. It will increase the redundancy which in turn increases the reliability of the coded data. So the coded data will be less prone to be affected by noise due to radiation. The data will go from detector to PC through multiple nodes through the communication channel. The computing resources are connected to a network which can be accessed by authorized person to prevent unauthorized data access which might happen by compromising the network security. Thus data encryption is essential. In order to make the data communication secure, advanced encryption standard [2] (AES - a symmetric key cryptography) and RSA [3], [4] (asymmetric key cryptography) are used after the channel coding. We have implemented GBTx emulator on two Xilinx Kintex-7 boards (KC705). One will act as transmitter and other will act as receiver and they are connected through optical fiber through small form-factor pluggable (SFP) port. We have tested the setup in the runtime environment using Xilinx Cliipscope Pro Analyzer. We also measure the resource utilization, throughput., power optimization of implemented design.

  7. New Measurements of High-Momentum Nucleons and Short-Range Structures in Nuclei

    SciTech Connect

    Fomin, N.; Arrington, J.; Asaturyan, R.; Benmokhtar, F.; Boeglin, W.; Bosted, P.; Bruell, A.; Bukhari, M. H. S.; Christy, M. E.; Chudakov, E.; Clasie, B.; Connell, S. H.; Dalton, M. M.; Daniel, A.; Day, D. B.; Dutta, D.; Ent, R.; El Fassi, L.; Fenker, H.; Filippone, B. W.; Garrow, K.; Gaskell, D.; Hill, C.; Holt, R. J.; Horn, T.; Jones, M. K.; Jourdan, J.; Kalantarians, N.; Keppel, C. E.; Kiselev, D.; Kotulla, M.; Lindgren, R.; Lung, A. F.; Malace, S.; Markowitz, P.; McKee, P.; Meekins, D. G.; Mkrtchyan, H.; Navasardyan, T.; Niculescu, G.; Opper, A. K.; Perdrisat, C.; Potterveld, D. H.; Punjabi, V.; Qian, X.; Reimer, P. E.; Roche, J.; Rodriguez, V. M.; Rondon, O.; Schulte, E.; Seely, J.; Segbefia, E.; Slifer, K.; Smith, G. R.; Solvignon, P.; Tadevosyan, V.; Tajima, S.; Tang, L.; Testa, G.; Trojer, R.; Tvaskis, V.; Vulcan, W. F.; Wasko, C.; Wesselmann, F. R.; Wood, S. A.; Wright, J.; Zheng, X.

    2012-02-01

    We present new, high-Q2 measurements of inclusive electron scattering from high-momentum nucleons in nuclei. This yields an improved extraction of the strength of two-nucleon correlations for several nuclei, including light nuclei where clustering effects can, for the first time, be examined. The data extend to the kinematic regime where three-nucleon correlations are expected to dominate and we observe significantly greater strength in this region than previous measurements.

  8. Innovative, High-Pressure, Cryogenic Control Valve: Short Face-to-Face, Reduced Cost

    NASA Technical Reports Server (NTRS)

    Wilkes, Karlin; Larsen, Ed; McCourt, Jackson

    2003-01-01

    A control valve that can throttle high-pressure cryogenic fluid embodies several design features that distinguish it over conventional valves designed for similar applications. Field and design engineers worked together to create a valve that would simplify installation, trim changes, and maintenance, thus reducing overall cost. The seals and plug stem packing were designed to perform optimally in cryogenic temperature ranges. Unlike conventional high-pressure cryogenic valves, the trim size can be changed independent of the body.

  9. High-Speed Switching Method of MOSFET Using Auxiliary Circuit Shorting Load

    NASA Astrophysics Data System (ADS)

    Noguchi, Toshihiko; Mizuno, Tomohiro

    This paper describes a high-speed switching method of MOSFETs applied to a chopper. By employing a set of auxiliary switch and diode in parallel with a load, the turn-off time can be reduced, which makes a high frequency drive possible. It was confirmed through experimental tests that an actual duty cycle of the main MOSFET was effectively improved by the proposed method, especially in a low-load range.

  10. New Measurements of High-Momentum Nucleons and Short-Range Structures in Nuclei

    DOE PAGESBeta

    Fomin, N.; Arrington, J.; Asaturyan, R.; Benmokhtar, F.; Boeglin, W.; Bosted, P.; Bruell, A.; Bukhari, M. H. S.; Christy, M. E.; Chudakov, E.; et al

    2012-02-01

    We present new, high-Q2 measurements of inclusive electron scattering from high-momentum nucleons in nuclei. This yields an improved extraction of the strength of two-nucleon correlations for several nuclei, including light nuclei where clustering effects can, for the first time, be examined. The data extend to the kinematic regime where three-nucleon correlations are expected to dominate and we observe significantly greater strength in this region than previous measurements.

  11. Short-term responses of the kidney to high altitude in mountain climbers

    PubMed Central

    Goldfarb-Rumyantzev, Alexander S.; Alper, Seth L.

    2014-01-01

    In high-altitude climbers, the kidneys play a crucial role in acclimatization and in mountain sickness syndromes [acute mountain sickness (AMS), high-altitude cerebral edema, high-altitude pulmonary edema] through their roles in regulating body fluids, electrolyte and acid–base homeostasis. Here, we discuss renal responses to several high-altitude-related stresses, including changes in systemic volume status, renal plasma flow and clearance, and altered acid–base and electrolyte status. Volume regulation is considered central both to high-altitude adaptation and to maladaptive development of mountain sickness. The rapid and powerful diuretic response to the hypobaric hypoxic stimulus of altitude integrates decreased circulating concentrations of antidiuretic hormone, renin and aldosterone, increased levels of natriuretic hormones, plasma and urinary epinephrine, norepinephrine, endothelin and urinary adrenomedullin, with increased insensible fluid losses and reduced fluid intake. The ventilatory and hormonal responses to hypoxia may predict susceptibility to AMS, also likely influenced by multiple genetic factors. The timing of altitude increases and adaptation also modifies the body's physiologic responses to altitude. While hypovolemia develops as part of the diuretic response to altitude, coincident vascular leak and extravascular fluid accumulation lead to syndromes of high-altitude sickness. Pharmacological interventions, such as diuretics, calcium blockers, steroids, phosphodiesterase inhibitors and β-agonists, may potentially be helpful in preventing or attenuating these syndromes. PMID:23525530

  12. A Framework for Assessing High School Students' Intercultural Communicative Competence in a Computer-Mediated Language Learning Project

    ERIC Educational Resources Information Center

    Peng, Hsinyi; Lu, Wei-Hsin; Wang, Chao-I

    2009-01-01

    The purposes of this study were to identify the essential dimensions of intercultural communicative competence (ICC) and to establish a framework for assessing the ICC level of high school students that included a self-report inventory and scoring rubrics for online interaction in intercultural contexts. A total of 472 high school students from

  13. Using a Computer-based Messaging System at a High School To Increase School/Home Communication.

    ERIC Educational Resources Information Center

    Burden, Mitzi K.

    Minimal communication between school and home was found to contribute to low performance by students at McDuffie High School (South Carolina). This report describes the experience of establishing a computer-based telephone messaging system in the high school and involving parents, teachers, and students in its use. Additional strategies employed…

  14. A Framework for Assessing High School Students' Intercultural Communicative Competence in a Computer-Mediated Language Learning Project

    ERIC Educational Resources Information Center

    Peng, Hsinyi; Lu, Wei-Hsin; Wang, Chao-I

    2009-01-01

    The purposes of this study were to identify the essential dimensions of intercultural communicative competence (ICC) and to establish a framework for assessing the ICC level of high school students that included a self-report inventory and scoring rubrics for online interaction in intercultural contexts. A total of 472 high school students from…

  15. High Performance Computing and Communications: Technology for the National Information Infrastructure. Supplement to the President's Fiscal Year 1995 Budget.

    ERIC Educational Resources Information Center

    Office of Science and Technology Policy, Washington, DC. National Science and Technology Council.

    The federal High Performance Computing and Communications (HPCC) program was created to accelerate the development of future generations of high performance computers and networks and the use of these resources in the federal government and throughout the American economy. This report describes the HPCC program which is developing computing,…

  16. Short-peptide fusion inhibitors with high potency against wild-type and enfuvirtide-resistant HIV-1.

    PubMed

    Chong, Huihui; Yao, Xue; Qiu, Zonglin; Sun, Jianping; Zhang, Meng; Waltersperger, Sandro; Wang, Meitian; Liu, Shan-Lu; Cui, Sheng; He, Yuxian

    2013-03-01

    Peptides derived from the C-terminal heptad repeat (C peptides) of HIV-1 gp41 are potent inhibitors against virus entry. However, development of a short C peptide possessing high anti-HIV potency is considered a daunting challenge. We recently discovered that the residues Met626 and Thr627 preceding the pocket-binding domain of the C peptide adopt a unique M-T hook structure that is crucial for the design of HIV-1 fusion inhibitors. In this study, we first presented a proof-of-concept prototype that the M-T hook residues can dramatically improve the antiviral activity and thermostability of a short C peptide. We then generated a 24-mer peptide termed MT-SC22EK by incorporating the M-T hook structure to the N terminus of the poorly active short C peptide SC22EK. Amazingly, MT-SC22EK inhibited HIV-1-mediated cell fusion and infection at a level comparable to C34, T1249, SC29EK, and sifuvirtide, and it was highly active against diverse HIV-1 subtypes and variants, including those T20 (enfuvirtide) and SC29EK-resistant viruses. The high-resolution crystal structure of MT-SC22EK reveals the N-terminal M-T hook conformation folded by incorporated Met626 and Thr627 and identifies the C-terminal boundary critical for the anti-HIV activity. Collectively, our studies provide new insights into the mechanisms of HIV-1 fusion and its inhibition. PMID:23233535

  17. Effects of Active Versus Passive Recovery on Power Output During Repeated Bouts of Short Term, High Intensity Exercise

    PubMed Central

    Connolly, Declan AJ.; Brennan, Kevin M.; Lauzon, Christie D.

    2003-01-01

    ATP repletion following exhaustive exercise is approximated to be 90-95% complete in 3 minutes, and is crucial in the performance of short duration, high intensity work. Few studies appear to have used this 3-minute interval in the investigation of recovery modes, blood lactate accumulation and power output. Thus, our aim was to investigate changes in peak power (PP), average power (AP) and blood lactate during repeated bouts of high intensity, short duration cycling, comprising active and passive recovery modes lasting 3 minutes. Seven male cyclists (age 21.8±3.3 yrs, mass 73.0±3.8kgs, height 177.3±3.4cm) performed both an active (3 min at 80rpm & 1kg resistance) and a passive recovery (no work between bouts) protocol. Following a warm-up, subjects performed six 15-second maximal sprints against a fixed workload of 5.5kg. Mean PP across the six trials was 775±11.2Watts (W) and 772±33.4W for active and passive protocols respectively; whereas mean AP was 671±26.4W and 664±10.0W, respectively. Neither was significantly different. There was a significant difference within trials for both peak power and average power (p<0.05), with both values decreasing over time. However, the decrease was significantly smaller for both PP and AP values during the active recovery protocol (p<0.05). In the current study, variation in power output cannot be explained by lactate values, as values did not differ between the active and passive protocol (p=0.37). Lactate values did differ significantly between trials within protocols (p<0.05). The results of this study suggest that an active recovery of 3 minutes between high intensity, short duration exercise bouts significantly increases PP and AP compared to a passive recovery, irrespective of changes in blood lactate levels. PMID:24616610

  18. Formation of short high-power laser radiation pulses in excimer mediums

    NASA Astrophysics Data System (ADS)

    Losev, V. F., Sr.; Ivanov, N. G.; Panchenko, Yu. N.

    2007-06-01

    Presently an excimer mediums continue are examined as one of variants for formation of powerful and over powerful pulses of laser radiation with duration from units of nanosecond up to tens femtosecond. The researches on such powerful installations as "NIKE" (USA) and << SUPER ASHURA >>, Japan) proceed in this direction. The main advantage of excimer mediums is the opportunity to work in a frequency mode, absence of restriction on the size of active area, high uniformity of a gas working medium, high efficiency (up to 10 %) and wide spectral range of laser radiation (KrF, XeCl ~ 2nm, XeF (C-A), Xe IICl ~ 50-100 nanometers). Research in area of high quality laser beams formation in excimer mediums and its amplification in high power amplifiers are carried out the long time in Institute of High Current Electronics SB RAS, Tomsk, Russia. The wide aperture XeCl laser system of MELS-4k is used for these investigations. Last time we take part in program on development of high power excimer laser system with a petawatt level of power. This system supposes the formation and amplification high quality laser beams with different pulse duration from units of nanosecond up to tens femtosecond. We research the possibility of laser beams formation in excimer mediums with ps-ns pulse duration having the low noise and divergence near to diffraction limit. In other hand, we are developing the wide aperture XeF(C-A) amplifier with optical pump on base electron accelerator. According to our estimations of the XeF(C-A) amplifier based on the converter of e-beam energy to the Xe II* fluorescence at 172 nm will allow to obtain up to 100 TW peak power in a 30 fs pulse.

  19. Electron dynamics and transverse-kick elimination in a high-field short-period helical microwave undulator

    SciTech Connect

    Chang, C.; Shumail, M.; Tantawi, S.; Neilson, J.; Pellegrini, C.

    2012-10-15

    Single electron dynamics for a circular polarized standing wave (CPSW) undulator synthesized from a corrugated cavity operating with a very low-loss HE{sub 11} mode are analyzed. The mechanism of the transverse drift of the CPSW undulator and its elimination are researched, and the tapered-field ends are found effectively to suppress the kick. A prototype of the CPSW undulator with the characters of short undulating-period 1.4 cm, high field K {approx} 1, large aperture {approx} 5 cm, and variable polarization is designed and modeled, whose 3-dimensional electromagnetic fields are used to research the suppression of the transverse kick.

  20. Isolated short attosecond pulse generated using a two-color laser and a high-order pulse

    SciTech Connect

    Du, Hongchuan; Hu, Bitao; Wang, Huiqiao

    2010-06-15

    An efficient method to generate an isolated short attosecond pulse is investigated theoretically. A broadband extreme ultraviolet supercontinuum harmonics can be generated when a model He{sup +} ion is exposed to the combination of an intense few-cycle laser pulse and a low-frequency field. By properly adding a 27th harmonics pulse to resonantly excite the He{sup +} ion, the intensity of the high-order harmonic generation (HHG) plateau is enhanced by 3-4 orders of magnitude. As a result, an isolated 24-as pulse with a bandwidth of 138 eV can be obtained directly from the supercontinuum around the cutoff of HHG.