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Sample records for call frequency variation

  1. Intraspecific variation in the advertisement call of the cloud-forest frog Eleutherodactylus glamyrus (Anura: Eleutherodactylidae).

    OpenAIRE

    Rodríguez, A; de la Nuez, D.; Alonso, R.

    2010-01-01

    We analyzed variation in the advertisement calls among three localities of Eleutherodactylus glamyrus, a frog endemic to the Sierra Maestra mountains in Eastern Cuba. We assessed the levels of withinmale variation of each call property and the influence of temperature and size of calling male on acoustical features. The typical single-note advertisement call of the species was described using temporal and spectral parameters. Rise time and frequency modulation were highly variable...

  2. Bats aloft: Variation in echolocation call structure at high altitudes

    Science.gov (United States)

    Bats alter their echolocation calls in response to changes in ecological and behavioral conditions, but little is known about how they adjust their call structure in response to changes in altitude. This study examines altitudinal variation in the echolocation calls of Brazilian free-tailed bats, T...

  3. SNP calling, genotype calling, and sample allele frequency estimation from new-generation sequencing data

    DEFF Research Database (Denmark)

    Nielsen, Rasmus; Korneliussen, Thorfinn Sand; Albrechtsen, Anders;

    2012-01-01

    calculated using a dynamic programming algorithm and numerically optimized using analytical derivatives. We then use a bayesian method for estimating the sample allele frequency in a single site, and show how the method can be used for genotype calling and SNP calling. We also show how the method can be...

  4. Geographic Variation in Advertisement Calls in a Tree Frog Species: Gene Flow and Selection Hypotheses

    Science.gov (United States)

    Jang, Yikweon; Hahm, Eun Hye; Lee, Hyun-Jung; Park, Soyeon; Won, Yong-Jin; Choe, Jae C.

    2011-01-01

    Background In a species with a large distribution relative to its dispersal capacity, geographic variation in traits may be explained by gene flow, selection, or the combined effects of both. Studies of genetic diversity using neutral molecular markers show that patterns of isolation by distance (IBD) or barrier effect may be evident for geographic variation at the molecular level in amphibian species. However, selective factors such as habitat, predator, or interspecific interactions may be critical for geographic variation in sexual traits. We studied geographic variation in advertisement calls in the tree frog Hyla japonica to understand patterns of variation in these traits across Korea and provide clues about the underlying forces for variation. Methodology We recorded calls of H. japonica in three breeding seasons from 17 localities including localities in remote Jeju Island. Call characters analyzed were note repetition rate (NRR), note duration (ND), and dominant frequency (DF), along with snout-to-vent length. Results The findings of a barrier effect on DF and a longitudinal variation in NRR seemed to suggest that an open sea between the mainland and Jeju Island and mountain ranges dominated by the north-south Taebaek Mountains were related to geographic variation in call characters. Furthermore, there was a pattern of IBD in mitochondrial DNA sequences. However, no comparable pattern of IBD was found between geographic distance and call characters. We also failed to detect any effects of habitat or interspecific interaction on call characters. Conclusions Geographic variations in call characters as well as mitochondrial DNA sequences were largely stratified by geographic factors such as distance and barriers in Korean populations of H. japoinca. Although we did not detect effects of habitat or interspecific interaction, some other selective factors such as sexual selection might still be operating on call characters in conjunction with restricted gene

  5. Geographic variation in advertisement calls in a tree frog species: gene flow and selection hypotheses.

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    Yikweon Jang

    Full Text Available BACKGROUND: In a species with a large distribution relative to its dispersal capacity, geographic variation in traits may be explained by gene flow, selection, or the combined effects of both. Studies of genetic diversity using neutral molecular markers show that patterns of isolation by distance (IBD or barrier effect may be evident for geographic variation at the molecular level in amphibian species. However, selective factors such as habitat, predator, or interspecific interactions may be critical for geographic variation in sexual traits. We studied geographic variation in advertisement calls in the tree frog Hyla japonica to understand patterns of variation in these traits across Korea and provide clues about the underlying forces for variation. METHODOLOGY: We recorded calls of H. japonica in three breeding seasons from 17 localities including localities in remote Jeju Island. Call characters analyzed were note repetition rate (NRR, note duration (ND, and dominant frequency (DF, along with snout-to-vent length. RESULTS: The findings of a barrier effect on DF and a longitudinal variation in NRR seemed to suggest that an open sea between the mainland and Jeju Island and mountain ranges dominated by the north-south Taebaek Mountains were related to geographic variation in call characters. Furthermore, there was a pattern of IBD in mitochondrial DNA sequences. However, no comparable pattern of IBD was found between geographic distance and call characters. We also failed to detect any effects of habitat or interspecific interaction on call characters. CONCLUSIONS: Geographic variations in call characters as well as mitochondrial DNA sequences were largely stratified by geographic factors such as distance and barriers in Korean populations of H. japonica. Although we did not detect effects of habitat or interspecific interaction, some other selective factors such as sexual selection might still be operating on call characters in conjunction with

  6. Harp Seals Do Not Increase Their Call Frequencies When It Gets Noisier.

    Science.gov (United States)

    Terhune, John M; Bosker, Thijs

    2016-01-01

    Some species avoid low-frequency masking by shifting their calls to higher frequencies. We addressed the hypothesis that Pagophilus groenlandicus (harp seals) will make more high-frequency underwater calls to avoid low-frequency conspecific masking as calling rates increase. The spectral shapes at high and low calling rates were compared (after equalizing the broadband amplitudes). There were no significant differences between the spectral shapes. Pagophilus groenlandicus do not alter the proportions of low- and high-frequency calls as it gets noisier. This suggests that they may not shift their calling frequencies when encountering low-frequency, broadband anthropogenic noise. PMID:26611080

  7. The Barbados Emergency Ambulance Service: High Frequency of Nontransported Calls

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    Sherwin E. Phillips

    2012-01-01

    Full Text Available Objectives. There are no published studies on the Barbados Emergency Ambulance Service and no assessment of the calls that end in nontransported individuals. We describe reasons for the nontransport of potential clients. Methods. We used the Emergency Medical Dispatch (Medical Priority Dispatch System instrument, augmented with five local call types, to collect information on types of calls. The calls were categorised under 7 headings. Correlations between call types and response time were calculated. Results. Most calls were from the category medical (54%. Nineteen (19% percent of calls were in the non-transported category. Calls from call type Cancelled accounted for most of these and this was related to response time, while Refused service was inversely related (. Conclusions. The Barbados Ambulance Service is mostly used by people with a known illness and for trauma cases. One-fifth of calls fall into a category where the ambulance is not used often due to cancellation which is related to response time. Other factors such as the use of alternative transport are also important. Further study to identify factors that contribute to the non-transported category of calls is necessary if improvements in service quality are to be made.

  8. Variation in chick-a-dee calls of a Carolina chickadee population, Poecile carolinensis: Identity and redundancy within note types

    Science.gov (United States)

    Freeberg, Todd M.; Lucas, Jeffrey R.; Clucas, Barbara

    2003-04-01

    Chick-a-dee calls of chickadee species are structurally complex because calls possess a rudimentary syntax governing the ordering of their different note types. Chick-a-dee calls were recorded in an aviary from female and male birds from two field sites. This paper reports sources of variation of acoustical parameters of notes in these calls. There were significant sex and microgeographic differences in some of the measured parameters of the notes in the calls. In addition, the syntax of the call itself influenced characteristics of each of the notes. For example, calls with many introductory notes began with a note of higher frequency and longer duration, relative to calls with few introductory notes. Furthermore, the number of introductory notes influenced frequency and duration components of notes later in the call. Thus, single notes are predictive of the note composition of the signaler's call. This suggests that a receiver might gain the meaning in the call even if it hears only part of the call. Further, single notes within these complex calls can contain information enabling receivers to predict the sex of the signaler, and whether it is from the local population.

  9. Moth hearing in response to bat echolocation calls manipulated independently in time and frequency.

    Science.gov (United States)

    Jones, G; Waters, D A

    2000-08-22

    We measured the auditory responses of the noctuid moth Noctua pronuba to bat echolocation calls which were manipulated independently in time and frequency. Such manipulations are important in understanding how insect hearing influences the evolution of echolocation call characteristics. We manipulated the calls of three bat species (Rhinolophus hipposideros, Myotis nattereri and Pipistrellus pipistrellus) that use different echolocation call features by doubling their duration or reducing their frequency, and measured the auditory thresholds from the A1 cells of the moths. Knowing the auditory responses of the moth we tested three predictions. (i) The ranking of the audibility of unmanipulated calls to the moths should be predictable from their temporal and/or frequency structure. This was supported. (ii) Doubling the duration of the calls should increase their audibility by ca. 3 dB for all species. Their audibility did indeed increase by 2.1-3.5 dB. (iii) Reducing the frequency of the calls would increase their audibility for all species. Reducing the frequency had small effects for the two bat species which used short duration (2.7-3.6 ms) calls. However, the relatively long-duration (50 ms), largely constant-frequency calls of R. hipposideros increased in audibility by 21.6 dB when their frequency was halved. Time and frequency changes influence the audibility of calls to tympanate moths in different ways according to call design. Large changes in frequency and time had relatively small changes on the audibility of calls for short, largely broadband calls. Channelling energy into the second harmonic of the call substantially decreased the audibility of calls for bats which use long-duration, constant-frequency components in echolocation calls. We discuss our findings in the contexts of the evolution of both bat echolocation call design and the potential responses of insects which hear ultrasound. PMID:11467425

  10. Seasonal variations of volcanic eruption frequencies

    Science.gov (United States)

    Stothers, Richard B.

    1989-01-01

    Do volcanic eruptions have a tendency to occur more frequently in the months of May and June? Some past evidence suggests that they do. The present study, based on the new eruption catalog of Simkin et al.(1981), investigates the monthly statistics of the largest eruptions, grouped according to explosive magnitude, geographical latitude, and year. At the 2-delta level, no month-to-month variations in eruption frequency are found to be statistically significant. Examination of previously published month-to-month variations suggests that they, too, are not statistically significant. It is concluded that volcanism, at least averaged over large portions of the globe, is probably not periodic on a seasonal or annual time scale.

  11. Adult Vampire Bats Produce Contact Calls When Isolated: Acoustic Variation by Species, Population, Colony, and Individual

    OpenAIRE

    Carter, Gerald G.; Logsdon, Ryane; Arnold, Bryan D.; Menchaca, Angelica; Medellin, Rodrigo A.

    2012-01-01

    Background Bat pups produce individually distinct isolation calls to facilitate maternal recognition. Increasing evidence suggests that, in group-living bat species, adults often use similar calls to maintain contact. We investigated if isolated adults from all three species of the highly cooperative vampire bats (Phyllostomidae: Desmodontinae) would produce vocally distinct contact calls when physically isolated. Methods/Principal Findings We assessed variation in contact calls recorded from...

  12. Adult Vampire Bats Produce Contact Calls When Isolated: Acoustic Variation by Species, Population, Colony, and Individual

    OpenAIRE

    Gerald G Carter; Ryane Logsdon; Arnold, Bryan D.; Angelica Menchaca; Medellin, Rodrigo A.

    2012-01-01

    BACKGROUND: Bat pups produce individually distinct isolation calls to facilitate maternal recognition. Increasing evidence suggests that, in group-living bat species, adults often use similar calls to maintain contact. We investigated if isolated adults from all three species of the highly cooperative vampire bats (Phyllostomidae: Desmodontinae) would produce vocally distinct contact calls when physically isolated. METHODS/PRINCIPAL FINDINGS: We assessed variation in contact calls recorded fr...

  13. Moth hearing in response to bat echolocation calls manipulated independently in time and frequency.

    OpenAIRE

    Jones, G.; Waters, D A

    2000-01-01

    We measured the auditory responses of the noctuid moth Noctua pronuba to bat echolocation calls which were manipulated independently in time and frequency. Such manipulations are important in understanding how insect hearing influences the evolution of echolocation call characteristics. We manipulated the calls of three bat species (Rhinolophus hipposideros, Myotis nattereri and Pipistrellus pipistrellus) that use different echolocation call features by doubling their duration or reducing the...

  14. Individual, contextual, and age-related acoustic variation in Simakobu (Simias concolor loud calls.

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    Wendy M Erb

    Full Text Available Primate loud calls have the potential to encode information about the identity, arousal, age, or physical condition of the caller, even at long distances. In this study, we conducted an analysis of the acoustic features of the loud calls produced by a species of Asian colobine monkey (simakobu, Simias concolor. Adult male simakobu produce loud calls spontaneously and in response to loud sounds and other loud calls, which are audible more than 500 m. Individual differences in calling rates and durations exist, but it is unknown what these differences signal and which other acoustic features vary among individuals. We aimed to describe the structure and usage of calls and to examine acoustic features that vary within and among individuals. We determined the context of 318 loud calls and analyzed 170 loud calls recorded from 10 adult males at an undisturbed site, Pungut, Siberut Island, Indonesia. Most calls (53% followed the loud call of another male, 31% were spontaneous, and the remaining 16% followed a loud environmental disturbance. The fundamental frequency (F0 decreased while inter-unit intervals (IUI increased over the course of loud call bouts, possibly indicating caller fatigue. Discriminant function analysis indicated that calls were not well discriminated by context, but spontaneous calls had higher peak frequencies, suggesting a higher level of arousal. Individual calls were distinct and individuals were mainly discriminated by IUI, call duration, and F0. Loud calls of older males had shorter IUI and lower F0, while middle-aged males had the highest peak frequencies. Overall, we found that calls were individually distinct and may provide information about the age, stamina, and arousal of the calling male, and could thus be a way for males and females to assess competitors and mates from long distances.

  15. A multivariate analysis of genetic variation in the advertisement call of the gray treefrog, Hyla versicolor.

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    Welch, Allison M; Smith, Michael J; Gerhardt, H Carl

    2014-06-01

    Genetic variation in sexual displays is crucial for an evolutionary response to sexual selection, but can be eroded by strong selection. Identifying the magnitude and sources of additive genetic variance underlying sexually selected traits is thus an important issue in evolutionary biology. We conducted a quantitative genetics experiment with gray treefrogs (Hyla versicolor) to investigate genetic variances and covariances among features of the male advertisement call. Two energetically expensive traits showed significant genetic variation: call duration, expressed as number of pulses per call, and call rate, represented by its inverse, call period. These two properties also showed significant genetic covariance, consistent with an energetic constraint to call production. Combining the genetic variance-covariance matrix with previous estimates of directional sexual selection imposed by female preferences predicts a limited increase in call duration but no change in call rate despite significant selection on both traits. In addition to constraints imposed by the genetic covariance structure, an evolutionary response to sexual selection may also be limited by high energetic costs of long-duration calls and by preferences that act most strongly against very short-duration calls. Meanwhile, the persistence of these preferences could be explained by costs of mating with males with especially unattractive calls. PMID:24621402

  16. Geographic variation in advertisement calls of a Microhylid frog - testing the role of drift and ecology.

    Science.gov (United States)

    Lee, Ko-Huan; Shaner, Pei-Jen L; Lin, Yen-Po; Lin, Si-Min

    2016-05-01

    Acoustic signals for mating are important traits that could drive population differentiation and speciation. Ecology may play a role in acoustic divergence through direct selection (e.g., local adaptation to abiotic environment), constraint of correlated traits (e.g., acoustic traits linked to another trait under selection), and/or interspecific competition (e.g., character displacement). However, genetic drift alone can also drive acoustic divergence. It is not always easy to differentiate the role of ecology versus drift in acoustic divergence. In this study, we tested the role of ecology and drift in shaping geographic variation in the advertisement calls of Microhyla fissipes. We examined three predictions based on ecological processes: (1) the correlation between temperature and call properties across M. fissipes populations; (2) the correlation between call properties and body size across M. fissipes populations; and (3) reproductive character displacement (RCD) in call properties between M. fissipes populations that are sympatric with and allopatric to a congener M. heymonsi. To test genetic drift, we examined correlations among call divergence, geographic distance, and genetic distance across M. fissipes populations. We recorded the advertisement calls from 11 populations of M. fissipes in Taiwan, five of which are sympatrically distributed with M. heymonsi. We found geographic variation in both temporal and spectral properties of the advertisement calls of M. fissipes. However, the call properties were not correlated with local temperature or the callers' body size. Furthermore, we did not detect RCD. By contrast, call divergence, geographic distance, and genetic distance between M. fissipes populations were all positively correlated. The comparisons between phenotypic Q st (P st) and F st values did not show significant differences, suggesting a role of drift. We concluded that genetic drift, rather than ecological processes, is the more likely

  17. Geographic variation in the advertisement calls of Hyla eximia and its possible explanations

    OpenAIRE

    Rodríguez-Tejeda, Ruth E.; María Guadalupe Méndez-Cárdenas; Valentina Islas-Villanueva; Constantino Macías Garcia

    2014-01-01

    Populations of species occupying large geographic ranges are often phenotypically diverse as a consequence of variation in selective pressures and drift. This applies to attributes involved in mate choice, particularly when both geographic range and breeding biology overlap between related species. This condition may lead to interference of mating signals, which would in turn promote reproductive character displacement (RCD). We investigated whether variation in the advertisement call of the ...

  18. Acoustic Repertoire of the Philippine Tarsier (Tarsius syrichta fraterculus and Individual Variation of Long-Distance Calls

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    Milada Řeháková-Petrů

    2012-01-01

    Full Text Available We present the spectrographic description of the vocal repertoire of the Philippine tarsier (Tarsius syrichta fraterculus, a solitary living nocturnal primate for which a very limited information about acoustic communication exists to date. The majority of vocalizations were performed around sunset and, less frequently, at sunrise. We identified eight call types. Five calls recorded during communication between adults included three long-distance calls—loud call, smack-whistle, and whistle—then a soft locust-like chirp and a bird-like trill. Two other calls—cheep and twitter—were recorded during mother-infant communication. One distress call was emitted by adults during handling. All calls were performed in the 9752 Hz to more than 22 kHz frequency range. This study provides the first evidence of individual variation in the long-distance calls performed by tarsiers. Moreover, our study provides a basis for future comparison within as well as between tarsier species taxonomy. Bioacoustic methods can be used in monitoring of these cryptic species and determining their distribution range. Thus, bioacoustic studies can help to improve conservation strategies of different population/species.

  19. Rapid differentiation of sexual signals in invasive toads: call variation among populations.

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    Yasumiba, Kiyomi; Duffy, Richard L; Parsons, Scott A; Alford, Ross A; Schwarzkopf, Lin

    2016-01-01

    Advertisement calls tend to differ among populations, based on morphological and environmental factors, or simply geographic distance, in many taxa. Invasive cane toads (Rhinella marina) were introduced to Australia in 1935 and their distribution has expanded at increasing rates over time. Rapid evolution occurred in morphological and behavioural characters that accelerate dispersal, but the effects of rapid expansion on sexual signals have not been examined. We collected advertisement calls from four populations of different ages since invasion, and analysed the geographic differentiation of seven call parameters. Our comparisons indicate that the calls of R. marina differ among Australian populations. The signal variation was not simply clinal with respect to population age, climate, or morphological differentiation. We suggest that selection on signalling among populations has been idiosyncratic and may reflect local female preferences or adaptation to environmental factors that are not clinal such as energy availability. PMID:27328666

  20. On variation of word frequencies in Russian literary texts

    Science.gov (United States)

    Kargin, Vladislav

    2016-03-01

    We study the variation of word frequencies in Russian literary texts. Our findings indicate that the standard deviation of a word's frequency across texts depends on its average frequency according to a power law with exponent 1/2 < α < 1, which shows that the rarer words have a relatively larger degree of frequency volatility (that is, higher "burstiness"). A latent factor model has been estimated to investigate the structure of the word frequency distribution. The findings suggest that the dependence of a word's frequency volatility on its average frequency can be explained by the asymmetry in the distribution of latent factors.

  1. Geographic variation in the advertisement calls of Hyla eximia and its possible explanations.

    Science.gov (United States)

    Rodríguez-Tejeda, Ruth E; Méndez-Cárdenas, María Guadalupe; Islas-Villanueva, Valentina; Macías Garcia, Constantino

    2014-01-01

    Populations of species occupying large geographic ranges are often phenotypically diverse as a consequence of variation in selective pressures and drift. This applies to attributes involved in mate choice, particularly when both geographic range and breeding biology overlap between related species. This condition may lead to interference of mating signals, which would in turn promote reproductive character displacement (RCD). We investigated whether variation in the advertisement call of the mountain treefrog (Hyla eximia) is linked to geographic distribution with respect to major Mexican river basins (Panuco, Lerma, Balsas and Magdalena), or to coexistence with its sister (the canyon treefrog, Hyla arenicolor) or another related species (the dwarf treefrog, Tlalocohyla smithii). We also evaluated whether call divergence across the main river basins could be linked to genetic structure. We found that the multidimensional acoustic space of calls from two basins where H. eximia currently interacts with T. smithii, was different from the acoustic space of calls from H. eximia elsewhere. Individuals from these two basins were also distinguishable from the rest by both the phylogeny inferred from mitochondrial sequences, and the genetic structure inferred from nuclear markers. The discordant divergence of H. eximia advertisement calls in the two separate basins where its geographic range overlaps that of T. smithii can be interpreted as the result of two independent events of RCD, presumably as a consequence of acoustic interference in the breeding choruses, although more data are required to evaluate this possibility. PMID:25024904

  2. Geographic variation in the advertisement calls of Hyla eximia and its possible explanations

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    Ruth E. Rodríguez-Tejeda

    2014-06-01

    Full Text Available Populations of species occupying large geographic ranges are often phenotypically diverse as a consequence of variation in selective pressures and drift. This applies to attributes involved in mate choice, particularly when both geographic range and breeding biology overlap between related species. This condition may lead to interference of mating signals, which would in turn promote reproductive character displacement (RCD. We investigated whether variation in the advertisement call of the mountain treefrog (Hyla eximia is linked to geographic distribution with respect to major Mexican river basins (Panuco, Lerma, Balsas and Magdalena, or to coexistence with its sister (the canyon treefrog, Hyla arenicolor or another related species (the dwarf treefrog, Tlalocohyla smithii. We also evaluated whether call divergence across the main river basins could be linked to genetic structure. We found that the multidimensional acoustic space of calls from two basins where H. eximia currently interacts with T. smithii, was different from the acoustic space of calls from H. eximia elsewhere. Individuals from these two basins were also distinguishable from the rest by both the phylogeny inferred from mitochondrial sequences, and the genetic structure inferred from nuclear markers. The discordant divergence of H. eximia advertisement calls in the two separate basins where its geographic range overlaps that of T. smithii can be interpreted as the result of two independent events of RCD, presumably as a consequence of acoustic interference in the breeding choruses, although more data are required to evaluate this possibility.

  3. Genetic population structure and call variation in a passerine bird, the satin bowerbird, Ptilonorhynchus violaceus.

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    Nicholls, J A; Austin, J J; Moritz, C; Goldizen, A W

    2006-06-01

    Geographic variation in vocalizations is widespread in passerine birds, but its origins and maintenance remain unclear. One hypothesis to explain this variation is that it is associated with geographic isolation among populations and therefore should follow a vicariant pattern similar to that typically found in neutral genetic markers. Alternatively, if environmental selection strongly influences vocalizations, then genetic divergence and vocal divergence may be disassociated. This study compared genetic divergence derived from 11 microsatellite markers with a metric of phenotypic divergence derived from male bower advertisement calls. Data were obtained from 16 populations throughout the entire distribution of the satin bowerbird, an Australian wet-forest-restricted passerine. There was no relationship between call divergence and genetic divergence, similar to most other studies on birds with learned vocalizations. Genetic divergence followed a vicariant model of evolution, with the differentiation of isolated populations and isolation-by-distance among continuous populations. Previous work on Ptilonorhynchus violaceus has shown that advertisement call structure is strongly influenced by the acoustic environment of different habitats. Divergence in vocalizations among genetically related populations in different habitats indicates that satin bowerbirds match their vocalizations to the environment in which they live, despite the homogenizing influence of gene flow. In combination with convergence of vocalizations among genetically divergent populations occurring in the same habitat, this shows the overriding importance that habitat-related selection can have on the establishment and maintenance of variation in vocalizations. PMID:16892977

  4. Interdecadal variation of TC frequency in Japan

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    Choi, Ki-Seon; Cha, Yu-Mi; Kang, Sung-Dae; Kim, Hae-Dong

    2015-07-01

    This study analyzed the climate regime shift using statistical change-point analysis on the time-series tropical cyclone (TC) frequency that affected Japan in July to September. The result showed that there was a significant change in 1995, and since then, it showed a trend of rapidly decreasing frequency. To determine the reason for this, differences between 1995 to 2012 (9512) period and 1978 to 1994 (7894) period were analyzed. First, regarding TC genesis, TCs during the 9512 period showed a characteristic of genesis from the southeast quadrant of the tropical and subtropical western North Pacific and TCs during the 7894 period showed their genesis from the northwest quadrant. Regarding a TC track, TCs in the 7894 period had a strong trend of moving from the far east sea of the Philippines via the East China Sea to the mid-latitude region in East Asia while TCs in the 9512 period showed a trend of moving from the Philippines toward the southern part of China westward. Thus, TC intensity in the 7894 period, which can absorb sufficient energy from the sea as they moved a long distance over the sea, was stronger than that of 9512. Large-scale environments were analyzed to determine the cause of such difference in TC activity occurred between two periods. During the 9512 period, anomalous cold and dry anticyclones were developed strongly in the East Asia continent. As a result, Korea and Japan were affected by the anomalous northerlies thereby preventing TCs in this period from moving toward the mid-latitude region in East Asia. Instead, anomalous easterlies (anomalous trade wind) were developed in the tropical western Pacific so that a high passage frequency from the Philippines to the south China region along the anomalous steering flows was revealed. The characteristics of the anomalous cold and dry anticyclone developed in the East Asia continent were also confirmed by the analysis of air temperature, relative humidity, and sensible heat net flux showing that

  5. Genetic divergence is more tightly related to call variation than landscape features in the Amazonian frogs Physalaemus petersi and P. freibergi.

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    Funk, W C; Cannatella, D C; Ryan, M J

    2009-09-01

    Behavioural isolation from divergence in male advertisement calls and female preferences is hypothesized to cause genetic divergence and speciation in the Amazonian frogs Physalaemus petersi and P. freibergi, yet the importance of call variation and landscape features in genetic divergence is unresolved. We tested for correlations between genetic divergence at microsatellite loci and (1) call variables; and (2) landscape variables among 10 populations of these frogs. Genetic divergence was not correlated with geographical distance, rivers or elevation. There was a strong positive relationship, however, between genetic divergence and inter-population differences in one call variable, whine dominant frequency. Effective population sizes varied among sites (range = 15-846) and were often small, suggesting that genetic drift could influence call evolution. Evidence for fine-scale genetic structure within sites was also found. Our results support the hypothesis that behavioural isolation from divergence in male calls and female preferences causes genetic divergence and speciation. PMID:19583696

  6. Acoustic characteristics of the low-frequency nest call of discomfort of the house mouse ( Mus musculus) early ontogenesis

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    Egorova, M. A.; Akimov, A. G.

    2010-05-01

    Acoustic characteristics of the low-frequency nest call signaling discomfort of mouse pups are considered. The spectral temporal analysis of the call is realized for house mouse pups. In the structure of some calls, the frequency modulation and components of the noise are established. Signal duration varies from 20 to 170 ms. A statistically significant decrease of call duration and its fundamental frequency is shown from the 6th to 29th day of the mouse pups’ lives. The most stable parameters of the call-the harmonic structure, low-frequency range (up to 20 kHz), and location of the fundamental frequency between 4 and 8 kHz are recognized.

  7. Ambient noise induces independent shifts in call frequency and amplitude within the Lombard effect in echolocating bats

    OpenAIRE

    Hage, Steffen R.; Jiang, Tinglei; Berquist, Sean W.; Feng, Jiang; Metzner, Walter

    2013-01-01

    The Lombard effect, an involuntary rise in call amplitude in response to masking ambient noise, represents one of the most efficient mechanisms to optimize signal-to-noise ratio. The Lombard effect occurs in birds and mammals, including humans, and is often associated with several other vocal changes, such as call frequency and duration. Most studies, however, have focused on noise-dependent changes in call amplitude. It is therefore still largely unknown how the adaptive changes in call ampl...

  8. On the variation of interaural time differences with frequency.

    Science.gov (United States)

    Benichoux, Victor; Rébillat, Marc; Brette, Romain

    2016-04-01

    Interaural time difference (ITD) is a major cue to sound localization in humans and animals. For a given subject and position in space, ITD depends on frequency. This variation is analyzed here using a head related transfer functions (HRTFs) database collected from the literature and comprising human HRTFs from 130 subjects and animal HRTFs from six specimens of different species. For humans, the ITD is found to vary with frequency in a way that shows consistent differences with respect to a spherical head model. Maximal ITD values were found to be about 800 μs in low frequencies and 600 μs in high frequencies. The ITD variation with frequency (up to 200 μs for some positions) occurs within the frequency range where ITD is used to judge the lateral position of a sound source. In addition, ITD varies substantially within the bandwidth of a single auditory filter, leading to systematic differences between envelope and fine-structure ITDs. Because the frequency-dependent pattern of ITD does not display spherical symmetries, it potentially provides cues to elevation and resolves front/back confusion. The fact that the relation between position and ITDs strongly depends on the sound's spectrum in turn suggests that humans and animals make use of this relationship for the localization of sounds. PMID:27106329

  9. Power-line Interference Removal from ECG in Case of Power-line Frequency Variations

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    Todor Stoyanov

    2008-10-01

    Full Text Available The original version of the most successful approach for power-line (PL interference removal from ECG, called subtraction procedure, is based on linear segment detection in the signal and hardware synchronised analogue-to-digital conversion to cope with the PL frequency variations. However, this is not feasible for battery supplied devices and some computer-aided ECG systems. Recent improvements of the procedure apply software measurement of the frequency variations that allow a re-sampling of the contaminated signal with the rated PL frequency followed by interference removal and back re-sampling for restoration of the original time intervals. This study deals with a more accurate software frequency measurement and introduces a notch filtration as alternative to the procedure when no linear segments are encountered for long time, e.g. in cases of ventricular fibrillation or tachycardia. The result obtained with large PL frequency variations demonstrate very small errors, usually in the range of ± 20 μV for the subtraction procedure and ± 60 μV for the notch filtration, the last values strongly depending on the frequency contents of the QRS complexes.

  10. Gravitational dynamos and the low-frequency geomagnetic secular variation.

    Science.gov (United States)

    Olson, P

    2007-12-18

    Self-sustaining numerical dynamos are used to infer the sources of low-frequency secular variation of the geomagnetic field. Gravitational dynamo models powered by compositional convection in an electrically conducting, rotating fluid shell exhibit several regimes of magnetic field behavior with an increasing Rayleigh number of the convection, including nearly steady dipoles, chaotic nonreversing dipoles, and chaotic reversing dipoles. The time average dipole strength and dipolarity of the magnetic field decrease, whereas the dipole variability, average dipole tilt angle, and frequency of polarity reversals increase with Rayleigh number. Chaotic gravitational dynamos have large-amplitude dipole secular variation with maximum power at frequencies corresponding to a few cycles per million years on Earth. Their external magnetic field structure, dipole statistics, low-frequency power spectra, and polarity reversal frequency are comparable to the geomagnetic field. The magnetic variability is driven by the Lorentz force and is characterized by an inverse correlation between dynamo magnetic and kinetic energy fluctuations. A constant energy dissipation theory accounts for this inverse energy correlation, which is shown to produce conditions favorable for dipole drift, polarity reversals, and excursions. PMID:18048345

  11. Variation of solar irradiance and mode frequencies during Maunder minimum

    OpenAIRE

    Bhatnagar, A; Jain, Kiran; Tripathy, S.C.

    2002-01-01

    Using the sunspot numbers reported during the Maunder minimum and the empirical relations between the mode frequencies and solar activity indices, the variations in the total solar irradiance and 10.7 cm radio flux for the period 1645 to 1715 is estimated. We find that the total solar irradiance and radio flux during the Maunder minimum decreased by 0.19% and 52% respectively, as compared to the values for solar cycle 22.

  12. Does advertisement call variation coincide with genetic variation in the genetically diverse frog taxon currently known as Leptodactylus fuscus (Amphibia: Leptodactylidae?

    Directory of Open Access Journals (Sweden)

    HEYER W. RONALD

    2003-01-01

    Full Text Available The frog Leptodactylus fuscus is found throughout much of South America in open and disturbed habitats. Previous study of genetic differentiation in L. fuscus demonstrated that there was lack of genetic exchange among population units consistent with multiple species, rather than a single species. We examine advertisement vocalizations of L. fuscus to determine whether call variation coincides with genetic differentiation. Calls were analyzed for 32 individual frogs from 25 localities throughout the distributional range of L. fuscus. Although there is variation in calls among geographic samples, call variation is not concordant with genetic variation or geographic distance and the call variation observed is less than that typically found among other closely related species of Leptodactylus. This study is an example of the rare pattern of strong genetic differentiation unaccompanied by salient differences in advertisement calls. The relative infrequency of this pattern as currently understood may only reflect the lack of detailed analyses of genetic and acoustic differentiation within population systems currently understood as single species with substantial geographic distributions.

  13. Evaluating variations of genotype calling: a potential source of spurious associations in genome-wide association studies

    Indian Academy of Sciences (India)

    Xuixiao Hong; Zhenqiang Su; Weigong Ge; Leming Shi; Roger Perkins; Hong Fang; Donna Mendrick; Weida Tong

    2010-04-01

    Genome-wide association studies (GWAS) examine the entire human genome with the goal of identifying genetic variants (usually single nucleotide polymorphisms (SNPs)) that are associated with phenotypic traits such as disease status and drug response. The discordance of significantly associated SNPs for the same disease identified from different GWAS indicates that false associations exist in such results. In addition to the possible sources of spurious associations that have been investigated and discussed intensively, such as sample size and population stratification, an accurate and reproducible genotype calling algorithm is required for concordant GWAS results from different studies. However, variations of genotype calling of an algorithm and their effects on significantly associated SNPs identified in downstream association analyses have not been systematically investigated. In this paper, the variations of genotype calling using the Bayesian Robust Linear Model with Mahalanobis distance classifier (BRLMM) algorithm and the resulting influence on the lists of significantly associated SNPs were evaluated using the raw data of 270 HapMap samples analysed with the Affymetrix Human Mapping 500K Array Set (Affy500K) by changing algorithmic parameters. Modified were the Dynamic Model (DM) call confidence threshold (threshold) and the number of randomly selected SNPs (size). Comparative analysis of the calling results and the corresponding lists of significantly associated SNPs identified through association analysis revealed that algorithmic parameters used in BRLMM affected the genotype calls and the significantly associated SNPs. Both the threshold and the size affected the called genotypes and the lists of significantly associated SNPs in association analysis. The effect of the threshold was much larger than the effect of the size. Moreover, the heterozygous calls had lower consistency compared to the homozygous calls.

  14. Rapid differentiation of sexual signals in invasive toads: call variation among populations

    OpenAIRE

    Kiyomi Yasumiba; Duffy, Richard L.; Parsons, Scott A.; Ross A Alford; Lin Schwarzkopf

    2016-01-01

    Advertisement calls tend to differ among populations, based on morphological and environmental factors, or simply geographic distance, in many taxa. Invasive cane toads (Rhinella marina) were introduced to Australia in 1935 and their distribution has expanded at increasing rates over time. Rapid evolution occurred in morphological and behavioural characters that accelerate dispersal, but the effects of rapid expansion on sexual signals have not been examined. We collected advertisement calls ...

  15. Circadian variation in dominant atrial fibrillation frequency in persistent atrial fibrillation

    International Nuclear Information System (INIS)

    Circadian variation in atrial fibrillation (AF) frequency is explored in this paper by employing recent advances in signal processing. Once the AF frequency has been estimated and tracked by a hidden Markov model approach, the resulting trend is analyzed for the purpose of detecting and characterizing the presence of circadian variation. With cosinor analysis, the results show that the short-term variations in the AF frequency exceed the variation that may be attributed to circadian. Using the autocorrelation method, circadian variation was found in 13 of 18 ambulatory ECG recordings (Holter) acquired from patients with long-standing persistent AF. Using the ensemble correlation method, the highest AF frequency usually occurred during the afternoon, whereas the lowest usually occurred during late night. It is concluded that circadian variation is present in most patients with long-standing persistent AF though the short-term variation in the AF frequency is considerable and should be taken into account

  16. Sensitivity Analysis on Variation of Vane Natural Frequency of a Typical Aero Engine Impeller

    Directory of Open Access Journals (Sweden)

    Selwyn Anbarasan

    2015-08-01

    Full Text Available Centrifugal compressors are widely used in small and medium class turbo shaft and turbo prop aero engines. Inevitably the variation in the manufacturing process will lead to variation in natural frequency of blade vanes in an impeller which usually termed as Mistuning. The variation in natural frequency will increase the forced frequency response of the vanes than the tuned vanes. In-service deterioration of vanes dimension due to erosion, corrosion and FOD also adds to further variation in natural frequency. The amplification factor of the response will lead to reduced HCF life of the vanes than the tuned vanes. It is important for the designer to envisage the variation of natural frequency of the vanes to estimate the life of the impeller to avoid premature failure. This also helps in monitoring the health of the impeller during service. This paper deals with prediction of the effects of manufacturing/geometry variation and variation in material properties on impeller vane natural frequency of a turbo shaft engine. FEM model is created to accommodate the geometry variation of the impeller. The parameters influencing the natural frequency are varied and its corresponding variation in frequency is predicted. Several conditions are also simulated and sensitivity analysis is carried out with the above result to predict the order of influencing parameters. Influencing parameters are ranked and the most influencing parameter is found to be the Young’s Modulus of the material for this case of impeller. Maximum influencing parameter Young’s modulus contributes to 5.8% variation and the least contributing factor density to 0.6% variation in natural frequency. This result enables the designer to forecast the possible range of natural frequencies in the design phase, so that he can limit the analysis to predict the response due to mistuning to the estimated range of frequencies.

  17. Further environmental factors causing variations of SCE frequencies

    International Nuclear Information System (INIS)

    The frequencies of spontaneously occurring sister chromatid exchanges (=SCE) were determined in control persons, persons exposed to very low doses of ionizing radiation and employees of a rubber factory. Besides smoking habits and the usage of oral contraceptives, background ultraviolet (=UV) radiation seems to exert the most pronounced effect on SCE levels in control persons. (Author)

  18. Variational quadratic form for low frequency electromagnetic perturbations; (I) formalism

    International Nuclear Information System (INIS)

    A variational formalism is obtained in the limit of large perpendicular wavenumber which simultaneously includes electrostatic and electromagnetic perturbations, finite Larmor radius corrections, equilibrium plasma rotation and arbitrary particle bounce effects. A tractable final expression is obtained and kinetic integrals are evaluated in special limits. The more accurate non-eikonal expression is obtained from the asymptotic matching of the eikonal form to a more restrictive non-eikonal quadratic forms derived elsewhere

  19. Low-frequency variation of a zonally localized jet stream: Observation and theory

    International Nuclear Information System (INIS)

    The climatological mean circulation in the extratropics of the Northern Hemisphere is characterized by two zonally localized jet streams over the east coasts of the two major continents. The zonal inhomogeneity of the climatological mean circulation is believed to be a primary factor determining the geographical locations of the maximum activity centers of the atmospheric transients, such as storm tracks over the east coasts of the two major continents and frequent blocking episodes occurring over the central regions of the two oceans. The impact of the transients on the zonally localized jet streams is studied mostly in the linear dynamics framework in terms of so-called open-quotes feedbackclose quotes diagnosis. This study investigates nonlinear instability of a zonally localized jet stream. The emphasis is on the nonlinear adjustment of a zonally localized jet stream associated with the development of the transients via local instability. The adjustment of a zonally localized jet stream would naturally consists of two parts: One is the time-invariant part and the other is the transient part (temporal variation of the adjustment). In conjunction with the observation, the time-mean adjustment is part of the climatological mean flow and hence is open-quotes invisible.close quotes The transient part of the adjustment is evidenced by the changes of the jet streams in terms of both location and intensity. In this study, we tend to relate the transient part of the adjustment of the jet stream to the maximum activity centers of low-frequency variability. The underlying mechanisms that are responsible for the temporal variation of the adjustment will be investigated. The time-mean adjustment will be also studied to better understand the temporal variation of the adjustment

  20. Evolution of acoustic communication in crickets: phylogeny of Eneopterinae reveals an adaptive radiation involving high-frequency calling (Orthoptera, Grylloidea, Eneopteridae

    Directory of Open Access Journals (Sweden)

    Robillard Tony

    2004-01-01

    Full Text Available Evolution of dominant frequencies in songs of Eneopterinae crickets was studied with respect to phylogeny. Two characters are optimized on the tree: the first describes the frequency resulting from the vibration of the harp (Fda, and the second is due to the vibration of other tegminal areas (Fdb. Fda was found to be relatively stable through the subfamily. Its low ancestral state is replaced by a high Fda only once, resulting in high-frequency calling in [Cardiodactylus (Lebinthus-Agnotecous]. A high Fdb component is added to the low ancestral Fda in Eneoptera guyanensis, resulting in frequency modulation. The onset of high Fd in this first subclade is accompanied by a high cladogenesis rate, which supports a hypothesis of adaptive radiation for high frequencies. The effectiveness of high-frequency calling is discussed in relation to the species behavior ecology.

  1. First Mode Schumann Resonance Frequency Variation During a Solar Proton Event

    Directory of Open Access Journals (Sweden)

    Minu Sanfui

    2016-04-01

    Full Text Available A severe X-ray flare occurred on 06 - 07 March 2012 followed by a solar proton event (SPE. During this event we studied the variation in frequency of the first Schumann resonance (SR spectra mode from the recorded data over Kolkata (22.56°N, 88.5°E. The first mode frequency enhanced (~8.14 Hz, 3.85% during the solar X-ray bursts and immediately after its value decreased (~7.44 Hz, 5.13% during the proton event. The influences of SPE and X-ray bursts upon the SR frequency fluctuation are explained in terms of the changes in medium ionization, i.e., the change in dielectric property and two layer reflection height variation in the waveguide. The geomagnetic storm effect on the modification of this frequency variation occurring during that time is also considered.

  2. Collective frequency variation in network synchronization and reverse PageRank

    Science.gov (United States)

    Skardal, Per Sebastian; Taylor, Dane; Sun, Jie; Arenas, Alex

    2016-04-01

    A wide range of natural and engineered phenomena rely on large networks of interacting units to reach a dynamical consensus state where the system collectively operates. Here we study the dynamics of self-organizing systems and show that for generic directed networks the collective frequency of the ensemble is not the same as the mean of the individuals' natural frequencies. Specifically, we show that the collective frequency equals a weighted average of the natural frequencies, where the weights are given by an outflow centrality measure that is equivalent to a reverse PageRank centrality. Our findings uncover an intricate dependence of the collective frequency on both the structural directedness and dynamical heterogeneity of the network, and also reveal an unexplored connection between synchronization and PageRank, which opens the possibility of applying PageRank optimization to synchronization. Finally, we demonstrate the presence of collective frequency variation in real-world networks by considering the UK and Scandinavian power grids.

  3. Solar cycle variation in solar f-mode frequencies and radius

    OpenAIRE

    Antia, H. M.; Basu, Sarbani; Pintar, J.; Pohl, B.

    2000-01-01

    Using data from the Global Oscillation Network Group (GONG) covering the period from 1995 to 1998, we study the change with solar activity in solar f-mode frequencies. The results are compared with similar changes detected from the Michelson Doppler Imager (MDI) data. We find variations in f-mode frequencies which are correlated with solar activity indices. If these changes are due to variation in solar radius then the implications are that the solar radius decreases by about 5 km from minimu...

  4. Language Choices by Teachers in EFL Classrooms in Cyprus: Bidialectism Meets Bilingualism with a Call for Teacher Training Programmes in Linguistic Variation

    Science.gov (United States)

    Yiakoumetti, Androula; Mina, Marina

    2013-01-01

    This study focuses on the interface between bidialectism and bilingualism and provides empirical support for the call for language educators to be trained in issues relating to linguistic variation. Drawing on the sociolinguistic setting of Cyprus, the study investigates the linguistic behaviour of bidialectal teachers in the English…

  5. Method for Precision Test of Fine Structure Constant Variation with Optical Frequency References

    OpenAIRE

    Torgerson, J. R.

    2000-01-01

    A new method for examining the possible space-time variation of the fine structure constant ($\\alpha$) is proposed. The technique uses a relatively simple measurement with an optical resonator to compare atom-stabilized optical frequency references. This method does not require that the exact frequency of each reference be measured, and has the potential to yield more than a 1000-fold improvement in experimental sensitivity to changes in $\\alpha$. A specific realization of an experiment using...

  6. The Variation of Photon Speed with Photon Frequency in Quantum Gravity

    OpenAIRE

    Dubey, Anuj Kumar; Sen, A.K.; Nath, Sonarekha

    2016-01-01

    In the present work, we have derived an expression of Planck mass or Planck energy by equating the Compton wavelength with Kerr gravitational radius of the Kerr rotating body. Then we have derived the modified expression for the photon energy-momentum dispersion relation and hence derived the variation of the photon propagation speed with photon frequency. We have found that the photon propagation speed, depends on the frequency of the photon, polarization state of photon, the rotation parame...

  7. Low-frequency wave modulations in an electronegative dusty plasma in the presence of charge variations.

    Science.gov (United States)

    Ghosh, Samiran; Sarkar, Subrata; Khan, Manoranjan; Gupta, M R

    2011-12-01

    The effects of dust charge variations on low-frequency wave modulations in an electronegative dusty plasma are investigated. The dynamics of the modulated wave is governed by a nonlinear Schrödinger equation with a dissipative term. The dissipation arises due to the nonsteady (nonadiabatic) dust charge variations. Theoretical and numerical investigations predict the formation of dissipative bright (envelope) and dark solitons. The nonsteady charge-variation-induced dissipation reduces the modulational instability growth rate and introduces a characteristic time scale to observe bright solitons. Results are discussed in the context of electronegative dusty plasma experiments. PMID:22304202

  8. Advertisement call and morphological variation of the poorly known and endemic Bokermannohyla juiju Faivovich, Lugli, Lourenço and Haddad, 2009 (Anura: Hylidae) from Central Bahia, Brazil.

    Science.gov (United States)

    Taucce, Pedro P G; Pinheiro, Paulo D P; Leite, Felipe S F; Garcia, Paulo C A

    2015-01-01

    Bokermannohyla juiju is a member of the B. martinsi species group and it was described based on one male specimen. In order to enhance the knowledge about the species, we describe its advertisement call and morphological variation, including for the first time data on females. We also provide additional comments about its natural history, geographic distribution, and conservation. The advertisement call of B. juiju consists of a single note, non-pulsed, harmonic structured call emitted several times in a row. Four out of five males were found calling in bromeliads. The female, as it is common in many Bokermannohyla species, presents some morphological features not shared with the males, like a non-hypertrophied forearm and less developed prepollex.  PMID:25662112

  9. Amplitude Variation of Bottom Simulating Reflection with Respect to Frequency - Transitional Base or Attenuation?

    Science.gov (United States)

    Lee, Myung W.

    2007-01-01

    The amplitude of a bottom simulating reflection (BSR), which occurs near the phase boundary between gas hydrate-bearing sediments and underlying gas-filled sediments, strongly depends on the frequency content of a seismic signal, as well as the impedance contrast across the phase boundary. A strong-amplitude BSR, detectable in a conventional seismic profile, is a good indicator of the presence of free gas beneath the phase boundary. However, the BSR as observed in low-frequency multichannel seismic data is generally difficult to identify in high-frequency, single-channel seismic data. To investigate the frequency dependence of BSR amplitudes, single-channel seismic data acquired with an air gun source at Blake Ridge, which is located off the shore of South Carolina, were analyzed in the frequency range of 10-240 Hz. The frequency-dependent impedance contrast caused by the velocity dispersion in partially gas saturated sediments is important to accurately analyze BSR amplitude. Analysis indicates that seismic attenuation of gas hydrate-bearing sediments, velocity dispersion, and a transitional base all contribute to the frequency-dependent BSR amplitude variation in the frequency range of 10-500 Hz. When velocity dispersion is incorporated into the BSR amplitude analysis, the frequency-dependent BSR amplitude at Blake Ridge can be explained with gas hydrate-bearing sediments having a quality factor of about 250 and a transitional base with a thickness of about 1 meter.

  10. CHARACTERISTICS OF FREQUENCY SPECTRUM VARIATION OF INTRASEASONAL OSCILLATION OF CONVECTION DURING SOUTH CHINA SEA SUMMER MONSOON

    Institute of Scientific and Technical Information of China (English)

    LIN Ai-lan; LIANG Jian-yin; LI Chun-hui

    2006-01-01

    Datasets of equivalent temperature of black body (TBB) and sea surface temperature (SST) ranging from 1980 to 1997 are used to diagnose and analyze the characteristics of frequency spectrum and strength of intraseasonal variation of convection. The relationship between the strength of intraseasonal oscillation of convection, strength of convection itself and SST in the South China Sea (SCS) is studied. It is shown that, there are distinguishable annual, interannual and interdecadal variations in both strength and frequency spectrum of intraseasonal variation of convection in SCS. There are connections between strength of convection, strength of ISO1 in the summer half (s.h.) year and SST in ensuing winter half (w.h.) year in SCS.The strong (weak) convection and strong (weak) ISO1 are associated with negative (positive) bias of SST in ensuing w.h. year in SCS.

  11. Comparing of Two Farsi Passages in Laboratory Evaluation of Mean and Fundamental Frequency Variations Range

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Keyhani

    2012-03-01

    Full Text Available Background and Aim: Voice disorders assess with the help of laboratory equipments and perceptual evaluation. Voice samples involve vowel prolongation, text-reading or conversational speech. In Iran, Rainbow text and Grandfather text, were developed for assessing voice.Methods: This study was cross-sectional and descriptive-analytical. Mean and fundamental frequency variations range in 120 normal males and females aging from 20-59 years old were studied. Voice samples of reading both texts were gathered and compared.Results: Mean fundamental frequency in males in Grandfather text was 137.93 with SD 1.2 and in Rainbow text was 135.09 with SD 1.1 (p>0.05, in females Grandfather and Rainbow texts were 206.07 with SD 0.9 and 204.23 with SD 2.1, respectively (p>0.05. Fundamental frequency variations range in Grandfather text in males was 88.10 with SD 0.8 and in females was 116.77 with SD 1.3 and in Rainbow text in males was 90.92 with SD 1.1, in females was 116.08 with SD 1.2 (p>0.05. Mean fundamental frequency of males in each text didn't show significant difference in age groups and just in 50-59 age group of the female population showed significant difference. Fundamental frequency variations range didn't show significant difference in males and females in both texts.Conclusion: These two texts were the same in measurement of average and fundamental frequency variations range in adults. Significant difference showed between 50-59 age group of the female population and other groups.

  12. Frequency variations of the earth's obliquity and the 100-kyr ice-age cycles

    Science.gov (United States)

    Liu, Han-Shou

    1992-01-01

    Changes in the earth's climate are induced by variations in the earth's orbital parameters which modulate the seasonal distribution of solar radiation. Periodicities in the geological climate record with cycles of 100, 41, and 23 kyr have been linked with changes in obliquity, eccentricity, and precession of the equinoxes. The effect of variations of eccentricity during a 100 kyr period is weak relative to the signals from obliquity and precession variations and it may therefore be expected that the 100 kyr signal in the climate record would be of low intensity. However, this signal dominates the climate record and internal nonlinear processes within the climate system have previously been proposed to account for this fact. The author shows that variations in the frequency of the obliquity cycle can give rise to strong 100-kyr forcing of climate.

  13. Novel Complete Probabilistic Models of Random Variation in High Frequency Performance of Nanoscale MOSFET

    Directory of Open Access Journals (Sweden)

    Rawid Banchuin

    2013-01-01

    Full Text Available The novel probabilistic models of the random variations in nanoscale MOSFET's high frequency performance defined in terms of gate capacitance and transition frequency have been proposed. As the transition frequency variation has also been considered, the proposed models are considered as complete unlike the previous one which take only the gate capacitance variation into account. The proposed models have been found to be both analytic and physical level oriented as they are the precise mathematical expressions in terms of physical parameters. Since the up-to-date model of variation in MOSFET's characteristic induced by physical level fluctuation has been used, part of the proposed models for gate capacitance is more accurate and physical level oriented than its predecessor. The proposed models have been verified based on the 65 nm CMOS technology by using the Monte-Carlo SPICE simulations of benchmark circuits and Kolmogorov-Smirnov tests as highly accurate since they fit the Monte-Carlo-based analysis results with 99% confidence. Hence, these novel models have been found to be versatile for the statistical/variability aware analysis/design of nanoscale MOSFET-based analog/mixed signal circuits and systems.

  14. Frequency variations of gravity waves interacting with a time-varying tide

    Energy Technology Data Exchange (ETDEWEB)

    Huang, C.M.; Zhang, S.D.; Yi, F.; Huang, K.M.; Gan, Q.; Gong, Y. [Wuhan Univ., Hubei (China). School of Electronic Information; Ministry of Education, Wuhan, Hubei (China). Key Lab. of Geospace Environment and Geodesy; State Observatory for Atmospheric Remote Sensing, Wuhan, Hubei (China); Zhang, Y.H. [Nanjing Univ. of Information Science and Technology (China). College of Hydrometeorolgy

    2013-11-01

    Using a nonlinear, 2-D time-dependent numerical model, we simulate the propagation of gravity waves (GWs) in a time-varying tide. Our simulations show that when aGW packet propagates in a time-varying tidal-wind environment, not only its intrinsic frequency but also its ground-based frequency would change significantly. The tidal horizontal-wind acceleration dominates the GW frequency variation. Positive (negative) accelerations induce frequency increases (decreases) with time. More interestingly, tidal-wind acceleration near the critical layers always causes the GW frequency to increase, which may partially explain the observations that high-frequency GW components are more dominant in the middle and upper atmosphere than in the lower atmosphere. The combination of the increased ground-based frequency of propagating GWs in a time-varying tidal-wind field and the transient nature of the critical layer induced by a time-varying tidal zonal wind creates favorable conditions for GWs to penetrate their originally expected critical layers. Consequently, GWs have an impact on the background atmosphere at much higher altitudes than expected, which indicates that the dynamical effects of tidal-GW interactions are more complicated than usually taken into account by GW parameterizations in global models.

  15. High Frequency Variations of Earth Rotation Parameters from GPS and GLONASS Observations

    Directory of Open Access Journals (Sweden)

    Erhu Wei

    2015-01-01

    Full Text Available The Earth’s rotation undergoes changes with the influence of geophysical factors, such as Earth’s surface fluid mass redistribution of the atmosphere, ocean and hydrology. However, variations of Earth Rotation Parameters (ERP are still not well understood, particularly the short-period variations (e.g., diurnal and semi-diurnal variations and their causes. In this paper, the hourly time series of Earth Rotation Parameters are estimated using Global Positioning System (GPS, Global Navigation Satellite System (GLONASS, and combining GPS and GLONASS data collected from nearly 80 sites from 1 November 2012 to 10 April 2014. These new observations with combining different satellite systems can help to decorrelate orbit biases and ERP, which improve estimation of ERP. The high frequency variations of ERP are analyzed using a de-trending method. The maximum of total diurnal and semidiurnal variations are within one milli-arcseconds (mas in Polar Motion (PM and 0.5 milli-seconds (ms in UT1-UTC. The semidiurnal and diurnal variations are mainly related to the ocean tides. Furthermore, the impacts of satellite orbit and time interval used to determinate ERP on the amplitudes of tidal terms are analyzed. We obtain some small terms that are not described in the ocean tide model of the IERS Conventions 2010, which may be caused by the strategies and models we used or the signal noises as well as artifacts. In addition, there are also small differences on the amplitudes between our results and IERS convention. This might be a result of other geophysical excitations, such as the high-frequency variations in atmospheric angular momentum (AAM and hydrological angular momentum (HAM, which needs more detailed analysis with more geophysical data in the future.

  16. Variational approach to low-frequency kinetic-MHD in the current coupling scheme

    CERN Document Server

    Burby, J W

    2016-01-01

    Hybrid kinetic-MHD models describe the interaction of an MHD bulk fluid with an ensemble of hot particles, which is described by a kinetic equation. When the Vlasov description is adopted for the energetic particles, different Vlasov-MHD models have been shown to lack an exact energy balance, which was recently recovered by the introduction of non-inertial force terms in the kinetic equation. These force terms arise from fundamental approaches based on Hamiltonian and variational methods. In this work we apply Hamilton's variational principle to formulate new current-coupling kinetic-MHD models in the low-frequency approximation (i.e. large Larmor frequency limit). More particularly, we formulate current-coupling hybrid schemes, in which energetic particle dynamics are expressed in either guiding-center or gyrocenter coordinates.

  17. Assessment of high to low frequency variations of isoprene emission rates using a neural network approach

    OpenAIRE

    Boissard, C.; Chervier, F.; Dutot, A. L.

    2007-01-01

    International audience Using a statistical approach based on artificial neural networks, an emission algorithm (ISO_LF) accounting for high (instantaneous) to low (seasonal) frequency variations was developed for isoprene. ISO_LF was optimised using an isoprene emission data base (ISO-DB) specifically designed for this work. ISO-DB consists of 1321 emission rates collected in the literature, together with 34 environmental variables, measured or assessed using NCDC (National Climatic Data C...

  18. National Variation in Use of Immunosuppression for Kidney Transplantation: A Call for Evidence-Based Regimen Selection.

    Science.gov (United States)

    Axelrod, D A; Naik, A S; Schnitzler, M A; Segev, D L; Dharnidharka, V R; Brennan, D C; Bae, S; Chen, J; Massie, A; Lentine, K L

    2016-08-01

    Immunosuppression management in kidney transplantation has evolved to include an increasingly diverse choice of medications. Although informed by patient and donor characteristics, choice of immunosuppression regimen varies widely across transplant programs. Using a novel database integrating national transplant registry and pharmacy fill records, immunosuppression use at 6-12 and 12-24 mo after transplant was evaluated for 22 453 patients transplanted in 249 U.S. programs in 2005-2010. Use of triple immunosuppression comprising tacrolimus, mycophenolic acid or azathioprine, and steroids varied widely (0-100% of patients per program), as did use of steroid-sparing regimens (0-77%), sirolimus-based regimens (0-100%) and cyclosporine-based regimens (0-78%). Use of triple therapy was more common in highly sensitized patients, women and recipients with dialysis duration >5 years. Sirolimus use appeared to diminish over the study period. Patient and donor characteristics explained only a limited amount of the observed variation in regimen use, whereas center choice explained 30-46% of the use of non-triple-therapy immunosuppression. The majority of patients who received triple-therapy (79%), cyclosporine-based (87.6%) and sirolimus-based (84.3%) regimens continued them in the second year after transplant. This population-based study of immunosuppression practice demonstrates substantial variation in center practice beyond that explained by differences in patient and donor characteristics. PMID:26901466

  19. Cyclic variations of high-frequency ultrasonic backscattering from blood under pulsatile flow.

    Science.gov (United States)

    Huang, Chih-Chung

    2009-08-01

    It was shown previously that ultrasonic scattering from whole blood varies during the flow cycle under pulsatile flow both in vitro and in vivo. It has been postulated that the cyclic variations of the backscattering signal are associated with red blood cell (RBC) aggregation in flowing whole blood. To obtain a better understanding of the relationship between blood backscattering and RBC aggregation behavior for pulsatile flowing blood, the present study used high-frequency ultrasound to characterize blood properties. The backscattering signals from both whole blood and an RBC suspension at different peak flow velocities (from 10 to 30 cm/s) and hematocrits (20% and 40%) under pulsatile flow (stroke rate of 20 beats/min) were measured with 3 single-element transducers at frequencies of 10, 35, and 50 MHz in a mock flow loop. To avoid the frequency response problem of a Doppler flowmeter, the integrated backscatter (IB) and flow velocity as functions of time were calculated directly using RF signals from flowing blood. The experimental results showed that cyclic variations of the IB curve were clearly observed at a low flow velocity and a hematocrit of 40% when using 50 MHz ultrasound, and that these variations became weaker as the peak flow velocity increased. However, these cyclic variations were detected only at 10 cm/s when using 10 MHz ultrasound. These results demonstrate that a high flow velocity can stop the formation of rouleaux and that a high hematocrit can promote RBC aggregation to produce cyclic variations of the backscattering signal under pulsatile flow. In addition, slight cyclic variations of the IB curve for an RBC suspension were observed at 35 and 50 MHz. Furthermore, the peak of the IB curve from whole blood led the peak of the velocity waveform when using high-frequency ultrasound, which could be explained by the assumption that a rapid flow can promote RBC aggregation under pulsatile flow. Together, the experimental results showed that the

  20. Variation in viscoelastic properties of bovine articular cartilage below, up to and above healthy gait-relevant loading frequencies

    OpenAIRE

    Sadeghi, Hamid; Espino, Daniel M; Shepherd, Duncan ET

    2015-01-01

    The aim of this study was to determine the variation in viscoelastic properties of femoral head bovine articular cartilage, on-bone, over five orders of magnitude of loading frequency. These frequencies ranged from below, up to and above healthy gait-relevant frequencies, using

  1. Gate line edge roughness amplitude and frequency variation effects on intra die MOS device characteristics

    Science.gov (United States)

    Hamadeh, Emad; Gunther, Norman G.; Niemann, Darrell; Rahman, Mahmud

    2006-06-01

    Random fluctuations in fabrication process outcomes such as gate line edge roughness (LER) give rise to corresponding fluctuations in scaled down MOS device characteristics. A thermodynamic-variational model is presented to study the effects of LER on threshold voltage and capacitance of sub-50 nm MOS devices. Conceptually, we treat the geometric definition of the MOS devices on a die as consisting of a collection of gates. In turn, each of these gates has an area, A, and a perimeter, P, defined by nominally straight lines subject to random process outcomes producing roughness. We treat roughness as being deviations from straightness consisting of both transverse amplitude and longitudinal wavelength each having lognormal distribution. We obtain closed-form expressions for variance of threshold voltage ( Vth), and device capacitance ( C) at Onset of Strong Inversion (OSI) for a small device. Using our variational model, we characterized the device electrical properties such as σ and σC in terms of the statistical parameters of the roughness amplitude and spatial frequency, i.e., inverse roughness wavelength. We then verified our model with numerical analysis of Vth roll-off for small devices and σ due to dopant fluctuation. Our model was also benchmarked against TCAD of σ as a function of LER. We then extended our analysis to predict variations in σ and σC versus average LER spatial frequency and amplitude, and oxide-thickness. Given the intuitive expectation that LER of very short wavelengths must also have small amplitude, we have investigated the case in which the amplitude mean is inversely related to the frequency mean. We compare with the situation in which amplitude and frequency mean are unrelated. Given also that the gate perimeter may consist of different LER signature for each side, we have extended our analysis to the case when the LER statistical difference between gate sides is moderate, as well as when it is significantly large.

  2. Variation in relapse frequency and the transmission potential of Plasmodium vivax malaria

    Science.gov (United States)

    White, Michael T.; Shirreff, George; Karl, Stephan; Ghani, Azra C.; Mueller, Ivo

    2016-01-01

    There is substantial variation in the relapse frequency of Plasmodium vivax malaria, with fast-relapsing strains in tropical areas, and slow-relapsing strains in temperate areas with seasonal transmission. We hypothesize that much of the phenotypic diversity in P. vivax relapses arises from selection of relapse frequency to optimize transmission potential in a given environment, in a process similar to the virulence trade-off hypothesis. We develop mathematical models of P. vivax transmission and calculate the basic reproduction number R0 to investigate how transmission potential varies with relapse frequency and seasonality. In tropical zones with year-round transmission, transmission potential is optimized at intermediate relapse frequencies of two to three months: slower-relapsing strains increase the opportunity for onward transmission to mosquitoes, but also increase the risk of being outcompeted by faster-relapsing strains. Seasonality is an important driver of relapse frequency for temperate strains, with the time to first relapse predicted to be six to nine months, coinciding with the duration between seasonal transmission peaks. We predict that there is a threshold degree of seasonality, below which fast-relapsing tropical strains are selected for, and above which slow-relapsing temperate strains dominate, providing an explanation for the observed global distribution of relapse phenotypes. PMID:27030414

  3. Low and high frequency Madden-Julian oscillations in austral summer: interannual variations

    Energy Technology Data Exchange (ETDEWEB)

    Izumo, Takeshi [Research Institute For Global Change (JAMSTEC), Yokohama (Japan); LOCEAN, IRD-CNRS-UPMC, Paris (France); Masson, Sebastien; Vialard, Jerome; Madec, Gurvan [LOCEAN, IRD-CNRS-UPMC, Paris (France); Boyer Montegut, Clement de [IFREMER, Brest (France); Behera, Swadhin K. [Research Institute For Global Change (JAMSTEC), Yokohama (Japan); Takahashi, Keiko [Earth Simulator Center (JAMSTEC), Yokohama (Japan); Yamagata, Toshio [Research Institute For Global Change (JAMSTEC), Yokohama (Japan); University of Tokyo, Tokyo (Japan)

    2010-09-15

    The Madden-Julian oscillation (MJO) is the main component of intraseasonal variability of the tropical convection, with clear climatic impacts at an almost-global scale. Based on satellite observations, it is shown that there are two types of austral-summer MJO events (broadly defined as 30-120 days convective variability with eastward propagation of about 5 m/s). Equatorial MJO events have a period of 30-50 days and tend to be symmetric about the equator, whereas MJO events centered near 8 S tend to have a longer period of 55-100 days. The lower-frequency variability is associated with a strong upper-ocean response, having a clear signature in both sea surface temperature and its diurnal cycle. These two MJO types have different interannual variations, and are modulated by the Indian Ocean Dipole (IOD). Following a negative IOD event, the lower-frequency southern MJO variability increases, while the higher-frequency equatorial MJO strongly diminishes. We propose two possible explanations for this change in properties of the MJO. One possibility is that changes in the background atmospheric circulation after an IOD favour the development of the low-frequency MJO. The other possibility is that the shallower thermocline ridge and mixed layer depth, by enhancing SST intraseasonal variability and thus ocean-atmosphere coupling in the southwest Indian Ocean (the breeding ground of southern MJO onset), favour the lower-frequency southern MJO variability. (orig.)

  4. Variations in High Degree Acoustic Mode Frequencies of the Sun during Solar Cycles 23 and 24

    Science.gov (United States)

    Tripathy, S. C.; Jain, K.; Hill, F.

    2015-10-01

    We examine continuous measurements of the high-degree acoustic mode frequencies of the Sun covering the period from 2001 July to 2014 June. These are obtained through the ring-diagram technique applied to the full-disk Doppler observations made by the Global Oscillation Network Group. The frequency shifts in the degree range of 180 ≤slant {\\ell } ≤slant 1200 are correlated with different proxies of solar activity, e.g., 10.7 cm radio flux, the International Sunspot Number, and the strength of the local magnetic field. In general, a good agreement is found between the shifts and activity indices, and the correlation coefficients are found to be comparable with intermediate-degree mode frequencies. Analyzing the frequency shifts separately for the two cycles, we find that cycle 24 is weaker than cycle 23. Since the magnetic activity is known to be different in the two hemispheres, for the first time, we compute the frequency shifts over the two hemispheres separately and find that the shifts also display hemispheric asymmetry; the amplitude of shifts in the northern hemisphere peaked during late 2011, more than two years earlier than in the south. We further correlate the hemispheric frequency shifts with the hemispheric sunspot number and mean magnetic activity index (MAI). Since the frequency shifts and the hemispheric activity indices are found to be significantly correlated, we suggest that the shifts be used as an indicator of hemispheric activity since not many indices are measured over the two hemispheres separately. We also investigate the variation at different latitudinal bands and conclude that the shifts in active latitudes correlate well with the local MAI.

  5. Assessment of high to low frequency variations of isoprene emission rates using a neural network approach

    Directory of Open Access Journals (Sweden)

    C. Boissard

    2007-08-01

    Full Text Available Using a statistical approach based on artificial neural networks, an emission algorithm (ISO_LF accounting for high (instantaneous to low (seasonal frequency variations was developed for isoprene. ISO_LF was optimised using an isoprene emission data base (ISO-DB specifically designed for this work. ISO-DB consists of 1321 emission rates collected in the literature, together with 34 environmental variables, measured or assessed using NCDC (National Climatic Data Center or NCEP (National Centers for Environmental Predictions meteorological databases. ISO-DB covers a large variety of emitters (25 species and environmental conditions (10° S to 60° N. When only instantaneous environmental regressors (air temperature and photosynthetic active radiation, PAR were used, a maximum of 60% of the overall isoprene variability was assessed and the highest emissions were underestimated. Considering a total of 9 high (instantaneous to low (up to 3 weeks frequency regressors, ISO_LF accounts for up to 91% of the isoprene emission variability, whatever the emission range, species or climate. Diurnal and seasonal variations are correctly reproduced for extit{Ulex europaeus} with a maximum factor of discrepancy of 4. ISO-LF was found to be mainly sensitive to air temperature cumulated over 3 weeks T21 and to instantaneous light L0 and air temperature T0 variations. T21, T0 and L0 only accounts for 76% of the overall variability. The use of ISO-LF for non stored monoterpene emissions was shown to give poor results.

  6. Does infectious disease cause global variation in the frequency of intrastate armed conflict and civil war?

    Science.gov (United States)

    Letendre, Kenneth; Fincher, Corey L; Thornhill, Randy

    2010-08-01

    Geographic and cross-national variation in the frequency of intrastate armed conflict and civil war is a subject of great interest. Previous theory on this variation has focused on the influence on human behaviour of climate, resource competition, national wealth, and cultural characteristics. We present the parasite-stress model of intrastate conflict, which unites previous work on the correlates of intrastate conflict by linking frequency of the outbreak of such conflict, including civil war, to the intensity of infectious disease across countries of the world. High intensity of infectious disease leads to the emergence of xenophobic and ethnocentric cultural norms. These cultures suffer greater poverty and deprivation due to the morbidity and mortality caused by disease, and as a result of decreased investment in public health and welfare. Resource competition among xenophobic and ethnocentric groups within a nation leads to increased frequency of civil war. We present support for the parasite-stress model with regression analyses. We find support for a direct effect of infectious disease on intrastate armed conflict, and support for an indirect effect of infectious disease on the incidence of civil war via its negative effect on national wealth. We consider the entanglements of feedback of conflict into further reduced wealth and increased incidence of disease, and discuss implications for international warfare and global patterns of wealth and imperialism. PMID:20377573

  7. Improved estimation of leak location of pipelines using frequency band variation

    International Nuclear Information System (INIS)

    Leakage is an important factor to be considered for the management of underground water supply pipelines in a smart water grid system, especially if the pipelines are aged and buried under the pavement or various structures of a highly populated city. Because the exact detection of the location of such leaks in pipelines is essential for their efficient operation, a new methodology for leak location detection based on frequency band variation, windowing filters, and probability is proposed in this paper. Because the exact detection of the leak location depends on the precision of estimation of time delay between sensor signals due to leak noise, some window functions that offer weightings at significant frequencies are applied for calculating the improved cross-correlation function. Experimental results obtained by applying this methodology to an actual buried water supply pipeline, ∼ 253.9 m long and made of cast iron, revealed that the approach of frequency band variation with those windows and probability offers better performance for leak location detection.

  8. An analytical model for Doppler frequency variations of ionospheric HF sounding caused by SSC

    Science.gov (United States)

    Pilipenko, V.; Fedorov, E.; Yumoto, K.; Ikeda, A.; Sun, T. R.

    2010-10-01

    A theoretical model to interpret the deviations of the Doppler sounding radio frequency during the SSC is proposed. The Doppler response is composed from long-period deviation with time scale ˜10 min and short-lived (˜1 min) positive spike. For the interpretation of this spike, the variations of Doppler velocity induced by compressional and Alfvén waves are theoretically estimated on the basis of the thin ionosphere approximation. The analytical model developed goes beyond the older numerical model which has been in use thus far to explain certain facets of the correlation between geomagnetic variations and HF Doppler shifts. This new model provides the possibility to easily estimate the Doppler frequency response to either Alfvén or compresssional modes for extraordinary and ordinary radio waves. A theoretical estimate indicates that, for the same amplitude of the ground magnetic disturbances, a large-scale compressional mode produces a larger ionospheric response than an Alfvén mode. The plasma vertical displacement caused by the ULF inductive electric field is shown to be the dominating effect. The magnitudes and waveforms of the simultaneously detected ionospheric and magnetic responses on SSC at a low-latitude site in Japan fit the considered model.

  9. Wolbachia in European Populations of the Invasive Pest Drosophila suzukii: Regional Variation in Infection Frequencies.

    Science.gov (United States)

    Cattel, Julien; Kaur, Rupinder; Gibert, Patricia; Martinez, Julien; Fraimout, Antoine; Jiggins, Francis; Andrieux, Thibault; Siozios, Stefanos; Anfora, Gianfranco; Miller, Wolfgang; Rota-Stabelli, Omar; Mouton, Laurence

    2016-01-01

    The invasive pest Drosophila suzukii is characterized by a specific fresh-fruit targeting behavior and has quickly become a menace for the fruit economy of newly infested North American and European regions. D. suzukii carries a strain of the endosymbiotic bacterium Wolbachia, named wSuz, which has a low infection frequency and no reproductive manipulation capabilities in American populations of D. suzukii. To further understand the nature of wSuz biology and assess its utility as a tool for controlling this pest's populations, we investigated the prevalence of Wolbachia in 23 European D. suzukii populations, and compared our results with those available in American populations. Our data showed a highly variable infection frequency with a mean prevalence of 46%, which is significantly higher than the 17% found in American populations. Based on Multilocus Sequence Typing analysis, a single wSuz strain was diagnosed in all European populations of D. suzukii. In agreement with American data, we found no evidence of cytoplasmic incompatibility induced by wSuz. These findings raise two questions: a) why Wolbachia is maintained in field populations of D. suzukii and b) what are the selective forces responsible for the variation in prevalence within populations, particularly between European and American continents? Our results provide new insights into the D. suzukii-Wolbachia association and highlight regional variations that await further investigation and that should be taken into account for using Wolbachia-based pest management programs. PMID:26809119

  10. Wolbachia in European Populations of the Invasive Pest Drosophila suzukii: Regional Variation in Infection Frequencies.

    Directory of Open Access Journals (Sweden)

    Julien Cattel

    Full Text Available The invasive pest Drosophila suzukii is characterized by a specific fresh-fruit targeting behavior and has quickly become a menace for the fruit economy of newly infested North American and European regions. D. suzukii carries a strain of the endosymbiotic bacterium Wolbachia, named wSuz, which has a low infection frequency and no reproductive manipulation capabilities in American populations of D. suzukii. To further understand the nature of wSuz biology and assess its utility as a tool for controlling this pest's populations, we investigated the prevalence of Wolbachia in 23 European D. suzukii populations, and compared our results with those available in American populations. Our data showed a highly variable infection frequency with a mean prevalence of 46%, which is significantly higher than the 17% found in American populations. Based on Multilocus Sequence Typing analysis, a single wSuz strain was diagnosed in all European populations of D. suzukii. In agreement with American data, we found no evidence of cytoplasmic incompatibility induced by wSuz. These findings raise two questions: a why Wolbachia is maintained in field populations of D. suzukii and b what are the selective forces responsible for the variation in prevalence within populations, particularly between European and American continents? Our results provide new insights into the D. suzukii-Wolbachia association and highlight regional variations that await further investigation and that should be taken into account for using Wolbachia-based pest management programs.

  11. Morphological variation, advertisement call, and tadpoles of Bokermannohyla nanuzae (Bokermann, 1973), and taxonomic status of B. feioi (Napoli & Caramaschi, 2004) (Anura, Hylidae, Cophomantini).

    Science.gov (United States)

    Walker, Marina; Lourenço, Ana Carolina Calijorne; Pimenta, Bruno V S; Nascimento, Luciana Barreto

    2015-01-01

    Bokermannohyla nanuzae (Bokermann & Sazima 1973) and B. feioi (Napoli & Caramaschi 2004) belong to the B. cir-cumdata species group. The type locality of the former is Serra do Cipó, Espinhaço mountain range, and of the latter is Parque Estadual do Ibitipoca, Mantiqueira mountain range, both in Minas Gerais State, Brazil. Differences on dorsal draw-ing pattern of adults, oral disc morphology of tadpoles, and temporal properties of calls were proposed to distinguish these two species. However, several specimens found between the two type localities remain unidentified because diagnostic characters and states occur in all of these populations. Thus, in order to assess these characters variations, we performed an analysis of the morphology and morphometry of adults, vocalization, and morphology of tadpoles. Specimens were divided into three operational taxonomic units (OTUs): B. nanuzae (Serra do Cipó and northwards, Espinhaço mountain range), B. cf. nanuzae (Quadrilátero Ferrífero, Espinhaço mountain range, south of Serra do Cipó), and B. feioi (Serra do Ibitipoca, Mantiqueira mountain range). Drawing patterns of the dorsum and limbs show clinal variation and the three units are morphometrically very similar. Temporal and spectral properties of calls overlap in these three units. The diagnostic differences originally proposed for tadpoles are intrapopulational variations and occur in specimens from all of the locations analyzed. We found that these three units are morphologically indistinguishable. Therefore, we designate Bok-ermannohyla feioi (Napoli & Caramaschi 2004) as a junior synonym of Bokermannohyla nanuzae (Bokermann & Sazima 1973), extending its geographical distribution to the Mantiqueira mountain range. PMID:25947466

  12. Mismatch correction modulates mutation frequency and pilus phase and antigenic variation in Neisseria gonorrhoeae.

    Science.gov (United States)

    Criss, Alison K; Bonney, Kevin M; Chang, Rhoda A; Duffin, Paul M; LeCuyer, Brian E; Seifert, H Steven

    2010-01-01

    The mismatch correction (MMC) system repairs DNA mismatches and single nucleotide insertions or deletions postreplication. To test the functions of MMC in the obligate human pathogen Neisseria gonorrhoeae, homologues of the core MMC genes mutS and mutL were inactivated in strain FA1090. No mutH homologue was found in the FA1090 genome, suggesting that gonococcal MMC is not methyl directed. MMC mutants were compared to a mutant in uvrD, the helicase that functions with MMC in Escherichia coli. Inactivation of MMC or uvrD increased spontaneous resistance to rifampin and nalidixic acid, and MMC/uvrD double mutants exhibited higher mutation frequencies than any single mutant. Loss of MMC marginally enhanced the transformation efficiency of DNA carrying a single nucleotide mismatch but not that of DNA with a 1-kb insertion. Unlike the exquisite UV sensitivity of the uvrD mutant, inactivating MMC did not affect survival after UV irradiation. MMC and uvrD mutants exhibited increased PilC-dependent pilus phase variation. mutS-deficient gonococci underwent an increased frequency of pilin antigenic variation, whereas uvrD had no effect. Recombination tracts in the mutS pilin variants were longer than in parental gonococci but utilized the same donor pilS loci. These results show that gonococcal MMC repairs mismatches and small insertion/deletions in DNA and also affects the recombination events underlying pilin antigenic variation. The differential effects of MMC and uvrD in gonococci unexpectedly reveal that MMC can function independently of uvrD in this human-specific pathogen. PMID:19854909

  13. Characterization of the LIGO 4 km Fabry-Perot cavities via their high-frequency dynamic responses to length and laser frequency variations

    International Nuclear Information System (INIS)

    Recent measurements at the LIGO Hanford Observatory have confirmed the predicted high-frequency dynamic response of km scale Fabry-Perot cavities to length and laser frequency variations. The dynamic response functions have been exploited to determine a number of cavity parameters including the cavity length and the resonance width. A new technique based on a variation of these measurements has been utilized to measure the interferometer arm cavity lengths with a precision of 80 μm. We present an overview of these measurements and discuss how the dynamic field responses could be used to measure the cavity g factors which are related to the mirror radii of curvature

  14. Seasonal variations in the frequency of atmospheric circulation types in European regions

    Science.gov (United States)

    Cahynova, Monika; Huth, Radan

    2010-05-01

    We propose two versions of an "index of seasonality" to study the annual course in the relative frequency of circulation types in several objective and subjective classifications from the COST733 database. The objective classifications have been developed for twelve European regions (domains D00-D11) in the period 1957-2002 and have fixed numbers of types (9, 18, and 27). Both indices are based on the long-term monthly relative frequency of individual circulation types. For each type we indicate the months with the highest and the lowest relative frequency and calculate their difference (range). The first index - "average seasonality" - is an average of the ranges of all types within a given classification. It is anti-correlated with the number of types - a higher number of types means a lower average seasonality. The second index - "maximum seasonality" - only takes into account the circulation type with the highest range (that is, the type with the most pronounced annual course). This index removes the dependence on the number of circulation types in some of the used classifications. Seasonal variations in the relative frequency of circulation types based on the two indices are generally the highest in the eastern Mediterranean (D11) and in whole Europe (D00). The lowest seasonality is found over the British Isles (D04) and Iceland (D01). There are large differences in the seasonality in the individual classifications, because the degree to which the classification identifies the natural seasonal circulation patterns strongly depends on the classification algorithm used. The research is conducted within the COST733 Action "Harmonisation and Applications of Weather Types Classifications for European Regions". The Czech participation in it is supported by the Ministry of Education, Youth, and Sports of the Czech Republic, contract OC115.

  15. Are short-term variations in solar oscillation frequencies the signature of a second solar dynamo?

    International Nuclear Information System (INIS)

    In addition to the well-known 11-year solar cycle, the Sun's magnetic activity also shows significant variation on shorter time scales, e.g. between one and two years. We observe a quasi-biennial (2-year) signal in the solar p-mode oscillation frequencies, which are sensitive probes of the solar interior. The signal is visible in Sun-as-a-star data observed by different instruments and here we describe the results obtained using BiSON, GOLF, and VIRGO data. Our results imply that the 2-year signal is susceptible to the influence of the main 11-year solar cycle. However, the source of the signal appears to be separate from that of the 11-year cycle. We speculate as to whether it might be the signature of a second dynamo, located in the region of near-surface rotational shear.

  16. High-frequency Earth rotation variations deduced from altimetry-based ocean tides

    Science.gov (United States)

    Madzak, Matthias; Schindelegger, Michael; Böhm, Johannes; Bosch, Wolfgang; Hagedoorn, Jan

    2016-06-01

    A model of diurnal and semi-diurnal variations in Earth rotation parameters (ERP) is constructed based on altimetry-measured tidal heights from a multi-mission empirical ocean tide solution. Barotropic currents contributing to relative angular momentum changes are estimated for nine major tides in a global inversion algorithm that solves the two-dimensional momentum equations on a regular 0.5° grid with a heavily weighted continuity constraint. The influence of 19 minor tides is accounted for by linear admittance interpolation of ocean tidal angular momentum, although the assumption of smooth admittance variations with frequency appears to be a doubtful concept for semi-diurnal mass terms in particular. A validation of the newly derived model based on post-fit corrections to polar motion and universal time (Δ UT1) from the analysis of Very Long Baseline Interferometry (VLBI) observations shows a variance reduction for semi-diurnal Δ UT1 residuals that is significant at the 0.05 level with respect to the conventional ERP model. Improvements are also evident for the explicitly modeled K_1 , Q_1 , and K_2 tides in individual ERP components, but large residuals of more than 15 μ as remain at the principal lunar frequencies of O_1 and M_2 . We attribute these shortcomings to uncertainties in the inverted relative angular momentum changes and, to a minor extent, to violation of mass conservation in the empirical ocean tide solution. Further dedicated hydrodynamic modeling efforts of these anomalous constituents are required to meet the accuracy standards of modern space geodesy.

  17. Nickel-silica nanocomposite: Variation of the blocking temperature with magnetic field and measuring frequency

    Science.gov (United States)

    Singh, V.; Seehra, M. S.; Bonevich, J.

    2008-04-01

    The variations of the blocking temperature TB with measuring frequency fm and applied field H are reported for Ni nanoparticles (NPs) embedded in SiO2 matrix with the nominal composition Ni /SiO2 (15/85). Transmission electron microscopy of the sol-gel prepared NPs yielded a log-normal distribution with diameter D =3.8(0.2)nm whereas x-ray diffraction data yielded D ≃3.3nm. The TB versus fm variation for fm=0.1-1000Hz fits the equation TB=Ta/ln(f0/fm) with f0=2.6×109Hz and Ta=270K whereas TB versus H data follows the equation TB(H)=33(1-H/H0)m with H0=3200Oe and m =2(3/2) for lower (higher) H. These results are compared with the predictions of the Néel-Brown model of magnetic relaxation in noninteracting NPs.

  18. Variation in humpback whale (Megaptera novaeangliae) song length in relation to low-frequency sound broadcasts

    Science.gov (United States)

    Fristrup, Kurt M.; Hatch, Leila T.; Clark, Christopher W.

    2003-06-01

    Humpback whale song lengths were measured from recordings made off the west coast of the island of Hawai'i in March 1998 in relation to acoustic broadcasts (``pings'') from the U.S. Navy SURTASS Low Frequency Active sonar system. Generalized additive models were used to investigate the relationships between song length and time of year, time of day, and broadcast factors. There were significant seasonal and diurnal effects. The seasonal factor was associated with changes in the density of whales sighted near shore. The diurnal factor was associated with changes in surface social activity. Songs that ended within a few minutes of the most recent ping tended to be longer than songs sung during control periods. Many songs that were overlapped by pings, and songs that ended several minutes after the most recent ping, did not differ from songs sung in control periods. The longest songs were sung between 1 and 2 h after the last ping. Humpbacks responded to louder broadcasts with longer songs. The fraction of variation in song length that could be attributed to broadcast factors was low. Much of the variation in humpback song length remains unexplained.

  19. Demeter/ICE Experiment: Study of low frequency transmitter intensity variations

    Science.gov (United States)

    Boudjada, M. Y.; Moldovan, I.; Schwingenschuh, K.; Al-Haddad, E.; Biagi, P. F.; Parrot, M.

    2012-04-01

    We report on low frequency (LF) transmitter signal recorded by the 'Instrument Capteur Electrique' (ICE) experiment onboard the DEMETER micro-satellite. We mainly consider the signal emitted by the Brasov broadcasting station (25.60E, 45.75N) at frequency of about 153 kHz. We analyze the reception conditions of this transmitter several weeks before the occurrence of the Vrancea earthquakes, on October, 27th, 2004. Ground-based observations revealed the presence of sudden decrease of the Y-component of the magnetic field at Muntele Rosu Observatory (Romania), at about 68 km from the epicenter, as reported by Moldovan et al. (Rom. Journ. Phys., Vol. 54, Nos. 1-2, p. 249-261, Bucharest, 2009). In this contribution we attempt to check if the LF Brasov signal was also subject to similar disturbances as observed by the ground-station. We focus on the variation of the LF transmitter intensity levels, several weeks before and after the Vrancea earthquake occurrence. We discuss the physical parameters which may disturb the signal reception in particular the geomagnetic activity and the signal to noise ratios.

  20. Compressive sensing : a strategy for fluttering target discrimination employed by bats emitting broadband calls

    OpenAIRE

    Fontaine, Bertrand; Peremans, Herbert

    2011-01-01

    Abstract: When foraging, so-called FM-bats emit sequences of frequency modulated (FM) calls in order to detect, identify, and localize edible prey. Once a potential target has been detected, various call and call sequence parameters, such as frequency sweep, pulse duration, and inter pulse interval (IPI) vary. In this paper, the possible functions of the variation of the IPI are studied. In particular, it is conjectured that the IPI patterns are an adaptive behavior that optimizes the signal ...

  1. PERIODIC VARIATIONS IN THE O - C DIAGRAMS OF FIVE PULSATION FREQUENCIES OF THE DB WHITE DWARF EC 20058-5234

    Energy Technology Data Exchange (ETDEWEB)

    Dalessio, J.; Provencal, J. L.; Shipman, H. L. [Department of Physics and Astronomy, University of Delaware, Newark, DE 19716 (United States); Sullivan, D. J.; Sullivan, T. [School of Chemical and Physical Sciences, Victoria University of Wellington, P.O. Box 600, Wellington 6012 (New Zealand); Kilkenny, D. [Department of Physics, University of the Western Cape, Private Bag X17, Bellville 7535 (South Africa); Fraga, L. [Southern Observatory for Astrophysical Research, Casilla 603, La Serena (Chile); Sefako, R. [South African Astronomical Observatory, P.O. Box 9, Observatory 7935 (South Africa)

    2013-03-01

    Variations in the pulsation arrival time of five independent pulsation frequencies of the DB white dwarf EC 20058-5234 individually imitate the effects of reflex motion induced by a planet or companion but are inconsistent when considered in unison. The pulsation frequencies vary periodically in a 12.9 year cycle and undergo secular changes that are inconsistent with simple neutrino plus photon-cooling models. The magnitude of the periodic and secular variations increases with the period of the pulsations, possibly hinting that the corresponding physical mechanism is located near the surface of the star. The phase of the periodic variations appears coupled to the sign of the secular variations. The standards for pulsation-timing-based detection of planetary companions around pulsating white dwarfs, and possibly other variables such as subdwarf B stars, should be re-evaluated. The physical mechanism responsible for this surprising result may involve a redistribution of angular momentum or a magnetic cycle. Additionally, variations in a supposed combination frequency are shown to match the sum of the variations of the parent frequencies to remarkable precision, an expected but unprecedented confirmation of theoretical predictions.

  2. Calling Dunbar's Numbers

    OpenAIRE

    MacCarron, Pádraig; Kaski, Kimmo; Dunbar, Robin

    2016-01-01

    The social brain hypothesis predicts that humans have an average of about 150 relationships at any given time. Within this 150, there are layers of friends of an ego, where the number of friends in a layer increases as the emotional closeness decreases. Here we analyse a mobile phone dataset, firstly, to ascertain whether layers of friends can be identified based on call frequency. We then apply different clustering algorithms to break the call frequency of egos into clusters and compare the ...

  3. Adaptive Feedforward Compensation by Specified Step Settling Considering Resonance Frequency Variation and Constraint on Control Input Amplitude

    Science.gov (United States)

    Maeda, Yoshihiro; Wada, Masatake; Iwasaki, Makoto; Hirai, Hiromu

    This paper presents an adaptive feedfowad (FF) compensation method based on a deadbeat control framework for fast and precise positioning in mechatronic systems. The conventional FF compensation approach can design a FF compensator by considering both the frequency shaping and amplitude of FF control input, to suppress the response variations due to the perturbations in plant resonance frequency. However, since the conventional approach is not adaptive against frequency variations, an overshoot and/or undershoot response at the settling region would deteriorate the positioning performance. In this research, therefore, the proposed FF compensation approach with an adaptive identification system for the resonance frequency is adopted to achieve the desired positioning performance. The effectiveness of the proposed FF compensation approach has been verified by experiments using a prototype of an industrial positioning device.

  4. School-Based Racial and Gender Discrimination among African American Adolescents: Exploring Gender Variation in Frequency and Implications for Adjustment

    OpenAIRE

    Cogburn, Courtney D.; Chavous, Tabbye M.; Griffin, Tiffany M.

    2011-01-01

    The present study examined school-based racial and gender discrimination experiences among African American adolescents in Grade 8 (n = 204 girls; n = 209 boys). A primary goal was exploring gender variation in frequency of both types of discrimination and associations of discrimination with academic and psychological functioning among girls and boys. Girls and boys did not vary in reported racial discrimination frequency, but boys reported more gender discrimination experiences. Multiple reg...

  5. frequency and seasonal variation of plasmodium species in southern districts of Khyber pakhtunkhwa

    International Nuclear Information System (INIS)

    To determine the frequency of malaria and seasonal variation of Plasmodium species in southern districts of Khyber Pakhtunkhwa. Study Design: Descriptive study. Place and Duration of study: Department of Pathology Combined Military Hospital (CMH), Bannu, from 1st January 2010 to 31st December 2011. Patients and Methods: Five thousand eight hundred and seventy eight (5878) patients with symptoms of fever, nausea, malaise and body aches irrespective of age and gender were included in the study. Samples were collected, thin and thick smears of the samples were prepared and stained with Giemsa's stain. Thick film was used for screening for malaria parasites and species identification was done on thin smears. Results: Out of 5878 patients, 1962 (28.8%) were found to be positive for malaria. Of them 1524 (90%) had plasmodium vivax infection, while 119 (7.0%) patients were infected with plasmodium falciparum, 49 (3.0%) of the patients were infected with both Plasmodium vivax and Plasmodium falciparum. Plasmodium vivax was most common in the months of August 203 (12.3%) patients, September 235 (14.3%) patients and October 317 (20%), whereas plasmodium falciparum infection was most common in the months of October 34 (28.6%) patients, November 19 (16%) patients and December 30 (25.2%) patients. Conclusion: Malaria is an endemic infectious disease in Pakistan, in the Southern districts of Khyber Pakhtunkhaw and tribal areas of North and South Waziristan. It is prevalent throughout the year and most noticeably from May to November. (author)

  6. Seasonal Variation and Frequency Distribution of Ectoparasites in Crossbreed Cattle in Southeastern Brazil

    Directory of Open Access Journals (Sweden)

    Maria do Socorro Ferraz da Costa

    2014-01-01

    Full Text Available The aims of this study were to evaluate the seasonal variation and frequency distribution of Rhipicephalus (Boophilus microplus, Haematobia irritans, and Dermatobia hominis on crossbred heifers under field conditions in the northeast of Minas Gerais state, southeastern Brazil. From November 2007 to September 2009 (23 months, 40 heifers aged 16.6±2.4 months were divided into groups A (1/4 Holstein × 3/4 Gir and B (1/2 Holstein × 1/2 Gir and had the monthly infestation estimated along with the climatic conditions. The mean maximum and minimum temperatures were 28.5 and 19°C, respectively. The ectoparasites were present on animals in all months of the year. The levels of ticks on the animals were low (3.0±0.2 ticks/animal, with the highest density in midwinter. The temperature was the climatic factor that most influenced the tick levels. The population of H. irritans (13.9±0.3 flies/animal and D. hominis (1.5±0.2 larvae/animal on heifers was more influenced by rainfall and exhibited two population peaks during the year. 1/2 Holstein heifers harbored significantly more H. irritans and D. hominis than 1/4 Holstein heifers. The results are discussed considering the most appropriate periods to apply ectoparasiticides and the genetic make-up of the animals.

  7. Radial-femoral concordance in time and frequency domain-based estimates of systemic arterial respiratory variation.

    Science.gov (United States)

    Thiele, Robert H; Colquhoun, Douglas A; Tucker-Schwartz, Jason M; Gillies, George T; Durieux, Marcel E

    2012-10-01

    Commonly used arterial respiratory variation metrics are based on mathematical analysis of arterial waveforms in the time domain. Because the shape of the arterial waveform is dependent on the site at which it is measured, we hypothesized that analysis of the arterial waveform in the frequency domain might provide a relatively site-independent means of measuring arterial respiratory variation. Radial and femoral arterial blood pressures were measured in nineteen patients undergoing liver transplantation. Systolic pressure variation (SPV), pulse pressure variation (PPV), area under the curve variation (AUCV), and mean arterial pressure variation (MAPV) at radial and femoral sites were calculated off-line. Two metrics, "Spectral Peak Ratio" (SPeR) and "Spectral Power Ratio" (SPoR) based on ratios of the spectral peak and spectral area (power) at the respiratory and cardiac frequencies, were calculated at both radial and femoral sites. Variance among radial-femoral differences was compared and correlation coefficients describing the relationship between respiratory variation at the radial and femoral sites were developed. The variance in radial-femoral differences were significantly different (p SPV, PPV, AUCV, MAPV, SPeR, and SPoR, respectively. Assuming a PPV treatment threshold of 12 % (or equivalent), differences in treatment decisions based on radial or femoral estimates would arise in 12, 14, 5.4, 5.7, 4.8, and 5.5 % of minutes for SPV, PPV, AUCV, MAPV, spectral peak ratio, and spectral power ratio, respectively. As compared to frequency domain-based estimates of respiratory variation, SPV and PPV are relatively dependent on the anatomic site at which they are measured. Spectral peak and power ratios are relatively site-independent means of measuring respiratory variation, and may offer a useful alternative to time domain-based techniques. PMID:22903732

  8. Detecting Jumps in High-Frequency Financial Series Using Multipower Variation

    OpenAIRE

    Carla Ysusi

    2006-01-01

    When the log-price process incorporates a jump component, realised variance will no longer estimate the integrated variance since its probability limit will be determined by the continuous and jump components. Instead realised bipower variation, tripower variation and quadpower variation are consistent estimators of integrated variance even in the presence of jumps. In this paper we derive the limit distributions of realised tripower and quadpower variation, allowing us to compare these three...

  9. Complex permeability and permittivity variation of carbonyl iron rubber in the frequency range of 2 to 18 GHz

    Directory of Open Access Journals (Sweden)

    Adriana Medeiros Gama

    2010-04-01

    Full Text Available The complex dielectric permittivity (e and magnetic permeability (m of Radar Absorbing Materials (RAM based on metallic magnetic particles (carbonyl iron particles embedded in a dielectric matrix (silicon rubber have been studied in the frequency range of 2 to 18 GHz. The relative permeability and permittivity of carbonyl iron-silicon composites for various mass fractions are measured by the transmission/reflection method using a vector network analyzer. The concentration dependence of permittivity and permeability on the frequency is analyzed. In a general way, the results show that e´ parameter shows a more significant variation among the evaluated parameters (e”, m”, m’. The comparison of dielectric and magnetic loss tangents (e”/e” and m”/m’, respectively shows more clearly the variation of both parameters (e and m according to the frequency. It is also observed that higher carbonyl iron content fractions favor both dielectric and magnetic loss tangents.

  10. Genome-wide variation of the somatic mutation frequency in transgenic plants

    OpenAIRE

    Kovalchuk, Igor; Kovalchuk, Olga; Hohn, Barbara

    2000-01-01

    In order to analyse the frequency of point mutations in whole plants, several constructs containing single nonsense mutations in the β-glucuronidase (uidA) gene were used to generate transgenic Arabidopsis thaliana plants. Upon histochemical staining of transgenic plants, sectors indicative of transgene reactivation appeared. Reversion frequencies were in the range of 10–7–10–8 events per base pair, exceeding the previous estimates for other eukaryotes at least 100-fold. The frequency was dep...

  11. Experimental frequency response for boiling two-phase flow to power variation

    International Nuclear Information System (INIS)

    This paper presents experimental data on power to void, and power to pressure drop frequency response of boiling two-phase flow in a vertical heated channel with Freon-113 as the working fluid. Experimental frequency response functions are measured with statistical method over a frequency range of 0.02 to 10 Hz. The data cover inlet subcooling of 7.5 and 20 K, mass flux of 500, 1000 and 2000 kg/m2s, and various power levels. Influence of each parameter on the frequency response are described. Finally the data are compared with theoretical value obtained by means of linearization technique. (author)

  12. EMERGENCY CALLS

    CERN Multimedia

    Medical Service

    2001-01-01

    IN URGENT NEED OF A DOCTOR GENEVA EMERGENCY SERVICES GENEVA AND VAUD 144 FIRE BRIGADE 118 POLICE 117 CERN FIREMEN 767-44-44 ANTI-POISONS CENTRE Open 24h/24h 01-251-51-51 Patient not fit to be moved, call family doctor, or: GP AT HOME, open 24h/24h 748-49-50 Association Of Geneva Doctors Emergency Doctors at home 07h-23h 322 20 20 Patient fit to be moved: HOPITAL CANTONAL CENTRAL 24 Micheli-du-Crest 372-33-11 ou 382-33-11 EMERGENCIES 382-33-11 ou 372-33-11 CHILDREN'S HOSPITAL 6 rue Willy-Donzé 372-33-11 MATERNITY 32 bvd.de la Cluse 382-68-16 ou 382-33-11 OPHTHALMOLOGY 22 Alcide Jentzer 382-33-11 ou 372-33-11 MEDICAL CENTRE CORNAVIN 1-3 rue du Jura 345 45 50 HOPITAL DE LA TOUR Meyrin EMERGENCIES 719-61-11 URGENCES PEDIATRIQUES 719-61-00 LA TOUR MEDICAL CENTRE 719-74-00 European Emergency Call 112 FRANCE EMERGENCY SERVICES 15 FIRE BRIGADE 18 POLICE 17 CERN FIREMEN AT HOME 00-41-22-767-44-44 ANTI-POISONS CENTRE Open 24h/24h 04-72-11-69-11 All doctors ...

  13. Time variation in the low frequency spectrum of Vela-like pulsar B1800-21

    CERN Document Server

    Basu, Rahul; Lewandowski, Wojciech; Kijak, Jarosław; Dembska, Marta

    2016-01-01

    We report the flux measurement of the Vela like pulsar B1800-21 at the low radio frequency regime over multiple epochs spanning several years. The spectrum shows a turnover around the GHz frequency range and represents a typical example of gigahertz-peaked spectrum (GPS) pulsar. Our observations revealed that the pulsar spectrum show a significant evolution during the observing period with the low frequency part of the spectrum becoming steeper, with a higher turnover frequency, for a period of several years before reverting back to the initial shape during the latest measurements. The spectral change over times spanning several years requires dense structures, with free electron densities around 1000--20000 cm$^{-3}$ and physical dimensions ~220 AU, in the interstellar medium (ISM) traversing across the pulsar line of sight. We look into the possible sites of such structures in the ISM and likely mechanisms particularly the thermal free-free absorption as possible explanations for the change.

  14. Frequency response variation of two offshore wind park transformers with different tap changer positions

    DEFF Research Database (Denmark)

    Arana Aristi, Iván; Holbøll, Joachim; Sørensen, T

    2010-01-01

    This paper presents the results of several sweep frequency response analysis (SFRA) measurements performed on two identical offshore wind farm transformers. A comparison is made between the transformers based on different recommended measurements and procedures, different measurement systems for...

  15. Frequency-dependent variation in the two-dimensional beam pattern of an echolocating dolphin

    OpenAIRE

    Starkhammar, Josefin; Moore, Patrick W.; Talmadge, Lois; Houser, Dorian S.

    2011-01-01

    Recent recordings of dolphin echolocation using a dense array of hydrophones suggest that the echolocation beam is dynamic and can at times consist of a single dominant peak, while at other times it consists of forward projected primary and secondary peaks with similar energy, partially overlapping in space and frequency bandwidth. The spatial separation of the peaks provides an area in front of the dolphin, where the spectral magnitude slopes drop off quickly for certain frequency bands. Thi...

  16. Frequency response variation of two offshore wind park transformers with different tap changer positions

    Energy Technology Data Exchange (ETDEWEB)

    Arana, Ivan; Soerensen, Troels [DONG Energy (Denmark); Holboell, Joachim [Technical Univ. of Denmark (Denmark)

    2010-07-01

    This paper presents the results of several sweep frequency response analysis (SFRA) measurements performed on two identical offshore wind farm transformers. A comparison is made between the transformers based on different recommended measurements and procedures, different measurement systems for frequency response analysis (FRA) and different tap changer positions. It was shown how the series impedance and capacitance between windings vary depending on the tap changer position. (orig.)

  17. Variations in High Degree Acoustic Mode Frequencies of the Sun during Solar Cycle 23 and 24

    CERN Document Server

    Tripathy, S C; Hill, F

    2015-01-01

    We examine continuous measurements of the high-degree acoustic mode frequencies of the Sun covering the period from 2001 July to June 2014. These are obtained through the ring-diagram technique applied to the full-disk Doppler observations made by the Global Oscillation Network Group (GONG). The frequency shifts in the degree range of 180-1200 are correlated with different proxies of solar activity e.g. 10.7 cm radio flux, the International Sunspot Number and the strength of the local magnetic field. In general, a good agreement is found between the shifts and activity indices, and the correlation coefficients are found to be comparable with intermediate degree mode frequencies. Analyzing the frequency shifts separately for the two cycles, we find that cycle 24 is weaker than cycle 23. Since the magnetic activity is known to be different in the two hemisphere, for the first time, we compute the frequency shifts over the two hemispheres separately and find that the shifts also display hemispheric asymmetry; th...

  18. Searches for high frequency variations in the 8-B neutrino flux at the Sudbury neutrino observatory

    Energy Technology Data Exchange (ETDEWEB)

    Rielage, Keith [Los Alamos National Laboratory; Seibert, Stanley R [Los Alamos National Laboratory; Hime, Andrew [Los Alamos National Laboratory; Elliott, Steven R [Los Alamos National Laboratory; Stonehill, L C [Los Alamos National Laboratory; Wouters, J M [Los Alamos National Laboratory; Aharmim, B [LAURENTIAN UNIV; Ahmed, S N [QUEEN' S UNIV; Anthony, A E [UNIV OF TEXAS; Barros, N [PORTUGAL; Beier, E W [UNIV OF PA; Bellerive, A [CARLETON UNIV; Belttran, B [UNIV OF ALBERTA; Bergevin, M [LBNL; Biller, S D [UNIV OF OXFORD; Boudjemline, K [CARLETON UNIV; Burritt, T H [UNIV OF WASHINGTON; Cai, B [QUEEN' S UNIV; Chan, Y D [LBNL; Chauhan, D [LAURENTIAN UNIV; Chen, M [QUEEN' S UNIV; Cleveland, B T [UNIV OF OXFORD; Cox - Mobrand, G A [UNIV OF WASHINGTON; Dai, X [QUEEN' S UNIV; Deng, H [UNIV OF PA; Detwiler, J [LBNL; Dimarco, M [QUEEN' S UNIV; Doe, P J [UNIV OF WASHINGTON; Drouin, P - L [CARLTON UNIV; Duba, C A [UNIV OF WASHINGTON; Duncan, F A [SNOLAB, SUDBURY; Dunford, M [UNIV OF PA; Earle, E D [QUEEN' S UNIV; Evans, H C [QUEEN' S UNIV; Ewan, G T [QUEEN' S UNIV; Farine, J [LAURENTTIAN UNIV; Fergani, H [UNIV OF OXFORD; Fleurot, F [LAURENTIAN UNIV; Ford, R J [SNOLAB, SUDBURY; Formaggilo, J A [MASSACHUSETTS INST. OF TECH.; Gagnon, N [UNIV OF WASHINGTON; Goon, J Tm [LOUISIANA STATE UNIV; Guillian, E [QUEEN' S UNIV; Habib, S [UNIV OF ALBERTA; Hahn, R L [BNL; Hallin, A L [UNIV OF ALBERTA; Hallman, E D [LAURENTIAN UNIV; Harvey, P J [QUEEN' S UNIV; Hazama, R [UNIV OF WASHINGTON; Heintzelman, W J [UNIV OF PA; Heise, J [SNOLAB, SUDBURY; Helmer, R L [TRIUMF; Howard, C [UNIV OF ALBERTA; Howe, M A [UNIV OF WASHINGTON; Huang, M [UNIV OF TEXAS; Jamieson, B [UNIV OF BRITISH COLUMBIA; Jelley, N A [UNIV OF OXFORD; Keeter, K J [SNOLAB, SUDBURY; Klein, J R [UNIV OF TEXAS; Kos, M [QUEEN' S UNIV; Kraus, C [QUEEN' S UNIV; Krauss, C B [UNIV OF ALBERTA; Kutter, T [LOUISIANA STATE UNIV; Kyba, C C M [UNIV OF PA; Law, J [UNIV OF GUELPH; Lawson, I T [SNOLAB, SUDBURY; Lesko, K T [LBNL; Leslie, J R [QUEEN' S UNIV; Loach, J C [UNIV OF OXFORD; Maclellan, R [QUEEN' S UNIV; Majerus, S [UNIV OF OXFORD; Mak, H B [QUEEN' S UNIV; Maneira, J [PORTUGAL; Martin, R [QUEEN' S UNIV; Mccauley, N [UNIV OF PA; Mc Donald, A B [QUEEN' S UNIV; Mcgee, S [UNIV OF WASHINGTON; Miffin, C [CARLETON UNIV; Miller, M L [MASSACHUSETTS INST. OF TECH.; Monreal, B [MASSACHUSETTS INST. OF TECH.; Monroe, J [MASSACHUSETTS INST. OF TECH; Morissette, B [SNOLAB, SUDBURY; Nickel, B G [UNIV OF GUELPH; Noble, A J [QUEEN' S UNIV; O' Keeffe, H M [UNIV OF OXFORD; Oblath, N S [UNIV OF WASHINGTON; Orebi Gann, G D [UNIV OF OXFORD; Oser, S M [UNIV OF BRITISH COLUMBIA; Ott, R A [MASSACHUSETTS INST. OF TECH.; Peeters, S J M [UNIV OF OXFORD; Poon, A W P [LBNL; Prior, G [LBNL; Reitzner, S D [UNIV OF GUELPH; Robertson, B C [QUEEN' S UNIV; Robertson, R G H [UNIV OF WASHINGTON; Rollin, E [CARLETON UNIV; Schwendener, M H [LAURENTIAN UNIV; Secrest, J A [UNIV OF PA; Seibert, S R [UNIV OF TEXAS; Simard, O [CARLETON UNIV; Sinclair, D [CARLETON UNIV; Sinclair, L [CARLETON UNIV; Skensved, P [QUEEN' S UNIV; Sonley, T J [MASSACHUSETTS INST. OF TECH.; Tesic, G [CARLETON UNIV; Tolich, N [UNIV OF WASHINGTON; Tsui, T [UNIV OF BRITISH COLUMBIA; Tunnell, C D [UNIV OF TEXAS; Van Berg, R [UNIV OF PA; Van Devender, B A [UNIV OF WASHINGTON; Virtue, C J [LAURENTIAN UNIV; Wall, B L [UNIV OF WASHINGTON; Waller, D [CARLETON UNIV; Wan Chan Tseung, H [UNIV OF OXFORD; West, N [UNIV OF OXFORD; Wilkerson, J F [UNIV OF WASHINGTON; Wilson, J R [UNIV OF OXFORD; Wright, A [QUEEN' S UNIV; Yeh, M [BNL; Zhang, F [CARLETON UNIV; Zuber, K [UNIV OF OXFORD

    2009-01-01

    We have peformed three searches for high-frequency signals in the solar neutrino flux measured by the Sudbury Neutrino Observatory (SNO), motivated by the possibility that solar g-mode oscillations could affect the production or propagation of solar {sup 8}B neutrinos. The first search looked for any significant peak in the frequency range l/day to 144/day, with a sensitivity to sinusoidal signals with amplitudes of 12% or greater. The second search focused on regions in which g-mode signals have been claimed by experiments aboard the SoHO satellite, and was sensitive to signals with amplitudes of 10% or greater. The third search looked for extra power across the entire frequency band. No statistically significant signal was detected in any of the three searches.

  19. Searches for high frequency variations in the 8-B neutrino flux at the Sudbury neutrino observatory

    International Nuclear Information System (INIS)

    We have peformed three searches for high-frequency signals in the solar neutrino flux measured by the Sudbury Neutrino Observatory (SNO), motivated by the possibility that solar g-mode oscillations could affect the production or propagation of solar 8B neutrinos. The first search looked for any significant peak in the frequency range l/day to 144/day, with a sensitivity to sinusoidal signals with amplitudes of 12% or greater. The second search focused on regions in which g-mode signals have been claimed by experiments aboard the SoHO satellite, and was sensitive to signals with amplitudes of 10% or greater. The third search looked for extra power across the entire frequency band. No statistically significant signal was detected in any of the three searches.

  20. Longitudinal frequency variation of long-lasting EMIC Pc1-Pc2 waves localized in the inner magnetosphere

    Science.gov (United States)

    Kim, K.-H.; Shiokawa, K.; Mann, I. R.; Park, J.-S.; Kwon, H.-J.; Hyun, K.; Jin, H.; Connors, M.

    2016-02-01

    Long-lasting (> 20 h) electromagnetic ion cyclotron (EMIC) Pc1-Pc2 waves were observed by the Athabasca (L =˜ 4.6) induction magnetometer and Canadian Array for Realtime Investigations of Magnetic Activity (L =˜ 4-6) fluxgate magnetometers on 5 April 2007. These waves showed a systematic frequency change with local time, the minimum frequency near dusk, and the maximum frequency near dawn. Assuming the plasmapause as a potential source region of the waves, we estimated the plasmapause location from localized proton enhancement (LPE) events observed at NOAA-Polar Orbiting Environmental Satellites and METOP-2 satellites. We found that the longitudinal frequency variation of EMIC waves has a clear correlation with the estimated plasmapause location and that the waves are in the frequency band between the equatorial helium and oxygen gyrofrequencies at the estimated plasmapause. With our analysis results we suggest that the LPE events are caused by wave-particle interaction with the helium band EMIC waves generated near the plasmapause.

  1. Variation in sister chromatid exchange frequencies between human and pig whole blood, plasma leukocyte, and mononuclear leukocyte cultures

    International Nuclear Information System (INIS)

    Sister chromatid exchange (SCE) induction by ultraviolet (UV) light was studied in both human and pig whole blood cultures (WBC) and plasma leukocyte cultures (PLC). No variation in SCE frequency was observed between pig WBC and PLC in control as well as in treated cells. Conversely, SCE frequencies of human PLC were consistently higher than those of WBC in control and UV-exposed cells. Thus, red blood cells (RBCs) do not influence the sensitivity of lymphocytes to UV LIGHT exposure, and there must be some different culture condition(s) in the inducation of SCEs between human WBC and PLC but not in swine lymphocyte cultures. Since the BrdUrd/lymphocyte ratio of WBC was halved in PLC, the effect of BrdUrd concentration in inducing the SCE baseline frequency of PLC may be ruled out. Neither the cell separation technique nor polymorphonuclear leukocytes had a significant role in the elevated SCE frequency of human PLC or MLC. Experiments where human RBCs were titrated into human PLC showed that the induction of an elevated SCE frequency of PLC was suppressed in a dose-dependent manner by the presence of RBCs in the culture medium. Since the incorporation of pig or human RBCs into human PLC as well as into MLC reduced the SCE frequency to that of WBC, a common component and/or function existing in these cells is suggested. Analysis of different RBC components showed that RBCs, specifically RBC ghosts, release a diffusible but not dialyzable corrective factor into culture medium that is able to reduce the SCE frequencies of PLC

  2. Vowel Identification by Listeners with Hearing Impairment in Response to Variation in Formant Frequencies

    Science.gov (United States)

    Molis, Michelle R.; Leek, Marjorie R.

    2011-01-01

    Purpose: This study examined the influence of presentation level and mild-to-moderate hearing loss on the identification of a set of vowel tokens systematically varying in the frequency locations of their second and third formants. Method: Five listeners with normal hearing (NH listeners) and five listeners with hearing impairment (HI listeners)…

  3. Investigation of switching frequency variations and EMI properties in self-oscillating class D amplifiers

    DEFF Research Database (Denmark)

    Nielsen, Dennis; Knott, Arnold; Pfaffinger, Gerhard; Andersen, Michael A. E.

    2009-01-01

    Class D audio amplifiers have gained significant influence in sound reproduction due to their high efficiency. One of the most commonly used control methods in these amplifiers is self-oscillation. A parameter of key interest in self-oscillating amplifiers is the switching frequency, which is kno...

  4. Automated detection of Antarctic blue whale calls.

    Science.gov (United States)

    Socheleau, Francois-Xavier; Leroy, Emmanuelle; Pecci, Andres Carvallo; Samaran, Flore; Bonnel, Julien; Royer, Jean-Yves

    2015-11-01

    This paper addresses the problem of automated detection of Z-calls emitted by Antarctic blue whales (B. m. intermedia). The proposed solution is based on a subspace detector of sigmoidal-frequency signals with unknown time-varying amplitude. This detection strategy takes into account frequency variations of blue whale calls as well as the presence of other transient sounds that can interfere with Z-calls (such as airguns or other whale calls). The proposed method has been tested on more than 105 h of acoustic data containing about 2200 Z-calls (as found by an experienced human operator). This method is shown to have a correct-detection rate of up to more than 15% better than the extensible bioacoustic tool package, a spectrogram-based correlation detector commonly used to study blue whales. Because the proposed method relies on subspace detection, it does not suffer from some drawbacks of correlation-based detectors. In particular, it does not require the choice of an a priori fixed and subjective template. The analytic expression of the detection performance is also derived, which provides crucial information for higher level analyses such as animal density estimation from acoustic data. Finally, the detection threshold automatically adapts to the soundscape in order not to violate a user-specified false alarm rate. PMID:26627784

  5. Modeling of the diurnal variation of the maximum applicable frequency for radio-communication on short waves considering solar activity

    International Nuclear Information System (INIS)

    Method of modeling of the diurnal variation of parameter maximum applicable frequency (MAF) has been developed. The method has been tested by the use of the data of Ionospheric Digital Database of the National Geophysical Data Center (NGDC), Boulder, Colorado, USA, namely, the data of Julruh - (φ=54,5°N). The type of the parameter dependence on solar activity has been studied and a model of diurnal variation of the median values in January has been made. The model is polynomial dependent on F10,7 allowing prediction of MAF. The model is made up according to data of 1958-1986 period. Prognosis was made for the next four years. Error is less than 15% for any hour and it is 10% less in the daytime. The method permits to make models for any point of the Earth (where the measurements are carried out during several cycles of solar activity) for each month. (author)

  6. Seasonal-longitudinal variation of substorm occurrence frequency: Evidence for ionospheric control

    OpenAIRE

    Wang, H.; Hermann Lühr

    2007-01-01

    Based on 2760 well-defined substorm onsets in the northern hemisphere and 1432 in the southern hemisphere observed by the FUV (Far Ultraviolet) Imager on board IMAGE (Imager for Magnetosphere-to-Aurora Global Exploration) spacecraft, a statistical study is performed for both hemispheres. The main emphasis is put on a possible dependence of the substorm occurrence frequency on season and longitude (S/L). It was found that around December solstice UT noon-time and around June solstice UT nightt...

  7. Wolbachia in European Populations of the Invasive Pest Drosophila suzukii: Regional Variation in Infection Frequencies

    OpenAIRE

    Cattel, Julien; Kaur, Rupinder; Gibert, Patricia; Martinez, Julien; Fraimout, Antoine; Jiggins, Francis; Andrieux, Thibault; Siozios, Stefanos; Anfora, Gianfranco; Miller, Wolfgang; Rota-Stabelli, Omar; Mouton, Laurence

    2016-01-01

    The invasive pest Drosophila suzukii is characterized by a specific fresh-fruit targeting behavior and has quickly become a menace for the fruit economy of newly infested North American and European regions. D. suzukii carries a strain of the endosymbiotic bacterium Wolbachia, named wSuz, which has a low infection frequency and no reproductive manipulation capabilities in American populations of D. suzukii. To further understand the nature of wSuz biology and assess its utility as a tool for ...

  8. Spatial variations in the frequency-magnitude distribution of earthquakes in the southwestern Okinawa Trough

    OpenAIRE

    Lin, Jing-yi; Sibuet, Jean-claude; Lee, Chao-Shing; Hsu, Shu-kun; Klingelhoefer, Frauke

    2007-01-01

    The relations between the frequency of occurrence and the magnitude of earthquakes are established in the southern Okinawa Trough for 2823 relocated earthquakes recorded during a passive ocean bottom seismometer experiment. Three high b-values areas are identified: (1) for an area offshore of the Ilan Plain, south of the andesitic Kueishantao Island from a depth of 50 km to the surface, thereby confirming the subduction component of the island andesites; (2) for a body lying along the 123.3 d...

  9. Monitoring of ULF (Ultra-Low-Frequency) Geomagnetic Variations Associated with Earthquakes

    OpenAIRE

    Kenji Ohta; Katsumi Hattori; Masashi Hayakawa

    2007-01-01

    ULF (ultra-low-frequency) electromagnetic emission is recently recognized as one of the most promising candidates for short-term earthquake prediction. This paper reviews previous convincing evidence on the presence of ULF emissions before a few large earthquakes. Then, we present our network of ULF monitoring in the Tokyo area by describing our ULF magnetic sensors and we finally present a few, latest results on seismogenic electromagnetic emissions for recent large earthquakes with the use ...

  10. Investigation of switching frequency variations in self-oscillating class D amplifiers

    DEFF Research Database (Denmark)

    Nielsen, Dennis; Knott, Arnold; Pfaffinger, Gerhard; Andersen, Michael A. E.

    2009-01-01

    Class D audio amplifiers have gained significant influence in sound reproduction due to their high efficiency. One of the most commonly used control methods in class D amplifiers is known as self-oscillation. An parameter of key interest in self-oscillating class D amplifiers is the switching fre...... distortion. The switching frequency is tracked through accurate spectrum measurements, and very good compliance with simulation results are observed....

  11. Atomic Transition Frequencies, Isotope Shifts, and Sensitivity to Variation of the Fine Structure Constant for Studies of Quasar Absorption Spectra

    Science.gov (United States)

    Berengut, J. C.; Dzuba, V. A.; Flambaum, V. V.; King, J. A.; Kozlov, M. G.; Murphy, M. T.; Webb, J. K.

    Theories unifying gravity with other interactions suggest spatial and temporal variation of fundamental "constants" in the Universe. A change in the fine structure constant, α = {e}2/hslash c , could be detected via shifts in the frequencies of atomic transitions in quasar absorption systems. Recent studies using 140 absorption systems from the Keck telescope and 153 from the Very Large Telescope, suggest that α varies spatially (61). That is, in one direction on the sky α seems to have been smaller at the time of absorption, while in the opposite direction it seems to have been larger.

  12. Variations of the Magnetosphere Resonance Frequencies During Magnetic Storm of July 15——16, 2000

    Institute of Scientific and Technical Information of China (English)

    A. Potapov; A. Polyakov; T. Polyushkina; H. Zhao

    2005-01-01

    ULF observations at two mid-latitude sites during the large geomagnetic storm of July 15-16,2000 were used to trace variations of resonance frequencies of the field line resonators. A brief description of the geomagnetic disturbance as it was observed on the ground, at the geostationary orbit, and before the Earth's bow shock is given. Then a detailed study of ULF dynamic spectra from Borok and Mondy is performed for8 succesive 6-hour intervals of July 15 and 16. In conclusion some tasks for the future work are listed.

  13. Size-related variation in arm damage frequency in the crown-of-thorns sea star, Acanthaster planci

    Institute of Scientific and Technical Information of China (English)

    Jairo Rivera-Posada; Ciemon F Caballes; Morgan S Pratchett

    2014-01-01

    Objective: To examine variation in the frequency of arm damage in different sizes of Acanthasterplanci (A. planci), assess how this damage is inflicted by fish predators, and infer the potential role of predation in population regulation. Methods:and arm damage frequency and severity was assessed. Frequency of arm damage was compared between sizes. Feeding behavior of fish predators was also observed in the laboratory. Results:This study demonstrates that sublethal predation by triggerfishes on A. planci result inDiameters of A. planci collected from three sites in the Philippines were measured extensive arm damage. Overall, 60% of A. planci sampled across all sites had sublethal injuries. The frequency of individuals with missing or regenerating arms was highest in medium-sized young adults (11-20 cm), which coincides with the phase where A. planci shift from cryptic to exposed daytime feeding. Conclusions: The high incidence of arm damage within intermediate-sized sea stars indicates that predators exercise some level of regulation on A. planci populations at a local scale. Identification and protection of putative predators that target the most vulnerable life history stages of A. planci are essential in developing population control strategies and reverse sustained declines in coral cover.

  14. Relating plate tectonics, mantle convection and variations in paleomagnetic reversal frequency

    Science.gov (United States)

    Choblet, Gael; Amit, Hagay; Husson, Laurent

    2014-05-01

    Mantle control through time-dependent CMB heat flux pattern and magnitude is a possible external cause to variable reversal frequency of the geodynamo. Necessary CMB heat flux characteristics for reversals in numerical dynamos include most notably a strong average value and a heat flux larger than average at low latitudes. Since plate tectonics affect mantle convection, and thus CMB heat flux and core dynamics, they constitute a possible influence on reversal frequency . We perform numerical experiments of mantle convection with a prescribed plate velocity history at the surface and analyze the time evolution of CMB heat flux in the light of specific criteria promoting or inhibiting reversals. These are systematically compared to the observed reversal frequency for the Earth. The main parameters we investigate for mantle convection are the rheology and the nature of a possibly denser layer in the lowermost region of the mantle. Our study includes a larger number of mantle convection models than previously considered by the few pioneering studies on the same topic and lead to methodological conclusions concerning which of the CMB heat flux criteria are most pertinent and on the time period during which a comparison with paleomagnetic data is meaningful. Preferred mantle models as well as general considerations on the buffering effect of mantle dynamics between plate tectonics and CMB heat flux will be presented. Combining paleomagnetic observations, models for the time-evolution of plate tectonics, inferences from numerical dynamos and mantle convection simulations, our results may provide an important constraint on the structure and dynamics of Earth's mantle.

  15. Variations in dream recall frequency and dream theme diversity by age and sex

    Directory of Open Access Journals (Sweden)

    Tore eNielsen

    2012-07-01

    Full Text Available We assessed dream recall frequency and dream theme diversity with an internet questionnaire among a cohort of 28,888 male and female participants aged 10 to 79 years in a cross-sectional design. Dream recall frequency increased from adolescence (ages 10-19 to early adulthood (20-29 and then decreased again for the next 20 years. The nature of this decrease differed for males and females. For males, it began earlier (30-39, proceeded more gradually, and reached a nadir earlier (40-49 than it did for females. For females, it began later (40-49, dropped more abruptly, and reached nadir later (50-59. Marked sex differences were observed for age strata 10-19 through 40-49 and year-by-year analyses estimated the window for these differences to be more precisely from 14-44 yrs. Dream theme diversity decreased linearly with age for both sexes up to 50-59 and then dropped even more sharply for 60-79. There was a sex difference favouring males on this measure but only for ages 10-19. Findings replicate, in a single sample, those from several previous studies showing an increase in dream recall frequency from adolescence to early adulthood, a subsequent decrease in dream recall frequency—primarily in early and middle adulthood, and different patterns of age-related decrease in the two sexes. Age-related changes in sleep structure, such as decreasing %REM sleep, parallel the observed dream recall changes but are much smaller and more gradual in nature. Changes in the phase and amplitude of circadian rhythms of REM propensity and generational differences in life experiences may also account for some part of the findings. However, that decreases in dream theme diversity parallel known age-related decreases in episodic and autobiographical memory may signify that the diversity measure indexes an aspect of autobiographical memory that is specific to dream recall.

  16. The temporal and spatial variations of low frequency geomagnetic pulsations at polar cusp and cap latitudes

    Directory of Open Access Journals (Sweden)

    J. Bitterly

    1999-06-01

    Full Text Available Geomagnetic field measurements at two Antarctic stations are compared during two weeks in the local summer (January 1-15, 1992. Low frequency (0.6-6 mHz pulsations are observed at each station near local magnetic noon. The same wave packets appear in some cases also at the other station, although with a significant attenuation, more clearly in the morning sector; the waves show a near noon reversal of the polarization sense from counter-clockwise in the morning to clockwise in the afternoon indicating a westward and an eastward propagation, respectively.

  17. Improving Processes of Mechanized Pulsed Arc Welding of Low-Frequency Range Variation of Mode Parameters

    Science.gov (United States)

    Saraev, Yu N.; Solodskiy, S. A.; Ulyanova, O. V.

    2016-04-01

    A new technology of low-frequency modulation of the arc current in MAG and MIG welding is presented. The technology provides control of thermal and crystallization processes, stabilizes the time of formation and crystallization of the weld pool. Conducting theoretical studies allowed formulating the basic criteria for obtaining strong permanent joints for high-duty structures, providing conditions for more equilibrium structure of the deposited metal and the smaller width of the HAZ. The stabilization of time of the formation and crystallization of the weld pool improves the formation of the weld and increases productivity in welding thin sheet metal.

  18. Seasonal Variation of Frequency of High Current Lightning Discharges Observed by JLDN

    Science.gov (United States)

    Saito, Mikihisa; Ishii, Masaru; Fujii, Fumiyuki; Matsui, Michihiro

    Seasonal variations of number of high current lightning discharges exceeding 100kA observed by JLDN (Japanese Lightning Detection Network) were analyzed. The months with averaged altitudes of -10°C level higher than 5.7km are classified as ordinary summer from the viewpoint of lightning activity. Meanwhile, on the coast of the Sea of Japan, more than 90% of negative high current lightning discharges were -GC (Ground to Cloud) strokes in the months when monthly averaged altitudes of -10°C level are lower than 2.7km. These months are classified as the winter lightning season when upward lightning flashes frequently occur. Months other than winter or summer are classified as spring or autumn. In these seasons, the proportions of positive high current lightning discharges are higher than those of negative discharges like winter. Thus, the charge structure in the thunderclouds of spring and autumn may be similar to that in winter, and high current lightning strokes tend to occur. Since this variation of seasons is different in each area of Japan, relation of seasons, areas, and densities of high current lightning discharges were analyzed.

  19. Calling Dunbar's Numbers

    CERN Document Server

    MacCarron, Pádraig; Dunbar, Robin

    2016-01-01

    The social brain hypothesis predicts that humans have an average of about 150 relationships at any given time. Within this 150, there are layers of friends of an ego, where the number of friends in a layer increases as the emotional closeness decreases. Here we analyse a mobile phone dataset, firstly, to ascertain whether layers of friends can be identified based on call frequency. We then apply different clustering algorithms to break the call frequency of egos into clusters and compare the number of alters in each cluster with the layer size predicted by the social brain hypothesis. In this dataset we find strong evidence for the existence of a layered structure. The clustering yields results that match well with previous studies for the innermost and outermost layers, but for layers in between we observe large variability.

  20. Atomic transition frequencies, isotope shifts, and sensitivity to variation of the fine structure constant for studies of quasar absorption spectra

    CERN Document Server

    Berengut, J C; Flambaum, V V; King, J A; Kozlov, M G; Murphy, M T; Webb, J K

    2010-01-01

    Theories unifying gravity with other interactions suggest spatial and temporal variation of fundamental "constants" in the Universe. A change in the fine structure constant, alpha, could be detected via shifts in the frequencies of atomic transitions in quasar absorption systems. Recent studies using 140 absorption systems from the Keck telescope and 153 from the Very Large Telescope, suggest that alpha varies spatially. That is, in one direction on the sky alpha seems to have been smaller at the time of absorption, while in the opposite direction it seems to have been larger. To continue this study we need accurate laboratory measurements of atomic transition frequencies. The aim of this paper is to provide a compilation of transitions of importance to the search for alpha variation. They are E1 transitions to the ground state in several different atoms and ions, with wavelengths ranging from around 900 - 6000 A, and require an accuracy of better than 10^{-4} A. We discuss isotope shift measurements that are...

  1. Assessment of high (diurnal to low (seasonal frequency variations of isoprene emission rates using a neural network approach

    Directory of Open Access Journals (Sweden)

    C. Boissard

    2008-04-01

    Full Text Available Using a statistical approach based on artificial neural networks, an emission algorithm (ISO-LF accounting for high to low frequency variations was developed for isoprene emission rates. ISO-LF was optimised using a data base (ISO-DB specifically designed for this work, which consists of 1321 emission rates collected in the literature and 34 environmental variables, measured or assessed using National Climatic Data Center or National Centers for Environmental Predictions meteorological databases. ISO-DB covers a large variety of emitters (25 species and environmental conditions (10° S to 60° N. When only instantaneous environmental regressors (instantaneous air temperature T0 and photosynthetic photon flux density L0 were used, a maximum of 60% of the overall isoprene variability was assessed with the highest emissions being strongly underestimated. ISO-LF includes a total of 9 high (instantaneous to low (up to 3 weeks frequency regressors and accounts for up to 91% of the isoprene emission variability, whatever the emission range, species or climate investigated. ISO-LF was found to be mainly sensitive to air temperature cumulated over 3 weeks (T21 and to L0 and T0 variations. T21, T0 and L0 only accounts for 76% of the overall variability.

  2. Can the Tibetan Plateau snow cover influence the interannual variations of Eurasian heat wave frequency?

    Science.gov (United States)

    Wu, Zhiwei; Zhang, Peng; Chen, Hua; Li, Yun

    2016-06-01

    The Eurasian continent has experienced significant year-to-year variations of summer heat waves during the past decades. Several possible factors, such as ocean temperature, soil moisture, and changes in land use and greenhouse gases, have been identified in previous studies, but the mechanisms are still unclear. In this study, it is found that the Tibetan Plateau snow cover (TPSC) is closely linked to the interannual variations of summer heat waves over Eurasia. The TPSC variability explains more than 30 % of the total variances of heat wave variability in the southern Europe and northeastern Asia (SENA) region. A set of numerical experiments reveal that the reduced TPSC may induce a distinct teleconnection pattern across the Eurasian continent, with two anomalous high pressure centers in the upper troposphere over the SENA region, which may lead to a reduction of the cloud formation near the surface. The less cloud cover tends to increase the net shortwave radiation and favor a stronger surface sensible heat flux in the dry surface condition over the SENA region, resulting in a deeper, warmer and drier atmospheric boundary layer that would further inhibit the local cloud formation. Such a positive land-atmosphere feedback may dry the surface even further, heat the near-surface atmosphere and thereby intensify the local heat waves. The above dynamical processes also operate on interdecadal time scales. Given the reduction of the TPSC could become more pronounced with increasing levels of greenhouse gases in a warming climate, we infer that the TPSC may play an increasingly important role in shaping the summer heat waves over the SENA region in next decades.

  3. Solar radial velocity variations and the search for Venus enabled by a laser frequency comb

    Science.gov (United States)

    Phillips, David F.; Dumusque, Xavier; Li, Chih-Hao; Glenday, Alexander; Sasselov, Dimitar; Szentgyorgyi, Andrew; Walsworth, Ronald L.

    2016-05-01

    We have recently demonstrated 50 cm/s sensitivity in measuring the radial velocity (RV) between the Earth and Sun using a simple, compact solar telescope feeding the HARPS-N spectrograph at the Italian National Telescope calibrated with our green astro-comb. The green astro-comb is a laser frequency comb optimized for calibrating astrophysical spectrographs. We have been operating the solar telescope to detect the RV signal of the Sun as a star for the past year both to study RV jitter associated with stellar (solar) fluctuations and to demonstrate sensitivity of these instruments to detect terrestrial exoplanets. In this talk I will present results from calibrating the HARPS-N exoplanet searcher spectrograph, solar RV stability, and the current status of our search for the signature of Venus.

  4. Characteristics Of Short-Term Variation Of The Jovian Synchrotron Radiation At A Frequency Of 327MHz

    Science.gov (United States)

    Nomura, S.; Misawa, H.; Tsuchiya, F.; Morioka, A.

    2006-12-01

    The Jovian synchrotron radiation (JSR) is a radio wave emitted from the relativistic electrons in the Jovian radiation belt, which have information of dynamics of high-energy particles and electromagnetic disturbances in the Jovian inner magnetosphere. The intensity variation of JSR, however, has been little understood in its timescales and origin. We have observed JSR for several months a year since 1994 to reveal characteristics of the flux variations especially at the time scales of days to months (short-term) and years (long-term). The regular observations have been made at a frequency of 327MHz by using parabolic cylinder antennas of the Solar Terrestrial Environment Laboratory, Nagoya University, Japan. The observed JSR flux includes apparent variation due to inevitable system gain variation of the radio receiving system. In order to compensate the system gain variation, we have evaluated system gain using a calibration star that was observed quasi-simultaneously with JSR, and made observations of 'actual' galactic back-ground (BG) radiation with the highly stable radio receiving system of Tohoku University. We have also derived the JSR flux densities to improve reliability of the JSR flux densities by revaluation of BG radiation using an other technique to estimate BG: we have observed calibration star which was actually used in the past JSR observations and BG radiation at a time by the electrically beam-switching method, which is just the same observation method as the actual observations for the calibration star and Jupiter. We confirmed JSR fluxes varies by more than 100% during only several days on the solar minimum phase (1995-1996). Though Miyoshi et al., (1999) indicated from the JSR observation at 2.3GHz that a short JSR flux variation is related to intensification of solar UV/EUV as a causality, this result suggests that the occurrence of rapidly enhanced radial diffusion induced by UV/EUV heating in Jupiter's upper atmosphere is not the only

  5. Variation in Holocene El Niño frequencies: Climate records and cultural consequences in ancient Peru

    Science.gov (United States)

    Sandweiss, Daniel H.; Maasch, Kirk A.; Burger, Richard L.; Richardson, James B., III; Rollins, Harold B.; Clement, Amy

    2001-07-01

    Analysis of mollusks from archaeological sites on the north and central coasts of Peru indicates that between ca. 5800 and 3200 2800 cal yr B.P., El Niño events were less frequent than today, with modern, rapid recurrence intervals achieved only after that time. For several millennia prior to 5.8 ka, El Niño events had been absent or very different from today. The phenomena called El Niño have had severe consequences for the modern and colonial (historically recorded) inhabitants of Peru, and El Niño events also influenced prehistoric cultural development: the onset of El Niño events at 5.8 ka correlates temporally with the beginning of monumental temple construction on the Peruvian coast, and the increase in El Niño frequency after 3.2 2.8 ka correlates with the abandonment of monumental temples in the same region.

  6. Telomere length affects the frequency and mechanism of antigenic variation in Trypanosoma brucei.

    Directory of Open Access Journals (Sweden)

    Galadriel A Hovel-Miner

    Full Text Available Trypanosoma brucei is a master of antigenic variation and immune response evasion. Utilizing a genomic repertoire of more than 1000 Variant Surface Glycoprotein-encoding genes (VSGs, T. brucei can change its protein coat by "switching" from the expression of one VSG to another. Each active VSG is monoallelically expressed from only one of approximately 15 subtelomeric sites. Switching VSG expression occurs by three predominant mechanisms, arguably the most significant of which is the non-reciprocal exchange of VSG containing DNA by duplicative gene conversion (GC. How T. brucei orchestrates its complex switching mechanisms remains to be elucidated. Recent work has demonstrated that an exogenous DNA break in the active site could initiate a GC based switch, yet the source of the switch-initiating DNA lesion under natural conditions is still unknown. Here we investigated the hypothesis that telomere length directly affects VSG switching. We demonstrate that telomerase deficient strains with short telomeres switch more frequently than genetically identical strains with long telomeres and that, when the telomere is short, switching preferentially occurs by GC. Our data supports the hypothesis that a short telomere at the active VSG expression site results in an increase in subtelomeric DNA breaks, which can initiate GC based switching. In addition to their significance for T. brucei and telomere biology, the findings presented here have implications for the many diverse pathogens that organize their antigenic genes in subtelomeric regions.

  7. Seasonal and longitudinal variations in the occurrence frequency of magnetospheric ionization ducts

    International Nuclear Information System (INIS)

    Seasonal effects in the occurrence frequency of conjugate echoes on top side sounder ionograms recorded at nine telemetry stations, located at various longitudes, are studied by using Alouette 2, Isis 1, and Isis 2 satellite data. The combined data from all telemetry stations (2.8 x 105 ionograms) show minimums in the percentage of ionograms containing conjugate echoes at the equinoxes (2 percent) and maximums in the percentage of ionograms containing conjugate echoes at the solstices (about 7 percent). However, data recorded at a single telemetry station may show a maximum at only one of the solstices depending upon the longitude of the station. A geometric model based on these results and on the observation that conjugate echoes are observed mainly during the nighttime hours is presented. According to this model, the conjugate ducts tend to be created when the angle between the geomagnetic axis and the normal to the plane of the ecliptic is maximum, that is, when the conjugate points of magnetic field lines are most asymmetric with respect to the sun-earth line. Magnetospheric currents flowing from one hemisphere to the other along geomagnetic field lines are suggested as the cause of the field-aligned ionization irregularities which produce the observed conjugate echoes on top side sounder ionograms. (U.S.)

  8. The Variation of Photon Speed with Photon Frequency in Quantum Gravity

    CERN Document Server

    Dubey, Anuj Kumar; Nath, Sonarekha

    2016-01-01

    Einstein's special relativity is Lorentz invariance; the postulate that all observers measure exactly the same speed of light in vacuum, independent of photon frequency. There is a fundamental scale the Planck scale, at which quantum effects are expected to strongly affect the nature of space-time. The commonly used ideas of space-time should break down at or before the Planck length is reached. It is then natural to question the exactness of the Lorentz invariance that is pervasive in all macroscopic theories. Quantum gravity effect could be seen from the dispersion relations violating Lorentz invariance, because the motivation for the Lorentz invariance violation is quantum gravity. Then it is expected that the energy-momentum dispersion relation could be modified to include the dependence on the ratio of the particle's energy and the quantum gravity energy. In the present work, we have derived an expression of Planck mass or Planck energy by equating the Compton wavelength with Kerr gravitational radius of...

  9. Spatial variations in the frequency-magnitude distribution of earthquakes in the southwestern Okinawa Trough

    Science.gov (United States)

    Lin, J.-Y.; Sibuet, J.-C.; Lee, C.-S.; Hsu, S.-K.; Klingelhoefer, F.

    2007-04-01

    The relations between the frequency of occurrence and the magnitude of earthquakes are established in the southern Okinawa Trough for 2823 relocated earthquakes recorded during a passive ocean bottom seismometer experiment. Three high b-values areas are identified: (1) for an area offshore of the Ilan Plain, south of the andesitic Kueishantao Island from a depth of 50 km to the surface, thereby confirming the subduction component of the island andesites; (2) for a body lying along the 123.3°E meridian at depths ranging from 0 to 50 km that may reflect the high temperature inflow rising up from a slab tear; (3) for a third cylindrical body about 15 km in diameter beneath the Cross Backarc Volcanic Trail, at depths ranging from 0 to 15 km. This anomaly might be related to the presence of a magma chamber at the base of the crust already evidenced by tomographic and geochemical results. The high b-values are generally linked to magmatic and geothermal activities, although most of the seismicity is linked to normal faulting processes in the southern Okinawa Trough.

  10. Temporal Variations of Power Frequency Magnetic Fields in Residential Buildings with Indoor Transformer Stations

    International Nuclear Information System (INIS)

    Beginning with the 1979 work by Wertheimer and Leeper, many epidemiological studies on the association between extremely low frequency (ELF) magnetic fields (MF) exposure and childhood leukemia have been performed. Two pooled analyses pointed to a consistent increase in the risk of developing childhood leukemia in children exposed to residential MF levels above 0.3-0.4 ìT. However, this might be attributed to selection bias. The international epidemiologic study TransExpo, which utilizes the MFs in apartments located above internal transformer stations (ITS), is intended to minimize the potential for selection bias. The MFs in such apartments were reported to be significantly higher than in other apartments in the same building. In the TransExpo study the exposure assessment will be based on the relative location of the apartments to the transformer rooms in the same building. Due to rarity of both the disease and the exposure of interest, TransExpo is planned as an international study involving several countries, so as to achieve a sufficient sample size for a meaningful study. Pilot studies, aiming to clarify the relation between MF levels and apartment location relative to the ITS, have been performed in Finland, Hungary, Israel, and Switzerland. These studies have shown that a simple classification of exposure into 'high'/'low' MFs, based on whether an apartment is located above an ITS is feasible with remarkable sensitivity and specificity. Here, the results of 24h continuous MF monitoring in some apartments are reported and analyzed

  11. Call Forecasting for Inbound Call Center

    OpenAIRE

    Peter Vinje

    2009-01-01

    In a scenario of inbound call center customer service, the ability to forecast calls is a key element and advantage. By forecasting the correct number of calls a company can predict staffing needs, meet service level requirements, improve customer satisfaction, and benefit from many other optimizations. This project will show how elementary statistics can be used to predict calls for a specific company, forecast the rate at which calls are increasing/decreasing, and determine if the calls may...

  12. THE RELATIONSHIP BETWEEN GLOBAL WARMING AND THE VARIATION IN TROPICAL CYCLONE FREQUENCY OVER THE WESTERN NORTH PACIFIC

    Institute of Scientific and Technical Information of China (English)

    MA Li-ping; CHEN Lian-shou

    2009-01-01

    The relationship between global warming and the variation in tropical cyclone (TC) genesis frequency is analyzed using the data of the Tropical Cyclone Year Book by the China Meteorological Administration and the National Centers for Environmental Prediction (NCEP) reanalysis data from 1949 to 2007. The observational results indicate that the average sea surface temperature (SST) in the Intertropieal Convergence Zone (ITCZ) region (10°N - 20°N,100°E - 140°E) increases by 0.6°C against thc background of global warming,while the frequency of tropical cyclone geneses in this region decreases significantly. Generally,the rise of SSTs is favorable tbr the genesis of tropical cyclones,but it is now shown to be contrary to the normal cffect. Most of the tropical cyclones in the western North Pacific (WNP) are generated in the ITCZ. This is quite different from the case in the Atlantic basin in which the tropical cyclones are mostly generated from thc easterly wave. Our research results demonstrate that the ITCZ has a weakening trend in strength,and it has moved much more equatorward in the past 40 years; both are disadvantageous to the fbrmation of tropical cyclones. Furthermore,our study also found that the ridge of the subtropical high tends to shift slightly equatorward,which is another adverse mechanism for the formation of tropical cyclones.

  13. THE CHARACTERISTICS OF THUNDERSTORM FREQUENCY VARIATION AND THEIR POSSIBLE RELATION WITH THE ADJUSTMENT OF CROP DISTRIBUTION IN THE LEIZHOU PENINSULA

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yu; NIU Sheng-jie

    2009-01-01

    In order to research possible influences of the adjustment of plant distribution on the development frequency of thunderstorms over the Leizhou Peninsula,mathematic statistic methods, including correlation analyses,11 kinds of fitting models and all-variable regression methods,were used for analyses and research. The results show that the average trend of the number of annual thunderstorm days is descending obviously,and there are thunderstorms in all seasons,in which warm post-midday thunderstorms have taken up the most part,and high frequency is found from May to September,and the starting and ending dates of thunderstorms have a great annual discrepancy. The vegetation structure has been improved along with the reduction of rice fields and the area increment of sugarcane and fruits planting,which results in the decrease of the number of thunderstorm days; the change in the characteristics of winter spare fields,which is caused by the planting of vegetables,limits the formation of thunderstorms in early winter and late spring. Meanwhile,the area adjustment of peanut planting has little influence on the variation of thunderstorm days. The adjustment of principal crop distribution,such as rice, sugarcane,fruits and vegetables,may have obvious influence on the formation of thunderstorms,and sugarcane has the largest effect,followed in turn by rice,vegetables and fruits,and the adjustment of crop distribution has little influence on the starting and ending dates of thunderstorms.

  14. Call Center ist nicht gleich Call Center

    OpenAIRE

    Baumgartner, Marc; Udris, Ivars

    2005-01-01

    Untersuchungen in 14 Schweizer Call Centers erbrachten vier Call Center-Typen, die sich hinsichtlich Arbeitstätigkeiten und Kommunikationsrichtung voneinander unterscheiden: (a) Beratungs- und Beschwerdemanagement, (b) Informationsmanagement, (c) Auftragsmanagement und (d) Kunden- und Kampagnenmanagement. Dies hat auch Auswirkungen auf die Personalstruktur, -selektion und -entwicklung der Call Center. Es wird der Frage nachgegangen, welche Kompetenzanforderungen in den unterschiedlichen Call ...

  15. Association of monthly frequencies of diverse diseases in the calls to the public emergency service of the city of Buenos Aires during 1999-2004 with meteorological variables and seasons

    Science.gov (United States)

    Alexander, P.

    2013-01-01

    This work aims to study associations between monthly averages of meteorological variables and monthly frequencies of diverse diseases in the calls to the public ambulance emergency service of the city of Buenos Aires during the years 1999-2004. Throughout this time period no changes were made in the classification codes of the illnesses. Heart disease, arrhythmia, heart failure, cardiopulmonary arrest, angina pectoris, psychiatric diseases, stroke, transient ischemic attack, syncope and the total number of calls were analyzed against 11 weather variables and the four seasons. All illnesses exhibited some seasonal behavior, except cardiorespiratory arrest and angina pectoris. The largest frequencies of illnesses that exhibited some association with the meteorological variables used to occur in winter, except the psychiatric cases. Heart failure, stroke, psychiatric diseases and the total number of calls showed significant correlations with the 11 meteorological variables considered, and the largest indices (absolute values above 0.6) were found for the former two pathologies. On the other side, cardiorespiratory arrest and angina pectoris revealed no significant correlations and nearly null indices. Variables associated with temperature were the meteorological proxies with the largest correlations against diseases. Pressure and humidity mostly exhibited positive correlations, which is the opposite of variables related to temperature. Contrary to all other diseases, psychiatric pathologies showed a clear predominance of positive correlations. Finally, the association degree of the medical dataset with recurrent patterns was further evaluated through Fourier analysis, to assess the presence of statistically significant behavior. In the Northern Hemisphere high morbidity and mortality rates in December are usually assigned to diverse factors in relation to the holidays, but such an effect is not observed in the present analysis. There seems to be no clearly preferred

  16. Periodic Variations in the O-C Diagrams of Five Pulsation Frequencies of the DB White Dwarf EC 20058-5234

    CERN Document Server

    Dalessio, James; Provencal, Judi; Shipman, Harry; Sullivan, Tiri; Kilkenny, Dave; Fraga, Luciano; Sefako, Ramotholo; 10.1088/0004-637X/765/1/5

    2013-01-01

    Variations in the pulsation arrival time of five independent pulsation frequencies of the DB white dwarf EC 20058-5234 individually imitate the effects of reflex motion induced by a planet or companion but are inconsistent when considered in unison. The pulsation frequencies vary periodically in a 12.9 year cycle and undergo secular changes that are inconsistent with simple neutrino plus photon-cooling models. The magnitude of the periodic and secular variations increases with the period of the pulsations, possibly hinting that the corresponding physical mechanism is located near the surface of the star. The phase of the periodic variations appears coupled to the sign of the secular variations. The standards for pulsation-timing-based detection of planetary companions around pulsating white dwarfs, and possibly other variables such as subdwarf B stars, should be re-evaluated. The physical mechanism responsible for this surprising result may involve a redistribution of angular momentum or a magnetic cycle. Add...

  17. Call Forecasting for Inbound Call Center

    Directory of Open Access Journals (Sweden)

    Peter Vinje

    2009-01-01

    Full Text Available In a scenario of inbound call center customer service, the ability to forecast calls is a key element and advantage. By forecasting the correct number of calls a company can predict staffing needs, meet service level requirements, improve customer satisfaction, and benefit from many other optimizations. This project will show how elementary statistics can be used to predict calls for a specific company, forecast the rate at which calls are increasing/decreasing, and determine if the calls may stop at some point.

  18. Malware Detection Through Call Graphs

    OpenAIRE

    Kinable, Joris

    2010-01-01

    Each day, anti-virus companies receive large quantities of potentially harmful executables. Many of the malicious samples among these executables are variations of earlier encountered malware, created by their authors to evade pattern-based detection. Consequently, robust detection approaches are required, capable of recognizing similar samples automatically.In this thesis, malware detection through call graphs is studied. In a call graph, the functions of a binary executable are represented ...

  19. The variations of ionosphere critical frequency of E layer over the equatorial geomagnetic region in Southeast Asia

    Science.gov (United States)

    Kenpankho, Prasert; Ishii, Mamoru; Supnithi, Pornchai

    2016-07-01

    We investigate the values of the critical frequency of the ionospheric E layer, foE, obtained at Chumphon ionospheric observatory station, Thailand. For a declining phase of the solar cycle 23 during the year 2005-2008 and an inclining phase of the solar cycle 24 during the year 2009-2013, the foE data have been used to investigate the foE variations over the equatorial geomagnetic region in Southeast Asia. A comparison between the observation data and International Reference Ionosphere (IRI) 2012 model has also been investigated and studied. The results show that the foE obtained from IRI 2012 model underestimates foE from Chumphon station especially during the period of 7-11 am and after 6 pm for each day and all seasons. As the results combining with the previous investigations, we suggest that the underestimation of ionospheric foE by IRI 2012 model is helpful for the correction and improvement of IRI model in an equatorial Asia region.

  20. Threatened peripheral populations in context: geographical variation in population frequency and size and sexual reproduction in a clonal woody shrub.

    Science.gov (United States)

    Yakimowski, Sarah B; Eckert, Christopher G

    2007-06-01

    Geographically peripheral populations of widespread species are often the focus of conservation because they are locally rare within political jurisdictions. Yet the ecology and genetics of these populations are rarely evaluated in a broader geographic context. Most expectations concerning the ecology and evolution of peripheral populations derive from the abundant-center model, which predicts that peripheral populations should be less frequent, smaller, less dense, and have a lower reproductive rate than central populations. We tested these predictions and in doing so evaluated the conservation value of peripheral populations for the clonal shrub Vaccinium stamineum L. (Ericaceae, deerberry), which is listed as threatened in Canada. Based on 51 populations sampled from the center to the northern range limits over 2 years, population frequency and size declined toward the range limit, but ramet density increased. Sexual reproductive output varied widely among populations and between years, with many populations producing very few seeds, but did not decline toward range margins. In fact seed mass increased steadily toward range limit, and this was associated with faster germination and seedling growth, which may be adaptive in seasonal northern environments. Our results did not support the prediction that clonal reproduction is more prevalent in peripheral populations or that it contributed antagonistically to the wide variation in seed production. Peripheral populations of V. stamineum are as productive as central populations and may be locally adapted to northern environments. This emphasizes the importance of a broad geographical perspective for evaluating the ecology, evolution, and conservation of peripheral populations. PMID:17531058

  1. Possible association of the western Tibetan Plateau snow cover with the decadal to interdecadal variations of northern China heatwave frequency

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Zhiwei [Nanjing University of Information Science and Technology, Key Laboratory of Meteorological Disaster of Ministry of Education, Nanjing (China); Chinese Academy of Sciences, State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics, Institute of Atmospheric Physics, Beijing (China); Jiang, Zhihong; Zhong, Shanshan; Wang, Lijuan [Nanjing University of Information Science and Technology, Key Laboratory of Meteorological Disaster of Ministry of Education, Nanjing (China); Li, Jianping [Chinese Academy of Sciences, State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics, Institute of Atmospheric Physics, Beijing (China)

    2012-11-15

    Northern China has been subject to increased heatwave frequency (HWF) in recent decades, which deteriorates the local droughts and desertification. More than half a billion people face drinking water shortages and worsening ecological environment. In this study, the variability in the western Tibetan Plateau snow cover (TPSC) is observed to have an intimate linkage with the first empirical orthogonal function mode of the summer HWF across China. This distinct leading mode is dominated by the decadal to inter-decadal variability and features a mono-sign pattern with the extreme value center prevailing over northern China and high pressure anomalies at mid- and upper troposphere over Mongolia and the adjacent regions. A simplified general circulation model is utilized to examine the possible physical mechanism. A reduced TPSC anomaly can induce a positive geopotential height anomaly at the mid- and upper troposphere and subsequently enhance the climatological high pressure ridge over Mongolia and the adjacent regions. The subsidence associated with the high pressure anomalies tends to suppress the local cloud formation, which increases the net radiation budget, heats the surface, and favors more heatwaves. On the other hand, the surface heating can excite high pressure anomalies at mid- and upper troposphere. The latter further strengthens the upper troposphere high pressure anomalies over Mongolia and the adjacent regions. Through such positive feedback effect, the TPSC is tied to the interdecadal variations of the northern China HWF. (orig.)

  2. Learning to be different: Acquired skills, social learning, frequency dependence, and environmental variation can cause behaviourally mediated foraging specializations

    Science.gov (United States)

    Tinker, M.T.; Mangel, M.; Estes, J.A.

    2009-01-01

    ) Offspring can learn foraging skills from their mothers (matrilineal social learning). (6) Food abundance is limited, such that average individual energy reserves are low Additionally, the following factors increase the likelihood of alternative specializations co-occurring in a predator population: (1) The predator exerts effective top-down control of prey abundance, resulting in frequency-dependent dynamics. (2) There is stochastic Variation in prey population dynamics, but this Variation is neither too extreme in magnitude nor too 'slow' with respect to the time required for an individual forager to learn new foraging skills. For a given predator population, we deduce that the degree of specialization will be highest for those prey types requiring complex capture or handling skills, while prey species that are both profitable and easy to capture and handle will be included in the diet of all individuals. Frequency-dependent benefits of selecting alternative prey types, combined with the ability of foragers to improve their foraging skills by learning, and transmit learned skills to offspring, can result in behaviourally mediated foraging specialization, and also lead to the co-existence of alternative specializations. The extent of such specialization is predicted to be a variable trait, increasing in locations or years when intra-specific competition is high relative to inter-specific competition. ?? 2009 M. Tim Tinker.

  3. Variation of Seismic Frequency in the Yunnan Region After the Indonesia Earthquake With Ms 8.7

    Institute of Scientific and Technical Information of China (English)

    Guo Tieshuan; Liu Jie; Zheng Dalin; Peng Keyin

    2007-01-01

    The seismic frequency increased significantly in the Yunnan region after the Indonesia earthquake with MS 8.7 on December 26,2004.This was estimated by analyzing the seismic frequency ratio between the influenced and normal times, the spatial distribution characteristics of the increased seismic frequency, the temporal-spatial distribution and types of seismic swarms.Seismic frequency increased at 71.3% of the statistical sites in the Yunnan area.The maximal increase ratio is 18.2.

  4. 瓦块固有频率对可倾瓦轴承频变刚度的影响%Effect of Pad Natural Frequency on Frequency-variation Stiffness of Tilting Pad Bearings

    Institute of Scientific and Technical Information of China (English)

    洪红伦; 许吉敏; 陈润霖; 张帆; 吴立明; 袁小阳

    2016-01-01

    为研究轻载工况下可倾瓦块固有频率和振动频率对轴承刚度的影响,基于长轴承理论建立求解可倾瓦推力轴承瓦块固有频率和频变刚度的润滑和动力学耦合模型,推导润滑模型的解析解和频变动力学特性的表达式,并通过实例计算分析载荷、支点系数(瓦进油边到支点的距离与瓦长的比值)、瓦块转动惯量等结构参数对瓦块固有频率和频变刚度的影响。结果表明:瓦块的惯性、油膜的刚度和阻尼共同决定瓦块振动的固有频率,瓦块在固有频率附近振动可以使轴承的频变刚度出现负值,甚至正负无穷大;小载荷的瓦(如非承载瓦)容易出现瓦块振动频率接近其固有频率的状况,使瓦发生共振;可倾瓦轴承设计中有必要考虑瓦块的固有频率和频变刚度来设计非承载瓦的支点系数和转动惯量,使瓦块的振动频率跨过固有频率而产生大的刚度。%In order to research the effect of natural frequency and vibration frequency of pad on stiffness of tilting⁃pad bearing,lubrication and dynamic coupling model based on long bearing theory was established to solve natural frequency and frequency⁃variation stiffness of pad in tilting pad thrust bearing.Analytical solution of this lubrication model and formulae of frequency⁃variation dynamic characteristics were deduced,and the influence of load,pivot coefficient ( Ratio of the distance between oil inlet and pivot to the pad length) ,rotational inertia and other structural parameters on natural frequency and fre⁃quency⁃variation stiffness were analyzed through example calculation.The results show that vibration natural frequency of tilt⁃ing pad is codetermined by inertia,stiffness and damping of oil film.When the vibration frequency of pad is close to its natu⁃ral frequency,frequency⁃variation stiffness of bearing presents negative value even with positive and negative infinite.The sit

  5. Photographic Records Showing the Variations of the Virtual Height of Reflection as a Function of the Radio Frequency

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The standard (analog) ionosonde produces photographic records known as ionograms, which show the variations of the virtual height of reflection as a function of the...

  6. [Bioacoustic of the advertisement call of Ceratophrys cranwelli (Anura: Ceratophryidae)].

    Science.gov (United States)

    Valetti, Julián Alonso; Salas, Nancy Edith; Martino, Adolfo Ludovico

    2013-03-01

    The advertisement call plays an important role in the life history of anuran amphibians, mainly during the breeding season. Call features represent an important character to discriminate species, and sound emissions are very effective to assure or reinforce genetic incompatibility, especially in the case of sibling species. Since frogs are ectotherms, acoustic properties of their calls will vary with temperature. In this study, we described the advertisement call of C. cranwelli, quantifying the temperature effect on its components. The acoustic emissions were recorded during 2007 using a DAT record Sony TCD-100 with stereo microphone ECM-MS907 Sony and tape TDK DAT-RGX 60. As males emit their calls floating in temporary ponds, water temperatures were registered after recording the advertisement calls with a digital thermometer TES 1300+/-0.1 degreeC. Altogether, 54 calls from 18 males were analyzed. The temporal variables of each advertisement call were measured using oscillograms and sonograms and the analyses of dominant frequency were performed using a spectrogram. Multiple correlation analysis was used to identify the temperature-dependent acoustic variables and the temperature effect on these variables was quantified using linear regression models. The advertisement call of C. cranwelli consists of a single pulse group. Call duration, Pulse duration and Pulse interval decreased with the temperature, whereas the Pulse rate increased with temperature. The temperature-dependent variables were standardized at 25 degreeC according to the linear regression model obtained. The acoustic variables that were correlated with the temperature are the variables which emissions depend on laryngeal muscles and the temperature constraints the contractile properties of muscles. Our results indicated that temperature explains an important fraction of the variability in some acoustic variables (79% in the Pulse rate), and demonstrated the importance of considering the effect of

  7. Call cultures in orang-utans?

    Directory of Open Access Journals (Sweden)

    Serge A Wich

    Full Text Available BACKGROUND: Several studies suggested great ape cultures, arguing that human cumulative culture presumably evolved from such a foundation. These focused on conspicuous behaviours, and showed rich geographic variation, which could not be attributed to known ecological or genetic differences. Although geographic variation within call types (accents has previously been reported for orang-utans and other primate species, we examine geographic variation in the presence/absence of discrete call types (dialects. Because orang-utans have been shown to have geographic variation that is not completely explicable by genetic or ecological factors we hypothesized that this will be similar in the call domain and predict that discrete call type variation between populations will be found. METHODOLOGY/PRINCIPAL FINDINGS: We examined long-term behavioural data from five orang-utan populations and collected fecal samples for genetic analyses. We show that there is geographic variation in the presence of discrete types of calls. In exactly the same behavioural context (nest building and infant retrieval, individuals in different wild populations customarily emit either qualitatively different calls or calls in some but not in others. By comparing patterns in call-type and genetic similarity, we suggest that the observed variation is not likely to be explained by genetic or ecological differences. CONCLUSION/SIGNIFICANCE: These results are consistent with the potential presence of 'call cultures' and suggest that wild orang-utans possess the ability to invent arbitrary calls, which spread through social learning. These findings differ substantially from those that have been reported for primates before. First, the results reported here are on dialect and not on accent. Second, this study presents cases of production learning whereas most primate studies on vocal learning were cases of contextual learning. We conclude with speculating on how these findings might

  8. Web Call Example Application

    OpenAIRE

    Li, Shanbo

    2009-01-01

    Web Call Example Application from Ericsson Developer Connection is an application that hosted at a web server and supplies functionality of VoIP phone calls. Users can access the service from desktop browser, mobile phone browser or Java ME Client. Users can also manage their contact books. Each user can have more than one VoIP service accounts, so they can choose the cheapest on when they make phone call. The Web Call Example Application supports two kinds of VoIP phone call connection: Rela...

  9. Time variation in the low-frequency spectrum of Vela-like pulsar B1800-21

    Science.gov (United States)

    Basu, Rahul; Rożko, Karolina; Lewandowski, Wojciech; Kijak, Jarosław; Dembska, Marta

    2016-05-01

    We report the flux measurement of the Vela-like pulsar B1800-21 at the low radio frequency regime over multiple epochs spanning several years. The spectrum shows a turnover around the GHz frequency range and represents a typical example of gigahertz-peaked spectrum (GPS) pulsar. Our observations revealed that the pulsar spectrum show a significant evolution during the observing period with the low-frequency part of the spectrum becoming steeper, with a higher turnover frequency, for a period of several years before reverting back to the initial shape during the latest measurements. The spectral change over times spanning several years requires dense structures, with free electron densities around 1000-20 000 cm-3 and physical dimensions ˜220 au, in the interstellar medium (ISM) traversing across the pulsar line of sight. We look into the possible sites of such structures in the ISM and likely mechanisms particularly the thermal free-free absorption as possible explanations for the change.

  10. Malware Classification based on Call Graph Clustering

    OpenAIRE

    Kinable, Joris; Kostakis, Orestis

    2010-01-01

    Each day, anti-virus companies receive tens of thousands samples of potentially harmful executables. Many of the malicious samples are variations of previously encountered malware, created by their authors to evade pattern-based detection. Dealing with these large amounts of data requires robust, automatic detection approaches. This paper studies malware classification based on call graph clustering. By representing malware samples as call graphs, it is possible to abstract certain variations...

  11. The Source of Variation in Policies around the World: The Case of Protection of Human Health from Extremely Low Frequency Electromagnetic Fields

    International Nuclear Information System (INIS)

    Scientific evidence supposedly plays a dominant role in environmental and public health regulation. This paper uses the example of Extremely Low Frequency Electromagnetic Fields regulation to test whether this is indeed the case. The paper first shows that there exists a significant variation in health protection policies for Extremely Low Frequencies Extremely Low Frequency Electromagnetic Fields around the world. Some countries adopt the international scientific-based guidelines while other countries choose to apply additional precautionary regulations of varying severity. Electromagnetic Fields policy makers around the world indicate that the Cost Benefit Analysis is one of the parameters considered for their choice among various policy options. A simple Cost Benefit Analysis framework is presented, utilizing scientific evidence on health risks from Extremely Low Frequencies as well as parameter values used in the Cost Benefit Analysis studies from California, Netherlands, Israel, and the United Kingdom to determine the justification of using several mitigation techniques. This Cost Benefit Analysis using data from the different countries leads to a clear conclusion: under all parameter values considered, only the low cost intervention measures, such as re-phasing and compacting lines, are justified. Re-routing lines, except in cases of very close proximity to residences, and under grounding existing lines cannot be justified due to the high costs involved and the small health benefits that are projected. Since the stringent policies cannot be accomplished with the low-cost measures, this suggests that if the Cost Benefit Analysis were indeed the basis for the policies implemented in different countries, one would expect a smaller variation in the worldwide policies observed today. The divergence between the policies that are implemented and those that can be supported by the Cost Benefit Analysis suggests that the Cost Benefit Analysis is either not used to

  12. Low-frequency variations in surface atmospheric humidity, temperature, and precipitation: Inferences from reanalyses and monthly gridded observational data sets

    Science.gov (United States)

    Simmons, A. J.; Willett, K. M.; Jones, P. D.; Thorne, P. W.; Dee, D. P.

    2010-01-01

    Evidence is presented of a reduction in relative humidity over low-latitude and midlatitude land areas over a period of about 10 years leading up to 2008, based on monthly anomalies in surface air temperature and humidity from comprehensive European Centre for Medium-Range Weather Forecasts reanalyses (ERA-40 and ERA-Interim) and from Climatic Research Unit and Hadley Centre analyses of monthly station temperature data (CRUTEM3) and synoptic humidity observations (HadCRUH). The data sets agree well for both temperature and humidity variations for periods and places of overlap, although the average warming over land is larger for the fully sampled ERA data than for the spatially and temporally incomplete CRUTEM3 data. Near-surface specific humidity varies similarly over land and sea, suggesting that the recent reduction in relative humidity over land may be due to limited moisture supply from the oceans, where evaporation has been limited by sea surface temperatures that have not risen in concert with temperatures over land. Continental precipitation from the reanalyses is compared with a new gauge-based Global Precipitation Climatology Centre (GPCC) data set, with the combined gauge and satellite products of the Global Precipitation Climatology Project (GPCP) and the Climate Prediction Center (CPC), Merged Analysis of Precipitation (CMAP), and with CPC's independent gauge analysis of precipitation over land (PREC/L). The reanalyses agree best with the new GPCC and latest GPCP data sets, with ERA-Interim significantly better than ERA-40 at capturing monthly variability. Shifts over time in the differences among the precipitation data sets make it difficult to assess their longer-term variations and any link with longer-term variations in humidity.

  13. Callings and Organizational Behavior

    Science.gov (United States)

    Elangovan, A. R.; Pinder, Craig C.; McLean, Murdith

    2010-01-01

    Current literature on careers, social identity and meaning in work tends to understate the multiplicity, historical significance, and nuances of the concept of calling(s). In this article, we trace the evolution of the concept from its religious roots into secular realms and develop a typology of interpretations using occupation and religious…

  14. Call Center Capacity Planning

    DEFF Research Database (Denmark)

    Nielsen, Thomas Bang

    The main topics of the thesis are theoretical and applied queueing theory within a call center setting. Call centers have in recent years become the main means of communication between customers and companies, and between citizens and public institutions. The extensively computerized infrastructure...

  15. High frequency variations of the main magnetic field: convergence of observations and theory (Petrus Peregrinus Medal Lecture)

    Science.gov (United States)

    Jault, Dominique

    2013-04-01

    Understanding the main magnetic field variations has been hindered by the discrepancy between the periods (from months to years) of the simplest linear wave phenomena and the relatively long time intervals (10 to 100 years) over which magnetic field changes can be confidently monitored. A theoretical description of short-period waves within the Earth's fluid core is at hand. Quasi-geostrophic inertial waves (akin to Rossby waves in the atmosphere) are slightly modified in the presence of magnetic fields and torsional oscillations consist of differential motion between coaxial rigid cylindrical annuli. Torsional oscillations are sensitive to the whole magnetic field that they shear in the course of their propagation. From their modelling, we have thus gained an estimate for the magnetic field strength in the core interior. There is now ongoing work to extend the theoretical framework to longer times. Furthermore, data collected from the Swarm constellation of three satellites to be launched this year by ESA will permit to better separate the internal and external magnetic signals. We may thus dream to detect quasi-geostrophic inertial waves. As the spectral ranges of theoretical models and observations begin to overlap, we can now go beyond the understanding of the magnetic field variations as the juxtaposition of partial models, arranged as a set of nested Matryoshka dolls. This talk will give illustrations for this statement, among which the question of induction in the lower mantle.

  16. Ultrasound call detection in capybara

    Directory of Open Access Journals (Sweden)

    Selene S.C. Nogueira

    2012-07-01

    Full Text Available The vocal repertoire of some animal species has been considered a non-invasive tool to predict distress reactivity. In rats ultrasound emissions were reported as distress indicator. Capybaras[ vocal repertoire was reported recently and seems to have ultrasound calls, but this has not yet been confirmed. Thus, in order to check if a poor state of welfare was linked to ultrasound calls in the capybara vocal repertoire, the aim of this study was to track the presence of ultrasound emissions in 11 animals under three conditions: 1 unrestrained; 2 intermediately restrained, and 3 highly restrained. The ultrasound track identified frequencies in the range of 31.8±3.5 kHz in adults and 33.2±8.5 kHz in juveniles. These ultrasound frequencies occurred only when animals were highly restrained, physically restrained or injured during handling. We concluded that these calls with ultrasound components are related to pain and restraint because they did not occur when animals were free of restraint. Thus we suggest that this vocalization may be used as an additional tool to assess capybaras[ welfare.

  17. Spontaneous micronucleus frequencies in human peripheral blood lymphocytes as a screening test for an individual variation in a different population and radiation-induced micronucleus induction

    International Nuclear Information System (INIS)

    Our studies were to evaluate the role of epigenetic factors in the variation of radiosensitivity on human peripheral blood lymphocytes by measuring the frequencies of micronucleus (MN) from 293 healthy subjects of different population for assessing the radiation health risk in Korea. We analyzed the frequencies of both spontaneous and in vitro 60Co γ-rays or 50MeV neutron-induced MNs. The frequencies of spontaneous NMs not only vary greatly between individuals, but also working or living areas. The increased levels of cells with spontaneous MNs were observed with an increasing age. The frequencies of spontaneous MNs were significantly higher in females than in males. For both sexes, MN frequency was significantly and positively correlated with age. Age and gender are the most important demographic variables impacting on the MN index. Donors who had ever smoked showed significantly increased frequencies of MNs compared to nonsmokers. The main lifestyle factors influencing the MN index in the subjects are correlated significantly and positively with smoke while measuring the spontaneous frequencies of micronuclei. Therefore, it is evident that with regard to the application of MN assay all future studies to evaluate the association between radiosensitivity and susceptibility for radiation health risks in different populations should take into account the effect of age, gender and lifestyle. For the dose-response study, the induced MNs were observed at all doses, and the numerical changes according to doses. The dose-response curves were fitted with a linear-quadratic forms of the dose, and the results were different for γ-rays and neutrons significantly. Neutrons were more effective than γ-rays in producing MN with a dose-dependent manner. The frequency of MN varies with dose. The RBE for a micronuclei was 2.37 ± 0.17. The results suggested that the MN assay have a high potential to ensure appropriate quality control and a standard documentation protocol, which

  18. Using recent high-frequency surveys to reconstitute 35 years of organic carbon variations in a eutrophic lowland river.

    Science.gov (United States)

    Minaudo, C; Moatar, F; Coynel, A; Etcheber, H; Gassama, N; Curie, F

    2016-01-01

    Concentrations of dissolved and particulate organic carbon (DOC and POC), total suspended solids (TSS), were measured daily, and phytoplankton pigments (chlorophyll-a and pheopigments) were measured every 3 days at three strategic stations along the eutrophic Loire River between November 2011 and November 2013 marked by a high annual and seasonal variability in hydrological regimes. This unique high-frequency dataset allowed to determine the POC origin (autochthonous or allochthonous). Some strong relationships were evidenced between POC, total pigments and TSS and were tested on a long-term database with a lower frequency (monthly data) to reconstitute unmeasured algal and detrital POC concentrations and estimate annual total organic carbon (TOC) fluxes from 1980 onwards. The results were subjected to only ≈25 % uncertainty and showed that the annual TOC fluxes at the outlet of the Loire River decreased from 520 10(3) tC year(-1) (i.e. 4.7 t km(-2) year(-1)) in the early 1990s to 150 10(3) tC year(-1) (i.e. 1.4 t km(-2) year(-1)) in 2012. Although DOC always dominates, the autochthonous POC represented 35 % of the TOC load at the basin outlet by the end of the 1980s and declined to finally represent 15 % only of the TOC. The control of phosphorus direct inputs and the invasion by Corbicula clams spp. which both occurred since the early 1990s probably highly reduced the development of phytoplankton. Consequently, the autochthonous POC contribution declined and TSS concentrations in summertime significantly decreased as well as a result of both less phytoplankton and less calcite precipitation. At the present time, at least 75 % of the POC has allochthonous origins in the upper Middle Loire but downstream, autochthonous POC dominates during summer phytoplanktonic blooms when total pigments concentrations reach up to 70 μg L(-1) (equivalent to 75 % of the total POC). PMID:26687084

  19. Reciprocity of mobile phone calls

    CERN Document Server

    Kovanen, Lauri; Kaski, Kimmo

    2010-01-01

    We present a study of the reciprocity of human behaviour based on mobile phone usage records. The underlying question is whether human relationships are mutual, in the sense that both are equally active in keeping up the relationship, or is it on the contrary typical that relationships are lopsided, with one party being significantly more active than the other. We study this question with the help of a mobile phone data set consisting of all mobile phone calls between 5.3 million customers of a single mobile phone operator. It turns out that lopsided relations are indeed quite common, to the extent that the variation cannot be explained by simple random deviations or by variations in personal activity. We also show that there is no non-trivial correlation between reciprocity and local network density.

  20. High frequency of the IVS2-2A>G DNA sequence variation in SLC26A5, encoding the cochlear motor protein prestin, precludes its involvement in hereditary hearing loss

    Directory of Open Access Journals (Sweden)

    Pereira Fred A

    2005-08-01

    Full Text Available Abstract Background Cochlear outer hair cells change their length in response to variations in membrane potential. This capability, called electromotility, is believed to enable the sensitivity and frequency selectivity of the mammalian cochlea. Prestin is a transmembrane protein required for electromotility. Homozygous prestin knockout mice are profoundly hearing impaired. In humans, a single nucleotide change in SLC26A5, encoding prestin, has been reported in association with hearing loss. This DNA sequence variation, IVS2-2A>G, occurs in the exon 3 splice acceptor site and is expected to abolish splicing of exon 3. Methods To further explore the relationship between hearing loss and the IVS2-2A>G transition, and assess allele frequency, genomic DNA from hearing impaired and control subjects was analyzed by DNA sequencing. SLC26A5 genomic DNA sequences from human, chimp, rat, mouse, zebrafish and fruit fly were aligned and compared for evolutionary conservation of the exon 3 splice acceptor site. Alternative splice acceptor sites within intron 2 of human SLC26A5 were sought using a splice site prediction program from the Berkeley Drosophila Genome Project. Results The IVS2-2A>G variant was found in a heterozygous state in 4 of 74 hearing impaired subjects of Hispanic, Caucasian or uncertain ethnicity and 4 of 150 Hispanic or Caucasian controls (p = 0.45. The IVS2-2A>G variant was not found in 106 subjects of Asian or African American descent. No homozygous subjects were identified (n = 330. Sequence alignment of SLC26A5 orthologs demonstrated that the A nucleotide at position IVS2-2 is invariant among several eukaryotic species. Sequence analysis also revealed five potential alternative splice acceptor sites in intron 2 of human SLC26A5. Conclusion These data suggest that the IVS2-2A>G variant may not occur more frequently in hearing impaired subjects than in controls. The identification of five potential alternative splice acceptor sites in

  1. Assessment of periodic sub-diurnal Earth rotation variations at tidal frequencies through transformation of VLBI normal equation systems

    Science.gov (United States)

    Artz, Thomas; Tesmer Née Böckmann, Sarah; Nothnagel, Axel

    2011-09-01

    We present an empirical model for periodic variations of diurnal and sub-diurnal Earth rotation parameters (ERPs) that was derived based on the transformation of normal equation (NEQ) systems of Very Long Baseline Interferometry (VLBI) observing sessions. NEQ systems that contain highly resolved polar motion and UT1-TAI with a temporal resolution of 15 min were generated and then transformed to the coefficients of the tidal ERP model to be solved for. To investigate the quality of this model, comparisons with empirical models from the Global Positioning System (GPS), another VLBI model and the model adopted by the conventions of the International Earth Rotation and Reference Systems Service (IERS) were performed. The absolute coefficients of these models agree almost completely within 7.5 μ as in polar motion and 0.5 μ s in UT1-TAI. Several bigger differences exist, which are discussed in this paper. To be able to compare the model estimates with results of the continuous VLBI campaigns, where signals with periods of 8 and 6 h were detected, terms in the ter- and quarter-diurnal band were included in the tidal ERP model. Unfortunately, almost no common features with the results of continuous VLBI campaigns or ERP predictions in these tidal bands can be seen.

  2. High frequency (hourly) variation in vertical distribution and abundance of meroplanktonic larvae in nearshore waters during strong internal tidal forcing

    Science.gov (United States)

    Liévana MacTavish, A.; Ladah, L. B.; Lavín, M. F.; Filonov, A.; Tapia, Fabian J.; Leichter, J.

    2016-04-01

    We related the vertical distribution and abundance of nearshore meroplankton at hourly time scales with internal tidal wave events. We proposed that significant changes in plankter abundance would occur across internal tidal fronts, and that surface and bottom strata would respond in opposite fashions. First-mode internal tidal bores propagating in the alongshore direction were detected in water-column currents and baroclinic temperature changes. Surface and bottom currents always flowed in opposite directions, and abrupt flow reversals coincided with large temperature changes during arrival of bores. Crab zoeae and barnacle cyprids were more abundant in the bottom strata, whereas barnacle nauplii showed the opposite pattern. Significant changes in vertical distribution and abundance of target meroplankters occurred across internal tidal fronts, especially for crabs at depth, with surface and bottom organisms responding in opposite fashions. Changes in plankter abundance were significantly correlated with current flows in the strata where they were most abundant. The manner in which plankters were affected (increasing or decreasing abundance) appeared to be modulated by their vertical position within the water column. The significant differences found at the high frequencies of this study, maintained across sampling days, suggest that nearshore meroplankton populations may have greater and more consistent temporal and vertical variability than previously considered.

  3. Electrical energy saving in motors and frequency variators; Ahorro de energia electrica en motores y variadores de frecuencia

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Neri, Roger [Comision Federal de Electricidad (CFE) (Mexico)

    2005-07-01

    The necessity of saving energy is urgent and undeniable. We must already begin with the rational use of energy. Which is obtaining the maximum benefit of the consumed energy and of the necessary facilities for its generation, transmission and use. Guaranteeing at the same time an operation free of interferences or interruptions for the users. The electricity in alternating current does not allow its storage, reason why it is necessary to generate and distribute it at the precise moment when it is required. This forces to determine the proportions of the generation facilities, to be able to feed the periods of maximum demand called {sup p}eaks{sup .} It is this very point where the problem of the inappropriate use of the electrical energy starts. The energy waste is self-evident during the periods of low demand because of the low efficiency of the sub-utilized facilities. Electrical motors of the induction type use approximately more than 60% of the energy in the industry. If we use high efficiency motors instead of standard motors, a better advantage of the energy demanded from Comision Federal de Electricidad (CFE) is obtained. [Spanish] Es impostergable e innegable la necesidad de ahorrar energia. Tenemos que empezar ya con el uso racional de la energia: Obtener el maximo beneficio de la energia consumida y de las instalaciones necesarias para su generacion, transmision y utilizacion. Garantizando a los usuarios un funcionamiento sin interferencias o interrupciones. La electricidad en corriente alterna no permite su almacenamiento, por lo que es necesario generarla y distribuirla en el momento preciso en que es requerida. Esto obliga a dimensionar las instalaciones de generacion, para poder alimentar los periodos de maxima demanda llamados pico. Desde esta parte inicia el problema de la mala utilizacion de la energia electrica. Ya que en los periodos de baja demanda, las instalaciones se encuentran subutilizadas y si su eficiencia es muy baja, el desperdicio de

  4. Celiac disease T-cell epitopes from gamma-gliadins: immunoreactivity depends on the genome of origin, transcript frequency, and flanking protein variation

    Directory of Open Access Journals (Sweden)

    Salentijn Elma MJ

    2012-06-01

    Full Text Available Abstract Background Celiac disease (CD is caused by an uncontrolled immune response to gluten, a heterogeneous mixture of wheat storage proteins. The CD-toxicity of these proteins and their derived peptides is depending on the presence of specific T-cell epitopes (9-mer peptides; CD epitopes that mediate the stimulation of HLA-DQ2/8 restricted T-cells. Next to the thoroughly characterized major T-cell epitopes derived from the α-gliadin fraction of gluten, γ-gliadin peptides are also known to stimulate T-cells of celiac disease patients. To pinpoint CD-toxic γ-gliadins in hexaploid bread wheat, we examined the variation of T-cell epitopes involved in CD in γ-gliadin transcripts of developing bread wheat grains. Results A detailed analysis of the genetic variation present in γ-gliadin transcripts of bread wheat (T. aestivum, allo-hexaploid, carrying the A, B and D genome, together with genomic γ-gliadin sequences from ancestrally related diploid wheat species, enabled the assignment of sequence variants to one of the three genomic γ-gliadin loci, Gli-A1, Gli-B1 or Gli-D1. Almost half of the γ-gliadin transcripts of bread wheat (49% was assigned to locus Gli-D1. Transcripts from each locus differed in CD epitope content and composition. The Gli-D1 transcripts contained the highest frequency of canonical CD epitope cores (on average 10.1 per transcript followed by the Gli-A1 transcripts (8.6 and the Gli-B1 transcripts (5.4. The natural variants of the major CD epitope from γ-gliadins, DQ2-γ-I, showed variation in their capacity to induce in vitro proliferation of a DQ2-γ-I specific and HLA-DQ2 restricted T-cell clone. Conclusions Evaluating the CD epitopes derived from γ-gliadins in their natural context of flanking protein variation, genome specificity and transcript frequency is a significant step towards accurate quantification of the CD toxicity of bread wheat. This approach can be used to predict relative levels of CD toxicity of

  5. 'Compromise' in Echolocation Calls between Different Colonies of the Intermediate Leaf-Nosed Bat (Hipposideros larvatus).

    Science.gov (United States)

    Chen, Yi; Liu, Qi; Su, Qianqian; Sun, Yunxiao; Peng, Xingwen; He, Xiangyang; Zhang, Libiao

    2016-01-01

    Each animal population has its own acoustic signature which facilitates identification, communication and reproduction. The sonar signals of bats can convey social information, such as species identity and contextual information. The goal of this study was to determine whether bats adjust their echolocation call structures to mutually recognize and communicate when they encounter the bats from different colonies. We used the intermediate leaf-nosed bats (Hipposideros larvatus) as a case study to investigate the variations of echolocation calls when bats from one colony were introduced singly into the home cage of a new colony or two bats from different colonies were cohabitated together for one month. Our experiments showed that the single bat individual altered its peak frequency of echolocation calls to approach the call of new colony members and two bats from different colonies adjusted their call frequencies toward each other to a similar frequency after being chronically cohabitated. These results indicate that the 'compromise' in echolocation calls might be used to ensure effective mutual communication among bats. PMID:27029005

  6. Transitant per Calle Mayor

    OpenAIRE

    Mestre Pérez, Rosanna

    2000-01-01

    RESUM Aquest treball és una lectura crítica de la pel.lícula Calle Mayor, dirigida per Juan Antonio Bardem en 1956, on pretenem analitzar de quina manera el film construeix un agosarat discurs de crítica social. Malgrat les dures limitacions extradiscursives en què la pel.lícula va veure la llum (censura oficial, empresonament del director durant el rodage...), Calle Mayor va aconseguir tractar allò del que no shi podia parlar (crítica sociopolítica) a través dun argument de...

  7. Too close to call

    DEFF Research Database (Denmark)

    Kurrild-Klitgaard, Peter

    2012-01-01

    The note briefly outlines a new model for the explanation of US presidential elections, founded on (a) recent economic growth and (b) a measure of what may be called “’the cost of ruling”. The former is based in changes in real disposable income for the period following a mid-term election, while...... a number of other frequent explanations and is found to be quite robust. When augmented with approval ratings for incumbent presidents, the explanatory power increases to 83 pct. and only incorrectly calls one of the last 15 US presidential elections. Applied to the 2012 election as a forecasting...

  8. Variations of the critical foE-frequency of the ionosphere connected with earthquakes. Evaluation of observations of the vertical sounding station "Tokyo"

    Science.gov (United States)

    Liperovskaya, Elena V.; Meister, Claudia-Veronika; Hoffmann, Dieter H. H.; Silina, Alexandra S.

    2016-04-01

    In the present work the critical frequencies foE and foF2 of the ionosphere are considered as possible earthquake precursors. The statistical analysis of the critical frequencies is carried out based on the data of the vertical sounding station (VSS) "Kokubunji" ("Tokyo") (ϕ = 35.7o N, λ = 139.5o E, 1957-1988) obtained every hour. Disturbances are considered on the background of seasonal, geomagnetic as well as 11-years and 27-days Solar variations. Special normalized parameters E and F are introduced, which represent the almost seasonal-independent parts of foE and foF2. Days with high Solar (Wolf number > 100) and geomagnetic (ΣKp > 25) activities are excluded from the analysis. For all data (observed every hour) analysed, no correlations of the normalized parameters E and F are found. One day before the seismic shock, a positive correlation is observed. The superimposed epochs method is used to determine the temporal behaviour of E and F. It is found that E and F decrease one day before the earthquakes provided that the seismic shocks occur at distances 600 5.5 is situated at depths smaller than 60 km. The reliability of the effect is larger than 98 %. Possible physical mechanisms of the phenomenon are discussed.

  9. Modeling the variations of reflection coefficient of Earth's lower ionosphere using very low frequency radio wave data by artificial neural network

    Science.gov (United States)

    Ghanbari, Keyvan; Khakian Ghomi, Mehdi; Mohammadi, Mohammad; Marbouti, Marjan; Tan, Le Minh

    2016-08-01

    The ionized atmosphere lying from 50 to 600 km above surface, known as ionosphere, contains high amount of electrons and ions. Very Low Frequency (VLF) radio waves with frequencies between 3 and 30 kHz are reflected from the lower ionosphere specifically D-region. A lot of applications in long range communications and navigation systems have been inspired by this characteristic of ionosphere. There are several factors which affect the ionization rate in this region, such as: time of day (presence of sun in the sky), solar zenith angle (seasons) and solar activities. Due to nonlinear response of ionospheric reflection coefficient to these factors, finding an accurate relation between these parameters and reflection coefficient is an arduous task. In order to model these kinds of nonlinear functionalities, some numerical methods are employed. One of these methods is artificial neural network (ANN). In this paper, the VLF radio wave data of 4 sudden ionospheric disturbance (SID) stations are given to a multi-layer perceptron ANN in order to simulate the variations of reflection coefficient of D region ionosphere. After training, validation and testing the ANN, outputs of ANN and observed values are plotted together for 2 random cases of each station. By evaluating the results using 2 parameters of pearson correlation coefficient and root mean square error, a satisfying agreement was found between ANN outputs and real observed data.

  10. A call for surveys

    DEFF Research Database (Denmark)

    Bernstein, Philip A.; Jensen, Christian S.; Tan, Kian-Lee

    2012-01-01

    The database field is experiencing an increasing need for survey papers. We call on more researchers to set aside time for this important writing activity. The database field is growing in population, scope of topics covered, and the number of papers published. Each year, thousands of new papers ...

  11. CALLING AQUARIUM LOVERS...

    CERN Multimedia

    2002-01-01

    CERN's anemones will soon be orphans. We are looking for someone willing to look after the aquarium in the main building, for one year. If you are interested, or if you would like more information, please call 73830. (The anemones living in the aquarium thank you in anticipation.)

  12. Artificial Intelligence and CALL.

    Science.gov (United States)

    Underwood, John H.

    The potential application of artificial intelligence (AI) to computer-assisted language learning (CALL) is explored. Two areas of AI that hold particular interest to those who deal with language meaning--knowledge representation and expert systems, and natural-language processing--are described and examples of each are presented. AI contribution…

  13. Flight calls and orientation

    DEFF Research Database (Denmark)

    Larsen, Ole Næsbye; Andersen, Bent Bach; Kropp, Wibke;

    2008-01-01

      In a pilot experiment a European Robin, Erithacus rubecula, expressing migratory restlessness with a stable orientation, was video filmed in the dark with an infrared camera and its directional migratory activity was recorded. The flight overhead of migrating conspecifics uttering nocturnal...... flight calls was simulated by sequential computer controlled activation of five loudspeakers placed in a linear array perpendicular to the bird's migration course. The bird responded to this stimulation by changing its migratory course in the direction of that of the ‘flying conspecifics' but after about...... 30 minutes it drifted back to its original migration course. The results suggest that songbirds migrating alone at night can use the flight calls from conspecifics as additional cues for orientation and that they may compare this information with other cues to decide what course to keep....

  14. A Call for Justice

    OpenAIRE

    Marques-Silva, Joao; Brahmachari, Debahuti; Sakallah, Karem; Lynce, Ines

    2015-01-01

    Abstract A new development can be identified within the civil society in Malaysia. A development that has resulted in a general call for justice, voiced through coalition groups that cut across categories of affiliation. This development is triggered by an increasing inculcation of Islamic values into the political system, which has interfered with the understanding of Malaysia as a country that can provide a framework for coexistence within a multicultural society. This thesis seeks ...

  15. Multimodality and CALL

    OpenAIRE

    Guichon, Nicolas; Cohen, Cathy

    2016-01-01

    This chapter explores the issues pertaining to multimodality, which has always been considered as a defining characteristic of CALL (Chapelle 2009). The chapter begins by critically examining the various definitions of multimodality, especially in the field of second language acquisition and cognitive psychology and explores the distinction between mode, modality and channel. With reference to specific studies conducted in the field, we then investigate the potential of multimodality for seco...

  16. The advertisement call of the giant spiny frog Paa spinosa

    OpenAIRE

    Baogen YU, Rongquan ZHENG

    2009-01-01

    We analyzed the advertisement call of Paa spinosa at Yuliang Mountain, Lanxi, Zhejiang province, in eastern China. Temporal and spectral call parameters were analyzed, along with call intensity. Calls comprised of three to seven notes, the last of which had the longest duration. Three formants (harmonics) were clearly distinguishable from the audio spectrogram. The dominant frequency ranged from 411-1534Hz, and was either the first or the second formant. The number of notes within a call was ...

  17. MEDICAL SERVICE - URGENT CALLS

    CERN Multimedia

    Service Médical

    2000-01-01

    IN URGENT NEED OF A DOCTOR GENEVA: EMERGENCY SERVICES GENEVA AND VAUD 144 FIRE BRIGADE 118 POLICE 117 CERN FIREMEN 767-44-44 ANTI-POISONS CENTRE Open 24h/24h 01-251-51-51 Patient not fit to be moved, call family doctor, or: GP AT HOME: Open 24h/24h 748-49-50 AMG- Association Of Geneva Doctors: Emergency Doctors at home 07h-23h 322 20 20 Patient fit to be moved: HOPITAL CANTONAL CENTRAL 24 Micheli-du-Crest 372-33-11 ou 382-33-11 EMERGENCIES 382-33-11 ou 372-33-11 CHILDREN'S HOSPITAL 6 rue Willy-Donzé 372-33-11 MATERNITY 32 bvd.de la Cluse 382-68-16 ou 382-33-11 OPHTHALMOLOGY 22 Alcide Jentzer 382-33-11 ou 372-33-11 MEDICAL CENTRE CORNAVIN 1-3 rue du Jura 345 45 50 HOPITAL DE LA TOUR Meyrin 719-61-11 EMERGENCIES 719-61-11 CHILDREN'S EMERGENCIES 719-61-00 LA TOUR MEDICAL CENTRE 719-74-00 European Emergency Call 112   FRANCE: EMERGENCY SERVICES 15 FIRE BRIGADE 18 POLICE 17 CERN FIREMEN AT HOME 00-41-22-767-44-44 ...

  18. An Island Called Cuba

    Directory of Open Access Journals (Sweden)

    Jean Stubbs

    2011-06-01

    Full Text Available Review of: An Island Called Home: Returning to Jewish Cuba. Ruth Behar, photographs by Humberto Mayol. New Brunswick NJ: Rutgers University Press, 2007. xiii + 297 pp. (Cloth US$ 29.95 Fidel Castro: My Life: A Spoken Autobiography. Fidel Castro & Ignacio Ramonet. New York: Scribner/Simon & Schuster, 2008. vii + 724 pp. (Paper US$ 22.00, e-book US$ 14.99 Cuba: What Everyone Needs to Know. Julia E. Sweig. New York: Oxford University Press, 2009. xiv + 279 pp. (Paper US$ 16.95 [First paragraph] These three ostensibly very different books tell a compelling story of each author’s approach, as much as the subject matter itself. Fidel Castro: My Life: A Spoken Autobiography is based on a series of long interviews granted by the then-president of Cuba, Fidel Castro, to Spanish-Franco journalist Ignacio Ramonet. Cuba: What Everyone Needs to Know, by U.S. political analyst Julia Sweig, is one of a set country series, and, like Ramonet’s, presented in question/answer format. An Island Called Home: Returning to Jewish Cuba, with a narrative by Cuban-American anthropologist Ruth Behar and photographs by Cuban photographer Humberto Mayol, is a retrospective/introspective account of the Jewish presence in Cuba. While from Ramonet and Sweig we learn much about the revolutionary project, Behar and Mayol convey the lived experience of the small Jewish community against that backdrop.

  19. Call for volunteers

    CERN Multimedia

    2008-01-01

    CERN is calling for volunteers from all members of the Laboratory for organizing the two exceptional Open days.CERN is calling for volunteers from all members of the Laboratory’s personnel to help with the organisation of these two exceptional Open Days, for the visits of CERN personnel and their families on the Saturday and above all for the major public Open Day on the Sunday. As for the 50th anniversary in 2004, the success of the Open Days will depend on a large number of volunteers. All those working for CERN as well as retired members of the personnel can contribute to making this event a success. Many guides will be needed at the LHC points, for the activities at the surface and to man the reception and information points. The aim of these major Open Days is to give the local populations the opportunity to discover the fruits of almost 20 years of work carried out at CERN. We are hoping for some 2000 volunteers for the two Open Days, on the Saturday from 9 a.m. to ...

  20. Malware Classification based on Call Graph Clustering

    CERN Document Server

    Kinable, Joris

    2010-01-01

    Each day, anti-virus companies receive tens of thousands samples of potentially harmful executables. Many of the malicious samples are variations of previously encountered malware, created by their authors to evade pattern-based detection. Dealing with these large amounts of data requires robust, automatic detection approaches. This paper studies malware classification based on call graph clustering. By representing malware samples as call graphs, it is possible to abstract certain variations away, and enable the detection of structural similarities between samples. The ability to cluster similar samples together will make more generic detection techniques possible, thereby targeting the commonalities of the samples within a cluster. To compare call graphs mutually, we compute pairwise graph similarity scores via graph matchings which approximately minimize the graph edit distance. Next, to facilitate the discovery of similar malware samples, we employ several clustering algorithms, including k-medoids and DB...

  1. The structure of stereotyped calls reflects kinship and social affiliation in resident killer whales ( Orcinus orca)

    Science.gov (United States)

    Deecke, Volker B.; Barrett-Lennard, Lance G.; Spong, Paul; Ford, John K. B.

    2010-05-01

    A few species of mammals produce group-specific vocalisations that are passed on by learning, but the function of learned vocal variation remains poorly understood. Resident killer whales live in stable matrilineal groups with repertoires of seven to 17 stereotyped call types. Some types are shared among matrilines, but their structure typically shows matriline-specific differences. Our objective was to analyse calls of nine killer whale matrilines in British Columbia to test whether call similarity primarily reflects social or genetic relationships. Recordings were made in 1985-1995 in the presence of focal matrilines that were either alone or with groups with non-overlapping repertoires. We used neural network discrimination performance to measure the similarity of call types produced by different matrilines and determined matriline association rates from 757 encounters with one or more focal matrilines. Relatedness was measured by comparing variation at 11 microsatellite loci for the oldest female in each group. Call similarity was positively correlated with association rates for two of the three call types analysed. Similarity of the N4 call type was also correlated with matriarch relatedness. No relationship between relatedness and association frequency was detected. These results show that call structure reflects relatedness and social affiliation, but not because related groups spend more time together. Instead, call structure appears to play a role in kin recognition and shapes the association behaviour of killer whale groups. Our results therefore support the hypothesis that increasing social complexity plays a role in the evolution of learned vocalisations in some mammalian species.

  2. Stream noise, hybridization, and uncoupled evolution of call traits in two lineages of poison frogs: Oophaga histrionica and Oophaga lehmanni.

    Directory of Open Access Journals (Sweden)

    Fernando Vargas-Salinas

    Full Text Available According to the acoustic adaptation hypothesis, communication signals are evolutionary shaped in a way that minimizes its degradation and maximizes its contrast against the background noise. To compare the importance for call divergence of acoustic adaptation and hybridization, an evolutionary force allegedly promoting phenotypic variation, we compared the mate recognition signal of two species of poison frogs (Oophaga histrionica and O. lehmanni at five localities: two (one per species alongside noisy streams, two away from streams, and one interspecific hybrid. We recorded the calls of 47 males and characterized the microgeographic variation in their spectral and temporal features, measuring ambient noise level, body size, and body temperature as covariates. As predicted, frogs living in noisy habitats uttered high frequency calls and, in one species, were much smaller in size. These results support a previously unconsidered role of noise on streams as a selective force promoting an increase in call frequency and pleiotropic effects in body size. Regarding hybrid frogs, their calls overlapped in the signal space with the calls of one of the parental lineages. Our data support acoustic adaptation following two evolutionary routes but do not support the presumed role of hybridization in promoting phenotypic diversity.

  3. To be called upon

    DEFF Research Database (Denmark)

    Kublitz, Anja

    2015-01-01

    When Danish Muslims explain what made them decide to travel to the Middle East and take up arms in the wake of the Arab Spring, they say that they were called upon. Displayed on videos on social media, women and sometimes children begged them to come to their rescue. In light of some of the...... responses to the Arab spring among Danish Muslims, this paper will offer some preliminary reflections on how we can understand ‘the mass’ and an ‘intimacy of the mass’ when the mass is no longer a crowd. According to Marx the mass grows quantitatively from the local to the global, but what happens to the...... mass if it is no longer a causal phenomenon that expands from small to big, but rather a simultaneous multitude of one to one relations that are neither local nor global? How are the one and the many related in this specific setting? Furthermore, many of the videos display dead bodies. How can we...

  4. Morocco calls for investors

    International Nuclear Information System (INIS)

    Morocco imported more than 96% of its energy between 2002 and 2009. Moreover the economic and social development of the country requires important energy needs that will grow by 5% a year. The Morocco government has launched an ambitious plan for developing renewable energies that aims at trebling its today's production of electricity by 2020. 2000 MW of solar energy will be installed on 5 sites and at least 2000 MW of wind energy will also be installed. Morocco's potential for wind energy is assessed to reach 25000 MW. The investment for the solar program will reach 6.5*109 euros. The aim of the energy policy is also to create jobs and develop local skills for manufacturing components of wind turbines and solar panels. The idea is that investors produce in Morocco for the local energy market and for export to African countries. Exports of renewable energy toward Europe will also be possible as Morocco is the only Arab country to be connected on the European frequency. A third submarine power cable between Morocco and Europe is being installed. (A.C.)

  5. UV frequency metrology on CO (a3Pi); isotope effects and sensitivity to a variation of the proton-to-electron mass ratio

    CERN Document Server

    de Nijs, Adrian J; Eikema, Kjeld S E; Ubachs, Wim; Bethlem, Hendrick L

    2011-01-01

    UV frequency metrology has been performed on the a3Pi - X1Sigma+ (0,0) band of various isotopologues of CO using a frequency-quadrupled injection-seeded narrow-band pulsed Titanium:Sapphire laser referenced to a frequency comb laser. The band origin is determined with an accuracy of 5 MHz (delta \

  6. Responses of squirrel monkeys to their experimentally modified mobbing calls

    Science.gov (United States)

    Fichtel, Claudia; Hammerschmidt, Kurt

    2003-05-01

    Previous acoustic analyses suggested emotion-correlated changes in the acoustic structure of squirrel monkey (Saimiri sciureus) vocalizations. Specifically, calls given in aversive contexts were characterized by an upward shift in frequencies, often accompanied by an increase in amplitude. In order to test whether changes in frequencies or amplitude are indeed relevant for conspecific listeners, playback experiments were conducted in which either frequencies or amplitude of mobbing calls were modified. Latency and first orienting response were measured in playback experiments with six adult squirrel monkeys. After broadcasting yaps with increased frequencies or amplitude, squirrel monkeys showed a longer orienting response towards the speaker than after the corresponding control stimuli. Furthermore, after broadcasting yaps with decreased frequencies or amplitude, squirrel monkeys showed a shorter orienting response towards the speaker than after the corresponding manipulated calls with higher frequencies or amplitude. These results suggest that changes in frequencies or amplitude were perceived by squirrel monkeys, indicating that the relationship between call structure and the underlying affective state of the caller agreed with the listener's assessment of the calls. However, a simultaneous increase in frequencies and amplitude did not lead to an enhanced response, compared to each single parameter. Thus, from the receiver's perspective, both call parameters may mutually replace each other.

  7. Your Wake-Up Call

    Science.gov (United States)

    ... Home Current Issue Past Issues Your Wake-Up Call Past Issues / Summer 2007 Table of Contents For ... infant younger than one year old. Some people call SIDS "crib death" because many babies who die ...

  8. Synergistic modeling of call center operations

    Directory of Open Access Journals (Sweden)

    Jon G. Vaver

    2006-05-01

    Full Text Available We synergistically apply queueing theory, integer programming, and stochastic simulation to determine an optimal staffing policy for a repair call handling center. A stationary Markovian queueing model is employed to determine minimal staffing levels for a sequence of time intervals with varying call volumes and mean handling times. These staffing requirements populate an integer program model for determining the mix of call agent shifts that will achieve service quality standards at minimum cost. Since the analytical modeling requires simplifying assumptions, expected performance of the optimal staffing policy is evaluated using stochastic simulation. Computational efficiency of the simulation is improved dramatically by employing the queueing model to generate an analytic control variate.

  9. Identification of sympatric bat species by the echolocation calls

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    One hundred and thirty-eight echolocation calls of 63 free-flying individuals of five bat species (Rhinolophus ferrumequinum,Myotis formosus,Myotis ikonnikovi,Myotis daubentoni and Murina leucogaster)were recorded (by ultrasonic bat detector (D980)) in Zhi'an village of Jilin Province,China.According to the frequency-time spectra,these calls were categorized into two types:FM/CF (constant frequency) / FM (R.ferrumequinum) and FM (frequency modulated)(M.formosus,M.ikonnikovi,M.daubentoni and M.leucogaster).Sonograms of the calls of R.ferrumequinum could easily be distinguished from those of the other four species.For the calls of the remaining four species,six echolocation call parameters,including starting frequency,ending frequency,peak frequency duration,longest inter-pulse interval and shortest inter-pulse interval,were examined by stepwise discriminant analysis.The results show that 84.1% of calls were correctly classified,which indicates that these parameters of echolocation calls play an important role in identifying bat species.These parameters can be used to test the accuracy of general predictions based on bats' morphology in the same forest and can provide essential information for assessing patterns of bat habitat use.

  10. Heterospecific Acoustic Interference: Effects on Calling in Oophaga pumilio.

    Science.gov (United States)

    Wong, Stefanie; Parada, Humberto; Narins, Peter M

    2009-01-01

    Call rate suppression is a common short-term solution for avoiding acoustic interference in animals. It has been widely documented between and within frog species, but the effects of non-anuran calling on frog vocalizations is less well known. Heterospecific acoustic interference on the calling of Oophaga pumilio (Bauer, 1994) (formerly Dendrobates pumilio) males was studied in a lowland, wet tropical forest in SE Nicaragua. Acoustic playback experiments were conducted to characterize the responses of O. pumilio males to interfering calls of cicadas, two species of crickets and a sympatric dendrobatid frog, Phyllobates lugubris. Call rate, call bout duration, percent of time calling, dominant frequency and latency to first-call were analyzed. Significant call rate suppression was observed during all stimulus playbacks, yet no significant differences were found in spontaneous call rates during pre- and post-playback trials. Dominant frequency significantly decreased after P. lugubris playback and first-call latency significantly decreased in response to both cicada and tree cricket playbacks. These results provide robust evidence that O. pumilio males can dynamically modify their calling pattern in unique ways, depending on the source of the heterospecific acoustic interference. PMID:20953296

  11. Robust Two Degrees-of-freedom Single-current Control Strategy for LCL-type Grid-Connected DG System under Grid-Frequency Fluctuation and Grid-impedance Variation

    DEFF Research Database (Denmark)

    Zhou, Leming; Chen, Yandong; Guerrero, Josep M.;

    2016-01-01

    For LCL - type grid - connected distribut ed generation (DG) system , the grid - frequency fluctuation and grid - impedance variation affect the active / reactive power control accuracy and resonance peak suppression respectively , which would reduce the system robustness . In this paper, a robust...... two degr ees - of - freedom single - current control (RTDOF - SCC) strategy is proposed, which mainly includes the synchronous reference frame quasi - proportional - integral (SRFQPI) control and robust grid - current - feedback active damping (RGCFAD) control . The proposed SRFQPI contr ol can...... compensate the local - load s reactive power, and regulate the instantaneous grid current with out steady - state error regardless of the fundamental frequency fluctuation. Simultaneously, the proposed RGCFAD control effectively damps the LCL - resona nce peak regardless of the grid - impedance variation...

  12. Does Vessel Noise Affect Oyster Toadfish Calling Rates?

    Science.gov (United States)

    Luczkovich, Joseph J; Krahforst, Cecilia S; Hoppe, Harry; Sprague, Mark W

    2016-01-01

    The question we addressed in this study is whether oyster toadfish respond to vessel disturbances by calling less when vessels with lower frequency spectra are present in a sound recording and afterward. Long-term data recorders were deployed at the Neuse (high vessel-noise site) and Pamlico (low vessel-noise site) Rivers. There were many fewer toadfish detections at the high vessel-noise site than the low-noise station. Calling rates were lower in the high-boat traffic area, suggesting that toadfish cannot call over loud vessel noise, reducing the overall calling rate, and may have to call more often when vessels are not present. PMID:26611015

  13. The advertisement call of the giant spiny frog Paa spinosa

    Directory of Open Access Journals (Sweden)

    Baogen YU, Rongquan ZHENG

    2009-12-01

    Full Text Available We analyzed the advertisement call of Paa spinosa at Yuliang Mountain, Lanxi, Zhejiang province, in eastern China. Temporal and spectral call parameters were analyzed, along with call intensity. Calls comprised of three to seven notes, the last of which had the longest duration. Three formants (harmonics were clearly distinguishable from the audio spectrogram. The dominant frequency ranged from 411-1534Hz, and was either the first or the second formant. The number of notes within a call was positively correlated to air temperature, so that calls contained more notes during the day. Also, the dominant frequency appeared to be lower at the highest temperature [Current Zoology 55 (6: 411 –415, 2009].

  14. Striking differences in the loud calls of howler monkey sister species (Alouatta pigra and A. palliata).

    Science.gov (United States)

    Bergman, Thore J; Cortés-Ortiz, Liliana; Dias, Pedro A D; Ho, Lucy; Adams, Dara; Canales-Espinosa, Domingo; Kitchen, Dawn M

    2016-07-01

    Comparing vocalizations across species is useful for understanding acoustic variation at mechanistic and evolutionary levels. Here, we take advantage of the divergent vocalizations of two closely related howler monkey species (Alouatta pigra and A. palliata) to better understand vocal evolution. In addition to comparing multiple acoustic and temporal features of roars and the calling bouts in which they are produced, we tested several predictions. First, A. pigra should have roars with lower fundamental frequency and lower formant dispersion because they are larger than A. palliata and have a larger hyoid apparatus. Second, A. pigra should have faster calling rates, longer roars, longer bouts, and exaggerated call features linked to vocal effort (e.g., nonlinear phenomena and emphasized frequencies) because they are the more aggressive species during intergroup encounters. We found significant interspecific differences supporting our predictions in every tested parameter of roars and bouts, except for roar duration and barking rate. Stepwise discriminant function analyses identified the best features for differentiating roars (acoustic features: formant dispersion followed by highest frequency; temporal features: longest syllable duration followed by number of syllables). Although resembling each other more than they resemble South American howler monkeys, our comparison revealed striking differences in the vocalizations of the two Mesoamerican species. While we cannot completely rule out the influence of body size or the environmental conditions in which the two species evolved, vocal differences were likely influenced by sexual selection. The exaggerated roars and intense calling patterns in A. pigra seem more suitable for intergroup competition, whereas A. palliata calls may be better suited for mate attraction and competition within groups. With interspecific acoustic differences quantified, we will now be able to examine how vocalizations contribute to the

  15. Individually specific call feature is not used to neighbour-stranger discrimination: the corncrake case.

    Directory of Open Access Journals (Sweden)

    Michał Budka

    Full Text Available In various contexts, animals rely on acoustic signals to differentiate between conspecifics. Currently, studies examining vocal signatures use two main approaches. In the first approach, researchers search for acoustic characteristics that have the potential to be individual specific. This approach yields information on variation in signal parameters both within and between individuals and generates practical tools that can be used in population monitoring. In the second approach, playback experiments with natural calls are conducted to discern whether animals are capable of discriminating among the vocal signatures of different individuals. However, both approaches do not reveal the exact signal characteristics that are being used in the discrimination process. In this study, we tested whether an individual-specific call characteristic--namely the length of the intervals between successive maximal amplitude peaks within syllables (PPD--is crucial in neighbour-stranger discrimination by males of the nocturnal and highly secretive bird species, the corncrake (Crex crex. We conducted paired playback experiments in which corncrakes (n = 47 were exposed to artificial calls with PPD characteristics of neighbour and stranger birds. These artificial calls differed only in PPD structure. The calls were broadcast from a speaker, and we recorded the birds' behavioural responses. Although corncrakes have previously been experimentally shown to discriminate between neighbours and strangers, we found no difference in the responses to the artificial calls representing neighbours versus strangers. This finding demonstrates that even if vocal signatures are individual specific within a species, it does not automatically mean that said signatures are being crucial in discrimination among individuals. At the same time, the birds' aggressive responses to the artificial calls indicated that the information transmitted by PPDs is important in species

  16. Application of Affect to CALL

    Institute of Scientific and Technical Information of China (English)

    李露

    2006-01-01

    This essay mainly attempts to discuss some affective factors in CALL, with focus on affective influence on English (foreign language) learning and thus concludes that in the process of CALL related affect should be activated and made good use of to better foreign language teaching and learning.

  17. When to Call Your Pediatrician

    Science.gov (United States)

    ... in Action Medical Editor & Editorial Advisory Board Sponsors Sponsorship Opporunities Spread the Word Shop AAP Find a ... to Call Your Pediatrician Page Content Article Body Is it OK to call my child's pediatrician even if I'm not sure my ...

  18. Features of amplitude and Doppler frequency variation of ELF/VLF waves generated by "beat-wave" HF heating at high latitudes

    Science.gov (United States)

    Tereshchenko, E. D.; Shumilov, O. I.; Kasatkina, E. A.; Gomonov, A. D.

    2014-07-01

    Observations of extremely low frequency (ELF, 3-3000 Hz) radio waves generated by a "beat-wave" (BW) high frequency (~ 4.04-4.9 MHz) ionospheric heating are presented. ELF waves were registered with the ELF receiver located at Lovozero (68°N, 35°E), 660 km east from the European Incoherent Scatter Tromso heating facility (69.6°N, 19.2°E). Frequency shifts between the generated beat-wave and received ELF waves were detected in all sessions. It is shown that the amplitudes of ELF waves depend on the auroral electrojet current strength. Our results showing a strong dependence of ELF signal intensities on the substorm development seem to support the conclusion that electrojet currents may affect the BW generation of ELF/VLF waves.

  19. Effect of frequence variation from the applied field and the neutronic irradiation on the magnetic behaviour of Fe Ni and Fe Ni Cr alloys

    International Nuclear Information System (INIS)

    The initial magnetic permeability from FeNiCr and FeNi alloys was followed during linear annealings between room temperature and a temperature above the Curie point Tc, making use of differents frequencies of the applied ac magnetic field. It was observed that Tc is independent of the frequence and for f < 200 Hz the Hopkinson effect is pronounced. For each temperature T a linear relationship between the permeability and the frequence is verified. Annealings performed during fast neutron irradiation showed a remarkable decrease in the values of the initial permeability due to neutron-produced increase in the rectangularity of the magnetic hysteresis curve. Post-irradiation experiments showed a recovery of the irradiation-produced defects. (author)

  20. Evolution of advertisement calls in African clawed frogs

    Science.gov (United States)

    Tobias, Martha L.; Evans, Ben J.; Kelley, Darcy B.

    2014-01-01

    Summary For most frogs, advertisement calls are essential for reproductive success, conveying information on species identity, male quality, sexual state and location. While the evolutionary divergence of call characters has been examined in a number of species, the relative impacts of genetic drift or natural and sexual selection remain unclear. Insights into the evolutionary trajectory of vocal signals can be gained by examining how advertisement calls vary in a phylogenetic context. Evolution by genetic drift would be supported if more closely related species express more similar songs. Conversely, a poor correlation between evolutionary history and song expression would suggest evolution shaped by natural or sexual selection. Here, we measure seven song characters in 20 described and two undescribed species of African clawed frogs (genera Xenopus and Silurana) and four populations of X. laevis. We identify three call types — click, burst and trill — that can be distinguished by click number, call rate and intensity modulation. A fourth type is biphasic, consisting of two of the above. Call types vary in complexity from the simplest, a click, to the most complex, a biphasic call. Maximum parsimony analysis of variation in call type suggests that the ancestral type was of intermediate complexity. Each call type evolved independently more than once and call type is typically not shared by closely related species. These results indicate that call type is homoplasious and has low phylogenetic signal. We conclude that the evolution of call type is not due to genetic drift, but is under selective pressure. PMID:24723737

  1. Evolution of advertisement calls in African clawed frogs.

    Science.gov (United States)

    Tobias, Martha L; Evans, Ben J; Kelley, Darcy B

    2011-01-01

    For most frogs, advertisement calls are essential for reproductive success, conveying information on species identity, male quality, sexual state and location. While the evolutionary divergence of call characters has been examined in a number of species, the relative impacts of genetic drift or natural and sexual selection remain unclear. Insights into the evolutionary trajectory of vocal signals can be gained by examining how advertisement calls vary in a phylogenetic context. Evolution by genetic drift would be supported if more closely related species express more similar songs. Conversely, a poor correlation between evolutionary history and song expression would suggest evolution shaped by natural or sexual selection. Here, we measure seven song characters in 20 described and two undescribed species of African clawed frogs (genera Xenopus and Silurana) and four populations of X. laevis. We identify three call types - click, burst and trill - that can be distinguished by click number, call rate and intensity modulation. A fourth type is biphasic, consisting of two of the above. Call types vary in complexity from the simplest, a click, to the most complex, a biphasic call. Maximum parsimony analysis of variation in call type suggests that the ancestral type was of intermediate complexity. Each call type evolved independently more than once and call type is typically not shared by closely related species. These results indicate that call type is homoplasious and has low phylogenetic signal. We conclude that the evolution of call type is not due to genetic drift, but is under selective pressure. PMID:24723737

  2. La calle de la Lona

    OpenAIRE

    Marín Reñasco, Alejandro

    2014-01-01

    Relato en el que se describe el ambiente cargado de realidad cotidiana de los habitantes de una calle, la calle de la lona. En el transcurso de la mañana de un sábado en una calle ubicado en una zona obrera de una ciudad cualquiera, el autor disecciona con un lenguaje preciso y brillante los juegos de los niños que aprovechan la mañana de libranza escolar para liberarse de la atmósfera cargada de sus casas alejándose del control familiar transgrediendo los límites de la calle…allá donde el mu...

  3. Variations of high frequency parameter of heart rate variability following osteopathic manipulative treatment in healthy subjects compared to control group and sham therapy: randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Nuria eRuffini

    2015-08-01

    Full Text Available Context: Heart Rate Variability (HRV indicates how heart rate changes in response to inner and external stimuli. HRV is linked to health status and it is an indirect marker of the autonomic nervous system (ANS function. Objective: To investigate the influence of osteopathic manipulative treatment (OMT on ANS activity through changes of High Frequency, a heart rate variability index indicating the parasympathetic activity, in healthy subjects, compared with sham therapy and control group.Methods: Sixty-six healthy subjects, both male and female, were included in the present 3-armed randomized placebo controlled within subject cross-over single blinded study. Participants were asymptomatic adults, both smokers and non-smokers and not on medications. At enrollment subjects were randomized in 3 groups: A, B, C. Standardized structural evaluation followed by a patient need-based osteopathic treatment was performed in the first session of group A and in the second session of group B. Standardized evaluation followed by a protocoled sham treatment was provided in the second session of group A and in the first session of group B. No intervention was performed in the two sessions of group C, acting as a time-control. The trial was registered on clinicaltrials.gov identifier: NCT01908920.Main Outcomes Measures: HRV was calculated from electrocardiography before, during and after the intervention, for a total amount time of 25 minutes.Results: OMT engendered a statistically significant increase of parasympathetic activity, as shown by High Frequency rate (p<0.001, and decrease of sympathetic activity, as revealed by Low Frequency rate (p<0.01; results also showed a reduction of Low Frequency/High Frequency ratio (p<0.001 and Detrended fluctuation scaling exponent (p<0.05. Conclusions: Findings suggested that OMT can influence ANS activity increasing parasympathetic function and decreasing sympathetic activity, compared to sham therapy and control group.

  4. Effect of tracheosyringeal denervation on call in greenfinch (Carduelis sinica)

    Institute of Scientific and Technical Information of China (English)

    李东风; 李杰; 汪大伟; 蒋锦昌; 杨新宇; 陈浩

    1999-01-01

    After sections of left or right tracheosyringeal nerve (NXⅡts), greenfinches may repeat everyday calls, with no effect on temporal properties. It is suggested that either side of syrinx may produce sound alone and ipsilateral innervation of NXⅡts for the syringeal muscles. After section of left NXIIts, the bird produces the vocal pattern of partial tone increase, and effects on the sound intensity and sentence length average 1.4 and 2.8 times those after section of right NXIIts, suggesting that the innervation of NXIIts has left side dominance. After bilateral section of NXIIts, the call rhythm in company with expiratory motions is 98-146 times/min,on an average, and lose all sentence types and syllable structure of normal call. But the call spectra produced by tympaniform membrane vibrations without innervation still reserve frequency components similar to the tonic frequency and harmonics of normal calls.

  5. Synchronization of human heart-rate indicators and geomagnetic field variations in the frequency range of 0.5-3.0 mHz

    Science.gov (United States)

    Zenchenko, T. A.; Medvedeva, A. A.; Khorseva, N. I.; Breus, T. K.

    2014-12-01

    Fifty-seven experiments have been conducted to monitor the minute indicators of heart rate at rest in 38 practically healthy individuals (9 men and 29 women) from 18 to 58 years old. The duration of each observation period is 60 to 200 min. We have measured the heart rate and the minute-averaged cardiac section durations reflecting the passage of electrical excitation over different parts of myocardium. A comparison of the dynamics of minute values of these physiological parameters with variations of the X and Z components of the geomagnetic field has shown that two-thirds of experiments revealed the synchronization of oscillations in the heart rate and variations in the components of the geomagnetic field. We have revealed both the matching of the observed periods of oscillations ranging between 4 and 30 min and an approximate synchronicity in the times of their appearance and disappearance.

  6. Disentangling the Roles of History and Local Selection in Shaping Clinal Variation of Allele Frequencies and Gene Expression in Norway Spruce (Picea abies)

    OpenAIRE

    J. Chen; Kallman, T.; Ma, X.; Gyllenstrand, N; Zaina, G.; M. Morgante; Bousquet, J; Eckert, A; Wegrzyn, J.; Neale, D.; Lagercrantz, U.; Lascoux, M

    2012-01-01

    Understanding the genetic basis of local adaptation is challenging due to the subtle balance among conflicting evolutionary forces that are involved in its establishment and maintenance. One system with which to tease apart these difficulties is clines in adaptive characters. Here we analyzed genetic and phenotypic variation in bud set, a highly heritable and adaptive trait, among 18 populations of Norway spruce (Picea abies), arrayed along a latitudinal gradient ranging from 47°N to 68°N. We...

  7. INFLUENCE OF JOINT INFLUENCE OF VARIATION MAGNETIC FIELDS OF THE INDUSTRIAL FREQUENCY OF 50 HZ AND CONTAMINATION BY NICKEL ON ENZYME ACTIVITY AND PHYTOTOXICITY OF THE CHERNOZEM OF THE SOUTHERN OF THE HALF-ISLAND OF KERCH'

    Directory of Open Access Journals (Sweden)

    Minnikova T. V.

    2015-10-01

    Full Text Available We have investigated the influence of nickel oxide in the amount 100, 1000 mg/kg of the soil (1, 10 MPC, combined with the influence of variation magnetic field with induction of 50, 100 and 650 μT power frequency of 50 Hz on the enzyme activity and phytotoxity of the southern chernozem. We have established significant reduction of enzyme activity of catalase and length of roots after the influence of the variation of magnetic fields. Pollution by nickel as an independent factor caused stimulation of enzyme activity of a dehydrogenaze and length of roots of radish. The greatest inhibition of the activity of all indicators was observed at joint influence of magnetic fields and pollution by nickel of concentration of 1 maximum permissible concentration (1 MPC. Enzyme activity of dehydrogenaze was significantly stimulated (p

  8. Divergence of a stereotyped call in northern resident killer whales.

    Science.gov (United States)

    Grebner, Dawn M; Parks, Susan E; Bradley, David L; Miksis-Olds, Jennifer L; Capone, Dean E; Ford, John K B

    2011-02-01

    Northern resident killer whale pods (Orcinus orca) have distinctive stereotyped pulsed call repertoires that can be used to distinguish groups acoustically. Repertoires are generally stable, with the same call types comprising the repertoire of a given pod over a period of years to decades. Previous studies have shown that some discrete pulsed calls can be subdivided into variants or subtypes. This study suggests that new stereotyped calls may result from the gradual modification of existing call types through subtypes. Vocalizations of individuals and small groups of killer whales were collected using a bottom-mounted hydrophone array in Johnstone Strait, British Columbia in 2006 and 2007. Discriminant analysis of slope variations of a predominant call type, N4, revealed the presence of four distinct call subtypes. Similar to previous studies, there was a divergence of the N4 call between members of different matrilines of the same pod. However, this study reveals that individual killer whales produced multiple subtypes of the N4 call, indicating that divergence in the N4 call is not the result of individual differences, but rather may indicate the gradual evolution of a new stereotyped call. PMID:21361462

  9. Call-Routing Schemes for Call-Center Outsourcing

    OpenAIRE

    Noah Gans; Yong-Pin Zhou

    2007-01-01

    Companies may choose to outsource parts, but not all, of their call-center operations. In some cases, they classify customers as high or low value, serving the former with their in-house operations and routing the latter to an outsourcer. Typically, they impose service-level constraints on the time each type of customer waits on hold. This paper considers four schemes for routing low-value calls between the client company and the outsourcer. These schemes vary in the complexity of their routi...

  10. A three-parameter model for classifying anurans into four genera based on advertisement calls.

    Science.gov (United States)

    Gingras, Bruno; Fitch, William Tecumseh

    2013-01-01

    The vocalizations of anurans are innate in structure and may therefore contain indicators of phylogenetic history. Thus, advertisement calls of species which are more closely related phylogenetically are predicted to be more similar than those of distant species. This hypothesis was evaluated by comparing several widely used machine-learning algorithms. Recordings of advertisement calls from 142 species belonging to four genera were analyzed. A logistic regression model, using mean values for dominant frequency, coefficient of variation of root-mean square energy, and spectral flux, correctly classified advertisement calls with regard to genus with an accuracy above 70%. Similar accuracy rates were obtained using these parameters with a support vector machine model, a K-nearest neighbor algorithm, and a multivariate Gaussian distribution classifier, whereas a Gaussian mixture model performed slightly worse. In contrast, models based on mel-frequency cepstral coefficients did not fare as well. Comparable accuracy levels were obtained on out-of-sample recordings from 52 of the 142 original species. The results suggest that a combination of low-level acoustic attributes is sufficient to discriminate efficiently between the vocalizations of these four genera, thus supporting the initial premise and validating the use of high-throughput algorithms on animal vocalizations to evaluate phylogenetic hypotheses. PMID:23297926

  11. On Data and Parameter Estimation Using the Variational Bayesian EM-algorithm for Block-fading Frequency-selective MIMO Channels

    DEFF Research Database (Denmark)

    Christensen, Lars P.B.; Larsen, Jan

    2006-01-01

    A general Variational Bayesian framework for iterative data and parameter estimation for coherent detection is introduced as a generalization of the EM-algorithm. Explicit solutions are given for MIMO channel estimation with Gaussian prior and noise covariance estimation with inverse-Wishart prior....... Simulation of a GSM-like system provides empirical proof that the VBEM-algorithm is able to provide better performance than the EM-algorithm. However, if the posterior distribution is highly peaked, the VBEM-algorithm approaches the EM-algorithm and the gain disappears. The potential gain is therefore...

  12. Optimizing Programs Using Call Graphs

    Directory of Open Access Journals (Sweden)

    Pravin Kandala

    2014-02-01

    Full Text Available When working with complex software, visualization improves understanding considerably. Thus enhancing the ability of programmers to picture the relationships between components in a complex program not only saves time but becomes progressively mission- critical with increasing software complexity. Call Graph Generation Tool is a visualization tool which provides programmers different metrics to assess the software code. The different metrics include total n umber of lines in the function, total number of executable lines, number of unreachable lines, and cyclomatic complexity of the program. It provides a graphical representation of the function calls in a tree like structure. The tool accepts a „C‟ program and generates a funct ions call graph along with the functional metrics. The call graph generation tool provides both static and dynamic view. The whole programming is done using java technology. Thus, this tool helps the developer to know the program flow and thereby decide the optimality of the program. In situations where in, a single program is to be selected from available programs, this tool helps to figure out it. This paper depicts usage of call graph Generator to assess the reachability and exactness of the programs.

  13. OPTIMIZING PROGRAMS USING CALL GRAPHS

    Directory of Open Access Journals (Sweden)

    Pravin Kandala

    2015-11-01

    Full Text Available When working with complex software, visualization improves understanding considerably. Thus enhancing the ability of programmers to picture the relationships between components in a complex program not only saves time but becomes progressively mission- critical with increasing software complexity. Call Graph Generation Tool is a visualization tool which provides programmers different metrics to assess the software code. The different metrics include total number of lines in the function, total number of executable lines, number of unreachable lines, and cyclomatic complexity of the program. It provides a graphical representation of the function calls in a tree like structure. The tool accepts a „C‟ program and generates a functions call graph along with the functional metrics. The call graph generation tool provides both static and dynamic view. The whole programming is done using java technology. Thus, this tool helps the developer to know the program flow and thereby decide the optimality of the program. In situations where in, a single program is to be selected from available programs, this tool helps to figure out it. This paper depicts usage of call graph Generator to assess the reachability and exactness of the programs.

  14. The Wireless Nursing Call System

    DEFF Research Database (Denmark)

    Jensen, Casper Bruun

    2006-01-01

    This paper discusses a research project in which social scientists were involved both as analysts and supporters during a pilot with a new wireless nursing call system. The case thus exemplifies an attempt to participate in developing dependable health care systems and offers insight into the cha......This paper discusses a research project in which social scientists were involved both as analysts and supporters during a pilot with a new wireless nursing call system. The case thus exemplifies an attempt to participate in developing dependable health care systems and offers insight...

  15. Why and when citizens call for emergency help

    DEFF Research Database (Denmark)

    Møller, Thea Palsgaard; Ersbøll, Annette Kjær; Tolstrup, Janne Schurmann;

    2015-01-01

    BACKGROUND: A medical emergency call is citizens' access to pre-hospital emergency care and ambulance services. Emergency medical dispatchers are gatekeepers to provision of pre-hospital resources and possibly hospital admissions. We explored causes for access, emergency priority levels......, and temporal variation within seasons, weekdays, and time of day for emergency calls to the emergency medical dispatch center in Copenhagen in a two-year study period (December 1(st), 2011 to November 30(th), 2013). METHODS: Descriptive analysis was performed for causes for access and emergency priority levels....... A Poisson regression model was used to calculate adjusted ratio estimates for the association between seasons, weekdays, and time of day overall and stratified by emergency priority levels. RESULTS: We analyzed 211,193 emergency calls for temporal variation. Of those, 167,635 calls were eligible...

  16. Nursing care as a calling.

    Science.gov (United States)

    Raatikainen, R

    1997-06-01

    A calling is a deep desire to devote oneself to serving people according to the high values of the task or profession. The aim of this study is to clarify the relationship between a calling experience and professional knowledge, nursing action and motivation. The data were collected from all the registered nurses (n = 179) at five hospitals. The response was 70%. The nurses who were committed to their profession and experienced their job as a calling, had a good knowledge about the ill feeling and maladjustment of their patients and were also good sources of support for their patients. They understood the importance of family ties and offered support to their patients' families. They were aware of the needs of dying patients and their concern with spiritual questions, and satisfied these needs well. It was characteristic for them to collaborate closely within a team, to experience the content of their work as enriching and to possess proficient professional abilities. They were therefore excellent in supporting both the individual patient and his or her family. They had a deep understanding of the whole process of patient care. According to these results the calling experience is not in conflict with professional principles. PMID:9181405

  17. Variations in voice level and fundamental frequency with changing background noise level and talker-to-listener distance while wearing hearing protectors: A pilot study

    DEFF Research Database (Denmark)

    Bouserhal, Rachel E.; MacDonald, Ewen; Falk, Tiago H.;

    2016-01-01

    concern for people wearing hearing protection devices (HPD). Although practical, radio communication is cumbersome, as it does not distinguish designated receivers. A smarter radio communication protocol must be developed to alleviate this problem. Thus, it is necessary to model speech production in noise...... while wearing HPDs. Such a model opens the door to radio communication systems that distinguish receivers and offer more efficient communication between persons wearing HPDs. Design: This paper presents the results of a pilot study aimed to investigate the effects of occluding the ear on changes in...... voice level and fundamental frequency in noise and with varying talker-to-listener distance. Study sample: Twelve participants with a mean age of 28 participated in this study. Results: Compared to existing data, results show a trend similar to the open ear condition with the exception of the occluded...

  18. Seasonal variability and detection range modeling of baleen whale calls in the Gulf of Alaska, 1999-2002.

    Science.gov (United States)

    Stafford, Kathleen M; Mellinger, David K; Moore, Sue E; Fox, Christopher G

    2007-12-01

    Five species of large whales, including the blue (Balaenoptera musculus), fin (B. physalus), sei (B. borealis), humpback (Megaptera novaeangliae), and North Pacific right (Eubalaena japonica), were the target of commercial harvests in the Gulf of Alaska (GoA) during the 19th through mid-20th Centuries. Since this time, there have been a few summer time visual surveys for these species, but no overview of year-round use of these waters by endangered whales primarily because standard visual survey data are difficult and costly. From October 1999-May 2002, moored hydrophones were deployed in six locations in the GoA to record whale calls. Reception of calls from fin, humpback, and blue whales and an unknown source, called Watkins' whale, showed seasonal and geographic variation. Calls were detected more often during the winter than during the summer, suggesting that animals inhabit the GoA year-round. To estimate the distance at which species-diagnostic calls could be heard, parabolic equation propagation loss models for frequencies characteristic of each of each call type were run. Maximum detection ranges in the subarctic North Pacific ranged from 45 to 250 km among three species (fin, humpback, blue), although modeled detection ranges varied greatly with input parameters and choice of ambient noise level. PMID:18247747

  19. Why and when citizens call for emergency help: an observational study of 211,193 medical emergency calls

    OpenAIRE

    Møller, Thea Palsgaard; Ersbøll, Annette Kjær; Tolstrup, Janne Schurmann; Østergaard, Doris; Viereck, Søren; Overton, Jerry; Folke, Fredrik; Lippert, Freddy

    2015-01-01

    Background A medical emergency call is citizens’ access to pre-hospital emergency care and ambulance services. Emergency medical dispatchers are gatekeepers to provision of pre-hospital resources and possibly hospital admissions. We explored causes for access, emergency priority levels, and temporal variation within seasons, weekdays, and time of day for emergency calls to the emergency medical dispatch center in Copenhagen in a two-year study period (December 1st, 2011 to November 30th, 2013...

  20. Variations in fire severity and frequency as a driver of changes in succession and long-term patterns of carbon storage in Alaskan boreal forests

    Science.gov (United States)

    Johnstone, J.; Kasischke, E. S.; Bourgeau-Chavez, L.; Chapin, F. S.

    2005-12-01

    Black spruce is the dominant forest cover type in the North American boreal region (they represent some 57 percent of all forests in this region). These spruce forests are a major North American terrestrial carbon reservoir because cold ground temperatures lead to low decomposition rates and the building up of carbon-rich layers of dead organic matter over century and longer time scales. The surface organic layers and living vegetation of these forests contain an estimated 22.6 Gt of carbon, with nearly two-thirds of this amount stored in the surface organic layer lying on top of mineral soil. There has been a significant increase in fire activity the boreal forest region of North America, with annual area burned doubling between the 1960s and 1990s in association with warming climates. This rise in temperature and disturbance from fire brings into question the fate of the large carbon reservoir present in the black spruce forests of this region. Here we present a conceptual framework based on a state-factors model that can be used to examine how variations in the fire regime alter successional pathways and carbon storage in the black spruce forests of Alaska. In particular, we focus on the factors and site conditions that will allow black spruce forests to switch to successional trajectories containing a significant deciduous component. To illustrate the concepts presented in this framework, results from recent research will be presented.

  1. Reference-free SNP calling: improved accuracy by preventing incorrect calls from repetitive genomic regions

    Directory of Open Access Journals (Sweden)

    Dou Jinzhuang

    2012-06-01

    Full Text Available Abstract Background Single nucleotide polymorphisms (SNPs are the most abundant type of genetic variation in eukaryotic genomes and have recently become the marker of choice in a wide variety of ecological and evolutionary studies. The advent of next-generation sequencing (NGS technologies has made it possible to efficiently genotype a large number of SNPs in the non-model organisms with no or limited genomic resources. Most NGS-based genotyping methods require a reference genome to perform accurate SNP calling. Little effort, however, has yet been devoted to developing or improving algorithms for accurate SNP calling in the absence of a reference genome. Results Here we describe an improved maximum likelihood (ML algorithm called iML, which can achieve high genotyping accuracy for SNP calling in the non-model organisms without a reference genome. The iML algorithm incorporates the mixed Poisson/normal model to detect composite read clusters and can efficiently prevent incorrect SNP calls resulting from repetitive genomic regions. Through analysis of simulation and real sequencing datasets, we demonstrate that in comparison with ML or a threshold approach, iML can remarkably improve the accuracy of de novo SNP genotyping and is especially powerful for the reference-free genotyping in diploid genomes with high repeat contents. Conclusions The iML algorithm can efficiently prevent incorrect SNP calls resulting from repetitive genomic regions, and thus outperforms the original ML algorithm by achieving much higher genotyping accuracy. Our algorithm is therefore very useful for accurate de novo SNP genotyping in the non-model organisms without a reference genome. Reviewers This article was reviewed by Dr. Richard Durbin, Dr. Liliana Florea (nominated by Dr. Steven Salzberg and Dr. Arcady Mushegian.

  2. Determination of the sputter rate variation pattern of a silicon carbide target for radio frequency magnetron sputtering using optical transmission measurements

    International Nuclear Information System (INIS)

    We produce amorphous silicon carbide thin films (a-SiC) by radio frequency (rf) magnetron sputtering from SiC bulk target. We present the emission pattern of the rf magnetron with SiC target as a function of process parameters, like target sample distance, rf power, sputtering rate and process gas pressure. The emission pattern is determined by means of thickness distribution of the deposited a-SiC films obtained from optical transmission measurements using a slightly improved method of Swanepoel concerning the determination of construction of the envelopes in the interference pattern of the transmission spectra. A calibration curve is presented which allows the conversion of integrated transmission to film thickness. Holding constant a set of process parameters and only varying the target sample distance the emission pattern of the rf magnetron with SiC target was determined, which allowed us to predict the deposition rate distribution for a wide range of process parameters and target geometry. In addition, we have found that the transmission spectra of the a-SiC films change with time and saturate after approximately 10 days. Within this process no change in thickness is involved, so that the determination of thickness using transmission data is justified.

  3. Distribution, Frequency and Variation of Stripe Rust Resistance Loci Yr10, Lr34/Yr18 and Yr36 in Chinese Wheat Cultivars

    Institute of Scientific and Technical Information of China (English)

    Cuiling Yuan; Hui Jiang; Honggang Wang; Kun Li; Heng Tang; Xianbin Li; Daolin Fu

    2012-01-01

    Wheat stripe rust is a devastating disease in many regions of the world.In wheat,49 resistance genes for stripe rust have been officially documented,but only three genes are cloned,including the race-specific resistance Yr10 candidate gene (Yr10CG) and slow-rusting genes Lr34/Yr18 (hereafter designated as Yr18) and Yr36.In this study,we developed gene-specific markers for these genes and used them to screen a collection of 659 wheat accessions,including 485 Chinese cultivars.Thirteen percent and eleven percent of the tested Chinese cultivars were positive for the markers for Yr10CG and Yr18RH (the resistant haplotype of Yr18),respectively,but none were positive for the Yr36 marker.Since there is a limited use of the Yr10 gene in Chinese wheat,the relatively high frequency of wheat varieties with the Yr10CG marker suggests that the identity of the Yr10 gene is unknown.With regards to the Yr18 gene,29% of the tested cultivars that are used in the Middle and Lower Yangtze Valleys' winter wheat zone were positive for Yr18RH markers.A non-functional allele of Yr18RHwas identified in ‘Mingxian 169',a commonly used susceptible check for studying stripe rust.The data presented here will provide useful information for marker-assisted selection for wheat stripe rust resistance.

  4. The Influence of Judgment Calls on Meta-Analytic Findings.

    Science.gov (United States)

    Tarrahi, Farid; Eisend, Martin

    2016-01-01

    Previous research has suggested that judgment calls (i.e., methodological choices made in the process of conducting a meta-analysis) have a strong influence on meta-analytic findings and question their robustness. However, prior research applies case study comparison or reanalysis of a few meta-analyses with a focus on a few selected judgment calls. These studies neglect the fact that different judgment calls are related to each other and simultaneously influence the outcomes of a meta-analysis, and that meta-analytic findings can vary due to non-judgment call differences between meta-analyses (e.g., variations of effects over time). The current study analyzes the influence of 13 judgment calls in 176 meta-analyses in marketing research by applying a multivariate, multilevel meta-meta-analysis. The analysis considers simultaneous influences from different judgment calls on meta-analytic effect sizes and controls for alternative explanations based on non-judgment call differences between meta-analyses. The findings suggest that judgment calls have only a minor influence on meta-analytic findings, whereas non-judgment call differences between meta-analyses are more likely to explain differences in meta-analytic findings. The findings support the robustness of meta-analytic results and conclusions. PMID:27055205

  5. Spatial and temporal variations of new particle formation in East Asia using an NPF-explicit WRF-chem model: North-south contrast in new particle formation frequency

    Energy Technology Data Exchange (ETDEWEB)

    Matsui, H.; Koike, Makoto; Takegawa, Nobuyuki; Kondo, Yutaka; Takami, A.; Takamura, T.; Yoon, Soh-joung; Kim, S. W.; Lim, Hyuntae; Fast, Jerome D.

    2013-10-27

    The new particle formation (NPF)-explicit version of the WRF-chem model, which we developed recently, can calculate the growth and sink of nucleated clusters explicitly with 20 aerosol size bins from 1 nm to 10 μm. In this study, the model is used to understand spatial and temporal variations of the frequency of NPF events and the concentrations of aerosols (condensation nuclei, CN) and cloud condensation nuclei (CCN) within the boundary layer in East Asia in spring 2009. Model simulations show distinct north-south contrast in the frequency and mechanism of NPF in East Asia. NPF mostly occurred over limited periods and regions between 30° and 45°N, such as northeast China, Korea, and Japan, including regions around active volcanoes (Miyakejima and Sakurajima). At these latitudes, NPF was considerably suppressed by high concentrations of preexisting particles under stagnant air conditions associated with high-pressure systems, while nucleation occurred more extensively on most days during the simulation period. Conversely, neither nucleation nor NPF occurred frequently south of 30°N because of lower SO2 emissions and H2SO4 concentrations. The period-averaged NPF frequency was 3 times higher at latitudes of 30° - 45°N than at latitudes of 20° - 30°N. The north-south contrast of NPF frequency is validated by surface measurements in outflow regions in East Asia. The period- and domain-averaged contribution of secondary particles is estimated to be 44% for CN (> 10 nm) and 26% for CCN at a supersaturation of 1.0% in our simulation, though the contribution is highly sensitive to the magnitudes and size distributions of primary aerosol emissions and the coefficients in the nucleation parameterizations.

  6. SVAMP: Sequence variation analysis, maps and phylogeny

    KAUST Repository

    Naeem, Raeece

    2014-04-03

    Summary: SVAMP is a stand-alone desktop application to visualize genomic variants (in variant call format) in the context of geographical metadata. Users of SVAMP are able to generate phylogenetic trees and perform principal coordinate analysis in real time from variant call format (VCF) and associated metadata files. Allele frequency map, geographical map of isolates, Tajima\\'s D metric, single nucleotide polymorphism density, GC and variation density are also available for visualization in real time. We demonstrate the utility of SVAMP in tracking a methicillin-resistant Staphylococcus aureus outbreak from published next-generation sequencing data across 15 countries. We also demonstrate the scalability and accuracy of our software on 245 Plasmodium falciparum malaria isolates from three continents. Availability and implementation: The Qt/C++ software code, binaries, user manual and example datasets are available at http://cbrc.kaust.edu.sa/svamp. © The Author 2014.

  7. Advanced Call Center Supporting WAP Access

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Traditional call centers can be accessed via speech only, and the call center based on web provides both data and speech access, but it needs a powerful terminal-computer. By analyzing traditional call centers and call centers based on web, this paper presents the framework of an advanced call center supporting WAP access. A typical service is also described in detail.

  8. 1957-2004年影响我国的强热带气旋频数和强度变化%Variations in Frequency and Intensity of Strong Tropical Cyclones Affecting China During 1957-2004

    Institute of Scientific and Technical Information of China (English)

    王小玲; 任福民

    2008-01-01

    Based on tropical cyclone track dataset in the western North Pacific from China Meteorological Administration(CMA),variations in frequency and intensity of tropical cyclones(TCs)in the western North Pacific,affecting-China TCs(ACTCs)and landfall TCs(LTCs)achieving a typhoon intensity during 1957-2004 were studied.Frequencies of strong tropical cyclones showed significant decreasing trends from 1957 to 2004 and the linear trend was much greater when the intensity was stronger.There was no linear trend in the portion of strong tropical cyclones achieving a typhoon(TY)intensity,while those reaching a strong typhoon(STY)and a super typhoon(SuperTY)intensity showed decreasing trends during 1957-2004.The maximum intensities of TCs,ACTCs and LTCs all decreased during the period of 1957-2004.The mean intensities of TCs and ACTCs displayed decreasing trends and the mean intensity of LTCs achieving a TY intensity also showed a decreasing trend.

  9. The structure of call-by-value

    OpenAIRE

    Führmann, Carsten

    2000-01-01

    Understanding procedure calls is crucial in computer science and everyday programming. Among the most common strategies for passing procedure arguments ('evaluation strategies') are 'call-by-name', 'call-by-need', and 'call-by-value', where the latter is the most commonly used. While reasoning about procedure calls is simple for call-by-name, problems arise for call-by-need and call-by-value, because it matters how often and in which order the arguments of a procedure are evaluated. We s...

  10. Frequency control : Pay for performance

    OpenAIRE

    Dahlborg, Elin

    2015-01-01

    The frequency control in the Nordic grid is to a large extent delivered by hydropower plants. The hydropower plants deliver frequency control of varying quality, meaning that a remuneration method based on more than just the static gain of the power plant is called for. This thesis has examined how three remuneration methods based on the hydropower plant output and the grid frequency deviation affects the grid stability. Using frequency data, the remunerated work along with the bandwidth and...

  11. Encoding voice fundamental frequency into vibrotactile frequency.

    Science.gov (United States)

    Rothenberg, M; Molitor, R D

    1979-10-01

    Measured in this study was the ability of eight hearing and five deaf subjects to identify the stress pattern in a short sentence from the variation in voice fundamental frequency (F0), when presented aurally (for hearing subjects) and when transformed into vibrotactile pulse frequency. Various transformations from F0 to pulse frequency were tested in an attempt to determine an optimum transformation, the amount of F0 information that could be transmitted, and what the limitations in the tactile channel might be. The results indicated that a one- or two-octave reduction of F0 vibrotactile frequency (transmitting every second or third glottal pulse) might result in a significant ability to discriminate the intonation patterns associated with moderate-to-strong patterns of sentence stress in English. However, accurate reception of the details of the intonation pattern may require a slower than normal pronounciation because of an apparent temporal indeterminacy of about 200 ms in the perception of variations in vibrotactile frequency. A performance deficit noted for the two prelingually, profoundly deaf subjects with marginally discriminable encodings offers some support for our previous hypothesis that there is a natural association between auditory pitch and perceived vibrotactile frequency. PMID:159917

  12. Are acoustical parameters of begging call elements of thin-billed prions related to chick condition?

    OpenAIRE

    Quillfeldt, Petra; Poisbleau, Maud; Mundry, Roger; Masello, Juan F.

    2010-01-01

    Chicks of burrowing petrels use begging calls to advertise their hunger levels when parents arrived at the nest. In a previous study, adult thin-billed prions Pachyptila belcheri responded to higher begging call rates of their single chick by regurgitating larger meals. We tested whether acoustic parameters of begging call elements may also be involved in signalling. To describe variation in begging, we determined begging session parameters, namely the duration, number of calls and the mean a...

  13. Advanced Call Center Supporting WAP Access

    Institute of Scientific and Technical Information of China (English)

    YUANXiao-hua; CHENJun-liang

    2001-01-01

    Traditional call centers can be accessed via speech only, and the call center based on web provides both da-ta and speech access,but it needs a powerful terminal-computer.By analyzing traditional call centers and call cen-ters based on web, this paper presents the framework of an advanced call center supporting WAP access.A typical service is also described in detail.

  14. A new genotype calling method for affymetrix SNP arrays.

    Science.gov (United States)

    Fu, Bilin; Xu, Jin

    2011-12-01

    Current genotype-calling methods such as Robust Linear Model with Mahalanobis Distance Classifier (RLMM) and Corrected Robust Linear Model with Maximum Likelihood Classification (CRLMM) provide accurate calling results for Affymetrix Single Nucleotide Polymorphisms (SNP) chips. However, these methods are computationally expensive as they employ preprocess procedures, including chip data normalization and other sophisticated statistical techniques. In the small sample case the accuracy rate may drop significantly. We develop a new genotype calling method for Affymetrix 100 k and 500 k SNP chips. A two-stage classification scheme is proposed to obtain a fast genotype calling algorithm. The first stage uses unsupervised classification to quickly discriminate genotypes with high accuracy for the majority of the SNPs. And the second stage employs a supervised classification method to incorporate allele frequency information either from the HapMap data or from a self-training scheme. Confidence score is provided for every genotype call. The overall performance is shown to be comparable to that of CRLMM as verified by the known gold standard HapMap data and is superior in small sample cases. The new algorithm is computationally simple and standalone in the sense that a self-training scheme can be used without employing any other training data. A package implementing the calling algorithm is freely available at http://www.sfs.ecnu.edu.cn/teachers/xuj_en.html. PMID:22084010

  15. Social calls of flying big brown bats (Eptesicus fuscus

    Directory of Open Access Journals (Sweden)

    GenevieveSpanjerWright

    2013-08-01

    Full Text Available Vocalizations serving a variety of social functions have been reported in many bat species (Order Chiroptera. While echolocation by big brown bats (Eptesicus fuscus has been the subject of extensive study, calls used by this species for communication have received comparatively little research attention. Here, we report on a rich repertoire of vocalizations produced by big brown bats in a large flight room equipped with synchronized high speed stereo video and audio recording equipment. Bats were studied individually and in pairs, while sex, age, and experience with a novel foraging task were varied. We used Discriminant Function Analysis to classify six different vocalizations that were recorded when two bats were present. Contingency table analyses revealed a higher prevalence of social calls when males were present, and some call types varied in frequency of emission based on trial type or bat age. Bats flew closer together around the time some social calls were emitted, indicating that communicative calls may be selectively produced when conspecifics fly near one another. These findings are the first reports of social calls from flying big brown bats and provide insight into the function of communicative vocalizations emitted by this species.

  16. Long-range acoustic detection and localization of blue whale calls in the northeast Pacific Ocean.

    Science.gov (United States)

    Stafford, K M; Fox, C G; Clark, D S

    1998-12-01

    Analysis of acoustic signals recorded from the U.S. Navy's SOund SUrveillance System (SOSUS) was used to detect and locate blue whale (Balaenoptera musculus) calls offshore in the northeast Pacific. The long, low-frequency components of these calls are characteristic of calls recorded in the presence of blue whales elsewhere in the world. Mean values for frequency and time characteristics from field-recorded blue whale calls were used to develop a simple matched filter for detecting such calls in noisy time series. The matched filter was applied to signals from three different SOSUS arrays off the coast of the Pacific Northwest to detect and associate individual calls from the same animal on the different arrays. A U.S. Navy maritime patrol aircraft was directed to an area where blue whale calls had been detected on SOSUS using these methods, and the presence of vocalizing blue whale was confirmed at the site with field recordings from sonobuoys. PMID:9857519

  17. The function of migratory bird calls

    DEFF Research Database (Denmark)

    Reichl, Thomas; Andersen, Bent Bach; Larsen, Ole Næsbye;

    The function of migratory bird calls: do they influence orientation and navigation?   Thomas Reichl1, Bent Bach Andersen2, Ole Naesbye Larsen2, Henrik Mouritsen1   1Institute of Biology, University of Oldenburg, Oldenburg, D-26111 Oldenburg, Germany 2Institute of Biology, University of Southern...... Denmark, Odense, DK-5230 Odense M, Denmark   Many migrating passerines emit special calls during nocturnal flight, the so-called flight calls. Several functions of the calls have been suggested but largely remain speculative. Flight calls have been hypothesized to maintain groups during nocturnal...... migration and to stimulate migratory restlessness in conspecifics. We wished to test if conspecific flight calls influence the flight direction of a nocturnal migrant, the European Robin (Erithacus rubecula), i.e. if flight calls help migrants keeping course. Wild caught birds showing migratory restlessness...

  18. Call packing bounds for overflow queues

    OpenAIRE

    van Dijk; Sluis, van der, B.

    2004-01-01

    Finite queueing loss systems are studied with overflow. For these systems there is no simple analytic expression for the loss probability or throughput. This paper aims to prove and promote easily computable bounds as based upon the so-called call packing principle. Under call packing a standard product form expression is available. It is proven that call packing leads to a guaranteed upper bound for the loss probability. In addition, an analytic error bound for the accuracy is derived which ...

  19. Analysis of a hospital call center

    OpenAIRE

    Budak, Ezel Ezgi

    2012-01-01

    Ankara : The Department of Industrial Engineering and the Graduate School of Engineering and Science of Bilkent University, 2012. Thesis (Master's) -- Bilkent University, 2012. Includes bibliographical refences. In this thesis, we study the call center operations of a particular hospital located in Ankara, namely Güven Hospital. The hospital call center takes role as a medical consulting and appointment center and also domestic call traffic flows over the call center. These ...

  20. Call packing bound for overflow loss systems

    NARCIS (Netherlands)

    N.M. van Dijk; E. van der Sluis

    2009-01-01

    Finite loss queues with overflow naturally arise in a variety of communications structures. For these systems, there is no simple analytic expression for the loss probability. This paper proves and promotes easily computable bounds based on the so-called call packing principle. Under call packing, a

  1. Call packing bounds for overflow queues

    NARCIS (Netherlands)

    N.M. van Dijk; E. van der Sluis

    2004-01-01

    Finite queueing loss systems are studied with overflow. For these systems there is no simple analytic expression for the loss probability or throughput. This paper aims to prove and promote easily computable bounds as based upon the so-called call packing principle. Under call packing a standard pro

  2. HOW TO CALL THE CERN FIRE BRIGADE

    CERN Multimedia

    2001-01-01

    The telephone numbers of the CERN Fire Brigade are: 74444 for emergency calls 74848 for other calls Note The number 112 will stay in use for emergency calls from 'wired' telephones, however, from mobile phones it leads to non-CERN emergency services.

  3. HOW TO CALL THE CERN FIRE BRIGADE

    CERN Multimedia

    2002-01-01

    The telephone numbers of the CERN Fire Brigade are: 74444 for emergency calls 74848 for other calls Note The number 112 will stay in use for emergency calls from 'wired' telephones, however, from mobile phones it leads to non-CERN emergency services.  

  4. HOW TO CALL THE CERN FIRE BRIGADE

    CERN Multimedia

    2001-01-01

    The telephone numbers of the CERN Fire Brigade are: 74444 for emergency calls 74848 for other calls Note: the number 112 will stay in use for emergency calls from 'wired' telephones, however, from mobile phones it leads to non-CERN emergency services.

  5. How to call the Fire Brigade

    CERN Multimedia

    2003-01-01

    The telephone numbers for the CERN Fire Brigade are: 74444 for emergency calls 74848 for other calls Note The number 112 will stay in use for emergency calls from "wired" telephones, however, from mobile phones it leads to non-CERN emergency services.

  6. HOW TO CALL THE CERN FIRE BRIGADE

    CERN Multimedia

    2002-01-01

    The telephone numbers of the CERN Fire Brigade are: 74444 for emergency calls 74848 for other calls Note The number 112 will stay in use for emergency calls from 'wired' telephones, however, from mobile phones it leads to non-CERN emergency services.

  7. 47 CFR 2.302 - Call signs.

    Science.gov (United States)

    2010-10-01

    ... citations affecting § 2.302, see the List of CFR Sections Affected in the Finding Aids section of this... 47 Telecommunication 1 2010-10-01 2010-10-01 false Call signs. 2.302 Section 2.302... RULES AND REGULATIONS Call Signs and Other Forms of Identifying Radio Transmissions § 2.302 Call...

  8. When to Call the Baby's Doctor

    Science.gov (United States)

    ... g n a n c y When to Call the Baby’s Doctor P rint - and -G o ... for new moms is figuring out when to call the doctor. As a general rule of thumb, ... suspect something is not right, you should always call the doctor. Even small changes in eating, sleeping, ...

  9. Perceiving a Calling, Living a Calling, and Job Satisfaction: Testing a Moderated, Multiple Mediator Model

    Science.gov (United States)

    Duffy, Ryan D.; Bott, Elizabeth M.; Allan, Blake A.; Torrey, Carrie L.; Dik, Bryan J.

    2012-01-01

    The current study examined the relation between perceiving a calling, living a calling, and job satisfaction among a diverse group of employed adults who completed an online survey (N = 201). Perceiving a calling and living a calling were positively correlated with career commitment, work meaning, and job satisfaction. Living a calling moderated…

  10. A devil in the detail: parameter cross-talk from the solar cycle and estimation of solar p-mode frequencies

    OpenAIRE

    Chaplin, W. J.; Jimenez-Reyes, S. J.; Eff-Darwich, A.; Elsworth, Y.; New, R.

    2008-01-01

    Frequencies, powers and damping rates of the solar p modes are all observed to vary over the 11-yr solar activity cycle. Here, we show that simultaneous variations of these parameters give rise to a subtle cross-talk effect, which we call the ``devil in the detail'', that biases p-mode frequencies estimated from analysis of long power frequency spectra. We also show that the resonant peaks observed in the power frequency spectra show small distortions due to the effect. Most of our paper is d...

  11. Bonobos extract meaning from call sequences.

    Directory of Open Access Journals (Sweden)

    Zanna Clay

    Full Text Available Studies on language-trained bonobos have revealed their remarkable abilities in representational and communication tasks. Surprisingly, however, corresponding research into their natural communication has largely been neglected. We address this issue with a first playback study on the natural vocal behaviour of bonobos. Bonobos produce five acoustically distinct call types when finding food, which they regularly mix together into longer call sequences. We found that individual call types were relatively poor indicators of food quality, while context specificity was much greater at the call sequence level. We therefore investigated whether receivers could extract meaning about the quality of food encountered by the caller by integrating across different call sequences. We first trained four captive individuals to find two types of foods, kiwi (preferred and apples (less preferred at two different locations. We then conducted naturalistic playback experiments during which we broadcasted sequences of four calls, originally produced by a familiar individual responding to either kiwi or apples. All sequences contained the same number of calls but varied in the composition of call types. Following playbacks, we found that subjects devoted significantly more search effort to the field indicated by the call sequence. Rather than attending to individual calls, bonobos attended to the entire sequences to make inferences about the food encountered by a caller. These results provide the first empirical evidence that bonobos are able to extract information about external events by attending to vocal sequences of other individuals and highlight the importance of call combinations in their natural communication system.

  12. Optical frequency combs generated mechanically

    CERN Document Server

    Sumetsky, M

    2016-01-01

    It is shown that a highly equidistant optical frequency comb can be generated by the parametric excitation of an optical bottle microresonator with nanoscale effective radius variation by its natural mechanical vibrations.

  13. Calling SNPs without a reference sequence

    Directory of Open Access Journals (Sweden)

    Schuster Stephan C

    2010-03-01

    Full Text Available Abstract Background The most common application for the next-generation sequencing technologies is resequencing, where short reads from the genome of an individual are aligned to a reference genome sequence for the same species. These mappings can then be used to identify genetic differences among individuals in a population, and perhaps ultimately to explain phenotypic variation. Many algorithms capable of aligning short reads to the reference, and determining differences between them have been reported. Much less has been reported on how to use these technologies to determine genetic differences among individuals of a species for which a reference sequence is not available, which drastically limits the number of species that can easily benefit from these new technologies. Results We describe a computational pipeline, called DIAL (De novo Identification of Alleles, for identifying single-base substitutions between two closely related genomes without the help of a reference genome. The method works even when the depth of coverage is insufficient for de novo assembly, and it can be extended to determine small insertions/deletions. We evaluate the software's effectiveness using published Roche/454 sequence data from the genome of Dr. James Watson (to detect heterozygous positions and recent Illumina data from orangutan, in each case comparing our results to those from computational analysis that uses a reference genome assembly. We also illustrate the use of DIAL to identify nucleotide differences among transcriptome sequences. Conclusions DIAL can be used for identification of nucleotide differences in species for which no reference sequence is available. Our main motivation is to use this tool to survey the genetic diversity of endangered species as the identified sequence differences can be used to design genotyping arrays to assist in the species' management. The DIAL source code is freely available at http://www.bx.psu.edu/miller_lab/.

  14. Multivariate Effects of Level of Education, Computer Ownership, and Computer Use on Female Students’ Attitudes towards CALL

    OpenAIRE

    Mehrak Rahimi; Samaneh Yadollahi

    2012-01-01

    The aim of this study was investigating Iranian female students’ attitude towards CALL and its relationship with their level of education, computer ownership, and frequency of use. One hundred and forty-two female students (50 junior high-school students, 49 high-school students and 43 university students) participated in this study. They filled in A-CALL questionnaire that assessed their attitudes towards CALL with respect to four factors: effectiveness of CALL vs. non-CALL, surplus value of...

  15. Synergistic modeling of call center operations

    OpenAIRE

    2006-01-01

    We synergistically apply queueing theory, integer programming, and stochastic simulation to determine an optimal staffing policy for a repair call handling center. A stationary Markovian queueing model is employed to determine minimal staffing levels for a sequence of time intervals with varying call volumes and mean handling times. These staffing requirements populate an integer program model for determining the mix of call agent shifts that will achieve service quality standards at minimum ...

  16. Bonobos extract meaning from call sequences

    OpenAIRE

    Clay, Zanna; Zuberbuehler, Klaus

    2011-01-01

    Studies on language-trained bonobos have revealed their remarkable abilities in representational and communication tasks. Surprisingly, however, corresponding research into their natural communication has largely been neglected. We address this issue with a first playback study on the natural vocal behaviour of bonobos. Bonobos produce five acoustically distinct call types when finding food, which they regularly mix together into longer call sequences. We found that individual call types were...

  17. Long-distance calls in Neotropical primates

    OpenAIRE

    Oliveira Dilmar A.G.; Ades César

    2004-01-01

    Long-distance calls are widespread among primates. Several studies concentrate on such calls in just one or in few species, while few studies have treated more general trends within the order. The common features that usually characterize these vocalizations are related to long-distance propagation of sounds. The proposed functions of primate long-distance calls can be divided into extragroup and intragroup ones. Extragroup functions relate to mate defense, mate attraction or resource defense...

  18. CALL for endangered languages: Challenges and rewards

    OpenAIRE

    Ward, Monica; Van Genabith, Josef

    2003-01-01

    The interaction between CALL and Endangered Languages (EL) is an under-researched and under-exploited field. It is perhaps no surprise that this should be the case as CALL in the EL context has to address additional requirements and deal with extra constraints over and above those that prevail in mainstream CALL. This article introduces the topic of Endangered Languages and lists two classifications for Endangered Languages (Terralingua, 2000; Unesco, 1993). It outlines why a language becomes...

  19. Performance Indicators for Call Centers with Impatience

    OpenAIRE

    Jouini, Oualid; Koole, Ger; Roubos, Alex

    2013-01-01

    International audience An important feature of call center modeling is the presence of impatient customers. In this paper, we consider single-skill call centers including customer abandonments. We study a number of different service level definitions, including all those used in practice, and show how to explicitly compute their performance measures. Based on data from different call centers, new models are defined that extend the common Erlang A model. We show that the new models fit real...

  20. Periodic Halpha variations in GL 581: Further evidence for an activity origin to GL 581d

    CERN Document Server

    Hatzes, Artie P

    2015-01-01

    Radial velocity measurements showed evidence that the M dwarf GL 581 might host a planet, GL 581d, in the so-called "habitable zone" of the star. A study of Halpha in GL 581 demonstrated that changes in this activity indicator correlated with radial velocity variations attributed to GL 581d. An exopplanet that was important for studies of planet habitability may be an artifact of stellar activity. Previous investigations analyzing the same activity data have reached different conclusions regarding the existence of GL 581d. We therfore investigated the Halpha variations for GL 581 to assess the nature of the radial velocity variations attributed to the possible planet GL 581d. We performed a Fourier analysis of the published Halpha measurements for GL 581d using a so-called pre-whitening process to isolate the variations at the orbital frequency of GL 581d. The frequency analysis yields five significant frequencies, one of which is associated with the 66.7 d orbital period of the presumed planet Gl 581d. The H...

  1. Call Duration Characteristics based on Customers Location

    Directory of Open Access Journals (Sweden)

    Žvinys Karolis

    2014-05-01

    Full Text Available Nowadays a lot of different researches are performed based on call duration distributions (CDD analysis. However, the majority of studies are linked with social relationships between the people. Therefore the scarcity of information, how the call duration is associated with a user's location, is appreciable. The goal of this paper is to reveal the ties between user's voice call duration and the location of call. For this reason we analyzed more than 5 million calls from real mobile network, which were made over the base stations located in rural areas, roads, small towns, business and entertainment centers, residential districts. According to these site types CDD’s and characteristic features for call durations are given and discussed. Submitted analysis presents the users habits and behavior as a group (not an individual. The research showed that CDD’s of customers being them in different locations are not equal. It has been found that users at entertainment, business centers are tend to talk much shortly, than people being at home. Even more CDD can be distorted strongly, when machinery calls are evaluated. Hence to apply a common CDD for a whole network it is not recommended. The study also deals with specific parameters of call duration for distinguished user groups, the influence of network technology for call duration is considered.

  2. Multidimensional views on mobile call network

    Institute of Scientific and Technical Information of China (English)

    Shengqi YANG; Bin WU; Bai WANG

    2009-01-01

    Recent studies on social network have spurred significant interests in human behaviors. Nowadays, various kinds of interpersonal human interactions, from mobile calls to emalls, provide particular avenues to explore the inher-ent properties of communication patterns. In this article, we present a comprehensive study on a massive anonymous call records obtained from a major mobile service operator. The important difference laid in our work and previous mainly topological analyses is that we report on multiple aspects of the dataset. By investigating the calls of the users, we find out that most calls tend to last within one minute. Call du-ration between two females is much longer than that of two males. But calls of males generally involve more stations than that of female, indicating a larger mobile range of the males. We also observed that people tend to communicate more with each other when they share similar characters. Besides, the network is well-connected and robust to random attack. We also demonstrate that the close-knit sub-groups with little discrepancy in the characteristics of its involved users usually evoke more calls. Another interesting discov-ery is that call behaviors among people between workdays and weekends is obviously distinct. Generally speaking, the goal that we research on call network through multidimen-sional analyses is to uncover the intricate patterns of human communications and put up reasonable insights into future service intelligence.

  3. Ultrasonic call characteristics of rat pups are altered following prenatal malnutrition.

    Science.gov (United States)

    Tonkiss, John; Bonnie, Kristin E; Hudson, Jamie L; Shultz, Penny L; Duran, Pilar; Galler, Janina R

    2003-09-01

    The male offspring of rats provided with a protein deficient diet (6% casein) for 5 weeks prior to mating and throughout pregnancy were subjected to a brief period of isolation and cooling at postnatal Days (P)7, 9, and 11, and their ultrasonic vocalizations were compared with those of well-nourished pups. Calls were categorized into 12 different types based upon their sonographic patterns. Although call rates were equal, the call characteristics of the prenatally malnourished pups differed significantly from those of well-nourished controls. At P7, their mean peak sound frequency (irrespective of call type) was significantly higher, and constant frequency calls were of both higher frequency and longer duration. Over the age range studied, prenatally malnourished pups emitted a smaller variety of calls, with significantly fewer ascending frequency vocalizations while producing either significantly fewer (P9) or greater (P11) descending frequency calls. Altered crying patterns have been related to brain damage in human babies, with more abnormal cries being associated with more severe neurological impairment. Therefore, the present results most likely reflect altered central nervous system development and function. Ultrasonic vocalization characteristics in rat pups may provide a useful early marker of the severity of disturbance to the development of the central nervous system following an insult, and offer the potential for predicting the degree of functional and behavioral deficits later in life. PMID:12918088

  4. Effect of lesion of nucleus robustus archistriatalis on call in bramble finch (Fringilla montifringilla)

    Institute of Scientific and Technical Information of China (English)

    蒋锦昌; 李东风; 李杰; 杨新宇

    2001-01-01

    The lesion of nucleus robustus archistriatalis (RA) has no effect on normal short calls in the bramble finch, but affects significantly the temporal and acoustic features of learned long calls.It causes the principal frequency of basic sound in monotone long calls to increase 500 cents, and to lose two upper partials. The lesion of RA not only results in the increased sound length of loud-sound and shortened coda of variable-tone long calls by 13.4%-22.1% and 21.2%-24.2% on average, respectively, but also makes the frequency rising coefficient (FRC) of even order partial tone in loud-sound drop 18.5%-25.8% on an average, and the step-up rate decrease 22.7% -24.0% on an average with the increase of frequencies. These results show that the control of temporal and frequency features of learned calls by RA matches to each other. Moreover, the lesion of bilateral RA can confuse the vocal pattern, and the produced long call has the character of both the mono- and variable-tone long calls. The prelude shows rising frequency, and the loud sound is monotone sound.

  5. When They Talk about CALL: Discourse in a Required CALL Class

    Science.gov (United States)

    Kessler, Greg

    2010-01-01

    This study investigates preservice teachers' discourse about CALL in a required CALL class which combines theory and practice. Thirty-three students in a Linguistics MA program CALL course were observed over a 10-week quarter. For all of these students, it was their first formal exposure to CALL as a discipline. Communication in the class…

  6. Tunable frequency 4-rod RFQ

    International Nuclear Information System (INIS)

    The frequency tunability of the 4-rod RFQ is investigated. By moving the shorting plate between the posts, which support the 4-rod electrodes, the resonant frequency can be varied almost twofold. Model studies and the calculation of the field uniformity, the variation of Q, and the shunt impedance are reported. (author)

  7. Lunch frequency among adolescents

    DEFF Research Database (Denmark)

    Pedersen, Trine Pagh; Holstein, Bjørn E; Krølner, Rikke;

    2016-01-01

    OBJECTIVE: To investigate: (i) how lunch frequency of adolescents varies between schools and between classes within schools; (ii) the associations between frequency of lunch and individual sociodemographic factors and school characteristics; and (iii) if any observed associations between lunch...... frequency and school characteristics vary by gender and age groups. DESIGN: Cross-sectional study in which students and school headmasters completed self-administered questionnaires. Associations were estimated by multilevel multivariate logistic regression. SETTING: The Danish arm of the Health Behaviour...... in School-Aged Children study 2010. SUBJECTS: Students (n 4922) aged 11, 13 and 15 years attending a random sample of seventy-three schools. RESULTS: The school-level and class-level variations in low lunch frequency were small (intraclass correlation coefficient <2·1 %). At the individual level, low...

  8. PGG: An Online Pattern Based Approach for Stream Variation Management

    Institute of Scientific and Technical Information of China (English)

    Lu-An Tang; Bin Cui; Hong-Yan Li; Gao-Shan Miao; Dong-Qing Yang; Xin-Biao Zhou

    2008-01-01

    Many database applications require efficient processing of data streams with value variations and fiuctuant sampling frequency. The variations typically imply fundamental features of the stream and important domain knowledge of underlying objects. In some data streams, successive events seem to recur in a certain time interval, but the data indeed evolves with tiny differences as time elapses. This feature, so called pseudo periodicity, poses a new challenge to stream variation management. This study focuses on the online management for variations over such streams. The idea can be applied to many scenarios such as patient vital signal monitoring in medical applications. This paper proposes a new method named Pattern Growth Graph (PGG) to detect and manage variations over evolving streams with following features: 1) adopts the wave-pattern to capture the major information of data evolution and represent them compactly;2) detects the variations in a single pass over the stream with the help of wave-pattern matching algorithm; 3) only stores different segments of the pattern for incoming stream, and hence substantially compresses the data without losing important information; 4) distinguishes meaningful data changes from noise and reconstructs the stream with acceptable accuracy.Extensive experiments on real datasets containing millions of data items, as well as a prototype system, are carried out to demonstrate the feasibility and effectiveness of the proposed scheme.

  9. Performance evaluation of Call-center with call redirection: Ocena performanc klicnega centra s preusmerjanjem klicev:

    OpenAIRE

    Efimushkin, Vladimir; Žepič, Drago

    2007-01-01

    The object of investigation is an analytical model for a Call-center functioning with a traffic distribution (call redirection) mechanism. Call-center functioning is described by the Markov process. A solution for stationary distribution is found and expressions for the main performance characteristics for the Call-center functioning are given. The proposed analytical model enables an investigation in different call traffic management schemes for the cases of agents overload and underload. ...

  10. Effect of gender and call duration on customer satisfaction in call center big data

    OpenAIRE

    Quim Llimona; Jordi Luque; Xabier Anguera; Zoraida Hidalgo; Souneil Park; Nuria Oliver

    2015-01-01

    Customer center call data is typically collected by organizations and corporations in order to improve customer experience through the analysis of such call data. In this paper, we report our findings when analysing more than 26 thousand calls to the call centers of a large corporation in a Latin American country. We focus on the impact of gender and call duration on selfreported customer satisfaction. Speech-based gender detection technology is employed to automatically detect the gender...

  11. Core Competencies Of A Call Centre AgentCore Competencies Of A Call Centre Agent

    OpenAIRE

    Christine White; Vera Roos

    2005-01-01

    Call centre agents are becoming increasingly important in the call centre context. They act as a contact point between the customer and the company. Call centre agents should have certain competencies to perform their duties sufficiently. Identifying competencies, required to be effective agents, will ease the task of training and recruitment. Due to the interrelatedness of the call centre agent, the management of a call centre and customers, all relevant role players’ perceptions were taken ...

  12. Frequency standards

    CERN Document Server

    Riehle, Fritz

    2006-01-01

    Of all measurement units, frequency is the one that may be determined with the highest degree of accuracy. It equally allows precise measurements of other physical and technical quantities, whenever they can be measured in terms of frequency.This volume covers the central methods and techniques relevant for frequency standards developed in physics, electronics, quantum electronics, and statistics. After a review of the basic principles, the book looks at the realisation of commonly used components. It then continues with the description and characterisation of important frequency standards

  13. Coaching "Callings" throughout the Adult Life Cycle.

    Science.gov (United States)

    Hudson, Frederic M.

    2001-01-01

    The process of "callings" continues throughout life. Coaching can connect the present to the future in a meaningful way. Callings represent a value shift requiring revision of the nature and scope of one's central purpose in life and meaningful activities. (JOW)

  14. 78 FR 21891 - Rural Call Completion

    Science.gov (United States)

    2013-04-12

    ... in Rulemaking Proceedings, 63 FR 24121 (1998). Electronic Filers: Comments may be filed..., we propose to apply these obligations to the first facilities-based provider in the call- delivery... call. In cases where the first facilities-based provider serves multiple non-facilities-...

  15. Applying Pedagogical Principles to CALL Courseware Development.

    Science.gov (United States)

    Wyatt, David H.

    This paper on the application of principles to computer-assisted language learning (CALL) first clarifies the the relationships between the capabilities of the computer (and computer-controlled technology) and the main approaches to second language learning. Fourteen common types of CALL programs are briefly reviewed. A "relational" classification…

  16. 78 FR 76218 - Rural Call Completion

    Science.gov (United States)

    2013-12-17

    ... choice. If that reseller making the initial long-distance call path choice uses VoIP technology, in the..., interexchange carriers (IXCs), commercial mobile radio service (CMRS) providers, and VoIP service providers... the prohibition on call blocking; made clear that carriers' blocking of VoIP-PSTN traffic...

  17. Call-Center – Rationalisierung im Dilemma

    OpenAIRE

    Holtgrewe, Ursula; Gundtoft, Lars

    2001-01-01

    Die Verfasser untersuchen Funktionen, Lösungen und Probleme der Organisationsform Call-Center. Aus organisationssoziologischer Sicht werden grundlegende Funktionen und Dilemmata organisationeller Grenzstellen beleuchtet und mit Informationen über Organisations- und Beschäftigtenstruktur, Arbeitsweisen und Kundenbeziehungen der verschiedenen Typen von Call-Centern abgeglichen. Die Untersuchung ist auf drei Ebenen angelegt: Aus systematisch-struktureller Sicht werden Organisationsdilemmata an d...

  18. A CALL for Improved School Leadership

    Science.gov (United States)

    Halverson, Richard; Kelley, Carolyn; Shaw, James

    2014-01-01

    The Comprehensive Assessment of Leadership for Learning (CALL) is a formative assessment that provides feedback to schools on the research-based leadership practices necessary to improve teaching and learning. Instead of focusing on an individual leader, CALL measures leadership practices in tasks carried out by actors across the school and…

  19. Communication cliques in mobile phone calling networks

    CERN Document Server

    Li, Ming-Xia; Jiang, Zhi-Qiang; Zhou, Wei-Xing

    2015-01-01

    People in modern societies form different social networks through numerous means of communication. These communication networks reflect different aspects of human's societal structure. The billing records of calls among mobile phone users enable us to construct a directed calling network (DCN) and its Bonferroni network (SVDCN) in which the preferential communications are statistically validated. Here we perform a comparative investigation of the cliques of the original DCN and its SVDCN constructed from the calling records of more than nine million individuals in Shanghai over a period of 110 days. We find that the statistical properties of the cliques of the two calling networks are qualitatively similar and the clique members in the DCN and the SVDCN exhibit idiosyncratic behaviors quantitatively. Members in large cliques are found to be spatially close to each other. Based on the clique degree profile of each mobile phone user, the most active users in the two calling networks can be classified in to seve...

  20. Call Admission Control in Mobile Cellular Networks

    CERN Document Server

    Ghosh, Sanchita

    2013-01-01

    Call Admission Control (CAC) and Dynamic Channel Assignments (DCA) are important decision-making problems in mobile cellular communication systems. Current research in mobile communication considers them as two independent problems, although the former greatly depends on the resulting free channels obtained as the outcome of the latter. This book provides a solution to the CAC problem, considering DCA as an integral part of decision-making for call admission. Further, current technical resources ignore movement issues of mobile stations and fluctuation in network load (incoming calls) in the control strategy used for call admission. In addition, the present techniques on call admission offers solution globally for the entire network, instead of considering the cells independently.      CAC here has been formulated by two alternative approaches. The first approach aimed at handling the uncertainty in the CAC problem by employing fuzzy comparators.  The second approach is concerned with formulation of CAC ...

  1. Echolocation Call Structure of Fourteen Bat Species in Korea

    Directory of Open Access Journals (Sweden)

    Fukui, Dai

    2015-07-01

    Full Text Available The echolocation calls of bats can provide useful information about species that are generally difficult to observe in the field. In many cases characteristics of call structure can be used to identify species and also to obtain information about aspects of the bat's ecology. We describe and compare the echolocation call structure of 14 of the 21 bat species found in Korea, for most of which the ecology and behavior are poorly understood. In total, 1,129 pulses were analyzed from 93 echolocation call sequences of 14 species. Analyzed pulses could be classified into three types according to the pulse shape: FM/CF/FM type, FM type and FM/QCF type. Pulse structures of all species were consistent with previous studies, although geographic variation may be indicated in some species. Overall classification rate provided by the canonical discriminant analysis was relatively low. Especially in the genera Myotis and Murina, there are large overlaps in spectral and temporal parameters between species. On the other hand, classification rates for the FM/QCF type species were relatively high. The results show that acoustic monitoring could be a powerful tool for assessing bat activity and distribution in Korea, at least for FM/QCF and FM/CF/FM species.

  2. Loud calls of adult male red howling monkeys (Alouatta seniculus).

    Science.gov (United States)

    Schön Ybarra, M A

    1986-01-01

    Loud calls of adult male red howlers (Alouatta seniculus) inhabiting a deciduous and semideciduous open woodland site in Venezuela were recorded opportunistically and categorized by ear and sonographically as barks and roars. Five to six different bark syllables were identified as occurring singly or in sequences of doublets and triplets. In barks, spectral energy was concentrated in bands at 350-400 Hz, 900-1,100 Hz, 1,800-2,200 Hz and 3,000-3,500 Hz, but not all higher bands were present in each syllable. Roars appeared sonographically like prolonged barks composed of a pulsated preface, a long legato climax and a brief, fractionated and at times pulsated coda; each part varied internally to the ear and in acoustic structure. All loud calls were of the noisy type (nonharmonic energy over a broad frequency range). Acoustic characteristics of the calls are interpreted in terms of the subserving vocal tract anatomy. I compare loud calls of red howlers with those of mantled (A. palliata) and black (A. caraya) howlers. PMID:3609972

  3. External GSM phone calls now made simpler

    CERN Multimedia

    2007-01-01

    On 2 July, the IT/CS Telecom Service introduced a new service making external calls from CERN GSM phones easier. A specific prefix is no longer needed for calls outside CERN. External calls from CERN GSM phones are to be simplified. It is no longer necessary to use a special prefix to call an external number from the CERN GSM network.The Telecom Section of the IT/CS Group is introducing a new system that will make life easier for GSM users. It is no longer necessary to use a special prefix (333) to call an external number from the CERN GSM network. Simply dial the number directly like any other Swiss GSM customer. CERN currently has its own private GSM network with the Swiss mobile operator, Sunrise, covering the whole of Switzerland. This network was initially intended exclusively for calls between CERN numbers (replacing the old beeper system). A special system was later introduced for external calls, allowing them to pass thr...

  4. Performance of Call to Order - photographs

    OpenAIRE

    Ritter, Kathleen; Maxwell, James; PARRC

    2012-01-01

    Call to Order is the translation—into musical sound—of the meeting minutes of the organizations behind Institutions by Artists: The Convention (PAARC, Fillip, and ARCA). Call to Order uses a prosaic form of administration as material for creative production. Musical scores were created from the meeting minutes of each organization by mapping Robert’s Rules of Order onto the implied rules of Piston’s Harmony and using both texts as comparative guides. Call to Order is the musical sound of a...

  5. Echolocation calls of Myotis frater (Chiroptera: Hipposi- deridae) during search flight

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Echolocation calls of Myotis frater emitted during the search phase consist of brief frequency-modulated pulses. The sound signals are comprised of three harmonics of which the first one is of the highest intensity and occurs in all echolocation calls. The frequency of this fundamental harmonic ranges from 110.8 to 50.2 kHz, and its duration is about 3.5 ms. The second and the third harmonics are relatively weak, occurring in 50.0% and 25.0% of echolocation calls respectively, with frequencies ranging from 138.4 to 116.6 kHz for the second harmonic and from 193.6 to 170.8 kHz for the third harmonic. We presume that, according to the echolocation call features, Myotis frater probably forages the insects on the ground of complex environments.

  6. Individual killer whale vocal variation during intra-group behavioral dynamics

    Science.gov (United States)

    Grebner, Dawn M.

    The scientific goal of this dissertation was to carefully study the signal structure of killer whale communications and vocal complexity and link them to behavioral circumstances. The overall objective of this research sought to provide insight into killer whale call content and usage which may be conveying information to conspecifics in order to maintain group cohesion. Data were collected in the summers of 2006 and 2007 in Johnstone Strait, British Columbia. For both individuals and small groups, vocalizations were isolated using a triangular hydrophone array and the behavioral movement patterns were captured by a theodolite and video camera positioned on a cliff overlooking the hyrophone locations. This dissertation is divided into four analysis chapters. In Chapter 3, discriminant analysis was used to validate the four N04 call subtypes which were originally parsed due to variations in slope segments. The first two functions of the discriminant analysis explained 97% of the variability. Most of the variability for the N04 call was found in the front convex and the terminal portions of the call, while very little variability was found in the center region of the call. This research revealed that individual killer whales produced multiple subtypes of the N04 call. No correlations of behaviors to acoustic parameters obtained were found. The aim of the Chapter 4 was to determine if killer whale calling behavior varied prior to and after the animals had joined. Pulsed call rates were found to be greater pre- compared to post-joining events. Two-way vocal exchanges were more common occurring 74% of the time during pre-joining events. In Chapter 5, initiated and first response to calls varied between age/sex class groups when mothers were separated from an offspring. Solo mothers and calves initiated pulsed calls more often than they responded. Most of the no vocal responses were due to mothers who were foraging. Finally, observations of the frequency split in N04

  7. The peripheral auditory characteristics of noctuid moths: responses to the search-phase echolocation calls of bats

    Science.gov (United States)

    Waters; Jones

    1996-01-01

    The noctuid moths Agrotis segetum and Noctua pronuba show peak auditory sensitivity between 15 and 25 kHz, and a maximum sensitivity of 35 dB SPL. A. segetum shows a temporal integration time of 69 ms. It is predicted that bats using high-frequency and short-duration calls will be acoustically less apparent to these moths. Short-duration frequency-modulated (FM) calls of Plecotus auritus are not significantly less acoustically apparent than those of other FM bats with slightly longer call durations, based on their combined frequency and temporal structure alone. Long-duration, high-frequency, constant-frequency (CF) calls of Rhinolophus hipposideros at 113 kHz are significantly less apparent than those of the FM bats tested. The predicted low call apparency of the 83 kHz CF calls of R. ferrumequinum appears to be counteracted by their long duration. It is proposed that two separate mechanisms are exploited by bats to reduce their call apparency, low intensity in FM bats and high frequency in CF bats. Within the FM bats tested, shorter-duration calls do not significantly reduce the apparency of the call at the peripheral level, though they may limit the amount of information available to the central nervous system. PMID:9318627

  8. Ensembl variation resources

    Directory of Open Access Journals (Sweden)

    Marin-Garcia Pablo

    2010-05-01

    Full Text Available Abstract Background The maturing field of genomics is rapidly increasing the number of sequenced genomes and producing more information from those previously sequenced. Much of this additional information is variation data derived from sampling multiple individuals of a given species with the goal of discovering new variants and characterising the population frequencies of the variants that are already known. These data have immense value for many studies, including those designed to understand evolution and connect genotype to phenotype. Maximising the utility of the data requires that it be stored in an accessible manner that facilitates the integration of variation data with other genome resources such as gene annotation and comparative genomics. Description The Ensembl project provides comprehensive and integrated variation resources for a wide variety of chordate genomes. This paper provides a detailed description of the sources of data and the methods for creating the Ensembl variation databases. It also explores the utility of the information by explaining the range of query options available, from using interactive web displays, to online data mining tools and connecting directly to the data servers programmatically. It gives a good overview of the variation resources and future plans for expanding the variation data within Ensembl. Conclusions Variation data is an important key to understanding the functional and phenotypic differences between individuals. The development of new sequencing and genotyping technologies is greatly increasing the amount of variation data known for almost all genomes. The Ensembl variation resources are integrated into the Ensembl genome browser and provide a comprehensive way to access this data in the context of a widely used genome bioinformatics system. All Ensembl data is freely available at http://www.ensembl.org and from the public MySQL database server at ensembldb.ensembl.org.

  9. Mourning Dove Call-count Survey

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Mourning Dove (Zenaida macroura) Call-Count Survey was developed to provide an index to population size and to detect annual changes in mourning dove breeding...

  10. Engineers call for US nuclear safety fix

    Science.gov (United States)

    Gwynne, Peter

    2016-04-01

    Seven Nuclear Regulatory Commission (NRC) engineers have called on the commission to force the owners of US nuclear reactors to repair a design flaw that could affect the safe operation of emergency core cooling systems.

  11. 17 CFR 31.18 - Margin calls.

    Science.gov (United States)

    2010-04-01

    ... after contact is effected in which to respond to a margin call. Twenty-four hours, excluding Saturdays... contract for a period of 5 business days at the then prevailing bid price in the case of a long...

  12. 76 FR 4896 - Call for Candidates

    Science.gov (United States)

    2011-01-27

    ... accepted accounting principles for federal government entities. Generally, non-federal Board members are... From the Federal Register Online via the Government Publishing Office FEDERAL ACCOUNTING STANDARDS ADVISORY BOARD Call for Candidates AGENCY: Federal Accounting Standards Advisory Board. ACTION:...

  13. 76 FR 36130 - Call for Candidates

    Science.gov (United States)

    2011-06-21

    ... establish generally accepted accounting principles for federal government entities. Generally, non- federal... From the Federal Register Online via the Government Publishing Office FEDERAL ACCOUNTING STANDARDS ADVISORY BOARD Call for Candidates AGENCY: Federal Accounting Standards Advisory Board. ACTION: Request...

  14. Calling patterns in human communication dynamics

    OpenAIRE

    Jiang, Zhi-Qiang; Xie, Wen-Jie; Li, Ming-Xia; Podobnik, Boris; Zhou, Wei-Xing; Stanley, H. Eugene

    2013-01-01

    Modern technologies not only provide a variety of communication modes, e.g., texting, cellphone conversation, and online instant messaging, but they also provide detailed electronic traces of these communications between individuals. These electronic traces indicate that the interactions occur in temporal bursts. Here, we study the inter-call durations of the 100,000 most-active cellphone users of a Chinese mobile phone operator. We confirm that the inter-call durations follow a power-law dis...

  15. Application for call center data analysis

    OpenAIRE

    KLEMENČIČ, DAMJAN

    2015-01-01

    Graduation thesis describes the planning and design of desktop application CTI Server that is used in call and dispatch centers, where they have communication server (PBX) Siemens. Application collects data that is sent from communication server and stores them in data base for subsequent processing. It also displays current status of agents and telephony connections, call history and agent logs for a certain period of time. With the data obtained from communication server the application ...

  16. Towards Building an Intelligent Call Routing System

    OpenAIRE

    Thien Khai Tran; Dung Minh Pham; Binh Van Huynh

    2016-01-01

    This paper presents EduICR - an Intelligent Call Routing system. This system can route calls to the most appropriate agent using routing rules built by the text classifier. EduICR includes the following main components: telephone communication network; Vietnamese speech recognition; Text classifier/ Natural language processor and Vietnamese speech synthesis. To our best knowledge, this is one of the first systems in Vietnam to implement the integration mechanism of text processing and speech ...

  17. Identifying users profiles from mobile calls habits

    OpenAIRE

    Furletti, Barbara; Gabrielli, Lorenzo; Rinzivillo, Salvatore; Renso, Chiara

    2012-01-01

    The huge quantity of positioning data registered by our mobile phones stimulates several research questions, mainly originating from the combination of this huge quantity of data with the extreme heterogeneity of the tracked user and the low granularity of the data. We propose a methodology to partition the users tracked by GSM phone calls into profiles like resident, commuters, in transit and tourists. The methodology analyses the phone calls with a combination of top-down and bottom up tech...

  18. Call-Center-Forschung: Ergebnisse und Theorien

    OpenAIRE

    Holtgrewe, Ursula

    2003-01-01

    "In den letzten Jahren haben sich ForscherInnen aus unterschiedlichen Richtungen der Industrie-, Arbeits- und Organisationssoziologie für Call Center interessiert. Der Grund dafür liegt nicht allein darin, dass es sich um einen schnell expandierenden Bereich der Dienstleistungsarbeit handelt. Es scheint vielmehr, dass sich in den Call Centern exemplarisch eine Reihe von Themen und Tendenzen bündelt, die die Arbeit in Dienstleistungs- und Wissensgesellschaften bestimmen. So s...

  19. Optimal Balanced Control for Call Centers

    OpenAIRE

    Bhulai, Sandjai; Farenhorst-Yuan, Taoying; Heidergott, Bernd; van der Laan, Dinard

    2010-01-01

    In this paper we study a challenging call center operation problem. The goal of our analysis is to identify an optimal policy for allocating tasks to agents. As a first step, we discuss promising randomized policies and use stochastic approximation for finding the optimal randomized policy when implemented via a Bernoulli scheme. As we will show in this paper, the performance of the call center can be improved if the randomized policy is implemented by a deterministic sequence satisfying some...

  20. BUSINESS MODELS FOR EXTENDING OF 112 EMERGENCY CALL CENTER CAPABILITIES WITH E-CALL FUNCTION INSERTION

    OpenAIRE

    Pop Dragos Paul; Botezatu Cornelia Paulina; Botezatu Cezar; Carutasu George

    2010-01-01

    The present article concerns present status of implementation in Romania and Europe of eCall service and the proposed business models regarding eCall function implementation in Romania. eCall system is used for reliable transmission in case of crush between In Vehicle System and Public Service Answering Point, via the voice channel of cellular and Public Switched Telephone Network (PSTN). eCall service could be initiated automatically or manual the driver. All data presented in this article a...

  1. Partition Decomposition for Roll Call Data

    CERN Document Server

    Leibon, Greg; Rockmore, Daniel N; Savell, Robert

    2011-01-01

    In this paper we bring to bear some new tools from statistical learning on the analysis of roll call data. We present a new data-driven model for roll call voting that is geometric in nature. We construct the model by adapting the "Partition Decoupling Method," an unsupervised learning technique originally developed for the analysis of families of time series, to produce a multiscale geometric description of a weighted network associated to a set of roll call votes. Central to this approach is the quantitative notion of a "motivation," a cluster-based and learned basis element that serves as a building block in the representation of roll call data. Motivations enable the formulation of a quantitative description of ideology and their data-dependent nature makes possible a quantitative analysis of the evolution of ideological factors. This approach is generally applicable to roll call data and we apply it in particular to the historical roll call voting of the U.S. House and Senate. This methodology provides a...

  2. Communication cliques in mobile phone calling networks

    Science.gov (United States)

    Li, Ming-Xia; Xie, Wen-Jie; Jiang, Zhi-Qiang; Zhou, Wei-Xing

    2015-11-01

    People in modern societies form different social networks through numerous means of communication. These communication networks reflect different aspects of human's societal structure. The billing records of calls among mobile phone users enable us to construct a directed calling network (DCN) and its Bonferroni network (SVDCN) in which the preferential communications are statistically validated. Here we perform a comparative investigation of the cliques of the original DCN and its SVDCN constructed from the calling records of more than nine million individuals in Shanghai over a period of 110 days. We find that the statistical properties of the cliques of the two calling networks are qualitatively similar and the clique members in the DCN and the SVDCN exhibit idiosyncratic behaviors quantitatively. Members in large cliques are found to be spatially close to each other. Based on the clique degree profile of each mobile phone user, the most active users in the two calling networks can be classified in to several groups. The users in different groups are found to have different calling behaviors. Our study unveils interesting communication behaviors among mobile phone users that are densely connected to each other.

  3. 47 CFR 22.921 - 911 call processing procedures; 911-only calling mode.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false 911 call processing procedures; 911-only calling mode. 22.921 Section 22.921 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON... procedures; 911-only calling mode. Mobile telephones manufactured after February 13, 2000 that are capable...

  4. Behavioral Preferences for Individual Securities : The Case for Call Warrants and Call Options

    NARCIS (Netherlands)

    Ter Horst, J.R.; Veld, C.H.

    2002-01-01

    Since 1998, large investment banks have flooded the European capital markets with issues of call warrants.This has led to a unique situation in the Netherlands, where now call warrants, traded on the stock exchange, and long-term call options, traded on the options exchange, exist.Both entitle their

  5. Frequency stability

    Czech Academy of Sciences Publication Activity Database

    Kroupa, Věnceslav František

    Bratislava: Department of Radio and Electronics, FEI STU, 2006 - (Píš, P.; Krajčušková, Z.), I.1-I.9 ISBN 80-227-2388-6. [ Radio elektronika 2006. Conference proceedings. Bratislava (SK), 25.04.2006-26.04.2006] R&D Projects: GA ČR(CZ) GA102/05/0852 Institutional research plan: CEZ:AV0Z20670512 Keywords : noise * frequency stability * frequency control Subject RIV: JW - Navigation, Links, Detection ; Counter-Measures

  6. Variational MCMC

    OpenAIRE

    De Freitas, Nando; Hojen-Sorensen, Pedro; Jordan, Michael I.; Russell, Stuart

    2013-01-01

    We propose a new class of learning algorithms that combines variational approximation and Markov chain Monte Carlo (MCMC) simulation. Naive algorithms that use the variational approximation as proposal distribution can perform poorly because this approximation tends to underestimate the true variance and other features of the data. We solve this problem by introducing more sophisticated MCMC algorithms. One of these algorithms is a mixture of two MCMC kernels: a random walk Metropolis kernel ...

  7. Temperature effect on the advertisement call of Pleurodema tucumanum (Anura: Leiuperidae.

    Directory of Open Access Journals (Sweden)

    Julián Alonso Valetti

    2012-12-01

    Full Text Available The advertisement call represents an important character to discriminate species, mainly between sibling species. The genus Pleurodema has cryptic species, therefore its acoustical characteristics could represent an useful tool to solve taxonomicproblems. It is expected that the advertisement call acoustic properties of the amphibian anurans will vary with the temperature because the frogs are ectotherms. We evaluated the effect of temperature in the acoustic variables of the advertisement call of Pleurodema tucumanum. The inter-call interval, number of pulses per call, inter-pulse interval and pulse rate showed covariation with temperature, whereas the call duration, pulse duration and dominant frequency were temperature-independent. The advertisement call of P.tucumanum corresponds to a single periodic pulse train. The call showed an average duration of 289 ms, dominant frequency of 2552 Hz and 35 pulses of 2.38 ms at 22˚C. The number of pulses increased with temperature. The discrimination of exogenous variabilityfrom the acoustic components allows one to analyze the intrinsic variability of the advertisement calls.

  8. Behavioral Preferences for Individual Securities : The Case for Call Warrants and Call Options

    OpenAIRE

    Ter Horst, J.R.; Veld, C.H.

    2002-01-01

    Since 1998, large investment banks have flooded the European capital markets with issues of call warrants.This has led to a unique situation in the Netherlands, where now call warrants, traded on the stock exchange, and long-term call options, traded on the options exchange, exist.Both entitle their holders to buy shares of common stock.We use the long-term call options in order to price the call warrants.Using the model of Black and Scholes (1973), the Square Root model version of the Consta...

  9. Call-by-name, call-by-value, call-by-need and the linear lambda calculus

    OpenAIRE

    Maraist, J.; Odersky, M.; Turner, D.N.; Wadler, P.

    1999-01-01

    Girard described two translations of intuitionistic logic into linear logic, one where A→B maps to (!A⊸B) and another where it maps to !(A⊸B). We detail the action of these translations on terms and show that the first corresponds to a call-by-name calculus, while the second corresponds to call-by-value. We further show that if the target of the translation is taken to be an affine calculus, where! controls contraction but weakening is allowed everywhere, then the second translation correspon...

  10. Call-by-name, Call-by-value, Call-by-need, and the Linear Lambda Calculus

    OpenAIRE

    Maraist, John; Odersky, Martin; Turner, David N.; Wadler, Philip

    1995-01-01

    Girard described two translations of intuitionistic logic into linear logic, one where A -> B maps to (!A) -o B, and another where it maps to !(A -o B). We detail the action of these translations on terms, and show that the first corresponds to a call-by-name calculus, while the second corresponds to call-by-value. We further show that if the target of the translation is taken to be an affine calculus, where ! controls contraction but weakening is allowed everywhere, then the second transl...

  11. Influence of atmospheric properties on detection of wood-warbler nocturnal flight calls

    Science.gov (United States)

    Horton, Kyle G.; Stepanian, Phillip M.; Wainwright, Charlotte E.; Tegeler, Amy K.

    2015-10-01

    Avian migration monitoring can take on many forms; however, monitoring active nocturnal migration of land birds is limited to a few techniques. Avian nocturnal flight calls are currently the only method for describing migrant composition at the species level. However, as this method develops, more information is needed to understand the sources of variation in call detection. Additionally, few studies examine how detection probabilities differ under varying atmospheric conditions. We use nocturnal flight call recordings from captive individuals to explore the dependence of flight call detection on atmospheric temperature and humidity. Height or distance from origin had the largest influence on call detection, while temperature and humidity also influenced detectability at higher altitudes. Because flight call detection varies with both atmospheric conditions and flight height, improved monitoring across time and space will require correction for these factors to generate standardized metrics of songbird migration.

  12. Analysis of L5 phase variations in GPS IIF satellites by the raw observation PPP approach

    Science.gov (United States)

    Liu, Sha; Becker, Matthias

    2015-04-01

    GPS modernization along with Glonass modernization and the emerging Galileo and Compass system has been highly anticipated by every GNSS user since several years. The third civilian L5 signal transmitted by the modernized GPS satellites brings us to the GNSS multi-frequency era. The first GPS IIF satellite was launched in May 2010, until now there are eight block IIF satellites in service and the remaining four IIF satellites are planned to be launched by 2016. The introduction of the third frequency to GPS and the usage of advanced atomic clocks not only provide the users more possibilities but also enable higher positioning accuracy. Nevertheless phase variations are found on the new L5 observation of GPS SVN62. Further investigations suggest that the variations of this satellite are strongly dependent on the satellite inner temperature variation caused by sun illumination. Besides achieving precise positioning accuracy, PPP is also frequently used as a tool to analyze and evaluate various GNSS errors, for instance, tropospheric delays and receiver clock errors. Other than with differential GNSS, it is possible to separate different errors and to identify the error sources with PPP. Conventional PPP is based on the ionosphere-free linear combination, in order to eliminate the first-order ionospheric delays. However only dual frequencies can be used to build ionosphere-free linear combination, which leads to the waste of the information on the third frequency. Furthermore, the frequency dependent errors can not be separated and traced. A new PPP approach that avoids using any linear combination is proposed recently, which is called the raw observation PPP. One advantage of the raw observation PPP approach is that data of all frequencies and all GNSS systems can be jointly used. In addition, the frequency dependent errors are possible to be separated, identified and analyzed. In this paper the raw observation PPP is utilized to analyze the phase variations on L5

  13. Calling patterns in human communication dynamics

    CERN Document Server

    Jiang, Zhi-Qiang; Li, Ming-Xia; Podobnik, Boris; Zhou, Wei-Xing; Stanley, H Eugene; 10.1073/pnas.1220433110

    2013-01-01

    Modern technologies not only provide a variety of communication modes, e.g., texting, cellphone conversation, and online instant messaging, but they also provide detailed electronic traces of these communications between individuals. These electronic traces indicate that the interactions occur in temporal bursts. Here, we study the inter-call durations of the 100,000 most-active cellphone users of a Chinese mobile phone operator. We confirm that the inter-call durations follow a power-law distribution with an exponential cutoff at the population level but find differences when focusing on individual users. We apply statistical tests at the individual level and find that the inter-call durations follow a power-law distribution for only 3460 individuals (3.46%). The inter-call durations for the majority (73.34%) follow a Weibull distribution. We quantify individual users using three measures: out-degree, percentage of outgoing calls, and communication diversity. We find that the cellphone users with a power-law...

  14. Dynamic routing based on call quality

    CERN Document Server

    Hammami, Oussama; Gabrielyan, Emin

    2009-01-01

    The telephony over IP (ToIP) is becoming a new trend in technology widely used nowadays in almost all business sectors. Its concepts rely on transiting the telephone communications through the IP network. Today, this technology is deployed increasingly what the cause of emergence of companies is offering this service as Switzernet. For several highly demanded destinations, recently fake vendors appeared in the market offering voice termination but providing only false answer supervision. The answered signal is returned immediately and calls are being charged without being connected. Different techniques are used to keep the calling party on the line. One of these techniques is to play a record of a ring back tone (while the call is already being charged). Another, more sophisticated technique is to play a human voice randomly picked up from a set of records containing contents similar to: hello, hello, I cannot hear you Apart the fact that the fallaciously established calls are charged at rates of real calls,...

  15. Periodic Hα variations in GL 581: Further evidence for an activity origin to GL 581d

    Science.gov (United States)

    Hatzes, A. P.

    2016-01-01

    Context. Radial velocity measurements initially showed evidence that the M dwarf GL 581 might host up to six planetary companions. Two of these, GL 581g and GL 581d had orbital distances in the so-called "habitable zone" of the star. The existence of both of these planets have been called into question. Additional radial velocity measurements for GL 581g could not confirm its presence. A study of Hα in GL 581 showed that changes in this activity indicator correlated with radial velocity variations attributed to GL 581d. Thus two planets that were important for studies of habitable planets may be artifacts of stellar activity. Aims: Previous investigations analyzing the same activity data have reached different conclusions regarding the existence of GL 581d. We therefore investigated the Hα variations for GL 581 to assess the nature of the radial velocity variations attributed to the possible planet GL 581d. Methods: We performed a Fourier analysis of the published Hα measurements for GL 581. Fourier components were selectively found and removed in a so-called pre-whitening process thus isolating any variations at the orbital frequency of GL 581d. Results: The frequency analysis yields five significant frequencies, one of which is associated with the 66.7 d orbital period of the presumed planet Gl 581d. The Hα variations at this period show sine-like variations that are 180° out-of-phase with the radial velocity variations of GL 581d. This is seen in the full data set that spans almost 7 years, as well as a subset of the data near the end of the time series that had good temporal sampling over 230 days. Furthermore, no significant temporal variations are found in the ratio of the amplitudes of the Hα index and radial velocity variations. This provides additional evidence that the radial velocity signal attributed to GL 581d is in fact due to stellar activity. Conclusions: The analysis confirms the anti-correlation of the radial velocity of GL 581d with the H

  16. Advertisement call of Scinax littoralis and S. angrensis (Amphibia: Anura: Hylidae, with notes on the reproductive activity of S. littoralis

    Directory of Open Access Journals (Sweden)

    Michel V. Garey

    2012-12-01

    Full Text Available Scinax littoralis and S. angrensis are poorly known Atlantic forest endemic species from the Scinax catharinae group, which is known from southern and southeastern Brazil. Herein, we describe the advertisement calls of these two species and compare them to other species within the S. catharinae group. Additionally, we provide information on breeding sites, and calling activity in S. littoralis. Advertisement calls of S. angrensis and S. littoralis are composed of multi-pulsed notes with multiple frequency bands and frequency modulation. Scinax littoralis has a higher minimum and maximum frequency, and lower dominant frequency than S. angrensis, while Scinax littoralis has a longer call. Scinax littoralis appears to be a habitat generalist, occurring from secondary to mature forests, and breeding both in temporary and in permanent ponds. Male S. littoralis were usually observed calling perched on shrub stems, and displayed satellite behavior when the male density was high.

  17. Call Center 服务创新

    Institute of Scientific and Technical Information of China (English)

    陈克胜

    2001-01-01

    @@ 市场的竞争说道底就是优质服务的竞争,所以提升服务的质量是各商家看好的利润增长点.电子商务被商家认为是减少成本增加收入的利器,而拥有call center 的电子商务才更为完善.call center已成功地在业界尤其是在金融业得到了运用,使客户服务水平有了根本的改观.而且在金融业,call center正在由成本中心向效益中心转型.

  18. Echolocation calls and communication calls are controlled differentially in the brainstem of the bat Phyllostomus discolor

    Directory of Open Access Journals (Sweden)

    Schuller Gerd

    2005-08-01

    Full Text Available Abstract Background Echolocating bats emit vocalizations that can be classified either as echolocation calls or communication calls. Neural control of both types of calls must govern the same pool of motoneurons responsible for vocalizations. Electrical microstimulation in the periaqueductal gray matter (PAG elicits both communication and echolocation calls, whereas stimulation of the paralemniscal area (PLA induces only echolocation calls. In both the PAG and the PLA, the current thresholds for triggering natural vocalizations do not habituate to stimuli and remain low even for long stimulation periods, indicating that these structures have relative direct access to the final common pathway for vocalization. This study intended to clarify whether echolocation calls and communication calls are controlled differentially below the level of the PAG via separate vocal pathways before converging on the motoneurons used in vocalization. Results Both structures were probed simultaneously in a single experimental approach. Two stimulation electrodes were chronically implanted within the PAG in order to elicit either echolocation or communication calls. Blockade of the ipsilateral PLA site with iontophoretically application of the glutamate antagonist kynurenic acid did not impede either echolocation or communication calls elicited from the PAG. However, blockade of the contralateral PLA suppresses PAG-elicited echolocation calls but not communication calls. In both cases the blockade was reversible. Conclusion The neural control of echolocation and communication calls seems to be differentially organized below the level of the PAG. The PLA is an essential functional unit for echolocation call control before the descending pathways share again the final common pathway for vocalization.

  19. The variational Poisson cohomolgy

    CERN Document Server

    De Sole, Alberto

    2011-01-01

    It is well known that the validity of the so called Lenard-Magri scheme of integrability of a bi-Hamiltonian PDE can be established if one has some precise information on the corresponding 1st variational Poisson cohomology for one of the two Hamiltonian operators. In the first part of the paper we explain how to introduce various cohomology complexes, including Lie superalgebra and Poisson cohomology complexes, and basic and reduced Lie conformal algebra and Poisson vertex algebra cohomology complexes, by making use of the corresponding universal Lie superalebra or Lie conformal superalgebra. The most relevant are certain subcomplexes of the basic and reduced Poisson vertex algebra cohomology complexes, which we identify (non-canonically) with the generalized de Rham complex and the generalized variational complex. In the second part of the paper we compute the cohomology of the generalized de Rham complex, and, via a detailed study of the long exact sequence, we compute the cohomology of the generalized var...

  20. Metacognitive knowledge, metacognitive strategies, and CALL

    OpenAIRE

    Hauck, M

    2005-01-01

    CALL Research Perspectives creates a foundation for the study and practice of computer-assisted language learning and provides an overview of ways to conceptualize and to conduct research in CALL. Its core assumptions are that all approaches to research have a place, and that researchers, teachers, and students all have a role to play in the study of computer-enhanced language learning. This is not a how-to-do-research text. Written by top researchers in the field, it offers an open-ended ...

  1. Optimization of Overflow Policies in Call Centers

    DEFF Research Database (Denmark)

    Koole, G.M.; Nielsen, B.F.; Nielsen, T.B.

    2015-01-01

    We examine how overflow policies in a multi-skill call center should be designed to accommodate performance measures that depend on waiting time percentiles such as service level. This is done using a discrete Markovian approximation of the waiting time of the first customers waiting in line. A...... Markov decision chain is used to determine the optimal policy. This policy outperforms considerably the ones used most often in practice, which use a fixed threshold. The present method can be used also for other call-center models and other situations where performance is based on actual waiting times...

  2. Remote Procedures Calls Implementing using Distributed Algorithm

    Directory of Open Access Journals (Sweden)

    G. MURALI

    2011-11-01

    Full Text Available Remote Procedure Call (RPC is a powerful primitive used for communication and synchronization between distributed processes. RPC poses a problem that it reduces the amount of parallelism, because of its synchronous nature. This paper shows how simple processes can be used to find a way of avoiding a difficulty in this problem. The combination of blocking RPC calls and light-weightprocesses provides both simple semantics and efficient exploitation of parallelism.We will describe how two important classes of algorithms, branch and bound can be run in a parallel way using this RPC. The results of some experiments comparing this algorithms on a single processor discussed

  3. Optimal balanced control for call centers

    OpenAIRE

    Bhulai, S.; Farenhorst - Yuan, T.; Heidergott, B.F.; Laan, van der, G.

    2010-01-01

    This discussion paper led to a publication in 'Annals op Operations Research' , 2012, 201(1), 39-62. In this paper we study a challenging call center operation problem. The goal of our analysis is to identify an optimal policy for allocating tasks to agents. As a first step, we discuss promising randomized policies and use stochastic approximation for finding the optimal randomized policy when implemented via a Bernoulli scheme. As we will show in this paper, the performance of the call cente...

  4. Securing Remote Procedure Calls over HTTPS

    CERN Document Server

    Kale, Ajinkya; Pradhan, Sudeep

    2009-01-01

    Remote Procedure Calls (RPC) are widely used over the Internet as they provide a simple and elegant way of interaction between the client and the server. This paper proposes a solution for securing the remote procedure calls (RPC) by tunneling it through HTTPS (Hypertext Transfer Protocol over Secure Socket Layer). RPC over HTTP actually uses the Secure Socket Layer (SSL) protocol as a transport for the traffic. SSL mandates that the server authenticates itself to the client using a digital certificate (and associated private key). SSL is normally configured to encrypt traffic before transmitting it between the server and client and vice versa.

  5. Variational analysis

    CERN Document Server

    Rockafellar, R Tyrrell

    1998-01-01

    From its origins in the minimization of integral functionals, the notion of 'variations' has evolved greatly in connection with applications in optimization, equilibrium, and control. It refers not only to constrained movement away from a point, but also to modes of perturbation and approximation that are best describable by 'set convergence', variational convergence of functions and the like. This book develops a unified framework and, in finite dimension, provides a detailed exposition of variational geometry and subdifferential calculus in their current forms beyond classical and convex analysis. Also covered are set-convergence, set-valued mappings, epi-convergence, duality, maximal monotone mappings, second-order subderivatives, measurable selections and normal integrands. The changes in this 3rd printing mainly concern various typographical corrections, and reference omissions that came to light in the previous printings. Many of these reached the authors' notice through their own re-reading, that of th...

  6. Below and beyond the call of duty: extended range EM-MWD tool reaches new depths

    Energy Technology Data Exchange (ETDEWEB)

    Ross, E.

    1999-10-01

    Characteristic features of the extended range electromagnetic MWD (measurement-while-drilling) system called the G-ER, developed by United GeoCom Drilling Services, are discussed. The G4-ER is a new tool that expands the applications range of electromagnetic measurement-while-drilling services. It is expected to play a major role in unlocking the promise of some deep foothills natural gas plays in western Canada. The tool uses an extended downhole wireline antenna that bypasses problem zones without sacrificing transmission times. The principle underlying electromagnetic telemetry is to inject and transmit a low frequency electromagnetic carrier wave into the ground, where it travels through the formation to surface, guided along the electrically-conductive drillstring. The low-voltage signal is detected, amplified and decoded at the surface. The antenna can vary in length from 900 metres to 3,000 metres, depending on what length is required for transmitting signals. Once the antenna is set, the operation is the same as the standard electromagnetic MWD. G4-ER was first run in Canada in 1998 by Talisman Energy, with good results. According to United GeoCom Drilling Services, savings of about $ 15,000 per day might be expected to result from using the extended range system, the savings subject to variation depending on depth and drilling time. 1 fig.

  7. Variational principles

    CERN Document Server

    Moiseiwitsch, B L

    2004-01-01

    This graduate-level text's primary objective is to demonstrate the expression of the equations of the various branches of mathematical physics in the succinct and elegant form of variational principles (and thereby illuminate their interrelationship). Its related intentions are to show how variational principles may be employed to determine the discrete eigenvalues for stationary state problems and to illustrate how to find the values of quantities (such as the phase shifts) that arise in the theory of scattering. Chapter-by-chapter treatment consists of analytical dynamics; optics, wave mecha

  8. Parent-offspring communication in the Nile crocodile Crocodylus niloticus: do newborns' calls show an individual signature?

    Science.gov (United States)

    Vergne, Amélie L.; Avril, Alexis; Martin, Samuel; Mathevon, Nicolas

    2007-01-01

    Young Nile crocodiles Crocodylus niloticus start to produce calls inside the egg and carry on emitting sounds after hatching. These vocalizations elicit maternal care and influence the behaviour of other juveniles. In order to investigate the acoustic structure of these calls, focusing on a possible individual signature, we have performed acoustic analyses on 400 calls from ten young crocodiles during the first 4 days after hatching. Calls have a complex acoustic structure and are strongly frequency modulated. We assessed the differences between the calls of the individuals. We found a weak individual signature. An individual call-based recognition of young by the mother is thus unlikely. In other respects, the call acoustic structure changes from the first to the fourth day after hatching: fundamental frequency progressively decreases. These modifications might provide important information to the mother about her offspring—age and size—allowing her to customize her protective care to best suit the needs of each individual.

  9. Intra- and interspecific responses to Rafinesque’s big-eared bat (Corynorhinus rafinesquii) social calls.

    Energy Technology Data Exchange (ETDEWEB)

    Loeb, Susan, C.; Britzke, Eric, R.

    2010-07-01

    Bats respond to the calls of conspecifics as well as to calls of other species; however, few studies have attempted to quantify these responses or understand the functions of these calls. We tested the response of Rafinesque’s big-eared bats (Corynorhinus rafinesquii) to social calls as a possible method to increase capture success and to understand the function of social calls. We also tested if calls of bats within the range of the previously designated subspecies differed, if the responses of Rafinesque’s big-eared bats varied with geographic origin of the calls, and if other species responded to the calls of C. rafinesquii. We recorded calls of Rafinesque’s big-eared bats at two colony roost sites in South Carolina, USA. Calls were recorded while bats were in the roosts and as they exited. Playback sequences for each site were created by copying typical pulses into the playback file. Two mist nets were placed approximately 50–500 m from known roost sites; the net with the playback equipment served as the Experimental net and the one without the equipment served as the Control net. Call structures differed significantly between the Mountain and Coastal Plains populations with calls from the Mountains being of higher frequency and longer duration. Ten of 11 Rafinesque’s big-eared bats were caught in the Control nets and, 13 of 19 bats of other species were captured at Experimental nets even though overall bat activity did not differ significantly between Control and Experimental nets. Our results suggest that Rafinesque’s big-eared bats are not attracted to conspecifics’ calls and that these calls may act as an intraspecific spacing mechanism during foraging.

  10. Don't Call It School

    Science.gov (United States)

    Robb, Daniel

    2006-01-01

    "Homeschooling," "deschooling," and "unschooling" are commonly used terms in the alternative-education world, but each lacks specificity. In this article, the author describes what he discovered during several visits to North Star. Known officially as North Star: Self-Directed Learning for Teens, it is not as structured as a so-called "free"…

  11. 76 FR 17934 - Infrastructure Protection Data Call

    Science.gov (United States)

    2011-03-31

    ... SECURITY Infrastructure Protection Data Call AGENCY: National Protection and Programs Directorate, DHS... of Infrastructure Protection (IP), will submit the following Information Collection Request to the... infrastructure and key resources (CIKR). At DHS, this responsibility is managed by IP within NPPD. Beginning...

  12. Using Software Design Methods in CALL

    Science.gov (United States)

    Ward, Monica

    2006-01-01

    The phrase "software design" is not one that arouses the interest of many CALL practitioners, particularly those from a humanities background. However, software design essentials are simply logical ways of going about designing a system. The fundamentals include modularity, anticipation of change, generality and an incremental approach. While CALL…

  13. Modeling and simulation of call centers.

    OpenAIRE

    Avramidis, A.N.; L'Ecuyer, P.

    2006-01-01

    In this review, we introduce key notions and describe the decision problems commonly encountered in call center management. Main themes are the central role of uncertainty throughout the decision hierarchy and the many operational complexities and relationships between decisions. We make connections to analytical models in the literature, emphasizing insights gained and model limitations. The high operational complexity and the prevalent uncertainty suggest th...

  14. Authenticity in CALL: Three Domains of "Realness"

    Science.gov (United States)

    Buendgens-Kosten, Judith

    2013-01-01

    This paper discusses the role of authenticity and authenticity claims in computer assisted language learning (CALL). It considers authenticity as the result of a social negotiation process rather than an innate feature of a text, object, person, or activity. From this basis, it argues that authenticity claims play an important role in both second…

  15. Make a 21st century phone call

    CERN Document Server

    Katarina Anthony

    2014-01-01

    Want to avoid roaming charges? Click to call anyone at CERN? How about merging your CERN landline with your existing smartphone? That's all easily done with Lync, CERN's new opt-in service that can take your calls to the next level.   The Lync application on Windows (left) and iPhone (right). Lync unites CERN's traditional telephone service with the digital sphere. "Lync gives you the gift of mobility, by letting you access your CERN landline on the go," explains Pawel Grzywaczewski, service manager of the Lync system. "Once you've registered your CERN telephone with the service, you can run the Lync application and make calls from a range of supported devices. No matter where you are in the world - be it simply out to lunch or off at an international conference - you can make a CERN call as though you were in the office. All you need is an Internet connection!" Following a recent upgrade, CERN's Lync service now has...

  16. Looking Back: Tracing Trends in Canadian CALL

    Science.gov (United States)

    Craven, Mary-Louise; Sinyor, Roberta

    2011-01-01

    "CCALLNET" ("The Canadian Computer-Assisted Language Learning Network at the Post-Secondary Level") was a semi-annual newsletter published from 1987 to 2002 that was distributed to colleagues across Canada who taught languages to university students. Its objective was to create a network of Canadian faculty interested in CALL by informing them…

  17. A Call for School Counseling Practitioner Research

    Science.gov (United States)

    Kaffenberger, Carol J.

    2012-01-01

    Despite the repeated call to increase the number of practitioner research manuscripts being published in counseling publications, practitioner research accounts for less than five percent of all manuscripts published. This article describes the challenges faced by practitioners seeking to publish their research, defines practitioner research, and…

  18. Breeding biology and advertisement call of the horned leaf-frog, Proceratophrys appendiculata (Amphibia: Anura: Odontophrynidae

    Directory of Open Access Journals (Sweden)

    Pedro Henrique dos Santos Dias

    2013-08-01

    Full Text Available We describe the breeding biology and the advertisement call of the horned leaf-frog, Proceratophrys appendiculata (Günther, 1873 in the Parque Nacional da Serra dos Órgãos, municipality of Teresópolis. The reproductive period of P. appendiculata is short and is associated with the end of the winter and the beginning of the spring, when males call night and day under large rocks in sandy bottom rock streams. The amplexus is axillary and one female laid about 656 viscous eggs. The advertisement call of P. appendiculata is unique among congeners. The call lasts approximately two seconds, with about 85 pulses/call at a rate of 45 pulses/s and frequency around 0.620 kHz. It is one of the longest calls and lowest in dominant frequency. Moreover, the call of P. appendiculata is characterized by the greatest number of pulses so far registered, reaching 129 pulses in a single call.

  19. Performance evaluation of indel calling tools using real short-read data

    OpenAIRE

    Hasan, Mohammad S.; Wu, Xiaowei; Zhang, Liqing

    2015-01-01

    Background Insertion and deletion (indel), a common form of genetic variation, has been shown to cause or contribute to human genetic diseases and cancer. With the advance of next-generation sequencing technology, many indel calling tools have been developed; however, evaluation and comparison of these tools using large-scale real data are still scant. Here we evaluated seven popular and publicly available indel calling tools, GATK Unified Genotyper, VarScan, Pindel, SAMtools, Dindel, GTAK Ha...

  20. Long-distance calls in Neotropical primates

    Directory of Open Access Journals (Sweden)

    Dilmar A.G. Oliveira

    2004-06-01

    Full Text Available Long-distance calls are widespread among primates. Several studies concentrate on such calls in just one or in few species, while few studies have treated more general trends within the order. The common features that usually characterize these vocalizations are related to long-distance propagation of sounds. The proposed functions of primate long-distance calls can be divided into extragroup and intragroup ones. Extragroup functions relate to mate defense, mate attraction or resource defense, while intragroup functions involve group coordination or alarm. Among Neotropical primates, several species perform long-distance calls that seem more related to intragroup coordination, markedly in atelines. Callitrichids present long-distance calls that are employed both in intragroup coordination and intergroup contests or spacing. Examples of extragroup directed long-distance calls are the duets of titi monkeys and the roars and barks of howler monkeys. Considerable complexity and gradation exist in the long-distance call repertoires of some Neotropical primates, and female long-distance calls are probably more important in non-duetting species than usually thought. Future research must focus on larger trends in the evolution of primate long-distance calls, including the phylogeny of calling repertoires and the relationships between form and function in these signals.Chamados de longo alcance são comuns em primatas. Muitas pesquisas enfocaram tais vocalizações em uma única ou em poucas espécies, enquanto poucos estudos lidaram com padrões mais gerais dentro da ordem. As características comuns que geralmente distinguem estas vocalizações são relacionadas com a transmissão de sons a longa distância. As funções propostas para estas vocalizações podem ser divididas entre intragrupais e extragrupais. Funções extragrupais se relacionam com a defesa e atração de parceiros sexuais ou com a defesa de recursos, enquanto as fun

  1. Chick Begging Calls Reflect Degree of Hunger in Three Auk Species (Charadriiformes: Alcidae)

    OpenAIRE

    Klenova, Anna V.

    2015-01-01

    Begging behaviour is an important element in the parent-offspring conflict; it has been studied in many avian species. However, the majority of the studies have been entirely based on the call counts, and they agreed that vocal activity was a good indicator of chick's nutritional need and/or condition. Fewer researches were dedicated to the temporal-frequency variables of the begging calls themselves and they showed contrary results. Here begging behaviour in three burrow nested, uniparous sp...

  2. Blue and fin whale call source levels and propagation range in the Southern Ocean

    OpenAIRE

    Sirovic, Anna; Hildebrand, John A.; Wiggins, Sean

    2007-01-01

    Blue (Balaenoptera musculus) and fin whales (B. physalus) produce high-intensity, low-frequency calls, which probably function for communication during mating and feeding. The source levels of blue and fin whale calls off the Western Antarctic Peninsula were calculated using recordings made with calibrated, bottom-moored hydrophones. Blue whales were located up to a range of 200 km using hyperbolic localization and time difference of arrival. The distance to fin whales, estimated using multi...

  3. Behavioral context of call production by eastern North Pacific blue whales

    OpenAIRE

    Oleson, Erin M.; Calambokidis, J.; Burgess, W C; McDonald, M.A.; LeDuc, C A; Hildebrand, J.A.

    2007-01-01

    We assessed the behavioral context of calls produced by blue whales Balaenoptera musculus off the California coast based on acoustic, behavioral, and dive data obtained through acoustic recording tags, sex determination from tissue sampling, and coordinated visual and acoustic observations. Approximately one-third of 38 monitored blue whales vocalized, with sounds categorized into 3 types: (1) low-frequency pulsed A and tonal B calls, in either rhythmic repetitive song sequences or as...

  4. Audience effects, but not environmental influences, explain variation in gorilla close distance vocalizations-A test of the acoustic adaptation hypothesis.

    Science.gov (United States)

    Hedwig, Daniela; Mundry, Roger; Robbins, Martha M; Boesch, Christophe

    2015-12-01

    Close distance vocalizations are an integral part of primate vocal communication. They exhibit large acoustic variation which has been suggested to constitute flexible responses to the highly variable social setting of group living animals. However, a recent study suggested that acoustic variation in close distance calls of baboons may also arise from acoustic adaptations to environmental factors in order to counteract sound degradation. We tested whether the variation in calling rate and acoustic structure of gorilla close distance vocalizations may serve to counteract distorting effects of vegetation during sound propagation. Using focal animal sampling we recorded the vocal behavior of 15 adult individuals living in two groups: one group of western lowland gorillas Gorilla gorilla gorilla and one group of mountain gorillas Gorilla beringei beringei. We considered the distance between the caller and its nearest neighbor as the minimum transmission distance of calls; while vegetation density was quantified through measures of visibility. Our analysis revealed vocal plasticity in gorilla close calls in relation to changes in visibility and nearest neighbor distance. However, the observed changes in fundamental frequency and calling rate are unlikely to counteract degrading effects of vegetation, but rather seem to reflect reactions to variation in spatial and visual separation from other group members, similar to the audience effects demonstrated in a range of other species. We propose that vocal plasticity to counteract distorting environmental effects may not be prevalent across taxa and perhaps confined to species living in heterogeneous habitats with highly variable transmission conditions. PMID:26352614

  5. Territorial calls in the Little Owl (Athene noctua): spatial dispersion and social interplay of mates and neighbours

    DEFF Research Database (Denmark)

    Jacobsen, Lars Bo; Sunde, Peter; Rahbek, Carsten;

    2013-01-01

    telemetry observations, but did not appear to be related tomate distance.With a sound pressure level of 82 dB(A) at 1-m distance, the territorial calls were estimated to be audible to a distance of 4.4 km. Call posts were on average 4.1 mabove the ground, which probably maximizes the transmission distance.......With the aim of quantifying spatio-temporal and social factors affecting territorial calls in LittleOwls,we collected data on the calling behaviour of radio tracked individuals from a low-density population in Northern Jutland, Denmark. There was considerable seasonal variation in calling activity...

  6. BUSINESS MODELS FOR EXTENDING OF 112 EMERGENCY CALL CENTER CAPABILITIES WITH E-CALL FUNCTION INSERTION

    Directory of Open Access Journals (Sweden)

    Pop Dragos Paul

    2010-12-01

    Full Text Available The present article concerns present status of implementation in Romania and Europe of eCall service and the proposed business models regarding eCall function implementation in Romania. eCall system is used for reliable transmission in case of crush between In Vehicle System and Public Service Answering Point, via the voice channel of cellular and Public Switched Telephone Network (PSTN. eCall service could be initiated automatically or manual the driver. All data presented in this article are part of researches made by authors in the Sectorial Contract Implementation study regarding eCall system, having as partners ITS Romania and Electronic Solution, with the Romanian Ministry of Communication and Information Technology as beneficiary.

  7. Calling Card Analysis in Budding Yeast.

    Science.gov (United States)

    Mayhew, David; Mitra, Robi D

    2016-02-01

    Calling card analysis is a high-throughput method for identifying the genomic binding sites of multiple transcription factors in a single experiment in budding yeast. By tagging a DNA-binding protein with a targeting domain that directs the insertion of the Ty5 retrotransposon, the genomic binding sites for that transcription factor are marked. The transposition locations are then identified en masse by Illumina sequencing. The calling card protocol allows for simultaneous analysis of multiple transcription factors. By cloning barcodes into the Ty5 transposon, it is possible to pair a unique barcode with every transcription factor in the experiment. The method presented here uses expression of transcription factors from their native loci; however, it can also be altered to measure binding sites of transcription factors overexpressed from a plasmid. PMID:26832687

  8. Towards Building an Intelligent Call Routing System

    Directory of Open Access Journals (Sweden)

    Thien Khai Tran

    2016-01-01

    Full Text Available This paper presents EduICR - an Intelligent Call Routing system. This system can route calls to the most appropriate agent using routing rules built by the text classifier. EduICR includes the following main components: telephone communication network; Vietnamese speech recognition; Text classifier/ Natural language processor and Vietnamese speech synthesis. To our best knowledge, this is one of the first systems in Vietnam to implement the integration mechanism of text processing and speech processing. This allows voice applications to be more intelligent, able to communicate with humans in natural language with high accuracy and reasonable speed. Having been built and tested in real environment, our system proves its accuracy attaining more than 95%.

  9. Call intercalation in dyadic interactions in natural choruses of Johnstone's whistling frog Eleutherodactylus johnstonei (Anura: Eleutherodactylidae).

    Science.gov (United States)

    Tárano, Zaida; Carballo, Luisana

    2016-05-01

    Communal signaling increases the likelihood of acoustic interference and impairs mate choice; consequently, mechanisms of interference avoidance are expected. Adjustment of the timing of the calls between signalers, specifically call alternation, is probably the most efficient strategy. For this reason, in the present study we analyzed call timing in dyads of males of E. johnstonei in six natural assemblages. We addressed whether males entrain their calls with those of other males at the assemblage and if they show selective attention in relation to perceived amplitude of the other males' calls, inter-male distance, or intrinsic call features (call duration, period or dominant frequency). We expected males to selectively attend to closer or louder males and/or to those of higher or similar attractiveness for females than themselves, because those would be their strongest competitors. We found that most males intercalated their calls with those of at least one male. In assemblages of 3 individuals, males seemed to attend to a fixed number of males regardless of their characteristics. In assemblages of more than 3 individuals, the perceived amplitude of the call of the neighboring male was higher, and the call periods of the males were more similar in alternating dyads than in the non-alternating ones. At the proximate level, selective attention based on perceived amplitude may relate to behavioral hearing thresholds. Selective attention based on the similarity of call periods may relate to the properties of the call oscillators controlling calling rhythms. At the ultimate level, selective attention may be related to the likelihood of acoustic competition for females. PMID:26988233

  10. CALL Implementation Strategies:A Case Study

    OpenAIRE

    BRIERLEY, Mark; Orlandini, Andrea

    2010-01-01

    This paper will begin by discussing changes in CALL (Computer Assisted Language Learning) over the past decade, identifying three modes: computers as teachers; computers used for communication between teachers and students; and communication among students. Next, we will investigate how key components of the Moodle LMS (Learning Management System), such as quizzes, forums and wikis can contribute to language acquisition by facilitating comprehensible input through task-based, communicative le...

  11. Sustainability Science: A Call to Collaborative Action

    OpenAIRE

    David D. Hart; Bell, Kathleen P.

    2013-01-01

    Sustainability science is an emerging field directed at advancing sustainable development. Informed by recent scholarship and institutional experiments, we identify key roles for economists and encourage their greater participation in this research. Our call to collaborative action comes from positive experiences with the Sustainability Solutions Initiative based at the University of Maine, where economists collaborate with other experts and diverse stakeholders on real-world problems involvi...

  12. First Class Call Stacks: Exploring Head Reduction

    OpenAIRE

    Johnson-Freyd, Philip; Downen, Paul; Ariola, Zena M.

    2016-01-01

    Weak-head normalization is inconsistent with functional extensionality in the call-by-name $\\lambda$-calculus. We explore this problem from a new angle via the conflict between extensionality and effects. Leveraging ideas from work on the $\\lambda$-calculus with control, we derive and justify alternative operational semantics and a sequence of abstract machines for performing head reduction. Head reduction avoids the problems with weak-head reduction and extensionality, while our operational ...

  13. Parental alarm calls suppress nestling vocalization.

    OpenAIRE

    Platzen, Dirk; Magrath, Robert D.

    2004-01-01

    Evolutionary models suggest that the cost of a signal can ensure its honesty. Empirical studies of nestling begging imply that predator attraction can impose such a cost. However, parents might reduce or abolish this cost by warning young of the presence of danger. We tested, in a controlled field playback experiment, whether alarm calls cause 5-, 8- and 11-day-old nestlings of the white-browed scrubwren, Sericornis frontalis, to suppress vocalization. In this species, nestlings vocalize when...

  14. Call Admission Control in Mobile Wireless

    OpenAIRE

    Goril, J.; Dobos, L.

    2002-01-01

    Some problems related to wireless network access are discussed in the article. Special attention is paid to Medium Access Control and Call Admission Control. Both have direct impact on communication link accession. While the first one dictates how to, the second one decides who can access the link. The problems with wireless medium access are mentioned and requirements on MAC protocols are named. Also need for CAC algorithms is illustrated and simple functional example is proposed. Finally, t...

  15. Message Classification in the Call Center

    OpenAIRE

    Busemann, Stephan; Schmeier, Sven; Arens, Roman G.

    2000-01-01

    Customer care in technical domains is increasingly based on e-mail communication, allowing for the reproduction of approved solutions. Identifying the customer's problem is often time-consuming, as the problem space changes if new products are launched. This paper describes a new approach to the classification of e-mail requests based on shallow text processing and machine learning techniques. It is implemented within an assistance system for call center agents that is used in a commercial se...

  16. Calling by domestic piglets during simulated crushing and isolation: a signal of need?

    Science.gov (United States)

    Illmann, Gudrun; Hammerschmidt, Kurt; Spinka, Marek; Tallet, Céline

    2013-01-01

    This study examined whether piglet distress vocalizations vary with age, body weight and health status, according to the predictions of the honest signalling of need evolutionary model. Vocalizations were recorded during manual squeezing (a simulation of being crushed by mother sow) and during isolation on Days 1 and 7 after birth in piglets from 15 litters. We predicted that during squeezing, younger, lighter and sick piglets would call more intensely because they are in higher risk of dying during crushing and therefore they benefit more from the sow's reaction to intensive vocalization. For isolation, we predicted that lighter and younger piglets would call more because they are more vulnerable to adverse effects of the separation. Calls were analyzed in their time and frequency domain. The rate of calling, call duration, proportion of high-pitched calls and eight acoustic parameters characterizing frequency distribution and tonality were used as indicators of acoustic signalling intensity. Piglets that experienced "squeezing" on Day 1 produced more intense acoustic distress signalling than on Day 7. Lighter piglets called more during squeezing than heavier piglets. Health status did not significantly affect any of the indicators of intensity of vocalization during squeezing. In isolation, none of the parameters of vocalization intensity were affected either by the age or by the weight of the piglets. In summary, the model of honest signalling of need was confirmed in the squeezed situation, but not in the isolation situation. PMID:24349527

  17. Calling by domestic piglets during simulated crushing and isolation: a signal of need?

    Directory of Open Access Journals (Sweden)

    Gudrun Illmann

    Full Text Available This study examined whether piglet distress vocalizations vary with age, body weight and health status, according to the predictions of the honest signalling of need evolutionary model. Vocalizations were recorded during manual squeezing (a simulation of being crushed by mother sow and during isolation on Days 1 and 7 after birth in piglets from 15 litters. We predicted that during squeezing, younger, lighter and sick piglets would call more intensely because they are in higher risk of dying during crushing and therefore they benefit more from the sow's reaction to intensive vocalization. For isolation, we predicted that lighter and younger piglets would call more because they are more vulnerable to adverse effects of the separation. Calls were analyzed in their time and frequency domain. The rate of calling, call duration, proportion of high-pitched calls and eight acoustic parameters characterizing frequency distribution and tonality were used as indicators of acoustic signalling intensity. Piglets that experienced "squeezing" on Day 1 produced more intense acoustic distress signalling than on Day 7. Lighter piglets called more during squeezing than heavier piglets. Health status did not significantly affect any of the indicators of intensity of vocalization during squeezing. In isolation, none of the parameters of vocalization intensity were affected either by the age or by the weight of the piglets. In summary, the model of honest signalling of need was confirmed in the squeezed situation, but not in the isolation situation.

  18. Workshop on Alcohol Use and Health Disparities 2002: a call to arms.

    Science.gov (United States)

    Russo, Denise; Purohit, Vishnudutt; Foudin, Laurie; Salin, Marvin

    2004-01-01

    The National Institute on Alcohol Abuse and Alcoholism (NIAAA) of the National Institutes of Health (NIH) sponsored a "Workshop on Alcohol Use and Health Disparities 2002: A Call to Arms," on December 5, 2002, in Bethesda, Maryland, USA. This workshop was part of the NIAAA/NIH comprehensive strategic plan to reduce, and ultimately eliminate, health disparities. Eleven topics were addressed: (1). biomedical risk factors that may contribute to disparities in the toxic effects of alcohol; (2). alcohol and gene-environment interactions that affect the health of diverse groups; (3). alcohol pharmacogenetics in Mexican-Americans; (4). determinants of risk for alcoholism in minority populations; (5). consideration of population groups in linkage-disequilibrium studies to identify genes associated with alcohol dependence; (6). interaction between alcohol dependence and African-American ethnicity in disordered sleep, nocturnal cytokines, and immunity; (7). disparities of brain functional reserve capacity affecting brain morbidity related to substance abuse; (8). alcohol and pregnancy disparities; (9). role of alcohol in cancer risk disparities; (10). ethnic diversity in alcoholic cardiomyopathy; and (11). postmenopausal health disparities. On the basis of these presentations, seven conclusions emerged: (1). Genetic variations in alcohol-metabolizing enzymes exist in various populations. (2). These enzymes play a role in the variation in health effect outcomes seen in different populations, owing to alcohol consumption. (3). Differences between and among population groups can be critically important for the design and interpretation of studies in genetics. These include differences in expression of phenotype, in locus heterogeneity, in risk alleles, and in population structure. (4). Incidence rates for fetal alcohol syndrome and fetal alcohol spectrum disorders are greater in African-Americans and Native-Americans than in Caucasians. Genetic polymorphisms, nutrition, and

  19. Study protocol of the YOU CALL - WE CALL TRIAL: impact of a multimodal support intervention after a "mild" stroke

    Directory of Open Access Journals (Sweden)

    Bravo Gina

    2010-01-01

    Full Text Available Abstract Background More than 60% of new strokes each year are "mild" in severity and this proportion is expected to rise in the years to come. Within our current health care system those with "mild" stroke are typically discharged home within days, without further referral to health or rehabilitation services other than advice to see their family physician. Those with mild stroke often have limited access to support from health professionals with stroke-specific knowledge who would typically provide critical information on topics such as secondary stroke prevention, community reintegration, medication counselling and problem solving with regard to specific concerns that arise. Isolation and lack of knowledge may lead to a worsening of health problems including stroke recurrence and unnecessary and costly health care utilization. The purpose of this study is to assess the effectiveness, for individuals who experience a first "mild" stroke, of a sustainable, low cost, multimodal support intervention (comprising information, education and telephone support - "WE CALL" compared to a passive intervention (providing the name and phone number of a resource person available if they feel the need to - "YOU CALL", on two primary outcomes: unplanned-use of health services for negative events and quality of life. Method/Design We will recruit 384 adults who meet inclusion criteria for a first mild stroke across six Canadian sites. Baseline measures will be taken within the first month after stroke onset. Participants will be stratified according to comorbidity level and randomised to one of two groups: YOU CALL or WE CALL. Both interventions will be offered over a six months period. Primary outcomes include unplanned use of heath services for negative event (frequency calendar and quality of life (EQ-5D and Quality of Life Index. Secondary outcomes include participation level (LIFE-H, depression (Beck Depression Inventory II and use of health services for

  20. Female preferences for spectral call properties in the western genetic lineage of Cope’s gray treefrog (Hyla chrysoscelis)

    OpenAIRE

    Schrode, Katrina M.; Ward, Jessica L; Vélez, Alejandro; Bee, Mark A.

    2012-01-01

    Female frogs discriminate among potential mates based on individual variation in male advertisement calls. While considerable data have accumulated allowing comparisons of female preference functions among species, we still lack fundamental knowledge about how and why the shapes of preference functions for particular call properties vary among populations within all but a few species. Here, we report results from a study aimed at describing female preference functions for spectral call proper...

  1. Calling activity of indian giant flying squirrel (Petaurista philippensis Elliot, 1839 in the tropical deciduous forests, India

    Directory of Open Access Journals (Sweden)

    V. Koli

    2014-10-01

    Full Text Available The calling behaviour of Petaurista philippensis was studied from March 2009 to February 2010, in the tropical deciduous forests of the Sitamata Wildlife Sanctuary, Rajasthan, India. Surveys were conducted from the dusk or 1900 hr to 0600 hr. A total of 134 calls were recorded. Females were found more vocal than males. Call frequency was highest in March 2009. The most vocal periods were midnight and early night, just before entering into the nest cavities. Annual, seasonal and daily call frequencies were insignificant (P > 0.05 between male and female. 5-10 min call bout category contained highest account (40%. Calling was mostly performed in the mid canopy area of the trees. Perch height was found positively related to tree height.

  2. Intraspecific scaling in frog calls: the interplay of temperature, body size and metabolic condition.

    Science.gov (United States)

    Ziegler, Lucia; Arim, Matías; Bozinovic, Francisco

    2016-07-01

    Understanding physiological and environmental determinants of strategies of reproductive allocation is a pivotal aim in biology. Because of their high metabolic cost, properties of sexual acoustic signals may correlate with body size, temperature, and an individual's energetic state. A quantitative theory of acoustic communication, based on the metabolic scaling with temperature and mass, was recently proposed, adding to the well-reported empirical patterns. It provides quantitative predictions for frequencies, call rate, and durations. Here, we analysed the mass, temperature, and body condition scaling of spectral and temporal attributes of the advertisement call of the treefrog Hypsiboas pulchellus. Mass dependence of call frequency followed metabolic expectations (f~M (-0.25), where f is frequency and M is mass) although non-metabolic allometry could also account for the observed pattern. Temporal variables scaled inversely with mass contradicting metabolic expectations (d~M (0.25), where d is duration), supporting instead empirical patterns reported to date. Temperature was positively associated with call rate and negatively with temporal variables, which is congruent with metabolic predictions. We found no significant association between temperature and frequencies, adding to the bulk of empirical evidence. Finally, a result of particular relevance was that body condition consistently determined call characteristics, in interaction with temperature or mass. Our intraspecific study highlights that even if proximate determinants of call variability are rather well understood, the mechanisms through which they operate are proving to be more complex than previously thought. The determinants of call characteristics emerge as a key topic of research in behavioural and physiological biology, with several clear points under debate which need to be analysed on theoretical and empirical grounds. PMID:26552381

  3. Calling SNPs without a reference sequence

    OpenAIRE

    Schuster Stephan C; Hayes Vanessa M; Zhang Yu; Ratan Aakrosh; Miller Webb

    2010-01-01

    Abstract Background The most common application for the next-generation sequencing technologies is resequencing, where short reads from the genome of an individual are aligned to a reference genome sequence for the same species. These mappings can then be used to identify genetic differences among individuals in a population, and perhaps ultimately to explain phenotypic variation. Many algorithms capable of aligning short reads to the reference, and determining differences between them have b...

  4. Calling SNPs without a reference sequence

    OpenAIRE

    Ratan, Aakrosh; Zhang, Yu; Hayes, Vanessa M.; Stephan C Schuster; Miller, Webb

    2010-01-01

    Background The most common application for the next-generation sequencing technologies is resequencing, where short reads from the genome of an individual are aligned to a reference genome sequence for the same species. These mappings can then be used to identify genetic differences among individuals in a population, and perhaps ultimately to explain phenotypic variation. Many algorithms capable of aligning short reads to the reference, and determining differences between them have been repor...

  5. Una propuesta urbana para la Calle Mayor

    OpenAIRE

    Sambricio, Carlos

    1996-01-01

    Estudiar el desarrollo y la configuración de la Calle Mayor de Madrid supone enfrentarse a uno de los hechos originarios en configuración urbana. La historia urbana -diferenciada de lo que tras entienden como "Historia de la ciudad"- se ha planteado generalmente desde el análisis del desarrollo, transformación e intervención en el hecho histórico. Frente a las políticas de vivienda, a la contraposición entre Ensanche o Extrarradio, a la definición de operaciones de reforma interior o propuest...

  6. Designing a Call Center with Impatient Customers

    OpenAIRE

    O. Garnet; Mandelbaum, A.; M. Reiman

    2002-01-01

    The most common model to support workforce management of telephone call centers is the M/M/N/B model, in particular its special cases M/M/N (Erlang C, which models out busy signals) and M/M/N/N (Erlang B, disallowing waiting). All of these models lack a central prevalent feature, namely, that impatient customers might decide to leave (abandon) before their service begins. In this paper, we analyze the simplest abandonment model, in which customers' patience is exponentially distributed and th...

  7. The so-called nuclear waste affair

    International Nuclear Information System (INIS)

    The so-called nuclear waste affair has placed the Hanau nuclear fuel company NUKEM and its daughter Transnuklear in the centre of public discussions about nuclear safety. The disclosed and alleged irregularities have led to preliminary investigation by the public prosecutor, a parliamentary inquiry commission has been set in, and the Hanau companies have been re-organised by order of the state: Transnuklear has been dissolved, and NUKEM will discontinue fuel element fabrication. The article in hand explains the foundation and the history of the NUKEM company and its daughter companies in order to reveal the significance of the current events. (orig./DG)

  8. Asymptotic analysis of American call options

    OpenAIRE

    Roland Mallier; Ghada Alobaidi

    2001-01-01

    American call options are financial derivatives that give the holder the right but not the obligation to buy an underlying security at a pre-determined price. They differ from European options in that they may be exercised at any time prior to their expiration, rather than only at expiration. Their value is described by the Black-Scholes PDE together with a constraint that arises from the possibility of early exercise. This leads to a free boundary problem for the optimal exercise boundary, w...

  9. Call center. Centrados en el cliente

    OpenAIRE

    Leal-Alonso-de-Castañeda, José Enrique

    2003-01-01

    La empresa actual ha de estar preparada para responder al Cliente tal y como éste espera, porque no se busca un cliente puntual, sino un cliente fiel. La globalización de la economía y del acceso a los mercados exige que la empresa sea capaz de atraer al cliente no sólo con un servicio de calidad, sino además con una atención de calidad. La implantación de un Call Center (Centro de Atención al Cliente, Centro de Atención de Llamadas) constituye por todo ello una estrategia de negocio qu...

  10. Changes in How Students Use and Are Called Homophobic Epithets over Time: Patterns Predicted by Gender, Bullying, and Victimization Status

    Science.gov (United States)

    Poteat, V. Paul; O'Dwyer, Laura M.; Mereish, Ethan H.

    2012-01-01

    This longitudinal study tested for changes in how students used and were called homophobic epithets as they progressed through high school. Boys used and were called these epithets with increased frequency over time, whereas girls reported decreases on both. Distinct gender socialization processes may contribute to these different patterns for…

  11. Classification of large acoustic datasets using machine learning and crowdsourcing: Application to whale calls

    NARCIS (Netherlands)

    Shamir, L.; Carol Yerby, C.; Simpson, R.; Benda-Beckmann, A.M. von; Tyack, P.; Samarra, F.; Miller, P.; Wallin, J.

    2014-01-01

    Vocal communication is a primary communication method of killer and pilot whales, and is used for transmitting a broad range of messages and information for short and long distance. The large variation in call types of these species makes it challenging to categorize them. In this study, sounds reco

  12. Chick Begging Calls Reflect Degree of Hunger in Three Auk Species (Charadriiformes: Alcidae.

    Directory of Open Access Journals (Sweden)

    Anna V Klenova

    Full Text Available Begging behaviour is an important element in the parent-offspring conflict; it has been studied in many avian species. However, the majority of the studies have been entirely based on the call counts, and they agreed that vocal activity was a good indicator of chick's nutritional need and/or condition. Fewer researches were dedicated to the temporal-frequency variables of the begging calls themselves and they showed contrary results. Here begging behaviour in three burrow nested, uniparous species of auks (Alcidae was studied. These objects provide an opportunity to study the signalling value of begging calls in the absence of important confounding factors such as nestling competition and predation pressure. I recorded calls of individual chicks in two conditions: during natural feeding and after experimental four-hour food deprivation. I found that almost all measured acoustic variables contain information about the chick's state in all studied species. The hungry chicks produced calls higher in fundamental frequency and power variables and at higher calling rate compared to naturally feeding chicks. The effect of food deprivation on most acoustic variables exceeded both the effects of individuality and species. In all studied species, the frequency variables were stronger affected by hunger than the calling rate and call durations. I suppose that such strong change of acoustic variables after food deprivation can be explained by absence of vocal individual identification in these birds. As parents do not need to check individuality of the chick in the burrow, which they find visually during the day time, the chicks could use all of the acoustic variables to communicate about their nutritional needs.

  13. Chick Begging Calls Reflect Degree of Hunger in Three Auk Species (Charadriiformes: Alcidae).

    Science.gov (United States)

    Klenova, Anna V

    2015-01-01

    Begging behaviour is an important element in the parent-offspring conflict; it has been studied in many avian species. However, the majority of the studies have been entirely based on the call counts, and they agreed that vocal activity was a good indicator of chick's nutritional need and/or condition. Fewer researches were dedicated to the temporal-frequency variables of the begging calls themselves and they showed contrary results. Here begging behaviour in three burrow nested, uniparous species of auks (Alcidae) was studied. These objects provide an opportunity to study the signalling value of begging calls in the absence of important confounding factors such as nestling competition and predation pressure. I recorded calls of individual chicks in two conditions: during natural feeding and after experimental four-hour food deprivation. I found that almost all measured acoustic variables contain information about the chick's state in all studied species. The hungry chicks produced calls higher in fundamental frequency and power variables and at higher calling rate compared to naturally feeding chicks. The effect of food deprivation on most acoustic variables exceeded both the effects of individuality and species. In all studied species, the frequency variables were stronger affected by hunger than the calling rate and call durations. I suppose that such strong change of acoustic variables after food deprivation can be explained by absence of vocal individual identification in these birds. As parents do not need to check individuality of the chick in the burrow, which they find visually during the day time, the chicks could use all of the acoustic variables to communicate about their nutritional needs. PMID:26536362

  14. Applicative Bisimilarities for Call-by-Name and Call-by-Value λμ-Calculus

    OpenAIRE

    Biernacki, Dariusz; Lenglet, Sergueï

    2014-01-01

    We propose the first sound and complete bisimilarities for the call-by-name and call-by-value untyped λµ-calculus, defined in the applicative style. We give equivalence examples to illustrate how our relations can be used; in particular, we prove David and Py's counter-example, which cannot be proved with Lassen's preexisting normal form bisimilarities for the λµ-calculus.

  15. "That's why they call it practice".

    Science.gov (United States)

    Fogarty, Colleen T; Mauksch, Larry B

    2014-12-01

    The authors discuss how, as their residency family medicine practices are transforming into Patient-Centered Medical Homes, they are witnessing shifting expectations for everyone: medical assistant, faculty and resident physician, licensed practical nurse, behavioral health clinician. At all levels of experience and expertise, they are called on to change. In the health care context, "practice" has multiple meanings. Practice, in the sense of "the clinical scope of work we do every day" corresponds to Merriam Webster's first definition of the word, "to be professionally engaged in" or "to do or perform often, customarily, or habitually." In this editorial, the authors call upon their colleagues to recognize the second definition of "practice" and build in opportunities to "train by repeated exercises" within day to day clinical activity. By this they mean, build in mechanisms to prompt reflection on your work, every day, seeking and incorporating feedback from others on your team. Effective primary care systems protect time for practice and learning. These organizations demonstrate "adaptive reserve," consisting of action and reflection cycles, facilitative leadership, a learning culture, the ability to improvise, and effective relationships and communication. PMID:25485824

  16. Detecting Motifs in System Call Sequences

    CERN Document Server

    Wilson, William O; Aickelin, Uwe

    2010-01-01

    The search for patterns or motifs in data represents an area of key interest to many researchers. In this paper we present the Motif Tracking Algorithm, a novel immune inspired pattern identification tool that is able to identify unknown motifs which repeat within time series data. The power of the algorithm is derived from its use of a small number of parameters with minimal assumptions. The algorithm searches from a completely neutral perspective that is independent of the data being analysed, and the underlying motifs. In this paper the motif tracking algorithm is applied to the search for patterns within sequences of low level system calls between the Linux kernel and the operating system's user space. The MTA is able to compress data found in large system call data sets to a limited number of motifs which summarise that data. The motifs provide a resource from which a profile of executed processes can be built. The potential for these profiles and new implications for security research are highlighted. A...

  17. Postavení a úloha call center

    OpenAIRE

    Blažej, Michal

    2008-01-01

    Tato diplomová práce zpracovává téma Postavení a Úloha Call Center v Telekomunikaci. Práce pojednává o alternativních způsobech komunikace zákazníka s mobilním operátorem, převážně prostřednictvím telefonu. Obsahem diplomové práce je charakteristika služeb, výčet jednotlivých způsobů komunikace mezi zákazníkem a mobilním operátorem, popis produktů T-Mobile CZ využívajících alternativních způsobů komunikace s operátorem, přehled činností Call centra T-Mobile CZ a výzkumná část. Cílem práce je ...

  18. Milton Nascimento: una calle llamada mundo

    Directory of Open Access Journals (Sweden)

    Alberto Carlos De Souza

    2011-08-01

    Full Text Available El punto de partida de este estudio consistirá en la exploración de la musicalidad de Milton Nascimento y de sus compañeros del “movimiento” “Clube da Esquina”, destacándose la relevancia del conjunto de esa obra para la cultura brasilera. El referido “movimiento” floreció en Minas Gerais en el auge de uno de los períodos más críticos de la historia contemporánea brasilera: la dictadura militar. En tanto, el “Clube da Esquina” – dado a la diversidad de los temas tratados en sus letras y su singularidad poética -, luego se difundió por todo el espacio cultural brasilero. Hablar del “Clube da Esquina” no es tarea fácil porque hay una dolorosa ausencia o pálida presencia de este movimiento en estudios que se ocupan de nuestra música popular. El “Clube da Esquina” fue un círculo de amigos que se reunieron en un pequeño pub en la esquina de la Calle Divinópolis y Calle Paraisópolis, en un bucólico barrio de Belo Horizonte (Minas Gerais - Brasil, llamado Santa Teresa. Era parte de esa hermandad, interesada en música, cine y poesía, Milton Nascimento, Wagner Tiso, Fernando Brant, Toninho Horta, Beto Guedes, Moura Tavinho, los hermanos Lô y Marcio Borges, Robertinho Silva, Nivaldo Ornelas, Ronaldo Bastos, Murilo Antunes Nelson Angelo y Novelli, entre otros. En estas reuniones, regadas con mucha cerveza, Milton Nascimento y sus compañeros. Milton fue y sigue siendo la mayor referencia del movimiento “Clube da Esquina”. Abstract The starting point of this study will explore the music of Milton Nascimento and his fellow "movement" "Clube da Esquina", highlighting the relevance of all this work to the Brazilian culture. The aforementioned "movement" flourished in Minas Gerais at the height of one of the most critical periods in Brazilian contemporary history: the military dictatorship. Meanwhile, the "Clube da Esquina" - given the diversity of topics in his lyrics and his unique poetic - and then spread

  19. Voltage, Temperature, Frequency Margin Test Report

    DEFF Research Database (Denmark)

    Denver, Troelz

    1999-01-01

    The purpose of the tests is to establish the camera functionality when it is exposed to an extreme environment for prolonged periods, thus simulating the end of life performance. This environment covers temperature, input clock frequency and supply voltage variation......The purpose of the tests is to establish the camera functionality when it is exposed to an extreme environment for prolonged periods, thus simulating the end of life performance. This environment covers temperature, input clock frequency and supply voltage variation...

  20. Frequency Standards and Metrology

    Science.gov (United States)

    Maleki, Lute

    2009-04-01

    Preface / Lute Maleki -- Symposium history / Jacques Vanier -- Symposium photos -- pt. I. Fundamental physics. Variation of fundamental constants from the big bang to atomic clocks: theory and observations (Invited) / V. V. Flambaum and J. C. Berengut. Alpha-dot or not: comparison of two single atom optical clocks (Invited) / T. Rosenband ... [et al.]. Variation of the fine-structure constant and laser cooling of atomic dysprosium (Invited) / N. A. Leefer ... [et al.]. Measurement of short range forces using cold atoms (Invited) / F. Pereira Dos Santos ... [et al.]. Atom interferometry experiments in fundamental physics (Invited) / S. W. Chiow ... [et al.]. Space science applications of frequency standards and metrology (Invited) / M. Tinto -- pt. II. Frequency & metrology. Quantum metrology with lattice-confined ultracold Sr atoms (Invited) / A. D. Ludlow ... [et al.]. LNE-SYRTE clock ensemble: new [symbol]Rb hyperfine frequency measurement - spectroscopy of [symbol]Hg optical clock transition (Invited) / M. Petersen ... [et al.]. Precise measurements of S-wave scattering phase shifts with a juggling atomic clock (Invited) / S. Gensemer ... [et al.]. Absolute frequency measurement of the [symbol] clock transition (Invited) / M. Chwalla ... [et al.]. The semiclassical stochastic-field/atom interaction problem (Invited) / J. Camparo. Phase and frequency noise metrology (Invited) / E. Rubiola ... [et al.]. Optical spectroscopy of atomic hydrogen for an improved determination of the Rydberg constant / J. L. Flowers ... [et al.] -- pt. III. Clock applications in space. Recent progress on the ACES mission (Invited) / L. Cacciapuoti and C. Salomon. The SAGAS mission (Invited) / P. Wolf. Small mercury microwave ion clock for navigation and radioScience (Invited) / J. D. Prestage ... [et al.]. Astro-comb: revolutionizing precision spectroscopy in astrophysics (Invited) / C. E. Kramer ... [et al.]. High frequency very long baseline interferometry: frequency standards and

  1. Radio labeling with preassigned frequencies.

    OpenAIRE

    2004-01-01

    A radio labeling of a graph G is an assignment of pairwise distinct, positive integer labels to the vertices of G such that labels of adjacent vertices differ by at least $2$. The radio labeling problem (RL) consists in determining a radio labeling that minimizes the maximum label that is used (the so-called span of the labeling). RL is a well-studied problem, mainly motivated by frequency assignment problems in which transmitters are not allowed to operate on the same frequency channel. We c...

  2. Subglottal pressure and fundamental frequency control in contact calls of juvenile Alligator mississippiensis

    OpenAIRE

    Riede, Tobias; Tokuda, Isao T.; Farmer, C. G.

    2011-01-01

    SUMMARY Vocalization is rare among non-avian reptiles, with the exception of the crocodilians, the sister taxon of birds. Crocodilians have a complex vocal repertoire. Their vocal and respiratory system is not well understood but appears to consist of a combination of features that are also found in the extremely vocal avian and mammalian taxa. Anatomical studies suggest that the alligator larynx is able to abduct and adduct the vocal folds, but not to elongate or shorten them, and is therefo...

  3. Mixed-species flock size affects contact call frequencies of the crested tit, Lophophanes cristatus

    OpenAIRE

    Murdoch, Henrik

    2012-01-01

    Ääntelemällä tapahtuva kommunikointi voi altistaa linnut saalistukselle, koska pedot voivat paikantaa saaliseläimet ääntelyn perusteella. Yksi mahdollinen tapa suojautua saalistajilta on liittyminen parviin. Parveutuminen voi vaikuttaa ääntelyfrekvensseihin lisääntyneen parvensisäisen kommunikointitarpeen kautta, mutta myös koska ääntely suuremmissa parvissa voi olla saalistusriskin suhteen turvallisempaa. Tässä tutkimuksessa tutkin lajienvälisen sekaparven koon vaikutusta töyhtötiaisen pitkä...

  4. A short regression during the last interglacial (5e) sea level high-stand, along the reef coast of Egypt: a possible evidence for high-frequency glacio-eustatic variations during pleistocene times?

    International Nuclear Information System (INIS)

    In the most stable localities of the NW Red Sea-Gulf of Suez, the Last Interglacial shore deposits have been dated (α Th/U) and give evidence of a two-stages 5.5 (5e) + 8/5 m transgression subdivided by a 10 m (at least) relative sea-level fall. The respective ages of the initial reef and beach unit and about 3 m lower bay-lagoon-gypsum salina deposits are not discriminable with the available dating method. This high-frequency oscillation during 5.5 high stand would be tentatively interpreted as a glacio-eustatic sea-level coinciding with the 5.52 event of δ18O isotopic terminology. (authors)

  5. 用李萨如图形变化的快慢测多普勒效应中的频率差(测速)%Measuring frequency shift (speed) in Doppler effect through the variation of Lissajous figures

    Institute of Scientific and Technical Information of China (English)

    周珺; 王婷; 郭鹏

    2013-01-01

    The measurement of frequency shift was difficult in speedometer system based on Doppler effect .The application of Lissajous figures in the system was introduced .The experiment was more practical because a remote controlled toy car was used to simulate real vehicle .%针对当前利用多普勒效应测速实验中的测量频率差难的问题,通过实验发现利用李萨如图形变化的快慢测多普勒效应中的频率差,效果很好。实验中设计了使用遥控赛车模拟现实中的车辆,实验更具现实性。

  6. SEE: improving nurse-patient communications and preventing software piracy in nurse call applications.

    Science.gov (United States)

    Unluturk, Mehmet S

    2012-06-01

    Nurse call system is an electrically functioning system by which patients can call upon from a bedside station or from a duty station. An intermittent tone shall be heard and a corridor lamp located outside the room starts blinking with a slow or a faster rate depending on the call origination. It is essential to alert nurses on time so that they can offer care and comfort without any delay. There are currently many devices available for a nurse call system to improve communication between nurses and patients such as pagers, RFID (radio frequency identification) badges, wireless phones and so on. To integrate all these devices into an existing nurse call system and make they communicate with each other, we propose software client applications called bridges in this paper. We also propose a window server application called SEE (Supervised Event Executive) that delivers messages among these devices. A single hardware dongle is utilized for authentication and copy protection for SEE. Protecting SEE with securities provided by dongle only is a weak defense against hackers. In this paper, we develop some defense patterns for hackers such as calculating checksums in runtime, making calls to dongle from multiple places in code and handling errors properly by logging them into database. PMID:21222218

  7. Do male birds intercept and use rival courtship calls to adjust paternity protection behaviours?

    DEFF Research Database (Denmark)

    Matessi, Giuliano; McGregor, Peter Kenneth; Peake, Thomas More;

    2005-01-01

    with the behaviour of males who received a control playback, territorial song. After playback of courtship display calls male rock sparrows increased the frequency of courtship displays directed towards their mate, as predicted, but not mate guarding. These results illustrate the interplay of...... reproductive and communication strategies, and extend our knowledge of how the social environment can affect within-pair dynamics....

  8. Beware of the Spirits that You Call!

    DEFF Research Database (Denmark)

    Vasquez, Consuelo; Schoeneborn, Dennis; Sergi, Viviane

    This article proposes to study the constitution of organization by acknowledging the fundamentally intertwined nature of order and disorder. Adopting a dialectical lens, we explore the (dis)ordering properties of communication by focusing on both the symbolic and the material dimensions of language...... use in texts. Drawing on empirical material from three qualitative case studies on project organizing, we show that attempts to create order through texts (i.e. by closing and fixing meaning) simultaneously trigger disorder (i.e. open up the possibility of multiple meanings). As we argue, this dynamic...... plays a key role in the development of projects (and more broadly organizations), keeping them in motion by calling forth continuous processes of meaning negotiation....

  9. Acoustic signal detection of manatee calls

    Science.gov (United States)

    Niezrecki, Christopher; Phillips, Richard; Meyer, Michael; Beusse, Diedrich O.

    2003-04-01

    The West Indian manatee (trichechus manatus latirostris) has become endangered partly because of a growing number of collisions with boats. A system to warn boaters of the presence of manatees, that can signal to boaters that manatees are present in the immediate vicinity, could potentially reduce these boat collisions. In order to identify the presence of manatees, acoustic methods are employed. Within this paper, three different detection algorithms are used to detect the calls of the West Indian manatee. The detection systems are tested in the laboratory using simulated manatee vocalizations from an audio compact disc. The detection method that provides the best overall performance is able to correctly identify ~=96% of the manatee vocalizations. However the system also results in a false positive rate of ~=16%. The results of this work may ultimately lead to the development of a manatee warning system that can warn boaters of the presence of manatees.

  10. Comprometimento organizacional de trabalhadores de call center

    Directory of Open Access Journals (Sweden)

    Kely César Martins Paiva

    2015-09-01

    Full Text Available RESUMOO Neste artigo, analisa-se como se apresenta o comprometimento organizacional de trabalhadores de um call center, localizado em Belo (A Horizonte (Minas Gerais, Brasil. Após o delineamento conceitual UJ do tema central, são expostos os resultados de um estudo de caso descritivo, realizado com abordagens quantitativa e qualitativa. Os dados de 399 questionários e 22 entrevistas são, respectivamente, tratados estatisticamente e submetidos à análise de conteúdo. A base de comprometimento que predominou entre esses infoproletários foi "obrigação pelo desempenho" e, em menor grau, "afetiva". Foi observado que quanto maior é o seu tempo de experiência nesse tipo de organização, menores são os níveis de comprometimento de modo geral, fatos esclarecidos, parcialmente, por meio das entrevistas.

  11. Dynamic High Frequency Trading Models

    OpenAIRE

    Andersen, Espen Teie

    2009-01-01

    This thesis considers constructing high-frequency quantitative trading models. The work is a continuation of my project thesis (spring 2009) and Birgitte Ringstad Vartdal's master thesis (2000). We build our trading model through what we call the Layer Approach. This includes letting different layers take control of the different risk and decision mechanisms of our system. The underlying regression model is the Rydberg-Shephard model, the regression models are fitted to a moving data set to ...

  12. MILTON NASCIMENTO: UNA CALLE LLAMADA MUNDO

    Directory of Open Access Journals (Sweden)

    Alberto Carlos de Souza

    2011-12-01

    Full Text Available El punto de partida de este estudio consistirá en la exploración de la musicalidad de Milton Nascimento y de sus compañeros del “movimiento” “Clube da Esquina”, destacándose la relevancia del conjunto de esa obra para la cultura brasilera. El referido “movimiento” floreció en Minas Gerais en el auge de uno de los períodos más críticos de la historia contemporánea brasilera: la dictadura militar. En tanto, el “Clube da Esquina” – dado a la diversidad de los temas tratados en sus letras y su singularidad poética -, luego se difundió por todo el espacio cultural brasilero. Hablar del “Clube da Esquina” no es tarea fácil porque hay una dolorosa ausencia o pálida presencia de este movimiento en estudios que se ocupan de nuestra música popular. El “Clube da Esquina” fue un círculo de amigos que se reunieron en un pequeño pub en la esquina de la Calle Divinópolis y Calle Paraisópolis, en un bucólico barrio de Belo Horizonte (Minas Gerais - Brasil, llamado Santa Teresa. Era parte de esa hermandad, interesada en música, cine y poesía, Milton Nascimento, Wagner Tiso, Fernando Brant, Toninho Horta, Beto Guedes, Moura Tavinho, los hermanos Lô y Marcio Borges, Robertinho Silva, Nivaldo Ornelas, Ronaldo Bastos, Murilo Antunes Nelson Angelo y Novelli, entre otros. En estas reuniones, regadas con mucha cerveza, Milton Nascimento y sus compañeros. Milton fue y sigue siendo la mayor referencia del movimiento “Clube da Esquina”.

  13. Assessing the value of multi-receiver low-frequency electromagnetic-induction (EMI) measurement for assessing variation in soil moisture content in field experiments with winter wheat (Triticum aestivum)

    Science.gov (United States)

    Shanahan, Peter; Binley, Andrew; Dodd, Ian; Whalley, Richard; Watts, Chris; Ashton, Rhys; Ober, Eric

    2014-05-01

    In large plant breeding field trials with multiple genotypes, measuring soil water status (an indicator of crop water uptake) by conventional techniques (e.g. core extraction and penetration resistance) is limited by the cost and effort needed to achieve sufficient replication to apply robust statistical analysis. Geophysical methods may provide a more cost-effective means of more assessing valuable information about soil water status for such studies. We present here results from a field experiment using geophysical techniques for remote mapping of soil water content on sandy loam and silt loam soils in spring/summer 2013 in the UK. The aim of the study was to assess electromagnetic-induction (EMI) conductivity measurements for sensitivity to variations in shallow soil electrical properties and the spatial and temporal mapping of soil water. The CMD Mini-Explorer (GF Instruments) operates with three receiver coils at fixed distances from a transmitter coil (0.32 m, 0.71 m, 1.2 m). Measurement of magnetic field quadrature in horizontal coplanar (HC) and vertical coplanar (VC) of the three receiver coils provides six depths of investigation for the given coil spacing cumulative sensitivities. At the two field sites the instrument was applied to measuring apparent electrical conductivity (ECa) below 7.0 x 1.8 m plots consisting of 23 rain fed winter wheat cultivars and bare soil fallow control plots. These plots were sown in March 2013 and organised into a randomised block design. Electrical resistivity tomography (ERT) surveys along 15 m transects were also conducted at the two sites in order to compare EMI measured ECa. Our results show that progressive soil drying at both sites due to crop uptake significantly decreased (p<0.05) soil ECa. The difference in soil ECa as a result of water uptake between cultivars was found to be significant (p<0.05) from one of the coil configurations (coil spacing 1.8m in HC mode), and only at the silty loam site (no significant

  14. The Relationship of On-Call Work with Fatigue, Work-Home Interference, and Perceived Performance Difficulties

    Directory of Open Access Journals (Sweden)

    Carla M. Ziebertz

    2015-01-01

    Full Text Available Objectives. This study examined the relationship between on-call duty exposure (active and total on-call hours a month, number of calls per duty and employees’ experiences of being on-call (stress due to unpredictability, ability to relax during inactive on-call periods, restrictions during on-call duties, on-call work demands, and satisfaction with compensation for on-call duties on the one hand and fatigue, strain-based and time-based work-home interference (WHI, and perceived on-call performance difficulties (PPD on the other hand. Methods. Cross-sectional survey data were collected among a large heterogeneous sample of Dutch employees (N=5437. The final sample consisted of 157 on-call workers (23–69 years, 71% males. Data were analyzed by means of hierarchical regression analyses (controlling for age and job characteristics. Results. Differences in on-call work exposure were not systematically related to fatigue, WHI, and PPD (all p’s >0.50. The experience of being on-call explained a medium proportion of the variation in fatigue and strain-based WHI and a medium to large proportion of the variation in time-based WHI and PPD over and above the control variables. Conclusions. Our results suggest that it is employees’ experience of being on-call, especially the experience of stress due to the unpredictability, rather than the amount of exposure, that is related to fatigue, WHI, and perceived on-call performance difficulties.

  15. Comments on "Intraspecific and geographic variation of West Indian manatee (Trichechus manatus spp.) vocalizations" [J. Acoust. Soc. Am. 114, 66-69 (2003)].

    Science.gov (United States)

    Sousa-Lima, Renata S

    2006-06-01

    This letter concerns the paper "Intraspecific and geographic variation of West Indian manatee (Trichechus manatus spp.) vocalizations" [Nowacek et al., J. Acoust. Soc. Am. 114, 66-69 (2003)]. The purpose here is to correct the fundamental frequency range and information on intraindividual variation in the vocalizations of Amazonian manatees reported by Nowacek et al. (2003) in citing the paper "Signature information and individual recognition in the isolation calls of Amazonian manatees, Trichechus inunguis (Mammalia: Sirenia)" [Sousa-Lima et al., Anim. Behav. 63, 301-310 (2002)]. PMID:16838493

  16. Sharing programming resources between Bio* projects through remote procedure call and native call stack strategies

    DEFF Research Database (Denmark)

    Prins, Pjotr; Goto, Naohisa; Yates, Andrew;

    2012-01-01

    Open-source software (OSS) encourages computer programmers to reuse software components written by others. In evolutionary bioinformatics, OSS comes in a broad range of programming languages, including C/C++, Perl, Python, Ruby, Java, and R. To avoid writing the same functionality multiple times...... for different languages, it is possible to share components by bridging computer languages and Bio* projects, such as BioPerl, Biopython, BioRuby, BioJava, and R/Bioconductor. In this chapter, we compare the two principal approaches for sharing software between different programming languages: either by remote...... procedure call (RPC) or by sharing a local call stack. RPC provides a language-independent protocol over a network interface; examples are RSOAP and Rserve. The local call stack provides a between-language mapping not over the network interface, but directly in computer memory; examples are R bindings, RPy...

  17. Mobile telephones: a comparison of radiated power between 3G VoIP calls and 3G VoCS calls.

    Science.gov (United States)

    Jovanovic, Dragan; Bragard, Guillaume; Picard, Dominique; Chauvin, Sébastien

    2015-01-01

    The purpose of this study is to assess the mean RF power radiated by mobile telephones during voice calls in 3G VoIP (Voice over Internet Protocol) using an application well known to mobile Internet users, and to compare it with the mean power radiated during voice calls in 3G VoCS (Voice over Circuit Switch) on a traditional network. Knowing that the specific absorption rate (SAR) is proportional to the mean radiated power, the user's exposure could be clearly identified at the same time. Three 3G (High Speed Packet Access) smartphones from three different manufacturers, all dual-band for GSM (900 MHz, 1800 MHz) and dual-band for UMTS (900 MHz, 1950 MHz), were used between 28 July and 04 August 2011 in Paris (France) to make 220 two-minute calls on a mobile telephone network with national coverage. The places where the calls were made were selected in such a way as to describe the whole range of usage situations of the mobile telephone. The measuring equipment, called "SYRPOM", recorded the radiation power levels and the frequency bands used during the calls with a sampling rate of 20,000 per second. In the framework of this study, the mean normalised power radiated by a telephone in 3G VoIP calls was evaluated at 0.75% maximum power of the smartphone, compared with 0.22% in 3G VoCS calls. The very low average power levels associated with use of 3G devices with VoIP or VoCS support the view that RF exposure resulting from their use is far from exceeding the basic restrictions of current exposure limits in terms of SAR. PMID:25352159

  18. Red shift, blue shift: investigating Doppler shifts, blubber thickness, and migration as explanations of seasonal variation in the tonality of Antarctic blue whale song.

    Science.gov (United States)

    Miller, Brian S; Leaper, Russell; Calderan, Susannah; Gedamke, Jason

    2014-01-01

    The song of Antarctic blue whales (Balaenoptera musculus intermedia) comprises repeated, stereotyped, low-frequency calls. Measurements of these calls from recordings spanning many years have revealed a long-term linear decline as well as an intra-annual pattern in tonal frequency. While a number of hypotheses for this long-term decline have been investigated, including changes in population structure, changes in the physical environment, and changes in the behaviour of the whales, there have been relatively few attempts to explain the intra-annual pattern. An additional hypothesis that has not yet been investigated is that differences in the observed frequency from each call are due to the Doppler effect. The assumptions and implications of the Doppler effect on whale song are investigated using 1) vessel-based acoustic recordings of Antarctic blue whales with simultaneous observation of whale movement and 2) long-term acoustic recordings from both the subtropics and Antarctic. Results from vessel-based recordings of Antarctic blue whales indicate that variation in peak-frequency between calls produced by an individual whale was greater than would be expected by the movement of the whale alone. Furthermore, analysis of intra-annual frequency shift at Antarctic recording stations indicates that the Doppler effect is unlikely to fully explain the observations of intra-annual pattern in the frequency of Antarctic blue whale song. However, data do show cyclical changes in frequency in conjunction with season, thus suggesting that there might be a relationship among tonal frequency, body condition, and migration to and from Antarctic feeding grounds. PMID:25229644

  19. Red shift, blue shift: investigating Doppler shifts, blubber thickness, and migration as explanations of seasonal variation in the tonality of Antarctic blue whale song.

    Directory of Open Access Journals (Sweden)

    Brian S Miller

    Full Text Available The song of Antarctic blue whales (Balaenoptera musculus intermedia comprises repeated, stereotyped, low-frequency calls. Measurements of these calls from recordings spanning many years have revealed a long-term linear decline as well as an intra-annual pattern in tonal frequency. While a number of hypotheses for this long-term decline have been investigated, including changes in population structure, changes in the physical environment, and changes in the behaviour of the whales, there have been relatively few attempts to explain the intra-annual pattern. An additional hypothesis that has not yet been investigated is that differences in the observed frequency from each call are due to the Doppler effect. The assumptions and implications of the Doppler effect on whale song are investigated using 1 vessel-based acoustic recordings of Antarctic blue whales with simultaneous observation of whale movement and 2 long-term acoustic recordings from both the subtropics and Antarctic. Results from vessel-based recordings of Antarctic blue whales indicate that variation in peak-frequency between calls produced by an individual whale was greater than would be expected by the movement of the whale alone. Furthermore, analysis of intra-annual frequency shift at Antarctic recording stations indicates that the Doppler effect is unlikely to fully explain the observations of intra-annual pattern in the frequency of Antarctic blue whale song. However, data do show cyclical changes in frequency in conjunction with season, thus suggesting that there might be a relationship among tonal frequency, body condition, and migration to and from Antarctic feeding grounds.

  20. Sharing programming resources between Bio* projects through remote procedure call and native call stack strategies.

    Science.gov (United States)

    Prins, Pjotr; Goto, Naohisa; Yates, Andrew; Gautier, Laurent; Willis, Scooter; Fields, Christopher; Katayama, Toshiaki

    2012-01-01

    Open-source software (OSS) encourages computer programmers to reuse software components written by others. In evolutionary bioinformatics, OSS comes in a broad range of programming languages, including C/C++, Perl, Python, Ruby, Java, and R. To avoid writing the same functionality multiple times for different languages, it is possible to share components by bridging computer languages and Bio* projects, such as BioPerl, Biopython, BioRuby, BioJava, and R/Bioconductor. In this chapter, we compare the two principal approaches for sharing software between different programming languages: either by remote procedure call (RPC) or by sharing a local call stack. RPC provides a language-independent protocol over a network interface; examples are RSOAP and Rserve. The local call stack provides a between-language mapping not over the network interface, but directly in computer memory; examples are R bindings, RPy, and languages sharing the Java Virtual Machine stack. This functionality provides strategies for sharing of software between Bio* projects, which can be exploited more often. Here, we present cross-language examples for sequence translation, and measure throughput of the different options. We compare calling into R through native R, RSOAP, Rserve, and RPy interfaces, with the performance of native BioPerl, Biopython, BioJava, and BioRuby implementations, and with call stack bindings to BioJava and the European Molecular Biology Open Software Suite. In general, call stack approaches outperform native Bio* implementations and these, in turn, outperform RPC-based approaches. To test and compare strategies, we provide a downloadable BioNode image with all examples, tools, and libraries included. The BioNode image can be run on VirtualBox-supported operating systems, including Windows, OSX, and Linux. PMID:22399473

  1. Advertisement and release calls of Phyllomedusa ayeaye (Anura: Hylidae with comments on the social context of emission

    Directory of Open Access Journals (Sweden)

    Renato C. Nali

    2015-08-01

    Full Text Available ABSTRACT Male calls play different roles in anuran social organization, such as spacing, territoriality and female attraction. However, calls and associated behaviors remain poorly described for many anuran species. Here we describe the advertisement and release calls of the tree frog Phyllomedusa ayeaye (Lutz, 1966 and report on the social context of emissions and a physical combat. Approximately 35 minutes of digital recordings were obtained from 34 hours of observations at one breeding site in the state of Minas Gerais, southeastern Brazil. Bioacoustic analysis showed that males emitted two types of advertisement calls: 1 simple call (a sequence of short pulsed notes and 2 composite call (a sequence of short pulsed notes followed by a long pulsed note. Composite calls were emitted more frequently during more intense chorus activity, with various active males at the breeding site. The release call was also composed by short pulsed notes, with a wider spectrum of frequencies and emitted more rapidly than the advertisement calls. Our results suggest that the composite call of P. ayeaye may represent a mixed advertisement call. Long notes might be the aggressive part directed to males, whereas short notes directed to females. Our description of call types, their functions, and male physical interactions will be useful for studies investigating the systematics and behavior of Phyllomedusa species.

  2. Bat calls while preying: A method for reconstructing the signal emitted by a directional sound source

    DEFF Research Database (Denmark)

    Guarato, Francesco; Hallam, John

    2010-01-01

    Understanding and modeling bat biosonar behavior should take into account what the bat actually emitted while exploring the surrounding environment. Recording of the bat calls could be performed by means of a telemetry system small enough to sit on the bat head, though filtering due to bat...... directivity affects recordings and not all bat species are able to carry such a device. Instead, remote microphone recordings of the bat calls could be processed by means of a mathematical method that estimates bat head orientation as a first step before calculating the amplitudes of each call for each...... frequency. This approach considers bat position with respect to each microphone, directivity, and head orientation for compensating microphone recordings of bat calls. The method has been tested in a laboratory environment using data from a Polaroid transducer as sound source: results are presented and...

  3. Time-frequency Representations Application in Psychological Testing

    Directory of Open Access Journals (Sweden)

    REIZ Romulus

    2015-10-01

    Full Text Available A psychological test is a test that is designed to measure one aspect of human behavior. These tests are usually designed to evaluate a person’s ability to complete tasks that were individual's performance on certain tasks that have usually been requested in advance. Usually a test score is used to compare with other results to measure the individual’s performance regarding cognitive ability, aptitude, personality, etc. One such test is the so called “finger tapping” test, designed to measure the integrity of the neuromuscular system and examine motor control. There are several ways to perform such a test. The purpose of this paper isn’t to study the finger tapping test which is well documented in the literature, but to develop if possible a simple way of performing such a test. Using the method presented in the paper a nonstationary signal was obtained and it was analyzed using the Short-time Fourier time frequency representation to obtain the signals frequency and its variation in time. The results presented in the paper show that this method can be used to perform the test and the frequency and spatial amplitude of the obtained tapping signal can be determined easily.

  4. IAEA Director General calls for DPRK restraint

    International Nuclear Information System (INIS)

    Full text: The IAEA received today a letter from Mr. Ri Je Son, Director General of the General Department of Atomic Energy of the Democratic People's Republic of Korea (DPRK), informing the IAEA of the DPRK's decision to 'lift the freeze' on its nuclear facilities maintained pursuant to the DPRK-USA Agreed Framework and to resume operations of these facilities for power generation. Dr. ElBaradei called on the DPRK to act with restraint in this tense situation- and not to take any unilateral action that might further complicate the IAEA's ability to determine whether the DPRK's inventory of nuclear material subject to safeguards was complete and correct. The DPRK's letter requests that the IAEA remove seals and monitoring cameras on all of its nuclear facilities. The Director General said, 'it is essential that the containment and surveillance measures which are currently in place continue to be maintained, and that the DPRK not take any steps unilaterally to remove or impede the functioning of such seals or cameras. Any such action,' he added, 'would not be in compliance with the requirements of the IAEA-DPRK Safeguards Agreement.' Dr. ElBaradei also asked the DPRK to agree to an urgent meeting of technical experts to discuss the practical arrangements involved in moving from the 'freeze' to normal safeguards operations, and particularly how the IAEA will fulfil its verification requirements under the IAEA-DPRK Safeguards Agreement. He called upon all concerned parties to the Agreed Framework to renew their commitment to its terms and to enter into a dialogue aimed at a resolution of the issue by peaceful means. 'The Agreed Framework was key to overcoming the 1994 nuclear crisis in DPRK and continues to serve as an important instrument for maintaining peace and stability on the Korean Peninsula,' Dr. ElBaradei said. The Agreed Framework was concluded in 1994 with the aim of ensuring that the DPRK comes into full compliance with its safeguards agreement, in return

  5. Moribund Ants Do Not Call for Help.

    Science.gov (United States)

    Miler, Krzysztof

    2016-01-01

    When an antlion captures a foraging ant, the victim's nestmates may display rescue behaviour. This study tested the hypothesis that the expression of rescue behaviour depends on the life expectancy of the captured ant. This hypothesis predicts that the expression of rescue behaviour will be less frequent when the captured ant has a lower life expectancy than when it has a higher life expectancy because such a response would be adaptive at the colony level. Indeed, significant differences were found in the frequency of rescue behaviours in response to antlion victims with differing life expectancies. In agreement with prediction, victims with lower life expectancies were rescued less frequently, and those rescues had a longer latency and shorter duration. There was also a qualitative difference in the behaviour of rescuers to victims from the low and high life expectancy groups. Several explanations for these findings are proposed. PMID:26986741

  6. Radiation budget is called to account

    International Nuclear Information System (INIS)

    Our atmosphere could absorb much more radiation from the Sun than previously thought - with far-reaching consequences for climate modelling and the evaporation and condensation of water. Earlier this year a group of some 70 scientists spent an intense week in the foothills of the Rocky Mountains in Colorado reviewing the current understanding of the radiation budget of the atmosphere. The meeting, the latest in the series of Chapman Conferences organized by the American Geophysical Union, focused on the so-called anomalous absorption of solar radiation in the atmosphere. Evidence gathered over the past 20 years has increasingly shown that the absorption of solar radiation predicted by models is significantly less than the absorption measured experimentally. Current models predict that, on a global average, the atmosphere absorbs about 65 W m-2, whereas observations from the top of the atmosphere and the Earth's surface show that the actual absorption is 95 W m-2. This mismatch of some 30 W m-2 corresponds to about 10% of the globally averaged incoming solar radiation, suggesting that some extra anomalous absorption needs to be added to the models. (U.K.)

  7. Another call to increase STEM education

    Science.gov (United States)

    Showstack, Randy

    2011-07-01

    As science, technology, engineering, and mathematics (STEM) education becomes increasingly important, U.S. students are lagging behind other nations on international assessments, according to a recent Trends in International Mathematics and Science study. A 22 June report from the U.S. National Research Council (NRC) calls for increasing the focus on STEM education in the United States. “To make progress in improving STEM education for all students, policy makers at the national, state, and local levels should elevate science to the same level of importance as reading and mathematics,” states the report, “Successful K-12 STEM Education: Identifying Effective Approaches in Science, Technology, Engineering, and Mathematics.” It outlines several goals: expand the number of students who pursue advanced degrees and careers in STEM fields; expand the STEM-capable workforce, while also broadening the participation of women and minorities; and increase STEM literacy for all students, whether or not they pursue STEM-related careers or additional study in those areas.

  8. McNamara calls for action now.

    Science.gov (United States)

    1992-05-01

    Robert McNamara outlined a 6 point global family planning (FP) program he designed to expand FP services to answer unmet need. The plan calls for Fp spending to increase to US$8 billion by 2000. For the US this would mean an increase from US$800 million to US$3.5 billion. This amount is very, very small compared to the total amount spent on official development assistance projected for Organization for Economic Cooperation and Development (OECD) countries. It is easily within the capabilities of OECD countries to meet this goal. The plan would develop a system in which the World Bank and the UNFPA would work together with each developing country to establish population target levels. The World Bank would assume responsibility for organizing external financing and serve as a last resort source of financing. Japan must also begin to take a leadership role more in line with its economic power. Currently it spends only .32% of its GNP to aid developing countries, despite the fact that its per capita income is 20% larger than any other OECD member. This means raising spending form US$9 billion to US$14.5 billion. This could be done easily by raising it US$500 million/year and planning to increase this US$1 billion by 2000. PMID:12285117

  9. REMINDER: In a medical emergency call 74444

    CERN Multimedia

    2005-01-01

    What happened? A CERN colleague, complaining of pains that might indicate serious heart problem, went to the ?infirmary' on the Prévessin site for medical aid. He was unaware that the ?infirmary' was in fact no such thing, but the office of the French contractors' medical practitioner, and, on top of that, it was closed. He therefore took his own car and went to the CERN Fire Station on the Meyrin Site (Building 65). The firemen and the CERN medical team took care of him and requested helicopter transport to the Geneva cantonal hospital, where he responded well to medical treatment. What do we learn from this event? You must call the CERN internal number 74444 in the event of serious and acute illness, and do not have to present yourself in person or get somebody to go with you. This number is not reserved exclusively for accident, pollution, fire etc. The Firemen can prodice professional assistance at all times as required: first aid on the spot, amulance transport and medical assistance as necessary. ...

  10. Solar cycle and seasonal variations of the solar an lunar daily variations of total electron content at lunping

    International Nuclear Information System (INIS)

    The solar and lunar daily variations of the ionospheric total electron content observed at Lunping, which lies close to the crest zone of the so-called equatorial anomaly, were analyzed by Chapman-Miller method. The lunisolar diurnal variation L1 and lunar semidiurnal variation L2 were found to have significant seasonal variations, with amplitude increasing steadily from summer to winter. The hours for L1 and L2 variations to attain their respective maximum values also increase steadily from summer to winter. The seasonal variation of the semidiurnal variation l2 was found to be explainable by the additional fountain effect caused by the similar seasonal variation of the lunar semidiurnal electric field induced at the equatorial region. However, the seasonal variation of the lunisolar variation L1 was found not to be explainable by the additional fountain effect. Seasonal variations for the harmonic components of the solar daily variation were found and described

  11. Mitigating Handoff Call Dropping in Wireless Cellular Networks: A Call Admission Control Technique

    Science.gov (United States)

    Ekpenyong, Moses Effiong; Udoh, Victoria Idia; Bassey, Udoma James

    2016-06-01

    Handoff management has been an important but challenging issue in the field of wireless communication. It seeks to maintain seamless connectivity of mobile users changing their points of attachment from one base station to another. This paper derives a call admission control model and establishes an optimal step-size coefficient (k) that regulates the admission probability of handoff calls. An operational CDMA network carrier was investigated through the analysis of empirical data collected over a period of 1 month, to verify the performance of the network. Our findings revealed that approximately 23 % of calls in the existing system were lost, while 40 % of the calls (on the average) were successfully admitted. A simulation of the proposed model was then carried out under ideal network conditions to study the relationship between the various network parameters and validate our claim. Simulation results showed that increasing the step-size coefficient degrades the network performance. Even at optimum step-size (k), the network could still be compromised in the presence of severe network crises, but our model was able to recover from these problems and still functions normally.

  12. Study on Somaclonal Variation of Spring Wheat

    Institute of Scientific and Technical Information of China (English)

    JIANG Shu-mei; HU Shang-lian; LI Wen-xiong

    2004-01-01

    Somaclonal variation of calli and regenerated plants of spring wheat ware detected by using technique RAPD in the study. Calli at different culture stages and regenerated plants derived from young spikes and immature embryos were used as materials. Molecular variation could be reflected from electrophoresis patternof RAPD fragments at different culture stage in calli, and in regenerated plants derived from different explants, even no phenotype variations were found. Somaclonal variation in calli and in regenerated plants appeared regularly: A higher frequency of variation in hybrids F2 was detected than that of the cultivar that is stable genetically. High variation frequency of RAPD fragments appeared in calli when cultured 75 days. The identical variations of RAPD fragments were observed in calli and in the regenerated plants induced from different genotype or explants. The variation frequency detected is higher in regenerated plants than that of in calli. RAPD could be applied easily and simply to determine variation in level of DNA at each stage cultured in vitro.

  13. Glucocorticoid and androgen signaling pathways diverge between advertisement calling and non-calling fish.

    Science.gov (United States)

    Genova, Rachel M; Marchaterre, Margaret A; Knapp, Rosemary; Fergus, Daniel; Bass, Andrew H

    2012-09-01

    Behavioral and neuroendocrine mechanisms of social vocalization in teleost fish are influenced by the glucocorticoid cortisol and the androgen 11-ketotestosterone (11kT). The relative abundance of both 11kT, which binds to androgen receptors (ARα, ARβ), and cortisol, which binds to glucocorticoid receptors (GR-1, GR-2), is regulated by 11β-hydroxylase (11βH) that converts 11-deoxycortisol to cortisol and testosterone to 11β-OH-testosterone, and 11β-hydroxysteroid dehydrogenase (11βHSD) that converts cortisol to the inactive metabolite cortisone and 11β-OH-testosterone to 11kT. In midshipman fish, we tested the hypothesis that plasma steroid levels, mRNA abundance for 11βH and 11βHSD in the vocal muscle and testis (known site of 11kT synthesis), and mRNA abundances for ARs and GRs in vocal muscle, would differ between males that did or did not recently produce 'hum' advertisement calls. Quantitative real-time PCR demonstrated that non-calling male vocal muscle had significantly higher mRNA levels for all receptors except ARα, and a strong trend for higher 11βHSD; 11βH was similar to that in calling males. Calling males had higher plasma and testis 11kT, but lower plasma cortisol, levels. Testis enzyme levels did not differ between male groups, although calling males showed a positive linear correlation between plasma 11kT and testis 11βHSD mRNA levels, consistent with testis being the main source of plasma 11kT. We propose that higher vocal muscle 11βHSD levels in non-calling males reflect increased local conversion of elevated cortisol to cortisone, providing protection from cortisol-related toxicity, while increased receptor expression in non-calling males functions as a preparatory mechanism for meeting the physiological demands of future vocalization. PMID:22884426

  14. Blue and fin whale call source levels and propagation range in the Southern Ocean.

    Science.gov (United States)

    Sirović, Ana; Hildebrand, John A; Wiggins, Sean M

    2007-08-01

    Blue (Balaenoptera musculus) and fin whales (B. physalus) produce high-intensity, low-frequency calls, which probably function for communication during mating and feeding. The source levels of blue and fin whale calls off the Western Antarctic Peninsula were calculated using recordings made with calibrated, bottom-moored hydrophones. Blue whales were located up to a range of 200 km using hyperbolic localization and time difference of arrival. The distance to fin whales, estimated using multipath arrivals of their calls, was up to 56 km. The error in range measurements was 3.8 km using hyperbolic localization, and 3.4 km using multipath arrivals. Both species produced high-intensity calls; the average blue whale call source level was 189+/-3 dB re:1 microPa-1 m over 25-29 Hz, and the average fin whale call source level was 189+/-4 dB re:1 microPa-1 m over 15-28 Hz. Blue and fin whale populations in the Southern Ocean have remained at low numbers for decades since they became protected; using source level and detection range from passive acoustic recordings can help in calculating the relative density of calling whales. PMID:17672667

  15. Optimal temporal placement of the call in beach volleyball

    Directory of Open Access Journals (Sweden)

    Stefan Künzell

    2016-05-01

    Full Text Available The call is a tactical component in beach volleyball attacks. Through the call, the setter indicates to his or her teammate an open spot in the opponent’s court. In two experimental conditions, we investigated the interval between the call and the ball-hand contact (“call shot interval”, CSI of top-level athletes. We show that the probability that a given call is followed is dependent on the duration of the CSI and the number of call options. Longer CSIs result in an increased probability that the given call will be followed, whilst increasing the call options results in a decrease in probability. On average, there is a 50% probability that the call will be followed if the call precedes the shot by 460 ms and if a single call option (“line” is expected. If the attacker has to choose between three call options (“line”, “cut”, “no-one” a 50% probability that the call will be followed is observed at an CSI of 542 ms. It did not appear that gender influenced the ability to follow a call. We recommend that in practice and in competition, players and coaches should consider the proper duration of the CSI for effective calling.

  16. Stress, anxiety, and depression among call handlers employed in international call centers in the national capital region of Delhi

    OpenAIRE

    Dinesh Raja Jeyapal; Sanjiv Kumar Bhasin; Anjur Tupil Kannan; Manjeet Singh Bhatia

    2015-01-01

    Background: Call handlers employed in call centers repeatedly undergo stress in their day-to-day lives and this can have deleterious effects on their health. Objectives: The objectives were to study the levels of stress, anxiety, and depression, and their predictors among call handlers employed in international call centers in the National Capital Region (NCR) of Delhi. Materials and Methods: A cross-sectional questionnaire-based survey was conducted among 375 call handlers aged 18-39 years. ...

  17. Calling under pressure: Short-finned pilot whales make social calls during deep foraging dives

    DEFF Research Database (Denmark)

    Jensen, Frants Havmand; Marrero Perez, Jacobo; Johnson, Mark;

    2011-01-01

    Toothed whales rely on sound to echolocate prey and communicate with conspecifics, but little is known about how extreme pressure affects pneumatic sound production in deep-diving species with a limited air supply. The short-finned pilot whale (Globicephala macrorhynchus) is a highly social species...... among the deep-diving toothed whales, in which individuals socialize at the surface but leave their social group in pursuit of prey at depths of up to 1000 m. To investigate if these animals communicate acoustically at depth and test whether hydrostatic pressure affects communication signals, acoustic...... DTAGs logging sound, depth and orientation were attached to 12 pilot whales. Tagged whales produced tonal calls during deep foraging dives at depths of up to 800 m. Mean call output and duration decreased with depth despite the increased distance to conspecifics at the surface. This shows that the...

  18. Temporal segregation of the Australian and Antarctic blue whale call types (Balaenoptera musculus spp.)

    OpenAIRE

    Tripovich, Joy S.; Klinck, Holger; Nieukirk, Sharon L; Adams, Tempe; Mellinger, David K.; Balcazar, Naysa E.; Klinck, Karolin; Hall, Evelyn J. S.; Tracey L Rogers

    2015-01-01

    We examined recordings from a 15-month (May 2009–July 2010) continuous acoustic data set collected from a bottom-mounted passive acoustic recorder at a sample frequency of 6kHz off Portland, Victoria, Australia (38°33′01″S, 141°15′13″E) off southern Australia. Analysis revealed that calls from both subspecies were recorded at this site, and general additive modeling revealed that the number of calls varied significantly across seasons. Antarctic blue whales were detected more frequently from ...

  19. Round-Trip System Available to Measure Path Length Variation in Korea VLBI System for Geodesy

    Science.gov (United States)

    Oh, Hongjong; Kondo, Tetsuro; Lee, Jinoo; Kim, Tuhwan; Kim, Myungho; Kim, Suchul; Park, Jinsik; Ju, Hyunhee

    2010-01-01

    The construction project of Korea Geodetic VLBI officially started in October 2008. The construction of all systems will be completed by the end of 2011. The project was named Korea VLBI system for Geodesy (KVG), and its main purpose is to maintain the Korea Geodetic Datum. In case of the KVG system, an observation room with an H-maser frequency standard is located in a building separated from the antenna by several tens of meters. Therefore KVG system will adopt a so-called round-trip system to transmit reference signals to the antenna with reduction of the effect of path length variations. KVG s round-trip system is designed not only to use either metal or optical fiber cables, but also to measure path length variations directly. We present this unique round trip system for KVG.

  20. Electric field variations generated by ground motion and their application to groundwater research

    International Nuclear Information System (INIS)

    Complete text of publication follows. Clear examples of electric field variations have been obtained in association with ground motion due to the passage of seismic waves. Such electric field variations have been interpreted mostly in terms of the so-called electrokinetic effect, as well documented in quite a few papers. Recently we found circularly polarized electric fields in association with natural and artificial (blasting) earthquakes in Japan and proposed another mechanism of electric field generation, which we call the seismic dynamo effect. This may be regarded as an extended model of the induction effect. In this model we consider ions motion in pores filled with groundwater, which is driven by ground motion in the Earth's magnetic field. This model is capable of showing the possibility of circular polarization of electric field when the resonance is realized between the frequency of ground velocity and the cyclotron frequency of ion, such as HCO3-, Cl-, Na+, etc. contained in pores, for the Earth's magnetic field at the observation site. Ions with negative charge show the circular polarization with polarity opposite to that for ions with positive charge. In the observations, circular polarizations with opposite polarities have also been found. An application of this model would be possible for groundwater research in relation to environmental researches. Concentration of specific ions in groundwater would be examined if experiments are properly designed in the field.

  1. A devil in the detail: parameter cross-talk from the solar cycle and estimation of solar p-mode frequencies

    CERN Document Server

    Chaplin, W J; Eff-Darwich, A; Elsworth, Y; New, R

    2008-01-01

    Frequencies, powers and damping rates of the solar p modes are all observed to vary over the 11-yr solar activity cycle. Here, we show that simultaneous variations of these parameters give rise to a subtle cross-talk effect, which we call the ``devil in the detail'', that biases p-mode frequencies estimated from analysis of long power frequency spectra. We also show that the resonant peaks observed in the power frequency spectra show small distortions due to the effect. Most of our paper is devoted to a study of the effect for Sun-as-a-star observations of the low-l p modes. We show that for these data the significance of the effect is marginal. We also touch briefly on the likely l dependence of the effect, and discuss the implications of these results for solar structure inversions.

  2. The advertisement call, color patterns and distribution of Ischnocnema izecksohni (Caramaschi and Kisteumacher, 1989 (Anura, Brachycephalidae

    Directory of Open Access Journals (Sweden)

    Pedro P. G. Taucce

    2012-01-01

    Full Text Available Ischnocnema izecksohni inhabits the gallery forests from the Quadrilátero Ferrífero, Southern Espinhaço range, state of Minas Gerais, southeastern Brazil, and it is considered endemic to this region. Its closest related species is I. nasuta according to the original description. We describe the advertisement call of I. izecksohni based on specimens recorded and collected at the municipality of Nova Lima, state of Minas Gerais, distant about 10 km straight line from its type locality. The advertisement call consists of a group of notes emitted sporadically without a regular interval between the calls. Call duration (n = 36 calls in four individuals ranged from 1.03 to 1.85 s (= 1.52 ± 0.21 s and the call rise time from 0.66 to 1.52 s (= 1.16 ± 0.25 s, with 34-57 notes per call (= 47.42 ± 6.03. Peak frequency ranged from 2250 to 2625 Hz, the dominant frequency from 1317.8 to 3128.0 Hz and interval between notes from 22.00 to 41.00 ms (= 28.63 ± 0.03 ms. From the examination of herpetological collections, morphological and bioacoustical data we extended the species known distribution ca. 200 km eastward, to ten new localities, all of them outside the Quadrilátero Ferrífero region, at the Mantiqueira mountain range. We analyzed color patterns and we find some dorsal patterns not described at the original description of I. izecksohni. We also make some comments concerning the taxonomic status of I. izecksohni and I. nasuta.

  3. Call Center Outsourcing: Coordinating Staffing Level and Service Quality

    OpenAIRE

    Z. Justin Ren; Yong-Pin Zhou

    2008-01-01

    In this paper, we study the contracting issues in an outsourcing supply chain consisting of a user company and a call center that does outsourcing work for the user company. We model the call center as a G/G/s queue with customer abandonment. Each call has a revenue potential, and we model the call center's service quality by the percentage of calls resolved (revenue realized). The call center makes two strategic decisions: how many agents to have and how much effort to exert to achieve servi...

  4. Caval variations in neurologically diseased patients

    International Nuclear Information System (INIS)

    The import of the cavum variation and its prevalence rate in healthy individuals is still not clear, likewise in neurologically diseased patients. To evaluate the frequency and pattern of caval variations in neurologically diseased patients. The presence or absence of the cavum septum pellucidum (CSP), cavum vergae (CV), or cavum velum interpositum (CVI) was reviewed from successive cranial computerized tomography (CT) images of patients who were aged 6 months and above. Two hundred and seventeen cranial CT images were reviewed. At least a cavum variation was noted in 130 (59.9%) of the CT scan images reviewed. The CV, CVI, and CSP were noted in 86 (39.6%), 53 (24.4%), and 50 images (23%), respectively. Caval multiplicity was noted in 102 patients (47%). There was no significant difference in the rate of occurrence of cavum variations in patients with congenital brain diseases and acquired brain conditions (P = 0.484), neither was there a significant difference in the frequency of cavum variation in children aged older than 6 months compared to adults (P = 0.101). Cava variations are relatively common in neurological brain diseases. Patients with congenital brain diseases did not have a higher frequency of cava variation when compared with those that had acquired lesions. The most common type of cavum variation noted in this study was the vergae variety, while the CSP is the rarest

  5. Harmonically excited orbital variations

    International Nuclear Information System (INIS)

    Rephrasing the equations of motion for orbital maneuvers in terms of Lagrangian generalized coordinates instead of Newtonian rectangular cartesian coordinates can make certain harmonic terms in the orbital angular momentum vector more readily apparent. In this formulation the equations of motion adopt the form of a damped harmonic oscillator when torques are applied to the orbit in a variationally prescribed manner. The frequencies of the oscillator equation are in some ways unexpected but can nonetheless be exploited through resonant forcing functions to achieve large secular variations in the orbital elements. Two cases are discussed using a circular orbit as the control case: (1) large changes in orbital inclination achieved by harmonic excitation rather than one impulsive velocity change, and (2) periodic and secular changes to the longitude of the ascending node using both stable and unstable excitation strategies. The implications of these equations are also discussed for both artificial satellites and natural satellites. For the former, two utilitarian orbits are suggested, each exploiting a form of harmonic excitation. 5 refs

  6. How do "mute" cicadas produce their calling songs?

    Directory of Open Access Journals (Sweden)

    Changqing Luo

    Full Text Available Insects have evolved a variety of structures and mechanisms to produce sounds, which are used for communication both within and between species. Among acoustic insects, cicada males are particularly known for their loud and diverse sounds which function importantly in communication. The main method of sound production in cicadas is the tymbal mechanism, and a relative small number of cicada species possess both tymbal and stridulatory organs. However, cicadas of the genus Karenia do not have any specialized sound-producing structures, so they are referred to as "mute". This denomination is quite misleading, as they indeed produce sounds. Here, we investigate the sound-producing mechanism and acoustic communication of the "mute" cicada, Karenia caelatata, and discover a new sound-production mechanism for cicadas: i.e., K. caelatata produces impact sounds by banging the forewing costa against the operculum. The temporal, frequency and amplitude characteristics of the impact sounds are described. Morphological studies and reflectance-based analyses reveal that the structures involved in sound production of K. caelatata (i.e., forewing, operculum, cruciform elevation, and wing-holding groove on scutellum are all morphologically modified. Acoustic playback experiments and behavioral observations suggest that the impact sounds of K. caelatata are used in intraspecific communication and function as calling songs. The new sound-production mechanism expands our knowledge on the diversity of acoustic signaling behavior in cicadas and further underscores the need for more bioacoustic studies on cicadas which lack tymbal mechanism.

  7. Calling song and phonotactic selectivity in the field cricket Teleogryllus emma (Orthoptera: Gryllidae

    Directory of Open Access Journals (Sweden)

    Soojin Jang

    2010-12-01

    Full Text Available Males of the field cricket Teleogryllus emma produce calling songs that are attractive to receptive females. The callingsongs of T. emma consist of two components, the long chirp that is composed of up to 12 single pulses, followed by avariable number of short chirps. Based on the analysis of coefficient of variation (CV, temporal characters of the longchirp were less variable than those of the short chirps in male calling songs. To test for phonotactic selectivity of females,we conducted a single-stimulus playback experiment in which five stimuli (standard, long chirp only, long chirp augmented,short chirps only, and short chirps augmented were used. The standard stimulus included both long and shortchirps whose characteristics were derived from the calling songs of field populations. Results of the playback experimentshowed that female crickets oriented more frequently toward the stimuli that included the long chirp (standard, longchirp only, and long chirp augmented stimuli than toward the stimuli lacking the long chirp (short chirps only and shortchirps augmented stimuli, indicating that the long chirp in the calling songs was required to elicit positive phonotaxis inthe female crickets. The result of CV analysis of the male calling songs and the findings of the female phonotaxis experimentsuggested that the long chirp of calling songs may play a role in species recognition in T. emma.

  8. Variational integrators for electric circuits

    International Nuclear Information System (INIS)

    In this contribution, we develop a variational integrator for the simulation of (stochastic and multiscale) electric circuits. When considering the dynamics of an electric circuit, one is faced with three special situations: 1. The system involves external (control) forcing through external (controlled) voltage sources and resistors. 2. The system is constrained via the Kirchhoff current (KCL) and voltage laws (KVL). 3. The Lagrangian is degenerate. Based on a geometric setting, an appropriate variational formulation is presented to model the circuit from which the equations of motion are derived. A time-discrete variational formulation provides an iteration scheme for the simulation of the electric circuit. Dependent on the discretization, the intrinsic degeneracy of the system can be canceled for the discrete variational scheme. In this way, a variational integrator is constructed that gains several advantages compared to standard integration tools for circuits; in particular, a comparison to BDF methods (which are usually the method of choice for the simulation of electric circuits) shows that even for simple LCR circuits, a better energy behavior and frequency spectrum preservation can be observed using the developed variational integrator

  9. Effectiveness of the Call in Beach Volleyball Attacking Play

    Directory of Open Access Journals (Sweden)

    Künzell Stefan

    2014-12-01

    Full Text Available In beach volleyball the setter has the opportunity to give her or his hitter a “call”. The call intends that the setter suggests to her or his partner where to place the attack in the opponent’s court. The effectiveness of a call is still unknown. We investigated the women’s and men’s Swiss National Beach Volleyball Championships in 2011 and analyzed 2185 attacks. We found large differences between female and male players. While men called in only 38.4% of attacks, women used calls in 85.5% of attacks. If the male players followed a given call, 63% of the attacks were successful. The success rate of attacks without any call was 55.8% and 47.6% when the call was ignored. These differences were not significant (χ2(2 = 4.55, p = 0.103. In women’s beach volleyball, the rate of successful attacks was 61.5% when a call was followed, 35% for attacks without a call, and 42.6% when a call was ignored. The differences were highly significant (χ2(2 = 23.42, p < 0.0005. Taking into account the findings of the present study, we suggested that the call was effective in women’s beach volleyball, while its effect in men’s game was unclear. Considering the quality of calls we indicate that there is a significant potential to increase the effectiveness of a call.

  10. Overlapped frequency-time division multiplexing

    Institute of Scientific and Technical Information of China (English)

    JIANG Hui; LI Dao-ben

    2009-01-01

    A technique named overlapped frequency-time division multiplexing (OVFTDM)) is proposed in this article. The technique is derived from Nyquist system and frequency-time division multiplexing system. When the signals are compactly overlapped without the orthogonality in time domain, the technique is named overlapped time division multiplexing (OVTDM), whereas when signals are compactly overlapped without the orthogonality in frequency domain, the technique is called overlapped frequency division multiplexing (OVFDM). To further improve spectral efficiency, the OVFTDM in which signals are overlapped both in frequency domain and in time domain is explored. OVFTDM does not depend on orthogonality whatever in time domain or in frequency domain like Nyquist system or OFDM system, but on the convolutional constraint relationship among signals. Therefore, not only the spectral efficiency but also the reliability is improved. The simulations verify the validity of this theory.

  11. Relationship between the transition frequency of local fluid flow and the peak frequency of attenuation

    Science.gov (United States)

    Cao, Cheng-Hao; Zhang, Hong-Bing; Pan, Yi-Xin; Teng, Xin-Bao

    2016-03-01

    Local fluid flow (LFF) at the mesoscopic scale is the main dissipation mechanism of seismic waves in heterogeneous porous media within the seismic frequency band. LFF is easily influenced by the structure and boundary conditions of the porous media, which leads to different behaviors of the peak frequency of attenuation. The associated transition frequency can provide detailed information about the trend of LFF; therefore, research on the transition frequency of LFF and its relationship with the peak frequency of the corresponding attenuation (i.e., inverse of quality factor) facilitates the detailed understanding of the effect of inner structures and boundary conditions in porous media. In this study, we firstly obtain the transition frequency of fluid flux based on Biot's theory of poroelasticity and the fast Fourier transform algorithm in a sample containing one repeating unit cell (RUC). We then analyze changes of these two frequencies in porous media with different porous properties. Finally, we extend our analysis to the influence of the undrained boundary condition on the transition frequency and peak frequency in porous media with multiple RUCs. This setup can facilitate the understanding of the effect from the undrained boundary condition. Results demonstrate that these two frequencies have the same trend at low water saturation, but amplitude variations differ between the frequencies as the amount of saturation increases. However, for cases of high water saturation, both the trend and the amplitude variation of these two frequencies fit well with each other.

  12. Purpose, Mission, and Context: The Call for Educating Future Leaders

    Science.gov (United States)

    Chunoo, Vivechkanand; Osteen, Laura

    2016-01-01

    This chapter calls on higher education to reclaim its role in leadership education. Specifically it examines higher education's purpose, context, and mission as clarion calls to embed leadership education throughout higher education institutions and focuses on why this is important.

  13. The call-by-need lambda calculus (unabridged).

    OpenAIRE

    Maraist, John; Odersky, Martin; Wadler, Phil

    2007-01-01

    We present a calculus that captures the operational semantics of call-by-need.We demonstrate that the calculus is confluent and standardizable and entails the same observational equivalences as call-by-name lambda calculus.

  14. Interday Forecasting and Intraday Updating of Call Center Arrivals

    OpenAIRE

    Haipeng Shen; Huang, Jianhua Z.

    2008-01-01

    Accurate forecasting of call arrivals is critical for staffing and scheduling of a telephone call center. We develop methods for interday and dynamic intraday forecasting of incoming call volumes. Our approach is to treat the intraday call volume profiles as a high-dimensional vector time series. We propose first to reduce the dimensionality by singular value decomposition of the matrix of historical intraday profiles and then to apply time series and regression techniques. Our approach takes...

  15. Titi monkey call sequences vary with predator location and type.

    OpenAIRE

    Casar, C.; Zuberbuhler, K.; Young, R. J.; Byrne, R.W.

    2013-01-01

    Animal alarm calls can encode information about a predator's category, size, distance or threat level. In non-human primates, alarm calls typically refer to broad classes of disturbances, in some instances to specific predators. Here, we present the results of a field experiment with a New World primate, the black-fronted titi monkey (Callicebus nigrifrons), designed to explore the information conveyed by their alarm call system. Adults produced sequences consisting of two main alarm call typ...

  16. Untrained Forward Observer (UFO) translator for call for fire

    OpenAIRE

    King, Regan R.

    2013-01-01

    Approved for public release; distribution is unlimited Many observers need indirect fire but are not proficient in Call for Fire, the procedure used to request indirect fire. To alleviate this, we propose the development of an application, which we call the Untrained Forward Observer (UFO) Translator, capable of assisting untrained observers in performing Call for Fire by asking a series of simple questions to generate a Call for Fire in the proper format. As a prior Forward Observer with ...

  17. Male monkeys remember which group members have given alarm calls

    OpenAIRE

    Wich, Serge A.; Vries, Han de

    2005-01-01

    Primates give alarm calls in response to the presence of predators. In some species, such as the Thomas langur (Presbytis thomasi), males only emit alarm calls if there is an audience. An unanswered question is whether the audience's behaviour influences how long the male will continue his alarm calling. We tested three hypotheses that might explain the alarm calling duration of male Thomas langurs: the fatigue, group size and group member behaviour hypotheses. Fatigue and group size did not ...

  18. A General Study on the Major Features of CALL

    Institute of Scientific and Technical Information of China (English)

    喻晖

    2009-01-01

    As Computer Assisted language Learning (CALL) has become a hot issue in the second language acquisition, this paper attempts to discuss two of the important features of CALL: the student-centered and interactiveness. It is ex-plained in the paper that these two features are the most important features characterized by CALL and they can be bet-ter realized in a CALL class than in a traditional class.

  19. Is a Convertible Bond Call Really Bad News?

    OpenAIRE

    Ederington, Louis H; Goh, Jeremy C

    2001-01-01

    We test and reject the hypothesis that managers call in-the-money convertibles when they view a decline in the value of the firm as likely. Inconsistent with this view, we find that insiders generally buy equity before conversion-forcing calls. Also, analysts tend to raise their earnings forecasts following a call. Thus, our evidence supports the alternative hypothesis that the price decline immediately following conversion-forcing calls is a purely transitory decline caused by the anticipate...

  20. The Structure and Function of Male Thomas Langur Loud Calls

    OpenAIRE

    Wich, Serge Alexander

    2002-01-01

    This study has addressed the acoustical structure of male loud calls and their function in Thomas langur social organisation. Thomas langurs are medium sized primate that lives in Sumatra, Indonesia. Ome of the characteristics of this species is the loud call of males. Several functions for loud calls have been suggested such as mate-defence, resource-defence and mate-attraction. In this study playback studies were applied to determine that loud calls function in between-group spacing and res...

  1. Electoronic Performance Monitoring in Call Centers: An Ethical Decision Model

    OpenAIRE

    Perkins, David

    2013-01-01

    Ever since it emerged on a widespread basis in the 1990s, electronic performance monitoring of employees has received significant scrutiny in the literature. Call centers have been the focus of many of these studies. This particular study addresses the issue of electronic performance monitoring in call centers from an ethical perspective. The following ethical dilemma is offered: "Is it ethical for a call center manager to evaluate the performance of a call center employee using electronic pe...

  2. On the modeling and forecasting of call center arrivals

    OpenAIRE

    Ibrahim, Rouba; Ye, Han; L'Ecuyer, Pierre; Shen, Haipeng

    2015-01-01

    International audience The effective management of call centers is a challenging task mainly because managers are consistently facing considerable uncertainty. Among important sources of uncertainty are call arrival rates which are typically time-varying, stochastic, dependent across time periods and across call types, and often affected by external events. Accurately modeling and forecasting future call arrival volumes is a complicated issue which is critical for making important operatio...

  3. Smart Grid Technology and Consumer Call Center Readiness

    OpenAIRE

    Schamber, Kelsey L.

    2010-01-01

    The following reasearch project deals with utility call center readiness to address customer concerns and questions about the Smart Grid and smart meter technology. Since consumer engagement is important for the benefits of the Smart Grid to be realized, the readiness and ability of utilities to answer consumer questions is an important issue. Assessing the readiness of utility call centers to address pertinant customer concerns was accomplished by calling utility call centers with Smart Grid...

  4. The So-Called 'Face on Mars'

    Science.gov (United States)

    2002-01-01

    (Released 13 April 2002) The Science The so called 'Face on Mars' can be seen slightly above center and to the right in this THEMIS visible image. This 3-km long knob, located near 10o N, 40o W (320o E), was first imaged by the Viking spacecraft in the 1970's and was seen by some to resemble a face carved into the rocks of Mars. Since that time the Mars Orbiter Camera on the Mars Global Surveyor spacecraft has provided detailed views of this hill that clearly show that it is a normal geologic feature with slopes and ridges carved by eons of wind and downslope motion due to gravity. A similar-size hill in Phoenix, Arizona resembles a camel lying on the ground, and Phoenicians whimsically refer to it as Camelback Mountain. Like the hills and knobs of Mars, however, Camelback Mountain was carved into its unusual shape by thousands of years of erosion. The THEMIS image provides a broad perspective of the landscape in this region, showing numerous knobs and hills that have been eroded into a remarkable array of different shapes. Many of these knobs, including the 'Face', have several flat ledges partway up the hill slopes. These ledges are made of more resistant layers of rock and are the last remnants of layers that once were continuous across this entire region. Erosion has completely removed these layers in most places, leaving behind only the small isolated hills and knobs seen today. Many of the hills and ridges in this area also show unusual deposits of material that occur preferentially on the cold, north-facing slopes. It has been suggested that these deposits were 'pasted' on the slopes, with the distinct, rounded boundary on their upslope edges being the highest remaining point of this pasted-on layer. In several locations, such as in the large knob directly south of the 'Face', these deposits occur at several different heights on the hill. This observation suggests the layer once draped the entire knob and has since been removed from all but the north

  5. Integrating mapping-, assembly- and haplotype-based approaches for calling variants in clinical sequencing applications.

    Science.gov (United States)

    Rimmer, Andy; Phan, Hang; Mathieson, Iain; Iqbal, Zamin; Twigg, Stephen R F; Wilkie, Andrew O M; McVean, Gil; Lunter, Gerton

    2014-08-01

    High-throughput DNA sequencing technology has transformed genetic research and is starting to make an impact on clinical practice. However, analyzing high-throughput sequencing data remains challenging, particularly in clinical settings where accuracy and turnaround times are critical. We present a new approach to this problem, implemented in a software package called Platypus. Platypus achieves high sensitivity and specificity for SNPs, indels and complex polymorphisms by using local de novo assembly to generate candidate variants, followed by local realignment and probabilistic haplotype estimation. It is an order of magnitude faster than existing tools and generates calls from raw aligned read data without preprocessing. We demonstrate the performance of Platypus in clinically relevant experimental designs by comparing with SAMtools and GATK on whole-genome and exome-capture data, by identifying de novo variation in 15 parent-offspring trios with high sensitivity and specificity, and by estimating human leukocyte antigen genotypes directly from variant calls. PMID:25017105

  6. The Additional Uses of CALL in the Endangered Language Context

    Science.gov (United States)

    Ward, Monica

    2004-01-01

    This paper considers the additional uses of CALL in the Endangered Language (EL) context. It briefly reviews ELs and reports on CALL for ELs in general. It then reviews the extra uses of CALL for ELs; these include changing negative attitudes towards the language, arousing interest in the language and contributing to language maintenance and…

  7. 47 CFR 25.284 - Emergency Call Center Service.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Emergency Call Center Service. 25.284 Section... SATELLITE COMMUNICATIONS Technical Operations § 25.284 Emergency Call Center Service. (a) Providers of mobile satellite service to end-user customers (part 25, subparts A-D) must provide Emergency Call...

  8. 76 FR 43688 - Committee Meeting via Conference Call

    Science.gov (United States)

    2011-07-21

    ... HUMAN SERVICES Administration for Children and Families Committee Meeting via Conference Call AGENCY..., August 16, 2011, from 1 p.m. to 2:30 pm E.S.T. This meeting, to be held via audio conference call, is open to the public. Details for accessing the full Committee Conference Call are cited below: Toll...

  9. 78 FR 35956 - Utah Resource Advisory Council Subgroup Conference Call

    Science.gov (United States)

    2013-06-14

    ... Bureau of Land Management Utah Resource Advisory Council Subgroup Conference Call AGENCY: Bureau of Land Management, Interior. ACTION: Conference Call. SUMMARY: In accordance with the Federal Land Policy and... Advisory Council (RAC) Subgroup will host a conference call. DATES: The Utah RAC Subgroup will host...

  10. 46 CFR 169.750 - Radio call sign.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Radio call sign. 169.750 Section 169.750 Shipping COAST... Control, Miscellaneous Systems, and Equipment Markings § 169.750 Radio call sign. Each vessel certificated for exposed or partially protected water service must have its radio call sign permanently...

  11. 29 CFR 785.17 - On-call time.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 3 2010-07-01 2010-07-01 false On-call time. 785.17 Section 785.17 Labor Regulations... On-call time. An employee who is required to remain on call on the employer's premises or so close thereto that he cannot use the time effectively for his own purposes is working while “on call”....

  12. 76 FR 17429 - Notice of FHA Debenture Call

    Science.gov (United States)

    2011-03-29

    ... URBAN DEVELOPMENT Notice of FHA Debenture Call AGENCY: Office of the Assistant Secretary for Housing--Federal Housing Commissioner, HUD. ACTION: Notice. SUMMARY: This Notice announces a debenture call of... the approval of the Secretary of the Treasury, announces the call of all FHA debentures, with a...

  13. 75 FR 16163 - Notice of FHA Debenture Call

    Science.gov (United States)

    2010-03-31

    ... URBAN DEVELOPMENT Notice of FHA Debenture Call AGENCY: Office of the Assistant Secretary for Housing... the Secretary of the Treasury, announces the call of all FHA debentures, with a coupon rate of 5..., ``outstanding'' as of March 31, 2010. The date of the call is July 1, 2010. The debentures will be redeemed...

  14. 77 FR 18258 - Notice of FHA Debenture Call

    Science.gov (United States)

    2012-03-27

    ... URBAN DEVELOPMENT Notice of FHA Debenture Call AGENCY: Office of the Assistant Secretary for Housing--Federal Housing Commissioner, HUD. ACTION: Notice. SUMMARY: This Notice announces a debenture call of... impairments may access this number through TTY by calling the toll-free Federal Relay Service at...

  15. No male identity information loss during call propagation through dense vegetation: the case of the corncrake.

    Science.gov (United States)

    Ręk, Paweł; Osiejuk, Tomasz S

    2011-03-01

    Individually specific acoustic signals in birds are used in territorial defence. These signals enable a reduction of energy expenditure due to individual recognition between rivals and the associated threat levels. Mechanisms and acoustic cues used for individual recognition seem to be versatile among birds. However, most studies so far have been conducted on oscine species. Few studies have focused on exactly how the potential for individual recognition changes with distance between the signaller and receiver. We studied a nocturnally active rail species, the corncrake, which utters a seemingly simple disyllabic call. The inner call structure, however, is quite complex and expressed as intervals between maximal amplitude peaks, called pulse-to-pulse durations (PPD). The inner call is characterized by very low within-individual variation and high between-individuals difference. These variations and differences enable recognition of individuals. We conducted our propagation experiments in a natural corncrake habitat. We found that PPD was not affected by transmission. Correct individual identification was possible regardless of the distance and position of the microphone which was above the ground. The results for sounds from the extreme distance propagated through the vegetation compared to those transmitted above the vegetation were even better. These results support the idea that PPD structure has evolved under selection favouring individual recognition in a species signalling at night, in a dense environment and close to the ground. PMID:21295119

  16. Frequency noise in frequency swept fiber laser

    DEFF Research Database (Denmark)

    Pedersen, Anders Tegtmeier; Rottwitt, Karsten

    2013-01-01

    This Letter presents a measurement of the spectral content of frequency shifted pulses generated by a lightwave synthesized frequency sweeper. We found that each pulse is shifted in frequency with very high accuracy. We also discovered that noise originating from light leaking through the acousto...

  17. Geometric constrained variational calculus. III: The second variation (Part II)

    Science.gov (United States)

    Massa, Enrico; Luria, Gianvittorio; Pagani, Enrico

    2016-03-01

    The problem of minimality for constrained variational calculus is analyzed within the class of piecewise differentiable extremaloids. A fully covariant representation of the second variation of the action functional based on a family of local gauge transformations of the original Lagrangian is proposed. The necessity of pursuing a local adaptation process, rather than the global one described in [1] is seen to depend on the value of certain scalar attributes of the extremaloid, here called the corners’ strengths. On this basis, both the necessary and the sufficient conditions for minimality are worked out. In the discussion, a crucial role is played by an analysis of the prolongability of the Jacobi fields across the corners. Eventually, in the appendix, an alternative approach to the concept of strength of a corner, more closely related to Pontryagin’s maximum principle, is presented.

  18. Social Calls Exhibit a Distributed Consensus Map in the Auditory Cortex of Mustached Bats

    OpenAIRE

    Jagmeet S Kanwal; Ohlemiller, Kevin K.

    2012-01-01

    During echolocation in mustached bats, Pteronotus parnellii, target distance is computed from pulse-echo delays and size and velocity are computed from relative shifts in amplitude and frequency, respectively, of the pulse from the echo. Several decades of research has shown that the representation of a moving physical target at any time is distributed across multiple areas (e.g., DSCF, CF/CF and FM-FM) in the auditory cortex of mustached bats (Suga, 1984). Previous studies of call processi...

  19. Food-related bray calls in wild bottlenose dolphins (Tursiops truncatus).

    OpenAIRE

    Janik, V. M.

    2000-01-01

    Because cetaceans are difficult to study in the wild, little is known about how they use their sounds in their natural environment. Only the recent development of passive acoustic localization systems has enabled observations of the communication behaviour of individuals for correlation with their surface behaviour. Using such a system, I show that bottlenose dolphins in the Moray Firth, Scotland, produce low-frequency bray calls which are clearly correlated with feeding on salmonids. The pro...

  20. Using accelerometers to determine the calling behavior of tagged baleen whales

    OpenAIRE

    Goldbogen, J.A.; Stimpert, A. K.; DeRuiter, S. L.; Calambokidis, J.; Friedlaender, A.S.; G. S. Schorr; Moretti, D. J.; Tyack, P.L.; Southall, B.L.

    2014-01-01

    The article of record as published may be found at http://dx.doi.org/10.1242/jeb.103259 Low-frequency acoustic signals generated by baleen whales can propagate over vast distances, making the assignment of calls to specific individuals problematic. Here, we report the novel use of acoustic recording tags equipped with high-resolution accelerometers to detect vibrations from the surface of two tagged fin whales that directly match the timing of recorded acoustic signals. A ta...

  1. Modulation of ionization on laser frequency in ultra-short pulse intense laser-gas-target

    Institute of Scientific and Technical Information of China (English)

    Hu Qiang-Lin; Liu Shi-Bing

    2006-01-01

    Based on the dispersion relation of intense laser pulse propagating in gradually ionized plasma, this paper discusses the frequency modulation induced by ionization of an ultra-short intense laser pulse interacting with a gas target.The relationship between the frequency modulation and the ionization rate, the plasmas frequency variation, and the polarization of atoms (ions) is analysed. The numerical results indicate that, at high frequency, the polarization of atoms (ions) plays a more important role than plasma frequency variation in modulating the laser frequency, and the laser frequency variation is different at different positions of the laser pulse.

  2. Frequency deviations and generation scheduling in the nordic system

    DEFF Research Database (Denmark)

    Li, Zhongwei; Samuelsson, Olaf; Garcia-Valle, Rodrigo

    2011-01-01

    High penetration of variable generation such as wind power increases the demands on frequency control. The same applies to island operation and in particular if this involves variable generation, which is planned at the Danish island Bornholm. While it is obvious that the frequency control need to...... the frequency deviations and hourly scheduled generation. A simple model is given to reproduce these deterministic frequency variations. Simulations indicate that smaller system size as is typical for island operation does not necessarily increase these frequency variations provided load, generation...

  3. Investigating on-call work in rail infrastructure maintenance

    OpenAIRE

    Cebola, Nuno M.F.

    2014-01-01

    The use of on-call work in industry has now surpassed that of shiftwork and night work. Industries as a whole make use of on-call work daily as a way to maintain 24/7 operations whilst also reducing costs. Despite this, on-call work remains underresearched and no best practice or management guidelines are available. As the first substantial piece of human factors work examining on-call work in the rail industry, this thesis has the overall aim of increasing the understanding of on-call sc...

  4. Spatial diffusion patterns of call-centers in the Netherlands

    OpenAIRE

    Bruinsma, Frank; Rietveld, Piet; Beekman, Michiel

    2002-01-01

    The focus in this paper is on spatial diffusion patterns of call centers in The Netherlands. The number of call centers has increased rapidly in the last decade and it seems that impacts of call centers on the labor market still underestimated. We will pay attention to two spatial levels: first urban versus rural and second local. Given the labor intensity and quality required by call centers and the absence of physical contacts with consumers one might expect that most call centers are locat...

  5. SIMULATION MODELS OF CALL ADMISSION CONTROL SCHEMES USING GPSS

    Directory of Open Access Journals (Sweden)

    Vassilya ABDULOVA

    2014-01-01

    Full Text Available In cellular wireless networks, a variety of channel allocation schemes have been developed for achieving high capacity with minimal interference. The choice of channel allocation scheme impacts the performance of the system, particularly as how calls are managed when a mobile user is handed off from one cell to another. Call Admission Control schemes take into account the effect of handoffs in the performance of the system, particularly call blocking probability and call dropping probability. In this study, we present simulation models and programs of some popular Call Admission Control schemes using GPSS simulation tool.

  6. A host-race difference in begging calls of nestling cuckoos Cuculus canorus develops through experience and increases host provisioning

    OpenAIRE

    Madden, Joah R.; Davies, Nicholas B.

    2006-01-01

    The structure of common cuckoo nestling begging calls differs between the two host-races parasitizing reed warblers (reed warbler-cuckoos) and dunnocks (dunnock-cuckoos; longer syllable duration, lower peak and maximum frequency, narrower bandwidth). Cross-fostering experiments demonstrated that this difference is not genetically fixed but develops through experience. When newly hatched reed warbler-cuckoos were transferred to dunnock nests, they developed begging calls more like those of dun...

  7. HVC contributes toward conspecific contact call responding in male Bengalese finches.

    Science.gov (United States)

    Urbano, Catherine M; Aston, Avery E; Cooper, Brenton G

    2016-05-01

    The processes of producing and acquiring birdsong, like human speech, utilize interdependent neural systems for vocal learning and production. In addition to song, these brain areas are undoubtedly used for other affiliative behaviors. Oscine sound production is lateralized because their vocal organ contains two independently controlled sound sources. Therefore, songbirds offer a unique opportunity to study the biological relevance of lateralized behavioral control. Bengalese finches (Lonchura striata domestica) produce different types of sound with each sound source: the left sound generator produces tonal frequencies from 1 to 4 kHz and the right sound source produces the lower frequency (b) both HVC nuclei contribute toward contact call production, but HVC ablation does not alter the number of short calls produced upon hearing a female contact call. These data are consistent with the emerging view that the motor production and auditory processing are linked and suggest that HVC may contribute toward affiliative behaviors by promoting the production of contact call responses. PMID:27014861

  8. Food-related bray calls in wild bottlenose dolphins (Tursiops truncatus).

    Science.gov (United States)

    Janik, V M

    2000-05-01

    Because cetaceans are difficult to study in the wild, little is known about how they use their sounds in their natural environment. Only the recent development of passive acoustic localization systems has enabled observations of the communication behaviour of individuals for correlation with their surface behaviour. Using such a system, I show that bottlenose dolphins in the Moray Firth, Scotland, produce low-frequency bray calls which are clearly correlated with feeding on salmonids. The production of these calls is followed by fast approaches by conspecifics in the area. In animals which use sound as a foraging tool, it is difficult to distinguish between food calls which have evolved because of their role in attracting conspecifics, and food manipulation or searching calls which may attract conspecifics as a by-product. However, the low-frequency structure of the bottlenose dolphin bray suggests that it evolved because of a role in manipulating prey rather than in attracting conspecifics. This conclusion suggests that dolphins exploit the perceptual systems of their prey to facilitate capture. PMID:10853736

  9. Inbreeding and courtship calling in the cricket Teleogryllus commodus.

    Science.gov (United States)

    Drayton, J M; Milner, R N C; Hall, M D; Jennions, M D

    2011-01-01

    Male field crickets produce two acoustic signals for mating: advertisement calls and courtship calls. While the importance of advertisement calling in mate attraction is well understood, the function of courtship calling is less clear. Here, we tested if the courtship call of male crickets Teleogryllus commodus signals aspects of male quality by comparing the calls of inbred and outbred males. We examined the effect of one generation of full sibling mating on fine-scale call structure, along with several life history traits. Inbreeding reduced nymph survival but had no significant effect on weight or development time. Inbreeding resulted in a small but significant change in two of the six call parameters measured. We then tested if inbreeding affects call trait combinations that are important to females by using the results of a previous selection analysis to compare the multivariate attractiveness of the calls of inbred and outbred males. There was no difference. We conclude that the courtship call of T. commodus is not a reliable signal of aspects of male quality that are affected by inbreeding (which generally reduces fitness-enhancing traits). It might, however, signal components of male fitness that are not affected by changes in heterozygosity. PMID:21054622

  10. Relationship between the transition frequency of local fl uidfl ow and the peak frequency of attenuation

    Institute of Scientific and Technical Information of China (English)

    Cao Cheng-Hao; Zhang Hong-Bing; Pan Yi-Xin; Teng Xin-Bao

    2016-01-01

    Localfl uidfl ow (LFF) at the mesoscopic scale is the main dissipation mechanism of seismic waves in heterogeneous porous media within the seismic frequency band. LFF is easily influenced by the structure and boundary conditions of the porous media, which leads to different behaviors of the peak frequency of attenuation. The associated transition frequency can provide detailed information about the trend of LFF; therefore, research on the transition frequency of LFF and its relationship with the peak frequency of the corresponding attenuation (i.e., inverse of quality factor) facilitates the detailed understanding of the effect of inner structures and boundary conditions in porous media. In this study, wefi rstly obtain the transition frequency of fluid flux based on Biot’s theory of poroelasticity and the fast Fourier transform algorithm in a sample containing one repeating unit cell (RUC). We then analyze changes of these two frequencies in porous media with different porous properties. Finally, we extend our analysis to the infl uence of the undrained boundary condition on the transition frequency and peak frequency in porous media with multiple RUCs. This setup can facilitate the understanding of the effect from the undrained boundary condition. Results demonstrate that these two frequencies have the same trend at low water saturation, but amplitude variations differ between the frequencies as the amount of saturation increases. However, for cases of high water saturation, both the trend and the amplitude variation of these two frequenciesfi t well with each other.

  11. Calibrating passive acoustic monitoring: correcting humpback whale call detections for site-specific and time-dependent environmental characteristics.

    Science.gov (United States)

    Helble, Tyler A; D'Spain, Gerald L; Campbell, Greg S; Hildebrand, John A

    2013-11-01

    This paper demonstrates the importance of accounting for environmental effects on passive underwater acoustic monitoring results. The situation considered is the reduction in shipping off the California coast between 2008-2010 due to the recession and environmental legislation. The resulting variations in ocean noise change the probability of detecting marine mammal vocalizations. An acoustic model was used to calculate the time-varying probability of detecting humpback whale vocalizations under best-guess environmental conditions and varying noise. The uncorrected call counts suggest a diel pattern and an increase in calling over a two-year period; the corrected call counts show minimal evidence of these features. PMID:24181982

  12. Then Why Do They Call Earth the Blue Planet?

    Science.gov (United States)

    2005-01-01

    While the most common photographs of Earth taken from space show the planet covered in blue water, NASA has managed to produce detailed color images, using satellite imagery, that show the remarkable variation of colors that actually make up the oceanic surface. An ocean s color is determined by the interaction of surface waters with sunlight, and surface waters can contain any number of different particles and dissolved substances, which could then change the color. Then Why Do They Call Earth the Blue Planet? The particles are mostly phytoplankton, the microscopic, single-celled ocean plants that are the primary food source for much marine life. Remote detection of phytoplankton provides information about the uptake and cycling of carbon by the ocean through photosynthesis, as well as the overall health of the water. Inorganic particles and substances dissolved in the water also affect its color, particularly in coastal regions. Satellite images can be used to calculate the concentrations of these materials in surface waters, as well as the levels of biological activity. The satellites allow a global view that is not available from ship or shore. NASA s orbiting satellites offer a unique vantage point for studying the oceans. By resolving the biological, chemical, and physical conditions in surface waters, they have allowed the oceanographic community to make huge leaps in its understanding of oceanographic processes on regional and global fronts. The study of ocean color, in particular, has been integral in helping researchers understand the natural and human-induced changes in the global environment and establishing the role of the oceans in the biochemical cycles of elements that influence the climate and the distribution of life on Earth.

  13. Cluster analysis of word frequency dynamics

    International Nuclear Information System (INIS)

    This paper describes the analysis and modelling of word usage frequency time series. During one of previous studies, an assumption was put forward that all word usage frequencies have uniform dynamics approaching the shape of a Gaussian function. This assumption can be checked using the frequency dictionaries of the Google Books Ngram database. This database includes 5.2 million books published between 1500 and 2008. The corpus contains over 500 billion words in American English, British English, French, German, Spanish, Russian, Hebrew, and Chinese. We clustered time series of word usage frequencies using a Kohonen neural network. The similarity between input vectors was estimated using several algorithms. As a result of the neural network training procedure, more than ten different forms of time series were found. They describe the dynamics of word usage frequencies from birth to death of individual words. Different groups of word forms were found to have different dynamics of word usage frequency variations

  14. Cluster analysis of word frequency dynamics

    Science.gov (United States)

    Maslennikova, Yu S.; Bochkarev, V. V.; Belashova, I. A.

    2015-01-01

    This paper describes the analysis and modelling of word usage frequency time series. During one of previous studies, an assumption was put forward that all word usage frequencies have uniform dynamics approaching the shape of a Gaussian function. This assumption can be checked using the frequency dictionaries of the Google Books Ngram database. This database includes 5.2 million books published between 1500 and 2008. The corpus contains over 500 billion words in American English, British English, French, German, Spanish, Russian, Hebrew, and Chinese. We clustered time series of word usage frequencies using a Kohonen neural network. The similarity between input vectors was estimated using several algorithms. As a result of the neural network training procedure, more than ten different forms of time series were found. They describe the dynamics of word usage frequencies from birth to death of individual words. Different groups of word forms were found to have different dynamics of word usage frequency variations.

  15. Effect of CALL-based and Non-CALL Based Methods of Teaching on L2 Vocabulary Learning

    OpenAIRE

    Effat Bagheri; Ali Roohani; Dariush Nejad Ansari

    2012-01-01

    The use of Computer Assisted Language Learning (CALL) in the field of education has increased remarkably in recent years due to the swift and modern changes in language software. However, CALL is not widely employed in the field of second/foreign (L2) language learning in Iran. Interested in the application of CALL, this study examines two methods of vocabulary teaching/learning (CALL-based versus non-CALL based) in the short and long-term learning in the area of L2 vocabulary. It seeks to se...

  16. Frequency spectrum of Calder Hall reactor noise

    International Nuclear Information System (INIS)

    The frequency spectrum of the noise power of Calder Hall reactor No. 1 has been obtained by analysing a tape recording of the backed off power. The root mean square noise power due to all frequencies above 0.001 cycles per second was found to be 0.13%. The noise power for this reactor, is due mainly to modulations of the power level by reactivity variations caused in turn by gas temperature changes. These gas temperature changes are caused by a Cyclic variation in the feedwater regulator to the heat exchanger. The apparatus and method used to determine the noise power are described in this memorandum. It is shown that for frequencies in the range 0.001 to 0.030 cycles per second the noise spectrum falls at 60 decibels per decade of frequency. (author)

  17. Demand as frequency controlled reserve

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Z.; Togeby, M.; OEstergaard, J.

    2008-09-15

    Using demand as frequency controlled reserve (DFR) is an emerging technology which allow demand to participate actively in maintaining the system operation without reducing the energy service delivered to the customer and without need of user interaction. The basic premise is that traditional frequency controlled reserves from power plants and interconnections with neighbouring systems can be costly, slow and not fulfil the need for future power grids with a high share of wind power and fewer central power plants, and an intention to perform flexible operation such as is landing. Electricity demands, on the other hand, have advantages as frequency reserve including fast activation speed, smooth linear activation, low expected costs, and well-dispersed in the distribution grid. The main challenge of DFR is new methods for monitoring the available capacity. This project has investigated the technology of using electricity demands for providing frequency reserve to power systems. Within the project the potential and economy of DFR compatible loads in Denmark has been investigated, control logic has been designed, power system impact has been investigated, potential business models has been evaluated and an implementation strategy has been suggested. The tasks and goals of the project have been successfully accomplished based on which the conclusion and future recommendation are made. This project has developed the DFR technology that enables electricity demands to autonomously disconnect or reconnect to the grid in response to system frequency variations. The developed DFR technology is proved to be a promising technology from several perspectives. Technically, using DFR is feasible to provide reserves and enhance power system frequency control, while fulfilling technical requirements such as linear activation (or reconnection) according to frequency (or time). Environmentally, the DFR technology is pollution free in contrast to traditional reserves from generation

  18. Vocal individuality and species divergence in the contact calls of banded penguins.

    Science.gov (United States)

    Favaro, Livio; Gili, Claudia; Da Rugna, Cristiano; Gnone, Guido; Fissore, Chiara; Sanchez, Daniel; McElligott, Alan G; Gamba, Marco; Pessani, Daniela

    2016-07-01

    Penguins produce contact calls to maintain social relationships and group cohesion. Such vocalisations have recently been demonstrated to encode individual identity information in the African penguin. Using a source-filter theory approach, we investigated whether acoustic cues of individuality can also be found in other Spheniscus penguins and the acoustic features of contact calls have diverged within this genus. We recorded vocalisations from two ex-situ colonies of Humboldt penguin and Magellanic penguin (sympatric and potentially interbreeding in the wild) and one ex-situ group of African penguins (allopatric although capable of interbreeding with the other two species in captivity). We measured 14 acoustic parameters from each vocalisation. These included temporal (duration), source-related (fundamental frequency, f0), and filter-related (formants) parameters. They were then used to carry out a series of stepwise discriminant function analyses (with cross-validation) and General Linear Model comparisons. We showed that contact calls allow individual discrimination in two additional species of the genus Spheniscus. We also found that calls can be classified according to species in a manner far greater than that attributable by chance, even though there is limited genetic distance among African, Humboldt, and Magellanic penguins. Our results provide further evidence that the source-filter theory is a valuable framework for investigating the biologically meaningful information contained in bird vocalisations. Our findings also provide novel insights into penguin vocal communication and suggest that contact calls of the penguin family are affected by selection for individuality. PMID:27102762

  19. Population effects of increased climate variation

    OpenAIRE

    Drake, John M.

    2005-01-01

    Global circulation models predict and numerous observations confirm that anthropogenic climate change has altered high-frequency climate variability. However, it is not yet well understood how changing patterns of environmental variation will affect wildlife population dynamics and other ecological processes. Theory predicts that a population's long-run growth rate is diminished and the chance of population extinction is increased as environmental variation increases. This results from the fa...

  20. An empirical analysis of the corporate call decision

    International Nuclear Information System (INIS)

    An economic study of the the behaviour of financial managers of utility companies was presented. The study examined whether or not an option pricing based model of the call decision does a better job of explaining callable preferred share prices and call decisions compared to other models. In this study, the Rust (1987) empirical technique was extended to include the use of information from preferred share prices in addition to the call decisions. Reasonable estimates were obtained from data of shares of the Pacific Gas and Electric Company (PGE) for the transaction costs associated with a call. It was concluded that the managers of the PGE clearly take into account the value of the option to delay the call when making their call decisions

  1. In- and Out-of-the-Money Convertible Bond Calls

    DEFF Research Database (Denmark)

    Bechman, Ken; Lunde, Asger; Zebedee, Allan

    2014-01-01

    call is predominantly explained by the subsequent order imbalances; and the stock market's reaction is spread over an entire trading day, which is consistent with the price pressure effect. In contrast, the announcement effect for the out-of-the-money call is driven by the size of the called......Convertible bond calls typically cause significant reactions in equity prices. The empirical research largely finds negative and positive announcement effects for the in-the-money and the out-of-the-money calls respectively. However, this research has difficulty distinguishing between the two main...... theoretical explanations: the signaling effect and the price pressure effect. In this paper, we differentiate between these two effects by using a unique data set of the in- and the out-of-the-money calls in the United States during the period of 1993 to 2007. We find that the announcement effect for the in-the-money...

  2. Voice and daytime calling of Scops Owls (Otus scops

    Directory of Open Access Journals (Sweden)

    Mikkola Anita

    2015-12-01

    Full Text Available The Scops Owl (Otus scops is one of the least studied owls in Europe and its loud and monotonous calls are not well documented. This paper summarises published alarm-like calls and presents data on daytime calling recorded in Lesencetomaj, Hungary between 9th and 17th September 2012. Calls were similar to the sound of an alarm on a reversing truck. The bird was most active around midday (11–13 hrs and in the afternoons between 15–17 hrs. No calling occurred before 09.00 or after 19.15 o’clock. Weather affected the intensity of calls and particularly high autumn temperatures are suggested as a possible reason for this unusual activity.

  3. On the occurrence of nocturnal and diurnal loud calls, differing in structure and duration, in red howlers (Alouatta seniculus) of French Guyana.

    Science.gov (United States)

    Drubbel, R V; Gautier, J P

    1993-01-01

    Structural patterns and 24-hour rhythms of the loud calls of Alouatta seniculus were studied in a wild population living in primary rain forest in French Guyana. These loud calls are low-pitched noisy hoarse sounds with an upper frequency limit around 3,000 Hz. Their spectral energy is concentrated in two clusters, each of which includes two dominant frequency bands. Loud calls comprise one or several vocal units with alternating crescendos and decrescendos. Five different types of units can be distinguished. Depending on their duration, loud calls can be roughly divided into two classes: long and short calls. Long calls (mean duration 3.28 min) include three phases. After the end of the calls, one or two blowing noises of weak amplitude may be heard. Short calls (mean duration 11 s) are frequently uttered in clusters of several calls given by the same troop at intervals of a few seconds to a few minutes. Observations carried out over the 24-hour cycle show that the calling rate is higher at night, with a peak around dawn and that long calls are more frequent at night, while short calls are mainly heard during the day. Most long calls are emitted from the sleeping sites and carry great distances. They probably play a role in inter-troop communication. Despite their intensity, short calls are used for short-distance communication. The occurrence of two different loud calls in Guyanan howlers and the amount of night calling in these monkeys are discussed with reference to studies of other howler populations. PMID:8300015

  4. The experience of work in a call centre environment

    OpenAIRE

    Sanet Hauptfleisch; J. S. UYS

    2006-01-01

    This qualitative research study explored the work experience in a call centre environment in an information technology call centre based in South Africa, which service foreign customers exclusively. Three data collection methods were used, namely narratives, in-depth interviews with call centre consultants, and observation. Following a grounded theory approach, four themes were elicited, namely the perceptions of team members, uncertainty created by a constantly changing environment, perceive...

  5. Heterospecific Acoustic Interference: Effects on Calling in Oophaga pumilio

    OpenAIRE

    Wong, Stefanie; Parada, Humberto; Narins, Peter M.

    2009-01-01

    Call rate suppression is a common short-term solution for avoiding acoustic interference in animals. It has been widely documented between and within frog species, but the effects of non-anuran calling on frog vocalizations is less well known. Heterospecific acoustic interference on the calling of Oophaga pumilio (Bauer, 1994) (formerly Dendrobates pumilio) males was studied in a lowland, wet tropical forest in SE Nicaragua. Acoustic playback experiments were conducted to characterize the res...

  6. Mental Accounting: A New Behavioral Explanation of Covered Call Performance

    OpenAIRE

    Siddiqi, Hammad

    2014-01-01

    The empirical performance of covered call writing is quite puzzling in the traditional finance framework. Covered call writing is typically a risk reducing strategy so its expected return should be less than the expected return on the underlying in an efficient market. However, recent empirical evidence suggests (covering a period from 1988 onwards) that the covered call writing has nearly the same return as the underlying whereas the standard deviation of returns is considerably less. Market...

  7. Mental, physical and social health problems of call centre workers

    OpenAIRE

    P Bhuyar; A. Banerjee; H Pandve; P Padmnabhan; Patil, A.; Duggirala, S.; Rajan, S.; Chaudhury, S.

    2008-01-01

    Background: Call centre workers in BPO face unique occupational hazards - mental, physical and psychosocial. Material & Method: A sample 100 call centre workers of both sexes and from two cities Pune and Mumbai were surveyed by both qualitative and quantitative methods for the above health problems. Results: A high proportion of workers faced sleep disturbances and associated mental stress and anxiety. Sleep disturbance and anxiety was significantly more in international call centres com...

  8. Effective Call Center Management: Evidence from Financial Services

    OpenAIRE

    Ann Evenson; Patrick T. Harker; Frances X. Frei

    1999-01-01

    Call centers are quickly becoming the major point of contact for serving customers and generating new revenue in a variety of industries. No where is this growth in the importance of call centers more apparent than in the financial services industry. This paper presents the results of a survey of the management of call center operations at major financial service firms. The results clearly indicate the importance of human resource management practices and technology in creating high-performan...

  9. Forecasting Demand for Rural Electric Cooperative Call Center

    OpenAIRE

    Kim, Taeyoon; Kenkel, Philip L.; Brorsen, B. Wade

    2009-01-01

    This research forecasts peak call volume to allow a centralized call center to minimize staffing costs. A Gaussian copula is used to capture the dependence among nonnormal distributions. Peak call volume can be easily and more accurately predicted using the marginal probability distribution with the copula function than without using a copula. The modeling approach allows simulating adding another cooperative. Ignoring the dependence that the copula includes, causes peak values to be underest...

  10. Arbeit im Call Center - Tätigkeitsstrukturen, Belastungen und Ressourcen

    OpenAIRE

    Timm, Elke

    2003-01-01

    Call Center-Dienstleistungen sind in Deutschland zu einem bedeutenden Wirtschaftsfaktor gewachsen und nehmen mittlerweile einen hohen Stellenwert auf dem Markt ein. Während sich eine Vielzahl von Untersuchungen im Call Center-Bereich mit den technischen oder betriebswirtschaftlichen Aspekten von Call Center-Organisationen beschäftigt, werden in dieser Dissertation die Arbeits- und Tätigkeitsstrukturen im Telefonservice aus arbeitspsychologischer Perspektive beleuchtet. Im Vordergrund steh...

  11. Evolution of advertisement calls in African clawed frogs

    OpenAIRE

    Tobias, Martha L.; Evans, Ben J; Kelley, Darcy B.

    2011-01-01

    For most frogs, advertisement calls are essential for reproductive success, conveying information on species identity, male quality, sexual state and location. While the evolutionary divergence of call characters has been examined in a number of species, the relative impacts of genetic drift or natural and sexual selection remain unclear. Insights into the evolutionary trajectory of vocal signals can be gained by examining how advertisement calls vary in a phylogenetic context. Evolution by g...

  12. 40 CFR 155.48 - Data Call-In.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Data Call-In. 155.48 Section 155.48... STANDARDS AND REGISTRATION REVIEW Registration Review Procedures § 155.48 Data Call-In. The Agency may issue a Data Call-In notice under FIFRA section 3(c)(2)(B) at any time if the Agency believes that...

  13. Two-stage Structural Damage Identification Based on PSO Combining withStatic Test and Variation of Base-frequency%结合静力测试与基频变化的PSO二阶段结构损伤识别

    Institute of Scientific and Technical Information of China (English)

    张伟

    2011-01-01

    提出了一种基于粒子群优化算法(PSO)的二阶段结构损伤识别方法.该方法利用实际结构测试中较为成熟且结果相对稳定、准确的静力位移及基频的变化为基础,通过损伤信号匹配技术以及PSO分别进行损伤初步定位及损伤最后定量.通过对平面桁架结构的数值模拟结果表明该方法对结构中的受损构件及其损伤程度能够做出正确高效的识别和判断.%A two-stage structural damage identification method based on Particle Swarm Optimization (PSO) is presented. The relatively mature and precisely test techniques including the detection of variation of static displacement and base-frequency are utilized. Combing Damage Signal Match (DSM) technique and PSO, the possible structural damage location and damage extent are respectively carried out. The numerical simulation results of damaged plane truss show that the presented method is able to efficiently identify the structural damage members and their damage extent.

  14. Variable food begging calls are harbingers of vocal learning.

    Directory of Open Access Journals (Sweden)

    Wan-chun Liu

    Full Text Available Vocal learning has evolved in only a few groups of mammals and birds. The developmental and evolutionary origins of vocal learning remain unclear. The imitation of a memorized sound is a clear example of vocal learning, but is that when vocal learning starts? Here we use an ontogenetic approach to examine how vocal learning emerges in a songbird, the chipping sparrow. The first vocalizations of songbirds, food begging calls, were thought to be innate, and vocal learning emerges later during subsong, a behavior reminiscent of infant babbling. Here we report that the food begging calls of male sparrows show several characteristics associated with learned song: male begging calls are highly variable between individuals and are altered by deafening; the production of food begging calls induces c-fos expression in a forebrain motor nucleus, RA, that is involved with the production of learned song. Electrolytic lesions of RA significantly reduce the variability of male calls. The male begging calls are subsequently incorporated into subsong, which in turn transitions into recognizable attempts at vocal imitation. Females do not sing and their begging calls are not affected by deafening or RA lesion. Our results suggest that, in chipping sparrows, intact hearing can influence the quality of male begging calls, auditory-sensitive vocal variability during food begging calls is the first step in a modification of vocal output that eventually culminates with vocal imitation.

  15. Effectiveness of the Call in Beach Volleyball Attacking Play

    OpenAIRE

    Künzell Stefan; Schweikart Florian; Köhn Daniel; Schläppi-Lienhard Olivia

    2014-01-01

    In beach volleyball the setter has the opportunity to give her or his hitter a “call”. The call intends that the setter suggests to her or his partner where to place the attack in the opponent’s court. The effectiveness of a call is still unknown. We investigated the women’s and men’s Swiss National Beach Volleyball Championships in 2011 and analyzed 2185 attacks. We found large differences between female and male players. While men called in only 38.4% of attacks, women used calls in 85.5% o...

  16. Modular Design of Call Control Layer in Telephony Software

    OpenAIRE

    Ilija Basicevic

    2011-01-01

    An important property of a telephony system is the call control model on which it is based. It is noted that many call control models in the past, especially those in PSTN/ISDN networks follow centralized model. For such a model, typical is significant coupling of modules belonging to different services with the basic call control module which is aware of all active telephony features in the system. Although sometimes based on distributed model, VoIP call control models still manifest some of...

  17. A simulation model for emergency medical services call centers

    OpenAIRE

    Buuren, van, R.; Kommer, G.J.; Mei,, H.; Bhulai, Sandjai

    2015-01-01

    In pre-hospital health care the call center plays an important role in the coordination of emergency medical services (EMS). An EMS call center handles inbound requests for EMS and dispatches an ambulance if necessary. The time needed for triage and dispatch is part of the total response time to the request, which, in turn, is an indicator for the quality of EMS. Calls entering an efficient EMS call center must have short waiting times, centralists should perform the triage efficiently and th...

  18. Calculus of variations

    CERN Document Server

    Elsgolc, L E; Stark, M

    1961-01-01

    Calculus of Variations aims to provide an understanding of the basic notions and standard methods of the calculus of variations, including the direct methods of solution of the variational problems. The wide variety of applications of variational methods to different fields of mechanics and technology has made it essential for engineers to learn the fundamentals of the calculus of variations. The book begins with a discussion of the method of variation in problems with fixed boundaries. Subsequent chapters cover variational problems with movable boundaries and some other problems; sufficiency

  19. Excitation and Ionisation dynamics in high-frequency plasmas

    Science.gov (United States)

    O'Connell, D.

    2008-07-01

    Non-thermal low temperature plasmas are widely used for technological applications. Increased demands on plasma technology have resulted in the development of various discharge concepts based on different power coupling mechanisms. Despite this, power dissipation mechanisms in these discharges are not yet fully understood. Of particular interest are low pressure radio-frequency (rf) discharges. The limited understanding of these discharges is predominantly due to the complexity of the underlying mechanisms and difficult diagnostic access to important parameters. Optical measurements are a powerful diagnostic tool offering high spatial and temporal resolution. Optical emission spectroscopy (OES) provides non-intrusive access, to the physics of the plasma, with comparatively simple experimental requirements. Improved advances in technology and modern diagnostics now allow deeper insight into fundamental mechanisms. In low pressure rf discharges insight into the electron dynamics within the rf cycle can yield vital information. This requires high temporal resolution on a nano-second time scale. The optical emission from rf discharges exhibits temporal variations within the rf cycle. These variations are particularly strong, in for example capacitively coupled plasmas (CCPs), but also easily observable in inductively coupled plasmas (ICPs), and can be exploited for insight into power dissipation. Interesting kinetic and non-linear coupling effects are revealed in capacitive systems. The electron dynamics exhibits a complex spatio-temporal structure. Excitation and ionisation, and, therefore, plasma sustainment is dominated through directed energetic electrons created through the dynamics of the plasma boundary sheath. In the relatively simple case of an asymmetric capacitively coupled rf plasma the complexity of the power dissipation is exposed and various mode transitions can be clearly observed and investigated. At higher pressure secondary electrons dominate the

  20. A joint chance-constrained programming approach for call center workforce scheduling under uncertain call arrival forecasts

    OpenAIRE

    Excoffier, M.; Gicquel, C.; Jouini, O.

    2016-01-01

    International audience A joint chance-constrained programming approach for call center workforce scheduling under uncertain call arrival forecasts Abstract We consider a workforce management problem arising in call centers, namely the shift-scheduling problem. It consists in determining the number of agents to be assigned to a set of predefined shifts so as to optimize the trade-off between manpower cost and customer quality of service. We focus on explicitly taking into account in the shi...