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Sample records for coder characteristics influence

  1. VLSI Universal Noiseless Coder

    NASA Technical Reports Server (NTRS)

    Rice, Robert F.; Lee, Jun-Ji; Fang, Wai-Chi

    1989-01-01

    Proposed universal noiseless coder (UNC) compresses stream of data signals for efficient transmission in channel of limited bandwidth. Noiseless in sense original data completely recoverable from output code. System built as very-large-scale integrated (VLSI) circuit, compressing data in real time at input rates as high as 24 Mb/s, and possibly faster, depending on specific design. Approach yields small, lightweight system operating reliably and consuming little power. Constructed as single, compact, low-power VLSI circuit chip. Design of VLSI circuit chip made specific to code algorithms. Entire UNC fabricated in single chip, worst-case power dissipation less than 1 W.

  2. Instruct coders' manual

    NASA Technical Reports Server (NTRS)

    Friend, J.

    1971-01-01

    A manual designed both as an instructional manual for beginning coders and as a reference manual for the coding language INSTRUCT, is presented. The manual includes the major programs necessary to implement the teaching system and lists the limitation of current implementation. A detailed description is given of how to code a lesson, what buttons to push, and what utility programs to use. Suggestions for debugging coded lessons and the error messages that may be received during assembly or while running the lesson are given.

  3. Computationally efficient lossless image coder

    NASA Astrophysics Data System (ADS)

    Sriram, Parthasarathy; Sudharsanan, Subramania I.

    1999-12-01

    Lossless coding of image data has been a very active area of research in the field of medical imaging, remote sensing and document processing/delivery. While several lossless image coders such as JPEG and JBIG have been in existence for a while, their compression performance for encoding continuous-tone images were rather poor. Recently, several state of the art techniques like CALIC and LOCO were introduced with significant improvement in compression performance over traditional coders. However, these coders are very difficult to implement using dedicated hardware or in software using media processors due to their inherently serial nature of their encoding process. In this work, we propose a lossless image coding technique with a compression performance that is very close to the performance of CALIC and LOCO while being very efficient to implement both in hardware and software. Comparisons for encoding the JPEG- 2000 image set show that the compression performance of the proposed coder is within 2 - 5% of the more complex coders while being computationally very efficient. In addition, the encoder is shown to be parallelizabl at a hierarchy of levels. The execution time of the proposed encoder is smaller than what is required by LOCO while the decoder is 2 - 3 times faster that the execution time required by LOCO decoder.

  4. Picture data compression coder using subband/transform coding with a Lempel-Ziv-based coder

    NASA Technical Reports Server (NTRS)

    Glover, Daniel R. (Inventor)

    1995-01-01

    Digital data coders/decoders are used extensively in video transmission. A digitally encoded video signal is separated into subbands. Separating the video into subbands allows transmission at low data rates. Once the data is separated into these subbands it can be coded and then decoded by statistical coders such as the Lempel-Ziv based coder.

  5. Image compression with QM-AYA adaptive binary arithmetic coder

    NASA Astrophysics Data System (ADS)

    Cheng, Joe-Ming; Langdon, Glen G., Jr.

    1993-01-01

    The Q-coder has been reported in the literature, and is a renorm-driven binary adaptive arithmetic coder. A similar renorm-driven coder, the QM coder, uses the same approach with an initial attack to more rapidly estimate the statistics in the beginning, and with a different state table. The QM coder is the adaptive binary arithmetic coder employed in the JBIG and JPEG image compression algorithms. The QM-AYA arithmetic coder is similar to the QM coder, with a different state table, that offers balanced improvements to the QM probability estimation for the less skewed distributions. The QM-AYA performs better when the probability estimate is near 0.5 for each binary symbol. An approach for constructing effective index change tables for Q-coder type adaptation is discussed.

  6. Serial turbo trellis coded modulation using a serially concatenated coder

    NASA Technical Reports Server (NTRS)

    Divsalar, Dariush (Inventor); Dolinar, Samuel J. (Inventor); Pollara, Fabrizio (Inventor)

    2010-01-01

    Serial concatenated trellis coded modulation (SCTCM) includes an outer coder, an interleaver, a recursive inner coder and a mapping element. The outer coder receives data to be coded and produces outer coded data. The interleaver permutes the outer coded data to produce interleaved data. The recursive inner coder codes the interleaved data to produce inner coded data. The mapping element maps the inner coded data to a symbol. The recursive inner coder has a structure which facilitates iterative decoding of the symbols at a decoder system. The recursive inner coder and the mapping element are selected to maximize the effective free Euclidean distance of a trellis coded modulator formed from the recursive inner coder and the mapping element. The decoder system includes a demodulation unit, an inner SISO (soft-input soft-output) decoder, a deinterleaver, an outer SISO decoder, and an interleaver.

  7. Serial turbo trellis coded modulation using a serially concatenated coder

    NASA Technical Reports Server (NTRS)

    Divsalar, Dariush (Inventor); Dolinar, Samuel J. (Inventor); Pollara, Fabrizio (Inventor)

    2011-01-01

    Serial concatenated trellis coded modulation (SCTCM) includes an outer coder, an interleaver, a recursive inner coder and a mapping element. The outer coder receives data to be coded and produces outer coded data. The interleaver permutes the outer coded data to produce interleaved data. The recursive inner coder codes the interleaved data to produce inner coded data. The mapping element maps the inner coded data to a symbol. The recursive inner coder has a structure which facilitates iterative decoding of the symbols at a decoder system. The recursive inner coder and the mapping element are selected to maximize the effective free Euclidean distance of a trellis coded modulator formed from the recursive inner coder and the mapping element. The decoder system includes a demodulation unit, an inner SISO (soft-input soft-output) decoder, a deinterleaver, an outer SISO decoder, and an interleaver.

  8. Novel wavelet coder for color image compression

    NASA Astrophysics Data System (ADS)

    Wang, Houng-Jyh M.; Kuo, C.-C. Jay

    1997-10-01

    A new still image compression algorithm based on the multi-threshold wavelet coding (MTWC) technique is proposed in this work. It is an embedded wavelet coder in the sense that its compression ratio can be controlled depending on the bandwidth requirement of image transmission. At low bite rates, MTWC can avoid the blocking artifact from JPEG to result in a better reconstructed image quality. An subband decision scheme is developed based on the rate-distortion theory to enhance the image fidelity. Moreover, a new quantization sequence order is introduced based on our analysis of error energy reduction in significant and refinement maps. Experimental results are given to demonstrate the superior performance of the proposed new algorithm in its high reconstructed quality for color and gray level image compression and low computational complexity. Generally speaking, it gives a better rate- distortion tradeoff and performs faster than most existing state-of-the-art wavelet coders.

  9. Research review: A comparison of levels of job satisfaction between traditional hospital coders and coders using computerized encoders.

    PubMed

    Osborn, C E; Zale, K E

    1996-08-01

    Computerized encoders that assist medical record department coders in making ICD-9-CM disease and operative code selections have been available for approximately 10 years but there have been no studies to evaluate job satisfaction among coders using this technology. The purpose of this study was to determine whether there is a difference in job satisfaction between coders who use computerized encoders and those who do not. The Job Descriptive Index was mailed to hospital medical record departments in Cleveland, Columbus, and Cincinnati, Ohio; the return rate was 93.5 percent. Results indicated that individuals in these three cities coding by the traditional manual method were more satisfied with their jobs than those who used computer technology. The coders in the traditional group were more challenged by their jobs and had more positive interactions with their peers and supervisors. Also traditional coders were satisfied with the pay they received; coders using computerized encoders believed that their pay was inadequate.

  10. Software Certification - Coding, Code, and Coders

    NASA Technical Reports Server (NTRS)

    Havelund, Klaus; Holzmann, Gerard J.

    2011-01-01

    We describe a certification approach for software development that has been adopted at our organization. JPL develops robotic spacecraft for the exploration of the solar system. The flight software that controls these spacecraft is considered to be mission critical. We argue that the goal of a software certification process cannot be the development of "perfect" software, i.e., software that can be formally proven to be correct under all imaginable and unimaginable circumstances. More realistically, the goal is to guarantee a software development process that is conducted by knowledgeable engineers, who follow generally accepted procedures to control known risks, while meeting agreed upon standards of workmanship. We target three specific issues that must be addressed in such a certification procedure: the coding process, the code that is developed, and the skills of the coders. The coding process is driven by standards (e.g., a coding standard) and tools. The code is mechanically checked against the standard with the help of state-of-the-art static source code analyzers. The coders, finally, are certified in on-site training courses that include formal exams.

  11. Application of region selective embedded zerotree wavelet coder in CT image compression.

    PubMed

    Li, Guoli; Zhang, Jian; Wang, Qunjing; Hu, Cungang; Deng, Na; Li, Jianping

    2005-01-01

    Compression is necessary in medical image preservation because of the huge data quantity. Medical images are different from the common images because of their own characteristics, for example, part of information in CT image is useless, and it's a kind of resource waste to save this part information. The region selective EZW coder was proposed with which only useful part of image was selected and compressed, and the test image provides good result.

  12. Design and performance of an analysis-by-synthesis class of predictive speech coders

    NASA Technical Reports Server (NTRS)

    Rose, Richard C.; Barnwell, Thomas P., III

    1990-01-01

    The performance of a broad class of analysis-by-synthesis linear predictive speech coders is quantified experimentally. The class of coders includes a number of well-known techniques as well as a very large number of speech coders which have not been named or studied. A general formulation for deriving the parametric representation used in all of the coders in the class is presented. A new coder, named the self-excited vocoder, is discussed because of its good performance with low complexity, and because of the insight this coder gives to analysis-by-synthesis coders in general. The results of a study comparing the performances of different members of this class are presented. The study takes the form of a series of formal subjective and objective speech quality tests performed on selected coders. The results of this study lead to some interesting and important observations concerning the controlling parameters for analysis-by-synthesis speech coders.

  13. Vector adaptive predictive coder for speech and audio

    NASA Technical Reports Server (NTRS)

    Chen, Juin-Hwey (Inventor); Gersho, Allen (Inventor)

    1990-01-01

    A real-time vector adaptive predictive coder which approximates each vector of K speech samples by using each of M fixed vectors in a first codebook to excite a time-varying synthesis filter and picking the vector that minimizes distortion. Predictive analysis for each frame determines parameters used for computing from vectors in the first codebook zero-state response vectors that are stored at the same address (index) in a second codebook. Encoding of input speech vectors s.sub.n is then carried out using the second codebook. When the vector that minimizes distortion is found, its index is transmitted to a decoder which has a codebook identical to the first codebook of the decoder. There the index is used to read out a vector that is used to synthesize an output speech vector s.sub.n. The parameters used in the encoder are quantized, for example by using a table, and the indices are transmitted to the decoder where they are decoded to specify transfer characteristics of filters used in producing the vector s.sub.n from the receiver codebook vector selected by the vector index transmitted.

  14. A robust CELP coder with source-dependent channel coding

    NASA Technical Reports Server (NTRS)

    Sukkar, Rafid A.; Kleijn, W. Bastiaan

    1990-01-01

    A CELP coder using Source Dependent Channel Encoding (SDCE) for optimal channel error protection is introduced. With SDCE, each of the CELP parameters are encoded by minimizing a perceptually meaningful error criterion under prevalent channel conditions. Unlike conventional channel coding schemes, SDCE allows for optimal balance between error detection and correction. The experimental results show that the CELP system is robust under various channel bit error rates and displays a graceful degradation in SSNR as the channel error rate increases. This is a desirable property to have in a coder since the exact channel conditions cannot usually be specified a priori.

  15. Successful Aging: Early Influences and Contemporary Characteristics

    ERIC Educational Resources Information Center

    Pruchno, Rachel A.; Wilson-Genderson, Maureen; Rose, Miriam; Cartwright, Francine

    2010-01-01

    Purpose: Positing that successful aging has independent, yet related, dimensions that are both objective and subjective, we examine how early influences and contemporary characteristics define 4 groups of people. Design and Methods: Data were gathered from 5,688 persons aged 50-74 years living in New Jersey who participated in telephone…

  16. A trellis-searched APC (adaptive predictive coding) speech coder

    SciTech Connect

    Malone, K.T. ); Fischer, T.R. . Dept. of Electrical and Computer Engineering)

    1990-01-01

    In this paper we formulate a speech coding system that incorporates trellis coded vector quantization (TCVQ) and adaptive predictive coding (APC). A method for optimizing'' the TCVQ codebooks is presented and experimental results concerning survivor path mergings are reported. Simulation results are given for encoding rates of 16 and 9.6 kbps for a variety of coder parameters. The quality of the encoded speech is deemed excellent at an encoding rate of 16 kbps and very good at 9.6 kbps. 13 refs., 2 figs., 4 tabs.

  17. Comparative performance of wavelets and JPEG coders at high quality

    NASA Astrophysics Data System (ADS)

    Algazi, V. Ralph; Estes, Robert R., Jr.

    1997-04-01

    In recent work, we have examined the performance of wavelet coders using a perceptually relevant image quality metric, the picture quality scale (PQS). In that study, we considered some of the design options available with respect to choice of wavelet basis, quantizer, and method for error- free encoding of the quantized coefficients, including the EZW methodology. A specific combination of these design options provides the best trade off between performance and PQS quality. Here, we extend this comparison by evaluating the performance of JPEG and the previously chosen optimal wavelet scheme, focusing principally on the high quality range.

  18. Influence of Rocket Engine Characteristics on Shaft Sealing Technology Needs

    NASA Technical Reports Server (NTRS)

    Keba, John E.

    1999-01-01

    This paper presents viewgraphs of The Influence of Rocket Engine Characteristics on Shaft Sealing Technology Needs. The topics include: 1) Rocket Turbomachinery Shaft Seals (Inter-Propellant-Seal (IPS) Systems, Lift-off Seal Systems, and Technology Development Needs); 2) Rocket Engine Characteristics (Engine cycles, propellants, missions, etc., Influence on shaft sealing requirements); and 3) Conclusions.

  19. The Influence of Personality Characteristics on Children's Intrinsic Reading Motivation

    ERIC Educational Resources Information Center

    Medford, Emma; McGeown, Sarah P.

    2012-01-01

    Research suggests that children's motivation to read is influenced by their level of reading skill and reading self-concept. However, it is possible that characteristics unrelated to reading, such as underlying personality characteristics, may also influence children's motivation to read. The current study examined the extent to which children's…

  20. Vector excitation speech or audio coder for transmission or storage

    NASA Technical Reports Server (NTRS)

    Davidson, Grant (Inventor); Gersho, Allen (Inventor)

    1989-01-01

    A vector excitation coder compresses vectors by using an optimum codebook designed off line, using an initial arbitrary codebook and a set of speech training vectors exploiting codevector sparsity (i.e., by making zero all but a selected number of samples of lowest amplitude in each of N codebook vectors). A fast-search method selects a number N.sub.c of good excitation vectors from the codebook, where N.sub.c is much smaller tha ORIGIN OF INVENTION The invention described herein was made in the performance of work under a NASA contract, and is subject to the provisions of Public Law 96-517 (35 USC 202) under which the inventors were granted a request to retain title.

  1. Multiresolutional encoding and decoding in embedded image and video coders

    NASA Astrophysics Data System (ADS)

    Xiong, Zixiang; Kim, Beong-Jo; Pearlman, William A.

    1998-07-01

    We address multiresolutional encoding and decoding within the embedded zerotree wavelet (EZW) framework for both images and video. By varying a resolution parameter, one can obtain decoded images at different resolutions from one single encoded bitstream, which is already rate scalable for EZW coders. Similarly one can decode video sequences at different rates and different spatial and temporal resolutions from one bitstream. Furthermore, a layered bitstream can be generated with multiresolutional encoding, from which the higher resolution layers can be used to increase the spatial/temporal resolution of the images/video obtained from the low resolution layer. In other words, we have achieved full scalability in rate and partial scalability in space and time. This added spatial/temporal scalability is significant for emerging multimedia applications such as fast decoding, image/video database browsing, telemedicine, multipoint video conferencing, and distance learning.

  2. A low-delay 8 Kb/s backward-adaptive CELP coder

    NASA Technical Reports Server (NTRS)

    Neumeyer, L. G.; Leblanc, W. P.; Mahmoud, S. A.

    1990-01-01

    Code excited linear prediction coding is an efficient technique for compressing speech sequences. Communications quality of speech can be obtained at bit rates below 8 Kb/s. However, relatively large coding delays are necessary to buffer the input speech in order to perform the LPC analysis. A low delay 8 Kb/s CELP coder is introduced in which the short term predictor is based on past synthesized speech. A new distortion measure that improves the tracking of the formant filter is discussed. Formal listening tests showed that the performance of the backward adaptive coder is almost as good as the conventional CELP coder.

  3. Influence of inlet conditions on vortex characteristics

    NASA Astrophysics Data System (ADS)

    Essiptchouk, A.

    2011-09-01

    Vortex chambers are normally used for arc stabilization in linear plasma torches. In the present work, the effect of uniformity of the gas inlet channel distribution on the stabilizing characteristics of a swirled flow is studied numerically. The formation of a complex flow pattern with a toroidal recirculating flow area inside the vortex chamber is observed. For some regimes, two local maxima of the tangential velocity are observed in the middle section of the chamber. It is shown that an increment of the number of gas inlet channels leads to a more uniform gas input with disappearance of the second maximum, which increases the velocity amplification coefficient and, correspondingly, results in a better stabilizing effect. The obtained profiles of the radial distribution of the tangential velocity are compared with the results of Oseen's equation for an unconfined vortex.

  4. How Friendship Network Characteristics Influence Subjective Well-Being

    ERIC Educational Resources Information Center

    van der Horst, Mariska; Coffe, Hilde

    2012-01-01

    This article explores how friendship network characteristics influence subjective well-being (SWB). Using data from the 2003 General Social Survey of Canada, three components of the friendship network are differentiated: number of friends, frequency of contact, and heterogeneity of friends. We argue that these characteristics shape SWB through the…

  5. Land Use and Hydrogeological Characteristics Influence Groundwater Invertebrate Communities.

    PubMed

    Tione, María Laura; Bedano, José Camilo; Blarasin, Mónica

    2016-08-01

    We examine the influence of land use and hydrogeological characteristics on the abundance, composition and structure of groundwater invertebrate communities in a loessic aquifer from Argentina. Seven wells, selected according to surrounding land use and hydrogeological characteristics, were sampled twice. Groundwater was characterized as sodium bicarbonate, bicarbonate sulfate or sulfate type. NO3(-) was detected in all samples. Land use in the area surrounding the well, unsaturated zone thickness and geochemical characteristics of groundwater influenced the abundance, composition and community structure of groundwater invertebrates. Copepoda, Oligochaeta, Cladocera, Ostracoda and Amphipoda were highly influenced by land use, particularly by point pollution sources that produced higher abundance and changes in taxonomic composition. The lowest invertebrate abundance was observed at the wells situated in areas with the thickest unsaturated zone. Groundwater salinity and geochemical type influenced the presence of certain species, particularly Stygonitocrella sp.

  6. Embedding adaptive arithmetic coder in chaos-based cryptography

    NASA Astrophysics Data System (ADS)

    Li, Heng-Jian; Zhang, Jia-Shu

    2010-05-01

    In this study an adaptive arithmetic coder is embedded in the Baptista-type chaotic cryptosystem for implementing secure data compression. To build the multiple lookup tables of secure data compression, the phase space of chaos map with a uniform distribution in the search mode is divided non-uniformly according to the dynamic probability estimation of plaintext symbols. As a result, more probable symbols are selected according to the local statistical characters of plaintext and the required number of iterations is small since the more probable symbols have a higher chance to be visited by the chaotic search trajectory. By exploiting non-uniformity in the probabilities under which a number of iteration to be coded takes on its possible values, the compression capability is achieved by adaptive arithmetic code. Therefore, the system offers both compression and security. Compared with original arithmetic coding, simulation results on Calgary Corpus files show that the proposed scheme suffers from a reduction in compression performance less than 12% and is not susceptible to previously carried out attacks on arithmetic coding algorithms.

  7. Custom CMOS Reed Solomon coder for the Hubble Space Telescope

    NASA Technical Reports Server (NTRS)

    Whitaker, S.; Cameron, K.; Owsley, P.; Maki, G.

    1990-01-01

    A VLSI coder is presented that can function either as an encoder or decoder for Reed-Solomon codes. VLSI is one approach to implementing high-performance Reed-Solomon decoders. There are three VLSI technologies that could be used: gate arrays, standard cells, and full custom. The first two approaches are relatively easy to implement, but are limited in both performance and density. Full-custom VLSI is used to achieve both circuit density and speed, and allows control of the amount of interconnect. Speed, which is a function of capacitance, which is a function of interconnect, is an important parameter in high-performance VLSI. A single 8.2 mm x 8.4 mm, 200,000 transistor CMOS chip implementation of the Reed-Solomon code required by the Hubble Space Telescope is reported. The chip features a 10-MHz sustained byte rate independent of error pattern. The 1.6-micron CMOS integrated circuit has complete decoder and encoder functions and uses a single data/system clock. Block lengths up to 255 bytes and shortened codes are supported with no external buffering. Erasure corrections and random error corrections are supported with programmable correction of up to 10 symbol errors. Correction time is independent of error pattern and the number of errors in the incoming message.

  8. Disparity in coding concordance: do physicians and coders agree?

    PubMed

    Lorence, Daniel P; Ibrahim, Ibrahim Awad

    2003-01-01

    Increasing demands for large-scale comparative analysis of health care costs has led to a similar demand for consistently classified data. Evidence-based medicine demands evidence that can be trusted. This study sought to assess managers' observed levels of agreement with physician code selections when classifying patient data. Using a non-sampled research design of both mailed and telephone surveys, we employ a nationwide cross-section of over 16,000 accredited US medical record managers. As a main outcome measure, we evaluate reported levels of agreement between physician and information manager code selections made when classifying patient data. Results indicate about 19 percent of respondents report that coder-physician classification disagreement occurred on more than 5 percent of all patient encounters. In some cases, disagreement occurred in 20 percent or more instances of code selection. This phenomenon shows significant variation across key demographic and market indicators. With the growing practice of measuring coded data quality as an outcome of health care financial performance, along with adoption of electronic classification and patient record systems, the accuracy of coded data is likely to remain uncertain in the absence of more consistent classification and coding practices.

  9. Inter-Coder Agreement in One-to-Many Classification: Fuzzy Kappa

    PubMed Central

    Kirilenko, Andrei P.; Stepchenkova, Svetlana

    2016-01-01

    Content analysis involves classification of textual, visual, or audio data. The inter-coder agreement is estimated by making two or more coders to classify the same data units, with subsequent comparison of their results. The existing methods of agreement estimation, e.g., Cohen’s kappa, require that coders place each unit of content into one and only one category (one-to-one coding) from the pre-established set of categories. However, in certain data domains (e.g., maps, photographs, databases of texts and images), this requirement seems overly restrictive. The restriction could be lifted, provided that there is a measure to calculate the inter-coder agreement in the one-to-many protocol. Building on the existing approaches to one-to-many coding in geography and biomedicine, such measure, fuzzy kappa, which is an extension of Cohen’s kappa, is proposed. It is argued that the measure is especially compatible with data from certain domains, when holistic reasoning of human coders is utilized in order to describe the data and access the meaning of communication. PMID:26933956

  10. Identity and environmentalism: the influence of community characteristics.

    PubMed

    Owen, Ann; Videras, Julio; Wu, Stephen

    2010-01-01

    This paper examines the influence of community characteristics on self-proclaimed environmentalism. We find that the composition of a community affects the likelihood that a person claims to be a strong environmentalist even after controlling for individual political leaning, socio-economic characteristics, and pro-environment behaviors. Individuals are more likely to claim to be strong environmentalists if they live in areas where a larger share of the population has post-graduate degrees, if they live in heavily Democratic areas, or if they live in heavily Republican areas. These community effects occur only when individuals are predisposed to take on an environmental identity.

  11. How Friendship Network Characteristics Influence Subjective Well-Being.

    PubMed

    van der Horst, Mariska; Coffé, Hilde

    2012-07-01

    This article explores how friendship network characteristics influence subjective well-being (SWB). Using data from the 2003 General Social Survey of Canada, three components of the friendship network are differentiated: number of friends, frequency of contact, and heterogeneity of friends. We argue that these characteristics shape SWB through the benefits they bring. Benefits considered are more social trust, less stress, better health, and more social support. Results confirm that higher frequency of contacts and higher number of friends, as well as lower heterogeneity of the friendship network are related to more social trust, less stress, and a better health. Frequency of contact and number of friends, as well as more heterogeneity of the friendship network increase the chance of receiving help from friends. With the exception of receiving help from friends, these benefits are in turn related to higher levels of SWB. Only the frequency of meeting friends face-to-face has a remaining positive direct influence on SWB.

  12. Influence of geophysical factors on oblique-sounder ionospheric characteristics

    SciTech Connect

    Baranets, A.N.; Blagoveshchenskaya, N.F.; Borisova, T.D.; Bubnov, V.A.

    1988-10-01

    The purpose of this paper is to study the influence of geophysical factors, including magnetoionospheric disturbances, on decameter wave propagation over extended paths using oblique sounding (OS) data, and also to compare experimental and calculated OS ionograms for various conditions of radio waver propagation (season, time of day). Variations of oblique-sounder ionospheric characteristics along a 9000 km long subauroral path for various geophysical conditions are considered. A comparison is made of experimental and calculated ionograms of oblique sounding.

  13. Development of the CODER System: A Testbed for Artificial Intelligence Methods in Information Retrieval.

    ERIC Educational Resources Information Center

    Fox, Edward A.

    1987-01-01

    Discusses the CODER system, which was developed to investigate the application of artificial intelligence methods to increase the effectiveness of information retrieval systems, particularly those involving heterogeneous documents. Highlights include the use of PROLOG programing, blackboard-based designs, knowledge engineering, lexicological…

  14. Characteristics of health maintenance organizations and their influence on efficiency.

    PubMed

    Draper, D A; Solti, I; Ozcan, Y A

    2000-02-01

    This study examines the efficiency of Health Maintenance Organizations (HMOs) based on a sample of 249 HMOs operating in the United States in 1995. Data Envelopment Analysis (DEA) was used to calculate the level of technical efficiency for each HMO included in the sample. Further descriptive analyses were conducted examining various structural and operational characteristics of HMOs and their impact on efficiency. Federal qualification status, Medicare programme participation, combined Medicare and Medicaid programmes participation, chain affiliation and size were found to be significant influences on HMO efficiency.

  15. The influence of product and oral characteristics on swallowing.

    PubMed

    Engelen, Lina; Fontijn-Tekamp, Anneke; van der Bilt, Andries

    2005-08-01

    The urge to swallow food could be triggered by a threshold level in both food particle size and lubrication of the food bolus. Thus, both oral physiology and product characteristics may influence the swallowing threshold. We quantified the swallowing threshold in a group of 266 healthy adult subjects (age 42 +/- 12 years) by counting the number of chewing cycles needed to prepare food for swallowing. The influence of oral physiology on the swallowing threshold was determined by measuring salivary flow rate, maximum bite force and masticatory performance. We used about 10 cm(3) of bread, toast, melba toast, breakfast cake, peanuts and cheese to determine the influence on the swallowing threshold of various food characteristics, e.g. hardness, moisture and fat. Furthermore, we tested the effect of buttering the bread, toast, melba toast and breakfast cake on the swallowing threshold. Salivary flow rates were significantly and negatively correlated with the number of chewing cycles of melba toast and breakfast cake. Hence, subjects with more saliva needed less chewing cycles for these dry products. Maximum bite force and masticatory performance had an influence on the swallowing threshold for the hard products only (carrot and peanut). Although significant, the correlation coefficients were less than 0.28. Thus, the oral physiology parameters explained less than 10% of the variance in the swallowing threshold. We found significantly different numbers of chewing cycles for the various foods, ranging from 17 for cake to 63 for carrot. Hard and dry products needed more chewing cycles until swallowing. Buttering the food significantly reduced the number of chewing cycles needed before swallowing. This was especially true for the dry products cake, melba toast and toast. Hard and dry products require more chewing cycles and longer time in mouth until swallowing for sufficient breakdown to take place and for enough saliva to be added to form a coherent bolus safe for

  16. A hardware architecture for a context-adaptive binary arithmetic coder

    NASA Astrophysics Data System (ADS)

    Sudharsanan, Subramania; Cohen, Adam

    2005-03-01

    The H.264 video compression standard uses a context-adaptive binary arithmetic coder (CABAC) as an entropy coding mechanism. While the coder provides excellent compression efficiency, it is computationally demanding. On typical general-purpose processors, it can take up to hundreds of cycles to encode a single bit. In this paper, we propose an architecture for a CABAC encoder that can easily be incorporated into system-on-chip designs for H.264 compression. The CABAC is inherently serial and we divide the problem into several stages to derive a design that can provide a throughput of two cycles per encoded bit. The engine proposed is capable of handling binarization of the syntactical elements and provides the coded bit-stream via a first-in first-out buffer. The design is implemented on an Altera FPGA platform that can run at 50 MHz enabling a 25 Mbps encoding rate.

  17. On the optimality of code options for a universal noiseless coder

    NASA Technical Reports Server (NTRS)

    Yeh, Pen-Shu; Rice, Robert F.; Miller, Warner

    1991-01-01

    A universal noiseless coding structure was developed that provides efficient performance over an extremely broad range of source entropy. This is accomplished by adaptively selecting the best of several easily implemented variable length coding algorithms. Custom VLSI coder and decoder modules capable of processing over 20 million samples per second are currently under development. The first of the code options used in this module development is shown to be equivalent to a class of Huffman code under the Humblet condition, other options are shown to be equivalent to the Huffman codes of a modified Laplacian symbol set, at specified symbol entropy values. Simulation results are obtained on actual aerial imagery, and they confirm the optimality of the scheme. On sources having Gaussian or Poisson distributions, coder performance is also projected through analysis and simulation.

  18. An ODA-based coder/decoder for multimedia medical documents.

    PubMed Central

    Marti, V.; Navio, J.; Salvador, C. H.; Pulido, N.; Muñoz, A.; Gonzalez, M. A.; Dueñas, A.

    1993-01-01

    This paper describes the prototype of a coder/decoder based on the Open Document Architecture (ODA) standard for management of medical documents, as well as the working environment in which it has been developed. The prototype has been assessed in an X-Windows-equipped workstation with a relational database containing patient folders (text and still images) from the departmental information system of the liver transplantation unit. PMID:8130599

  19. A 4.8 kbps code-excited linear predictive coder

    NASA Technical Reports Server (NTRS)

    Tremain, Thomas E.; Campbell, Joseph P., Jr.; Welch, Vanoy C.

    1988-01-01

    A secure voice system STU-3 capable of providing end-to-end secure voice communications (1984) was developed. The terminal for the new system will be built around the standard LPC-10 voice processor algorithm. The performance of the present STU-3 processor is considered to be good, its response to nonspeech sounds such as whistles, coughs and impulse-like noises may not be completely acceptable. Speech in noisy environments also causes problems with the LPC-10 voice algorithm. In addition, there is always a demand for something better. It is hoped that LPC-10's 2.4 kbps voice performance will be complemented with a very high quality speech coder operating at a higher data rate. This new coder is one of a number of candidate algorithms being considered for an upgraded version of the STU-3 in late 1989. The problems of designing a code-excited linear predictive (CELP) coder to provide very high quality speech at a 4.8 kbps data rate that can be implemented on today's hardware are considered.

  20. A progressive transmission image coder using linear phase uniform filterbanks as block transforms.

    PubMed

    Tran, T D; Nguyen, T Q

    1999-01-01

    This paper presents a novel image coding scheme using M-channel linear phase perfect reconstruction filterbanks (LPPRFBs) in the embedded zerotree wavelet (EZW) framework introduced by Shapiro (1993). The innovation here is to replace the EZWs dyadic wavelet transform by M-channel uniform-band maximally decimated LPPRFBs, which offer finer frequency spectrum partitioning and higher energy compaction. The transform stage can now be implemented as a block transform which supports parallel processing and facilitates region-of-interest coding/decoding. For hardware implementation, the transform boasts efficient lattice structures, which employ a minimal number of delay elements and are robust under the quantization of lattice coefficients. The resulting compression algorithm also retains all the attractive properties of the EZW coder and its variations such as progressive image transmission, embedded quantization, exact bit rate control, and idempotency. Despite its simplicity, our new coder outperforms some of the best image coders published previously in the literature, for almost all test images (especially natural, hard-to-code ones) at almost all bit rates.

  1. Maternal characteristics influence response to DHA during pregnancy.

    PubMed

    Gould, J F; Anderson, A J; Yelland, L N; Gibson, R A; Makrides, M

    2016-05-01

    We explored the degree to which maternal and offspring outcomes resulting from consuming prenatal docosahexaenoic acid (DHA, 800mg/day) in a clinical trial were influenced by maternal characteristics. Among non-smokers, women who received DHA had heavier babies (adjusted mean difference (MD)=99g 95% CI 45-153, p<0.01; interaction p=0.01) and fewer low birth weight babies than control women (adjusted relative risk=0.43 95% CI 0.25-0.74, p<0.01; interaction p=0.01). From women who had not completed further education, children in the DHA group had higher cognitive scores at 18 months compared with control children (adjusted MD=3.15 95% CI 0.93-5.37, p=0.01; interaction p<0.01). Conversely, the children of women who completed further education in the DHA group had lower language scores than control children (adjusted MD -2.82 95% CI -4.90 to -0.73, p=0.01; interaction p=0.04). Our results support the notion that responsiveness to prenatal DHA may depend on the characteristics of specific population subgroups.

  2. Influence of Students' Characteristics and Feelings on Cognitive Achievement in Religious Education

    ERIC Educational Resources Information Center

    van der Zee, Theo; Hermans, Chris; Aarnoutse, Cor

    2008-01-01

    Whereas educational research has provided evidence that students' characteristics affect their performance, at this stage little is known about which characteristics influence their learning processes and achievement in religious education. This article looks into characteristics that influence students' cognitive achievement in religious…

  3. Gamma radiation influence on technological characteristics of wheat flour

    NASA Astrophysics Data System (ADS)

    Teixeira, Christian A. H. M.; Inamura, Patricia Y.; Uehara, Vanessa B.; Mastro, Nelida L. d.

    2012-08-01

    This study aimed at determining the influence of gamma radiation on technological characteristics of wheat (Triticum sativum) flour and physical properties of pan breads made with this flour. The bread formulation included wheat flour, water, milk, salt, sugar, yeast and butter. The α-amylase activity of wheat flour irradiated with 1, 3 and 9 kGy in a Gammacell 220 (AECL), one day, five days and one month after irradiation was evaluated. Deformation force, height and weight of breads prepared with the irradiated flour were also determined. The enzymatic activity increased—reduction of falling number time—as radiation dose increased, their values being 397 s (0 kGy), 388 s (1 kGy), 343 s (3 kGy) and 293 s (9 kGy) respectively, remaining almost constant over the period of one month. Pan breads prepared with irradiated wheat flour showed increased weight. Texture analysis showed that bread made of irradiated flour presented an increase in maximum deformation force. The results indicate that wheat flour ionizing radiation processing may confer increased enzymatic activity on bread making and depending on the irradiation dose, an increase in weight, height and deformation force parameters of pan breads made of it.

  4. Influence of habitat characteristics on shore-spawning kokanee

    USGS Publications Warehouse

    Whitlock, Steven L.; Quist, Michael; Dux, Andrew M.

    2014-01-01

    Sockeye Salmon Oncorhynchus nerka and kokanee (lacustrine Sockeye Salmon) commonly spawn in both lentic and lotic environments; however, the habitat requirements of shore spawners are virtually unknown relative to those of stream spawners. A laboratory experiment and an in situ incubation study were conducted to better understand the influence of habitat characteristics on the shoreline incubation success of kokanee. The laboratory experiment assessed kokanee intragravel survival, fry emergence, and fry condition in response to eight substrate treatments. The in situ study, conducted at three major shoreline spawning sites in Lake Pend Oreille, Idaho, evaluated the effect of depth, substrate composition, dissolved oxygen, shoreline slope, and groundwater on intragravel survival. Substrate size composition was generally a poor predictor of survival in both the laboratory experiment and in situ study; although, fry condition and counts of emerged fry in the laboratory were lowest for the substrate treatment that had the highest proportion of fine sediment. Results of the in situ study suggest that groundwater flow plays an important role in enhancing intragravel survival in habitats generally considered unsuitable for spawning.

  5. Island characteristics within wetlands influence waterbird nest success and abundance

    USGS Publications Warehouse

    Hartman, Christopher; Ackerman, Josh; Herzog, Mark

    2016-01-01

    Coastal waterbird populations are threatened by habitat loss and degradation from urban and agricultural development and forecasted sea level rise associated with climate change. Remaining wetlands often must be managed to ensure that waterbird habitat needs, and other ecosystem functions, are met. For many waterbirds, the availability of island nesting habitat is important for conserving breeding populations. We used linear mixed models to investigate the influence of pond and island landscape characteristics on nest abundance and nest success of American avocets (Recurvirostra americana), black-necked stilts (Himantopus mexicanus), and Forster's terns (Sterna forsteri) in San Francisco Bay, California, USA, based on a 9-year dataset that included >9,000 nests. Nest abundance and nest success were greatest within ponds and on individual islands located either <1 km or >4 km from San Francisco Bay. Further, nest abundance was greater within ponds with relatively few islands, and on linear-shaped, highly elongated islands compared to more rounded islands. Nest success was greater on islands located away from the nearest surrounding pond levee. Compared to more rounded islands, linear islands contained more near-water habitat preferred by many nesting waterbirds. Islands located away from pond levees may provide greater protection from terrestrial egg and chick predators. Our results indicate that creating and maintaining a few, relatively small, highly elongated and narrow islands away from mainland levees, in as many wetland ponds as possible would be effective at providing waterbirds with preferred nesting habitat.

  6. MeshEZW: an image coder using mesh and finite elements

    NASA Astrophysics Data System (ADS)

    Landais, Thomas; Bonnaud, Laurent; Chassery, Jean-Marc

    2003-08-01

    In this paper, we present a new method to compress the information in an image, called MeshEZW. The proposed approach is based on the finite elements method, a mesh construction and a zerotree method. The zerotree method is an adaptive of the EZW algorithm with two new symbols for increasing the performance. These steps allow a progressive representation of the image by the automatic construction of a bitstream. The mesh structure is adapted to the image compression domain and is defined to allow video comrpession. The coder is described and some preliminary results are discussed.

  7. Bipolar disorder with seasonal pattern: clinical characteristics and gender influences

    PubMed Central

    Geoffroy, Pierre Alexis; Bellivier, Frank; Scott, Jan; Boudebesse, Carole; Lajnef, Mohamed; Gard, Sébastien; Kahn, Jean-Pierre; Azorin, Jean-Michel; Henry, Chantal; Leboyer, Marion; Etain, Bruno

    2013-01-01

    Bipolar disorder (BD) has a multifactorial etiology with heterogeneous clinical presentations. Around 25% of BD patients may present with a depressive seasonal pattern (SP). However, there is limited scientific data on the prevalence of SP, its clinical manifestations and any gender influence. Four hundred and fifty-two BD I and II cases (62% female), recruited from three French university-affiliated psychiatric departments, were assessed for SP. Clinical, treatments and socio-demographic variables were obtained from structured interviews. One hundred and two (23%) cases met DSM-IV criteria for SP, with similar frequency according to gender. Multivariate analysis showed a significant association between SP and BD II (OR=1.99, p=0.01), lifetime history of rapid cycling (OR=2.05, p=0.02), eating disorders (OR=2.94, p=0.003) and total number of depressive episodes (OR=1.13, p=0.002). 71% of cases were correctly classified by this analysis. However, when stratifying the analyses by gender, SP was associated with BD II subtype (OR=2.89, p=0.017) and total number of depressive episodes (OR=1.21, p=0.0018) in males but with rapid cycling (OR=3.02, p=0.0027) and eating disorders (OR=2.60, p=0.016) in females. This is the first study to identify different associations between SP and clinical characteristics of BD according to gender. We suggest that SP represents a potentially important specifier of BD. Our findings indicate that seasonality may reflect increased severity or complexity of disorder. PMID:23931033

  8. The Influence of Job Characteristics and Self-Directed Learning Orientation on Workplace Learning

    ERIC Educational Resources Information Center

    Raemdonck, Isabel; Gijbels, David; van Groen, Willemijn

    2014-01-01

    Given the increasing importance of learning at work, we set out to examine the factors which influence workplace learning behaviour. The study investigated the influence of the job characteristics from Karasek's Job Demand Control Support model and the personal characteristic self-directed learning orientation on workplace learning. A total…

  9. Influence of toxic endophyte-infected fescue on sperm characteristics and endocrine factors of yearling Brahman-influenced bulls

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sixteen (mean age = 1.1 +/- 0.1 yr; mean BW = 478 +/- 34 kg) Brahman-influenced bulls were used to determine the influence of fescue type on sperm characteristics and serum concentrations of prolactin, cortisol, and testosterone. Bulls were blocked by BW, scrotal circumference (SC), and pregrazing...

  10. Do the Managerial Characteristics of Schools Influence Their Performance?

    ERIC Educational Resources Information Center

    Agasisti, Tommaso; Bonomi, Francesca; Sibiano, Piergiacomo

    2012-01-01

    Purpose: The purpose of this paper is to investigate the role of governance and managerial characteristics of schools. More specifically, the aim is to individuate the factors that are associated to higher schools' performances, as measured through student achievement. Design/methodology/approach: The research is conducted by means of a survey in…

  11. Individual Characteristics Influencing Teachers' Class Use of Computers.

    ERIC Educational Resources Information Center

    van Braak, Johan

    2001-01-01

    Describes a study of Belgian secondary school teachers that investigated the relationship between computer use in the classroom and influencing factors on an individual level. Considers age, gender, teaching a technology-related subject, computer attitudes, and innovativeness; and uses stepwise logistic regression to analyze the strongest…

  12. Adolescent Characteristics Influencing Parental Power Perceptions in the Family.

    ERIC Educational Resources Information Center

    McDonald, Gerald W.

    The influence of the sex, grade, religiosity and birth order of adolescents on adolescents perceptions of the parental power structure in the family was examined in this study. Parental Power was conceptualized as a multidimensional variable following the French and Raven (1959) formulation of social power bases. The parental power dimensions…

  13. Polymerization Parameters Influencing the QCM Response Characteristics of BSA MIP

    PubMed Central

    Phan, Nam V. H.; Sussitz, Hermann F.; Lieberzeit, Peter A.

    2014-01-01

    Designing Molecularly Imprinted Polymers for sensing proteins is still a somewhat empirical process due to the inherent complexity of protein imprinting. Based on Bovine Serum Albumin as a model analyte, we explored the influence of a range of experimental parameters on the final sensor responses. The optimized polymer contains 70% cross linker. Lower amounts lead to higher sensitivity, but also sensor response times substantially increase (to up to 10 h) at constant imprinting effect (signal ratio MIP/NIP on quartz crystal microbalance—QCM). However, by shifting the polymer properties to more hydrophilic by replacing methacrylic acid by acrylic acid, part of the decreased sensitivity can be recovered leading to appreciable sensor responses. Changing polymer morphology by bulk imprinting and nanoparticle approaches has much lower influence on sensitivity. PMID:25587416

  14. Sargassum filipendula alginate from Brazil: seasonal influence and characteristics.

    PubMed

    Bertagnolli, Caroline; Espindola, Ana Paula D M; Kleinübing, Sirlei Jaiana; Tasic, Ljubica; da Silva, Meuris Gurgel Carlos

    2014-10-13

    The aim of this work is focused on the extraction and characterization of the Brazilian seaweed Sargassum filipendula alginate. Alginates obtained at different seasons were characterized by liquid state nuclear magnetic resonance spectroscopy and scanning electron microscopy. The alginate extraction efficiency was about 20%. Different seasons of the year and different stages in the life cycle of Sargassum sp. in southeastern Brazil influenced the M/G and, consequently, the technological properties of extracted alginates.

  15. How Landscape Characteristics Influence Spatial Patterns of Transpiration

    NASA Astrophysics Data System (ADS)

    Hassler, S. K.; Weiler, M.; Zehe, E.; Blume, T.

    2015-12-01

    Quantifying transpiration in landscapes remains a challenging task. Especially bridging the gap between tree- or plot-scale measurements and information on the landscape scale which could be gathered from remote sensing, digital elevation models or forest inventories still poses considerable problems. These problems reach from errors associated with the measurements to the reliability of representing transpiration amounts by large-scale data. In this study we analyse spatial patterns of sap velocity to identify the importance of tree- or site-specific characteristics for transpiration at the landscape scale. We set up multiple linear regression models for a dataset of daily sap velocities for 61 trees at 24 locations in mixed beech and oak forests in a catchment in Luxemburg, recorded during the growing season of 2014. As predictors we use the tree-specific characteristics species, diameter and height and the site-specific characteristics basal area and number of stems for the respective stands as well as landscape attributes such as aspect, slope position and geology. Analysing the importance of these predictors could be useful for upscaling tree-based measurements to the landscape-scale based on data from digital elevation models, forest inventories or remote sensing. We also assess the temporal dynamics of the importance of tree- vs. site-specific predictors and link them to typical controls for sap flow such as atmospheric demand and soil moisture. First results indicate that site-specific predictors contribute considerably to the explained variance of the linear models. However, remotely sensed information explained very little of the variation in daily sap velocity patterns. Further analyses will quantify to which extent we can use the landscape-scale information from digital elevation models, geology and forest inventories to upscale tree-based transpiration estimates.

  16. Chemistry in interstellar space. [environment characteristics influencing reaction dynamics

    NASA Technical Reports Server (NTRS)

    Donn, B.

    1973-01-01

    The particular characteristics of chemistry in interstellar space are determined by the unique environmental conditions involved. Interstellar matter is present at extremely low densities. Large deviations from thermodynamic equilibrium are, therefore, to be expected. A relatively intense ultraviolet radiation is present in many regions. The temperatures are in the range from 5 to 200 K. Data concerning the inhibiting effect of small activation energies in interstellar clouds are presented in a table. A summary of measured activation energies or barrier heights for exothermic exchange reactions is also provided. Problems of molecule formation are discussed, taking into account gas phase reactions and surface catalyzed processes.

  17. Strong focusing influence on high gain FEL characteristics

    SciTech Connect

    Smirnov, A.; Varfolomeev, A.

    1995-12-31

    The use of intrinsic alternating focusing in a linac-driven FEL with planar undulator is considered numerically. The analysis is done on the basis of TDA code for soft X-ray FEL with FD lattice implementing focusing of quadrupole and periodic sextupole type. The influence of the focusing (type and phase advance) on FEL performance and the reasons of difference in FEL performance for focusing of two kinds are analyzed. A possibility of some kind of beam conditioning for intrinsic focusing is discussed.

  18. Influence of technology on magnetic tape storage device characteristics

    NASA Technical Reports Server (NTRS)

    Gniewek, John J.; Vogel, Stephen M.

    1994-01-01

    There are available today many data storage devices that serve the diverse application requirements of the consumer, professional entertainment, and computer data processing industries. Storage technologies include semiconductors, several varieties of optical disk, optical tape, magnetic disk, and many varieties of magnetic tape. In some cases, devices are developed with specific characteristics to meet specification requirements. In other cases, an existing storage device is modified and adapted to a different application. For magnetic tape storage devices, examples of the former case are 3480/3490 and QIC device types developed for the high end and low end segments of the data processing industry respectively, VHS, Beta, and 8 mm formats developed for consumer video applications, and D-1, D-2, D-3 formats developed for professional video applications. Examples of modified and adapted devices include 4 mm, 8 mm, 12.7 mm and 19 mm computer data storage devices derived from consumer and professional audio and video applications. With the conversion of the consumer and professional entertainment industries from analog to digital storage and signal processing, there have been increasing references to the 'convergence' of the computer data processing and entertainment industry technologies. There has yet to be seen, however, any evidence of convergence of data storage device types. There are several reasons for this. The diversity of application requirements results in varying degrees of importance for each of the tape storage characteristics.

  19. Characteristics of leadership that influence clinical learning: a narrative review.

    PubMed

    Walker, Rachel; Cooke, Marie; Henderson, Amanda; Creedy, Debra K

    2011-11-01

    Leadership has been consistently implied in fostering clinical learning. However there is a lack of clarity about the form leadership should take. Limited quantitative research indicated a narrative approach to review literature from a broad perspective. A framework to guide the synthesis was developed to ensure a rigorous review process. Preliminary reading and review of papers using search terms nursing and leadership and clinical learning and learning culture narrowed the inclusion criteria to 245 papers published between 2000 and 2010. Given the diversity of the papers' focus, aim and context, a refined screening process justified the inclusion of twenty-six papers in the review. A critical appraisal of these peer-reviewed quantitative, qualitative and commentary papers identified factors/elements integral to effective leadership. Across the literature leadership was discussed in relation to two broad themes: influence of leadership on organisational learning and development and; influence of leadership on undergraduate clinical education. The factors central to leadership emerged as transformative principles, the role of the nurse unit/ward manager, collaboration and relationship building and role-modelling. The review has raised some suggestions for future research aimed at examining the impact of a leadership capacity building intervention that supports clinical learning.

  20. Individual Variation in Life History Characteristics Can Influence Extinction Risk

    SciTech Connect

    Jager, H I

    2001-01-01

    The white sturgeon (Acipenser transmontanus) shows great individual variation in the age at maturation. This study examines the consequences of model assumptions about individual variation in the age at maturation on predicted population viability. I considered: (1) the effects of variation in age at maturation alone; (2) the effects of heritability; and (3) the influence of a stable and an altered selective regime. Two selective regimes represented conditions before and after the impoundment of a river, blocking access of anadromous white sturgeon populations to the ocean. In contrast to previous simulation studies, I found that increased individual variation in the age at maturity did not necessarily lead to a higher likelihood of persistence. Individual variation increased the simulated likelihood of persistence when the variation was heritable and the selective regime had changed such that the mean age at maturity was no longer optimal.

  1. Donor characteristics can influence overall transplant activities: the Italian experience.

    PubMed

    Bertoni, E; Rosati, A; Zanazzi, M; Becherelli, P; Gallo, M; Salvadori, M

    2004-01-01

    The notable increase in organ donations and transplants in Italy in recent years has lead to the development of an atypical approach to kidney transplantation. All propitious considerations left aside regarding the organ donation rate which has placed Italy among the European leaders, a careful comparative evaluation of the data taken from Italian and international registries demonstrates that renal transplantations in Italy have not shared the same significant growth. The typology of the donors has influenced in a decisive way not only the number of renal transplantations, but also the access to transplant for some age groups and probably even the quality and cost. The overall view which emerges is complex and somewhat contradictory, but we believe that this perspective can furnish solid arguments for choices that need not to be delayed for the living donor transplant, the divulgence of a donation culture in the population, and the criteria for the allocation of the organs.

  2. Manual Signing in Adults with Intellectual Disability: Influence of Sign Characteristics on Functional Sign Vocabulary

    ERIC Educational Resources Information Center

    Meuris, Kristien; Maes, Bea; De Meyer, Anne-Marie; Zink, Inge

    2014-01-01

    Purpose: The purpose of this study was to investigate the influence of sign characteristics in a key word signing (KWS) system on the functional use of those signs by adults with intellectual disability (ID). Method: All 507 signs from a Flemish KWS system were characterized in terms of phonological, iconic, and referential characteristics.…

  3. Exploring Factors of Media Characteristic Influencing Flow in Learning through Virtual Worlds

    ERIC Educational Resources Information Center

    Choi, Beomkyu; Baek, Youngkyun

    2011-01-01

    This study aims to find out factors of media characteristic which are considered to influence flow in learning through virtual worlds. One hundred ninety eight elementary students who are eleven to twelve years old participated in this study. After the exploratory factor analysis, to extract media characteristics of virtual worlds, seventy-eight…

  4. The Influence of Perceived Characteristics of Management Development Programs on Employee Outcomes

    ERIC Educational Resources Information Center

    Ardts, Joost C. A.; van der Velde, Mandy E. G.; Maurer, Todd J.

    2010-01-01

    Employees' perceptions of Management Development (MD) programs is the topic of this study. The purpose is to examine the influence of three important perceived characteristics of MD programs on relevant MD outcomes. The MD characteristics are: availability of role models, perceived control, and understanding the MD program. Outcomes are:…

  5. Well characteristics influencing arsenic concentrations in ground water.

    PubMed

    Erickson, Melinda L; Barnes, Randal J

    2005-10-01

    Naturally occurring arsenic contamination is common in ground water in the upper Midwest. Arsenic is most likely to be present in glacial drift and shallow bedrock wells that lie within the footprint of northwest provenance Late Wisconsinan glacial drift. Elevated arsenic is more common in domestic wells and in monitoring wells than it is in public water system wells. Arsenic contamination is also more prevalent in domestic wells with short screens set in proximity to an upper confining unit, such as glacial till. Public water system wells have distinctly different well-construction practices and well characteristics when compared to domestic and monitoring wells. Construction practices such as exploiting a thick, coarse aquifer and installing a long well screen yield good water quantity for public water system wells. Coincidentally, these construction practices also often yield low arsenic water. Coarse aquifer materials have less surface area for adsorbing arsenic, and thus less arsenic available for potential mobilization. Wells with long screens set at a distance from an upper confining unit are at lower risk of exposure to geochemical conditions conducive to arsenic mobilization via reductive mechanisms such as reductive dissolution of metal hydroxides and reductive desorption of arsenic.

  6. Influence of sociodemographic characteristics on human mobility [corrected].

    PubMed

    Lenormand, Maxime; Louail, Thomas; Cantú-Ros, Oliva G; Picornell, Miguel; Herranz, Ricardo; Arias, Juan Murillo; Barthelemy, Marc; Miguel, Maxi San; Ramasco, José J

    2015-05-20

    Human mobility has been traditionally studied using surveys that deliver snapshots of population displacement patterns. The growing accessibility to ICT information from portable digital media has recently opened the possibility of exploring human behavior at high spatio-temporal resolutions. Mobile phone records, geolocated tweets, check-ins from Foursquare or geotagged photos, have contributed to this purpose at different scales, from cities to countries, in different world areas. Many previous works lacked, however, details on the individuals' attributes such as age or gender. In this work, we analyze credit-card records from Barcelona and Madrid and by examining the geolocated credit-card transactions of individuals living in the two provinces, we find that the mobility patterns vary according to gender, age and occupation. Differences in distance traveled and travel purpose are observed between younger and older people, but, curiously, either between males and females of similar age. While mobility displays some generic features, here we show that sociodemographic characteristics play a relevant role and must be taken into account for mobility and epidemiological modelization.

  7. Maternal characteristics and clinical diagnoses influence obstetrical outcomes in Indonesia.

    PubMed

    Adisasmita, Asri; Smith, Carl V; El-Mohandes, Ayman A E; Deviany, Poppy Elvira; Ryon, Judith J; Kiely, Michele; Rogers-Bloch, Quail; Gipson, Reginald F

    2015-07-01

    This Indonesian study evaluates associations between near-miss status/death with maternal demographic, health care characteristics, and obstetrical complications, comparing results using retrospective and prospective data. The main outcome measures were obstetric conditions and socio-economic factors to predict near-miss/death. We abstracted all obstetric admissions (1,358 retrospective and 1,240 prospective) from two district hospitals in East Java, Indonesia between 4/1/2009 and 5/15/2010. Prospective data added socio-economic status, access to care and referral patterns. Reduced logistic models were constructed, and multivariate analyses used to assess association of risk variables to outcome. Using multivariate analysis, variables associated with risk of near-miss/death include postpartum hemorrhage (retrospective AOR 5.41, 95 % CI 2.64-11.08; prospective AOR 10.45, 95 % CI 5.59-19.52) and severe preeclampsia/eclampsia (retrospective AOR 1.94, 95 % CI 1.05-3.57; prospective AOR 3.26, 95 % CI 1.79-5.94). Associations with near-miss/death were seen for antepartum hemorrhage in retrospective data (AOR 9.34, 95 % CI 4.34-20.13), and prospectively for poverty (AOR 2.17, 95 % CI 1.33-3.54) and delivering outside the hospital (AOR 2.04, 95 % CI 1.08-3.82). Postpartum hemorrhage and severe preeclampsia/eclampsia are leading causes of near-miss/death in Indonesia. Poverty and delivery outside the hospital are significant risk factors. Prompt recognition of complications, timely referrals, standardized care protocols, prompt hospital triage, and structured provider education may reduce obstetric mortality and morbidity. Retrospective data were reliable, but prospective data provided valuable information about barriers to care and referral patterns.

  8. Filter characteristics influencing circulating tumor cell enrichment from whole blood.

    PubMed

    Coumans, Frank A W; van Dalum, Guus; Beck, Markus; Terstappen, Leon W M M

    2013-01-01

    A variety of filters assays have been described to enrich circulating tumor cells (CTC) based on differences in physical characteristics of blood cells and CTC. In this study we evaluate different filter types to derive the properties of the ideal filter for CTC enrichment. Between 0.1 and 10 mL of whole blood spiked with cells from tumor cell lines were passed through silicon nitride microsieves, polymer track-etched filters and metal TEM grids with various pore sizes. The recovery and size of 9 different culture cell lines was determined and compared to the size of EpCAM+CK+CD45-DNA+ CTC from patients with metastatic breast, colorectal and prostate cancer. The 8 µm track-etched filter and the 5 µm microsieve had the best performance on MDA-231, PC3-9 and SKBR-3 cells, enriching >80% of cells from whole blood. TEM grids had poor recovery of ∼25%. Median diameter of cell lines ranged from 10.9-19.0 µm, compared to 13.1, 10.7, and 11.0 µm for breast, prostate and colorectal CTC, respectively. The 11.4 µm COLO-320 cell line had the lowest recovery of 17%. The ideal filter for CTC enrichment is constructed of a stiff, flat material, is inert to blood cells, has at least 100,000 regularly spaced 5 µm pores for 1 ml of blood with a ≤10% porosity. While cell size is an important factor in determining recovery, other factors must be involved as well. To evaluate a filtration procedure, cell lines with a median size of 11-13 µm should be used to challenge the system.

  9. Influence of smoking on audiological characteristics of hearing function.

    PubMed

    Gegenava, Kh A; Japaridze, Sh V; Kevanishvile, Z Sh; Lomidze, L S; Khechenashvili, T R

    2015-02-01

    Cigarette smoking and related diseases are global problem of health. Discussion regarding influence of smoking on hearing function has been continued about 20 years. The aim of our study was estimation of relation between smoking and development of cochlear neuritis. Research was conducted at Ltd. National Centre of ENT - Japaridze-Kevanishvili clinic and Ltd.Audiology National Center. The data were collected from September 2011 to December 2013. Cross- sectional observational study was carried out. 600 persons (mean age - 45.4±10.4) were enrolled in the research. After filling the informed consent persons were divided into two groups: smokers (300 smokers, apparently healthy persons, mean age 44.3±10.6 years) and control group (300 healthy non-smoker persons, mean age 46.5±10.2 years). All persons completed a questionnaire, which includes questions about smoking status too. The inclusion criterion in smokers group was a smoking habit during 5 years at least 10 cigarettes per day. Otoscopy and Acoustic impedance test (timpanometry, reflexometry, testing for Eustachian tube conductivity) were used for verification of outer and middle-ear normality. Pure Tone Audiometry was performed for hearing measure and identifies hearing nerve condition. Obtained results were statistically treated by the student's t-distribution. For minimal level of significance was taken p<0,05. In smokers group hearing loss was proved in 31.33% (94 persons) and in control group - in 17.34% (52 persons). Hearing-loss vs. normal-hearing ratio amounted hence to 0.46 (P<0.01) in the smokers group and to 0.21 (P<0.01) in the nonsmokers'. Hearing loss in smokers may be provided by different pathological mechanisms.

  10. Influence of the seismic noise characteristics on noise correlations

    NASA Astrophysics Data System (ADS)

    Krüger, F.; Pedersen, H. A.

    2005-12-01

    Cross-correlating seismic noise to obtain the Green function between two seismic sensors is a promising new technique for crustal tomography. We use data from 38 temporary broadband sensors in Finland to study how the nature of the seismic noise influences noise correlations. The study area is particularly well adapted for this study as the lateral variations of surface wave velocities are very small. We apply a processing technique which makes it possible to extract broadband signals between 2s and 35s period without applying any signal clipping. The extracted Green's functions are symmetrical at low and high-frequencies, but are strongly direction dependent around the two microseismic peaks (at approximately 15s and 8s). For these periods the signal amplitude varies by a factor of 90 between different azimuths. The maximum amplitudes are obtained for east-west profiles for the first microseismic peak and for east-west and north-south profiles for the second microseismic peak. The phase velocities when defined are however correct for all azimuths when all the traces in a given direction are used for slant stack. The group velocities calculated on individual traces do on the contrary vary strongly with azimuth, with a 1/cos dependence. We also apply f-k analysis on data from the NORSAR (Norway) and Gräfenberg (Germany) arrays as well as a small-aperture array in Finland to constrain the arrival directions of the coherent part of the noise. The microseismic noise generation is located west of the array for the first microseismic peak and west and north of the array for the second microseismic peak, in excellent agreement with the noise correlations. The f-k analysis also confirms that the noise generators are more randomly distributed for the long period (25s-50s) and short period (2s-4s) part of the noise. We conclude that in some frequency bands the noise in the study area is dominated by plane energy wavefronts, with strong phase perturbations. The profile

  11. Toward enhancing the distributed video coder under a multiview video codec framework

    NASA Astrophysics Data System (ADS)

    Lee, Shih-Chieh; Chen, Jiann-Jone; Tsai, Yao-Hong; Chen, Chin-Hua

    2016-11-01

    The advance of video coding technology enables multiview video (MVV) or three-dimensional television (3-D TV) display for users with or without glasses. For mobile devices or wireless applications, a distributed video coder (DVC) can be utilized to shift the encoder complexity to decoder under the MVV coding framework, denoted as multiview distributed video coding (MDVC). We proposed to exploit both inter- and intraview video correlations to enhance side information (SI) and improve the MDVC performance: (1) based on the multiview motion estimation (MVME) framework, a categorized block matching prediction with fidelity weights (COMPETE) was proposed to yield a high quality SI frame for better DVC reconstructed images. (2) The block transform coefficient properties, i.e., DCs and ACs, were exploited to design the priority rate control for the turbo code, such that the DVC decoding can be carried out with fewest parity bits. In comparison, the proposed COMPETE method demonstrated lower time complexity, while presenting better reconstructed video quality. Simulations show that the proposed COMPETE can reduce the time complexity of MVME to 1.29 to 2.56 times smaller, as compared to previous hybrid MVME methods, while the image peak signal to noise ratios (PSNRs) of a decoded video can be improved 0.2 to 3.5 dB, as compared to H.264/AVC intracoding.

  12. Impact of video parameters on the DCT coefficient distribution for H.264-like video coders

    NASA Astrophysics Data System (ADS)

    Kamaci, Nejat; Al-Regib, Ghassan

    2012-01-01

    We examine the impact of various encoding parameters on the distribution of the DCT coefficients for H.264-like video coders. We model the distribution of the frame DCT coefficients using the most common Laplacian and Cauchy distributions. We show that the resolution, the quantization levels and the coding type have significant impact on the accuracy of the Laplacian and Cauchy distribution based models. We also show that the transform kernel (4 ×4 vs 8 × 8) has little impact. Moreover, we show that for the video sources that have little temporal or spatial detail, such as flat regions, the distribution of the frame DCT coefficients resembles a Laplacian distribution. When the video source exhibits more detail, such as texture and edges, the distribution of the frame DCT coefficients resembles a Cauchy distribution. The correlation between the details of the video source to the two probability distributions can be used to further improve the estimation of the distribution of the frame DCT coefficients, by using a classification based approach.

  13. Influences of Formal Learning, Personal Characteristics, and Work Environment Characteristics on Informal Learning among Middle Managers in the Korean Banking Sector

    ERIC Educational Resources Information Center

    Choi, Woojae

    2010-01-01

    The purpose of this study was to investigate the influences of formal learning, personal characteristics, and work environment characteristics on informal learning among middle managers in the Korean banking sector. The conceptual framework identified three factors influencing informal learning. For this study, data collection was conducted in the…

  14. Experimental studies of influence of oil on the plants' optical characteristics

    NASA Astrophysics Data System (ADS)

    Timchenko, Elena V.; Timchenko, Pavel E.; Tregub, Nikolay V.; Selezneva, Ekaterina A.; Kornilin, Dmitriy V.

    2016-09-01

    The results of studies of influence of oil on vegetative biological objects using Raman spectroscopy method are presented. The characteristics of Raman spectra of plants growing under the influence of oil fractions were obtained. The main changes were detected at 605 cm-1 , 840 cm-1 , 2120 cm-1 wavenumbers, which is associated with increasing concentration of bromine, aromatic carbons and methane in plant leaves.

  15. Influence of gas heating on high pressure dc microdischarge I V characteristics

    NASA Astrophysics Data System (ADS)

    Belostotskiy, Sergey G.; Donnelly, Vincent M.; Economou, Demetre J.

    2008-11-01

    Experimental I-V characteristics of dc microdischarges in helium at different operating pressures (p = 300-800 Torr) reveal that the classical scaling law of the cathode layer (sheath) does not apply. It is shown that a modified semi-analytical model of the cathode layer that accounts for neutral gas heating is able to reproduce the trends of the experimental I-V characteristics. The model can also be used to quantify the influence of gas heating on microdischarge characteristics and to estimate conditions for stable operation of microdischarges.

  16. Biomarkers of asbestos-induced lung injury: the influence of fiber characteristics and exposure methodology

    EPA Science Inventory

    ATS 2013 Biomarkers of asbestos-induced lung injury: the influence of fiber characteristics and exposure methodology Urmila P Kodavanti, Debora Andrews, Mette C Schaldweiler, Jaime M Cyphert, Darol E Dodd, and Stephen H Gavett NHEERL, U.S. EPA, Research Triangle Park, NC; NIEH...

  17. The Influence of Learning Characteristics on Evaluation of Audience Response Technology

    ERIC Educational Resources Information Center

    MacGeorge, Erina L.; Homan, Scott R.; Dunning, John B.; Elmore, David; Bodie, Graham D.; Evans, Ed; Khichadia, Sangeetha; Lichti, Steven M.

    2008-01-01

    Audience Response Technology (ART) has been widely adopted on college campuses, and prior research indicates that, on average, it receives positive evaluations from students. However, research has not yet examined how characteristics of students as learners influence their responses to ART. The current study examined aptitude for learning,…

  18. Influence of Teacher Characteristics on African American Student Math Achievement in Texas

    ERIC Educational Resources Information Center

    West, Dorthery Barron

    2012-01-01

    The achievement gap between African American and White students continues to be an issue of great concern for educators. The purpose of this study was to examine the influence of teacher characteristics on African American student math achievement: More specifically, the study examined years of teaching experience, campus teacher turnover, and the…

  19. Analysis of influence factors on 2 μm Tm3+-doped fiber laser output characteristics

    NASA Astrophysics Data System (ADS)

    Yu, Miao; Jin, Guang-yong; Wang, Ji

    2016-10-01

    The affecting factors of 2 μm Tm3+-doped fiber laser output characteristics were theoretical analyzed. On the basis of the energy level structure and optical absorption properties of Tm3+ ion, combining with the basic principle of Tm3+-doped fiber laser, and starting from the energy level structures and the cross relaxation processes of Tm3+ ion, the three pumping methods of Tm doped fiber laser (TDF) were analyzed and discussed. The influences of output characteristics by different influence factors were simulated. Based on optimization of the equations, for different fiber lengths, doping concentrations and pumping absorption coefficients and other influence factors, the laser output characteristics under different conditions were obtained and analyzed. Combination the simulation analysis, through the reasonable design and the selection of the optimum parameters of the laser system, the high laser output performance scan be achieved by improving the injection power and controlling of fiber coil diameter. The influences of different factors on the output characteristics were analyzed in the issue. The high laser output performances can be obtained and the laser loss was reduced by selecting the parameters of the laser system properly.

  20. The Monosyllable Imitation Test for Toddlers: Influence of Stimulus Characteristics on Imitation, Compliance and Diagnostic Accuracy

    ERIC Educational Resources Information Center

    Hodges, Rosemary; Munro, Natalie; Baker, Elise; McGregor, Karla; Heard, Rob

    2017-01-01

    Background: Although verbal imitation can provide a valuable window into the developing language abilities of toddlers, some toddlers find verbal imitation challenging and will not comply with tests that involve elicited verbal imitation. The characteristics of stimuli that are offered to toddlers for imitation may influence how easy or hard it is…

  1. Evaluating Iowa Community College Student Demographics, Characteristics, Enrollment Factors, and Educational Goals Influence on Retention Rates

    ERIC Educational Resources Information Center

    Mitchley-McAvoy, Joan A.

    2012-01-01

    This study examined the influence that previously researched and affirmed persistence and early withdrawal factors such as student demographics, enrollment status factors, student characteristics, and student educational goals had on Iowa community college retention rates for the 2005, 2007, and 2009 academic years. It is the researcher's…

  2. Family and Religious Characteristics' Influence on Delinquency Trajectories from Adolescence to Young Adulthood

    ERIC Educational Resources Information Center

    Petts, Richard J.

    2009-01-01

    This study takes a life-course approach to examine whether family and religious characteristics influence individual-level delinquency trajectories from early adolescence through young adulthood. Based on data from the NLSY79, results suggest that residing with two parents deters youths from becoming delinquent and that supportive parenting…

  3. A Short Report: Word-Level Phonological and Lexical Characteristics Interact to Influence Phoneme Awareness

    ERIC Educational Resources Information Center

    Hogan, Tiffany P.

    2010-01-01

    In this study, we examined the influence of word-level phonological and lexical characteristics on early phoneme awareness. Typically developing children, ages 61 to 78 months, completed a phoneme-based, odd-one-out task that included consonant-vowel-consonant word sets (e.g., "chair-chain-ship") that varied orthogonally by a phonological…

  4. The influence of formulation and manufacturing process parameters on the characteristics of lyophilized orally disintegrating tablets.

    PubMed

    Jones, Rhys J; Rajabi-Siahboomi, Ali; Levina, Marina; Perrie, Yvonne; Mohammed, Afzal R

    2011-07-20

    Gelatin is a principal excipient used as a binder in the formulation of lyophilized orally disintegrating tablets. The current study focuses on exploiting the physicochemical properties of gelatin by varying formulation parameters to determine their influence on orally disintegrating tablet (ODT) characteristics. Process parameters, namely pH and ionic strength of the formulations, and ball milling were investigated to observe their effects on excipient characteristics and tablet formation. The properties and characteristics of the formulations and tablets which were investigated included: glass transition temperature, wettability, porosity, mechanical properties, disintegration time, morphology of the internal structure of the freeze-dried tablets, and drug dissolution. The results from the pH study revealed that adjusting the pH of the formulation away from the isoelectric point of gelatin, resulted in an improvement in tablet disintegration time possibly due to increase in gelatin swelling resulting in greater tablet porosity. The results from the ionic strength study revealed that the inclusion of sodium chloride influenced tablet porosity, tablet morphology and the glass transition temperature of the formulations. Data from the milling study showed that milling the excipients influenced formulation characteristics, namely wettability and powder porosity. The study concludes that alterations of simple parameters such as pH and salt concentration have a significant influence on formulation of ODT.

  5. What Characteristics of College Students Influence Their Decisions to Select Online Courses?

    ERIC Educational Resources Information Center

    Mann, John T.; Henneberry, Shida R.

    2012-01-01

    The primary goal of this study was to identify a wide range of characteristics of college students that may influence their decisions to select online courses. The motivation underlying this study is the realization that online courses are no longer exclusively being taken by non-traditional students (for undergraduates, that would be students age…

  6. Child and Family Characteristics Influencing Intervention Choices in Autism Spectrum Disorders

    ERIC Educational Resources Information Center

    Patten, Elena; Baranek, Grace T.; Watson, Linda R.; Schultz, Beth

    2013-01-01

    A myriad of treatment options are available for children with autism spectrum disorders, yet little is understood regarding characteristics of parents (e.g., education) and children (e.g., severity of autism symptoms) that influence types and numbers of therapies utilized. Interviews from 70 caregivers were analyzed to determine potential…

  7. A stimulus-dependent spike threshold is an optimal neural coder

    PubMed Central

    Jones, Douglas L.; Johnson, Erik C.; Ratnam, Rama

    2015-01-01

    A neural code based on sequences of spikes can consume a significant portion of the brain's energy budget. Thus, energy considerations would dictate that spiking activity be kept as low as possible. However, a high spike-rate improves the coding and representation of signals in spike trains, particularly in sensory systems. These are competing demands, and selective pressure has presumably worked to optimize coding by apportioning a minimum number of spikes so as to maximize coding fidelity. The mechanisms by which a neuron generates spikes while maintaining a fidelity criterion are not known. Here, we show that a signal-dependent neural threshold, similar to a dynamic or adapting threshold, optimizes the trade-off between spike generation (encoding) and fidelity (decoding). The threshold mimics a post-synaptic membrane (a low-pass filter) and serves as an internal decoder. Further, it sets the average firing rate (the energy constraint). The decoding process provides an internal copy of the coding error to the spike-generator which emits a spike when the error equals or exceeds a spike threshold. When optimized, the trade-off leads to a deterministic spike firing-rule that generates optimally timed spikes so as to maximize fidelity. The optimal coder is derived in closed-form in the limit of high spike-rates, when the signal can be approximated as a piece-wise constant signal. The predicted spike-times are close to those obtained experimentally in the primary electrosensory afferent neurons of weakly electric fish (Apteronotus leptorhynchus) and pyramidal neurons from the somatosensory cortex of the rat. We suggest that KCNQ/Kv7 channels (underlying the M-current) are good candidates for the decoder. They are widely coupled to metabolic processes and do not inactivate. We conclude that the neural threshold is optimized to generate an energy-efficient and high-fidelity neural code. PMID:26082710

  8. Here comes the judge: the influence of judge personal characteristics on federal sexual harassment case outcomes.

    PubMed

    Kulik, Carol T; Perry, Elissa L; Pepper, Molly B

    2003-02-01

    This study explored the effects of judges' personal characteristics (gender, race, age, and political affiliation) and case characteristics on the outcomes of federal cases of hostile environment sexual harassment. Results revealed that even after controlling for the effects of relevant case characteristics (e.g., severity of the harassment), judges' personal characteristics influenced case outcomes. Specifically, younger judges and Democrat judges were more likely to find for the plaintiff (the alleged victim of harassment). The probability that the decision would favor the plaintiff was only 16% when the case was heard by an older judge but 45% when heard by a younger judge. The probability that the decision would favor the plaintiff was only 18% when the case was heard by a judge who had been appointed by a Republican president but 46% when the judge had been appointed by a Democrat president.

  9. Socioeconomic characteristics of enrollees appear to influence performance scores for medicare part D contractors.

    PubMed

    Young, Gary J; Rickles, Nathaniel M; Chou, Chia-Hung; Raver, Eli

    2014-01-01

    More than 150 private companies contract with the federal government to provide Part D prescription drug benefits to Medicare beneficiaries, either through stand-alone drug plans or as part of Medicare Advantage plans. The Centers for Medicare and Medicaid Services (CMS) evaluates these companies on a set of performance measures, including plan enrollees' medication adherence. We used 2012 data from CMS and data from the US Census Bureau to investigate whether these performance ratings are influenced by the socioeconomic characteristics of enrollee populations. We found that some companies have a substantial advantage over others because of their enrollees' socioeconomic characteristics, with more than a third of the variation in adherence scores tied to these characteristics. CMS should seriously consider adjusting adherence scores to account for differences in the socioeconomic characteristics of enrollee populations.

  10. Influence of the Laminar Plasma Torch Construction on the Jet Characteristics

    NASA Astrophysics Data System (ADS)

    Cao, Xiuquan; Yu, Deping; Xiang, Yong; Yao, Jin; Miao, Jianguo

    2016-07-01

    Based on two typical laminar plasma torches (LPT), i.e. a multi-electrode plasma torch (MEPT) with segmented anode structure and a two-electrode plasma torch (TEPT) with conventional structure, this paper studied the influence of the LPTs construction on the jet characteristics. Experiments were designed to measure their arc voltage, jet length, thermal efficiency and specific enthalpy using a home-made data acquisition system. With them, the jet characteristics of the two different LPTs were compared in detail. Results show that different plasma torch construction leads to distinctively different characteristics of the generated plasma jet. Based on the different jet characteristics, a plasma torch with appropriate construction could be used to meet the different application requirements. supported by National Natural Science Foundation of China (No. 51405315) and the Laboratory of Precision Manufacturing Technology, CAEP (No. KF15002)

  11. Predators, environment and host characteristics influence the probability of infection by an invasive castrating parasite.

    PubMed

    Gehman, Alyssa-Lois M; Grabowski, Jonathan H; Hughes, A Randall; Kimbro, David L; Piehler, Michael F; Byers, James E

    2017-01-01

    Not all hosts, communities or environments are equally hospitable for parasites. Direct and indirect interactions between parasites and their predators, competitors and the environment can influence variability in host exposure, susceptibility and subsequent infection, and these influences may vary across spatial scales. To determine the relative influences of abiotic, biotic and host characteristics on probability of infection across both local and estuary scales, we surveyed the oyster reef-dwelling mud crab Eurypanopeus depressus and its parasite Loxothylacus panopaei, an invasive castrating rhizocephalan, in a hierarchical design across >900 km of the southeastern USA. We quantified the density of hosts, predators of the parasite and host, the host's oyster reef habitat, and environmental variables that might affect the parasite either directly or indirectly on oyster reefs within 10 estuaries throughout this biogeographic range. Our analyses revealed that both between and within estuary-scale variation and host characteristics influenced L. panopaei prevalence. Several additional biotic and abiotic factors were positive predictors of infection, including predator abundance and the depth of water inundation over reefs at high tide. We demonstrate that in addition to host characteristics, biotic and abiotic community-level variables both serve as large-scale indicators of parasite dynamics.

  12. Evaluating the Influence of Surface and Precipitation Characteristics on TMI and GMI Precipitation Retrievals.

    NASA Astrophysics Data System (ADS)

    Carr, N.; Kirstetter, P.; Hong, Y.; Gourley, J. J.; Ferraro, R. R.; Kummerow, C. D.; Petersen, W. A.; Schwaller, M.; Wang, N. Y.

    2014-12-01

    To evaluate the influence of surface and precipitation characteristics on Passive microwave (PMW) precipitation retrievals, precipitation products obtained from both the TRMM Microwave Imager (TMI) and the GPM Microwave Imager (GMI) were evaluated relative to independent high-resolution reference precipitation products obtained using the NOAA/NSSL ground radar-based Multi-Radar Multi-Sensor (MRMS) system. Specifically the ability of each sensor to detect, classify, and quantify instantaneous surface precipitation at its native pixel resolution is examined and linked to surface and precipitation characteristics. Surface characteristics were derived optically using NASA's Moderate Resolution Imaging Spectroradiometer (MODIS). Precipitation mesoscale characteristics such as convective-stratiform classification and spatial structure were obtained from the high-resolution reference data. The quality of both PMW sensors' retrievals varied considerably with surface characteristics; both sensors displayed decreased detection and quantification statistics over sparsely vegetated and dry surfaces. Similarly, the quality of the precipitation retrievals was affected by precipitation characteristics and high relative errors were evident in isolated and small-scale precipitation events as well as in mixed stratiform-convective events. The error characteristics of the two sensors also differed in several significant aspects, namely TMI tended to overestimate precipitation relative to the reference, while GMI underestimated precipitation. The influence of the precipitation and surface characteristics was less evident in the more sophisticated GMI retrievals. An additional outcome of the study was the adaptation of the comparison framework between space and ground precipitation estimates to accommodate the new probabilistic features of the GPM-era PMW precipitation retrievals.

  13. Toward an ecological analysis of Bayesian inferences: how task characteristics influence responses

    PubMed Central

    Hafenbrädl, Sebastian; Hoffrage, Ulrich

    2015-01-01

    In research on Bayesian inferences, the specific tasks, with their narratives and characteristics, are typically seen as exchangeable vehicles that merely transport the structure of the problem to research participants. In the present paper, we explore whether, and possibly how, task characteristics that are usually ignored influence participants’ responses in these tasks. We focus on both quantitative dimensions of the tasks, such as their base rates, hit rates, and false-alarm rates, as well as qualitative characteristics, such as whether the task involves a norm violation or not, whether the stakes are high or low, and whether the focus is on the individual case or on the numbers. Using a data set of 19 different tasks presented to 500 different participants who provided a total of 1,773 responses, we analyze these responses in two ways: first, on the level of the numerical estimates themselves, and second, on the level of various response strategies, Bayesian and non-Bayesian, that might have produced the estimates. We identified various contingencies, and most of the task characteristics had an influence on participants’ responses. Typically, this influence has been stronger when the numerical information in the tasks was presented in terms of probabilities or percentages, compared to natural frequencies – and this effect cannot be fully explained by a higher proportion of Bayesian responses when natural frequencies were used. One characteristic that did not seem to influence participants’ response strategy was the numerical value of the Bayesian solution itself. Our exploratory study is a first step toward an ecological analysis of Bayesian inferences, and highlights new avenues for future research. PMID:26300791

  14. ASRDI oxygen technology survey, Volume 7: Characteristics of metals that influence system safety

    NASA Technical Reports Server (NTRS)

    Pelouch, J. J., Jr.

    1974-01-01

    A literature survey and analysis of the material and process factors affecting the safety of metals in oxygen systems is presented. In addition, the practices of those who specify, build, or use oxygen systems relative to the previous is summarized. Alloys based on iron, copper, nickel, and aluminum were investigated representing the bulk of metals found in oxygen systems. Safety-related characteristics of other miscellaneous metals are summarized. It was found that factors affecting the safety of metals in oxygen systems exit in all phases of the evolutionary process, from smelting and mill techniques through end-production fabrication. The safety of a given metal in an oxygen system was determined to be influenced by the particular service requirement. The metal characteristics should favorably influence fulfillment of these requirements. Thus, no singular metal or alloy could be classified as safest for all types of oxygen service.

  15. Cylinder wake influence on the tonal noise and aerodynamic characteristics of a NACA0018 airfoil

    NASA Astrophysics Data System (ADS)

    Takagi, Y.; Fujisawa, N.; Nakano, T.; Nashimoto, A.

    2006-11-01

    The influence of cylinder wake on discrete tonal noise and aerodynamic characteristics of a NACA0018 airfoil is studied experimentally in a uniform flow at a moderate Reynolds number. The experiments are carried out by measuring sound pressure levels and spectrum, separation and the reattachment points, pressure distribution, fluid forces, mean-flow and turbulence characteristics around the airfoil with and without the cylinder wake. Present results indicate that the tonal noise from the airfoil is suppressed by the influence of the cylinder wake and the aerodynamic characteristics are improved in comparison with the case without the cylinder wake. These are mainly due to the separation control of boundary layers over the airfoil caused by the wake-induced transition, which is observed by surface flow visualization with liquid- crystal coating. The PIV measurements of the flow field around the airfoil confirm that highly turbulent velocity fluctuation of the cylinder wake induces the transition of the boundary layers and produces an attached boundary layer over the airfoil. Then, the vortex shedding phenomenon near the trailing edge of pressure surface is removed by the influence of the wake and results in the suppression of tonal noise.

  16. A high quality voice coder with integrated echo canceller and voice activity detector for mobile satellite applications

    NASA Technical Reports Server (NTRS)

    Kondoz, A. M.; Evans, B. G.

    1993-01-01

    In the last decade, low bit rate speech coding research has received much attention resulting in newly developed, good quality, speech coders operating at as low as 4.8 Kb/s. Although speech quality at around 8 Kb/s is acceptable for a wide variety of applications, at 4.8 Kb/s more improvements in quality are necessary to make it acceptable to the majority of applications and users. In addition to the required low bit rate with acceptable speech quality, other facilities such as integrated digital echo cancellation and voice activity detection are now becoming necessary to provide a cost effective and compact solution. In this paper we describe a CELP speech coder with integrated echo canceller and a voice activity detector all of which have been implemented on a single DSP32C with 32 KBytes of SRAM. The quality of CELP coded speech has been improved significantly by a new codebook implementation which also simplifies the encoder/decoder complexity making room for the integration of a 64-tap echo canceller together with a voice activity detector.

  17. Influence of population and exercise protocol characteristics on hemodynamic determinants of post-aerobic exercise hypotension.

    PubMed

    Brito, L C; Queiroz, A C C; Forjaz, C L M

    2014-08-01

    Due to differences in study populations and protocols, the hemodynamic determinants of post-aerobic exercise hypotension (PAEH) are controversial. This review analyzed the factors that might influence PAEH hemodynamic determinants, through a search on PubMed using the following key words: "postexercise" or "post-exercise" combined with "hypotension", "blood pressure", "cardiac output", and "peripheral vascular resistance", and "aerobic exercise" combined only with "blood pressure". Forty-seven studies were selected, and the following characteristics were analyzed: age, gender, training status, body mass index status, blood pressure status, exercise intensity, duration and mode (continuous or interval), time of day, and recovery position. Data analysis showed that 1) most postexercise hypotension cases are due to a reduction in systemic vascular resistance; 2) age, body mass index, and blood pressure status influence postexercise hemodynamics, favoring cardiac output decrease in elderly, overweight, and hypertensive subjects; 3) gender and training status do not have an isolated influence; 4) exercise duration, intensity, and mode also do not affect postexercise hemodynamics; 5) time of day might have an influence, but more data are needed; and 6) recovery in the supine position facilitates systemic vascular resistance decrease. In conclusion, many factors may influence postexercise hypotension hemodynamics, and future studies should directly address these specific influences because different combinations may explain the observed variability in postexercise hemodynamic studies.

  18. Influence of characteristics of micro-bubble clouds on backscatter lidar signal.

    PubMed

    Li, Wei; Yang, Kecheng; Xia, Min; Rao, Jionghui; Zhang, Wei

    2009-09-28

    Marine micro-bubbles are one of those important constituents that influence scattering characteristics of water column. Monte Carlo Based simulations show that a water entrained bubble cloud generate a characteristic backscatter of incident laser light [M. Xia, J. Opt. A: Pure Appl. Opt. 8, 350 (2006)]. This characteristic can be used to detect and localize bubble clouds, leading to wide ranging applications, especially in optical remote sensing. This paper describes tests of an underwater lidar system applied to detecting cloud of micro-bubbles. Laboratory experiments demonstrate that the system is capable of detecting bubbles ranging from diameter 10 microm approximately 200 microm, over a distance of 7-12 m from the detector. The dependence of the lidar return signal on size distribution of bubbles, concentration, thickness and location of bubble clouds is studied and compared with simulation results.

  19. Influence of the association of the EVA and NBR on the characteristics of modified bitumen

    NASA Astrophysics Data System (ADS)

    Bensaada, A.; Soudani, K.; Haddadi, S.; Saoula, S.

    2015-03-01

    Durability and the performance of pavement depend mainly on the characteristics of materials which change over time like all other organic substances. They are subject to significant changes due to environmental conditions during the different phases of use. In the present work we investigated experimentally the influence of the association of ethyl vinyl acetate polymer (EVA) with an industrial waste, acrylonitrile-butadiene rubber (NBR) on the modification of bitumen AC 35-50 and its rheological behavior. The incorporation of NBR and EVA in the bitumen improved its intrinsic characteristics (softening point, penetration and ductility). In addition to improving the characteristics of bituminous binders that will affect the durability of bituminous structures, the environment will be preserved by the recycling of industrial waste.

  20. Influence of working liquid on the onset characteristics of a thermoacoustic engine with gas and liquid

    NASA Astrophysics Data System (ADS)

    Tang, Ke; Lei, Tian; Jin, Tao

    2012-11-01

    This paper analyzes the influence of working liquid on the onset characteristics in a thermoacoustic engine with gas and liquid. The governing equations have been derived by the electro-acoustic analogy with thermoacoustics. According to the formulation of the liquid column impedance, we focus on the impact of density and kinematic viscosity of the working liquid on the onset characteristics. The calculations show that the onset temperature increases with a rise in the liquid's kinematic viscosity, and the oscillation frequency decreases with a rise in the liquid's density. Three liquids, i.e., water, potassium formate aqueous solution, and [EMIM][BF4], are used in the experiments to observe the onset characteristics of the engine. The comparison between calculation and experimental results confirms that the liquid's viscosity should be included in the calculation to obtain a better agreement with the experiment.

  1. Structural parameters that influence the noise reduction characteristics of typical general aviation materials

    NASA Technical Reports Server (NTRS)

    Roskam, J.; Grosveld, F.

    1980-01-01

    Effect of panel curvature and oblique angle of sound incidence on noise reduction characteristics of an aluminum panel are experimentally investigated. Panel curvature results show significant increase in stiffness with comparable decrease of sound transmission through the panel in the frequency region below the panel/cavity resonance frequency. Noise reduction data have been achieved for aluminum panels with clamped, bonded and riveted edge conditions. These edge conditions are shown to influence noise reduction characteristics of aluminum panels. Experimentally measured noise reduction characteristics of flat aluminum panels with uniaxial and biaxial in-plane stresses are presented and discussed. Results indicate important improvement in noise reduction of these panels in the frequency range below the fundamental panel/cavity resonance frequency.

  2. The influence of acceleration loading curve characteristics on traumatic brain injury.

    PubMed

    Post, Andrew; Blaine Hoshizaki, T; Gilchrist, Michael D; Brien, Susan; Cusimano, Michael D; Marshall, Shawn

    2014-03-21

    To prevent brain trauma, understanding the mechanism of injury is essential. Once the mechanism of brain injury has been identified, prevention technologies could then be developed to aid in their prevention. The incidence of brain injury is linked to how the kinematics of a brain injury event affects the internal structures of the brain. As a result it is essential that an attempt be made to describe how the characteristics of the linear and rotational acceleration influence specific traumatic brain injury lesions. As a result, the purpose of this study was to examine the influence of the characteristics of linear and rotational acceleration pulses and how they account for the variance in predicting the outcome of TBI lesions, namely contusion, subdural hematoma (SDH), subarachnoid hemorrhage (SAH), and epidural hematoma (EDH) using a principal components analysis (PCA). Monorail impacts were conducted which simulated falls which caused the TBI lesions. From these reconstructions, the characteristics of the linear and rotational acceleration were determined and used for a PCA analysis. The results indicated that peak resultant acceleration variables did not account for any of the variance in predicting TBI lesions. The majority of the variance was accounted for by duration of the resultant and component linear and rotational acceleration. In addition, the components of linear and rotational acceleration characteristics on the x, y, and z axes accounted for the majority of the remainder of the variance after duration.

  3. Influence of formulation and preparation process on ambroxol hydrochloride dry powder inhalation characteristics and aerosolization properties.

    PubMed

    Ren, Yachao; Yu, Chaoqun; Meng, Kangkang; Tang, Xing

    2008-09-01

    The objective of this study is to evaluate the influence of formulation and preparation process on ambroxol hydrochloride (AH) dry powder inhalation (DPI) characteristics and aerosolization properties. Spray-dried samples of AH, AH/leucine, and AH/leucine/mannitol were prepared from their corresponding water solutions under the same conditions to study the influence of the composition, and the AH/leucine/mannitol (2.5/0.5/1 by weight) formulation was used for investigation of the effect of the preparation process. Following spray-drying, the resulting powders were characterized using scanning electron microscopy, laser diffraction, tapped density, and angle of repose measurements, and the aerosolization performance was determined using a twin-stage liquid impinger. AH/leucine/mannitol (2.5/0.5/1 by weight) obtained by cospray-drying improved the AH aerosolization properties. The AH/leucine/mannitol (2.5/0.5/1 by weight) preparation exhibited the following properties: 62.34% yield, 0.34 g/cm(3) tap density, 2.71 microm d(ae), 33.45 degrees angle of repose, and 30.93% respirable fraction. The influence of the preparation process on DPI characteristics and aerosolization properties was relatively small, but the influence of the composition was relatively large. Optimization of DPI can be achieved by selecting the most appropriate formulation and preparation process.

  4. Antibacterial Properties of Copper Nanoparticle Dispersions: Influence of Synthesis Conditions and Physicochemical Characteristics

    NASA Astrophysics Data System (ADS)

    Godymchuk, A.; Frolov, G.; Gusev, A.; Zakharova, O.; Yunda, E.; Kuznetsov, D.; Kolesnikov, E.

    2015-11-01

    The production of bactericidal plasters, bandages and medicines with the inclusion of copper nanoparticles and copper ions may have a great potential in terms of their biomedical application. The work considers the influence of the synthesis conditions, size, aggregation status, and charge of nanoparticles in aqueous solutions as well as the type of microorganisms to the antibacterial properties of water suspensions of electroexplosive copper nanoparticles in the conditions in vitro in relation to strains Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Bacillus cereus. Water dispersions of copper nanoparticles were shown to inhibit the growth of test cells for both G+ and G- microbacteria but the degree of such an influence strongly depended on the type of a test strain. The authors have demonstrated that use of deeply purified water and alcohol-containing stabilizers at the synthesis of nanoparticles via metals electric erosion in the liquid prevents the copper nanoparticles coagulation and significantly influences on their physicochemical characteristics and, consequently, antibacterial properties.

  5. CFD investigation of the influence of volute geometrical variations on hydrodynamic characteristics of circulator pump

    NASA Astrophysics Data System (ADS)

    Wu, Denghao; Yuan, Shouqi; Ren, Yun; Mu, Jiegang; Yang, Youdong; Liu, Jian

    2016-03-01

    Improper design of volute geometry can be the main cause that leads to unsteady pressure pulsation and radial force in pumps. Therefore, it is important to understand the influence of volute geometrical parameters on hydrodynamic characteristics of pump and the mechanism. However, the existing studies are limited to investigate the influence of only one or two volute geometrical parameters each time, and a systematic study of the influence of the combinations of different volute geometrical parameters on the pump's hydrodynamic characteristics is missing. In this paper, a study on the understanding of the influence of volute geometrical variations on hydrodynamic characteristics of a high speed circulator pump by using computational fluid dynamics(CFD) technology is presented. Five main volute geometrical parameters D 3, A 8, α 0, φ 0 and R t are selected and 25 different volute configurations are generated by using design of experiments(DOE) method. The 3D unsteady flow numerical simulations, which are based on the SST k- w turbulence model and sliding mesh technique provided by CFX, are executed on the 25 different volute configurations. The hydraulic performance, pressure pulsation and unsteady radial force inside the pump at design condition are obtained and analyzed. It has been found that volute geometrical parameters D 3 and A 8 are major influence factors on hydrodynamic characteristics of the pump, while α 0, φ 0 and R t are minor influence factors. The minimum contribution from both D 3 and A 8 is 58% on head, and maximum contribution from both D 3 and A 8 is 90% on pressure pulsation. Regarding the pressure pulsation intensity, two peaks can be found. One is in the tongue area and the other is in the diffusor area. The contributions are around 60% from tongue and 25% from diffusor, respectively. The amplitude of pressure pulsation has a quadratic polynomial functional relationship with respect to D 3/ D 2 and A 8/ A 10, and fluctuating level of

  6. Influence of topography and forest characteristics on snow distributions in a forested catchment

    NASA Astrophysics Data System (ADS)

    Fujihara, Yoichi; Takase, Keiji; Chono, Shunsuke; Ichion, Eiji; Ogura, Akira; Tanaka, Kenji

    2017-03-01

    Stored water within snowpack is important for the hydrological balance in many mountainous environments around the world. However, monitoring the spatial and temporal dynamics of snow in such mountainous environments remains rather challenging. We therefore developed a snow depth meter using small temperature loggers. Small temperature loggers were attached to poles at 20 cm intervals from the ground surface. Snow depths were estimated by assessing the daily variations in temperatures. Using this snow depth meter, we continuously observed snow depths at 21 stations in a forested catchment in Japan over three winter seasons. Using correlation analysis, we then analyzed the influence of topography (i.e., elevation and aspect) and forest (i.e., canopy openness) on snow depths. Moreover, we estimated daily snow distributions in the area using multi-regression analysis, thus describing seasonal characteristics of snow distributions. Finally we investigated the relation between number of stations and estimation accuracies of snow distributions using a Monte Carlo sensitivity analysis. We observed that the influence of topographical and forest characteristics changed considerably during the study period, with elevation having a major impact on snow depths. Further, aspect and forest cover had a great influence on the snow depths during the melting period. The regression of elevation slopes was 0.8-2.1 mm/m during rich snow years and 0.5-0.6 mm/m in little snow years. Also, the snow distribution during the melting period was found to be less uniform than during the snow accumulation period using histograms of snow depths. Monte Carlo sensitivity analysis shows that one station per 2.0-2.5 ha is enough to estimate accurate snow distributions. Given the above, we concluded that our proposed approach was quite useful for investigating the influence of topography and forest characteristics on snow accumulation and melting.

  7. Demographic characteristics of Ghanaian optometry students and factors influencing their career choice and institution of learning.

    PubMed

    Boadi-Kusi, Samuel Bert; Kyei, Samuel; Mashige, Khathutshelo Percy; Abu, Emmanuel Kwasi; Antwi-Boasiako, Daniel; Carl Halladay, Abraham

    2015-03-01

    Optometry is only provided at tertiary level in two institutions in Ghana, with an average of 50 students graduating each year for a population of approximately 24.6 million. No information on the demography of optometry students and factors that influence their choice of optometry as a career and institution of learning is available. This information is important as it will assist optometry institutions to formulate effective student recruitment strategies. To assess the demographic characteristics of Ghanaian optometry students, the factors that influence their selection of optometry as a career and institution of learning. We conducted a cross sectional study among Ghanaian optometry students using a structured questionnaire to collect data on the demographic characteristics and factors that might influence their choice of optometry as a career as well as choice of institution of learning. Two hundred and eighty students from the two optometry training institutions in Ghana; University of Cape Coast (48.2%) and Kwame Nkrumah University of Science and Technology (51.8%) responded to the questionnaire. Their ages ranged from 17 to 28 years with most being males (72.5%), and the majority (79%) being from urban areas. The main factors that influenced their career choice were job availability after graduation (90%) and desire to help other people (89.2%). Factors that influenced their institution choice were preference for an institution (36.8%) and proximity to home (24.4%). In the absence of adequate optometry jobs in the public health sector, women will remain marginalised specifically those in rural areas. This marginalisation is however, a reflection of a broader societal disadvantage for women. Greater effort needs to be made to recruit high school students from rural areas to study optometry and more institutions need to provide optometry instruction throughout the country.

  8. The Influence of Anthropometric Characteristics on Kinematic Parameters of Children's Sprinter's Running.

    PubMed

    Blažević, Iva; Babić, Vesna; Zagorac, Nebojša

    2015-07-01

    Children's sprinters running differs from the adults' one primarily in their motoric abilities, anthropometric characteristics, physiological and biochemical characteristics, as well as psychological and sociological characteristics. This research's aim was to examine the influence of anthropometric characteristics on kinematic parameters of children's sprinter's running. The sample of variables consisted of variables which determine anthropometric characteristics (14 anthropometric characteristics) and of 5 kinematic parameters'variables of sprinter's running. Kinematic parameters of sprinter's running in the phase of maximal speed have been collected by applying the Optojump technology (Microgate, Italy) and the sprinter's running times were measured every 5 meters on a 50 m lap. The results obtained from the multiple regression analysis between the group of anthropometric characteristics and the 50 m running results indicate that the percentage of fatty tissue is a statistically significant variable with boys, while the same variable with girls is near the limit of statistical significance. In the factor structure of anthropometric characteristics two factors have been set apart with boys and three with girls. The first factor set apart with both boys and girls is the factor of body voluminosity, the second factor with boys is the factor of longitudinal dimensionality, while with girls it is the factor of fatty tissue quantity. The factor of longitudinal dimensionality is the third girls' factor. For most variables a negative correlation has been determined with a higher percentage of fat or a higher quantity of subcutaneous fatty tissue with both boys and girls. Boys having a lower quantity of subcutaneous fatty tissue achieve better results in 50 m running, they have a shorter duration of contact with the pad, a longer duration of the flight phase and a longer step length when compared to boys with a higher quantity of subcutaneous fatty tissue. Boys with a

  9. [Influence of temperature and humidity on physico-pharmaceutical characteristics of Rasilez(®) tablets].

    PubMed

    Nakamura, Yuki; Nakajima, Takanori; Iwata, Masanori; Hayashi, Yoshihiro; Takayama, Kozo; Saito, Hiroshi; Sako, Ken-ichi; Matsuda, Yoshikazu; Kimura, Masayuki

    2014-01-01

    Rasilez(®) tablets (RTs) contain the active ingredient aliskiren, which is a direct renin inhibitor of the renin-angiotensin system and used for the treatment of hypertension. We examined the influence of temperature and humidity on the physico-pharmaceutical characteristics (mass, volume, hardness, elution) of RTs. The RTs were preserved under conditions in which the temperature and humidity were altered using the second-order spherical composite experimental design for multi-objective problems. The characteristics of RTs were influenced more by the humidity than temperature, and differed markedly with over 55% relative humidity (RH). The mass and volume were increased with increasing humidity, and the tablets swelled. The hardness after vacuum-drying of the tablets, which preserved moisture conditions, was increased. Semitransparent particles were observed in the cross-section of the drying tablets in which aliskiren crystal forms were changed to amorphous forms. The mean dissolution time (MDT) of tablets was reduced with increasing humidity. The critical relative humidity (CRH) of the tablets was 36.1%RH at 30°C. These results suggest that RTs, on moisture absorption, showed changes in not their appearance and hardness, but also in crystal forms and the elution characteristics of aliskiren.

  10. The influence of lightning activity and anthropogenic factors on large-scale characteristics of natural fires

    NASA Astrophysics Data System (ADS)

    Eliseev, A. V.; Mokhov, I. I.; Chernokulsky, A. V.

    2017-01-01

    A module for simulating of natural fires (NFs) in the climate model of the A.M. Obukhov Institute of Atmospheric Physics, Russian Academy of Sciences (IAP RAS CM), is extended with respect to the influence of lightning activity and population density on the ignition frequency and fire suppression. The IAP RAS CM is used to perform numerical experiments in accordance with the conditions of the project that intercompares climate models, CMIP5 (Coupled Models Intercomparison Project, phase 5). The frequency of lightning flashes was assigned in accordance with the LIS/OTD satellite data. In the calculations performed, anthropogenic ignitions play an important role in NF occurrences, except for regions at subpolar latitudes and, to a lesser degree, tropical and subtropical regions. Taking into account the dependence of fire frequency on lightning activity and population density intensifies the influence of characteristics of natural fires on the climate changes in tropics and subtropics as compared to the version of the IAP RAS CM that does not take the influence of ignition sources on the large-scale characteristics of NFs into consideration.

  11. Landscape characteristics influence pond occupancy by frogs after accounting for detectability

    USGS Publications Warehouse

    Mazerolle, M.J.; Desrochers, A.; Rochefort, L.

    2005-01-01

    Many investigators have hypothesized that landscape attributes such as the amount and proximity of habitat are important for amphibian spatial patterns. This has produced a number of studies focusing on the effects of landscape characteristics on amphibian patterns of occurrence in patches or ponds, most of which conclude that the landscape is important. We identified two concerns associated with these studies: one deals with their applicability to other landscape types, as most have been conducted in agricultural landscapes; the other highlights the need to account for the probability of detection. We tested the hypothesis that landscape characteristics influence spatial patterns of amphibian occurrence at ponds after accounting for the probability of detection in little-studied peatland landscapes undergoing peat mining. We also illustrated the costs of not accounting for the probability of detection by comparing our results to conventional logistic regression analyses. Results indicate that frog occurrence increased with the percent cover of ponds within 100, 250, and 1000 m, as well as the amount of forest cover within 1000 m. However, forest cover at 250 m had a negative influence on frog presence at ponds. Not accounting for the probability of detection resulted in underestimating the influence of most variables on frog occurrence, whereas a few were overestimated. Regardless, we show that conventional logistic regression can lead to different conclusions than analyses accounting for detectability. Our study is consistent with the hypothesis that landscape characteristics are important in determining the spatial patterns of frog occurrence at ponds. We strongly recommend estimating the probability of detection in field surveys, as this will increase the quality and conservation potential of models derived from such data. ?? 2005 by the Ecological Society of America.

  12. The influence of travel time on breast cancer characteristics, receipt of primary therapy, and surveillance mammography.

    PubMed

    Onega, Tracy; Cook, Andrea; Kirlin, Beth; Shi, Xun; Alford-Teaster, Jennifer; Tuzzio, Leah; Buist, Diana S M

    2011-08-01

    Travel time has been shown to influence some aspects of cancer characteristics at diagnosis and care for women with breast cancer, but important gaps remain in our understanding of its impact. We examined the influence of travel time to the nearest radiology facility on breast cancer characteristics, treatment, and surveillance for women with early-stage invasive breast cancer. We included 1,012 women with invasive breast cancer (stages I and II) who had access to care within an integrated health care delivery system in western Washington State. The travel times to the nearest radiology facility were calculated for all the U.S. Census blocks within the study area and assigned to women based on residence at diagnosis. We collected cancer characteristics, primary and adjuvant therapies, and surveillance mammography for at least 2.5 years post diagnosis and used multivariable analyses to test the associations of travel time. The majority of women (68.6%) lived within 20 min of the nearest radiology facility, had stage I disease (72.7%), received breast conserving therapy (68.7%), and had annual surveillance mammography the first 2 years after treatment (73.7%). The travel time was not significantly associated with the stage or surveillance mammography after adjusting for covariates. Primary therapy was significantly related to travel time, with greater travel time (>30 min vs. ≤ 10 min) associated with a higher likelihood of mastectomy compared to breast conserving surgery (RR = 1.53; 95% CI, 1.16-2.01). The travel time was not associated with the stage at diagnosis or surveillance mammography receipt. The travel time does seem to influence the type of primary therapy among women with breast cancer, suggesting that women may prefer low frequency services, such as mastectomy, if geographic access to a radiology facility is limited.

  13. Sensory characteristics of antioxidant extracts from Uruguayan native plants: influence of deodorization by steam distillation.

    PubMed

    Miraballes, Marcelo; Gámbaro, Adriana; Ares, Gastón

    2013-12-01

    Polyphenolic-rich antioxidant extracts from native plants have potential applications as ingredients in functional foods; however, their intense characteristic flavour is a major limitation to their application. In this context, the aim of the present work was to evaluate the influence of steam distillation on the sensory and physicochemical characteristics of extracts of five native Uruguayan plants (Acca sellowiana, Achyrocline satureioides, Aloysia gratisima, Baccharis trimera and Mikania guaco). Aqueous extracts from the five native plants were obtained. Steam distillation was used to produce two types of deodorized extracts: extracts from deodorized leaves and extracts deodorized after the extraction. The extracts were characterized in terms of their total polyphenolic content and antioxidant activity (using 2,2-diphenyl-1-picryl-hydrazyl and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid methods). A trained assessor panel evaluated characteristic odour, characteristic flavour, bitterness and astringency of the extracts. The total polyphenolic content of the extracts ranged from 112.4 to 974.4 mg/100 mL, whereas their antioxidant capacity ranged from 9.6 to 1008.7 mg vitamin C equivalents/100 mL, depending on the type of extract and the method being considered. Steam distillation was effective in reducing the characteristic odour and flavour of the extracts, without causing large changes in their polyphenolic content and antioxidant activity. In general, in terms of sensory characteristics, steam distillation performed on the extracts gave better results than when performed on the leaves; whereas the opposite trend was found for polyphenolic content and antioxidant activity. Results suggested that steam distillation could be a promising low-cost procedure for the production of antioxidant extracts for food products.

  14. Axisymmetric electromagnetic field influence on the characteristic velocity of an arc-jet

    NASA Technical Reports Server (NTRS)

    Oggero, M.; Gennuso, D.

    1984-01-01

    Tests for determining the influence of an axisymmetric EM field on the characteristic velocity of an arc jet are presented. The experimental set up is briefly described. Tests were performed with rotation induced by the centrifugal and magnetic fields in the same sense. The fuels used were HE and N2 and the results are discussed. It is found that by variation of the induction, current, and arc jet strength, the behavior is determined essentially by the shape of the cathodic and anodic blobs on the electrodes together with their movement under the combined effect of the aerodynamic and magnetic fields. In view of the different characteristics of He and N2 in respect to the dissociation heat and ionization, it is expected that the regime of the arc jet when used with H2 fuel will be similar to that with He.

  15. SGC tests for influence of material composition on compaction characteristic of asphalt mixtures.

    PubMed

    Chen, Qun; Li, Yuzhi

    2013-01-01

    Compaction characteristic of the surface layer asphalt mixture (13-type gradation mixture) was studied using Superpave gyratory compactor (SGC) simulative compaction tests. Based on analysis of densification curve of gyratory compaction, influence rules of the contents of mineral aggregates of all sizes and asphalt on compaction characteristic of asphalt mixtures were obtained. SGC Tests show that, for the mixture with a bigger content of asphalt, its density increases faster, that there is an optimal amount of fine aggregates for optimal compaction and that an appropriate amount of mineral powder will improve workability of mixtures, but overmuch mineral powder will make mixtures dry and hard. Conclusions based on SGC tests can provide basis for how to adjust material composition for improving compaction performance of asphalt mixtures, and for the designed asphalt mixture, its compaction performance can be predicted through these conclusions, which also contributes to the choice of compaction schemes.

  16. Influence of hot spot features on the initiation characteristics of heterogeneous nitromethane

    SciTech Connect

    Dattelbaum, Dana M; Sheffield, Stephen A; Stahl, David B; Dattelbaum, Andrew M; Engelke, Ray

    2010-01-01

    To gain insights into the critical hot spot features influencing energetic materials initiation characteristics, well-defined micron-scale particles have been intentionally introduced into the homogeneous explosive nitromethane (NM). Two types of potential hot spot origins have been examined - shock impedance mismatches using solid silica beads, and porosity using hollow microballoons - as well as their sizes and inter-particle separations. Here, we present the results of several series of gas gun-driven plate impact experiments on NM/particle mixtures with well-controlled shock inputs. Detailed insights into the nature of the reactive flow during the build-up to detonation have been obtained from the response of in-situ electromagnetic gauges, and the data have been used to establish Pop-plots (run-distance-to-detonation vs. shock input pressure) for the mixtures. Comparisons of sensitization effects and energy release characteristics relative to the initial shock front between the solid and hollow beads are presented.

  17. Influence of self-made saliva substitutes on tribological characteristics of human enamel.

    PubMed

    Andrysewicz, Edyta; Mystkowska, Joanna; Dąbrowski, Jan Ryszard; Olchowik, Rafał

    2014-01-01

    This paper describes the results of tests on the influence of human saliva and its substitutes on tribological characteristics of friction pairs. Each pair consists of enamel and one of the following materials: ceramics, the Meridian B2 dental composite, the GK dental amalgam, and Ti-6Al-4V titanium alloy. The saliva substitutes used were prepared using pyrophosphates, xanthan gum, and mucins dissolved in a saline buffer. The results of the tribological tests show that the values of the parameters under investigation (coefficient of friction and linear wear) were different from each other. Some similarity was observed between the evaluated level of wear characteristics after the friction process in the environment of human saliva and that in the environment of one of the mucins tested. Microscopic observations of the surfaces of the enamel samples after friction revealed varied forms of tribological wear.

  18. Suicide in the City: Do Characteristics of Place Really Influence Risk?*

    PubMed Central

    Denney, Justin T.; Wadsworth, Tim; Rogers, Richard G.; Pampel, Fred C.

    2015-01-01

    Objective This article investigates the role of social context on individual suicide mortality with attention paid to the possibility that contextual effects are simply the sum of individual characteristics associated with suicide. Methods We use restricted data from the 1986–2006 National Health Interview Survey-Linked Mortality Files, which include nearly one million records and 1,300 suicides, to examine the role of familial and socioeconomic context on adult suicide. Results Results show that adults living in cities with more socioeconomic disadvantage and fewer families living together have higher odds of suicidal death than adults living in less disadvantaged cities and cities with more families living together, respectively, after controlling for individual-level socioeconomic status, marital status, and family size. Conclusion The findings support classic sociological arguments that the risk of suicide is indeed influenced by the social milieu and cannot simply be explained by the aggregation of individual characteristics. PMID:26236047

  19. Young parents' relationship characteristics, shared sexual behaviors, perception of partner risks, and dyadic influences.

    PubMed

    Koniak-Griffin, Deborah; Huang, Rong; Lesser, Janna; Gonzalez-Figueroa, Evelyn; Takayanagi, Sumiko; Cumberland, William G

    2009-01-01

    Rising rates of heterosexually transmitted HIV among youth and young adults, particularly from ethnic minorities, create an urgent need to understand risk factors and perceptions of risk within the context of couple relationships. This study examined reports of young mothers and fathers (predominantly Latino) about background characteristics, relationship quality and length, HIV-related risk factors, and perceptions of partners' behaviors and personal history. Higher concordance was found for relationship characteristics and partners' personal history (e.g., incarceration) than on shared sexual behaviors. Most males and females stated that they were monogamous; however, those whose partners reported concurrency were unaware of this. Many were unaware of their partners' HIV testing status. Relationship quality was higher when females accurately perceived their partners' self-reported HIV-related risk behaviors. Length of the relationship did not influence concordance. Findings support the need for HIV prevention programs to promote open discussion about condom use and HIV testing within sexual partnerships.

  20. Influence of drug physicochemical characteristics on in vitro transdermal absorption of hydrophobic drug nanosuspensions.

    PubMed

    Shen, Cheng-Ying; Li, Rui-Sheng; Shen, Bao-de; Shen, Gang; Wang, Li-Qiang; Zheng, Juan; Li, Xiao-Rong; Min, Hong-Yan; Han, Jin; Yuan, Hai-Long

    2015-01-01

    The purpose of this paper was to study the influence of drug physicochemical characteristics on in vitro transdermal absorption of hydrophobic drug nanosuspensions. Four drug nanosuspensions were produced by high-pressure homogenization technique, which were the same in stabilizer and similar in particle size. Differential scanning calorimetry and powder X-ray diffraction analysis showed that the crystalline state of the nanocrystals did not change. In vitro permeation study demonstrated that the drug nanosuspensions have a higher rate of permeation that ranged from 1.69- to 3.74-fold compared to drug microsuspensions. Correlation analysis between drug physicochemical properties and Jss revealed that log P and pKa were factors that influenced the in vitro transdermal absorption of hydrophobic drug nanosuspensions, and drugs with a log P value around 3 and a higher pKa value (when pKa < pH+2) would gain higher Jss in this paper.

  1. Interpersonal Privacy Management in Distributed Collaboration: Situational Characteristics and Interpretive Influences

    NASA Astrophysics Data System (ADS)

    Patil, Sameer; Kobsa, Alfred; John, Ajita; Brotman, Lynne S.; Seligmann, Doree

    To understand how collaborators reconcile the often conflicting needs of awareness and privacy, we studied a large software development project in a multinational corporation involving individuals at sites in the U.S. and India. We present a theoretical framework describing privacy management practices and their determinants that emerged from field visits, interviews, and questionnaire responses. The framework identifies five relevant situational characteristics: issue(s) under consideration, physical place(s) involved in interaction(s), temporal aspects, affordances and limitations presented by technology, and nature of relationships among parties. Each actor, in turn, interprets the situation based on several simultaneous influences: self, team, work site, organization, and cultural environment. This interpretation guides privacy management action(s). Past actions form a feedback loop refining and/or reinforcing the interpretive influences. The framework suggests that effective support for privacy management will require that designers follow a socio-technical approach incorporating a wider scope of situational and interpretive differences.

  2. Child and family characteristics influencing intervention choices in autism spectrum disorders.

    PubMed

    Patten, Elena; Baranek, Grace T; Watson, Linda R; Schultz, Beth

    2013-09-01

    A myriad of treatment options are available for children with autism, yet little is understood regarding characteristics of parents (e.g., education) and children (e.g., severity of autism symptoms) that influence types and amounts of therapy utilization. Interviews from 70 families were analyzed to determine potential influences on utilization (e.g., start of first services, use of traditional services). Descriptive findings regarding therapy types were similar to national studies. However, only three of the variables predicted utilization of specific therapies: severity of sensory processing problems was associated with earlier initiation of services in general, and higher maternal and paternal education was associated with the use of dietary and/or vitamin therapy as well as with more types of services. No other variables had predictive value; thus, the amount and type of therapies received may be more related to diagnostic practices and/or to the affordances/constraints of service delivery and reimbursement systems at particular ages.

  3. Identification of influencing municipal characteristics regarding household waste generation and their forecasting ability in Biscay

    SciTech Connect

    Oribe-Garcia, Iraia Kamara-Esteban, Oihane; Martin, Cristina; Macarulla-Arenaza, Ana M.; Alonso-Vicario, Ainhoa

    2015-05-15

    Highlights: • We have modelled household waste generation in Biscay municipalities. • We have identified relevant characteristics regarding household waste generation. • Factor models are used in order to identify the best subset of explicative variables. • Biscay’s municipalities are grouped by means of hierarchical clustering. - Abstract: The planning of waste management strategies needs tools to support decisions at all stages of the process. Accurate quantification of the waste to be generated is essential for both the daily management (short-term) and proper design of facilities (long-term). Designing without rigorous knowledge may have serious economic and environmental consequences. The present works aims at identifying relevant socio-economic features of municipalities regarding Household Waste (HW) generation by means of factor models. Factor models face two main drawbacks, data collection and identifying relevant explanatory variables within a heterogeneous group. Grouping similar characteristics observations within a group may favour the deduction of more robust models. The methodology followed has been tested with Biscay Province because it stands out for having very different municipalities ranging from very rural to urban ones. Two main models are developed, one for the overall province and a second one after clustering the municipalities. The results prove that relating municipalities with specific characteristics, improves the results in a very heterogeneous situation. The methodology has identified urban morphology, tourism activity, level of education and economic situation as the most influencing characteristics in HW generation.

  4. The relative influence of road characteristics and habitat on adjacent lizard populations in arid shrublands

    USGS Publications Warehouse

    Hubbard, Kaylan A.; Chalfoun, Anna D.; Gerow, Kenneth G.

    2016-01-01

    As road networks continue to expand globally, indirect impacts to adjacent wildlife populations remain largely unknown. Simultaneously, reptile populations are declining worldwide and anthropogenic habitat loss and fragmentation are frequently cited causes. We evaluated the relative influence of three different road characteristics (surface treatment, width, and traffic volume) and habitat features on adjacent populations of Northern Sagebrush Lizards (Sceloporus graciosus graciosus), Plateau Fence Lizards (S. tristichus), and Greater Short-Horned Lizards (Phrynosoma hernandesi) in mixed arid shrubland habitats in southwest Wyoming. Neither odds of lizard presence nor relative abundance was significantly related to any of the assessed road characteristics, although there was a trend for higher Sceloporus spp. abundance adjacent to paved roads. Sceloporus spp. relative abundance did not vary systematically with distance to the nearest road. Rather, both Sceloporus spp. and Greater Short-Horned Lizards were associated strongly with particular habitat characteristics adjacent to roads. Sceloporus spp. presence and relative abundance increased with rock cover, relative abundance was associated positively with shrub cover, and presence was associated negatively with grass cover. Greater Short-Horned Lizard presence increased with bare ground and decreased marginally with shrub cover. Our results suggest that habitat attributes are stronger correlates of lizard presence and relative abundance than individual characteristics of adjacent roads, at least in our system. Therefore, an effective conservation approach for these species may be to consider the landscape through which new roads and their associated development would occur, and the impact that placement could have on fragment size and key habitat elements.

  5. Influence of the electrode system on the emission characteristics of a vacuum spark

    SciTech Connect

    Bashutin, O. A. Alkhimova, M. A.; Vovchenko, E. D.; Dodulad, E. I.; Savelov, A. S.; Sarantsev, S. A.

    2013-11-15

    The influence of the electrode system on the emission characteristics of a high-current low-inductance vacuum spark is investigated. It is shown that the structure and composition of the spark plasma radiating in the X-ray spectral range depend substantially on the geometry and relative position of the electrodes. A mechanism related to the effect of the initial distribution of the electric field in the electrode gap is proposed to explain such a dependence. The conditions in which the radiating plasma forms from the erosion products of one or both electrodes are determined.

  6. Influence of multiple water-quality characteristics on copper toxicity to fathead minnows (Pimephales promelas)

    USGS Publications Warehouse

    Sciera, K.L.; Isely, J.J.; Tomasso, J.R.; Klaine, S.J.

    2004-01-01

    Water quality influences the bioavailability and toxicity of copper to aquatic organisms. Understanding the relationships between water-quality parameters and copper toxicity may facilitate the development of site-specific criteria for water quality and result in better protection of aquatic biota. Many studies have examined the influence of a single water-quality parameter on copper toxicity, but the interactions of several characteristics have not been well studied in low-hardness water. The goal of the present research was to examine the interactions among water-quality characteristics and their effects on copper toxicity to larval fathead minnows (Pimephales promelas). The effects of dissolved organic carbon (DOC) concentration, DOC source, pH, and hardness on acute copper toxicity were determined using a complete factorially designed experiment. Hardness, pH, DOC, and interaction of pH and DOC all significantly affected copper toxicity. A predictive model based on these data described 88% of the variability in copper toxicity. This model also explained 58% of the variability in copper toxicity for an independent dataset of South Carolina (USA) waters. The biotic ligand model underpredicted the acute copper toxicity to fathead minnows when compared with observed values.

  7. Influence of landscape characteristics on retention of expandable radiocollars on young ungulates

    USGS Publications Warehouse

    Grovenburg, Troy W.; Klaver, Robert W.; Jacques, Christopher N.; Brinkman, Todd J.; Swanson, Christopher C.; DePerno, Christopher S.; Monteith, Kevin L.; Sievers, Jaret D.; Bleich, Vernon C.; Kie, John G.; Jenks, Jonathan A.

    2014-01-01

    One tool used for wildlife management is the deployment of radiocollars to gain knowledge of animal populations. Understanding the influence of individual factors (e.g., species, collar characteristics) and landscape characteristics (e.g., forested cover, shrubs, and fencing) on retention of expandable radiocollars for ungulates is important for obtaining empirical data on factors influencing ecology of young-of-the-year ungulates. During 2001–2009, we captured and radiocollared 198 white-tailed deer (Odocoileus virginianus) fawns, 142 pronghorn (Antilocapra americana) fawns, and 73 mule deer (O. hemionus) fawns in South Dakota, Minnesota, and California, USA. We documented 72 (36.4%), 8 (5.6%), and 7 (9.6%) premature (2, SE = 0.1, n = 75) compared with areas where fawns shed collars (x = 3.24 km/km2, SE = 0.1, n = 56) prior to 270 days. Researchers of fawns should consider that radiocollars can be shed prematurely when estimating desired sample size to yield a suitable strength of inference about some natural process of interest.

  8. Using a PBPK model to study the influence of different characteristics of nanoparticles on their biodistribution

    NASA Astrophysics Data System (ADS)

    Li, D.; Emond, C.; Johanson, G.; Jolliet, O.

    2013-04-01

    The studies on potential health risks possessed by engineered nanoparticles (NPs) have been growing rapidly. However, detailed and systemic knowledge on the uptake and biodistribution of NPs in body is still limited. Moreover, there is a need to characterize the relation between the characteristics of NPs (size, surface modifications, etc.) and their behaviours in the body. The aim of this study is to explore how these characteristics will influence the NPs uptake and biodistribution. We have successfully developed a Physiologically Based Pharmacokinetic (PBPK) model for the biodistribution of polyethylene glycol-coated polyacrylamide NPs in rats, modelling the capture and removal of NPs by phagocytizing cells. Based on this PBPK model, the behaviours of other nanoparticles (polymeric, quantum dot, silver, titanium oxide and cerium oxide NPs) are investigated, based on data from several experiments published in the literature. Size is one of the important properties to consider. Our model parameterization suggests that the uptake rate by phagocytizing cells will decrease as the size of nanoparticles increases when the removal rates for these nanoparticles are similar. This could indicate that the phagocytizing cells are saturated by the number of NPs rather than absolute mass. Nevertheless, surface modification, such as polyethylene glycol coating, may reduce the uptake rate by phagocytizing cells. With phagocytizing cells serving as a deposit of NPs, these influences of different characteristics of NPs to the behavior of phagocytizing cells could affect the fate of NPs in the body not only during the initial uptake within the first hour but also in long-term at the kinetic and dynamic levels.

  9. The influence of titania-zirconia-zirconium titanate nanotube characteristics on osteoblast cell adhesion.

    PubMed

    Minagar, Sepideh; Li, Yuncang; Berndt, Christopher C; Wen, Cuie

    2015-01-01

    Studies of biomaterial surfaces and their influence on cell behavior provide insights concerning the design of surface physicochemical and topography properties of implant materials. Fabrication of biocompatible metal oxide nanotubes on metallic biomaterials, especially titanium alloys such as Ti50Zr via anodization, alters the surface chemistry as well as surface topography of the alloy. In this study, four groups of TiO2-ZrO2-ZrTiO4 nanotubes that exhibit diverse nanoscale dimensional characteristics (i.e. inner diameter Di, outer diameter Do and wall thicknesses Wt) were fabricated via anodization. The nanotubes were annealed and characterized using scanning electron microscopy and 3-D profilometry. The potential applied during anodization influenced the oxidation rate of titanium and zirconium, thereby resulting in different nanoscale characteristics for the nanotubes. The different oxidation and dissolution rates both led to changes in the surface roughness parameters. The in vitro cell response to the nanotubes with different nanoscale dimensional characteristics was assessed using osteoblast cells (SaOS2). The results of the MTS assay indicated that the nanotubes with inner diameter (Di)≈40nm exhibited the highest percentage of cell adhesion of 41.0%. This result can be compared to (i) 25.9% cell adhesion at Di≈59nm, (ii) 33.1% at Di≈64nm, and (iii) 33.5% at Di≈82nm. The nanotubes with Di≈59nm exhibited the greatest roughness parameter of Sa (mean roughness), leading to the lowest ability to interlock with SaOS2 cells.

  10. The influence of population characteristics on variation in general practice based morbidity estimations

    PubMed Central

    2011-01-01

    Background General practice based registration networks (GPRNs) provide information on morbidity rates in the population. Morbidity rate estimates from different GPRNs, however, reveal considerable, unexplained differences. We studied the range and variation in morbidity estimates, as well as the extent to which the differences in morbidity rates between general practices and networks change if socio-demographic characteristics of the listed patient populations are taken into account. Methods The variation in incidence and prevalence rates of thirteen diseases among six Dutch GPRNs and the influence of age, gender, socio economic status (SES), urbanization level, and ethnicity are analyzed using multilevel logistic regression analysis. Results are expressed in median odds ratios (MOR). Results We observed large differences in morbidity rate estimates both on the level of general practices as on the level of networks. The differences in SES, urbanization level and ethnicity distribution among the networks' practice populations are substantial. The variation in morbidity rate estimates among networks did not decrease after adjusting for these socio-demographic characteristics. Conclusion Socio-demographic characteristics of populations do not explain the differences in morbidity estimations among GPRNs. PMID:22111707

  11. Influence of Aromatic Residues on the Material Characteristics of Aβ Amyloid Protofibrils at the Atomic Scale.

    PubMed

    Chang, Hyun Joon; Baek, Inchul; Lee, Myeongsang; Na, Sungsoo

    2015-08-03

    Amyloid fibrils, which cause a number of degenerative diseases, are insoluble under physiological conditions and are supported by native contacts. Recently, the effects of the aromatic residues on the Aβ amyloid protofibril were investigated in a ThT fluorescence study. However, the relationship between the material characteristics of the Aβ protofibril and its aromatic residues has not yet been investigated on the atomic scale. Here, we successfully constructed wild-type (WT) and mutated types of Aβ protofibrils by using molecular dynamics simulations. Through principle component analysis, we established the structural stability and vibrational characteristics of F20L Aβ protofibrils and compared them with WT and other mutated models such as F19L and F19LF20L. In addition, structural stability was assessed by calculating the elastic modulus, which showed that the F20L model has higher values than the other models studied. From our results, it is shown that aromatic residues influence the structural and material characteristics of Aβ protofibrils.

  12. Identification of influencing municipal characteristics regarding household waste generation and their forecasting ability in Biscay.

    PubMed

    Oribe-Garcia, Iraia; Kamara-Esteban, Oihane; Martin, Cristina; Macarulla-Arenaza, Ana M; Alonso-Vicario, Ainhoa

    2015-05-01

    The planning of waste management strategies needs tools to support decisions at all stages of the process. Accurate quantification of the waste to be generated is essential for both the daily management (short-term) and proper design of facilities (long-term). Designing without rigorous knowledge may have serious economic and environmental consequences. The present works aims at identifying relevant socio-economic features of municipalities regarding Household Waste (HW) generation by means of factor models. Factor models face two main drawbacks, data collection and identifying relevant explanatory variables within a heterogeneous group. Grouping similar characteristics observations within a group may favour the deduction of more robust models. The methodology followed has been tested with Biscay Province because it stands out for having very different municipalities ranging from very rural to urban ones. Two main models are developed, one for the overall province and a second one after clustering the municipalities. The results prove that relating municipalities with specific characteristics, improves the results in a very heterogeneous situation. The methodology has identified urban morphology, tourism activity, level of education and economic situation as the most influencing characteristics in HW generation.

  13. The influence of donor characteristics and preparation methods on the potency of human cryoprecipitate.

    PubMed

    Burka, E R; Puffer, T; Martinez, J

    1975-01-01

    An investigation of the influence of donor characteristics and preparative procedural variation on the potency of human cryoprecipitate was carried out on 30 whole blood and 139 plasmapheresis donors. Recovery of plasma Factor VIII in cryoprecipitate ranged from 11.2 to 89.4 per cent (average, 38 +/- 18%). The Factor VIII content of bags of cryoprecipitate ranged from 29 to 379 units (average, 111 +/- 77 units). No difference existed between whole blood donors and regular plasmapheresis donors. The only donor characteristic which was related to the potency of cryoprecipitate was the plasma concentration of Factor VIII which varied as much as sixfold on repeated visits of the same donor. The findings indicate that, within the limitations imposed by the regulations of the American Association of Blood Banks and the practicalities of an ordinary blood bank workload, no donor characteristic or variation in preparative procedures was of predictive value in obtaining cryoprecipitate of high potency. The potency of cryoprecipitate from individual donors appears to be related to factors inherent in the donor plasma itself.

  14. The influence of farmer demographic characteristics on environmental behaviour: a review.

    PubMed

    Burton, Rob J F

    2014-03-15

    Many agricultural studies have observed a relationship between farmer demographic characteristics and environmental behaviours. These relationships are frequently employed in the construction of models, the identification of farmer types, or as part of more descriptive analyses aimed at understanding farmers' environmental behaviour. However, they have also often been found to be inconsistent or contradictory. Although a considerable body of literature has built up around the subject area, research has a tendency to focus on factors such as the direction, strength and consistency of the relationship - leaving the issue of causality largely to speculation. This review addresses this gap by reviewing literature on 4 key demographic variables: age, experience, education, and gender for hypothesised causal links. Overall the review indicates that the issue of causality is a complex one. Inconsistent relationships can be attributed to the presence of multiple causal pathways, the role of scheme factors in determining which pathway is important, inadequately specified measurements of demographic characteristics, and the treatment of non-linear causalities as linear. In addition, all demographic characteristics were perceived to be influenced (to varying extents) by cultural-historical patterns leading to cohort effects or socialised differences in the relationship with environmental behaviour. The paper concludes that more work is required on the issue of causality.

  15. Influence of electrode geometry on the high-field characteristics of photoconductive silicon wafers

    SciTech Connect

    Madangarli, V.P.; Gradinaru, G.; Korony, G.; Sudarshan, T.S.; Loubriel, G.M.; Zutavern, F.J.; Patterson, P.E.

    1994-07-01

    A series of experiment were conducted to study the influence of electrode geometry on the prebreakdown (and breakdown) characteristics of high resistivity ({rho} > 30 k{Omega}-cm), p-type Si wafers under quasi-uniform and non-uniform electric field configurations. In the quasi-uniform field configuration, the 1mm thick Si wafer was mounted between the slots of two plane parallel stainless steel disc electrodes (parallel), while the non-uniform field was obtained by mounting the wafer between two pillar-type electrodes with a hemispherical tip (pillar). The main objective of the above investigation was to verify if the uniform field configuration under a parallel system has a positive influence by reducing the field enhancement at the contact region, as opposed to the definite field enhancement present in the case of the non-uniform pillar system. Also, it was proposed to study the effect of the contact profile on the field distribution over the wafer surface and hence its influence on the high-field performance of the Si wafers.

  16. Influence mechanism on flow and heat transfer characteristics for air-cooled steam condenser cells

    NASA Astrophysics Data System (ADS)

    He, Wei Feng; Dai, Yi Ping; Li, Mao Qing; Ma, Qing Zhong

    2012-09-01

    Air-cooled steam condensers (ACSCs) have been extensively utilized to reject waste heat in power industry to save water resources. However, ACSC performance is so sensitive to ambient wind that almost all the air-cooled power plants in China are less efficient compared to design conditions. It is shown from previous research that the influence of ambient wind on the cell performance differs from its location in the condenser. As a result, a numerical model including two identical ACSC cells are established, and the different influence on the performance of the cells is demonstrated and analyzed through the computational fluid dynamics method. Despite the great influence from the wind speeds, similar cell performance is obtained for the two cells under both windless and wind speed conditions when the wind parallels to the steam duct. Fan volumetric effectiveness which characterizes the fan performance, as well as the exchanger heat transfer rate, drops obviously with the increasing wind speed, and performance difference between the exchanger pair in the same A-frame also rises continuously. Furthermore, different flow and heat transfer characteristics of the windward and leeward cell are obtained at different wind angles, and ambient wind enhances the performance of the leeward cell, while that of the windward one changes little.

  17. Influence of guide vane setting in pump mode on performance characteristics of a pump-turbine

    NASA Astrophysics Data System (ADS)

    Li, Deyou; Wang, Hongjie; Nielsen, Torbjørn K.; Gong, Ruzhi; Wei, Xianzhu; Qin, Daqing

    2016-11-01

    Performance characteristics in pump mode of pump-turbines are vital for the safe and effective operation of pumped storage power plants. They are resultant of Euler head (power input) and hydraulic losses (power dissipation). In this paper, 3-D steady simulations were performed under 13mm, 19mm and 25mm guide vane openings (GVOs). Three groups of operating points under the three GVOs were chosen based on experimental validation to investigate the influence of guide vane setting on flow patterns upstream and downstream. Analysed results show that, the guide vane setting will obviously change the flow pattern downstream, which in turn influences the flow upstream. It shows a strong effect on hydraulic losses in guide and stay vanes. In addition, at the large part load conditions, the change of GVO will increase the relative flow angle at the runner outlet. As a consequence, it decreases the Euler head. However, at other operating conditions, it only has a little influence on Euler head. Flow patterns in pump mode are very dependent on the GVO and discharge.

  18. Variation in habitat soundscape characteristics influences settlement of a reef-building coral

    PubMed Central

    Bohnenstiehl, DelWayne; Peters, Jason W.; Eggleston, David

    2016-01-01

    Coral populations, and the productive reef ecosystems they support, rely on successful recruitment of reef-building species, beginning with settlement of dispersing larvae into habitat favourable to survival. Many substrate cues have been identified as contributors to coral larval habitat selection; however, the potential for ambient acoustic cues to influence coral settlement responses is unknown. Using in situ settlement chambers that excluded other habitat cues, larval settlement of a dominant Caribbean reef-building coral, Orbicella faveolata, was compared in response to three local soundscapes, with differing acoustic and habitat properties. Differences between reef sites in the number of larvae settled in chambers isolating acoustic cues corresponded to differences in sound levels and reef characteristics, with sounds at the loudest reef generating significantly higher settlement during trials compared to the quietest site (a 29.5 % increase). These results suggest that soundscapes could be an important influence on coral settlement patterns and that acoustic cues associated with reef habitat may be related to larval settlement. This study reports an effect of soundscape variation on larval settlement for a key coral species, and adds to the growing evidence that soundscapes affect marine ecosystems by influencing early life history processes of foundational species. PMID:27761342

  19. Physical Model of Solar Activity Influence on Climate Characteristics of Troposphere.

    NASA Astrophysics Data System (ADS)

    Molodykh, S. I.; Zherebtsov, G. A.; Kovalenko, V. A.

    2009-10-01

    A new model of solar activity influence on the parameters of the terrestrial climate system is discussed. The main points of the model of solar activity effect on the terrestrial climate system are presented. The key conception of this model is the influence of heliogeophysical disturbances on the terrestrial climate system parameters controlling the energy flux going from the Earth to the space in polar regions. The model is based on the physical mechanism of the influence of heliogeophysical factors on climate characteristics and atmospheric circulation in high-latitude troposphere through atmospheric electricity. According to this model, the growth of solar activity results in the decrease of radiative cooling in high-latitude regions, increase of temperature of lower and middle troposphere, reorganization of the thermobaric field, decrease of the mean meridional gradient of temperature between polar and equatorial regions, which determine the meridional transportation of heat. The decrease of heat flow-out from low-latitude regions results in temperature increase in lower and middle latitude regions, and increase of heat content of the ocean and climate system. Some observational data are presented that confirm the proposed model.

  20. Variation in habitat soundscape characteristics influences settlement of a reef-building coral.

    PubMed

    Lillis, Ashlee; Bohnenstiehl, DelWayne; Peters, Jason W; Eggleston, David

    2016-01-01

    Coral populations, and the productive reef ecosystems they support, rely on successful recruitment of reef-building species, beginning with settlement of dispersing larvae into habitat favourable to survival. Many substrate cues have been identified as contributors to coral larval habitat selection; however, the potential for ambient acoustic cues to influence coral settlement responses is unknown. Using in situ settlement chambers that excluded other habitat cues, larval settlement of a dominant Caribbean reef-building coral, Orbicella faveolata, was compared in response to three local soundscapes, with differing acoustic and habitat properties. Differences between reef sites in the number of larvae settled in chambers isolating acoustic cues corresponded to differences in sound levels and reef characteristics, with sounds at the loudest reef generating significantly higher settlement during trials compared to the quietest site (a 29.5 % increase). These results suggest that soundscapes could be an important influence on coral settlement patterns and that acoustic cues associated with reef habitat may be related to larval settlement. This study reports an effect of soundscape variation on larval settlement for a key coral species, and adds to the growing evidence that soundscapes affect marine ecosystems by influencing early life history processes of foundational species.

  1. Design Characteristics Influence Performance of Clinical Prediction Rules in Validation: A Meta-Epidemiological Study

    PubMed Central

    Ban, Jong-Wook; Emparanza, José Ignacio; Urreta, Iratxe; Burls, Amanda

    2016-01-01

    Background Many new clinical prediction rules are derived and validated. But the design and reporting quality of clinical prediction research has been less than optimal. We aimed to assess whether design characteristics of validation studies were associated with the overestimation of clinical prediction rules’ performance. We also aimed to evaluate whether validation studies clearly reported important methodological characteristics. Methods Electronic databases were searched for systematic reviews of clinical prediction rule studies published between 2006 and 2010. Data were extracted from the eligible validation studies included in the systematic reviews. A meta-analytic meta-epidemiological approach was used to assess the influence of design characteristics on predictive performance. From each validation study, it was assessed whether 7 design and 7 reporting characteristics were properly described. Results A total of 287 validation studies of clinical prediction rule were collected from 15 systematic reviews (31 meta-analyses). Validation studies using case-control design produced a summary diagnostic odds ratio (DOR) 2.2 times (95% CI: 1.2–4.3) larger than validation studies using cohort design and unclear design. When differential verification was used, the summary DOR was overestimated by twofold (95% CI: 1.2 -3.1) compared to complete, partial and unclear verification. The summary RDOR of validation studies with inadequate sample size was 1.9 (95% CI: 1.2 -3.1) compared to studies with adequate sample size. Study site, reliability, and clinical prediction rule was adequately described in 10.1%, 9.4%, and 7.0% of validation studies respectively. Conclusion Validation studies with design shortcomings may overestimate the performance of clinical prediction rules. The quality of reporting among studies validating clinical prediction rules needs to be improved. PMID:26730980

  2. Platelet serotonin transporter (5HTt): physiological influences on kinetic characteristics in a large human population.

    PubMed

    Banović, Miroslav; Bordukalo-Niksić, Tatjana; Balija, Melita; Cicin-Sain, Lipa; Jernej, Branimir

    2010-01-01

    The present study had two goals: first, to give a detailed description of a reliable method for full kinetic analysis of serotonin transporter (5HTt) on the membrane of human platelets, and second, as a main issue, to report on physiological influences on kinetic characteristics of this transmembrane transport on a large population of healthy individuals. Full kinetic analyses of platelet serotonin uptake were performed on 334 blood donors of both sexes by the use of 14C-radioisotopic method, which was first optimized according to assumptions of enzyme kinetic analyses, with regard to platelet concentration, duration of uptake, concentration of substrate as well as important technical parameters (underpressure of filtration, blanks, incubating temperature, etc). Kinetic parameters of platelet serotonin uptake in the whole population were for V(max): 142 +/- 25.3 pmol 5HT/10(8) platelets/minute and for K(m): 0.404 +/- 0.089 microM 5HT. Besides the report on kinetic values of 5HT transporter protein, we have also described major physiological influences on the mentioned parameters, V(max), K(m) and their derivative, V(max)/K(m) (transporter efficiency): range and frequency distribution of normal values, intraindividual stability over time, lack of age influence, gender dependence and seasonal variations. The report on kinetic values and main physiological influences on platelet serotonin transport kinetics, obtained by the use of thoroughly reassessed methodology, and on by far the largest human population studied until now, offers a reliable frame of reference for pathophysiological studies of this parameter in various clinical fields.

  3. Non-local sub-characteristic zones of influence in unsteady interactive boundary-layers

    NASA Technical Reports Server (NTRS)

    Rothmayer, A. P.

    1992-01-01

    The properties of incompressible, unsteady, interactive, boundary layers are examined for a model hypersonic boundary layer and internal flow past humps or, equivalently, external flow past short-scaled humps. Using a linear high frequency analysis, it is shown that the domains of dependence within the viscous sublayer may be a strong function of position within the sublayer and may be strongly influenced by the pressure displacement interaction, or the prescribed displacement condition. Detailed calculations are presented for the hypersonic boundary layer. This effect is found to carry over directly to the fully viscous problem as well as the nonlinear problem. In the fully viscous problem, the non-local character of the domains of dependence manifests itself in the sub-characteristics. Potential implications of the domain of dependence structure on finite difference computations of unsteady boundary layers are briefly discussed.

  4. Influence of the cooling liquid on surface quality characteristics in milling

    NASA Astrophysics Data System (ADS)

    Tampu, N. C.; Brabie, G.; Chirita, B. A.; Herghelegiu, E.; Radu, M. C.

    2015-11-01

    Cooling system and cooling liquid characteristics are among the main factors influencing surface quality and tool wear. The aim of this study is to analyse the effect of the cooling liquid, used in different concentrations and at different temperatures, on the quality of the surface layer processed by milling. In order to make this analysis a Minimum Quantity Lubrication (MQL) cooling device is used. Three different volumetric ratios were used to modify the concentration of the cooling fluid (25% water to 75% emulsion, 50% water to 50% emulsion, 75% water to 25% emulsion) and three different temperatures. The studies revealed that surface roughness can be correlated with the variation of the cooling liquid temperature while surface flatness can be correlated to both, cooling liquid temperature and concentration.

  5. Influence of Aloe vera on collagen characteristics in healing dermal wounds in rats.

    PubMed

    Chithra, P; Sajithlal, G B; Chandrakasan, G

    1998-04-01

    Wound healing is a fundamental response to tissue injury that results in restoration of tissue integrity. This end is achieved mainly by the synthesis of the connective tissue matrix. Collagen is the major protein of the extracellular matrix, and is the component which ultimately contributes to wound strength. In this work, we report the influence of Aloe vera on the collagen content and its characteristics in a healing wound. It was observed that Aloe vera increased the collagen content of the granulation tissue as well as its degree of crosslinking as seen by increased aldehyde content and decreased acid solubility. The type I/type III collagen ratio of treated groups were lower than that of the untreated controls, indicating enhanced levels of type III collagen. Wounds were treated either by topical application or oral administration of Aloe vera to rats and both treatments were found to result in similar effects.

  6. Black deaf individuals' reading skills: influence of ASL, culture, family characteristics, reading experience, and education.

    PubMed

    Myers, Candace; Clark, M Diane; Musyoka, Millicent M; Anderson, Melissa L; Gilbert, Gizelle L; Agyen, Selina; Hauser, Peter C

    2010-01-01

    Previous research on the reading abilities of Deaf individuals from various cultural groups suggests that Black Deaf and Hispanic Deaf individuals lag behind their White Deaf peers. The present study compared the reading skills of Black Deaf and White Deaf individuals, investigating the influence of American Sign Language (ASL), culture, family characteristics, reading experience, and education. (The descriptor Black is used throughout the present article, as Black Deaf individuals prefer this term to African American. For purposes of parallel construction, the term White is used instead of European American.) It was found that Black Deaf study participants scored lower on measures of both reading and ASL. These findings provide implications for possible interventions at the primary, secondary, and college levels of education.

  7. Influence of configuration details on the subsonic characteristics of a space shuttle orbiter design

    NASA Technical Reports Server (NTRS)

    Decker, J. P.; Phillips, W. P.

    1974-01-01

    An investigation was conducted in the Langley low-turbulence pressure tunnel of a model of a space shuttle orbiter design in order to determine the influence of minor configuration geometric details on the aerodynamic characteristics at subsonic speeds. A plane wing was tested with a small planform fillet; a twisted wing was tested with both a small and a large planform fillet. Tailored attitude-control propulsion-system wing-tip and body pods, trisegmented elevons, and canopy effects were also investigated. The tests were conducted at angles of attack from -3 deg to 24 deg for sideslip angles of 0 deg and 6 deg and at a Mach number of 0.25.

  8. Influence of humidity on the characteristics of negative corona discharge in air

    SciTech Connect

    Xu, Pengfei Zhang, Bo He, Jinliang Chen, Shuiming

    2015-09-15

    Detailed negative corona discharge characteristics, such as the pulse amplitude, repetition frequency, average corona current, rise time, and half-wave time, are systematically studied under various air humidities with a single artificial defect electrode. The experimental result reveals that the pulse amplitude increases with the increase of air humidity; meanwhile, the repetition frequency deceases as the air humidity increases. Empirical formulae are first established for the pulse amplitude and repetition frequency with the humidity factor taken into consideration. The effective ionization integral is calculated and a positive correlation is found between the integral and the pulse amplitude. Furthermore, a simplified negative-ion cloud model is built up to investigate the mechanism of the humidity's influence on negative corona discharge. Based on the theoretical analyses, the correlation between pulse amplitude, repetition frequency, and air humidity is well explained.

  9. Influence of Impactor Mass on the Damage Characteristics and Failure Strength of Laminated Composite Plates

    NASA Technical Reports Server (NTRS)

    Ambur, Damodar R.; Kemmerly, Heather L.

    1998-01-01

    The results of an experimental study of the effect of impactor mass on the low-speed impact response of laminated flat composite plates is presented. Dropped weight impact response, damage characteristics, and residual strengths of quasi-isotropic flat plates are presented for a range of energy levels by systematically varying the mass of the impactor. Measured contact forces and damage areas are also presented. The results indicate that the contact force and damage area are nonlinear functions of the impactor mass and vary considerably over the entire range of energy levels considered. The different damage levels induced in a plate specimen when impacted at a given energy level with impactors of different masses significantly influence its compressive residual strength. The results provide clear and consistent trends in contact force, damage area, and compression-after-impact strength when the data are expressed as a function of the impactor momentum.

  10. The influence of water body characteristics on phytoplankton diversity and production in the Celtic Sea

    NASA Astrophysics Data System (ADS)

    Pemberton, Katharine; Rees, Andrew P.; Miller, Peter I.; Raine, Robin; Joint, Ian

    2004-11-01

    The influence of water body characteristics on phytoplankton biodiversity and production has been studied in stratified, mixed and frontal water masses in the Celtic Sea. The stations were in close geographical proximity to each other, yet very different phytoplankton assemblages were found. The factors that control phytoplankton biodiversity were investigated. Satellite remote sensing was used to map the development of stratification and fronts in spring and this placed the stations within a strong temporal context. Stations with a well-mixed water column had high nutrient concentrations, high rates of production and the phytoplankton assemblage was dominated by diatoms. At those stations with a stratified water column, nutrient concentrations were depleted but the assemblage was dominated by dinoflagellates and microflagellates. The ratios of depth-integrated primary production to depth-integrated chlorophyll concentration ( P/B ratio) were higher at those stations with mixed water columns than at those in stratified waters. That is, under the low nutrient/high light conditions at the stratified station, there was less production than might have been expected for the quantity of chlorophyll present. The photosynthetic characteristics of the phytoplankton assemblages were determined at the stratified stations. P mB values varied from 1.43 to 4.79 mg C [mg Chl] -1 h -1, while α B ranged from 0.011 to 0.047 mg C [mg Chl] -1 h -1 (μmol photons m -2 s -1) -1. Phytoplankton biodiversity was low at every station and did not appear to influence primary production rates; the highest rate of daily primary production measured (2.4 g C m -2 d -1) was at a station where a single species accounted for >70% of the phytoplankton biomass.

  11. Influence of hydrophibization of impellers of centrifugal pumps on their operating characteristics

    NASA Astrophysics Data System (ADS)

    Volkov, A. V.; Parygin, A. G.; Naumov, A. V.; Vikhlyantsev, A. A.; Šoukal, J.; Sedlář, M.; Komárek, M.

    2016-12-01

    This work presents experimental estimation results of changing of basic operation characteristics of a group of centrifugal pumps covering a range of values of dimensionless power-speed coefficient n s from 33 to 330 after hydrophobization of their impellers' surfaces. Hydrophobization of functional surfaces of impellers in all experiments was performed by formation of structures of organic covers by technology of MPEI NRU, which provides increasing of limiting wetting angle of surfaces to 120° and greater. Results of experimental researches of the influence of hydrophobization of impeller surfaces for high-speed pump ( n s = 330) on its characteristics is presented for the first time. Positive effect of applying hydrophobization technology to impeller surfaces in all the considered range of power-speed coefficient was generalized and estimated. It was shown that hydrophobization of impeller surfaces of centrifugal pumps provides increment to their efficiency factors within an acceptable operation range from 0.5 to 7.5%. Empiric function defining dependencies of efficiency factor increment of pump on relative supply and power-speed coefficient are suggested. Possibilities and estimation of extending acceptable operation range of a pump depending on powerspeed coefficient as a result of impeller surface hydrophobization are shown. Experimental data of comparative cavitation tests of high-speed pumps before and after hydrophobization of their impeller surfaces are generalized for the first time for considered range of power-speed coefficient values. The influence of power-speed coefficient on changing of critical net pump suction head (critical positive suction pressure) is shown. Based on existing knowledge on pumps, an attempt to validate experimentally obtained lows of changing of power and anticavitation features of centrifugal pumps after hydrophobization of their impeller surfaces is made.

  12. Influence of drying air parameters on mass transfer characteristics of apple slices

    NASA Astrophysics Data System (ADS)

    Beigi, Mohsen

    2016-10-01

    To efficiently design both new drying process and equipment and/or to improve the existing systems, accurate values of mass transfer characteristics are necessary. The present study aimed to investigate the influence of drying air parameters (i.e. temperature, velocity and relative humidity) on effective diffusivity and convective mass transfer coefficient of apple slices. The Dincer and Dost model was used to determine the mass transfer characteristics. The obtained Biot number indicated that the moisture transfer in the apple slices was controlled by both internal and external resistance. The effective diffusivity and mass transfer coefficient values obtained to be in the ranges of 7.13 × 10-11-7.66 × 10-10 and 1.46 × 10-7-3.39 × 10-7 m s-1, respectively and the both of them increased with increasing drying air temperature and velocity, and decreasing relative humidity. The validation of the model showed that the model predicted the experimental drying curves of the samples with a good accuracy.

  13. Neighborhood Characteristics: Influences on Pain and Physical Function in Youth at Risk for Chronic Pain

    PubMed Central

    Schild, Cathleen; Reed, Emily A.; Hingston, Tessa; Dennis, Catlin H.; Wilson, Anna C.

    2016-01-01

    Neighborhood features such as community socioeconomic status, recreational facilities, and parks have been correlated to the health outcomes of the residents living within those neighborhoods, especially with regard to health-related quality of life, body mass index, and physical activity. The interplay between one’s built environment and one’s perceptions may affect physical health, well-being, and pain experiences. In the current study, neighborhood characteristics and attitudes about physical activity were examined in a high-risk (youths with a parent with chronic pain) and low-risk (youths without a parent with chronic pain) adolescent sample. There were significant differences in neighborhood characteristics between the high-risk (n = 62) and low-risk (n = 77) samples (ages 11–15), with low-risk participants living in residences with more walkability, closer proximity to parks, and higher proportion of neighborhood residents having college degrees. Results indicate that neighborhood features (e.g., walkability and proximity to parks), as well as positive attitudes about physical activity were correlated with lower levels of pain and pain-related disability, and higher performance in physical functioning tests. These findings suggest that the built environment may contribute to pain outcomes in youth, above and beyond the influence of family history of pain. PMID:27869773

  14. Influence of Shot Peening on Surface Characteristics of High-Speed Steels

    NASA Astrophysics Data System (ADS)

    Harada, Yasunori; Fukaura, Kenzo

    High-speed steels are generally used for the cutting of other hard materials. These are hard materials, and can be used at high temperatures. Therefore, some of them are used for warm metal forming such as forging. However, in the tools used in hot working, an excellent hot hardness and long-life fatigue are strongly required. In the present study, the influence of shot peening on the surface characteristics of high-speed steels was investigated. Shot peening imparts compressive residual stresses on the metal surface, thus improving the fatigue life of the machine parts. In the experiment, the shot peening treatment was performed using an air-type shot peening machine. The shots made of cemented carbide were used. The workpieces were two types, W-type and Mo-type alloys. Surface roughness, compressive residual stress, and hardness of the peened workpieces were measured. It was found that shot peening using the hard shot media was effective in improving the surface characteristics of high-speed steels.

  15. Total mercury and methylmercury accumulation in periphyton of Boreal Shield lakes: influence of watershed physiographic characteristics.

    PubMed

    Desrosiers, Mélanie; Planas, Dolors; Mucci, Alfonso

    2006-02-15

    Little is known about Hg accumulation in littoral communities, especially in periphyton biofilm of unperturbed lakes. The objectives of this study were to investigate and establish relationships between total mercury (THg) and methylmercury (MeHg) concentrations in periphyton communities of Boreal lakes and watershed physiographic and lake morphometric characteristics. This study was carried out on 23 Boreal Canadian Shield lakes located between 47-50 degrees N and 73-77 degrees W. Periphyton was sampled on rocks, the dominant periphyton substrate in the littoral zone of these lakes. Periphyton algal biomass (Chla) ranged from 12 to 164 mg m(-2) whereas THg concentrations varied from 42 to 271 ng g(-1) DW and MeHg levels varied from 3 to 55 ng Hg g(-1) DW. Periphyton biomass was positively correlated to latitude, watershed wetland area and negatively correlated to watershed slope and depth of the lake. THg concentrations in periphyton were negatively correlated to watershed wetland area whereas MeHg concentrations were negatively correlated to latitude and positively correlated to watershed slope, dissolved sulfate concentration and the presence of beavers in the lake. This study confirms that periphyton can accumulate large amounts of Hg and the accumulation is strongly influenced by watershed characteristics and periphyton biomass.

  16. Clinical characteristics of persistent ectopic pregnancy after salpingostomy and influence on ongoing pregnancy

    PubMed Central

    Zhang, Yongli; Chen, Jinhong; Lu, Wen; Li, Bilan; Du, Guiqiang

    2017-01-01

    Abstract Aim The aim of this study was to assay the clinical characteristics of persistent ectopic pregnancy (PEP) and its influence on ongoing pregnancy. Methods We retrospectively reviewed 2498 patients who received salpingostomies as primary management for ectopic pregnancies from January 2004 to December 2009, using medical records and telephone inquiries. Clinical characteristics of the 52 patients (2.08%) who were diagnosed with PEP after salpingostomy were compared with those who received satisfactory treatment. The odds ratios and 95% confidential intervals were calculated for each variable by univariate and (for significantly different factors) multivariate analysis. Results Preoperatively, patients with PEP after salpingostomy significantly differed from the non‐PEP patients in gestational age, mass size and pelvic adhesiolysis. Serum β‐human chorionic gonadotropin levels in PEP patients were monitored after surgery, which had declined by 28.31% on postoperative day (POD) 4, 40.22% on POD 7, 51.46% on POD 10 and 53.43% on POD 21. Repeat ectopic pregnancy (REP) tended to occur more frequently in PEP patients (PEP: 5 cases, 10.20%; non‐PEP: 4 cases, 2.80%; P = 0.034). Multivariate analysis showed that pelvic adhesions and PEP were the strongest independent predictors of REP. Conclusion Gestational age, mass size and pelvic adhesions were significantly correlated with PEP. PEP was an independent prognostic factor for REP. However, a multicenter study is needed to support and extend our findings. PMID:28127836

  17. Cryptococcus neoformans infection in organ transplant recipients: variables influencing clinical characteristics and outcome.

    PubMed Central

    Husain, S.; Wagener, M. M.; Singh, N.

    2001-01-01

    Unique clinical characteristics and other variables influencing the outcome of Cryptococcus neoformans infection in organ transplant recipients have not been well defined. From a review of published reports, we found that C. neoformans infection was documented in 2.8% of organ transplant recipients (overall death rate 42%). The type of primary immunosuppressive agent used in transplantation influenced the predominant clinical manifestation of cryptococcosis. Patients receiving tacrolimus were significantly less likely to have central nervous system involvement (78% versus 11%, p =0.001) and more likely to have skin, soft-tissue, and osteoarticular involvement (66% versus 21%, p = 0.006) than patients receiving nontacrolimus- based immunosuppression. Renal failure at admission was the only independently significant predictor of death in these patients (odds ratio 16.4, 95% CI 1.9-143, p = 0.004). Hypotheses based on these data may elucidate the pathogenesis and may ultimately guide the management of C. neoformans infection in organ transplant recipients. PMID:11384512

  18. TECNAIRE winter field campaign: turbulent characteristics and their influence on air quality conditions

    NASA Astrophysics Data System (ADS)

    Yagüe, Carlos; Román Cascón, Carlos; Maqueda, Gregorio; Sastre, Mariano; Arrillaga, Jon A.; Artíñano, Begoña; Diaz-Ramiro, Elías; Gómez-Moreno, Francisco J.; Borge, Rafael; Narros, Adolfo; Pérez, Javier

    2016-04-01

    An urban field campaign was conducted at an air pollution hot spot in Madrid city (Spain) during winter 2015 (from 16th February to 2nd March). The zone selected for the study is a square (Plaza Fernández Ladreda) located in the southern part of the city. This area is an important intersection of several principal routes, and therefore a significant impact in the air quality of the area is found due to the high traffic density. Meteorological data (wind speed and direction, air temperature, relative humidity, pressure, precipitation and global solar radiation) were daily recorded as well as micrometeorological measurements obtained from two sonic anemometers. To characterize this urban atmospheric boundary layer (uABL), micrometeorological parameters (turbulent kinetic energy -TKE-, friction velocity -u∗- and sensible heat flux -H-) are calculated, considering 5-minute average for variance and covariance evaluations. Furthermore, synoptic atmospheric features were analyzed. As a whole, a predominant influence of high pressure systems was found over the Atlantic Ocean and western Spain, affecting Madrid, but during a couple of days (17th and 21st February) some atmospheric instability played a role. The influence of the synoptic situation and specially the evolution of the micrometeorological conditions along the day on air quality characteristics (Particulate Matter concentrations: PM10, PM2.5 and PM1, and NOx concentrations) are analyzed and shown in detail. This work has been financed by Madrid Regional Research Plan through TECNAIRE (P2013/MAE-2972).

  19. The Influence of topography on formation characteristics of hygroscopic and condensate water in Shapotou

    NASA Astrophysics Data System (ADS)

    Pan, Yanxia; Li, Xinrong; Hui, Rong; Zhao, Yang

    2016-04-01

    The formation characteristics of hygroscopic and condensate water for different topographic positions were observed using the PVC pipes manual weighing and CPM method in the typical mobile dunes fixed by straw checkerboard barriers in Shapotou. The results indicated that the formation amounts and duration of hygroscopic and condensate water show moderate spatial heterogeneity at the influence of topography. The formation amounts of hygroscopic and condensate water at different aspects conform to the classical convection model, in which the hygroscopic and condensate water amounts are highest at hollow, and windward aspect gets more water than leeward aspect, the hygroscopic and condensate water amounts at different aspects are expressed as: hollow>Western-faced aspect>Northern-faced aspect>hilltop>Southern-faced aspect>Eastern-faced aspect. The hygroscopic and condensate water amounts at different slope positions for every aspect are as follows: the foot of slope>middle slope>hilltop. A negatively linear correlation is got between slope angles and hygroscopic and condensate water amounts, hygroscopic and condensate water amounts decrease gradually along with the increase of slope angles, the amounts of hygroscopic and condensate water at the vertical aspect are only half of horizontal aspect, which indicated topography were important influence factors for the formation of the hygroscopic and condensate water in arid area.

  20. Influence of submission form characteristics on clinical information received in biopsy accession.

    PubMed

    Brannick, Erin M; Zhang, Jianying; Zhang, Xiaoli; Stromberg, Paul C

    2012-11-01

    Clinical information supplied to diagnostic laboratories through biopsy submission forms is crucial to accurate, timely diagnosis and to clinicopathologic correlation between microscopic findings and the clinical condition of the patient. The current study attempts to quantify the prevalence of deficient and inadequate submissions in veterinary biopsy service and to determine whether form characteristics, such as the open or closed nature of the form and the presence of specific prompts, influence reporting of essential case information. The hypotheses of this study are, first, that deficient and inadequate biopsy submissions do occur in veterinary medicine and, second, that open-type biopsy submission forms elicit quantitatively and qualitatively more complete case information overall, and in specific content areas, compared to closed-type biopsy submission forms. Three percent of submissions reviewed were information deficient, devoid of information beyond patient signalment, and more than 88% of forms supplied inadequate clinical information in at least 1 key content area. Both form type and specific prompts significantly influenced reporting of important clinical information. This study demonstrates the need and lays the foundation for informational completeness research in veterinary medicine.

  1. [Variation characteristics and influencing factors of air pollution index in China].

    PubMed

    Li, Xiao-Fei; Zhang, Ming-Jun; Wang, Sheng-Jie; Zhao, Ai-Fang; Ma, Qian

    2012-06-01

    Based on the daily air pollution index (API), primary pollutant, air quality level and status of 42 cities in China during 2001-2010, the characteristics of air quality were analyzed. The results showed that the atmosphere was significantly influenced by consumption of coal. The primary pollutant was PM10, and the air quality status was excellent (0 < API < 50), good (50 < API <100) and slightly polluted (100 < API < 150) in the majority. The air pollution status varied seasonally, which was the most serious in winter, and slightest in summer. The air quality was better and better in the observed period generally; The spatial distribution of urban air environment displayed a worsening trend from the south to the north and from the coasts to the inland; The local emission and natural dust transmission from the Northwest China was the main sources of urban air pollution; The air pollutants were impacted by the meteorological elements, and the air pollution index correlated linearly with precipitation, wind speed and temperature inversion; The distribution of weather conditions, which was affected by the terrain, also could influence the air quality; In addition, the human activities had both positive and negative functions on the urban air quality.

  2. Relationship between involvement and functional milk desserts intention to purchase. Influence on attitude towards packaging characteristics.

    PubMed

    Ares, Gastón; Besio, Mariángela; Giménez, Ana; Deliza, Rosires

    2010-10-01

    Consumers perceive functional foods as member of the particular food category to which they belong. In this context, apart from health and sensory characteristics, non-sensory factors such as packaging might have a key role on determining consumers' purchase decisions regarding functional foods. The aims of the present work were to study the influence of different package attributes on consumer willingness to purchase regular and functional chocolate milk desserts; and to assess if the influence of these attributes was affected by consumers' level of involvement with the product. A conjoint analysis task was carried out with 107 regular milk desserts consumers, who were asked to score their willingness to purchase of 16 milk dessert package concepts varying in five features of the package, and to complete a personal involvement inventory questionnaire. Consumers' level of involvement with the product affected their interest in the evaluated products and their reaction towards the considered conjoint variables, suggesting that it could be a useful segmentation tool during food development. Package colour and the presence of a picture on the label were the variables with the highest relative importance, regardless of consumers' involvement with the product. The importance of these variables was higher than the type of dessert indicating that packaging may play an important role in consumers' perception and purchase intention of functional foods.

  3. Influence of long-term variation in storage on hydrological drought characteristics

    NASA Astrophysics Data System (ADS)

    van Huijgevoort, Marjolein; van Lanen, Henny; Teuling, Adriaan; Uijlenhoet, Remko

    2014-05-01

    Characteristics of drought events in streamflow, like drought duration and deficit, are largely determined by catchment processes. Understanding and identification of these processes that affect drought development is important to ensure water availability in the future, especially because drought severity is projected to increase in many regions of the world. In this study, we analysed the influence of storage processes on drought characteristics to quantify the relationship between long-term variation in storage and drought characteristics. For this analysis, a large dataset with discharge observations from 1737 catchments (made available by GRDC and MOPEX) was used. The catchments are situated in Europe and the United States. The discharge time series were divided in three components with a Seasonal-Trend decomposition procedure based on Loess (STL). The long-term trend component derived with the STL method was used as a proxy for the long-term variation in storage. Hydrological drought events were identified from the observations with the variable threshold level method. The contribution of the trend component to the total discharge indicates the importance of the long-term storage variation for drought development in the catchment. A high contribution of the trend component was found in slowly-responding catchments compared to fast-responding catchments. Features of drought propagation (pooling, lag, lengthening and attenuation) were identified in slowly-responding catchments. The contribution of the trend component was linked to the mean drought duration. As expected the catchments with a high contribution experienced relatively long drought events as compared to catchments with a low contribution of the trend component. This relation was less clear for the mean standardized deficit volume. A high contribution of the trend component was only found in smaller catchments, which reflects the importance of storage processes in these catchments. With the STL

  4. Incubation Temperature during Fetal Development Influences Morphophysiological Characteristics and Preferred Ambient Temperature of Chicken Hatchlings

    PubMed Central

    Morita, Viviane de Souza; de Almeida, Vitor Rosa; Matos, João Batista; Vicentini, Tamiris Iara; van den Brand, Henry; Boleli, Isabel Cristina

    2016-01-01

    Skin and feather characteristics, which play a critical role in body temperature maintenance, can be affected by incubation circumstances, such as incubation temperature. However, no study to date has assessed the influence of incubation temperature during the fetal stage on morphometric characteristics and vascular development of the skin, feather characteristics, and their relationship to hormone levels and preferred temperature in later life in chickens. Broiler breeder eggs were exposed to low (36°C), control (37.5°C), or high (39°C) temperatures (treatments LT, CK, and HT, respectively) from day 13 of incubation onward, because it is known that the endocrine axes are already established at this time. During this period, eggshell temperature of HT eggs (38.8±0.33°C) was higher than of LT (37.4±0.08°C) and CK eggs (37.8 ±0.15°C). The difference between eggshell and incubator air temperature diminished with the increasing incubation temperature, and was approximately zero for HT. HT hatchlings had higher surface temperature on the head, neck, and back, and thinner and more vascularized skin than did CK and LT hatchlings. No differences were found among treatments for body weight, total feather weight, number and length of barbs, barbule length, and plasma T4 concentration. LT hatchlings showed lower plasma T3 and GH, as well as lower T3/T4 ratio and decreased vascularity in the neck, back, and thigh skin compared to CK hatchlings. On the other hand, HT hatchlings had decreased skin thickness and increased vascularity, and preferred a higher ambient temperature compared to CK and HT hatchlings. In addition, for all treatments, surface temperature on the head was higher than of the other body regions. We conclude that changes in skin thickness and vascularity, as well as changes in thyroid and growth hormone levels, are the result of embryonic strategies to cope with higher or lower than normal incubation temperatures. Additionally exposure to increased

  5. Influence of seasonal canopy development on turbulent flow characteristics in a hedgerow vineyard

    NASA Astrophysics Data System (ADS)

    Vendrame, Nadia; Tezza, Luca; Tha Paw U, Kyaw; Pitacco, Andrea

    2016-04-01

    Turbulence is the main driver of vegetation-atmosphere exchanges. Flow characteristics determine the transport of energy and matter between different layers of the canopy and the atmosphere, defining local microclimatic conditions and influencing physiological processes of the vegetation. Therefore, studying turbulent flow dynamics inside and above the canopy is crucial to correctly predict overall fluxes of matter and energy and to understand their nature. Numerous studies have already investigated the characteristics of canopy turbulence over a wide range of vegetation types, leading to a thorough description of canopy turbulence. However, only a few studies have investigated the influence of gradual canopy structural changes such as foliage density (on multi-day time scales) on turbulence field properties. We hypothesize that seasonal variations of foliage density play a crucial role modifying foliage drag and canopy roughness, determining the degree of coupling between vegetation and the atmosphere, and changing the profiles of turbulent moments. The aim of this study was to follow the continuous evolution of turbulent flow characteristics from leaf budbreak to fully developed foliage in a hedgerow vineyard in the North East of Italy. Synchronous measurements from a vertical profile of five sonic anemometers on a 5 m tower have been collected at 20 Hz from beginning of April to end of July 2015.Detailed measurements of Leaf Area Density (LAD) profile and canopy architecture were performed at regular intervals (ca. weekly) around the tower. The canopy bulk drag coefficient increased during the growing season, suggesting that the coupling between the vegetation and the atmosphere increased with LAD. Vertical profiles of turbulent statistics showed to be highly correlated to local values of LAD. The penetration of momentum flux in the canopy decreased with the gradual increase of foliage. Most of the drag was exerted by the part of the canopy with denser foliage

  6. Influence of mixture characteristics on the oxidative aging of asphalt binders

    NASA Astrophysics Data System (ADS)

    Morian, Nathan E.

    The objective of this research effort focused on the evaluation of asphalt mixtures with respect to thermal cracking. Preliminary investigations soon indicated that a fundamental evaluation of thermal cracking was highly dependent upon the more complicated understanding of asphalt binder oxidation. The oxidation of asphalt binders within an asphalt mixture were understood to potentially be influenced by the mixture characteristics (i.e. air void levels, binder content, etc.) and aggregate properties (i.e. aggregate absorption, gradation, etc.). Therefore, this study was conducted in order to investigate and quantify the effects different aggregate sources and mixture properties may have on the oxidation and thermal cracking performance of asphalt mixtures. The investigation specifically focused on quantifying the oxidation of the asphalt binder alone and as part of the asphalt mixture when subjected to isothermal oven aging. The oxidation parameters of pan-aged asphalt binders were quantified, according to the standard of practice in the industry. These parameters were then compared to extracted and recovered mixture-aged asphalt binders to examine the influence of the main aggregate and mixture factors on the binder oxidation. The study observed differences between the pan-aged and mixture-aged asphalt binders in terms of oxidation kinetics, rheological measures, and the combined effect represented as the hardening susceptibility. Further evaluation of the binder oxidation based upon the dynamic modulus measures indicated marked influences of the mixture characteristics, the individual component materials, and the interactions between the investigated factors. Differentiation of the experimental factors was further identified by the newly developed low-temperature evaluation method, Uniaxial Thermal Stress and Strain Test (UTSST). The UTSST provides a fundamental approach to characterize the thermo-viscoelastic properties of asphalt mixtures permitting the

  7. Ultra-fast analog-to-digital converter based on a nonlinear triplexer and an optical coder with a photonic crystal structure.

    PubMed

    Mehdizadeh, Farhad; Soroosh, Mohammad; Alipour-Banaei, Hamed; Farshidi, Ebrahim

    2017-03-01

    In this paper, we propose what we believe is a novel all-optical analog-to-digital converter (ADC) based on photonic crystals. The proposed structure is composed of a nonlinear triplexer and an optical coder. The nonlinear triplexer is for creating discrete levels in the continuous optical input signal, and the optical coder is for generating a 2-bit standard binary code out of the discrete levels coming from the nonlinear triplexer. Controlling the resonant mode of the resonant rings through optical intensity is the main objective and working mechanism of the proposed structure. The maximum delay time obtained for the proposed structure was about 5 ps and the total footprint is about 1520  μm2.

  8. Influence of season on testicular morphometry and semen characteristics in Martina Franca jackasses.

    PubMed

    Carluccio, A; Panzani, S; Contri, A; Bronzo, V; Robbe, D; Veronesi, M C

    2013-02-01

    with spring and autumn, and a lower curvilinear velocity compared with winter were found. No differences in amplitude of lateral head displacement, beat cross frequency, straightness and linearity were observed neither between seasons nor in SS versus AW. Seminal pH did not show any seasonal difference; also sperm morphology did not show any significant difference during the whole year. This study demonstrated that under our climatic and management conditions Martina Franca donkey stallions do not show significant differences in testicular morphometric characteristics during the year, even if a certain seasonal influence exists on reaction time and some seminal parameters. Considering the variable temperature and photoperiod during the four seasons where the study was performed, this lack of substantial differences could be related to a characteristic of the Martina Franca breed.

  9. Influence of metal oxides on the adsorption characteristics of PPy/metal oxides for Methylene Blue.

    PubMed

    Chen, Jie; Feng, Jiangtao; Yan, Wei

    2016-08-01

    In this paper, the pure PPy and PPy/metal oxide composites including PPy/SiO2, PPy/Al2O3, and PPy/Fe3O4 as well as PPy coated commercial SiO2 and Al2O3 (PPy/SiO2(C) and PPy/Al2O3(C)) were successfully synthetized via chemical oxidative polymerization in acid aqueous medium to investigate the influence of metal oxides on adsorption capacity and their adsorption characteristics for Methylene Blue (MB). The composites were characterized by Zeta potential analysis, BET analysis, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA) and scanning electron microscope (SEM). The results indicate that the metal oxides have great impact on textural properties, morphology, Zeta potential and PPy polymerization on their surface, further influence the adsorption capacity of their composites. The PPy/Al2O3(C) composite owns the highest specific surface area, rougher surface and most PPy content, and show the highest monolayer adsorption capacity reaching 134.77mg/g. In the adsorption characteristic studies, isotherm investigation shows an affinity order of PPy/metal oxides of PPy/Al2O3(C)>PPy/Al2O3>PPy/SiO2(C)>PPy/SiO2>PPy/Fe3O4>PPy, stating the affinity between PPy and MB was greatly improved by metal oxide, and Al2O3 owns high affinity for MB, followed by SiO2 and Fe3O4. Kinetic data of the composites selected (PPy/SiO2(C), PPy/Al2O3(C) and PPy/Fe3O4) were described more appropriately by the pseudo-second-order model, and the order of K2 is PPy/Al2O3>PPy/SiO2>PPy/Fe3O4, further showing a fast adsorption and good affinity of PPy/Al2O3(C) for MB. The regeneration method by HCl-elution and NaOH-activation was available, and the composites selected still owned good adsorption and desorption efficiency after six adsorption-desorption cycles.

  10. Watershed land use influences on river discharge and channel characteristics across northern New Jersey

    NASA Astrophysics Data System (ADS)

    Galster, J. C.; Palmer, K.; Birrer, M.; Espinosa, S.; Pope, G. A.; Feng, H.; Wu, M. S.

    2012-12-01

    River characteristics such as sediment size, channel dimensions, and discharges can be strongly controlled by watershed land use. This project investigated three watersheds in northern New Jersey with varying degrees of forested, agriculture, and urban land uses to determine the effects of land use on these rivers. The watersheds are the Flatbrook, the Wallkill, and the Rockaway rivers and are predominantly forested, forested/agricultural, and forested/urban respectively. Eight sites across these fourth and fifth-order watersheds were investigated including: 1) the grain size using the Wolman pebble count method, 2) channel dimensions (slope, width, depth) with a total station, and 3) channel stability using the rapid geomorphic assessment (RGA). Channel width changes from 1930 to present were determined using historic aerial photographs, and river discharge characteristics were compiled using custom software to determine the flashiness (as measured by the Reynolds-Baker Index) and the Baseflow Index. The three adjacent watersheds have minimal variations in potential confounding variables such as watershed slope, climate, and precipitation, allowing for the isolation of the effects of land use changes. While some of the general relationship between how land use changes affect rivers (e.g., urban streams typically have larger grain sizes and flashier discharges), studies such as this one are important in determining how rivers respond locally. Across the studied watersheds, forested land uses are positively associated with rapid geomorphic assessments scores, indicating the influence of upstream land use and the importance of vegetation. Forested land use is also associated with efficient discharges as measured by hydraulic radius, although there were not significant changes in channel width from 1930 to present. The flashiness of all rivers has increased over time while the baseflow index has decreased, which may be a climatic signal as opposed to being influenced

  11. Influence of granule characteristics on microstructure quality of compacts made from spray-dried powders

    NASA Astrophysics Data System (ADS)

    Balasubramanian, Sreeram

    Powder compaction is a widely used technique for the manufacture of high volume of ceramic components that have simple shapes and sizes. However, this technique is inherently prone to strength-limiting defects like large intergranular pores and remnants of the initial granule structure. These defects are a major obstacle that hinder the use of powder compaction to fabricate parts for applications where strength is an important criterion. The objective of this work is to understand the important factors that control the elimination of strength-limiting defects in compacts made from spray dried powders. The influence of granule density, internal lubricants, particle shape and external application of a plasticizer to already spray dried powders on compaction behavior was investigated. Emphasis was placed on role of these factors in the elimination of large intergranular pores and persistent granule interfaces. The powders were spray dried under varying conditions to tailor the granule characteristics, including granule density, granule size distribution, binder content and lubricant content. These powders were compacted at different pressures, and the microstructures of green and sintered compacts were then evaluated, and strength-limiting features were quantified. Comparisons were made on the basis of compaction curves, green strength, green density and microstructure quality at different pressures. Lowering the granule density reduced the number of granule relics and large intergranular pores. The presence of an internal lubricant improved particle packing and yielded compacts with higher green density and fewer large intergranular pores at comparable pressures. Spray dried powders with the externally applied plasticizer deformed at lower compaction pressures. This allowed easier knitting of particles across granule interfaces and elimination of large intergranular pores and persistent granule interfaces. Spherical (equiaxed) particles rearranged better at granule

  12. [Influence of double rice cropping system innovation on paddy soil profile form and soil characteristics].

    PubMed

    Zeng, Xi-Bai; Sun, Nan; Gao, Ju-Sheng; Li, Lian-Fang; Wang, Bo-Ren; Bai, Ling-Yu

    2008-05-01

    Field experiments were conducted on the double rice cropping paddy field in red soil area to evaluate the influence of cropping system innovation on soil profile form and related soil characteristics. Four cropping systems of rice-rice-Chinese Milkvetch (Astragalus sinicus Linn.), forage, paddy-upland rotation, and upland were substituted for the double rice cropping system. The results indicated that compared with those under double rice cropping system, the thickness of cultivated horizon under upland cropping system increased by 4 cm, that of plow pan declined by 2 cm, > 2 mm aggregates in wet-sieved particle-size fractions increased by 6.94%, wet-sieved mean-mass diameter increased by 0.37 mm, contents of humic acid carbon and fulvic acid carbon increased by 0.15 and 0.49 g kg(-1), respectively, and quotient of aggregates water stability was 0.78 times higher. Under paddy-upland rotation, the quotient of aggregates water stability was higher (95.86), while soil nutrient contents changed a little. Under rice-rice-Chinese Milkvetch system, soil organic matter content increased by 1.3 g kg(-1), quotient of aggregates water stability declined by 8.82, but other parameters had less changes. Under forage system, the thickness of cultivated and transitional horizons increased by 2 cm and 9 cm, respectively, quotient of aggregates water stability increased by 1.39, while the contents of soil organic matter and total potassium decreased by 5.6 and 2.8 g kg(-1), respectively. Among all test cropping systems, forage system had the greatest changes in soil characteristics. It was completely feasible to substitute the local double rice cropping system for paddy-upland rotation or upland cropping, particularly in the areas where full irrigation was not available. However, attention should be paid to the decrease of soil potassium content when the cropping system innovation was practiced.

  13. Influence of G-jitter on the characteristics of a non-premixed flame: Experimental approach

    NASA Astrophysics Data System (ADS)

    Joulain, Pierre; Cordeiro, Pierre; Rouvreau, Sébastien; Legros, Guillaume; Fuentes, Andres; Torero, José L.

    2005-03-01

    The combustion of a flat plate in a boundary layer under microgravity conditions, which was first described by Emmons, is studied using a gas burner. Magnitude of injection and blowing velocities are chosen to be characteristic of pyrolyzing velocity of solid fuels, and of ventilation systems in space stations. These velocities are about 0.1 m/s for oxidiser flow and 0.004m/s for fuel flow. In this configuration, flame layout results from a coupled interaction between oxidiser flow, fuel flow and thermal expansion. Influences of these parameters are studied experimentally by means of flame length and standoff distance measurements using CH* chemiluminescence's and visible emission of the flame. Flow was also studied with Particle Image Velocimetry (PIV). Inert flows, with and without injection, and reacting flow in a microgravity environment were considered to distinguish aerodynamic from thermal effect. Thermal expansion effects have been shown by means of the acceleration of oxidiser flow. Three-dimensional effects, which are strongly marked for high injection velocities were studied. Three-dimensional tools adaptability to parabolic flights particular conditions were of concern. Flame sensitivity to g-jitters was investigated according to g-jitters frequency and range involved by parabolic flights. It appears that flame location (standoff distance), flame characteristics (length, thickness, brightness) and the aerodynamic field of the low velocity reacting flow are very much affected by the fluctuation of the gravity level or g-jitter. The lower the g-jitter frequency is, the higher the perturbation. Consequently it is difficult to perform relevant experiments for a main flow velocity lower than 0.05m/s. DNS calculations confirm the present observations, but most of the results are presented elsewhere.

  14. Burst packet loss concealment using multiple codebooks and comfort noise for CELP-type speech coders in wireless sensor networks.

    PubMed

    Park, Nam In; Kim, Hong Kook; Jung, Min A; Lee, Seong Ro; Choi, Seung Ho

    2011-01-01

    In this paper, a packet loss concealment (PLC) algorithm for CELP-type speech coders is proposed in order to improve the quality of decoded speech under burst packet loss conditions in a wireless sensor network. Conventional receiver-based PLC algorithms in the G.729 speech codec are usually based on speech correlation to reconstruct the decoded speech of lost frames by using parameter information obtained from the previous correctly received frames. However, this approach has difficulty in reconstructing voice onset signals since the parameters such as pitch, linear predictive coding coefficient, and adaptive/fixed codebooks of the previous frames are mostly related to silence frames. Thus, in order to reconstruct speech signals in the voice onset intervals, we propose a multiple codebook-based approach that includes a traditional adaptive codebook and a new random codebook composed of comfort noise. The proposed PLC algorithm is designed as a PLC algorithm for G.729 and its performance is then compared with that of the PLC algorithm currently employed in G.729 via a perceptual evaluation of speech quality, a waveform comparison, and a preference test under different random and burst packet loss conditions. It is shown from the experiments that the proposed PLC algorithm provides significantly better speech quality than the PLC algorithm employed in G.729 under all the test conditions.

  15. Characteristics influencing the variability of urban CO 2 fluxes in Melbourne, Australia

    NASA Astrophysics Data System (ADS)

    Coutts, Andrew M.; Beringer, Jason; Tapper, Nigel J.

    Urban areas are significant contributors to global carbon dioxide emissions. Vehicle emissions and other anthropogenic related activities are a frequent source of CO 2 to the atmosphere, contributing to global warming. Micrometeorological techniques used for observations in Northern Hemisphere cities have found that urban CO 2 fluxes are consistently a source. This study investigates CO 2 fluxes in an Australian city, adding to the global database of CO 2 fluxes in a bid to aid in future development of planning policies concerning reductions in CO 2 emissions. Using the eddy covariance approach, fluxes of CO 2 were measured at a suburban site (Preston) in Melbourne, Australia from February 2004 to June 2005 to investigate temporal variability. A second site (Surrey Hills) with differing surface characteristics (in particular, greater vegetation cover) was also established in Melbourne and ran simultaneously for 6 months (February 2004-July 2004). Results showed that both sites were a net source of CO 2 to the atmosphere. Diurnal patterns of fluxes were largely influenced by traffic volumes, with two distinct peaks occurring at the morning and evening traffic peak hours, with the winter morning peak averaging 10.9 μmol m -2 s -1 at Preston. Summer time fluxes were lower than during winter due to greater vegetative influence and reduced natural gas combustion. Vegetation limited the source of CO 2 in the afternoon, yet was not enough to combat the strong local anthropogenic emissions. Surrey Hills showed higher fluxes of CO 2 despite greater vegetation cover because of higher local traffic volumes. Annual emissions from Preston were estimated at 84.9 t CO 2 ha -1 yr -1. Magnitudes and patterns of suburban CO 2 fluxes in Melbourne were similar to those observed in Northern Hemisphere suburban areas.

  16. Characteristics of nitrogen loading and its influencing factors in several typical agricultural watersheds of subtropical China.

    PubMed

    Li, Yuyuan; Jiao, Junxia; Wang, Yi; Yang, Wen; Meng, Cen; Li, Baozhen; Li, Yong; Wu, Jinshui

    2015-02-01

    Increasingly, the characteristics of nitrogen (N) loading have been recognized to be critical for the maintenance and restoration of water quality in agricultural watersheds, in response to the spread of water eutrophication. This paper estimates N loading and investigates its influencing factors in ten small watersheds variously dominated by forest and agricultural land use types in the subtropics of China, over an observation period of 23-29 months. The results indicate that the average concentrations of total nitrogen (TN), NH4 (+)-N, and NO3 (-)-N were 0.83, 0.07, and 0.46 mg N L(-1) in the forest watersheds and 1.49-5.16, 0.21-3.23, and 0.99-1.30 mg N L(-1) in the agricultural watersheds, respectively. Such concentrations exceed the national criteria for nutrient pollution in surface waters considerably, suggesting severe stream pollution in the studied agricultural watersheds. The average annual TN loadings (ANL) were estimated to be 1,640.8 kg N km(-2) year(-1) in the agricultural watersheds, 63.3-86.1 % of which was composed of dissolved inorganic N (DIN; comprising NO3 (-)-N and NH4 (+)-N). The watershed with intensive livestock production (i.e., the maximum livestock density of 2.66 animal units (AU) ha(-1)) exhibited the highest ANL (2,928.7 kg N km(-2) year(-1)) related to N loss with effluent discharge. The results of correlation and principle component analysis suggest that livestock production was the dominant influencing factor for the TN and NH4 (+)-N loadings and that the percentages of cropland in watersheds can significantly increase the NO3 (-)-N loading in agricultural watersheds. Therefore, to restore and maintain water quality, animal production regulations and more careful planning of land use are necessary in the agricultural watersheds of subtropical China.

  17. Influence of pregnancy on body weight, ruminal characteristics, and visceral organ mass in beef heifers.

    PubMed

    Scheaffer, A N; Caton, J S; Bauer, M L; Reynolds, L P

    2001-09-01

    Crossbred heifers (initially 24 mo, approximate age and 378 +/- 32.1 kg BW) were used to evaluate the influence of pregnancy and advancing gestation on DMI, BW, carcass weight, ruminal characteristics, and visceral organ mass. Heifers (naturally serviced (n = 22; nonpregnant controls, n = 17), were grouped in common pens. Heifers were provided corn silage and hay-based diets formulated to provide 0.45 kg of ADG. Treatments were pregnancy and nonpregnancy; pregnant and nonpregnant heifers were slaughtered on d 40, 120, 200, and 270. Live weight at slaughter and BW change throughout the trial were not influenced by pregnancy (P > 0.1). Carcass weight per unit of BW was decreased due to pregnancy (P < 0.05) and an interaction was found in eviscerated BW (EvBW; P < 0.1), with the pregnant heifers having greater live weights, carcass weights, and EvBW at the d-200 slaughter period. Ruminal fluid fill and total fill (g/kg BW) declined as slaughter period advanced, resulting in the pregnant heifers having less fill at d 270 (P< 0.07). However, ME intake was not different between pregnant and nonpregnant heifers (P > 0.1) at any of the slaughter periods. Heart mass responded differently when nonpregnant and pregnant were analyzed over time and an interaction was detected as slaughter period advanced (P < 0.1). Liver, duodenum, jejunum, and large intestinal mass were not responsive to pregnancy (P > 0.1). Data indicate that ruminal fill is altered by pregnancy but visceral organ mass is not greatly changed by treatment.

  18. Air quality resolution for health impacts assessment: influence of regional characteristics

    NASA Astrophysics Data System (ADS)

    Thompson, T. M.; Saari, R. K.; Selin, N. E.

    2013-05-01

    We evaluate how regional characteristics of weather, population, and background pollution might impact the selection of optimal model resolution when calculating the human health impacts of changes to air quality. Using an approach consistent with air quality policy evaluation, we use a regional chemical transport model (CAMx) and a health benefits mapping program (BenMAP) to calculate the human health impacts associated with changes in ozone and fine particulate matter resulting from an emissions reduction scenario. We evaluate this same scenario at 36, 12 and 4 km resolution for nine regions in the Eastern US representing varied characteristics. We find that the human health benefits associated with changes in ozone concentrations are sensitive to resolution, especially in urban areas where we estimate that benefits calculated using coarse resolution results are on average two times greater than benefits calculated using finer scale results. In three urban areas we analyzed, results calculated using 36 km resolution modeling fell outside the uncertainty range of results calculated using finer scale modeling. In rural areas the influence of resolution is less pronounced with only an 8% increase in the estimated health impacts when using 36 km resolution over finer scales. In contrast, health benefits associated with changes in PM2.5 concentrations were not sensitive to resolution and did not follow a pattern based on any regional characteristics evaluated. The largest difference between the health impacts estimated using 36 km modeling results and either 12 or 4 km results was at most ±10% in any region. Several regions showed increases in estimated benefits as resolution increased (opposite the impact seen with ozone modeling) due to a higher contribution of primary PM in those regions, while some regions showed decreases in estimated benefits as resolution increased due to a higher contribution of secondary PM. Given that changes in PM2.5 dominate the human

  19. Air quality resolution for health impact assessment: influence of regional characteristics

    NASA Astrophysics Data System (ADS)

    Thompson, T. M.; Saari, R. K.; Selin, N. E.

    2014-01-01

    We evaluate how regional characteristics of population and background pollution might impact the selection of optimal air quality model resolution when calculating the human health impacts of changes to air quality. Using an approach consistent with air quality policy evaluation, we use a regional chemical transport model (CAMx) and a health benefit mapping program (BenMAP) to calculate the human health impacts associated with changes in ozone and fine particulate matter resulting from an emission reduction scenario. We evaluate this same scenario at 36, 12 and 4 km resolution for nine regions in the eastern US representing varied characteristics. We find that the human health benefits associated with changes in ozone concentrations are sensitive to resolution. This finding is especially strong in urban areas where we estimate that benefits calculated using coarse resolution results are on average two times greater than benefits calculated using finer scale results. In three urban areas we analyzed, results calculated using 36 km resolution modeling fell outside the uncertainty range of results calculated using finer scale modeling. In rural areas the influence of resolution is less pronounced with only an 8% increase in the estimated health impacts when using 36 km resolution over finer scales. In contrast, health benefits associated with changes in PM2.5 concentrations were not sensitive to resolution and did not follow a pattern based on any regional characteristics evaluated. The largest difference between the health impacts estimated using 36 km modeling results and either 12 or 4 km results was at most ±10% in any region. Several regions showed increases in estimated benefits as resolution increased (opposite the impact seen with ozone modeling), while some regions showed decreases in estimated benefits as resolution increased. In both cases, the dominant contribution was from secondary PM. Additionally, we found that the health impacts calculated using

  20. Influence of atomic vacancies on the dynamic characteristics of nanoresonators based on double walled carbon nanotube

    NASA Astrophysics Data System (ADS)

    Patel, Ajay M.; Joshi, Anand Y.

    2015-06-01

    The dynamic analysis of double walled carbon nanotubes (DWCNTs) with different boundary conditions has been performed using atomistic finite element method. The double walled carbon nanotube is modeled considering it as a space frame structure similar to a three dimensional beam. The elastic properties of beam element are calculated by considering mechanical characteristics of covalent bonds between the carbon atoms in the hexagonal lattice. Spring elements are used to describe the interlayer interactions between the inner and outer tubes caused due to the van der Waals forces. The mass of each beam element is assumed as point mass at nodes coinciding with carbon atoms at inner and outer wall of DWCNT. It has been reported that atomic vacancies are formed during the manufacturing process in DWCNT which tend to migrate leading to a change in the mechanical characteristics of the same. Simulations have been carried out to visualize the behavior of such defective DWCNTs subjected to different boundary conditions and when used as mass sensing devices. The variation of such atomic vacancies in outer wall of Zigzag and Armchair DWCNT is performed along the length and the change in response is noted. Moreover, as CNTs have been used as mass sensors extensively, the present approach is focused to explore the use of zigzag and armchair DWCNT as sensing device with a mono-atomic vacancy in it. The results clearly state that the dynamic characteristics are greatly influenced by defects like vacancies in it. A higher frequency shift is observed when the vacancy is located away from the fixed end for both Armchair as well as zigzag type of CNTs. A higher frequency shift is reported for armchair CNT for a mass of 10-22 g which remains constant for 10-21 g and then decreases gradually. Comparison with the other experimental and theoretical studies exhibits good association which suggests that defective DWCNTs can further be explored for mass sensing. This investigation is helpful

  1. High-pressure processing of Gorgonzola cheese: influence on Listeria monocytogenes inactivation and on sensory characteristics.

    PubMed

    Carminati, D; Gatti, M; Bonvini, B; Neviani, E; Mucchetti, G

    2004-08-01

    The presence of Listeria monocytogenes on the rind of Gorgonzola cheese is difficult to avoid. This contamination can easily occur as a consequence of handling during ripening. The aims of this study were to determine the efficiency of high-pressure processing (HPP) for inactivation of L. monocytogenes on cheese rind and to evaluate the influence of HPP treatments on sensory characteristics. Gorgonzola cheese rinds, after removal, were inoculated (about 7.0 log CFU/g) with L. monocytogenes strains previously isolated from other Gorgonzola cheeses. The inoculated cheese rinds were processed with an HPP apparatus under conditions of pressure and time ranging from 400 to 700 MPa for 1 to 15 min. Pressures higher than 600 MPa for 10 min or 700 MPa for 5 min reduced L. monocytogenes more than 99%. A reduction higher than 99.999% was achieved pressurizing cheese rinds at 700 MPa for 15 min. Lower pressure or time treatments were less effective and varied in effectiveness with the cheese sample. Changes in sensory properties possibly induced by the HPP were evaluated on four different Gorgonzola cheeses. A panel of 18 members judged the treated and untreated cheeses in a triangle test. Only one of the four pressurized cheeses was evaluated as different from the untreated sample. HPP was effective in the reduction of L. monocytogenes on Gorgonzola cheese rinds without significantly changing its sensory properties. High-pressure technology is a useful tool to improve the safety of this type of cheese.

  2. [Influence of microcystin-LR on cell viability and surface characteristics of Pseudomonas putida].

    PubMed

    Deng, Ting-jin; Ye, Jin-shao; Peng, Hui; Liu, Zhi-chen; Liu, Ze-hua; Yin, Hua; Chen, Shuo-na

    2015-01-01

    In microcystin-LR (MC-LR) degradation system, the change in surface characteristics and cell viability of Pseudomonas putida was studied. The purpose of this study was to reveal the influence of MC-LR on P. putida and elucidate the toxicity of MC-LR on microorganisms. The result demonstrated that MC-LR enhanced the cytoplasmic membrane permeability, as well as affected the ion metabolism and protein release of P. putida. The soluble sugar and Na+, Cl-release increased with the rising concentration of MC-LR ranging from 0 mg x L(-1) to 2.0 mg x L(-1). Flow Cytometry Method(FCM) analysis revealed that MC-LR accelerated the death of P. putida, and the death rate increased with the ascending concentration of MC-LR. Compared with the control, the death rate on day 5 increased by nearly 30% when 2.5 mg x L(-1) MC-LR was added. Scanning electron microscopy (SEM) analysis showed that the cells were deformed under the toxicity of MC-LR. After 5-day exposure to 2.5 mg x L(-1) MC-LR, the majority of the cells were ruptured and the intracellular materials flew out. The cellular structure was severely damaged under this condition.

  3. Influences of dissolved organic matter characteristics on trihalomethanes formation during chlorine disinfection of membrane bioreactor effluents.

    PubMed

    Ma, Defang; Peng, Bo; Zhang, Yuhang; Gao, Baoyu; Wang, Yan; Yue, Qinyan; Li, Qian

    2014-08-01

    Dissolved organic matter (DOM) in MBR-treated municipal wastewater intended for reuse was fractionated through ultrafiltration and XAD-8 resin adsorption and characterized by fluorescence spectroscopy. To probe the influences of DOM characteristics on trihalomethanes (THMs) formation reactivity during chlorination, THMs yield and speciation of DOM fractions was investigated. It was found that chlorine reactivity of DOM decreased with the decrease of molecular weight (MW), and MW>30kDa fractions produced over 55% of total THMs in chlorinated MBR effluent. Hydrophobic organics had much higher THMs formation reactivity than hydrophilic substances. Particularly, hydrophobic acids exhibited the highest chlorine reactivity and contributed up to 71% of total THMs formation. Meanwhile, low-MW and hydrophilic DOM were susceptible to produce bromine-containing THMs. Of the fluorescent DOM in MBR effluent, aromatic moieties and humic acid-like had higher chlorine reactivity. Conclusively, macromolecular and hydrophobic organics containing aromatic moieties and humic acid-like must be removed to reduce THMs formation.

  4. Influence of meat exudates on the quality characteristics of fresh and freeze-thawed pork.

    PubMed

    Kim, Gap-Don; Jung, Eun-Young; Lim, Hyun-Jung; Yang, Han-Sul; Joo, Seon-Tea; Jeong, Jin-Yeon

    2013-10-01

    The influence of the accumulated exudates released from pork loin of itself on the quality characteristics of fresh and freeze-thawed pork during cold storage was investigated. Pork loins were divided into four groups (fresh pork with exudates, fresh pork without exudates, freeze-thawed pork with exudates and freeze-thawed pork without exudates) and stored at 1.0°C for 7 days. Exudate amount increased due to freeze-thawing and with storage, and most quality traits such as drip loss, cooking loss, tenderness, lightness, redness, and moisture content were affected by freeze-thawing (p<0.05). Freeze-thaw increased drip loss but decreased moisture content, cooking loss, tenderness, lightness and redness of meat (p<0.05). Microbial growth was solely affected by exudate removal and the removal of initial exudates decreased microbial growth (p<0.05). Exudates were positively correlated with total protein content and total plate count but negatively correlated with pH and cooking loss. Therefore, removing meat exudates and avoiding freeze can slow down the quality deterioration of pork during cold storage.

  5. Influence of Lubricant Additives on Friction and Wear Characteristics of Compressor parts under the Alternative Refrigerant

    NASA Astrophysics Data System (ADS)

    Yamaguchi, Hidehiro; Imai, Hachiro; Yamamoto, Tetsuya; Yamamoto, Tsutomu; Ueki, Yutaka; Takizawa, Kikuo; Fukushima, Kiyoshi

    From the standpoint of lubricative deficit under the alternative refrigerant/lubricants coexistence, the influence of additives on friction and wear characteristics for compressor parts have been investigated by the wear tester reappeared on friction condition similarly to actual compressor. It has been shown that an ester type base oil containing TCP (tricresyl phosphate) as an extreme pressure agents indicates satisfactory lubrication because of its EP effect. However owning to the deterioration of base oil caused by a cresol which is a reactant of TCP, a hydrolysis inhibitor must be necessary. The results indicates that a hydrolysis inhibitor added to POE is able to not only prevent the base oil from deteriorating but also feed the strength into oil films. On the other hands, in such a case that TCP concentration added in an alkylbenzen type base oil is excess or wear track temperature is higher, wear amounts of compressor parts are increased on account of corrosion wear. The reactivity of TCP depends on wear track temperature and its concentration. Consequently, it is possible that EP effect of TCP has been considered in terms of its concentration and temperature to be appropriated.

  6. Influence of ground surface characteristics on the mean radiant temperature in urban areas

    NASA Astrophysics Data System (ADS)

    Lindberg, Fredrik; Onomura, Shiho; Grimmond, C. S. B.

    2016-09-01

    The effect of variations in land cover on mean radiant temperature ( T mrt ) is explored through a simple scheme developed within the radiation model SOLWEIG. Outgoing longwave radiation is parameterised using surface temperature observations on a grass and an asphalt surface, whereas outgoing shortwave radiation is modelled through variations in albedo for the different surfaces. The influence of ground surface materials on T mrt is small compared to the effects of shadowing. Nevertheless, altering ground surface materials could contribute to a reduction in T mrt to reduce the radiant load during heat-wave episodes in locations where shadowing is not an option. Evaluation of the new scheme suggests that despite its simplicity it can simulate the outgoing fluxes well, especially during sunny conditions. However, it underestimates at night and in shadowed locations. One grass surface used to develop the parameterisation, with very different characteristics compared to an evaluation grass site, caused T mrt to be underestimated. The implications of using high temporal resolution (e.g. 15 minutes) meteorological forcing data under partly cloudy conditions are demonstrated even for fairly proximal sites.

  7. Chemically- and mechanically-mediated influences on the transport and mechanical characteristics of rock fractures

    SciTech Connect

    Min, K.-B.; Rutqvist, J.; Elsworth, D.

    2009-02-01

    A model is presented to represent changes in the mechanical and transport characteristics of fractured rock that result from coupled mechanical and chemical effects. The specific influence is the elevation of dissolution rates on contacting asperities, which results in a stress- and temperature-dependent permanent closure. A model representing this pressure-dissolution-like behavior is adapted to define the threshold and resulting response in terms of fundamental thermodynamic properties of a contacting fracture. These relations are incorporated in a stress-stiffening model of fracture closure to define the stress- and temperature-dependency of aperture loss and behavior during stress and temperature cycling. These models compare well with laboratory and field experiments, representing both decoupled isobaric and isothermal responses. The model was applied to explore the impact of these responses on heated structures in rock. The result showed a reduction in ultimate induced stresses over the case where chemical effects were not incorporated, with permanent reduction in final stresses after cooling to ambient conditions. Similarly, permeabilities may be lower than they were in the case where chemical effects were not considered, with a net reduction apparent even after cooling to ambient temperature. These heretofore-neglected effects may have a correspondingly significant impact on the performance of heated structures in rock, such as repositories for the containment of radioactive wastes.

  8. Microbiological influenced corrosion resistance characteristics of a 304L-Cu stainless steel against Escherichia coli.

    PubMed

    Nan, Li; Xu, Dake; Gu, Tingyue; Song, Xiu; Yang, Ke

    2015-03-01

    Cu-bearing antibacterial stainless steels have been gaining popularity in recent years due to their strong antibacterial performances. However, only a few studies were reported for their actual performances against microbiologically influenced corrosion (MIC). In this study, electrochemical methods and surface analytical techniques were applied to study the MIC resistance characteristics of a 304L-Cu stainless steel (SS) against Escherichia coli in comparison with 304L SS as control. Corrosion tests for specimens after a 21-day exposure to a Luria-Bertani (LB) culture medium with E. coli demonstrated that the 304L-Cu SS considerably reduced the maximum MIC pit depth and the specific weight loss compared with 304L SS (8.3μm and 0.2mg/cm(2) vs. 13.4μm and 0.6mg/cm(2)). Potentiodynamic polarization tests showed that the corrosion current density of the 304L-Cu SS was as much as 4 times lower than that of the 304L SS, indicating that the 304L-Cu SS is a better choice for applications in MIC-prone environments.

  9. Specific image characteristics influence attitudes about chimpanzee conservation and use as pets.

    PubMed

    Ross, Stephen R; Vreeman, Vivian M; Lonsdorf, Elizabeth V

    2011-01-01

    Chimpanzees are endangered in their native Africa but in the United States, they are housed not only in zoos and research centers but owned privately as pets and performers. In 2008, survey data revealed that the public is less likely to think that chimpanzees are endangered compared to other great apes, and that this is likely the result of media misportrayals in movies, television and advertisements. Here, we use an experimental survey paradigm with composite images of chimpanzees to determine the effects of specific image characteristics. We found that those viewing a photograph of a chimpanzee with a human standing nearby were 35.5% more likely to consider wild populations to be stable/healthy compared to those seeing the exact same picture without a human. Likewise, the presence of a human in the photograph increases the likelihood that they consider chimpanzees as appealing as a pet. We also found that respondents seeing images in which chimpanzees are shown in typically human settings (such as an office space) were more likely to perceive wild populations as being stable and healthy compared to those seeing chimpanzees in other contexts. These findings shed light on the way that media portrayals of chimpanzees influence public attitudes about this important and endangered species.

  10. Characteristics and influence factors of pathologic transformation in the subclasses of class IV lupus nephritis.

    PubMed

    Gao, Jian-jun; Cai, Guang-yan; Liu, Shu-wen; Tang, Li; Zhang, Xue-guang; Yang, Yang; Chen, Pu; Liu, Shu-xin; Ji, Jia-yao; Shi, Suo-zhu; Yin, Zhong; Chen, Xiang-mei

    2012-06-01

    The study explored the characteristics and correlation factors of transformation in subclasses of class IV lupus nephritis. Patients with class IV lupus nephritis were subjected to repeat biopsies after 6 months of induction treatment. Transformation rate between two subclasses, class IV-S and class IV-G, was compared. Influence Factors of transformation were evaluated. Class IV-G had more severe hypertension and higher score of immunofluorescence index, glomerular active lesions, tubular and vascular lesions. Class IV-S had a higher percentage of glomerular fibrinoid necrosis. Class IV-S appeared a higher rate of transformation to class II than class IV-G (57% vs. 27%). In each subclass, active lesion also showed a higher rate of transformation to class II than active/chronic lesion (IV-G: 41.2% vs. 12.5%; IV-S: 71.4% vs. 42.8%). Patients who maintained class IV had higher blood pressure, obvious proteinuria, declined kidney function, and lower C3 level. Immunosuppressive therapy, urine protein, and vascular lesions were independent risk factors for the pathologic transformation. The rate of transformation in class IV-S was higher than that in class IV-G. The transformation is most likely to benefit from immunosuppressive therapy. Urine protein and vascular lesions are correlated with the transformation in class IV lupus nephritis.

  11. INFLUENCE OF CONSOLIDATION CHARACTERISTICS ON CONE PENETRATION RESISTANCE AND LIQUEFACTION RESISTANCE IN SILTY SOILS

    NASA Astrophysics Data System (ADS)

    Ecemis, N.; Thevanayagam, S.

    2009-12-01

    A unique correlation between liquefaction resistance and penetration resistance is not possible to justify without considering the effects of hydraulic conductivity, k, compressibility, mv, and coefficient of consolidation, ch on cone penetration resistance (Thevanayagam and Martin 2002). Therefore, CPT liquefaction screening chart revised to take into account the consolidation characteristics on penetration resistance. Recently, it has been observed that k and ch magnitudes vary between sand and sand-silt mixtures even evaluated at the same liquefaction resistance. The combined effects of penetration rate, v, cone diameter, d, and ch also influences the cone penetration resistance. Silt content affects the liquefaction resistance as well. Several numerical simulations performed by Thevanayagam and Ecemis in 2008 to explore the transition from undrained to drained conditions by varying the non-dimensional parameter T(=vd/ch) with a range of coefficient of consolidation for a single soil type, Ottawa sand-silt mix. Numerical simulation suggested the drained and undrained limits for T are respectively around 0.01 and 10. Tests on circular foundations reported by Finnie and Randolph (1994) suggested the limits of 0.01 and 30. Tests with a cylindrical T-bar penetrometer suggested narrower limits of 0.1 and 10 (House et al. 2001). Finally, the correlation between T, normalized cone resistance and cyclic resistance to liquefaction is proposed and compared with the current liquefaction screening method by CPT (Fig.1). Fig.1: Proposed & Current Liquefaction Screening Method

  12. Physico-Chemical Characteristics of Lipoplexes Influence Cell Uptake Mechanisms and Transfection Efficacy

    PubMed Central

    Resina, Sarah; Prevot, Paul; Thierry, Alain R.

    2009-01-01

    Background Formulation of DNA/cationic lipid complexes (lipoplexes) designed for nucleic acid delivery mostly results in positively charged particles which are thought to enter cells by endocytosis. We recently developed a lipoplex formulation called Neutraplex that allows preparation of both cationic and anionic stable complexes with similar lipid content and ultrastructure. Methodology/Principal Findings To assess whether the global net charge could influence cell uptake and activity of the transported oligonucleotides (ON), we prepared lipoplexes with positive and negative charges and compared: (i) their physicochemical properties by zeta potential analysis and dynamic light scattering, (ii) their cell uptake by fluorescence microscopy and flow cytometry, and (iii) the biological activity of the transported ON using a splicing correction assay. We show that positively or negatively charged lipoplexes enter cells cells using both temperature-dependent and -independent uptake mechanisms. Specifically, positively charged lipoplexes predominantly use a temperature-dependent transport when cells are incubated OptiMEM medium. Anionic lipoplexes favour an energy-independent transport and show higher ON activity than cationic lipoplexes in presence of serum. However, lipoplexes with high positive global net charge and OptiMEM medium give the highest uptake and ON activity levels. Conclusions These findings suggest that, in addition to endocytosis, lipoplexes may enter cell via a temperature-independent mechanism, which could be mediated by lipid mixing. Such characteristics might arise from the specific lipoplex ultrastructure and should be taken into consideration when developing lipoplexes designed for in vivo or ex vivo nucleic acid transfer. PMID:19557145

  13. Investigating the influence of effective parameters on molecular characteristics of bovine serum albumin nanoparticles

    NASA Astrophysics Data System (ADS)

    Rohiwal, S. S.; Satvekar, R. K.; Tiwari, A. P.; Raut, A. V.; Kumbhar, S. G.; Pawar, S. H.

    2015-04-01

    The protein nanoparticles formulation is a challenging task as they are prone to undergo conformational transitions while processing which may affect bioavailability for bioactive compounds. Herein, a modified desolvation method is employed to prepare Bovine Serum Albumin nanoparticles, with controllable particle size ranging from 100 to 300 nm and low polydispersity index. The factors influencing the size and structure of BSA NPs viz. protein concentration, pH and the conditions for purification are well investigated. The structure of BSA NPs is altered due to processing, and may affect the effective binding ability with drugs and bioactive compounds. With that aims, investigations of molecular characteristics of BSA NPs are carried out in detail by using spectroscopic techniques. UV-visible absorption and Fourier Transform Infrared demonstrate the alteration in protein structure of BSA NPs whereas the FT-Raman spectroscopy investigates changes in the secondary and tertiary structures of the protein. The conformational changes of BSA NPs are observed by change in fluorescence intensity and emission maximum wavelength of tryptophan residue by fluorescence spectroscopy. The field emission scanning electron and atomic force microscopy micrographs confirm the size and semi-spherical morphology of the BSA NPs. The effect of concentration and pH on particle size distribution is studied by particle size analyzer.

  14. The Relationship between Clinicians' Confidence and Accuracy, and the Influence of Child Characteristics, in the Screening of Autism Spectrum Disorder

    ERIC Educational Resources Information Center

    Hedley, Darren; Brewer, Neil; Nevill, Rose; Uljarevic, Mirko; Butter, Eric; Mulick, James A.

    2016-01-01

    The study examined the confidence accuracy relationship, and the influence of child characteristics on clinician confidence, when predicting a diagnosis of Autism Spectrum Disorder during screening of 125 referred children aged under 3.5 years. The diagnostic process included observation, interview, language and developmental testing. Clinical…

  15. Beyond Behavior: Multilevel Analysis of the Influence of Sociodemographics and School Characteristics on Students' Risk of Suspension

    ERIC Educational Resources Information Center

    Sullivan, Amanda L.; Klingbeil, David A.; Van Norman, Ethan R.

    2013-01-01

    Minority disproportionality in school discipline outcomes continues to trouble practitioners and scholars. The purpose of this study was to examine the influence of sociodemographic characteristics and indicators of school policy enactment (e.g., retention rates, special education identification) on students' risk of suspension. The sample…

  16. The Influence of New Product Characteristics on Rate of Adoption: Increasing Student Comprehension with the "Bidding for Buyers" Game

    ERIC Educational Resources Information Center

    Vander Schee, Brian A.

    2012-01-01

    The five characteristics that influence new product rate of adoption are routinely covered in the Principles of Marketing course. Any particular marketing concept such as relative advantage, compatibility, complexity, divisibility, and communicability may not capture interest or engagement among students who take the course as a graduation…

  17. INFLUENCE OF SOLVENT AND SORBENT CHARACTERISTICS ON DISTRIBUTION OF PENTACHLOROPHENOL IN OCTANOL-WATER AND SOIL-WATER SYSTEMS

    EPA Science Inventory

    Sorbent and solvent characteristics influencing sorption of pentachlorophenol (PCP) were investigated. Analysis of aqueous sorption data for several sorbents over a broad pH range suggested hydrophobic sorption of neutral PCP predominates at pH 7. At pH > 7, sorption of the penta...

  18. Adolescent Drug Use in Mexico and among Mexican American Adolescents in the United States: Environmental Influences and Individual Characteristics.

    ERIC Educational Resources Information Center

    Felix-Ortiz, Maria; Velazuez, Jorge A Villatoro; Medina-Mora, Maria Elena; Newcomb, Michael D.

    2001-01-01

    Compares cigarette, alcohol, and illegal drug use among high school students in Baja California Norte (BCN), Mexico with Mexican American students in Los Angeles (LA), California (N=516). Demographic variables, individual characteristics, and environmental influences were considered. Reports that more BCN students used alcohol and more LA students…

  19. Red rice (Oryza sativa L.) emergence characteristics and influence on rice (O. sativa) yield at different planting dates

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cultivated rice yield losses due to red rice infestation vary by cultivar, red rice density, and duration of interference. The competition effects of red rice could be influenced further by emergence characteristics, red rice biotype, and planting time of cultivated rice. We aimed to characterize th...

  20. Influence of selected water quality characteristics on the toxicity of lambda-cyhalothrin and gamma-cyhalothrin to Hyalella azteca

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study was conducted to assess the influence of suspended solids, dissolved organic carbon, and phytoplankton (as chlorophyll a) water quality characteristics on lambda-cyhalothrin and gamma-cyhalothrin aqueous toxicity to Hyalella azteca using natural water from 12 ponds and lakes in Mississipp...

  1. Concentrations and characteristics of organic carbon in surface water in Arizona: Influence of urbanization

    USGS Publications Warehouse

    Westerhoff, P.; Anning, D.

    2000-01-01

    DOC concentration (p<0.05) and exhibited less variability in concentration than inflows to the reservoirs. Specific ultraviolet absorbance values at 254 nm were typically less than 2 m-1(milligram DOC per liter)-1 and lower than values found in most temperate-region rivers, but specific ultraviolet absorbance values increased during runoff events. Fluorescence measurements indicated that DOC in desert streams typically exhibit characteristics of autochthonous sources; however, DOC in unregulated upland rivers and desert streams experienced sudden shifts from autochthonous to allochthonous sources during runoff events. The urban water system (reservoir systems and wastewater-treatment plants) was found to affect temporal variability in DOC concentration and composition.The influence of urbanization, becoming increasingly common in arid regions, on dissolved organic carbon (DOC) concentrations in surface water resources was studied. DOC concentration and composition, seasonal watershed runoff events, streamflow variations, water management practices, and urban infrastructure in several Arizona watersheds were monitored. Ephemeral sites had the highest DOC levels, and unregulated perennial sites and lower concentrations than unregulated intermittent sites, regulated sites, and sites downstream from wastewater treatment plants. Reservoir outflows and wastewater treatment plant effluent had higher and less variable DOC concentrations than inflows to reservoirs. UV absorbance values, fluorescence measurements, and other indicators suggest that urban water systems (reservoirs and wastewater treatment plants) affect temporal variability in DOC concentration and composition.

  2. Analysis of regional albedo characteristics and its influence in the regional climate model REMO

    NASA Astrophysics Data System (ADS)

    Preuschmann, S.; Jacob, D.

    2010-09-01

    The effects of land-use changes on climate have a high priority in climate impact researches. Nevertheless it is not trivial to integrate land-use changes in the Regional atmospherical climate Model REMO (Jacob 2001) so that characteristics of a typical land-use type can be created and therewith systematical effects can be analyzed. As in many regional dynamical climate models, REMO is calculating in the target resolution with parameters which are independent of land-use classes. Considering only one of these parameters, e.g. the albedo, the processing chain (Rechid et al. 2008) to construct the underlying model-albedo uses a number of assumptions which levels phase and amplitude of the albedo-cycle of a regional typical land cover. The albedo data product ALBEDOMAP (Fischer et al. 2006) of the Medium Resolution Imaging Spectrometer (MERIS) on the ESA platform ENVISAT is used as comparative data set. The annual cycle of the ALBEDOMAP data exceeds the modeled variability of the annual albedo cycle permanently in some cases by a factor of ten. Results of REMO-sensitivity studies show, that even small changes in the albedo about one percent is influencing the simulation. Within this study the relevance of characteristically surface information concerning land-use change for fine resolutions in REMO were shown. Fischer, J. ; Preusker, R.; Muller, J.-P. & M. Zühlke (2007): ALBEDOMAP -Validation Report - ESA AO/1-4559/04/I-LG, Online-Publikation: http://www.brockmann-consult.de/albedomap/pdf/MERIS-AlbedoMap-Validation-1.0.pdf. Jacob, D. (2001): A note to the simulation of the annual and inter-annual variability of the water budget over the Baltic Sea drainage basin; Meteorol. Amtos. Phys., 77, 61-73, 2001. Rechid, D.; Raddatz, T. & D. Jacob (2008): Parameterization of snow-free land surface albedo as a function of vegetation phenology based on MODIS data and applied in climate modelling.; Theor. Appl. Climatol., DOI 10.1007/s00704-008-0003-y.

  3. Surface characteristics of implants influence their bone integration after simultaneous placement of implant and GBR membrane.

    PubMed

    Lima, Luiz A; Fuchs-Wehrle, Anita M; Lang, Niklaus P; Hämmerle, Christoph H F; Liberti, Edson; Pompeu, Eduardo; Todescan, José H

    2003-12-01

    The purpose of this study was to evaluate the influence of titanium surface characteristics on bone integration of implants, and to describe the pattern of peri-implant tissue healing after simultaneous implant placement and guided bone regeneration. In four healthy mongrel dogs mandibular premolars were extracted. Two weeks following full mouth prophylaxis and 4 months after extractions, simultaneous membrane and implant surgeries were performed. Efforts were made to produce bony defects with dimensions of 7 x 7 x 7 mm. Into these, 24 standard ITI implants (diameter = 4.1 mm; length = 8 mm) with either a titanium plasma-sprayed (TPS) or a machined surface (MS) were placed. Although implants were inserted 4 mm into cancellous bone, difficulties in achieving optimal primary stability were encountered. All dogs were maintained on a soft diet. Chlorhexidine rinses were performed three times a week. Full mouth prophylaxis was performed every 2 weeks. In the case of membrane exposure, the membranes were removed prematurely (4-6 or 14-15 weeks after surgery). Two dogs were sacrificed at 16 weeks and two at 24 weeks after surgery. Nondecalcified histologic sections were processed and histometric analyses were carried out. When membranes were removed after 4-6 weeks, a vertical bone growth (VB) of 45-61% of the original defect was noted. After membrane removal at 14-15 weeks, similar VB was observed. However, if membranes were left in situ for 24 weeks, VB was between 79% and 96%. In this group of sites, the VB was 66% at 16 weeks and 86% at 24 weeks. Osseointegration in the regenerated bone area ranged from 12% to 32% for the TPS and from 0.0% to 3.6% for the MS implants at 16 and 24 weeks combined. Osseointegration in the pristine host bone area ranged from 16% to 35% for the TPS and from 0.0% to 11% for the MS sites at 16 and 24 weeks. In conclusion, the fraction of implant-bone integration was much higher in the pristine bone compared to that in the regenerated bone

  4. Influence of climate on landscape characteristics in safety assessments of repositories for radioactive wastes.

    PubMed

    Becker, J K; Lindborg, T; Thorne, M C

    2014-12-01

    In safety assessments of repositories for radioactive wastes, large spatial and temporal scales have to be considered when developing an approach to risk calculations. A wide range of different types of information may be required. Local to the site of interest, temperature and precipitation data may be used to determine the erosional regime (which may also be conditioned by the vegetation characteristics adopted, based both on climatic and other considerations). However, geomorphological changes may be governed by regional rather than local considerations, e.g. alteration of river base levels, river capture and drainage network reorganisation, or the progression of an ice sheet or valley glacier across the site. The regional climate is in turn governed by the global climate. In this work, a commentary is presented on the types of climate models that can be used to develop projections of climate change for use in post-closure radiological impact assessments of geological repositories for radioactive wastes. These models include both Atmosphere-Ocean General Circulation Models and Earth Models of Intermediate Complexity. The relevant outputs available from these models are identified and consideration is given to how these outputs may be used to inform projections of landscape development. Issues of spatial and temporal downscaling of climate model outputs to meet the requirements of local-scale landscape development modelling are also addressed. An example is given of how climate change and landscape development influence the radiological impact of radionuclides potentially released from the deep geological disposal facility for spent nuclear fuel that SKB (the Swedish Nuclear Fuel and Waste Management Company) proposes to construct at Forsmark, Sweden.

  5. [Ecological Footprint Evolution Characteristics and Its Influencing Factors in China from 2000 to 2010].

    PubMed

    Huang, Bao-rong; Cui, Shu-hong; Li, Ying-ming

    2016-02-15

    According to global average land productivities in 2000, this study calculated ecological footprint (EF) in China from 2000 to 2010, and analyzed its dynamic characteristics and socio-economic driving forces. The results showed that the total EF in China increased from 1.769 to 3.259 billion global hectares (gha) from 2000 to 2010, and its annual growth rate was 6.30%. Carbon Footprint was the fastest growth type of EF. It increased from 0.742 to 1.805 billion gha, and its annual growth rate was 9.29%. The net increase of cropland Footprint was also large in comparison to other types of Footprint. It increased from 0.678 to 0.891 billion gha. Per capita EF in China increased from 1.40 to 2.43 gha in this period. Although it was still below the world average level, it was far beyond per capita ecological carrying capacity in China, which led to serious ecological deficit and severe ecological crisis in China. The fast growth of per capita EF was the main driving force for the growth of total EF in China during the study period. Further, the growth of per capita EF was positively influenced by the growth of per capita consumption of products and severs, which was driven by economic growth and urbanization. Meanwhile, a large amount of exports of resource-intensive products in international trade was also an important driving force for EF growth. According to the evolution route of per capita EF in developed countries, along with China moving from middle-income to high-income country, per capita EF will maintain rapid growth, and ecological deficit in China will further exacerbate.

  6. Urban influence on increasing ozone concentrations in a characteristic Mediterranean agglomeration

    NASA Astrophysics Data System (ADS)

    Escudero, M.; Lozano, A.; Hierro, J.; Valle, J. del; Mantilla, E.

    2014-12-01

    Air quality in cities has been extensively studied due to the high population density potentially exposed to high levels of pollutants. The main problems in urban areas have been related to particulate matter (PM) and NO2. Less attention has been directed towards O3 because urban levels are generally lower than those recorded in rural areas. The implementation of air quality plans, together with technological improvements, have resulted in reductions of PM and NO2 levels in many European cities. In contrast, urban O3 levels have experimented increases which may respond to declining NOx emission trends. It is therefore necessary to intensify the study of urban O3 and its potential relation with NOx variations. In the agglomeration of Zaragoza (NE Spain), traffic circulation through the centre has dropped by 28.3% since 2008 due to several factors such as the implementation of a mobility plan, the completion of major construction projects and the economic crisis in Spain. The study of this case offers a unique opportunity to evaluate the impact of reductions in NOx emissions on the levels of O3 in a characteristic Mediterranean city. This work analyses the variability and trends of ambient air levels of O3 and NOx in Zaragoza and the Ebro valley from 2007 to 2012. Results demonstrate that, although the main factor explaining O3 variability is still linked to meteorology, changes in NOx emissions strongly influence O3 variability and trends, mainly due to interaction with fresh NO. Specific analysis of the O3 "weekend effect" show a significant correlation (r2 = 0.81) between the drop of NO concentrations (associated to emissions) and the increment of O3 levels during weekends. Moreover, trend analyses reveal that the decline in NOx emissions in Zaragoza from 2007 to 2012 can be associated with significant increments in O3 levels.

  7. Do Biological and Bedsite Characteristics Influence Survival of Neonatal White-Tailed Deer?

    PubMed Central

    Chitwood, M. Colter; Lashley, Marcus A.; Kilgo, John C.; Pollock, Kenneth H.; Moorman, Christopher E.; DePerno, Christopher S.

    2015-01-01

    Coyotes recently expanded into the eastern U.S. and potentially have caused localized white-tailed deer population declines. Research has focused on quantifying coyote predation on neonates, but little research has addressed the potential influence of bedsite characteristics on survival. In 2011 and 2012, we radiocollared 65 neonates, monitored them intensively for 16 weeks, and assigned mortality causes. We used Program MARK to estimate survival to 16 weeks and included biological covariates (i.e., sex, sibling status [whether or not it had a sibling], birth weight, and Julian date of birth). Survival to 16 weeks was 0.141 (95% CI = 0.075-0.249) and the top model included only sibling status, which indicated survival was lower for neonates that had a sibling. Predation was the leading cause of mortality (35 of 55; 64%) and coyotes were responsible for the majority of depredations (30 of 35; 86%). Additionally, we relocated neonates for the first 10 days of life and measured distance to firebreak, visual obstruction, and plant diversity at bedsites. Survival of predation to 10 days (0.726; 95% CI = 0.586-0.833) was weakly associated with plant diversity at bedsites but not related to visual obstruction. Our results indicate that neonate survival was low and coyote predation was an important source of mortality, which corroborates several recent studies from the region. Additionally, we detected only weak support for bedsite cover as a covariate to neonate survival, which indicates that mitigating effects of coyote predation on neonates may be more complicated than simply managing for increased hiding cover. PMID:25734333

  8. Influence of tobacco smoke on indoor PM 10 particulate matter characteristics

    NASA Astrophysics Data System (ADS)

    Paoletti, L.; De Berardis, B.; Arrizza, L.; Granato, V.

    In this study we evaluate the influence of tobacco smoke on the physico-chemical characteristics of PM 10 in different environments: outdoors, a smoking room, the same room after a 7-day absence of smokers and in a smoke-free office. The latter office was close to the smoking room, separated by a corridor. The coarse (PM 10-2.1) and fine (PM 2.1) fractions of PM 10 collected in the monitored areas were analysed by scanning electron microscopy, equipped with a thin-window system for X-ray microanalysis (SEM/EDX). Photo-electron spectroscopy (XPS) was used to study the elemental composition of the particulate and to identify the chemical state of atomic species detected. Four clusters of particles for both "fine" and "coarse" fractions were identified: carbonaceous particles, soil erosion particles, Ca-sulphates and metal compound particles. EDX spectra showed that a percentage of carbonaceous particles carried S, Si and metal traces. High-resolution XPS spectra of the C1s region showed a significant greater occurrence of the C-O/C-N functional group in the particulate fine fraction collected in the smoking room compared to that collected outdoors. The carbonaceous component of coarse fraction collected in the smoking room appeared dissimilar from the same component detected in the other areas. After the 7-day absence of smokers this component of the PM 10-2.1 fraction was similar to the corresponding coarse fraction collected at the outdoor location. The carbonaceous component of fine fraction collected in the smoking room, containing tobacco smoke products, such as organic carbon and nicotine, was traceable in the neighbouring areas, even several days after suspension of smoking activity.

  9. Evidence that life history characteristics of wild birds influence infection and exposure to influenza A viruses.

    PubMed

    Ely, Craig R; Hall, Jeffrey S; Schmutz, Joel A; Pearce, John M; Terenzi, John; Sedinger, James S; Ip, Hon S

    2013-01-01

    We report on life history characteristics, temporal, and age-related effects influencing the frequency of occurrence of avian influenza (AI) viruses in four species of migratory geese breeding on the Yukon-Kuskokwim Delta, Alaska. Emperor geese (Chen canagica), cackling geese (Branta hutchinsii), greater white-fronted geese (Anser albifrons), and black brant (Branta bernicla), were all tested for active infection of AI viruses upon arrival in early May, during nesting in June, and while molting in July and August, 2006-2010 (n = 14,323). Additionally, prior exposure to AI viruses was assessed via prevalence of antibodies from sera samples collected during late summer in 2009 and 2010. Results suggest that geese are uncommonly infected by low pathogenic AI viruses while in Alaska. The percent of birds actively shedding AI viruses varied annually, and was highest in 2006 and 2010 (1-3%) and lowest in 2007, 2008, and 2009 (<0.70%). Contrary to findings in ducks, the highest incidence of infected birds was in late spring when birds first arrived from staging and wintering areas. Despite low prevalence, most geese were previously exposed to AI viruses, as indicated by high levels of seroprevalence during late summer (47%-96% across species; n = 541). Seroprevalence was >95% for emperor geese, a species that spends part of its life cycle in Asia and is endemic to Alaska and the Bering Sea region, compared to 40-60% for the other three species, whose entire life cycles are within the western hemisphere. Birds <45 days of age showed little past exposure to AI viruses, although antibodies were detected in samples from 5-week old birds in 2009. Seroprevalence of known age black brant revealed that no birds <4 years old had seroconverted, compared to 49% of birds ≥4 years of age.

  10. The influence of seatback characteristics on cervical injury risk in severe rear impacts.

    PubMed

    Burnett, Roger; Carter, Jarrod; Roberts, Verne; Myers, Barry

    2004-07-01

    The determination of the optimum seatback characteristics for the mitigation of serious and catastrophic neck injury during high-speed rear-end collisions remains a topic of continued investigation. Despite a number of prior research efforts, both field data and sled test studies have yet to define a single optimal seatback performance criterion. Further, recent developments in seatbacks have introduced new designs into the field that have not been compared to more traditional designs. Analysis of NASS data from 1980 to 1999 demonstrated that at changes in velocity (DeltaV) above 40 kph, rear-end collisions have a dramatically lower risk for catastrophic injury than frontal, near-side or far-side impacts. Unfortunately, owing to the small penetration of newer seatback designs in the automotive fleet, it is not possible to examine the influence of seatback design parameters on serious neck injury using these data alone. Accordingly, seven rear impact HYGE sled tests were conducted using a wide range of seat designs. Upper and lower neck load cells were used to measure neck forces and moments in restrained 50th male Hybrid III anthropomorphic test devices (ATD). Additionally, the neck injury criteria (Nij) was computed. Unlike prior studies that have examined the standard seated ATD or the dramatically out-of-position ATD, these tests were conducted using an ATD seated in non-standard but typical driving position. The results of this study indicate that several descriptions of seatback behavior, such as quasi-static ultimate force are poor predictors of ATD neck loading. It also suggests that, for the severe crash studied, an optimum range of seatback stiffness exists, which appears to be in the mid-range of seatback stiffnesses available in current production vehicles. These data continue to illustrate the complex relationship of seatback design parameters to neck injury risk.

  11. Influence of Coal Particle Size on Coal Adsorption and Desorption Characteristics

    NASA Astrophysics Data System (ADS)

    Zhang, Lei; Aziz, Naj; Ren, Ting; Nemcik, Jan; Tu, Shihao

    2014-10-01

    Accurate testing coal isotherm can play a significant role in the areas of coal seam gas drainage, outburst control, CO2 geo-sequestration, coalbed methane (CBM) and enhanced coalbed methane recovery (ECBM) etc. The effect of particle size on the CO2 and CH4 sorption capacity of bituminous coal from Illawarra, Australia was investigated at 35°C and at pressure up to 4 MPa. A unique indirect gravimetric apparatus was used to measure the gas adsorption and desorption isotherms of coal of different particle sizes ranging from around 150 urn to 16 mm. Langmuir model was used to analysis the experimental results of all gases. Coal particle size was found to have an apparent effect on the coal ash content and helium density results. Coal with larger particle size had higher ash content and higher helium density. The sorption isotherm was found to be highly sensitive with helium density of coal which was determined in the procedure of testing the void volume of sample cell. Hence, coal particle size had a significant influence on the coal sorption characteristics including sorption capacity and desorption hysteresis for CO2 and CH4, especially calculated with dry basis of coal. In this study, the 150-212 um (150 um) coal samples achieved higher sorption capacity and followed by 2.36-3.35 mm (2.4 mm), 8-9.5 mm (8 mm) and 16-19 mm (16 mm) particle size samples. However, the differences between different coal particles were getting smaller when the sorption isotherms are calculated with dry ash free basis. Test with 150 um coal samples were also found to have relatively smaller desorption hysteresis compared with the other larger particle size samples. The different results including adsorption/desorption isotherm, Langmuir parameters and coal hysteresis were all analysed with the CO2 and CH4 gases.

  12. The genetic influences on oxycodone response characteristics in human experimental pain.

    PubMed

    Olesen, Anne E; Sato, Hiroe; Nielsen, Lecia M; Staahl, Camilla; Droney, Joanne; Gretton, Sophy; Branford, Ruth; Drewes, Asbjørn M; Arendt-Nielsen, Lars; Riley, Julia; Ross, Joy

    2015-08-01

    Human experimental pain studies are of value to study basic pain mechanisms under controlled conditions. The aim of this study was to investigate whether genetic variation across selected mu-, kappa- and delta-opioid receptor genes (OPRM1, OPRK1and OPRD1, respectively) influenced analgesic response to oxycodone in healthy volunteers. Experimental multimodal, multitissue pain data from previously published studies carried out in Caucasian volunteers were used. Data on thermal skin pain tolerance threshold (PTT) (n = 37), muscle pressure PTT (n = 31), mechanical visceral PTT (n = 43) and thermal visceral PTT (n = 41) were included. Genetic associations with pain outcomes were explored. Nineteen opioid receptor genetic polymorphisms were included in this study. Variability in oxycodone response to skin heat was associated with OPRM1 single-nucleotide polymorphisms (SNPs) rs589046 (P < 0.0001) and rs563649 (P < 0.0001). Variability in oxycodone response to visceral pressure was associated with four OPRM1 SNPs: rs589046 (P = 0.015), rs1799971 (P = 0.045), rs9479757 (P = 0.009) and rs533586 (P = 0.046). OPRM1 SNPs were not associated with oxycodone visceral heat threshold, however, one OPRD1 rs419335 reached significance (P = 0.015). Another OPRD1 SNP rs2234918 (P = 0.041) was associated with muscle pressure. There were no associations with OPRK1 SNPs and oxycodone response for any of the pain modalities. Associations were found between analgesic effects of oxycodone and OPRM1 and OPRD1 SNPs; therefore, variation in opioid receptor genes may partly explain responder characteristics to oxycodone.

  13. [Characteristics of Adsorption Leaching and Influencing Factors of Dimethyl Phthalate in Purple Soil].

    PubMed

    Wang, Qiang; Song, Jiao-yan; Zeng, Wei; Wang, Fa

    2016-02-15

    The typical soil-purple soil in Three Gorges Reservoir was the tested soil, the characteristics of adsorption leaching of dimethyl phthalate (DMP) in contaminated water by the soil, and the influencing factors in the process were conducted using soil column leaching experiment. The results showed that the parabolic equation was the best equation describing adsorption kinetics of DMP by soils. The concentration of DMP in the leaching solution had significant effect on the adsorption amounts of DMP. With the increasing concentration of DMP in the leaching solution, the adsorption capacities of DMP by purple soil increased linearly. The ionic strength and pH in leaching solution had significant effects on adsorption of DMP. On the whole, increasing of the ionic strength restrained the adsorption. The adsorption amounts at pH 5.0-7.0 were more than those under other pH condition. The addition of exogenous organic matter (OM) in purple soil increased the adsorption amount of DMP by purple soil. However, the adsorption amount was less than those with other addition amounts of exogenous OM when the addition of exogenous OM was too high (> or = 30 g x kg(-1)). The addition of surfactant sodium dodecylbenzene sulfonic acid (SDBS) in purple soil increased the adsorption amount of DMP by purple soil. The adsorption amount was maximal when the addition amount of SDBS was 50 mg x kg(-1). However, the adsorption amounts decreased with increasing addition amounts of SDBS although the adsorption amounts were still more than that of the control group, and the adsorption amount was almost equal to that of the control group when the addition amount of SDBS was 800 mg x kg(-1). Continuous leaching time affected the vertical distribution of DMP in the soil column. When the leaching time was shorter, the upper soil column adsorbed more DMP, while the DMP concentrations in upper and lower soil columns became similar with the extension of leaching time.

  14. Self-Esteem in Hearing-Impaired Children: The Influence of Communication, Education, and Audiological Characteristics

    PubMed Central

    Theunissen, Stephanie C. P. M.; Rieffe, Carolien; Netten, Anouk P.; Briaire, Jeroen J.; Soede, Wim; Kouwenberg, Maartje; Frijns, Johan H. M.

    2014-01-01

    Objective Sufficient self-esteem is extremely important for psychosocial functioning. It is hypothesized that hearing-impaired (HI) children have lower levels of self-esteem, because, among other things, they frequently experience lower language and communication skills. Therefore, the aim of this study was to compare HI children's self-esteem across different domains with those of normal hearing (NH) children and to investigate the influence of communication, type of education, and audiological characteristics. Methods This large (N = 252) retrospective, multicenter study consisted of two age- and gender-matched groups: 123 HI children and 129 NH controls (mean age  = 11.8 years). Self-reports were used to measure self-esteem across four domains: perceived social acceptance by peers, perceived parental attention, perceived physical appearance, and global self-esteem. Results HI children experienced lower levels of self-esteem regarding peers and parents than NH controls. Particularly HI children who attended special education for the deaf were at risk, even after correcting for their language development and intelligence. Yet, levels of global self-esteem and self-esteem involving physical appearance in HI children equalled those of NH controls. Furthermore, younger age at implantation and longer duration of having cochlear implants (CIs) were related to higher levels of self-esteem. Conclusion HI children experience lower levels of self-esteem in the social domains. Yet, due to the heterogeneity of the HI population, there is high variability in levels of self-esteem. Discussion Clinicians must always be aware of the risk and protective factors related to self-esteem in order to help individual patients reach their full potential. PMID:24722329

  15. Do biological and bedsite characteristics influence survival of neonatal white-tailed deer?

    PubMed

    Chitwood, M Colter; Lashley, Marcus A; Kilgo, John C; Pollock, Kenneth H; Moorman, Christopher E; DePerno, Christopher S

    2015-01-01

    Coyotes recently expanded into the eastern U.S. and potentially have caused localized white-tailed deer population declines. Research has focused on quantifying coyote predation on neonates, but little research has addressed the potential influence of bedsite characteristics on survival. In 2011 and 2012, we radiocollared 65 neonates, monitored them intensively for 16 weeks, and assigned mortality causes. We used Program MARK to estimate survival to 16 weeks and included biological covariates (i.e., sex, sibling status [whether or not it had a sibling], birth weight, and Julian date of birth). Survival to 16 weeks was 0.141 (95% CI = 0.075-0.249) and the top model included only sibling status, which indicated survival was lower for neonates that had a sibling. Predation was the leading cause of mortality (35 of 55; 64%) and coyotes were responsible for the majority of depredations (30 of 35; 86%). Additionally, we relocated neonates for the first 10 days of life and measured distance to firebreak, visual obstruction, and plant diversity at bedsites. Survival of predation to 10 days (0.726; 95% CI = 0.586-0.833) was weakly associated with plant diversity at bedsites but not related to visual obstruction. Our results indicate that neonate survival was low and coyote predation was an important source of mortality, which corroborates several recent studies from the region. Additionally, we detected only weak support for bedsite cover as a covariate to neonate survival, which indicates that mitigating effects of coyote predation on neonates may be more complicated than simply managing for increased hiding cover.

  16. Benthic foraminifera (Protista) as tools in deep-water palaeoceanography: environmental influences on faunal characteristics.

    PubMed

    Gooday, Andrew J

    2003-01-01

    Foraminiferal research lies at the border between geology and biology. Benthic foraminifera are a major component of marine communities, highly sensitive to environmental influences, and the most abundant benthic organisms preserved in the deep-sea fossil record. These characteristics make them important tools for reconstructing ancient oceans. Much of the recent work concerns the search for palaeoceanographic proxies, particularly for the key parameters of surface primary productivity and bottom-water oxygenation. At small spatial scales, organic flux and pore-water oxygen profiles are believed to control the depths at which species live within the sediment (their 'microhabitats'). Epifaunal/shallow infaunal species require oxygen and labile food and prefer relatively oligotrophic settings. Some deep infaunal species can tolerate anoxia and are closely linked to redox fronts within the sediment; they consume more refractory organic matter, and flourish in relatively eutrophic environments. Food and oxygen availability are also key factors at large (i.e. regional) spatial scales. Organic flux to the sea floor, and its seasonality, strongly influences faunal densities, species compositions and diversity parameters. Species tend to be associated with higher or lower flux rates and the annual flux range of 2-3 g Corg m-2 appears to mark an important faunal boundary. The oxygen requirements of benthic foraminifera are not well understood. It has been proposed that species distributions reflect oxygen concentrations up to fairly high values (3 ml l-1 or more). Other evidence suggests that oxygen only begins to affect community parameters at concentrations < 0.5 ml l-1. Different species clearly have different thresholds, however, creating species successions along oxygen gradients. Other factors such as sediment type, hydrostatic pressure and attributes of bottom-water masses (particularly carbonate undersaturation and current flow) influence foraminiferal distributions

  17. A study of the influence of the rolling of moving part on the dynamic characteristics of OPU actuator

    NASA Astrophysics Data System (ADS)

    Ru, Jigang; Pan, Longfa; Ma, Jianshe; Shi, Hongwei

    2005-09-01

    As the executive part, the actuator of optical pick-up (OPU) accomplishes the servo action actually. The dynamic characteristics of the OPU actuator determine the precision of focusing and tracking servo system, so it will influence the reading performance of optical pick-up. As the density of optical storage increases, the OPU actuator has a high servo bandwidth for its focusing and tracking control to follow dynamic disturbances by high density and high rotational speed of disk. The dynamic response curve should be as smooth as possible in its linear area. In this paper, the influence of the rolling of moving part on the actuator's dynamic characteristics is studied. Because of some design reasons, the moving part of the actuator may roll in three dimensions during the working status. It's one of the most important factors to influence the dynamic characteristics of actuator. Firstly, the reason of rolling and the influence on dynamic characteristics are studied. In the design of actuator we should pay attention to three important points, which are the gravitational point, the equivalent driving force point and the equivalent sustained point. When the three points are not accordant during the moving action, the rolling occurs. The dynamic response curve will have some unexpected resonances at certain frequency area. This phenomenon is analyzed by kinetic method. Secondly, a model of the actuator is founded referring to an actual type of actuator. By finite element analysis software (ANSYS), the mechanical and magnetic simulation is performed. The special distributing of electromagnetic field is described and the driving force is analyzed. Thirdly, the dynamic characteristics of some actuators with rolling are tested. The experimental result is consistent with the simulation result. So the validity of this study is verified. At last, the possible methods to avoid rolling of moving part are introduced.

  18. Influence of tool speeds on dissimilar friction stir spot welding characteristics of bulk metallic glass/Mg alloy

    NASA Astrophysics Data System (ADS)

    Shin, Hyung-Seop; Jung, Yoon-Chul; Lee, Jin-Kyu

    2012-08-01

    A small-scale joining technique of dissimilar friction stir spot welding (FSSW) between bulk metallic glass and Mg alloy sheet has been tried using an apparatus which was devised with a CNC milling machine to give a precise control of tool speeds. The influence of tool speeds on the joining characteristics during FSSW was investigated. As a result, it was found that the rotation speed and plunge speed of a tool during FSSW significantly influenced the welding performance of dissimilar FSSW between bulk metallic glasses and Mg alloy.

  19. Aedes (Stegomyia) albopictus' dynamics influenced by spatiotemporal characteristics in a Brazilian dengue-endemic risk city.

    PubMed

    Bezerra, Juliana M T; Araújo, Raphaela G P; Melo, Fabrício F; Gonçalves, Caroline M; Chaves, Bárbara A; Silva, Breno M; Silva, Luciana D; Brandão, Silvana T; Secundino, Nágila F C; Norris, Douglas E; Pimenta, Paulo F P

    2016-12-01

    Brazil reported the majority of the dengue cases in Americas during the last two decades, where the occurrence of human dengue cases is exclusively attributed to the Aedes (Stegomyia) aegypti (Linnaeus). Nowadays, other recognized Dengue virus (DENV) vector in Asian countries, Aedes (Stegomyia) albopictus (Skuse), has been detected in more than half of the 5565 Brazilian municipalities. Therefore, the aim of the present study was to investigate the presence of, and determine the Ae. albopictus' dynamics influenced by spatiotemporal characteristics in a dengue-endemic risk city of Belo Horizonte, Minas Gerais State's capital. Aedes albopictus were collected across four consecutive DENV transmission seasons from 2010 to 2014. These mosquitoes were caught in three selected districts, which had been reported in the previous ten years as having high mosquito densities and an elevated concentration of human dengue cases during epidemic seasons. All field-caught Ae. albopictus was individually processed by real-time RT-PCR, to research the DENV presence. The third season (p<0.05) and the Pampulha district (p<0.05) had the highest proportions of field-caught Ae. albopictus, respectively. The second season had the highest proportion of DENV-infected field-caught females (p<0.05), but there was no difference among the proportions of DENV-infected Ae. albopictus when comparing the collection in the three districts (p=0.98). Minimum (p=0.004) and maximum (p<0.0001) temperature were correlated with the field-caught Ae. albopictus in four different periods and districts. In the generalized linear model of Poisson, the field-caught DENV-infected Ae. albopictus (p=0.005), East district (p=0.003), minimum temperature (p<0.0001) and relative humidity (p=0.001) remained associated with the total number of human dengue cases. Our study demonstrated that the number of field-caught DENV-infected Ae. albopictus was inversed correlated with the number of human dengue cases. Our study

  20. Physicochemical characteristics of drip waters: Influence on mineralogy of recent cave carbonate precipitates

    NASA Astrophysics Data System (ADS)

    Riechelmann, Sylvia; Schröder-Ritzrau, Andrea; Wassenburg, Jasper A.; Richter, Detlev K.; Riechelmann, Dana FC; Terente, Mihai; Constantin, Silviu; Immenhauser, Adrian

    2015-04-01

    Speleothems are one of the most intensively explored archives of palaeoclimate variability in continental settings. Considerable advances with respect to climatic and cave forcing of drip characteristics and related speleothem proxy data have been made during the last decades. The parameters, however, that control speleothem mineralogy and its changes with time and space are still poorly understood. In order to shed light on processes influencing speleothem mineralogy, precipitation experiments of recent carbonate crystals on watch glasses and glass plates were performed in seven selected caves. These include three caves in Germany as well as Morocco and one cave in Romania, which are situated in both limestone and dolostone. Drip water sites of these caves were analysed for their fluid Mg/Ca molar ratio, pH, degree of saturation for calcite and aragonite and drip rates. Corresponding precipitates were analysed with respect to their mineralogy using a high resolution scanning electron microscope (SEM). The following results are found: High fluid Mg/Ca ratios are observed only for caves situated in dolostone, hence the hostrock lithology indirectly controls the carbonate mineralogy of speleothems. The precipitation of aragonite in place of calcite occurred only in dolostone caves and is bound to very specific conditions, which are: high fluid Mg/Ca ratios (≥ 0.5), high fluid pH (> 8.2) and low fluid saturation indices for calcite (< 0.8). These specific conditions are induced by slow drip rates of < 0.2 ml/min (often under more arid conditions), causing the precipitation of calcite / aragonite prior to reaching the stalagmite top. Due to this, fluid chemistry is altered, which in turn leads to changes in carbonate mineralogy and geochemistry on the stalagmite top. Interestingly, all of the above mentioned factors must act in a concerted manner. If this is not the case, calcite is the dominant phase. The threshold, where only aragonite precipitates is at fluid Mg

  1. The Influence of Facilitator and Facilitation Characteristics on Participants' Ratings of Stepfamily Education

    ERIC Educational Resources Information Center

    Higginbotham, Brian J.; Myler, Cory

    2010-01-01

    We examine the relative importance of facilitator and facilitation characteristics on participant ratings of a stepfamily education program. Data from 48 facilitators and 598 participants suggest that quality facilitation is more meaningful to participants than whether facilitators have comparable demographic characteristics or life experiences.…

  2. Urban School Principals' Preferred Teacher Characteristics and How They Influence Hiring Practices

    ERIC Educational Resources Information Center

    Wiley, Monika Maria

    2016-01-01

    This dissertation uses sequential mixed methods analysis to examine what characteristics principals seek when hiring teachers and whether they match the perceived characteristics of the teachers who were recommended for hire. The sample included 56 principals on the initial survey and 34 principals responded to the questionnaire. Data analysis…

  3. The influence of electrode configuration on light emission profiles and electrical characteristics of an atmospheric-pressure plasma jet

    NASA Astrophysics Data System (ADS)

    Maletić, Dejan; Puač, Nevena; Malović, Gordana; Đorđević, Antonije; Petrović, Zoran Lj

    2017-04-01

    In this paper we focus on the influence of the type of electrodes, their dimensions and inter-electrode gap on the formation of a helium plasma jet. Plasma emission profiles are recorded by an ICCD camera simultaneously with volt–ampere characteristics for three different copper electrode configurations. The delivered power was up to 6.5 W, but it may be set and controlled to 0.1 W. This study shows how the electrode configuration shapes and controls temporal and spatial plasma development as well as electrical characteristics of an atmospheric pressure plasma jet. It is shown that, in our system, the width of the grounded electrode has no significant influence on the formation and properties of pulsed atmospheric-pressure streamers (PAPS) outside the tube, while the width of the powered electrode is crucial in their formation.

  4. Ice slurry cooling research: Microscale study of ice particles characteristics, role of freezing point depressant, and influence on slurry fluidity

    SciTech Connect

    Hayashi, K.; Kasza, K.

    2000-05-03

    The influences of freezing-point-depressants on ice slurry characteristics in the form of ice slurry fluidity and on the microscale ice particle features are studied. The results identify microscale features of ice particles such as surface roughness that greatly influence slurry fluidity that are altered favorably by the use of a freezing point depressant. The engineering of a workable and efficient ice slurry cooling system depends very strongly on the characteristics of the individual ice particles in the slurry and, in turn, on the method of ice production. Findings from this study provide guidance on the fluidity and handleability of slurry produced by several methods currently under development and already many achieved.

  5. The "Secret Seduction" of the Press? Aspects of Characteristics of PR Influencing Media Coverage.

    ERIC Educational Resources Information Center

    Frohlich, Romy

    As yet, little research exists in Germany on the influence of public relations on news coverage, although for years American studies have shown that public relations widely determine media content. A study in Germany examined the qualities of news coverage as influenced by public relations efforts. Local media coverage (201 articles) in Munich…

  6. The Influence of Communicator Characteristics on the Nutrition Attitudes and Behavior of High School Students.

    ERIC Educational Resources Information Center

    Feldman, Robert H. L.

    1984-01-01

    School health educators can increase teaching effectiveness by emphasizing common interests with their students. High school students were studied to observe the influence of the communicator in a health program on nutrition. Results indicate that the greater the perceived similarities, the greater the influence of the communicator. Research…

  7. Local anaesthetics and additives for spinal anaesthesia--characteristics and factors influencing the spread and duration of the block.

    PubMed

    Pitkänen, Mikko; Rosenberg, Per H

    2003-09-01

    Different characteristics of patients and local anaesthetic formulations will influence the spread of spinal anaesthesia. The predictability of the spread of spinal anaesthesia can be improved by altering both baricity of the solution, and the position of the patient during the intrathecal local anaesthetic injection. The role of adrenaline and clonidine in prolonging the block and associated side effects is discussed. The role of opioids added to local anaesthetic solutions is discussed from a cost/benefit point of view.

  8. The influence of vegetation and soil characteristics on active-layer thickness of permafrost soils in boreal forest.

    PubMed

    Fisher, James P; Estop-Aragonés, Cristian; Thierry, Aaron; Charman, Dan J; Wolfe, Stephen A; Hartley, Iain P; Murton, Julian B; Williams, Mathew; Phoenix, Gareth K

    2016-09-01

    Carbon release from thawing permafrost soils could significantly exacerbate global warming as the active-layer deepens, exposing more carbon to decay. Plant community and soil properties provide a major control on this by influencing the maximum depth of thaw each summer (active-layer thickness; ALT), but a quantitative understanding of the relative importance of plant and soil characteristics, and their interactions in determine ALTs, is currently lacking. To address this, we undertook an extensive survey of multiple vegetation and edaphic characteristics and ALTs across multiple plots in four field sites within boreal forest in the discontinuous permafrost zone (NWT, Canada). Our sites included mature black spruce, burned black spruce and paper birch, allowing us to determine vegetation and edaphic drivers that emerge as the most important and broadly applicable across these key vegetation and disturbance gradients, as well as providing insight into site-specific differences. Across sites, the most important vegetation characteristics limiting thaw (shallower ALTs) were tree leaf area index (LAI), moss layer thickness and understory LAI in that order. Thicker soil organic layers also reduced ALTs, though were less influential than moss thickness. Surface moisture (0-6 cm) promoted increased ALTs, whereas deeper soil moisture (11-16 cm) acted to modify the impact of the vegetation, in particular increasing the importance of understory or tree canopy shading in reducing thaw. These direct and indirect effects of moisture indicate that future changes in precipitation and evapotranspiration may have large influences on ALTs. Our work also suggests that forest fires cause greater ALTs by simultaneously decreasing multiple ecosystem characteristics which otherwise protect permafrost. Given that vegetation and edaphic characteristics have such clear and large influences on ALTs, our data provide a key benchmark against which to evaluate process models used to predict

  9. The defining characteristics of Web 2.0 and their potential influence in the online vaccination debate.

    PubMed

    Witteman, Holly O; Zikmund-Fisher, Brian J

    2012-05-28

    The emergence of Web 2.0 has led to more and more Web-based resources demonstrating three defining characteristics: user participation, openness and network effects. This paper discusses these characteristics in the context of the online vaccination debate, explores how they structurally alter the way people might interact with vaccination information online, and describes ways in which such characteristics support particular tendencies in human decision making processes. Specifically, user participation supports the influence of narratives and personal accounts, openness shapes expectations for greater levels of detail and movement toward models of informed decision making, and network effects demonstrate the social nature of decision making, the influence of like-minded others and thus, the pitfalls of polarization in the online vaccination debate. Web 2.0 means that concerns about vaccination information online must expand beyond simply the possibility that people might access information of varying quality to incorporate a more comprehensive understanding of how people use current Web functionality, how such usage influences expectations about information sources and decision making processes, and the implications for communication strategies about vaccination.

  10. Flow characteristics and spillage mechanisms of an inclined quad-vortex range hood subject to influence from draft.

    PubMed

    Huang, Rong Fung; Chen, Jia-Kun; Lin, Jyun-Hua

    2015-01-01

    The flow and spillage characteristics of an inclined quad-vortex (IQV) range hood subject to the influence of drafts from various directions were studied. The laser-assisted smoke flow visualization technique was used to reveal the flow characteristics, and the tracer-gas (sulfur hexafluoride) concentration detection method was used to indicate the quantitative values of the capture efficiency of the hood. It was found that the leakage mechanisms of the IQV range hood are closely related to the flow characteristics. A critical draft velocity of about 0.5 m/s and a critical face velocity of about 0.25 m/s for the IQV range hood were found. When the IQV range hood was influenced by a draft with a velocity larger than the critical draft velocity, the spillage of pollutants became significant and the pollutant spillage rate increased with increasing draft velocity. At draft velocities less than or equal to the critical value, no containment leakages induced by the turbulence diffusion, reverse flow, or boundary-layer separation were observed, and the capture efficiency was about 100%. The IQV range hood exhibited a high ability to resist the influences of lateral and frontal drafts. The capture efficiency of the IQV range hood operated at the suction flow rate 5 to 9 m(3)/min is higher than that of the conventional range hood operated at 11 to 15 m(3)/min.

  11. Influence of fabrication conditions on characteristics of phenanthrenequinone-doped poly(methyl methacrylate) photopolymer for holographic memory

    NASA Astrophysics Data System (ADS)

    Lin, Shiuan Huei; Cho, Sheng-Lung; Lin, June-Hua; Hsu, Ken Y.; Chi, Sien

    2014-06-01

    In this paper, we experimentally investigate the influence of the fabrication conditions on holographic characteristics in phenanthrenequinone-doped poly(methyl methacrylate) (PQ:PMMA) bulk photopolymer. In our investigation, the PQ:PMMA bulk samples are fabricated by use of a two-step thermo-polymerization method. We firstly propose to monitor relative viscosity of the monomer solution during the sample preparation to obtain a reliable criterion for material fabrication. We then compare experimentally characteristics of 2-mm thick samples fabricated with different conditions for holographic memory. The results show that the conditions in the first step play a important rule for fabricating bulk PQ:PMMA samples with good optical uniformity. In addition, the conditions in the second step play the rule for controlling the concentration of residual monomer and determine holographic characteristics. These results can provide a useful rule for fabricating bulk PQ:PMMA photopolymers for further applications on volume holographic data storage.

  12. Factors influencing characteristics of steam-flaked corn and utilization by finishing cattle.

    PubMed

    Sindt, J J; Drouillard, J S; Montgomery, S P; Loe, E R

    2006-01-01

    Three experiments were conducted to identify factors influencing steam-flaked corn (SFC) characteristics and feeding value. In Exp. 1, corn samples (n = 108) were tempered for 2 h using 6, 10, or 14% moisture containing 0 or 0.67 mL of surfactant/L. Samples were steamed for 20 or 40 min and flaked to 360, 335, or 310 g/L. Treatments were arranged in a 3 x 2 x 2 x 3 factorial. No interactions existed in Exp. 1. Increasing tempering moisture linearly (P < 0.001) increased corn moisture after tempering, steaming, and flaking; however, SFC moisture was not increased (quadratic; P < 0.001) greatly by applying more than 10% water during tempering. The surfactant, steam time, and flake density had no effect (P = 0.16 to 0.93) on corn moisture after tempering, steaming, or flaking, but adding a surfactant during tempering decreased (P = 0.05) moisture loss after flaking. Starch availability was unaffected (P = 0.31 to 0.84) by tempering moisture concentration, tempering with a surfactant, or steam time but was increased (linear; P < 0.01) by decreasing flake density. Flake durability was increased by increasing tempering moisture (linear; P < 0.001), tempering with a surfactant (P = 0.04), increasing steam time (P < 0.001), and decreasing flake density (linear; P = 0.02). In Exp. 2, 89 heifers (initial BW = 350 kg) were fed 75% SFC-based diets for 108 d to determine the effects of SFC particle size on performance and carcass traits. Treatments were SFC that was mixed for 0 (4,667 microm) or 15 min (3,330 microm) before addition of other ingredients. Heifers fed 3,330-microm SFC tended (P = 0.13) to eat less DM, but ADG and G:F did not differ (P = 0.58 to 0.65) between treatments. Carcass traits did not differ, except that heifers fed 3,330-microm SFC had less (P = 0.008) KPH. In Exp. 3, 96 heifers (initial BW = 389 kg) were fed for 82 d diets containing 73% SFC that was either 18 or 36% moisture. Heifers fed 36% moisture SFC ate less DM (P = 0.02) and gained slower (P = 0

  13. [Influence of the Composition of the Initial Mixtures on the Physicochemical and Biological Properties and Spectral Characteristics of Composts].

    PubMed

    Song, Cai-hong; Li, Ming-xiao; Wei, Zi-min; Xi, Bei-dou; Zhao, Yue; Jia, Xuan; Liu, Ya-ru; Liu, Dong-ming

    2015-08-01

    In this work, biogas residues, the remnant of the anaerobic digestion, was used for composting with livestock manure as the co-substrate. It is important for improving the soil quality in China, because the negative influence of biogas residues being utilized directly as organic fertilizer (a mainstream way of disposing biogas residues in China) on the soil could be eliminated or mitigated via composting. The composition of composting substrate has a great influence on the composting process. To explore the influence of the composition of the initial mixtures on the physicochemical properties and spectroscopic characteristics of composts, fifteen co-composting of biogas residue, pig manure and chicken manure, with different material ratios, were carried out. Physicochemical and biological indicators were determined. Meanwhile, spectroscopic methods, such as UV-Vis, synchronous fluorescence and 3D-EEM spectra were used for identifying characteristic spectral parameters companied with FRI and PARAFAC. Therefore, spectroscopic characteristics of composts were characterized. The relationship between physicochemical properties of composts and the composition of the initial mixtures was established using CCA. Similarly, that between spectroscopic characteristics of composts and the composition of the initial mixtures was also established. The results showed that: physicochemical properties of composts exhibits a significant correlation with the composition of the initial mixtures. A significant correlation between spectroscopic characteristics of composts and the composition of the initial mixtures was also observed. In the two CCA, the former four axes account for 83.9% and 97.5% of the total sample variation. The influence of enviro nmental factors on physicochemical properties of composts was in the order of pig manure amount>chicken manure amount>biogas residue amount and that on spectroscopic characteristics of composts was in the order of biogas residue amount

  14. Evaluating the drivers of and obstacles to the willingness to use cognitive enhancement drugs: the influence of drug characteristics, social environment, and personal characteristics

    PubMed Central

    2014-01-01

    Background The use of cognitive enhancement (CE) by means of pharmaceutical agents has been the subject of intense debate both among scientists and in the media. This study investigates several drivers of and obstacles to the willingness to use prescription drugs non-medically for augmenting brain capacity. Methods We conducted a web-based study among 2,877 students from randomly selected disciplines at German universities. Using a factorial survey, respondents expressed their willingness to take various hypothetical CE-drugs; the drugs were described by five experimentally varied characteristics and the social environment by three varied characteristics. Personal characteristics and demographic controls were also measured. Results We found that 65.3% of the respondents staunchly refused to use CE-drugs. The results of a multivariate negative binomial regression indicated that respondents’ willingness to use CE-drugs increased if the potential drugs promised a significant augmentation of mental capacity and a high probability of achieving this augmentation. Willingness decreased when there was a high probability of side effects and a high price. Prevalent CE-drug use among peers increased willingness, whereas a social environment that strongly disapproved of these drugs decreased it. Regarding the respondents’ characteristics, pronounced academic procrastination, high cognitive test anxiety, low intrinsic motivation, low internalization of social norms against CE-drug use, and past experiences with CE-drugs increased willingness. The potential severity of side effects, social recommendations about using CE-drugs, risk preferences, and competencies had no measured effects upon willingness. Conclusions These findings contribute to understanding factors that influence the willingness to use CE-drugs. They support the assumption of instrumental drug use and may contribute to the development of prevention, policy, and educational strategies. PMID:24484640

  15. INSTRUCT Coders' Manual.

    ERIC Educational Resources Information Center

    Friend, Jamesine

    The coding language INSTRUCT is a high-level programing language designed for programing computer-assisted instruction lessons. As it is presently implemented on the PDP-10 computer, a "lesson processor" transforms the INSTRUCT lessons into a numeric code that can be understood by a teaching program called INST. INST controls the…

  16. Influence of Morphological Characteristics on Physical and Physiological Performances of Tunisian Elite Male Handball Players

    PubMed Central

    Moncef, Cherif; Said, Mohamed; Olfa, Najlaoui; Dagbaji, Gomri

    2012-01-01

    Purpose The purpose of this study was to describe the body structure and morphological characteristics of Tunisian elite handball players, and to determine the effect of these variables on functional and physical performance levels. Methods A sample of 42 male handball players (mean age 21.98±3.24 years; training duration 12 years) at international level was submitted to a test battery comprising morphological, physical and physiological assessments. Tests were yo-yo intermittent recovery test, squat jump test, countermovement jump test, vertical-jump test, and Repeated sprint Ability. Measures for assessment of anthropometric characteristics were age, size, weight, body mass index, body fat, fat mass and thin mass. Results Weight was negatively correlated to the squat jump and the countermovement jump performance. Age, weight, and body composition measures (fat and thin body mass) were additionally negatively related to the maximal oxygen uptake, and to the maximal velocity obtained in the Yo-Yo recovery test. No relationship was found between size, body mass index, body fat and the physical abilities considered. Concerning the effects of physical characteristics on the functional performances, we can note a positive relationship between squat jump, countermovement jump, and the yo-yo recovery test performance. No relationship was found between vertical jump, repeated sprint ability, and the physiological performances. Conclusions Study results point to the existence of strong correlation between morphological and physical characteristics with functional characteristics. In handball, it is possible to have a reliable estimate of anthropometric measurements, physical and physiological performances. PMID:22942992

  17. Characteristics influencing weight reduction among veterans in the MOVE!® Program.

    PubMed

    Garvin, Jane T; Marion, Lucy N; Narsavage, Georgia L; Finnegan, Lorna

    2015-01-01

    Obesity is a common health problem for veterans. This study explored background and program characteristics associated with a 5% weight reduction for veterans enrolled in MOVE!(®), a weight management program. For data analysis, 404 veteran records were examined using logistic regression. Background characteristics included socio-demographic variables, comorbidity, body mass index, rurality, and Veterans Administration (VA) priority group. Program characteristics included the program type (group attendee or self-managed) as well as the number and type of provider contacts. Thirteen percent of participants achieved a 5% weight reduction. Age in years (odds ratio [OR] = 1.04) and the number of group visits (OR = 1.05) were significant predictors for achieving a 5% weight reduction. Given the importance of weight reduction, health professionals should consider these significant predictors when planning weight-reduction programs for veterans.

  18. Laws of Influence of Structural Characteristics on the Strength and Crack Resistance of Aging Metallic Materials

    NASA Astrophysics Data System (ADS)

    Nizhnik, S. B.; Usikova, G. I.

    2005-01-01

    The structural characteristics (the volume fraction, size, and shape of and the distance among hardening-phase particles) of aging alloys and steels, which define the behavior of the critical stress intensity factor during thermal hardening, are determined using the structural-mechanical approach we have developed. It is experimentally demonstrated for maraging steels that our approach is capable of proving the correlations of strength, plasticity, and crack- resistance with the structural characteristics, which were varied by changing the chemical composition of steel and thermokinetic aging conditions

  19. Influence of immobilization strategies on biosensing response characteristics: A comparative study.

    PubMed

    Kaur, Gurpreet; Saha, Shibu; Tomar, Monika; Gupta, Vinay

    2016-01-01

    The immobilization technique plays an important role in fabrication of a biosensor. NiO based cholesterol biosensor has been used to study the effect of various immobilization techniques on the biosensing response characteristics. The biosensors were fabricated by immobilizing cholesterol oxidase on NiO thin films by three different immobilization techniques viz. physisorption, cross-linking and covalent binding. The study reveals a strong dependence of biosensing response on corresponding immobilization technique. The biosensor based on immobilization by covalent bonding shows superior response characteristics as compared to others owing to its zero length. The results highlight the significance of immobilization technique for biosensor fabrication.

  20. The influence of collagen fiber orientation and other histocompositional characteristics on the mechanical properties of equine cortical bone.

    PubMed

    Skedros, John G; Dayton, Michael R; Sybrowsky, Christian L; Bloebaum, Roy D; Bachus, Kent N

    2006-08-01

    This study examined relative influences of predominant collagen fiber orientation (CFO), mineralization (% ash), and other microstructural characteristics on the mechanical properties of equine cortical bone. Using strain-mode-specific (S-M-S) testing (compression testing of bone habitually loaded in compression; tension testing of bone habitually loaded in tension), the relative mechanical importance of CFO and other material characteristics were examined in equine third metacarpals (MC3s). This model was chosen since it had a consistent non-uniform strain distribution estimated by finite element analysis (FEA) near mid-diaphysis of a thoroughbred horse, net tension in the dorsal/lateral cortices and net compression in the palmar/medial cortices. Bone specimens from regions habitually loaded in tension or compression were: (1) tested to failure in both axial compression and tension in order to contrast S-M-S vs non-S-M-S behavior, and (2) analyzed for CFO, % ash, porosity, fractional area of secondary osteonal bone, osteon cross-sectional area, and population densities of secondary osteons and osteocyte lacunae. Multivariate multiple regression analyses revealed that in S-M-S compression testing, CFO most strongly influenced total energy (pre-yield elastic energy plus post-yield plastic energy); in S-M-S tension testing CFO most strongly influenced post-yield energy and total energy. CFO was less important in explaining S-M-S elastic modulus, and yield and ultimate stress. Therefore, in S-M-S loading CFO appears to be important in influencing energy absorption, whereas the other characteristics have a more dominant influence in elastic modulus, pre-yield behavior and strength. These data generally support the hypothesis that differentially affecting S-M-S energy absorption may be an important consequence of regional histocompositional heterogeneity in the equine MC3. Data inconsistent with the hypothesis, including the lack of highly longitudinal collagen in the

  1. The influences of soil and nearby structures on dispersion characteristics of wave propagating along buried plastic pipes

    NASA Astrophysics Data System (ADS)

    Liu, Shuyong; Jiang, J.; Parr, Nicola

    2016-09-01

    Water loss in distribution systems is a global problem for the water industry and governments. According to the international water supply association (IWSA), as a result of leaks from distribution pipes, 20% to 30% of water is lost while in transit from treatment plants to consumers. Although governments have tried to push the water industry to reduce the water leaks, a lot of experts have pointed out that a wide use of plastic pipes instead of metal pipes in recent years has caused difficulties in the detection of leaks using current acoustic technology. Leaks from plastic pipes are much quieter than traditional metal pipes and comparing to metal pipes the plastic pipes have very different coupling characteristics with soil, water and surrounding structures, such as other pipes, road surface and building foundations. The dispersion characteristics of wave propagating along buried plastic pipes are investigated in this paper using finite element and boundary element based models. Both empty and water- filled pipes were considered. Influences from nearby pipes and building foundations were carefully studied. The results showed that soil condition and nearby structures have significant influences on the dispersion characteristics of wave propagating along buried plastic pipes.

  2. Influence of infrared stimulation on spectroscopy characteristics of co-planar grid CdZnTe detectors

    SciTech Connect

    Fjodorov, V.; Ivanov, V.; Loutchanski, A.

    2015-07-01

    It was previously found that illumination with monochromatic infrared (IR) light with wavelengths close to the absorption edge of the CdZnTe exert significant positive influence on the spectrometric characteristics of quasi-hemispherical CdZnTe detectors at room temperature. In this paper, preliminary results of IR stimulation on the spectrometric characteristics of coplanar-grid CdZnTe detectors as well as results of further studies of planar and quasi-hemispherical detectors are presented. Coplanar-grid detectors of 10 mm x 10 mm x 10 mm from Redlen Technologies and commercial available IR LEDs with different wavelengths of 800-1000 nm were used in the experiments. Influence of intensity and direction of IR illumination on the detector's characteristics was studied. Analysis of signals shapes from the preamplifiers outputs at registration of alpha particles showed that IR illumination leads to a change in the shapes of these signals. This may indicate changes in electric fields distributions. An improvement in energy resolution at gamma-energy of 662 keV was observed with quasi-hemispherical and co-planar detectors at the certain levels of IR illumination intensity. The most noticeable effect of IR stimulation was observed with quasi-hemispherical detectors. It is due with optimization of charge collection conditions in the quasi-hemispherical detectors under IT stimulation. (authors)

  3. Influence of lactation stage and some flock management practices on sensory characteristics of goat milk from Brazilian Saanen breed.

    PubMed

    de Cássia Ramos do Egypto Queiroga, Rita; Costa, Roberto Germano; Madruga, Marta Suely; de Medeiros, Ariosvaldo Nunes; Dos Santos Garruti, Deborah; Magnani, Marciane; de Souza, Evandro Leite

    2016-04-01

    This study evaluated the influence of lactation stage (early, middle, late) and management practices (milking hygiene and buck presence) on the sensory attributes of Saanen goat milk. Goats were randomly divided in four groups in respect of different milking sanitary procedures and the presence/absence of the buck in the barn. Milk samples were analyzed for sensory attributes including quantitative descriptive analysis (QDA) and acceptance. The milking hygiene practice caused no significant influence on microbiological parameters. Results of QDA revealed that the buck presence increased the characteristic odor of milk at the middle and late lactation stages. The off-odor and off-flavor descriptors showed a distinct response since a higher intensity of these sensory characteristics was noted in the samples obtained from goats maintained without the buck. Odor and flavor contributed most in characterizing the different samples regardless of the management practice and lactation stage. The acceptance of odor showed to be influenced only by the lactation stage, while the acceptance of flavor was only through the presence of the buck. Odor acceptance correlated negatively to off-odor and off-flavor, suggesting that these two sensory attributes impaired the preference for the aroma of the milk samples.

  4. The Influence of Student Characteristics on the Use of Adaptive E-Learning Material

    ERIC Educational Resources Information Center

    van Seters, J. R.; Ossevoort, M. A.; Tramper, J.; Goedhart, M. J.

    2012-01-01

    Adaptive e-learning materials can help teachers to educate heterogeneous student groups. This study provides empirical data about the way academic students differ in their learning when using adaptive e-learning materials. Ninety-four students participated in the study. We determined characteristics in a heterogeneous student group by collecting…

  5. Influences of Natural Menopause on Psychological Characteristics and Symptoms of Middle-Aged Healthy Women.

    ERIC Educational Resources Information Center

    Matthews, Karen A.; And Others

    1990-01-01

    Investigated psychological and symptom consequences of natural menopause in longitudinal study of 541 initially premenopausal healthy women. Findings 3 years later from 101 menopausal women and control group of 101 premenopausal women revealed that natural menopause led to few changes in psychological characteristics, with only decline in…

  6. Energy Systems of Ukraine: Characteristics, Dependence and Influence on Economic and Political Self-Determination

    DTIC Science & Technology

    2005-06-01

    CHARACTERISTICS OF THE COAL MINING INDUSTRY .................6 D. ELECTRICITY PRODUCTION AND CONSUMPTION IN UKRAINE...divided onto four parts: oil production, consumption, and oil transit; natural gas production, consumption, and gas transit; coal mining industry ; and... mining industry was completely state-owned and had been managed by the vertical structure of numerous state

  7. Teacher-Child Relationships in Prekindergarten: The Influences of Child and Teacher Characteristics

    ERIC Educational Resources Information Center

    Koles, Bernadett; O'Connor, Erin; McCartney, Kathleen

    2009-01-01

    The purpose of the current study was to investigate child and teacher characteristics associated with closeness and conflict in prekindergarten teacher-child relationships. Child gender and temperament were significantly associated with closeness and conflict. Specifically, higher levels of shyness correlated with closer relationships for boys…

  8. [Influence of human body target's spectral characteristics on visual range of low light level image intensifiers].

    PubMed

    Zhang, Jun-Ju; Yang, Wen-Bin; Xu, Hui; Liu, Lei; Tao, Yuan-Yaun

    2013-11-01

    To study the effect of different human target's spectral reflective characteristic on low light level (LLL) image intensifier's distance, based on the spectral characteristics of the night-sky radiation and the spectral reflective coefficients of common clothes, we established a equation of human body target's spectral reflective distribution, and analyzed the spectral reflective characteristics of different human targets wearing the clothes of different color and different material, and from the actual detection equation of LLL image intensifier distance, discussed the detection capability of LLL image intensifier for different human target. The study shows that the effect of different human target's spectral reflective characteristic on LLL image intensifier distance is mainly reflected in the average reflectivity rho(-) and the initial contrast of the target and the background C0. Reflective coefficient and spectral reflection intensity of cotton clothes are higher than polyester clothes, and detection capability of LLL image intensifier is stronger for the human target wearing cotton clothes. Experimental results show that the LLL image intensifiers have longer visual ranges for targets who wear cotton clothes than targets who wear same color but polyester clothes, and have longer visual ranges for targets who wear light-colored clothes than targets who wear dark-colored clothes. And in the full moon illumination conditions, LLL image intensifiers are more sensitive to the clothes' material.

  9. Investigating the Influence of Professor Characteristics on Student Satisfaction and Dissatisfaction: A Comparative Study

    ERIC Educational Resources Information Center

    Gruber, Thorsten; Lowrie, Anthony; Brodowsky, Glen H.; Reppel, Alexander E.; Voss, Roediger; Chowdhury, Ilma Nur

    2012-01-01

    This research uses the Kano model of satisfaction to investigate professor characteristics that create student satisfaction as well as those attributes that can cause their dissatisfaction. Kano questionnaires were handed out to 104 undergraduate students at a university in the Southwest and to 147 undergraduate students at a university in the…

  10. Characteristics of Abuse that Influence When Adults Molested as Children Seek Treatment.

    ERIC Educational Resources Information Center

    Kendall-Tackett, Kathleen A.

    This study explored the relationship between characteristics of abuse and time before seeking treatment for adults molested as children. Those who sought early treatment were called early presenters; those who sought treatment later in life were called late presenters. Data were collected from intake interviews of 364 adults molested as children.…

  11. Cultural Factors in Decision-Making about Child Physical Abuse: Identifying Reporter Characteristics Influencing Reporting Tendencies

    ERIC Educational Resources Information Center

    Ibanez, Elizabeth S.; Borrego, Joaquin, Jr.; Pemberton, Joy R.; Terao, Sherri

    2006-01-01

    Objective: This study examined cultural factors that may influence child physical abuse reporting. Relevant cultural factors such as the respondents' ethnic identity and corporal punishment acceptability were investigated as proximal variables of ethnicity that affect child physical abuse reporting tendencies. Method: Participants consisted of 378…

  12. Self-Other Agreement in Multisource Feedback: The Influence of Doctor and Rater Group Characteristics

    ERIC Educational Resources Information Center

    Roberts, Martin J.; Campbell, John L.; Richards, Suzanne H.; Wright, Christine

    2013-01-01

    Introduction: Multisource feedback (MSF) ratings provided by patients and colleagues are often poorly correlated with doctors' self-assessments. Doctors' reactions to feedback depend on its agreement with their own perceptions, but factors influencing self-other agreement in doctors' MSF ratings have received little attention. We aimed to identify…

  13. Long-term influence of normal variation in neonatal characteristics on human brain development

    PubMed Central

    Walhovd, Kristine B.; Fjell, Anders M.; Brown, Timothy T.; Kuperman, Joshua M.; Chung, Yoonho; Hagler, Donald J.; Roddey, J. Cooper; Erhart, Matthew; McCabe, Connor; Akshoomoff, Natacha; Amaral, David G.; Bloss, Cinnamon S.; Libiger, Ondrej; Schork, Nicholas J.; Darst, Burcu F.; Casey, B. J.; Chang, Linda; Ernst, Thomas M.; Frazier, Jean; Gruen, Jeffrey R.; Kaufmann, Walter E.; Murray, Sarah S.; van Zijl, Peter; Mostofsky, Stewart; Dale, Anders M.; Jernigan, Terry L.; McCabe, Connor; Chang, Linda; Akshoomoff, Natacha; Newman, Erik; Dale, Anders M.; Ernst, Thomas; Dale, Anders M.; Van Zijl, Peter; Kuperman, Joshua; Murray, Sarah; Bloss, Cinnamon; Schork, Nicholas J.; Appelbaum, Mark; Gamst, Anthony; Thompson, Wesley; Bartsch, Hauke; Jernigan, Terry L.; Dale, Anders M.; Akshoomoff, Natacha; Chang, Linda; Ernst, Thomas; Keating, Brian; Amaral, David; Sowell, Elizabeth; Kaufmann, Walter; Van Zijl, Peter; Mostofsky, Stewart; Casey, B.J.; Ruberry, Erika J.; Powers, Alisa; Rosen, Bruce; Kenet, Tal; Frazier, Jean; Kennedy, David; Gruen, Jeffrey

    2012-01-01

    It is now recognized that a number of cognitive, behavioral, and mental health outcomes across the lifespan can be traced to fetal development. Although the direct mediation is unknown, the substantial variance in fetal growth, most commonly indexed by birth weight, may affect lifespan brain development. We investigated effects of normal variance in birth weight on MRI-derived measures of brain development in 628 healthy children, adolescents, and young adults in the large-scale multicenter Pediatric Imaging, Neurocognition, and Genetics study. This heterogeneous sample was recruited through geographically dispersed sites in the United States. The influence of birth weight on cortical thickness, surface area, and striatal and total brain volumes was investigated, controlling for variance in age, sex, household income, and genetic ancestry factors. Birth weight was found to exert robust positive effects on regional cortical surface area in multiple regions as well as total brain and caudate volumes. These effects were continuous across birth weight ranges and ages and were not confined to subsets of the sample. The findings show that (i) aspects of later child and adolescent brain development are influenced at birth and (ii) relatively small differences in birth weight across groups and conditions typically compared in neuropsychiatric research (e.g., Attention Deficit Hyperactivity Disorder, schizophrenia, and personality disorders) may influence group differences observed in brain parameters of interest at a later stage in life. These findings should serve to increase our attention to early influences. PMID:23169628

  14. Demographic Characteristics of Ghanaian Optometry Students and Factors Influencing Their Career Choice and Institution of Learning

    ERIC Educational Resources Information Center

    Boadi-Kusi, Samuel Bert; Kyei, Samuel; Mashige, Khathutshelo Percy; Abu, Emmanuel Kwasi; Antwi-Boasiako, Daniel; Halladay, Abraham Carl

    2015-01-01

    Optometry is only provided at tertiary level in two institutions in Ghana, with an average of 50 students graduating each year for a population of approximately 24.6 million. No information on the demography of optometry students and factors that influence their choice of optometry as a career and institution of learning is available. This…

  15. Selective Influence of Circadian Modulation and Task Characteristics on Motor Imagery Time

    ERIC Educational Resources Information Center

    Debarnot, Ursula; Sahraoui, Djafar; Champely, Stephane; Collet, Christian; Guillot, Aymeric

    2012-01-01

    In this study, we examined the effect of circadian modulation on motor imagery (MI) time while also considering the effects of task complexity and duration. The ability to imagine in real time was influenced by circadian modulation in a simple walking condition, with longer MI times in the morning and evening sessions. By contrast, there was no…

  16. Influence of Teacher Characteristics on Affective Evaluation of Social Studies Teachers in Nigeria

    ERIC Educational Resources Information Center

    Otote, Celia O.; Omo-Ojugo, Matthew

    2009-01-01

    Nigerian secondary schools are under pressure to make their impact on society through the development of values that promote civic responsibility (Iyamu and Otote, 2003). Nwankwo (2000) posits that human attitude is the greatest dimension of any national development issue. Education is one of the active media for influencing this attitude. The…

  17. Characteristics of Interactive Oral and Computer-Mediated Peer Group Talk and Its Influence on Revision.

    ERIC Educational Resources Information Center

    Hewett, Beth L.

    2000-01-01

    Details a functional and qualitative study of interactive oral and computer-mediated communication (CMC)-generated (Norton "Connect") peer response group talk and its influence on revision. Finds the interactive peer groups in both environments talked primarily about their writing; however, the talk had different qualities when students used…

  18. Black Deaf Individuals' Reading Skills: Influence of ASL, Culture, Family Characteristics, Reading Experience, and Education

    ERIC Educational Resources Information Center

    Myers, Candace; Clark, M. Diane; Musyoka, Millicent M.; Anderson, Melissa L.; Gilbert, Gizelle L.; Agyen, Selina; Hauser, Peter C.

    2010-01-01

    Previous research on the reading abilities of Deaf individuals from various cultural groups suggests that Black Deaf and Hispanic Deaf individuals lag behind their White Deaf peers. The present study compared the reading skills of Black Deaf and White Deaf individuals, investigating the influence of American Sign Language (ASL), culture, family…

  19. The Influence of Students' Loans Borrowers' Characteristics on Default Rate in Tanzania

    ERIC Educational Resources Information Center

    Nyahende, Veronica R.

    2013-01-01

    The cost of students' loans defaulting has lead to a serious discussion among participants. Substantial attention has been made on the students' loans and its impact on higher education finances while researches on students' loans defaults have not been taken for more than a decade. Therefore this study examines the influence of student loans…

  20. Characteristics of the Human Host Have Little Influence on Which Local Schistosoma mansoni Populations Are Acquired

    PubMed Central

    Barbosa, Lúcio M.; Silva, Luciano K.; Reis, Eliana A.; Azevedo, Theomira M.; Costa, Jackson M.; Blank, Walter A.; Reis, Mitermayer G.; Blanton, Ronald E.

    2013-01-01

    Background Brazil remains the country in the Americas with the highest prevalence of schistosomiasis. A combination of control efforts and development, however, has sharply reduced its intensity and distribution. The acquisition of specific schistosome populations may be dependent on host characteristics such as sex, age, geography, work, habits and culture. How these and other host characteristics align with parasite subpopulations may guide approaches to improve control. Methodology A cohort of more than 90% of the residents in two rural communities in Brazil participated in an epidemiologic survey of demographic, socio-economic and behavioral characteristics. The variables sex, age, intensity of infection, socio-economic index, % lifetime spent on site, previous infection, and trips outside the district were used to group parasites infecting individuals. Schistosoma mansoni infection status was determined by examination of stools submitted on 3 different days. The aggregate of eggs collected from the whole stool was used to determine degree of population differentiation from allele frequencies for 15 microsatellites. Conclusions/Significance Infection prevalence was 41% for these communities, and the epidemiologic characteristics were similar to many of the endemic areas of Brazil and the world. Parasite population structuring was observed between the two communities (Jost's D 0.046, CI95% 0.042–0.051), although separated by only 8 km and connected by a highway. No structuring was observed when infected individuals were stratified by host's biologic, demographic or epidemiologic characteristics. Those most heavily infected best reflected the communities' overall parasite diversity. The lack of differentiation within villages suggests that individuals are likely to get infected at the same sites or that the same parasite multilocus genotypes can be found at most sites. The geographic structuring between villages and the lack of structuring by age of the host

  1. Influence of lipid extraction process on the rheological characteristics, swelling power, and granule size of rice starches in excess water.

    PubMed

    Kar, Aditi; Jacquier, Jean-Christophe; Morgan, Desmond J; Lyng, James G; McKenna, Brian M

    2005-10-19

    The influence of the lipid extraction process on both macroscopic and microscopic characteristics of nonwaxy rice starch gelatinization in excess water was examined. Surface lipids extraction did not change the thermodynamics of starch gelatinization but lead to a significant reduction (33%) in the enthalpy of starch-lipid complex melting at high temperature, resulting in less viscous dispersions. Internal lipid extraction using hot aqueous alcoholic solutions resulted in an irreversible increase in starch granule diameter (50% increase in D[4,3]) and a dramatic change in cooking characteristics of the starch. Instead of the bimodal swelling observed for native nonwaxy rice starch, only one broad transition in swelling, solubility, granule size, and viscosity was observed in the case of the totally defatted starch. While the total removal of lipids resulted in a slight increase in starch swelling at intermediate temperatures, the harshness of the process caused irreparable changes leading to notably lower swelling at high temperatures.

  2. Influence of surface charge on the transport characteristics of nanowire-field effect transistors in liquid environments

    SciTech Connect

    Nozaki, Daijiro E-mail: research@nano.tu-dresden.de; Kunstmann, Jens; Zörgiebel, Felix; Cuniberti, Gianaurelio

    2015-05-18

    One dimensional nanowire field effect transistors (NW-FETs) are a promising platform for sensor applications. The transport characteristics of NW-FETs are strongly modified in liquid environment due to the charging of surface functional groups accompanied with protonation or deprotonation. In order to investigate the influence of surface charges and ionic concentrations on the transport characteristics of Schottky-barrier NW-FETs, we have combined the modified Poisson-Boltzmann theory with the Landauer-Büttiker transport formalism. For a typical device, the model is able to capture the reduction of the sensitivity of NW-FETs in ionic solutions due to the screening from counter ions as well as a local gating from surface functional groups. Our approach allows to model, to investigate, and to optimize realistic Schottky-barrier NW-FET devices in liquid environment.

  3. Influence of the chopped frequency of light on optical transport characteristics of human skin including at acupuncture points

    NASA Astrophysics Data System (ADS)

    Yang, Hong-qin; Xie, Shu-sen; Liu, Song-hao; Li, Hui; Wang, Yu-hua; Guo, Zhou-yi

    2007-11-01

    An experimental protocol was established for noninvasively measuring the optical transport characteristics of skin tissue along human meridian direction over body surface including at acupuncture points. The diffuse remittance for 658 nm light radiation along the pericardium meridian and non-meridian directions were measured respectively. The influence of the chopped frequency of light on the detected light signal was investigated. It is shown that the optical transport characteristics of skin tissue accords with the Beer's exponential attenuation law along the meridian including at acupuncture points and non-median directions. However there is an obvious difference between the propagations along the meridian direction and non-meridian direction (P<0.05). Furthermore, the chopped frequency can affect the detected signal. The diffuse remittance signal decreased with the chopped frequency's increase and it was different between the meridian and non-meridian directions. These findings are important and meaningful for interpreting the human meridian phenomena by biomedical optics.

  4. Experimental Study of the Influence of the Concentration of Organic Water-Coal Fuel Components on the Integral Ignition Characteristics

    NASA Astrophysics Data System (ADS)

    Vershinina, K. Yu.; Kuznetsov, G. V.; Strizhak, P. A.

    2017-01-01

    To enlarge the power raw material base, the processes of stable initiation of combustion of drops of organic watercoal fuels have been investigated. For the main components, we used filter cakes (coal processing waste), anthracite, bituminous and brown coals of brands D and B2, water, and spent machine, turbine, and transformer oils. We have established the influence of concentrations of components on the minimum (limiting) ignition temperatures of organic water-coal fuels and the ignition delay times of drops of fuel components with initial sizes of 0.25-1.5 mm. Investigations were carried out for oxidizer temperatures of 600-1100 K and its velocities of 0.5-5 m/s characteristic of units, aggregates, and large and small power plants. We have determined the characteristic differences of organic water-coal fuel from water-coal fuel and the close laws of the investigated processes for these fuels.

  5. The influence of carbon and oxygen on the magnetic characteristics of press-less sintered NdFeB magnets

    NASA Astrophysics Data System (ADS)

    Xia, M.; Abrahamsen, A. B.; Bahl, C. R. H.; Veluri, B.; Søegaard, A. I.; Bøjsøe, P.; Millot, S.

    2017-01-01

    The Pressless Process (PLP) was adopted to manufacture NdFeB sintered magnets, where the investigations on carbon and oxygen residues from heptane milling liquid media and graphite crucibles used for sintering were quantified to evaluate the influence on the magnetic characteristics. The carbon and oxygen content in the magnets produced from wet ball milling of strip cast flakes was found to be of the order 104 ppm and 4·104 ppm respectively, which resulted in soft magnetic behavior. However using jet milling the carbon and oxygen concentration were decreased by an order of magnitude resulting in coercivity of up to 829 kA/m. Thus the influence of the carbon from the graphite crucibles is small.

  6. From left to right: how the personality system allows basic traits to influence politics via characteristic moral adaptations.

    PubMed

    Lewis, Gary J; Bates, Timothy C

    2011-08-01

    Research on the association of personality to political orientation has suggested that direct influences are modest. Here we used a personality system model in which direct influences on political behaviour flow from moral values, with personality mostly acting on these characteristic moral adaptations, rather than directly affecting political attitudes. Study 1 in 447 subjects supported this model, with significant effects on political orientation flowing from four of the five-factor model personality domains, but largely mediated through moral values concerning the importance of group order and individual rights. This personality system model was replicated in an independent study (n= 476) using a US sample and including a different measure of politics. Both studies support predictions that personality has significant effects on political attitudes, but that these are exerted largely via moral values. These findings help to explain inconsistencies in previous studies attempting to link personality to political orientation that have not included the intermediary level of values.

  7. Influence of feedstock chemical composition on product formation and characteristics derived from the hydrothermal carbonization of mixed feedstocks.

    PubMed

    Lu, Xiaowei; Berge, Nicole D

    2014-08-01

    As the exploration of the carbonization of mixed feedstocks continues, there is a distinct need to understand how feedstock chemical composition and structural complexity influence the composition of generated products. Laboratory experiments were conducted to evaluate the carbonization of pure compounds, mixtures of the pure compounds, and complex feedstocks comprised of the pure compounds (e.g., paper, wood). Results indicate that feedstock properties do influence carbonization product properties. Carbonization product characteristics were predicted using results from the carbonization of the pure compounds and indicate that recovered solids energy contents are more accurately predicted than solid yields and the carbon mass in each phase, while predictions associated with solids surface functional groups are more difficult to predict using this linear approach. To more accurately predict carbonization products, it may be necessary to account for feedstock structure and/or additional feedstock properties.

  8. Influence of boron doping on magnetic properties and microwave characteristics of MnIr/FeCoB multilayers

    SciTech Connect

    Phuoc, Nguyen N.; Ong, C. K.

    2012-04-15

    A detailed investigation of the influence of B doping on the magnetic properties and high frequency characteristics of FeCoB/MnIr multilayered thin films was carried out. Exchange bias was found to decrease monotonically with B doping possibly due to less favorable of AF phase of MnIr in the samples with rich B concentration. However, with small amount of doping up to 9% of B concentration, the MnIr fcc (111) peaks become more prominent and the real part of permeability enhanced. Our results suggest no correlation between the structural phase of MnIr and the exchange bias. Also, the influences of B doping on several static and dynamic parameters, such as rotational magnetic anisotropy field, coercivity, saturation magnetization, resonance frequency, and effective damping factor are presented and discussed. Our results support the claim that the coercivity enhancement and the arising of rotational anisotropy may have the same physical origin.

  9. Flow-Field Characteristics of High-Temperature Annular Buoyant Jets and Their Development Laws Influenced by Ventilation System

    PubMed Central

    Liu, Jiaping; Wang, Hai; Liu, Qiuhan

    2013-01-01

    The flow-field characteristics of high-temperature annular buoyant jets as well as the development laws influenced by ventilation system were studied using numerical methods to eliminate the pollutants effectively in this paper. The development laws of high-temperature annular buoyant jets were analyzed and compared with previous studies, including radial velocity distribution, axial velocity and temperature decay, reattachment position, cross-section diameter, volumetric flow rate, and velocity field characteristics with different pressures at the exhaust hood inlet. The results showed that when the ratio of outer diameter to inner diameter of the annulus was smaller than 5/2, the flow-field characteristics had significant difference compared to circular buoyant jets with the same outer diameter. For similar diameter ratios, reattachment in this paper occurred further downstream in contrast to previous study. Besides, the development laws of volumetric flow rate and cross-section diameter were given with different initial parameters. In addition, through analyzing air distribution characteristics under the coupling effect of high-temperature annular buoyant jets and ventilation system, it could be found that the position where maximum axial velocity occurred was changing gradually when the pressure at the exhaust hood inlet changed from 0 Pa to −5 Pa. PMID:24000278

  10. Influence of the MgO barrier thickness on the lifetime characteristics of magnetic tunnelling junctions for sensors

    NASA Astrophysics Data System (ADS)

    Conca, A.; Casper, F.; Paul, J.; Lehndorff, R.; Jakob, G.; Kläui, M.; Hillebrands, B.; Leven, B.

    2016-06-01

    Magnetic tunnelling junctions increasingly enter the market for magnetic sensor applications. Thus, technological parameters such as the lifetime characteristics become more and more important. Here, an analysis of the lifetime characteristics of magnetic tunnelling junctions using the Weibull statistical distribution for CoFeB/MgO/CoFeB junctions is presented. The Weibull distribution is governed by two parameters, the characteristic lifetime η of the population and the shape parameter β, which gives information about the presence of an infant mortality. The suitability of the Weibull distribution is demonstrated for the description of dielectric breakdown processes in MgO-based tunnelling junctions at different voltages. A study of the dependence of the characteristic lifetime extrapolated to the low voltage regime, and the β parameter on the nominal barrier thickness and the resistance  ×  area product of the MgO barrier is shown. The influence of the RF deposition power for the MgO barrier and an annealing step on the Weibull parameters is also discussed.

  11. Flow-field characteristics of high-temperature annular buoyant jets and their development laws influenced by ventilation system.

    PubMed

    Wang, Yi; Huang, Yanqiu; Liu, Jiaping; Wang, Hai; Liu, Qiuhan

    2013-01-01

    The flow-field characteristics of high-temperature annular buoyant jets as well as the development laws influenced by ventilation system were studied using numerical methods to eliminate the pollutants effectively in this paper. The development laws of high-temperature annular buoyant jets were analyzed and compared with previous studies, including radial velocity distribution, axial velocity and temperature decay, reattachment position, cross-section diameter, volumetric flow rate, and velocity field characteristics with different pressures at the exhaust hood inlet. The results showed that when the ratio of outer diameter to inner diameter of the annulus was smaller than 5/2, the flow-field characteristics had significant difference compared to circular buoyant jets with the same outer diameter. For similar diameter ratios, reattachment in this paper occurred further downstream in contrast to previous study. Besides, the development laws of volumetric flow rate and cross-section diameter were given with different initial parameters. In addition, through analyzing air distribution characteristics under the coupling effect of high-temperature annular buoyant jets and ventilation system, it could be found that the position where maximum axial velocity occurred was changing gradually when the pressure at the exhaust hood inlet changed from 0 Pa to -5 Pa.

  12. Study on the influence of back blade shape on the wear characteristics of centrifugal slurry pump

    NASA Astrophysics Data System (ADS)

    Cai, X.; Zhou, S. P.; Li, S.

    2016-05-01

    CFX particle inhomogeneous model was introduced for the mechanism analysis of a centrifugal slurry pump which is equipped with back blades on impeller shrouds. Combining with the total efficiency correction, the simulation showed good prediction accuracy of external characteristics results compared with the experimental values. Vorticity and Q-Criterion were chosen as the variables to illustrate the abrasion morphology and wear mechanism by contrasting simulation result with worn impeller in engineering. The analysis showed that the large vorticity intensity areas are distributed at the edge of impeller shroud and intensively behind the back blades. Moreover, the vorticity scattered on suction surface of back blade shows the largest intensity. The contour of Q-Criterion demonstrated that the swirl scale in front cavity is obviously larger than that in back cavity. The distribution of vorticity on both front and back shrouds can reasonably explain the impeller wear characteristics. Finally, the forward curved back blade proved to be excellence performance in vorticity distribution.

  13. Influence of the physicochemical characteristics of pollutants on their uptake in moss

    NASA Astrophysics Data System (ADS)

    Varela, Z.; Fernández, J. A.; Real, C.; Carballeira, A.; Aboal, J. R.

    2015-02-01

    Bryophytes are commonly used as biomonitors to estimate the atmospheric deposition of heavy metals and metalloids. However, the tissue concentrations of these elements in moss do not always accurately reflect atmospheric levels. The aim of the present study was to investigate whether element uptake in moss is affected by the physicochemical characteristics of the elements. Factor analysis was used to identify any patterns of covariance in the accumulation of elements in samples of the moss Pseudoscleropodium purum collected from the surroundings of different factories and from control sites. The variation in the concentrations of elements was similar in moss from both types of sites and was related to the binding properties of the elements. This suggests that the physicochemical characteristics of the elements determine the uptake of metals and metalloids from the atmosphere. Therefore, in studies that use multiple correlations among elements as indicators of a common origin of contaminants, erroneous conclusions may be reached by overlooking the adsorption properties of the moss.

  14. Safety in passenger ships: The influence of environmental design characteristics on people's perception of safety.

    PubMed

    Ahola, Markus; Mugge, Ruth

    2017-03-01

    Although objective safety is a widely studied topic in ergonomics, subjective safety has received far less research attention. Nevertheless, most of human decision-making and behavior depends on how we perceive our environment. This study investigates the effects of various environmental design characteristics on people's safety perception in a passenger ship context. Five different environmental design characteristics were manipulated to increase the openness of the space or to create more clear navigation, resulting in 20 different cabin corridors for a passenger ship. Ninety-seven respondents were asked to rate these corridors on the perceived safety in an experiment. The results showed that people feel more safe when the corridors have a curved ceiling, when the walls do not have a split-level design, and when there is a view to the outside. Designers can use these insights when designing future environments.

  15. The Influence of Carbon Nanofillers on Structure-Sensitive Characteristics of a Polyurethane-Base Resistive Composite

    NASA Astrophysics Data System (ADS)

    Potekaev, A. I.; Malinovskaya, T. D.; Melentyev, S. V.; Shulepov, I. A.

    2016-10-01

    The effect of the nature of carbon nanofillers on the structure-sensitive characteristics of resistive composites with polyurethane binders is investigated. The influence of the size, shape, concentration of carbon nanofibers (K-163 channel black, GE-3 graphite element, C-1 colloid graphite) and the method of their introduction into the binder on the formation of an electrically conductive mesh in the structure of the composite is identified. It is experimentally found that an introduction of C-1 colloid graphite ensures optimal parameters of specific volume resistivity, hardness, and adhesion strength, as well as low values of the percolation threshold.

  16. Computational assessment of the influence of the overlap ratio on the power characteristics of a Classical Savonius wind turbine

    NASA Astrophysics Data System (ADS)

    Kacprzak, Konrad; Sobczak, Krzysztof

    2015-09-01

    An influence of the overlap on the performance of the Classical Savonius wind turbine was investigated. Unsteady two-dimensional numerical simulations were carried out for a wide range of overlap ratios. For selected configurations computation quality was verified by comparison with three-dimensional simulations and the wind tunnel experimental data available in literature. A satisfactory agreement was achieved. Power characteristics were determined for all the investigated overlap ratios for selected tip speed ratios. Obtained results indicate that the maximum device performance is achieved for the buckets overlap ratio close to 0.

  17. Influences of Models on the Unsteady Pressure Characteristics of the NASA National Transonic Facility

    NASA Technical Reports Server (NTRS)

    Jones, Gregory; Balakrishna, Sundareswara; DeMoss, Joshua; Goodliff, Scott; Bailey, Matthew

    2015-01-01

    Pressure fluctuations have been measured over the course of several tests in the National Transonic Facility to study unsteady phenomenon both with and without the influence of a model. Broadband spectral analysis will be used to characterize the length scales of the tunnel. Special attention will be given to the large-scale, low frequency data that influences the Mach number and force and moment variability. This paper will also discuss the significance of the vorticity and sound fields that can be related to the Common Research Model and will also highlight the comparisons to an empty tunnel configuration. The effectiveness of vortex generators placed at the interface of the test section and wind tunnel diffuser showed promise in reducing the empty tunnel unsteadiness, however, the vortex generators were ineffective in the presence of a model.

  18. The influence of imitated microgravity on the amyloplast structure, the composition and characteristics of potato minituber

    NASA Astrophysics Data System (ADS)

    Nedukha, O. M.; Kordyum, Ye. L.; Schnyukova, Ye. I.

    The influence of imitated microgravity (clinorotation, 2 rev/min) of long-term duration on the structural-functional organization of Solanum tuberosum L. (cv Adreta) minituber cells is studied. An essential influence on 45-day minituber size, on the content and composition of starch, on the solubility of starch in water and on the structure of amyloplasts in the storage parenchyma of potato minitubers is detected. The appearance of a fraction of "gigantic" amyloplasts in starch-storage parenchyma is observed during horizontal clinorotation of long-term duration. The correlation between the decrease of content amylose and the inhibition of starch solubility in water is detected under long-term clinorotation. The results point to some changes of the carbohydrate metabolism of potato storage organs under the effect of microgravity imitation.

  19. The Influence of Nursing Unit Characteristics on RN Vacancies in Specialized Hospice and Palliative Care.

    PubMed

    Lindley, Lisa C; Mixer, Sandra J; Cozad, Melanie J

    2016-07-01

    The nursing shortage is projected to intensify in the United States. Organizations providing specialized hospice and palliative care will be particularly hard hit. The purpose of our study was to examine the influence of the nursing unit on registered nurse (RN) vacancies and test the moderating role of recruitment strategies in perinatal hospices. We estimated the association between the nursing unit and RN vacancies and tested the interaction effects of recruitment strategies (signing bonus and recruitment bonus). Our findings showed that increasing RN unit size and nursing leadership directly affected vacancies and that recruitment bonuses had stronger influence on reducing vacancies than signing bonuses. The findings offer critical insights for hospice administrators in attracting nurses among specialized hospice and palliative care providers.

  20. Influences of rhythm- and timbre-related musical features on characteristics of music-induced movement.

    PubMed

    Burger, Birgitta; Thompson, Marc R; Luck, Geoff; Saarikallio, Suvi; Toiviainen, Petri

    2013-01-01

    Music makes us move. Several factors can affect the characteristics of such movements, including individual factors or musical features. For this study, we investigated the effect of rhythm- and timbre-related musical features as well as tempo on movement characteristics. Sixty participants were presented with 30 musical stimuli representing different styles of popular music, and instructed to move along with the music. Optical motion capture was used to record participants' movements. Subsequently, eight movement features and four rhythm- and timbre-related musical features were computationally extracted from the data, while the tempo was assessed in a perceptual experiment. A subsequent correlational analysis revealed that, for instance, clear pulses seemed to be embodied with the whole body, i.e., by using various movement types of different body parts, whereas spectral flux and percussiveness were found to be more distinctly related to certain body parts, such as head and hand movement. A series of ANOVAs with the stimuli being divided into three groups of five stimuli each based on the tempo revealed no significant differences between the groups, suggesting that the tempo of our stimuli set failed to have an effect on the movement features. In general, the results can be linked to the framework of embodied music cognition, as they show that body movements are used to reflect, imitate, and predict musical characteristics.

  1. Influence of person- and situation-specific characteristics on collision avoidance behavior in human locomotion.

    PubMed

    Knorr, Alexander G; Willacker, Lina; Hermsdörfer, Joachim; Glasauer, Stefan; Krüger, Melanie

    2016-09-01

    In everyday situations, pedestrians deploy successful strategies to avoid collisions with other persons crossing their paths. In this study, 2 experiments were conducted to investigate to what extent personal or situational characteristics affect role attribution and contribution to successful collision avoidance in human locomotion. Pairs of subjects walked at their natural speed from a start to a goal point. Walking paths were defined in such a way that subjects would collide halfway on their trajectory, if they did not actively avoid colliding by speed or path adjustments. In the first experiment, we investigated whether crossing order, path, and speed adjustments correlate with subject-specific parameters, such as gender, height, and personality traits. It is interesting that individuals' collision avoidance behavior was not correlated with any of these factors. In the second experiment, initial walking speed and heading were used to predict the crossing order. It was found that these 2 parameters are sufficient to estimate future role attribution with 95% confidence already 2.5 m before the crossing; that is, even before any collision avoidance behavior is initiated. In sum, this suggests that collision avoidance strategies in human locomotion are based on situational rather than on personal characteristics. These situational characteristics result in role attributions, which are highly predictable within and across pairs of pedestrians, whereby the role-dependent contribution of the pedestrian giving way is of greater relevance for successful collision avoidance. (PsycINFO Database Record

  2. [Characteristics and influencing factors of air pollution in and out of the highway toll gates].

    PubMed

    Chen, Ke-Jun; Chen, Ke-Liang; Zhang, Lan-Jun; Leng, Guang-Yi

    2007-08-01

    During June and July 2003, CO, NO2, THC and PM10 were sampled at the four highway toll gates in Chongqing. Air temperature, air pressure, wind velocity and traffic flow were also monitored simultaneously. The relation between air pollution parameters and influencing factors was analyzed by applying the methods of bivariate correlation and partial correlation. As shown in the monitoring result, the outdoor average concentrations of CO and PM10 exceed indoor ones, but NO2 and THC are reverse. The average concentrations of CO and NO2 at the toll gates don't exceed the indoor and outdoor air quality standards except for the toll gate in Chongqing and Chayuan. One-hour average concentrations of outdoor and indoor THC are 7.728 mg/m3 and 7.216 mg/m3 respectively, and exceed ten times of the indoor air quality standard. One-hour average concentrations of indoor and outdoor PM10 change acutely respectively, and the their maximum concentrations are 0.631 mg/m3 and 0.217 mg/m3 which exceed indoor air quality standard and the second class of ambient air quality standard. Polluting state of Chongqing toll is the worst among the four sampled tolls, and three indexes are bigger than others. Indoor and outdoor air pollutants have correlativity. Correlations of CO, PM10 and NO2 are significant at the 0.01 level respectively, and correlations between indoor and outdoor THC are significant at the 0.05 level. In the influencing factors analysis, traffic flow is significantly correlative with NO2, THC and PM10 (p < 0.01 or 0.01 < p < 0.05), and not significantly correlative with CO (p > 0.01). Air pressure and ambient temperature are predominating factors which influencing the concentration variation, and wind speed is a minor meteorological factor influencing the fluctuations of the data.

  3. Which histological characteristics of basal cell carcinomas influence the quality of optical coherence tomography imaging?

    NASA Astrophysics Data System (ADS)

    Mogensen, M.; Thrane, L.; Joergensen, T. M.; Nürnberg, B. M.; Jemec, G. B. E.

    2009-07-01

    We explore how histopathology parameters influence OCT imaging of basal cell carcinomas (BCC) and address whether such parameters correlate with the quality of the recorded OCT images. Our results indicate that inflammation impairs OCT imaging and that sun-damaged skin can sometimes provide more clear-cut images of skin cancer lesions using OCT imaging when compared to skin cancer surrounded by skin without sun-damage.

  4. The influence of professional status on maximal and rapid isometric torque characteristics in elite soccer referees.

    PubMed

    Palmer, Ty B; Hawkey, Matt J; Smith, Doug B; Thompson, Brennan J

    2014-05-01

    The purpose of this study was to examine the effectiveness of maximal and rapid isometric torque characteristics of the posterior muscles of the hip and thigh and lower-body power to discriminate between professional status in full-time and part-time professional soccer referees. Seven full-time (mean ± SE: age = 36 ± 2 years; mass = 82 ± 4 kg; and height = 179 ± 3 cm) and 9 part-time (age = 34 ± 2 years; mass = 84 ± 2 kg; and height = 181 ± 2 cm) professional soccer referees performed 2 isometric maximal voluntary contractions (MVCs) of the posterior muscles of the hip and thigh. Peak torque (PT) and absolute and relative rate of torque development (RTD) were calculated from a torque-time curve that was recorded during each MVC. Lower-body power output was assessed through a vertical jump test. Results indicated that the rapid torque characteristics were greater in the full-time compared with the part-time referees for absolute RTD (p = 0.011) and relative RTD at 1/2 (p = 0.022) and 2/3 (p = 0.033) of the normalized torque-time curve. However, no differences were observed for PT (p = 0.660) or peak power (Pmax, p = 0.149) between groups. These findings suggest that rapid torque characteristics of the posterior muscles of the hip and thigh may be sensitive and effective measures for discriminating between full-time and part-time professional soccer referees. Strength and conditioning coaches may use these findings to help identify professional soccer referees with high explosive strength-related capacities and possibly overall refereeing ability.

  5. Indicators of Walking Speed in Rheumatoid Arthritis: Relative Influence of Articular, Psychosocial, and Body Composition Characteristics

    PubMed Central

    Lusa, Amanda L; Amigues, Isabelle; Kramer, Henry R; Dam, Thuy-Tien; Giles, Jon T

    2014-01-01

    Objective To explore the contributions from and interactions between articular swelling and damage, psychosocial factors, and body composition characteristics on walking speed in rheumatoid arthritis (RA). Methods RA patients underwent the timed 400 meter long-corridor walk. Demographics, self-reported levels of depressive symptoms and fatigue, RA characteristics, and body composition [using whole-body dual-energy X-ray absorptiometry (DXA), and abdominal and thigh computed tomography (CT)] were assessed and their associations with walking speed explored. Results A total of 132 RA patients had data for the 400 meter walk, among whom 107 (81%) completed the full 400 meters. Significant multivariable indicators of slower walking speed were older age, higher depression scores, higher reported pain and fatigue, higher swollen and replaced joint counts, higher cumulative prednisone exposure, non-treatment with disease-modifying anti-rheumatic drugs (DMARDs), and worse body composition. These features accounted for 60% of the modeled variability in walking speed. Among specific articular features, slower walking speed was primarily correlated with large/medium lower-extremity joint involvement. However, these articular features accounted for only 21% of the explainable variability in walking speed. Having any relevant articular characteristics was associated with a 20% lower walking speed among those with worse body composition (p<0.001) compared with only a 6% lower speed among those with better body composition (p-value for interaction=0.010). Conclusions Psychosocial factors and body composition are potentially reversible contributors to walking speed in RA. Relative to articular disease activity and damage, non-articular indicators were collectively more potent indicators of an individual's mobility limitations. PMID:25155859

  6. Postprandial glycaemic response: how is it influenced by characteristics of cereal products?

    PubMed

    Meynier, Alexandra; Goux, Aurélie; Atkinson, Fiona; Brack, Olivier; Vinoy, Sophie

    2015-06-28

    Cereal products exhibit a wide range of glycaemic indexes (GI), but the interaction of their different nutrients and starch digestibility on blood glucose response is not well known. The objective of this analysis was to evaluate how cereal product characteristics can contribute to GI and insulinaemic index and to the parameters describing glycaemic or insulinaemic responses (incremental AUC, maximum concentration and Δpeak). Moreover, interactions between the different cereal products characteristics and glycaemic response parameters were assessed for the first time. Relationships between the cereal products characteristics and the glycaemic response were analysed by partial least square regressions, followed by modelling. A database including 190 cereal products tested by the usual GI methodology was used. The model on glycaemic responses showed that slowly digestible starch (SDS), rapidly digestible starch (RDS) and fat and fibres, and several interactions involving them, significantly explain GI by 53 % and Δpeak of glycaemia by 60 %. Fat and fibres had important contributions to glycaemic response at low and medium SDS contents in cereal products, but this effect disappears at high SDS levels. We showed also for the first time that glycaemic response parameters are dependent on interactions between starch digestibility (interaction between SDS and RDS) and nutritional composition (interaction between fat and fibres) of the cereal products. We also demonstrated the non-linear effect of fat and fibres (significant effect of their quadratic terms). Hence, optimising both the formula and the manufacturing process of cereal products can improve glucose metabolism, which is recognised as strongly influential on human health.

  7. The Influence of Leaf Angle and Leaf Surface Characteristics on the Process of Rainfall Interception

    NASA Astrophysics Data System (ADS)

    Holder, C.; Ginebra, R.; Webb, R.

    2015-12-01

    Individual choice in plant selection for household landscaping influences differences in runoff from urban watersheds because the variation in plant canopy architecture results in rainfall interception differences. Understanding the variables that influence rainfall interception and understanding the mechanism of rainfall interception are important concepts for sustainable watershed management. The broad objective of this study was to explore the influence of leaf hydrophobicity, water droplet retention, and leaf angle on the mechanism and process of rainfall interception and raindrop impaction on leaf surfaces of common tree species from the semi-arid regions of the western United States. Leaf hydrophobicity is determined by the cohesive forces of the water molecules among themselves and the adhesive forces that result from the molecular interactions between the water droplet and the leaf surface. Water droplet retention is a measure of how easily a water droplet drains off a leaf surface. The specific hypotheses examined were 1) larger raindrops falling on leaf surfaces will deflect the leaf to an angle greater than the water droplet retention angle; 2) an increased leaf angle, whether from natural position or deflection due to droplet impact and retention, reduces interception from raindrop impaction on hydrophobic and hydrophilic leaf surfaces; and 3) increased droplet size and frequency decrease rainfall interception more significantly in the hydrophilic case. These hypotheses were addressed in a laboratory experiment by 1) measuring leaf hydrophobicity and water droplet retention using a goniometer with a tilting base; 2) measuring leaf traits such as leaf area, leaf surface roughness, trichome density, and specific storage capacity; 3) examining raindrop splash on leaf surfaces with varying leaf hydrophobicity, water droplet retention, and leaf angle with a raindrop generator and high-speed video camera; and 4) modeling the impact of raindrop splash on leaf

  8. Influence of Pitching Moment Characteristics on Departure and Uncoordinated Roll Reversal Boundaries for Fighter Configurations.

    DTIC Science & Technology

    1980-02-01

    Charts 16 1. C Study 17mq 2. C Study 17 3. Static Margin Study 18 B. Departure Boundary 18 1. C Study 19m q 2. C Study 20ml81 3. Unaugmented Static...Yawing moment coefficient models 32 3 Pitch damping derivative, Cm , models 34 q 4 Pitching moment cross derivative, C models 35mIBi 5 Pitching moment...attack criterion for a 9% static margin airplane 11 Simple feedback augmentation block diagram 45 12 Influence of C on design charts for determin- 46m q

  9. The Influence of the Diameter Ratio on the Characteristics Diagram of the Axial Compressor

    NASA Technical Reports Server (NTRS)

    Eckert, B.; Pflueger, F.; Weinig, F.

    1948-01-01

    With the further development of axial blowers into highly loaded flow machines, the influence of the diameter ratio upon air output and efficiency gains in significance. Clarification of this matter is important for single-stage axial compressors, and is of still greater importance for multistage ones, and particularly for aircraft power plants. Tests with a single-stage axial blower gave a decrease in the attainable maximum pressure coefficient and optimum efficiency as the diameter ratio increased. The decrease must be ascribed chiefly to the guide surface of the hub and housing between the blades increasing with the diameter ratio.

  10. Influence of surface defects in ZnO thin films on its biosensing response characteristic

    NASA Astrophysics Data System (ADS)

    Saha, Shibu; Gupta, Vinay

    2011-09-01

    Highly c-axis oriented zinc oxide (ZnO) thin films deposited by rf magnetron sputtering under varying processing pressure (20-50 mT) in a reactive gas mixture of argon and oxygen were studied for biosensing application. The as-deposited ZnO thin films were in a state of compressive stress having defects related to interstitial Zn and antisite oxygen. Glucose oxidase has been chosen as the model enzyme in the present study and was immobilized on the surface of ZnO thin films deposited on indium tin oxide coated Corning Glass substrate. The studies reveal a correlation between the biosensing characteristic and the presence of defects in the ZnO films. The ZnO films deposited under high pressure (50 mT) are found to be more sensitive for biosensing application due to availability of more surface area for effective immobilization of biomolecules and exhibits a suitable microenvironment with good electron transfer characteristic. The obtained results highlight the importance of desired microstate besides availability of suitable native defects in the ZnO thin film for exhibiting enhanced biosensing response.

  11. Quality Characteristics of Marinated Chicken Breast as Influenced by the Methods of Mechanical Processing

    PubMed Central

    Kim, Hack-Youn; Kim, Kon-Joong; Lee, Jong-Wan; Kim, Gye-Woong; Choe, Ju-Hui; Kim, Hyun-Wook; Yoon, Yohan; Kim, Cheon-Jei

    2015-01-01

    The aim of this study was to investigate the effects of various marination processes on the quality characteristics of chicken breast prepared with chicken feet gelatin and wheat fiber. The chicken feet gelatin was swollen with hydrochloric solution (0.1 N HCl, pH 1.31±0.02) and dehydrated by freeze-drying. The composition (w/w) of the marinade was water (10%), soy sauce (12%), phosphate (0.3%), wheat fiber (1.5%), and chicken feet gelatin (1.5%). Three samples of chicken breast were manufactured with Tumbler (only tumbler), Tenderizer (tenderizer and tumbler), and Injector (injector and tumbler). The water content of the Injector sample was significantly higher than those of the Tumbler and Tenderizer samples (p<0.05). During heating, the lightness of all chicken breasts increased and the redness decreased. The tumbling and cooking yield of the Injector sample were significantly higher than those of the Tumbler and Tenderizer samples (p<0.05). The shear force of the Tenderizer sample was significantly lower than that of the Tumbler and Injector samples (p<0.05). No significant differences, except for color, were observed in the sensory analysis of the samples. Thus, the proper selection of mechanical processing is important to improve the quality characteristics of marinated chicken breast, considering the types of final products. PMID:26761806

  12. Influence of groundwater recharge and well characteristics on dissolved arsenic concentrations in southeastern Michigan groundwater

    USGS Publications Warehouse

    Meliker, J.R.; Slotnick, M.J.; Avruskin, G.A.; Haack, S.K.; Nriagu, J.O.

    2009-01-01

    Arsenic concentrations exceeding 10 ??g/l, the United States maximum contaminant level and the World Health Organization guideline value, are frequently reported in groundwater from bedrock and unconsolidated aquifers of southeastern Michigan. Although arsenic-bearing minerals (including arsenian pyrite and oxide/hydroxide phases) have been identified in Marshall Sandstone bedrock of the Mississippian aquifer system and in tills of the unconsolidated aquifer system, mechanisms responsible for arsenic mobilization and subsequent transport in groundwater are equivocal. Recent evidence has begun to suggest that groundwater recharge and characteristics of well construction may affect arsenic mobilization and transport. Therefore, we investigated the relationship between dissolved arsenic concentrations, reported groundwater recharge rates, well construction characteristics, and geology in unconsolidated and bedrock aquifers. Results of multiple linear regression analyses indicate that arsenic contamination is more prevalent in bedrock wells that are cased in proximity to the bedrock-unconsolidated interface; no other factors were associated with arsenic contamination in water drawn from bedrock or unconsolidated aquifers. Conditions appropriate for arsenic mobilization may be found along the bedrock-unconsolidated interface, including changes in reduction/oxidation potential and enhanced biogeochemical activity because of differences between geologic strata. These results are valuable for understanding arsenic mobilization and guiding well construction practices in southeastern Michigan, and may also provide insights for other regions faced with groundwater arsenic contamination. ?? Springer-Verlag 2008.

  13. Influence of groundwater recharge and well characteristics on dissolved arsenic concentrations in southeastern Michigan groundwater.

    PubMed

    Meliker, Jaymie R; Slotnick, Melissa J; Avruskin, Gillian A; Haack, Sheridan K; Nriagu, Jerome O

    2009-02-01

    Arsenic concentrations exceeding 10 microg/l, the United States maximum contaminant level and the World Health Organization guideline value, are frequently reported in groundwater from bedrock and unconsolidated aquifers of southeastern Michigan. Although arsenic-bearing minerals (including arsenian pyrite and oxide/hydroxide phases) have been identified in Marshall Sandstone bedrock of the Mississippian aquifer system and in tills of the unconsolidated aquifer system, mechanisms responsible for arsenic mobilization and subsequent transport in groundwater are equivocal. Recent evidence has begun to suggest that groundwater recharge and characteristics of well construction may affect arsenic mobilization and transport. Therefore, we investigated the relationship between dissolved arsenic concentrations, reported groundwater recharge rates, well construction characteristics, and geology in unconsolidated and bedrock aquifers. Results of multiple linear regression analyses indicate that arsenic contamination is more prevalent in bedrock wells that are cased in proximity to the bedrock-unconsolidated interface; no other factors were associated with arsenic contamination in water drawn from bedrock or unconsolidated aquifers. Conditions appropriate for arsenic mobilization may be found along the bedrock-unconsolidated interface, including changes in reduction/oxidation potential and enhanced biogeochemical activity because of differences between geologic strata. These results are valuable for understanding arsenic mobilization and guiding well construction practices in southeastern Michigan, and may also provide insights for other regions faced with groundwater arsenic contamination.

  14. Assessment of the influence of use on ecotoxicological characteristics of synthetic ester lubricants.

    PubMed

    Maxam, Gudrun; Hahn, Stefan; Dott, Wolfgang; Eisentraeger, Adolf

    2002-10-01

    Synthetic ester lubricants need optimisation about their technical and their ecotoxicological characteristics. To determine the ecotoxicological potential the required examinations can be based on the procedure for a risk assessment of chemicals. At present risk classification of lubricant oils is carried out with new oil fluids that are normally prepared before application in aqueous bioassays. In order to improve the ecotoxicological characteristics of some lubricant oils, the quality of the preparation method has been optimised. The resulting preparation protocol leads to aqueous extracts of the oil fluids that can be tested using biological assays. The extent of the changes of the chemical composition caused by the use as well as the ecotoxicological effects caused by additives have to be taken into consideration. For this reason various used lubricants are tested in addition to new oil fluids. In this work various lubricant samples were examined with standardised bacterial growth assays with Vibrio fischeri and Pseudomonas putida, luminescence inhibition assay with V. fischeri, survival assay with Daphnia magna and algal growth inhibition assay with Scenedesmus subspicatus. The chemical characterisation of the aqueous extracts included the determination of pH, conductivity, heavy metals, the content of dissolved organic carbon, inorganic anions and the content of phosphorus. The results emphasize the thesis that environmentally acceptable lubricants can undergo a change of their ecotoxicological potential during the use. Some of the substances that are normally added to base fluids in order to enhance the applicability of the oils may possess a high toxicological potential.

  15. Influence of volunteer and project characteristics on data quality of biological surveys.

    PubMed

    Lewandowski, Eva; Specht, Hannah

    2015-06-01

    Volunteer involvement in biological surveys is becoming common in conservation and ecology, prompting questions on the quality of data collected in such surveys. In a systematic review of the peer-reviewed literature on the quality of data collected by volunteers, we examined the characteristics of volunteers (e.g., age, prior knowledge) and projects (e.g., systematic vs. opportunistic monitoring schemes) that affect data quality with regards to standardization of sampling, accuracy and precision of data collection, spatial and temporal representation of data, and sample size. Most studies (70%, n = 71) focused on the act of data collection. The majority of assessments of volunteer characteristics (58%, n = 93) examined the effect of prior knowledge and experience on quality of the data collected, often by comparing volunteers with experts or professionals, who were usually assumed to collect higher quality data. However, when both groups' data were compared with the same accuracy standard, professional data were more accurate in only 4 of 7 cases. The few studies that measured precision of volunteer and professional data did not conclusively show that professional data were less variable than volunteer data. To improve data quality, studies recommended changes to survey protocols, volunteer training, statistical analyses, and project structure (e.g., volunteer recruitment and retention).

  16. Assessment of human-natural system characteristics influencing global freshwater supply vulnerability

    NASA Astrophysics Data System (ADS)

    Padowski, Julie C.; Gorelick, Steven M.; Thompson, Barton H.; Rozelle, Scott; Fendorf, Scott

    2015-10-01

    Global freshwater vulnerability is a product of environmental and human dimensions, however, it is rarely assessed as such. Our approach identifies freshwater vulnerability using four broad categories: endowment, demand, infrastructure, and institutions, to capture impacts on natural and managed water systems within the coupled human-hydrologic environment. These categories are represented by 19 different endogenous and exogenous characteristics affecting water supply vulnerability. By evaluating 119 lower per capita income countries (<10 725), we find that every nation experiences some form of vulnerability. Institutional vulnerability is experienced most commonly, occurring in 44 nations, and 23 countries suffer deficiencies in all four categories. Of these highly vulnerable countries, Jordan is the most vulnerable, reporting the greatest number of characteristics (5 of 19) at critical vulnerability levels, with Yemen and Djibouti nearly as vulnerable. Surprising similarities in vulnerability were also found among geographically disparate nations such as Vietnam, Sri Lanka, and Guatemala. Determining shared patterns of freshwater vulnerability provides insights into why water supply vulnerabilities are manifested in human-water systems at the national scale.

  17. Influence of activated carbon characteristics on toluene and hexane adsorption: Application of surface response methodology

    NASA Astrophysics Data System (ADS)

    Izquierdo, Mª Teresa; de Yuso, Alicia Martínez; Valenciano, Raquel; Rubio, Begoña; Pino, Mª Rosa

    2013-01-01

    The objective of this study was to evaluate the adsorption capacity of toluene and hexane over activated carbons prepared according an experimental design, considering as variables the activation temperature, the impregnation ratio and the activation time. The response surface methodology was applied to optimize the adsorption capacity of the carbons regarding the preparation conditions that determine the physicochemical characteristics of the activated carbons. The methodology of preparation produced activated carbons with surface areas and micropore volumes as high as 1128 m2/g and 0.52 cm3/g, respectively. Moreover, the activated carbons exhibit mesoporosity, ranging from 64.6% to 89.1% the percentage of microporosity. The surface chemistry was characterized by TPD, FTIR and acid-base titration obtaining different values of surface groups from the different techniques because the limitation of each technique, but obtaining similar trends for the activated carbons studied. The exhaustive characterization of the activated carbons allows to state that the measured surface area does not explain the adsorption capacity for either toluene or n-hexane. On the other hand, the surface chemistry does not explain the adsorption results either. A compromise between physical and chemical characteristics can be obtained from the appropriate activation conditions, and the response surface methodology gives the optimal activated carbon to maximize adsorption capacity. Low activation temperature, intermediate impregnation ratio lead to high toluene and n-hexane adsorption capacities depending on the activation time, which a determining factor to maximize toluene adsorption.

  18. Energy Status Characteristics of Porcine Oocytes During In Vitro Maturation is Influenced by Their Meiotic Competence.

    PubMed

    Milakovic, I; Jeseta, M; Hanulakova, S; Knitlova, D; Hanzalova, K; Hulinska, P; Machal, L; Kempisty, B; Antosik, P; Machatkova, M

    2015-10-01

    The characteristics of energy status in porcine oocytes as related to their meiotic competence and in vitro maturation were studied. Cycling pubertal gilts in the early luteal to early follicular phases of the ovarian cycle were used as oocyte donors. The oocytes recovered from medium (MF) or small follicles (SF) were considered meiotically more or less competent, respectively. A half of oocytes from each category was matured by the standard protocol. The oocytes were examined before or after maturation by confocal microscopy, a bioluminescent cell assay and Western blotting. Four experiments, each in triplicate, were performed to assess both SF and MF oocytes in terms of metabolic units formed by mitochondria and lipids, ATP and lipid consumption and lipid droplets with adipose differentiation-related protein (ADRP) expression. The proportion of oocytes with metabolic units, the mean ATP content and the number of lipid droplets per oocyte, and the relative number of lipid droplets with ADRP expression were significantly higher in the MF compared to SF oocytes before maturation. On the other hand, after maturation, there was an increase in the proportion of oocytes with metabolic units and the relative number of lipid droplets with ADRP expression in the SF compared to MF oocytes. In conclusion, specific differences in energy characteristics between porcine oocytes with different meiotic competence were found. Meiotically more competent oocytes are more advanced in terms of energy reserves before maturation, while meiotically less competent oocytes are more active in replenishing energy stores during maturation.

  19. Influence of lipid coatings on surface wettability characteristics of silicone hydrogels.

    PubMed

    Bhamla, M Saad; Nash, Walter L; Elliott, Stacey; Fuller, Gerald G

    2015-04-07

    Insoluble lipids serve vital functions in our bodies and interact with biomedical devices, e.g., the tear film on a contact lens. Over a period of time, these naturally occurring lipids form interfacial coatings that modify the wettability characteristics of these foreign synthetic surfaces. In this study, we examine the deposition and consequences of tear film lipids on silicone hydrogel (SiHy) contact lenses. We use bovine meibum, which is a complex mixture of waxy esters, cholesterol esters, and lipids that is secreted from the meibomian glands located on the upper and lower eyelids of mammals. For comparison, we study two commercially available model materials: dipalmitoylphosphatidylcholine (DPPC) and cholesterol. Upon deposition, we find that DPPC and meibum remain closer to the SiHy surface than cholesterol, which diffuses further into the porous SiHy matrix. In addition, we also monitor the fate of unstable thin liquid films that consequently rupture and dewet on these lipid-decorated surfaces. This dewetting provides valuable qualitative and quantitative information about the wetting characteristics of these SiHy substrates. We observe that decorating the SiHy surface with simple model lipids such as DPPC and cholesterol increases the hydrophilicity, which consequently inhibits dewetting, whereas meibum behaves conversely.

  20. Temporal characteristics of the influence of punishment on perceptual decision making in the human brain.

    PubMed

    Blank, Helen; Biele, Guido; Heekeren, Hauke R; Philiastides, Marios G

    2013-02-27

    Perceptual decision making is the process by which information from sensory systems is combined and used to influence our behavior. In addition to the sensory input, this process can be affected by other factors, such as reward and punishment for correct and incorrect responses. To investigate the temporal dynamics of how monetary punishment influences perceptual decision making in humans, we collected electroencephalography (EEG) data during a perceptual categorization task whereby the punishment level for incorrect responses was parametrically manipulated across blocks of trials. Behaviorally, we observed improved accuracy for high relative to low punishment levels. Using multivariate linear discriminant analysis of the EEG, we identified multiple punishment-induced discriminating components with spatially distinct scalp topographies. Compared with components related to sensory evidence, components discriminating punishment levels appeared later in the trial, suggesting that punishment affects primarily late postsensory, decision-related processing. Crucially, the amplitude of these punishment components across participants was predictive of the size of the behavioral improvements induced by punishment. Finally, trial-by-trial changes in prestimulus oscillatory activity in the alpha and gamma bands were good predictors of the amplitude of these components. We discuss these findings in the context of increased motivation/attention, resulting from increases in punishment, which in turn yields improved decision-related processing.

  1. Influence of Parent Artery Segmentation and Boundary Conditions on Hemodynamic Characteristics of Intracranial Aneurysms

    PubMed Central

    Hua, Yufeng; Oh, Je Hoon

    2015-01-01

    Purpose The purpose of this study is to explore the influence of segmentation of the upstream and downstream parent artery and hemodynamic boundary conditions (BCs) on the evaluated hemodynamic factors for the computational fluid dynamics (CFD) analysis of intracranial aneurysms. Materials and Methods Three dimensional patient-specific aneurysm models were analyzed by applying various combinations of inlet and outlet BCs. Hemodynamic factors such as velocity pattern, streamline, wall shear stress, and oscillatory shear index at the systolic time were visualized and compared among the different cases. Results Hemodynamic factors were significantly affected by the inlet BCs while there was little influence of the outlet BCs. When the inlet length was relatively short, different inlet BCs showed different hemodynamic factors and the calculated hemodynamic factors were also dependent on the inlet length. However, when the inlet length (L) was long enough (L>20D, where D is the diameter of inlet section), the hemodynamic factors became similar regardless of the inlet BCs and lengths. The error due to different inlet BCs was negligible. The effect of the outlet length on the hemodynamic factors was similar to that of the inlet length. Conclusion Simulated hemodynamic factors are highly sensitive to inlet BCs and upstream parent artery segmentation. The results of this work can provide an insight into how to build models and to apply BCs for more accurate estimation of hemodynamic factors from CFD simulations of intracranial aneurysms. PMID:26256976

  2. Influence of limestone characteristics on mercury re-emission in WFGD systems.

    PubMed

    Ochoa-González, Raquel; Díaz-Somoano, Mercedes; Martínez-Tarazona, M Rosa

    2013-03-19

    This work evaluates the influence of the effect of the properties of limestones on their reactivity and the re-emission of mercury under typical wet scrubber conditions. The influence of the composition, particle size, and porosity of limestones on their reactivity and the effect of sorbent concentration, pH, redox potential, and the sulphite and iron content of the slurry on Hg(0) re-emission was assessed. A small particle size, a high porosity and a low magnesium content increased the high reactivity of the limestones. Moreover, it was found that the higher the reactivity of the sample the greater the amount of mercury captured in the scrubber. Although sulphite ions did not cause the re-emission of mercury from the suspensions of the gypsums, the limestones enriched in iron increased Hg(0) re-emission under low oxygen conditions. It was observed that the low pH values of the gypsum suspensions favored the cocapture of mercury because Fe(2+) formation was avoided. The partitioning of the mercury in the byproducts of the scrubber depended on the impurities of the limestones rather than on their particle size. No leaching of mercury from the gypsum samples occurred suggesting that mercury was either tightly bound to the impurities of the limestone or was transformed into insoluble mercury species.

  3. Influence of base carrier lifetime on the characteristics of 4H-SiC BJTs

    NASA Astrophysics Data System (ADS)

    Lei, Yuan; Qingwen, Song; Xiaoyan, Tang; Yimeng, Zhang; Shuai, Yang; Yimen, Zhang; Lixin, Guo; Li, Xiao; Liangyong, Wang; Yuming, Zhang

    2017-02-01

    The optimum range of the base electron lifetime (τnB0) in silicon carbide (SiC) bipolar junction transistors (BJTs) is qualitatively investigated in this paper, considering both the static and dynamic performance. The TCAD simulation results show that there is tradeoff between the current gain (β) and the turn-off time (tF). With τnB0 increasing, both β and tF increase. However, with a fixed base width, the base transport factor tends toward saturation when τnB0 exceeds certain value. Thus, the eclectic values of base electron lifetime with different base thickness are obtained. The influence of the base drive current is also discussed. According to the charge control theory, the excessive storage charge caused by overdrive has a great influence on turn-off delay time (tD). To solve this, a suitable base drive current is necessary. For the common 4H-SiC BJT structure, appropriate base drive under variable base and collector doping concentration is suggested.

  4. Emotional Effects on University Choice Behavior: The Influence of Experienced Narrators and Their Characteristics

    PubMed Central

    Callejas-Albiñana, Ana I.; Callejas-Albiñana, Fernando E.; Martínez-Rodríguez, Isabel

    2016-01-01

    This study analyzes the influence that experienced users of university resources might have as narrative sources of information for other students in the process of choosing their schools. Informative videos about the benefits of studying at the university provide a reference model. In these videos, a group of young people present their views and explain their reasons for choosing the university in which they are pursuing their degrees; the various narrators detail all the resources available. This study investigates whether the individual identifiers of these narrators (e.g., gender, age, physical appearance, nonverbal gestures such as smiling, posture) influence perceptions of the credibility of the information they provide. Among a sample of 150 students in their last year of pre-university training, the results demonstrate that the students' ability to identify with the narrators provides information and arouses emotions that inform their perceptions of reliability and therefore their consumption choices. None of these predictors appear to serve as determinants that can be generalized, but if emotional attitudes in response to narratives about the topic (i.e., the university) are positive, then they prompt a change in attitude toward that reference topic too. PMID:27252664

  5. Women's labour force participation and socioeconomic development: influences of local context and individual characteristics in Brazil.

    PubMed

    Evans, M D; Saraiva, H U

    1993-03-01

    We address several key hypotheses about the effects of socioeconomic development on women's labour force participation during the transition from agriculture to industrialism. To this end, we explore differences in women's labour force participation in Brazil by education, marital status, age, and urban or rural residence. We also show how socioeconomic development affects the overall level of women's participation and the differentials by education, etc. Our data are drawn from a large 1973 PNAD (Pequisa Nacional por Amostra de Domicilos) survey conducted by the Brazilian census bureau. Socioeconomic development in different parts of Brazil ranges from pre-industrial agriculture to heavy industry. Using logistic regression, we show that the general level of women's labour force participation does not change with the level of development. Highly educated women are much more likely than the less educated to be in the labour force (net of other influences); this difference is substantially greater than in post-industrial societies. Somewhat surprisingly, the influence of education is the same across the range of development levels in Brazil. Single women are more likely to be in the labour force than married women, and the difference grows during development. Age has a curvilinear relationship to labour force participation, and the old are much less likely to participate in more developed places. Rural women are slightly more likely to be in the labour force at all levels of development.

  6. Influence of air composition during egg storage on egg characteristics, embryonic development, hatchability, and chick quality.

    PubMed

    Reijrink, I A M; van Duijvendijk, L A G; Meijerhof, R; Kemp, B; van den Brand, H

    2010-09-01

    Egg storage beyond 7 d is associated with an increase in incubation duration and a decrease in hatchability and chick quality. Negative effects of prolonged egg storage may be caused by changes in the embryo, by changes in egg characteristics, or by both. An adjustment in storage air composition may reduce negative effects of prolonged egg storage because it may prevent changes in the embryo and in egg characteristics. An experiment was conducted to investigate the effects of high CO(2) concentrations or a low O(2) concentration in the storage air on egg characteristics, embryonic development, hatchability, and chick quality. Eggs were stored for 14 d in 4 different storage air compositions: normal air (control; 20.9% O(2), 0.05% CO(2), 78.1% N(2)), 0.74% CO(2) treatment (20.8% O(2), 0.74% CO(2), 77.5% N(2)), 1.5% CO(2) treatment (20.6% O(2), 1.5% CO(2), 77.0% N(2))(,) or 3.0% O(2) treatment (3.0% O(2), 0.04% CO(2), 96.0% N(2)). The storage temperature was 16 degrees C and the RH was 75%. Results showed that the change in albumen pH and albumen height between oviposition and the end of storage was less in the 0.74 and 1.5% CO(2) treatments than in the control and 3.0% O(2) treatments (P < 0.001 and P < 0.001, respectively). None of the treatments affected the stage of embryonic development on d 4 of incubation, hatchability, or chick quality on the day of hatch in terms of BW, chick length, and yolk-free body mass. Although high CO(2) concentrations in the storage air had a positive effect on albumen height and albumen pH, it is concluded that the storage air compositions, studied in the current study, do not affect embryonic development, hatchability, or chick quality when eggs are stored for 14 d at a storage temperature of 16 degrees C.

  7. Influence of Habitat and Intrinsic Characteristics on Survival of Neonatal Pronghorn.

    PubMed

    Jacques, Christopher N; Jenks, Jonathan A; Grovenburg, Troy W; Klaver, Robert W

    2015-01-01

    Increased understanding of the influence of habitat (e.g., composition, patch size) and intrinsic (e.g., age, birth mass) factors on survival of neonatal pronghorn (Antilocapra americana) is a prerequisite to successful management programs, particularly as they relate to population dynamics and the role of population models in adaptive species management. Nevertheless, few studies have presented empirical data quantifying the influence of habitat variables on survival of neonatal pronghorn. During 2002-2005, we captured and radiocollared 116 neonates across two sites in western South Dakota. We documented 31 deaths during our study, of which coyote (Canis latrans) predation (n = 15) was the leading cause of mortality. We used known fate analysis in Program MARK to investigate the influence of intrinsic and habitat variables on neonatal survival. We generated a priori models that we grouped into habitat and intrinsic effects. The highest-ranking model indicated that neonate mortality was best explained by site, percent grassland, and open water habitat; 90-day survival (0.80; 90% CI = 0.71-0.88) declined 23% when grassland and water increased from 80.1 to 92.3% and 0.36 to 0.40%, respectively, across 50% natal home ranges. Further, our results indicated that grassland patch size and shrub density were important predictors of neonate survival; neonate survival declined 17% when shrub density declined from 5.0 to 2.5 patches per 100 ha. Excluding the site covariates, intrinsic factors (i.e., sex, age, birth mass, year, parturition date) were not important predictors of survival of neonatal pronghorns. Further, neonatal survival may depend on available land cover and interspersion of habitats. We have demonstrated that maintaining minimum and maximum thresholds for habitat factors (e.g., percentages of grassland and open water patches, density of shrub patches) throughout natal home ranges will in turn, ensure relatively high (>0.50) neonatal survival rates, especially

  8. Influence of Habitat and Intrinsic Characteristics on Survival of Neonatal Pronghorn

    PubMed Central

    2015-01-01

    Increased understanding of the influence of habitat (e.g., composition, patch size) and intrinsic (e.g., age, birth mass) factors on survival of neonatal pronghorn (Antilocapra americana) is a prerequisite to successful management programs, particularly as they relate to population dynamics and the role of population models in adaptive species management. Nevertheless, few studies have presented empirical data quantifying the influence of habitat variables on survival of neonatal pronghorn. During 2002–2005, we captured and radiocollared 116 neonates across two sites in western South Dakota. We documented 31 deaths during our study, of which coyote (Canis latrans) predation (n = 15) was the leading cause of mortality. We used known fate analysis in Program MARK to investigate the influence of intrinsic and habitat variables on neonatal survival. We generated a priori models that we grouped into habitat and intrinsic effects. The highest-ranking model indicated that neonate mortality was best explained by site, percent grassland, and open water habitat; 90-day survival (0.80; 90% CI = 0.71–0.88) declined 23% when grassland and water increased from 80.1 to 92.3% and 0.36 to 0.40%, respectively, across 50% natal home ranges. Further, our results indicated that grassland patch size and shrub density were important predictors of neonate survival; neonate survival declined 17% when shrub density declined from 5.0 to 2.5 patches per 100 ha. Excluding the site covariates, intrinsic factors (i.e., sex, age, birth mass, year, parturition date) were not important predictors of survival of neonatal pronghorns. Further, neonatal survival may depend on available land cover and interspersion of habitats. We have demonstrated that maintaining minimum and maximum thresholds for habitat factors (e.g., percentages of grassland and open water patches, density of shrub patches) throughout natal home ranges will in turn, ensure relatively high (>0.50) neonatal survival rates

  9. Influence of habitat and intrinsic characteristics on survival of neonatal pronghorn

    USGS Publications Warehouse

    Jacques, Christopher N.; Jenks, Jonathan A.; Grovenburg, Troy W.; Klaver, Robert W.

    2015-01-01

    Increased understanding of the influence of habitat (e.g., composition, patch size) and intrinsic (e.g., age, birth mass) factors on survival of neonatal pronghorn (Antilocapra americana) is a prerequisite to successful management programs, particularly as they relate to population dynamics and the role of population models in adaptive species management. Nevertheless, few studies have presented empirical data quantifying the influence of habitat variables on survival of neonatal pronghorn. During 2002–2005, we captured and radiocollared 116 neonates across two sites in western South Dakota. We documented 31 deaths during our study, of which coyote (Canis latrans) predation (n = 15) was the leading cause of mortality. We used known fate analysis in Program MARK to investigate the influence of intrinsic and habitat variables on neonatal survival. We generated a priori models that we grouped into habitat and intrinsic effects. The highest-ranking model indicated that neonate mortality was best explained by site, percent grassland, and open water habitat; 90-day survival (0.80; 90% CI = 0.71–0.88) declined 23% when grassland and water increased from 80.1 to 92.3% and 0.36 to 0.40%, respectively, across 50% natal home ranges. Further, our results indicated that grassland patch size and shrub density were important predictors of neonate survival; neonate survival declined 17% when shrub density declined from 5.0 to 2.5 patches per 100 ha. Excluding the site covariates, intrinsic factors (i.e., sex, age, birth mass, year, parturition date) were not important predictors of survival of neonatal pronghorns. Further, neonatal survival may depend on available land cover and interspersion of habitats. We have demonstrated that maintaining minimum and maximum thresholds for habitat factors (e.g., percentages of grassland and open water patches, density of shrub patches) throughout natal home ranges will in turn, ensure relatively high (>0.50) neonatal survival rates

  10. Detectability in Audio-Visual Surveys of Tropical Rainforest Birds: The Influence of Species, Weather and Habitat Characteristics.

    PubMed

    Anderson, Alexander S; Marques, Tiago A; Shoo, Luke P; Williams, Stephen E

    2015-01-01

    Indices of relative abundance do not control for variation in detectability, which can bias density estimates such that ecological processes are difficult to infer. Distance sampling methods can be used to correct for detectability, but in rainforest, where dense vegetation and diverse assemblages complicate sampling, information is lacking about factors affecting their application. Rare species present an additional challenge, as data may be too sparse to fit detection functions. We present analyses of distance sampling data collected for a diverse tropical rainforest bird assemblage across broad elevational and latitudinal gradients in North Queensland, Australia. Using audio and visual detections, we assessed the influence of various factors on Effective Strip Width (ESW), an intuitively useful parameter, since it can be used to calculate an estimate of density from count data. Body size and species exerted the most important influence on ESW, with larger species detectable over greater distances than smaller species. Secondarily, wet weather and high shrub density decreased ESW for most species. ESW for several species also differed between summer and winter, possibly due to seasonal differences in calling behavior. Distance sampling proved logistically intensive in these environments, but large differences in ESW between species confirmed the need to correct for detection probability to obtain accurate density estimates. Our results suggest an evidence-based approach to controlling for factors influencing detectability, and avenues for further work including modeling detectability as a function of species characteristics such as body size and call characteristics. Such models may be useful in developing a calibration for non-distance sampling data and for estimating detectability of rare species.

  11. Detectability in Audio-Visual Surveys of Tropical Rainforest Birds: The Influence of Species, Weather and Habitat Characteristics

    PubMed Central

    Anderson, Alexander S.; Marques, Tiago A.; Shoo, Luke P.; Williams, Stephen E.

    2015-01-01

    Indices of relative abundance do not control for variation in detectability, which can bias density estimates such that ecological processes are difficult to infer. Distance sampling methods can be used to correct for detectability, but in rainforest, where dense vegetation and diverse assemblages complicate sampling, information is lacking about factors affecting their application. Rare species present an additional challenge, as data may be too sparse to fit detection functions. We present analyses of distance sampling data collected for a diverse tropical rainforest bird assemblage across broad elevational and latitudinal gradients in North Queensland, Australia. Using audio and visual detections, we assessed the influence of various factors on Effective Strip Width (ESW), an intuitively useful parameter, since it can be used to calculate an estimate of density from count data. Body size and species exerted the most important influence on ESW, with larger species detectable over greater distances than smaller species. Secondarily, wet weather and high shrub density decreased ESW for most species. ESW for several species also differed between summer and winter, possibly due to seasonal differences in calling behavior. Distance sampling proved logistically intensive in these environments, but large differences in ESW between species confirmed the need to correct for detection probability to obtain accurate density estimates. Our results suggest an evidence-based approach to controlling for factors influencing detectability, and avenues for further work including modeling detectability as a function of species characteristics such as body size and call characteristics. Such models may be useful in developing a calibration for non-distance sampling data and for estimating detectability of rare species. PMID:26110433

  12. Influence of colorant and film thickness on thermal aging characteristics of oxo-biodegradable plastic bags

    NASA Astrophysics Data System (ADS)

    Leuterio, Giselle Lou D.; Pajarito, Bryan B.; Domingo, Carla Marie C.; Lim, Anna Patricia G.

    2016-05-01

    Functional, lightweight, strong and cheap plastic bags incorporated with pro-oxidants undergo accelerated degradation under exposure to heat and oxygen. This work investigated the effect of colorant and film thickness on thermal aging characteristics of commercial oxo-biodegradable plastic bag films at 70 °C. Degradation is monitored through changes in infrared absorption, weight, and tensile properties of thermally aged films. The presence of carbonyl band in infrared spectrum after 672 h of thermal aging supports the degradation behavior of exposed films. Results show that incorporation of colorant and increasing thickness exhibit low maximum weight uptake. Titanium dioxide as white colorant in films lowers the susceptibility of films to oxygen uptake but enhances physical degradation. Higher amount of pro-oxidant loading also contributes to faster degradation. Opaque films are characterized by low tensile strength and high elastic modulus. Decreasing the thickness contributes to lower tensile strength of films. Thermally aged films with colorant and low thickness promote enhanced degradation.

  13. Influence of Surface Carburization of Machinable Ceramics on Its Pulsed Flashover Characteristics in Vacuum

    NASA Astrophysics Data System (ADS)

    Zheng, Nan; Huang, Xuezeng; Mu, Haibao; Zhang, Guanjun

    2011-12-01

    For pulsed power devices, surface flashover phenomena across solid insulators greatly restrict their overall performance. In recent decades, much attention has been paid on enhancing the surface electric withstanding strength of insulators, and it is found that surface treatment of material is useful to improve the surface flashover voltage. The carburization treatment is employed to modify the surface components of newly-developed machinable ceramics (MC) materials. A series of MC samples with different glucose solution concentration (0%, 10%, 20%, 30% and 40%) are prepared by chemical reactions for surface carburization modification, and their surface flashover characteristics are investigated under pulsed voltage in vacuum. It is found that the surface carburization treatment greatly modifies the surface resistivity of MCs and hence the flashover behaviors. Based on the reduction of surface resistivity and the secondary electron emission avalanche (SEEA) theory, the adjustment of flashover withstanding ability can be reasonably explained.

  14. Influence of loading volume of mefenamic acid on granules and tablet characteristics using a compaction simulator.

    PubMed

    Kimura, Go; Betz, Gabriele; Leuenberger, Hans

    2008-01-01

    Mefenamic acid (MA), a poorly water-soluble drug, was used as a model substance to investigate granules and tablet characteristics to be optimized for the loading volume of MA (0-74.1% v/v) in the formulation including lactose monohydrate/maize starch (7/3) as excipients. The compactibility of granules increased with loading volume of MA. This was related to the brittle behavior of MA during compression and the increase of intragranular pore volume of granules. The minimum disintegration time (266 +/- 8.3 s) was found in the tablet that was composed of 55.1% v/v MA and 13.6% v/v maize starch. The determination of the critical concentration of disintegrant (% v/v) required for a minimum disintegration time may be useful for solid dosage form design.

  15. Influence of laser beam characteristics and focusing optics on optical laser-induced breakdown detection

    NASA Astrophysics Data System (ADS)

    Walther, C.; Hauser, W.

    2009-12-01

    Laser-induced breakdown detection (LIBD) is a well established technique for measuring size and concentration of inorganic colloids in liquids. However, most applications of LIBD are restricted to the measurement of mean sizes, which is problematic in cases of wide colloid size distributions (PSD) as typically is the case in natural systems. Evaluation of PSDs from LIBD is possible but requires detailed control of the power density within the laser focus. In the present work we describe the mathematical treatment how to calculate this power density from the beam characteristics of the light source and the optical properties of the focusing optics. The results are compared to measured spatial distributions of breakdown events of three LIBD setups.

  16. Influences of carrier diffusion and radial mode field pattern on high speed characteristics for microring lasers

    SciTech Connect

    Lv, Xiao-Meng; Huang, Yong-Zhen Yang, Yue-De; Zou, Ling-Xiu; Long, Heng; Liu, Bo-Wen; Xiao, Jin-Long; Du, Yun

    2014-04-21

    High-speed directly modulated microlasers are potential light sources for on-chip optical interconnection and photonic integrated circuits. In this Letter, dynamic characteristics are studied for microring lasers by rate equation analysis considering radial carrier hole burning and diffusion and experimentally. The coupled modes with a wide radial field pattern and the injection current focused in the edge area of microring resonator can greatly improve the high speed response curve due to the less carrier hole burning. The small-signal response curves of a microring laser connected with an output waveguide exhibit a larger 3 dB bandwidth and smaller roll-off at low frequency than that of the microdisk laser with the same radius of 15 μm, which accords with the simulation results.

  17. The developmental characteristics of mastoid pneumatisation in cleft palate children: the genetic influence.

    PubMed

    Srzentić, Mladen; Handzić, Jadranka; Trotić, Robert

    2012-09-01

    Physiologic and developmental role of mastoid pneumatisation in children with otitis media with effusion (OME) is still controversial. For measuring mastoid pneumatisation and examine developmental characteristics, we used children with orofacial malformation of high risk for long term negative pressure in the middle ear and are expected to have lower rate of size and growth of pneumatisation. Mastoid were measured on Schuller's mastoid X-ray pictures planimetrically in study group of 146 children with bilateral (BCLP), unilateral (UCLP) and isolated (ICP) cleft palate, and control group of non-cleft 52 children, both groups with confirmed otitis media with effusion and no previous otological surgery. The lowest pneumatisation found in BCLE, BCLP and UCLP showed no growth of mastoid with age and lower mastoid size than OME controls. ICP is the only cleft type with growth of mastoid with aging. OME patients has the highest size of mastoid and growth rate with aging.

  18. Influence of the physico-chemical characteristics of chito-oligosaccharides (COS) on antioxidant activity.

    PubMed

    Mengíbar, Marian; Mateos-Aparicio, Inmaculada; Miralles, Beatriz; Heras, Angeles

    2013-09-12

    Chito-oligosaccharides (COS) are being used as important functional materials for many applications due to their bioactivities. The aim of this research has been to assess the relationship between the physico-chemical characteristics, average molecular weight (Mw), acetylation degree (DA), polymerization degree (DP) and specially sequence composition determined by MALDI-TOF MS and the antioxidant properties of COS. These oligosaccharides were obtained by enzymatic depolymerization with chitosanase and lysozyme using a specific chitosan and its reacetylated product. The COS fraction below 5 kDa obtained from chitosanase depolymerization showed the highest capacity to scavenge DPPH radicals and to reduce Fe(3+). A correlation was found between the relative amount of molecules with a given A/D (acetylated vs deacetylated units) ratio within the COS and their antioxidant activity, which could be used to predict the antioxidant behavior of a fraction of chito-oligosaccharides.

  19. The Influence of Facial Characteristics on the Relation between Male 2D:4D and Dominance

    PubMed Central

    Ryckmans, Jan; Millet, Kobe; Warlop, Luk

    2015-01-01

    Although relations between 2D:4D and dominance rank in both baboons and rhesus macaques have been observed, evidence in humans is mixed. Whereas behavioral patterns in humans have been discovered that are consistent with these animal findings, the evidence for a relation between dominance and 2D:4D is weak or inconsistent. The present study provides experimental evidence that male 2D:4D is related to dominance after (fictitious) male-male interaction when the other man has a dominant, but not a submissive or neutral face. This finding provides evidence that the relationship between 2D:4D and dominance emerges in particular, predictable situations and that merely dominant facial characteristics of another person are enough to activate supposed relationships between 2D:4D and dominance. PMID:26600255

  20. Influence of molybdenum doping on the switching characteristic in silicon oxide-based resistive switching memory

    NASA Astrophysics Data System (ADS)

    Chen, Yu-Ting; Chang, Ting-Chang; Huang, Jheng-Jie; Tseng, Hsueh-Chih; Yang, Po-Chun; Chu, Ann-Kuo; Yang, Jyun-Bao; Huang, Hui-Chun; Gan, Der-Shin; Tsai, Ming-Jinn; Sze, Simon M.

    2013-01-01

    This report compares Mo-doped and undoped SiO2 thin films of a similar thickness as well as MoOx. The Mo-doped SiO2 film exhibited switching behavior after the forming process, unlike the undoped SiO2 film. Through material analyses, a self-assembled layer is observed in the Mo-doped SiO2 film. Due to the formation of this layer, the thickness required to be broken down is effectively reduced. Subsequently, the occurrence of the switching behavior in the thinner SiO2 film further confirmed the supposition. A comparison of the two switching behaviors shows that SiO2 dominates the switching characteristic of the Mo-doped SiO2.

  1. The influence of substrates rates on the germination characteristic of a soil seed bank

    NASA Astrophysics Data System (ADS)

    Zhao, N.; He, M. X.; Li, H. Y.; Meng, W. Q.

    2016-08-01

    Soil seed bank (SSB) is considered as an important way of vegetation restoration, it can fleetly achieved vegetation diversification and the course of succession when the topsoil mixed with planting substrates. In this paper, a greenhouse germination method was used to explore the effect on germination characteristic of soil seed bank by adding different inorganic substrates, such as activated carbon, perlite and vermiculite. The results showed that perlite and vermiculite can effectively promote the germination of soil seed bank, but also significantly promote Shannon-Wiener diversity index. When vermiculite mixed with the topsoil in 40%, the germination effect of soil seed bank was more obviously than other groups; at this time, the density of soil seed bank reached 6 X 105 plants/m2 , Shannon Wiener diversity index reached 1.4354. Therefore, it was more conducive to improve the soil seed bank density and species diversity by adding 40% vermiculite in the topsoil.

  2. Influence of sediment characteristics on the composition of soft-sediment intertidal communities in the northern Gulf of Mexico

    PubMed Central

    Henkel, Jessica R.; Sigel, Bryan J.; Taylor, Caz M.

    2015-01-01

    Benthic infaunal communities are important components of coastal ecosystems. Understanding the relationships between the structure of these communities and characteristics of the habitat in which they live is becoming progressively more important as coastal systems face increasing stress from anthropogenic impacts and changes in climate. To examine how sediment characteristics and infaunal community composition were related along the northern Gulf of Mexico coast, we sampled intertidal infaunal communities at seven sites covering common habitat types at a regional scale. Across 69 samples, the communities clustered into four distinct groups on the basis of faunal composition. Nearly 70% of the variation in the composition of the communities was explained by salinity, median grain size, and total organic content. Our results suggest that at a regional level coarse habitat characteristics are able to explain a large amount of the variation among sites in infaunal community structure. By examining the relationships between infaunal communities and their sedimentary habitats, we take a necessary first step that will allow the exploration of how changes in habitat and community composition influence higher trophic levels and ecosystem scale processes. PMID:26157603

  3. Influences of NOM composition and bacteriological characteristics on biological stability in a full-scale drinking water treatment plant.

    PubMed

    Park, Ji Won; Kim, Hyun-Chul; Meyer, Anne S; Kim, Sungpyo; Maeng, Sung Kyu

    2016-10-01

    The influences of natural organic matter (NOM) and bacteriological characteristics on the biological stability of water were investigated in a full-scale drinking water treatment plant. We found that prechlorination decreased the hydrophobicity of the organic matter and significantly increased the high-molecular-weight (MW) dissolved organic matter, such as biopolymers and humic substances. High-MW organic matter and structurally complex compounds are known to be relatively slowly biodegradable; however, because of the prechlorination step, the indigenous bacteria could readily utilise these fractions as assimilable organic carbon. Sequential coagulation and sedimentation resulted in the substantial removal of biopolymer (74%), humic substance (33%), bacterial cells (79%), and assimilable organic carbon (67%). Rapid sand and granular activated carbon filtration induced an increase in the low-nucleic-acid content bacteria; however, these bacteria were biologically less active in relation to enzymatic activity and ATP. The granular activated carbon step was essential to securing biological stability (the ability to prevent bacterial growth) by removing the residual assimilable organic carbon that had formed during the ozone treatment. The growth potential of Escherichia coli and indigenous bacteria were found to differ in respect to NOM characteristics. In comparison with E. coli, the indigenous bacteria utilised a broader range of NOM as a carbon source. Principal component analysis demonstrated that the measured biological stability of water could differ, depending on the NOM characteristics, as well as on the bacterial inoculum selected for the analysis.

  4. Influence of root-exudates concentration on pyrene degradation and soil microbial characteristics in pyrene contaminated soil.

    PubMed

    Xie, Xiao-mei; Liao, Min; Yang, Jing; Chai, Juan-juan; Fang, Shu; Wang, Run-han

    2012-08-01

    The effect of ryegrass (Lolium perenne L.) root-exudates concentration on pyrene degradation and the microbial ecological characteristics in the pyrene contaminated soil was investigated by simulating a gradually reducing concentration of root exudates with the distance away from root surface in the rhizosphere. Results showed that, after the root-exudates were added 15 d, the pyrene residue in contaminated soil responded nonlinearly in the soils with the same pyrene contaminated level as the added root-exudates concentration increased, which decreased first and increased latter with the increase of the added root-exudates concentration. The lowest pyrene concentration appeared when the root exudates concentration of 32.75 mg kg(-1) total organic carbon (TOC) was added. At the same time, changes of microbial biomass carbon (MBC, C(mic)) and microbial quotient (C(mic)/C(org)) were opposite to the trend of pyrene degradation as the added root-exudates concentration increased. Phospholipid fatty acid (PLFA) analysis revealed that bacteria was the dominating microbial community in pyrene contaminated soil, and the changing trends of pyrene degradation and bacteria number were the same. The changing trend of endoenzyme-dehydrogenase activity was in accordance with that of soil microbe, indicating which could reflect the quantitative characteristic of detoxification to pyrene by soil microbe. The changes in the soils microbial community and corresponding microbial biochemistry characteristics were the ecological mechanism influencing pyrene degradation with increasing concentration of the added root-exudates in the pyrene contaminated soil.

  5. Influences on the diet quality of preschool children: importance of maternal psychological characteristics

    PubMed Central

    Jarman, Megan; Inskip, Hazel; Ntani, Georgia; Cooper, Cyrus; Baird, Janis; Robinson, Sian; Barker, Mary

    2015-01-01

    Objective To test the hypothesis that maternal psychological profiles relate to children’s quality of diet. Design Cross-sectional study. Mothers provided information on their health-related psychological factors and aspects of their child’s mealtime environment. Children’s diet quality was assessed using a food frequency questionnaire from which weekly intakes of foods and a diet z-score was calculated. A high score described children with a better quality diet. Cluster analysis was performed to assess grouping of mothers based on psychological factors. Mealtime characteristics, describing how often children ate whilst sitting at a table or in front of the television, their frequency of take-away food consumption, maternal covert control and food security, and children’s quality of diet were examined, according to mothers cluster membership. Subjects 324 mother-child pairs, in the Southampton Initiative for Health. Children were aged between 2-5 years. Setting Hampshire, UK. Results Two main clusters were identified. Mothers in cluster one had significantly higher scores for all psychological factors than mothers in cluster two (all P<0.001). Clusters were termed ‘more resilient’ and ‘less resilient’ respectively. Children of mothers in the less resilient cluster ate meals sitting at a table less often (p=0.03) and watched more television (p=0.01). These children had significantly poorer quality diets (β −0.61, 95% CI −0.82, −0.40, p=<0.001). This association was attenuated, but remained significant after controlling for confounding factors, that included maternal education and home/mealtime characteristics (p=0.006). Conclusion This study suggests that mothers should be offered psychological support as part of interventions to improve children’s quality of diet. PMID:25409750

  6. Landscape characteristics and livestock presence influence common ravens: Relevance to greater sage-grouse conservation

    USGS Publications Warehouse

    Coates, Peter S.; Brussee, Brianne E.; Howe, Kristy; Gustafson, K. Ben; Casazza, Michael L.; Delehanty, David J.

    2016-01-01

    Common raven (Corvus corax; hereafter, raven) population abundance in the sagebrush steppe of the American West has increased threefold during the previous four decades, largely as a result of unintended resource subsidies from human land-use practices. This is concerning because ravens frequently depredate nests of species of conservation concern, such as greater sage-grouse (Centrocercus urophasianus; hereafter, sage-grouse). Grazing by livestock in sagebrush ecosystems is common practice on most public lands, but associations between livestock and ravens are poorly understood. The primary objective of this study was to identify the effects of livestock on raven occurrence while accounting for landscape characteristics within human-altered sagebrush steppe habitat, particularly in areas occupied by breeding sage-grouse. Using data from southeastern Idaho collected during spring and summer across 3 yr, we modeled raven occurrence as a function of the presence of livestock while accounting for multiple landscape covariates, including land cover features, topographical features, and proximity to sage-grouse lek sites (breeding grounds), as well as site-level anthropogenic features. While accounting for landscape characteristics, we found that the odds of raven occurrence increased 45.8% in areas where livestock were present. In addition, ravens selected areas near sage-grouse leks, with the odds of occurrence decreasing 8.9% for every 1-km distance, increase away from the lek. We did not find an association between livestock use and distance to lek. We also found that ravens selected sites with relatively lower elevation containing increased amounts of cropland, wet meadow, and urbanization. Limiting raven access to key anthropogenic subsidies and spatially segregating livestock from sage-grouse breeding areas would likely reduce exposure of predatory ravens to sage-grouse nests and chicks.

  7. The transmission of vertical vibration through seats: Influence of the characteristics of the human body

    NASA Astrophysics Data System (ADS)

    Toward, Martin G. R.; Griffin, Michael J.

    2011-12-01

    The transmission of vibration through a seat depends on the impedance of the seat and the apparent mass of the seat occupant. This study was designed to determine how factors affecting the apparent mass of the body (age, gender, physical characteristics, backrest contact, and magnitude of vibration) affect seat transmissibility. The transmission of vertical vibration through a car seat was measured with 80 adults (41 males and 39 females aged 18-65) at frequencies between 0.6 and 20 Hz with two backrest conditions (no backrest and backrest), and with three magnitudes of random vibration (0.5, 1.0, and 1.5 m s -2 rms). Linear regression models were used to study the effects of subject physical characteristics (age, gender, and anthropometry) and features of their apparent mass (resonance frequency, apparent mass at resonance and at 12 Hz) on the measured seat transmissibility. The strongest predictor of both the frequency of the principal resonance in seat transmissibility and the seat transmissibility at resonance was subject age, with other factors having only marginal effects. The transmissibility of the seat at 12 Hz depended on subject age, body mass index, and gender. Although subject weight was strongly associated with apparent mass, weight was not strongly associated with seat transmissibility. The resonance frequency of the seat decreased with increases in the magnitude of the vibration excitation and increased when subjects made contact with the backrest. Inter-subject variability in the resonance frequency and transmissibility at resonance was less with greater vibration excitation, but was largely unaffected by backrest contact. A lumped parameter seat-person model showed that changes in seat transmissibility with age can be predicted from changes in apparent mass with age, and that the dynamic stiffness of the seat appeared to increase with increased loading so as to compensate for increases in subject apparent mass associated with increased sitting

  8. Influence of air abrasion tips and operation modes on enamel-cutting characteristics

    PubMed Central

    Peruchi, Cláudia; Santos-Pinto, Ary; Dias, Tereza Cristina; Oliveira, Ana Carolina Mascarenhas; Santos-Pinto, Lourdes

    2013-01-01

    Objective: To assess the influence of air abrasion tips and system operation modes on enamel cutting. Methods: Forty bovine teeth were abraded with the air abrasion system Mach 4.1 for 10 and 15 seconds, employing conventional and sonic tips of 0.45-mm inner diameter and a 90° angle, and 27.5-μm aluminum oxide at 5.51 bar air pressure in continuous and pulsed modes. The width and depth of the resulting cuts were measured in SEM. Results: The multivariate analysis of variances revealed that, compared to the sonic tip, the conventional tip produced shallower cuts independent of the operation mode and the application period. Conclusions: The cutting patterns observed in this study suggest that the pulsed mode produced deeper cuts when both the conventional and sonic tips were used, and that the sonic tip cut more dental tissue than the conventional one. PMID:23408157

  9. Selective influence of circadian modulation and task characteristics on motor imagery time.

    PubMed

    Debarnot, Ursula; Sahraoui, Djafar; Champely, Stéphane; Collet, Christian; Guillot, Aymeric

    2012-09-01

    In this study, we examined the effect of circadian modulation on motor imagery (MI) time while also considering the effects of task complexity and duration. The ability to imagine in real time was influenced by circadian modulation in a simple walking condition, with longer MI times in the morning and evening sessions. By contrast, there was no effect of circadian rhythm in the complex, short or long walking conditions. We concluded that motor imagery time is modulated during the course of the day, but the effect of task difficulty is stronger than circadian modulation in altering the temporal congruence between physical practice and MI performance. Practical applications in motor learning and rehabilitation are discussed.

  10. Individual variation in life history characteristics can influence extinction risk (vol 144, pg 61, 2001) Correction

    SciTech Connect

    Jager, Yetta

    2009-01-01

    The white sturgeon (Acipenser transmontanus) shows great individual variation in the age at maturation. This study examines the consequences of model assumptions about individual variation in the age at maturation on predicted population viability. I considered: (1) the effects of variation in age at maturation alone; (2) the effects of heritability; and (3) the influence of a stable and an altered selective regime. Two selective regimes represented conditions before and after the impoundment of a river, blocking access of anadromous white sturgeon populations to the ocean. In contrast to previous simulation studies, I found that increased individual variation in the age at maturity did not necessarily lead to a higher likelihood of persistence. Individual variation increased the simulated likelihood of persistence when the variation was heritable and the selective regime had changed such that the mean age at maturity was no longer optimal.

  11. Oxidation of coal and coal pyrite mechanisms and influence on surface characteristics. [Coal pyrite electrodes

    SciTech Connect

    Doyle, F.M.

    1992-01-01

    The objective of this research is to develop a mechanistic understanding of the oxidation of coal and coal pyrite, and to correlate the intrinsic physical and chemical properties of these minerals, along with changes resulting from oxidation, with those surface properties that influence the behavior in physical cleaning processes. The results will provide fundamental insight into oxidation, in terms of the bulk and surface chemistry, the microstructure, and the semiconductor properties of the pyrite. During the eighth quarter, wet chemical and dry oxidation tests were done on Upper Freeport coal from the Troutville [number sign]2 Mine, Clearfield County, Pennsylvania. In addition electrochemical experiments were done on electrodes prepared from Upper Freeport coal pyrite and Pittsburgh coal pyrite samples provided by the US Bureau of Mines, Pittsburgh Research Center, Pennsylvania.

  12. Local aerosol concentrations and optical characteristics influenced by the Indonesian forest fire

    NASA Astrophysics Data System (ADS)

    Ru, Jianfei; Minomura, Mitsuo; Kuze, Hiroaki; Takeuchi, Nobuo

    1998-08-01

    Indonesian forest fire took place on Kalimantan and Sumatera islands in 1997 and continuously influenced the atmospheric conditions of South-East Asia nearly throughout the last half of that year. The color composed images of visible, near IR and IR channels from NOAA AVHRR daily data, arbitrarily assigned to red, green and blue respectively, were synthesized for distinguishing the smoke area. The data of three periods, the beginning, mid, and ending parts of the fire, were collected and analyzed in order to show the variation of atmosphere with the development of fire. A retrieval algorithm was established by use of Mie theory calculation and the radiative transfer codes. Local aerosol concentrations and properties over ocean parts between the two islands were derived. It is found that the aerosol optical thickness increased in accordance with the exacerbation of the fires. The changes of angstrom exponents show that smaller particle amounts were raised by the effects of burning.

  13. Analysis of temperature influences on the amplitude-frequency characteristics of Rn gas concentration.

    PubMed

    Finkelstein, Michael; Eppelbaum, Lev V; Price, Colin

    2006-01-01

    The ventilation mechanism of Rn gas in underground environments is considered. Ventilation plays an important role in influencing the variability (harmonics) of Rn gas in the porous space below the earth's surface. We propose a new physical-environmental model of relating Rn gas concentrations to air temperature variations at the earth's surface. Applicability of this model was tested after searching for Rn gas indicators of geodynamic processes in two underground tunnels in central and southern Israel. The theoretical estimation of Rn gas concentrations shows a good agreement with the observed values. We demonstrate the possibility of Rn gas anomalies being caused by atmospheric temperature variations and the necessity to take these effects into account when investigating geodynamic processes.

  14. Influence on grip of knife handle surface characteristics and wearing protective gloves.

    PubMed

    Claudon, Laurent

    2006-11-01

    Ten subjects were asked to apply maximum torques on knife handles with either their bare hand or their hand wearing a Kevlar fibre protective glove. Four knife handles (2 roughnesses, 2 hardnesses) were tested. Surface electromyograms of 6 upper limb and shoulder muscles were recorded and subject opinions on both knife handle hardness and friction in the hand were also assessed. The results revealed the significant influence of wearing gloves (p<0.0001), knife type (p<0.0005) and handle hardness (p<0.005) on the applied torque. Wearing Kevlar fibre gloves greatly increased the torque independently of the other two parameters. Under the bare hand condition, a 90 degrees ShA slightly rough handle provided the greatest torque. Subject opinion agreed with the observed effects on recorded torque values except for the hardness factor, for which a preference for the 70 degrees ShA value over the 90 degrees ShA value emerged.

  15. Oxidation of coal and coal pyrite mechanisms and influence on surface characteristics. Progress report

    SciTech Connect

    Doyle, F.M.

    1995-02-28

    The objective of this research is to develop a mechanistic understanding of the oxidation of coal and coal pyrite, and to correlate the intrinsic physical and chemical properties of these minerals, along with changes resulting from oxidation, with those surface properties that influence the behavior in physical cleaning processes. Work during the eighteenth quarter has focused on severe oxidation of coal by thermal and chemical treatment, and on investigating the partition of metal ions between such strongly oxidized coal samples and aqueous solutions. This partitioning behavior is being followed to obtain further information on the chemistry of the coal surfaces after different oxidation treatments, for example, whether partition occurs by an ion-exchange mechanism, or whether the surface is capable of changing the oxidation state of metallic species, with concurrent surface or bulk precipitation.

  16. The influence of domain size on the response characteristics of a hurricane storm surge model

    NASA Astrophysics Data System (ADS)

    Blain, C. A.; Westerink, J. J.; Luettich, R. A.

    1994-09-01

    The influence of domain size on boundary condition specification and on computed storm surge response is investigated. Storm surge response along the Florida shelf in the Gulf of Mexico due to Hurricane Kate is examined over three domains using two different open ocean boundary forcing functions, a still water (or zero elevation) condition and an inverted barometer condition which accounts for the atmospheric pressure component of the meteorological forcing. The first domain is relatively small and is situated primarily on the continental shelf in the region of intense storm surge generation. A second domain includes the entire Gulf of Mexico basin. The final domain covers the Gulf of Mexico, contiguous basins, and extends out into the deep Atlantic Ocean. The computed storm surge response indicates that the small domain is inadequate, since cross-shelf boundaries are in regions of significant storm surge generation where surge and therefore boundary conditions are not known a priori. Also, the behavior of resonant modes that are physically excited within the Gulf of Mexico due to the passage of the hurricane is unknown at the boundaries of this small domain. The domain that includes the entire Gulf of Mexico captures the primary storm surge well but may not correctly model resonant modes. In general, these resonant modes are difficult to accurately set up by boundary condition specification, since they may be dependent on interactions between the Gulf and contiguous basins. The primary storm surge response as well as resonant modes excited by the storm are best represented using a domain which encompasses the western North Atlantic Ocean, the Caribbean Sea, and the Gulf of Mexico. This domain with deep Atlantic Ocean boundaries facilitates simple boundary condition specification and minimizes the influence of boundary conditions on storm surge generation in coastal regions. Basin resonant modes and basin to basin interactions are also captured.

  17. Influence of air pressure on the detailed characteristics of corona current pulse due to positive corona discharge

    NASA Astrophysics Data System (ADS)

    Li, Xuebao; Cui, Xiang; Lu, Tiebing; Li, Dayong; Chen, Bo; Fu, Yuke

    2016-12-01

    Air pressure is one of the main factors affecting the corona discharge and influence of air pressure should be carefully investigated. In order to obtain the influence of air pressure on the detailed characteristics of corona current pulse, such as pulse amplitude, rise time, pulse width, duration time, and pulse repetition frequency, a systematic investigation is carried out though a coaxial conductor-cylinder electrode structure with a corona point on the conductor. The electrodes are put into a pressure chamber for adjusting the air pressure. The results show that pulse amplitude increases with the increase of air pressure, while rise time, pulse width, duration time, and pulse repetition frequency decrease significantly at the same ratio between applied voltage and onset voltage (U/U0). Empirical formulas for the pulse amplitude, rise time, pulse width, and duration time varying with air pressure are first established. On the basis of the development of positive corona discharge, the influence of air pressure on the typical time intervals and experimental results are qualitatively explained.

  18. Multi-scale factors influencing the characteristics of avian communities in urban parks across Beijing during the breeding season

    NASA Astrophysics Data System (ADS)

    Xie, Shilin; Lu, Fei; Cao, Lei; Zhou, Weiqi; Ouyang, Zhiyun

    2016-07-01

    Understanding the factors that influence the characteristics of avian communities using urban parks at both the patch and landscape level is important to focus management effort towards enhancing bird diversity. Here, we investigated this issue during the breeding season across urban parks in Beijing, China, using high-resolution satellite imagery. Fifty-two bird species were recorded across 29 parks. Analysis of residence type of birds showed that passengers were the most prevalent (37%), indicating that Beijing is a major node in the East Asian–Australasian Flyway. Park size was crucial for total species abundance, but foliage height diversity was the most important factor influencing avian species diversity. Thus, optimizing the configuration of vertical vegetation structure in certain park areas is critical for supporting avian communities in urban parks. Human visitation also showed negative impact on species diversity. At the landscape level, the percentage of artificial surface and largest patch index of woodland in the buffer region significantly affected total species richness, with insectivores and granivores being more sensitive to the landscape pattern of the buffer region. In conclusion, urban birds in Beijing are influenced by various multi-scale factors; however, these effects vary with different feeding types.

  19. Multi-scale factors influencing the characteristics of avian communities in urban parks across Beijing during the breeding season

    PubMed Central

    Xie, Shilin; Lu, Fei; Cao, Lei; Zhou, Weiqi; Ouyang, Zhiyun

    2016-01-01

    Understanding the factors that influence the characteristics of avian communities using urban parks at both the patch and landscape level is important to focus management effort towards enhancing bird diversity. Here, we investigated this issue during the breeding season across urban parks in Beijing, China, using high-resolution satellite imagery. Fifty-two bird species were recorded across 29 parks. Analysis of residence type of birds showed that passengers were the most prevalent (37%), indicating that Beijing is a major node in the East Asian–Australasian Flyway. Park size was crucial for total species abundance, but foliage height diversity was the most important factor influencing avian species diversity. Thus, optimizing the configuration of vertical vegetation structure in certain park areas is critical for supporting avian communities in urban parks. Human visitation also showed negative impact on species diversity. At the landscape level, the percentage of artificial surface and largest patch index of woodland in the buffer region significantly affected total species richness, with insectivores and granivores being more sensitive to the landscape pattern of the buffer region. In conclusion, urban birds in Beijing are influenced by various multi-scale factors; however, these effects vary with different feeding types. PMID:27404279

  20. The changes of spectroscopic characteristics of sulfurreducing bacteria Desulfuromonas acetoxidans under the influence of different metal ions

    NASA Astrophysics Data System (ADS)

    Vasyliv, Oresta M.; Bilyy, Olexandr I.; Getman, Vasyl B.; Kushkevych, Ivan V.; Hnatush, Svitlana O.

    2011-10-01

    Desulfuromonas acetoxidans, which is regarded to the oldest microorganisms that exist in the Earth, are uncoloured gram-negative obligatory anaerobic bacteria that have an ability to reduce S0 to H2S. This process supports bacteria with sufficient amount of energy which they need for growth. At the same time high concentrations of hydrogen sulfide are very toxic towards all living organisms. Different metal ions that exist in surrounding environment in small concentrations are essential for microorganisms because they support normal functionality of them. But in high concentrations they have a detrimental influence on cell structure and it functions. Srains of D. acetoxidans bacteria that have high toxic metals resistance can neutralize the toxicity of hydrogen sulfide, which is the final product of dissimilative sulfurreduction, and these metals as the result of their particular binding and forming the insoluble precipitations. Light scattering changes and metals accumulation ability of D. acetoxidans bacterial cells under the influence of CuSO4, PbNO3, ZnSO4 and CdSO4 have been investigated. The changes of light scattering characteristics of bacterial D. acetoxidans cells on the base of their size distribution and relative content under the influence of investigated metal salts have been observed by the new method of measurement.

  1. A simulator investigation of the influence of engine response characteristics on the approach and landing for an externally blown flap aircraft. Part 2: Aerodynamic model

    NASA Technical Reports Server (NTRS)

    Ciffone, D. L.; Robinson, G. H.

    1973-01-01

    An analysis of the influence of engine response characteristics on the approach and landing of an externally blown flap aircraft was conducted using flight simulator facilities. The configuration of the aerodynamic model is described. The aerodynamic characteristics as a function of angle of attack, thrust coefficient, and flap deflection are presented in tabular form and as graphs.

  2. Influence of Obesity on Foot Loading Characteristics in Gait for Children Aged 1 to 12 Years

    PubMed Central

    Mueller, Steffen; Carlsohn, Anja; Mueller, Juliane; Baur, Heiner; Mayer, Frank

    2016-01-01

    Background Overweight and obesity are increasing health problems that are not restricted to adults only. Childhood obesity is associated with metabolic, psychological and musculoskeletal comorbidities. However, knowledge about the effect of obesity on the foot function across maturation is lacking. Decreased foot function with disproportional loading characteristics is expected for obese children. The aim of this study was to examine foot loading characteristics during gait of normal-weight, overweight and obese children aged 1–12 years. Methods A total of 10382 children aged one to twelve years were enrolled in the study. Finally, 7575 children (m/f: n = 3630/3945; 7.0±2.9yr; 1.23±0.19m; 26.6±10.6kg; BMI: 17.1±2.4kg/m2) were included for (complete case) data analysis. Children were categorized to normal-weight (≥3rd and <90th percentile; n = 6458), overweight (≥90rd and <97th percentile; n = 746) or obese (>97th percentile; n = 371) according to the German reference system that is based on age and gender-specific body mass indices (BMI). Plantar pressure measurements were assessed during gait on an instrumented walkway. Contact area, arch index (AI), peak pressure (PP) and force time integral (FTI) were calculated for the total, fore-, mid- and hindfoot. Data was analyzed descriptively (mean ± SD) followed by ANOVA/Welch-test (according to homogeneity of variances: yes/no) for group differences according to BMI categorization (normal-weight, overweight, obesity) and for each age group 1 to 12yrs (post-hoc Tukey Kramer/Dunnett’s C; α = 0.05). Results Mean walking velocity was 0.95 ± 0.25 m/s with no differences between normal-weight, overweight or obese children (p = 0.0841). Results show higher foot contact area, arch index, peak pressure and force time integral in overweight and obese children (p<0.001). Obese children showed the 1.48-fold (1 year-old) to 3.49-fold (10 year-old) midfoot loading (FTI) compared to normal-weight. Conclusion Additional

  3. Influences of Host Community Characteristics on Borrelia burgdorferi Infection Prevalence in Blacklegged Ticks

    PubMed Central

    Chiu, Grace S.; Smouse, Peter E.; Fonseca, Dina M.; Brisson, Dustin; Morin, Peter J.; Ostfeld, Richard S.

    2017-01-01

    Lyme disease is a major vector-borne bacterial disease in the USA. The disease is caused by Borrelia burgdorferi, and transmitted among hosts and humans, primarily by blacklegged ticks (Ixodes scapularis). The ~25 B. burgdorferi genotypes, based on genotypic variation of their outer surface protein C (ospC), can be phenotypically separated as strains that primarily cause human diseases—human invasive strains (HIS)—or those that rarely do. Additionally, the genotypes are non-randomly associated with host species. The goal of this study was to examine the extent to which phenotypic outcomes of B. burgdorferi could be explained by the host communities fed upon by blacklegged ticks. In 2006 and 2009, we determined the host community composition based on abundance estimates of the vertebrate hosts, and collected host-seeking nymphal ticks in 2007 and 2010 to determine the ospC genotypes within infected ticks. We regressed instances of B. burgdorferi phenotypes on site-specific characteristics of host communities by constructing Bayesian hierarchical models that properly handled missing data. The models provided quantitative support for the relevance of host composition on Lyme disease risk pertaining to B. burgdorferi prevalence (i.e. overall nymphal infection prevalence, or NIPAll) and HIS prevalence among the infected ticks (NIPHIS). In each year, NIPAll and NIPHIS was found to be associated with host relative abundances and diversity. For mice and chipmunks, the association with NIPAll was positive, but tended to be negative with NIPHIS in both years. However, the direction of association between shrew relative abundance with NIPAll or NIPHIS differed across the two years. And, diversity (H') had a negative association with NIPAll, but positive association with NIPHIS in both years. Our analyses highlight that the relationships between the relative abundances of three primary hosts and the community diversity with NIPAll, and NIPHIS, are variable in time and

  4. How the basin characteristics influence the climate change impact on flood frequency

    NASA Astrophysics Data System (ADS)

    Camici, Stefania; Brocca, Luca; Moramarco, Tommaso

    2014-05-01

    Extreme hydrological events are increasing in magnitude and decision-makers expect reliable information on future climate scenarios as a basis for adaption strategies. In this context, identification of measures requires the estimates of changes in the frequency and magnitude of floods. For this purpose, global circulation models (GCMs) may address the matter by providing the climate change scenarios that are used as input for hydrological models. However, for small/medium catchments (<1000 km2) the spatial resolution of GCMs climate scenarios is inadequate for forcing a hydrological model and downscaling techniques are required, e.g. statistical based on bias correction, or dynamical, using regional climate models (RCMs) which are initialized by GCMs. Therefore, the downscaled future time series, reflecting an established scenarios, are used as input in the rainfall-runoff modeling to simulate the hydrological response to climate forcing. Each step in this chain introduces, however, uncertainty mainly for the too many variables involved in the hydrological processes and the reliability of climate change impact studies might be poor. Therefore, the issue could be overcome by capturing the most important hydrological processes that affect the change rather than identify the magnitudes of changes. Based on that, this study addresses the hydrological sensitivity of catchment to climate changes as a function of the soil, land use and topographic characteristic by a procedure based on: 1) downscaling several GCMs climate scenarios using approach, the Quantile Mapping statistics approach in this case; 2) generating long-term hourly time series of rainfall, temperature and discharge through stochastic weather generators and used to initialize a continuous rainfall-runoff model; 3) assessing the changing of frequency of annual maxima rainfall and discharge for the future period. For assessing how the hydrological sensitivity may depends on geomorphological characteristics

  5. Sex and age as determinants of rat T-cell phenotypic characteristics: influence of peripubertal gonadectomy.

    PubMed

    Arsenović-Ranin, Nevena; Kosec, Duško; Pilipović, Ivan; Nacka-Aleksić, Mirjana; Bufan, Biljana; Stojić-Vukanić, Zorica; Leposavić, Gordana

    2017-03-09

    The study examined the influence of age, sex and peripubertal gonadectomy on a set of T-cell phenotypic parameters. Rats of both sexes were gonadectomised at the age of 1 month and peripheral blood and spleen T lymphocytes from non-gonadectomised and gonadectomised 3- and 11-month-old rats were examined for the expression of differentiation/activation (CD90/CD45RC) and immunoregulatory markers. Peripheral blood T lymphocytes from non-gonadectomised rats showed age-dependent sexual dimorphisms in (1) total count (lower in female than male 11-month-old rats); (2) CD4+:CD8 + cell ratio (higher in female than male rats of both ages); (3) the proportion of recent thymic emigrants in CD8 + T cells (lower in female than male 3-month-old rats) and (4) the proportions of mature naïve and memory/activated cells (irrespective of age, the proportion of naïve cells was higher, whereas that of memory/activated cells was lower in females). Gonadectomy influenced magnitudes or direction of these sex differences. Additionally, sex differences in peripheral blood T-lymphocyte parameters did not fully correspond to those observed in T-splenocyte parameters, suggesting the compartment-specific regulation of the major T-cell subpopulations' and their subsets' composition. Furthermore, there was no sexual dimorphism in the proportion of either CD25 + Foxp3 + cells among CD4 + or CD161+ (NKT) cells within CD8 + T lymphocytes. However, there was gonadal hormone-independent age-associated sexual dimorphism in the proportion of CD161 + cells (NKT cells) in CD8 + T splenocytes. Overall, the study revealed age-dependent variations in sexual dimorphisms in T-cell parameters relevant for immune response efficacy and showed that they are T-cell compartment-specific and partly gonadal hormone-related.

  6. Which Morphological Characteristics Are Most Influenced by the Host Matrix in Downy Mildews? A Case Study in Pseudoperonospora cubensis

    PubMed Central

    Runge, Fabian; Ndambi, Beninweck; Thines, Marco

    2012-01-01

    Before the advent of molecular phylogenetics, species concepts in the downy mildews, an economically important group of obligate biotrophic oomycete pathogens, have mostly been based upon host range and morphology. While molecular phylogenetic studies have confirmed a narrow host range for many downy mildew species, others, like Pseudoperonospora cubensis affect even different genera. Although often morphological differences were found for new, phylogenetically distinct species, uncertainty prevails regarding their host ranges, especially regarding related plants that have been reported as downy mildew hosts, but were not included in the phylogenetic studies. In these cases, the basis for deciding if the divergence in some morphological characters can be deemed sufficient for designation as separate species is uncertain, as observed morphological divergence could be due to different host matrices colonised. The broad host range of P. cubensis (ca. 60 host species) renders this pathogen an ideal model organism for the investigation of morphological variations in relation to the host matrix and to evaluate which characteristics are best indicators for conspecificity or distinctiveness. On the basis of twelve morphological characterisitcs and a set of twelve cucurbits from five different Cucurbitaceae tribes, including the two species, Cyclanthera pedata and Thladiantha dubia, hitherto not reported as hosts of P. cubensis, a significant influence of the host matrix on pathogen morphology was found. Given the high intraspecific variation of some characteristics, also their plasticity has to be taken into account. The implications for morphological species determination and the confidence limits of morphological characteristics are discussed. For species delimitations in Pseudoperonospora it is shown that the ratio of the height of the first ramification to the sporangiophore length, ratio of the longer to the shorter ultimate branchlet, and especially the length and

  7. How do organisational characteristics influence teamwork and service delivery in lung cancer diagnostic assessment programmes? A mixed-methods study

    PubMed Central

    Honein-AbouHaidar, Gladys N; Stuart-McEwan, Terri; Waddell, Tom; Salvarrey, Alexandra; Smylie, Jennifer; Dobrow, Mark J; Brouwers, Melissa C; Gagliardi, Anna R

    2017-01-01

    Objectives Diagnostic assessment programmes (DAPs) can reduce wait times for cancer diagnosis, but optimal DAP design is unknown. This study explored how organisational characteristics influenced multidisciplinary teamwork and diagnostic service delivery in lung cancer DAPs. Design A mixed-methods approach integrated data from descriptive qualitative interviews and medical record abstraction at 4 lung cancer DAPs. Findings were analysed with the Integrated Team Effectiveness Model. Setting 4 DAPs at 2 teaching and 2 community hospitals in Canada. Participants 22 staff were interviewed about organisational characteristics, target service benchmarks, and teamwork processes, determinants and outcomes; 314 medical records were reviewed for actual service benchmarks. Results Formal, informal and asynchronous team processes enabled service delivery and yielded many perceived benefits at the patient, staff and service levels. However, several DAP characteristics challenged teamwork and service delivery: referral volume/workload, time since launch, days per week of operation, rural–remote population, number and type of full-time/part-time human resources, staff colocation, information systems. As a result, all sites failed to meet target benchmarks (from referral to consultation median 4.0 visits, median wait time 35.0 days). Recommendations included improved information systems, more staff in all specialties, staff colocation and expanded roles for patient navigators. Findings were captured in a conceptual framework of lung cancer DAP teamwork determinants and outcomes. Conclusions This study identified several DAP characteristics that could be improved to facilitate teamwork and enhance service delivery, thereby contributing to knowledge of organisational determinants of teamwork and associated outcomes. Findings can be used to update existing DAP guidelines, and by managers to plan or evaluate lung cancer DAPs. Ongoing research is needed to identify ideal roles for

  8. Influence of temperature, precipitation, and cultivar characteristics on changes in the spectrum of pathogenic fungi in winter wheat

    NASA Astrophysics Data System (ADS)

    Hýsek, Josef; Vavera, Radek; Růžek, Pavel

    2016-12-01

    In view of the threat posed by climate change, we studied the influence of temperature, precipitation, cultivar characteristics, and technical management measures on the occurrence of phytopathogenic fungi in wheat during 2009-2013. This work involved experiments at two sites differing in average temperatures and precipitation. Temperature and precipitation appear to influence differences in the spectrum of phytopathogenic fungi at the individual sites. In 2009 (the warmest year), Alternaria triticina was dominant. In 2010 (having the smallest deviations from the average for individual years), Septoria tritici dominated. In 2011, Puccinia triticina was most prominent, while in 2012, the genus Drechslera (Pyrenophora) and in 2013, S. tritici and Drechslera tritici-repentis (DTR) dominated. Temperature and precipitation levels in the individual spring months (warmer March to May) played a large role, especially for the leaf rust P. triticina in 2011. A change of only 1 °C with different precipitation during a year played a significant role in changing wheat's fungal spectrum. Cluster analysis showed the differences between single pathogenic fungi on wheat in a single year due to temperature and precipitation. Alternaria abundance was strongly influenced by year (p < 0.001) while locality was significant only in certain years (2012, 2013; p = 0.004 and 0.015, respectively). The same factors were revealed to be significant in the case of Puccinia, but locality played a role (p < 0.001) in different years (2011, 2013). The abundance of S. tritici and Pyrenophora tritici-repentis (Drechslera tritici-repentis) was influenced only by year (p < 0.001).

  9. Influence of temperature, precipitation, and cultivar characteristics on changes in the spectrum of pathogenic fungi in winter wheat.

    PubMed

    Hýsek, Josef; Vavera, Radek; Růžek, Pavel

    2016-12-14

    In view of the threat posed by climate change, we studied the influence of temperature, precipitation, cultivar characteristics, and technical management measures on the occurrence of phytopathogenic fungi in wheat during 2009-2013. This work involved experiments at two sites differing in average temperatures and precipitation. Temperature and precipitation appear to influence differences in the spectrum of phytopathogenic fungi at the individual sites. In 2009 (the warmest year), Alternaria triticina was dominant. In 2010 (having the smallest deviations from the average for individual years), Septoria tritici dominated. In 2011, Puccinia triticina was most prominent, while in 2012, the genus Drechslera (Pyrenophora) and in 2013, S. tritici and Drechslera tritici-repentis (DTR) dominated. Temperature and precipitation levels in the individual spring months (warmer March to May) played a large role, especially for the leaf rust P. triticina in 2011. A change of only 1 °C with different precipitation during a year played a significant role in changing wheat's fungal spectrum. Cluster analysis showed the differences between single pathogenic fungi on wheat in a single year due to temperature and precipitation. Alternaria abundance was strongly influenced by year (p < 0.001) while locality was significant only in certain years (2012, 2013; p = 0.004 and 0.015, respectively). The same factors were revealed to be significant in the case of Puccinia, but locality played a role (p < 0.001) in different years (2011, 2013). The abundance of S. tritici and Pyrenophora tritici-repentis (Drechslera tritici-repentis) was influenced only by year (p < 0.001).

  10. Characteristics of urban natural areas influencing winter bird use in southern Ontario, Canada.

    PubMed

    Smith, Paul G R

    2007-03-01

    Characteristics of urban natural areas and surrounding landscapes were identified that best explain winter bird use for 28 urban natural areas in southern Ontario, Canada. The research confirms for winter birds the importance of area (size) and natural vegetation, rather than managed, horticultural parkland, within urban natural areas as well as percent urban land use and natural habitat in surrounding landscapes. Alien bird density and percent ground feeding species increased with percent surrounding urban land use. Higher percent forest cover was associated with higher percentages of forest, bark feeding, small (<20 g) and insectivorous species. Natural area size (ha) was related to higher species richness, lower evenness and higher percentages of insectivorous, forest interior, area-sensitive, upper canopy, bark feeding, and non-resident species. Higher number of habitat types within natural areas and percent natural habitat in surrounding landscapes were also associated with higher species richness. Common, resident bird species dominated small areas (<6.5 ha), while less common non-residents increased with area, indicative of a nested distribution. Areas at least 6.5 ha and more generally >20 ha start to support some area-sensitive species. Areas similar to rural forests had >25% insectivores, >25% forest interior species, >25% small species, and <5% alien species. Indicator species separated urban natural areas from rural habitats and ordination placed urban natural areas along a gradient between urban development and undisturbed, rural forests. More attention is needed on issues of winter bird conservation in urban landscapes.

  11. Roadside bear viewing opportunities in Yellowstone National Park: characteristics, trends, and influence of whitebark pine

    USGS Publications Warehouse

    Haroldson, Mark A.; Gunther, Kerry

    2014-01-01

    Opportunities for viewing grizzly bears (Ursus arctos) and American black bears (U. americanus) from roadways in Yellowstone National Park (YNP) have increased in recent years. Unlike the panhandling bears common prior to the 1970s, current viewing usually involves bears feeding on natural foods. We define roadside bear viewing opportunities that cause traffic congestion as ‘‘bear-jams.’’ We investigated characteristics of bear-jams and their frequency relative to whitebark pine (Pinus albicaulis) cone production, an important fall food for bears, during 1990–2004. We observed a difference in diel distribution of bear-jams between species (x2=70.609, 4 df, P<0.001) with the occurrence of grizzly bear-jams being more crepuscular. We found evidence for decreasing distances between bears and roadways and increasing durations of bears-jams. The annual proportion of bear-jams for both species occurring after the week of 13–19 August were 3–4 times higher during poor cone crop years than good. We suggest that native foods found in road corridors may be especially important to some individual bears during years exhibiting poor whitebark pine crops. We discuss management implications of threats to whitebark pine and increasing habituation of bears to people.

  12. Influence of propane additives on the detonation characteristics of H2-air mixtures

    NASA Astrophysics Data System (ADS)

    Cheng, Guanbing; Bauer, Pascal; Zitoun, Ratiba

    2014-03-01

    Hydrogen is more and more considered as a potential fuel for propulsion applications. However, due to its low ignition energy and wide flammability limits, H2-air mixtures raise a concern in terms of safety. This aspect can be partly solved by adding an alkane to these mixtures, which plays the role of an inhibitor. The present paper provides data on such binary fuel-air mixtures where various amounts of propane are added to hydrogen. The behavior of the corresponding mixtures, in terms of detonation characteristics and other fundamental properties, such as the cell size of the detonation front and induction delay, are presented and discussed for a series of equivalence ratios and propane addition. The experimental detonation velocity is in good agreement with calculated theoretical Chapman-Jouguet values. Based on soot tracks records, the cell size λ is measured, whereas the induction length L i is derived from data using a GRI-Mech kinetic mechanism. These data allow providing a value of the coefficient K = λ/L i .

  13. Bacterial growth rates are influenced by cellular characteristics of individual species when immersed in electromagnetic fields.

    PubMed

    Tessaro, Lucas W E; Murugan, Nirosha J; Persinger, Michael A

    2015-03-01

    Previous studies have shown that exposure to extremely low-frequency electromagnetic fields (ELF-EMFs) have negative effects on the rate of growth of bacteria. In the present study, two Gram-positive and two Gram-negative species were exposed to six magnetic field conditions in broth cultures. Three variations of the 'Thomas' pulsed frequency-modulated pattern; a strong-static "puck" magnet upwards of 5000G in intensity; a pair of these magnets rotating opposite one another at ∼30rpm; and finally a strong dynamic magnetic field generator termed the 'Resonator' with an average intensity of 250μT were used. Growth rate was discerned by optical density (OD) measurements every hour at 600nm. ELF-EMF conditions significantly affected the rates of growth of the bacterial cultures, while the two static magnetic field conditions were not statistically significant. Most interestingly, the 'Resonator' dynamic magnetic field increased the rates of growth of three species (Staphylococcus epidermidis, Staphylococcus aureus, and Escherichia coli), while slowing the growth of one (Serratia marcescens). We suggest that these effects are due to individual biophysical characteristics of the bacterial species.

  14. Do therapist cultural characteristics influence the outcome of substance abuse treatment for Spanish-speaking adults?

    PubMed Central

    Suarez-Morales, Lourdes; McCabe, Brian E.; Feaster, Daniel J.; Martino, Steve; Cuzmar, Ivette Y.; Carroll, Kathleen M.; Bedregal, Luis; Paris, Manuel; Szapocznik, José

    2010-01-01

    This secondary data analysis of the Clinical Trials Network’s Motivational Enhancement Therapy effectiveness trial with Spanish-speaking substance users examined whether the degree of birthplace and acculturation similarities between clients and therapists, as well as the therapists’ own level of acculturation and birthplace were related to the clients’ participation in treatment and level of substance use during outpatient substance use treatment. Sixteen therapists and their 235 clients from the larger effectiveness trial were included in the analyses for this study. Results of the multilevel regression models for client participation in substance use treatment and client days of substance use taking into account within and between therapist cultural characteristics revealed that birthplace match and acculturation similarity between each therapist and his/her clients did not predict client outcomes. Instead, therapists’ birthplace and level of acculturation independently predicted days of substance use, but not treatment participation for monolingual Spanish-speaking clients. These findings are discussed in the context of the results of the main effectiveness trial and of psychotherapy research with ethnic minority populations, in particular Hispanic minorities. PMID:20438158

  15. Consistency of rapid muscle force characteristics: influence of muscle contraction onset detection methodology.

    PubMed

    Thompson, Brennan J; Ryan, Eric D; Herda, Trent J; Costa, Pablo B; Walter, Ashley A; Sobolewski, Eric J; Cramer, Joel T

    2012-12-01

    The purpose of this study was to investigate the consistency of commonly reported rapid force characteristics utilizing both automated and manual muscle contraction onset detection methods. Twenty-four healthy volunteers performed isometric strength testing of the plantar flexor muscle group on two nonconsecutive days. Test-retest reliability was evaluated using intraclass correlation coefficients (ICCs), standard errors of measurement (SEM), and the SEM as a percentage of the mean (SEM%) for rate of force development (RFD), relative RFD, contractile impulse, and absolute force-time values at various epoch durations using automated and manual onset detection methods. For all rapid force variables, ICC and SEM% values ranged from 0.52 to 0.96 and 7.56% to 37.56%, respectively. For the majority of these variables (20 of 23), the automated onset detection method resulted in higher ICC and lower SEM% values compared to the manual onset detection method. Regardless of onset detection methodology, the consistency of relative RFD values declined following 50% of MVC. Collectively, these findings indicated that commonly evaluated rapid muscle force variables demonstrated acceptable relative and absolute consistency values. However, these values were generally superior for the automated onset detection methodology. Additionally, the consistency of relative RFD values declines following 50% MVC and therefore should be evaluated with caution.

  16. Influence of origin and extraction method on argan oil physico-chemical characteristics and composition.

    PubMed

    Hilali, Miloudi; Charrouf, Zoubida; Soulhi, Abd El Aziz; Hachimi, Larbi; Guillaume, Dominique

    2005-03-23

    Twenty one samples of argan oil of different geographical origin (Tidzi, Tamanar, Benaiznassen, Ait mzal, Ait Baha, Ighrem, Aoulouz) and/or prepared following a different process (traditional, mechanical, or industrial) were collected and their physico-chemical properties analyzed. Sample acidity was found between 0.14 and 1.40%, unsaponifiable matter between 0.34 and 0.79%, saponification value between 180.0 and 199.6, highest peroxide index was 5.72 meq/kg, refractive index (20 degrees C) between 1.4644 and 1.4705, and UV absorption at 270 nm between 0.228 and 0.605. This study, carried out on randomly selected samples, clearly demonstrates that press extraction does not alter either the chemical composition of argan oil or its physico-chemical characteristics. It also demonstrates that press extraction respects the critical factors reported for traditionally prepared oils and necessary to obtain a beneficial effect on human health (a specific fatty acid balance and high tocopherol and sterol levels). In addition, this study should be useful for the establishment of a national quality standard.

  17. Influence of horizontally curved roadway section characteristics on motorcycle-to-barrier crash frequency.

    PubMed

    Gabauer, Douglas J; Li, Xiaolong

    2015-04-01

    The purpose of this study was to investigate motorcycle-to-barrier crash frequency on horizontally curved roadway sections in Washington State using police-reported crash data linked with roadway data and augmented with barrier presence information. Data included 4915 horizontal curved roadway sections with 252 of these sections experiencing 329 motorcycle-to-barrier crashes between 2002 and 2011. Negative binomial regression was used to predict motorcycle-to-barrier crash frequency using horizontal curvature and other roadway characteristics. Based on the model results, the strongest predictor of crash frequency was found to be curve radius. This supports a motorcycle-to-barrier crash countermeasure placement criterion based, at the very least, on horizontal curve radius. With respect to the existing horizontal curve criterion of 820 feet or less, curves meeting this criterion were found to increase motorcycle-to-barrier crash frequency rate by a factor of 10 compared to curves not meeting this criterion. Other statistically significant predictors were curve length, traffic volume and the location of adjacent curves. Assuming curves of identical radius, the model results suggest that longer curves, those with higher traffic volume, and those that have no adjacent curved sections within 300 feet of either curve end would likely be better candidates for a motorcycle-to-barrier crash countermeasure.

  18. Characteristics of Urban Natural Areas Influencing Winter Bird Use in Southern Ontario, Canada

    NASA Astrophysics Data System (ADS)

    Smith, Paul G. R.

    2007-03-01

    Characteristics of urban natural areas and surrounding landscapes were identified that best explain winter bird use for 28 urban natural areas in southern Ontario, Canada. The research confirms for winter birds the importance of area (size) and natural vegetation, rather than managed, horticultural parkland, within urban natural areas as well as percent urban land use and natural habitat in surrounding landscapes. Alien bird density and percent ground feeding species increased with percent surrounding urban land use. Higher percent forest cover was associated with higher percentages of forest, bark feeding, small (<20 g) and insectivorous species. Natural area size (ha) was related to higher species richness, lower evenness and higher percentages of insectivorous, forest interior, area-sensitive, upper canopy, bark feeding, and non-resident species. Higher number of habitat types within natural areas and percent natural habitat in surrounding landscapes were also associated with higher species richness. Common, resident bird species dominated small areas (<6.5 ha), while less common non-residents increased with area, indicative of a nested distribution. Areas at least 6.5 ha and more generally >20 ha start to support some area-sensitive species. Areas similar to rural forests had >25% insectivores, >25% forest interior species, >25% small species, and <5% alien species. Indicator species separated urban natural areas from rural habitats and ordination placed urban natural areas along a gradient between urban development and undisturbed, rural forests. More attention is needed on issues of winter bird conservation in urban landscapes.

  19. Influence of landscape characteristics on migration strategies of white-tailed deer

    USGS Publications Warehouse

    Grovenburg, T.W.; Jacques, C.N.; Klaver, R.W.; Deperno, C.S.; Brinkman, T.J.; Swanson, C.C.; Jenks, J.A.

    2011-01-01

    A trade-off exists for migrating animals as to whether to migrate or remain residents. Few studies have documented relationships between landscape variables and deer migration strategies. From 2000 to 2007 we captured 267 adult female white-tailed deer (Odocoileus virginianus) at 7 study sites in Minnesota and South Dakota and monitored 149 individuals through ≥3 seasonal migration periods (585 deer-migration seasons). All deer classified as obligate migrators with ≥3 migrations (range 3–9 migration seasons) maintained their obligate status for the duration of the study. Multinomial logistic odds ratios from generalized estimating equations indicated that the odds of being a resident increased by 1.4 and 1.3 per 1-unit increase in forest patch density and mean area, respectively, compared to migrating deer. Odds of being an obligate migrator increased by 0.7 and 0.8 per 1-unit decrease in forest patch density and mean area, respectively, compared to resident or conditional migrating deer. Areas inhabited by resident deer were characterized by greater number of forest patches per 100 ha and larger mean forest patch area than conditional and obligate migrant areas. Odds of migrating increased by 1.1 per 1-unit increase in deer winter severity index. Migration behavior of white-tailed deer varied among regions, and land-cover and landscape characteristics provided predictive indicators of migration strategies for deer that could have important implications for conservation, metapopulation dynamics, and species management.

  20. The influence of short-term exposure to tropical sunlight on boar seminal characteristics

    NASA Astrophysics Data System (ADS)

    Egbunike, G. N.; Dede, T. I.

    1980-06-01

    The seminal characteristics of 4 Large White boars exposed to direct tropical sunlight 45 min daily for three days were compared to those of their mates that were maintained under shade in the barn. During the period of exposure, both respiratory rate and rectal temperature increased significantly by 276.84 and 5.13% respectively in the exposed over the unexposed boars, thus indicating a high degree of hyperthermia. Although libido, as judged from the reaction time, was unaffected, the ejaculation time appeared to be longer for the stressed than unstressed animals. Gel mass, semen volume and pH appeared to be stable inspite of the treatment, unlike sperm motility and concentration which deteriorated. Also, the dehydrogenase activity of the semen was inferior in the stressed animals. Sperm output per ejaculate dropped drastically only in the week following exposure from 58.22 to 28.42 billion sperm as compared to corresponding values of 54.83 and 47.87 by the unexposed boars. Similarly, the frequency of sperm abnormality was higher in the stressed boars in this period after which the animals appeared to have recovered.

  1. Influence of gate overlap engineering on ambipolar and high frequency characteristics of tunnel-CNTFET

    NASA Astrophysics Data System (ADS)

    Shaker, Ahmed; Ossaimee, Mahmoud; Zekry, A.; Abouelatta, Mohamed

    2015-10-01

    In this paper, we have investigated the effect of gate overlapping-on-drain on the ambipolar behavior and high frequency performance of tunnel CNTFET (T-CNTFET). It is found that gate overlapping-on-drain suppresses the ambipolar behavior and improves OFF-state current. The simulation results show that there is an optimum choice for the overlapped length. On the other hand, this overlap deteriorates the high frequency performance. The high frequency figure of merit is analyzed in terms of the unit-gain cutoff frequency (fT). Further, we propose two different approaches to improve the high frequency performance of the overlapped T-CNTFET. The first one is based on inserting a high-dielectric constant material below the overlapped part of the gate and the second is based on depositing a different work function gate metal for the overlapped region. The two solutions show very good improvement in the high frequency performance with maintaining the suppression of the ambipolar characteristics.

  2. Measurements of Pilot Time Delay as Influenced by Controller Characteristics and Vehicles Time Delays

    NASA Technical Reports Server (NTRS)

    Privoznik, C. M.; Berry, D. T.; Bartoli, A. G.

    1984-01-01

    A study to measure and compare pilot time delay when using a space shuttle rotational hand controller and a more conventional control stick was conducted at NASA Ames Research Center's Dryden Flight Research Facility. The space shuttle controller has a palm pivot in the pitch axis. The more conventional controller used was a general-purpose engineering simulator stick that has a pivot length between that of a typical aircraft center stick and a sidestick. Measurements of the pilot's effective time delay were obtained through a first-order, closed-loop, compensatory tracking task in pitch. The tasks were implemented through a space shuttle cockpit simulator and a critical task tester device. The study consisted of 450 data runs with four test pilots and one nonpilot, and used three control stick configurations and two system delays. Results showed that the heavier conventional stick had the lowest pilot effective time delays associated with it, whereas the shuttle and light conventional sticks each had similar higher pilot time delay characteristics. It was also determined that each control stick showed an increase in pilot time delay when the total system delay was increased.

  3. Vehicle and driving characteristics that influence in-cabin particle number concentrations.

    PubMed

    Hudda, Neelakshi; Kostenidou, Evangelia; Sioutas, Constantinos; Delfino, Ralph J; Fruin, Scott A

    2011-10-15

    In-transit microenvironments experience elevated levels of vehicle-related pollutants such as ultrafine particles. However, in-vehicle particle number concentrations are frequently lower than on-road concentrations due to particle losses inside vehicles. Particle concentration reduction occurs due to a complicated interplay between a vehicle's air-exchange rate (AER), which determines particle influx rate, and particle losses due to surfaces and the in-cabin air filter. Accurate determination of inside-to-outside particle concentration ratios is best made under realistic aerodynamic and AER conditions because these ratios and AER are determined by vehicle speed and ventilation preference, in addition to vehicle characteristics such as age. In this study, 6 vehicles were tested at 76 combinations of driving speeds, ventilation conditions (i.e., outside air or recirculation), and fan settings. Under recirculation conditions, particle number attenuation (number reduction for 10-1000 nm particles) averaged 0.83 ± 0.13 and was strongly negatively correlated with increasing AER, which in turn depended on speed and the age of the vehicle. Under outside air conditions, attenuation averaged 0.33 ± 0.10 and primarily decreased at higher fan settings that increased AER. In general, in-cabin particle number reductions did not vary strongly with particle size, and cabin filters exhibited low removal efficiencies.

  4. Characteristics and Gel Properties of Gelatin from Goat Skin as Influenced by Alkaline-pretreatment Conditions

    PubMed Central

    Mad-Ali, Sulaiman; Benjakul, Soottawat; Prodpran, Thummanoon; Maqsood, Sajid

    2016-01-01

    Characteristics and properties of gelatin from goat skin pretreated with NaOH solutions (0.50 and 0.75 M) for various times (1 to 4 days) were investigated. All gelatins contained α-chains as the predominant component, followed by β-chain. Gelling and melting temperatures of those gelatins were 23.02°C to 24.16°C and 33.07°C to 34.51°C, respectively. Gel strength of gelatins increased as NaOH concentration and pretreatment time increased (p<0.05). Pretreatment for a longer time yielded gelatin with a decrease in L*-value but an increase in b*-value. Pretreatment of goat skin using 0.75 M NaOH for 2 days rendered the highest yield (15.95%, wet weight basis) as well as high gel strength (222.42 g), which was higher than bovine gelatin (199.15 g). Gelatin obtained had the imino acid content of 226 residues/1,000 residues and the gelatin gel had a fine and ordered structure. Therefore, goat skin gelatin could be used as a potential replacer of commercial gelatin. PMID:26954127

  5. A review of the factors influencing the physicochemical characteristics of underground coal gasification

    SciTech Connect

    Yang, L.H.

    2008-07-01

    In this article, the physicochemical characteristics of the oxidation zone, the reduction zone, and the destructive distillation and dry zone in the process of underground coal gasification (UCG) were explained. The effect of such major factors as temperature, coal type, water-inrush or -intake rate, the quantity and quality of wind blasting, the thickness of coal seams, operational pressure, the length, and the section of gasification gallery on the quality of the underground gas and their interrelationship were discussed. Research showed that the temperature conditions determined the underground gas compositions; the appropriate water-inrush or -intake rate was conducive to the improvement in gas heat value; the properties of the gasification agent had an obvious effect on the compositions and heat value of the product gas. Under the cyclically changing pressure, heat losses decreased by 60%, with the heat efficiency and gasification efficiency being 1.4 times and 2 times those of constant pressure, respectively. The test research further proved that the underground gasifier with a long channel and a big cross-section, to a large extent, improved the combustion-gasification conditions.

  6. Anthropometric characteristics and sex influence magnitude of skin cooling following exposure to whole body cryotherapy.

    PubMed

    Hammond, L E; Cuttell, S; Nunley, P; Meyler, J

    2014-01-01

    This study explored whether anthropometric measures influence magnitude of skin cooling following exposure to whole body cryotherapy (WBC). Height, weight, body fat percentage, and lean mass were measured in 18 male and 14 female participants. Body surface area, body surface area to mass ratio, body mass index, fat-free mass index, and fat mass index were calculated. Thermal images were captured before and after WBC (-60°C for 30 seconds, -110°C for 2 minutes). Skin temperature was measured at the chest, arm, thigh, and calf. Mean skin temperature before and after WBC and change in mean skin temperature (ΔT sk) were calculated. ΔT sk was significantly greater in females (12.07 ± 1.55°C) than males (10.12 ± 1.86°C; t(30) = -3.09, P = .004). A significant relationship was observed between body fat percentage and ΔT sk in the combined dataset (P = .002, r = .516) and between fat-free mass index and ΔT sk in males (P = .005, r = .622). No other significant associations were found. Skin response of individuals to WBC appears to depend upon anthropometric variables and sex, with individuals with a higher adiposity cooling more than thinner individuals. Effects of sex and anthompometrics should be considered when designing WBC research or treatment protocols.

  7. Flow Scales of Influence on the Settling Velocities of Particles with Varying Characteristics

    PubMed Central

    Jacobs, Corrine N.; Merchant, Wilmot; Jendrassak, Marek; Limpasuvan, Varavut; Gurka, Roi; Hackett, Erin E.

    2016-01-01

    The settling velocities of natural, synthetic, and industrial particles were measured in a grid turbulence facility using optical measurement techniques. Particle image velocimetry and 2D particle tracking were used to measure the instantaneous velocities of the flow and the particles’ trajectories simultaneously. We find that for particles examined in this study (Rep = 0.4–123), settling velocity is either enhanced or unchanged relative to stagnant flow for the range of investigated turbulence conditions. The smallest particles’ normalized settling velocities exhibited the most consistent trends when plotted versus the Kolmogorov-based Stokes numbers suggesting that the dissipative scales influence their dynamics. In contrast, the mid-sized particles were better characterized with a Stokes number based on the integral time scale. The largest particles were largely unaffected by the flow conditions. Using proper orthogonal decomposition (POD), the flow pattern scales are compared to particle trajectory curvature to complement results obtained through dimensional analysis using Stokes numbers. The smallest particles are found to have trajectories with curvatures of similar scale as the small flow scales (higher POD modes) whilst mid-sized particle trajectories had curvatures that were similar to the larger flow patterns (lower POD modes). The curvature trajectories of the largest particles did not correspond to any particular flow pattern scale suggesting that their trajectories were more random. These results provide experimental evidence of the “fast tracking” theory of settling velocity enhancement in turbulence and demonstrate that particles align themselves with flow scales in proportion to their size. PMID:27513958

  8. Influence of pulse duration on the plasma characteristics in high-power pulsed magnetron discharges

    SciTech Connect

    Konstantinidis, S.; Dauchot, J.P.; Ganciu, M.; Ricard, A.; Hecq, M.

    2006-01-01

    High-power pulsed magnetron discharges have drawn an increasing interest as an approach to produce highly ionized metallic vapor. In this paper we propose to study how the plasma composition and the deposition rate are influenced by the pulse duration. The plasma is studied by time-resolved optical emission and absorption spectroscopies and the deposition rate is controlled thanks to a quartz microbalance. The pulse length is varied between 2.5 and 20 {mu}s at 2 and 10 mTorr in pure argon. The sputtered material is titanium. For a constant discharge power, the deposition rate increases as the pulse length decreases. With 5 {mu}s pulse, for an average power of 300 W, the deposition rate is {approx}70% of the deposition rate obtained in direct current magnetron sputtering at the same power. The increase of deposition rate can be related to the sputtering regime. For long pulses, self-sputtering seems to occur as demonstrated by time-resolved optical emission diagnostic of the discharge. In contrary, the metallic vapor ionization rate, as determined by absorption measurements, diminishes as the pulses are shortened. Nevertheless, the ionization rate is in the range of 50% for 5 {mu}s pulses while it lies below 10% in the case of a classical continuous magnetron discharge.

  9. Anthropometric Characteristics and Sex Influence Magnitude of Skin Cooling following Exposure to Whole Body Cryotherapy

    PubMed Central

    Hammond, L. E.; Cuttell, S.; Nunley, P.; Meyler, J.

    2014-01-01

    This study explored whether anthropometric measures influence magnitude of skin cooling following exposure to whole body cryotherapy (WBC). Height, weight, body fat percentage, and lean mass were measured in 18 male and 14 female participants. Body surface area, body surface area to mass ratio, body mass index, fat-free mass index, and fat mass index were calculated. Thermal images were captured before and after WBC (−60°C for 30 seconds, −110°C for 2 minutes). Skin temperature was measured at the chest, arm, thigh, and calf. Mean skin temperature before and after WBC and change in mean skin temperature (ΔTsk) were calculated. ΔTsk was significantly greater in females (12.07 ± 1.55°C) than males (10.12 ± 1.86°C; t(30) = −3.09, P = .004). A significant relationship was observed between body fat percentage and ΔTsk in the combined dataset (P = .002, r = .516) and between fat-free mass index and ΔTsk in males (P = .005, r = .622). No other significant associations were found. Skin response of individuals to WBC appears to depend upon anthropometric variables and sex, with individuals with a higher adiposity cooling more than thinner individuals. Effects of sex and anthompometrics should be considered when designing WBC research or treatment protocols. PMID:25061612

  10. Influence of terrain on metabolic and temporal gait characteristics of unilateral transtibial amputees.

    PubMed

    Paysant, Jean; Beyaert, Christian; Datié, Ange-Michel; Martinet, Noël; André, Jean-Marie

    2006-01-01

    The difficulties confronted by amputees during overground walking are rarely investigated. In this study, we evaluated, in real-world situations, the influence of ground surface on walking in young, active amputees by measuring temporal and spatial gait parameters (free walking speed [FWS], step length [SL], step rate), energy expenditure (EE) (e.g., oxygen uptake, oxygen cost [O(2)C]), and Rating of Perceived Exertion (RPE). Ten active transtibial amputees and ten nondisabled control subjects walked at self-selected speeds on three types of ground surface (asphalt, mown lawn, and high grass). No significant differences were observed between the two groups on asphalt and mown lawn. Differences between nondisabled subjects and amputees occurred for FWS (p = 0.03) and O(2)C (p = 0.04) on asphalt and mown lawn and for all variables in high grass. When amputees (even though very active) were exposed to a particularly difficult environment, their FWS decreased (p = 0.008) and their EE and RPE increased (p = 0.005) compared with nondisabled subjects. In high grass, both groups reduced their self-selected speeds (-15% for control subjects and -16% for amputees). Control subjects reduced their velocity by reducing both SL (-8.7%) and cadence (-7.1%), whereas amputees reduced their velocity by reducing SL (-17%) only.

  11. Oxidation of coal and coal pyrite mechanisms and influence on surface characteristics. Technical progress report

    SciTech Connect

    Doyle, F.M.

    1995-05-31

    The objective of this research is to develop a mechanistic understanding of the oxidation of coal and coal pyrite, and to correlate the intrinsic physical and chemical properties of these minerals, along with changes resulting from oxidation, with those surface properties that influence the behavior in physical cleaning processes. Work during the nineteenth quarter has concluded studies of the surface functional groups produced on coal by severe thermal and chemical oxidation, and on investigating the partition of metal ions between such strongly oxidized coal samples and aqueous solutions. This partitioning behavior was being followed to obtain further information on the chemistry of the coal surfaces after different oxidation treatments. Adsorption isotherms for the uptake of Cd{sup 2+} on coal oxidized by different methods were obtained, and these and the Cu{sup 2+} adsorption isotherms reported in the last report have been scrutinized, and interpreted more exhaustively. The apparent discrepancies noted in the last report for the analysis of surface functional groups have been investigated further. The adsorption behavior has been related to the surface chemistry of Upper Freeport coal oxidized by different methods.

  12. [Characteristics and influencing factors of trichloroethylene adsorption in different soil types].

    PubMed

    He, Long; Qiu, Zhao-Fu; Lü, Shu-Guang; Lu, Zhi-Chang; Wang, Zhi-Li; Sui, Qian; Lin, Kuang-Fei; Liu, Yong-Di

    2012-11-01

    Adsorption plays an important role in the transport and the fate of trichloroethylene (TCE) in soil. Six types of soil, including two types of natural soil with different organic carbon content and four types of soil with the low aggregation of "soft carbon" pre-treated by hydrogen peroxide or with all organic carbon removed by high temperature ignition from the original soil, were adopted as adsorbents. The effects of parameters (organic carbon content and composition, minerals, the initial TCE concentration, solution pH, moisture content and ionic strength) on TCE adsorption capacity were examined. The results showed that the soil adsorption isotherm was non-linear within the experimental range. The TCE adsorption capacity was increased and the contribution rate of the minerals to the sorption was reduced with the increase of the organic carbon content. The adsorption of TCE in the soil was the result of the combined action of both organic carbon and minerals, in which organic carbon played a major part, whereas the role of minerals could not be neglected. As the initial TCE concentration increased, the contribution rate of the minerals to the sorption went down. The adsorption isotherm of "soft carbon" was linear, while the "hard carbon" was non-linear. Moreover, the adsorption capacity was increased by increasing the ionic strength. In contrast, neither pH nor moisture content had any influence on TCE adsorption.

  13. Influence of silicon dioxide capping layers on pore characteristics in nanocrystalline silicon membranes.

    PubMed

    Qi, Chengzhu; Striemer, Christopher C; Gaborski, Thomas R; McGrath, James L; Fauchet, Philippe M

    2015-02-06

    Porous nanocrystalline silicon (pnc-Si) membranes are a new class of membrane material with promising applications in biological separations. Pores are formed in a silicon film sandwiched between nm thick silicon dioxide layers during rapid thermal annealing. Controlling pore size is critical in the size-dependent separation applications. In this work, we systematically studied the influence of the silicon dioxide capping layers on pnc-Si membranes. Even a single nm thick top oxide layer is enough to switch from agglomeration to pore formation after annealing. Both the pore size and porosity increase with the thickness of the top oxide, but quickly reach a plateau after 10 nm of oxide. The bottom oxide layer acts as a barrier layer to prevent the a-Si film from undergoing homo-epitaxial growth during annealing. Both the pore size and porosity decrease as the thickness of the bottom oxide layer increases to 100 nm. The decrease of the pore size and porosity is correlated with the increased roughness of the bottom oxide layer, which hinders nanocrystal nucleation and nanopore formation.

  14. [Variation characteristic in soil respiration of apple orchard and its biotic and abiotic influencing factors].

    PubMed

    Wang, Rui; Guo, Sheng-Li; Liu, Qing-Fang; Zhang, Yan-Jun; Jiang, Ji-Shao; Guo, Hui-Min; Li, Ru-Jian

    2014-05-01

    To evaluate the orchard variability of soil respiration and the response of soil respiration to its influencing factors is helpful for a deep understanding about the effects of converting cropland to apple orchard. A field experiment was conducted in the Changwu State Key Agro-Ecological Station. Soil respiration, soil temperature, soil moisture and roots biomasses were periodically measured in a mature apple orchard during 2011 and 2012. Soil respiration decreased as the distance from the trunk increased. The cumulative soil respiration in the 0.5 m-distance from the trunk was 20% and 31% higher than that in the 2 m-distance from the trunk, respectively in 2011 and 2012. The temperature sensitivity of soil respiration (Q10) was relatively lower in the 2 m-distance than that in the 0. 5 m-distance in both years. Soil temperature and soil moisture were slightly higher in the 2 m-distance, but there was no significant difference between the 2 m-distance and the 0. 5 m-distance. Soil respiration and soil temperature showed a significant exponential relationship, but there was no positive correlation between soil moisture and soil respiration. Soil temperature changes can explain seasonal variation of soil respiration well, but it could not explain its spatial variability. Root density was an important factor for the spatial variability of soil respiration and Q15. Variation of soil respiration coefficient was 23% -31%. Therefore, the distance from the trunk should be considered when estimating orchards soil respiration.

  15. Role of Alternative Fuels on Particulate Matter (PM) Characteristics and Influence of the Diesel Oxidation Catalyst.

    PubMed

    Fayad, Mohammed A; Herreros, Jose M; Martos, Francisco J; Tsolakis, Athanasios

    2015-10-06

    The influence of a platinum:palladium (Pt:Pd)-based diesel oxidation catalyst (DOC) on the engine-out particulate matter (PM) emissions morphology and structure from the combustion of alternative fuels (including alcohol-diesel blends and rapeseed oil methyl ester (RME) biodiesel) was studied. PM size distribution was measured using a scanning mobility particulate spectrometer (SMPS), and the PM morphology and microstructure (including size distribution, fractal geometry, and number of primary particles) was obtained using high-resolution transmission electron microscopy (TEM). It is concluded that the DOC does not modify the size or the microstructural parameters of the primary particulates that make up the soot agglomerates. The PM reduction seen in the DOC is due to the trapping effect, and oxidation of the PM's volatile components. The DOC performance in reducing gaseous (e.g., carbon monoxide (CO) and unburnt hydrocarbons (HCs)) and PM emissions at low exhaust temperatures was improved from the combustion of alternative fuels due to the reduced level of engine-out pollutants.

  16. Influence irradiation argon ion SnO2 on optical and electrical characteristics

    NASA Astrophysics Data System (ADS)

    Asainov, O.; Umnov, S.; Temenkov, V.

    2017-01-01

    Tin oxide in the form of films has been deposited by reactive magnetron sputtering on glass substrates a room temperature. Process was carried out in such mode when the deposited films were conductive. The deposited films were irradiated with argon ions. Have been studied happening at that the changes optical and electric properties of films. Have been investigated optical properties of films in the range of 300-1100 nanometers by means of photometry. For research structure of films was used the x-ray diffractometry. Diffractometric researches have shown that the films deposited on a substrate have crystal structure from shares of a quasicrystal phase and after influence of argon ions she completely became quasicrystal. It is established that change transmission of a film correlates with change her electric resistance. Average value transmission in the range of 380-1100 nanometers as well as the electric resistance of a film with growth of irradiation time increases to the values exceeding initial. At the same time at irradiation time ∼ 13,2 sec. are observed their slight decrease. To this value of irradiation time there corresponds the minimum value of electric resistance and transmission films. Change of transmission coefficient correlates with change of surface resistance.

  17. Interaction of triprolidine hydrochloride with serum albumins: thermodynamic and binding characteristics, and influence of site probes.

    PubMed

    Sandhya, B; Hegde, Ashwini H; Kalanur, Shankara S; Katrahalli, Umesha; Seetharamappa, J

    2011-04-05

    The interaction between triprolidine hydrochloride (TRP) to serum albumins viz. bovine serum albumin (BSA) and human serum albumin (HSA) has been studied by spectroscopic methods. The experimental results revealed the static quenching mechanism in the interaction of TRP with protein. The number of binding sites close to unity for both TRP-BSA and TRP-HSA indicated the presence of single class of binding site for the drug in protein. The binding constant values of TRP-BSA and TRP-HSA were observed to be 4.75 ± 0.018 × 10(3) and 2.42 ± 0.024 × 10(4)M(-1) at 294 K, respectively. Thermodynamic parameters indicated that the hydrogen bond and van der Waals forces played the major role in the binding of TRP to proteins. The distance of separation between the serum albumin and TRP was obtained from the Förster's theory of non-radioactive energy transfer. The metal ions viz., K(+), Ca(2+), Co(2+), Cu(2+), Ni(2+), Mn(2+) and Zn(2+) were found to influence the binding of the drug to protein. Displacement experiments indicated the binding of TRP to Sudlow's site I on both BSA and HSA. The CD, 3D fluorescence spectra and FT-IR spectral results revealed the changes in the secondary structure of protein upon interaction with TRP.

  18. Influence of dissolved oxygen on the protectiveness and morphological characteristics of calcareous deposits with galvanostatic polarization

    NASA Astrophysics Data System (ADS)

    Li, Chengjie; Du, Min; Gao, Rongjie

    2017-04-01

    The influence of dissolved oxygen on calcareous deposits formed under galvanostatic polarization mode was studied. When the dissolved oxygen concentration was less than 7 mg L-1, the cathodic protection potential showed a plateau at the initial polarization, and then quickly shifted negatively. While the dissolved oxygen was more than 9 mg L-1, the potential shifted negatively in a linear form. After 168 h of polarization, the final protection potential shifted negatively with the decreasing dissolved oxygen concentration. The deposition progress was monitored by electrochemical impedance spectroscopy, and only one single loop was found in Nyquist diagram, indicating deposits of ineffective protectiveness precipitation under the experimental conditions. The protection factor of deposits increased with the decreasing dissolved oxygen concentration which was detected by linear polarization resistance technique. The cathodic electrochemical reaction could change very shortly from oxygen reduction to hydrogen evolution after cathodic protection under very low dissolved oxygen concentration, such as 1 mg L-1, resulting in the hydrogen bubbling from the metallic surface and the decrease of deposits protection factor. Observation by scanning electron microscopy and X-ray diffraction analysis demonstrated that the deposits were mainly of calcite under the experimental conditions, and that dissolved oxygen had no effect on the crystalline types of calcium carbonate.

  19. Organic contaminant release from melting snow. 2. Influence of snow pack and melt characteristics.

    PubMed

    Meyer, Torsten; Lei, Ying Duan; Muradi, Ibrahim; Wania, Frank

    2009-02-01

    Large reservoirs of organic contaminants in seasonal snowpack can be released in short pulses during spring snowmelt, potentially impacting the receiving ecosystems. Laboratory experiments using artificial snow spiked with organic target substances were conducted to investigate the behavior of six organic contaminants with widely variable distribution properties in melting snow. Whereas the influence of a chemical's equilibrium phase partitioning on the elution behavior is explored in a companion paper, we discuss here the impact of snow properties and melt features, including the snowpack depth, the temperature at the interface between soil and snow, the meltwater content the internal ice surface area, and the existence of distinct snow layers. Water-soluble organic substances are released in high concentrations at the beginning of a melt period when a deep and aged snowpack undergoes intense melting. Warm ground can cause notable melting at the snow bottom leading to a delayed and dampened concentration peak. Hydraulic barriers in layered snow packs cause preferential meltwater flow which also mitigates the early contaminant flush. Hydrophobic organic pollutants that are associated with particles accumulate near the snow surface and are released at the end of melting. Dirt cones at the surface of a dense snowpack enhance this enrichment. The findings of this laboratory study will aid in the understanding of the behavior of organic pollutants during the melting of more complex, natural snow covers.

  20. Influence of tropical seasonal variations on landfill leachate characteristics--results from lysimeter studies.

    PubMed

    Tränkler, J; Visvanathan, C; Kuruparan, P; Tubtimthai, O

    2005-01-01

    Considering the quality of design and construction of landfills in developing countries, little information can be derived from randomly taken leachate samples. Leachate generation and composition under monsoon conditions have been studied using lysimeters to simulate sanitary landfills and open cell settings. In this study, lysimeters were filled with domestic waste, highly organic market waste and pre-treated waste. Results over two subsequent dry and rainy seasons indicate that the open cell lysimeter simulation showed the highest leachate generation throughout the rainy season, with leachate flow in all lysimeters coming to a halt during the dry periods. More than 60% of the precipitation was found in the form of leachate. The specific COD and TKN load discharged from the open cell was 20% and 180% more than that of the sanitary landfill lysimeters. Types of waste material and kind of pre-treatment prior to landfilling strongly influenced the pollutant load. Compared to the sanitary landfill lysimeter filled with domestic waste, the specific COD and TKN load discharged from the pre-treated waste lysimeter accounted for only 4% and 16%, respectively. Considering the local settings of tropical landfills, these results suggest that landfill design and operation has to be adjusted. Leachate can be collected and stored during the rainy season, and recirculation of leachate is recommended to maintain a steady and even accelerated degradation during the prolonged dry season. The open cell approach in combination with leachate recirculation is suggested as an option for interim landfill operations.

  1. Influence of Physiochemical and watershed characteristics on mercury concentration in walleye, Sander vitreus, M.

    USGS Publications Warehouse

    Hayer, Cari-Ann; Chipps, Steven R.; Stone, James J.

    2011-01-01

    Elevated mercury concentration has been documented in a variety of fish and is a growing concern for human consumption. Here, we explore the influence of physiochemical and watershed attributes on mercury concentration in walleye (Sander vitreus, M.) from natural, glacial lakes in South Dakota. Regression analysis showed that water quality attributes were poor predictors of walleye mercury concentration (R2 = 0.57, p = 0.13). In contrast, models based on watershed features (e.g., lake level changes, watershed slope, agricultural land, wetlands) and local habitat features (i.e., substrate composition, maximum lake depth) explained 81% (p = 0.001) and 80% (p = 0.002) of the variation in walleye mercury concentration. Using an information theoretic approach we evaluated hypotheses related to water quality, physical habitat and watershed features. The best model explaining variation in walleye mercury concentration included local habitat features (Wi = 0.991). These results show that physical habitat and watershed features were better predictors of walleye mercury concentration than water chemistry in glacial lakes of the Northern Great Plains.

  2. The spatiotemporal characteristics of soil physio-chemical parameters and their influence on cotton growth under mulched drip irrigation

    NASA Astrophysics Data System (ADS)

    Hu, H.; Tian, F.; Zhang, Z.; Hu, H.

    2013-12-01

    The spatiotemporal characteristics of the physio-chemical parameters of soil and their impacts on crop growth are the key issues affecting precision agriculture. However, quantitative research in cotton fields under mulched drip irrigation is rare. One hundred experimental plots (6 m× 6 m) were set up for the above purpose in an agricultural experimental field in Xinjiang Uygur Autonomous Region of China. Soil samples were collected to measure the soil texture, moisture and salinity at depths of 5, 10, 20, 30, 50 and 80 cm in the near-tape zone and the inter-film zone in each experimental plot in March, April, June and September of 2012. The number and height of the cotton plants in June and the yield of cotton in September were also surveyed in 3 sample units (75 cm × 75 cm) in each experimental plot. The results indicate that the soil composition of clay and silt was highest at a soil depth of 5 to 20 cm due to the cultivation practices, and the Cv (coefficient of variation) values of soil texture increased with depth. The spring flush led to an 8% decrease in soil salinity and reduced the Cv values of soil salinity, soil moisture and soil texture. The Cv values of soil salinity and soil moisture increased as mulched drip irrigation was applied. The Cv values of soil salinity and moisture under the near tape zone were higher than under the interfilm zone; the difference was up to twofold in September. The validity of a theoretical semivariogram model of soil moisture is greater than that of texture, soil salinity and crop trait when comparing the estimation of the theoretical semivariogram with measured values. The influence of soil physiochemical characteristics on the number of cotton plants is largest in April, and their influence on the height of cotton plants is greatest in June. However, the influence of soil physiochemical characteristics on cotton yield is smaller than that on cotton number and height in April and June. The soil salt under the near tape

  3. Influences on Bythotrephes longimanus life-history characteristics in the Great Lakes

    USGS Publications Warehouse

    Pothoven, Steven A.; Vanderploeg, Henry A.; Warner, David M.; Schaeffer, Jeffrey S.; Ludsin, Stuart A.; Claramunt, Randall M.; Nalepa, Thomas F.

    2012-01-01

    We compared Bythotrephes population demographics and dynamics to predator (planktivorous fish) and prey (small-bodied crustacean zooplankton) densities at a site sampled through the growing season in Lakes Michigan, Huron, and Erie. Although seasonal average densities of Bythotrephes were similar across lakes (222/m2 Erie, 247/m2 Huron, 162/m2 Michigan), temporal trends in abundance differed among lakes. In central Lake Erie where Bythotrephes' prey assemblage was dominated by small individuals (60%), where planktivorous fish densities were high (14,317/ha), and where a shallow water column limited availability of a deepwater refuge, the Bythotrephes population was characterized by a small mean body size, large broods with small neonates, allocation of length increases mainly to the spine rather than to the body, and a late summer population decline. By contrast, in Lake Michigan where Bythotrephes' prey assemblage was dominated by large individuals (72%) and planktivorous fish densities were lower (5052/ha), the Bythotrephes population was characterized by a large mean body size (i.e., 37–55% higher than in Erie), small broods with large neonates, nearly all growth in body length occurring between instars 1 and 2, and population persistence into fall. Life-history characteristics in Lake Huron tended to be intermediate to those found in Lakes Michigan and Erie, reflecting lower overall prey and predator densities (1224/ha) relative to the other lakes. Because plasticity in life history can affect interactions with other species, our findings point to the need to understand life-history variation among Great Lakes populations to improve our ability to model the dynamics of these ecosystems.

  4. Influence of the titanium dioxide addition in matrix formulation on the radwaste-mortar matrix characteristics

    SciTech Connect

    Peric, A.D.

    1996-08-01

    The rutile form of titanium dioxide (TiO{sub 2}) was added to mortar matrix preparations with to improve the mechanical and physico-chemical characteristics of the radwaste-mortar matrix mixtures, in particular the leach-rate of the immobilized radionuclide. The final solidified radwaste form was made with high water-to-cement ratio (0.36) for easy leaching of the immobilized radionuclide, {sup 137}Cs. TiO{sub 2} was added to the mortar formulation, replacing the appropriate amount of cement, in the amounts of 1, 2, 5, 8 and 10 weight percents of total cement weight. In the highly basic environment of the mortar (pH {approx_equal} 12), the titanium will form a HTiO-type membrane, which is semipermeable and selective for the cations like Cs{sup +} in the pH range above 5.5. Only the rutile form of TiO{sub 2} was observed in the prospected radwaste mortar mixture samples, using X-ray Fluorescence Spectrometry. Nevertheless, {sup 137}Cs leach-rate for the matrix formulations prepared with TiO{sub 2} was notably lower than the normally prepared (TiO{sub 2} free) samples. Furthermore, the mechanical strength of the samples prepared with TiO{sub 2} was higher than that of the TiO{sub 2}-free samples, and the correlation between the mechanical strength and TiO{sub 2} content appears to be exponential over the composition range explored here. Improvement of the physico-chemical properties of the titanium prepared formulations, is a topic of further investigations.

  5. Environmental mobility of cobalt-Influence of solid phase characteristics and groundwater chemistry.

    PubMed

    Payne, T E; Itakura, T; Comarmond, M J; Harrison, J J

    2009-01-01

    The adsorption of cobalt on samples from a potential waste repository site in an arid region was investigated in batch experiments, as a function of various solution phase parameters including the pH and ionic strength. The samples were characterized using a range of techniques, including BET surface area measurements, total clay content and quantitative X-ray diffraction. The statistical relationships between the measured cobalt distribution coefficients (K(d) values) and the solid and liquid phase characteristics were assessed. The sorption of cobalt increased with the pH of the aqueous phase. In experiments with a fixed pH value, the measured K(d) values were strongly correlated to the BET surface area, but not to the amount of individual clay minerals (illite, kaolinite or smectite). A further set of sorption experiments was undertaken with two samples of distinctive mineralogy and surface area, and consequently different sorption properties. A simple surface complexation model (SCM) that conceptualized the surface sites as having equivalent sorption properties to amorphous Fe-oxide was moderately successful in explaining the pH dependence of the sorption data on these samples. Two different methods of quantifying the input parameters for the SCM were assessed. While a full SCM for cobalt sorption on these complex environmental substrates is not yet possible, the basic applicability and predictive capability of this type of modeling is demonstrated. A principal requirement to further develop the modeling approach is adequate models for cobalt sorption on component mineral phases of complex environmental sorbents.

  6. Greenhouse gas emissions during MSW landfilling in China: influence of waste characteristics and LFG treatment measures.

    PubMed

    Yang, Na; Zhang, Hua; Shao, Li-Ming; Lü, Fan; He, Pin-Jing

    2013-11-15

    Reducing greenhouse gas (GHG) emissions from municipal solid waste (MSW) treatment can be highly cost-effective in terms of GHG mitigation. This study investigated GHG emissions during MSW landfilling in China under four existing scenarios and in terms of seven different categories: waste collection and transportation, landfill management, leachate treatment, fugitive CH4 (FM) emissions, substitution of electricity production, carbon sequestration and N2O and CO emissions. GHG emissions from simple sanitary landfilling technology where no landfill gas (LFG) extraction took place (Scenario 1) were higher (641-998 kg CO2-eq·t(-1)ww) than those from open dump (Scenario 0, 480-734 kg CO2-eq·t(-1)ww). This was due to the strictly anaerobic conditions in Scenario 1. LFG collection and treatment reduced GHG emissions to 448-684 kg CO2-eq·t(-1)ww in Scenario 2 (with LFG flare) and 214-277 kg CO2-eq·t(-1)ww in Scenario 3 (using LFG for electricity production). Amongst the seven categories, FM was the predominant contributor to GHG emissions. Global sensitivity analysis demonstrated that the parameters associated with waste characteristics (i.e. CH4 potential and carbon sequestered faction) and LFG management (i.e. LFG collection efficiency and CH4 oxidation efficiency) were of great importance. A further learning on the MSW in China indicated that water content and dry matter content of food waste were the basic factors affecting GHG emissions. Source separation of food waste, as well as increasing the incineration ratio of mixed collected MSW, could effectively mitigate the overall GHG emissions from landfilling in a specific city. To increase the LFG collection and CH4 oxidation efficiencies could considerably reduce GHG emissions on the landfill site level. While, the improvement in the LFG utilization measures had an insignificant impact as long as the LFG is recovered for energy generation.

  7. Geographic clustering of underage drinking and the influence of community characteristics.

    PubMed

    Reboussin, Beth A; Preisser, John S; Song, Eun-Young; Wolfson, Mark

    2010-01-01

    The aim of this paper was to examine the extent to which underage drinking clusters geographically in a sample of communities, and to investigate the manner in which community-level contexts are related to this process. We used data from a randomized community trial of underage drinking to provide the first quantitative estimates of the magnitude of the geographic clustering of underage drinking based upon pairwise odds ratios (PWORs). The Enforcing Underage Drinking Laws Randomized Community Trial provided data from repeated cross-sectional samples of youth aged 14-20 from 68 communities surveyed in 2004, 2006, and 2007 (n=18,730). Past 30-day drinking, binge drinking, getting drunk, experiencing non-violent consequences as a result of drinking and making a purchase attempt all significantly clustered within-communities with PWORs ranging from 1.05 to 1.21. After adjustment for individual-level characteristics, results remained relatively unchanged. However, there was evidence that the magnitude of the clustering varied as a function of neighborhood disadvantage, neighborhood disorder, and family structure. Clustering of drunkenness and experiencing non-violent consequences as a result of drinking was greatest in the least economically disadvantaged and least disordered communities with the greatest percentage of married-couple families. The clustering of making a purchase attempt, however, was greatest in more disordered communities, specifically the largest communities with the highest degree of residential mobility and housing density. These findings that clustering of underage drinking behaviors varies by community context has the potential for identifying the types of communities to target for underage drinking behavior-specific preventive interventions.

  8. Influence of Cigarette Smoking on Burden and Characteristics of Coronary Artery Plaques in Chinese Men

    PubMed Central

    Sun, Yujiao; Yu, Xin; Zhi, Ying; Geng, Song; Li, Hua; Liu, Ting; Xu, Ke; Qi, Guoxian

    2015-01-01

    Background It is generally well-known that smoking has a substantial impact on general health, and cardiovascular health in particular. The purpose of this study was to analyze the effects of different smoking status on the burden and characteristics of coronary artery plaques in Chinese men. Methods Our study enrolled 1920 individuals with suspected coronary artery disease undergoing 256-detector-row computed tomography scan after clinical assessment. These study participants were stratified into three groups: never smoker, current smoker, and former smoker, according to their smoking status. Thereafter, the associations of different smoking status with the coronary artery plaques were assessed using both univariable and multivariable logistic regression. Results The prevalences of any plaque, significant stenosis and coronary artery calcium score (CACS) ≥ 10 were highest in the current smokers (all p < 0.05). The proportion of calcified plaques was the lowest and the prevalence of non-calcified plaques was the highest in current smokers (p = 0.004). The higher pack-years group had significantly elevated percentages of any plaque, significant stenosis, ≥ 2/LM vessel disease and CACS ≥ 10 than the lower pack-years group (all p < 0.001). The percent of calcified plaques was lower and the percent of non-calcified plaques was higher in the higher (> 20) pack-years group than in the lower pack-years group (≤ 20) (p = 0.024). Current smoking with higher pack-years was the independent risk factor for any plaque, significant stenosis, CACS ≥ 10, non-calcified and mixed plaques (all p < 0.05) after multivariate adjustments. Conclusions The current smokers had the most serious burden of coronary artery plaques and the highest percentage of non-calcified plaques. Current smoking with higher pack-years was a significant risk factor for coronary artery plaque burden and non-calcified and mixed plaques. PMID:27122899

  9. Spectral reflectance characteristics of soils in northeastern Brazil as influenced by salinity levels.

    PubMed

    Pessoa, Luiz Guilherme Medeiros; Freire, Maria Betânia Galvão Dos Santos; Wilcox, Bradford Paul; Green, Colleen Heather Machado; De Araújo, Rômulo José Tolêdo; De Araújo Filho, José Coelho

    2016-11-01

    In northeastern Brazil, large swaths of once-productive soils have been severely degraded by soil salinization, but the true extent of the damage has not been assessed. Emerging remote sensing technology based on hyperspectral analysis offers one possibility for large-scale assessment, but it has been unclear to what extent the spectral properties of soils are related to salinity characteristics. The purpose of this study was to characterize the spectral properties of degraded (saline) and non-degraded agricultural soils in northeastern Brazil and determine the extent to which these properties correspond to soil salinity. We took soil samples from 78 locations within a 45,000-km(2) site in Pernambuco State. We used cluster analysis to group the soil samples on the basis of similarities in salinity and sodicity levels, and then obtained spectral data for each group. The physical properties analysis indicated a predominance of the coarse sand fraction in almost all the soil groups, and total porosity was similar for all the groups. The chemical analysis revealed different levels of degradation among the groups, ranging from non-degraded to strongly degraded conditions, as defined by the degree of salinity and sodicity. The soil properties showing the highest correlation with spectral reflectance were the exchangeable sodium percentage followed by fine sand. Differences in the reflectance curves for the various soil groups were relatively small and were not significant. These results suggest that, where soil crusts are not present, significant challenges remain for using hyperspectral remote sensing to assess soil salinity in northeastern Brazil.

  10. Influence of Injury Characteristics and Payer Status on Burn Treatment Location in Washington State

    PubMed Central

    Klein, Matthew B.; Mack, Christopher D.; Kramer, C. Bradley; Heimbach, David M.; Gibran, Nicole S.; Rivara, Frederick P.

    2011-01-01

    The provision of optimal burn care is a resource-intensive endeavor. The American Burn Association has developed criteria to help guide the decision to refer a patient to a burn center for definitive injury care. The purpose of this study was to compare the patient and injury characteristics of patients admitted to the single verified burn center in Washington State with those treated at other facilities in the state. We performed a retrospective review of all patients admitted to a hospital with a burn injury in Washington State from 1987 to 2005 using the state’s discharge database (Comprehensive Hospital Abstract Reporting System). Patient and injury factors of patients admitted to the state’s single verified burn center or at other hospitals were compared. Multivariate poisson regression was used to calculate the relative risk of injury and patient factors that were significantly associated with admission to the verified burn center. From 1987 to 2005, a total of 16,531 patients were admitted to a Washington State hospital after burn injury. Of these patients, 8624 (52.2%) were treated definitively at the University of Washington Burn Center. Patients treated at this verified center had larger overall burn size (7.4% vs 4.5% TBSA, P < .001), higher percent full-thickness burn (4.3% vs 1.2%, P < .001), and higher rates of inhalation injury (2.3% vs 1.5%, P = .005). Uninsured status (relative risk = 1.46, 95% confidence interval = 1.4–1.5) was also significantly associated with treatment at the verified burn center. Injury severity and payer status were both found to be independent predictors of treatment at the single verified burn center in Washington. PMID:18388579

  11. Propagule pressure and stream characteristics influence introgression: cutthroat and rainbow trout in British Columbia.

    PubMed

    Bennett, Stephen N; Olson, John R; Kershner, Jeffrey L; Corbett, Peter

    2010-01-01

    Hybridization and introgression between introduced and native salmonids threaten the continued persistence of many inland cutthroat trout species. Environmental models have been developed to predict the spread of introgression, but few studies have assessed the role of propagule pressure. We used an extensive set of fish Stocking records and geographic information system (GIS) data to produce a spatially explicit index of potential propagule pressure exerted by introduced rainbow trout in the Upper Kootenay River, British Columbia, Canada. We then used logistic regression and the information-theoretic approach to test the ability of a set of environmental and spatial variables to predict the level of introgression between native westslope cutthroat trout and introduced rainbow trout. Introgression was assessed using between four and seven co-dominant, diagnostic nuclear markers at 45 sites in 31 different streams. The best model for predicting introgression included our GIS propagule pressure index and an environmental variable that accounted for the biogeoclimatic zone of the site (r2=0.62). This model was 1.4 times more likely to explain introgression than the next-best model, which consisted of only the propagule pressure index variable. We created a composite model based on the model-averaged results of the seven top models that included environmental, spatial, and propagule pressure variables. The propagule pressure index had the highest importance weight (0.995) of all variables tested and was negatively related to sites with no introgression. This study used an index of propagule pressure and demonstrated that propagule pressure had the greatest influence on the level of introgression between a native and introduced trout in a human-induced hybrid zone.

  12. Influence of pin and hammer mill on grinding characteristics, thermal and antioxidant properties of coriander powder.

    PubMed

    Barnwal, P; Singh, K K; Sharma, Alka; Choudhary, A K; Saxena, S N

    2015-12-01

    In present study, influence of grinding (hammer and pin mills) and moisture content (range: 6.4-13.6 % dry basis) on the quality traits of coriander powder were investigated. These include grinding parameters, colour parameters, specific heat, thermal conductivity, thermal diffusivity, glass transition temperature, essential oil, total phenolic content, total flavonoid content and DPPH scavenging (%) of coriander powder. For coriander seed, the geometric properties such as major, medium, minor dimensions, geometric mean diameter, arithmetic mean diameter, sphericity, surface area and volume of coriander seeds increased significantly with increasing moisture (6.4-13.6 % db). For coriander powder, the grinding parameters such as average particle size, volume surface mean diameter and volume mean diameter increased significantly with increasing moisture (6.4-13.6 % db). With the grinding method, the colour attributes of coriander powder such as L-value, a-value, b-value, hue angle and browning index varied significantly. It was observed that the specific heat followed second order polynomial relationship with temperature and moisture whereas thermal conductivity varied linearly with temperature and moisture content. The variation of glass transition temperature with moisture can be best represented in quadratic manner. Total flavonoid content (mg QE/g crude seed extract) and DPPH scavenging % activity of coriander powder is significantly affected by grinding methods. A lower value of specific heat was observed for hammer ground coriander powder as compared to pin mill ground coriander powder. The thermal conductivity of hammer mill ground coriander powder was higher as compared to pin mill ground coriander. It was observed that hammer mill yields more fine coriander powder in comparison to pin mill. The browning index was more in hammer mill ground coriander powder.

  13. Perceptions of variability in facial emotion influence beliefs about the stability of psychological characteristics.

    PubMed

    Weisbuch, Max; Grunberg, Rebecca L; Slepian, Michael L; Ambady, Nalini

    2016-10-01

    Beliefs about the malleability versus stability of traits (incremental vs. entity lay theories) have a profound impact on social cognition and self-regulation, shaping phenomena that range from the fundamental attribution error and group-based stereotyping to academic motivation and achievement. Less is known about the causes than the effects of these lay theories, and in the current work the authors examine the perception of facial emotion as a causal influence on lay theories. Specifically, they hypothesized that (a) within-person variability in facial emotion signals within-person variability in traits and (b) social environments replete with within-person variability in facial emotion encourage perceivers to endorse incremental lay theories. Consistent with Hypothesis 1, Study 1 participants were more likely to attribute dynamic (vs. stable) traits to a person who exhibited several different facial emotions than to a person who exhibited a single facial emotion across multiple images. Hypothesis 2 suggests that social environments support incremental lay theories to the extent that they include many people who exhibit within-person variability in facial emotion. Consistent with Hypothesis 2, participants in Studies 2-4 were more likely to endorse incremental theories of personality, intelligence, and morality after exposure to multiple individuals exhibiting within-person variability in facial emotion than after exposure to multiple individuals exhibiting a single emotion several times. Perceptions of within-person variability in facial emotion-rather than perceptions of simple diversity in facial emotion-were responsible for these effects. Discussion focuses on how social ecologies shape lay theories. (PsycINFO Database Record

  14. Head rotational acceleration characteristics influence behavioral and diffusion tensor imaging outcomes following concussion.

    PubMed

    Stemper, Brian D; Shah, Alok S; Pintar, Frank A; McCrea, Michael; Kurpad, Shekar N; Glavaski-Joksimovic, Aleksandra; Olsen, Christopher; Budde, Matthew D

    2015-05-01

    A majority of traumatic brain injuries (TBI) in motor vehicle crashes and sporting environments are mild and caused by high-rate acceleration of the head. For injuries caused by rotational acceleration, both magnitude and duration of the acceleration pulse were shown to influence injury outcomes. This study incorporated a unique rodent model of rotational acceleration-induced mild TBI (mTBI) to quantify independent effects of magnitude and duration on behavioral and neuroimaging outcomes. Ninety-two Sprague-Dawley rats were exposed to head rotational acceleration at peak magnitudes of 214 or 350 krad/s(2) and acceleration pulse durations of 1.6 or 3.4 ms in a full factorial design. Rats underwent a series of behavioral tests including the Composite Neuroscore (CN), Elevated Plus Maze (EPM), and Morris Water Maze (MWM). Ex vivo diffusion tensor imaging (DTI) of the fixed brains was conducted to assess the effects of rotational injury on brain microstructure as revealed by the parameter fractional anisotropy (FA). While the injury did not cause significant locomotor or cognitive deficits measured with the CN and MWM, respectively, a main effect of duration was consistently observed for the EPM. Increased duration caused significantly greater activity and exploratory behaviors measured as open arm time and number of arm changes. DTI demonstrated significant effects of both magnitude and duration, with the FA of the amygdala related to both the magnitude and duration. Increased duration also caused FA changes at the interface of gray and white matter. Collectively, the findings demonstrate that the consequences of rotational acceleration mTBI were more closely associated with duration of the rotational acceleration impulse, which is often neglected as an independent factor, and highlight the need for animal models of TBI with strong biomechanical foundations to associate behavioral outcomes with brain microstructure.

  15. Propagule pressure and stream characteristics influence introgression: Cutthroat and rainbow trout in British Columbia

    USGS Publications Warehouse

    Bennett, S.N.; Olson, J.R.; Kershner, J.L.; Corbett, P.

    2010-01-01

    Hybridization and introgression between introduced and native salmonids threaten the continued persistence of many inland cutthroat trout species. Environmental models have been developed to predict the spread of introgression, but few studies have assessed the role of propagule pressure. We used an extensive set of fish stocking records and geographic information system (GIS) data to produce a spatially explicit index of potential propagule pressure exerted by introduced rainbow trout in the Upper Kootenay River, British Columbia, Canada. We then used logistic regression and the information-theoretic approach to test the ability of a set of environmental and spatial variables to predict the level of introgression between native westslope cutthroat trout and introduced rainbow trout. Introgression was assessed using between four and seven co-dominant, diagnostic nuclear markers at 45 sites in 31 different streams. The best model for predicting introgression included our GIS propagule pressure index and an environmental variable that accounted for the biogeoclimatic zone of the site (r2 = 0.62). This model was 1.4 times more likely to explain introgression than the next-best model, which consisted of only the propagule pressure index variable. We created a composite model based on the model-averaged results of the seven top models that included environmental, spatial, and propagule pressure variables. The propagule pressure index had the highest importance weight (0.995) of all variables tested and was negatively related to sites with no introgression. This study used an index of propagule pressure and demonstrated that propagule pressure had the greatest influence on the level of introgression between a native and introduced trout in a human-induced hybrid zone. ?? 2010 by the Ecological Society of America.

  16. Influences of fireworks on chemical characteristics of atmospheric fine and coarse particles during Taiwan's Lantern Festival

    NASA Astrophysics Data System (ADS)

    Tsai, Hsieh-Hung; Chien, Li-Hsing; Yuan, Chung-Shin; Lin, Yuan-Chung; Jen, Yi-Hsiu; Ie, Iau-Ren

    2012-12-01

    In recent years, the celebration activities of various folk-custom festivals have been getting more and more attention from the citizens in Taiwan. Festivities throughout the whole island are traditionally accompanied by loud and brightly colored firework displays. Among these activities, the firework displays during Taiwan's Lantern Festival in Kaohsiung harbor is one of the largest festivals in Taiwan each year. Therefore, it is of importance to investigate the influence of fireworks displays on the ambient air quality during the Taiwan's Lantern Festival. Field measurements of atmospheric particulate matter (PM) were conducted on February 9th-11th, 2009 during Taiwan's Lantern Festival in Kaohsiung City. Moreover, three kinds of fireworks powders obtained from the same manufacturing factory producing Kaohsiung Lantern Festival fireworks were burned in a self-designed combustion chamber to determine the physicochemical properties of the fireworks' particles and to establish the source profile of firework burning. Several metallic elements of PM during the firework display periods were notably higher than those during the non-firework periods. The concentrations of Mg, K, Pb, and Sr in PM2.5 during the firework periods were 10 times higher than those during the non-firework periods. Additionally, the Cl-/Na+ ratio was approximately 3 during the firework display periods as Cl- came from the chlorine content of the firework powder. Moreover, the OC/EC ratio increased up to 2.8. Results obtained from PCA and CMB receptor modeling showed that major sources of atmospheric particles during the firework display periods in Kaohsiung harbor were fireworks, vehicular exhausts, soil dusts and marine sprays. Particularly, on February 10th, the firework displays contributed approximately 25.2% and 16.6% of PM10 at two downwind sampling sites, respectively.

  17. Influence of whipping temperature on the whipping properties and rheological characteristics of whipped cream.

    PubMed

    Ihara, K; Habara, K; Ozaki, Y; Nakamura, K; Ochi, H; Saito, H; Asaoka, H; Uozumi, M; Ichihashi, N; Iwatsuki, K

    2010-07-01

    The effects of whipping temperature (5 to 15 degrees C) on the whipping (whipping time and overrun) and rheological properties of whipped cream were studied. Fat globule aggregation (aggregation ratio of fat globules and serum viscosity) and air bubble factors (overrun, diameter, and surface area) were measured to investigate the mechanism of whipping. Whipping time, overrun, and bubble diameters decreased with increasing temperature, with the exception of bubble size at 15 degrees C. The aggregation ratio of fat globules tended to increase with increasing temperature. Changes in hardness and bubble size during storage were relatively small at higher temperatures (12.5 and 15 degrees C). Changes in overrun during storage were relatively small in the middle temperature range (7.5 to 12.5 degrees C). From the results, the temperature range of 7.5 to 12.5 degrees C is recommended for making whipped creams with a good texture, and a specific temperature should be decided when taking into account the preferred overrun. The correlation between the whipped cream strain hardness and serum viscosity was high (R(2)=0.906) and persisted throughout the temperature range tested (5 to 15 degrees C). A similar result was obtained at a different whipping speed (140 rpm). The multiple regression analysis in the range of 5 to 12.5 degrees C indicated a high correlation (R(2)=0.946) in which a dependent variable was the storage modulus of whipped cream and independent variables were bubble surface area and serum viscosity. Therefore, fat aggregation and air bubble properties are important factors in the development of cream hardness. The results of this study suggest that whipping temperature influences fat globule aggregation and the properties of air bubbles in whipped cream, which alters its rheological properties.

  18. Compound bioflocculant and polyaluminum chloride in kaolin-humic acid coagulation: factors influencing coagulation performance and floc characteristics.

    PubMed

    Li, Ruihua; Gao, Baoyu; Huang, Xin; Dong, Hongyu; Li, Xiaochen; Yue, Qinyan; Wang, Yan; Li, Qian

    2014-11-01

    The objective of this study was to investigate the influence of coagulant dosage and pH on coagulation performance and floc properties using polyaluminum chloride (PAC) and compound bioflocculant (CBF) dual-coagulant in kaolin-humic acid (HA) treatment. Results showed that as PAC dosage rose, comparatively better coagulation efficiencies and floc characteristics were achieved due to stronger charge neutralization and sweeping effect. Addition of CBF could enhance coagulation performance and floc properties, including size, strength and recoverability, except fractal dimension. Solution pH had a significant effect on coagulation efficiencies and flocs formation. Under acidic condition, flocs showed higher strength and recoverability but lower fractal dimension, where charge neutralization was the foremost mechanism. More compact flocs were generated under alkaline condition due to the sweeping effect of hydrolyzed Al species.

  19. The influence of synthesis methods on the morpho - structural and luminescent characteristics of rare earth silicate phosphors

    SciTech Connect

    Muresan, L. E.; Cadis, A. I.; Perhaita, I.; Oprea, B. F.; Silipas, D. T.

    2013-11-13

    Cerium activated yttrium silicate (Y{sub 2}SiO{sub 5}:Ce) phosphors were prepared by two different wet-chemical synthesis routes namely: simultaneous addition of reagents (SimAd) and solution combustion (SC) using yttriumcerium nitrate and urea as starting materials. TEOS or SiO{sub 2} fume were used as Si sources. A comparative study regarding the morpho-structural and luminescent properties of Y{sub 2}SiO{sub 5}:Ce phosphors is presented. The influence of the silicon source, same as the firing temperature on the samples characteristics were discussed. TG-SDTA, FT-IR, SEM, XRD and photoluminescence investigations were used to characterize the precursors and the corresponding phosphors.

  20. Pressure influence on the structural characteristics of modified absorptive glass mat separators: A standard contact porosimetry study

    NASA Astrophysics Data System (ADS)

    Burashnikova, M. M.; Khramkova, T. S.; Kazarinov, I. A.; Shmakov, S. L.

    2015-09-01

    The article presents a comparative analysis of the structural characteristics of absorptive glass mats manufactured by "Hollingsworth & Vose" (a 2.8 mm thickness) and "Bernard Dumas" (a 3.0 mm thickness) modified by impregnation with polymeric emulsions based on polyvinylidene fluoride, a polyvinylpyrrolidone styrene copolymer, and polytetrafluoroethylene, by means of standard contact porosimetry. The key study is influence of features of the porous structure on the compression properties, the rate of wicking, and the oxygen cycle efficiency in lead-acid battery mock-ups under several plate-group compression pressures. It is found that the treatment of the absorptive glass mat separators with polymeric emulsions leads to redistribution of their pores by size. An increased pressure in the electrode unit insignificantly changes the pore structure of the modified absorptive glass mat separators, and the oxygen cycle efficiency rises in comparison with unmodified separators.

  1. Influence of the spectral distribution of light on the characteristics of photovoltaic panel. Comparison between simulation and experimental

    NASA Astrophysics Data System (ADS)

    Chadel, Meriem; Bouzaki, Mohammed Moustafa; Chadel, Asma; Petit, Pierre; Sawicki, Jean-Paul; Aillerie, Michel; Benyoucef, Boumediene

    2017-02-01

    We present and analyze experimental results obtained with a laboratory setup based on a hardware and smart instrumentation for the complete study of performance of PV panels using for illumination an artificial radiation source (Halogen lamps). Associated to an accurate analysis, this global experimental procedure allows the determination of effective performance under standard conditions thanks to a simulation process originally developed under Matlab software environment. The uniformity of the irradiated surface was checked by simulation of the light field. We studied the response of standard commercial photovoltaic panels under enlightenment measured by a spectrometer with different spectra for two sources, halogen lamps and sunlight. Then, we bring a special attention to the influence of the spectral distribution of light on the characteristics of photovoltaic panel, that we have performed as a function of temperature and for different illuminations with dedicated measurements and studies of the open circuit voltage and short-circuit current.

  2. The Relationship Between Clinicians' Confidence and Accuracy, and the Influence of Child Characteristics, in the Screening of Autism Spectrum Disorder.

    PubMed

    Hedley, Darren; Brewer, Neil; Nevill, Rose; Uljarević, Mirko; Butter, Eric; Mulick, James A

    2016-07-01

    The study examined the confidence accuracy relationship, and the influence of child characteristics on clinician confidence, when predicting a diagnosis of Autism Spectrum Disorder during screening of 125 referred children aged under 3.5 years. The diagnostic process included observation, interview, language and developmental testing. Clinical judgement accuracy was compared against final diagnosis for high and low confidence levels (with confidence assessed on a 0-100 % scale). We identified a significant CA relationship with predictive accuracy highest at confidence levels of 90-100 %. Parent report of unusual behaviors was the only significant independent predictor of confidence. Clinicians' confidence may be important when evaluating decisions to refer, or not to refer, children for further diagnostic assessment.

  3. The Influence of Soil Characteristics on the Toxicity of Oil Refinery Waste for the Springtail Folsomia candida (Collembola).

    PubMed

    Reinecke, Adriaan J; van Wyk, Mia; Reinecke, Sophie A

    2016-06-01

    We determined the toxicity of oil refinery waste in three soils using the springtail Folsomia candida (Collembola) in bioassays. Sublethal exposure to a concentration series of API-sludge presented EC50's for reproduction of 210 mg/kg in site soil; 880 mg/kg in LUFA2.2- and 3260 mg/kg in OECD-soil. The sludge was the least toxic in the OECD-soil with the highest clay and organic matter content, the highest maximum water holding capacity, and the least amount of sand. It was the most toxic in the reference site soil with the lowest organic matter content and highest sand content. The results emphasized the important role of soil characteristics such as texture and organic matter content in influencing toxicity, possibly by affecting bioavailability of toxicants.

  4. How proton pulse characteristics influence protoacoustic determination of proton-beam range: simulation studies.

    PubMed

    Jones, Kevin C; Seghal, Chandra M; Avery, Stephen

    2016-03-21

    The unique dose deposition of proton beams generates a distinctive thermoacoustic (protoacoustic) signal, which can be used to calculate the proton range. To identify the expected protoacoustic amplitude, frequency, and arrival time for different proton pulse characteristics encountered at hospital-based proton sources, the protoacoustic pressure emissions generated by 150 MeV, pencil-beam proton pulses were simulated in a homogeneous water medium. Proton pulses with Gaussian widths ranging up to 200 μs were considered. The protoacoustic amplitude, frequency, and time-of-flight (TOF) range accuracy were assessed. For TOF calculations, the acoustic pulse arrival time was determined based on multiple features of the wave. Based on the simulations, Gaussian proton pulses can be categorized as Dirac-delta-function-like (FWHM < 4 μs) and longer. For the δ-function-like irradiation, the protoacoustic spectrum peaks at 44.5 kHz and the systematic error in determining the Bragg peak range is <2.6 mm. For longer proton pulses, the spectrum shifts to lower frequencies, and the range calculation systematic error increases (⩽ 23 mm for FWHM of 56 μs). By mapping the protoacoustic peak arrival time to range with simulations, the residual error can be reduced. Using a proton pulse with FWHM = 2 μs results in a maximum signal-to-noise ratio per total dose. Simulations predict that a 300 nA, 150 MeV, FWHM = 4 μs Gaussian proton pulse (8.0 × 10(6) protons, 3.1 cGy dose at the Bragg peak) will generate a 146 mPa pressure wave at 5 cm beyond the Bragg peak. There is an angle dependent systematic error in the protoacoustic TOF range calculations. Placing detectors along the proton beam axis and beyond the Bragg peak minimizes this error. For clinical proton beams, protoacoustic detectors should be sensitive to <400 kHz (for -20 dB). Hospital-based synchrocyclotrons and cyclotrons are promising sources of proton pulses for generating clinically measurable protoacoustic

  5. Influence of carbohydrate source on ruminal fermentation characteristics, performance, and microbial protein synthesis in dairy cows.

    PubMed

    Gozho, G N; Mutsvangwa, T

    2008-07-01

    Eight multiparous Holstein cows (676 +/- 57 kg of body weight; 121 +/- 17 d-in-milk) were used in a replicated 4 x 4 Latin square design to determine the effects of 4 sources of carbohydrate on milk yield and composition, ruminal fermentation, and microbial N flow to the duodenum. Four cows in one of the Latin squares were fitted with permanent ruminal cannulae. Diets contained (DM basis) 50% forage in combinations of alfalfa hay and barley silage, and 50% concentrate. The concentrate portion of the diets contained barley, corn, wheat, or oats grain as the primary source of carbohydrate. Intake of DM ranged from 24.0 to 26.2 kg/d, and it tended to be lower in cows fed the wheat-based diet compared with those fed the barley-based diet; consequently, milk yield tended to be lower in cows fed the wheat-based diet compared with those fed the barley-based diet. Cows fed the barley- or wheat-based diets had a lower milk fat content compared with those fed the corn-based diet. Ruminal fermentation characteristics were largely unaffected by the source of dietary carbohydrate, with similar ruminal pH and volatile fatty acid and ammonia concentrations for the first 6 h after the morning feeding. Dietary treatment did not affect total tract apparent digestibility of DM, organic matter, and neutral detergent fiber; however, total tract apparent digestibility of starch in cows fed the oats-based diet was higher compared with those fed the corn-and wheat-based diets. Nitrogen that was used for productive purposes (i.e., N secreted in milk + N apparently retained by the cow) tended to be lower in cows fed the wheat-based diet compared with cows fed the barley-, corn-, or oats-based diets. Urinary purine derivative (PD) excretion was similar in cows fed the barley-, corn-, and wheat-based diets; however, purine derivative excretion was higher in cows fed the barley-based diet compared with those fed the oats-based diet. Consequently, estimated microbial N flow to the duodenum was

  6. Influence of experimental set-up on the infiltration characteristics during managed aquifer recharge operation

    NASA Astrophysics Data System (ADS)

    Fichtner, Thomas; Vanzella de Melo, Julio Augusto; Stefan, Catalin

    2016-04-01

    The main focus during operation of managed aquifer recharge (MAR) is on clogging processes, specifically on the changes of infiltration capacities and degradation of infiltrated organic substances including vadose zone oxygen dynamics. Lab scale experiments are one opportunity to understand and characterize these processes under different drying and wetting cycles and infiltration rates. However, the multitude of assumptions and scale-related limitations of downscale investigations often lead to over- or underestimations, rendering their results useless when translated to field-like conditions. Therefore, the specific objective of this investigation is to compare the results obtained from two different experimental set-ups with different scales: a 3D, rectangular shaped, stainless steel lysimeter (1.5 x 1.0 x 1.0 m) with an infiltration basin installed in the centre of its surface and a 1D soil column (1m, ᴓ 0.15 m) with the infiltration over the complete column surface. The study focuses on the influence of the experimental setup conditions on the soil clogging, water flow pattern, oxygen dynamics and degradation of organic substances. The results should allow making statements about the suitability of these lab experiments for the investigation of processes taking place in the unsaturated soil zone during operation of MAR. Both experimental units were packed with the same soil and equipped with tensiometers, TDR-probes, oxygen probes and suction cups in two depths for the estimation of spatial and temporal distribution of soil moisture, oxygen and infiltrated substances. The lysimeter and the column were placed inside of a fully automatic climate tent, which facilitates the exact control of air temperature and humidity. The first results confirm that both infiltration units are suitable to simulate the clogging and the oxidation of easily degradable organic substances. However, the velocity of water transport is higher in the column compared with the lysimeter

  7. Influence of test configuration on the combustion characteristics of polymers as ignition sources

    NASA Technical Reports Server (NTRS)

    Julien, Howard L.

    1993-01-01

    analysis where the economical solution of parabolic equations is involved. The products for the summer period are: (1) a conceptual-level redesign of the test apparatus, and (2) the development and use of an approximate integral boundary layer analysis to demonstrate the influence of geometry changes prior to testing. A computer code STAN5, an accurate numerical boundary layer model whose earlier versions were developed for the NASA Lewis Research Center by the Fellow, also was installed and validated on the WSTF and New Mexico State University computer systems as a starting point in the development of a more detailed fluid mechanics and combustion model.

  8. Geochemistry characteristics of Seamounts in the Tonga arc : Influence of subduction component

    NASA Astrophysics Data System (ADS)

    Myeong, B.; Kim, J. H.; Woo, H.; Jang, Y. D.

    2015-12-01

    Located in the southwest Pacific ocean, The seamounts, from TA07 seamount to TA26, in the Tonga arc are located from 20 °S to 25 °S. At 25 °S, the Tonga trench is intersected by the Louisville ridge, a ~4,300-km-long chain of seamounts and the Osbourn trough, a paleo-spreading center. For this reason, magma which created these seamounts may have various origin. Based on this, the seamounts which forming the Tonga arc are divided into three groups; including group 1(region that the earliest Louisville ridge subduction arised, correspond to TA07-12), group 2(region that the second Louisville ridge subduction arised, correspond to TA14-24); and group 3(region that the Louisville ridge and the Osbourn trough are subducting, correspond to TA25-26). These seamounts are mostly stratovolcanoes with caldera. Rocks recovered by dredging have been identified as pumice, dacite, andesite, basaltic andesites and basalts(most abundant). Major element concentrations are constant, trace element concentrations are enriched LILE, depleted HFSE compared with MORB. The Tonga arc is affected by subduction components divided into the shallow and deep subduction components. Related to subduction components, variables include mantle source, AOC(altered oceanic crust), PS(pelagic sediment), LSC(Louisville seamount chain) and OS(Osbourn trough). In the case of shallow subduction component, it tends to have higher contents in group 1, 3 and lower contents in group 2. Thus, comparatively speaking, it seems that group 1, 3 have been heavily influenced by the fluid. However, origin of the fluid seems to be different, since its locations are not continuous. In the case of deep subduction component, it shows similar range in the group 1, 2, and shows a significantly lower ratio in the group 3. The reason why its values are similar is that it is effected by the melt during the Louisville ridge was subducting and the reason why the ratio in the group 3 shown lower is because of the fluid effect

  9. Technical match characteristics and influence of body anthropometry on playing performance in male elite team handball.

    PubMed

    Michalsik, Lars Bojsen; Madsen, Klavs; Aagaard, Per

    2015-02-01

    Modern team handball match-play imposes substantial physical and technical demands on elite players. However, only limited knowledge seems to exist about the specific working requirements in elite team handball. Thus, the purpose of this study was to examine the physical demands imposed on male elite team handball players in relation to playing position and body anthropometry. Based on continuous video recording of individual players during elite team handball match-play (62 tournament games, ∼4 players per game), computerized technical match analysis was performed in male elite team handball players along with anthropometric measurements over a 6 season time span. Technical match activities were distributed in 6 major types of playing actions (shots, breakthroughs, fast breaks, tackles, technical errors, and defense errors) and further divided into various subcategories (e.g., hard or light tackles, type of shot, claspings, screenings, and blockings). Players showed 36.9 ± 13.1 (group mean ± SD) high-intense technical playing actions per match with a mean total effective playing time of 53.85 ± 5.87 minutes. In offense, each player performed 6.0 ± 5.2 fast breaks, received 34.5 ± 21.3 tackles in total, and performed in defense 3.7 ± 3.5 blockings, 3.9 ± 3.0 claspings, and 5.8 ± 3.6 hard tackles. Wing players (84.5 ± 5.8 kg, 184.9 ± 5.7 cm) were less heavy and smaller (p < 0.001) than backcourt players (94.7 ± 7.1 kg, 191.9 ± 5.4 cm) and pivots (99.4 ± 6.2 kg, 194.8 ± 3.6 cm). In conclusion, modern male elite team handball match-play is characterized by a high number of short-term, high-intense intermittent technical playing actions. Indications of technical fatigue were observed. Physical demands differed between playing positions with wing players performing more fast breaks and less physical confrontations with opponent players than backcourt players and pivots. Body anthropometry seemed to have an important influence on playing performance

  10. Influence of Peritoneal Transport Characteristics on Nutritional Status and Clinical Outcome in Chinese Diabetic Nephropathy Patients on Peritoneal Dialysis

    PubMed Central

    Guan, Ji-Chao; Bian, Wei; Zhang, Xiao-Hui; Shou, Zhang-Fei; Chen, Jiang-Hua

    2015-01-01

    Background: High peritoneal transport status was previously thought to be a poor prognostic factor in peritoneal dialysis (PD) patients. However, its effect on diabetic nephropathy PD patients is unclear in consideration of the adverse impact of diabetes itself. The purpose of this study was to investigate the influence of peritoneal transport characteristics on nutritional status and clinical outcome in diabetic nephropathy patients on PD. Methods: One hundred and two diabetic nephropathy patients on PD were enrolled in this observational cohort study. According to the initial peritoneal equilibration test result, patients were divided into two groups: Higher transport group (HT, including high and high average transport) and lower transport group (LT, including low and low-average transport). Demographic characteristics, biochemical data, dialysis adequacy, and nutritional status were evaluated. Clinical outcomes were compared. Risk factors for death-censored technique failure and mortality were analyzed. Results: Compared with LT group (n = 37), serum albumin was significantly lower and the incidence of malnutrition by subjective global assessment was significantly higher in HT group (n = 65) (P < 0.05). Kaplan–Meier analyses showed that death-censored technique failure and mortality were significantly increased in HT group compared with that in LT group. On multivariate Cox analyses, higher peritoneal transport status and lower residual renal function (RRF) were independent predictors of death-censored technique failure when adjusted for serum albumin and total weekly urea clearance (Kt/V). Independent predictors of mortality were advanced age, anemia, hypoalbuminemia, and lower RRF, but not higher peritoneal transport status. Conclusions: Higher peritoneal transport status has an adverse influence on nutrition for diabetic nephropathy patients on PD. Higher peritoneal transport status is a significant independent risk factor for death-censored technique

  11. A statistical evaluation of the influence of housing characteristics and geogenic radon potential on indoor radon concentrations in France.

    PubMed

    Demoury, C; Ielsch, G; Hemon, D; Laurent, O; Laurier, D; Clavel, J; Guillevic, J

    2013-12-01

    Radon-222 is a radioactive natural gas produced by the decay of radium-226, known to be the main contributor to natural background radiation exposure. Effective risk management needs to determine the areas in which the density of buildings with high radon levels is likely to be highest. Predicting radon exposure from the location and characteristics of a dwelling could also contribute to epidemiological studies. Beginning in the nineteen-eighties, a national radon survey consisting in more than 10,000 measurements of indoor radon concentrations was conducted in French dwellings by the Institute for Radiological Protection and Nuclear Safety (IRSN). Housing characteristics, which may influence radon accumulation in dwellings, were also collected. More recently, the IRSN generated a French geogenic radon potential map based on the interpretation of geological features. The present study analyzed the two datasets to investigate the factors influencing indoor radon concentrations using statistical modeling and to determine the optimum use of the information on geogenic radon potential that showed the best statistical association with indoor radon concentration. The results showed that the variables associated with indoor radon concentrations were geogenic radon potential, building material, year of construction, foundation type, building type and floor level. The model, which included the surrounding geogenic radon potential (i.e. the average geogenic radon potential within a disc of radius 20 km centered on the indoor radon measurement point) and variables describing house-specific factors and lifestyle explained about 20% of the overall variability of the logarithm of radon concentration. The surrounding geogenic radon potential was fairly closely associated with the local average indoor radon concentration. The prevalence of exposure to radon above specific thresholds and the average exposures to radon clearly increased with increasing classes of geogenic radon

  12. Physical activity on prescription schemes (PARS): do programme characteristics influence effectiveness? Results of a systematic review and meta-analyses

    PubMed Central

    Arsenijevic, Jelena; Groot, Wim

    2017-01-01

    Background Physical activity on prescription schemes (PARS) are health promotion programmes that have been implemented in various countries. The aim of this study was to outline the differences in the design of PARS in different countries. This study also explored the differences in the adherence rate to PARS and the self-reported level of physical activity between PARS users in different countries. Method A systematic literature review and meta-analyses were conducted. We searched PubMed and EBASCO in July 2015 and updated our search in September 2015. Studies that reported adherence to the programme and self-reported level of physical activity, published in the English language in a peer-reviewed journal since 2000, were included. The difference in the pooled adherence rate after finishing the PARS programme and the adherence rate before or during the PARS programme was 17% (95% CI 9% to 24%). The difference in the pooled physical activity was 0.93 unit score (95 CI −3.57 to 1.71). For the adherence rate, a meta-regression was conducted. Results In total, 37 studies conducted in 11 different countries met the inclusion criteria. Among them, 31 reported the adherence rate, while the level of physical activity was reported in 17 studies. Results from meta-analyses show that PARS had an effect on the adherence rate of physical activity, while the results from the meta-regressions show that programme characteristics such as type of chronic disease and the follow-up period influenced the adherence rate. Conclusions The effects of PARS on adherence and self-reported physical activity were influenced by programme characteristics and also by the design of the study. Future studies on the effectiveness of PARS should use a prospective longitudinal design and combine quantitative and qualitative data. Furthermore, future evaluation studies should distinguish between evaluating the adherence rate and the self-reported physical activity among participants with different

  13. Habitat characteristics influence macrofaunal communities in coralline turf more than mesoscale coastal upwelling on the coast of Northern Chile

    NASA Astrophysics Data System (ADS)

    Kelaher, Brendan P.; Carlos Castilla, Juan

    2005-04-01

    Rocky shore communities are often influenced by near-shore coastal upwelling. For macrofauna in algal turf, these effects may be caused directly by well-studied bottom-up mechanisms or indirectly via changes in habitat structure provided by algal turf associated high nutrient loads. Here, we investigated possible interactions between upwelling and habitat structure by sampling diverse faunal assemblages in coralline algal turf on seven rocky intertidal shores in northern Chile, ranging from El Cobre [23°17'1″S, 70°31'40″W] to La Lobería [23°03'40″S, 70°33'14″W]. Some of these shores were located adjacent to strong upwelling centers, while others were in areas rarely affected. On each shore, we sampled four (2 × 2 m) sites separated by 15-50 m. In each site, we collected three replicate cores (80 mm in diameter) from which we measured macrofauna greater than 850 μm, biomass of sediment and epiphytes, frond density and average frond length. We used mean water temperature and its variation at 1-1.5 m water depth (below Extreme Low Water Spring, ELWS) to represent local upwelling intensity because long-term data have shown that these variables make excellent indicators for this region. In total, we found 94 macrofaunal taxa in coralline turf, which is almost three times higher than has previously been reported in Chile. Although macrofaunal assemblages varied significantly among shores, there were no patterns to suggest mesoscale variation in upwelling intensity affected either faunal assemblages or local habitat characteristics. In contrast, multivariate and univariate correlations highlighted sediment and frond density as strong determinants of community structure. We therefore conclude that traditionally studied habitat characteristics, such as structural complexity and habitat heterogeneity, have greater influence on faunal assemblages in mat-like habitats on rocky shores than environmental variables associated with mesoscale coastal upwelling.

  14. The Influence of Neighborhood Characteristics on Police Officers’ Encounters with Persons Suspected to Have a Serious Mental Illness

    PubMed Central

    Krishan, Shaily; Bakeman, Roger; Broussard, Beth; Cristofaro, Sarah L.; Hankerson-Dyson, Dana; Husbands, Letheshia; Watson, Amy C.; Compton, Michael T.

    2014-01-01

    Objective Police officers’ decisions and behaviors are impacted by the neighborhood context in which police encounters occur. For example, officers may use greater force and be more likely to make arrests in disadvantaged neighborhoods. We examined whether neighborhood characteristics influence police encounters with individuals suspected to have a serious mental illness, addictive disorder, or developmental disability. Method We obtained data on 916 encounters from 166 officers in six jurisdictions in Georgia, USA and abstracted geographical data pertaining to the location of these encounters from United States Decennial Census data. Encounters were nested within 163 census tracts. Officer-reported data covered general encounter characteristics, the officer’s perception of the subject’s condition, subject demographics, use of force, and disposition of the encounter (e.g., arrest v. referral or transport to treatment services). Geographical data included 17 variables representing population and housing characteristics of the census tracts, from which three indices pertaining to neighborhood income, stability, and immigration status were derived using factor-analytic techniques. We then examined associations of these indices with various encounter-related variables using multi-level analysis. Results Encounters taking place in higher-income and higher-stability census tracts were more likely to be dispatch-initiated and take place in a private home compared to those in lower-income and lower-stability neighborhoods. In higher-income neighborhoods, encounters were more likely to involve a subject suspected to have a mental illness (as opposed to an addictive disorder or developmental disability) and less likely to involve a subject suspected to have alcohol problems. The officer’s level of force used was not associated with neighborhood factors. Regarding disposition, although the likelihood of arrest was unrelated to neighborhood characteristics, encounters

  15. Frictional Behavior of Oceanic Transform Faults and Influence on Earthquake Characteristics

    NASA Astrophysics Data System (ADS)

    Liu, Y.; Behn, M. D.; McGuire, J. J.

    2010-12-01

    The relatively simple thermal and kinematic structures of mid-ocean ridge transform faults (RTFs) make them the ideal sites to study earthquake behavior in the strike-slip tectonic setting. Based on a global compilation of 65 RTFs with a combined length of 16,410 km, Boettcher and Jordan [JGR, 2004] and Boettcher and McGuire [GRL, 2009] summarized the following earthquake scaling relations. (1) By contrast to continental strike-slip faults, a small percentage, ~15%, of total moment on RTFs is released in seismic events. The effective seismic area scales linearly with the total potential seismogenic area AT above a reference isotherm, typically, 600oC. (2) The largest earthquake does not rupture the entire AT. Rather, its rupture area scales with √AT. (3) Seismicity (1964-2009 GCMT and ISC catalogs) follows a tapered frequency-moment distribution, which can be predicted for future time periods using plate-motion rates, fault-lengths, and constants from fitting relations (1) and (2) to past time periods. In this study, we apply the lab-derived rate and state friction law to simulate RTF earthquake cycles, in order to understand the above characteristics and scaling relations. We use gabbro friction data under hydrothermal conditions [He et al., Tectonophys., 2007] constrained by the thermal structure from a half-space cooling model. Earthquakes of various magnitudes, as well as aseismic events, spontaneously occur at different locations on the fault over many cycles. In two end-member scenarios: (1) short and fast spreading RTF (fault length L=100 km, spreading rate V=140 mm/yr), and (2) long and slow spreading RTF (L=625 km, V=30 mm/yr), we found that ~60% of total moment is released in a slow slip mode, that is, slip is above plate-motion rate but not related to earthquakes. For the short/fast case, every 2-4 years magnitude 4 or less earthquakes repeatedly rupture a small (< 0.1L) region around the along-strike center where the width of the frictionally unstable

  16. How national context, project design, and local community characteristics influence success in community-based conservation projects.

    PubMed

    Brooks, Jeremy S; Waylen, Kerry A; Borgerhoff Mulder, Monique

    2012-12-26

    Community-based conservation (CBC) promotes the idea that conservation success requires engaging with, and providing benefits for, local communities. However, CBC projects are neither consistently successful nor free of controversy. Innovative recent studies evaluating the factors associated with success and failure typically examine only a single resource domain, have limited geographic scope, consider only one outcome, or ignore the nested nature of socioecological systems. To remedy these issues, we use a global comparative database of CBC projects identified by systematic review to evaluate success in four outcome domains (attitudes, behaviors, ecological, economic) and explore synergies and trade-offs among these outcomes. We test hypotheses about how features of the national context, project design, and local community characteristics affect these measures of success. Using bivariate analyses and multivariate proportional odds logistic regressions within a multilevel analysis and model-fitting framework, we show that project design, particularly capacity-building in local communities, is associated with success across all outcomes. In addition, some characteristics of the local community in which projects are conducted, such as tenure regimes and supportive cultural beliefs and institutions, are important for project success. Surprisingly, there is little evidence that national context systematically influences project outcomes. We also find evidence of synergies between pairs of outcomes, particularly between ecological and economic success. We suggest that well-designed and implemented projects can overcome many of the obstacles imposed by local and national conditions to succeed in multiple domains.

  17. Influence of basin characteristics on the effectiveness and downstream reach of interbasin water transfers: displacing a problem

    NASA Astrophysics Data System (ADS)

    Emanuel, Ryan E.; Buckley, John J.; Caldwell, Peter V.; McNulty, Steven G.; Sun, Ge

    2015-12-01

    Interbasin water transfers are globally important water management strategies, yet little is known about their role in the hydrologic cycle at regional and continental scales. Specifically, there is a dearth of centralized information on transfer locations and characteristics, and few analyses place transfers into a relevant hydrological context. We assessed hydrological characteristics of interbasin transfers (IBTs) in the conterminous US using a nationwide inventory of transfers together with historical climate data and hydrological modeling. Supplying and receiving drainage basins share similar hydroclimatological conditions, suggesting that climatological drivers of water shortages in receiving basins likely have similar effects on supplying basins. This result calls into question the effectiveness of transfers as a strategy to mitigate climate-driven water shortages, as the water shortage may be displaced but not resolved. We also identified hydrologically advantageous and disadvantageous IBTs by comparing the water balances of supplying and receiving basins. Transfer magnitudes did not vary between the two categories, confirming that factors driving individual IBTs, such as patterns of human water demand or engineering constraints, also influence the continental-scale distribution of transfers. Some IBTs impact streamflow for hundreds of kilometers downstream. Transfer magnitude, hydroclimate and organization of downstream river networks mediate downstream impacts, and these impacts have the potential to expand downstream nonlinearly during years of drought. This work sheds new light on IBTs and emphasizes the need for updated inventories and analyses that place IBTs in an appropriate hydrological context.

  18. Influence of gas temperature on self-sustained volume discharge characteristics in working mixtures of a repetitively pulsed COIL

    SciTech Connect

    Aksinin, V I; Kazantsev, S Yu; Kononov, I G; Podlesnykh, S V; Firsov, K N; Antsiferov, S A; Velikanov, S D; Kalinovskii, V V; Konovalov, V V; Mikhalkin, V N; Sevryugin, I V

    2014-02-28

    The influence of gas temperature on the characteristics of a self-sustained volume discharge was studied in the working mixtures of a chemical oxygen – iodine laser with pulsed electricdischarge production of iodine atoms. In experiments, laser working mixtures were modelled by the mixture of air and iodide C{sub 2}H{sub 5}I. It was established that mixture heating is accompanied by an increase in the voltage across the discharge plasma and by a decrease in the discharge current. By varying the temperature of the mixture with the iodine content of ∼2.7% and initial pressure p=12 Torr from 22 °C to 96 °C, the current amplitude falls by ∼12%, and at the instant corresponding to a maximal current the voltage raises by ∼22%. Such a change in the discharge characteristics is explained by a higher rate of electron attachment to vibrationally excited iodide molecules at elevated temperatures. (active media)

  19. Influence of pulsed nanosecond volume discharge in atmospheric-pressure air on the electrical characteristics of MCT epitaxial films

    NASA Astrophysics Data System (ADS)

    Grigoryev, Denis V.; Voitsekhovskii, Alexandr V.; Lozovoy, Kirill A.; Nesmelov, Sergey N.; Dzyadukh, Stanislav M.; Tarasenko, Viktor F.; Shulepov, Michail A.; Dvoretskii, Sergei A.

    2015-12-01

    The purpose of this paper was investigating the effect of volume nanosecond discharge in air at atmospheric pressure on the electro-physical properties of the HgCdTe (MCT) epitaxial films grown by molecular beam epitaxy. Hall measurements of electro-physical parameters of MCT samples after irradiation have shown that there is a layer of epitaxial films exhibiting n-type conductivity that is formed in the near-surface area. After more than 600 pulses of influence parameters and thickness of the resulting n-layer is such that the measured field dependence of Hall coefficient corresponds to the material of n-type conductivity. Also it is shown that the impact of the discharge leads to significant changes in electro-physical characteristics of MIS structures. This fact is demonstrated by increase in density of positive fixed charge, change in the hysteresis type of the capacitance-voltage characteristic, an increase in density of surface states. The preliminary results show that it is possible to use such actions in the development of technologies of the controlled change in the properties of MCT.

  20. Influence of ionic strength and soil characteristics on the behavior of Cryptosporidium oocysts in saturated porous media.

    PubMed

    Balthazard-Accou, Ketty; Fifi, Urbain; Agnamey, Patrice; Casimir, Justin André; Brasseur, Philippe; Emmanuel, Evens

    2014-05-01

    The physico-chemical behavior of Cryptosporidium oocysts was investigated during their transfer through an alluvial formation from Les Cayes (Haiti) via batch tests. Five approximately 3 kg soil samples were collected and combined prior to batch tests from the alluvial formations. The experiments were carried out at soil pH by equilibrating different ranges of pure oocysts concentrations and soil samples with 3mM CaCl2 and 1mM NaBr as electrolyte. We used the Debye-Hückel equation describing ion activity in a solution for a given ionic strength. The equilibrium adsorption mechanism is used to enumerate the oocysts in the soil. The results suggest that the oocysts behavior in porous media depends on soil characteristics such as soil pH, the nature of the mineral and organic constituents of the soil and the ionic strength and activities in solution. These results show that a total transfer in batch containing NaBr solutions against a partial one in batch containing CaCl2 solutions depends on the oocysts media concentration. To confirm the oocysts number retained in soil, confocal microscopy was successfully used and the images demonstrate that the majority of oocysts were retained at the range of concentrations tested. The findings from this study demonstrated that the retention of C. Parvum in soils may be influenced by chemical conditions and soils characteristics, which are important for groundwater risk assessment.

  1. Influences of current density on tribological characteristics of ceramic coatings on ZK60 Mg alloy by plasma electrolytic oxidation.

    PubMed

    Wu, Xiaohong; Su, Peibo; Jiang, Zhaohua; Meng, Song

    2010-03-01

    Current density is a key factor of plasma electrolytic oxidation process. Its influences on structure, mechanical, and tribological characteristics of ceramic coatings on ZK60 Mg alloy by pulsed bipolar microplasma oxidation in Na(3)PO(4) solution were studied in this paper. Thickness, structure, composition, mechanical property, and tribological characteristics of the coatings were studied by eddy current coating thickness gauge, scanning electron microscope (SEM), X-ray diffraction (XRD), nanoindentation measurements, and ball-on-disk friction testing. The results show that all the coatings prepared under different current densities are composed of MgO phase. The amount of MgO phase, thickness and friction coefficient of the coatings increased with the increasing current density. Among three ceramic coatings produced under three current densities, the coating produced under the current density of 7 A/dm(2) got the highest nanohardness and lowest wear rate with the value of 1.7 GPa and 1.27 x 10(-5) mm(3)/Nm.

  2. How national context, project design, and local community characteristics influence success in community-based conservation projects

    PubMed Central

    Brooks, Jeremy S.; Waylen, Kerry A.; Borgerhoff Mulder, Monique

    2012-01-01

    Community-based conservation (CBC) promotes the idea that conservation success requires engaging with, and providing benefits for, local communities. However, CBC projects are neither consistently successful nor free of controversy. Innovative recent studies evaluating the factors associated with success and failure typically examine only a single resource domain, have limited geographic scope, consider only one outcome, or ignore the nested nature of socioecological systems. To remedy these issues, we use a global comparative database of CBC projects identified by systematic review to evaluate success in four outcome domains (attitudes, behaviors, ecological, economic) and explore synergies and trade-offs among these outcomes. We test hypotheses about how features of the national context, project design, and local community characteristics affect these measures of success. Using bivariate analyses and multivariate proportional odds logistic regressions within a multilevel analysis and model-fitting framework, we show that project design, particularly capacity-building in local communities, is associated with success across all outcomes. In addition, some characteristics of the local community in which projects are conducted, such as tenure regimes and supportive cultural beliefs and institutions, are important for project success. Surprisingly, there is little evidence that national context systematically influences project outcomes. We also find evidence of synergies between pairs of outcomes, particularly between ecological and economic success. We suggest that well-designed and implemented projects can overcome many of the obstacles imposed by local and national conditions to succeed in multiple domains. PMID:23236173

  3. The influences of four types of soil on the growth, physiological and biochemical characteristics of Lycoris aurea (L’ Her.) Herb

    PubMed Central

    Quan, Miaohua; Liang, Juan

    2017-01-01

    Based on the characteristics of Lycoris aurea (L. aurea) natural distribution and local soil types, we selected four representative types of soil, including humus soil, sandy soil, garden soil and yellow-brown soil, for conducting the cultivation experiments to investigate key soil factors influencing its growth and development and to select the soil types suitable for cultivating it. We found that there existed significant differences in the contents of mineral elements and the activities of soil enzymes (urease, phosphatase, sucrase and catalase) etc. Among which, the contents of organic matters, alkali-hydrolysable nitrogen, Ca and Mg as well as the activities of soil enzymes in humus soil were the highest ones. In yellow-brown soil, except for Fe, the values of all the other items were the lowest ones. Net photosynthetic rate (Pn), biomass and lycorine content in humus soil were all the highest ones, which were increased by 31.02, 69.39 and 55.79%, respectively, as compared to those of yellow-brown soil. Stepwise multiple regression analysis and path analysis indicated that alkali-hydrolysable nitrogen, and Ca etc. were key soil factors influencing Pn, biomass and lycorine content of L. aurea. Thus, humus soil can be used as medium suitable for artificial cultivation of L. aurea. PMID:28240308

  4. The influence of sodium on the point defect characteristics in off stoichiometric CuInSe2

    NASA Astrophysics Data System (ADS)

    Stephan, Christiane; Greiner, Dieter; Schorr, Susan; Kaufmann, Christian A.

    2016-11-01

    The device performance of polycrystalline chalcogenide thin film solar cells is strongly influenced by different kinds of defects within the material. The presence of sodium or other alkali metals like potassium during the deposition process is well known to influence the electronic properties of the solar cell and thus to improve the efficiency of the final device. Structural analysis of neutron powder diffraction data collected at low temperatures and subsequent profile analysis by the LeBail and Rietveld method demonstrates the impact of sodium on the point defect characteristics in off stoichiometric CuInSe2. The analyzed materials are powder and thin film solar absorber material with addition of NaF and free of sodium. It is illustrated, the so called "sodium effect" cannot be reduced to one single origin. A range of effects, the reduction of InCu donors with a followed increase of VCu acceptors is possible. The main effect is an increased ordered character of the chalcopyrite crystal structure at off stoichiometric composition, when containing sodium.

  5. The CUPID (Cultural and Psychosocial Influences on Disability) Study: Methods of Data Collection and Characteristics of Study Sample

    PubMed Central

    Coggon, David; Ntani, Georgia; Palmer, Keith T.; Felli, Vanda E.; Harari, Raul; Barrero, Lope H.; Felknor, Sarah A.; Gimeno, David; Cattrell, Anna; Serra, Consol; Bonzini, Matteo; Solidaki, Eleni; Merisalu, Eda; Habib, Rima R.; Sadeghian, Farideh; Kadir, Masood; Warnakulasuriya, Sudath S. P.; Matsudaira, Ko; Nyantumbu, Busisiwe; Sim, Malcolm R.; Harcombe, Helen; Cox, Ken; Marziale, Maria H.; Sarquis, Leila M.; Harari, Florencia; Freire, Rocio; Harari, Natalia; Monroy, Magda V.; Quintana, Leonardo A.; Rojas, Marianela; Salazar Vega, Eduardo J.; Harris, E. Clare; Vargas-Prada, Sergio; Martinez, J. Miguel; Delclos, George; Benavides, Fernando G.; Carugno, Michele; Ferrario, Marco M.; Pesatori, Angela C.; Chatzi, Leda; Bitsios, Panos; Kogevinas, Manolis; Oha, Kristel; Sirk, Tuuli; Sadeghian, Ali; Peiris-John, Roshini J.; Sathiakumar, Nalini; Wickremasinghe, A. Rajitha; Yoshimura, Noriko; Kielkowski, Danuta; Kelsall, Helen L.; Hoe, Victor C. W.; Urquhart, Donna M.; Derett, Sarah; McBride, David; Gray, Andrew

    2012-01-01

    Background The CUPID (Cultural and Psychosocial Influences on Disability) study was established to explore the hypothesis that common musculoskeletal disorders (MSDs) and associated disability are importantly influenced by culturally determined health beliefs and expectations. This paper describes the methods of data collection and various characteristics of the study sample. Methods/Principal Findings A standardised questionnaire covering musculoskeletal symptoms, disability and potential risk factors, was used to collect information from 47 samples of nurses, office workers, and other (mostly manual) workers in 18 countries from six continents. In addition, local investigators provided data on economic aspects of employment for each occupational group. Participation exceeded 80% in 33 of the 47 occupational groups, and after pre-specified exclusions, analysis was based on 12,426 subjects (92 to 1018 per occupational group). As expected, there was high usage of computer keyboards by office workers, while nurses had the highest prevalence of heavy manual lifting in all but one country. There was substantial heterogeneity between occupational groups in economic and psychosocial aspects of work; three- to five-fold variation in awareness of someone outside work with musculoskeletal pain; and more than ten-fold variation in the prevalence of adverse health beliefs about back and arm pain, and in awareness of terms such as “repetitive strain injury” (RSI). Conclusions/Significance The large differences in psychosocial risk factors (including knowledge and beliefs about MSDs) between occupational groups should allow the study hypothesis to be addressed effectively. PMID:22792189

  6. Young Women's use of a microbicide surrogate: the complex influence of relationship characteristics and perceived male partners' evaluations.

    PubMed

    Tanner, Amanda E; Fortenberry, J Dennis; Zimet, Gregory D; Reece, Michael; Graham, Cynthia A; Murray, Maresa

    2010-06-01

    Currently in clinical trials, vaginal microbicides are proposed as a female-initiated method of sexually transmitted infection prevention. Much of microbicide acceptability research has been conducted outside of the United States and frequently without consideration of the social interaction between sex partners, ignoring the complex gender and power structures often inherent in young women's (heterosexual) relationships. Accordingly, the purpose of this study was to build on existing microbicide research by exploring the role of male partners and relationship characteristics on young women's use of a microbicide surrogate, an inert vaginal moisturizer (VM), in a large city in the United States. Individual semi-structured interviews were conducted with 40 young women (18-23 years old; 85% African American; 47.5% mothers) following use of the VM during coital events for a 4 week period. Overall, the results indicated that relationship dynamics and perceptions of male partners influenced VM evaluation. These two factors suggest that relationship context will need to be considered in the promotion of vaginal microbicides. The findings offer insights into how future acceptability and use of microbicides will be influenced by gendered power dynamics. The results also underscore the importance of incorporating men into microbicide promotion efforts while encouraging a dialogue that focuses attention on power inequities that can exist in heterosexual relationships. Detailed understanding of these issues is essential for successful microbicide acceptability, social marketing, education, and use.

  7. Prevalence and characteristics of ESBL-producing E. coli in Dutch recreational waters influenced by wastewater treatment plants.

    PubMed

    Blaak, Hetty; de Kruijf, Patrick; Hamidjaja, Raditijo A; van Hoek, Angela H A M; de Roda Husman, Ana Maria; Schets, Franciska M

    2014-07-16

    Outside health care settings, people may acquire ESBL-producing bacteria through different exposure routes, including contact with human or animal carriers or consumption of contaminated food. However, contact with faecally contaminated surface water may also represent a possible exposure route. The current study investigated the prevalence and characteristics of ESBL-producing Escherichia coli in four Dutch recreational waters and the possible role of nearby waste water treatment plants (WWTP) as contamination source. Isolates from recreational waters were compared with isolates from WWTP effluents, from surface water upstream of the WWTPs, at WWTP discharge points, and in connecting water bodies not influenced by the studied WWTPs. ESBL-producing E. coli were detected in all four recreational waters, with an average concentration of 1.3 colony forming units/100ml, and in 62% of all samples. In surface waters not influenced by the studied WWTPs, ESBL-producing E. coli were detected in similar concentrations, indicating the existence of additional ESBL-E. coli contamination sources. Isolates with identical ESBL-genes, phylogenetic background, antibiotic resistance profiles, and sequence type, were obtained from effluent and different surface water sites in the same watershed, on the same day; occasionally this included isolates from recreational waters. Recreational waters were identified as a potential exposure source of ESBL-producing E. coli. WWTPs were shown to contribute to the presence of these bacteria in surface waters, but other (yet unidentified) sources likely co-contribute.

  8. The influences of iron characteristics, operating conditions and solution chemistry on contaminants removal by zero-valent iron: A review.

    PubMed

    Sun, Yuankui; Li, Jinxiang; Huang, Tinglin; Guan, Xiaohong

    2016-09-01

    For successful application of a zero-valent iron (ZVI) system, of particular interest is the performance of ZVI under various conditions. The current review comprehensively summarizes the potential effects of the major influencing factors, such as iron intrinsic characteristics (e.g., surface area, iron impurities and oxide films), operating conditions (e.g., pH, dissolved oxygen, iron dosage, iron pretreatment, mixing conditions and temperature) and solution chemistry (e.g., anions, cations and natural organic matter) on the performance of ZVI reported in literature. It was demonstrated that all of the factors could exert significant effects on the ZVI performance toward contaminants removal, negatively or positively. Depending on the removal mechanisms of the respective contaminants and other environmental conditions, an individual variable may exhibit different effects. On the other hand, many of these influences have not been well understood or cannot be individually isolated in experimental or natural systems. Thus, more research is required in order to elucidate the exact roles and mechanisms of each factor in affecting the performance of ZVI. Furthermore, based on these understandings, future research may attempt to establish some feasible strategies to minimize the deteriorating effects and utilize the positive effects so as to improve the performance of ZVI.

  9. Influence of electron-beam lithography exposure current level on the transport characteristics of graphene field effect transistors

    NASA Astrophysics Data System (ADS)

    Kang, Sangwoo; Movva, Hema C. P.; Sanne, Atresh; Rai, Amritesh; Banerjee, Sanjay K.

    2016-03-01

    Many factors have been identified to influence the electrical transport characteristics of graphene field-effect transistors. In this report, we examine the influence of the exposure current level used during electron beam lithography (EBL) for active region patterning. In the presence of a self-assembled hydrophobic residual layer generated by oxygen plasma etching covering the top surface of the graphene channel, we show that the use of low EBL current level results in higher mobility, lower residual carrier density, and charge neutrality point closer to 0 V, with reduced device-to-device variations. We show that this correlation originates from the resist heating dependent release of radicals from the resist material, near its interface with graphene, and its subsequent trapping by the hydrophobic polymer layer. Using a general model for resist heating, we calculate the difference in resist heating for different EBL current levels. We further corroborate our argument through control experiments, where radicals are either intentionally added or removed by other processes. We also utilize this finding to obtain mobilities in excess of 18 000 cm2/V s on silicon dioxide substrates. We believe these results are applicable to other 2D materials such as transition metal dichalcogenides and nanoscale devices in general.

  10. Influence of aeration modes on leachate characteristic of landfills that adopt the aerobic-anaerobic landfill method.

    PubMed

    Wu, Chuanfu; Shimaoka, Takayuki; Nakayama, Hirofumi; Komiya, Teppei; Chai, Xiaoli; Hao, Yongxia

    2014-01-01

    As far as the optimal design, operation, and field application of the Aerobic-Anaerobic Landfill Method (AALM) are concerned, it is very important to understand how aeration modes (different combinations of aeration depth and air injection rate) affect the biodegradation of organic carbon and the transformation of nitrogen in landfill solid waste. Pilot-scale lysimeter experiments were carried out under different aeration modes to obtain detailed information regarding the influence of aeration modes on leachate characteristics. Results from these lysimeter experiments revealed that aeration at the bottom layer was the most effective for decomposition of organic carbon when compared with aeration at the surface or middle layers. Moreover, the air injection rate led to different nitrogen transformation patterns, unlike the lesser influence it has on organic carbon decomposition. Effective simultaneous nitrification and denitrification were observed for the aeration mode with a higher air injection rate (=1.0 L/min). On the other hand, the phenomenon of sequenced nitrification and denitrification could be observed when a low air injection rate (=0.5L/min.) was employed. Finally, it is concluded that, for AALM, air injection with a higher air injection rate at the deepest layer near the leachate collection pipe tends to accelerate the stabilization of landfill waste as defined in terms of the enhancement of denitrification as well as organic carbon decomposition.

  11. The relative influence of neighbourhood incivilities, cognitive social capital, club membership and individual characteristics on positive mental health.

    PubMed

    Jones, Russell; Heim, Derek; Hunter, Simon; Ellaway, Anne

    2014-07-01

    Previous research indicates that residents׳ perceptions of their neighbourhoods can have an adverse influence on their health and wellbeing over and above the influence of structural disadvantage. Contrary to most prior research, this study employed an indicator of positive wellbeing and assessed the impact of individual characteristics, perceived social and environmental incivilities, indicators of cognitive and structural social capital, and perceived safety. Analyses of data from a large regional UK representative study (n=8237; 69.64% response rate) found the most influential determinants of wellbeing were physical health problems, age, SES and cognitive social capital. Smaller, significant effects were also found for environmental and social incivilities, and for perceived safety. The effect of cognitive social capital was moderated by age, with a stronger effect found among those aged 65 years and over than among younger participants. Findings indicate that the promotion of positive mental health within communities may be facilitated by efforts to foster a greater sense of belonging among residents, and that older adults may benefit most from such efforts.

  12. An exploratory study on the influence of socio-demographic characteristics on water end uses inside buildings.

    PubMed

    Matos, Cristina; Teixeira, Carlos A; Bento, Ricardo; Varajão, João; Bentes, Isabel

    2014-01-01

    Any strategy of water demand management needs the collaboration of the population involved and so it is important to know how characteristics as residence area, number of residents, presence/absence of children/elders, income level, and educational level, among others, may influence the use of water. Empirical studies that quantify relationship between socio-demographic factors and the water end use patterns inside buildings are still largely lacking. To help to fill this gap this paper gathers information about the characterization of water end use per domestic device in three regions of north of Portugal with different socio-demographic characteristics. The main research goal was to establish indoor water end use patterns per domestic device and to evaluate possible relations between these patterns with the socio-demographic characteristics of the area where the household is, namely the number of residents, the presence/absence of children/elders, the income level and educational level. The washbasin is in average the domestic device with more number of uses in a day (responsible for 34% of the total use), close followed by the kitchen sink (32%), the toilet flush (23%), the bathtub (6%) and finally the dishwasher (3%) and the washing machine (2%). The results found might reflect differences in rural and urban lifestyles once that, with the exception of the kitchen sink, Valpaços is the city that registers the lowest number of uses in the appliances monitored. Significant correlations were found in the following cases: between the residence area and the number of uses in washbasin and in the toilet flush; between the presence of children in the household and the use in the dishwasher; between the income level and the number of uses in the washbasin, in the bathtub, in the washing machine and in the dishwasher.

  13. Numerical study for characteristic change of Asian summer monsoon circulation and its influence mechanism during the El Nino period

    NASA Astrophysics Data System (ADS)

    Ni, Yunqi; Lin, Yuanbi

    1990-05-01

    In this paper, the relation between Asian summer monsoon circulation and sea surface temperature anomalies over equatorial central-eastern Pacific is investigated by using a global spectral model. This model has nine layers in the vertical and the model variables are represented in the horizontal as truncated expansions of the surface spherical harmonics with rhomboidal truncation at wave number 15. The model involves comparatively complete physical processes and parameterizations with mountains. Using the above model, two experimental schemes are designed, namely control case and anomalous sea surface temperature case. The above two schemes are respectively integrated for forty days and the simulated results are obtained from the last 30-day averaged simulations. The simulations show that positive SST anomalies over equatorial central-eastern Pacific weakens Indian monsoon circulation, decreases precipitation in Indian sub-continent whereas it intensifies East Asian monsoon circulation and increases precipitation in East Asian area. All these results reflect the characteristics of Asian summer monsoon during the El Nino period. In this paper, SST anomalies over equatorial central-eastern Pacific have a direct influence on the intensity and position of subtropical high via the wave train over Northern Hemisphere, which is similar to that suggested by Nitta(1987) and the wave train over Southern Hemisphere has an influence on the intensity of Mascarene high and Australia high resulting in affecting cross equatorial flow. As a result, atmospheric interior heat sources and sinks are redistributed because of the change of cross equatorial flow. And the response of atmosphere to the new heat source and sink has a significant influence on Asian summer monsoon.

  14. Influence of Ionophore Supplementation on Growth Performance, Dietary Energetics and Carcass Characteristics in Finishing Cattle during Period of Heat Stress

    PubMed Central

    Barreras, A.; Castro-Pérez, B. I.; López-Soto, M. A.; Torrentera, N. G.; Montaño, M. F.; Estrada-Angulo, A.; Ríos, F. G.; Dávila-Ramos, H.; Plascencia, A.; Zinn, R. A.

    2013-01-01

    Forty-eight crossbred heifers (378.1±18 kg) were used in a 56-d feeding trial (four pens per treatment in a randomised complete block design) to evaluate the influence of ionophore supplementation on growth performance, dietary energetics and carcass characteristics in finishing cattle during a period of heat stress. Heifers were fed a diet based on steam-flaked corn (2.22 Mcal NEm/kg) with and without an ionophore. Treatments were: i) control, no ionophore; ii) 30 mg/kg monensin sodium (RUM30); iii) 20 mg/kg lasalocid sodium (BOV20), and iv) 30 mg/kg lasalocid sodium (BOV30). Both dry matter intake (DMI) and climatic variables were measured daily and the temperature humidity index (THI) was estimated. The maximum THI during the study averaged 93, while the minimum was 70 (THI average = 79.2±2.3). Compared to controls, monensin supplementation did not influence average daily gain, the estimated NE value of the diet, or observed-to-expected DMI, but tended (p = 0.07) to increase (4.8%) gain to feed. Compared to controls, the group fed BOV30 increased (p≤0.03) daily gain (11.8%), gain to feed (8.3%), net energy of the diet (5%), and observed-to-expected DMI (5.2%). Daily weight gain was greater (7.6%, p = 0.05) for heifers fed BOV30 than for heifers fed MON30. Otherwise, differences between the two treatments in DMI, gain to feed, and dietary NE were not statistically significant (p>0.11). Plotting weekly intakes versus THI, observed intake of controls was greater (p<0.05) at THI values ≤77 than ionophore groups. When THI values were greater than 79, DMI of control and MON30 were not different (p = 0.42), although less than that of groups fed lasalocid (p = 0.04). Variation in energy intake was lower (p>0.05) in the ionophores group (CV = 1.7%) than in the control group (CV = 4.5%). Inclusion of ionophores in the diet resulted in relatively minor changes in carcass characteristics. It is concluded that ionophore supplementation did not exacerbate the decline of

  15. An experimental study into the influence of aquatic plant motion characteristics on the generation of a fluvial turbulent flow field

    NASA Astrophysics Data System (ADS)

    Hardy, R. J.; Marjoribanks, T.; Parsons, D. R.; Thomas, R. E.

    2015-12-01

    Aquatic vegetation has a determining effect on flow and consequently sediment transport as it generates both skin friction and form drag. The measurement of flow above the vegetation canopy has received much attention and there is now a good process understanding of mean and turbulent flow, although, much of this research has focused on rigid vegetation with relatively simple morphology. However, vegetation immersed in a flow experiences several forces (buoyancy; drag; virtual mass; Basset; and Saffman) which are counteracted by the properties of the vegetation (flexural rigidity; modulus of elasticity; the plant area exposed to the flow and; the packing density of the stems). The ratio of these forces determines the plant motion characteristics which are generally classified as either i) erect with no movement; ii) gently swaying; iii) strong, coherent swaying or; iv) prone. Here we report on an investigation into the influence of plant motion on the turbulence structure in the mixing zone as vortices in this region have been shown to account for the majority of the momentum transport between the canopy and the open flow. We report on a series of flume experiments where flow over a canopy of surrogate aquatic vegetation was measured using PIV at a spatial resolution of ~1mm2 and at a temporal resolution of 100 Hz. This provided whole flow field measurements for all three components of flow over the vegetation canopy. Plant motion characteristics were altered by modifying the flow Reynolds number through both velocity and depth. The influences of plant stem length were also assessed. The measured flows were analysed by standard Reynolds decomposition approaches and Eulerian and Lagrangian coherent flow structure identification methods. Kelvin-Helmholtz and Görtler-type vortices were identified within the canopy shear layer that are generated close to the canopy top and evolve downstream into span-wise roller vortices, which expand with both distance and time. When

  16. Influence of resonators on the acoustic and propulsion performance characteristics of a ramjet ejector chamber under conditions with vibration hydrogen combustion

    NASA Astrophysics Data System (ADS)

    Potapkin, A. V.; Moskvichev, D. Yu.

    2008-09-01

    The influence of acoustic resonators on the acoustic and propulsion performance characteristics of a ramjet ejector chamber under conditions with vibration hydrogen combustion was experimentally examined. In the study, resonators having identical throats and different cavity diameters were used. For fixed-volume resonators the best propulsion performance characteristics were achieved in the case in which the cavity diameter differed little from the resonator throat diameter.

  17. Predicting the Influence of Pore Characteristics on Ductility of Thin-Walled High Pressure Die Casting Magnesium

    SciTech Connect

    Sun, Xin; Choi, Kyoo Sil; Li, Dongsheng

    2013-06-10

    In this paper, a two-dimensional microstructure-based finite element modeling method is adopted to investigate the effects of porosity in thin-walled high pressure die casting Mg materials on their ductility. For this purpose, the cross-sections of AM50 and AM60 casting samples are first examined using optical microscope to obtain the overall information on the pore characteristics. The experimentally quantified pore characteristics are then used to generate a series of synthetic microstructures with different pore sizes, pore volume fractions and pore size distributions. Pores are explicitly represented in the synthetic microstructures and meshed out for the subsequent finite element analysis. In the finite element analysis, an intrinsic critical strain value is used for the Mg matrix material, beyond which work-hardening is no longer permissible. With no artificial failure criterion prescribed, ductility levels are predicted for the various microstructures in the form of strain localization. Mesh size effect study is also conducted, from which a mesh size dependent critical strain curve is determined. A concept of scalability of pore size effects is then presented and examined with the use of the mesh size dependent critical strain curve. The results in this study show that, for the regions with lower pore size and lower volume fraction, the ductility generally decreases as the pore size and pore volume fraction increase whereas, for the regions with larger pore size and larger pore volume fraction, other factors such as the mean distance between the pores begin to have some substantial influence on the ductility. The results also indicate that the pore size effects may be scalable for the models with good-representative pore shape and distribution with the use of the mesh size dependent critical strain curve.

  18. Quality Matters: Influences of Citrus Flush Physicochemical Characteristics on Population Dynamics of the Asian Citrus Psyllid (Hemiptera: Liviidae)

    PubMed Central

    Simpson, Catherine R.; Alabi, Olufemi J.; Nelson, Shad D.; Telagamsetty, Srilakshmi; Jifon, John L.

    2016-01-01

    Studies were conducted to relate the influence of the physical characteristics, leaf nutrient content and phloem sap amino acid concentration of citrus flush shoots on the densities of various Diaphorina citri life stages. Adult D. citri preferentially selected young shoots for feeding and numbers of D. citri immatures were positively correlated with flush shoot softness. Young flush shoots had higher concentrations of macro and micro nutrients relative to mature ones and this was associated with higher densities of all D. citri life stages. All D. citri life stages were positively correlated with higher nitrogen-carbon (N:C), nitrogen:sulfur (N:S) and nitrogen:calcium (N:Ca) ratios in leaf tissue, while densities of adults were negatively related to calcium, manganese and boron levels. Concentrations of total and essential amino acids were highest in phloem sap of young expanding flush shoots in both grapefruit and lemon, but dramatically declined as flush shoots matured. The sulfur-containing amino acids cystine, methionine and taurine occurred only in younger flush shoots. In contrast, cystathionine was only present in phloem sap of mature shoots. These results clearly indicate that young citrus flush shoots are a nutritionally richer diet relative to mature shoots, thus explaining their preference by D. citri for feeding and reproduction. Conversely, tissue hardness and the lower nutritional quality of mature flush shoots may limit oviposition and immature development. The data suggest that both physical characteristics and nutritional composition of flush shoots and their phloem sap are important factors regulating host colonization and behavior of D. citri, and this interaction can impact the dynamics and spread of HLB in citrus groves. PMID:28030637

  19. Quality Matters: Influences of Citrus Flush Physicochemical Characteristics on Population Dynamics of the Asian Citrus Psyllid (Hemiptera: Liviidae).

    PubMed

    Sétamou, Mamoudou; Simpson, Catherine R; Alabi, Olufemi J; Nelson, Shad D; Telagamsetty, Srilakshmi; Jifon, John L

    2016-01-01

    Studies were conducted to relate the influence of the physical characteristics, leaf nutrient content and phloem sap amino acid concentration of citrus flush shoots on the densities of various Diaphorina citri life stages. Adult D. citri preferentially selected young shoots for feeding and numbers of D. citri immatures were positively correlated with flush shoot softness. Young flush shoots had higher concentrations of macro and micro nutrients relative to mature ones and this was associated with higher densities of all D. citri life stages. All D. citri life stages were positively correlated with higher nitrogen-carbon (N:C), nitrogen:sulfur (N:S) and nitrogen:calcium (N:Ca) ratios in leaf tissue, while densities of adults were negatively related to calcium, manganese and boron levels. Concentrations of total and essential amino acids were highest in phloem sap of young expanding flush shoots in both grapefruit and lemon, but dramatically declined as flush shoots matured. The sulfur-containing amino acids cystine, methionine and taurine occurred only in younger flush shoots. In contrast, cystathionine was only present in phloem sap of mature shoots. These results clearly indicate that young citrus flush shoots are a nutritionally richer diet relative to mature shoots, thus explaining their preference by D. citri for feeding and reproduction. Conversely, tissue hardness and the lower nutritional quality of mature flush shoots may limit oviposition and immature development. The data suggest that both physical characteristics and nutritional composition of flush shoots and their phloem sap are important factors regulating host colonization and behavior of D. citri, and this interaction can impact the dynamics and spread of HLB in citrus groves.

  20. Space-time clustering analysis of wildfires: The influence of dataset characteristics, fire prevention policy decisions, weather and climate.

    PubMed

    Parente, Joana; Pereira, Mário G; Tonini, Marj

    2016-07-15

    The present study focuses on the dependence of the space-time permutation scan statistics (STPSS) (1) on the input database's characteristics and (2) on the use of this methodology to assess changes on the fire regime due to different type of climate and fire management activities. Based on the very strong relationship between weather and the fire incidence in Portugal, the detected clusters will be interpreted in terms of the atmospheric conditions. Apart from being the country most affected by the fires in the European context, Portugal meets all the conditions required to carry out this study, namely: (i) two long and comprehensive official datasets, i.e. the Portuguese Rural Fire Database (PRFD) and the National Mapping Burnt Areas (NMBA), respectively based on ground and satellite measurements; (ii) the two types of climate (Csb in the north and Csa in the south) that characterizes the Mediterranean basin regions most affected by the fires also divide the mainland Portuguese area; and, (iii) the national plan for the defence of forest against fires was approved a decade ago and it is now reasonable to assess its impacts. Results confirmed (1) the influence of the dataset's characteristics on the detected clusters, (2) the existence of two different fire regimes in the country promoted by the different types of climate, (3) the positive impacts of the fire prevention policy decisions and (4) the ability of the STPSS to correctly identify clusters, regarding their number, location, and space-time size in spite of eventual space and/or time splits of the datasets. Finally, the role of the weather on days when clustered fires were active was confirmed for the classes of small, medium and large fires.

  1. The Obstetric Hemorrhage Initiative (OHI) in Florida: The Role of Intervention Characteristics in Influencing Implementation Experiences among Multidisciplinary Hospital Staff.

    PubMed

    Vamos, Cheryl A; Cantor, Allison; Thompson, Erika L; Detman, Linda A; Bronson, Emily A; Phelps, Annette; Louis, Judette M; Gregg, Anthony R; Curran, John S; Sappenfield, William M

    2016-10-01

    Objectives Obstetric hemorrhage is one of the leading causes of maternal mortality. The Florida Perinatal Quality Collaborative coordinates a state-wide Obstetric Hemorrhage Initiative (OHI) to assist hospitals in implementing best practices related to this preventable condition. This study examined intervention characteristics that influenced the OHI implementation experiences among Florida hospitals. Methods Purposive sampling was employed to recruit diverse hospitals and multidisciplinary staff members. A semi-structured interview guide was developed based on the following constructs from the intervention characteristics domain of the Consolidated Framework for Implementation Research: evidence strength; complexity; adaptability; and packaging. Interviews were audio-recorded, transcribed and analyzed using Atlas.ti. Results Participants (n = 50) across 12 hospitals agreed that OHI is evidence-based and supported by various information sources (scientific literature, experience, and other epidemiologic or quality improvement data). Participants believed the OHI was 'average' in complexity, with variation depending on participant's role and intervention component. Participants discussed how the OHI is flexible and can be easily adapted and integrated into different hospital settings, policies and resources. The packaging was also found to be valuable in providing materials and supports (e.g., toolkit; webinars; forms; technical assistance) that assisted implementation across activities. Conclusions for Practice Participants reflected positively with regards to the evidence strength, adaptability, and packaging of the OHI. However, the complexity of the initiative adversely affected implementation experiences and required additional efforts to maximize the initiative effectiveness. Findings will inform future efforts to facilitate implementation experiences of evidence-based practices for hemorrhage prevention, ultimately decreasing maternal morbidity and

  2. Influence of the binder types on the electrochemical characteristics of natural graphite electrode in room-temperature ionic liquid

    NASA Astrophysics Data System (ADS)

    Ui, Koichi; Towada, Jun; Agatsuma, Sho; Kumagai, Naoaki; Yamamoto, Keigo; Haruyama, Hiroshi; Takeuchi, Ken; Koura, Nobuyuki

    To improve the electrochemical characteristics of the natural graphite (NG-3) negative electrode in the LiCl saturated AlCl 3-1-ethyl-3-methylimizadolium chloride + thionyl chloride (SOCl 2) melt as the electrolyte for non-flammable lithium-ion batteries, we examined the influence of the binder types on its electrochemical characteristics. The cyclic voltammograms showed that the reduction current at 1.2-3.2 V vs. Li/Li(I) was repressed using polyacrylic acid (PAA) as the binder. The charge-discharge tests showed that the discharge capacity and the charge-discharge efficiency of the NG-3 electrode coated with the PAA binder at the 1st cycle were 322.8 mAh g -1 and 65.6%, respectively. Compared with the NG-3 electrode using the conventional poly(vinylidene fluoride) binder, it showed considerably a better cyclability with the discharge capacity of 302.1 mAh g -1 at the 50th cycle. Li(I) ion intercalation into the graphite layers could be improved because the NG-3 electrode coated with the PAA binder changed to a golden-yellow color after the 1st charging, and the formation of first stage LiC 6 was demonstrated by X-ray diffraction (XRD) measurement. In addition, the XRD and X-ray photoelectron spectroscopy indicated that one of the side reactions during charging was the formation of LiCl on the graphite surface regardless of the binder types.

  3. Influence of environmental factors on spectral characteristic of chromophoric dissolved organic matter (CDOM) in Inner Mongolia Plateau, China

    NASA Astrophysics Data System (ADS)

    Wen, Z. D.; Song, K. S.; Zhao, Y.; Du, J.; Ma, J. H.

    2015-06-01

    Spectral characteristics of chromophoric dissolved organic matter (CDOM) were examined in conjunction with environmental factors in the waters of 22 rivers and 26 terminal waters in Hulun Buir plateau, northeast China. Dissolved organic carbon (DOC), total nitrogen (TN), and total phosphorous (TP) were significantly higher in terminal waters than rivers waters (p < 0.01). Principal component analysis (PCA) indicated that non-water light absorption and anthropogenic nutrient disturbances might be the causes of the diversity of water quality parameters in Hulun Buir plateau. CDOM absorption in river waters was significantly lower than terminal waters (p < 0.01). Analysis of ratio of absorption at 250-365 nm (E250 : 365), specific UV absorbance (SUVA254), and spectral slope ratio (Sr) indicated that CDOM in river waters had higher aromaticity, molecular weight, and vascular plant contribution than in terminal waters. Furthermore, results showed that DOC concentration, CDOM light absorption, and the proportion of autochthonous sources of CDOM in plateau waters were all higher than in other freshwater rivers reported in the literature. The strong evapoconcentration, intense ultraviolet irradiance and landscape features of Hulun Buir plateau may be responsible for the above phenomenon. Redundancy analysis (RDA) indicated that the environmental variables TSM, TN, and EC had a strong correlation with light absorption characteristics, followed by TDS and chlorophyll a. In most sampling locations, CDOM was the dominant non-water light-absorbing substance. Light absorption by non-algal particles often exceeded that by phytoplankton in the plateau waters. Study of these optical-physicochemical correlations is helpful in the evaluation of the potential influence of water quality factors on non-water light absorption in cold plateau water environments. And the study on organic carbon in plateau lakes had a vital contribution to global carbon balance estimation.

  4. Influence of environmental factors on spectral characteristics of chromophoric dissolved organic matter (CDOM) in Inner Mongolia Plateau, China

    NASA Astrophysics Data System (ADS)

    Wen, Z. D.; Song, K. S.; Zhao, Y.; Du, J.; Ma, J. H.

    2016-02-01

    Spectral characteristics of chromophoric dissolved organic matter (CDOM) were examined in conjunction with environmental factors in the waters of rivers and terminal lakes within the Hulun Buir plateau, northeast China. Dissolved organic carbon (DOC), total nitrogen (TN), and total phosphorous (TP) were significantly higher in terminal lakes than rivers waters (p < 0.01). Principal component analysis (PCA) indicated that non-water light absorption and anthropogenic nutrient disturbances were the likely causes of the diversity of water quality parameters. CDOM absorption in river waters was significantly lower than terminal lakes. Analysis of the ratio of absorption at 250 to 365 nm (E250 : 365), specific ultraviolet (UV) absorbance (SUVA254), and the spectral slope ratio (Sr) indicated that CDOM in river waters had higher aromaticity, molecular weight, and vascular plant contribution than in terminal lakes. Furthermore, results showed that DOC concentration, CDOM light absorption, and the proportion of autochthonous sources of CDOM in plateau waters were all higher than in other freshwater rivers reported in the literature. The strong evapoconcentration, intense ultraviolet irradiance, and landscape features of the Hulun Buir plateau may be responsible for the above phenomenon. Redundancy analysis (RDA) indicated that the environmental variables total suspended matter (TSM), TN, and electrical conductivity (EC) had a strong correlation with light absorption characteristics, followed by total dissolved solid (TDS) and chlorophyll a. In most sampling locations, CDOM was the dominant non-water light-absorbing substance. Light absorption by non-algal particles often exceeded that by phytoplankton in the plateau waters. Study of these optical-physicochemical correlations is helpful in the evaluation of the potential influence of water quality factors on non-water light absorption in cold plateau water environments. The construction of a correlation between DOC

  5. Numerical investigation of influence on heat transfer characteristics to pneumatically conveyed dense phase flow by selecting models and boundary conditions

    NASA Astrophysics Data System (ADS)

    Zheng, Y.; Liu, Q.; Li, Y.

    2012-03-01

    Solids moving with a gas stream in a pipeline can be found in many industrial processes, such as power generation, chemical, pharmaceutical, food and commodity transfer processes. A mass flow rate of the solids is important characteristic that is often required to be measured (and controlled) to achieve efficient utilization of energy and raw materials in pneumatic conveying systems. The methods of measuring the mass flow rate of solids in a pneumatic pipeline can be divided into direct and indirect (inferential) measurements. A thermal solids' mass flow-meter, in principle, should ideally provide a direct measurement of solids flow rate, regardless of inhomogeneities in solids' distribution and environmental impacts. One key issue in developing a thermal solids' mass flow-meter is to characterize the heat transfer between the hot pipe wall and the gas-solids dense phase flow. The Eulerian continuum modeling with gas-solid two phases is the most common method for pneumatic transport. To model a gas-solid dense phase flow passing through a heated region, the gas phase is described as a continuous phase and the particles as the second phase. This study aims to describe the heat transfer characteristics between the hot wall and the gas-solids dense phase flow in pneumatic pipelines by modeling a turbulence gas-solid plug passing through the heated region which involves several actual and crucial issues: selections of interphase exchange coefficient, near-wall region functions and different wall surface temperatures. A sensitivity analysis was discussed to identify the influence on the heat transfer characteristics by selecting different interphase exchange coefficient models and different boundary conditions. Simulation results suggest that sensitivity analysis in the choice of models is very significant. The simulation results appear to show that a combination of choosing the Syamlal-O'Brien interphase exchange coefficient model and the standard k-ɛ model along with

  6. Characteristics of Successful and Unsuccessful Mental Health Referrals of Refugees.

    PubMed

    Shannon, Patricia J; Vinson, Gregory A; Cook, Tonya L; Lennon, Evelyn

    2016-07-01

    In this community based participatory research study, we explored key characteristics of mental health referrals of refugees using stories of providers collected through an on-line survey. Ten coders sorted 60 stories of successful referrals and 34 stories of unsuccessful referrals into domains using the critical incident technique. Principal components analysis yielded categories of successful referrals that included: active care coordination, establishing trust, proactive resolution of barriers, and culturally responsive care. Unsuccessful referrals were characterized by cultural barriers, lack of care coordination, refusal to see refugees, and system and language barriers. Recommendations for training and policy are discussed.

  7. Caller sex and orientation influence spectral characteristics of "two-voice" stereotyped calls produced by free-ranging killer whales.

    PubMed

    Miller, Patrick J O; Samarra, Filipa I P; Perthuison, Aurélie D

    2007-06-01

    This study investigates how particular received spectral characteristics of stereotyped calls of sexually dimorphic adult killer whales may be influenced by caller sex, orientation, and range. Calls were ascribed to individuals during natural behavior using a towed beamforming array. The fundamental frequency of both high-frequency and low-frequency components did not differ consistently by sex. The ratio of peak energy within the fundamental of the high-frequency component relative to summed peak energy in the first two low-frequency component harmonics, and the number of modulation bands off the high-frequency component, were significantly greater when whales were oriented towards the array, while range and adult sex had little effect. In contrast, the ratio of peak energy in the first versus second harmonics of the low-frequency component was greater in calls produced by adult females than adult males, while orientation and range had little effect. The dispersion of energy across harmonics has been shown to relate to body size or sex in terrestrial species, but pressure effects during diving are thought to make such a signal unreliable in diving animals. The observed spectral differences by signaler sex and orientation suggest that these types of information may be transmitted acoustically by freely diving killer whales.

  8. Leader-Member Exchange across two hierarchical levels of leadership: concurrent influences on work characteristics and employee psychological health

    PubMed Central

    Karanika-Murray, Maria; Bartholomew, Kimberley J.; Williams, Glenn A.; Cox, Tom

    2015-01-01

    Leader-Member Exchange (LMX) theory suggests that the quality of the leader–employee relationship is linked to employee psychological health. Leaders who reside at different hierarchical levels have unique roles and spheres of influence and potentially affect employees' work experiences in different ways. Nevertheless, research on the impact of leadership on employee psychological health has largely viewed leaders as a homogeneous group. Expanding on LMX theory, we argue that (1) LMX sourced at the levels of the line manager (LM) and senior management (SM) team will be differentially linked to employee psychological health (assessed as worn-out) and that (2) these relationships will be mediated by perceived work characteristics (reward and recognition, workload management, quality of relationships with colleagues and physical environment). Structural equation modelling on data from 337 manual workers partially supported the hypotheses. Perceptions of the physical environment mediated the relationship between LMX at the LM level and employee psychological health, whereas perceptions of workload management mediated the relationship between LMX at the SM level and psychological health. These findings corroborate arguments that leaders are not a uniform group and as such the effects of LMX on employees will depend on leadership hierarchy. Implications for expanding leadership theory are discussed. PMID:25999635

  9. The Influence of Pretreatment Characteristics and Radiotherapy Parameters on Time Interval to Development of Radiation-Associated Meningioma

    SciTech Connect

    Paulino, Arnold C.; Ahmed, Irfan M.; Mai, Wei Y.; Teh, Bin S.

    2009-12-01

    Purpose: To identify pretreatment characteristics and radiotherapy parameters which may influence time interval to development of radiation-associated meningioma (RAM). Methods and Materials: A Medline/PUBMED search of articles dealing with RAM yielded 66 studies between 1981 and 2006. Factors analyzed included patient age and gender, type of initial tumor treated, radiotherapy (RT) dose and volume, and time interval from RT to development of RAM. Results: A total of 143 patients with a median age at RT of 12 years form the basis of this report. The most common initial tumors or conditions treated with RT were medulloblastoma (n = 27), pituitary adenoma (n = 20), acute lymphoblastic leukemia (n = 20), low-grade astrocytoma (n = 19), and tinea capitis (n = 14). In the 116 patients whose RT fields were known, 55 (47.4%) had a portion of the brain treated, whereas 32 (27.6%) and 29 (25.0%) had craniospinal and whole-brain fields. The median time from RT to develop a RAM or latent time (LT) was 19 years (range, 1-63 years). Male gender (p = 0.001), initial diagnosis of leukemia (p = 0.001), and use of whole brain or craniospinal field (p <= 0.0001) were associated with a shorter LT, whereas patients who received lower doses of RT had a longer LT (p < 0.0001). Conclusions: The latent time to develop a RAM was related to gender, initial tumor type, radiotherapy volume, and radiotherapy dose.

  10. Influences of Variations of Characteristic Parameters of Protein Molecules on States of Soliton Transported Bio-Energy

    NASA Astrophysics Data System (ADS)

    Pang, Xiao-Feng; Zhang, Huai-Wu; Yu, Jia-Feng; Luo, Yu-Hui

    We simulate numerically the dynamic properties of new soliton with quasi-coherent two quanta in the improved model by fourth-order Runge-Kutta way. We observed that the window of formation of new soliton is shifted toward smaller values of coupling constants when compared with the Davydov's soliton with one quantum and Förner's soliton with two quantum model. The new soliton formation starts at (χ1+χ2)=20 PN, and pinning starts from (χ1+χ2)=86 PN. The pinned solitons are also observed if both quanta are on the same end of the chain in the initial state. The behaviors of new soliton are varied under influences for variations of characteristic parameters arising from the structure nonuniformity of protein molecules. Although the new soliton is also sensitive to the dipole-dipole interaction and diagonal disorder, the sensitivity to the impurity is weaker than that of the Davydov's and Förner's solitons. Therefore, the new soliton is robust against the fluctuations of coupled constant, dipole-dipole interaction and diagonal disorder arising from the impurity or structure nonuniformity, when compared with that of the Davydov's and Förner's solitons.

  11. [Influence of floor surface and access to pasture on claw characteristics in dairy cows kept in cubicle housing systems].

    PubMed

    Haufe, H C; Friedli, K; Gygax, L; Wechsler, B

    2014-04-01

    This study aimed at investigating the effect of the floor type used in the walking area of cubicle housing systems and of access to pasture on claw dimensions and claw shape in dairy cows. Data were collected on 36 farms, 12 farms each fitted with mastic asphalt, slatted concrete or solid rubber flooring. With each floor type, cows on half of the farms had access to pasture in summer. The farms were visited three times at intervals of about 6 months and data were collected from 10 cows during each visit. Net growth of the claw horn was highest on rubber flooring and lowest on mastic asphalt. On all floor types, claw angles were larger after the winter period and smaller after the summer period. With regard to claw shape, floor type had an effect on the occurrence of flat, concave and overgrown claw soles. In conclusion, none of the investigated floor types was clearly superior to the others with regard to claw dimensions and claw shape, and access to pasture during summer (median 4 h per day) had only little influence on the investigated claw characteristics.

  12. Influence of extended aging on beef quality characteristics and sensory perception of steaks from the biceps femoris and semimembranosus.

    PubMed

    Colle, M J; Richard, R P; Killinger, K M; Bohlscheid, J C; Gray, A R; Loucks, W I; Day, R N; Cochran, A S; Nasados, J A; Doumit, M E

    2016-09-01

    The objective was to determine the influence of post-fabrication aging (2, 14, 21, 42, and 63days) on beef quality characteristics and consumer sensory perception of biceps femoris (BF) and semimembranosus (SM) steaks. Lipid oxidation and aerobic plate counts increased (P<0.05) with longer aging periods and retail display times. An aging period by day of retail display interaction (P<0.05) was observed for a* and b* values of the BF and SM. Warner-Bratzler shear force values decreased (P<0.05) with longer aging for the SM, while no difference was observed for the BF. Consumer panel results revealed that longer aging periods increased (P<0.05) acceptability of the SM, tenderness of both muscles, and tended to increase (P=0.07) juiciness of the SM. Our results show that extended aging reduces retail color stability yet has positive effects on consumer perception of tenderness of both muscles and overall acceptability of the SM.

  13. Influence of hole mobility on the response characteristics of p-type nickel oxide thin film based glucose biosensor.

    PubMed

    Tyagi, Manisha; Tomar, Monika; Gupta, Vinay

    2012-05-13

    RF sputtered p-type nickel oxide (NiO) thin film exhibiting tunable semiconductor character which in turns enhanced its functional properties. NiO thin film with high hole mobility is developed as a potential matrix for the realization of glucose biosensor. NiO thin film prepared under the optimized deposition conditions offer good electrical conductivity (1.5×10(-3) Ω(-1)-cm(-1)) with high hole mobility (2.8 cm(2) V(-1) s(-1)). The bioelectrode (GO(x)/NiO/ITO/glass) exhibits a low value of Michaelis-Menten constant (K(m)=1.05 mM), indicating high affinity of the immobilized GO(x) toward the analyte (glucose). Due to the high surface coverage (2.32×10(-7) mol cm(-2)) of the immobilized enzyme on to the NiO matrix and its high electrocatalytic activity, the prepared biosensor exhibits a high sensitivity of 0.1 mA(mM(-1)-cm(-2)) and a good linearity from 25 to 300 mg dL(-1) of glucose concentration with fast response time of 5 s. Various functional properties of the material (mobility, crystallinity and stress) are found to influence the charge communication feature of NiO thin film matrix to a great extent, resulting in enhanced sensing response characteristics.

  14. Influence of seasonal variation on the hydro-biogeochemical characteristics of two upland lakes in the Southeastern Amazon, Brazil.

    PubMed

    Sahoo, Prafulla K; Guimarães, José T F; Souza-Filho, Pedro W M; Silva, Marcio S DA; Silva, Renato O; Pessim, Gustavo; Moraes, Bergson C DE; Pessoa, Paulo F P; Rodrigues, Tarcísio M; Costa, Marlene F DA; Dall'agnol, Roberto

    2016-01-01

    Limnological characteristics of the Violão and Amendoim lakes, in the Serra dos Carajás, Amazon, were studied interannually (2013-2014). Climate data indicate anomalous conditions during the 2013 rainy period with higher rainfall and lower temperature in the beginning (November). Lake levels were influenced after the first and second hour of each rainfall, which showed a strong synchronization between seasonal fluctuation of lake levels and local weather patterns. Based on the water quality, both lakes are classified as classes "1" and "2" in the CONAMA (Conselho Nacional do Meio Ambiente) scheme and as "excellent" to "good" in the WQI (Water Quality Index) categories. However, the limnology is distinctly different between the lakes and seasons. Higher trophic state and phytoplankton productivity were observed mainly during the rainy period in Violão Lake compared to Amendoim Lake. This may be due to deposition of leached nutrients in the former, mainly total phosphorus (TP), which was probably derived from mafic soils and guano. This is consistent with the significant positive correlation between Chlorophyll-a and TP at the end of the rainy period (March-April), whereas this was not observed in the beginning (November). This could possibly be a consequence of the more intense cloud cover, and unusual high rainfall that limits nutrient availability.

  15. The influence of zeta potential and yield stress on the filtration characteristics of a magnesium hydroxide simulant

    SciTech Connect

    Biggs, Simon; Nabi, Rafiq; Poole, Colin

    2007-07-01

    In the UK, irradiated fuels from Magnox reactors are often stored in water-filled ponds under alkaline conditions, so as to minimise corrosion of fuel cladding. This is important to prevent or reduce leakage of soluble fission products and actinides to the pond water. A variety of intermediate level wastes derived from Magnox materials are stored at power stations. Under these alkaline conditions, various species of magnesium are formed, of which magnesium hydroxide is the dominant material. The particle-fluid interactions are significant for the design and operation of facilities for hydraulic retrieval, filtration, dewatering and ion exchange treatment of fuel storage pond water and stored wet Magnox wastes. Here we describe a study of particulate properties and filtration characteristics of oxide particle simulants under laboratory conditions. Cake and medium resistance data were correlated across a range of pH conditions with electro-acoustic zeta potential and shear yield stress measurements, as a function of particle volume fractions. The influence of zeta potential on filtration properties arises directly from the interaction of particles within the sediment cake. (authors)

  16. The load and release characteristics on a strong cationic ion-exchange fiber: kinetics, thermodynamics, and influences.

    PubMed

    Yuan, Jing; Gao, Yanan; Wang, Xinyu; Liu, Hongzhuo; Che, Xin; Xu, Lu; Yang, Yang; Wang, Qifang; Wang, Yan; Li, Sanming

    2014-01-01

    Ion-exchange fibers were different from conventional ion-exchange resins in their non-cross-linked structure. The exchange was located on the surface of the framework, and the transport resistance reduced significantly, which might mean that the exchange is controlled by an ionic reaction instead of diffusion. Therefore, this work aimed to investigate the load and release characteristics of five model drugs with the strong cationic ion-exchange fiber ZB-1. Drugs were loaded using a batch process and released in United States Pharmacopoeia (USP) dissolution apparatus 2. Opposing exchange kinetics, suitable for the special structure of the fiber, were developed for describing the exchange process with the help of thermodynamics, which illustrated that the load was controlled by an ionic reaction. The molecular weight was the most important factor to influence the drug load and release rate. Strong alkalinity and rings in the molecular structures made the affinity between the drug and fiber strong, while logP did not cause any profound differences. The drug-fiber complexes exhibited sustained release. Different kinds and concentrations of counter ions or different amounts of drug-fiber complexes in the release medium affected the release behavior, while the pH value was independent of it. The groundwork for in-depth exploration and further application of ion-exchange fibers has been laid.

  17. Influence of coal nature and structure on ash size formation characteristic and related pollutant emissions during CFB combustion

    NASA Astrophysics Data System (ADS)

    Qian, Min; Boelle, Arnaud; Jaud, Philippe; Na, Yongjie; Lu, Qinggang; Bao, Shaolin; Cui, Ping; Jiao, Weihong; Zhao, Huanming

    2000-09-01

    The size distribution of coal particles in a Circulating Fluidized Bed (CFB) boiler plays a crucial role in the complicated combustion, heat exchange and pollutant emissions in such a plant. Therefore, it is fundamental to study the different factors having influence on the size distribution of coal particles. Above all, the coal itself and in particular, the coal comminution phenomenon is a very influent factor. In the frame of this work, the coal nature (elementary composition) and coal internal structure (mineral components) are studied in detail. At this intermediary stage, experiments on three typical Chinese coals on a 1.5 MWt CFBC pilot plant have been made. Some primary fragmentation tests have also been made in a small lab scale fluidized bed reactor. The results from the hot pilot test show i) the variation of coal ash distributions and other CFB performance data due to the cyclone and the coal characteristics and ii) the variation of desulfurization efficiency with limestone. Whereas the bench scale primary fragmentation test, likely linked to the caking propriety of a coal, does not seem to change considerably the char size distribution.

  18. Influences of watershed, riparian-corridor, and reach-scale characteristics on aquatic biota in agricultural watersheds

    USGS Publications Warehouse

    Stewart, J.S.; Wang, L.; Lyons, J.; Horwatich, J.A.; Bannerman, R.

    2001-01-01

    Multivariate analyses and correlations revealed strong relations between watershed and riparian-corridor land cover, and reach-scale habitat versus fish and macroinvertebrate assemblages in 38 warmwater streams in eastern Wisconsin. Watersheds were dominated by agricultural use, and ranged in size from 9 to 71 km2. Watershed land cover was summarized from satellite-derived data for the area outside a 30-m buffer. Riparian land cover was interpreted from digital orthophotos within 10-, 10- to 20-, and 20- to 30-m buffers. Reach-scale habitat, fish, and macroinvertebrates were collected in 1998 and biotic indices calculated. Correlations between land cover, habitat, and stream-quality indicators revealed significant relations at the watershed, riparian-corridor, and reach scales. At the watershed scale, fish diversity, intolerant fish and EPT species increased, and Hilsenhoff biotic index (HBI) decreased as percent forest increased. At the riparian-corridor scale, EPT species decreased and HBI increased as riparian vegetation became more fragmented. For the reach, EPT species decreased with embeddedness. Multivariate analyses further indicated that riparian (percent agriculture, grassland, urban and forest, and fragmentation of vegetation), watershed (percent forest) and reach-scale characteristics (embeddedness) were the most important variables influencing fish (IBI, density, diversity, number, and percent tolerant and insectivorous species) and macroinvertebrate (HBI and EPT) communities.

  19. Leader-Member Exchange across two hierarchical levels of leadership: concurrent influences on work characteristics and employee psychological health.

    PubMed

    Karanika-Murray, Maria; Bartholomew, Kimberley J; Williams, Glenn A; Cox, Tom

    2015-01-02

    Leader-Member Exchange (LMX) theory suggests that the quality of the leader-employee relationship is linked to employee psychological health. Leaders who reside at different hierarchical levels have unique roles and spheres of influence and potentially affect employees' work experiences in different ways. Nevertheless, research on the impact of leadership on employee psychological health has largely viewed leaders as a homogeneous group. Expanding on LMX theory, we argue that (1) LMX sourced at the levels of the line manager (LM) and senior management (SM) team will be differentially linked to employee psychological health (assessed as worn-out) and that (2) these relationships will be mediated by perceived work characteristics (reward and recognition, workload management, quality of relationships with colleagues and physical environment). Structural equation modelling on data from 337 manual workers partially supported the hypotheses. Perceptions of the physical environment mediated the relationship between LMX at the LM level and employee psychological health, whereas perceptions of workload management mediated the relationship between LMX at the SM level and psychological health. These findings corroborate arguments that leaders are not a uniform group and as such the effects of LMX on employees will depend on leadership hierarchy. Implications for expanding leadership theory are discussed.

  20. Predictors of Intelligence at the Age of 5: Family, Pregnancy and Birth Characteristics, Postnatal Influences, and Postnatal Growth

    PubMed Central

    Eriksen, Hanne-Lise Falgreen; Kesmodel, Ulrik Schiøler; Underbjerg, Mette; Kilburn, Tina Røndrup; Bertrand, Jacquelyn; Mortensen, Erik Lykke

    2013-01-01

    Parental education and maternal intelligence are well-known predictors of child IQ. However, the literature regarding other factors that may contribute to individual differences in IQ is inconclusive. The aim of this study was to examine the contribution of a number of variables whose predictive status remain unclarified, in a sample of basically healthy children with a low rate of pre- and postnatal complications. 1,782 5-year-old children sampled from the Danish National Birth Cohort (2003–2007) were assessed with a short form of the Wechsler Preschool and Primary Scale of Intelligence – Revised. Information on parental characteristics, pregnancy and birth factors, postnatal influences, and postnatal growth was collected during pregnancy and at follow-up. A model including study design variables and child’s sex explained 7% of the variance in IQ, while parental education and maternal IQ increased the explained variance to 24%. Other predictors were parity, maternal BMI, birth weight, breastfeeding, and the child’s head circumference and height at follow-up. These variables, however, only increased the explained variance to 29%. The results suggest that parental education and maternal IQ are major predictors of IQ and should be included routinely in studies of cognitive development. Obstetrical and postnatal factors also predict IQ, but their contribution may be of comparatively limited magnitude. PMID:24236109

  1. Influence of chestnut tannins on welfare, carcass characteristics, meat quality, and lipid oxidation in rabbits under high ambient temperature.

    PubMed

    Liu, Huawei; Zhou, Daowei; Tong, Jianming; Vaddella, Venkata

    2012-01-01

    A study was conducted to evaluate the influence of chestnut tannins (CT) on welfare, carcass characteristics, meat quality, and lipid oxidation in rabbits under high ambient temperature. Rabbits in one group were raised at 20°C and fed with basal diet (N) and other three groups (33°C) were fed basal diet with 0 (C), 5 (CT5), and 10 g (CT10) of CT/kg of diet. Compared with the C group, rabbits in CT10 had higher pH(24) and lower cooking loss and thiobarbituric acid reacting substance values at 0, 30, and 60 min of forced oxidation. Rabbits in C group had higher cortisol levels, creatine kinase activities, white blood cell counts, neutrophil percentage, neutrophil:lymphocyte ratio and lower T(3), T(4) levels, lymphocyte percentage than N and CT10 groups. Supplementation of CT seemed to have a positive effect on growth performance, welfare, and meat quality of rabbits under high ambient temperature.

  2. Characteristics of heavy metal transfer and their influencing factors in different soil-crop systems of the industrialization region, China.

    PubMed

    Chen, Hongyan; Yuan, Xuyin; Li, Tianyuan; Hu, Sun; Ji, Junfeng; Wang, Cheng

    2016-04-01

    Soil heavy metals and their bioaccumulation in agricultural products have attracted widespread concerns, yet the transfer and accumulation characteristics of heavy metals in different soil-crop systems was rarely investigated. Soil and crop samples were collected from the typical agricultural areas in the Yangtze River Delta region, China. The concentrations of Cu, Pb, Zn, Cd and Hg in the soils, roots and grains of rice (Oryza Sativa L.), wheat (Triticum L.) and canola (Brassica napus L.) were determined in this study. Transfer ability of heavy metals in soil-rice system was stronger than those in soil-wheat and soil-canola systems. The wheat showed a strong capacity to transfer Zn, Cu and Cd from root to the grain while canola presented a restricting effect to the intake of Cu and Cd. Soil pH and total organic matter were major factors influencing metal transfer from soil to rice, whereas soil Al2O3 contents presented a negative effect on heavy metal mobility in wheat and canola cultivation systems. The concentration of Zn and Cd in crop grains could well predicted according to the stepwise multiple linear regression models, which could help to quantitatively evaluate the ecologic risk of heavy metal accumulation in crops in the study area.

  3. Further GPU implementation of prediction-based lower triangular transform using a zero-order entropy coder for ultraspectral sounder data compression

    NASA Astrophysics Data System (ADS)

    Wei, Shih-Chieh; Huang, Bormin

    2012-10-01

    The ultraspectral sounder data consists of two dimensional pixels, each containing thousands of channels. In retrieval of geophysical parameters, the sounder data is sensitive to noises. Therefore lossless compression is highly desired for storing and transmitting the huge volume data. The prediction-based lower triangular transform (PLT) features the same de-correlation and coding gain properties as the Karhunen-Loeve transform (KLT), but with a lower design and implementational cost. In previous work, we have shown that PLT has the perfect reconstruction property which allows its direct use for lossless compression of sounder data. However PLT is time-consuming in doing compression. To speed up the PLT encoding scheme, we have recently exploited the parallel compute power of modern graphics processing unit (GPU) and implemented several important transform stages to compute the transform coefficients on GPU. In this work, we further incorporated a GPU-based zero-order entropy coder for the last stage of compression. The experimental result shows that our full implementation of the PLT encoding scheme on GPU shows a speedup of 88x compared to its original full implementation on CPU.

  4. The Co-Occurrence of Substance Use and Bullying Behaviors among U.S. Adolescents: Understanding Demographic Characteristics and Social Influences

    ERIC Educational Resources Information Center

    Luk, Jeremy W.; Wang, Jing; Simons-Morton, Bruce G.

    2012-01-01

    This study examined the co-occurrence of subtypes of substance use and bullying behaviors using latent class analysis and evaluated latent class differences in demographic characteristics, peer and parental influences. Self-reported questionnaire data were collected from a nationally representative sample (N = 7508) of 6-10th grade adolescents in…

  5. Urban Middle-School Science Teachers Beliefs about the Influence of Their Astronomer-Educator Partnerships on Students' Astronomy Learner Characteristics

    ERIC Educational Resources Information Center

    Miranda, Rommel J.

    2012-01-01

    This qualitative study investigates the extent to which urban middle-school science teachers' beliefs about their students' astronomy learner characteristics were influenced by their partnership with an astronomer in their classroom. Twelve urban middle-school science teachers were interviewed after their participation in Project ASTRO during the…

  6. Do Student Characteristics Influence the Effectiveness of the Tools for Getting along Curriculum? An Examination Using a Cognitive-Behavioral Intervention

    ERIC Educational Resources Information Center

    Barnes, Tia Navelene; Smith, Stephen W.; Daunic, Ann P.; Leite, Walter L.

    2016-01-01

    Cognitive-behavioral interventions (CBIs) are effective in decreasing externalizing behavior in school-aged children. To ensure that CBIs meet the needs of a diverse student population, it is important to examine whether intervention effectiveness is influenced by characteristics common to students identified with problem behaviors. In this study,…

  7. The Influence of Properties of the Test and Their Interactions with Reader Characteristics on Reading Comprehension: An Explanatory Item Response Study

    ERIC Educational Resources Information Center

    Kulesz, Paulina A.; Francis, David J.; Barnes, Marcia A.; Fletcher, Jack M.

    2016-01-01

    Component skills and discourse frameworks of reading have identified characteristics of readers and texts that influence comprehension. However, these 2 frameworks have not previously been integrated in a comprehensive and systematic way to explain performance on any standardized assessment of reading comprehension that is in widespread use across…

  8. Age-Differences in Work Motivation and Job Satisfaction. The Influence of Age on the Relationships between Work Characteristics and Workers' Outcomes

    ERIC Educational Resources Information Center

    Boumans, Nicolle P. G.; de Jong, Ad H. J.; Janssen, Sara M.

    2011-01-01

    This study investigated the influence of age on the relationship between work characteristics and workers' work motivation and job satisfaction. In total, 1036 workers of a Dutch division of a multinational organization participated. Data were collected by a digital questionnaire. Two interaction terms in the regression on work motivation were…

  9. Case, Teacher and School Characteristics Influencing Teachers' Detection and Reporting of Child Physical Abuse and Neglect: Results from an Australian Survey

    ERIC Educational Resources Information Center

    Walsh, Kerryann; Bridgstock, Ruth; Farrell, Ann; Rassafiani, Mehdi; Schweitzer, Robert

    2008-01-01

    Objective: To identify the influence of multiple case, teacher and school characteristics on Australian primary school teachers' propensity to detect and report child physical abuse and neglect using vignettes as short hypothetical cases. Methods: A sample of 254 teachers completed a self-report questionnaire. They responded to a series of 32…

  10. Influencing Work-Related Learning: The Role of Job Characteristics and Self-Directed Learning Orientation in Part-Time Vocational Education

    ERIC Educational Resources Information Center

    Gijbels, David; Raemdonck, Isabel; Vervecken, Dries

    2010-01-01

    Based on the Demand-Control-Support (DCS) model, the present paper aims to investigate the influence of job characteristics such as job demands, job control, social support at work and self-directed learning orientation on the work-related learning behaviour of workers. The present study was conducted in a centre for part-time vocational education…

  11. Complex contextual influences on the communicative interactions of students with multiple and severe disabilities.

    PubMed

    De Bortoli, Tania; Arthur-Kelly, Michael; Foreman, Phil; Balandin, Susan; Mathisen, Bernice

    2011-10-01

    The aim of this study was to explore teachers' perceptions and experiences of supports and obstacles to engaging students with multiple and severe disabilities (MSD) in communicative interactions at school. Eleven teachers of students with MSD participated in two in-depth interviews. Interview transcripts were analysed for narrative structure and content themes. Inter-coder reliability for coding of content themes was 87.5%. Participants identified a broad range of factors, including: characteristics of individual students, attitudes, perceptions and beliefs of teachers and other staff, class structure, staffing, opportunities for collegiality, resources, funding, infrastructure, collaboration with speech-language pathologists, appropriate communication education for teachers, the role of government departments, and broader societal factors. The findings suggest that there are complex contextual influences on the communicative interactions of students with MSD. While inadequate systemic supports appear to contribute to low frequencies of communication, systemic factors can be structured so that students participate in activities and have opportunities for communication. Further research is required with teachers of students with MSD to substantiate these findings.

  12. Chemical characteristics of aerosol and rain water during an El Niño and PDO influenced Indian summer monsoon

    NASA Astrophysics Data System (ADS)

    Rajeev, Pradhi; Rajput, Prashant; Gupta, Tarun

    2016-11-01

    According to the meteorological long-term variability pattern, year 2015 was influenced by El Niño and PDO (Pacific Decadal Oscillation; causes weakening of Indian Summer Monsoon). These conditions facilitate the assessment of chemical characteristics of fine-mode ambient aerosols (PM2.5; n = 48) and individual rain waters (pH: 6.4-7.6; n = 15) during the South-west monsoon (July-September 2015) in the central Indo-Gangetic Plain (IGP; Kanpur). Water-soluble ionic species (WSIS) have been measured to assess the undergoing processes (neutralization, formation and below-cloud scavenging) and estimate their dry and wet deposition fluxes. The ∑WSIS varies from 4 to 32 μg/m3 in PM2.5, whereas it ranges from 32 to 102 mg/L in rain waters. The NH4+ and SO42- are found to be predominant in PM2.5 (16-120 μg/m3), whereas HCO3- and Ca2+ are predominant in rain water samples. The difference in chemical composition of PM2.5 and rain water is largely attributed to additional contribution of coarse-mode mineral dust in rain water. The Ca2+ and Mg2+ in both aerosols and rain water samples are associated with HCO3-. The NO3- and SO42- are neutralized predominantly by NH4+ and ∑-/∑+ ratio is ≈ 1 in both aerosols and rain waters. Furthermore, co-variability of NO3- with nss-Ca2+ in PM2.5 indicates role of fine-mode mineral dust surface in the formation of ammonium nitrate. Characteristic mass ratios (HCO3-/Ca2+ and SO42-/NH4+) in rain water look quite similar to those in aerosols (PM2.5). This suggests that below-cloud scavenging is predominant mechanism of aerosols wash-out. Dry deposition fluxes of Mg2+, NH4+ and SO42- are ∼13% of their wet deposition fluxes, whereas for K+, Ca2+ and NO3- it is <6%.

  13. The influence of the wooden equipment employed for cheese manufacture on the characteristics of a traditional stretched cheese during ripening.

    PubMed

    Di Grigoli, Antonino; Francesca, Nicola; Gaglio, Raimondo; Guarrasi, Valeria; Moschetti, Marta; Scatassa, Maria Luisa; Settanni, Luca; Bonanno, Adriana

    2015-04-01

    The influence of the wooden equipment used for the traditional cheese manufacturing from raw milk was evaluated on the variations of chemico-physical characteristics and microbial populations during the ripening of Caciocavallo Palermitano cheese. Milk from two farms (A, extensive; B, intensive) was processed in traditional and standard conditions. Chemical and physical traits of cheeses were affected by the farming system and the cheese making technology, and changed during ripening. Content in NaCl and N soluble was lower, and paste consistency higher in cheese from the extensive farm and traditional technology, whereas ripening increased the N soluble and the paste yellow and consistency. The ripening time decreased the number of all lactic acid bacteria (LAB) groups, except enterococci detected at approximately constant levels (10(4) and 10(5) cfu g(-1) for standard and traditional cheeses, respectively), till 120 d of ripening. In all productions, at each ripening time, the levels detected for enterococci were lower than those for the other LAB groups. The canonical discriminant analysis of chemical, physical and microbiological data was able to separate cheeses from different productions and ripening time. The dominant LAB were isolated, phenotypically characterised and grouped, genetically differentiated at strain level and identified. Ten species of LAB were found and the strains detected at the highest levels were Pediococcus acidilactici and Lactobacillus casei. Ten strains, mainly belonging to Lactobacillus rhamnosus and Lactobacillus fermentum showed an antibacterial activity. The comparison of the polymorphic profiles of the LAB strains isolated from the wooden vat with those of the strains collected during maturation, showed the persistence of three enterococci in traditional cheeses, with Enterococcus faecalis found at dominant levels over the Enterococcus population till 120 d; the absence of these strains in the standard productions evidenced the

  14. The influences of purple sweet potato anthocyanin on the growth characteristics of human retinal pigment epithelial cells

    PubMed Central

    Sun, Min; Lu, Xiaoling; Hao, Lei; Wu, Tao; Zhao, Huanjiao; Wang, Chao

    2015-01-01

    Background Anthocyanins have been proven to be beneficial to the eyes. However, information is scarce about the effects of purple sweet potato (Ipomoea batatas, L.) anthocyanin (PSPA), a class of anthocyanins derived from purple sweet potato roots, on visual health. Objective The aim of this study was to investigate whether PSPA could have influences on the growth characteristics (cellular morphology, survival, and proliferation) of human retinal pigment epithelial (RPE) cells, which perform essential functions for the visual process. Methods The RPE cell line D407 was used in the present study. The cytotoxicity of PSPA was assessed by MTT assay. Then, cellular morphology, viability, cell cycle, Ki67expression, and PI3K/MAPK activation of RPE cells treated with PSPA were determined. Results PSPA exhibited dose-dependent promotion of RPE cell proliferation at concentrations ranging from 10 to 1,000 µg/ml. RPE cells treated with PSPA demonstrated a predominantly polygonal morphology in a mosaic arrangement, and colony-like cells displayed numerous short apical microvilli and typical ultrastructure. PSPA treatment also resulted in a better platform growing status, statistically higher viability, an increase in the S-phase, and more Ki67+ cells. However, neither pAkt nor pERK were detected in either group. Conclusions We found that PSPA maintained high cell viability, boosted DNA synthesis, and preserved a high percentage of continuously cycling cells to promote cell survival and division without changing cell morphology. This paper lays the foundation for further research about the damage-protective activities of PSPA on RPE cells or human vision. PMID:26070791

  15. Human Activity and Habitat Characteristics Influence Shorebird Habitat Use and Behavior at a Vancouver Island Migratory Stopover Site.

    PubMed

    Murchison, Colleen R; Zharikov, Yuri; Nol, Erica

    2016-09-01

    Pacific Rim National Park Reserve on Vancouver Island, British Columbia, Canada, has 16 km of coastal beaches that attract many thousands of people and shorebirds (S.O. Charadrii) every year. To identify locations where shorebirds concentrate and to determine the impact of human activity and habitat characteristics on shorebirds, we conducted shorebird and visitor surveys at 20 beach sectors (across 20 total km of beach) during fall migration in 2011-2014 and spring migration in 2012 and 2013. Using zero-inflated negative binomial regression and a model selection approach, we found that beach width and number of people influenced shorebird use of beach sectors (Bayesian information criterion weight of top model = 0.69). Shorebird absence from beaches was associated with increasing number of people (parameter estimate from top model: 0.38; 95 % CI 0.19, 0.57) and decreasing beach width (parameter estimate: -0.32; 95 % CI -0.47, -0.17). Shorebirds spent more time at wider beaches (parameter estimate: 0.68; 95 % CI 0.49, 0.87). Close proximity to people increased the proportion of time shorebirds spent moving, while shorebirds spent more time moving and less time foraging on wider beaches than on narrower ones. Shorebird disturbance increased with proximity of people, activity speed, and presence of dogs. Based on our findings, management options, for reducing shorebird disturbance at Pacific Rim National Park Reserve and similar shorebird stopover areas, include mandatory buffer distances between people and shorebirds, restrictions on fast-moving activities (e.g., running, biking), prohibiting dogs, and seasonal closures of wide beach sections.

  16. Which patient characteristics influence length of hospital stay after primary total hip arthroplasty in a 'fast-track' setting?

    PubMed

    den Hartog, Y M; Mathijssen, N M C; Hannink, G; Vehmeijer, S B W

    2015-01-01

    After implementation of a 'fast-track' rehabilitation protocol in our hospital, mean length of hospital stay for primary total hip arthroplasty decreased from 4.6 to 2.9 nights for unselected patients. However, despite this reduction there was still a wide range across the patients' hospital duration. The purpose of this study was to identify which specific patient characteristics influence length of stay after successful implementation of a 'fast-track' rehabilitation protocol. A total of 477 patients (317 female and 160 male, mean age 71.0 years; 39.3 to 92.6, mean BMI 27.0 kg/m(2);18.8 to 45.2) who underwent primary total hip arthroplasty between 1 February 2011 and 31 January 2013, were included in this retrospective cohort study. A length of stay greater than the median was considered as an increased duration. Logistic regression analyses were performed to identify potential factors associated with increased durations. Median length of stay was two nights (interquartile range 1), and the mean length of stay 2.9 nights (1 to 75). In all, 266 patients had a length of stay ≤ two nights. Age (odds ratio (OR) 2.46; 95% confidence intervals (CI) 1.72 to 3.51; p < 0.001), living situation (alone vs living together with cohabitants, OR 2.09; 95% CI 1.33 to 3.30; p = 0.002) and approach (anterior approach vs lateral, OR 0.29; 95% CI 0.19 to 0.46; p < 0.001) (posterolateral approach vs lateral, OR 0.24; 95% CI 0.10 to 0.55; p < 0.001) were factors that were significantly associated with increased length of stay in the multivariable logistic regression model.

  17. Sleep Deprivation and Recovery Sleep Prior to a Noxious Inflammatory Insult Influence Characteristics and Duration of Pain

    PubMed Central

    Vanini, Giancarlo

    2016-01-01

    Study Objectives: Insufficient sleep and chronic pain are public health epidemics. Sleep loss worsens pain and predicts the development of chronic pain. Whether previous, acute sleep loss and recovery sleep determine pain levels and duration remains poorly understood. This study tested whether acute sleep deprivation and recovery sleep prior to formalin injection alter post-injection pain levels and duration. Methods: Male Sprague-Dawley rats (n = 48) underwent sleep deprivation or ad libitum sleep for 9 hours. Thereafter, rats received a subcutaneous injection of formalin or saline into a hind paw. In the recovery sleep group, rats were allowed 24 h between sleep deprivation and the injection of formalin. Mechanical and thermal nociception were assessed using the von Frey test and Hargreaves' method. Nociceptive measures were performed at 1, 3, 7, 10, 14, 17 and 21 days post-injection. Results: Formalin caused bilateral mechanical hypersensitivity (allodynia) that persisted for up to 21 days post-injection. Sleep deprivation significantly enhanced bilateral allodynia. There was a synergistic interaction when sleep deprivation preceded a formalin injection. Rats allowed a recovery sleep period prior to formalin injection developed allodynia only in the injected limb, with higher mechanical thresholds (less allodynia) and a shorter recovery period. There were no persistent changes in thermal nociception. Conclusion: The data suggest that acute sleep loss preceding an inflammatory insult enhances pain and can contribute to chronic pain. The results encourage studies in a model of surgical pain to test whether enhancing sleep reduces pain levels and duration. Citation: Vanini G. Sleep deprivation and recovery sleep prior to a noxious inflammatory insult influence characteristics and duration of pain. SLEEP 2016;39(1):133–142. PMID:26237772

  18. Human Activity and Habitat Characteristics Influence Shorebird Habitat Use and Behavior at a Vancouver Island Migratory Stopover Site

    NASA Astrophysics Data System (ADS)

    Murchison, Colleen R.; Zharikov, Yuri; Nol, Erica

    2016-09-01

    Pacific Rim National Park Reserve on Vancouver Island, British Columbia, Canada, has 16 km of coastal beaches that attract many thousands of people and shorebirds (S.O. Charadrii) every year. To identify locations where shorebirds concentrate and to determine the impact of human activity and habitat characteristics on shorebirds, we conducted shorebird and visitor surveys at 20 beach sectors (across 20 total km of beach) during fall migration in 2011-2014 and spring migration in 2012 and 2013. Using zero-inflated negative binomial regression and a model selection approach, we found that beach width and number of people influenced shorebird use of beach sectors (Bayesian information criterion weight of top model = 0.69). Shorebird absence from beaches was associated with increasing number of people (parameter estimate from top model: 0.38; 95 % CI 0.19, 0.57) and decreasing beach width (parameter estimate: -0.32; 95 % CI -0.47, -0.17). Shorebirds spent more time at wider beaches (parameter estimate: 0.68; 95 % CI 0.49, 0.87). Close proximity to people increased the proportion of time shorebirds spent moving, while shorebirds spent more time moving and less time foraging on wider beaches than on narrower ones. Shorebird disturbance increased with proximity of people, activity speed, and presence of dogs. Based on our findings, management options, for reducing shorebird disturbance at Pacific Rim National Park Reserve and similar shorebird stopover areas, include mandatory buffer distances between people and shorebirds, restrictions on fast-moving activities (e.g., running, biking), prohibiting dogs, and seasonal closures of wide beach sections.

  19. Potential pollutant sources in a Choptank River (USA) subwatershed and the influence of land use and watershed characteristics

    USGS Publications Warehouse

    Nino de Guzman, Gabriela T.; Hapeman, Cathleen J.; Prabhakara, Kusuma; Codling, Eton E.; Shelton, Daniel R.; Rice, Clifford P.; Hively, W. Dean; McCarty, Gregory W.; Lang, Megan W.; Torrents, Alba

    2012-01-01

    Row-crop and poultry production have been implicated as sources of water pollution along the Choptank River, an estuary and tributary of the Chesapeake Bay. This study examined the effects of land use, subwatershed characteristics, and climatic conditions on the water quality parameters of a subwatershed in the Choptank River watershed. The catchments within the subwatershed were defined using advanced remotely-sensed data and current geographic information system processing techniques. Water and sediment samples were collected in May–October 2009 and April–June 2010 under mostly baseflow conditions and analyzed for select bacteria, nitrate-N, ammonium-N, total arsenic, total phosphorus (TP), orthophosphate (ortho-P), and particle-phase phosphorus (PP); n = 96 for all analytes except for arsenic, n = 136, and for bacteria, n = 89 (aqueous) and 62 (sediment). Detections of Enterococci and Escherichia coli concentrations were ubiquitous in this subwatershed and showed no correlation to location or land use, however larger bacterial counts were observed shortly after precipitation. Nitrate-N concentrations were not correlated with agricultural lands, which may reflect the small change in percent agriculture and/or the similarity of agronomic practices and crops produced between catchments. Concentration data suggested that ammonia emission and possible deposition to surface waters occurred and that these processes may be influenced by local agronomic practices and climatic conditions. The negative correlation of PP and arsenic concentrations with percent forest was explained by the stronger signal of the head waters and overland flow of particulate phase analytes versus dissolved phase inputs from groundwater. Service roadways at some poultry production facilities were found to redirect runoff from the facilities to neighboring catchment areas, which affected water quality parameters. Results suggest that in this subwatershed, catchments with poultry production

  20. Investigation on the precaecal and faecal digestibility of lactulose and inulin and their influence on nutrient digestibility and microbial characteristics.

    PubMed

    Branner, Gertraud R; Böhmer, Barbara M; Erhardt, W; Henke, Julia; Roth-Maier, Dora A

    2004-10-01

    This study was conducted to determine the pre-caecal and faecal digestibility of lactulose and inulin and the influence of these substances on nutrient digestibility and microbial characteristics. In metabolic trials three of six male growing pigs (German Landrace x Pietrain) were fitted with an ileo-rectal anastomosis (IRA) in end-to-end technique with preserved ileo-caeco-colic valve. The metabolic trials were conducted from day 21-63 after surgery. The remaining pigs were used as intact partners (IN) for the IRA pigs. The experimental diets, based on corn, wheat, barley and soybean meal, were supplemented with either 1.5% lactulose or 2% inulin in replacement of diatomaceous earth (control). Pre-caecal digestibility of lactulose and inulin was assessed to be 79 and 98%, respectively. faecal digestibility was determined as 100%. The supplementation of lactulose and inulin had only minor effects on the pre-caecal and faecal digestibility of nutrients. Significant differences in nutrient digestibility were obvious between IRA and IN pigs, whereas the IRA pigs showed lower digestibility values with the exception of ether extracts (EE). Bacterial population in the digesta of IRA and IN pigs were not affected by the experimental diets except the concentration of gram-negative anaerobes, which inclined when the IRA pigs received the lactulose diet. The pH of chyme was significantly lower than the pH of faeces, however the pH was unaffected by the different supplemented diets. The concentration of volatile fatty acids (VFA) in pre-caecal chyme decreased significantly when IRA pigs received the lactulose supplemented diet whereas VFA in faeces were unaffected by the supplementation. IRA pigs administered with lactulose excreted more N via the urine, but the nitrogen balance remained unaffected. From the present investigation it can be concluded that lactulose and inulin did only partly or scarcely fulfill the expectation of acting as prebiotics in pigs.

  1. Dual permeability modeling of tile drain management influences on hydrologic and nutrient transport characteristics in macroporous soil

    NASA Astrophysics Data System (ADS)

    Frey, Steven K.; Hwang, Hyoun-Tae; Park, Young-Jin; Hussain, Syed I.; Gottschall, Natalie; Edwards, Mark; Lapen, David R.

    2016-04-01

    Tile drainage management is considered a beneficial management practice (BMP) for reducing nutrient loads in surface water. In this study, 2-dimensional dual permeability models were developed to simulate flow and transport following liquid swine manure and rhodamine WT (strongly sorbing) tracer application on macroporous clay loam soils under controlled (CD) and free drainage (FD) tile management. Dominant flow and transport characteristics were successfully replicated, including higher and more continuous tile discharge and lower peak rhodamine WT concentrations in FD tile effluent; in relation to CD, where discharge was intermittent, peak rhodamine concentrations higher, and mass exchange from macropores into the soil matrix greater. Explicit representation of preferential flow was essential, as macropores transmitted >98% of surface infiltration, tile flow, and tile solute loads for both FD and CD. Incorporating an active 3rd type lower boundary condition that facilitated groundwater interaction was imperative for simulating CD, as the higher (relative to FD) water table enhanced water and soluble nutrient movement from the soil profile into deeper groundwater. Scenario analysis revealed that in conditions where slight upwards hydraulic gradients exist beneath tiles, groundwater upwelling can influence the concentration of surface derived solutes in tile effluent under FD conditions; whereas the higher and flatter CD water table can restrict groundwater upwelling. Results show that while CD can reduce tile discharge, it can also lead to an increase in surface-application derived nutrient concentrations in tile effluent and hence surface water receptors, and it can promote NO3 loading into groundwater. This study demonstrates dual permeability modeling as a tool for increasing the conceptual understanding of tile drainage BMPs.

  2. Influences of oxygen content on characteristics of atmospheric pressure dielectric barrier discharge in argon/oxygen mixtures

    NASA Astrophysics Data System (ADS)

    Fang, Zhi; Shao, Tao; Wang, Ruixue; Yang, Jing; Zhang, Cheng

    2016-04-01

    The dielectric barrier discharge generated in argon/oxygen mixtures at atmospheric pressure is investigated, and the effect of oxygen content on discharge characteristics at applied voltage of 4.5 kV is studied by means of electrical measurements and optical diagnostics. The results show that the filaments in the discharge regime become more densely packed with the increasing in the oxygen content, and the distribution of the filaments is more uniform in the gap. An increase in the oxygen content results in a decrease in the average power consumed and transported charges, while there exists an optimal value of oxygen content for the production of oxygen radicals. The maximal yield of oxygen radicals is obtained in mixtures of argon with 0.3% oxygen addition, and the oxygen radicals then decrease with the further increase in the oxygen content. The oxygen/argon plasma is employed to modify surface hydrophilicity of the PET films to estimate the influence of oxygen content on the surface treatment, and the static contact angles before and after the treatments are measured. The lowest contact angle is obtained at a 0.3% addition of oxygen to argon, which is in accordance with the optimum oxygen content for oxygen radicals generation. The electron density and electron temperature are estimated from the measured current and optical emission spectroscopy, respectively. The electron density is found to reduce significantly at a higher oxygen content due to the increased electron attachment, while the estimated electron temperature do not change apparently with the oxygen content. Contribution to the Topical Issue "Recent Breakthroughs in Microplasma Science and Technology", edited by Kurt Becker, Jose Lopez, David Staack, Klaus-Dieter Weltmann and Wei Dong Zhu.

  3. [Influence of different concentration Ni and Cu on the photosynthesis and chlorophyll fluorescence characteristics of Peganum harmala].

    PubMed

    Lu, Yan; Li, Xin-rong; He, Ming-zhu; Su, Yan-gui; Zeng, Fan-jiang

    2011-04-01

    A pot experiment was conducted to study the influence of different concentration (0, 50, 100, 200, and 400 mg kg(-1)) Ni and Cu on the growth, photosynthesis, and chlorophyll fluorescence characteristics of Peganum harmala seedlings. With increasing concentration Ni in the medium, the seedlings growth parameters, photosynthetic pigment content, net photosynthetic rate (P(n)), stomatal conductance (G(s)), transpiration rate (T(r)), maximal photochemical efficiency of PS II (F(v)/F(m)), quantum efficiency of electric transport of PS II (phi (PS II)), and coefficient of photochemical quenching (q(P)) of P. harmala decreased significantly, while the intercellular CO2 concentration (C(i)) and the coefficient of non-photochemical quenching (q(N)) were in adverse. The decrease of P(n) under Ni stress was mainly caused by non-stomatal limitation. At 50 mg kg(-1) Cu, the growth parameters, photosynthetic pigment content, P(n), G(s), T(r), C(i), F(v)/F(m), phi(PS II), and q(P) reached their peak values; at 100 mg kg(-1) Cu, the growth parameters, chlorophyll a and b contents, P(n), G(s), T(r), C(i), and F(v)/F(m) were still slightly higher than the control; while with the further increasing Cu concentration in the medium, all the test indices except q(N) tended to decrease. The decrease of P(n) under Cu stress was mainly caused by stomatal limitation.

  4. Influence of blade thickness on transient flow characteristics of centrifugal slurry pump with semi-open impeller

    NASA Astrophysics Data System (ADS)

    Tao, Yi; Yuan, Shouqi; Liu, Jianrui; Zhang, Fan; Tao, Jianping

    2016-10-01

    As the critical component, the impellers of the slurry pumps usually have blades of a large thickness. The increasing excretion coefficient of the blades affects the flow in the impeller resulting in a relatively higher hydraulic loss, which is rarely reported. In order to investigate the influence of blade thickness on the transient flow characteristics of a centrifugal slurry pump with a semi-open impeller, transient numerical simulations were carried out on six impellers, of which the meridional blade thickness from the leading edge to trailing edge varied from 5-10 mm, 5-15 mm, 5-20 mm, 10-10 mm, 10-15 mm, and 10-20 mm, respectively. Then, two of the six impellers, namely cases 4 and 6, were manufactured and experimentally tested for hydraulic performance to verify the simulation results. Results of these tests agreed reasonably well with those of the numerical simulation. The results demonstrate that when blade thickness increases, pressure fluctuations at the outlet of the impeller become severe. Moreover, the standard deviation of the relative velocity in the middle portion of the suction sides of the blades decreases and that at the outlet of the impeller increases. Thus, the amplitude of the impeller head pulsation for each case increases. Meanwhile, the distribution of the time-averaged relative flow angle becomes less uniform and decreases at the outlet of the impeller. Hence, as the impeller blade thickness increases, the pump head drops rapidly and the maximum efficiency point is offset to a lower flow rate condition. As the thickness of blade trailing edge increases by 10 mm, the head of the pump drops by approximately 5 m, which is approximately 10 % of the original pump head. Futhermore, it is for the first time that the time-averaged relative flow angle is being considered for the analysis of transient flow in centrifugal pump. The presented work could be a useful guideline in engineering practice when designing a centrifugal slurry pump with thick

  5. Meteorological Factors and Tree Characteristics Influencing the Initiation and Rate of Stemflow from Deciduous Trees in an Urban Park

    NASA Astrophysics Data System (ADS)

    Schooling, J. T.; Carlyle-Moses, D. E.

    2013-12-01

    Stemflow, SF, represents that portion of precipitation that is intercepted by a tree's canopy and diverted to the ground at the tree base by flowing along branches and down the bole. The focused input of water and nutrients associated with SF have been shown to be of hydrological and biogeochemical importance in a number of plant communities and forest environments. Although the concentrated water volume and the nutrient / pollutant fluxes associated with SF in urban areas may be highly relevant for stormwater quantity and quality management, they have received only minor study in built environments. In an urban park in Kamloops, British Columbia, Canada, SF volumes generated from 40 deciduous trees representing 22 species were sampled on a precipitation event basis over a period of 16 months. Using this data, we derived the threshold rainfall depth required for SF initiation from each tree by taking the absolute value of the y-intercept of the linear regression of SF volume versus rainfall depth divided by the slope of that regression. The SF discharge rate once the threshold rainfall depth had been reached was taken as the slope of the linear regression equation. Thus, a simplified SF equation was developed: SFv = QSF x (Pg = Pg''), where SFv is stemflow volume (litres), QSF is the discharge rate (litres / mm), and Pg and Pg' represent the precipitation depth and the threshold precipitation depth, respectively. We then examined the influence of meteorological factors (precipitation type [rain / snow / rain + snow], precipitation depth, rainfall intensity, wind speed and direction, and vapour pressure deficit), and tree characteristics (tree diameter at breast height, tree height, leaf size and orientation, bark roughness, crown projection area, leaf area index, canopy cover fraction, branching angle, the proportion of the crown that was comprised of branches, and overlap with other tree canopies) on QSF and Pg' in order to expand on the simplified model and

  6. Inside the Black Box of Doctoral Education: What Program Characteristics Influence Doctoral Students' Attrition and Graduation Probabilities?

    ERIC Educational Resources Information Center

    Ehrenberg, Ronald G.; Jakubson, George H.; Groen, Jeffrey A.; So, Eric; Price, Joseph

    2007-01-01

    The Andrew W. Mellon Foundation's Graduate Education Initiative (GEI) provided funding to 54 departments in the humanities and related social sciences during the 1990s to improve their PhD programs. This article estimates the aspects of PhD programs the GEI influenced and how these aspects influenced attrition and graduation probabilities. It uses…

  7. Evaluation and Analysis of the ANSI X3T9.5 (FDDI) PMD and Proposed SMF-PMD as Influenced by Various Fiber Link Characteristics

    NASA Technical Reports Server (NTRS)

    Wernicki, M. Chris

    1991-01-01

    The purpose of this project is to evaluate the operational parameters of the Kennedy Space Center (KSC) fiber optic cable plant. The evaluation is based on the Fiber Distributed Data Interface (FDDI) Physical Medium Dependent (PMD) and Single Mode Fiber (SMF) PMD standards. From the KSC fiber profile, it would be necessary to develop the modifications needed in existing FDDI PMD and proposed SMF-PMD standards to provide for FDDI implementation and operation at KSC. This analysis should examine the major factors that influence the operating conditions of the KSC fiber plant. These factors would include, but are not limited to the number and type of connectors, attenuation and dispersion characteristics of the fiber, non-standard fiber sizes, modal bandwidth, and many other relevant or significant fiber plant characteristics that effect FDDI characteristics. This analysis is needed to gain a better understanding of overall impact that each of these factors have on FDDI performance at KSC.