Vertical zonation of soil fungal community structure in a Korean pine forest on Changbai Mountain, China.

PubMed

Ping, Yuan; Han, Dongxue; Wang, Ning; Hu, Yanbo; Mu, Liqiang; Feng, Fujuan

2017-01-01

Changbai Mountain, with intact montane vertical vegetation belts, is located at a sensitive area of global climate change and a central distribution area of Korean pine forest. Broad-leaved Korean pine mixed forest (Pinus koraiensis as an edificator) is the most representative zonal climax vegetation in the humid region of northeastern China; their vertical zonation is the most intact and representative on Changbai Mountain. In this study, we analyzed the composition and diversity of soil fungal communities in the Korean pine forest on Changbai Mountain at elevations ranging from 699 to 1177 m using Illumina High-throughput sequencing. We obtained a total 186,663 optimized sequences, with an average length of 268.81 bp. We found soil fungal diversity index was decreased with increasing elevation from 699 to 937 m and began to rise after reaching 1044 m; the richness and evenness indices were decreased with an increase in elevation. Soil fungal compositions at the phylum, class and genus levels varied significantly at different elevations, but with the same dominant fungi. Beta-diversity analysis indicated that the similarity of fungal communities decreased with an increased vertical distance between the sample plots, showing a distance-decay relationship. Variation partition analysis showed that geographic distance (mainly elevation gradient) only explained 20.53 % of the total variation of fungal community structure, while soil physicochemical factors explained 69.78 %.

Association between reliance on devices and people for walking and ability to walk community distances among persons with spinal cord injury.

PubMed

Brotherton, Sandra S; Saunders, Lee L; Krause, James S; Morrisette, David C

2012-05-01

To identify and describe the frequency of reliance on assistive devices and/or people for ambulating distances and stair climbing. Survey. A total of 429 adults with traumatic spinal cord injury who were able to walk at least 10 m were identified through inpatient and outpatient hospital databases at a specialty hospital in the southeast United States. Data were collected using a self-report questionnaire including items related to distances walked and devices used for ambulation. Participants best able to ambulate community distances were those who were independent with ambulation and those who used one cane or crutch. Reliance on people or use of a walker was associated with walking shorter distances. Regression analysis indicated reliance on devices or people for walking predicted variation in ability to ambulate community distances after controlling for demographic and injury characteristics. This study suggests that reliance on devices or a person for assistance is important to consider when assessing potential for achieving functional community ambulation.

Dancing to her own beat: honey bee foragers communicate via individually calibrated waggle dances.

PubMed

Schürch, Roger; Ratnieks, Francis L W; Samuelson, Elizabeth E W; Couvillon, Margaret J

2016-05-01

Communication signals often vary between individuals, even when one expects selection to favour accuracy and precision, such as the honey bee waggle dance, where foragers communicate to nestmates the direction and distance to a resource. Although many studies have examined intra-dance variation, or the variation within a dance, less is known about inter-dance variation, or the variation between dances. This is particularly true for distance communication. Here, we trained individually marked bees from three colonies to forage at feeders of known distances and monitored their dances to determine individual communication variation. We found that each honey bee possesses her own calibration: individual duration-distance calibrations varied significantly in both slopes and intercepts. The variation may incur a cost for communication, such that a dancer and recruit may misunderstand the communicated distance by as much as 50%. Future work is needed to understand better the mechanisms and consequences of individual variation in communication. © 2016. Published by The Company of Biologists Ltd.

Length Variation of Cag/Caa Trinucleotide Repeats in Natural Populations of Drosophila Melanogaster and Its Relation to the Recombination Rate

PubMed Central

Michalakis, Y.; Veuille, M.

1996-01-01

Eleven genes distributed along the Drosophila melanogaster chromosome 2 and showing exonic tandem repeats of glutamine codons (CAG or CAA) were surveyed for length variation in a sample of four European and African populations. Only one gene was monomorphic. Eight genes were polymorphic in all populations, with a total number of alleles varying between five and 12 for 120 chromosomes. The average heterozygozity per locus and population was 0.41. Selective neutrality in length variation could not be rejected under the assumptions of the infinite allele model. Significant population subdivision was found though no geographical pattern emerged, all populations being equally different. Significant linkage disequilibrium was found in four out of seven cases where the genetic distance between loci was <1 cM and was negligible when the distance was larger. There is evidence that these associations were established after the populations separated. An unexpected result was that variation at each locus was independent of the coefficient of exchange, although the latter ranged from zero to the relatively high value of 6.7%. This would indicate that background selection and selective hitchhiking, which are thought to affect levels of nucleotide substitution polymorphism, have no effect on trinucleotide repeat variation. PMID:8844158

Comparative epigenetic and genetic spatial structure of the perennial herb Helleborus foetidus: Isolation by environment, isolation by distance, and functional trait divergence.

PubMed

Herrera, Carlos M; Medrano, Mónica; Bazaga, Pilar

2017-08-16

Epigenetic variation can play a role in local adaptation; thus, there should be associations among epigenetic variation, environmental variation, and functional trait variation across populations. This study examines these relationships in the perennial herb Helleborus foetidus (Ranunculaceae). Plants from 10 subpopulations were characterized genetically (AFLP, SSR markers), epigenetically (MSAP markers), and phenotypically (20 functional traits). Habitats were characterized using six environmental variables. Isolation-by-distance (IBD) and isolation-by-environment (IBE) patterns of genetic and epigenetic divergence were assessed, as was the comparative explanatory value of geographical and environmental distance as predictors of epigenetic, genetic, and functional differentiation. Subpopulations were differentiated genetically, epigenetically, and phenotypically. Genetic differentiation was best explained by geographical distance, while epigenetic differentiation was best explained by environmental distance. Divergence in functional traits was correlated with environmental and epigenetic distances, but not with geographical and genetic distances. Results are compatible with the hypothesis that epigenetic IBE and functional divergence reflected responses to environmental variation. Spatial analyses simultaneously considering epigenetic, genetic, phenotypic and environmental information provide a useful tool to evaluate the role of environmental features as drivers of natural epigenetic variation between populations. © 2017 Botanical Society of America.

Monitoring Elite Soccer Players' External Loads Using Real-Time Data.

PubMed

Barrett, Steve

2017-11-01

To assess the validity of measuring locomotor activities and PlayerLoad using real-time (RT) data collection during soccer training. Twenty-nine English soccer players participated. Each player wore the same MEMS device (Micromechanical Electrical Systems; S5, Optimeye; CatapultSports, Melbourne, Australia) during 21 training sessions (N = 331 data sets) in the 2015-16 and 2016-17 seasons. An RT receiver (TRX; Catapultsports, Melbourne, Australia) was used to collect the locomotor activities and PlayerLoad data in RT and compared with the postevent downloaded (PED) data. PlayerLoad and locomotor activities (total distance covered; total high-speed running distance covered, >5.5#x00A0;m/s; total sprinting distance covered, >7 m/s; maximum velocity) were analyzed. Correlations were near perfect for all variables analyzed (r = .98-1.00), with a varied level of noise between RT and PED also (0.3-9.7% coefficient of variation). Locomotor activities and PlayerLoad can use both RT and PED concurrently to quantify a player's physical output during a training session. Caution should be taken with higher-velocity-based locomotor activities during RT compared to PED.

Environment and geographic distance differ in relative importance for determining fungal community of rhizosphere and bulk soil.

PubMed

Zhang, Kaoping; Adams, Jonathan M; Shi, Yu; Yang, Teng; Sun, Ruibo; He, Dan; Ni, Yingying; Chu, Haiyan

2017-09-01

Rhizospheric fungi play major roles in both natural and agricultural ecosystems. However, little is known about the determinants of their diversity and biogeographic patterns. Here, we compared fungal communities in rhizosphere and bulk soils of wheat fields in the North China Plain. The rhizosphere had a lower fungal diversity (observed OTUs and Chao1) than bulk soil, and a distinct fungal community structure in rhizosphere compared with bulk soil. The relative importance of environmental factors and geographic distance for fungal distribution differed between rhizosphere and bulk soil. Environmental factors were the primary cause of variations in total fungal community and major fungal phyla in bulk soil. By contrast, fungal communities in soils loosely attached to roots were predictable from both environmental factors and influences of geographic distance. Communities in soils tightly attached to roots were mainly determined by geographic distance. Our results suggest that both contemporary environment processes (present-day abiotic and biotic environment characters) and historical processes (spatial isolation, dispersal limitation occurred in the past) dominate variations of fungal communities in wheat fields, but their relative importance of all these processes depends on the proximity of fungal community to the plant roots. © 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.

Time-dependent polar distribution of outgassing from a spacecraft

NASA Technical Reports Server (NTRS)

Scialdone, J. J.

1974-01-01

A technique has been developed to obtain a characterization of the self-generated environment of a spacecraft and its variation with time, angular position, and distance. The density, pressure, outgassing flux, total weight loss, and other important parameters were obtained from data provided by two mass measuring crystal microbalances, mounted back to back, at distance of 1 m from the spacecraft equivalent surface. A major outgassing source existed at an angular position of 300 deg to 340 deg, near the rocket motor, while the weakest source was at the antennas. The strongest source appeared to be caused by a material diffusion process which produced a directional density at 1 m distance of about 1.6 x 10 to the 11th power molecules/cu cm after 1 hr in vacuum and decayed to 1.6 x 10 to the 9th power molecules/cu cm after 200 hr. The total average outgassing flux at the same distance and during the same time span changed from 1.2 x 10 to the minus 7th power to 1.4 x to the minus 10th power g/sq cm/s. These values are three times as large at the spacecraft surface. Total weight loss was 537 g after 10 hr and about 833 g after 200 hr. Self-contamination of the spacecraft was equivalent to that in orbit at about 300-km altitude.

Sedimentation and mobility of PDCs: a reappraisal of ignimbrites' aspect ratio.

PubMed

Giordano, Guido; Doronzo, Domenico M

2017-06-30

The aspect ratio of ignimbrites is a commonly used parameter that has been related to the energy of the parent pyroclastic density currents (PDCs). However this parameter, calculated as the ratio between the average thickness and the average lateral extent of ignimbrites, does not capture fundamental differences in pyroclastic flow mobility nor relates to lithofacies variations of the final deposits. We herein introduce the "topological aspect ratio" (ARt) as the ratio of the local deposit thickness (Ht) to the distance between the local site and the maximum runout distance (Lt), where Ht is a proxy for the PDC tendency to deposit, and Lt a proxy for the PDC mobility or its tendency to further transport the pyroclastic material. The positive versus negative spatial gradient d(ARt)/dx along flow paths discriminate zones where PDCs are forced (i.e. where they transport the total energy under the action of mass discharge rate) from zones where they are inertial (i.e. where they transport the total energy under the action of viscous or turbulent fluidization). Though simple to apply, the topological aspect ratio and its spatial gradient are powerful descriptors of the interplay between sedimentation and mobility of PDCs, and of the resulting lithofacies variations.

How to calculate H3 better.

PubMed

Pavanello, Michele; Tung, Wei-Cheng; Adamowicz, Ludwik

2009-11-14

Efficient optimization of the basis set is key to achieving a very high accuracy in variational calculations of molecular systems employing basis functions that are explicitly dependent on the interelectron distances. In this work we present a method for a systematic enlargement of basis sets of explicitly correlated functions based on the iterative-complement-interaction approach developed by Nakatsuji [Phys. Rev. Lett. 93, 030403 (2004)]. We illustrate the performance of the method in the variational calculations of H(3) where we use explicitly correlated Gaussian functions with shifted centers. The total variational energy (-1.674 547 421 Hartree) and the binding energy (-15.74 cm(-1)) obtained in the calculation with 1000 Gaussians are the most accurate results to date.

Temporal variation in the mating structure of Sanday, Orkney Islands.

PubMed

Brennan, E R; Relethford, J H

1983-01-01

Pedigree and vital statistics data from the population of Sanday, Orkney Islands, Scotland, were used to assess temporal changes in population structure. Secular trends in patterns of mate choice were analysed for three separate birth cohorts of spouses: 1855-1884, 1885-1924 and 1925-1964. The degree to which mating was random or assortative with respect to both genealogical and geographic distance was determined by comparing average characteristics of all potential mates of married males with those of actual wives. We integrated this procedure, originally developed by Dyke (1971), into a three-fold investigation of population structure: (1) comparison of random and non-random components of relatedness as measured from pedigree data; (2) an analysis of marital distance distributions for actual and potential mates of married males; and (3) the relationship between genealogical relatedness and geographic distance. As population size decreased from 1881 to the present, total kinship and spatial distances between spouses increased. Whereas the random component of relatedness increased over time, consanguinity avoidance was sufficient to decrease the total coefficient of kinship over time. Part of the increase in consanguinity avoidance was associated with isolate breakdown, as distances between island-born spouses, as well as the total amount of off-island migration, increased from the mid-nineteenth century to the present. Mate choice was influenced by geographic distance for all time periods, although this effect diminished over time. Since decreases in population size, concomitant with increases in consanguinity avoidance and community exogamy, have probably occurred quite frequently in small human populations, as well as in rural Western communities in the past century, observed secular trends illustrate the potential for change in population structure characteristic of isolate breakdown.

Target distance-dependent variation of hearing sensitivity during echolocation in a false killer whale.

PubMed

Supin, Alexander Ya; Nachtigall, Paul E; Breese, Marlee

2010-06-01

Evidence of varying hearing sensitivity according to the target distance was obtained in a false killer whale Pseudorca crassidens during echolocation. Auditory evoked potentials (AEPs) triggered by echolocation clicks were recorded. The target distance varied from 1 to 6 m. The records contained AEPs to the self-heard emitted click and AEPs to the echoes. Mean level of echolocation clicks depended on distance (the longer the distance, the higher the click level), however, the effect of click level on AEP amplitude was eliminated by extracting AEPs to clicks of certain particular levels. The amplitude of the echo-provoked AEP was almost independent of distance, however, the amplitude of the AEP to the emitted click, did depend on distance within a range from 1 to 4 m: the longer the distance, the higher the amplitude. The latter result is interpreted as confirmational evidence that the animal is capable of varying hearing sensitivity according to target distance. The variation of hearing sensitivity may help to compensate for the echo attenuation with distance; as a secondary effect, this variation manifested itself in a variation of the amplitude of the AEP to emitted clicks.

Does Imprecision in The Waggle Dance Fit Patterns Predicted by The Tuned-Error Hypothesis?

PubMed

Tanner, David A; Visscher, P Kirk

2010-05-01

The waggle dance of the honey bee is used to recruit nest mates to a resource, though direction indicated for a resource may vary greatly within a single dance. Some authors suggest that this variation exits as an adaptation to distribute recruits across a patch of flowers, and that, due to the variation's inverse relationship with distance, the shape of the recruit distribution will remain constant for resources at different distances. In this study, we test this hypothesis by examining how variation in the indication of direction and distance changes with respect to distance. We find that imprecision in the communication of direction does not diminish rapidly enough to accommodate an adaptive-error hypothesis, and we also find that variation in the indication of distance has a positive relationship with the distance of a resource from the hive.

SEXUAL SPECIES ARE SEPARATED BY LARGER GENETIC GAPS THAN ASEXUAL SPECIES IN ROTIFERS

PubMed Central

Tang, Cuong Q; Obertegger, Ulrike; Fontaneto, Diego; Barraclough, Timothy G

2014-01-01

Why organisms diversify into discrete species instead of showing a continuum of genotypic and phenotypic forms is an important yet rarely studied question in speciation biology. Does species discreteness come from adaptation to fill discrete niches or from interspecific gaps generated by reproductive isolation? We investigate the importance of reproductive isolation by comparing genetic discreteness, in terms of intra- and interspecific variation, between facultatively sexual monogonont rotifers and obligately asexual bdelloid rotifers. We calculated the age (phylogenetic distance) and average pairwise genetic distance (raw distance) within and among evolutionarily significant units of diversity in six bdelloid clades and seven monogonont clades sampled for 4211 individuals in total. We find that monogonont species are more discrete than bdelloid species with respect to divergence between species but exhibit similar levels of intraspecific variation (species cohesiveness). This pattern arises because bdelloids have diversified into discrete genetic clusters at a faster net rate than monogononts. Although sampling biases or differences in ecology that are independent of sexuality might also affect these patterns, the results are consistent with the hypothesis that bdelloids diversified at a faster rate into less discrete species because their diversification does not depend on the evolution of reproductive isolation. PMID:24975991

Barcoding the Dendrobium (Orchidaceae) Species and Analysis of the Intragenomic Variation Based on the Internal Transcribed Spacer 2

PubMed Central

Wang, Xiaoyue; Yang, Pei; Wang, Lili

2017-01-01

Many species belonging to the genus Dendrobium are of great commercial value. However, their difficult growth conditions and high demand have caused many of these species to become endangered. Indeed, counterfeit Dendrobium products are common, especially in medicinal markets. This study aims to assess the suitability of the internal transcribed spacer 2 (ITS2) region as a marker for identifying Dendrobium and to evaluate its intragenomic variation in Dendrobium species. In total, 29,624 ITS2 copies from 18 species were obtained using 454 pyrosequencing to evaluate intragenomic variation. In addition, 513 ITS2 sequences from 26 Dendrobium species were used to assess its identification suitability. The highest intragenomic genetic distance was observed in Dendrobium chrysotoxum (0.081). The average intraspecific genetic distances of each species ranged from 0 to 0.032. Phylogenetic trees based on ITS2 sequences showed that most Dendrobium species are monophyletic. The intragenomic and intraspecies divergence analysis showed that greater intragenomic divergence is mostly correlated with larger intraspecific variation. As a major ITS2 variant becomes more common in genome, there are fewer intraspecific variable sites in ITS2 sequences at the species level. The results demonstrated that the intragenomic multiple copies of ITS2 did not affect species identification. PMID:29181391

Barcoding the Dendrobium (Orchidaceae) Species and Analysis of the Intragenomic Variation Based on the Internal Transcribed Spacer 2.

PubMed

Wang, Xiaoyue; Chen, Xiaochen; Yang, Pei; Wang, Lili; Han, Jianping

2017-01-01

Many species belonging to the genus Dendrobium are of great commercial value. However, their difficult growth conditions and high demand have caused many of these species to become endangered. Indeed, counterfeit Dendrobium products are common, especially in medicinal markets. This study aims to assess the suitability of the internal transcribed spacer 2 (ITS2) region as a marker for identifying Dendrobium and to evaluate its intragenomic variation in Dendrobium species. In total, 29,624 ITS2 copies from 18 species were obtained using 454 pyrosequencing to evaluate intragenomic variation. In addition, 513 ITS2 sequences from 26 Dendrobium species were used to assess its identification suitability. The highest intragenomic genetic distance was observed in Dendrobium chrysotoxum (0.081). The average intraspecific genetic distances of each species ranged from 0 to 0.032. Phylogenetic trees based on ITS2 sequences showed that most Dendrobium species are monophyletic. The intragenomic and intraspecies divergence analysis showed that greater intragenomic divergence is mostly correlated with larger intraspecific variation. As a major ITS2 variant becomes more common in genome, there are fewer intraspecific variable sites in ITS2 sequences at the species level. The results demonstrated that the intragenomic multiple copies of ITS2 did not affect species identification.

Frequencies of genes for coat colour and horns in Nordic cattle breeds

PubMed Central

Kantanen, Juha; Olsaker, Ingrid; Brusgaard, Klaus; Eythorsdottir, Emma; Holm, Lars-Erik; Lien, Sigbjørn; Danell, Birgitta; Adalsteinsson, Stefan

2000-01-01

Gene frequencies of coat colour and horn types were assessed in 22 Nordic cattle breeds in a project aimed at establishing genetic profiles of the breeds under study. The coat colour loci yielding information on genetic variation were: extension, agouti, spotting, brindle, dun dilution and colour sided. The polled locus was assessed for two alleles. A profound variation between breeds was observed in the frequencies of both colour and horn alleles, with the older breeds generally showing greater variation in observed colour, horn types and segregating alleles than the modern breeds. The correspondence between the present genetic distance matrix and previous molecular marker distance matrices was low (r = 0.08 – 0.12). The branching pattern of a neighbour-joining tree disagreed to some extent with the molecular data structure. The current data indicates that 70% of the total genetic variation could be explained by differences between the breeds, suggesting a much greater breed differentiation than typically found at protein and microsatellite loci. The marked differentiation of the cattle breeds and observed disagreements with the results from the previous molecular data in the topology of the phylogenetic trees are most likely a result of selection on phenotypic characters analysed in this study. PMID:14736370

Influence of Inter-Electrode Distance on EMG

DTIC Science & Technology

2001-10-25

has been observed that at low levels of muscle contraction there was no significant variation due to the change in the distance between the...a variation of the spectral content of the EMG with change in the IED. The study also has shown that there is a variation of the EMG with muscle ... contraction but that the comparison should be done if the distance between the electrodes has been kept constant.

Phenotypic Characterization and Multivariate Analysis to Explain Body Conformation in Lesser Known Buffalo (Bubalus bubalis) from North India

PubMed Central

Vohra, V.; Niranjan, S. K.; Mishra, A. K.; Jamuna, V.; Chopra, A.; Sharma, Neelesh; Jeong, Dong Kee

2015-01-01

Phenotypic characterization and body biometric in 13 traits (height at withers, body length, chest girth, paunch girth, ear length, tail length, length of tail up to switch, face length, face width, horn length, circumference of horn at base, distances between pin bone and hip bone) were recorded in 233 adult Gojri buffaloes from Punjab and Himachal Pradesh states of India. Traits were analysed by using varimax rotated principal component analysis (PCA) with Kaiser Normalization to explain body conformation. PCA revealed four components which explained about 70.9% of the total variation. First component described the general body conformation and explained 31.5% of total variation. It was represented by significant positive high loading of height at wither, body length, heart girth, face length and face width. The communality ranged from 0.83 (hip bone distance) to 0.45 (horn length) and unique factors ranged from 0.16 to 0.55 for all these 13 different biometric traits. Present study suggests that first principal component can be used in the evaluation and comparison of body conformation in buffaloes and thus provides an opportunity to distinguish between early and late maturing to adult, based on a small group of biometric traits to explain body conformation in adult buffaloes. PMID:25656215

Identification of Vibrotactile Patterns Encoding Obstacle Distance Information.

PubMed

Kim, Yeongmi; Harders, Matthias; Gassert, Roger

2015-01-01

Delivering distance information of nearby obstacles from sensors embedded in a white cane-in addition to the intrinsic mechanical feedback from the cane-can aid the visually impaired in ambulating independently. Haptics is a common modality for conveying such information to cane users, typically in the form of vibrotactile signals. In this context, we investigated the effect of tactile rendering methods, tactile feedback configurations and directions of tactile flow on the identification of obstacle distance. Three tactile rendering methods with temporal variation only, spatio-temporal variation and spatial/temporal/intensity variation were investigated for two vibration feedback configurations. Results showed a significant interaction between tactile rendering method and feedback configuration. Spatio-temporal variation generally resulted in high correct identification rates for both feedback configurations. In the case of the four-finger vibration, tactile rendering with spatial/temporal/intensity variation also resulted in high distance identification rate. Further, participants expressed their preference for the four-finger vibration over the single-finger vibration in a survey. Both preferred rendering methods with spatio-temporal variation and spatial/temporal/intensity variation for the four-finger vibration could convey obstacle distance information with low workload. Overall, the presented findings provide valuable insights and guidance for the design of haptic displays for electronic travel aids for the visually impaired.

Influences of roads and development on bird communities in protected Chihuahuan Desert landscapes

USGS Publications Warehouse

Gutzwiller, K.J.; Barrow, W.C.

2003-01-01

Our objective was to improve knowledge about effects of broad-scale road and development variables on bird communities in protected desert landscapes. Bird species richness and the relative abundance or probability of occurrence of many species were significantly associated with total length of roads within each of two spatial extents (1- and 2-km radii), distance to the nearest road, distance to the nearest development, or the two-way interactions of these variables. Regression models reflected non-linear relations, interaction effects, spatial-extent effects, and interannual variation. Road and development effects warrant special attention in protected areas because such places may be important sources of indigenous bird communities in a region.

Effect of reaction time on the formation of disinfection byproducts

USGS Publications Warehouse

Rathbun, R.E.

1997-01-01

The effect of reaction time on the trihalomethane and nonpurgeable total organic-halide formation potentials was determined by chlorinating water samples from the Mississippi, Missouri, and Ohio Rivers. Samples were collected for three seasons at 12 locations on the Mississippi from Minneapolis, Minnesota, to New Orleans, Louisiana, and on the Missouri and Ohio 1.6 kilometers above their confluences with the Mississippi. Both types of compounds formed rapidly during the initial stages of the reaction-time period, with formation rates decreasing with time. The ratio of the nonpurgeable total organic-halide and trihalomethane concentrations decreased with time, with the nonpurgeable total organic-halide compounds forming faster during the first stages of the time period and the trihalomethane compounds forming faster during the latter stages of the time period. Variation with distance along the Mississippi River of the formation rates approximately paralleled the variation of the dissolved organic carbon concentration, indicating that the rates of formation, as well as the concentrations of the compounds formed, depended on the dissolved organic carbon concentration.

Neither artificial light at night, anthropogenic noise nor distance from roads are associated with oxidative status of nestlings in an urban population of songbirds.

PubMed

Casasole, Giulia; Raap, Thomas; Costantini, David; AbdElgawad, Hamada; Asard, Han; Pinxten, Rianne; Eens, Marcel

2017-08-01

Increasing urbanization is responsible for road-related pollutants and causes an unprecedented increase in light and noise pollution, with potential detrimental effects for individual animals, communities and ecosystems. These stressors rarely act in isolation but studies dissecting the effects of these multiple stressors are lacking. Moreover, studies on urban stressors have mainly focused on adults, while exposure in early-life may be detrimental but is largely ignored. To fill this important knowledge gap, we studied if artificial light at night, anthropogenic noise and road-related pollution (using distance from roads as a proxy) explain variation in oxidative status in great tit nestlings (Parus major) in an urban population. Artificial light at night, anthropogenic noise and distance from roads were not associated with variation of the nine studied metrics of oxidative status (superoxide dismutase-SOD-, glutathione peroxidase-GPX, catalase-CAT-, non-enzymatic total antioxidant capacity-TAC-, reduced glutathione-GSH-, oxidized glutathione-GSSG-, ratio GSH/GSSG, protein carbonyls and thiobarbituric acid reactive substances-TBARS). Interestingly, for all oxidative status metrics, we found that there was more variation in oxidative status among individuals of the same nest compared to between different nests. We also showed an increase in protein carbonyls and a decrease of the ratio GSH/GSSG as the day advanced, and an increase of GPX when weather conditions deteriorated. Our study suggests that anthropogenic noise, artificial light at night and road-related pollution are not the most important sources of variation in oxidative status in great tit nestlings. It also highlights the importance of considering bleeding time and weather conditions in studies with free-living animals. Copyright © 2017. Published by Elsevier Inc.

Maxillary Sinus Dimensions Decrease as Age and Tooth Loss Increase.

PubMed

Velasco-Torres, Miguel; Padial-Molina, Miguel; Avila-Ortiz, Gustavo; García-Delgado, Raúl; OʼValle, Francisco; Catena, Andrés; Galindo-Moreno, Pablo

2017-04-01

To investigate the correlation between patient-dependent variables and dimensional variations of the maxillary sinus. In this cross-sectional study, a total of 394 individual cone-beam computed tomography scans were evaluated by one calibrated examiner to measure the total volume of the maxillary sinus, the distance between the medial and the lateral walls at 5, 10, and 15 mm vertically from the sinus floor, the height of septa (if present), and the height of the maxillary sinus cavity from both the alveolar crest and the sinus floor to the meatus. Recorded patient-dependent variables were age, gender, and edentulism status. Total maxillary sinus volume was significantly smaller in completely and partially edentulous patients than in dentate subjects. This finding was influenced by age, as older patients exhibited less volume, regardless of gender and edentulism status. Age showed an indirect correlation with the distance to the meatus, the sinus volume, and the mediolateral dimensions. Additionally, the prevalence of accessory meatus in this population was 29.19%. The dimensions of the maxillary sinus are influenced by age and edentulism status being reduced by aging and tooth loss.

The kinetic energy operator for distance-dependent effective nuclear masses: Derivation for a triatomic molecule.

PubMed

Khoma, Mykhaylo; Jaquet, Ralph

2017-09-21

The kinetic energy operator for triatomic molecules with coordinate or distance-dependent nuclear masses has been derived. By combination of the chain rule method and the analysis of infinitesimal variations of molecular coordinates, a simple and general technique for the construction of the kinetic energy operator has been proposed. The asymptotic properties of the Hamiltonian have been investigated with respect to the ratio of the electron and proton mass. We have demonstrated that an ad hoc introduction of distance (and direction) dependent nuclear masses in Cartesian coordinates preserves the total rotational invariance of the problem. With the help of Wigner rotation functions, an effective Hamiltonian for nuclear motion can be derived. In the derivation, we have focused on the effective trinuclear Hamiltonian. All necessary matrix elements are given in closed analytical form. Preliminary results for the influence of non-adiabaticity on vibrational band origins are presented for H 3 + .

[A variation of the recurrent laryngeal nerve at its entry to larynx found in the thyroid surgery].

PubMed

Shao, Tang-lei; Qiu, Wei-hua; Wang, Yang; Li, Jun; Yang, Wei-ping; Cai, Wei-yao; Li, Hong-wei

2010-11-01

To describe a new variation of the recurrent laryngeal nerve (RLN) at its entry to larynx. A retrospective study including 3 078 consecutive cases received thyroidectomy was performed from January 1998 to December 2008. The age ranged from 15 to 82 years, 2 395 cases were female and 683 cases were male. A total of 4 241 RLNs were exposed successfully for avoiding the injury of the nerve. A kind of variation of the RLN was reported in this study. Forty-four varied RLNs were identified at the entry into the larynx (1.0%, 44/4241). Variation happened at the truck or the branches of RLN entering the larynx far from the posterior cricothyroid joints. The distance from the entry to the back of cricothyroid joints was over 5 mm. Among these, eight RLNs (23.5%, 8/34) walked distally from the dorsal cricothyroid joint without extra laryngeal branches and entered the larynx at the abnormal point. There were four different kinds of sub-variations identified: type I: there was no branch in RLN and the varied RLN entered the larynx far from the posterior cricothyroid joints, total 35 cases (79.6%, 35/44); type II: there were two branches in RLN, one branch entered the larynx at the posterior cricothyroid joints and the other far from the posterior cricothyroid joints, total 5 cases (11.4%, 5/44); type III: there were two branches in RLN, and both branches entered the larynx far from the posterior cricothyroid joints, total 3 cases (6.8%, 3/44); type IV: there were three branches in RLN, the lateral branch of the varied RLN entered the larynx far from the posterior cricothyroid joints, total 1 case (2.2%, 1/44). Four varied RLNs were injured during the operation (9.1%, 4/44). The variation of RLN reported in this study is more dangerous and should be paid more attention to lower the injury of the nerve.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

The following appendices to volume I are presented: biomass of dominant microzooplankton; biomass of zooplankton in surface waters of Jobos Bay; comparison of zooplankton caught during day and night; variations in surface temperature and salinity at collection sites; distance, depth, and temperature related to dominant vegetation and sea grass; total biomass of Thalassia testudium; photosynthetic pigment diversity; invertebrate species and frequency of occurrence; distribution of macrobenthic organisms; species found on mangrove roots; distribution of fish species; and seasonal occurrence of fish species. (HLW)

Does Imprecision in The Waggle Dance Fit Patterns Predicted by The Tuned-Error Hypothesis?

PubMed Central

Visscher, P. Kirk

2010-01-01

The waggle dance of the honey bee is used to recruit nest mates to a resource, though direction indicated for a resource may vary greatly within a single dance. Some authors suggest that this variation exits as an adaptation to distribute recruits across a patch of flowers, and that, due to the variation’s inverse relationship with distance, the shape of the recruit distribution will remain constant for resources at different distances. In this study, we test this hypothesis by examining how variation in the indication of direction and distance changes with respect to distance. We find that imprecision in the communication of direction does not diminish rapidly enough to accommodate an adaptive-error hypothesis, and we also find that variation in the indication of distance has a positive relationship with the distance of a resource from the hive. PMID:20414338

Species richness and biomass explain spatial turnover in ecosystem functioning across tropical and temperate ecosystems.

PubMed

Barnes, Andrew D; Weigelt, Patrick; Jochum, Malte; Ott, David; Hodapp, Dorothee; Haneda, Noor Farikhah; Brose, Ulrich

2016-05-19

Predicting ecosystem functioning at large spatial scales rests on our ability to scale up from local plots to landscapes, but this is highly contingent on our understanding of how functioning varies through space. Such an understanding has been hampered by a strong experimental focus of biodiversity-ecosystem functioning research restricted to small spatial scales. To address this limitation, we investigate the drivers of spatial variation in multitrophic energy flux-a measure of ecosystem functioning in complex communities-at the landscape scale. We use a structural equation modelling framework based on distance matrices to test how spatial and environmental distances drive variation in community energy flux via four mechanisms: species composition, species richness, niche complementarity and biomass. We found that in both a tropical and a temperate study region, geographical and environmental distance indirectly influence species richness and biomass, with clear evidence that these are the dominant mechanisms explaining variability in community energy flux over spatial and environmental gradients. Our results reveal that species composition and trait variability may become redundant in predicting ecosystem functioning at the landscape scale. Instead, we demonstrate that species richness and total biomass may best predict rates of ecosystem functioning at larger spatial scales. © 2016 The Author(s).

Sexual species are separated by larger genetic gaps than asexual species in rotifers.

PubMed

Tang, Cuong Q; Obertegger, Ulrike; Fontaneto, Diego; Barraclough, Timothy G

2014-10-01

Why organisms diversify into discrete species instead of showing a continuum of genotypic and phenotypic forms is an important yet rarely studied question in speciation biology. Does species discreteness come from adaptation to fill discrete niches or from interspecific gaps generated by reproductive isolation? We investigate the importance of reproductive isolation by comparing genetic discreteness, in terms of intra- and interspecific variation, between facultatively sexual monogonont rotifers and obligately asexual bdelloid rotifers. We calculated the age (phylogenetic distance) and average pairwise genetic distance (raw distance) within and among evolutionarily significant units of diversity in six bdelloid clades and seven monogonont clades sampled for 4211 individuals in total. We find that monogonont species are more discrete than bdelloid species with respect to divergence between species but exhibit similar levels of intraspecific variation (species cohesiveness). This pattern arises because bdelloids have diversified into discrete genetic clusters at a faster net rate than monogononts. Although sampling biases or differences in ecology that are independent of sexuality might also affect these patterns, the results are consistent with the hypothesis that bdelloids diversified at a faster rate into less discrete species because their diversification does not depend on the evolution of reproductive isolation. © 2014 The Authors. Evolution published by Wiley Periodicals, Inc. on behalf of The Society for the Study of Evolution.

Yo-Yo Intermittent Recovery Test Performance in Subelite Gaelic Football Players From Under Thirteen to Senior Age Groups.

PubMed

Roe, Mark; Malone, Shane

2016-11-01

Roe, M and Malone, S. Yo-Yo intermittent recovery test performance in subelite Gaelic football players from under thirteen to senior age groups. J Strength Cond Res 30 (11): 3187-3193, 2016-Gaelic football is indigenous to Ireland and has similar locomotion profiles to soccer and Australian Football. Given the increasing attention on long-term player development, investigations on age-related variation in Yo-Yo intermittent recovery test level 1 (Yo-YoIR1) performance may provide useful information in talent identification, program design, and player monitoring. Therefore, the aim of this study was to evaluate Yo-YoIR1 performance across Gaelic football age groups. Male participants (n = 355) were recruited from division one, Gaelic football teams. Participants were allocated to one of the 7 groups according to respective age groups from under 13 (U13), under 14, under 15 (U15), under 16 (U16), minor, under 21 (U21), to senior age groups. Total Yo-YoIR1 distance (m) increased progressively from U13 (885 ± 347 m) to U16 (1,595 ± 380 m) equating to a rate of change of 180.2%. In comparison to U13, total distance at minor (1,206 ± 327 m) increased by 136.4%. Subsequent increases were observed in U21 (1,585 ± 445 m) and senior players (2,365 ± 489). Minimum (800-880 m) and maximum (2,240-2,280 m) total distances were comparable for U15, U16, and U21 players. Differences in total distance (m) for all age groups were statistically significant when compared to U13 players (p < 0.002). In comparison to U13 players, the magnitude of differences between age groups for total distance was deemed to be large (effect size > 0.8). Similar trends were observed for maximum velocity and estimated V[Combining Dot Above]O2max. The evolution of Yo-YoIR1 performance in Gaelic football players from adolescents to adulthood highlights how maturation may influence sport-related running ability. Changes in Yo-YoIR1 performance should be closely monitored to optimize interventions for individuals transitioning across age groups.

Variability of soccer referees' match performances.

PubMed

Weston, M; Drust, B; Atkinson, G; Gregson, W

2011-03-01

The aim of the present study was to determine the between-match variability in soccer referees' match performances. 1 269 individual match observations were undertaken on 59 referees (range 2-79 games per referee) officiating in the English Premier League and Championship from 2003/2004 to 2007/2008 using a computerised tracking system (Prozone (®), Leeds, England). Between-match coefficients of variation (CV) were calculated for all games and then compared between referee age and experience groups. High mean CVs were observed for high-speed running distance (25.9±10.1%), recovery time (32.7±13.8%), explosive sprints (34.3±16.6%), total number of sprints (54.0±20.7%) and number of match fouls (28±4.6%). Smaller CVs were observed for total distance covered (3.8±1.5%), top sprinting speed (5.6±10.9%), distance from the ball (4.2±1.9%) and the distance from fouls (9.9±4.3%). Variability in match activities was not influenced by referee age or experience. The present study's findings demonstrate that variability in soccer referees' match performances is high in some variables and not dependent on referee age or experience. Such variability means that research requires large sample sizes to detect real systematic changes in a number of performance characteristics when studied during matches. © Georg Thieme Verlag KG Stuttgart · New York.

Molecular phylogenetic analysis of Chinese indigenous blue-shelled chickens inferred from whole genomic region of the SLCO1B3 gene.

PubMed

Dalirsefat, Seyed Benyamin; Dong, Xianggui; Deng, Xuemei

2015-08-01

In total, 246 individuals from 8 Chinese indigenous blue- and brown-shelled chicken populations (Yimeng Blue, Wulong Blue, Lindian Blue, Dongxiang Blue, Lushi Blue, Jingmen Blue, Dongxiang Brown, and Lushi Brown) were genotyped for 21 SNP markers from the SLCO1B3 gene to evaluate phylogenetic relationships. As a representative of nonblue-shelled breeds, White Leghorn was included in the study for reference. A high proportion of SNP polymorphism was observed in Chinese chicken populations, ranging from 89% in Jingmen Blue to 100% in most populations, with a mean of 95% across all populations. The White Leghorn breed showed the lowest polymorphism, accounting for 43% of total SNPs. The mean expected heterozygosity varied from 0.11 in Dongxiang Blue to 0.46 in Yimeng Blue. Analysis of molecular variation (AMOVA) for 2 groups of Chinese chickens based on eggshell color type revealed 52% within-group and 43% between-group variations of the total genetic variation. As expected, FST and Reynolds' genetic distance were greatest between White Leghorn and Chinese chicken populations, with average values of 0.40 and 0.55, respectively. The first and second principal coordinates explained approximately 92% of the total variation and supported the clustering of the populations according to their eggshell color type and historical origins. STRUCTURE analysis showed a considerable source of variation among populations for the clustering into blue-shelled and nonblue-shelled chicken populations. The low estimation of genetic differentiation (FST) between Chinese chicken populations is possibly due to a common historical origin and high gene flow. Remarkably similar population classifications were obtained with all methods used in the study. Aligning endogenous avian retroviral (EAV)-HP insertion sequences showed no difference among the blue-shelled chickens. © 2015 Poultry Science Association Inc.

van der Waals model for the surface tension of liquid 4He near the λ point

NASA Astrophysics Data System (ADS)

Tavan, Paul; Widom, B.

1983-01-01

We develop a phenomenological model of the 4He liquid-vapor interface. With it we calculate the surface tension of liquid helium near the λ point and compare with the experimental measurements by Magerlein and Sanders. The model is a form of the van der Waals surface-tension theory, extended to apply to a phase equilibrium in which the simultaneous variation of two order parameters-here the superfluid order parameter and the total density-is essential. The properties of the model are derived analytically above the λ point and numerically below it. Just below the λ point the superfluid order parameter is found to approach its bulk-superfluid-phase value very slowly with distance on the liquid side of the interface (the characteristic distance being the superfluid coherence length), and to vanish rapidly with distance on the vapor side, while the total density approaches its bulk-phase values rapidly and nearly symmetrically on the two sides. Below the λ point the surface tension has a |ɛ|32 singularity (ɛ~T-Tλ) arising from the temperature dependence of the spatially varying superfluid order parameter. This is the mean-field form of the more general |ɛ|μ singularity predicted by Sobyanin and by Hohenberg, in which μ (which is in reality close to 1.35 at the λ point of helium) is the exponent with which the interfacial tension between two critical phases vanishes. Above the λ point the surface tension in this model is analytic in ɛ. A singular term |ɛ|μ may in reality be present in the surface tension above as well as below the λ point, although there should still be a pronounced asymmetry. The variation with temperature of the model surface tension is overall much like that in experiment.

A newly identified variation at the entry of the recurrent laryngeal nerve into the larynx.

PubMed

Shao, Tanglei; Yang, Weiping; Zhang, Tao; Wang, Yang; Jin, Xiaotai; Li, Qinyu; Kuang, Jie; Qiu, Weihua; Chu, Peiguo G; Yen, Yun

2010-12-01

We aimed to highlight a new anatomical variation of the recurrent laryngeal nerve (RLN), and to emphasize its implications for thyroid surgery. A prospective study was carried out in a group of 3,078 consecutive thyroidectomies from 1998 to 2008. Total, near-total, subtotal, and partial thyroidectomy were performed for various thyroid diseases. The RLN was routinely identified and exposed in its entire course until the entry into the larynx. The postoperative complications of patients with different variations were compared. 4,241 RLNs were successfully identified in all patients unilaterally or bilaterally. In addition to extralaryngeal branching and nonrecurrent laryngeal nerves, an unreported variation was identified in 44 RLNs (1.04%) at their entries into the larynx. The variation happened at the trunk or the branches of the RLN entering the larynx far from the posterior of cricothyroid joint, and the entry was higher than the superior cornu of the thyroid cartilage and the arch of the cricoid. The median distance from the entry to the posterior of cricothyroid joint was more than 5 mm. As the trunk or the branches had to travel along the lateral edge of the upper 1/3 of the thyroid before entering the larynx, the incidence of RLN palsy was higher than that in extralaryngeal branching variations (p < .05). This newly discovered variation of the RLN is more vulnerable to injury and should be brought to the attention of surgeons.

Some anomalies observed in wind-tunnel tests of a blunt body at transonic and supersonic speeds

NASA Technical Reports Server (NTRS)

Brooks, J. D.

1976-01-01

An investigation of anomalies observed in wind tunnel force tests of a blunt body configuration was conducted at Mach numbers from 0.20 to 1.35 in the Langley 8-foot transonic pressure tunnel and at Mach numbers of 1.50, 1,80, and 2.16 in the Langley Unitary Plan wind tunnel. At a Mach number of 1.35, large variations occurred in axial force coefficient at a given angle of attack. At transonic and low supersonic speeds, the total drag measured in the wind tunnel was much lower than that measured during earlier ballistic range tests. Accurate measurements of total drag for blunt bodies will require the use of models smaller than those tested thus far; however, it appears that accurate forebody drag results can be obtained by using relatively large models. Shock standoff distance is presented from experimental data over the Mach number range from 1.05 to 4.34. Theory accurately predicts the shock standoff distance at Mach numbers up to 1.75.

Prediction of Short-Distance Aerial Movement of Phakopsora pachyrhizi Urediniospores Using Machine Learning.

PubMed

Wen, L; Bowen, C R; Hartman, G L

2017-10-01

Dispersal of urediniospores by wind is the primary means of spread for Phakopsora pachyrhizi, the cause of soybean rust. Our research focused on the short-distance movement of urediniospores from within the soybean canopy and up to 61 m from field-grown rust-infected soybean plants. Environmental variables were used to develop and compare models including the least absolute shrinkage and selection operator regression, zero-inflated Poisson/regular Poisson regression, random forest, and neural network to describe deposition of urediniospores collected in passive and active traps. All four models identified distance of trap from source, humidity, temperature, wind direction, and wind speed as the five most important variables influencing short-distance movement of urediniospores. The random forest model provided the best predictions, explaining 76.1 and 86.8% of the total variation in the passive- and active-trap datasets, respectively. The prediction accuracy based on the correlation coefficient (r) between predicted values and the true values were 0.83 (P < 0.0001) and 0.94 (P < 0.0001) for the passive and active trap datasets, respectively. Overall, multiple machine learning techniques identified the most important variables to make the most accurate predictions of movement of P. pachyrhizi urediniospores short-distance.

Supervised Variational Relevance Learning, An Analytic Geometric Feature Selection with Applications to Omic Datasets.

PubMed

Boareto, Marcelo; Cesar, Jonatas; Leite, Vitor B P; Caticha, Nestor

2015-01-01

We introduce Supervised Variational Relevance Learning (Suvrel), a variational method to determine metric tensors to define distance based similarity in pattern classification, inspired in relevance learning. The variational method is applied to a cost function that penalizes large intraclass distances and favors small interclass distances. We find analytically the metric tensor that minimizes the cost function. Preprocessing the patterns by doing linear transformations using the metric tensor yields a dataset which can be more efficiently classified. We test our methods using publicly available datasets, for some standard classifiers. Among these datasets, two were tested by the MAQC-II project and, even without the use of further preprocessing, our results improve on their performance.

Genetic differentiation and phylogeny relationships of functional ApoVLDL-II gene in red jungle fowl and domestic chicken populations.

PubMed

Musa, Hassan H; Cheng, Jin H; Bao, Wen B; Li, Bi C; Mekki, Dafaalla M; Chen, Guo H

2007-08-01

A total of 243 individuals from Red Jungle Fowl (Gallus gallus spadiceus), Rugao, Anka, Wenchang and Silikes chicken populations were used for polymorphism analysis in functional apoVLDL-II gene by Restriction fragment length polymorphism and single strand conformation polymorphism markers. The results show that Anka population has highest gene diversity and Shannon information index, while Red jungle fowl shows highest effective number of allele. In addition, the higher coefficient of genetic differentiation (Gst) across all loci in apoVLDL-II was indicating that high variation is proportioned among populations. As expected total gene diversity (Ht) has upper estimate compared with within population genetic diversity (Hs) across all loci. The mean Gst value across all loci was (0.194) indicating about 19.4% of total genetic variation could be explained by breeds differences, while the remaining 80.6% was accounted for differences among individuals. The average apoVLDL-II gene flow across all loci in five chicken populations was 1.189. The estimates of genetic identity and distance confirm that these genes are significantly different between genetically fat and lean population, because fat type breed Anka shows highest distance with the other Silikes and Rugao whish are genetically lean. In addition, Wenchang and Red jungle fowl were found more closely and genetically related than the other breeds with 49.4% bootstrapping percentages, then they were related to Silikes by 100% bootstrapping percentages followed by Rugao and finally all of them are related with exotic fat breed Anka.

Effects of English admixture and geographic distance on anthropometric variation and genetic structure in 19th-century Ireland.

PubMed

Relethford, J H

1988-05-01

The analysis of anthropometric data often allows investigation of patterns of genetic structure in historical populations. This paper focuses on interpopulational anthropometric variation in seven populations in Ireland using data collected in the 1890s. The seven populations were located within a 120-km range along the west coast of Ireland and include islands and mainland isolates. Two of the populations (the Aran Islands and Inishbofin) have a known history of English admixture in earlier centuries. Ten anthropometric measures (head length, breadth, and height; nose length and breadth; bizygomatic and bigonial breadth; stature; hand length; and forearm length) on 259 adult Irish males were analyzed following age adjustment. Discriminant and canonical variates analysis were used to determine the degree and pattern of among-group variation. Mahalanobis' distance measure, D2, was computed between each pair of populations and compared to distance measures based on geographic distance and English admixture (a binary measure indicating whether either of a pair of populations had historical indications of admixture). In addition, surname frequencies were used to construct distance measures based on random isonymy. Correlations were computed between distance measures, and their probabilities were derived using the Mantel matrix permutation method. English admixture has the greatest effect on anthropometric variation among these populations, followed by geographic distance. The correlation between anthropometric distance and geographic distance is not significant (r = -0.081, P = .590), but the correlation of admixture and anthropometric distance is significant (r = 0.829, P = .047). When the two admixed populations are removed from the analysis the correlation between geographic and anthropometric distance becomes significant (r = 0.718, P = .025). Isonymy distance shows a significant correlation with geographic distance (r = 0.425, P = .046) but not with admixture distance (r = -0.052, P = .524). The fact that anthropometrics show past patterns of gene flow and surnames do not reflects the greater impact of stochastic processes on surnames, along with the continued extinction of surnames. This study shows that 1) anthropometrics can be extremely useful in assessing population structure and history, 2) differential gene flow into populations can have a major impact on local genetic structure, and 3) microevolutionary processes can have different effects on biological characters and surnames.

The biogeography of fungal communities in wetland sediments along the Changjiang River and other sites in China

PubMed Central

Wu, Bing; Tian, Jianqing; Bai, Chunming; Xiang, Meichun; Sun, Jingzu; Liu, Xingzhong

2013-01-01

Whether fungal community structure depends more on historical factors or on contemporary factors is controversial. This study used culture-dependent and -independent (polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE)) methods to assess the influence of historical and contemporary factors on the distributions of fungi in the wetland sediments at 10 locations along the Changjiang River and at 10 other locations in China. The culture-dependent approach detected greater species diversity (177 operational taxonomic units (OTUs)) than PCR-DGGE analysis (145 OTUs), and the species in the genera of Penicillium (relative frequency=16.8%), Fusarium (15.4%), Aspergillus (7.6%), Trichoderma (5.8%) and Talaromyces (4.2%) were dominant. On the basis of DGGE data, fungal diversity along the Changjiang River increased from upstream to downstream; altitude explained 44.8% of this variation in diversity. And based on the data from all 20 locations, the fungal communities were geographically clustered into three groups: Southern China, Northern China and the Qinghai-Tibetan Plateau. Multivariate regression tree analysis for data from the 20 locations indicated that the fungal community was influenced primarily by location (which explained 61.8% of the variation at a large scale), followed by total potassium (9.4%) and total nitrogen (3.5%) at a local scale. These results are consistent with the concept that geographic distance is the dominant factor driving variation in fungal diversity at a regional scale (1000–4000 km), whereas environmental factors (total potassium and total nitrogen) explain variation in fungal diversity at a local scale (<1000 km). PMID:23446835

Molar intercuspal dimensions: genetic input to phenotypic variation.

PubMed

Townsend, G; Richards, L; Hughes, T

2003-05-01

Molecular studies indicate that epigenetic events are important in determining how the internal enamel epithelium folds during odontogenesis. Since this process of folding leads to the subsequent arrangement of cusps on molar teeth, we hypothesized that intercuspal distances of human molar teeth would display greater phenotypic variation but lower heritabilities than overall crown diameters. Intercuspal distances and maximum crown diameters were recorded from digitized images of dental casts in 100 monozygotic and 74 dizygotic twin pairs. Intercuspal distances displayed less sexual dimorphism in mean values but greater relative variability and fluctuating asymmetry than overall crown measures. Correlations between intercuspal distances and overall crown measures were low. Models incorporating only environmental effects accounted for observed variation in several intercuspal measures. For those intercuspal variables displaying significant additive genetic variance, estimates of heritability ranged from 43 to 79%, whereas those for overall crown size were higher generally, ranging from 60 to 82%. Our finding of high phenotypic variation in intercuspal distances with only moderate genetic contribution is consistent with substantial epigenetic influence on the progressive folding of the internal enamel epithelium, following formation of the primary and secondary enamel knots.

Uncertainty quantification for complex systems with very high dimensional response using Grassmann manifold variations

NASA Astrophysics Data System (ADS)

Giovanis, D. G.; Shields, M. D.

2018-07-01

This paper addresses uncertainty quantification (UQ) for problems where scalar (or low-dimensional vector) response quantities are insufficient and, instead, full-field (very high-dimensional) responses are of interest. To do so, an adaptive stochastic simulation-based methodology is introduced that refines the probability space based on Grassmann manifold variations. The proposed method has a multi-element character discretizing the probability space into simplex elements using a Delaunay triangulation. For every simplex, the high-dimensional solutions corresponding to its vertices (sample points) are projected onto the Grassmann manifold. The pairwise distances between these points are calculated using appropriately defined metrics and the elements with large total distance are sub-sampled and refined. As a result, regions of the probability space that produce significant changes in the full-field solution are accurately resolved. An added benefit is that an approximation of the solution within each element can be obtained by interpolation on the Grassmann manifold. The method is applied to study the probability of shear band formation in a bulk metallic glass using the shear transformation zone theory.

Time Variation of the Distance Separating Bomb and Dive Bomber Subsequent to Bomb Release

NASA Technical Reports Server (NTRS)

Mathews, Charles W.

1952-01-01

A study has been made of the variation of the distance separating bomb and aircraft with time after release as applied to dive-bombing operations, Separation distances determined from this study are presented in terms of two variables only, dive angle and maximum airplane accelerometer reading; the values of separation distance include the effects of delay in initiation of the pull-out and lag in attainment of the maximum normal acceleration.Contains analysis and calculations of the separation distances between bomb and dive bomber following bomb release, Separation distances as determined by the dive angle and the maximum airplane accelerometer reading are presented in a single chart.

Genetic mapping and QTL analysis of agronomic traits in Indian Mucuna pruriens using an intraspecific F₂population.

PubMed

Mahesh, S; Leelambika, M; Jaheer, Md; Anithakumari, A M; Sathyanarayana, N

2016-03-01

Mucuna pruriens is a well-recognized agricultural and horticultural crop with important medicinal use. However, antinutritional factors in seed and adverse morphological characters have negatively affected its cultivation. To elucidate the genetic control of agronomic traits, an intraspecific genetic linkage map of Indian M. pruriens has been developed based on amplified fragment length polymorphism (AFLP) markers using 200 F₂ progenies derived from a cross between wild and cultivated genotypes. The resulting linkage map comprised 129 AFLP markers dispersed over 13 linkage groups spanning a total distance of 618.88 cM with an average marker interval of 4.79 cM. For the first time, three QTLs explaining about 6.05-14.77% of the corresponding total phenotypic variation for three quantitative (seed) traits and, eight QTLs explaining about 25.96% of the corresponding total phenotypic variation for three qualitative traits have been detected on four linkage groups. The map presented here will pave a way for mapping of genes/QTLs for the important agronomic and horticultural traits contrasting between the parents used in this study.

Among-Population Variation in Microbial Community Structure in the Floral Nectar of the Bee-Pollinated Forest Herb Pulmonaria officinalis L

PubMed Central

Jacquemyn, Hans; Lenaerts, Marijke; Brys, Rein; Willems, Kris; Honnay, Olivier; Lievens, Bart

2013-01-01

Background Microbial communities in floral nectar have been shown to be characterized by low levels of species diversity, yet little is known about among-plant population variation in microbial community composition. Methodology/Principal Findings We investigated the microbial community structure (yeasts and bacteria) in floral nectar of ten fragmented populations of the bee-pollinated forest herb Pulmonaria officinalis. We also explored possible relationships between plant population size and microbial diversity in nectar, and related microbial community composition to the distance separating plant populations. Culturable bacteria and yeasts occurring in the floral nectar of a total of 100 plant individuals were isolated and identified by partially sequencing the 16S rRNA gene and D1/D2 domains of the 26S rRNA gene, respectively. A total of 9 and 11 yeast and 28 and 39 bacterial OTUs was found, taking into account a 3% (OTU0.03) and 1% sequence dissimilarity cut-off (OTU0.01). OTU richness at the plant population level (i.e. the number of OTUs per population) was low for yeasts (mean: 1.7, range: 0–4 OTUs0.01/0.03 per population), whereas on average 6.9 (range: 2–13) OTUs0.03 and 7.9 (range 2–16) OTUs0.01 per population were found for bacteria. Both for yeasts and bacteria, OTU richness was not significantly related to plant population size. Similarity in community composition among populations was low (average Jaccard index: 0.14), and did not decline with increasing distance between populations. Conclusions/Significance We found low similarity in microbial community structure among populations, suggesting that the assembly of nectar microbiota is to a large extent context-dependent. Although the precise factors that affect variation in microbial community structure in floral nectar require further study, our results indicate that both local and regional processes may contribute to among-population variation in microbial community structure in nectar. PMID:23536759

Among-population variation in microbial community structure in the floral nectar of the bee-pollinated forest herb Pulmonaria officinalis L.

PubMed

Jacquemyn, Hans; Lenaerts, Marijke; Brys, Rein; Willems, Kris; Honnay, Olivier; Lievens, Bart

2013-01-01

Microbial communities in floral nectar have been shown to be characterized by low levels of species diversity, yet little is known about among-plant population variation in microbial community composition. We investigated the microbial community structure (yeasts and bacteria) in floral nectar of ten fragmented populations of the bee-pollinated forest herb Pulmonaria officinalis. We also explored possible relationships between plant population size and microbial diversity in nectar, and related microbial community composition to the distance separating plant populations. Culturable bacteria and yeasts occurring in the floral nectar of a total of 100 plant individuals were isolated and identified by partially sequencing the 16S rRNA gene and D1/D2 domains of the 26S rRNA gene, respectively. A total of 9 and 11 yeast and 28 and 39 bacterial OTUs was found, taking into account a 3% (OTU0.03) and 1% sequence dissimilarity cut-off (OTU0.01). OTU richness at the plant population level (i.e. the number of OTUs per population) was low for yeasts (mean: 1.7, range: 0-4 OTUs0.01/0.03 per population), whereas on average 6.9 (range: 2-13) OTUs0.03 and 7.9 (range 2-16) OTUs0.01 per population were found for bacteria. Both for yeasts and bacteria, OTU richness was not significantly related to plant population size. Similarity in community composition among populations was low (average Jaccard index: 0.14), and did not decline with increasing distance between populations. We found low similarity in microbial community structure among populations, suggesting that the assembly of nectar microbiota is to a large extent context-dependent. Although the precise factors that affect variation in microbial community structure in floral nectar require further study, our results indicate that both local and regional processes may contribute to among-population variation in microbial community structure in nectar.

Validity and reliability of 6-a-side small-sided game locomotor performance in assessing physical fitness in football players.

PubMed

Stevens, Tom Gerardus Antonia; De Ruiter, Cornelis Johannes; Beek, Peter Jan; Savelsbergh, Geert Jozef Peter

2016-01-01

In order to determine whether small-sided game (SSG) locomotor performance can serve as a fitness indicator, we (1) compared 6-a-side (6v6) SSG-intensity of players varying in fitness and skill, (2) examined the relationship of the 6v6-SSG and Yo-Yo IR2 and (3) assessed the reliability of the 6v6-SSG. Thirty-three professional senior, 30 professional youth, 62 amateur and 16 professional woman football players performed 4 × 7 min 6v6-SSGs recorded by a Local Position Measurement system. A substantial subgroup (N = 113) also performed the Yo-Yo IR2. Forty-seven amateur players performed two or three 6v6-SSGs. No differences in 6v6-SSG time-motion variables were found between professional senior and professional youth players. Amateurs showed lower values than professional seniors on almost all time-motion variables (ES = 0.59-1.19). Women displayed lower high-intensity time-motion variables than all other subgroups. Total distance run during 6v6-SSG was only moderately related to Yo-Yo IR2 distance (r = 0.45), but estimated metabolic power, high speed (>14.4 km · h(-1)), high acceleration (>2 m · s(-2)), high power (>20 W · kg(-1)) and very high (35 W · kg(-1)) power showed higher correlations (r = 0.59-0.70) with Yo-Yo IR2 distance. Intraclass correlation coefficient values were higher for total distance (0.84) than other time-motion variables (0.74‒0.78). Although total distance and metabolic power during 6v6-SSG showed good reproducibility (coefficient of variation (CV) < 5%), CV was higher (8-14%) for all high-intensity time-motion variables. It was therefore concluded that standardised SSG locomotor performance cannot serve used as a valid and reliable fitness indicator for individual players.

Utilisation of a direct access echocardiography service by general practitioners in a remote and rural area--distance and rurality are not barriers to referral.

PubMed

Choo, Wai K; McGeary, Katie; Farman, Colin; Greyling, Andre; Cross, Stephen J; Leslie, Stephen J

2014-01-01

This study aimed to examine whether general practitioner (GP) practice locations in remote and rural areas affected the pattern of direct access echocardiography referral and to assess any variations in echocardiographic findings. All referrals made by all GP practices in the Scottish Highlands over a 36-month period were analysed. Referral patterns were examined according to distance and rurality based on the Scottish Government's Urban-Rural Classification. Reasons for referral and cardiac abnormality detection rates were also examined. In total, 1188 referrals were made from 49 different GP practices; range of referral rates was 0.3-20.1 per 1000 population with a mean of 6.5 referrals per 1000 population. Referral rates were not significantly different between urban and rural practices after correction for population size. There was no correlation between the referral rates and the distance from the centre (r2=0.004, p=0.65). The most common reason for referral was the presence of new murmur (46%). The most common presenting symptom was breathlessness (44%). Overall, 28% of studies had significant abnormal findings requiring direct input from a cardiologist. There was no clear relationship between referral rates and cardiac abnormality detection rates (r2=0.07, p=0.37). The average cardiac abnormality detection rate was 56%, (range 52-60%), with no variation based on rurality (p=0.891). In this cohort, rurality and distance were not barriers to an equitable direct access echocardiography service. Cardiac abnormality detection rates are consistent with that of other studies.

Floating and Tether-Coupled Adhesion of Bacteria to Hydrophobic and Hydrophilic Surfaces

PubMed Central

2018-01-01

Models for bacterial adhesion to substratum surfaces all include uncertainty with respect to the (ir)reversibility of adhesion. In a model, based on vibrations exhibited by adhering bacteria parallel to a surface, adhesion was described as a result of reversible binding of multiple bacterial tethers that detach from and successively reattach to a surface, eventually making bacterial adhesion irreversible. Here, we use total internal reflection microscopy to determine whether adhering bacteria also exhibit variations over time in their perpendicular distance above surfaces. Streptococci with fibrillar surface tethers showed perpendicular vibrations with amplitudes of around 5 nm, regardless of surface hydrophobicity. Adhering, nonfibrillated streptococci vibrated with amplitudes around 20 nm above a hydrophobic surface. Amplitudes did not depend on ionic strength for either strain. Calculations of bacterial energies from their distances above the surfaces using the Boltzman equation showed that bacteria with fibrillar tethers vibrated as a harmonic oscillator. The energy of bacteria without fibrillar tethers varied with distance in a comparable fashion as the DLVO (Derjaguin, Landau, Verwey, and Overbeek)-interaction energy. Distance variations above the surface over time of bacteria with fibrillar tethers are suggested to be governed by the harmonic oscillations, allowed by elasticity of the tethers, piercing through the potential energy barrier. Bacteria without fibrillar tethers “float” above a surface in the secondary energy minimum, with their perpendicular displacement restricted by their thermal energy and the width of the secondary minimum. The distinction between “tether-coupled” and “floating” adhesion is new, and may have implications for bacterial detachment strategies. PMID:29649869

No relationship exists between urinary NT-proBNP and GPS technology in professional rugby union.

PubMed

Lindsay, Angus; Lewis, John G; Gill, Nicholas; Draper, Nick; Gieseg, Steven P

2017-08-01

We investigated the level of cardiovascular stress associated with professional rugby union and whether these changes could be explained through external workload systems like GPS and video analysis. Urine samples (14 in game one and 13 in game two) were collected from professional rugby players before, immediately post- and 36h post-play in two consecutive games. Urine was analysed for NT-proBNP by ELISA. Comparison with GPS (player-load and distance covered at specific speed bands) and video analysis (total impacts) were conducted. There was a significant increase in urinary NT-proBNP during game one (31.6±5.4 to 53.5±10.8pg/mL) and game two (35.4±3.9 to 49.8±11.7pg/mL) that did not correlate with the number of impacts, total distance covered, distance covered at pre-determined speed bands or player-load. Concentrations returned to pre-game concentrations 36h post-game whilst a large inter-individual variation in NT-proBNP was observed among players (p<0.001). Professional rugby union causes a transient increase in cardiovascular stress that seems to be independent of the external workload characteristics of a player. Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Strategies for preventing invasive plant outbreaks after prescribed fire in ponderosa pine forest

USGS Publications Warehouse

Symstad, Amy J.; Newton, Wesley E.; Swanson, Daniel J.

2014-01-01

Land managers use prescribed fire to return a vital process to fire-adapted ecosystems, restore forest structure from a state altered by long-term fire suppression, and reduce wildfire intensity. However, fire often produces favorable conditions for invasive plant species, particularly if it is intense enough to reveal bare mineral soil and open previously closed canopies. Understanding the environmental or fire characteristics that explain post-fire invasive plant abundance would aid managers in efficiently finding and quickly responding to fire-caused infestations. To that end, we used an information-theoretic model-selection approach to assess the relative importance of abiotic environmental characteristics (topoedaphic position, distance from roads), pre-and post-fire biotic environmental characteristics (forest structure, understory vegetation, fuel load), and prescribed fire severity (measured in four different ways) in explaining invasive plant cover in ponderosa pine forest in South Dakota’s Black Hills. Environmental characteristics (distance from roads and post-fire forest structure) alone provided the most explanation of variation (26%) in post-fire cover of Verbascum thapsus (common mullein), but a combination of surface fire severity and environmental characteristics (pre-fire forest structure and distance from roads) explained 36–39% of the variation in post-fire cover of Cirsium arvense (Canada thistle) and all invasives together. For four species and all invasives together, their pre-fire cover explained more variation (26–82%) in post-fire cover than environmental and fire characteristics did, suggesting one strategy for reducing post-fire invasive outbreaks may be to find and control invasives before the fire. Finding them may be difficult, however, since pre-fire environmental characteristics explained only 20% of variation in pre-fire total invasive cover, and less for individual species. Thus, moderating fire intensity or targeting areas of high severity for post-fire invasive control may be the most efficient means for reducing the chances of post-fire invasive plant outbreaks when conducting prescribed fires in this region.

Eddington-limited X-Ray Bursts as Distance Indicators. I. Systematic Trends and Spherical Symmetry in Bursts from 4U 1728-34

NASA Astrophysics Data System (ADS)

Galloway, Duncan K.; Psaltis, Dimitrios; Chakrabarty, Deepto; Muno, Michael P.

2003-06-01

We investigate the limitations of thermonuclear X-ray bursts as a distance indicator for the weakly magnetized accreting neutron star 4U 1728-34. We measured the unabsorbed peak flux of 81 bursts in public data from the Rossi X-Ray Timing Explorer (RXTE). The distribution of peak fluxes was bimodal: 66 bursts exhibited photospheric radius expansion (presumably reaching the local Eddington limit) and were distributed about a mean bolometric flux of 9.2×10-8ergscm-2s-1, while the remaining (non-radius expansion) bursts reached 4.5×10-8ergscm-2s-1, on average. The peak fluxes of the radius expansion bursts were not constant, exhibiting a standard deviation of 9.4% and a total variation of 46%. These bursts showed significant correlations between their peak flux and the X-ray colors of the persistent emission immediately prior to the burst. We also found evidence for quasi-periodic variation of the peak fluxes of radius expansion bursts, with a timescale of ~=40 days. The persistent flux observed with RXTE/ASM over 5.8 yr exhibited quasi-periodic variability on a similar timescale. We suggest that these variations may have a common origin in reflection from a warped accretion disk. Once the systematic variation of the peak burst fluxes is subtracted, the residual scatter is only ~=3%, roughly consistent with the measurement uncertainties. The narrowness of this distribution strongly suggests that (1) the radiation from the neutron star atmosphere during radius expansion episodes is nearly spherically symmetric and (2) the radius expansion bursts reach a common peak flux that may be interpreted as a standard candle intensity. Adopting the minimum peak flux for the radius expansion bursts as the Eddington flux limit, we derive a distance for the source of 4.4-4.8 kpc (assuming RNS=10 km), with the uncertainty arising from the probable range of the neutron star mass MNS=1.4-2 Msolar.

Geographic variation and acoustic structure of the underwater vocalization of harbor seal (Phoca vitulina) in Norway, Sweden and Scotland.

PubMed

Bjørgesaeter, Anders; Ugland, Karl Inne; Bjørge, Arne

2004-10-01

The male harbor seal (Phoca vitulina) produces broadband nonharmonic vocalizations underwater during the breeding season. In total, 120 vocalizations from six colonies were analyzed to provide a description of the acoustic structure and for the presence of geographic variation. The complex harbor seal vocalizations may be described by how the frequency bandwidth varies over time. An algorithm that identifies the boundaries between noise and signal from digital spectrograms was developed in order to extract a frequency bandwidth contour. The contours were used as inputs for multivariate analysis. The vocalizations' sound types (e.g., pulsed sound, whistle, and broadband nonharmonic sound) were determined by comparing the vocalizations' spectrographic representations with sound waves produced by known sound sources. Comparison between colonies revealed differences in the frequency contours, as well as some geographical variation in use of sound types. The vocal differences may reflect a limited exchange of individuals between the six colonies due to long distances and strong site fidelity. Geographically different vocal repertoires have potential for identifying discrete breeding colonies of harbor seals, but more information is needed on the nature and extent of early movements of young, the degree of learning, and the stability of the vocal repertoire. A characteristic feature of many vocalizations in this study was the presence of tonal-like introductory phrases that fit into the categories pulsed sound and whistles. The functions of these phrases are unknown but may be important in distance perception and localization of the sound source. The potential behavioral consequences of the observed variability may be indicative of adaptations to different environmental properties influencing determination of distance and direction and plausible different male mating tactics.

Status, distribution and morphometric/meristic characteristics of Cobitis elongata Heckel et Kner 1858 from Slovenia.

PubMed

Povz, Meta; Sumer, Suzana

2003-01-01

Cobitis elongata Heckel et Kner inhabits the rivers Sava, Kolpa, Krka, Gracnica and Hudinja (the Danube river basin). The species is common in its distribution area. In the Red List of endangered Pisces and Cyclostomata in Slovenia, it is classified as endangered. Status and distribution data of the species from previous reports and recent research were summarized. A total of 31 specimens from the river Kolpa were morphologically studied. Sixteen morphometric and four meristic characteristics were analysed using standard numerical taxonomic techniques. 99.8% of the total variation of standard length was explained by preanal distance, dorsal and ventral fin lengths as well as minimum body height.

Generalising Ward's Method for Use with Manhattan Distances.

PubMed

Strauss, Trudie; von Maltitz, Michael Johan

2017-01-01

The claim that Ward's linkage algorithm in hierarchical clustering is limited to use with Euclidean distances is investigated. In this paper, Ward's clustering algorithm is generalised to use with l1 norm or Manhattan distances. We argue that the generalisation of Ward's linkage method to incorporate Manhattan distances is theoretically sound and provide an example of where this method outperforms the method using Euclidean distances. As an application, we perform statistical analyses on languages using methods normally applied to biology and genetic classification. We aim to quantify differences in character traits between languages and use a statistical language signature based on relative bi-gram (sequence of two letters) frequencies to calculate a distance matrix between 32 Indo-European languages. We then use Ward's method of hierarchical clustering to classify the languages, using the Euclidean distance and the Manhattan distance. Results obtained from using the different distance metrics are compared to show that the Ward's algorithm characteristic of minimising intra-cluster variation and maximising inter-cluster variation is not violated when using the Manhattan metric.

The Influence Of Team Rating On Running Performance In Elite Gaelic Football.

PubMed

Mangan, Shane; Malone, Shane; Ryan, Martin; Gahan, Jason Mc; Warne, Joe; Martin, Denise; O'Neill, Cian; Burns, Con; Collins, Kieran

2017-11-06

It is currently unknown how team rating influences running performance in Gaelic football. GPS technologies were used to quantify match-running performance within 5 elite Gaelic football teams over a period of 5 years (2012-2016). In total 780 player data sets were collected over 95 matches. Running performance variables included total distance, high-speed distance (≥17 km h) and the percentage of high-speed distance. Team ratings were determined objectively using the Elo Ratings System for Gaelic football. Reference team rating had trivial effects on total distance (p = 0.011, partial η2 = 0.008) and high-speed distance (p = 0.011, partial η2 = 0.008). Opposition team rating had small effects on total distance (p = 0.005, partial η2 = 0.016) and high-speed distance (p = 0.001, partial η2 = 0.020). Top tier teams cover greater total distances and high-speed distance than lower tier teams. Players cover considerably less total distance and high-speed distance against tier 3 and tier 4 teams. Tier 1 players ran a significantly higher percentage of distance at high-speed, than players who played for tier 2 teams (p = 0.020). The competitive advantage of top tier Gaelic football teams is closely linked with their ability to demonstrate a higher physical intensity than lower tier teams.

Analysis of physical match performance in English Premier League soccer referees with particular reference to first half and player work rates.

PubMed

Weston, Matthew; Castagna, Carlo; Impellizzeri, Franco M; Rampinini, Ermanno; Abt, Grant

2007-12-01

The aim of the present study was to examine the influence of first half activity, overall match intensity and seasonal variation on the physical match performances of English Premier League football referees. Match analysis data was collected using the Prozone match analysis system from 19 full-time professional referees during a total of 254 matches in the 2004-2005 season. Physical match performances were classified into three separate categories: 1, total distance covered (TD); 2, high-intensity running distance (running speed>5.5m/s, HIR); 3, average distance from infringements (DI). Using these match activity variables the influence of first half TD and HIR distances on second half activities and also the influence of players' match activities upon the referees' physical match performances were examined. The main finding of the present study was that the physical match performances of the referees were partly related to those of the players, in that the referees' HIR correlated with players' HIR (r=0.43, p<0.0001, n=212). Furthermore, first half TD and HIR distances were found to be related to second half coverage in referees (r=0.47 and r=0.52, respectively, p<0.001, n=254). These results demonstrate a need to assess the overall match intensity prior to examining the physical match performance of the referee. Further examination is required as to whether reduced physical performances in the second half of matches are a consequence of referee fatigue, tactical strategies on behalf of the referee or reduced player match activities resulting in a slower tempo of match.

Both natural selection and isolation by distance explain phenotypic divergence in bill size and body mass between South Australian little penguin colonies.

PubMed

Colombelli-Négrel, Diane

2016-11-01

Morphological variation between populations of the same species can arise as a response to genetic variation, local environmental conditions, or a combination of both. In this study, I examined small-scale geographic variation in bill size and body mass in little penguins ( Eudyptula minor ) across five breeding colonies in South Australia separated by <150 km. To help understand patterns driving the differences, I investigated these variations in relation to environmental parameters (air temperature, sea surface temperature, and water depth) and geographic distances between the colonies. I found substantial morphological variation among the colonies for body mass and bill measurements (except bill length). Colonies further located from each other showed greater morphological divergence overall than adjacent colonies. In addition, phenotypic traits were somewhat correlated to environmental parameters. Birds at colonies surrounded by hotter sea surface temperatures were heavier with longer and larger bills. Birds with larger and longer bills were also found at colonies surrounded by shallower waters. Overall, the results suggest that both environmental factors (natural selection) and interpopulation distances (isolation by distance) are causes of phenotypic differentiation between South Australian little penguin colonies.

Dependency distance distribution - from the perspective of genre variation. Comment on "Dependency distance: a new perspective on syntactic patterns in natural languages" by Haitao Liu et al.

NASA Astrophysics Data System (ADS)

Wang, Yaqin

2017-07-01

Language can be regarded as a system where different components fit together, according to Saussure [1]. Likewise, the central axiom of synergetic linguistic is that language is a self-organized and self-adapting system. One of its main concerns is to view language as ;a psycho-social phenomenon and a biological-cognitive one at the same time; [2, 760]. Based on this assumption, Liu, Xu and Liang propose a novel approach, i.e., dependency distance, to study the general tendency hidden beneath diverse human languages [3]. As the authors describe in sections 1-3, variations within and between human languages all show the similar tendency towards dependency distance minimization (DDM). In sections 4-5, they introduce certain syntactic patterns related to both short and long dependency distances. However, the effect of genre seems to be given less sufficient attention by the authors. A study suggests that different distributions of closeness and degree centralities across genres can broaden the understanding of dependency distance distribution [4]. Another one shows that different genres have different parameters in terms of modeling dependency distance distribution [5]. Further research on the genre variation, therefore, can provide additional support for this issue.

[Effect of a surgical mask on six minute walking distance].

PubMed

Person, E; Lemercier, C; Royer, A; Reychler, G

2018-03-01

Six minutes walking test (6MWT) is regularly used in pulmonology. To minimize the risk of cross-infection, some patients must wear surgical mask at rest and sometimes during exercise. To evaluate the effect of wearing a surgical mask during 6MWT in healthy subjects. It is a prospective study on 44 healthy subjects. After a first 6MWT for training, they performed randomly two 6MWT: with or without a surgical mask. Distance and dyspnea, heart rate and saturation variations were recorded. Distance was not modified by the mask (P=0.99). Dyspnea variation was significantly higher with surgical mask (+5.6 vs. +4.6; P<0.001) and the difference was clinically relevant. No difference was found for the variation of other parameters. Wearing a surgical mask modifies significantly and clinically dyspnea without influencing walked distance. Copyright © 2017 SPLF. Published by Elsevier Masson SAS. All rights reserved.

Space-based Coronagraphic Imaging Polarimetry of the TW Hydrae Disk: Shedding New Light on Self-shadowing Effects

NASA Astrophysics Data System (ADS)

Poteet, Charles A.; Chen, Christine H.; Hines, Dean C.; Perrin, Marshall D.; Debes, John H.; Pueyo, Laurent; Schneider, Glenn; Mazoyer, Johan; Kolokolova, Ludmilla

2018-06-01

We present Hubble Space Telescope Near-Infrared Camera and Multi-Object Spectrometer coronagraphic imaging polarimetry of the TW Hydrae protoplanetary disk. These observations simultaneously measure the total and polarized intensity, allowing direct measurement of the polarization fraction across the disk. In accord with the self-shadowing hypothesis recently proposed by Debes et al., we find that the total and polarized intensity of the disk exhibits strong azimuthal asymmetries at projected distances consistent with the previously reported bright and dark ring-shaped structures (∼45–99 au). The sinusoidal-like variations possess a maximum brightness at position angles near ∼268°–300° and are up to ∼28% stronger in total intensity. Furthermore, significant radial and azimuthal variations are also detected in the polarization fraction of the disk. In particular, we find that regions of lower polarization fraction are associated with annuli of increased surface brightness, suggesting that the relative proportion of multiple-to-single scattering is greater along the ring and gap structures. Moreover, we find strong (∼20%) azimuthal variation in the polarization fraction along the shadowed region of the disk. Further investigation reveals that the azimuthal variation is not the result of disk flaring effects, but is instead from a decrease in the relative contribution of multiple-to-single scattering within the shadowed region. Employing a two-layer scattering surface, we hypothesize that the diminished contribution in multiple scattering may result from shadowing by an inclined inner disk, which prevents direct stellar light from reaching the optically thick underlying surface component.

The coupling between hydrodynamic and purification efficiencies of ecological porous spur-dike in field drainage ditch

NASA Astrophysics Data System (ADS)

Rao, Lei; Wang, Pei-fang; Dai, Qing-song; Wang, Chao

2018-05-01

In this study, a series of ecological porous spur-dikes are arranged in an experiment channel to simulate a real field drainage ditch. The inside and outside flow fields of spur-dikes are determined by numerical simulations and experimental methods. An Ammonia-Nitrogen (NH3-N) degradation evaluation model is built to calculate the pollution removal rate by coupling with the inner flow field of the porous spur-dikes. The variations of the total pollutant removal rate in the channel are discussed in terms of different porosities and gap distances between spur-dikes and inlet flow velocities. It is indicated that a reasonable parameter matching of the porosity and the gap distance with the flow velocity of the ditch can bring about a satisfactory purification efficiency with a small delivery quantity of ecological porous materials.

Invariance of evoked-potential echo-responses to target strength and distance in an echolocating false killer whale

NASA Astrophysics Data System (ADS)

Supin, Alexander Ya.; Nachtigall, Paul E.; Au, Whitlow W. L.; Breese, Marlee

2005-06-01

Brain auditory evoked potentials (AEPs) were recorded in a false killer whale Pseudorca crassidens trained to accept suction-cup EEG electrodes and to detect targets by echolocation. AEP collection was triggered by echolocation pulses transmitted by the animal. The target strength varied from -22 to -40 dB the distance varied from 1.5 to 6 m. All the records contained two AEP sets: the first one of a constant latency (transmission-related AEP) and a second one with a delay proportional to the distance (echo-related AEP). The amplitude of echo-related AEPs was almost independent of both target strength and distance, though combined variation of these two parameters resulted in echo intensity variation within a range of 42 dB. The amplitude of transmission-related AEPs was independent of distance but dependent on target strength: the less the target strength, the higher the amplitude. Recording of transmitted pulses has not shown their intensity dependence on target strength. It is supposed that the constancy of echo-related AEP results from variation of hearing sensitivity depending on the target strength and release of echo-related responses from masking by transmitted pulses depending on the distance. .

Invariance of evoked-potential echo-responses to target strength and distance in an echolocating false killer whale.

PubMed

Supin, Alexander Ya; Nachtigall, Paul E; Au, Whitlow W L; Breese, Marlee

2005-06-01

Brain auditory evoked potentials (AEPs) were recorded in a false killer whale Pseudorca crassidens trained to accept suction-cup EEG electrodes and to detect targets by echolocation. AEP collection was triggered by echolocation pulses transmitted by the animal. The target strength varied from -22 to -40 dB; the distance varied from 1.5 to 6 m. All the records contained two AEP sets: the first one of a constant latency (transmission-related AEP) and a second one with a delay proportional to the distance (echo-related AEP). The amplitude of echo-related AEPs was almost independent of both target strength and distance, though combined variation of these two parameters resulted in echo intensity variation within a range of 42 dB. The amplitude of transmission-related AEPs was independent of distance but dependent on target strength: the less the target strength, the higher the amplitude. Recording of transmitted pulses has not shown their intensity dependence on target strength. It is supposed that the constancy of echo-related AEP results from variation of hearing sensitivity depending on the target strength and release of echo-related responses from masking by transmitted pulses depending on the distance.

Preliminary assessment of the variability of UK offshore wind speed as a function of distance to the coast

NASA Astrophysics Data System (ADS)

Soler-Bientz, Rolando; Watson, Simon

2016-09-01

In the UK, there is an interest in the expected offshore wind resource given ambitious national plans to expand offshore capacity. There is also an increasing interest in alternative datasets to evaluate wind seasonal and inter-annual cycles which can be very useful in the initial stages of the design of wind farms in order to identify prospective areas where local measurements can then be applied to determine small-scale variations in the marine wind climate. In this paper we analyse both MERRA2 reanalysis data and measured offshore mast data to determine patterns in wind speed variation and how they change as a function of the distance from the coast. We also identify an empirical expression to estimate wind speed based on the distance from the coast. From the analysis, it was found that the variations of the seasonal cycles seem to be almost independent of the distance to the nearest shore and that they are an order of magnitude larger than the variations of the diurnal cycles. It was concluded that the diurnal variations decreased to less than a half for places located more than 100km from the nearest shore and that the data from the MERRA2 reanalysis grid points give an under-prediction of the average values of wind speed for both the diurnal and seasonal cycles. Finally, even though the two offshore masts were almost the same nearest distance from the coast and were geographically relatively close, they exhibited significantly different behaviour in terms of the strength of their diurnal and seasonal cycles which may be due to the distance from the coast for the prevailing wind direction being quite different for the two sites.

CLUSFAVOR 5.0: hierarchical cluster and principal-component analysis of microarray-based transcriptional profiles

PubMed Central

Peterson, Leif E

2002-01-01

CLUSFAVOR (CLUSter and Factor Analysis with Varimax Orthogonal Rotation) 5.0 is a Windows-based computer program for hierarchical cluster and principal-component analysis of microarray-based transcriptional profiles. CLUSFAVOR 5.0 standardizes input data; sorts data according to gene-specific coefficient of variation, standard deviation, average and total expression, and Shannon entropy; performs hierarchical cluster analysis using nearest-neighbor, unweighted pair-group method using arithmetic averages (UPGMA), or furthest-neighbor joining methods, and Euclidean, correlation, or jack-knife distances; and performs principal-component analysis. PMID:12184816

Influence of urban vegetation on air pollution and noise exposure - A case study in Gothenburg, Sweden.

PubMed

Klingberg, Jenny; Broberg, Malin; Strandberg, Bo; Thorsson, Pontus; Pleijel, Håkan

2017-12-01

Air pollution levels (NO 2 , PAHs, O 3 ) were investigated, before (BLE) and after (ALE) leaf emergence, in the urban landscape of Gothenburg, Sweden. The aims were to study the 1) spatial and temporal variation in pollution levels between urban green areas, 2) effect of urban vegetation on air pollution levels at the same distance from a major emission source (traffic route), 3) improvement of urban air quality in urban parks compared to adjacent sites near traffic, 4) correlation between air pollution and noise in a park. O 3 varied little over the urban landscape. NO 2 varied strongly and was higher in situations strongly influenced by traffic. Four PAH variables were included: total PAH, total particle-bound PAH, the quantitatively important gaseous phenanthrene and the highly toxic particle-bound benzo(a)pyrene. The variation of PAHs was similar to NO 2 , but for certain PAHs the difference between highly and less polluted sites was larger than for NO 2 . At a vegetated site, NO 2 and particulate PAH levels were lower than at a non-vegetated site at a certain distance from a busy traffic route. This effect was significantly larger ALE compared to BLE for NO 2 , indicating green leaf area to be highly significant factor for air quality improvement. For particulate PAHs, the effect was similar BLE and ALE, indicating that tree bark and branches also could be an important factor in reducing air pollution. Parks represented considerably cleaner local environments (park effect), which is likely to be a consequence of both a dilution (distance effect) and deposition. Noise and air pollution (NO 2 and PAH) levels were strongly correlated. Comparison of noise levels BLE and ALE also showed that the presence of leaves significantly reduced noise levels. Our results are evidence that urban green spaces are beneficial for urban environmental quality, which is important to consider in urban planning. Copyright © 2017 Elsevier B.V. All rights reserved.

Voluntary wheel running in dystrophin-deficient (mdx) mice: Relationships between exercise parameters and exacerbation of the dystrophic phenotype.

PubMed

Smythe, Gayle M; White, Jason D

2011-12-18

Voluntary wheel running can potentially be used to exacerbate the disease phenotype in dystrophin-deficient mdx mice. While it has been established that voluntary wheel running is highly variable between individuals, the key parameters of wheel running that impact the most on muscle pathology have not been examined in detail. We conducted a 2-week test of voluntary wheel running by mdx mice and the impact of wheel running on disease pathology. There was significant individual variation in the average daily distance (ranging from 0.003 ± 0.005 km to 4.48 ± 0.96 km), culminating in a wide range (0.040 km to 67.24 km) of total cumulative distances run by individuals. There was also variation in the number and length of run/rest cycles per night, and the average running rate. Correlation analyses demonstrated that in the quadriceps muscle, a low number of high distance run/rest cycles was the most consistent indicator for increased tissue damage. The amount of rest time between running bouts was a key factor associated with gastrocnemius damage. These data emphasize the need for detailed analysis of individual running performance, consideration of the length of wheel exposure time, and the selection of appropriate muscle groups for analysis, when applying the use of voluntary wheel running to disease exacerbation and/or pre-clinical testing of the efficacy of therapeutic agents in the mdx mouse.

Characteristics of Leachate and Their Effect on Shallow Groundwater Quality (Case Study : TPA Cipayung, Depok)

NASA Astrophysics Data System (ADS)

Widiastuti, Atika; Hartono, Djoko M.; Moersidik, Setyo S.; Gusniani, Irma

2018-03-01

The problems arising from landfill activity is leaked leachate that is not absorbed well into leachate stabilization pond which furthermore contaminates shallow groundwater around landfill, include Cipayung landfill. The aims of this study is to determine the characteristics of leachate and their effect on shallow groundwater quality around landfill based on temperature, pH, Total Suspended Solids (TSS), Biological Oxygen Demand (BOD), Chemical Oxygen Demand (COD), Total Nitrogen (TN), Mercury (Hg), and fecal coliform. Data were analyzed based on leachate samples at influent point, effluent point, and 7 sampling points of residents’s well with distance variation every 100 meters within 300 meters radius having leachate stabilization pond as benchmark. According to the standard of Indonesia’s Ministry of Environment and Forestry law No. 59 of 2016, the results showed that leachate quality was still above the standard of BOD, COD, and Total Nitrogen parameters; 4178.0 mg/L, 70556.0 mg/L and 373.3 mg/L for influent point, and 3142.0 mg/L, 9055.2 mg/L, and 350 mg/L for the effluent point. Pollution Index of shallow groundwater is between lightly and moderately contaminated. This study showed that the further the distance between sampling point and leachate stabilization pond is, the lower the Polution Index is.

Genetic analysis of QTL for eye cross and eye diameter in common carp (Cyprinus carpio L.) using microsatellites and SNPs.

PubMed

Jin, S B; Zhang, X F; Lu, J G; Fu, H T; Jia, Z Y; Sun, X W

2015-04-17

A group of 107 F1 hybrid common carp was used to construct a linkage map using JoinMap 4.0. A total of 4877 microsatellite and single nucleotide polymorphism (SNP) markers isolated from a genomic library (978 microsatellite and 3899 SNP markers) were assigned to construct the genetic map, which comprised 50 linkage groups. The total length of the linkage map for the common carp was 4775.90 cM with an average distance between markers of 0.98 cM. Ten quantitative trait loci (QTL) were associated with eye diameter, corresponding to 10.5-57.2% of the total phenotypic variation. Twenty QTL were related to eye cross, contributing to 10.8-36.9% of the total phenotypic variation. Two QTL for eye diameter and four QTL for eye cross each accounted for more than 20% of the total phenotypic variation and were considered to be major QTL. One growth factor related to eye diameter was observed on LG10 of the common carp genome, and three growth factors related to eye cross were observed on LG10, LG35, and LG44 of the common carp genome. The significant positive relationship of eye cross and eye diameter with other commercial traits suggests that eye diameter and eye cross can be used to assist in indirect selection for many commercial traits, particularly body weight. Thus, the growth factor for eye cross may also contribute to the growth of body weight, implying that aggregate breeding could have multiple effects. These findings provide information for future genetic studies and breeding of common carp.

A Simple Demonstration of a General Rule for the Variation of Magnetic Field with Distance

ERIC Educational Resources Information Center

Kodama, K.

2009-01-01

We describe a simple experiment demonstrating the variation in magnitude of a magnetic field with distance. The method described requires only an ordinary magnetic compass and a permanent magnet. The proposed graphical analysis illustrates a unique method for deducing a general rule of magnetostatics. (Contains 1 table and 6 figures.)

Assessment of auditory distance in a territorial songbird: accurate feat or rule of thumb?

PubMed

Naguib; Klump; Hillmann; Grießmann; Teige

2000-04-01

Territorial passerines presumably benefit from their ability to use auditory cues to judge the distance to singing conspecifics, by increasing the efficiency of their territorial defence. Here, we report data on the approach of male territorial chaffinches, Fringilla coelebs, to a loudspeaker broadcasting conspecific song simulating a rival at various distances by different amounts of song degradation. Songs were degraded digitally in a computer-simulated forest emulating distances of 0, 20, 40, 80 and 120 m. The approach distance of chaffinches towards the loudspeaker increased with increasing amounts of degradation indicating a perceptual representation of differences in distance of a sound source. We discuss the interindividual variation of male responses with respect to constraints resulting from random variation of ranging cues provided by the environmental song degradation, the perception accuracy and the decision rules. Copyright 2000 The Association for the Study of Animal Behaviour.

Multiple Weather Factors Affect Apparent Survival of European Passerine Birds

PubMed Central

Salewski, Volker; Hochachka, Wesley M.; Fiedler, Wolfgang

2013-01-01

Weather affects the demography of animals and thus climate change will cause local changes in demographic rates. In birds numerous studies have correlated demographic factors with weather but few of those examined variation in the impacts of weather in different seasons and, in the case of migrants, in different regions. Using capture-recapture models we correlated weather with apparent survival of seven passerine bird species with different migration strategies to assess the importance of selected facets of weather throughout the year on apparent survival. Contrary to our expectations weather experienced during the breeding season did not affect apparent survival of the target species. However, measures for winter severity were associated with apparent survival of a resident species, two short-distance/partial migrants and a long-distance migrant. Apparent survival of two short distance migrants as well as two long-distance migrants was further correlated with conditions experienced during the non-breeding season in Spain. Conditions in Africa had statistically significant but relatively minor effects on the apparent survival of the two long-distance migrants but also of a presumably short-distance migrant and a short-distance/partial migrant. In general several weather effects independently explained similar amounts of variation in apparent survival for the majority of species and single factors explained only relatively low amounts of temporal variation of apparent survival. Although the directions of the effects on apparent survival mostly met our expectations and there are clear predictions for effects of future climate we caution against simple extrapolations of present conditions to predict future population dynamics. Not only did weather explains limited amounts of variation in apparent survival, but future demographics will likely be affected by changing interspecific interactions, opposing effects of weather in different seasons, and the potential for phenotypic and microevolutionary adaptations. PMID:23593131

Frequency Dependence of Helioseismic Measurements of the Center-to-Limb Effect and Flow-induced Travel-time Shifts

NASA Astrophysics Data System (ADS)

Chen, Ruizhu; Zhao, Junwei

2018-02-01

Time–distance helioseismology measures acoustic travel times to infer the structure and flow field of the solar interior; however, both the mean travel times and the travel-time shifts suffer systematic center-to-limb variations, which complicate the interpretation and inversions of the time–distance measurements. In particular, the center-to-limb variation in travel-time shifts (CtoL effect) has a significant impact on the inference of the Sun’s meridional circulation, and needs to be removed from the helioseismic measurements, although the observational properties and the physical cause of the CtoL effect have yet to be investigated. In this study, we measure the CtoL effect in the frequency domain using Doppler-velocity data from the Solar Dynamics Observatory/Helioseismic and Magnetic Imager, and study its properties as a function of disk-centric distance, travel distance, and frequency of acoustic waves. It is found that the CtoL effect has a significant frequency dependence—it reverses sign at a frequency around 5.4 mHz and reaches maximum at around 4.0 mHz before the sign reversal. The tendency of frequency dependence varies with disk-centric distance in a way that both the sign-reversal frequency and the maximum-value frequency decrease closer to the limb. The variation tendency does not change with travel distance, but the variation magnitude is approximately proportional to travel distance. For comparison, the flow-induced travel-time shifts show little frequency dependence. These observational properties provide more clues on the nature of the CtoL effect, and also possibly lead to new ways of effect-removal for a more robust determination of the deep meridional flow.

Effects of detector-source distance and detector bias voltage variations on time resolution of general purpose plastic scintillation detectors.

PubMed

Ermis, E E; Celiktas, C

2012-12-01

Effects of source-detector distance and the detector bias voltage variations on time resolution of a general purpose plastic scintillation detector such as BC400 were investigated. (133)Ba and (207)Bi calibration sources with and without collimator were used in the present work. Optimum source-detector distance and bias voltage values were determined for the best time resolution by using leading edge timing method. Effect of the collimator usage on time resolution was also investigated. Copyright © 2012 Elsevier Ltd. All rights reserved.

Genomic validation of the differential preservation of population history in modern human cranial anatomy.

PubMed

Reyes-Centeno, Hugo; Ghirotto, Silvia; Harvati, Katerina

2017-01-01

In modern humans, the significant correlation between neutral genetic loci and cranial anatomy suggests that the cranium preserves a population history signature. However, there is disagreement on whether certain parts of the cranium preserve this signature to a greater degree than other parts. It is also unclear how different quantitative measures of phenotype affect the association of genetic variation and anatomy. Here, we revisit these matters by testing the correlation of genetic distances and various phenotypic distances for ten modern human populations. Geometric morphometric shape data from the crania of adult individuals (n = 224) are used to calculate phenotypic P ST , Procrustes, and Mahalanobis distances. We calculate their correlation to neutral genetic distances, F ST , derived from single nucleotide polymorphisms (SNPs). We subset the cranial data into landmark configurations that include the neurocranium, the face, and the temporal bone in order to evaluate whether these cranial regions are differentially correlated to neutral genetic variation. Our results show that P ST , Mahalanobis, and Procrustes distances are correlated with F ST distances to varying degrees. They indicate that overall cranial shape is significantly correlated with neutral genetic variation. Of the component parts examined, P ST distances for both the temporal bone and the face have a stronger association with F ST distances than the neurocranium. When controlling for population divergence time, only the whole cranium and the temporal bone have a statistically significant association with F ST distances. Our results confirm that the cranium, as a whole, and the temporal bone can be used to reconstruct modern human population history. © 2016 Wiley Periodicals, Inc.

Travel Distance and the Use of Inpatient Care among Patients with Schizophrenia

PubMed Central

Hemenway, David; Kawachi, Ichiro; Subramanian, S. V.; Chen, Wei J.

2009-01-01

This study examines the variations in the use of inpatient care that can be explained by travel distance among patients with schizophrenia living in Taiwan. Data were drawn from the Psychiatric Inpatient Medical Claims Database. We used mediation analysis and multilevel analysis to identify associations. Travel distance did not significantly account for lower readmission rates after an index admission, but significantly explained the longer length of stay of an index admission by 9.3 days (P < 0.001, 85% of variation) between remote and non-remote regions. Policies are discussed aimed at reducing the impact of travel distance on rural mental health care through inter-disciplinary collaboration and telepsychiatry. PMID:18512144

Regional Variation in the Structural Response and Geometrical Properties of Human Ribs

PubMed Central

Cormier, Joseph M.; Stitzel, Joel D.; Duma, Stefan M.; Matsuoka, Fumio

2005-01-01

By incorporating material and geometrical properties into a model of the human thorax one can develop an injury criterion that is a function of stress and strain of the material and not a function of the global response of the thorax. Previous research on the mechanical properties of ribs has focused on a limited set of specific ribs. For this study a total of 52 rib specimens were removed from four cadaver subjects. Variation in peak moment by thoracic region was significant (p < 0.01) with average values of 2, 2.9 and 3.9 N-m for the anterior, lateral and posterior regions respectively. Two geometrical properties, radius of gyration and distance from the neutral axis, showed significant variation by region (p < 0.0001) as well as by rib level (p = < 0.01, 0.05). The results of this study can be used to update current models of the human thorax to account for the variation in strength and geometrical properties throughout the rib cage. Accounting for the variation in rib properties by region will improve injury predictive measures and, therefore, the ability to design systems to prevent thoracic injury. PMID:16179146

Vaccination strategies for future influenza pandemics: a severity-based cost effectiveness analysis

PubMed Central

2013-01-01

Background A critical issue in planning pandemic influenza mitigation strategies is the delay between the arrival of the pandemic in a community and the availability of an effective vaccine. The likely scenario, born out in the 2009 pandemic, is that a newly emerged influenza pandemic will have spread to most parts of the world before a vaccine matched to the pandemic strain is produced. For a severe pandemic, additional rapidly activated intervention measures will be required if high mortality rates are to be avoided. Methods A simulation modelling study was conducted to examine the effectiveness and cost effectiveness of plausible combinations of social distancing, antiviral and vaccination interventions, assuming a delay of 6-months between arrival of an influenza pandemic and first availability of a vaccine. Three different pandemic scenarios were examined; mild, moderate and extreme, based on estimates of transmissibility and pathogenicity of the 2009, 1957 and 1918 influenza pandemics respectively. A range of different durations of social distancing were examined, and the sensitivity of the results to variation in the vaccination delay, ranging from 2 to 6 months, was analysed. Results Vaccination-only strategies were not cost effective for any pandemic scenario, saving few lives and incurring substantial vaccination costs. Vaccination coupled with long duration social distancing, antiviral treatment and antiviral prophylaxis was cost effective for moderate pandemics and extreme pandemics, where it saved lives while simultaneously reducing the total pandemic cost. Combined social distancing and antiviral interventions without vaccination were significantly less effective, since without vaccination a resurgence in case numbers occurred as soon as social distancing interventions were relaxed. When social distancing interventions were continued until at least the start of the vaccination campaign, attack rates and total costs were significantly lower, and increased rates of vaccination further improved effectiveness and cost effectiveness. Conclusions The effectiveness and cost effectiveness consequences of the time-critical interplay of pandemic dynamics, vaccine availability and intervention timing has been quantified. For moderate and extreme pandemics, vaccination combined with rapidly activated antiviral and social distancing interventions of sufficient duration is cost effective from the perspective of life years saved. PMID:23398722

Vaccination strategies for future influenza pandemics: a severity-based cost effectiveness analysis.

PubMed

Kelso, Joel K; Halder, Nilimesh; Milne, George J

2013-02-11

A critical issue in planning pandemic influenza mitigation strategies is the delay between the arrival of the pandemic in a community and the availability of an effective vaccine. The likely scenario, born out in the 2009 pandemic, is that a newly emerged influenza pandemic will have spread to most parts of the world before a vaccine matched to the pandemic strain is produced. For a severe pandemic, additional rapidly activated intervention measures will be required if high mortality rates are to be avoided. A simulation modelling study was conducted to examine the effectiveness and cost effectiveness of plausible combinations of social distancing, antiviral and vaccination interventions, assuming a delay of 6-months between arrival of an influenza pandemic and first availability of a vaccine. Three different pandemic scenarios were examined; mild, moderate and extreme, based on estimates of transmissibility and pathogenicity of the 2009, 1957 and 1918 influenza pandemics respectively. A range of different durations of social distancing were examined, and the sensitivity of the results to variation in the vaccination delay, ranging from 2 to 6 months, was analysed. Vaccination-only strategies were not cost effective for any pandemic scenario, saving few lives and incurring substantial vaccination costs. Vaccination coupled with long duration social distancing, antiviral treatment and antiviral prophylaxis was cost effective for moderate pandemics and extreme pandemics, where it saved lives while simultaneously reducing the total pandemic cost. Combined social distancing and antiviral interventions without vaccination were significantly less effective, since without vaccination a resurgence in case numbers occurred as soon as social distancing interventions were relaxed. When social distancing interventions were continued until at least the start of the vaccination campaign, attack rates and total costs were significantly lower, and increased rates of vaccination further improved effectiveness and cost effectiveness. The effectiveness and cost effectiveness consequences of the time-critical interplay of pandemic dynamics, vaccine availability and intervention timing has been quantified. For moderate and extreme pandemics, vaccination combined with rapidly activated antiviral and social distancing interventions of sufficient duration is cost effective from the perspective of life years saved.

Morphometric assessment of the red stripe weevils, Rhynchophorus vulneratus (Coleoptera: Curculionidae) from several localities in Malaysia

NASA Astrophysics Data System (ADS)

Sazali, Siti Nurlydia; Hazmi, Izfa Riza; Rahim, Faszly; Abang, Fatimah; Jemain, Abdul Aziz

2018-04-01

The recognition of intraspecific variation could enhance knowledge and understanding on the population divergence that might be resulted from different geographical areas. To study the possible effect derived from different locations, a morphometric study of the red stripe weevils, Rhynchophorus vulneratus from different localities in Malaysia was conducted using field and voucher specimens. A total of twenty-three morphological characters were examined from 108 individuals of R. vulneratus representing population of Kota Samarahan, Mukah and central of Peninsular Malaysia. The data were subjected to univariate one-way single factor analysis of variance (ANOVA) and analysed in factor analysis using SPSS version 22.0 software. Univariate ANOVA showed that all tested variables were significantly different (p<0.05) except for mesocoxal distance (MSD), meanwhile from the factor analysis, the first three factors with eigenvalues greater than 1.0 were successfully extracted, resulting in a high variation of 82.687%. For factor 1, 39.213% of total variation was recorded, factor 2 accounted for 34.096% and factor 3 contributing to 9.377%, respectively. The mixed plotting among the twenty-three morphological characters suggests a strong correlation among the parameters examined and further statistical analysis should be conducted to include environmental factors such as habitat types, food availability and predation effect.

Genetic structure of the Mon-Khmer speaking groups and their affinity to the neighbouring Tai populations in Northern Thailand

PubMed Central

2011-01-01

Background The Mon-Khmer speaking peoples inhabited northern Thailand before the arrival of the Tai speaking people from southern China in the thirteenth century A.D. Historical and anthropological evidence suggests a close relationship between the Mon-Khmer groups and the present day majority northern Thai groups. In this study, mitochondrial and Y-chromosomal DNA polymorphisms in more than 800 volunteers from eight Mon-Khmer and ten Tai speaking populations were investigated to estimate the degree of genetic divergence between these major linguistic groups and their internal structure. Results A large fraction of genetic variation is observed within populations (about 80% and 90% for mtDNA and the Y-chromosome, respectively). The genetic divergence between populations is much higher in Mon-Khmer than in Tai speaking groups, especially at the paternally inherited markers. The two major linguistic groups are genetically distinct, but only for a marginal fraction (1 to 2%) of the total genetic variation. Genetic distances between populations correlate with their linguistic differences, whereas the geographic distance does not explain the genetic divergence pattern. Conclusions The Mon-Khmer speaking populations in northern Thailand exhibited the genetic divergence among each other and also when compared to Tai speaking peoples. The different drift effects and the post-marital residence patterns between the two linguistic groups are the explanation for a small but significant fraction of the genetic variation pattern within and between them. PMID:21672265

Population Genetic Structure of a Widespread Bat-Pollinated Columnar Cactus

PubMed Central

Bustamante, Enriquena; Búrquez, Alberto; Scheinvar, Enrique; Eguiarte, Luis Enrique

2016-01-01

Bats are the main pollinators and seed dispersers of Stenocereus thurberi, a xenogamous columnar cactus of northwestern Mexico and a good model to illustrate spatial dynamics of gene flow in long-lived species. Previous studies in this cactus showed differences among populations in the type and abundance of pollinators, and in the timing of flowering and fruiting. In this study we analyzed genetic variability and population differentiation among populations. We used three primers of ISSR to analyze within and among populations genetic variation from eight widely separated populations of S. thurberi in Sonora, Mexico. Sixty-six out of 99 of the ISSR bands (P = 66.7%) were polymorphic. Total heterozygosity for all populations sampled revealed high genetic diversity (Hsp = 0.207, HBT = 0.224). The AMOVA showed that most of the genetic variation was within populations (80.5%). At the species level, estimates of population differentiation, θ = 0.175 and θB = 0.194, indicated moderate gene flow among populations. The absence of a significant correlation between genetic and geographic distances indicated little isolation by geographic distance. The large genetic variation and diversity found in S. thurberi is consistent with its open reproductive system and the high mobility of bats, a major pollinator. However, small changes in number or kind of pollinators and seed dispersal agents, in the directionality of migratory routes, and/or in the timing of flowering and fruiting among populations, can critically affect gene flow dynamics. PMID:27015281

Genetic structure of the Mon-Khmer speaking groups and their affinity to the neighbouring Tai populations in Northern Thailand.

PubMed

Kutanan, Wibhu; Kampuansai, Jatupol; Fuselli, Silvia; Nakbunlung, Supaporn; Seielstad, Mark; Bertorelle, Giorgio; Kangwanpong, Daoroong

2011-06-15

The Mon-Khmer speaking peoples inhabited northern Thailand before the arrival of the Tai speaking people from southern China in the thirteenth century A.D. Historical and anthropological evidence suggests a close relationship between the Mon-Khmer groups and the present day majority northern Thai groups. In this study, mitochondrial and Y-chromosomal DNA polymorphisms in more than 800 volunteers from eight Mon-Khmer and ten Tai speaking populations were investigated to estimate the degree of genetic divergence between these major linguistic groups and their internal structure. A large fraction of genetic variation is observed within populations (about 80% and 90% for mtDNA and the Y-chromosome, respectively). The genetic divergence between populations is much higher in Mon-Khmer than in Tai speaking groups, especially at the paternally inherited markers. The two major linguistic groups are genetically distinct, but only for a marginal fraction (1 to 2%) of the total genetic variation. Genetic distances between populations correlate with their linguistic differences, whereas the geographic distance does not explain the genetic divergence pattern. The Mon-Khmer speaking populations in northern Thailand exhibited the genetic divergence among each other and also when compared to Tai speaking peoples. The different drift effects and the post-marital residence patterns between the two linguistic groups are the explanation for a small but significant fraction of the genetic variation pattern within and between them. © 2011 Kutanan et al; licensee BioMed Central Ltd.

Population Genetic Structure of a Widespread Bat-Pollinated Columnar Cactus.

PubMed

Bustamante, Enriquena; Búrquez, Alberto; Scheinvar, Enrique; Eguiarte, Luis Enrique

2016-01-01

Bats are the main pollinators and seed dispersers of Stenocereus thurberi, a xenogamous columnar cactus of northwestern Mexico and a good model to illustrate spatial dynamics of gene flow in long-lived species. Previous studies in this cactus showed differences among populations in the type and abundance of pollinators, and in the timing of flowering and fruiting. In this study we analyzed genetic variability and population differentiation among populations. We used three primers of ISSR to analyze within and among populations genetic variation from eight widely separated populations of S. thurberi in Sonora, Mexico. Sixty-six out of 99 of the ISSR bands (P = 66.7%) were polymorphic. Total heterozygosity for all populations sampled revealed high genetic diversity (Hsp = 0.207, HBT = 0.224). The AMOVA showed that most of the genetic variation was within populations (80.5%). At the species level, estimates of population differentiation, θ = 0.175 and θB = 0.194, indicated moderate gene flow among populations. The absence of a significant correlation between genetic and geographic distances indicated little isolation by geographic distance. The large genetic variation and diversity found in S. thurberi is consistent with its open reproductive system and the high mobility of bats, a major pollinator. However, small changes in number or kind of pollinators and seed dispersal agents, in the directionality of migratory routes, and/or in the timing of flowering and fruiting among populations, can critically affect gene flow dynamics.

Morphometry, asymmetry and variations of cerebral sulci on superolateral surface of cerebrum in autopsy cases.

PubMed

Gonul, Yucel; Songur, Ahmet; Uzun, Ibrahim; Uygur, Ramazan; Alkoc, Ozan Alper; Caglar, Veli; Kucuker, Hudaverdi

2014-09-01

The cerebral sulci are known as main microanatomical borders that serve as a gateway and surgical passage to reach the ventricles or to the deeper lesions. It is a matter of curiosity that whether there is a convergence between the morphological asymmetry and the functional asymmetry, and also its significance in surgery. The aim of this study is make morphometric measurements and evaluate asymmetry of several sulci on the lateral aspects of the cerebrum in regard to main sulci and related reference key points. A total of 100 cerebral hemispheres from 50 autopsy cadavers were examined. The lengths of several sulci on the superolateral aspect of the hemispheres and the distances between the sulci and nearby sulci and the reference key points were measured. Encountered variations were examined and photographed. Evaluation of the variations: superior frontal sulcus (SFS), inferior frontal sulcus, superior temporal sulcus (STS), precentral sulcus and postcentral sulcus were found to be discontinuous in 60, 46, 41, 84 and 70 % of the hemispheres, respectively. Evaluation of the asymmetry: the distances between SFS posterior end and longitudinal fissure, STS posterior end and lateral sulcus posterior end, as well as lengths of external occipital fissure (EOF), and discontinuous course of STS were significantly different between left and right hemispheres. There is usually a morphological partial asymmetry between the right and left hemispheres for any individual. Also, some of our measurements were found to be compatible with the ones in the literature, while others were incompatible.

Communications network design and costing model technical manual

NASA Technical Reports Server (NTRS)

Logan, K. P.; Somes, S. S.; Clark, C. A.

1983-01-01

This computer model provides the capability for analyzing long-haul trunking networks comprising a set of user-defined cities, traffic conditions, and tariff rates. Networks may consist of all terrestrial connectivity, all satellite connectivity, or a combination of terrestrial and satellite connectivity. Network solutions provide the least-cost routes between all cities, the least-cost network routing configuration, and terrestrial and satellite service cost totals. The CNDC model allows analyses involving three specific FCC-approved tariffs, which are uniquely structured and representative of most existing service connectivity and pricing philosophies. User-defined tariffs that can be variations of these three tariffs are accepted as input to the model and allow considerable flexibility in network problem specification. The resulting model extends the domain of network analysis from traditional fixed link cost (distance-sensitive) problems to more complex problems involving combinations of distance and traffic-sensitive tariffs.

A Review of Depth and Normal Fusion Algorithms

PubMed Central

Štolc, Svorad; Pock, Thomas

2018-01-01

Geometric surface information such as depth maps and surface normals can be acquired by various methods such as stereo light fields, shape from shading and photometric stereo techniques. We compare several algorithms which deal with the combination of depth with surface normal information in order to reconstruct a refined depth map. The reasons for performance differences are examined from the perspective of alternative formulations of surface normals for depth reconstruction. We review and analyze methods in a systematic way. Based on our findings, we introduce a new generalized fusion method, which is formulated as a least squares problem and outperforms previous methods in the depth error domain by introducing a novel normal weighting that performs closer to the geodesic distance measure. Furthermore, a novel method is introduced based on Total Generalized Variation (TGV) which further outperforms previous approaches in terms of the geodesic normal distance error and maintains comparable quality in the depth error domain. PMID:29389903

Distribution, enrichment and accumulation of heavy metals in coastal sediments of Alang-Sosiya ship scrapping yard, India.

PubMed

Reddy, M Srinivasa; Basha, Shaik; Sravan Kumar, V G; Joshi, H V; Ramachandraiah, G

2004-06-01

Since its inception in 1982, the Alang-Sosiya yard has become the largest ship scrapping works in the world. Several hundreds of ships arrive every year. The degree of heavy metal contamination has been studied in bulk and fine sediments from the intertidal zone of this ship scrapping yard, two stations, one on either side at 5 km distance and one reference station 60 km distance near Mahuva, towards the south. The samples have been subjected to a total digestion technique and analysed for elements: Cd, Co, Cu, Cr, Fe, Mn, Ni, Pb, Zn and Al, and %TOC. The absolute metal concentrations reflected variations in BF and FF sediment samples with organic matter content. Enrichment factors (EF) and geoaccumulation indices (Igeo) have been calculated and the relative contamination levels are assessed at these sites. At Alang-Sosiya, the enrichment of heavy metals has been observed to be relatively high.

Specificity vs. Generalizability: Emergence of Especial Skills in Classical Archery

PubMed Central

Czyż, Stanisław H.; Moss, Sarah J.

2016-01-01

There is evidence that the recall schema becomes more refined after constant practice. It is also believed that massive amounts of constant practice eventually leads to the emergence of especial skills, i.e., skills that have an advantage in performance over other actions from within the same class of actions. This advantage in performance was noticed when one-criterion practice, e.g., basketball free throws, was compared to non-practiced variations of the skill. However, there is no evidence whether multi-criterion massive amounts of practice would give an advantage to the trained variations of the skill over non-trained, i.e., whether such practice would eventually lead to the development of (multi)-especial skills. The purpose of this study was to determine whether massive amount of practice involving four criterion variations of the skill will give an advantage in performance to the criterions over the class of actions. In two experiments, we analyzed data from female (n = 8) and male classical archers (n = 10), who were required to shoot 30 shots from four accustomed distances, i.e., males at 30, 50, 70, and 90 m and females at 30, 50, 60, and 70 m. The shooting accuracy for the untrained distances (16 distances in men and 14 in women) was used to compile a regression line for distance over shooting accuracy. Regression determined (expected) values were then compared to the shooting accuracy of the trained distances. Data revealed no significant differences between real and expected results at trained distances, except for the 70 m shooting distance in men. The F-test for lack of fit showed that the regression computed for trained and non-trained shooting distances was linear. It can be concluded that especial skills emerge only after very specific practice, i.e., constant practice limited to only one variation of the skill. PMID:27547196

Specificity vs. Generalizability: Emergence of Especial Skills in Classical Archery.

PubMed

Czyż, Stanisław H; Moss, Sarah J

2016-01-01

There is evidence that the recall schema becomes more refined after constant practice. It is also believed that massive amounts of constant practice eventually leads to the emergence of especial skills, i.e., skills that have an advantage in performance over other actions from within the same class of actions. This advantage in performance was noticed when one-criterion practice, e.g., basketball free throws, was compared to non-practiced variations of the skill. However, there is no evidence whether multi-criterion massive amounts of practice would give an advantage to the trained variations of the skill over non-trained, i.e., whether such practice would eventually lead to the development of (multi)-especial skills. The purpose of this study was to determine whether massive amount of practice involving four criterion variations of the skill will give an advantage in performance to the criterions over the class of actions. In two experiments, we analyzed data from female (n = 8) and male classical archers (n = 10), who were required to shoot 30 shots from four accustomed distances, i.e., males at 30, 50, 70, and 90 m and females at 30, 50, 60, and 70 m. The shooting accuracy for the untrained distances (16 distances in men and 14 in women) was used to compile a regression line for distance over shooting accuracy. Regression determined (expected) values were then compared to the shooting accuracy of the trained distances. Data revealed no significant differences between real and expected results at trained distances, except for the 70 m shooting distance in men. The F-test for lack of fit showed that the regression computed for trained and non-trained shooting distances was linear. It can be concluded that especial skills emerge only after very specific practice, i.e., constant practice limited to only one variation of the skill.

Phylogenetic turnover along local environmental gradients in tropical forest communities.

PubMed

Baldeck, C A; Kembel, S W; Harms, K E; Yavitt, J B; John, R; Turner, B L; Madawala, S; Gunatilleke, N; Gunatilleke, S; Bunyavejchewin, S; Kiratiprayoon, S; Yaacob, A; Supardi, M N N; Valencia, R; Navarrete, H; Davies, S J; Chuyong, G B; Kenfack, D; Thomas, D W; Dalling, J W

2016-10-01

While the importance of local-scale habitat niches in shaping tree species turnover along environmental gradients in tropical forests is well appreciated, relatively little is known about the influence of phylogenetic signal in species' habitat niches in shaping local community structure. We used detailed maps of the soil resource and topographic variation within eight 24-50 ha tropical forest plots combined with species phylogenies created from the APG III phylogeny to examine how phylogenetic beta diversity (indicating the degree of phylogenetic similarity of two communities) was related to environmental gradients within tropical tree communities. Using distance-based redundancy analysis we found that phylogenetic beta diversity, expressed as either nearest neighbor distance or mean pairwise distance, was significantly related to both soil and topographic variation in all study sites. In general, more phylogenetic beta diversity within a forest plot was explained by environmental variables this was expressed as nearest neighbor distance versus mean pairwise distance (3.0-10.3 % and 0.4-8.8 % of variation explained among plots, respectively), and more variation was explained by soil resource variables than topographic variables using either phylogenetic beta diversity metric. We also found that patterns of phylogenetic beta diversity expressed as nearest neighbor distance were consistent with previously observed patterns of niche similarity among congeneric species pairs in these plots. These results indicate the importance of phylogenetic signal in local habitat niches in shaping the phylogenetic structure of tropical tree communities, especially at the level of close phylogenetic neighbors, where similarity in habitat niches is most strongly preserved.

Size and shape in Melipona quadrifasciata anthidioides Lepeletier, 1836 (Hymenoptera; Meliponini).

PubMed

Nunes, L A; Passos, G B; Carvalho, C A L; Araújo, E D

2013-11-01

This study aimed to identify differences in wing shape among populations of Melipona quadrifasciata anthidioides obtained in 23 locations in the semi-arid region of Bahia state (Brazil). Analysis of the Procrustes distances among mean wing shapes indicated that population structure did not determine shape variation. Instead, populations were structured geographically according to wing size. The Partial Mantel Test between morphometric (shape and size) distance matrices and altitude, taking geographic distances into account, was used for a more detailed understanding of size and shape determinants. A partial Mantel test between morphometris (shape and size) variation and altitude, taking geographic distances into account, revealed that size (but not shape) is largely influenced by altitude (r = 0.54 p < 0.01). These results indicate greater evolutionary constraints for the shape variation, which must be directly associated with aerodynamic issues in this structure. The size, however, indicates that the bees tend to have larger wings in populations located at higher altitudes.

Evidence for enhanced discrimination of virtual auditory distance among blind listeners using level and direct-to-reverberant cues.

PubMed

Kolarik, Andrew J; Cirstea, Silvia; Pardhan, Shahina

2013-02-01

Totally blind listeners often demonstrate better than normal capabilities when performing spatial hearing tasks. Accurate representation of three-dimensional auditory space requires the processing of available distance information between the listener and the sound source; however, auditory distance cues vary greatly depending upon the acoustic properties of the environment, and it is not known which distance cues are important to totally blind listeners. Our data show that totally blind listeners display better performance compared to sighted age-matched controls for distance discrimination tasks in anechoic and reverberant virtual rooms simulated using a room-image procedure. Totally blind listeners use two major auditory distance cues to stationary sound sources, level and direct-to-reverberant ratio, more effectively than sighted controls for many of the virtual distances tested. These results show that significant compensation among totally blind listeners for virtual auditory spatial distance leads to benefits across a range of simulated acoustic environments. No significant differences in performance were observed between listeners with partial non-correctable visual losses and sighted controls, suggesting that sensory compensation for virtual distance does not occur for listeners with partial vision loss.

Accuracy enhanced distance measurement system using double-sideband modulated frequency scanning interferometry

NASA Astrophysics Data System (ADS)

Chen, Xilun; Wang, Xiangchuan; Pan, Shilong

2017-03-01

An implementation of a distance measurement system using double-sideband with suppressed carrier modulation (DSB-SC) frequency scanning interferometry is proposed to reduce the variations in the optical path and improve the measurement accuracy. In this proposed system, the electro-optic DSB-SC is used to create dual-swept signals with opposite scanning directions. For each swept signal, the relative distance between the reference arm and the measuring arm is determined by the beat frequency of signals from two arms. By multiplying both beat signals, measurement errors caused by variations in the optical path can be greatly reduced. As an experimental demonstration, a vibration was introduced in the optical path length. The experimental results show that the variations can be suppressed for over 19.9 dB.

Predicting performance for ecological restoration: A case study using Spartina altemiflora

USGS Publications Warehouse

Travis, S.E.; Grace, J.B.

2010-01-01

The success of population-based ecological restoration relies on the growth and reproductive performance of selected donor materials, whether consisting of whole plants or seed. Accurately predicting performance requires an understanding of a variety of underlying processes, particularly gene flow and selection, which can be measured, at least in part, using surrogates such as neutral marker genetic distances and simple latitudinal effects. Here we apply a structural equation modeling approach to understanding and predicting performance in a widespread salt marsh grass, Spartina alterniflora, commonly used for ecological restoration throughout its native range in North America. We collected source materials from throughout this range, consisting of eight clones each from 23 populations, for transplantation to a common garden site in coastal Louisiana and monitored their performance. We modeled performance as a latent process described by multiple indicator variables (e.g., clone diameter, stem number) and estimated direct and indirect influences of geographic and genetic distances on performance. Genetic distances were determined by comparison of neutral molecular markers with those from a local population at the common garden site. Geographic distance metrics included dispersal distance (the minimum distance over water between donor and experimental sites) and latitude. Model results indicate direct effects of genetic distance and latitude on performance variation among the donor sites. Standardized effect strengths indicate that performance was roughly twice as sensitive to variation in genetic distance as to latitudinal variation. Dispersal distance had an indirect influence on performance through effects on genetic distance, indicating a typical pattern of genetic isolation by distance. Latitude also had an indirect effect on genetic distance through its linear relationship with dispersal distance. Three performance indicators had significant loadings on performance alone (mean clone diameter, mean number of stems, mean number of inflorescences), while the performance indicators mean stem height and mean stem width were also influenced by latitude. We suggest that dispersal distance and latitude should provide an adequate means of predicting performance in future S. alterniflora restorations and propose a maximum sampling distance of 300 km (holding latitude constant) to avoid the sampling of inappropriate ecotypes. ?? 2010 by the Ecological Society of America.

GENETIC STRUCTURE OF NORWAY SPRUCE (PICEA ABIES): CONCORDANCE OF MORPHOLOGICAL AND ALLOZYMIC VARIATION.

PubMed

Lagercrantz, Ulf; Ryman, Nils

1990-02-01

This study describes the population structure of Norway spruce (Picea abies) as revealed by protein polymorphisms and morphological variation. Electrophoretically detectable genetic variability was examined at 22 protein loci in 70 populations from the natural range of the species in Europe. Like other conifers, Norway spruce exhibits a relatively large amount of genetic variability and little differentiation among populations. Sixteen polymorphic loci (73%) segregate for a total of 51 alleles, and average heterozygosity per population is 0.115. Approximately 5% of the total genetic diversity is explained by differences between populations (G ST = 0.052), and Nei's standard genetic distance is less than 0.04 in all cases. We suggest that the population structure largely reflects relatively recent historical events related to the last glaciation and that Norway spruce is still in a process of adaptation and differentiation. There is a clear geographic pattern in the variation of allele frequencies. A major part of the allelefrequency variation can be accounted for by a few synthetic variables (principal components), and 80% of the variation of the first principal component is "explained" by latitude and longitude. The central European populations are consistently depauperate of genetic variability, most likely as an effect of severe restrictions of population size during the last glaciation. The pattern of differentiation at protein loci is very similar to that observed for seven morphological traits examined. This similarity suggests that the same evolutionary forces have acted upon both sets of characters. © 1990 The Society for the Study of Evolution.

Consanguineous marriages and matrimonial distance: a study among three South Indian caste groups.

PubMed

Reddy, P G

1988-12-01

Reddy studies consanguineous marriages and matrimonial distance in 3 castes of Nellore district, Andhra Pradesh, South India. The castes include the well-to-do agricultural caste, the Desuri Kapu; the 2nd, artisan caste in the middle of the hierarchy, the Devanga; and the third caste at the bottom of the social ladder, the Mala. During field work conducted in 1978-1979, prominent elders of the villages were approached; information on the consanguinity of marriage and matrimonial distance was gathered through intensive interviews of both men and women from all the households of the 3 castes. Among the total of 979 marriages, 28.9% occurred within the village, the proportion of intra-village marriages being significantly higher in Nellore taluk than in Sullurpet. The 3 castes overall show little difference in the incidence of intra-village marriages, but there is some within caste regional variation in the incidence of intra-village marriages, the Devanga showing a significantly higher incidence in Nellore than in Sullurpet. Intra-village marriages are more common among consanguineous couples (41.5%) than among non-consanguineous (18.3%), a highly significant excess in each of the caste groups. In short, Reddy concludes that intra-village marriages are more common among consanguineous couples than non-consanguineous, and mean matrimonial distance is also lower.

Genetic variation assessment of acid lime accessions collected from south of Iran using SSR and ISSR molecular markers.

PubMed

Sharafi, Ata Allah; Abkenar, Asad Asadi; Sharafi, Ali; Masaeli, Mohammad

2016-01-01

Iran has a long history of acid lime cultivation and propagation. In this study, genetic variation in 28 acid lime accessions from five regions of south of Iran, and their relatedness with other 19 citrus cultivars were analyzed using Simple Sequence Repeat (SSR) and Inter-Simple Sequence Repeat (ISSR) molecular markers. Nine primers for SSR and nine ISSR primers were used for allele scoring. In total, 49 SSR and 131 ISSR polymorphic alleles were detected. Cluster analysis of SSR and ISSR data showed that most of the acid lime accessions (19 genotypes) have hybrid origin and genetically distance with nucellar of Mexican lime (9 genotypes). As nucellar of Mexican lime are susceptible to phytoplasma, these acid lime genotypes can be used to evaluate their tolerance against biotic constricts like lime "witches' broom disease".

Prediction of Tensile Behavior of UHSFRC Considering the Flow Field in the Placing Dominated by Shear Flow.

PubMed

Moon, Joon-Shik; Kang, Su-Tae

2018-01-26

Considering the case of fabricating a UHSFRC (ultra-high strength fiber-reinforced concrete) beam with the method of one end placing and self-flowing to the other end, it was intended to simulate the variation of the fiber orientation distribution according to the flow distance and the variation of the resultant tensile behaviors. Then the validity of the simulation approach was shown by comparing the simulated results with experimental ones. A three-point bending test with a notched beam was adopted for the experiment and a finite element analysis was performed to obtain the simulated results for the bending test considering the flow-dependent tensile behavior of the UHSFRC. From the simulation for the fiber orientation distribution according to the flow distance, it could be found that the major change in the fiber orientation distribution took place within a short flow distance and most of the fibers became nearly aligned to the flow direction. After some flow distance, there was a not-so-remarkable variation in the fiber orientation distribution that could influence the tensile behavior of the composite. For this flow region, the consistent flexural test results, regardless of flow distance, demonstrate the reliability of the simulation.

Match-to-match variability in high-speed running activity in a professional soccer team.

PubMed

Carling, Christopher; Bradley, Paul; McCall, Alan; Dupont, Gregory

2016-12-01

This study investigated variability in competitive high-speed running performance in an elite soccer team. A semi-automated tracking system quantified running performance in 12 players over a season (median 17 matches per player, 207 observations). Variability [coefficient of variation (CV)] was compared for total sprint distance (TSD, >25.2 km/h), high-speed running (HSR, 19.8-25.2 km/h), total high-speed running (THSR, ≥19.8 km/h); THSR when the team was in and out of ball possession, in individual ball possession, in the peak 5 min activity period; and distance run according to individual maximal aerobic speed (MAS). Variability for % declines in THSR and distance covered at ≥80% MAS across halves, at the end of play (final 15 min vs. mean for all 15 min periods) and transiently (5 min period following peak 5 min activity period), was analysed. Collectively, variability was higher for TSD versus HSR and THSR and lowest for distance run at ≥80% MAS (CVs: 37.1%, 18.1%, 19.8% and 11.8%). THSR CVs when the team was in/out of ball possession, in individual ball possession and during the peak 5 min period were 31.5%, 26.1%, 60.1% and 23.9%. Variability in THSR declines across halves, at the end of play and transiently, ranged from 37.1% to 142.6%, while lower CVs were observed in these metrics for running at ≥80% MAS (20.9-53.3%).These results cast doubt on the appropriateness of general measures of high-speed activity for determining variability in an elite soccer team, although individualisation of HSR thresholds according to fitness characteristics might provide more stable indicators of running performance and fatigue occurrence.

Variable population exposure and distributed travel speeds in least-cost tsunami evacuation modelling

NASA Astrophysics Data System (ADS)

Fraser, S. A.; Wood, N. J.; Johnston, D. M.; Leonard, G. S.; Greening, P. D.; Rossetto, T.

2014-11-01

Evacuation of the population from a tsunami hazard zone is vital to reduce life-loss due to inundation. Geospatial least-cost distance modelling provides one approach to assessing tsunami evacuation potential. Previous models have generally used two static exposure scenarios and fixed travel speeds to represent population movement. Some analyses have assumed immediate departure or a common evacuation departure time for all exposed population. Here, a method is proposed to incorporate time-variable exposure, distributed travel speeds, and uncertain evacuation departure time into an existing anisotropic least-cost path distance framework. The method is demonstrated for hypothetical local-source tsunami evacuation in Napier City, Hawke's Bay, New Zealand. There is significant diurnal variation in pedestrian evacuation potential at the suburb level, although the total number of people unable to evacuate is stable across all scenarios. Whilst some fixed travel speeds approximate a distributed speed approach, others may overestimate evacuation potential. The impact of evacuation departure time is a significant contributor to total evacuation time. This method improves least-cost modelling of evacuation dynamics for evacuation planning, casualty modelling, and development of emergency response training scenarios. However, it requires detailed exposure data, which may preclude its use in many situations.

Variable population exposure and distributed travel speeds in least-cost tsunami evacuation modelling

NASA Astrophysics Data System (ADS)

Fraser, S. A.; Wood, N. J.; Johnston, D. M.; Leonard, G. S.; Greening, P. D.; Rossetto, T.

2014-06-01

Evacuation of the population from a tsunami hazard zone is vital to reduce life-loss due to inundation. Geospatial least-cost distance modelling provides one approach to assessing tsunami evacuation potential. Previous models have generally used two static exposure scenarios and fixed travel speeds to represent population movement. Some analyses have assumed immediate evacuation departure time or assumed a common departure time for all exposed population. In this paper, a method is proposed to incorporate time-variable exposure, distributed travel speeds, and uncertain evacuation departure time into an existing anisotropic least-cost path distance framework. The model is demonstrated for a case study of local-source tsunami evacuation in Napier City, Hawke's Bay, New Zealand. There is significant diurnal variation in pedestrian evacuation potential at the suburb-level, although the total number of people unable to evacuate is stable across all scenarios. Whilst some fixed travel speeds can approximate a distributed speed approach, others may overestimate evacuation potential. The impact of evacuation departure time is a significant contributor to total evacuation time. This method improves least-cost modelling of evacuation dynamics for evacuation planning, casualty modelling, and development of emergency response training scenarios.

Variable population exposure and distributed travel speeds in least-cost tsunami evacuation modelling

USGS Publications Warehouse

Fraser, Stuart A.; Wood, Nathan J.; Johnston, David A.; Leonard, Graham S.; Greening, Paul D.; Rossetto, Tiziana

2014-01-01

Evacuation of the population from a tsunami hazard zone is vital to reduce life-loss due to inundation. Geospatial least-cost distance modelling provides one approach to assessing tsunami evacuation potential. Previous models have generally used two static exposure scenarios and fixed travel speeds to represent population movement. Some analyses have assumed immediate departure or a common evacuation departure time for all exposed population. Here, a method is proposed to incorporate time-variable exposure, distributed travel speeds, and uncertain evacuation departure time into an existing anisotropic least-cost path distance framework. The method is demonstrated for hypothetical local-source tsunami evacuation in Napier City, Hawke's Bay, New Zealand. There is significant diurnal variation in pedestrian evacuation potential at the suburb level, although the total number of people unable to evacuate is stable across all scenarios. Whilst some fixed travel speeds approximate a distributed speed approach, others may overestimate evacuation potential. The impact of evacuation departure time is a significant contributor to total evacuation time. This method improves least-cost modelling of evacuation dynamics for evacuation planning, casualty modelling, and development of emergency response training scenarios. However, it requires detailed exposure data, which may preclude its use in many situations.

Logistics of air medical transport: When and where does helicopter transport reduce prehospital time for trauma?

PubMed

Chen, Xilin; Gestring, Mark L; Rosengart, Matthew R; Peitzman, Andrew B; Billiar, Timothy R; Sperry, Jason L; Brown, Joshua B

2018-05-04

Trauma is a time sensitive disease. Helicopter emergency medical services (HEMS) have shown benefit over ground EMS (GEMS), which may be related to reduced prehospital time. The distance at which this time benefit emerges depends on many factors that can vary across regions. Our objective was to determine the threshold distance at which HEMS has shorter prehospital time than GEMS under different conditions. Patients in the PA trauma registry 2000-2013 were included. Distance between zip centroid and trauma center was calculated using straight-line distance for HEMS and driving distance from GIS network analysis for GEMS. Contrast margins from linear regression identified the threshold distance at which HEMS had a significantly lower prehospital time than GEMS, indicated by non-overlapping 95% confidence intervals. The effect of peak traffic times and adverse weather on the threshold distance was evaluated. Geographic effects across EMS regions were also evaluated. A total of 144,741 patients were included with 19% transported by HEMS. Overall, HEMS became faster than GEMS at 7.7miles from the trauma center (p=0.043). HEMS became faster at 6.5miles during peak traffic (p=0.025) compared to 7.9miles during off-peak traffic (p=0.048). Adverse weather increased the distance at which HEMS was faster to 17.1miles (p=0.046) from 7.3miles in clear weather (p=0.036). Significant variation occurred across EMS regions, with threshold distances ranging from 5.4miles to 35.3miles. There was an inverse but non-significant relationship between urban population and threshold distance across EMS regions (ρ -0.351, p=0.28). This is the first study to demonstrate that traffic, weather, and geographic region significantly impact the threshold distance at which HEMS is faster than GEMS. HEMS was faster at shorter distances during peak traffic while adverse weather increased this distance. The threshold distance varied widely across geographic region. These factors must be considered to guide appropriate HEMS triage protocols. III, Therapeutic.

Single Versus Customized Treatment Planning for Image-guided High-Dose-Rate Brachytherapy for Cervical Cancer: Dosimetric Comparison and Predicting Factor for Organs at Risk Overdose With Single Plan Approach

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chi, Alexander; Gao Mingcheng; Sinacore, James

2009-09-01

Purpose: To compare the dose distribution between customized planning (CP) and adopting a single plan (SP) in multifractionated high-dose-rate brachytherapy and to establish predictors for the necessity of CP in a given patient. Methods and Materials: A total of 50 computed tomography-based plans for 10 patients were evaluated. Each patient had received 6 Gy for five fractions. The clinical target volume and organs at risk (i.e., rectum, bladder, sigmoid, and small bowel) were delineated on each computed tomography scan. For the SP approach, the same dwell position and time was used for all fractions. For the CP approach, the dwellmore » position and time were reoptimized for each fraction. Applicator position variation was determined by measuring the distance between the posterior bladder wall and the tandem at the level of the vaginal fornices. Results: The organs at risk D{sub 2cc} (dose to 2 cc volume) was increased with the SP approach. The dose variation was statistically similar between the tandem and ring and tandem and ovoid groups. The bladder D{sub 2cc} dose was 81.95-105.42 Gy{sub 2} for CP and 82.11-122.49 Gy{sub 2} for SP. In 5 of the 10 patients, the bladder would have been significantly overdosed with the SP approach. The variation of the posterior bladder wall distance from that in the first fraction was correlated with the increase in the bladder D{sub 2cc} (SP/CP), with a correlation coefficient of -0.59. Conclusion: Our results support the use of CP instead of the SP approach to help avoid a significant overdose to the bladder. This is especially true for a decrease in the posterior wall distance of {>=}0.5 cm compared with that in the first fraction.« less

The Aymara of Western Bolivia. IV. Gene frequencies for eight blood groups and 19 protein and erythrocyte enzyme systems.

PubMed Central

Ferrell, R E; Bertin, T; Young, R; Barton, S A; Murillo, F; Schull, W J

1978-01-01

A total of 315 individuals, mainly of Aymara origin, from western Bolivia were examined for genetic variation at eight red cell antigen and 19 serum protein and red cell enzyme loci. The gene frequencies for polymorphic loci and the discovery of several rare variants are discussed in terms of previous work among the Aymara and the closely related Quechua. The effect of inclusion of related individuals in the sample on gene frequency, variance of gene frequency and genetic distance, is discussed. Images Fig. 1 PMID:736042

Debris perturbed by radiation pressure: relative velocities across circular orbits

NASA Astrophysics Data System (ADS)

Celestino, C.; Winter, O.; Prado, A.

It is widely know that there is a large amount of space debris and meteoroid particles around the Earth. The objects larger than 10 cm can be tracked by radar and others means allowing the satellites/ships to be maneuvered to avoid collisions. However, the detection and the attendance of the orbital dynamics of objects smaller than 10 cm (particles) is very difficult. These particles can be generated by explosions of larger objects, collisions between large objects, or simply for the reaction of the oxygen in the wall of an object could generate the escape of paint pieces. The importance of studying the dynamics of these particles is that they can have relative high speeds and their effects in a collision could cause damages and even compromise the space missions. In this present work we considered a dynamical system of mm size particles around the Earth subject to the effects of radiation pressure. Our main goal is to study the evolution of its relative velocity to the circular orbits that it crosses.Firstly, it is considered that the particle is initially in circular orbit. The effect of the radiation pressure produces variations in its eccentricity, resulting in a change in its orbital velocity. The results show that the variation of the radial distance and the relative velocity can be divided in three parts: secular, long period and short period. For the radial distance the secular variation is constant, because the semi-axis is constant. The long period variation presents a configuration that repeats with period inferior to the orbital period of the Earth. And, finally, the short period variation presents points of local maxima and minima for the variation of the width of the radial distance. When considering the variation of the relative velocity we have that the secular behavior and of long period are similar to those obtained for the variation of the radial distance. However, for the short period variation, we have a larger number of local maxima and minima in comparison to the radial distance. The relative velocity for particles initially geostationary of size 5,0 mm are around 4,0 km/s. Acknowledgments: The authors thank FAPESP, CNPq and FUNDUNESP for the financial support.

Genetic diversity and environmental associations of sacsaoul ( Haloxylon ammodendron)

NASA Astrophysics Data System (ADS)

Zhang, Linjing; Zhao, Guifang; Yue, Ming; Pan, Xiaoling

2003-07-01

Random amplified polymorphic DNA (RAPD) markers were used to assess levels and patterns of genetic diversity in H. ammodendron (Chenopodiaceae). A total of 117 plants from 6 subpopulations on oasis-desert ecotone was analyzed by 16 arbitrarily chosen primers resulting in highly reproducible RAPD bands. The analysis of molecular variance (AMOVA) with distances among individuals showed that most of the variation (74%) occurred among individuals within subpopulations, which is expected for a crossing organism, and 26% of variation among subpopulations. Estimates of Shannon index and Nei"s index from allele frequencies corroborated AMOVA partitioning in H. ammodendron. UPGMA cluster analyses, based on genetic distance, do not revealed grouping of some geographically proximate populations. This is the first report of the partitioning of genetic variability within and between subpopulations of H. ammodendron and provides important baseline data for optimizing sampling strategies and for conserving the genetic resources of this species. The Percentage of polymorphic loci was as high as 96%, presumably being response to oasis-desert ecotone. There were gene flows (Nm=5.38 individuals/generation), based on gene differentiation coefficient (GST was 0.1567) between subpopulations, and strong habitat selection override the gene flow to maintain the subpopulation differentiation. Correlation analyses showed that there was significant relationship between genetic diversity and soil CL ion.

Genetic variation of Sargassum horneri populations detected by inter-simple sequence repeats.

PubMed

Ren, J R; Yang, R; He, Y Y; Sun, Q H

2015-01-30

The seaweed Sargassum horneri is an important brown alga in the marine environment, and it is an important raw material in the alginate industry. Unfortunately, the fixed resource that was originally reported is now reduced or disappeared, and increased floating populations have been reported in recent years. We sampled a floating population and 4 fixed cultivated populations of S. horneri along the coast of Zhejiang, China. Inter-simple sequence repeat (ISSR) markers were applied in this research to analyze the genetic variation between floating populations and fixed cultivated populations of S. horneri. In total, 220 loci were amplified with 23 ISSR primers. The percentage of polymorphic loci within each population ranged from 53.64 to 95.45%. The highest diversity was observed in population 3, which was the local species that was suspension cultured in the lab and then fixed cultivated in the Nanji Islands before sampling. The lowest diversity was obtained in the floating population 4. The genetic distances among the 5 S. horneri populations ranged from 0.0819 to 0.2889, and the distance tendency confirmed the genetic diversity. The results suggest that the floating population had the lowest genetic diversity and could not be joined into the cluster branch of the fixed cultivated populations.

A model for the global Wolf-Rayet population of the Milky Way

NASA Astrophysics Data System (ADS)

Rosslowe, Christopher K.; Crowther, Paul A.

2013-06-01

Prompted by the rapidly increasing discovery rate of Galactic Wolf-Rayet stars, we have produced a new near-IR absolute magnitude-spectral subtype calibration from Wolf-Rayet stars at known distances (mostly via cluster membership). We combine this with the relative distribution of WR subtypes for the inner disk, solar circle, and outer disk to model the global WR population in the Milky Way. We adopt the observed vertical scale height of known WR stars plus the measured spatial distribution of dust to produce an expected variation in apparent near-IR magnitudes, of relevance to future spectroscopic surveys. Finally, we use our model apparent magnitude distribution to quantify the total Galactic WR population, and compare this total to expectations from various star formation rate indicators.

Learner Self-Regulation in Distance Education: A Cross-Cultural Study

ERIC Educational Resources Information Center

Al-Harthi, Aisha S.

2010-01-01

This study investigated cultural variations between two samples of Arab and American distance learners (N = 190). The overarching purpose was to chart the underlying relationships between learner self-regulation and cultural orientation within distance education environments using structural equation modeling. The study found significant…

The Impact of Child-Care Subsidies on Child Development: Evidence from Geographic Variation in the Distance to Social Service Agencies

ERIC Educational Resources Information Center

Herbst, Chris M.; Tekin, Erdal

2016-01-01

In this paper, we examine the impact of U.S. child-care subsidies on the cognitive and behavioral development of children in low-income female-headed families. We identify the effect of subsidy receipt by exploiting geographic variation in the distance that families must travel from home to reach the nearest social service agency that administers…

Taxonomic Identity of the Invasive Fruit Fly Pest, Bactrocera invadens: Concordance in Morphometry and DNA Barcoding

PubMed Central

Khamis, Fathiya M.; Masiga, Daniel K.; Mohamed, Samira A.; Salifu, Daisy; de Meyer, Marc; Ekesi, Sunday

2012-01-01

In 2003, a new fruit fly pest species was recorded for the first time in Kenya and has subsequently been found in 28 countries across tropical Africa. The insect was described as Bactrocera invadens, due to its rapid invasion of the African continent. In this study, the morphometry and DNA Barcoding of different populations of B. invadens distributed across the species range of tropical Africa and a sample from the pest's putative aboriginal home of Sri Lanka was investigated. Morphometry using wing veins and tibia length was used to separate B. invadens populations from other closely related Bactrocera species. The Principal component analysis yielded 15 components which correspond to the 15 morphometric measurements. The first two principal axes contributed to 90.7% of the total variance and showed partial separation of these populations. Canonical discriminant analysis indicated that only the first five canonical variates were statistically significant. The first two canonical variates contributed a total of 80.9% of the total variance clustering B. invadens with other members of the B. dorsalis complex while distinctly separating B. correcta, B. cucurbitae, B. oleae and B. zonata. The largest Mahalanobis squared distance (D2 = 122.9) was found to be between B. cucurbitae and B. zonata, while the lowest was observed between B. invadens populations against B. kandiensis (8.1) and against B. dorsalis s.s (11.4). Evolutionary history inferred by the Neighbor-Joining method clustered the Bactrocera species populations into four clusters. First cluster consisted of the B. dorsalis complex (B. invadens, B. kandiensis and B. dorsalis s. s.), branching from the same node while the second group was paraphyletic clades of B. correcta and B. zonata. The last two are monophyletic clades, consisting of B. cucurbitae and B. oleae, respectively. Principal component analysis using the genetic distances confirmed the clustering inferred by the NJ tree. PMID:23028649

A genome-wide SNP-association study confirms a sequence variant (g.66493737C>T) in the equine myostatin (MSTN) gene as the most powerful predictor of optimum racing distance for Thoroughbred racehorses

PubMed Central

2010-01-01

Background Thoroughbred horses have been selected for traits contributing to speed and stamina for centuries. It is widely recognized that inherited variation in physical and physiological characteristics is responsible for variation in individual aptitude for race distance, and that muscle phenotypes in particular are important. Results A genome-wide SNP-association study for optimum racing distance was performed using the EquineSNP50 Bead Chip genotyping array in a cohort of n = 118 elite Thoroughbred racehorses divergent for race distance aptitude. In a cohort-based association test we evaluated genotypic variation at 40,977 SNPs between horses suited to short distance (≤ 8 f) and middle-long distance (> 8 f) races. The most significant SNP was located on chromosome 18: BIEC2-417495 ~690 kb from the gene encoding myostatin (MSTN) [Punadj. = 6.96 × 10-6]. Considering best race distance as a quantitative phenotype, a peak of association on chromosome 18 (chr18:65809482-67545806) comprising eight SNPs encompassing a 1.7 Mb region was observed. Again, similar to the cohort-based analysis, the most significant SNP was BIEC2-417495 (Punadj. = 1.61 × 10-9; PBonf. = 6.58 × 10-5). In a candidate gene study we have previously reported a SNP (g.66493737C>T) in MSTN associated with best race distance in Thoroughbreds; however, its functional and genome-wide relevance were uncertain. Additional re-sequencing in the flanking regions of the MSTN gene revealed four novel 3' UTR SNPs and a 227 bp SINE insertion polymorphism in the 5' UTR promoter sequence. Linkage disequilibrium was highest between g.66493737C>T and BIEC2-417495 (r2 = 0.86). Conclusions Comparative association tests consistently demonstrated the g.66493737C>T SNP as the superior variant in the prediction of distance aptitude in racehorses (g.66493737C>T, P = 1.02 × 10-10; BIEC2-417495, Punadj. = 1.61 × 10-9). Functional investigations will be required to determine whether this polymorphism affects putative transcription-factor binding and gives rise to variation in gene and protein expression. Nonetheless, this study demonstrates that the g.66493737C>T SNP provides the most powerful genetic marker for prediction of race distance aptitude in Thoroughbreds. PMID:20932346

A genome-wide SNP-association study confirms a sequence variant (g.66493737C>T) in the equine myostatin (MSTN) gene as the most powerful predictor of optimum racing distance for Thoroughbred racehorses.

PubMed

Hill, Emmeline W; McGivney, Beatrice A; Gu, Jingjing; Whiston, Ronan; Machugh, David E

2010-10-11

Thoroughbred horses have been selected for traits contributing to speed and stamina for centuries. It is widely recognized that inherited variation in physical and physiological characteristics is responsible for variation in individual aptitude for race distance, and that muscle phenotypes in particular are important. A genome-wide SNP-association study for optimum racing distance was performed using the EquineSNP50 Bead Chip genotyping array in a cohort of n = 118 elite Thoroughbred racehorses divergent for race distance aptitude. In a cohort-based association test we evaluated genotypic variation at 40,977 SNPs between horses suited to short distance (≤ 8 f) and middle-long distance (> 8 f) races. The most significant SNP was located on chromosome 18: BIEC2-417495 ~690 kb from the gene encoding myostatin (MSTN) [P(unadj.) = 6.96 x 10⁻⁶]. Considering best race distance as a quantitative phenotype, a peak of association on chromosome 18 (chr18:65809482-67545806) comprising eight SNPs encompassing a 1.7 Mb region was observed. Again, similar to the cohort-based analysis, the most significant SNP was BIEC2-417495 (P(unadj.) = 1.61 x 10⁻⁹; P(Bonf.) = 6.58 x 10⁻⁵). In a candidate gene study we have previously reported a SNP (g.66493737C>T) in MSTN associated with best race distance in Thoroughbreds; however, its functional and genome-wide relevance were uncertain. Additional re-sequencing in the flanking regions of the MSTN gene revealed four novel 3' UTR SNPs and a 227 bp SINE insertion polymorphism in the 5' UTR promoter sequence. Linkage disequilibrium was highest between g.66493737C>T and BIEC2-417495 (r² = 0.86). Comparative association tests consistently demonstrated the g.66493737C>T SNP as the superior variant in the prediction of distance aptitude in racehorses (g.66493737C>T, P = 1.02 x 10⁻¹⁰; BIEC2-417495, P(unadj.) = 1.61 x 10⁻⁹). Functional investigations will be required to determine whether this polymorphism affects putative transcription-factor binding and gives rise to variation in gene and protein expression. Nonetheless, this study demonstrates that the g.66493737C>T SNP provides the most powerful genetic marker for prediction of race distance aptitude in Thoroughbreds.

A low-cost method for estimating energy expenditure during soccer refereeing.

PubMed

Ardigò, Luca Paolo; Padulo, Johnny; Zuliani, Andrea; Capelli, Carlo

2015-01-01

This study aimed to apply a validated bioenergetics model of sprint running to recordings obtained from commercial basic high-sensitivity global positioning system receivers to estimate energy expenditure and physical activity variables during soccer refereeing. We studied five Italian fifth division referees during 20 official matches while carrying the receivers. By applying the model to the recorded speed and acceleration data, we calculated energy consumption during activity, mass-normalised total energy consumption, total distance, metabolically equivalent distance and their ratio over the entire match and the two halves. Main results were as follows: (match) energy consumption = 4729 ± 608 kJ, mass normalised total energy consumption = 74 ± 8 kJ · kg(-1), total distance = 13,112 ± 1225 m, metabolically equivalent distance = 13,788 ± 1151 m and metabolically equivalent/total distance = 1.05 ± 0.05. By using a very low-cost device, it is possible to estimate the energy expenditure of soccer refereeing. The provided predicting mass-normalised total energy consumption versus total distance equation can supply information about soccer refereeing energy demand.

Confirmation of an anatomic variation of the recurrent laryngeal nerve at site of entry into the larynx in Chinese population.

PubMed

Shao, Tanglei; Qiu, Weihua; Yang, Weiping

2016-01-01

This study was aimed at analyzing the frequency of the newly reported variation and the frequency of postoperative palsy associated with three different kinds of known variations. We conducted a retrospective study on the data of 2068 consecutive Chinese patients who underwent thyroidectomy. The study included 1362 left and 1507 right (2869 in total) RLNs. Among all the RLNs, 548 were found to have variations at the laryngeal entry of the RLN. The most frequent variation was extralaryngeal branching (n=322), followed by the fan-shaped branching (n=201). Our newly identified variation was also noted in 25 of our patients. In these cases, the RLN entered the larynx from sites that were distant from the posterior cricothyroid joint. The distance from the entry of the RLN to the back of cricothyroid joints was over 5mm. Compared to the rates reported from other countries, the rate of the first type of variation is lower, while that of the second type is higher. The frequency of the new variation has not been reported in other populations, but it is consistent with our previous finding. The incidence of postoperative palsy was greater for RLNs with the first and third types of variations than in the normal RLNs. We confirmed that the incidence of patients with the new type of variation of the RLN at the entry of the larynx was about 1% in Chinese. Awareness among surgeons regarding this variation is important to avoid postoperative palsy. Copyright © 2016 Elsevier Inc. All rights reserved.

Population characteristics of DNA fingerprints in humpback whales (Megaptera novaeangliae).

PubMed

Baker, C S; Gilbert, D A; Weinrich, M T; Lambertsen, R; Calambokidis, J; McArdle, B; Chambers, G K; O'Brien, S J

1993-01-01

Humpback whales exhibit a remarkable social organization that is characterized by seasonal long-distance migration (> 10,000 km/year) between summer feeding grounds in high latitudes and winter calving and breeding grounds in tropical or near-tropical waters. All populations are currently considered endangered as a result of intensive commercial exploitation during the last 200 years. Using three hypervariable minisatellite DNA probes (33.15, 3'HVR, and M13) originally developed for studies of human genetic variation, we examined genetic variation within and among three regional subpopulations of humpback whales from the North Pacific and one from the North Atlantic oceans. Analysis of DNA extracted from skin tissues collected by biopsy darting from free-ranging whales revealed considerable variation in each subpopulation. The extent of this variation argues against a recent history of inbreeding among humpback whales as a result of nineteenth- and twentieth-century hunting. A canonical variate analysis suggested a relationship between scaled genetic distance, based on similarities of DNA fingerprints, and geographic distance (i.e., longitude of regional subpopulation). Significant categorical differences were found between the two oceanic populations using a multivariate analysis of variance (MANOVA) with a modification of the Mantel nonparametric permutation test. The relationship between DNA fingerprint similarities and geographic distance suggests that nuclear gene flow between regional subpopulations within the North Pacific is restricted by relatively low rates of migratory interchange between breeding grounds or assortative mating on common wintering grounds.

Observing the variation of asteroid thermal inertia with heliocentric distance

NASA Astrophysics Data System (ADS)

Rozitis, B.; Green, S. F.; MacLennan, E.; Emery, J. P.

2018-06-01

Thermal inertia is a useful property to characterize a planetary surface, since it can be used as a qualitative measure of the regolith grain size. It is expected to vary with heliocentric distance because of its dependence on temperature. However, no previous investigation has conclusively observed a change in thermal inertia for any given planetary body. We have addressed this by using NEOWISE data and the Advanced Thermophysical Model to study the thermophysical properties of the near-Earth asteroids (1036) Ganymed, (1580) Betulia, and (276 049) 2002 CE26 as they moved around their highly eccentric orbits. We confirm that the thermal inertia values of Ganymed and 2002 CE26 do vary with heliocentric distance, although the degree of variation observed depends on the spectral emissivity assumed in the thermophysical modelling. We also confirm that the thermal inertia of Betulia did not change for three different observations obtained at the same heliocentric distance. Depending on the spectral emissivity, the variations for Ganymed and 2002 CE26 are potentially more extreme than that implied by theoretical models of heat transfer within asteroidal regoliths, which might be explained by asteroids having thermal properties that also vary with depth. Accounting for this variation reduces a previously observed trend of decreasing asteroid thermal inertia with increasing size, and suggests that the surfaces of small and large asteroids could be much more similar than previously thought. Furthermore, this variation can affect Yarkovsky orbital drift predictions by a few tens of per cent.

An Active Tutorial on Distance Sampling

ERIC Educational Resources Information Center

Richardson, Alice

2007-01-01

The technique of distance sampling is widely used to monitor biological populations. This paper documents an in-class activity to introduce students to the concepts and the mechanics of distance sampling in a simple situation that is relevant to their own experiences. Preparation details are described. Variations and extensions to the activity are…

SU-E-I-92: Accuracy Evaluation of Depth Data in Microsoft Kinect.

PubMed

Kozono, K; Aoki, M; Ono, M; Kamikawa, Y; Arimura, H; Toyofuku, F

2012-06-01

Microsoft Kinect has potential for use in real-time patient position monitoring in diagnostic radiology and radiotherapy. We evaluated the accuracy of depth image data and the device-to-device variation in various conditions simulating clinical applications in a hospital. Kinect sensor consists of infrared-ray depth camera and RGB camera. We developed a computer program using OpenNI and OpenCV for measuring quantitative distance data. The program displays depth image obtained from Kinect sensor on the screen, and the cartesian coordinates at an arbitrary point selected by mouse-clicking can be measured. A rectangular box without luster (300 × 198 × 50 mm 3 ) was used as a measuring object. The object was placed on the floor at various distances ranging from 0 to 400 cm in increments of 10 cm from the sensor, and depth data were measured for 10 points on the planar surface of the box. The measured distance data were calibrated by using the least square method. The device-to-device variations were evaluated using five Kinect sensors. There was almost linear relationship between true and measured values. Kinect sensor was unable to measure at a distance of less than 50 cm from the sensor. It was found that distance data calibration was necessary for each sensor. The device-to-device variation error for five Kinect sensors was within 0.46% at the distance range from 50 cm to 2 m from the sensor. The maximum deviation of the distance data after calibration was 1.1 mm at a distance from 50 to 150 cm. The overall average error of five Kinect sensors was 0.18 mm at a distance range of 50 to 150 cm. Kinect sensor has distance accuracy of about 1 mm if each device is properly calibrated. This sensor will be useable for positioning of patients in diagnostic radiology and radiotherapy. © 2012 American Association of Physicists in Medicine.

Application of two tests of multivariate discordancy to fisheries data sets

USGS Publications Warehouse

Stapanian, M.A.; Kocovsky, P.M.; Garner, F.C.

2008-01-01

The generalized (Mahalanobis) distance and multivariate kurtosis are two powerful tests of multivariate discordancies (outliers). Unlike the generalized distance test, the multivariate kurtosis test has not been applied as a test of discordancy to fisheries data heretofore. We applied both tests, along with published algorithms for identifying suspected causal variable(s) of discordant observations, to two fisheries data sets from Lake Erie: total length, mass, and age from 1,234 burbot, Lota lota; and 22 combinations of unique subsets of 10 morphometrics taken from 119 yellow perch, Perca flavescens. For the burbot data set, the generalized distance test identified six discordant observations and the multivariate kurtosis test identified 24 discordant observations. In contrast with the multivariate tests, the univariate generalized distance test identified no discordancies when applied separately to each variable. Removing discordancies had a substantial effect on length-versus-mass regression equations. For 500-mm burbot, the percent difference in estimated mass after removing discordancies in our study was greater than the percent difference in masses estimated for burbot of the same length in lakes that differed substantially in productivity. The number of discordant yellow perch detected ranged from 0 to 2 with the multivariate generalized distance test and from 6 to 11 with the multivariate kurtosis test. With the kurtosis test, 108 yellow perch (90.7%) were identified as discordant in zero to two combinations, and five (4.2%) were identified as discordant in either all or 21 of the 22 combinations. The relationship among the variables included in each combination determined which variables were identified as causal. The generalized distance test identified between zero and six discordancies when applied separately to each variable. Removing the discordancies found in at least one-half of the combinations (k=5) had a marked effect on a principal components analysis. In particular, the percent of the total variation explained by second and third principal components, which explain shape, increased by 52 and 44% respectively when the discordancies were removed. Multivariate applications of the tests have numerous ecological advantages over univariate applications, including improved management of fish stocks and interpretation of multivariate morphometric data. ?? 2007 Springer Science+Business Media B.V.

Travel patterns of cancer surgery patients in a regionalized system.

PubMed

Smith, Andrew K; Shara, Nawar M; Zeymo, Alexander; Harris, Katherine; Estes, Randy; Johnson, Lynt B; Al-Refaie, Waddah B

2015-11-01

Regionalization of complex surgeries has increased patient travel distances possibly leaving a substantial burden on those at risk for poorer surgical outcomes. To date, little is known about travel patterns of cancer surgery patients in regionalized settings. To inform this issue, we sought to assess travel patterns of those undergoing a major cancer surgery within a regionalized system. We identified 4733 patients who underwent lung, esophageal, gastric, liver, pancreatic, and colorectal resections from 2002-2014 within a multihospital system in the Mid-Atlantic region of the United States. Patient age, race and/or ethnicity, and insurance status were extracted from electronic health records. We used Geographical Information System capabilities in R software to estimate travel distance and map patient addresses based on cancer surgery type and these characteristics. We used visual inspection, analysis of variance, and interaction analyses to assess the distribution of travel distances between patient populations. A total of 48.2% of patients were non-white, 49.9% were aged >65 y, and 54.9% had private insurance. Increased travel distance was associated with decreasing age and those undergoing pancreatic and esophageal resections. Also, black patients tend to travel shorter distances than other racial and/or ethnic groups. These maps offer a preliminary understanding into variations of geospatial travel patterns among patients receiving major cancer surgery in a Mid-Atlantic regionalized setting. Future research should focus on the impact of regionalization on timely delivery of surgical care and other quality metrics. Copyright © 2015 Elsevier Inc. All rights reserved.

Spatial genetic structure of the sea sandwort (Honckenya peploides) on Surtsey: an immigrant's journey

NASA Astrophysics Data System (ADS)

Árnason, S. H.; Thórsson, Ae. Th.; Magnússon, B.; Philipp, M.; Adsersen, H.; Anamthawat-Jónsson, K.

2014-11-01

Sea sandwort (Honckenya peploides) was one of the first plants to successfully colonize and reproduce on the volcanic island Surtsey, formed in 1963 off the southern coast of Iceland. Using amplified fragment length polymorphic (AFLP) markers, we examined levels of genetic variation and differentiation among populations of H. peploides on Surtsey in relation to populations on the nearby island Heimaey and from the southern coast of Iceland. Selected populations from Denmark and Greenland were used for comparison. In addition, we tested whether the effects of isolation by distance could be seen in the Surtsey populations. Using two primer combinations, we obtained 173 AFLP markers from a total of 347 plant samples. The resulting binary matrix was then analysed statistically. The main results include the following: (i) Surtsey had the highest proportion of polymorphic markers as well as a comparatively high genetic diversity (55.5% proportion of polymorphic loci, PLP; 0.1974 HE) and Denmark the lowest (31.8% PLP; 0.132 HE), indicating rapid expansion during an early stage of population establishment on Surtsey and/or multiple origins of immigrants; (ii) the total genetic differentiation (FST) among Surtsey (0.0714) and Heimaey (0.055) populations was less than half of that found among the mainland populations in Iceland (0.1747), indicating substantial gene flow on the islands; (iii) most of the genetic variation (79%, p < 0.001) was found within localities, possibly due to the outcrossing and subdioecious nature of the species; (iv) a significant genetic distance was found within Surtsey, among sites, and this appeared to correlate with the age of plant colonization; and (v) the genetic structure analysis indicated multiple colonization episodes on Surtsey, whereby H. peploides most likely immigrated from the nearby island of Heimaey and directly from the southern coast of Iceland.

Spatial genetic structure of the Sea Sandwort on Surtsey: an immigrant's journey

NASA Astrophysics Data System (ADS)

Árnason, S. H.; Thórsson, Th.; Magnússon, B.; Philipp, M.; Adsersen, H. E.; Anamthawat-Jónsson, K.

2014-06-01

Sea Sandwort (Honckenya peploides) is one of the first plants to successfully colonize and reproduce on the volcanic island Surtsey, formed in 1963 off the southern coast of Iceland. Using amplified fragment length polymorphic (AFLP) markers we examined levels of genetic variation and differentiation among populations of H. peploides on Surtsey in relation to populations on the nearby island Heimaey and from the southern coast of Iceland. Selected populations from Denmark and Greenland were used for comparison. In addition, we tested whether the effects of isolation by distance can be seen in the Surtsey populations. Using two primer combinations, we obtained 173 AFLP markers from a total of 347 plant samples. The resulting binary matrix was then analyzed statistically. Main results include the followings: (i) Surtsey has the highest proportion of polymorphic markers as well as a comparatively high genetic diversity (55.5% PLP; 0.1974 HE) and Denmark the lowest (31.8% PLP; 0.132 HE), indicating rapid expansion during an early stage of population establishment on Surtsey and/or multiple origins of immigrants; (ii) the total genetic differentiation (FST) among Surtsey (0.0714) and Heimaey (0.055) populations was less than half of that found among the mainland populations in Iceland (0.1747), indicating substantial gene flow on the islands; (iii) most of the genetic variation (79%, p<0.001) was found within localities, possibly due to the outcrossing and subdioecious nature of the species; (iv) a significant genetic distance was found within Surtsey, among sites, and this appears to correlate with the age of plant colonization; and (v) the genetic structure analysis indicated multiple colonization episodes on Surtsey, whereby H. peploides most likely immigrated from the nearby island of Heimaey and directly from the southern coast of Iceland.

Quantitative complete tooth variation among east Asians and Native Americans: developmental biology as a tool for the assessment of human divergence.

PubMed

Shields, E D

1996-01-01

The quantification of total tooth structure derived from X-rays of Vietnamese, Southern Chinese, Mongolians, Western Eskimos, and Peruvian pre-Inca (Huari Empire) populations was used to examine dental divergence and the morphogenetics of change. Multivariate derived distances between the samples helped identify a quasicontinuous web of ethnic groups with two binary clusters ensconced within the web. One cluster was composed of Mongolians, Western Eskimos, and pre-Inca, and the other group consisted of the Southern Chinese and Vietnamese. Mongolians entered the quasicontinuum from a divergent angle (externally influenced) from that of the Southeast Asians. The Chinese and pre-Inca formed the polar samples of the distance superstructure. The pre-Inca sample was the most isolated, its closest neighbor being the Western Eskimos. Univariate and multivariate analyses suggested that the pre-Inca, whose ancestors arrived in America perhaps approximately 30,000 years ago, was the least derived sample. Clearly, microevolutionary change occurred among the samples, but the dental phenotype was resistant to environmental developmental perturbations. An assessment of dental divergence and developmental biology suggested that the overall dental phenotype is a complex multigenic morphological character, and that the observed variation evolved through total genomic drift. The quantified dental phenotype is greater than its highly multigenic algorithm and its development homeostasis is tightly controlled, or canalized, by the deterministic organization of a complex nonlinear epigenetic milieu. The overall dental phenotype quantified here was selectively neutral and a good character to help reconstruct the sequence of human evolution, but if the outlying homeostatic threshold was or will be exceeded in antecedents and descendants, respectively, evolutionary saltation occurs.

Variations in the concentration of plutonium, strontium-90 and total alpha-emitters in human teeth collected within the British Isles.

PubMed

O'Donnell, R G; Mitchell, P I; Priest, N D; Strange, L; Fox, A; Henshaw, D L; Long, S C

1997-08-18

Concentrations of plutonium-239, plutonium-240, strontium-90 and total alpha-emitters have been measured in children's teeth collected throughout Great Britain and Ireland. The concentrations of plutonium and strontium-90 were measured in batched samples, each containing approximately 50 teeth, using low-background radiochemical methods. The concentrations of total alpha-emitters were determined in single teeth using alpha-sensitive plastic track detectors. The results showed that the average concentrations of total alpha-emitters and strontium-90 were approximately one to three orders of magnitude greater than the equivalent concentrations of plutonium-239,240. Regression analyses indicated that the concentrations of plutonium, but not strontium-90 or total alpha-emitters, decreased with increasing distance from the Sellafield nuclear fuel reprocessing plant-suggesting that this plant is a source of plutonium contamination in the wider population of the British Isles. Nevertheless, the measured absolute concentrations of plutonium (mean = 5 +/- 4 mBq kg-1 ash wt.) were so low that they are considered to present an insignificant radiological hazard.

Stress hormones in relation to breeding status and territory location in colonial king penguin: a role for social density?

PubMed

Viblanc, Vincent A; Gineste, Benoit; Stier, Antoine; Robin, Jean-Patrice; Groscolas, René

2014-07-01

Because glucocorticoid (stress) hormones fundamentally affect various aspects of the behaviour, life history and fitness of free-living vertebrates, there is a need to understand the environmental factors shaping their variation in natural populations. Here, we examined whether spatial heterogeneity in breeding territory quality affected the stress of colonial king penguin (Aptenodytes patagonicus). We assessed the effects of local climate (wind, sun and ambient temperature) and social conditions (number of neighbours, distance to neighbours) on the baseline levels of plasma total corticosterone (CORT) in 77 incubating and 42 chick-brooding birds, breeding on territories of central or peripheral colony location. We also assessed the oxidative stress status of a sub-sample of central vs. peripheral chick-brooders to determine whether chronic stress arose from breeding on specific territories. On average, we found that brooders had 55% higher CORT levels than incubators. Regardless of breeding status, central birds experienced greater social density (higher number of neighbours, shorter distance between territories) and had higher CORT levels than peripheral birds. Increasing social density positively explained 40% of the variation in CORT levels of both incubators and brooders, but the effect was more pronounced in brooders. In contrast, climate was similar among breeding territories and did not significantly affect the CORT levels of breeding birds. In brooders, oxidative stress status was not affected by local density or weather conditions. These results highlight that local heterogeneity in breeding (including social) conditions may strongly affect the stress levels of breeding seabirds. The fitness consequences of such variation remain to be investigated.

Temporal Epidemiology of Sudden Oak Death in Oregon.

PubMed

Peterson, Ebba K; Hansen, Everett M; Kanaskie, Alan

2015-07-01

An effort to eradicate Phytophthora ramorum, causal agent of sudden oak death, has been underway since its discovery in Oregon forests. Using an information-theoretical approach, we sought to model yearly variation in the size of newly infested areas and dispersal distance. Maximum dispersal distances were best modeled by spring and winter precipitation 2 years before detection, and infestation size the year prior. Infestation size was best modeled by infestation size and spring precipitation the year prior. In our interpretation, there is a 2-year delay between the introduction of inoculum and onset of mortality for a majority of sites. The year-long gap in between allows ample time for the production of inoculum contributing to the spread of P. ramorum. This is supported by epidemic development following changes in eradication protocols precipitated by an outbreak in 2011, attributable to a 2009 treatment delay and an uncharacteristically wet spring in 2010. Posteradication, we have observed an increase in the total area of new outbreaks and increased frequency in dispersal distances greater than 4 km. Although the eradication program has not eliminated P. ramorum from Oregon forests, it has likely moderated this epidemic, emphasizing the need for prompt treatment of future invasive forest pathogens.

Resolution of low-velocity control in golf putting differentiates professionals from amateurs.

PubMed

Hasegawa, Yumiko; Fujii, Keisuke; Miura, Akito; Yamamoto, Yuji

2017-07-01

It is difficult for humans to apply small amounts of force precisely during motor control. However, experts who have undergone extended training are thought to be able to control low-velocity movement with precision. We investigated the resolution of motor control in golf putting. A total of 10 professional and 10 high-level amateur golfers participated. Putting distances were 0.6-3.3 m, in increments of 0.3 m. We measured the impact velocity and the club-face angle at impact, and the acceleration profile of the downswing. The professionals showed significantly smaller coefficients of variation with respect to impact velocity and smaller root mean square errors in relation to acceleration profiles than did the amateurs. To examine the resolution of motor control for impact velocity, we investigated intra-participant differences in the impact velocity of the club head at two adjacent distances. We found that professionals had higher velocity precision when putting small distance intervals than did amateurs. That is, professionals had higher resolution of low-velocity control than did high-level amateurs. Our results suggest that outstanding performance at a task involves the ability to recognise small distinctions and to produce appropriate movements.

Tests of the Weak Equivalence Principal Below Fifty Microns

NASA Astrophysics Data System (ADS)

Leopardi, Holly; Hoyle, C. D.; Smith, Dave; Cardenas, Crystal; Harter, Andrew Conrad

2014-03-01

Due to the incompatibility of the Standard Model and General Relativity, tests of gravity remain at the forefront of experimental physics research. The Weak Equivalence Principle (WEP), which states that in a uniform gravitational field all objects fall with the same acceleration regardless of composition, total mass, or structure, is fundamentally the result of the equality of inertial mass and gravitational mass. The WEP has been effectively studied since the time of Galileo, and is a central feature of General Relativity; its violation at any length scale would bring into question fundamental aspects of the current model of gravitational physics. A variety of scenarios predict possible mechanisms that could result in a violation of the WEP. The Humboldt State University Gravitational Physics Laboratory is using a torsion pendulum with equal masses of different materials (a ``composition dipole'' configuration) to determine whether the WEP holds below the 50-micron distance scale. The experiment will measure the twist of a torsion pendulum as an attractor mass is oscillated nearby in a parallel-plate configuration, providing a time varying torque on the pendulum. The size and distance dependence of the torque variation will provide means to determine deviations from accepted models of gravity on untested distance scales. P.I.

High spatial resolution measurements of NO2 applying Topographic Target Light scattering-Differential Optical Absorption Spectroscopy (ToTaL-DOAS)

NASA Astrophysics Data System (ADS)

Frins, E.; Platt, U.; Wagner, T.

2008-06-01

Tomographic Target Light scattering - Differential Optical Absorption Spectroscopy (ToTaL-DOAS), also called Target-DOAS, is a novel experimental procedure to retrieve trace gas concentrations present in the low atmosphere. Scattered sunlight (partially or totally) reflected from natural or artificial targets of similar albedo located at different distances is analyzed to retrieve the concentration of different trace gases like NO2, SO2 and others. We report high spatial resolution measurements of NO2 mixing ratios in the city of Montevideo (Uruguay) observing three buildings as targets with a Mini-DOAS instrument. Our instrument was 146 m apart from the first building, 196 m from the second and 286 m from the third one. All three buildings are located along a main Avenue. We obtain temporal variation of NO2 mixing ratios between 30 ppb and 65 ppb (±2 ppb). Our measurements demonstrate that ToTaL-DOAS measurements can be made over very short distances. In polluted air masses, the retrieved absorption signal was found to be strong enough to allow measurements over distances in the range of several ten meters, and achieve a spatial resolution of 50 m approximately.

Intraspecific Variation in Physiological Condition of Reef-Building Corals Associated with Differential Levels of Chronic Disturbance

PubMed Central

Pisapia, Chiara; Anderson, Kristen; Pratchett, Morgan S.

2014-01-01

Even in the absence of major disturbances (e.g., cyclones, bleaching), corals are subject to high levels of partial or whole-colony mortality, often caused by chronic and small-scale disturbances. Depending on levels of background mortality, these chronic disturbances may undermine individual fitness and have significant consequences on the ability of colonies to withstand subsequent acute disturbances or environmental change. This study quantified intraspecific variations in physiological condition (measured based on total lipid content and zooxanthellae density) through time in adult colonies of two common and widespread coral species (Acropora spathulata and Pocillopora damicornis), subject to different levels of biological and physical disturbances along the most disturbed reef habitat, the crest. Marked intraspecific variation in the physiological condition of A. spathulata was clearly linked to differences in local disturbance regimes and habitat. Specifically, zooxanthellae density decreased (r2 = 26, df = 5,42, p<0.02, B =  −121255, p = 0.03) and total lipid content increased (r2 = 14, df = 5,42, p = 0.01, B = 0.9, p = 0.01) with increasing distance from exposed crests. Moreover, zooxanthellae density was strongly and negatively correlated with the individual level of partial mortality (r2 = 26, df = 5,42, p<0.02, B =  −7386077, p = 0.01). Conversely, P. damicornis exhibited very limited intraspecific variation in physiological condition, despite marked differences in levels of partial mortality. This is the first study to relate intraspecific variation in the condition of corals to localized differences in chronic disturbance regimes. The next step is to ascertain whether these differences have further ramifications for susceptibility to periodic acute disturbances, such as climate-induced coral bleaching. PMID:24626395

Intraspecific variation in physiological condition of reef-building corals associated with differential levels of chronic disturbance.

PubMed

Pisapia, Chiara; Anderson, Kristen; Pratchett, Morgan S

2014-01-01

Even in the absence of major disturbances (e.g., cyclones, bleaching), corals are subject to high levels of partial or whole-colony mortality, often caused by chronic and small-scale disturbances. Depending on levels of background mortality, these chronic disturbances may undermine individual fitness and have significant consequences on the ability of colonies to withstand subsequent acute disturbances or environmental change. This study quantified intraspecific variations in physiological condition (measured based on total lipid content and zooxanthellae density) through time in adult colonies of two common and widespread coral species (Acropora spathulata and Pocillopora damicornis), subject to different levels of biological and physical disturbances along the most disturbed reef habitat, the crest. Marked intraspecific variation in the physiological condition of A. spathulata was clearly linked to differences in local disturbance regimes and habitat. Specifically, zooxanthellae density decreased (r2 = 26, df = 5,42, p<0.02, B =  -121255, p = 0.03) and total lipid content increased (r2 = 14, df = 5,42, p = 0.01, B = 0.9, p = 0.01) with increasing distance from exposed crests. Moreover, zooxanthellae density was strongly and negatively correlated with the individual level of partial mortality (r2 = 26, df = 5,42, p<0.02, B =  -7386077, p = 0.01). Conversely, P. damicornis exhibited very limited intraspecific variation in physiological condition, despite marked differences in levels of partial mortality. This is the first study to relate intraspecific variation in the condition of corals to localized differences in chronic disturbance regimes. The next step is to ascertain whether these differences have further ramifications for susceptibility to periodic acute disturbances, such as climate-induced coral bleaching.

Hydrodynamic conditioning of diversity and functional traits in subtidal estuarine macrozoobenthic communities

NASA Astrophysics Data System (ADS)

van der Wal, Daphne; Lambert, Gwladys I.; Ysebaert, Tom; Plancke, Yves M. G.; Herman, Peter M. J.

2017-10-01

Variations in abundance and diversity of estuarine benthic macrofauna are typically described along the salinity gradient. The influence of gradients in water depth, hydrodynamic energy and sediment properties are less well known. We studied how these variables influence the distribution of subtidal macrofauna in the polyhaline zone of a temperate estuary (Westerschelde, SW Netherlands). Macrofauna density, biomass and species richness, combined in a so-called ecological richness, decreased with current velocities and median grain-size and increased with organic carbon of the sediment, in total explaining 39% of the variation. The macrofauna community composition was less well explained by the three environmental variables (approx. 12-15% in total, with current velocity explaining approx. 8%). Salinity, water depth and distance to the intertidal zone had a very limited effect on both ecological richness and the macrofauna community. The proportion of (surface) deposit feeders (including opportunistic species), decreased relative to that of omnivores and carnivores with increasing current velocity and sediment grain-size. In parallel, the proportion of burrowing sessile benthic species decreased relative to that of mobile benthic species that are able to swim. Correspondingly, spatial variations in hydrodynamics yielded distinct hotspots and coldspots in ecological richness. The findings highlight the importance of local hydrodynamic conditions for estuarine restoration and conservation. The study provides a tool based on a hydrodynamic model to assess and predict ecological richness in estuaries.

Comparison of efficiency of distance measurement methodologies in mango (Mangifera indica) progenies based on physicochemical descriptors.

PubMed

Alves, E O S; Cerqueira-Silva, C B M; Souza, A M; Santos, C A F; Lima Neto, F P; Corrêa, R X

2012-03-14

We investigated seven distance measures in a set of observations of physicochemical variables of mango (Mangifera indica) submitted to multivariate analyses (distance, projection and grouping). To estimate the distance measurements, five mango progeny (total of 25 genotypes) were analyzed, using six fruit physicochemical descriptors (fruit weight, equatorial diameter, longitudinal diameter, total soluble solids in °Brix, total titratable acidity, and pH). The distance measurements were compared by the Spearman correlation test, projection in two-dimensional space and grouping efficiency. The Spearman correlation coefficients between the seven distance measurements were, except for the Mahalanobis' generalized distance (0.41 ≤ rs ≤ 0.63), high and significant (rs ≥ 0.91; P < 0.001). Regardless of the origin of the distance matrix, the unweighted pair group method with arithmetic mean grouping method proved to be the most adequate. The various distance measurements and grouping methods gave different values for distortion (-116.5 ≤ D ≤ 74.5), cophenetic correlation (0.26 ≤ rc ≤ 0.76) and stress (-1.9 ≤ S ≤ 58.9). Choice of distance measurement and analysis methods influence the.

Temporal and spatial distribution of waterborne mercury in a gold miner's river.

PubMed

Picado, Francisco; Bengtsson, Göran

2012-10-26

We examined the spatial and temporal (hourly) variation of aqueous concentrations of mercury in a gold miner's river to determine factors that control transport, retention, and export of mercury. The mercury flux was estimated to account for episodic inputs of mercury through mining tailings, variations in flow rate, and the partitioning of mercury between dissolved and particulate phases. Water samples were collected upstream and downstream of two gold mining sites in the Artiguas river, Nicaragua. The samples were analyzed for dissolved and suspended mercury, total solids, dissolved organic carbon, and total iron in water. Water velocity was also measured at the sampling sites. We found that mercury was mainly transported in a suspended phase, with a temporal pattern of diurnal peaks corresponding to the amalgamation schedules at the mining plants. The concentrations decreased with distance from the mining sites, suggesting dilution by tributaries or sedimentation of particle-bound mercury. The lowest total mercury concentrations in the water were less than 0.1 μg l(-1) and the highest concentration was 5.0 μg l(-1). The mercury concentrations are below the present WHO guidelines of 6 μg l(-1) but are considered to lead to a higher risk to aquatic bacteria and fish in the stream than to humans. The aqueous concentrations exceed the hazard endpoints for both groups by a probability of about 1%. Particulate mercury accounted for the largest variation of mercury fluxes, whereas dissolved mercury made up most of the long-range transport along the stream. The estimated total mass of mercury retained due to sedimentation of suspended solids was 2.7 kg per year, and the total mass exported downstream from the mining area was 1.6 kg per year. This study demonstrates the importance of the temporal and spatial resolution of observations in describing the occurrence and fate of mercury in a river affected by anthropogenic activities.

Spatial variations in δ13C and δ15N values of primary consumers in a coastal lagoon

NASA Astrophysics Data System (ADS)

Como, S.; Magni, P.; Van Der Velde, G.; Blok, F. S.; Van De Steeg, M. F. M.

2012-12-01

The analysis of the contribution of a food source to a consumer's diet or the trophic position of a consumer is highly sensitive to the variability of the isotopic values used as input data. However, little is known in coastal lagoons about the spatial variations in the isotopic values of primary consumers considered 'end members' in the isotope mixing models for quantifying the diet of secondary consumers or as a baseline for estimating the trophic position of consumers higher up in the food web. We studied the spatial variations in the δ13C and δ15N values of primary consumers and sedimentary organic matter (SOM) within a selected area of the Cabras lagoon (Sardinia, Italy). Our aim was to assess how much of the spatial variation in isotopic values of primary consumers was due to the spatial variability between sites and how much was due to differences in short distances from the shore. Samples were collected at four stations (50-100 m apart) selected randomly at two sites (1.5-2 km apart) chosen randomly at two distances from the shore (i.e. in proximity of the shore -Nearshore - and about 200 m away from the shore -Offshore). The sampling was repeated in March, May and August 2006 using new sites at the two chosen distances from the shore on each date. The isotopic values of size-fractionated seston and macrophytes were also analyzed as a complementary characterization of the study area. While δ15N did not show any spatial variations, the δ13C values of deposit feeders, Alitta (=Neanthes) succinea, Lekanesphaera hookeri, Hydrobia acuta and Gammarus aequicauda, were more depleted Offshore than Nearshore. For these species, there were significant effects of distance or distance × dates in the mean δ13C values, irrespective of the intrinsic variation between sites. SOM showed similar spatial variations in δ13C values, with Nearshore-Offshore differences up to 6‰. This indicates that the spatial isotopic changes are transferred from the food sources to the deposit feeders studied. In contrast, δ13C and δ15N values of suspension feeders, Ficopomatus enigmaticus and Amphibalanus amphitrite, did not show major variations, either between sites, or between Nearshore and Offshore. These different patterns between deposit feeders and suspension feeders are probably due to a weaker trophic link of the latter with SOM. We suggest that the Nearshore-Offshore gradient might be an important source of isotopic variation that needs to be considered in future web studies in coastal lagoons.

Effects of habitat composition and landscape structure on worker foraging distances of five bumble bee species.

PubMed

Redhead, John W; Dreier, Stephanie; Bourke, Andrew F G; Heard, Matthew S; Jordan, William C; Sumner, Seirian; Wang, Jinliang; Carvell, Claire

2016-04-01

Bumble bees (Bombus spp.) are important pollinators of both crops and wildflowers. Their contribution to this essential ecosystem service has been threatened over recent decades by changes in land use, which have led to declines in their populations. In order to design effective conservation measures, it is important to understand the effects of variation in landscape composition and structure on the foraging activities of worker bumble bees. This is because the viability of individual colonies is likely to be affected by the trade-off between the energetic costs of foraging over greater distances and the potential gains from access to additional resources. We used field surveys, molecular genetics, and fine resolution remote sensing to estimate the locations of wild bumble bee nests and to infer foraging distances across a 20-km² agricultural landscape in southern England, UK. We investigated five species, including the rare B. ruderatus and ecologically similar but widespread B. hortorum. We compared worker foraging distances between species and examined how variation in landscape composition and structure affected foraging distances at the colony level. Mean worker foraging distances differed significantly between species. Bombus terrestris, B. lapidarius, and B. ruderatus exhibited significantly greater mean foraging distances (551, 536, and 501 m, respectively) than B. hortorum and B. pascuorum (336 and 272 m, respectively). There was wide variation in worker foraging distances between colonies of the same species, which was in turn strongly influenced by the amount and spatial configuration of available foraging habitats. Shorter foraging distances were found for colonies where the local landscape had high coverage and low fragmentation of semi-natural vegetation, including managed agri-environmental field margins. The strength of relationships between different landscape variables and foraging distance varied between species, for example the strongest relationship for B. ruderatus being with floral cover of preferred forage plants. Our findings suggest that management of landscape composition and configuration has the potential to reduce foraging distances across a range of bumble bee species. There is thus potential for improvements in the design and implementation of landscape management options, such as agri-environment schemes, aimed at providing foraging habitat for bumble bees and enhancing crop pollination services.

Estimation of density of mongooses with capture-recapture and distance sampling

USGS Publications Warehouse

Corn, J.L.; Conroy, M.J.

1998-01-01

We captured mongooses (Herpestes javanicus) in live traps arranged in trapping webs in Antigua, West Indies, and used capture-recapture and distance sampling to estimate density. Distance estimation and program DISTANCE were used to provide estimates of density from the trapping-web data. Mean density based on trapping webs was 9.5 mongooses/ha (range, 5.9-10.2/ha); estimates had coefficients of variation ranging from 29.82-31.58% (X?? = 30.46%). Mark-recapture models were used to estimate abundance, which was converted to density using estimates of effective trap area. Tests of model assumptions provided by CAPTURE indicated pronounced heterogeneity in capture probabilities and some indication of behavioral response and variation over time. Mean estimated density was 1.80 mongooses/ha (range, 1.37-2.15/ha) with estimated coefficients of variation of 4.68-11.92% (X?? = 7.46%). Estimates of density based on mark-recapture data depended heavily on assumptions about animal home ranges; variances of densities also may be underestimated, leading to unrealistically narrow confidence intervals. Estimates based on trap webs require fewer assumptions, and estimated variances may be a more realistic representation of sampling variation. Because trap webs are established easily and provide adequate data for estimation in a few sample occasions, the method should be efficient and reliable for estimating densities of mongooses.

Photovoltaic array for Martian surface power

NASA Technical Reports Server (NTRS)

Appelbaum, J.; Landis, G. A.

1992-01-01

Missions to Mars will require electric power. A leading candidate for providing power is solar power produced by photovoltaic arrays. To design such a power system, detailed information on solar-radiation availability on the Martian surface is necessary. The variation of the solar radiation on the Martian surface is governed by three factors: (1) variation in Mars-Sun distance; (2) variation in solar zenith angle due to Martian season and time of day; and (3) dust in the Martian atmosphere. A major concern is the dust storms, which occur on both local and global scales. However, there is still appreciable diffuse sunlight available even at high opacity, so that solar array operation is still possible. Typical results for tracking solar collectors are also shown and compared to the fixed collectors. During the Northern Hemisphere spring and summer the isolation is relatively high, 2-5 kW-hr/sq m-day, due to the low optical depth of the Martian atmosphere. These seasons, totalling a full terrestrial year, are the likely ones during which manned mission will be carried out.

Noise measurements for various configurations of a model of a mixer nozzle externally blown flap system

NASA Technical Reports Server (NTRS)

Goodykoontz, J. H.; Wagner, J. M.; Sargent, N. B.

1973-01-01

Noise data were taken for variations to a large scale model of an externally blown flap lift augmentation system. The variations included two different mixer nozzles (7 and 8 lobes), two different wing models (2 and 3 flaps), and different lateral distances between the wing chord line and the nozzle centerline. When the seven lobe was used with the trailing flap in the 60 deg position, increasing the wing to nozzle distance had no effect on the sound level. When the eight lobe nozzle was used there was a decrease in sound level. With the 20 deg flap setting the noise level decreased when the distance was increased using either nozzle.

A variational dynamic programming approach to robot-path planning with a distance-safety criterion

NASA Technical Reports Server (NTRS)

Suh, Suk-Hwan; Shin, Kang G.

1988-01-01

An approach to robot-path planning is developed by considering both the traveling distance and the safety of the robot. A computationally-efficient algorithm is developed to find a near-optimal path with a weighted distance-safety criterion by using a variational calculus and dynamic programming (VCDP) method. The algorithm is readily applicable to any factory environment by representing the free workspace as channels. A method for deriving these channels is also proposed. Although it is developed mainly for two-dimensional problems, this method can be easily extended to a class of three-dimensional problems. Numerical examples are presented to demonstrate the utility and power of this method.

Genetic divergence of the common bean (Phaseolus vulgaris L.) group Carioca using morpho-agronomic traits by multivariate analysis.

PubMed

Gonçalves Ceolin, Ana Cristina; Gonçalves-Vidigal, Maria Celeste; Soares Vidigal Filho, Pedro; Vinícius Kvitschal, Marcus; Gonela, Adriana; Alberto Scapim, Carlos

2007-03-01

The objective of this study was to evaluate the genetic divergence among the common bean group Carioca by the Tocher method (based on Mahalanobis distance) and graphic dispersion of canonic variables, aiming to identify populations with wide genetic variability. Eighteen genotypes were evaluated in four seasons using a randomized block design with four replications. The mean weight of 100 seeds, in three experiments, and the mean number of pods per plant, in one experiment, were the most important characteristics for the genetic divergence, representing more than 46% of the total variation in the first canonic variable. The first two canonic variables were sufficient to explain about 88.23% of the total variation observed in the average of the four environments. The results showed that CNFC 8008 and CNFC 8009 genotypes presented the best yield averages in all the experiments. While Pérola, Princesa and CNFC 8005 cultivars were the most dissimilar for morpho-agronomic traits. Therefore, the combinations of PérolaxCNFC 8008, CNFC 8005xCNFC 8009, PérolaxCNFC 8009, PrincesaxCNFC 8008 and PrincesaxCNFC 8009 were indicated for interpopulational breeding.

Assessment of the influence of field size on maize gene flow using SSR analysis.

PubMed

Palaudelmàs, M; Melé, E; Monfort, A; Serra, J; Salvia, J; Messeguer, J

2012-06-01

One of the factors that may influence the rate of cross-fertilization is the relative size of the pollen donor and receptor fields. We designed a spatial distribution with four varieties of genetically-modified (GM) yellow maize to generate different sized fields while maintaining a constant distance to neighbouring fields of conventional white kernel maize. Samples of cross-fertilized, yellow kernels in white cobs were collected from all of the adjacent fields at different distances. A special series of samples was collected at distances of 0, 2, 5, 10, 20, 40, 80 and 120 m following a transect traced in the dominant down-wind direction in order to identify the origin of the pollen through SSR analysis. The size of the receptor fields should be taken into account, especially when they extend in the same direction than the GM pollen flow is coming. From collected data, we then validated a function that takes into account the gene flow found in the field border and that is very useful for estimating the % of GM that can be found in any point of the field. It also serves to predict the total GM content of the field due to cross fertilization. Using SSR analysis to identify the origin of pollen showed that while changes in the size of the donor field clearly influence the percentage of GMO detected, this effect is moderate. This study demonstrates that doubling the donor field size resulted in an approximate increase of GM content in the receptor field of 7%. This indicates that variations in the size of the donor field have a smaller influence on GM content than variations in the size of the receptor field.

Soil plutonium and cesium in stream channels and banks of Los Alamos liquid effluent-receiving areas.

PubMed

Nyhan, J W; White, G C; Trujillo, G

1982-10-01

Stream channel sediments and adjacent bank soils found in three intermittent streams used for treated liquid effluent disposal at Los Alamos, New Mexico were sampled to determine the distribution of 238Pu, 239,240Pu and 137Cs. Radionuclide concentrations and inventories were determined as functions of distance downstream from the waste outfall and from the center of the stream channel, soil sampling depth, stream channel-bank physiography, and the waste use history of each disposal area. Radionuclide concentrations in channel sediments were inversely related to distances up to 10 km downstream from the outfalls. For sites receiving appreciable waste effluent additions, contaminant concentrations in bank soils decreased with perpendicular distances greater than 0.38 m from the stream channel, and with stream bank sampling depths greater than 20-40 cm. Concentrations and total inventories of radionuclides in stream bank soils generally decreased as stream bank height increased. Inventory estimates of radionuclides in channel sediments exhibited coefficients of variation that ranged 0.41-2.6, reflecting the large variation in radionuclide concentrations at each site. Several interesting temporal relationships of these radionuclides in intermittent streams were gleaned from the varying waste use histories of the three effluent-receiving areas. Eleven yr after liquid wastes were added to one canyon, the major radionuclide inventories were found in the stream bank soils, unlike most of the other currently-used receiving areas. A period of time greater than 6 yr seems to be required before the plutonium in liquid wastes currently added to the canyon is approximately equilibrated with the plutonium in the bank soils. These observations are discussed relative to waste management practices in these southwestern intermittent streams.

New determination of the solar apex

NASA Astrophysics Data System (ADS)

Fehrenbach, Ch.; Duflot, M.; Burnage, R.

2001-04-01

Many studies recently have been performed to determine the velocity vector of the Sun, mainly using the latest data on proper motions and parallaxes given by the Hipparcos satellite. We wished to carry out a similar study using totally independent data: the numerous radial velocities (RV) obtained with the Fehrenbach Objective Prisms (PO). This method allows the determination of the RVs of all the stars contained in the same field. These RVs are relative to each other but are linked to the IAU standard system by means of at least two calibration stars of known RV belonging to that field. These data are very homogeneous. We discuss the precision of the results, and deduce that this material is relevant for the computation of the movement of the Sun towards its Apex. We have performed several studies: 1) With 6965 stars of magnitudes ranging from 7 to 10, measured with the small PO of 15 cm diameter (PPO), with the whole sample and with the same sample split into blue and red stars. 2) With 11 978 stars of magnitudes ranging from 7 to 11, by adding to the previous sample the stars measured with the 60 cm diameter PO associated with the Schmidt telescope of Observatoire de Haute Provence (SPO). The results of both studies are consistent. 3) We have estimated the distance D of all stars studied and determined U, V, W and S for four groups of stars selected according to their distances: D<100, ~ 100500 parsecs. We have determined the variation of U, V, W and S with respect to the distance of the stars. The variation of U, V and S is linear up to 500 parsecs. We can consider that W is constant.

Geoid Anomalies and the Near-Surface Dipole Distribution of Mass

NASA Technical Reports Server (NTRS)

Turcotte, D. L.; Ockendon, J. R.

1978-01-01

Although geoid or surface gravity anomalies cannot be uniquely related to an interior distribution of mass, they can be related to a surface mass distribution. However, over horizontal distances greater than about 100 km, the condition of isostatic equilibrium above the asthenosphere is a good approximation and the total mass per unit column is zero. Thus the surface distribution of mass is also zero. For this case we show that the surface gravitational potential anomaly can be uniquely related to a surface dipole distribution of mass. Variations in the thickness of the crust and lithosphere can be expected to produce undulations in the geoid.

A volatility index for comets

NASA Technical Reports Server (NTRS)

Whipple, Fred L.

1992-01-01

The variations in total brightness of a comet when it is most active, near perihelion, are presently used as the bases of a volatility index (VI) for short-period (SP) and long-period (LP) comets. Volatility does not correlate with period among the LP comets, and thereby shows no 'aging' effect; similarly, the VI measurements are the same for SP and for LP comets and exhibit no correlation with (1) absolute magnitude near perihelion, (2) orbital inclination, or (3) activity index measuring the intrinsic brightness change from great solar distances to the maximum near perihelion. Active comets are shown to be basically alike irrespective of their orbits or 'ages'.

Amplified effect of Brownian motion in bacterial near-surface swimming

PubMed Central

Li, Guanglai; Tam, Lick-Kong; Tang, Jay X.

2008-01-01

Brownian motion influences bacterial swimming by randomizing displacement and direction. Here, we report that the influence of Brownian motion is amplified when it is coupled to hydrodynamic interaction. We examine swimming trajectories of the singly flagellated bacterium Caulobacter crescentus near a glass surface with total internal reflection fluorescence microscopy and observe large fluctuations over time in the distance of the cell from the solid surface caused by Brownian motion. The observation is compared with computer simulation based on analysis of relevant physical factors, including electrostatics, van der Waals force, hydrodynamics, and Brownian motion. The simulation reproduces the experimental findings and reveals contribution from fluctuations of the cell orientation beyond the resolution of present observation. Coupled with hydrodynamic interaction between the bacterium and the boundary surface, the fluctuations in distance and orientation subsequently lead to variation of the swimming speed and local radius of curvature of swimming trajectory. These results shed light on the fundamental roles of Brownian motion in microbial motility, nutrient uptake, and adhesion. PMID:19015518

A speckle hologram of the interstellar plasma

NASA Technical Reports Server (NTRS)

Desai, K. M.; Gwinn, C. R.; Reynolds, J.; King, E. A.; Jauncey, D.; Flanagan, C.; Nicolson, G.; Preston, R. A.; Jones, D. L.

1992-01-01

Observations of a speckle hologram of scattering material along the line of sight to the Vela pulsar indicate that this material is concentrated in the Vela supernova remnant, deep within the Gum Nebula. The speckle hologram is observed through the amplitude and phase variations of the interferometric cross-power spectrum with time and frequency. These variations describe the density fluctuations of the interstellar plasma, in a holographic fashion. The decorrelation due to the phase variations of the speckles yields the angular size of the scattering disk; comparison with the bandwidth of their amplitude variations yields a characteristic distance from earth to the scattering material of 0.81 +/- 0.03 of the distance from earth to the pulsar. This result is consistent with theories of irregularities associated with particle acceleration in shocks in supernova remnants.

Functional acclimation across microgeographic scales in Dodonaea viscosa

PubMed Central

Baruch, Zdravko; Jones, Alice R; Hill, Kathryn E; McInerney, Francesca A; Blyth, Colette; Caddy-Retalic, Stefan; Christmas, Matthew J; Gellie, Nicholas J C; Lowe, Andrew J; Martin-Fores, Irene; Nielson, Kristine E

2018-01-01

Abstract Intraspecific plant functional trait variation provides mechanistic insight into persistence and can infer population adaptive capacity. However, most studies explore intraspecific trait variation in systems where geographic and environmental distances co-vary. Such a design reduces the certainty of trait–environment associations, and it is imperative for studies that make trait–environment associations be conducted in systems where environmental distance varies independently of geographic distance. Here we explored trait variation in such a system, and aimed to: (i) quantify trait variation of parent and offspring generations, and associate this variation to parental environments; (ii) determine the traits which best explain population differences; (iii) compare parent and offspring trait–trait relationships. We characterized 15 plant functional traits in eight populations of a shrub with a maximum separation ca. 100 km. Populations differed markedly in aridity and elevation, and environmental distance varied independently of geographic distance. We measured traits in parent populations collected in the field, as well as their offspring reared in greenhouse conditions. Parent traits regularly associated with their environment. These associations were largely lost in the offspring generation, indicating considerable phenotypic plasticity. An ordination of parent traits showed clear structure with strong influence of leaf area, specific leaf area, stomatal traits, isotope δ13C and δ15N ratios, and Narea, whereas the offspring ordination was less structured. Parent trait–trait correlations were in line with expectations from the leaf economic spectrum. We show considerable trait plasticity in the woody shrub over microgeographic scales (<100 km), indicating it has the adaptive potential within a generation to functionally acclimate to a range of abiotic conditions. Since our study shrub is commonly used for restoration in southern Australia and local populations do not show strong genetic differentiation in functional traits, the potential risks of transferring seed across the broad environmental conditions are not likely to be a significant issue.

Gender differences in knee morphology and the prospects for implant design in total knee replacement.

PubMed

Asseln, Malte; Hänisch, Christoph; Schick, Fabian; Radermacher, Klaus

2018-05-14

Morphological differences between female and male knees have been reported in the literature, which led to the development of so-called gender-specific implants. However, detailed morphological descriptions covering the entire joint are rare and little is known regarding whether gender differences are real sexual dimorphisms or can be explained by overall differences in size. We comprehensively analysed knee morphology using 33 features of the femur and 21 features of the tibia to quantify knee shape. The landmark recognition and feature extraction based on three-dimensional surface data were fully automatically applied to 412 pathological (248 female and 164 male) knees undergoing total knee arthroplasty. Subsequently, an exploratory statistical analysis was performed and linear correlation analysis was used to investigate normalization factors and gender-specific differences. Statistically significant differences between genders were observed. These were pronounced for distance measurements and negligible for angular (relative) measurements. Female knees were significantly narrower at the same depth compared to male knees. The correlation analysis showed that linear correlations were higher for distance measurements defined in the same direction. After normalizing the distance features according to overall dimensions in the direction of their definition, gender-specific differences disappeared or were smaller than the related confidence intervals. Implants should not be linearly scaled according to one dimension. Instead, features in medial/lateral and anterior/posterior directions should be normalized separately (non-isotropic scaling). However, large inter-individual variations of the features remain after normalization, suggesting that patient-specific design solutions are required for an improved implant design, regardless of gender. Copyright © 2018 Elsevier B.V. All rights reserved.

[Spatiotemporal variation of Populus euphratica's radial increment at lower reaches of Tarim River after ecological water transfer].

PubMed

An, Hong-Yan; Xu, Hai-Liang; Ye, Mao; Yu, Pu-Ji; Gong, Jun-Jun

2011-01-01

Taking the Populus euphratica at lower reaches of Tarim River as test object, and by the methods of tree dendrohydrology, this paper studied the spatiotemporal variation of P. euphratic' s branch radial increment after ecological water transfer. There was a significant difference in the mean radial increment before and after ecological water transfer. The radial increment after the eco-water transfer was increased by 125%, compared with that before the water transfer. During the period of ecological water transfer, the radial increment was increased with increasing water transfer quantity, and there was a positive correlation between the annual radial increment and the total water transfer quantity (R2 = 0.394), suggesting that the radial increment of P. euphratica could be taken as the performance indicator of ecological water transfer. After the ecological water transfer, the radial increment changed greatly with the distance to the River, i.e. , decreased significantly along with the increasing distance to the River (P = 0.007). The P. euphratic' s branch radial increment also differed with stream segment (P = 0.017 ), i.e. , the closer to the head-water point (Daxihaizi Reservoir), the greater the branch radial increment. It was considered that the limited effect of the current ecological water transfer could scarcely change the continually deteriorating situation of the lower reaches of Tarim River.

Reserve size and fragmentation alter community assembly, diversity, and dynamics.

PubMed

Lasky, Jesse R; Keitt, Timothy H

2013-11-01

Researchers have disputed whether a single large habitat reserve will support more species than many small reserves. However, relatively little is known from a theoretical perspective about how reserve size affects competitive communities structured by spatial abiotic gradients. We investigate how reserve size affects theoretical communities whose assembly is governed by dispersal limitation, abiotic niche differentiation, and source-sink dynamics. Simulations were conducted with varying scales of dispersal across landscapes with variable environmental spatial autocorrelation. Landscapes were inhabited by simulated trees with seedling and adult stages. For a fixed total area in reserves, we found that small reserve systems increased the distance between environments dominated by different species, diminishing the effects of source-sink dynamics. As reserve size decreased, environmental limitations to community assembly became stronger, α species richness decreased, and γ richness increased. When dispersal occurred across short distances, a large reserve strategy caused greater stochastic community variation, greater α richness, and lower γ richness than in small reserve systems. We found that reserve size variation trades off between preserving different aspects of natural communities, including α diversity versus γ diversity. Optimal reserve size will depend on the importance of source-sink dynamics and the value placed on different characteristics of natural communities. Anthropogenic changes to the size and separation of remnant habitats can have far-reaching effects on community structure and assembly.

Conservation Genetics of an Endangered Lady’s Slipper Orchid: Cypripedium japonicum in China

PubMed Central

Qian, Xin; Li, Quan-Jian; Liu, Fen; Gong, Mao-Jiang; Wang, Cai-Xia; Tian, Min

2014-01-01

Knowledge about the population genetic variation of the endangered orchid, Cypripedium japonicum, is conducive to the development of conservation strategies. Here, we examined the levels and partitioning of inter-simple sequence repeat (ISSR) diversity (109 loci) in five populations of this orchid to gain insight into its genetic variation and population structure in Eastern and Central China. It harbored considerably lower levels of genetic diversity both at the population (percentage of polymorphic loci (PPL) = 11.19%, Nei’s gene diversity (H) = 0.0416 and Shannon’s information index (I) = 0.0613) and species level (PPL = 38.53%, H = 0.1273 and I = 0.1928) and a significantly higher degree of differentiation among populations (the proportion of the total variance among populations (Φpt) = 0.698) than those typical of ISSR-based studies in other orchid species. Furthermore, the Nei’s genetic distances between populations were independent of the corresponding geographical distances. Two main clusters are shown in an arithmetic average (UPGMA) dendrogram, which is in agreement with the results of principal coordinate analysis (PCoA) analysis and the STRUCTURE program. In addition, individuals within a population were more similar to each other than to those in other populations. Based on the genetic data and our field survey, the development of conservation management for this threatened orchid should include habitat protection, artificial gene flow and ex situ measures. PMID:24983476

Through the Lens of Cultural Awareness: A Primer for US Armed Forces Deploying to Arab and Middle Eastern Countries

DTIC Science & Technology

2006-01-01

Willingness to Compromise •Risk Avoidance •Time to Decision •Etc. The “What” ral Variation Behaviors •Context Sensitivity Values •Individualism vs ...Collectivism •Power Distance •Formality vs . informality •Uncertainty Avoidance •Relationship vs . Deal Focus •Long-term vs . Short term orientation •Time...Orientation Cognition •Reasoning Styles Cultural Variations Behaviors •Context Sensitivity Values •Individualism vs . Collectivism •Power Distance •Formality

Responses of Bacterial Communities in Arable Soils in a Rice-Wheat Cropping System to Different Fertilizer Regimes and Sampling Times

PubMed Central

Zhao, Jun; Ni, Tian; Li, Yong; Xiong, Wu; Ran, Wei; Shen, Biao; Shen, Qirong; Zhang, Ruifu

2014-01-01

Soil physicochemical properties, soil microbial biomass and bacterial community structures in a rice-wheat cropping system subjected to different fertilizer regimes were investigated in two seasons (June and October). All fertilizer regimes increased the soil microbial biomass carbon and nitrogen. Both fertilizer regime and time had a significant effect on soil physicochemical properties and bacterial community structure. The combined application of inorganic fertilizer and manure organic-inorganic fertilizer significantly enhanced the bacterial diversity in both seasons. The bacterial communities across all samples were dominated by Proteobacteria, Acidobacteria and Chloroflexi at the phylum level. Permutational multivariate analysis confirmed that both fertilizer treatment and season were significant factors in the variation of the composition of the bacterial community. Hierarchical cluster analysis based on Bray-Curtis distances further revealed that bacterial communities were separated primarily by season. The effect of fertilizer treatment is significant (P = 0.005) and accounts for 7.43% of the total variation in bacterial community. Soil nutrients (e.g., available K, total N, total P and organic matter) rather than pH showed significant correlation with the majority of abundant taxa. In conclusion, both fertilizer treatment and seasonal changes affect soil properties, microbial biomass and bacterial community structure. The application of NPK plus manure organic-inorganic fertilizer may be a sound fertilizer practice for sustainable food production. PMID:24465530

SU-E-T-748: Theoretical Investigation On Using High Energy Proton Beam for Total-Body-Irradiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, M; Zou, J; Chen, T

2015-06-15

Purpose: The broad-slow-rising entrance dose region proximal to the Bragg peak made by a mono-energetic proton beam could potentially be used for total body irradiation (TBI). Due to the quasi-uniform dose deposition, customized thickness compensation may not be required to deliver a uniform dose to patients with varied thickness. We investigated the possibility, efficacy, and hardware requirement to use such proton beam for TBI. Methods: A wedge shaped water phantom with thickness varying from 2 cm to 40 cm was designed to mimic a patient. Geant4 based Monte Carlo code was used to simulate broad mono-energetic proton beams with energymore » ranging from 250 MeV to 300 MeV radiating the phantom. A 6 MV photon with 1 cm water equivalent build-up used for conventional TBI was also calculated. A paired-opposing beam arrangement with no thickness compensation was used to generate TBI plans for all beam energies. Dose from all particles were scored on a grid size of 2 mm{sup 3}. Dose uniformity across the phantom was calculated to evaluate the plan. The field size limit and the dose uniformity of Mevion S250 proton system was examined by using radiochromic films placed at extended treatment distance with the open large applicator and 90° gantry angle. Results: To achieve a maximum ± 7.5% dose variation, the largest patient thickness variation allowed for 250 MeV, 275 MeV, and 300 MeV proton beams were 27.0 cm, 34.9 cm and 36.7 cm. The value for 6 MV photon beam was only 8.0 cm to achieve the same dose variation. With open gantry, Mevion S250 system allows 5 m source-to-surface distance producing an expected 70 cm{sup 2} field size. Conclusion: Energetic proton beam can potentially be used to deliver TBI. Treatment planning and delivery would be much simple since no thickness compensation is required to achieve a uniform dose distribution.« less

Distances to Nearby Galaxies via Long Period Variables

NASA Astrophysics Data System (ADS)

Jurcevic, John S.

A new method of measuring extra-Galactic distances has been developed based on the relationship between the luminosity of red supergiant variable (RSV) stars at optical wavelengths and the period of their luminosity variation. This period-luminosity (PL) relationship has been calibrated with RSVs from the Galactic Perseus OB1 association, the Large Magellanic Cloud, and M33 in the broadband optical R and I-bands, in a narrow part of the I-band at 8250 Å, and in the infrared K-band. By using these RSV PL relations, the distances to a sample of nearby galaxies (M101, NGC 2403, and NGC 2366) were determined. These galaxies were chosen because they had existing Cepheid based distances which allowed for a comparison between the two methods and provided a means of verifying the effectiveness of the RSV PL relation. The galaxies were also chosen to span a range of metallicity to allow an investigation of any effects due to metallicity differences. Photometry in the R-band was obtained over a period of three years for the galaxies with a coverage of 20, 17, and 13 epochs for M101, NGC 2403, and NGC 2366, respectively. By looking for red variable stars with periods in the range 100-1200 days the total number of RSVs discovered in the three galaxies was 123. Assuming a distance modulus for the Large Magellanic Cloud of 18.5 +/- 0.1 mag, single epoch I-band photometry of the RSVs was used to construct random phase PL relations resulting in distance moduli for M101, NGC 2403, and NGC 2366 of 29.40 +/- 0.16, 27.67 +/- 0.16, and 27.86 +/- 0.20 mag, respectively. Similarly, PL relations were also found using phase averaged R-band magnitudes which produced distance moduli of 29.09 +/- 0.16, 27.56 +/- 0.16, and 27.76 +/- 0.21 mag, respectively. These distances have been corrected for extinction by assuming values of E(B - V) = 0.10, 0.04, and 0.04 mag. The distances derived agree with those found via Cepheids which indicates that RSVs provide a very useful new method for measuring distances.

Metallurgical Effects of Shunting Current on Resistance Spot-Welded Joints of AA2219 Sheets

NASA Astrophysics Data System (ADS)

Jafari Vardanjani, M.; Araee, A.; Senkara, J.; Jakubowski, J.; Godek, J.

2016-08-01

Shunting effect is the loss of electrical current via the secondary circuit provided due to the existence of previous nugget in a series of welding spots. This phenomenon influences on metallurgical aspects of resistance spot-welded (RSW) joints in terms of quality and performance. In this paper RSW joints of AA2219 sheets with 1 mm thickness are investigated metallurgically for shunted and single spots. An electro-thermal finite element analysis is performed on the RSW process of shunted spot and temperature distribution and variation are obtained. These predictions are then compared with experimental micrographs. Three values of 5 mm, 20 mm, and infinite (i.e., single spot) are assumed for welding distance. Numerical and experimental results are matching each other in terms of nugget and HAZ geometry as increasing distance raised nugget size and symmetry of HAZ. In addition, important effect of shunting current on nugget thickness, microstructure, and Copper segregation on HAZ grain boundaries were discovered. A quantitative analysis is also performed about the influence of welding distance on important properties including ratio of nugget thickness and diameter ( r t), ratio of HAZ area on shunted and free side of nugget ( r HA), and ratio of equivalent segregated and total amount of Copper, measured in sample ( r Cu) on HAZ. Increasing distance from 5 mm to infinite, indicated a gain of 111.04, -45.55, and -75.15% in r t, r HA, and r Cu, respectively, while obtained ratios for 20 mm welding distance was suitable compared to single spot.

Spatial Characteristics of Tree Diameter Distributions in a Temperate Old-Growth Forest

PubMed Central

Zhao, Xiuhai; von Gadow, Klaus

2013-01-01

This contribution identifies spatial characteristics of tree diameter in a temperate forest in north-eastern China, based on a fully censused observational study area covering 500×600 m. Mark correlation analysis with three null hypothesis models was used to determine departure from expectations at different neighborhood distances. Tree positions are clumped at all investigated scales in all 37 studied species, while the diameters of most species are spatially negatively correlated, especially at short distances. Interestingly, all three cases showing short-distance attraction of dbh marks are associated with light-demanding shrub species. The short-distance attraction of dbh marks indicates spatially aggregated cohorts of stems of similar size. The percentage of species showing significant dbh suppression peaked at a 4 m distance under the heterogeneous Poisson model. At scales exceeding the peak distance, the percentage of species showing significant dbh suppression decreases sharply with increasing distances. The evidence from this large observational study shows that some of the variation of the spatial characteristics of tree diameters is related variations of topography and soil chemistry. However, an obvious interpretation of this result is still lacking. Thus, removing competitors surrounding the target trees is an effective way to avoid neighboring competition effects reducing the growth of valuable target trees in forest management practice. PMID:23527066

Spatial characteristics of tree diameter distributions in a temperate old-growth forest.

PubMed

Zhang, Chunyu; Wei, Yanbo; Zhao, Xiuhai; von Gadow, Klaus

2013-01-01

This contribution identifies spatial characteristics of tree diameter in a temperate forest in north-eastern China, based on a fully censused observational study area covering 500×600 m. Mark correlation analysis with three null hypothesis models was used to determine departure from expectations at different neighborhood distances. Tree positions are clumped at all investigated scales in all 37 studied species, while the diameters of most species are spatially negatively correlated, especially at short distances. Interestingly, all three cases showing short-distance attraction of dbh marks are associated with light-demanding shrub species. The short-distance attraction of dbh marks indicates spatially aggregated cohorts of stems of similar size. The percentage of species showing significant dbh suppression peaked at a 4 m distance under the heterogeneous Poisson model. At scales exceeding the peak distance, the percentage of species showing significant dbh suppression decreases sharply with increasing distances. The evidence from this large observational study shows that some of the variation of the spatial characteristics of tree diameters is related variations of topography and soil chemistry. However, an obvious interpretation of this result is still lacking. Thus, removing competitors surrounding the target trees is an effective way to avoid neighboring competition effects reducing the growth of valuable target trees in forest management practice.

Probing the Importance of Charge Flux in Force Field Modeling.

PubMed

Sedghamiz, Elaheh; Nagy, Balazs; Jensen, Frank

2017-08-08

We analyze the conformational dependence of atomic charges and molecular dipole moments for a selection of ∼900 conformations of peptide models of the 20 neutral amino acids. Based on a set of reference density functional theory calculations, we partition the changes into effects due to changes in bond distances, bond angles, and torsional angles and into geometry and charge flux contributions. This allows an assessment of the limitations of fixed charge force fields and indications for how to design improved force fields. The torsional degrees of freedom are the main contribution to conformational changes of atomic charges and molecular dipole moments, but indirect effects due to change in bond distances and angles account for ∼25% of the variation. Charge flux effects dominate for changes in bond distances and are also the main component of the variation in bond angles, while they are ∼25% compared to the geometry variations for torsional degrees of freedom. The geometry and charge flux contributions to some extent produce compensating effects.

Knowledge Distance, Cognitive-Search Processes, and Creativity

PubMed Central

Acar, Oguz Ali; van den Ende, Jan

2016-01-01

Prior research has provided conflicting arguments and evidence about whether people who are outsiders or insiders relative to a knowledge domain are more likely to demonstrate scientific creativity in that particular domain. We propose that the nature of the relationship between creativity and the distance of an individual’s expertise from a knowledge domain depends on his or her cognitive processes of problem solving (i.e., cognitive-search effort and cognitive-search variation). In an analysis of 230 solutions generated in a science contest platform, we found that distance was positively associated with creativity when problem solvers engaged in a focused search (i.e., low cognitive-search variation) and exerted a high level of cognitive effort. People whose expertise was close to a knowledge domain, however, were more likely to demonstrate creativity in that domain when they drew on a wide variety of different knowledge elements for recombination (i.e., high cognitive-search variation) and exerted substantial cognitive effort. PMID:27016241

Knowledge Distance, Cognitive-Search Processes, and Creativity: The Making of Winning Solutions in Science Contests.

PubMed

Acar, Oguz Ali; van den Ende, Jan

2016-05-01

Prior research has provided conflicting arguments and evidence about whether people who are outsiders or insiders relative to a knowledge domain are more likely to demonstrate scientific creativity in that particular domain. We propose that the nature of the relationship between creativity and the distance of an individual's expertise from a knowledge domain depends on his or her cognitive processes of problem solving (i.e., cognitive-search effort and cognitive-search variation). In an analysis of 230 solutions generated in a science contest platform, we found that distance was positively associated with creativity when problem solvers engaged in a focused search (i.e., low cognitive-search variation) and exerted a high level of cognitive effort. People whose expertise was close to a knowledge domain, however, were more likely to demonstrate creativity in that domain when they drew on a wide variety of different knowledge elements for recombination (i.e., high cognitive-search variation) and exerted substantial cognitive effort. © The Author(s) 2016.

A female black bear denning habitat model using a geographic information system

USGS Publications Warehouse

Clark, J.D.; Hayes, S.G.; Pledger, J.M.

1998-01-01

We used the Mahalanobis distance statistic and a raster geographic information system (GIS) to model potential black bear (Ursus americanus) denning habitat in the Ouachita Mountains of Arkansas. The Mahalanobis distance statistic was used to represent the standard squared distance between sample variates in the GIS database (forest cover type, elevation, slope, aspect, distance to streams, distance to roads, and forest cover richness) and variates at known bear dens. Two models were developed: a generalized model for all den locations and another specific to dens in rock cavities. Differences between habitat at den sites and habitat across the study area were represented in 2 new GIS themes as Mahalanobis distance values. Cells similar to the mean vector derived from the known dens had low Mahalanobis distance values, and dissimilar cells had high values. The reliability of the predictive model was tested by overlaying den locations collected subsequent to original model development on the resultant den habitat themes. Although the generalized model demonstrated poor reliability, the model specific to rock dens had good reliability. Bears were more likely to choose rock den locations with low Mahalanobis distance values and less likely to choose those with high values. The model can be used to plan the timing and extent of management actions (e.g., road building, prescribed fire, timber harvest) most appropriate for those sites with high or low denning potential. 

Diverse spore rains and limited local exchange shape fern genetic diversity in a recently created habitat colonized by long-distance dispersal

PubMed Central

De Groot, G. A.; During, H. J.; Ansell, S. W.; Schneider, H.; Bremer, P.; Wubs, E. R. J.; Maas, J. W.; Korpelainen, H.; Erkens, R. H. J.

2012-01-01

Background and Aims Populations established by long-distance colonization are expected to show low levels of genetic variation per population, but strong genetic differentiation among populations. Whether isolated populations indeed show this genetic signature of isolation depends on the amount and diversity of diaspores arriving by long-distance dispersal, and time since colonization. For ferns, however, reliable estimates of long-distance dispersal rates remain largely unknown, and previous studies on fern population genetics often sampled older or non-isolated populations. Young populations in recent, disjunct habitats form a useful study system to improve our understanding of the genetic impact of long-distance dispersal. Methods Microsatellite markers were used to analyse the amount and distribution of genetic diversity in young populations of four widespread calcicole ferns (Asplenium scolopendrium, diploid; Asplenium trichomanes subsp. quadrivalens, tetraploid; Polystichum setiferum, diploid; and Polystichum aculeatum, tetraploid), which are rare in The Netherlands but established multiple populations in a forest (the Kuinderbos) on recently reclaimed Dutch polder land following long-distance dispersal. Reference samples from populations throughout Europe were used to assess how much of the existing variation was already present in the Kuinderbos. Key Results A large part of the Dutch and European genetic diversity in all four species was already found in the Kuinderbos. This diversity was strongly partitioned among populations. Most populations showed low genetic variation and high inbreeding coefficients, and were assigned to single, unique gene pools in cluster analyses. Evidence for interpopulational gene flow was low, except for the most abundant species. Conclusions The results show that all four species, diploids as well as polyploids, were capable of frequent long-distance colonization via single-spore establishment. This indicates that even isolated habitats receive dense and diverse spore rains, including genotypes capable of self-fertilization. Limited gene flow may conserve the genetic signature of multiple long-distance colonization events for several decades. PMID:22323427

Variation in coastal Antarctic microbial community composition at sub-mesoscale: spatial distance or environmental filtering?

PubMed

Moreno-Pino, Mario; De la Iglesia, Rodrigo; Valdivia, Nelson; Henríquez-Castilo, Carlos; Galán, Alexander; Díez, Beatriz; Trefault, Nicole

2016-07-01

Spatial environmental heterogeneity influences diversity of organisms at different scales. Environmental filtering suggests that local environmental conditions provide habitat-specific scenarios for niche requirements, ultimately determining the composition of local communities. In this work, we analyze the spatial variation of microbial communities across environmental gradients of sea surface temperature, salinity and photosynthetically active radiation and spatial distance in Fildes Bay, King George Island, Antarctica. We hypothesize that environmental filters are the main control of the spatial variation of these communities. Thus, strong relationships between community composition and environmental variation and weak relationships between community composition and spatial distance are expected. Combining physical characterization of the water column, cell counts by flow cytometry, small ribosomal subunit genes fingerprinting and next generation sequencing, we contrast the abundance and composition of photosynthetic eukaryotes and heterotrophic bacterial local communities at a submesoscale. Our results indicate that the strength of the environmental controls differed markedly between eukaryotes and bacterial communities. Whereas eukaryotic photosynthetic assemblages responded weakly to environmental variability, bacteria respond promptly to fine-scale environmental changes in this polar marine system. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Genetic Variation and Geographic Differentiation Among Populations of the Nonmigratory Agricultural Pest Oedaleus infernalis (Orthoptera: Acridoidea) in China

PubMed Central

Sun, Wei; Dong, Hui; Gao, Yue-Bo; Su, Qian-Fu; Qian, Hai-Tao; Bai, Hong-Yan; Zhang, Zhu-Ting; Cong, Bin

2015-01-01

The nonmigratory grasshopper Oedaleus infernalis Saussure (Orthoptera : Acridoidea) is an agricultural pest to crops and forage grasses over a wide natural geographical distribution in China. The genetic diversity and genetic variation among 10 geographically separated populations of O. infernalis was assessed using polymerase chain reaction-based molecular markers, including the intersimple sequence repeat and mitochondrial cytochrome oxidase sequences. A high level of genetic diversity was detected among these populations from the intersimple sequence repeat (H: 0.2628, I: 0.4129, Hs: 0.2130) and cytochrome oxidase analyses (Hd: 0.653). There was no obvious geographical structure based on an unweighted pair group method analysis and median-joining network. The values of FST, θII, and Gst estimated in this study are low, and the gene flow is high (Nm > 4). Analysis of the molecular variance suggested that most of the genetic variation occurs within populations, whereas only a small variation takes place between populations. No significant correlation was found between the genetic distance and geographical distance. Overall, our results suggest that the geographical distance plays an unimpeded role in the gene flow among O. infernalis populations. PMID:26496789

Native South American genetic structure and prehistory inferred from hierarchical modeling of mtDNA.

PubMed

Lewis, Cecil M; Long, Jeffrey C

2008-03-01

Genetic diversity in Native South Americans forms a complex pattern at both the continental and local levels. In comparing the West to the East, there is more variation within groups and smaller genetic distances between groups. From this pattern, researchers have proposed that there is more variation in the West and that a larger, more genetically diverse, founding population entered the West than the East. Here, we question this characterization of South American genetic variation and its interpretation. Our concern arises because others have inferred regional variation from the mean variation within local populations without taking into account the variation among local populations within the same region. This failure produces a biased view of the actual variation in the East. In this study, we analyze the mitochondrial DNA sequence between positions 16040 and 16322 of the Cambridge reference sequence. Our sample represents a total of 886 people from 27 indigenous populations from South (22), Central (3), and North America (2). The basic unit of our analyses is nucleotide identity by descent, which is easily modeled and proportional to nucleotide diversity. We use a forward modeling strategy to fit a series of nested models to identity by descent within and between all pairs of local populations. This method provides estimates of identity by descent at different levels of population hierarchy without assuming homogeneity within populations, regions, or continents. Our main discovery is that Eastern South America harbors more genetic variation than has been recognized. We find no evidence that there is increased identity by descent in the East relative to the total for South America. By contrast, we discovered that populations in the Western region, as a group, harbor more identity by descent than has been previously recognized, despite the fact that average identity by descent within groups is lower. In this light, there is no need to postulate separate founding populations for the East and the West because the variability in the East could serve as a source for the Western gene pools.

Patterns and Processes in Marine Microeukaryotic Community Biogeography from Xiamen Coastal Waters and Intertidal Sediments, Southeast China

PubMed Central

Chen, Weidong; Pan, Yongbo; Yu, Lingyu; Yang, Jun; Zhang, Wenjing

2017-01-01

Microeukaryotes play key roles in the structure and functioning of marine ecosystems. Little is known about the relative importance of the processes that drive planktonic and benthic microeukaryotic biogeography in subtropical offshore areas. This study compares the microeukaryotic community compositions (MCCs) from offshore waters (n = 12) and intertidal sediments (n = 12) around Xiamen Island, southern China, using high-throughput sequencing of 18S rDNA. This work further quantifies the relative contributions of spatial and environmental variables on the distribution of marine MCCs (including total, dominant, rare and conditionally rare taxa). Our results showed that planktonic and benthic MCCs were significantly different, and the benthic richness (6627 OTUs) was much higher than that for plankton (4044 OTUs) with the same sequencing effort. Further, we found that benthic MCCs exhibited a significant distance-decay relationship, whereas the planktonic communities did not. After removing two unique sites (N2 and N3), however, 72% variation in planktonic community was explained well by stochastic processes. More importantly, both the environmental and spatial factors played significant roles in influencing the biogeography of total and dominant planktonic and benthic microeukaryotic communities, although their relative effects on these community variations were different. However, a high proportion of unexplained variation in the rare taxa (78.1–97.4%) and conditionally rare taxa (49.0–81.0%) indicated that more complex mechanisms may influence the assembly of the rare subcommunity. These results demonstrate that patterns and processes in marine microeukaryotic community assembly differ among the different habitats (coastal water vs. intertidal sediment) and different communities (total, dominant, rare and conditionally rare microeukaryotes), and provide novel insight on the microeukaryotic biogeography and ecological mechanisms in coastal waters and intertidal sediments at local scale. PMID:29075237

Genetic linkage map construction and QTL mapping of salt tolerance traits in Zoysiagrass (Zoysia japonica).

PubMed

Guo, Hailin; Ding, Wanwen; Chen, Jingbo; Chen, Xuan; Zheng, Yiqi; Wang, Zhiyong; Liu, Jianxiu

2014-01-01

Zoysiagrass (Zoysia Willd.) is an important warm season turfgrass that is grown in many parts of the world. Salt tolerance is an important trait in zoysiagrass breeding programs. In this study, a genetic linkage map was constructed using sequence-related amplified polymorphism markers and random amplified polymorphic DNA markers based on an F1 population comprising 120 progeny derived from a cross between Zoysia japonica Z105 (salt-tolerant accession) and Z061 (salt-sensitive accession). The linkage map covered 1211 cM with an average marker distance of 5.0 cM and contained 24 linkage groups with 242 marker loci (217 sequence-related amplified polymorphism markers and 25 random amplified polymorphic DNA markers). Quantitative trait loci affecting the salt tolerance of zoysiagrass were identified using the constructed genetic linkage map. Two significant quantitative trait loci (qLF-1 and qLF-2) for leaf firing percentage were detected; qLF-1 at 36.3 cM on linkage group LG4 with a logarithm of odds value of 3.27, which explained 13.1% of the total variation of leaf firing and qLF-2 at 42.3 cM on LG5 with a logarithm of odds value of 2.88, which explained 29.7% of the total variation of leaf firing. A significant quantitative trait locus (qSCW-1) for reduced percentage of dry shoot clipping weight was detected at 44.1 cM on LG5 with a logarithm of odds value of 4.0, which explained 65.6% of the total variation. This study provides important information for further functional analysis of salt-tolerance genes in zoysiagrass. Molecular markers linked with quantitative trait loci for salt tolerance will be useful in zoysiagrass breeding programs using marker-assisted selection.

Dental and phylogeographic patterns of variation in gorillas.

PubMed

Pilbrow, Varsha

2010-07-01

Gorilla patterns of variation have great relevance for studies of human evolution. In this study, molar morphometrics were used to evaluate patterns of geographic variation in gorillas. Dental specimens of 323 adult individuals, drawn from the current distribution of gorillas in equatorial Africa were divided into 14 populations. Discriminant analyses and Mahalanobis distances were used to study population structure. Results reveal that: 1) the West and East African gorillas form distinct clusters, 2) the Cross River gorillas are well separated from the rest of the western populations, 3) gorillas from the Virunga mountains and the Bwindi Forest can be differentiated from the lowland gorillas of Utu and Mwenga-Fizi, 4) the Tshiaberimu gorillas are distinct from other eastern gorillas, and the Kahuzi-Biega gorillas are affiliated with them. These findings provide support for a species distinction between Gorilla gorilla and Gorilla beringei, with subspecies G. g. diehli, G. g. gorilla, G. b. graueri, G. b. beringei, and possibly, G. b. rex-pygmaeorum. Clear correspondence between dental and other patterns of taxonomic diversity demonstrates that dental data reveal underlying genetic patterns of differentiation. Dental distances increased predictably with altitude but not with geographic distances, indicating that altitudinal segregation explains gorilla patterns of population divergence better than isolation-by-distance. The phylogeographic pattern of gorilla dental metric variation supports the idea that Plio-Pleistocene climatic fluctuations and local mountain building activity in Africa affected gorilla phylogeography. I propose that West Africa comprised the historic center of gorilla distribution and experienced drift-gene flow equilibrium, whereas Nigeria and East Africa were at the periphery, where climatic instability and altitudinal variation promoted drift and genetic differentiation. This understanding of gorilla population structure has implications for gorilla conservation, and for understanding the distribution of sympatric chimpanzees and Plio-Pleistocene hominins.

Assessment of Geographic and Host-Associated Population Variations of the Carob Moth, Ectomyelois ceratoniae, on Pomegranate, Fig, Pistachio and Walnut, Using AFLP Markers

PubMed Central

Mozaffarian, Fariba; Mardi, Mohsen; Sarafrazi, Alimorad; Nouri Ganbalani, Gadir

2008-01-01

The carob moth, Ectomyelois ceratoniae (Zeller 1839) (Lepidoptera: Pyralidae) is the most important pest of pomegranate, Punica granatum L. (Myrtales: Ponicaceae), in Iran. In this study, 6 amplified fragment length polymorphism primer combinations were used to survey the genetic structure of the geographic and putative host-associated populations of this pest in Iran. An AMOVA was performed on test populations. Pairwise differences, Mantel test, multidimensional analysis, cluster analysis and migration rate were calculated for 5 geographic populations of E. ceratoniae sharing the same host, pomegranate. In another part of the study, 3 comparisons were performed on pairwise populations that were collected on different hosts (pomegranate, fig, pistachio and walnut) in same geographic regions. The results showed high within population variation (85.51% of total variation), however geographic populations differed significantly. The Mantel test did not show correlations between genetic and geographic distances. The probable factors that affect genetic distances are discussed. Multidimensional scaling analysis, migration rate and cluster analysis on geographic populations showed that the Arsanjan population was the most different from the others while the Saveh population was more similar to the Sabzevar population. The comparisons didn't show any host fidelity in test populations. It seems that the ability of E. ceratoniae to broaden its host range with no fidelity to hosts can decrease the efficiency of common control methods that are used on pomegranate. The results of this study suggest that in spite of the effects of geographic barriers, high within-population genetic variation, migration rate and gene flow can provide the opportunity for emerging new phenotypes or behaviors in pest populations, such as broadening host range, changing egg lying places, or changing over-wintering sites to adapt to difficult conditions such as those caused by intensive control methods. PMID:20345296

Community turnover of wood-inhabiting fungi across hierarchical spatial scales.

PubMed

Abrego, Nerea; García-Baquero, Gonzalo; Halme, Panu; Ovaskainen, Otso; Salcedo, Isabel

2014-01-01

For efficient use of conservation resources it is important to determine how species diversity changes across spatial scales. In many poorly known species groups little is known about at which spatial scales the conservation efforts should be focused. Here we examined how the community turnover of wood-inhabiting fungi is realised at three hierarchical levels, and how much of community variation is explained by variation in resource composition and spatial proximity. The hierarchical study design consisted of management type (fixed factor), forest site (random factor, nested within management type) and study plots (randomly placed plots within each study site). To examine how species richness varied across the three hierarchical scales, randomized species accumulation curves and additive partitioning of species richness were applied. To analyse variation in wood-inhabiting species and dead wood composition at each scale, linear and Permanova modelling approaches were used. Wood-inhabiting fungal communities were dominated by rare and infrequent species. The similarity of fungal communities was higher within sites and within management categories than among sites or between the two management categories, and it decreased with increasing distance among the sampling plots and with decreasing similarity of dead wood resources. However, only a small part of community variation could be explained by these factors. The species present in managed forests were in a large extent a subset of those species present in natural forests. Our results suggest that in particular the protection of rare species requires a large total area. As managed forests have only little additional value complementing the diversity of natural forests, the conservation of natural forests is the key to ecologically effective conservation. As the dissimilarity of fungal communities increases with distance, the conserved natural forest sites should be broadly distributed in space, yet the individual conserved areas should be large enough to ensure local persistence.

Community Turnover of Wood-Inhabiting Fungi across Hierarchical Spatial Scales

PubMed Central

Abrego, Nerea; García-Baquero, Gonzalo; Halme, Panu; Ovaskainen, Otso; Salcedo, Isabel

2014-01-01

For efficient use of conservation resources it is important to determine how species diversity changes across spatial scales. In many poorly known species groups little is known about at which spatial scales the conservation efforts should be focused. Here we examined how the community turnover of wood-inhabiting fungi is realised at three hierarchical levels, and how much of community variation is explained by variation in resource composition and spatial proximity. The hierarchical study design consisted of management type (fixed factor), forest site (random factor, nested within management type) and study plots (randomly placed plots within each study site). To examine how species richness varied across the three hierarchical scales, randomized species accumulation curves and additive partitioning of species richness were applied. To analyse variation in wood-inhabiting species and dead wood composition at each scale, linear and Permanova modelling approaches were used. Wood-inhabiting fungal communities were dominated by rare and infrequent species. The similarity of fungal communities was higher within sites and within management categories than among sites or between the two management categories, and it decreased with increasing distance among the sampling plots and with decreasing similarity of dead wood resources. However, only a small part of community variation could be explained by these factors. The species present in managed forests were in a large extent a subset of those species present in natural forests. Our results suggest that in particular the protection of rare species requires a large total area. As managed forests have only little additional value complementing the diversity of natural forests, the conservation of natural forests is the key to ecologically effective conservation. As the dissimilarity of fungal communities increases with distance, the conserved natural forest sites should be broadly distributed in space, yet the individual conserved areas should be large enough to ensure local persistence. PMID:25058128

Testosterone, migration distance, and migratory timing in song sparrows Melospiza melodia.

PubMed

Lymburner, Alannah H; Kelly, Tosha R; Hobson, Keith A; MacDougall-Shackleton, Elizabeth A; MacDougall-Shackleton, Scott A

2016-09-01

In seasonally migratory animals, migration distance often varies substantially within populations such that individuals breeding at the same site may overwinter different distances from the breeding grounds. Shorter migration may allow earlier return to the breeding grounds, which may be particularly advantageous to males competing to acquire a breeding territory. However, little is known about potential mechanisms that may mediate migration distance. We investigated naturally-occurring variation in androgen levels at the time of arrival to the breeding site and its relationship to overwintering latitude in male and female song sparrows (Melospiza melodia). We used stable isotope analysis of hydrogen (δ(2)H) in winter-grown claw tissue to infer relative overwintering latitude (migration distance), combined with 14years of capture records from a long-term study population to infer the arrival timing of males versus females. Relative to females, males had higher circulating androgen levels, migrated shorter distances, and were more likely to be caught early in the breeding season. Males that migrate short distances may benefit from early arrival at the breeding grounds, allowing them to establish a breeding territory. Even after controlling for sex and date, androgen levels were highest in individuals that migrated shorter distances. Our findings indicate that androgens and migration distance are correlated traits within and between sexes that may reflect individual variation within an integrated phenotype in which testosterone has correlated effects on behavioral traits such as migration. Copyright © 2016 Elsevier Inc. All rights reserved.

A Comparison of Measures of Boldness and Their Relationships to Survival in Young Fish

PubMed Central

White, James R.; Meekan, Mark G.; McCormick, Mark I.; Ferrari, Maud C. O.

2013-01-01

Boldness is the propensity of an animal to engage in risky behavior. Many variations of novel-object or novel-environment tests have been used to quantify the boldness of animals, although the relationship between test outcomes has rarely been investigated. Furthermore, the relationship of outcomes to any ecological aspect of fitness is generally assumed, rather than measured directly. Our study is the first to compare how the outcomes of the same test of boldness differ among observers and how different tests of boldness relate to the survival of individuals in the field. Newly-metamorphosed lemon damselfish, Pomacentrus moluccensis, were placed onto replicate patches of natural habitat. Individual behavior was quantified using four tests (composed of a total of 12 different measures of behavior): latency to enter a novel environment, activity in a novel environment, and reactions to threatening and benign novel objects. After behavior was quantified, survival was monitored for two days during which time fish were exposed to natural predators. Variation among observers was low for most of the 12 measures, except distance moved and the threat test (reaction to probe thrust), which displayed unacceptable amounts of inter-observer variation. Overall, the results of the behavioral tests suggested that novel environment and novel object tests quantified similar behaviors, yet these behavioral measures were not interchangeable. Multiple measures of behavior within the context of novel environment or object tests were the most robust way to assess boldness and these measures have a complex relationship with survivorship of young fish in the field. Body size and distance ventured from shelter were the only variables that had a direct and positive relationship with survival. PMID:23874804

A comparison of measures of boldness and their relationships to survival in young fish.

PubMed

White, James R; Meekan, Mark G; McCormick, Mark I; Ferrari, Maud C O

2013-01-01

Boldness is the propensity of an animal to engage in risky behavior. Many variations of novel-object or novel-environment tests have been used to quantify the boldness of animals, although the relationship between test outcomes has rarely been investigated. Furthermore, the relationship of outcomes to any ecological aspect of fitness is generally assumed, rather than measured directly. Our study is the first to compare how the outcomes of the same test of boldness differ among observers and how different tests of boldness relate to the survival of individuals in the field. Newly-metamorphosed lemon damselfish, Pomacentrus moluccensis, were placed onto replicate patches of natural habitat. Individual behavior was quantified using four tests (composed of a total of 12 different measures of behavior): latency to enter a novel environment, activity in a novel environment, and reactions to threatening and benign novel objects. After behavior was quantified, survival was monitored for two days during which time fish were exposed to natural predators. Variation among observers was low for most of the 12 measures, except distance moved and the threat test (reaction to probe thrust), which displayed unacceptable amounts of inter-observer variation. Overall, the results of the behavioral tests suggested that novel environment and novel object tests quantified similar behaviors, yet these behavioral measures were not interchangeable. Multiple measures of behavior within the context of novel environment or object tests were the most robust way to assess boldness and these measures have a complex relationship with survivorship of young fish in the field. Body size and distance ventured from shelter were the only variables that had a direct and positive relationship with survival.

Does the presence of cosmic dust influence the displacement of the Earth's Magnetopause?

NASA Astrophysics Data System (ADS)

Mann, I.; Hamrin, M.

2012-04-01

In a recent paper Treumann and Baumjohann propose that dust particles in interplanetary space occasionally cause large compressions of the magnetopause that, in the absence of coronal mass ejections, are difficult to explain by other mechanisms (R.A. Treumann and W. Baumjohann, Ann. Geophys. 30, 119-130, 2012). They suggest that enhanced dust number density raises the contribution of the dust component to the solar wind dynamical pressure and hence to the pressure balance that determines the extension of the magnetopause. They quantify the influence of the dust component in terms of a variation of the magnetopause stagnation point distance. As a possible event to trigger the compressions they propose the encounters with meteoroid dust streams along Earth's orbit. We investigate the conditions under which these compressions may occur. The estimate by Treumann and Baumjohann of the magnetopause variation presupposes that the dust particles have reached solar wind speed. Acceleration by electromagnetic forces is efficient in the solar wind for dust particles that have a sufficiently large ratio of surface charge to mass (Mann et al. Plasma Phys. Contr. Fusion, Vol. 52, 124012, 2010). This applies to small dust particles that contribute little to the total dust mass in meteoroid streams. The major fraction of dust particles that reach high speed in the solar wind are nanometer-sized dust particles that form and are accelerated in the inner solar system (Czechowski and Mann, ApJ, Vol. 714, 89, 2010). Observations suggest that the flux of these nanodust particles near 1 AU is highly time-variable (Meyer-Vernet, et al. Solar Physics, Vol. 256, 463, 2009). We estimate a possible variation of the magnetopause stagnation point distance caused by these nanodust fluxes and by the dust associated to meteoroid streams. We conclude that the Earth's encounters with meteoroid dust streams are not likely to strongly influence the magnetopause according to the proposed effect. We further use the expression for the magnetopause stagnation point distance used by Treumann and Baumjohann to investigate the possible influence of time-variable nanoddust fluxes on the magnetopause.

The relationship between observational scale and explained variance in benthic communities

PubMed Central

Flood, Roger D.; Frisk, Michael G.; Garza, Corey D.; Lopez, Glenn R.; Maher, Nicole P.

2018-01-01

This study addresses the impact of spatial scale on explaining variance in benthic communities. In particular, the analysis estimated the fraction of community variation that occurred at a spatial scale smaller than the sampling interval (i.e., the geographic distance between samples). This estimate is important because it sets a limit on the amount of community variation that can be explained based on the spatial configuration of a study area and sampling design. Six benthic data sets were examined that consisted of faunal abundances, common environmental variables (water depth, grain size, and surficial percent cover), and sonar backscatter treated as a habitat proxy (categorical acoustic provinces). Redundancy analysis was coupled with spatial variograms generated by multiscale ordination to quantify the explained and residual variance at different spatial scales and within and between acoustic provinces. The amount of community variation below the sampling interval of the surveys (< 100 m) was estimated to be 36–59% of the total. Once adjusted for this small-scale variation, > 71% of the remaining variance was explained by the environmental and province variables. Furthermore, these variables effectively explained the spatial structure present in the infaunal community. Overall, no scale problems remained to compromise inferences, and unexplained infaunal community variation had no apparent spatial structure within the observational scale of the surveys (> 100 m), although small-scale gradients (< 100 m) below the observational scale may be present. PMID:29324746

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

PubMed Central

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 flow. PMID:21858061

Stability, Visibility, and Histologic Analysis of a New Implanted Fiducial for Use as a Kilovoltage Radiographic or Radioactive Marker for Patient Positioning and Monitoring in Radiotherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Neustadter, David, E-mail: david.n@navotek.co; Tune, Michal; Zaretsky, Asaph

Purpose: To analyze the stability, visibility, and histology of a novel implantable soft-tissue marker (nonradioactive and radioactive) implanted in dog prostate and rabbit liver. Methods and Materials: A total of 34 nonradioactive and 35 radioactive markers were implanted in 1 dog and 16 rabbits. Stability was assessed by measuring intermarker distance (IMD) variation relative to IMDs at implantation. The IMDs were measured weekly for 4 months in the dog and biweekly for 2-4 weeks in the rabbits. Ultrasound and X-ray imaging were performed on all subjects. Computed tomography and MRI were performed on the dog. Histologic analysis was performed onmore » the rabbits after 2 or 4 months. Results: A total of 139 measurements had a mean ({+-} SD) absolute IMD variation of 1.1 {+-} 1.1 mm. These IMD variations are consistent with those reported in the literature as due to random organ deformation. The markers were visible, identifiable, and induced minimal or no image artifacts in all tested imaging modalities. Histologic analysis revealed that all pathologic changes were highly localized and not expected to be clinically significant. Conclusions: The markers were stable from the time of implantation. The markers were found to be compatible with all common medical imaging modalities. The markers caused no significant histologic effects. With respect to marker stability, visibility, and histologic analysis these implanted fiducials are appropriate for soft-tissue target positioning in radiotherapy.« less

[Variation trends of the vegetations in distribution region of Amur tiger based on MODIS NDVI].

PubMed

Wang, Hua-Ru; Wang, Tian-Ming; Ge, Han-Ping

2012-10-01

By using the averaged 250 m MODIS NDVI data in growth seasons of 2000-2010 and the approach of ordinary linear regression, this paper analyzed the variation trends of the vegetations in the distribution region of Amur tiger (Panthera tigris altaica), the Far East region of Russia and the eastern part of Northeast China, as well as the relationships between these variation trends and the anthropogenic activities. In 2000 - 2010, the areas with significantly decreased NDVI were sparsely distributed and accounted for 9.6% of the total, while the areas with significantly increased NDVI were mainly concentrated in the central part of northern Russia Far East Region and only accounted for 0.5% of the total. The percentage of the areas with significantly decreased NDVI in the distribution region of Amur tiger was slightly higher than that in the whole study region. The areas with significantly decreased NDVI were mainly distributed in the places of low elevation, gentle slope, and close to roads/railroads. The number of the pixels with significantly decreased NDVI increased with the increase of the nearest distance to residential locations first, and then decreased gradually. The significant decrease of the NDVI was closely related to the anthropogenic activities, and thus, to adopt effective measures to reduce human disturbances could control the vegetation degradation, and further, provide sustainable basis for the protection of Amur tiger and the conservation of the biodiversity in the studied region.

Optical coherence tomography for an in-vivo study of posterior-capsule-opacification types and their influence on the total-pulse energy required for Nd:YAG capsulotomy: a case series.

PubMed

Hawlina, Gregor; Perovšek, Darko; Drnovšek-Olup, Brigita; MoŽina, Janez; Gregorčič, Peter

2014-11-18

Posterior capsule opacification (PCO) is the most common post-operative complication associated with cataract surgery and is mostly treated with Nd:YAG laser capsulotomy. Here, we demonstrate the use of high-resolution spectral-domain optical coherence tomography (OCT) as a technique for PCO analysis. Additionally, we evaluate the influence of PCO types and the distance between the intraocular lens (IOL) and the posterior capsule (PC), i.e., the IOL/PC distance, on the total-pulse energy required for the Nd:YAG laser posterior capsulotomy. 47 eyes with PCO scheduled for the Nd:YAG procedure were examined and divided into four categories: fibrosis, pearl, mixed type and late-postoperative capsular bag distension syndrome. Using custom-made computer software for OCT image analysis, the IOL/PC distances in two dimensions were measured. The IOL/PC distances were compared with those of a control group of 15 eyes without PCO. The influence of the different PCO types and the IOL/PC distance on the total-pulse energy required for the Nd:YAG procedure was analyzed. The total-pulse energy required for a laser capsulotomy differs significantly between PCO types (p = 0.005, Kruskal-Wallis test). The highest energy was required for the fibrosis PCO type, followed by mixed, pearl and late-postoperative capsular bag distension syndrome. The IOL/PC distance also significantly influenced the total-pulse energy required for laser capsulotomy (p = 0.028, linear regression). Lower total-pulse energy was expected for a larger IOL/PC distance. Our study indicates that the PCO types and the IOL/PC distance influence the total-pulse energy required for Nd:YAG capsulotomy. The presented OCT method has the potential to become an additional tool for PCO characterization. Our results are important for a better understanding of the photodisruptive mechanisms in Nd:YAG capsulotomy.

An independent Cepheid distance scale: Current status

NASA Technical Reports Server (NTRS)

Barnes, T. G., III

1980-01-01

An independent distance scale for Cepheid variables is discussed. The apparent magnitude and the visual surface brightness, inferred from an appropriate color index, are used to determine the angular diameter variation of the Cepheid. When combined with the linear displacement curve obtained from the integrated radial velocity curve, the distance and linear radius are determined. The attractiveness of the method is its complete independence of all other stellar distance scales, even though a number of practical difficulties currently exist in implementing the technique.

Variational Problems with Long-Range Interaction

NASA Astrophysics Data System (ADS)

Soave, Nicola; Tavares, Hugo; Terracini, Susanna; Zilio, Alessandro

2018-06-01

We consider a class of variational problems for densities that repel each other at a distance. Typical examples are given by the Dirichlet functional and the Rayleigh functional D(u) = \\sum_{i=1}^k \\int_{Ω} |\

Bird diversity along a gradient of fragmented habitats of the Cerrado.

PubMed

Jesus, Shayana DE; Pedro, Wagner A; Bispo, Arthur A

2018-01-01

Understanding the factors that affect biodiversity is of central interest to ecology, and essential to species conservation and ecosystems management. We sampled bird communities in 17 forest fragments in the Cerrado biome, the Central-West region of Brazil. We aimed to know the communities structure pattern and the influence of geographical distance and environmental variables on them, along a gradient of fragmented habitats at both local and landscape scales. Eight structural variables of the fragments served as an environmental distance measurement at the local scale while five metrics served as an environmental distance measurement at the landscape scale. Species presence-absence data were used to calculate the dissimilarity index. Beta diversity was calculated using three indices (βsim, βnes and βsor), representing the spatial species turnover, nestedness and total beta diversity, respectively. Spatial species turnover was the predominant pattern in the structure of the communities. Variations in beta diversity were explained only by the environmental variables of the landscape with spatial configuration being more important than the composition. This fact indicates that, in Cerrado of Goiás avian communities structure, deterministic ecological processes associated to differences in species responses to landscape fragmentation are more important than stochastic processes driven by species dispersal.

[Genetic differentiation of Isaria farinosa populations in Anhui Province of East China].

PubMed

Sun, Zhao-Hong; Luan, Feng-Gang; Zhang, Da-Min; Chen, Ming-Jun; Wang, Bin; Li, Zeng-Zhi

2011-11-01

Isaria farinosa is an important entomopathogenic fungus. By using ISSR, this paper studied the genetic heterogeneity of six I. farinosa populations at different localities of Anhui Province, East China. A total of 98.5% polymorphic loci were amplified with ten polymorphic primers, but the polymorphism at population level varied greatly, within the range of 59.6%-93.2%. The genetic differentiation index (G(st)) between the populations based on Nei's genetic heterogenesis analysis was 0.3365, and the gene flow (N(m)) was 0.4931. The genetic differentiation between the populations was lower than that within the populations, suggesting that the genetic variation of I. farinosa mainly come from the interior of the populations. The UPGMA clustering based on the genetic similarities between the isolates revealed that the Xishan population was monophylectic, while the other five populations were polyphylectic, with the Yaoluoping population being the most heterogenic and the Langyashan population being the least heterogenic. No correlations were observed between the geographic distance and the genetic distance of the populations. According to the UPGMA clustering based on the genetic distance between the populations, the six populations were classified into three groups, and this classification was accorded with the clustering based on geographic environment, suggesting the effects of environmental heterogeneity on the population heterogeneity.

Temporal shifts and temperature sensitivity of avian spring migratory phenology: a phylogenetic meta-analysis.

PubMed

Usui, Takuji; Butchart, Stuart H M; Phillimore, Albert B

2017-03-01

There are wide reports of advances in the timing of spring migration of birds over time and in relation to rising temperatures, though phenological responses vary substantially within and among species. An understanding of the ecological, life-history and geographic variables that predict this intra- and interspecific variation can guide our projections of how populations and species are likely to respond to future climate change. Here, we conduct phylogenetic meta-analyses addressing slope estimates of the timing of avian spring migration regressed on (i) year and (ii) temperature, representing a total of 413 species across five continents. We take into account slope estimation error and examine phylogenetic, ecological and geographic predictors of intra- and interspecific variation. We confirm earlier findings that on average birds have significantly advanced their spring migration time by 2·1 days per decade and 1·2 days °C -1 . We find that over time and in response to warmer spring conditions, short-distance migrants have advanced spring migratory phenology by more than long-distance migrants. We also find that larger bodied species show greater advance over time compared to smaller bodied species. Our results did not reveal any evidence that interspecific variation in migration response is predictable on the basis of species' habitat or diet. We detected a substantial phylogenetic signal in migration time in response to both year and temperature, suggesting that some of the shifts in migratory phenological response to climate are predictable on the basis of phylogeny. However, we estimate high levels of species and spatial variance relative to phylogenetic variance, which is consistent with plasticity in response to climate evolving fairly rapidly and being more influenced by adaptation to current local climate than by common descent. On average, avian spring migration times have advanced over time and as spring has become warmer. While we are able to identify predictors that explain some of the true among-species variation in response, substantial intra- and interspecific variation in migratory response remains to be explained. © 2016 The Authors. Journal of Animal Ecology published by John Wiley & Sons Ltd on behalf of British Ecological Society.

Modeling Speech Level as a Function of Background Noise Level and Talker-to-Listener Distance for Talkers Wearing Hearing Protection Devices

ERIC Educational Resources Information Center

Bouserhal, Rachel E.; Bockstael, Annelies; MacDonald, Ewen; Falk, Tiago H.; Voix, Jérémie

2017-01-01

Purpose: Studying the variations in speech levels with changing background noise level and talker-to-listener distance for talkers wearing hearing protection devices (HPDs) can aid in understanding communication in background noise. Method: Speech was recorded using an intra-aural HPD from 12 different talkers at 5 different distances in 3…

Estimating vehicle height using homographic projections

DOEpatents

Cunningham, Mark F; Fabris, Lorenzo; Gee, Timothy F; Ghebretati, Jr., Frezghi H; Goddard, James S; Karnowski, Thomas P; Ziock, Klaus-peter

2013-07-16

Multiple homography transformations corresponding to different heights are generated in the field of view. A group of salient points within a common estimated height range is identified in a time series of video images of a moving object. Inter-salient point distances are measured for the group of salient points under the multiple homography transformations corresponding to the different heights. Variations in the inter-salient point distances under the multiple homography transformations are compared. The height of the group of salient points is estimated to be the height corresponding to the homography transformation that minimizes the variations.

Insensitivity of The Distance Ladder Hubble Constant Determination to Cepheid Calibration Modeling Choices

NASA Astrophysics Data System (ADS)

Follin, B.; Knox, L.

2018-03-01

Recent determination of the Hubble constant via Cepheid-calibrated supernovae by Riess et al. (2016) (R16) find ˜3σ tension with inferences based on cosmic microwave background temperature and polarization measurements from Planck. This tension could be an indication of inadequacies in the concordance ΛCDM model. Here we investigate the possibility that the discrepancy could instead be due to systematic bias or uncertainty in the Cepheid calibration step of the distance ladder measurement by R16. We consider variations in total-to-selective extinction of Cepheid flux as a function of line-of-sight, hidden structure in the period-luminosity relationship, and potentially different intrinsic colour distributions of Cepheids as a function of host galaxy. Considering all potential sources of error, our final determination of H0 = 73.3 ± 1.7 km/s/Mpc (not including systematic errors from the treatment of geometric distances or Type Ia Supernovae) shows remarkable robustness and agreement with R16. We conclude systematics from the modelling of Cepheid photometry, including Cepheid selection criteria, cannot explain the observed tension between Cepheid-variable and CMB-based inferences of the Hubble constant. Considering a `model-independent' approach to relating Cepheids in galaxies with known distances to Cepheids in galaxies hosting a Type Ia supernova and finding agreement with the R16 result, we conclude no generalization of the model relating anchor and host Cepheid magnitude measurements can introduce significant bias in the H0 inference.

Performance analysis of deciduous morphology for detecting biological siblings.

PubMed

Paul, Kathleen S; Stojanowski, Christopher M

2015-08-01

Family-centered burial practices influence cemetery structure and can represent social group composition in both modern and ancient contexts. In ancient sites dental phenotypic data are often used as proxies for underlying genotypes to identify potential biological relatives. Here, we test the performance of deciduous dental morphological traits for differentiating sibling pairs from unrelated individuals from the same population. We collected 46 deciduous morphological traits for 69 sibling pairs from the Burlington Growth Centre's long term Family Study. Deciduous crown features were recorded following published standards. After variable winnowing, inter-individual Euclidean distances were generated using 20 morphological traits. To determine whether sibling pairs are more phenotypically similar than expected by chance we used bootstrap resampling of distances to generate P values. Multidimensional scaling (MDS) plots were used to evaluate the degree of clustering among sibling pairs. Results indicate an average distance between siblings of 0.252, which is significantly less than 9,999 replicated averages of 69 resampled pseudo-distances generated from: 1) a sample of non-relative pairs (P < 0.001), and 2) a sample of relative and non-relative pairs (P < 0.001). MDS plots indicate moderate to strong clustering among siblings; families occupied 3.83% of the multidimensional space on average (versus 63.10% for the total sample). Deciduous crown morphology performed well in identifying related sibling pairs. However, there was considerable variation in the extent to which different families exhibited similarly low levels of phenotypic divergence. © 2015 Wiley Periodicals, Inc.

Insensitivity of the distance ladder Hubble constant determination to Cepheid calibration modelling choices

NASA Astrophysics Data System (ADS)

Follin, B.; Knox, L.

2018-07-01

Recent determination of the Hubble constant via Cepheid-calibrated supernovae by Riess et al.find ˜3σ tension with inferences based on cosmic microwave background (CMB) temperature and polarization measurements from Planck. This tension could be an indication of inadequacies in the concordance Λcold dark matter model. Here, we investigate the possibility that the discrepancy could instead be due to systematic bias or uncertainty in the Cepheid calibration step of the distance ladder measurement by Riess et al. We consider variations in total-to-selective extinction of Cepheid flux as a function of line of sight, hidden structure in the period-luminosity relationship, and potentially different intrinsic colour distributions of Cepheids as a function of host galaxy. Considering all potential sources of error, our final determination of H0 = 73.3 ± 1.7 km s-1Mpc-1 (not including systematic errors from the treatment of geometric distances or Type Ia supernovae) shows remarkable robustness and agreement with Riess et al. We conclude systematics from the modelling of Cepheid photometry, including Cepheid selection criteria, cannot explain the observed tension between Cepheid-variable and CMB-based inferences of the Hubble constant. Considering a `model-independent' approach to relating Cepheids in galaxies with known distances to Cepheids in galaxies hosting a Type Ia supernova and finding agreement with the Riess et al. result, we conclude no generalization of the model relating anchor and host Cepheid magnitude measurements can introduce significant bias in the H0 inference.

Do unpaved, low-traffic roads affect bird communities?

NASA Astrophysics Data System (ADS)

Mammides, Christos; Kounnamas, Constantinos; Goodale, Eben; Kadis, Costas

2016-02-01

Unpaved, low traffic roads are often assumed to have minimal effects on biodiversity. To explore this assertion, we sampled the bird communities in fifteen randomly selected sites in Pafos Forest, Cyprus and used multiple regression to quantify the effects of such roads on the total species richness. Moreover, we classified birds according to their migratory status and their global population trends, and tested each category separately. Besides the total length of unpaved roads, we also tested: a. the site's habitat diversity, b. the coefficient of variation in habitat (patch) size, c. the distance to the nearest agricultural field, and d. the human population size of the nearest village. We measured our variables at six different distances from the bird point-count locations. We found a strong negative relationship between the total bird richness and the total length of unpaved roads. The human population size of the nearest village also had a negative effect. Habitat diversity was positively related to species richness. When the categories were tested, we found that the passage migrants were influenced more by the road network while resident breeders were influenced by habitat diversity. Species with increasing and stable populations were only marginally affected by the variables tested, but the effect of road networks on species with decreasing populations was large. We conclude that unpaved and sporadically used roads can have detrimental effects on the bird communities, especially on vulnerable species. We propose that actions are taken to limit the extent of road networks within protected areas, especially in sites designated for their rich avifauna, such as Pafos Forest, where several of the affected species are species of European and global importance.

Proximity to the US-Mexico border: a key to explaining geographic variation in US methamphetamine, cocaine and heroin purity.

PubMed

Cunningham, James K; Maxwell, Jane Carlisle; Campollo, Octavio; Cunningham, Kathryn I; Liu, Lon-Mu; Lin, Hui-Lin

2010-10-01

Although illicit drug purity is a widely discussed health risk, research explaining its geographic variation within a country is rare. This study examines whether proximity to the US-Mexico border, the United States' primary drug import portal, is associated with geographic variation in US methamphetamine, heroin and cocaine purity. Distances (proximity) between the US-Mexico border and locations of methamphetamine, cocaine and heroin seizures/acquisitions (n = 239,070) recorded in STRIDE (System to Retrieve Information from Drug Evidence) were calculated for the period of 1990-2004. The association of drug purity with these distances and other variables, including time and seizure/acquisition size, was examined using hierarchical multivariate linear modeling (HMLM). Coterminous United States. Methamphetamine, cocaine and heroin purity generally decreased with distance from the US-Mexico border. Heroin purity, however, after initially declining with distance, turned upwards-a U-shaped association. During 2000-04, methamphetamine purity also had a U-shaped association with distance. For each of the three drugs, temporal changes in the purity of small acquisitions (<10 g) were typically more dynamic in areas closer to the US-Mexico border. Geographic variance in methamphetamine, cocaine and heroin purity throughout the coterminous United States was associated with US-Mexico border proximity. The U-shaped associations between border-distance and purity for heroin and methamphetamine may be due to imports of those drugs via the eastern United States and southeast Canada, respectively. That said, areas closer to the US-Mexico border generally had relatively high illicit drug purity, as well as more dynamic change in the purity of small ('retail level') drug amounts. © 2010 The Authors, Addiction © 2010 Society for the Study of Addiction.

The Size Frequency Distribution of Small Main-Belt Asteroids

NASA Technical Reports Server (NTRS)

Burt, Brian J.; Trilling, David E.; Hines, Dean C.; Stapelfeldt, Karl R.; Rebull, Luisa M.; Fuentes, Cesar I.; Hulsebus, Alan

2012-01-01

The asteroid size distribution informs us about the formation and composition of the Solar System. We build on our previous work in which we harvest serendipitously observed data of the Taurus region and measure the brightness and size distributions of Main-belt asteroids. This is accomplished with the highly sensitive MIPS 24 micron channel. We expect to catalog 104 asteroids, giving us a statistically significant data set. Results from this investigation will allow us to characterize the total population of small, Main-belt asteroids. Here we will present new results on the completeness of our study; on the presence of size distribution variations with inclination and radial distance in the belt; and early result on other archival fields.

Distance-dependent varieties of microbial community structure and metabolic functions in the rhizosphere of Sedum alfredii Hance during phytoextraction of a cadmium-contaminated soil.

PubMed

Yang, Wenhao; Zhang, Taoxiang; Lin, Sen; Ni, Wuzhong

2017-06-01

The recovery of microbial community and activities is crucial to the remediation of contaminated soils. Distance-dependent variations of microbial community composition and metabolic characteristics in the rhizospheric soil of hyperaccumulator during phytoextraction are poorly understood. A 12-month phytoextraction experiment with Sedum alfredii in a Cd-contaminated soil was conducted. A pre-stratified rhizobox was used for separating sub-layer rhizospheric (0-2, 2-4, 4-6, 6-8, 8-10 mm from the root mat)/bulk soils. Soil microbial structure and function were analyzed by phospholipid fatty acid (PLFA) and MicroResp™ methods. The concentrations of total and specified PLFA biomarkers and the utilization rates for the 14 substrates (organic carbon) in the 0-2-mm sub-layer rhizospheric soil were significantly increased, as well as decreased with the increase in the distance from the root mat. Microbial structure measured by the ratios of different groups of PLFAs such as fungal/bacterial, monounsaturated/saturated, ratios of Gram-positive to Gram-negative (GP/GN) bacterial, and cyclopropyl/monoenoic precursors and 19:0 cyclo/18:1ω7c were significantly changed in the 0-2-mm soil. The PLFA contents and substrate utilization rates were negatively correlated with pH and total, acid-soluble, and reducible fractions of Cd, while positively correlated with labile carbon. The dynamics of microbial community were likely due to root exudates and Cd uptake by S. alfredii. This study revealed the stimulations and gradient changes of rhizosphere microbial community through phytoextraction, as reduced Cd concentration, pH, and increased labile carbons are due to the microbial community responses.

Vocal Dose Measures: Quantifying Accumulated Vibration Exposure in Vocal Fold Tissues

PubMed Central

Titze, Ingo R.; Švec, Jan G.; Popolo, Peter S.

2011-01-01

To measure the exposure to self-induced tissue vibration in speech, three vocal doses were defined and described: distance dose, which accumulates the distance that tissue particles of the vocal folds travel in an oscillatory trajectory; energy dissipation dose, which accumulates the total amount of heat dissipated over a unit volume of vocal fold tissues; and time dose, which accumulates the total phonation time. These doses were compared to a previously used vocal dose measure, the vocal loading index, which accumulates the number of vibration cycles of the vocal folds. Empirical rules for viscosity and vocal fold deformation were used to calculate all the doses from the fundamental frequency (F0) and sound pressure level (SPL) values of speech. Six participants were asked to read in normal, monotone, and exaggerated speech and the doses associated with these vocalizations were calculated. The results showed that large F0 and SPL variations in speech affected the dose measures, suggesting that accumulation of phonation time alone is insufficient. The vibration exposure of the vocal folds in normal speech was related to the industrial limits for hand-transmitted vibration, in which the safe distance dose was derived to be about 500 m. This limit was found rather low for vocalization; it was related to a comparable time dose of about 17 min of continuous vocalization, or about 35 min of continuous reading with normal breathing and unvoiced segments. The voicing pauses in normal speech and dialogue effectively prolong the safe time dose. The derived safety limits for vocalization will likely require refinement based on a more detailed knowledge of the differences in hand and vocal fold tissue morphology and their response to vibrational stress, and on the effect of recovery of the vocal fold tissue during voicing pauses. PMID:12959470

Vocal dose measures: quantifying accumulated vibration exposure in vocal fold tissues.

PubMed

Titze, Ingo R; Svec, Jan G; Popolo, Peter S

2003-08-01

To measure the exposure to self-induced tissue vibration in speech, three vocal doses were defined and described: distance dose, which accumulates the distance that tissue particles of the vocal folds travel in an oscillatory trajectory; energy dissipation dose, which accumulates the total amount of heat dissipated over a unit volume of vocal fold tissues; and time dose, which accumulates the total phonation time. These doses were compared to a previously used vocal dose measure, the vocal loading index, which accumulates the number of vibration cycles of the vocal folds. Empirical rules for viscosity and vocal fold deformation were used to calculate all the doses from the fundamental frequency (F0) and sound pressure level (SPL) values of speech. Six participants were asked to read in normal, monotone, and exaggerated speech and the doses associated with these vocalizations were calculated. The results showed that large F0 and SPL variations in speech affected the dose measures, suggesting that accumulation of phonation time alone is insufficient. The vibration exposure of the vocal folds in normal speech was related to the industrial limits for hand-transmitted vibration, in which the safe distance dose was derived to be about 500 m. This limit was found rather low for vocalization; it was related to a comparable time dose of about 17 min of continuous vocalization, or about 35 min of continuous reading with normal breathing and unvoiced segments. The voicing pauses in normal speech and dialogue effectively prolong the safe time dose. The derived safety limits for vocalization will likely require refinement based on a more detailed knowledge of the differences in hand and vocal fold tissue morphology and their response to vibrational stress, and on the effect of recovery of the vocal fold tissue during voicing pauses.

Relation of exercise capacity with lung volumes before and after 6-minute walk test in subjects with COPD.

PubMed

Wibmer, Thomas; Rüdiger, Stefan; Kropf-Sanchen, Cornelia; Stoiber, Kathrin M; Rottbauer, Wolfgang; Schumann, Christian

2014-11-01

There is growing evidence that exercise-induced variation in lung volumes is an important source of ventilatory limitation and is linked to exercise intolerance in COPD. The aim of this study was to compare the correlations of walk distance and lung volumes measured before and after a 6-min walk test (6MWT) in subjects with COPD. Forty-five subjects with stable COPD (mean pre-bronchodilator FEV1: 47 ± 18% predicted) underwent a 6MWT. Body plethysmography was performed immediately pre- and post-6MWT. Correlations were generally stronger between 6-min walk distance and post-6MWT lung volumes than between 6-min walk distance and pre-6MWT lung volumes, except for FEV1. These differences in Pearson correlation coefficients were significant for residual volume expressed as percent of total lung capacity (-0.67 vs -0.58, P = .043), percent of predicted residual volume expressed as percent of total lung capacity (-0.68 vs -0.59, P = .026), inspiratory vital capacity (0.65 vs 0.54, P = .019), percent of predicted inspiratory vital capacity (0.49 vs 0.38, P = .037), and percent of predicted functional residual capacity (-0.62 vs -0.47, P = .023). In subjects with stable COPD, lung volumes measured immediately after 6MWT are more closely related to exercise limitation than baseline lung volumes measured before 6MWT, except for FEV1. Therefore, pulmonary function testing immediately after exercise should be included in future studies on COPD for the assessment of exercise-induced ventilatory constraints to physical performance that cannot be adequately assessed from baseline pulmonary function testing at rest. Copyright © 2014 by Daedalus Enterprises.

Precision Timing of PSR J0437-4715: An Accurate Pulsar Distance, a High Pulsar Mass, and a Limit on the Variation of Newton's Gravitational Constant

NASA Astrophysics Data System (ADS)

Verbiest, J. P. W.; Bailes, M.; van Straten, W.; Hobbs, G. B.; Edwards, R. T.; Manchester, R. N.; Bhat, N. D. R.; Sarkissian, J. M.; Jacoby, B. A.; Kulkarni, S. R.

2008-05-01

Analysis of 10 years of high-precision timing data on the millisecond pulsar PSR J0437-4715 has resulted in a model-independent kinematic distance based on an apparent orbital period derivative, dot Pb , determined at the 1.5% level of precision (Dk = 157.0 +/- 2.4 pc), making it one of the most accurate stellar distance estimates published to date. The discrepancy between this measurement and a previously published parallax distance estimate is attributed to errors in the DE200 solar system ephemerides. The precise measurement of dot Pb allows a limit on the variation of Newton's gravitational constant, |Ġ/G| <= 23 × 10-12 yr-1. We also constrain any anomalous acceleration along the line of sight to the pulsar to |a⊙/c| <= 1.5 × 10-18 s-1 at 95% confidence, and derive a pulsar mass, mpsr = 1.76 +/- 0.20 M⊙, one of the highest estimates so far obtained.

The radial gradients and collisional properties of solar wind electrons

NASA Technical Reports Server (NTRS)

Gilvie, K. W.; Scudder, J. D.

1977-01-01

The plasma instrument on Mariner 10 carried out measurements of electron density and temperature in the interplanetary medium between heliocentric distances of 0.85 and 0.45 AU. Due to the stable coronal configuration and low solar activity during the period of observation, the radial variations of these quantities could be obtained. The power-law exponent of the core temperature was measured to be -0.3 + or - 0.04, and the halo temperature was found to be almost independent of heliocentric distance. The exponent of the power law for the density variation was 2.5 + or - 0.2 and the extrapolated value at 1 AU was consistent with measured values during the same period. Calculations of the core electron self-collision time, and the core-halo equipartition time were made as a function of radial distance. These measurements indicate a macroscale picture of a Coulomb-collisional core and a collisionless isothermal halo. Extrapolating back to the sun, core and halo temperatures become equal at a radial distance of approx. 2-15 radii.

Assessing intraspecific variation in effective dispersal along an altitudinal gradient: a test in two Mediterranean high-mountain plants.

PubMed

Lara-Romero, Carlos; Robledo-Arnuncio, Juan J; García-Fernández, Alfredo; Iriondo, Jose M

2014-01-01

Plant recruitment depends among other factors on environmental conditions and their variation at different spatial scales. Characterizing dispersal in contrasting environments may thus be necessary to understand natural intraspecific variation in the processes underlying recruitment. Silene ciliata and Armeria caespitosa are two representative species of cryophilic pastures above the tree line in Mediterranean high mountains. No explicit estimations of dispersal kernels have been made so far for these or other high-mountain plants. Such data could help to predict their dispersal and recruitment patterns in a context of changing environments under ongoing global warming. We used an inverse modelling approach to analyse effective seed dispersal patterns in five populations of both Silene ciliata and Armeria caespitosa along an altitudinal gradient in Sierra de Guadarrama (Madrid, Spain). We considered four commonly employed two-dimensional seedling dispersal kernels exponential-power, 2Dt, WALD and log-normal. No single kernel function provided the best fit across all populations, although estimated mean dispersal distances were short (<1 m) in all cases. S. ciliata did not exhibit significant among-population variation in mean dispersal distance, whereas significant differences in mean dispersal distance were found in A. caespitosa. Both S. ciliata and A. caespitosa exhibited among-population variation in the fecundity parameter and lacked significant variation in kernel shape. This study illustrates the complexity of intraspecific variation in the processes underlying recruitment, showing that effective dispersal kernels can remain relatively invariant across populations within particular species, even if there are strong variations in demographic structure and/or physical environment among populations, while the invariant dispersal assumption may not hold for other species in the same environment. Our results call for a case-by-case analysis in a wider range of plant taxa and environments to assess the prevalence and magnitude of intraspecific dispersal variation.

Hot and Hypoxic Environments Inhibit Simulated Soccer Performance and Exacerbate Performance Decrements When Combined

PubMed Central

Aldous, Jeffrey W. F.; Chrismas, Bryna C. R.; Akubat, Ibrahim; Dascombe, Ben; Abt, Grant; Taylor, Lee

2016-01-01

The effects of heat and/or hypoxia have been well-documented in match-play data. However, large match-to-match variation for key physical performance measures makes environmental inferences difficult to ascertain from soccer match-play. Therefore, the present study aims to investigate the hot (HOT), hypoxic (HYP), and hot-hypoxic (HH) mediated-decrements during a non-motorized treadmill based soccer-specific simulation. Twelve male University soccer players completed three familiarization sessions and four randomized crossover experimental trials of the intermittent Soccer Performance Test (iSPT) in normoxic-temperate (CON: 18°C 50% rH), HOT (30°C; 50% rH), HYP (1000 m; 18°C 50% rH), and HH (1000 m; 30°C; 50% rH). Physical performance and its performance decrements, body temperatures (rectal, skin, and estimated muscle temperature), heart rate (HR), arterial blood oxygen saturation (SaO2), perceived exertion, thermal sensation (TS), body mass changes, blood lactate, and plasma volume were all measured. Performance decrements were similar in HOT and HYP [Total Distance (−4%), High-speed distance (~−8%), and variable run distance (~−12%) covered] and exacerbated in HH [total distance (−9%), high-speed distance (−15%), and variable run distance (−15%)] compared to CON. Peak sprint speed, was 4% greater in HOT compared with CON and HYP and 7% greater in HH. Sprint distance covered was unchanged (p > 0.05) in HOT and HYP and only decreased in HH (−8%) compared with CON. Body mass (−2%), temperatures (+2–5%), and TS (+18%) were altered in HOT. Furthermore, SaO2 (−8%) and HR (+3%) were changed in HYP. Similar changes in body mass and temperatures, HR, TS, and SaO2 were evident in HH to HOT and HYP, however, blood lactate (p < 0.001) and plasma volume (p < 0.001) were only significantly altered in HH. Perceived exertion was elevated (p < 0.05) by 7% in all conditions compared with CON. Regression analysis identified that absolute TS and absolute rise in skin and estimated muscle temperature (r = 0.82, r = 0.84 r = 0.82, respectively; p < 0.05) predicted the hot-mediated-decrements in HOT. The hot, hypoxic, and hot-hypoxic environments impaired physical performance during iSPT. Future interventions should address the increases in TS and body temperatures, to attenuate these decrements on soccer performance. PMID:26793122

Anthropometric Study of the Piriformis Muscle and Sciatic Nerve: A Morphological Analysis in a Polish Population

PubMed Central

Haładaj, Robert; Pingot, Mariusz; Polguj, Michał; Wysiadecki, Grzegorz; Topol, Mirosław

2015-01-01

Background The aim of this study was to determine relationships between piriformis muscle (PM) and sciatic nerve (SN) with reference to sex and anatomical variations. Material/Methods Deep dissection of the gluteal region was performed on 30 randomized, formalin-fixed human lower limbs of adults of both sexes of the Polish population. Anthropometric measurements were taken and then statistically analyzed. Results The conducted research revealed that, apart from the typical structure of the piriformis muscle, the most common variation was division of the piriformis muscle into two heads, with the common peroneal nerve running between them (20%). The group with anatomical variations of the sciatic nerve course displayed greater diversity of morphometric measurement results. There was a statistically significant correlation between the lower limb length and the distance from the sciatic nerve to the greater trochanter in the male specimens. On the other hand, in the female specimens, a statistically significant correlation was observed between the lower limb length and the distance from the sciatic nerve to the ischial tuberosity. The shortest distance from the sciatic nerve to the greater trochanter measured at the level of the inferior edge of the piriformis was 21 mm, while the shortest distance to the ischial tuberosity was 63 mm. Such correlations should be taken into account during invasive medical procedures performed in the gluteal region. Conclusions It is possible to distinguish several anatomical variations of the sciatic nerve course within the deep gluteal region. The statistically significant correlations between some anthropometric measurements were only present within particular groups of male and female limbs. PMID:26629744

The physiological basis of the migration continuum in brown trout (Salmo trutta).

PubMed

Boel, Mikkel; Aarestrup, Kim; Baktoft, Henrik; Larsen, Torben; Søndergaard Madsen, Steffen; Malte, Hans; Skov, Christian; Svendsen, Jon C; Koed, Anders

2014-01-01

Partial migration is common in many animal taxa; however, the physiological variation underpinning migration strategies remains poorly understood. Among salmonid fishes, brown trout (Salmo trutta) is one of the species that exhibits the most complex variation in sympatric migration strategies, expressed as a migration continuum, ranging from residency to anadromy. In looking at brown trout, our objective with this study was to test the hypothesis that variation in migration strategies is underpinned by physiological variation. Prior to migration, physiological samples were taken from fish in the stream and then released at the capture site. Using telemetry, we subsequently classified fish as resident, short-distance migrants (potamodromous), or long-distance migrants (potentially anadromous). Our results revealed that fish belonging to the resident strategy differed from those exhibiting any of the two migratory strategies. Gill Na,K-ATPase activity, condition factor, and indicators of nutritional status suggested that trout from the two migratory strategies were smoltified and energetically depleted before leaving the stream, compared to those in the resident strategy. The trout belonging to the two migratory strategies were generally similar; however, lower triacylglycerides levels in the short-distance migrants indicated that they were more lipid depleted prior to migration compared with the long-distance migrants. In the context of migration cost, we suggest that additional lipid depletion makes migrants more inclined to terminate migration at the first given feeding opportunity, whereas individuals that are less lipid depleted will migrate farther. Collectively, our data suggest that the energetic state of individual fish provides a possible mechanism underpinning the migration continuum in brown trout.

Genetic structure in striped skunks (Mephitis mephitis) on the southern high plains of Texas

USGS Publications Warehouse

Hansen, L.A.; Mathews, N.E.; Hansen, R.W.; Vander Lee, B. A.; Scott, Lutz R.

2003-01-01

Genetic variation within populations reflects population-level social and demographic processes and influences how a population behaves as an evolutionary unit. We examined partitioning of genetic variation in striped skunks (Mephitis mephitis) from the Southern High Plains of Texas during 1994-1995. Sixty-nine male and 35 female skunks were sampled on four 12.8-km2 study plots. Plot centers ranged from 17.6 to 61.6 km apart. We used multi-locus DNA fingerprinting with 2 probes, pV47 and CTTxAGG, to test 3 hypotheses: (1) females are more genetically similar to other females than males are to other males on the same plot (indicating greater female philopatry than male philopatry), (2) genetic similarity is greater within plots than among plots (indicating partitioning of genetic variation in space), and (3) genetic similarity of males decreases as the distance separating males increases (indicating geographic distance affects rates of gene flow). In general, males on a plot had lower average genetic similarity than females. Genetic similarity within plots was not different from genetic similarity among plots for males or for females. Genetic similarity of males did not decrease with increasing distance among plots. The lack of geographical genetic structure in striped skunks suggests at the scale of this study (<60 km) that gene flow of biparentally inherited genes is not distance-mediated. However, the higher similarity values for females than for males on the same plot supports an effect of male-biased dispersal and female philopatry on partitioning of genetic variation between sexes.

The Effects of Distance to Dentists and Dentist Supply on Children's Use of Dental Care.

PubMed

Wehby, George L; Shane, Dan M; Joshi, Adweta; Momany, Elizabeth; Chi, Donald L; Kuthy, Raymond A; Damiano, Peter C

2017-10-01

To examine the effects of distance to dentists and dentist supply on dental services use among children with Medicaid coverage in Iowa. Iowa Medicaid claims for enrolled children between 2000 and 2009. The study sample included 41,554 children (providing 158,942 child-year observations) who were born in Iowa between 2000 and 2006 and enrolled from birth in the Iowa Medicaid program. Children were followed through 2009. We used logistic regression to simultaneously examine the effects of distance (miles to nearest dentist) and county-level dentist supply on a broad range of dental services controlling for key confounders. Additional models only used within-child variation over time to remove unobservable time-invariant confounders. Distance was related to lower utilization of comprehensive dental exams (2 percent lower odds per 1 mile increase in distance), an effect that also held in models using within-child variation only. Dentist supply was positively related to comprehensive exams and other preventive services and negatively related to major dental treatments; however, these associations became smaller and insignificant when examining within-child changes except for other preventive services. Longer distance to dentists is a barrier for use of comprehensive dental exams, conditional on dentist supply. © Health Research and Educational Trust.

Suppression of Systematic Errors of Electronic Distance Meters for Measurement of Short Distances

PubMed Central

Braun, Jaroslav; Štroner, Martin; Urban, Rudolf; Dvořáček, Filip

2015-01-01

In modern industrial geodesy, high demands are placed on the final accuracy, with expectations currently falling below 1 mm. The measurement methodology and surveying instruments used have to be adjusted to meet these stringent requirements, especially the total stations as the most often used instruments. A standard deviation of the measured distance is the accuracy parameter, commonly between 1 and 2 mm. This parameter is often discussed in conjunction with the determination of the real accuracy of measurements at very short distances (5–50 m) because it is generally known that this accuracy cannot be increased by simply repeating the measurement because a considerable part of the error is systematic. This article describes the detailed testing of electronic distance meters to determine the absolute size of their systematic errors, their stability over time, their repeatability and the real accuracy of their distance measurement. Twenty instruments (total stations) have been tested, and more than 60,000 distances in total were measured to determine the accuracy and precision parameters of the distance meters. Based on the experiments’ results, calibration procedures were designed, including a special correction function for each instrument, whose usage reduces the standard deviation of the measurement of distance by at least 50%. PMID:26258777

Suppression of Systematic Errors of Electronic Distance Meters for Measurement of Short Distances.

PubMed

Braun, Jaroslav; Štroner, Martin; Urban, Rudolf; Dvoček, Filip

2015-08-06

In modern industrial geodesy, high demands are placed on the final accuracy, with expectations currently falling below 1 mm. The measurement methodology and surveying instruments used have to be adjusted to meet these stringent requirements, especially the total stations as the most often used instruments. A standard deviation of the measured distance is the accuracy parameter, commonly between 1 and 2 mm. This parameter is often discussed in conjunction with the determination of the real accuracy of measurements at very short distances (5-50 m) because it is generally known that this accuracy cannot be increased by simply repeating the measurement because a considerable part of the error is systematic. This article describes the detailed testing of electronic distance meters to determine the absolute size of their systematic errors, their stability over time, their repeatability and the real accuracy of their distance measurement. Twenty instruments (total stations) have been tested, and more than 60,000 distances in total were measured to determine the accuracy and precision parameters of the distance meters. Based on the experiments' results, calibration procedures were designed, including a special correction function for each instrument, whose usage reduces the standard deviation of the measurement of distance by at least 50%.

Regional variations in the diversity and predicted metabolic potential of benthic prokaryotes in coastal northern Zhejiang, East China Sea

PubMed Central

Wang, Kai; Ye, Xiansen; Zhang, Huajun; Chen, Heping; Zhang, Demin; Liu, Lian

2016-01-01

Knowledge about the drivers of benthic prokaryotic diversity and metabolic potential in interconnected coastal sediments at regional scales is limited. We collected surface sediments across six zones covering ~200 km in coastal northern Zhejiang, East China Sea and combined 16 S rRNA gene sequencing, community-level metabolic prediction, and sediment physicochemical measurements to investigate variations in prokaryotic diversity and metabolic gene composition with geographic distance and under local environmental conditions. Geographic distance was the most influential factor in prokaryotic β-diversity compared with major environmental drivers, including temperature, sediment texture, acid-volatile sulfide, and water depth, but a large unexplained variation in community composition suggested the potential effects of unmeasured abiotic/biotic factors and stochastic processes. Moreover, prokaryotic assemblages showed a biogeographic provincialism across the zones. The predicted metabolic gene composition similarly shifted as taxonomic composition did. Acid-volatile sulfide was strongly correlated with variation in metabolic gene composition. The enrichments in the relative abundance of sulfate-reducing bacteria and genes relevant with dissimilatory sulfate reduction were observed and predicted, respectively, in the Yushan area. These results provide insights into the relative importance of geographic distance and environmental condition in driving benthic prokaryotic diversity in coastal areas and predict specific biogeochemically-relevant genes for future studies. PMID:27917954

Interchange rotation factors and player characteristics influence physical and technical performance in professional Australian Rules football.

PubMed

Dillon, Patrick A; Kempton, Thomas; Ryan, Samuel; Hocking, Joel; Coutts, Aaron J

2018-03-01

To examine the effects of match-related and individual player characteristics on activity profile and technical performance during rotations in professional Australian football. Longitudinal observational study. Global positioning system data and player rating scores were collected from 33 professional Australian football players during 15 Australian football League matches. Player rating scores were time aligned with their relative total and high-speed running (HSR) distance (>20kmh -1 ) for each on ground rotation. Individual players' maximal aerobic running speed (MAS) was determined from a two-kilometre trial. A multilevel linear mixed model was used to examine the influence of rotations on physical activity profiles and skill execution during match play. Rotation duration and accumulated distance resulted in a trivial-to-moderate reduction in relative total and HSR distances as well as relative rating points. The number of disposals in a rotation had a small positive effect on relative total and HSR distances and a large positive effect on relative rating points. MAS was associated with a moderate-to-large increase in relative total distance, but had a large negative effect on relative rating points. Previous rotation time, stoppages and the number of rotations in the quarter had a trivial-to-small negative effect on relative total and HSR distances. A greater speed (mmin -1 ) was associated with a trivial increase in rating points during a rotation, while there was a trivial decrease in relative total distance as rating points increased. The complex relationship between factors that influence activity profile and technical performance during rotations in Australian football needs to be considered when interpreting match performance. Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

An improved approach to the analysis of drug-protein binding by distance geometry

NASA Technical Reports Server (NTRS)

Goldblum, A.; Kieber-Emmons, T.; Rein, R.

1986-01-01

The calculation of side chain centers of coordinates and the subsequent generation of side chain-side chain and side chain-backbone distance matrices is suggested as an improved method for viewing interactions inside proteins and for the comparison of protein structures. The use of side chain distance matrices is demonstrated with free PTI, and the use of difference distance matrices for side chains is shown for free and trypsin-bound PTI as well as for the X-ray structures of trypsin complexes with PTI and with benzamidine. It is found that conformational variations are reflected in the side chain distance matrices much more than in the standard C-C distance representations.

Characterization of local goat breeds using RAP-DNA markers

NASA Astrophysics Data System (ADS)

Al-Barzinji, Yousif M. S.; Hamad, Aram O.

2017-09-01

The present study was conducted on different colors of local goat breeds. A number of 216 does were sampled from the seven groups. Genomic DNA was extracted from the blood samples. From the twenty used RAPD primers 12 of them were amplified, and presence of bands. The total fragment number of 12 primers over all the goat breed samples was 485 fragments. Out of the 485 fragments, 90 of them were Polymorphic fragments numbers (PFN). From all bands obtained, 20 of them possessed unique bands. The highest unique band was found in locus RAP 6 which has 4 unique bands, three of them in the Maraz Brown and one in the local Koor. Nei's gene diversity and Shanon's information index in this study were averaged 0.38 and 0.60, respectively. The genetic distance among several goat breeds ranged from 9.11 to 43.33%. The highest genetic distance 43.33% recorded between Maraz goat and other goat breeds and between local Koor and other goat (except Maraz goats) breeds (37.79%). However, the lowest genetic distance recorded between local white and Pnok. The distance between (local Black and Pnok) and (local Black and local white) was 22.75%. In conclusions, the high distance among these goat breeds, polymorphism and high numbers of unique bands found in present study indicates that these goat breeds have the required amount of genetic variation to made genetic improvement. This study helps us to clarify the image of the genetic diversity of the local goat breeds and the breeders can used it for mating system when need to make the crossing among these goat breeds.

Reconstruction based finger-knuckle-print verification with score level adaptive binary fusion.

PubMed

Gao, Guangwei; Zhang, Lei; Yang, Jian; Zhang, Lin; Zhang, David

2013-12-01

Recently, a new biometrics identifier, namely finger knuckle print (FKP), has been proposed for personal authentication with very interesting results. One of the advantages of FKP verification lies in its user friendliness in data collection. However, the user flexibility in positioning fingers also leads to a certain degree of pose variations in the collected query FKP images. The widely used Gabor filtering based competitive coding scheme is sensitive to such variations, resulting in many false rejections. We propose to alleviate this problem by reconstructing the query sample with a dictionary learned from the template samples in the gallery set. The reconstructed FKP image can reduce much the enlarged matching distance caused by finger pose variations; however, both the intra-class and inter-class distances will be reduced. We then propose a score level adaptive binary fusion rule to adaptively fuse the matching distances before and after reconstruction, aiming to reduce the false rejections without increasing much the false acceptances. Experimental results on the benchmark PolyU FKP database show that the proposed method significantly improves the FKP verification accuracy.

Measuring the diffusion of linguistic change

PubMed Central

Nerbonne, John

2010-01-01

We examine situations in which linguistic changes have probably been propagated via normal contact as opposed to via conquest, recent settlement and large-scale migration. We proceed then from two simplifying assumptions: first, that all linguistic variation is the result of either diffusion or independent innovation, and, second, that we may operationalize social contact as geographical distance. It is clear that both of these assumptions are imperfect, but they allow us to examine diffusion via the distribution of linguistic variation as a function of geographical distance. Several studies in quantitative linguistics have examined this relation, starting with Séguy (Séguy 1971 Rev. Linguist. Romane 35, 335–357), and virtually all report a sublinear growth in aggregate linguistic variation as a function of geographical distance. The literature from dialectology and historical linguistics has mostly traced the diffusion of individual features, however, so that it is sensible to ask what sort of dynamic in the diffusion of individual features is compatible with Séguy's curve. We examine some simulations of diffusion in an effort to shed light on this question. PMID:21041207

Measuring the diffusion of linguistic change.

PubMed

Nerbonne, John

2010-12-12

We examine situations in which linguistic changes have probably been propagated via normal contact as opposed to via conquest, recent settlement and large-scale migration. We proceed then from two simplifying assumptions: first, that all linguistic variation is the result of either diffusion or independent innovation, and, second, that we may operationalize social contact as geographical distance. It is clear that both of these assumptions are imperfect, but they allow us to examine diffusion via the distribution of linguistic variation as a function of geographical distance. Several studies in quantitative linguistics have examined this relation, starting with Séguy (Séguy 1971 Rev. Linguist. Romane 35, 335-357), and virtually all report a sublinear growth in aggregate linguistic variation as a function of geographical distance. The literature from dialectology and historical linguistics has mostly traced the diffusion of individual features, however, so that it is sensible to ask what sort of dynamic in the diffusion of individual features is compatible with Séguy's curve. We examine some simulations of diffusion in an effort to shed light on this question.

The Jovian magnetotail and its current sheet

NASA Technical Reports Server (NTRS)

Behannon, K. W.; Burlaga, L. F.; Ness, N. F.

1980-01-01

Analyses of Voyager magnetic field measurements have extended the understanding of the structural and temporal characteristics of Jupiter's magnetic tail. The magnitude of the magnetic field in the lobes of the tail is found to decrease with Jovicentric distance approximately as r to he-1.4, compared with the power law exponent of -1.7 found for the rate of decrease along the Pioneer 10 outbound trajectory. Voyager observations of magnetic field component variations with Jovicentric distance in the tail do not support the uniform radial plasma outflow model derived from Pioneer data. Voyager 2 has shown that the azimuthal current sheet which surrounds Jupiter in the inner and middle magnetosphere extends tailward (in the anti-Sun direction) to a distance of at least 100 R sub J. In the tail this current sheet consists of a plasma sheet and embedded neutral sheet. In the region of the tail where the sheet is observed, the variation of the magnetic field as a result of the sheet structure and its 10 hr periodic motion is the dominant variation seen.

Assessing genetic structure, diversity of bacterial aerosol from aeration system in an oxidation ditch wastewater treatment plant by culture methods and bio-molecular tools.

PubMed

Li, Lin; Han, Yunping; Liu, Junxin

2013-01-01

Airborne bacteria emissions from oxidation ditch with rotating aeration brushes were investigated in a municipal wastewater treatment plant in Beijing, China. Microbial samples were collected at different distances from the rotating brushes, different heights above the water surface, and different operation state over a 3-month period (April, May, and June) in order to estimate the seasonal variation and site-related distribution characteristics of the microorganisms present. The concentration of bacterial aerosol was analyzed by culture methods, while their dominant species, genetic structure and diversity were assayed using bio-molecular tools. Results showed that total microbial concentrations were highest in June and lowest in April. The mechanical rotation caused remarkable variation in concentration and diversity of culturable airborne bacteria before and after the rotating brushes. The highest concentration was observed near the rotating brushes (931 ± 129-3,952 ± 730 CFU/m(3)), with concentration decreasing as distance and height increased. Bacterial community polymerase chain reaction and denaturing gradient gel electrophoresis indicated that diversity decreased gradually with increasing height above the water surface but remained relatively constant at the same height. All dominant bacteria identified by DNA sequence analysis belonged to Firmicutes. Pathogenic species such as Moraxella nonliquefaciens and Flavobacterium odoratum were isolated from the bioaerosols. Due to the serious health risks involved, exposure of sewage workers to airborne microorganisms caused by brush aerators should be monitored and controlled.

Impact of anthropogenic pressure on the formation of population structure and genetic diversity of raccoon dog Nyctereutes procyonoides

PubMed Central

Griciuvienė, Loreta; Paulauskas, Algimantas; Radzijevskaja, Jana; Žukauskienė, Judita; Pūraitė, Irma

2016-01-01

Abstract The raccoon dog Nyctereutes procyonoides experienced an active introduction and acclimatization in the European part of Russia followed by its migration to and colonization in the neighboring countries. Eventually, it has spread rapidly into many European countries. N. procyonoides probably invaded Lithuania from the neighboring countries of Belarus and Latvia where the species was introduced. However, the data on genetic diversity and population structure of the raccoon dogs in the recently invaded territories are still scarce. The objectives of this study were to investigate genetic diversity of N. procyonoides in Lithuania after acclimatization, and to assess the impact of anthropogenic pressure on the formation of population structure. A total of 147 N. procyonoides individuals collected from different regions of Lithuania were genotyped using 17 microsatellite markers. The microsatellite analysis of raccoon dogs indicated high levels of genetic diversity within the population. The Bayesian clustering analysis in STRUCTURE identified 4 genetic clusters among sampled raccoon dogs that could not reveal a clear separation between subpopulations. The widespread distribution of raccoon dogs in Lithuania, high level of genetic variation observed within subpopulations, and low level of variation portioned among subpopulations suggest migration and gene flow among locations. The significant correlation between genetic and geographic distances indicated isolation that reflected the distance between locations. The fencing of highways and very intensive traffic could be barriers to gene flow between the western and eastern sampling areas of raccoon dogs. PMID:29491930

Behavioral metabolomics analysis identifies novel neurochemical signatures in methamphetamine sensitization

PubMed Central

Adkins, Daniel E.; McClay, Joseph L.; Vunck, Sarah A.; Batman, Angela M.; Vann, Robert E.; Clark, Shaunna L.; Souza, Renan P.; Crowley, James J.; Sullivan, Patrick F.; van den Oord, Edwin J.C.G.; Beardsley, Patrick M.

2014-01-01

Behavioral sensitization has been widely studied in animal models and is theorized to reflect neural modifications associated with human psychostimulant addiction. While the mesolimbic dopaminergic pathway is known to play a role, the neurochemical mechanisms underlying behavioral sensitization remain incompletely understood. In the present study, we conducted the first metabolomics analysis to globally characterize neurochemical differences associated with behavioral sensitization. Methamphetamine-induced sensitization measures were generated by statistically modeling longitudinal activity data for eight inbred strains of mice. Subsequent to behavioral testing, nontargeted liquid and gas chromatography-mass spectrometry profiling was performed on 48 brain samples, yielding 301 metabolite levels per sample after quality control. Association testing between metabolite levels and three primary dimensions of behavioral sensitization (total distance, stereotypy and margin time) showed four robust, significant associations at a stringent metabolome-wide significance threshold (false discovery rate < 0.05). Results implicated homocarnosine, a dipeptide of GABA and histidine, in total distance sensitization, GABA metabolite 4-guanidinobutanoate and pantothenate in stereotypy sensitization, and myo-inositol in margin time sensitization. Secondary analyses indicated that these associations were independent of concurrent methamphetamine levels and, with the exception of the myo-inositol association, suggest a mechanism whereby strain-based genetic variation produces specific baseline neurochemical differences that substantially influence the magnitude of MA-induced sensitization. These findings demonstrate the utility of mouse metabolomics for identifying novel biomarkers, and developing more comprehensive neurochemical models, of psychostimulant sensitization. PMID:24034544

Data assimilation of GNSS zenith total delays from a Nordic processing centre

NASA Astrophysics Data System (ADS)

Lindskog, Magnus; Ridal, Martin; Thorsteinsson, Sigurdur; Ning, Tong

2017-11-01

Atmospheric moisture-related information estimated from Global Navigation Satellite System (GNSS) ground-based receiver stations by the Nordic GNSS Analysis Centre (NGAA) have been used within a state-of-the-art kilometre-scale numerical weather prediction system. Different processing techniques have been implemented to derive the moisture-related GNSS information in the form of zenith total delays (ZTDs) and these are described and compared. In addition full-scale data assimilation and modelling experiments have been carried out to investigate the impact of utilizing moisture-related GNSS data from the NGAA processing centre on a numerical weather prediction (NWP) model initial state and on the ensuing forecast quality. The sensitivity of results to aspects of the data processing, station density, bias-correction and data assimilation have been investigated. Results show benefits to forecast quality when using GNSS ZTD as an additional observation type. The results also show a sensitivity to thinning distance applied for GNSS ZTD observations but not to modifications to the number of predictors used in the variational bias correction applied. In addition, it is demonstrated that the assimilation of GNSS ZTD can benefit from more general data assimilation enhancements and that there is an interaction of GNSS ZTD with other types of observations used in the data assimilation. Future plans include further investigation of optimal thinning distances and application of more advanced data assimilation techniques.

Global diversity in the human salivary microbiome.

PubMed

Nasidze, Ivan; Li, Jing; Quinque, Dominique; Tang, Kun; Stoneking, Mark

2009-04-01

The human salivary microbiome may play a role in diseases of the oral cavity and interact with microbiomes from other parts of the human body (in particular, the intestinal tract), but little is known about normal variation in the salivary microbiome. We analyzed 14,115 partial ( approximately 500 bp) 16S ribosomal RNA (rRNA) sequences from saliva samples from 120 healthy individuals (10 individuals from each of 12 worldwide locations). These sequences could be assigned to 101 known bacterial genera, of which 39 were not previously reported from the human oral cavity; phylogenetic analysis suggests that an additional 64 unknown genera are present. There is high diversity in the salivary microbiome within and between individuals, but little geographic structure. Overall, approximately 13.5% of the total variance in the composition of genera is due to differences among individuals, which is remarkably similar to the fraction of the total variance in neutral genetic markers that can be attributed to differences among human populations. Investigation of some environmental variables revealed a significant association between the genetic distances among locations and the distance of each location from the equator. Further characterization of the enormous diversity revealed here in the human salivary microbiome will aid in elucidating the role it plays in human health and disease, and in the identification of potentially informative species for studies of human population history.

Morphometric and electrophoretic analysis of 13 populations of Anatolian black pine in Turkey.

PubMed

Turna, Ibrahim; Yahyaoglu, Zeki; Yüksek, Filiz; Ayaz, F Ahmet; Guney, Deniz

2006-07-01

The genetic variation in populations of Anatolian black pine (Pinus nigra Arn. subsp. pallasiana (L.) Holmboe.), one of the species covering large areas in Turkey, was investigated. Open pollinated seeds were collected from 13 populations in a natural distribution range. Six characters of seeds (length, width, ratio of length to width, weight/1000 seeds) and seedling characters (cotyledon number and hypocotyls height) and two enzyme systems viz. leucine aminopeptidase (LAP) and glutamate oxaloacetate transaminase, (GOT) were investigated. Significant differences were detected among the populations for the morphological characters. In addition, isozyme patterns of two enzyme systems revealed that LAP has two loci (one with 2 alleles and the other with 3), while GOT has three loci (two with 3 alleles and the third one with 2 alleles). Polymorphic loci were 74% on the average. The mean number of alleles per loci was 1.94 and expected heterozygosity was 19%. The mean total genetic diversity was calculated as 0.203; the mean gene diversity within populations was determined as 0.188, and the average between subpopulations diversity was 0.016. The relative magnitude of genetic differentiation among subpopulations was measured as 0.074 indicating that only 7.4% of the total genetic diversity was there between populations. Average genetic distance was 0.093 according to Gregorius. Nei's genetic distance was 0.022.

Edge effects and beta diversity in ground and canopy beetle communities of fragmented subtropical forest

PubMed Central

Catterall, Carla P.; Stork, Nigel E.

2018-01-01

Clearing of dry forests globally creates edges between remnant forest and open anthropogenic habitats. We used flight intercept traps to evaluate how forest beetle communities are influenced by distance from such edges, together with vertical height, spatial location, and local vegetation structure, in an urbanising region (Brisbane, Australia). Species composition (but not total abundance or richness) differed greatly between ground and canopy. Species composition also varied strongly among sites at both ground and canopy levels, but almost all other significant effects occurred only at ground level, where: species richness declined from edge to interior; composition differed between positions near edges (<10 m) and interiors (> 50 m); high local canopy cover was associated with greater total abundance and richness and differing composition; and greater distances to the city centre were associated with increased total abundances and altered composition. Analyses of individual indicator species associated with this variation enabled further biological interpretations. A global literature synthesis showed that most spatially well-replicated studies of edge effects on ground-level beetles within forest fragments have likewise found that positions within tens of metres from edges with open anthropogenic habitats had increased species richness and different compositions from forest interior sites, with fewer effects on abundance. Accordingly, negative edge effects will not prevent relatively small compact fragments (if >10–20 ha) from supporting forest-like beetle communities, although indirect consequences of habitat degradation remain a threat. Retention of multiple spatially scattered forest areas will also be important in conserving forest-dependent beetles, given high levels of between-site diversity. PMID:29494680

Edge effects and beta diversity in ground and canopy beetle communities of fragmented subtropical forest.

PubMed

Stone, Marisa J; Catterall, Carla P; Stork, Nigel E

2018-01-01

Clearing of dry forests globally creates edges between remnant forest and open anthropogenic habitats. We used flight intercept traps to evaluate how forest beetle communities are influenced by distance from such edges, together with vertical height, spatial location, and local vegetation structure, in an urbanising region (Brisbane, Australia). Species composition (but not total abundance or richness) differed greatly between ground and canopy. Species composition also varied strongly among sites at both ground and canopy levels, but almost all other significant effects occurred only at ground level, where: species richness declined from edge to interior; composition differed between positions near edges (<10 m) and interiors (> 50 m); high local canopy cover was associated with greater total abundance and richness and differing composition; and greater distances to the city centre were associated with increased total abundances and altered composition. Analyses of individual indicator species associated with this variation enabled further biological interpretations. A global literature synthesis showed that most spatially well-replicated studies of edge effects on ground-level beetles within forest fragments have likewise found that positions within tens of metres from edges with open anthropogenic habitats had increased species richness and different compositions from forest interior sites, with fewer effects on abundance. Accordingly, negative edge effects will not prevent relatively small compact fragments (if >10-20 ha) from supporting forest-like beetle communities, although indirect consequences of habitat degradation remain a threat. Retention of multiple spatially scattered forest areas will also be important in conserving forest-dependent beetles, given high levels of between-site diversity.

Radiation effects on moisture variation in ponderosa pine litter

Treesearch

Clive M. Countryman

1977-01-01

This exploratory study indicated that considerable variation in the moisture content of litter can occur within short horizontal distances. The variations ere found to be caused primarily by differences in the amount of solar radiation received by the litter and in the degree of cooling by radiation at night. Because actual fuel moisture lags behind equilibrium...

The effects of landscape position on plant species density: Evidence of past environmental effects in a coastal wetland

USGS Publications Warehouse

Grace, J.B.; Guntenspergen, G.R.

1999-01-01

Here we propose that an important cause of variation in species density may be prior environmental conditions that continue to influence current patterns. In this paper we investigated the degree to which species density varies with location within the landscape, independent of contemporaneous environmental conditions. The area studied was a coastal marsh landscape subject to periodic storm events. To evaluate the impact of historical effects, it was assumed that the landscape position of a plot relative to the river's mouth ('distance from sea') and to the edge of a stream channel ('distance from shore') would correlate with the impact of prior storm events, an assumption supported by previous studies. To evaluate the importance of spatial location on species density, data were collected from five sites located at increasing distances from the river's mouth along the Middle Pearl River in Louisiana. At each site, plots were established systematically along transects perpendicular to the shoreline. For each of the 175 Plots, we measured elevation, soil salinity, percent of plot recently disturbed, percent of sunlight captured by the plant canopy (as a measure of plant abundance), and plant species density. Structural equation analysis ascertained the degree to which landscape position variables explained variation in species density that could not be explained by current environmental indicators. Without considering landscape variables, 54% of the variation in species density could be explained by the effects of salinity, flooding, and plant abundance. When landscape variables were included, distance from shore was unimportant but distance from sea explained an additional 12% of the variance in species density (R2 of final model = 66%). Based on these results it appears that at least some of the otherwise unexplained variation in species density can be attributed to landscape position, and presumably previous storm events. We suggest that future studies may gain additional insight into the factors controlling current patterns of species density by examining the effects of position within the landscape.

Multivariate model of female black bear habitat use for a Geographic Information System

USGS Publications Warehouse

Clark, Joseph D.; Dunn, James E.; Smith, Kimberly G.

1993-01-01

Simple univariate statistical techniques may not adequately assess the multidimensional nature of habitats used by wildlife. Thus, we developed a multivariate method to model habitat-use potential using a set of female black bear (Ursus americanus) radio locations and habitat data consisting of forest cover type, elevation, slope, aspect, distance to roads, distance to streams, and forest cover type diversity score in the Ozark Mountains of Arkansas. The model is based on the Mahalanobis distance statistic coupled with Geographic Information System (GIS) technology. That statistic is a measure of dissimilarity and represents a standardized squared distance between a set of sample variates and an ideal based on the mean of variates associated with animal observations. Calculations were made with the GIS to produce a map containing Mahalanobis distance values within each cell on a 60- × 60-m grid. The model identified areas of high habitat use potential that could not otherwise be identified by independent perusal of any single map layer. This technique avoids many pitfalls that commonly affect typical multivariate analyses of habitat use and is a useful tool for habitat manipulation or mitigation to favor terrestrial vertebrates that use habitats on a landscape scale.

Stereoscopic depth constancy

PubMed Central

Guan, Phillip

2016-01-01

Depth constancy is the ability to perceive a fixed depth interval in the world as constant despite changes in viewing distance and the spatial scale of depth variation. It is well known that the spatial frequency of depth variation has a large effect on threshold. In the first experiment, we determined that the visual system compensates for this differential sensitivity when the change in disparity is suprathreshold, thereby attaining constancy similar to contrast constancy in the luminance domain. In a second experiment, we examined the ability to perceive constant depth when the spatial frequency and viewing distance both changed. To attain constancy in this situation, the visual system has to estimate distance. We investigated this ability when vergence, accommodation and vertical disparity are all presented accurately and therefore provided veridical information about viewing distance. We found that constancy is nearly complete across changes in viewing distance. Depth constancy is most complete when the scale of the depth relief is constant in the world rather than when it is constant in angular units at the retina. These results bear on the efficacy of algorithms for creating stereo content. This article is part of the themed issue ‘Vision in our three-dimensional world’. PMID:27269596

A test of the influence of continental axes of orientation on patterns of human gene flow

PubMed Central

Ramachandran, Sohini; Rosenberg, Noah A.

2012-01-01

The geographic distribution of genetic variation reflects trends in past population migrations, and can be used to make inferences about these migrations. It has been proposed that the east-west orientation of the Eurasian landmass facilitated the rapid spread of ancient technological innovations across Eurasia, while the north-south orientation of the Americas led to a slower diffusion of technology there. If the diffusion of technology was accompanied by gene flow, then this hypothesis predicts that genetic differentiation in the Americas along lines of longitude will be greater than that in Eurasia along lines of latitude. We use 678 microsatellite loci from 68 indigenous populations in Eurasia and the Americas to investigate the spatial axes that underlie population-genetic variation. We find that genetic differentiation increases more rapidly along lines of longitude in the Americas than along lines of latitude in Eurasia. Distance along lines of latitude explains a sizeable portion of genetic distance in Eurasia, whereas distance along lines of longitude does not explain a large proportion of Eurasian genetic variation. Genetic differentiation in the Americas occurs along both latitudinal and longitudinal axes and has a greater magnitude than corresponding differentiation in Eurasia, even when adjusting for the lower level of genetic variation in the American populations. These results support the view that continental orientation has influenced migration patterns and has played an important role in determining both the structure of human genetic variation and the distribution and spread of cultural traits. (240 words) PMID:21913175

Photo-ionization and modification of nanoparticles on transparent substrates by ultrashort laser pulses

NASA Astrophysics Data System (ADS)

Gruzdev, Vitaly; Komolov, Vladimir; Li, Hao; Yu, Qingsong; Przhibel'skii, Sergey; Smirnov, Dmitry

2011-02-01

The objective of this combined experimental and theoretical research is to study the dynamics and mechanisms of nanoparticle interaction with ultrashort laser pulses and related modifications of substrate surface. For the experimental effort, metal (gold), dielectric (SiO2) and dielectric with metal coating (about 30 nm thick) spherical nanoparticles deposited on glass substrate are utilized. Size of the particles varies from 20 to 200 nm. Density of the particles varies from low (mean inter-particle distance 100 nm) to high (mean inter-particle distance less than 1 nm). The nanoparticle assemblies and the corresponding empty substrate surfaces are irradiated with single 130-fs laser pulses at wavelength 775 nm and different levels of laser fluence. Large diameter of laser spot (0.5-2 mm) provides gradient variations of laser intensity over the spot and allows observing different laser-nanoparticle interactions. The interactions vary from total removal of the nanoparticles in the center of laser spot to gentle modification of their size and shape and totally non-destructive interaction. The removed particles frequently form specific sub-micrometer-size pits on the substrate surface at their locations. The experimental effort is supported by simulations of the nanoparticle interactions with high-intensity ultrashort laser pulse. The simulation employs specific modification of the molecular dynamics approach applied to model the processes of non-thermal particle ablation following laser-induced electron emission. This technique delivers various characteristics of the ablation plume from a single nanoparticle including energy and speed distribution of emitted ions, variations of particle size and overall dynamics of its ablation. The considered geometry includes single isolated particle as well a single particle on a flat substrate that corresponds to the experimental conditions. The simulations confirm existence of the different regimes of laser-nanoparticle interactions depending on laser intensity and wavelength. In particular, implantation of ions departing from the nanoparticles towards the substrate is predicted.

Investigation on using high-energy proton beam for total body irradiation (TBI).

PubMed

Zhang, Miao; Qin, Nan; Jia, Xun; Zou, Wei J; Khan, Atif; Yue, Ning J

2016-09-08

This work investigated the possibility of using proton beam for total body irradia-tion (TBI). We hypothesized the broad-slow-rising entrance dose from a monoen-ergetic proton beam can deliver a uniform dose to patient with varied thickness. Comparing to photon-based TBI, it would not require any patient-specific com-pensator or beam spoiler. The hypothesis was first tested by simulating 250 MeV, 275 MeV, and 300 MeV protons irradiating a wedge-shaped water phantom in a paired opposing arrangement using Monte Carlo (MC) method. To allow ± 7.5% dose variation, the maximum water equivalent thickness (WET) of a treatable patient separation was 29 cm for 250 MeV proton, and > 40 cm for 275 MeV and 300 MeV proton. The compared 6 MV photon can only treat patients with up to 15.5 cm water-equivalent separation. In the second step, we simulated the dose deposition from the same beams on a patient's whole-body CT scan. The maximum patient separation in WET was 23 cm. The calculated whole-body dose variations were ± 8.9%, ± 9.0%, ± 9.6%, and ± 14% for 250 MeV proton, 275 MeV proton, 300 MeV proton, and 6 MV photon. At last, we tested the current machine capability to deliver a monoenergetic proton beam with a large uniform field. Experiments were performed on a compact double scattering single-gantry proton system. With its C-shaped gantry design, the source-to-surface distance (SSD) reached 7 m. The measured dose deposition curve had 22 cm relatively flat entrance region. The full width half maximum field size was measured 105 cm. The current scatter filter had to be redesigned to produce a uniform intensity at such treatment distance. In con-clusion, this work demonstrated the possibility of using proton beam for TBI. The current commercially available proton machines would soon be ready for such task. © 2016 The Authors.

Evidence that Magnetic Navigation and Geomagnetic Imprinting Shape Spatial Genetic Variation in Sea Turtles.

PubMed

Brothers, J Roger; Lohmann, Kenneth J

2018-04-23

The canonical drivers of population genetic structure, or spatial genetic variation, are isolation by distance and isolation by environment. Isolation by distance predicts that neighboring populations will be genetically similar and geographically distant populations will be genetically distinct [1]. Numerous examples also exist of isolation by environment, a phenomenon in which populations that inhabit similar environments (e.g., same elevation, temperature, or vegetation) are genetically similar even if they are distant, whereas populations that inhabit different environments are genetically distinct even when geographically close [2-4]. These dual models provide a widely accepted conceptual framework for understanding population structure [5-8]. Here, we present evidence for an additional, novel process that we call isolation by navigation, in which the navigational mechanism used by a long-distance migrant influences population structure independently of isolation by either distance or environment. Specifically, we investigated the population structure of loggerhead sea turtles (Caretta caretta) [9], which return to nest on their natal beaches by seeking out unique magnetic signatures along the coast-a behavior known as geomagnetic imprinting [10-12]. Results reveal that spatial variation in Earth's magnetic field strongly predicts genetic differentiation between nesting beaches, even when environmental similarities and geographic proximity are taken into account. The findings provide genetic corroboration of geomagnetic imprinting [10, 13]. Moreover, they provide strong evidence that geomagnetic imprinting and magnetic navigation help shape the population structure of sea turtles and perhaps numerous other long-distance migrants that return to their natal areas to reproduce [13-17]. Copyright © 2018 Elsevier Ltd. All rights reserved.

Influences of traffic on Pb, Cu and Zn concentrations in roadside soils of an urban park in Dublin, Ireland.

PubMed

Dao, Ligang; Morrison, Liam; Zhang, Hongxuan; Zhang, Chaosheng

2014-06-01

Soils in the vicinity of roads are recipients of contaminants from traffic emissions. In order to obtain a better understanding of the impacts of traffic on soils, a total of 225 surface soil samples were collected from an urban park (Phoenix Park, Dublin, Ireland) in a grid system. Metal (Pb, Cu and Zn) concentrations were determined using a portable X-ray fluorescence analyzer. Strong spatial variations for the concentrations of Pb, Cu and Zn were observed. The spatial distribution maps created using geographical information system techniques revealed elevated metal concentrations close to the main traffic route in the park. The relationships between the accumulation of Pb, Cu and Zn in the roadside soils and the distance from the road were well fitted with an exponential model. Elevated metal concentrations from traffic pollution extended to a distance of approximately 40 m from the roadside. The results of this study provide useful information for the management of urban parks particularly in relation to policies aimed at reducing the impact of traffic related pollution on soils.

Point spread functions and deconvolution of ultrasonic images.

PubMed

Dalitz, Christoph; Pohle-Fröhlich, Regina; Michalk, Thorsten

2015-03-01

This article investigates the restoration of ultrasonic pulse-echo C-scan images by means of deconvolution with a point spread function (PSF). The deconvolution concept from linear system theory (LST) is linked to the wave equation formulation of the imaging process, and an analytic formula for the PSF of planar transducers is derived. For this analytic expression, different numerical and analytic approximation schemes for evaluating the PSF are presented. By comparing simulated images with measured C-scan images, we demonstrate that the assumptions of LST in combination with our formula for the PSF are a good model for the pulse-echo imaging process. To reconstruct the object from a C-scan image, we compare different deconvolution schemes: the Wiener filter, the ForWaRD algorithm, and the Richardson-Lucy algorithm. The best results are obtained with the Richardson-Lucy algorithm with total variation regularization. For distances greater or equal twice the near field distance, our experiments show that the numerically computed PSF can be replaced with a simple closed analytic term based on a far field approximation.

Genetic and morphological characterisation of the Ankole Longhorn cattle in the African Great Lakes region.

PubMed

Ndumu, Deo B; Baumung, Roswitha; Hanotte, Olivier; Wurzinger, Maria; Okeyo, Mwai A; Jianlin, Han; Kibogo, Harrison; Sölkner, Johann

2008-01-01

The study investigated the population structure, diversity and differentiation of almost all of the ecotypes representing the African Ankole Longhorn cattle breed on the basis of morphometric (shape and size), genotypic and spatial distance data. Twentyone morphometric measurements were used to describe the morphology of 439 individuals from 11 sub-populations located in five countries around the Great Lakes region of central and eastern Africa. Additionally, 472 individuals were genotyped using 15 DNA microsatellites. Femoral length, horn length, horn circumference, rump height, body length and fore-limb circumference showed the largest differences between regions. An overall FST index indicated that 2.7% of the total genetic variation was present among sub-populations. The least differentiation was observed between the two sub-populations of Mbarara south and Luwero in Uganda, while the highest level of differentiation was observed between the Mugamba in Burundi and Malagarasi in Tanzania. An estimated membership of four for the inferred clusters from a model-based Bayesian approach was obtained. Both analyses on distance-based and model-based methods consistently isolated the Mugamba sub-population in Burundi from the others.

Wellbeing perception and the impact on external training output among elite soccer players.

PubMed

Malone, Shane; Owen, Adam; Newton, Matt; Mendes, Bruno; Tiernan, Leo; Hughes, Brian; Collins, Kieran

2018-01-01

The objective of the investigation was to observe the impact of player wellbeing on the training output of elite soccer players. Prospective cohort design. Forty-eight soccer players (age: 25.3±3.1years; height: 183±7cm; mass: 72±7kg) were involved in this single season observational study across two teams. Each morning, pre-training, players completed customised perceived wellbeing questionnaires. Global positioning technology devices were used to measure external load (total distance, total high-speed running distance, high speed running, player load, player load slow, maximal velocity, maximal velocity exposures). Players reported ratings of perceived exertion using the modified Borg CR-10 scale. Integrated training load ratios were also analysed for total distance:RPE, total high speed distance:RPE player load:RPE and player load slow:RPE respectively. Mixed-effect linear models revealed significant effects of wellbeing Z-score on external and integrated training load measures. A wellbeing Z-score of -1 corresponded to a -18±2m (-3.5±1.1%), 4±1m (-4.9±2.1%,) 0.9±0.1kmh -1 (-3.1±2.1%), 1±1 (-4.6±2.9%), 25±3AU (-4.9±3.1%) and 11±0.5AU (-8.9±2.9%) reduction in total high speed distance, high speed distance, maximal velocity, maximal velocity exposures, player load and player load slow respectively. A reduction in wellbeing impacted external:internal training load ratios and resulted in -0.49±0.12mmin -1 , -1.20±0.08mmin -1 ,-0.02±0.01AUmin -1 in total distance:RPE, total high speed distance:RPE and player load slow:RPE respectively. The results suggest that systematic monitoring of player wellbeing within soccer cohorts can provide coaches with information about the training output that can be expected from individual players during a training session. Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Fast magnetic resonance imaging based on high degree total variation

NASA Astrophysics Data System (ADS)

Wang, Sujie; Lu, Liangliang; Zheng, Junbao; Jiang, Mingfeng

2018-04-01

In order to eliminating the artifacts and "staircase effect" of total variation in Compressive Sensing MRI, high degree total variation model is proposed for dynamic MRI reconstruction. the high degree total variation regularization term is used as a constraint to reconstruct the magnetic resonance image, and the iterative weighted MM algorithm is proposed to solve the convex optimization problem of the reconstructed MR image model, In addtion, one set of cardiac magnetic resonance data is used to verify the proposed algorithm for MRI. The results show that the high degree total variation method has a better reconstruction effect than the total variation and the total generalized variation, which can obtain higher reconstruction SNR and better structural similarity.

Interspecific Comparison of the Performance of Soaring Migrants in Relation to Morphology, Meteorological Conditions and Migration Strategies

PubMed Central

Mellone, Ugo; Klaassen, Raymond H. G.; García-Ripollés, Clara; Limiñana, Ruben; López-López, Pascual; Pavón, Diego; Strandberg, Roine; Urios, Vicente; Vardakis, Michalis; Alerstam, Thomas

2012-01-01

Background Performance of migrating birds can be affected by a number of intrinsic and extrinsic factors like morphology, meteorological conditions and migration strategies. We compared travel speeds of four raptor species during their crossing of the Sahara desert. Focusing the analyses on this region allows us to compare different species under equivalent conditions in order to disentangle which factors affect migratory performance. Methodology/Principal Finding We tracked raptors using GPS satellite transmitters from Sweden, Spain and Italy, and evaluated their migratory performance at both an hourly and a daily scale. Hourly data (flight speed and altitude for intervals of two hours) were analyzed in relation to time of day, species and season, and daily data (distance between roosting sites) in relation to species, season, day length and tailwind support. Conclusions/Significance Despite a clear variation in morphology, interspecific differences were generally very small, and did only arise in spring, with long-distance migrants (>5000 km: osprey and Western marsh-harrier) being faster than species that migrate shorter distances (Egyptian vulture and short-toed eagle). Our results suggest that the most important factor explaining hourly variation in flight speed is time of day, while at a daily scale, tailwind support is the most important factor explaining variation in daily distance, raising new questions about the consequences of possible future changes in worldwide wind patterns. PMID:22768314

Shallow temperature differences along the Deep Creek Range front, Idaho

NASA Astrophysics Data System (ADS)

Ore, H. T.; Wiegand, G. H.

1990-02-01

The extent of the solvolysis reaction of a tertiary butyl chloride solution placed in vials buried about 1.2 m below the ground surface is dependent on average temperature at that depth over the period of burial. This method is herein used to indicate differences in shallow temperature from the western flank of the Basin and Range Deep Creek Range front, about 5 km westward into Rockland Valley in southeastern Idaho. Ninety-three samples, distributed to allow determination of lateral and vertical sample-site variation in total reaction amount, were analyzed after being in place for 3 months. Results from two sample lines, 3.5 km apart, show that subsurface total reaction amount declines slightly for the first 1.6 km away from the mountain front, rises abruptly to several times initial reaction, slowly declines for the next several km, then tends to slowly rise again. Plots of extent of reaction vs distance for the two traverses are nearly parallel; in both the abrupt increase in total reaction coincides with a line of springs, suggesting that hydrologic activity is at least related to the effects noted.

How variations in distance affect eyewitness reports and identification accuracy.

PubMed

Lindsay, R C L; Semmler, Carolyn; Weber, Nathan; Brewer, Neil; Lindsay, Marilyn R

2008-12-01

Witnesses observe crimes at various distances and the courts have to interpret their testimony given the likely quality of witnesses' views of events. We examined how accurately witnesses judged the distance between themselves and a target person, and how distance affected description accuracy, choosing behavior, and identification test accuracy. Over 1,300 participants were approached during normal daily activities, and asked to observe a target person at one of a number of possible distances. Under a Perception, Immediate Memory, or Delayed Memory condition, witnesses provided a brief description of the target, estimated the distance to the target, and then examined a 6-person target-present or target-absent lineup to see if they could identify the target. Errors in distance judgments were often substantial. Description accuracy was mediocre and did not vary systematically with distance. Identification choosing rates were not affected by distance, but decision accuracy declined with distance. Contrary to previous research, a 15-m viewing distance was not critical for discriminating accurate from inaccurate decisions.

The utility of protein structure as a predictor of site-wise dN/dS varies widely among HIV-1 proteins.

PubMed

Meyer, Austin G; Wilke, Claus O

2015-10-06

Protein structure acts as a general constraint on the evolution of viral proteins. One widely recognized structural constraint explaining evolutionary variation among sites is the relative solvent accessibility (RSA) of residues in the folded protein. In influenza virus, the distance from functional sites has been found to explain an additional portion of the evolutionary variation in the external antigenic proteins. However, to what extent RSA and distance from a reference site in the protein can be used more generally to explain protein adaptation in other viruses and in the different proteins of any given virus remains an open question. To address this question, we have carried out an analysis of the distribution and structural predictors of site-wise dN/dS in HIV-1. Our results indicate that the distribution of dN/dS in HIV follows a smooth gamma distribution, with no special enrichment or depletion of sites with dN/dS at or above one. The variation in dN/dS can be partially explained by RSA and distance from a reference site in the protein, but these structural constraints do not act uniformly among the different HIV-1 proteins. Structural constraints are highly predictive in just one of the three enzymes and one of three structural proteins in HIV-1. For these two proteins, the protease enzyme and the gp120 structural protein, structure explains between 30 and 40% of the variation in dN/dS. Finally, for the gp120 protein of the receptor-binding complex, we also find that glycosylation sites explain just 2% of the variation in dN/dS and do not explain gp120 evolution independently of either RSA or distance from the apical surface. © 2015 The Author(s).

THE STAR FORMATION HISTORY AND EXTENDED STRUCTURE OF THE HERCULES MILKY WAY SATELLITE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sand, David J.; Seth, Anil; Olszewski, Edward W.

2009-10-20

We present imaging of the recently discovered Hercules Milky Way satellite and its surrounding regions to study its structure, star formation history and to thoroughly search for signs of disruption. We robustly determine the distance, luminosity, size, and morphology of Hercules utilizing a bootstrap approach to characterize our uncertainties. We derive a distance to Hercules via a comparison to empirical and theoretical isochrones, finding a best match with the isochrone of M92, which yields a distance of 133 +- 6 kpc. As previous studies have found, Hercules is very elongated, with epsilon = 0.67 +- 0.03 and a half-light radiusmore » of r{sub h} approx = 230 pc. Using the color-magnitude-fitting package StarFISH, we determine that Hercules is old (>12 Gyr) and metal-poor ([Fe/H] approx -2.0), with a spread in metallicity, in agreement with previous spectroscopic work. This result is robust with respect to slight variations in the distance to Hercules and mismatches between the observed Hercules color-magnitude diagram and theoretical isochrones. We infer a total absolute magnitude of M{sub V} = -6.2 +- 0.4. Our innovative search for external Hercules structure both in the plane of the sky and along the line of sight yields some evidence that Hercules is embedded in a larger stream of stars. A clear stellar extension is seen to the northwest with several additional candidate stellar overdensities along the position angle of Hercules out to approx35' (approx1.3 kpc). While the association of any of the individual stellar overdensities with Hercules is difficult to determine, we do show that the summed color-magnitude diagram of all three is consistent with Hercules' stellar population. Finally, we estimate that any change in the distance to Hercules across its face is at most approx6 kpc, and the data are consistent with Hercules being at the same distance throughout.« less

A complete VLBI delay model for deforming radio telescopes: the Effelsberg case

NASA Astrophysics Data System (ADS)

Artz, T.; Springer, A.; Nothnagel, A.

2014-12-01

Deformations of radio telescopes used in geodetic and astrometric very long baseline interferometry (VLBI) observations belong to the class of systematic error sources which require correction in data analysis. In this paper we present a model for all path length variations in the geometrical optics of radio telescopes which are due to gravitational deformation. The Effelsberg 100 m radio telescope of the Max Planck Institute for Radio Astronomy, Bonn, Germany, has been surveyed by various terrestrial methods. Thus, all necessary information that is needed to model the path length variations is available. Additionally, a ray tracing program has been developed which uses as input the parameters of the measured deformations to produce an independent check of the theoretical model. In this program as well as in the theoretical model, the illumination function plays an important role because it serves as the weighting function for the individual path lengths depending on the distance from the optical axis. For the Effelsberg telescope, the biggest contribution to the total path length variations is the bending of the main beam located along the elevation axis which partly carries the weight of the paraboloid at its vertex. The difference in total path length is almost 100 mm when comparing observations at 90 and at 0 elevation angle. The impact of the path length corrections is validated in a global VLBI analysis. The application of the correction model leads to a change in the vertical position of mm. This is more than the maximum path length, but the effect can be explained by the shape of the correction function.

Observations of Fe XIV Line Intensity Variations in the Solar Corona During the 21 August 2017 Solar Eclipse

NASA Astrophysics Data System (ADS)

Johnson, Payton; Ladd, Edwin

2018-01-01

We present time- and spatially-resolved observations of the inner solar corona in the 5303 Å line of Fe XIV, taken during the 21 August 2017 solar eclipse from a field observing site in Crossville, TN. These observations are used to characterize the intensity variations in this coronal emission line, and to compare with oscillation predictions from models for heating the corona by magnetic wave dissipation.The observations were taken with two Explore Scientific ED 102CF 102 mm aperture triplet apochromatic refractors. One system used a DayStar custom-built 5 Å FWHM filter centered on the Fe XIV coronal spectral line and an Atik Titan camera for image collection. The setup produced images with a pixel size of 2.15 arcseconds (~1.5 Mm at the distance to the Sun), and a field of view of 1420 x 1060 arcseconds, covering approximately 20% of the entire solar limb centered near the emerging sunspot complex AR 2672. We obtained images with an exposure time of 0.22 seconds and a frame rate of 2.36 Hz, for a total of 361 images during totality.An identical, co-aligned telescope/camera system observed the same portion of the solar corona, but with a 100 Å FWHM Baader Planetarium solar continuum filter centered on a wavelength of 5400 Å. Images with an exposure time of 0.01 seconds were obtained with a frame rate of 4.05 Hz. These simultaneous observations are used as a control to monitor brightness variations not related to coronal line oscillations.

Biomechanical effects, lithological variations, and local pedodiversity in some forest soils of Arkansas

Treesearch

Jonathan D. Phillips; Daniel A. Marion

2005-01-01

A high degree of soil variability over short distances and small areas is common, particularly in forest soils. This variability is sometimes, but not always, related to readily apparent variations in the environmental factors that control soil formation. This study examines the potential role of biomechanical effects of trees and of lithological variations within the...

Climatic suitability, isolation by distance and river resistance explain genetic variation in a Brazilian whiptail lizard.

PubMed

Oliveira, Eliana Faria; Martinez, Pablo Ariel; São-Pedro, Vinícius Avelar; Gehara, Marcelo; Burbrink, Frank Thomas; Mesquita, Daniel Oliveira; Garda, Adrian Antonio; Colli, Guarino Rinaldi; Costa, Gabriel Correa

2018-03-01

Spatial patterns of genetic variation can help understand how environmental factors either permit or restrict gene flow and create opportunities for regional adaptations. Organisms from harsh environments such as the Brazilian semiarid Caatinga biome may reveal how severe climate conditions may affect patterns of genetic variation. Herein we combine information from mitochondrial DNA with physical and environmental features to study the association between different aspects of the Caatinga landscape and spatial genetic variation in the whiptail lizard Ameivula ocellifera. We investigated which of the climatic, environmental, geographical and/or historical components best predict: (1) the spatial distribution of genetic diversity, and (2) the genetic differentiation among populations. We found that genetic variation in A. ocellifera has been influenced mainly by temperature variability, which modulates connectivity among populations. Past climate conditions were important for shaping current genetic diversity, suggesting a time lag in genetic responses. Population structure in A. ocellifera was best explained by both isolation by distance and isolation by resistance (main rivers). Our findings indicate that both physical and climatic features are important for explaining the observed patterns of genetic variation across the xeric Caatinga biome.

Actualistic models of mantle metasomatism documented in a composite xenolith from Dish Hill, California

USGS Publications Warehouse

Nielson, J.E.; Budahn, J.R.; Unruh, D.M.; Wilshire, H.G.

1993-01-01

Major and trace-element whole rock and mineral variations in composite hornblendite-peridotite xenolith Ba-2-1, from Dish Hill, CA, are due to a single event of metasomatism in the mantle. The hornblendite is the crystallized selvage of a dike conduit charged with incompatible-element-enriched hydrous mafic magma. The magma infiltrated the refractory peridotite wallrock, reacted with its constituent minerals, and simultaneously deposited amphibole. The systematic data from this study show considerable variation in isotopic values and trace elements. These data provide insight into a mantle process that was defined previously from samples without context, lacking evidence about the number or source of metasomatic events. In the contact zone of Ba-2-1, peridotite is enriched in Fe, Ti, CO2) and H2O; clinopyroxene and amphibole also are enriched in Fe and Ti, but clinopyroxene appears slightly depleted in CaO. Compared to chondrites, peridotite, clinopyroxene, and probably amphibole are enriched in light rare earth (LREEcn) and other incompatible trace elements. Values of 87Sr 86Sr and 143Nd 144Nd in the contact zone are close to isotopic equilibrium with the dike. Whole rock and constituent clinopyroxene compositions change to those of refractory peridotite with distance from the contact. These compositional variations were modelled using Gresens' equation for whole-rock major and minor elements, and calculations for isotopic ratios and REEs, which emulate the effects of Chromatographic fractionation. The choice of endmembers was restricted to compositions actually present in mantle samples from Dish Hill. Model results indicate that: 1. (1) the variations can be explained as the result of a single metasomatic event, probably a single pulse of previously fractionated liquid; 2. (2) the ratio of total interacting liquid to peridotite was at least 1:3 by weight in the contact zone; and 3. (3) the composition of the metasomatic liquid changed progressively as it infiltrated beyond that zone. The small distance over which variations occur is due to the small amount of liquid that infiltrated. Only in the contact zone was peridotite wallrock saturated by a liquid composition similar to the dike. Comparison of the Ba-2-1 data with those of another xenolith from Dish Hill suggests that the compositional variations of mantle metasomatism result from both the compositional contrast between the metasomatizing liquid and wallrock and the relative abundances of each. Compositional and volumetric variations of mantle partial melts and their fractionates, and repeated events of melting and reaction in contiguous mantle, can create broad ranges of metasomatic "signatures" from the same process. ?? 1993.

Match-play demands of elite youth Gaelic football using global positioning system tracking.

PubMed

Reilly, Brian; Akubat, Ibrahim; Lyons, Mark; Collins, D Kieran

2015-04-01

Global positioning systems (GPS) technology has made athlete-tracking a convenient and accepted technique to specify movement patterns and physical demands in sport. The purpose of this study was to examine positional demands of elite youth Gaelic football match-play using portable GPS technology to examine movement patterns and heart rates across match periods. Fifty-six elite youth male Gaelic footballers (age, 15 ± 0.66 years) fitted with portable 4-Hz GPS units were observed during 6 competitive matches (60 minutes). Data provided from the GPS unit included total distance, high-intensity (≥17·km·h(-1)) distance, sprint (≥22 km·h(-1)) distance, and total number of sprints. Heart rate was monitored continuously throughout the games. Players covered a mean distance of 5732 ± 1047 m, and the mean intensity of match-play was 85% of the peak heart rate. There was a significant (p = 0.028) drop in the total distance covered in the second half (2783 ± 599 m) compared with the first half (2948 ± 580 m). In particular, there is a noticeable drop in the distance covered in the third quarter of the game (after half-time), which has implications for re-warming up at the end of the half-time interval. There was a highly significant (p < .001) difference in the distance traveled across the 5 positional groups with midfielders covering the greatest total distance (6740 ± 384 m). The significant differences found with respect to positional groups support the implementation of individual, position-specific strength and conditioning programs.

Diversity and distribution of genetic variation in gammarids: Comparing patterns between invasive and non-invasive species.

PubMed

Baltazar-Soares, Miguel; Paiva, Filipa; Chen, Yiyong; Zhan, Aibin; Briski, Elizabeta

2017-10-01

Biological invasions are worldwide phenomena that have reached alarming levels among aquatic species. There are key challenges to understand the factors behind invasion propensity of non-native populations in invasion biology. Interestingly, interpretations cannot be expanded to higher taxonomic levels due to the fact that in the same genus, there are species that are notorious invaders and those that never spread outside their native range. Such variation in invasion propensity offers the possibility to explore, at fine-scale taxonomic level, the existence of specific characteristics that might predict the variability in invasion success. In this work, we explored this possibility from a molecular perspective. The objective was to provide a better understanding of the genetic diversity distribution in the native range of species that exhibit contrasting invasive propensities. For this purpose, we used a total of 784 sequences of the cytochrome c oxidase subunit I of mitochondrial DNA (mtDNA-COI) collected from seven Gammaroidea, a superfamily of Amphipoda that includes species that are both successful invaders ( Gammarus tigrinus , Pontogammarus maeoticus, and Obesogammarus crassus ) and strictly restricted to their native regions ( Gammarus locusta , Gammarus salinus , Gammarus zaddachi, and Gammarus oceanicus ). Despite that genetic diversity did not differ between invasive and non-invasive species, we observed that populations of non-invasive species showed a higher degree of genetic differentiation. Furthermore, we found that both geographic and evolutionary distances might explain genetic differentiation in both non-native and native ranges. This suggests that the lack of population genetic structure may facilitate the distribution of mutations that despite arising in the native range may be beneficial in invasive ranges. The fact that evolutionary distances explained genetic differentiation more often than geographic distances points toward that deep lineage divergence holds an important role in the distribution of neutral genetic diversity.

A land use regression application into assessing spatial variation of intra-urban fine particulate matter (PM2.5) and nitrogen dioxide (NO2) concentrations in City of Shanghai, China.

PubMed

Liu, Chao; Henderson, Barron H; Wang, Dongfang; Yang, Xinyuan; Peng, Zhong-Ren

2016-09-15

Intra-urban assessment of air pollution exposure has become a priority study while international attention was attracted to PM2.5 pollution in China in recent years. Land Use Regression (LUR), which has previously been proved to be a feasible way to describe the relationship between land use and air pollution level in European and American cities, was employed in this paper to explain the correlations and spatial variations in Shanghai, China. PM2.5 and NO2 concentrations at 35-45 monitoring locations were selected as dependent variables, and a total of 44 built environmental factors were extracted as independent variables. Only five factors showed significant explanatory value for both PM2.5 and NO2 models: longitude, distance from monitors to the ocean, highway intensity, waterbody area, and industrial land area for PM2.5 model; residential area, distance to the coast, industrial area, urban district, and highway intensity for NO2 model. Respectively, both PM2.5 and NO2 showed anti-correlation with coastal proximity (an indicator of clean air dilution) and correlation with highway and industrial intensity (source indicators). NO2 also showed significant correlation with local indicators of population density (residential intensity and urban classification), while PM2.5 showed significant correlation with regional dilution (longitude as a indicator of distance from polluted neighbors and local water features). Both adjusted R squared values were strong with PM2.5 (0.88) being higher than NO2 (0.62). The LUR was then used to produce continuous concentration fields for NO2 and PM2.5 to illustrate the features and, potentially, for use by future studies. Comparison to PM2.5 studies in New York and Beijing show that Shanghai PM2.5 pollutant distribution was more sensitive to geographic location and proximity to neighboring regions. Copyright © 2015. Published by Elsevier B.V.

The match-to-match variation of match-running in elite female soccer.

PubMed

Trewin, Joshua; Meylan, César; Varley, Matthew C; Cronin, John

2018-02-01

The purpose of this study was to examine the match-to-match variation of match-running in elite female soccer players utilising GPS, using full-match and rolling period analyses. Longitudinal study. Elite female soccer players (n=45) from the same national team were observed during 55 international fixtures across 5 years (2012-2016). Data was analysed using a custom built MS Excel spreadsheet as full-matches and using a rolling 5-min analysis period, for all players who played 90-min matches (files=172). Variation was examined using co-efficient of variation and 90% confidence limits, calculated following log transformation. Total distance per minute exhibited the smallest variation when both the full-match and peak 5-min running periods were examined (CV=6.8-7.2%). Sprint-efforts were the most variable during a full-match (CV=53%), whilst high-speed running per minute exhibited the greatest variation in the post-peak 5-min period (CV=143%). Peak running periods were observed as slightly more variable than full-match analyses, with the post-peak period very-highly variable. Variability of accelerations (CV=17%) and Player Load (CV=14%) was lower than that of high-speed actions. Positional differences were also present, with centre backs exhibiting the greatest variation in high-speed movements (CV=41-65%). Practitioners and researchers should account for within player variability when examining match performances. Identification of peak running periods should be used to assist worst case scenarios. Whilst micro-sensor technology should be further examined as to its viable use within match-analyses. Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Spatial variability in airborne pollen concentrations.

PubMed

Raynor, G S; Ogden, E C; Hayes, J V

1975-03-01

Tests were conducted to determine the relationship between airborne pollen concentrations and distance. Simultaneous samples were taken in 171 tests with sets of eight rotoslide samplers spaced from one to 486 M. apart in straight lines. Use of all possible pairs gave 28 separation distances. Tests were conducted over a 2-year period in urban and rural locations distant from major pollen sources during both tree and ragweed pollen seasons. Samples were taken at a height of 1.5 M. during 5-to 20-minute periods. Tests were grouped by pollen type, location, year, and direction of the wind relative to the line. Data were analyzed to evaluate variability without regard to sampler spacing and variability as a function of separation distance. The mean, standard deviation, coefficient of variation, ratio of maximum to the mean, and ratio of minimum to the mean were calculated for each test, each group of tests, and all cases. The average coefficient of variation is 0.21, the maximum over the mean, 1.39 and the minimum over the mean, 0.69. No relationship was found with experimental conditions. Samples taken at the minimum separation distance had a mean difference of 18 per cent. Differences between pairs of samples increased with distance in 10 of 13 groups. These results suggest that airborne pollens are not always well mixed in the lower atmosphere and that a sample becomes less representative with increasing distance from the sampling location.

Spatial Self-Organization of Vegetation Subject to Climatic Stress-Insights from a System Dynamics-Individual-Based Hybrid Model.

PubMed

Vincenot, Christian E; Carteni, Fabrizio; Mazzoleni, Stefano; Rietkerk, Max; Giannino, Francesco

2016-01-01

In simulation models of populations or communities, individual plants have often been obfuscated in favor of aggregated vegetation. This simplification comes with a loss of biological detail and a smoothing out of the demographic noise engendered by stochastic individual-scale processes and heterogeneities, which is significant among others when studying the viability of small populations facing challenging fluctuating environmental conditions. This consideration has motivated the development of precise plant-centered models. The accuracy gained in the representation of plant biology has then, however, often been balanced by the disappearance in models of important plant-soil interactions (esp. water dynamics) due to the inability of most individual-based frameworks to simulate complex continuous processes. In this study, we used a hybrid modeling approach, namely integrated System Dynamics (SD)-Individual-based (IB), to illustrate the importance of individual plant dynamics to explain spatial self-organization of vegetation in arid environments. We analyzed the behavior of this model under different parameter sets either related to individual plant properties (such as seed dispersal distance and reproductive age) or the environment (such as intensity and yearly distribution of precipitation events). While the results of this work confirmed the prevailing theory on vegetation patterning, they also revealed the importance therein of plant-level processes that cannot be rendered by reaction-diffusion models. Initial spatial distribution of plants, reproductive age, and average seed dispersal distance, by impacting patch size and vegetation aggregation, affected pattern formation and population survival under climatic variations. Besides, changes in precipitation regime altered the demographic structure and spatial organization of vegetation patches by affecting plants differentially depending on their age and biomass. Water availability influenced non-linearly total biomass density. Remarkably, lower precipitation resulted in lower mean plant age yet higher mean individual biomass. Moreover, seasonal variations in rainfall greater than a threshold (here, ±0.45 mm from the 1.3 mm baseline) decreased mean total biomass and generated limit cycles, which, in the case of large variations, were preceded by chaotic demographic and spatial behavior. In some cases, peculiar spatial patterns (e.g., rings) were also engendered. On a technical note, the shortcomings of the present model and the benefit of hybrid modeling for virtual investigations in plant science are discussed.

Spatial Self-Organization of Vegetation Subject to Climatic Stress—Insights from a System Dynamics—Individual-Based Hybrid Model

PubMed Central

Vincenot, Christian E.; Carteni, Fabrizio; Mazzoleni, Stefano; Rietkerk, Max; Giannino, Francesco

2016-01-01

In simulation models of populations or communities, individual plants have often been obfuscated in favor of aggregated vegetation. This simplification comes with a loss of biological detail and a smoothing out of the demographic noise engendered by stochastic individual-scale processes and heterogeneities, which is significant among others when studying the viability of small populations facing challenging fluctuating environmental conditions. This consideration has motivated the development of precise plant-centered models. The accuracy gained in the representation of plant biology has then, however, often been balanced by the disappearance in models of important plant-soil interactions (esp. water dynamics) due to the inability of most individual-based frameworks to simulate complex continuous processes. In this study, we used a hybrid modeling approach, namely integrated System Dynamics (SD)—Individual-based (IB), to illustrate the importance of individual plant dynamics to explain spatial self-organization of vegetation in arid environments. We analyzed the behavior of this model under different parameter sets either related to individual plant properties (such as seed dispersal distance and reproductive age) or the environment (such as intensity and yearly distribution of precipitation events). While the results of this work confirmed the prevailing theory on vegetation patterning, they also revealed the importance therein of plant-level processes that cannot be rendered by reaction-diffusion models. Initial spatial distribution of plants, reproductive age, and average seed dispersal distance, by impacting patch size and vegetation aggregation, affected pattern formation and population survival under climatic variations. Besides, changes in precipitation regime altered the demographic structure and spatial organization of vegetation patches by affecting plants differentially depending on their age and biomass. Water availability influenced non-linearly total biomass density. Remarkably, lower precipitation resulted in lower mean plant age yet higher mean individual biomass. Moreover, seasonal variations in rainfall greater than a threshold (here, ±0.45 mm from the 1.3 mm baseline) decreased mean total biomass and generated limit cycles, which, in the case of large variations, were preceded by chaotic demographic and spatial behavior. In some cases, peculiar spatial patterns (e.g., rings) were also engendered. On a technical note, the shortcomings of the present model and the benefit of hybrid modeling for virtual investigations in plant science are discussed. PMID:27252707

Vibration-based damage detection in a concrete beam under temperature variations using AR models and state-space approaches

NASA Astrophysics Data System (ADS)

Clément, A.; Laurens, S.

2011-07-01

The Structural Health Monitoring of civil structures subjected to ambient vibrations is very challenging. Indeed, the variations of environmental conditions and the difficulty to characterize the excitation make the damage detection a hard task. Auto-regressive (AR) models coefficients are often used as damage sensitive feature. The presented work proposes a comparison of the AR approach with a state-space feature formed by the Jacobian matrix of the dynamical process. Since the detection of damage can be formulated as a novelty detection problem, Mahalanobis distance is applied to track new points from an undamaged reference collection of feature vectors. Data from a concrete beam subjected to temperature variations and damaged by several static loading are analyzed. It is observed that the damage sensitive features are effectively sensitive to temperature variations. However, the use of the Mahalanobis distance makes possible the detection of cracking with both of them. Early damage (before cracking) is only revealed by the AR coefficients with a good sensibility.

The precision of locomotor odometry in humans.

PubMed

Durgin, Frank H; Akagi, Mikio; Gallistel, Charles R; Haiken, Woody

2009-03-01

Two experiments measured the human ability to reproduce locomotor distances of 4.6-100 m without visual feedback and compared distance production with time production. Subjects were not permitted to count steps. It was found that the precision of human odometry follows Weber's law that variability is proportional to distance. The coefficients of variation for distance production were much lower than those measured for time production for similar durations. Gait parameters recorded during the task (average step length and step frequency) were found to be even less variable suggesting that step integration could be the basis for non-visual human odometry.

The Link between Microbial Diversity and Nitrogen Cycling in Marine Sediments Is Modulated by Macrofaunal Bioturbation.

PubMed

Yazdani Foshtomi, Maryam; Braeckman, Ulrike; Derycke, Sofie; Sapp, Melanie; Van Gansbeke, Dirk; Sabbe, Koen; Willems, Anne; Vincx, Magda; Vanaverbeke, Jan

2015-01-01

The marine benthic nitrogen cycle is affected by both the presence and activity of macrofauna and the diversity of N-cycling microbes. However, integrated research simultaneously investigating macrofauna, microbes and N-cycling is lacking. We investigated spatio-temporal patterns in microbial community composition and diversity, macrofaunal abundance and their sediment reworking activity, and N-cycling in seven subtidal stations in the Southern North Sea. Our results indicated that bacteria (total and β-AOB) showed more spatio-temporal variation than archaea (total and AOA) as sedimentation of organic matter and the subsequent changes in the environment had a stronger impact on their community composition and diversity indices in our study area. However, spatio-temporal patterns of total bacterial and β-AOB communities were different and related to the availability of ammonium for the autotrophic β-AOB. Highest bacterial richness and diversity were observed in June at the timing of the phytoplankton bloom deposition, while richness of β-AOB as well as AOA peaked in September. Total archaeal community showed no temporal variation in diversity indices. Distance based linear models revealed that, independent from the effect of grain size and the quality and quantity of sediment organic matter, nitrification and N-mineralization were affected by respectively the diversity of metabolically active β-AOB and AOA, and the total bacteria, near the sediment-water interface. Separate models demonstrated a significant and independent effect of macrofaunal activities on community composition and richness of total bacteria, and diversity indices of metabolically active AOA. Diversity of β-AOB was significantly affected by macrofaunal abundance. Our results support the link between microbial biodiversity and ecosystem functioning in marine sediments, and provided broad correlative support for the hypothesis that this relationship is modulated by macrofaunal activity. We hypothesized that the latter effect can be explained by their bioturbating and bio-irrigating activities, increasing the spatial complexity of the biogeochemical environment.

The Inverse-Square Law with Data Loggers

ERIC Educational Resources Information Center

Bates, Alan

2013-01-01

The inverse-square law for the intensity of light received at a distance from a light source has been verified using various experimental techniques. Typical measurements involve a manual variation of the distance between a light source and a light sensor, usually by sliding the sensor or source along a bench, measuring the source-sensor distance…

The assembly of ecological communities inferred from taxonomic and functional composition

Treesearch

Eric R. Sokol; E.F. Benfield; Lisa K. Belden; H. Maurice. Valett

2011-01-01

Among-site variation in metacommunities (beta diversity) is typically correlated with the distance separating the sites (spatial lag). This distance decay in similarity pattern has been linked to both niche-based and dispersal-based community assembly hypotheses. Here we show that beta diversity patterns in community composition, when supplemented with functional-trait...

Temporal epidemiology of sudden oak death in Oregon

Treesearch

Ebba K. Peterson; Everett M. Hansen; Alan Kanaskie

2015-01-01

An effort to eradicate Phytophthora ramorum, causal agent of sudden oak death, has been underway since its discovery in Oregon forests. Using an information-theoretical approach, we sought to model yearly variation in the size of newly infested areas and dispersal distance. Maximum dispersal distances were best modeled by spring and winter...

Training Habits and Injury Experience in Distance Runners: Age- and Sex-Related Factors.

ERIC Educational Resources Information Center

Walter, Stephen D.

1988-01-01

An 80-item questionnaire was used to study variations by age and sex in the training habits and injury experience of 688 adult distance runners. The results are analyzed according to these variables. Methodology is discussed. This is part of a longitudinal study of 1,700 runners. (Author/JL)

Solar wind conditions in the outer heliosphere and the distance to the termination shock

NASA Technical Reports Server (NTRS)

Belcher, John W.; Lazarus, Alan J.; Mcnutt, Ralph L., Jr.; Gordon, George S., Jr.

1993-01-01

The Plasma Science experiment on the Voyager 2 spacecraft has measured the properties of solar wind protons from 1 to 40.4 AU. We use these observations to discuss the probable location and motion of the termination shock of the solar wind. Assuming that the interstellar pressure is due to a 5 micro-G magnetic field draped over the upstream face of the heliopause, the radial variation of ram pressure implies that the termination shock will be located at an average distance near 89 AU. This distance scales inversely as the assumed field strength. There are also large variations in ram pressure on time scales of tens of days, due primarily to large variations in solar wind density at a given radius. Such rapid changes in the solar wind ram pressure can cause large perturbations in the location of the termination shock. We study the nonequilibrium location of the termination shock as it responds to these ram pressure changes. The results of this study suggest that the position of the termination shock can vary by as much as 10 AU in a single year, depending on the nature of variations in the ram pressure, and that multiple crossings of the termination shock by a given outer heliosphere spacecraft are likely. After the first crossing, such models of shock motion will be useful for predicting the timing of subsequent crossings.

Variations in the sonographic measurement techniques of BI-RADS 3 breast masses.

PubMed

Francisco, Juliana; Jales, Rodrigo Menezes; de Oliveira, André Desuó Bueno; Arguello, Carlos Henrique Francisco; Derchain, Sophie

2017-06-01

To evaluate the differences in sonographic (US) distance and volume measurements from different sonologists and identify the optimal parameters to avoid clinically relevant variations in the measurement of BI-RADS 3 breast masses. For this cross-sectional study with prospectively collected data, four physicians with various levels of experience in US, herein called sonologists, performed distance and volume US measurements of 80 masses classified as BI-RADS 3. The Cochran Q test was used to compare the matched sets of rates of clinically relevant variability between all pairs of sonologists' measurements. There were clinically relevant differences between sonologists in the measurements of the longest diameter (range, 17.5-43.7%, p = 0.003), the longest diameter perpendicular to the previous one (anteroposterior diameter) (17.5-33.7%, p = 0.06), the third diameter orthogonal to the plane defined by the previous two (transverse diameter) (28.7-55%, p = 0.001), and at least two of those three diameters (18.7-38.7%, p = 0.015). The smallest clinically relevant differences were observed with volume measurements (range of differences, 6.2-13.7%, p = 0.51). Volume measurement technique was associated with the least variations, whereas distance measurements, which are used routinely, were associated with unacceptable rates of clinically relevant variations. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 45:252-260, 2017. © 2017 Wiley Periodicals, Inc.

Solar wind temperature observations in the outer heliosphere

NASA Technical Reports Server (NTRS)

Gazis, P. R.; Barnes, A.; Mihalov, J. D.; Lazarus, A. J.

1992-01-01

The Pioneer 10, Pioneer 11, and Voyager 2 spacecraft are now at heliocentric distances of 50, 32 and 33 AU, and heliographic latitudes of 3.5 deg N, 17 deg N, and 0 deg N, respectively. Pioneer 11 and Voyager 2 are at similar celestial longitudes, while Pioneer l0 is on the opposite side of the sun. The baselines defined by these spacecraft make it possible to resolve radial, longitudinal, and latitudinal variations of solar wind parameters. The solar wind temperature decreases with increasing heliocentric distance out to a distance of 10-15 AU. At larger heliocentric distances, this gradient disappears. These high solar wind temperatures in the outer heliosphere have persisted for at least 10 years, which suggests that they are not a solar cycle effect. The solar wind temperature varied with heliographic latitude during the most recent solar minimum. The solar wind temperature at Pioneer 11 and Voyager 2 was higher than that seen at Pioneer 10 for an extended period of time, which suggests the existence of a large-scale variation of temperature with celestial longitude, but the contribution of transient phenomena is yet to be clarified.

Valuing water resources in Switzerland using a hedonic price model

NASA Astrophysics Data System (ADS)

van Dijk, Diana; Siber, Rosi; Brouwer, Roy; Logar, Ivana; Sanadgol, Dorsa

2016-05-01

In this paper, linear and spatial hedonic price models are applied to the housing market in Switzerland, covering all 26 cantons in the country over the period 2005-2010. Besides structural house, neighborhood and socioeconomic characteristics, we include a wide variety of new environmental characteristics related to water to examine their role in explaining variation in sales prices. These include water abundance, different types of water bodies, the recreational function of water, and water disamenity. Significant spatial autocorrelation is found in the estimated models, as well as nonlinear effects for distances to the nearest lake and large river. Significant effects are furthermore found for water abundance and the distance to large rivers, but not to small rivers. Although in both linear and spatial models water related variables explain less than 1% of the price variation, the distance to the nearest bathing site has a larger marginal contribution than many neighborhood-related distance variables. The housing market shows to differentiate between different water related resources in terms of relative contribution to house prices, which could help the housing development industry make more geographically targeted planning activities.

Rotation and scale invariant shape context registration for remote sensing images with background variations

NASA Astrophysics Data System (ADS)

Jiang, Jie; Zhang, Shumei; Cao, Shixiang

2015-01-01

Multitemporal remote sensing images generally suffer from background variations, which significantly disrupt traditional region feature and descriptor abstracts, especially between pre and postdisasters, making registration by local features unreliable. Because shapes hold relatively stable information, a rotation and scale invariant shape context based on multiscale edge features is proposed. A multiscale morphological operator is adapted to detect edges of shapes, and an equivalent difference of Gaussian scale space is built to detect local scale invariant feature points along the detected edges. Then, a rotation invariant shape context with improved distance discrimination serves as a feature descriptor. For a distance shape context, a self-adaptive threshold (SAT) distance division coordinate system is proposed, which improves the discriminative property of the feature descriptor in mid-long pixel distances from the central point while maintaining it in shorter ones. To achieve rotation invariance, the magnitude of Fourier transform in one-dimension is applied to calculate angle shape context. Finally, the residual error is evaluated after obtaining thin-plate spline transformation between reference and sensed images. Experimental results demonstrate the robustness, efficiency, and accuracy of this automatic algorithm.

Analysis of the Variation of Energetic Electron Flux with Respect to Longitude and Distance Normal to the Magnetic Equatorial Plane for Galileo Energetic Particle Detector Data

NASA Technical Reports Server (NTRS)

Swimm, Randall; Garrett, Henry B.; Jun, Insoo; Evans, Robin W.

2004-01-01

In this study we examine ten-minute omni-directional averages of energetic electron data measured by the Galileo spacecraft Energetic Particle Detector (EPD). Count rates from electron channels B1, DC2, and DC3 are evaluated using a power law model to yield estimates of the differential electron fluxes from 1 MeV to 11 MeV at distances between 8 and 51 Jupiter radii. Whereas the orbit of the Galileo spacecraft remained close to the rotational equatorial plane of Jupiter, the approximately 11 degree tilt of the magnetic axis of Jupiter relative to its rotational axis allowed the EPD instrument to sample high energy electrons at limited distances normal to the magnetic equatorial plane. We present a Fourier analysis of the semi-diurnal variation of electron fluxes with longitude.

Geographic variation and genetic structure in Spotted Owls

USGS Publications Warehouse

Haig, Susan M.; Wagner, R.S.; Forsman, E.D.; Mullins, Thomas D.

2001-01-01

We examined genetic variation, population structure, and definition of conservation units in Spotted Owls (Strix occidentalis). Spotted Owls are mostly non-migratory, long-lived, socially monogamous birds that have decreased population viability due to their occupation of highly-fragmented late successional forests in western North America. To investigate potential effects of habitat fragmentation on population structure, we used random amplified polymorphic DNA (RAPD) to examine genetic variation hierarchically among local breeding areas, subregional groups, regional groups, and subspecies via sampling of 21 breeding areas (276 individuals) among the three subspecies of Spotted Owls. Data from 11 variable bands suggest a significant relationship between geographic distance among local breeding groups and genetic distance (Mantel r = 0.53, P < 0.02) although multi-dimensional scaling of three significant axes did not identify significant grouping at any hierarchical level. Similarly, neighbor-joining clustering of Manhattan distances indicated geographic structure at all levels and identified Mexican Spotted Owls as a distinct clade. RAPD analyses did not clearly differentiate Northern Spotted Owls from California Spotted Owls. Among Northern Spotted Owls, estimates of population differentiation (FST) ranged from 0.27 among breeding areas to 0.11 among regions. Concordantly, within-group agreement values estimated via multi-response permutation procedures of Jaccarda??s distances ranged from 0.22 among local sites to 0.11 among regions. Pairwise comparisons of FST and geographic distance within regions suggested only the Klamath region was in equilibrium with respect to gene flow and genetic drift. Merging nuclear data with recent mitochondrial data provides support for designation of an Evolutionary Significant Unit for Mexican Spotted Owls and two overlapping Management Units for Northern and California Spotted Owls.

Water production activity of nine long-period comets from SOHO/SWAN observations of hydrogen Lyman-alpha: 2013-2016

NASA Astrophysics Data System (ADS)

Combi, M. R.; Mäkinen, T. T.; Bertaux, J.-L.; Quémerais, E.; Ferron, S.; Avery, M.; Wright, C.

2018-01-01

Nine recently discovered long-period comets were observed by the Solar Wind Anisotropies (SWAN) Lyman-alpha all-sky camera on board the Solar and Heliosphere Observatory (SOHO) satellite during the period of 2013 to 2016. These were C/2012 K1 (PanSTARRS), C/2013 US10 (Catalina), C/2013 V5 (Oukaimeden), C/2013 R1 (Lovejoy), C/2014 E2 (Jacques), C/2014 Q2 (Lovejoy), C/2015 G2 (MASTER), C/2014 Q1 (PanSTARRS) and C/2013 XI (PanSTARRS). Of these 9 comets 6 were long-period comets and 3 were possibly dynamically new. Water production rates were calculated from each of the 885 images using our standard time-resolved model that accounts for the whole water photodissociation chain, exothermic velocities and collisional escape of H atoms. For most of these comets there were enough observations over a broad enough range of heliocentric distances to calculate power-law fits to the variation of production rate with heliocentric distances for pre- and post-perihelion portions of the orbits. Comet C/2014 Q1 (PanSTARRS), with a perihelion distance of only ∼0.3 AU, showed the most unusual variation of water production rate with heliocentric distance and the resulting active area variation, indicating that when the comet was within 0.7 AU its activity was dominated by the continuous release of icy grains and chunks, greatly increasing the active sublimation area by more than a factor of 10 beyond what it had at larger heliocentric distances. A possible interpretation suggests that a large fraction of the comet's mass was lost during the apparition.

Variation in angler distribution and catch rates of stocked rainbow trout in a small reservoir

USGS Publications Warehouse

Harmon, Brian S.; Martin, Dustin R.; Chizinski, Christopher J.; Pope, Kevin L.

2018-01-01

We investigated the spatial and temporal relationship of catch rates and angler party location for two days following a publicly announced put-and-take stocking of rainbow trout (Oncorhynchus mykiss). Catch rates declined with time since stocking and distance from stocking. We hypothesized that opportunity for high catch rates would cause anglers to fish near the stocking location and disperse with time, however distance between angler parties and stocking was highly variable at any given time. Spatially explicit differences in catch rates can affect fishing quality. Further research could investigate the variation between angler distribution and fish distribution within a waterbody.

Evaluating the Consistency of Current Mainstream Wearable Devices in Health Monitoring: A Comparison Under Free-Living Conditions

PubMed Central

Wen, Dong; Zhang, Xingting; Liu, Xingyu

2017-01-01

Background Wearable devices are gaining increasing market attention; however, the monitoring accuracy and consistency of the devices remains unknown. Objective The purpose of this study was to assess the consistency of the monitoring measurements of the latest wearable devices in the state of normal activities to provide advice to the industry and support to consumers in making purchasing choices. Methods Ten pieces of representative wearable devices (2 smart watches, 4 smart bracelets of Chinese brands or foreign brands, and 4 mobile phone apps) were selected, and 5 subjects were employed to simultaneously use all the devices and the apps. From these devices, intact health monitoring data were acquired for 5 consecutive days and analyzed on the degree of differences and the relationships of the monitoring measurements ​​by the different devices. Results The daily measurements by the different devices fluctuated greatly, and the coefficient of variation (CV) fluctuated in the range of 2-38% for the number of steps, 5-30% for distance, 19-112% for activity duration, .1-17% for total energy expenditure (EE), 22-100% for activity EE, 2-44% for sleep duration, and 35-117% for deep sleep duration. After integrating the measurement data of 25 days among the devices, the measurements of the number of steps (intraclass correlation coefficient, ICC=.89) and distance (ICC=.84) displayed excellent consistencies, followed by those of activity duration (ICC=.59) and the total EE (ICC=.59) and activity EE (ICC=.57). However, the measurements for sleep duration (ICC=.30) and deep sleep duration (ICC=.27) were poor. For most devices, there was a strong correlation between the number of steps and distance measurements (R2>.95), and for some devices, there was a strong correlation between activity duration measurements and EE measurements (R2>.7). A strong correlation was observed in the measurements of steps, distance and EE from smart watches and mobile phones of the same brand, Apple or Samsung (r>.88). Conclusions Although wearable devices are developing rapidly, the current mainstream devices are only reliable in measuring the number of steps and distance, which can be used as health assessment indicators. However, the measurement consistencies of activity duration, EE, sleep quality, and so on, are still inadequate, which require further investigation and improved algorithms. PMID:28270382

Simplified cost models for prefeasibility mineral evaluations

USGS Publications Warehouse

Camm, Thomas W.

1991-01-01

This report contains 2 open pit models, 6 underground mine models, 11 mill models, and cost equations for access roads, power lines, and tailings ponds. In addition, adjustment factors for variation in haulage distances are provided for open pit models and variation in mining depths for underground models.

Phylogenetic congruence of lichenised fungi and algae is affected by spatial scale and taxonomic diversity.

PubMed

Buckley, Hannah L; Rafat, Arash; Ridden, Johnathon D; Cruickshank, Robert H; Ridgway, Hayley J; Paterson, Adrian M

2014-01-01

The role of species' interactions in structuring biological communities remains unclear. Mutualistic symbioses, involving close positive interactions between two distinct organismal lineages, provide an excellent means to explore the roles of both evolutionary and ecological processes in determining how positive interactions affect community structure. In this study, we investigate patterns of co-diversification between fungi and algae for a range of New Zealand lichens at the community, genus, and species levels and explore explanations for possible patterns related to spatial scale and pattern, taxonomic diversity of the lichens considered, and the level sampling replication. We assembled six independent datasets to compare patterns in phylogenetic congruence with varied spatial extent of sampling, taxonomic diversity and level of specimen replication. For each dataset, we used the DNA sequences from the ITS regions of both the fungal and algal genomes from lichen specimens to produce genetic distance matrices. Phylogenetic congruence between fungi and algae was quantified using distance-based redundancy analysis and we used geographic distance matrices in Moran's eigenvector mapping and variance partitioning to evaluate the effects of spatial variation on the quantification of phylogenetic congruence. Phylogenetic congruence was highly significant for all datasets and a large proportion of variance in both algal and fungal genetic distances was explained by partner genetic variation. Spatial variables, primarily at large and intermediate scales, were also important for explaining genetic diversity patterns in all datasets. Interestingly, spatial structuring was stronger for fungal than algal genetic variation. As the spatial extent of the samples increased, so too did the proportion of explained variation that was shared between the spatial variables and the partners' genetic variation. Different lichen taxa showed some variation in their phylogenetic congruence and spatial genetic patterns and where greater sample replication was used, the amount of variation explained by partner genetic variation increased. Our results suggest that the phylogenetic congruence pattern, at least at small spatial scales, is likely due to reciprocal co-adaptation or co-dispersal. However, the detection of these patterns varies among different lichen taxa, across spatial scales and with different levels of sample replication. This work provides insight into the complexities faced in determining how evolutionary and ecological processes may interact to generate diversity in symbiotic association patterns at the population and community levels. Further, it highlights the critical importance of considering sample replication, taxonomic diversity and spatial scale in designing studies of co-diversification.

Impacts on seafloor geology of drilling disturbance in shallow waters.

PubMed

Corrêa, Iran C S; Toldo, Elírio E; Toledo, Felipe A L

2010-08-01

This paper describes the effects of drilling disturbance on the seafloor of the upper continental slope of the Campos Basin, Brazil, as a result of the project Environmental Monitoring of Offshore Drilling for Petroleum Exploration--MAPEM. Field sampling was carried out surrounding wells, operated by the company PETROBRAS, to compare sediment properties of the seafloor, including grain-size distribution, total organic carbon, and clay mineral composition, prior to drilling with samples obtained 3 and 22 months after drilling. The sampling grid used had 74 stations, 68 of which were located along 7 radials from the well up to a distance of 500 m. The other 6 stations were used as reference, and were located 2,500 m from the well. The results show no significant sedimentological variation in the area affected by drilling activity. The observed sedimentological changes include a fining of grain size, increase in total organic carbon, an increase in gibbsite, illite, and smectite, and a decrease in kaolinite after drilling took place.

Dependence of the Interplanetary Magnetic Field on Heliocentric Distance between 0.3 and 1.7 AU from MESSENGER, ACE and MAVEN data

NASA Astrophysics Data System (ADS)

Hanneson, C.; Johnson, C.; Al Asad, M.

2017-12-01

Magnetometer data from the MErcury Surface, Space ENvironment, GEochemistry and Ranging (MESSENGER), Advanced Composition Explorer (ACE) and Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft were used to characterize the variation of the interplanetary magnetic field (IMF) with heliocentric distance from 0.3 to 1.7 AU. MESSENGER and ACE data form a set of simultaneous observations that spans eight years, from March 2007 until April 2015, with ACE observations continuing until the present. MAVEN data have been collected since November 2014. Furthermore, for the period 2008-2015, MESSENGER and ACE observations were taken over the same range of heliocentric distances: 0.31-0.47 AU and 0.94-1.00 AU respectively. The IMF varies with the solar sunspot cycle, and so data taken simultaneously at different heliocentric distances allow solar-cycle effects to be decoupled from the radial evolution of the IMF. The data were averaged temporally by taking 1-hour means, and median values were then computed in 0.01-AU bins. For the time interval spanned by all observations, the median value of the magnitude of the IMF decreases steadily from 30.1 nT at 0.3 AU to 4.3 nT at 1.0 AU and 2.5 nT at 1.6 AU. The magnitude of the IMF was found to decay with heliocentric distance according to an inverse power law with an exponent equal to the adiabatic index for an ideal monatomic gas, 5/3, within 95% confidence limits. The magnitude of the radial component decays with distance as an inverse square law within 95% confidence limits. We also consider temporal variations of the heliocentric-dependence of the IMF over the current solar cycle by computing power law fits to the simultaneous MESSENGER and ACE observations using a moving window. Our study complements the recent study of Gruesbeck et al. (2017) that used Juno data to consider the variation in IMF properties over the heliocentric distance range 1 to 6 AU.

Acoustic variation of spider monkeys' contact calls (whinnies) is related to distance between vocalizing individuals and immediate caller behavior.

PubMed

Ordóñez-Gómez, José D; Santillán-Doherty, Ana M; Fischer, Julia; Hammerschmidt, Kurt

2018-04-01

Due to several factors such as ecological conditions, group size, and social organization, primates frequently spend time out of visual contact with individuals of their own group. Through the use of long-distance vocalizations, often termed "contact calls," primates are able to maintain contact with out-of-sight individuals. Contact calls have been shown to be individually distinct, and reverberation and attenuation provide information about caller distance. It is less clear, however, whether callers actively change the structure of contact calls depending on the distance to the presumed listeners. We studied this question in spider monkeys (Ateles geoffroyi), a species with complex spatial dynamics (fission-fusion society) that produces highly frequency modulated contact calls, denominated "whinnies." We determined the acoustic characteristics of 566 whinnies recorded from 35 free-ranging spider monkeys that belong to a community located in Mexico, and used cluster analyses, discriminant function analyses, and generalized linear mixed models to assess if they varied in relation to the presumed distance to the listener. Whinnies could be grouped into five subtypes. Since the lowest frequency subtype was mainly produced by spider monkeys that exchanged whinnies at longer distances, and lower frequency calls propagate across longer distances, our results suggest that whinnies vary in order to enhance vocal contact between individuals separated by different distances. Our results also revealed that whinnies convey potential information about caller immediate behaviors and corroborated that these calls are individually distinct. Overall, our results suggest that whinny acoustic variation facilitates the maintenance of vocal contact between individuals living in a society with complex spatial dynamics. © 2018 Wiley Periodicals, Inc.

Read distance performance and variation of 5 low-frequency radio frequency identification panel transceiver manufacturers.

PubMed

Ryan, S E; Blasi, D A; Anglin, C O; Bryant, A M; Rickard, B A; Anderson, M P; Fike, K E

2010-07-01

Use of electronic animal identification technologies by livestock managers is increasing, but performance of these technologies can be variable when used in livestock production environments. This study was conducted to determine whether 1) read distance of low-frequency radio frequency identification (RFID) transceivers is affected by type of transponder being interrogated; 2) read distance variation of low-frequency RFID transceivers is affected by transceiver manufacturer; and 3) read distance of various transponder-transceiver manufacturer combinations meet the 2004 United States Animal Identification Plan (USAIP) bovine standards subcommittee minimum read distance recommendation of 60 cm. Twenty-four transceivers (n = 5 transceivers per manufacturer for Allflex, Boontech, Farnam, and Osborne; n = 4 transceivers for Destron Fearing) were tested with 60 transponders [n = 10 transponders per type for Allflex full duplex B (FDX-B), Allflex half duplex (HDX), Destron Fearing FDX-B, Farnam FDX-B, and Y-Tex FDX-B; n = 6 for Temple FDX-B (EM Microelectronic chip); and n = 4 for Temple FDX-B (HiTag chip)] presented in the parallel orientation. All transceivers and transponders met International Organization for Standardization 11784 and 11785 standards. Transponders represented both one-half duplex and full duplex low-frequency air interface technologies. Use of a mechanical trolley device enabled the transponders to be presented to the center of each transceiver at a constant rate, thereby reducing human error. Transponder and transceiver manufacturer interacted (P < 0.0001) to affect read distance, indicating that transceiver performance was greatly dependent upon the transponder type being interrogated. Twenty-eight of 30 combinations of transceivers and transponders evaluated met the minimum recommended USAIP read distance. The mean read distance across all 30 combinations was 45.1 to 129.4 cm. Transceiver manufacturer and transponder type interacted to affect read distance variance (P < 0.05). Maximum read distance performance of low-frequency RFID technologies with low variance can be achieved by selecting specific transponder-transceiver combinations.

Genetic structure and isolation by distance in a landrace of Thai rice

PubMed Central

Pusadee, Tonapha; Jamjod, Sansanee; Chiang, Yu-Chung; Rerkasem, Benjavan; Schaal, Barbara A.

2009-01-01

Rice is among the 3 most important crops worldwide. While much of the world's rice harvest is based on modern high-yield varieties, traditional varieties of rice grown by indigenous groups have great importance as a resource for future crop improvement. These local landraces represent an intermediate stage of domestication between a wild ancestor and modern varieties and they serve as reservoirs of genetic variation. Such genetic variation is influenced both by natural processes such as selection and drift, and by the agriculture practices of local farmers. How these processes interact to shape and change the population genetics of landrace rice is unknown. Here, we determine the population genetic structure of a single variety of landrace rice, Bue Chomee, cultivated by Karen people of Thailand. Microsatellite markers reveal high level of genetic variation despite predominant inbreeding in the crop. Bue Chomee rice shows slight but significant genetic differentiation among Karen villages. Moreover, genetically determined traits such as flowering time can vary significantly among villages. An unanticipated result was the overall pattern of genetic differentiation across villages which conforms to an isolation by distance model of differentiation. Isolation by distance is observed in natural plant species where the likelihood of gene flow is inversely related to distance. In Karen rice, gene flow is the result of farmers' seed sharing networks. Taken together, these data suggest that landrace rice is a dynamic genetic system that responds to evolutionary forces, both natural and those imposed by humans. PMID:19651617

Sediment size of surface floodplain sediments along a large lowland river

NASA Astrophysics Data System (ADS)

Swanson, K. M.; Day, G.; Dietrich, W. E.

2007-12-01

Data on size distribution of surface sediment across a floodplain should place important constraints of modeling of floodplain deposition. Diffusive or advective models would predict that, generally, grain size should decrease away from channel banks. Variations in grain size downstream along floodplains may depend on downstream fining of river bed material, exchange rate with river banks and net deposition onto the floodplain. Here we report detailed grain size analyses taken from 17 floodplain transects along 450 km (along channel distance) reach of the middle Fly River, Papua New Guinea. Field studies have documented a systematic change in floodplain characteristics downstream from forested, more topographically elevated and topography bounded by an actively shifting mainstem channel to a downstream swamp grass, low elevation topography along which the river meanders are currently stagnant. Frequency and duration of flooding increase downstream. Flooding occurs both by overbank flows and by injections of floodwaters up tributary and tie channels connected to the mainstem. Previous studies show that about 40% of the total discharge of water passes across the floodplain, and, correspondingly, about 40% of the total load is deposited on the plain - decreasing exponentially from channel bank. We find that floodplain sediment is most sandy at the channel bank. Grain size rapidly declines away from the bank, but surprisingly two trends were also observed. A relatively short distance from the bank the surface material is finest, but with further distance from the bank (out to greater than 1 km from the 250 m wide channel) clay content decreases and silt content increases. The changes are small but repeated at most of the transects. The second trend is that bank material fines downstream, corresponding to a downstream finding bed material, but once away from the bank, there is a weak tendency for a given distance away from the bank the floodplain surface deposits to slightly coarsen downstream. We also find that sand is present (about 4%) in these surface sediments out to 1 km from the channel bank. These trends are not consistent with simple lateral transport models, and other factors, including effects of flocculation, local flow patterns, and possibly dry season wind effects may matter.

[Variations on hemagglutinin gene of Zhejiang measles virus strains and differences with measles strains circulated both at home and abroad].

PubMed

Feng, Yan; Zhong, Shu-ling; Xu, Chang-ping; Lu, Yi-yu

2013-07-01

To investigate the variations on hemagglutinin (H) gene of measles virus (MV) in Zhejiang province, and to analyze the differences with strains circulated both at home and abroad. In total, 33 MV strains isolated in Zhejiang province between 1999 and 2011 were collected.RNA of the isolated MV strains was extracted and the complete sequences on H gene were amplified using RT-PCR assay. The products were compared with the Chinese vaccine strain Shanghai-191, which was downloaded from GenBank, and other 95 different MV strains from all over the world. 33 MV strains, isolated from the throat swab specimens collected from MV patients in Zhejiang province during 1999 to 2001, were used to conduct phylogenetic analysis with MV strains circulated in other areas of China during 1993 to 2007. The phylogenetic tree based on H gene sequences showed that all the Zhejiang MV strains located in H1a cluster, and no apparent time series and geographic restrictions were observed. Compared to the referenced vaccine strain Shanghai-191, the average variation rate on nucleotides and amino acids, and the evolutionary rate of H1a viruses from China during 2003 to 2011 were separately 5.15%, 4.44% and 5.81%, which were higher than the rates of H1a viruses during 1965 to 1993 (4.75%, 3.86% and 5.30%), and the rates of viruses during 1994 to 2002 (4.80%, 4.08% and 5.37%).However, the dn/ds ratios of strains within the three time periods were 0.19,0.21 and 0.23 respectively, which indicated that no evidence of positive selection was found on H1a MV strains during 1993 to 2011. A 24 stable amino acid variation sites on H gene was found between H1a viruses during 2003 to 2011 and the vaccine strain Shanghai-191. The largest variation occurred between vaccine and H1a strains, with 0.053 of the p-distance and 26-28 of amino acid mutations.However, only 15 stable amino acid variations were found between vaccine strain and genotype B3 or D4 strains.In addition, significant differences were found between H1a viruses and genotype B or D viruses, with 0.074 and 0.071 of p-distance and 27-33 of amino acid differences. Significant differences were found on H gene between MV strains subtype H1a and vaccine strains and other genotype strains. The variations were enlarged with the time coursing; therefore, the surveillance on variation of Chinese MV strains should be taken into account.

Transport of Escherichia coli in 25 m quartz sand columns

NASA Astrophysics Data System (ADS)

Lutterodt, G.; Foppen, J. W. A.; Maksoud, A.; Uhlenbrook, S.

2011-01-01

To help improve the prediction of bacteria travel distances in aquifers laboratory experiments were conducted to measure the distant dependent sticking efficiencies of two low attaching Escherichia coli strains (UCFL-94 and UCFL-131). The experimental set up consisted of a 25 m long helical column with a diameter of 3.2 cm packed with 99.1% pure-quartz sand saturated with a solution of magnesium sulfate and calcium chloride. Bacteria mass breakthrough at sampling distances ranging from 6 to 25.65 m were observed to quantify bacteria attachment over total transport distances ( αL) and sticking efficiencies at large intra-column segments ( αi) (> 5 m). Fractions of cells retained ( Fi) in a column segment as a function of αi were fitted with a power-law distribution from which the minimum sticking efficiency defined as the sticking efficiency of 0.001% bacteria fraction of the total input mass retained that results in a 5 log removal were extrapolated. Low values of αL in the order 10 - 4 and 10 - 3 were obtained for UCFL-94 and UCFL-131 respectively, while αi-values ranged between 10 - 6 to 10 - 3 for UCFL-94 and 10 - 5 to 10 - 4 for UCFL-131. In addition, both αL and αi reduced with increasing transport distance, and high coefficients of determination (0.99) were obtained for power-law distributions of αi for the two strains. Minimum sticking efficiencies extrapolated were 10 - 7 and 10 - 8 for UCFL-94 and UCFL-131, respectively. Fractions of cells exiting the column were 0.19 and 0.87 for UCFL-94 and UCL-131, respectively. We concluded that environmentally realistic sticking efficiency values in the order of 10 - 4 and 10 - 3 and much lower sticking efficiencies in the order 10 - 5 are measurable in the laboratory, Also power-law distributions in sticking efficiencies commonly observed for limited intra-column distances (< 2 m) are applicable at large transport distances(> 6 m) in columns packed with quartz grains. High fractions of bacteria populations may possess the so-called minimum sticking efficiency, thus expressing their ability to be transported over distances longer than what might be predicted using measured sticking efficiencies from experiments with both short (< 1 m) and long columns (> 25 m). Also variable values of sticking efficiencies within and among the strains show heterogeneities possibly due to variations in cell surface characteristics of the strains. The low sticking efficiency values measured express the importance of the long columns used in the experiments and the lower values of extrapolated minimum sticking efficiencies makes the method a valuable tool in delineating protection areas in real-world scenarios.

Orthopedic workforce planning in Germany – an analysis of orthopedic accessibility

PubMed Central

Müller, Peter; Maier, Werner; Groneberg, David A.

2017-01-01

In Germany, orthopedic workforce planning relies on population-to-provider-ratios represented by the ‘official degree of care provision’. However, with geographic information systems (GIS), more sophisticated measurements are available. By utilizing GIS-based technologies we analyzed the current state of demand and supply of the orthopedic workforce in Germany (orthopedic accessibility) with the integrated Floating Catchment Area method. The analysis of n = 153,352,220 distances revealed significant geographical variations on national scale: 5,617,595 people (6.9% of total population) lived in an area with significant low orthopedic accessibility (average z-score = -4.0), whereas 31,748,161 people (39.0% of total population) lived in an area with significant high orthopedic accessibility (average z-score = 8.0). Accessibility was positively correlated with the degree of urbanization (r = 0.49; p<0.001) and the official degree of care provision (r = 0.33; p<0.001) and negatively correlated with regional social deprivation (r = -0.47; p<0.001). Despite advantages of simpler measures regarding implementation and acceptance in health policy, more sophisticated measures of accessibility have the potential to reduce costs as well as improve health care. With this study, significant geographical variations were revealed that show the need to reduce oversupply in less deprived urban areas in order to enable adequate care in more deprived rural areas. PMID:28178335

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Jiali; Swati, F. N. U.; Stein, Michael L.

Regional climate models (RCMs) are a standard tool for downscaling climate forecasts to finer spatial scales. The evaluation of RCMs against observational data is an important step in building confidence in the use of RCMs for future prediction. In addition to model performance in climatological means and marginal distributions, a model’s ability to capture spatio-temporal relationships is important. This study develops two approaches: (1) spatial correlation/variogram for a range of spatial lags, with total monthly precipitation and non-seasonal precipitation components used to assess the spatial variations of precipitation; and (2) spatio-temporal correlation for a wide range of distances, directions, andmore » time lags, with daily precipitation occurrence used to detect the dynamic features of precipitation. These measures of spatial and spatio-temporal dependence are applied to a high-resolution RCM run and to the National Center for Environmental Prediction (NCEP)-U.S. Department of Energy (DOE) AMIP II reanalysis data (NCEP-R2), which provides initial and lateral boundary conditions for the RCM. The RCM performs better than NCEP-R2 in capturing both the spatial variations of total and non-seasonal precipitation components and the spatio-temporal correlations of daily precipitation occurrences, which are related to dynamic behaviors of precipitating systems. The improvements are apparent not just at resolutions finer than that of NCEP-R2, but also when the RCM and observational data are aggregated to the resolution of NCEP-R2.« less

Joint reconstruction via coupled Bregman iterations with applications to PET-MR imaging

NASA Astrophysics Data System (ADS)

Rasch, Julian; Brinkmann, Eva-Maria; Burger, Martin

2018-01-01

Joint reconstruction has recently attracted a lot of attention, especially in the field of medical multi-modality imaging such as PET-MRI. Most of the developed methods rely on the comparison of image gradients, or more precisely their location, direction and magnitude, to make use of structural similarities between the images. A challenge and still an open issue for most of the methods is to handle images in entirely different scales, i.e. different magnitudes of gradients that cannot be dealt with by a global scaling of the data. We propose the use of generalized Bregman distances and infimal convolutions thereof with regard to the well-known total variation functional. The use of a total variation subgradient respectively the involved vector field rather than an image gradient naturally excludes the magnitudes of gradients, which in particular solves the scaling behavior. Additionally, the presented method features a weighting that allows to control the amount of interaction between channels. We give insights into the general behavior of the method, before we further tailor it to a particular application, namely PET-MRI joint reconstruction. To do so, we compute joint reconstruction results from blurry Poisson data for PET and undersampled Fourier data from MRI and show that we can gain a mutual benefit for both modalities. In particular, the results are superior to the respective separate reconstructions and other joint reconstruction methods.

Size of Douglas-fir trees in relation to distance from a mixed red alder - Douglas-fir stand

Treesearch

R.E. Miller; D.L. Reukema; T.A. Max

1993-01-01

Variation in diameter, height, and stem volume of 57-year-old Douglas-fir(Pseudotsuga menziesii var. menziesii (Mirb.) Franco) was related to distance of these trees from a 27 m wide strip in the same Douglas-fir plantation that had been interplanted with red alder (Alnus rubra Bong.). Within the...

Opportunities to Notice: Chinese Prospective Teachers Noticing Students' Ideas in a Distance Formula Lesson

ERIC Educational Resources Information Center

Ding, Lin; Domínguez, Higinio

2016-01-01

This paper investigates the noticing of six Chinese mathematics prospective teachers (PSTs) when looking at a procedural error and responding to three specific tasks related to that error. Using video clips of one student's procedural error consisting of exchanging the order of coordinates when applying the distance formula, some variation was…

Inferring the effects of potential dispersal routes on the metacommunity structure of stream insects: as the crow flies, as the fish swims or as the fox runs?

PubMed

Kärnä, Olli-Matti; Grönroos, Mira; Antikainen, Harri; Hjort, Jan; Ilmonen, Jari; Paasivirta, Lauri; Heino, Jani

2015-09-01

1. Metacommunity research relies largely on proxies for inferring the effect of dispersal on local community structure. Overland and watercourse distances have been typically used as such proxies. A good proxy for dispersal should, however, take into account more complex landscape features that can affect an organism's movement and dispersal. The cost distance approach does just that, allowing determining the path of least resistance across a landscape. 2. Here, we examined the distance decay of assemblage similarity within a subarctic stream insect metacommunity. We tested whether overland, watercourse and cumulative cost distances performed differently as correlates of dissimilarity in assemblage composition between sites. We also investigated the effect of body size and dispersal mode on metacommunity organization. 3. We found that dissimilarities in assemblage composition correlated more strongly with environmental than physical distances between sites. Overland and watercourse distances showed similar correlations to assemblage dissimilarity between sites, being sometimes significantly correlated with biological variation of entire insect communities. In metacommunities deconstructed by body size or dispersal mode, contrary to our expectation, passive dispersers showed a slightly stronger correlation than active dispersers to environmental differences between sites, although passive dispersers also showed a stronger correlation than active dispersers to physical distances between sites. The strength of correlation between environmental distance and biological dissimilarity also varied slightly among the body size classes. 4. After controlling for environmental differences between sites, cumulative cost distances were slightly better correlates of biological dissimilarities than overland or watercourse distances between sites. However, quantitative differences in correlation coefficients were small between different physical distances. 5. Although environmental differences typically override physical distances as determinants of the composition of stream insect assemblages, correlations between environmental distances and biological dissimilarities are typically rather weak. This undetermined variation may be attributable to dispersal processes, which may be captured using better proxies for the process. We suggest that further modifying the measurement of cost distances may be a fruitful avenue, especially if complemented by more direct natural history information on insect dispersal behaviour and distances travelled by them. © 2015 The Authors. Journal of Animal Ecology © 2015 British Ecological Society.

Evidence of bottleneck and isolation by distance in an endangered species from the Tropical Andean hotspot

USDA-ARS?s Scientific Manuscript database

The Tropical Andes is the most diverse of the recognized plant conservation hotspots. In contrast, there exists scant knowledge about patterns of genetic variation within its constituent species. Understanding genetic variation is essential to develop successful conservation plans. Phaedranassa tun...

Inferring Genetic Variation and Demographic History of Michelia yunnanensis Franch. (Magnoliaceae) from Chloroplast DNA Sequences and Microsatellite Markers

PubMed Central

Zhang, Xue; Shen, Shikang; Wu, Fuqin; Wang, Yuehua

2017-01-01

Michelia yunnanensis Franch., is a traditional ornamental, aromatic, and medicinal shrub that endemic to Yunnan Province in southwest China. Although the species has a large distribution pattern and is abundant in Yunnan Province, the populations are dramatically declining because of overexploitation and habitat destruction. Studies on the genetic variation and demography of endemic species are necessary to develop effective conservation and management strategies. To generate such knowledge, we used 3 pairs of universal cpDNA markers and 10 pairs of microsatellite markers to assess the genetic diversity, genetic structure, and demographic history of 7 M. yunnanensis populations. We calculated a total of 88 alleles for 10 polymorphic loci and 10 haplotypes for a combined 2,089 bp of cpDNA. M. yunnanensis populations showed high genetic diversity (Ho = 0.551 for nuclear markers and Hd = 0.471 for cpDNA markers) and low genetic differentiation (FST = 0.058). Geographical structure was not found among M. yunnanensis populations. Genetic distance and geographic distance were not correlated (P > 0.05), which indicated that geographic isolation is not the primary cause of the low genetic differentiation of M. yunnanensis. Additionally, M. yunnanensis populations contracted ~20,000–30,000 years ago, and no recent expansion occurred in current populations. Results indicated that the high genetic diversity of the species and within its populations holds promise for effective genetic resource management and sustainable utilization. Thus, we suggest that the conservation and management of M. yunnanensis should address exotic overexploitation and habitat destruction. PMID:28484472

Light intensity of curved laryngoscope blades in Philadelphia emergency departments.

PubMed

Levitan, Richard M; Kelly, John J; Kinkle, William C; Fasano, Charles

2007-09-01

Laryngoscopy and tracheal intubation requires laryngeal exposure and illumination. The objective of this study is to assess variation in laryngoscope lights across different emergency departments (EDs). A convenience sample of 3 Mac #4 blade and handle pairs in each of 17 Philadelphia area EDs was tested with a digital light meter to derive the median lux at the distal tip. For each blade tested, we characterized blade design (American, English, or German) and light type (fiber-illuminated versus conventional bulb-on-blade) and measured light-to-tip distance. A total of 50 blades and handle pairs were tested (one ED had only 2 Mac #4 blades). American designs were the most common (38/50), followed by English (6/50) and German (3/50) designs. Three blades had hybrid design features and acrylic light-conducting fibers. Median luminance varied from 11 lux to 5,627 lux. The glass fiber-illuminated blades (n=13) produced greater luminance (median 1,205 lux; interquartile range [IQR] 726 to 2,176 lux) than bulb-on-blade designs (median 689 lux; IQR 290 to 906 lux). German fiber-illuminated blades produced the highest luminance (median 1,937 lux; IQR 1,453 to 3,782 lux). English bulb-on-blade designs produced more luminance (median 915 lux; IQR 745 to 1270 lux) than American (median 689 lux; IQR 269 to 807 lux). German and English blades had shorter light-to-tip distances (median 51 mm and 47 mm, respectively) than American blades (65 mm). Curved laryngoscope blades in different EDs have marked variation in light intensity. The contribution of luminance to laryngoscopy performance warrants investigation.

Genetic Diversity of Picocyanobacteria in Tibetan Lakes: Assessing the Endemic and Universal Distributions

PubMed Central

Hu, Anyi; Liu, Xiaobo; Chen, Feng; Yao, Tandong; Jiao, Nianzhi

2014-01-01

The phylogenetic diversity of picocyanobacteria in seven alkaline lakes on the Tibetan Plateau was analyzed using the molecular marker 16S-23S rRNA internal transcribed spacer sequence. A total of 1,077 environmental sequences retrieved from the seven lakes were grouped into seven picocyanobacterial clusters, with two clusters newly described here. Each of the lakes was dominated by only one or two clusters, while different lakes could have disparate communities, suggesting low alpha diversity but high beta diversity of picocyanobacteria in these high-altitude freshwater and saline lakes. Several globally distributed clusters were found in these Tibetan lakes, such as subalpine cluster I and the Cyanobium gracile cluster. Although other clusters likely exhibit geographic restriction to the plateau temporally, reflecting endemicity, they can indeed be distributed widely on the plateau. Lakes with similar salinities may have similar genetic populations despite a large geographic distance. Canonical correspondence analysis identified salinity as the only environmental factor that may in part explain the diversity variations among lakes. Mantel tests suggested that the community similarities among lakes are independent of geographic distance. A portion of the picocyanobacterial clusters appear to be restricted to a narrow salinity range, while others are likely adapted to a broad range. A seasonal survey of Lake Namucuo across 3 years did not show season-related variations in diversity, and depth-related population partitioning was observed along a vertical profile of the lake. Our study emphasizes the high dispersive potential of picocyanobacteria and suggests that the regional distribution may result from adaptation to specified environments. PMID:25281375

Testing the link between population genetic differentiation and clade diversification in Costa Rican orchids.

PubMed

Kisel, Yael; Moreno-Letelier, Alejandra C; Bogarín, Diego; Powell, Martyn P; Chase, Mark W; Barraclough, Timothy G

2012-10-01

Species population genetics could be an important factor explaining variation in clade species richness. Here, we use newly generated amplified fragment length polymorphism (AFLP) data to test whether five pairs of sister clades of Costa Rican orchids that differ greatly in species richness also differ in average neutral genetic differentiation within species, expecting that if the strength of processes promoting differentiation within species is phylogenetically heritable, then clades with greater genetic differentiation should diversify more. Contrary to expectation, neutral genetic differentiation does not correlate directly with total diversification in the clades studied. Neutral genetic differentiation varies greatly among species and shows no heritability within clades. Half of the variation in neutral genetic differentiation among populations can be explained by ecological variables, and species-level traits explain the most variation. Unexpectedly, we find no isolation by distance in any species, but genetic differentiation is greater between populations occupying different niches. This pattern corresponds with those observed for microscopic eukaryotes and could reflect effective widespread dispersal of tiny and numerous orchid seeds. Although not providing a definitive answer to whether population genetics processes affect clade diversification, this work highlights the potential for addressing new macroevolutionary questions using a comparative population genetic approach. © 2012 The Author(s). Evolution© 2012 The Society for the Study of Evolution.

Morphometric variation in Periglischrus torrealbai (Acari: Spinturnicidae) on three species of host bats (Chiroptera: Phyllostomidae) with a new record of host species.

PubMed

de Almeida, Juliana Cardoso; Gomes, Luiz Antonio Costa; Owen, Robert D

2018-01-01

We evaluated morphometric variation of the mite Periglischrus torrealbai (Spinturnicidae) on three species of host bats: Phyllostomus discolor, P. hastatus, and Tonatia bidens (Phyllostomidae). A total of 67 females and 74 males of P. torrealbai were collected from 41 host individuals of these three bat species that were sampled in Brazil, Paraguay, and Peru. Twenty-one measurements from the dorsal side and 28 from the ventral side were recorded from female mites and 21 dorsal and 34 ventral measurements were taken from males. To evaluate morphological variation of P. torrealbai on different species of host bats, principal component analysis and unweighted pair-group method using arithmetic averages cluster analysis with Euclidean distances were used. Both analyses showed three groups of mites clearly separated: group 1 comprised all ectoparasites collected from T. bidens, group 2 included all mites from P. hastatus, and group 3 had all those from P. discolor. This result indicates that P. torrealbai varies morphologically by host bat species and suggests that this nominal species comprises three morphologically distinct species. In the present study, we record for the first time, the association between P. torrealbai and T. bidens. Our data reinforce the high relationship of specificity between Periglischrus mites and phyllostomid bat species.

Propagule Limitation, Disparate Habitat Quality, and Variation in Phenotypic Selection at a Local Species Range Boundary

PubMed Central

Moore, Kara A.; Stanton, Maureen L.

2014-01-01

Adaptation to novel conditions beyond current range boundaries requires the presence of suitable sites within dispersal range, but may be impeded when emigrants encounter poor habitat and sharply different selection pressures. We investigated fine-scale spatial heterogeneity in ecological dynamics and selection at a local population boundary of the annual plant Gilia tricolor. In two years, we planted G. tricolor seeds in core habitat, margin habitat at the edge of the local range, and exterior habitat in order to measure spatial and temporal variation in habitat quality, opportunity for selection, and selection on phenotypic traits. We found a striking decline in average habitat quality with distance from the population core, yet some migrant seeds were successful in suitable, unoccupied microsites at and beyond the range boundary. Total and direct selection on four out of five measured phenotypic traits varied across habitat zones, as well as between years. Moreover, the margin habitat often exerted unique selection pressures that were not intermediate between core and exterior habitats. This study reveals that a combination of ecological and evolutionary forces, including propagule limitation, variation in habitat quality and spatial heterogeneity in phenotypic selection may reduce opportunities for adaptive range expansion, even across a very local population boundary. PMID:24717472

[Quantification of acetabular coverage in normal adult].

PubMed

Lin, R M; Yang, C Y; Yu, C Y; Yang, C R; Chang, G L; Chou, Y L

1991-03-01

Quantification of acetabular coverage is important and can be expressed by superimposition of cartilage tracings on the maximum cross-sectional area of the femoral head. A practical Autolisp program on PC AutoCAD has been developed by us to quantify the acetabular coverage through numerical expression of the images of computed tomography. Thirty adults (60 hips) with normal center-edge angle and acetabular index in plain X ray were randomly selected for serial drops. These slices were prepared with a fixed coordination and in continuous sections of 5 mm in thickness. The contours of the cartilage of each section were digitized into a PC computer and processed by AutoCAD programs to quantify and characterize the acetabular coverage of normal and dysplastic adult hips. We found that a total coverage ratio of greater than 80%, an anterior coverage ratio of greater than 75% and a posterior coverage ratio of greater than 80% can be categorized in a normal group. Polar edge distance is a good indicator for the evaluation of preoperative and postoperative coverage conditions. For standardization and evaluation of acetabular coverage, the most suitable parameters are the total coverage ratio, anterior coverage ratio, posterior coverage ratio and polar edge distance. However, medial coverage and lateral coverage ratios are indispensable in cases of dysplastic hip because variations between them are so great that acetabuloplasty may be impossible. This program can also be used to classify precisely the type of dysplastic hip.

Seismic-refraction measurements of crustal structure between Nevada Test Site and Ludlow, California

USGS Publications Warehouse

Gibbs, J.F.; Roller, J.C.

1964-01-01

Seismic-refraction measurements from nuclear and chemical explosions were made along a line from the Nevada Test Site (NTS) to Ludlow, California, and additional recordings from nuclear explosions were made southward toward Calexico, California. The time of first arrivals from the Ludlow shotpoint is expressed as T0 = 0.00 + Δ/2.50 (assumed), T1 = 1.00 + Δ6.10, T2 = 2.81 + Δ/6.80, and T3 = 5.48 + ~7.76, where T is in seconds and distance Δ is in km. First arrival times from NTS fit the lines T1 = 0.74 + Δ/6.10, T2 = 2.81 + Δ/6.80 (assumed), T3 = 6.70 + Δ/8.04 to a distance of 265 km, beyond 265 km T3 = 5.83 + Δ/7.75. The difference in the apparent velocities of the Pn (T3) arrival is caused by variations in the dip of the Mohorovicic discontinuity. The thickness of the successive layers at NTS are H0 s 1.0 km (V0 ~ 2.5 km/sec), H1 = 13 km (v1 = 6.1 km/sec), and H2 = 20 km (v2 = 6.8 km/ sec); the total crustal thickness is 34 km. The successive crustal layers at Ludlow have a thickness of H0 = 1.4 km, H1 = 13 km, and H2 = 13 km; the total crustal thickness is 27 km.

Comparative mapping of Raphanus sativus genome using Brassica markers and quantitative trait loci analysis for the Fusarium wilt resistance trait.

PubMed

Yu, Xiaona; Choi, Su Ryun; Ramchiary, Nirala; Miao, Xinyang; Lee, Su Hee; Sun, Hae Jeong; Kim, Sunggil; Ahn, Chun Hee; Lim, Yong Pyo

2013-10-01

Fusarium wilt (FW), caused by the soil-borne fungal pathogen Fusarium oxysporum is a serious disease in cruciferous plants, including the radish (Raphanus sativus). To identify quantitative trait loci (QTL) or gene(s) conferring resistance to FW, we constructed a genetic map of R. sativus using an F2 mapping population derived by crossing the inbred lines '835' (susceptible) and 'B2' (resistant). A total of 220 markers distributed in 9 linkage groups (LGs) were mapped in the Raphanus genome, covering a distance of 1,041.5 cM with an average distance between adjacent markers of 4.7 cM. Comparative analysis of the R. sativus genome with that of Arabidopsis thaliana and Brassica rapa revealed 21 and 22 conserved syntenic regions, respectively. QTL mapping detected a total of 8 loci conferring FW resistance that were distributed on 4 LGs, namely, 2, 3, 6, and 7 of the Raphanus genome. Of the detected QTL, 3 QTLs (2 on LG 3 and 1 on LG 7) were constitutively detected throughout the 2-year experiment. QTL analysis of LG 3, flanked by ACMP0609 and cnu_mBRPGM0085, showed a comparatively higher logarithm of the odds (LOD) value and percentage of phenotypic variation. Synteny analysis using the linked markers to this QTL showed homology to A. thaliana chromosome 3, which contains disease-resistance gene clusters, suggesting conservation of resistance genes between them.

The physical characteristics of match-play in English schoolboy and academy rugby union.

PubMed

Read, Dale B; Jones, Ben; Phibbs, Padraic J; Roe, Gregory A B; Darrall-Jones, Joshua; Weakley, Jonathon J S; Till, Kevin

2018-03-01

The aim was to compare the physical characteristics of under-18 academy and schoolboy rugby union competition by position (forwards and backs). Using a microsensor unit, match characteristics were recorded in 66 players. Locomotor characteristics were assessed by maximum sprint speed (MSS) and total, walking, jogging, striding and sprinting distances. The slow component (<2 m · s -1 ) of PlayerLoad TM (PL slow ), which is the accumulated accelerations from the three axes of movement, was analysed as a measure of low-speed activity (e.g., rucking). A linear mixed-model was assessed with magnitude-based inferences. Academy forwards and backs almost certainly and very likely covered greater total distance than school forwards and backs. Academy players from both positions were also very likely to cover greater jogging distances. Academy backs were very likely to accumulate greater PL slow and the academy forwards a likely greater sprinting distance than school players in their respective positions. The MSS, total, walking and sprinting distances were greater in backs (likely-almost certainly), while forwards accumulated greater PL slow (almost certainly) and jogging distance (very likely). The results suggest that academy-standard rugby better prepares players to progress to senior competition compared to schoolboy rugby.

Working against gravity: horizontal honeybee waggle runs have greater angular scatter than vertical waggle runs

PubMed Central

Couvillon, Margaret J.; Phillipps, Hunter L. F.; Schürch, Roger; Ratnieks, Francis L. W.

2012-01-01

The presence of noise in a communication system may be adaptive or may reflect unavoidable constraints. One communication system where these alternatives are debated is the honeybee (Apis mellifera) waggle dance. Successful foragers communicate resource locations to nest-mates by a dance comprising repeated units (waggle runs), which repetitively transmit the same distance and direction vector from the nest. Intra-dance waggle run variation occurs and has been hypothesized as a colony-level adaptation to direct recruits over an area rather than a single location. Alternatively, variation may simply be due to constraints on bees' abilities to orient waggle runs. Here, we ask whether the angle at which the bee dances on vertical comb influences waggle run variation. In particular, we determine whether horizontal dances, where gravity is not aligned with the waggle run orientation, are more variable in their directional component. We analysed 198 dances from foragers visiting natural resources and found support for our prediction. More horizontal dances have greater angular variation than dances performed close to vertical. However, there is no effect of waggle run angle on variation in the duration of waggle runs, which communicates distance. Our results weaken the hypothesis that variation is adaptive and provide novel support for the constraint hypothesis. PMID:22513277

Working against gravity: horizontal honeybee waggle runs have greater angular scatter than vertical waggle runs.

PubMed

Couvillon, Margaret J; Phillipps, Hunter L F; Schürch, Roger; Ratnieks, Francis L W

2012-08-23

The presence of noise in a communication system may be adaptive or may reflect unavoidable constraints. One communication system where these alternatives are debated is the honeybee (Apis mellifera) waggle dance. Successful foragers communicate resource locations to nest-mates by a dance comprising repeated units (waggle runs), which repetitively transmit the same distance and direction vector from the nest. Intra-dance waggle run variation occurs and has been hypothesized as a colony-level adaptation to direct recruits over an area rather than a single location. Alternatively, variation may simply be due to constraints on bees' abilities to orient waggle runs. Here, we ask whether the angle at which the bee dances on vertical comb influences waggle run variation. In particular, we determine whether horizontal dances, where gravity is not aligned with the waggle run orientation, are more variable in their directional component. We analysed 198 dances from foragers visiting natural resources and found support for our prediction. More horizontal dances have greater angular variation than dances performed close to vertical. However, there is no effect of waggle run angle on variation in the duration of waggle runs, which communicates distance. Our results weaken the hypothesis that variation is adaptive and provide novel support for the constraint hypothesis.

High precision, fast ultrasonic thermometer based on measurement of the speed of sound in air

NASA Astrophysics Data System (ADS)

Huang, K. N.; Huang, C. F.; Li, Y. C.; Young, M. S.

2002-11-01

This study presents a microcomputer-based ultrasonic system which measures air temperature by detecting variations in the speed of sound in the air. Changes in the speed of sound are detected by phase shift variations of a 40 kHz continuous ultrasonic wave. In a test embodiment, two 40 kHz ultrasonic transducers are set face to face at a constant distance. Phase angle differences between transmitted and received signals are determined by a FPGA digital phase detector and then analyzed in an 89C51 single-chip microcomputer. Temperature is calculated and then sent to a LCD display and, optionally, to a PC. Accuracy of measurement is within 0.05 degC at an inter-transducer distance of 10 cm. Temperature variations are displayed within 10 ms. The main advantages of the proposed system are high resolution, rapid temperature measurement, noncontact measurement and easy implementation.

Lack of congruence between morphometric evolution and genetic differentiation suggests a recent dispersal and local habitat adaptation of the Madeiran lizard Lacerta dugesii

PubMed Central

Brehm, António; Khadem, Mahnaz; Jesus, José; Andrade, Paula; Vicente, Luis

2001-01-01

Genetic differentiation among nine populations of the endemic lizard Lacerta dugesii Milne-Edwards 1829 (Lacertidae) from four groups of islands constituting the Archipelago of Madeira, was investigated by protein electrophoresis at 23 enzyme loci. Among twenty polymorphic loci, the total genetic diversity was due primarily to intra-population variation. The allele and genotypic frequencies among populations showed some heterogeneity, allowing the species to present a structuring pattern compatible with their geographical clustering. Some evidence suggests that selection acting on some loci in different ecological conditions may be responsible for the clustering of the populations studied. There was no apparent isolation effect expected under an "island" model of population divergence, and no correlation was found between genetic and geographic distances among populations. Morphological variation of the proposed three L. dugesii subspecies is not congruent with the allozyme analysis. This most probably suggests a rapid colonization of the islands followed by a strong effect of selection operating over the morphological characters used to define the subspecies. PMID:11742635

Standard Fog Collector Measurements Along the Central and Northern California Coast During the 2014 and 2015 Fog Seasons

NASA Astrophysics Data System (ADS)

Fernandez, D.; Torregrosa, A.; Weiss-Penzias, P. S.; Mairs, A. A.; Wilson, S.; Bowman, M.; Barkley, T.; Gravelle, M.; Oliphant, A. J.

2015-12-01

Since 2014 an extensive network of standard fog collectors has been deployed along the coast of California, from as far south as southern Big Sur (36.1° N) to as far north as Arcata (40.8° N) at over a dozen sites that contain a total of several dozen of the fog collecting devices. This research is being done in conjunction with the Fognet Project that is looking at the levels of monomethyl mercury in fog water. Data collected reveal a fascinating variability in the amount of fog water collected across different scales of distance, elevation, time and location. In addition, a number of different types of mesh have been deployed and co-located to examine the variation in their fog water collecting capability in identical conditions. Mesh variations exhibit smaller variability across mesh type than had previously been expected. This study documents results found thus far across the network and also discusses the quantification of the errors associated with tipping bucket rain gauge measurements of water volumes and thus the importance of tipping bucket rain gauge calibration.

Microbiological characteristics of multi-media PRB reactor in the bioremediation of groundwater contaminated by petroleum hydrocarbons.

PubMed

Liu, Hong; Zhang, Lanying; Deng, Haijing; Liu, Na; Liu, Cuizhu

2011-10-01

A multi-media bio-PRB reactor was designed to treat groundwater contaminated with petroleum hydrocarbons. After a 208-day bioremediation, combined with the total petroleum hydrocarbons content in the groundwater flowed through the reactor, microbiological characteristics of the PRB reactor including microbes immobilized and its dehydrogenase activity were investigated. TPH was significantly reduced by as much as 65% in the back of the second media layer, whereas in the third layer, the TPH content reached lower than 1 mg l⁻¹. For microbes immobilized on the media, the variations with depth in different media were significantly the same and the regularity was obvious in the forepart of the media, which increased with depth at first and then reduced gradually, while in the back-end, the microbes almost did not have any variations with depth but decreased with the distance. The dehydrogenase activity varied from 2.98 to 16.16 mg TF L⁻¹ h⁻¹ and its distribution illustrated a similar trend with numbers of microbial cell, therefore, the noticeable correlation was found between them.

The visual perception of distance ratios outdoors.

PubMed

Norman, J Farley; Adkins, Olivia C; Dowell, Catherine J; Shain, Lindsey M; Hoyng, Stevie C; Kinnard, Jonathan D

2017-05-01

We conducted an experiment to evaluate the ability of 32 younger and older adults to visually perceive distances in an outdoor setting. On any given trial, the observers viewed 2 environmental distances and were required to estimate the distance ratio-the length of the (usually) larger distance relative to that of the shorter. The stimulus distance ratios ranged from 1.0 (the stimulus distances were identical) to 8.0 (1 distance interval was 8.0 times longer than the other). The stimulus distances were presented within a 26 m × 60 m portion of a grassy field. The observers were able to reliably estimate the stimulus distance ratios: The overall Pearson r correlation coefficient relating the judged and actual distance ratios was 0.762. Fifty-eight percent of the variance in the observers' perceived distance ratios could thus be accounted for by variations in the actual stimulus ratios. About half of the observers significantly underestimated the distance ratios, while the judgments of the remainder were essentially accurate. Significant modulatory effects of sex and age occurred, such that the male observers' judgments were the most precise, while those of the older males were the most accurate.

Geographical variation of St. Lucia Parrot flight vocalizations

USGS Publications Warehouse

Kleeman, Patrick M.; Gilardi, James D.

2005-01-01

Parrots are vocal learners and many species of parrots are capable of learning new calls, even as adults. This capability gives parrots the potential to develop communication systems that can vary dramatically over space. St. Lucia Parrot (Amazona versicolor) flight vocalizations were examined for geographic variation between four different sites on the island of St. Lucia. Spectrographic cross-correlation analysis of a commonly used flight vocalization, the p-chow call, demonstrated quantitative differences between sites. Additionally, the similarity of p-chows decreased as the distance between sites increased. Flight call repertoires also differed among sites; parrots at the Des Bottes and Quilesse sites each used one flight call unique to those sites, while parrots at the Barre de L'Isle site used a flight call that Quilesse parrots gave only while perched. It is unclear whether the vocal variation changed clinally with distance, or whether there were discrete dialect boundaries as in a congener, the Yellow-naped Parrot (Amazona auropalliata, Wright 1996). The geographical scale over which the St. Lucia Parrot's vocal variation occurred was dramatically smaller than that of the Yellow-naped Parrot. Similar patterns of fine-scale vocal variation may be more widespread among other parrot species in the Caribbean than previously documented.

Orbit analysis of a geostationary gravitational wave interferometer detector array

NASA Astrophysics Data System (ADS)

Tinto, Massimo; de Araujo, Jose C. N.; Kuga, Helio K.; Alves, Márcio E. S.; Aguiar, Odylio D.

2015-09-01

We analyze the trajectories of three geostationary satellites forming the geostationary gravitational wave interferometer (GEOGRAWI) [1], a space-based laser interferometer mission aiming to detect and study gravitational radiation in the (10-4-10) Hz band. The combined effects of the gravity fields of the Earth, the Sun and the Moon make the three satellites deviate from their nominally stationary, equatorial and equilateral configuration. Since changes in the satellites’s relative distances and orientations could negatively affect the precision of the laser heterodyne measurements, we have derived the time-dependence of the inter-satellite distances and velocities, the variations of the polar angles made by the constellation’s three arms with respect to a chosen reference frame and the time changes of the triangle’s enclosed angles. We find that during the time between two consecutive station-keeping maneuvers (about two weeks) the relative variations of the inter-satellite distances do not exceed a value of 0.05%, while the relative velocities between pairs of satellites remain smaller than about 0.7 m s-1. In addition, we find the angles made by the arms of the triangle with the equatorial plane to be periodic functions of time whose amplitudes grow linearly with time; the maximum variations experienced by these angles as well as by those within the triangle remain smaller than 3 arc-minutes, while the east-west angular variations of the three arms remain smaller than about 15 arc-minutes during the two-week period.

Environmental heterogeneity explains the genetic structure of Continental and Mediterranean populations of Fraxinus angustifolia Vahl.

PubMed

Temunović, Martina; Franjić, Jozo; Satovic, Zlatko; Grgurev, Marin; Frascaria-Lacoste, Nathalie; Fernández-Manjarrés, Juan F

2012-01-01

Tree species with wide distributions often exhibit different levels of genetic structuring correlated to their environment. However, understanding how environmental heterogeneity influences genetic variation is difficult because the effects of gene flow, drift and selection are confounded. We investigated the genetic variation and its ecological correlates in a wind-pollinated Mediterranean tree species, Fraxinus angustifolia Vahl, within a recognised glacial refugium in Croatia. We sampled 11 populations from environmentally divergent habitats within the Continental and Mediterranean biogeographical regions. We combined genetic data analyses based on nuclear microsatellite loci, multivariate statistics on environmental data and ecological niche modelling (ENM). We identified a geographic structure with a high genetic diversity and low differentiation in the Continental region, which contrasted with the significantly lower genetic diversity and higher population divergence in the Mediterranean region. The positive and significant correlation between environmental and genetic distances after controlling for geographic distance suggests an important influence of ecological divergence of the sites in shaping genetic variation. The ENM provided support for niche differentiation between the populations from the Continental and Mediterranean regions, suggesting that contemporary populations may represent two divergent ecotypes. Ecotype differentiation was also supported by multivariate environmental and genetic distance analyses. Our results suggest that despite extensive gene flow in continental areas, long-term stability of heterogeneous environments have likely promoted genetic divergence of ashes in this region and can explain the present-day genetic variation patterns of these ancient populations.

Environmental Heterogeneity Explains the Genetic Structure of Continental and Mediterranean Populations of Fraxinus angustifolia Vahl

PubMed Central

Temunović, Martina; Franjić, Jozo; Satovic, Zlatko; Grgurev, Marin; Frascaria-Lacoste, Nathalie; Fernández-Manjarrés, Juan F.

2012-01-01

Tree species with wide distributions often exhibit different levels of genetic structuring correlated to their environment. However, understanding how environmental heterogeneity influences genetic variation is difficult because the effects of gene flow, drift and selection are confounded. We investigated the genetic variation and its ecological correlates in a wind-pollinated Mediterranean tree species, Fraxinus angustifolia Vahl, within a recognised glacial refugium in Croatia. We sampled 11 populations from environmentally divergent habitats within the Continental and Mediterranean biogeographical regions. We combined genetic data analyses based on nuclear microsatellite loci, multivariate statistics on environmental data and ecological niche modelling (ENM). We identified a geographic structure with a high genetic diversity and low differentiation in the Continental region, which contrasted with the significantly lower genetic diversity and higher population divergence in the Mediterranean region. The positive and significant correlation between environmental and genetic distances after controlling for geographic distance suggests an important influence of ecological divergence of the sites in shaping genetic variation. The ENM provided support for niche differentiation between the populations from the Continental and Mediterranean regions, suggesting that contemporary populations may represent two divergent ecotypes. Ecotype differentiation was also supported by multivariate environmental and genetic distance analyses. Our results suggest that despite extensive gene flow in continental areas, long-term stability of heterogeneous environments have likely promoted genetic divergence of ashes in this region and can explain the present-day genetic variation patterns of these ancient populations. PMID:22905171

A CO2-rich coma model applied to the neutral coma of Comet West

NASA Technical Reports Server (NTRS)

Mitchell, G. F.; Swift, M. B.; Huntress, W. T.

1982-01-01

Models of the cometary coma in which the dominant volatile is CO2 have been constructed for a range of heliocentric distances. Model coma abundances of C2, C3, and CN are compared with the abundances observed in Comet West and are found to be in good agreement. Furthermore, the variation with heliocentric distance of C2, C3, and CN model abundances agree well with the observed variation in Comet West. The present work lends detailed support to a previous suggestion that a substance more volatile than water, such as CO2, controls the evaporation of the nucleus of Comet West. The implications for cometary formation are briefly discussed.

Genetic Variation and Association Mapping of Seed-Related Traits in Cultivated Peanut (Arachis hypogaea L.) Using Single-Locus Simple Sequence Repeat Markers.

PubMed

Zhao, Jiaojiao; Huang, Li; Ren, Xiaoping; Pandey, Manish K; Wu, Bei; Chen, Yuning; Zhou, Xiaojing; Chen, Weigang; Xia, Youlin; Li, Zeqing; Luo, Huaiyong; Lei, Yong; Varshney, Rajeev K; Liao, Boshou; Jiang, Huifang

2017-01-01

Cultivated peanut ( Arachis hypogaea L.) is an allotetraploid (AABB, 2 n = 4 x = 40), valued for its edible oil and digestible protein. Seed size and weight are important agronomical traits significantly influence the yield and nutritional composition of peanut. However, the genetic basis of seed-related traits remains ambiguous. Association mapping is a powerful approach for quickly and efficiently exploring the genetic basis of important traits in plants. In this study, a total of 104 peanut accessions were used to identify molecular markers associated with seed-related traits using 554 single-locus simple sequence repeat (SSR) markers. Most of the accessions had no or weak relationship in the peanut panel. The linkage disequilibrium (LD) decayed with the genetic distance of 1cM at the genome level and the LD of B subgenome decayed faster than that of the A subgenome. Large phenotypic variation was observed for four seed-related traits in the association panel. Using mixed linear model with population structure and kinship, a total of 30 significant SSR markers were detected to be associated with four seed-related traits ( P < 1.81 × 10 -3 ) in different environments, which explained 11.22-32.30% of the phenotypic variation for each trait. The marker AHGA44686 was simultaneously and repeatedly associated with seed length and hundred-seed weight in multiple environments with large phenotypic variance (26.23 ∼ 32.30%). The favorable alleles of associated markers for each seed-related trait and the optimal combination of favorable alleles of associated markers were identified to significantly enhance trait performance, revealing a potential of utilization of these associated markers in peanut breeding program.

Simultaneous analytical optimization of variational parameters in Gaussian-type functions with full configuration interaction of multicomponent molecular orbital method by elimination of translational and rotational motions: application to isotopomers of the hydrogen molecule.

PubMed

Ishimoto, Takayoshi; Tachikawa, Masanori; Nagashima, Umpei

2008-04-28

We have extended the multicomponent molecular orbital (MCMO) method to the full-configuration interaction (full-CI) fully variational molecular orbital method by elimination of translational and rotational motion components from total Hamiltonian. In the MCMO scheme, the quantum effects of protons and deuterons as well as electrons can be directly taken into account. All variational parameters in the full-CI scheme, i.e., exponents and centers (alpha and R) in the Gaussian-type function (GTF) basis set as well as the CI coefficients, are simultaneously optimized by using their analytical gradients. The total energy of the H(2) molecule calculated using the electronic [6s3p2d1f] and nuclear [1s1p1d1f] GTFs is -1.161 726 hartree, which can be compared to the energy of -1.164 025 hartree reported using a 512 term-explicitly correlated GTF calculation. Although the d- and f-type nuclear GTFs contribute to the improvement of energy convergence, the convergence of electron-nucleus correlation energy is slower than that of electron-electron one. The nuclear wave functions are delocalized due to the electron-nucleus correlation effect compared to the result of Hartree-Fock level of MCMO method. In addition, the average internuclear distances of all diatomic molecules are within 0.001 A of the previously reported experimental results. The dipole moment of the HD molecule estimated by our method is 8.4 x 10(-4) D, which is in excellent agreement with the experimental result of (8-10) x 10(-4) D.

The surgical vascular anatomy of the minimally invasive lateral lumbar interbody approach: a cadaveric and radiographic analysis.

PubMed

Alkadhim, Mustafa; Zoccali, Carmine; Abbasifard, Salman; Avila, Mauricio J; Patel, Apar S; Sattarov, Kamran; Walter, Christina M; Baaj, Ali A

2015-11-01

The minimally invasive (MI) lateral lumbar interbody fusion (LLIF) approach has become increasingly popular for the treatment of degenerative lumbar spine disease. The neural anatomy of the lumbar plexus has been studied; however, the pertinent surgical vascular anatomy has not been examined in detail. The goal of this study is to examine the vascular structures that are relevant in relation to the MI-LLIF approach. Anatomic dissection of the lumbar spines and associated vasculature was performed in three embalmed, adult cadavers. Right and left surgeon perspective views during LLIF were for a total of six approaches. During the dissection, all vascular elements were noted and photographed, and anatomical relationships to the vertebral bodies and disc spaces were analyzed. In addition, several axial and sagittal MRI images of the lumbar spine were analyzed to complement the cadaveric analysis. The aorta descends along the left anterior aspect of lumbar vertebra with an average distance of 2.1 cm (range 1.9-2.3 cm) to the center of each intervertebral disc. The vena cava descends along the right anterior aspect of lumbar vertebrates with average distance of 1.4 cm (range 1.3-1.6 cm) to the center of the intervertebral disc. Each vertebral body has two lumbar arteries (direct branches from the aorta); one exits to the left and one to the right side of the vertebral body. The lumbar arteries pass underneath the sympathetic trunk, run in the superior margin of the vertebral body and extend all the way across it, with average length of 3.8 cm (range 2.5-5 cm). The mean distance between the arteries and the inferior plate of the superior disc space is 4.2 mm (range 2-5 mm) and mean distance of 3.1 cm (range 2.8-3.8 cm) between two arteries in adjacent vertebrae. One of the cadavers had an expected normal anatomical variation where the left arteries at L3-L4 anastomosed dorsally of the vertebral bodies at the middle of the intervertebral disc. Understanding the vascular anatomy of the lateral and anterior lumbar spine is paramount for successfully and safely executing the LLIF procedure. It is imperative to identify anatomical variations in lumbar arteries and veins with careful assessment of the preoperative imaging.

Lateral variations of the Guerrero-Oaxaca subduction zone (Mexico) derived from weak seismicity (Mb3.5+) detected on a single array at teleseismic distance

NASA Astrophysics Data System (ADS)

Letort, Jean; Retailleau, Lise; Boué, Pierre; Radiguet, Mathilde; Gardonio, Blandine; Cotton, Fabrice; Campillo, Michel

2018-05-01

Detections of pP and sP phase arrivals (the so-called depth phases) at teleseismic distance provide one of the best ways to estimate earthquake focal depth, as the P-pP and the P-sP delays are strongly dependent on the depth. Based on a new processing workflow and using a single seismic array at teleseismic distance, we can estimate the depth of clusters of small events down to magnitude Mb 3.5. Our method provides a direct view of the relative variations of the seismicity depth from an active area. This study focuses on the application of this new methodology to study the lateral variations of the Guerrero subduction zone (Mexico) using the Eielson seismic array in Alaska (USA). After denoising the signals, 1232 Mb 3.5 + events were detected, with clear P, pP, sP and PcP arrivals. A high-resolution view of the lateral variations of the depth of the seismicity of the Guerero-Oaxaca area is thus obtained. The seismicity is shown to be mainly clustered along the interface, coherently following the geometry of the plate as constrained by the receiver-function analysis along the Meso America Subduction Experiment profile. From this study, the hypothesis of tears on the western part of Guerrero and the eastern part of Oaxaca are strongly confirmed by dramatic lateral changes in the depth of the earthquake clusters. The presence of these two tears might explain the observed lateral variations in seismicity, which is correlated with the boundaries of the slow slip events.

Study of Pressure Oscillations in Supersonic Parachute

NASA Astrophysics Data System (ADS)

Dahal, Nimesh; Fukiba, Katsuyoshi; Mizuta, Kazuki; Maru, Yusuke

2018-04-01

Supersonic parachutes are a critical element of planetary mission whose simple structure, light-weight characteristics together with high ratio of aerodynamic drag makes them the most suitable aerodynamic decelerators. The use of parachute in supersonic flow produces complex shock/shock and wake/shock interaction giving rise to dynamic pressure oscillations. The study of supersonic parachute is difficult, because parachute has very flexible structure which makes obtaining experimental pressure data difficult. In this study, a supersonic wind tunnel test using two rigid bodies is done. The wind tunnel test was done at Mach number 3 by varying the distance between the front and rear objects, and the distance of a bundle point which divides suspension lines and a riser. The analysis of Schlieren movies revealed shock wave oscillation which was repetitive and had large pressure variation. The pressure variation differed in each case of change in distance between the front and rear objects, and the change in distance between riser and the rear object. The causes of pressure oscillation are: interaction of wake caused by front object with the shock wave, fundamental harmonic vibration of suspension lines, interference between shock waves, and the boundary layer of suspension lines.

Thermoregulation of dancing bees: thoracic temperature of pollen and nectar foragers in relation to profitability of foraging and colony need.

PubMed

Stabentheiner, A

2001-04-01

The thorax surface temperature of dancing honeybees (Apis mellifera carnica) recruiting nestmates to natural sources of nectar and pollen around Graz (Austria) was measured by real-time infrared thermography without touching them or disturbing social interactions. Thorax temperature during dancing was quite variable (31.4-43 degrees C). In the course of a foraging season it varied considerably and was always lower than in bees foraging from a highly profitable food source (2 molar sucrose 120 m from the hive). It averaged 38.0 degrees C (SD=2.24, n=224 dances) in the nectar foragers and 37.4 degrees C (SD=1.64, n=171) in the pollen foragers, resembling that of dancers foraging 0.5 molar sucrose from feeders with unlimited flow. Hive air temperature accounted only for about 3-8% of total variation. Foraging distance modulated dancing temperature in a way that, according to the decrease of the profitability of foraging with distance, maximum temperatures decreased and, in accordance with the increase of the dancing threshold with distance, minumum temperatures increased with distance, this way providing new support for the hypothesis that the dancing temperature is modulated by the profitability of foraging and the dancing and foraging motivation of the bees. Dancing temperature of both nectar and pollen dancers correlated with several parameters of the hive status, increasing with the amount of brood and decreasing with the amount of honey and pollen. These correlations are discussed with respect to literature reports on a colony's need for pollen and nectar, in particular the effect of brood and the amount of pollen on pollen foraging, and the effect of honey stores and demand for nectar on nectar foraging.

Quantum speedup of Monte Carlo methods.

PubMed

Montanaro, Ashley

2015-09-08

Monte Carlo methods use random sampling to estimate numerical quantities which are hard to compute deterministically. One important example is the use in statistical physics of rapidly mixing Markov chains to approximately compute partition functions. In this work, we describe a quantum algorithm which can accelerate Monte Carlo methods in a very general setting. The algorithm estimates the expected output value of an arbitrary randomized or quantum subroutine with bounded variance, achieving a near-quadratic speedup over the best possible classical algorithm. Combining the algorithm with the use of quantum walks gives a quantum speedup of the fastest known classical algorithms with rigorous performance bounds for computing partition functions, which use multiple-stage Markov chain Monte Carlo techniques. The quantum algorithm can also be used to estimate the total variation distance between probability distributions efficiently.

Genetic structure of seven Mexican indigenous populations based on five polymarker loci.

PubMed

Buentello-Malo, Leonora; Peñaloza-Espinosa, Rosenda I; Loeza, Francisco; Salamanca-Gomez, Fabio; Cerda-Flores, Ricardo M

2003-01-01

This descriptive study investigates the genetic structure of seven Mexican indigenous populations (Mixteca Alta, Mixteca Baja, Otomies, Purepecha, Nahuas-Guerrero, Nahuas-Xochimilco, and Tzeltales) on the basis of five PCR-based polymorphic DNA loci: LDLR, GYPA, HBGG, D7S8, and GC. Genetic distance and diversity analyses indicate that these Mexican indigenous are similar and that more than 96% of the total gene diversity (H(T)) can be attributed to individual variation within populations. Mixteca-Alta, Mixteca-Baja, and Nahuas-Xochimilco show indications of higher admixture with European-derived persons. The demonstration of a relative genetic homogeneity of Mexican Indians for the markers studied suggests that this population is suitable for studying disease-marker associations in the search for candidate genes of complex diseases. Copyright 2002 Wiley-Liss, Inc.

Quantum speedup of Monte Carlo methods

PubMed Central

Montanaro, Ashley

2015-01-01

Monte Carlo methods use random sampling to estimate numerical quantities which are hard to compute deterministically. One important example is the use in statistical physics of rapidly mixing Markov chains to approximately compute partition functions. In this work, we describe a quantum algorithm which can accelerate Monte Carlo methods in a very general setting. The algorithm estimates the expected output value of an arbitrary randomized or quantum subroutine with bounded variance, achieving a near-quadratic speedup over the best possible classical algorithm. Combining the algorithm with the use of quantum walks gives a quantum speedup of the fastest known classical algorithms with rigorous performance bounds for computing partition functions, which use multiple-stage Markov chain Monte Carlo techniques. The quantum algorithm can also be used to estimate the total variation distance between probability distributions efficiently. PMID:26528079

Significance of localization of mandibular foramen in an inferior alveolar nerve block.

PubMed

Thangavelu, K; Kannan, R; Kumar, N Senthil; Rethish, E; Sabitha, S; Sayeeganesh, N

2012-07-01

The mandibular foramen (MF) is an opening on the internal surface of the ramus for divisions of the mandibular vessels and nerve to pass. The aim of this study is to determine the position of the MF from various anatomical landmarks in several dry adult mandibles. A total of 102 human dry mandibles were examined, of which 93 were of dentulous and 9 were of edentulous. The measurements were taken from the anterior border of the ramus (coronoid notch) to the midportion of the MF and then from the midportion of the MF to the other landmarks such as internal oblique ridge, inferior border, sigmoid notch, and condyle were measured and recorded. The data were compared using Student's t-test. The MF is positioned at a mean distance of 19 mm (with SD 2.34) from coronoid notch of the anterior border of the ramus. Superio-inferiorly from the condyle to the inferior border MF is situated 5 mm inferior to the midpoint of condyle to the inferior border distance (ramus height). We conclude that failures in the anesthesia of the inferior alveolar nerve are due to the operator error and not due to the anatomical variation.

Advances and Environmental Conditions of Spring Migration Phenology of American White Pelicans

NASA Astrophysics Data System (ADS)

King, D. Tommy; Wang, Guiming; Yang, Zhiqiang; Fischer, Justin W.

2017-01-01

Spring migration phenology of birds has advanced under warming climate. Migration timing of short-distance migrants is believed to be responsive to environmental changes primarily under exogenous control. However, understanding the ecological causes of the advancement in avian spring migration phenology is still a challenge due to the lack of long-term precise location data. We used 11 years of Global Positioning System relocation data to determine four different migration dates of the annual migration cycle of the American white pelican (Pelecanus erythrorhynchos), a short-distance migrant. We also tested the hypothesis that increases in winter temperature and precipitation on the wintering grounds would advance pelican spring migration. Pelican spring departures and arrivals advanced steadily from 2002 to 2011. Spring departure timing exhibited high repeatability at the upper end of migration timing repeatability reported in literature. However, individual spring departure and arrival dates were not related to winter daily temperature, total winter precipitation, and detrended vegetation green-up dates indexed by the normalized difference vegetation index. Despite high repeatability, the observed between-year variation of spring departure dates was still sufficient for the advancement of spring departure timing.

Genetic and morphological characterisation of the Ankole Longhorn cattle in the African Great Lakes region

PubMed Central

Ndumu, Deo B; Baumung, Roswitha; Hanotte, Olivier; Wurzinger, Maria; Okeyo, Mwai A; Jianlin, Han; Kibogo, Harrison; Sölkner, Johann

2008-01-01

The study investigated the population structure, diversity and differentiation of almost all of the ecotypes representing the African Ankole Longhorn cattle breed on the basis of morphometric (shape and size), genotypic and spatial distance data. Twentyone morphometric measurements were used to describe the morphology of 439 individuals from 11 sub-populations located in five countries around the Great Lakes region of central and eastern Africa. Additionally, 472 individuals were genotyped using 15 DNA microsatellites. Femoral length, horn length, horn circumference, rump height, body length and fore-limb circumference showed the largest differences between regions. An overall FST index indicated that 2.7% of the total genetic variation was present among sub-populations. The least differentiation was observed between the two sub-populations of Mbarara south and Luwero in Uganda, while the highest level of differentiation was observed between the Mugamba in Burundi and Malagarasi in Tanzania. An estimated membership of four for the inferred clusters from a model-based Bayesian approach was obtained. Both analyses on distance-based and model-based methods consistently isolated the Mugamba sub-population in Burundi from the others. PMID:18694545

Assessment of groundwater quality in a typical rural settlement in southwest Nigeria.

PubMed

Adekunle, I M; Adetunji, M T; Gbadebo, A M; Banjoko, O P

2007-12-01

In most rural settlements in Nigeria, access to clean and potable water is a great challenge, resulting in water borne diseases. The aim of this study was to assess the levels of some physical, chemical, biochemical and microbial water quality parameters in twelve hand - dug wells in a typical rural area (Igbora) of southwest region of the country. Seasonal variations and proximity to pollution sources (municipal waste dumps and defecation sites) were also examined. Parameters were determined using standard procedures. All parameters were detected up to 200 m from pollution source and most of them increased in concentration during the rainy season over the dry periods, pointing to infiltrations from storm water. Coliform population, Pb, NO3- and Cd in most cases, exceeded the World Health Organization recommended thresholds for potable water. Effect of distance from pollution sources was more pronounced on fecal and total coliform counts, which decreased with increasing distance from waste dumps. The qualities of the well water samples were therefore not suitable for human consumption without adequate treatment. Regular monitoring of groundwater quality, abolishment of unhealthy waste disposal practices and introduction of modern techniques are recommended.

Advances and Environmental Conditions of Spring Migration Phenology of American White Pelicans.

PubMed

King, D Tommy; Wang, Guiming; Yang, Zhiqiang; Fischer, Justin W

2017-01-16

Spring migration phenology of birds has advanced under warming climate. Migration timing of short-distance migrants is believed to be responsive to environmental changes primarily under exogenous control. However, understanding the ecological causes of the advancement in avian spring migration phenology is still a challenge due to the lack of long-term precise location data. We used 11 years of Global Positioning System relocation data to determine four different migration dates of the annual migration cycle of the American white pelican (Pelecanus erythrorhynchos), a short-distance migrant. We also tested the hypothesis that increases in winter temperature and precipitation on the wintering grounds would advance pelican spring migration. Pelican spring departures and arrivals advanced steadily from 2002 to 2011. Spring departure timing exhibited high repeatability at the upper end of migration timing repeatability reported in literature. However, individual spring departure and arrival dates were not related to winter daily temperature, total winter precipitation, and detrended vegetation green-up dates indexed by the normalized difference vegetation index. Despite high repeatability, the observed between-year variation of spring departure dates was still sufficient for the advancement of spring departure timing.

A Study of Korean EFL Learners' Apology Speech Acts: Strategy and Pragmatic Transfer Influenced by Sociolinguistic Variations.

ERIC Educational Resources Information Center

Yang, Tae-Kyoung

2002-01-01

Examines how apology speech act strategies frequently used in daily life are transferred in the framework of interlanguage pragmatics and sociolinguistics and how they are influenced by sociolinguistic variations such as social status, social distance, severity of offense, and formal or private relationships. (Author/VWL)

Genetic variation and differentiation of bison (Bison bison) subspecies and cattle (Bos taurus) breeds and subspecies

USDA-ARS?s Scientific Manuscript database

Genetic variation was quantified at 29 polymorphic microsatellite DNA loci in nine herds of plains bison (Bison bison bison), three herds of wood bison (B. b. athabascae), fourteen breeds of taurine cattle (Bos taurus taurus), and two breeds of indicine cattle (Bos taurus indicus). Genetic distances...

Genetic variation in bison (bison bison) subspecies and cattle (Bos taurus) breeds and subspecies

USDA-ARS?s Scientific Manuscript database

Genetic variation was quantified at 29 polymorphic microsatellite DNA loci in nine herds of plains bison (Bison bison bison), three herds of wood bison (B.b. athabascae), fourteen breeds of taurine cattle (Bos Taurus Taurus), and two breeds of indicine cattle (Bos Taurus indicus). Genetic distances,...

Activity profiles in U17, U20 and senior women's Brazilian National soccer teams during international competitions: Are there meaningful differences?

PubMed

Ramos, Guilherme P; Nakamura, Fábio Y; Penna, Eduardo M; Wilke, Carolina Franco; Pereira, Lucas A; Loturco, Irineu; Capelli, Luciano; Mahseredjian, Fábio; Silami-Garcia, Emerson; Coimbra, Cândido C

2017-07-31

The aim of this study was to compare locomotor activity profiles of Brazilian top-class female soccer players competing at distinct age brackets (U17, U20, and Senior). External match load of 14 U17, 14 U20, and 17 Senior female soccer players competing in 6-7 full official international matches were assessed using global positioning systems (GPS). Total distance covered, distance covered in high intensity (HID:15.6-20 kmh), distance covered in sprints (sprint:>20 kmh), number of accelerations (Acc)>1 ms, decelerations (Dec) >-1 ms, and Player Load generally increased across the age brackets (U17

The Minimum Binding Energy and Size of Doubly Muonic D3 Molecule

NASA Astrophysics Data System (ADS)

Eskandari, M. R.; Faghihi, F.; Mahdavi, M.

The minimum energy and size of doubly muonic D3 molecule, which two of the electrons are replaced by the much heavier muons, are calculated by the well-known variational method. The calculations show that the system possesses two minimum positions, one at typically muonic distance and the second at the atomic distance. It is shown that at the muonic distance, the effective charge, zeff is 2.9. We assumed a symmetric planar vibrational model between two minima and an oscillation potential energy is approximated in this region.

Reference equation for prediction of a total distance during six-minute walk test using Indonesian anthropometrics.

PubMed

Nusdwinuringtyas, Nury; Widjajalaksmi; Yunus, Faisal; Alwi, Idrus

2014-04-01

to develop a reference equation for prediction of the total distance walk using Indonesian anthropometrics of sedentary healthy subjects. Subsequently, the prediction obtained was compared to those calculated by the Caucasian-based Enright prediction equation. the cross-sectional study was conducted among 123 healthy Indonesian adults with sedentary life style (58 male and 65 female subjects in an age range between 18 and 50 years). Heart rate was recorded using Polar with expectation in the sub-maximal zone (120-170 beats per minute). The subjects performed two six-minute walk tests, the first one on a 15-meter track according to the protocol developed by the investigator. The second walk was carried out on Biodex®gait trainer as gold standard. an average total distance of 547±54.24 m was found, not significantly different from the gold standard of 544.72±54.11 m (p>0.05). Multiple regression analysis was performed to develop the new equation. the reference equation for prediction of the total distance using Indonesian anthropometrics is more applicable in Indonesia.

30 CFR 219.414 - How will MMS determine each Gulf producing State's share of the qualified OCS revenues?

Code of Federal Regulations, 2010 CFR

2010-07-01

... applicable leased tract and, using the great circle distance method, will determine the closest distance from... total, over all applicable leased tracts, the mathematical inverses of the distances between the points...

Time-evolution of uniform momentum zones in a turbulent boundary layer

NASA Astrophysics Data System (ADS)

Laskari, Angeliki; Hearst, R. Jason; de Kat, Roeland; Ganapathisubramani, Bharathram

2016-11-01

Time-resolved planar particle image velocimetry (PIV) is used to analyse the organisation and evolution of uniform momentum zones (UMZs) in a turbulent boundary layer. Experiments were performed in a recirculating water tunnel on a streamwise-wall-normal plane extending approximately 0 . 5 δ × 1 . 8 δ , in x and y, respectively. In total 400,000 images were captured and for each of the resulting velocity fields, local peaks in the probability density distribution of the streamwise velocity were detected, indicating the instantaneous presence of UMZs throughout the boundary layer. The main characteristics of these zones are outlined and more specifically their velocity range and wall-normal extent. The variation of these characteristics with wall normal distance and total number of zones are also discussed. Exploiting the time information available, time-scales of zones that have a substantial coherence in time are analysed and results show that the zones' lifetime is dependent on both their momentum deficit level and the total number of zones present. Conditional averaging of the flow statistics seems to further indicate that a large number of zones is the result of a wall-dominant mechanism, while the opposite implies an outer-layer dominance.

Palaeoenvironmental implication of grain-size compositions of terrace deposits on the western Chinese Loess Plateau

NASA Astrophysics Data System (ADS)

Liu, Xingxing; Sun, Youbin; Vandenberghe, Jef; Li, Ying; An, Zhisheng

2018-06-01

Sedimentary sequences that developed on river terraces have been widely investigated to reconstruct high-resolution palaeoclimatic changes since the last deglaciation. However, frequent changes in sedimentary facies make palaeoenvironmental interpretation of grain-size variations relatively complicated. In this paper, we employed multiple grain-size parameters to discriminate the sedimentary characteristics of aeolian and fluvial facies in the Dadiwan (DDW) section on the western Chinese Loess Plateau. We found that wind and fluvial dynamics have quite different impacts on the grain-size compositions, with distinctive imprints on the distribution pattern. By using a lognormal distribution fitting approach, two major grain-size components sensitive to aeolian and fluvial processes, respectively, were distinguished from the grain-size compositions of the DDW terrace deposits. The fine grain-size component (GSC2) represents mixing of long-distance aeolian and short-distance fluvial inputs, whilst the coarse grain-size component (GSC3) is mainly transported by wind from short-distance sources. Thus GSC3 can be used to infer the wind intensity. Grain-size variations reveal that the wind intensity experienced a stepwise shift from large-amplitude variations during the last deglaciation to small-amplitude oscillations in the Holocene, corresponding well to climate changes from regional to global context.

Drift-driven evolution of electric signals in a Neotropical knifefish.

PubMed

Picq, Sophie; Alda, Fernando; Bermingham, Eldredge; Krahe, Rüdiger

2016-09-01

Communication signals are highly diverse traits. This diversity is usually assumed to be shaped by selective forces, whereas the null hypothesis of divergence through drift is often not considered. In Panama, the weakly electric fish Brachyhypopomus occidentalis is widely distributed in multiple independent drainage systems, which provide a natural evolutionary laboratory for the study of genetic and signal divergence in separate populations. We quantified geographic variation in the electric signals of 109 fish from five populations, and compared it to the neutral genetic variation estimated from cytochrome oxidase I (COI) sequences of the same individuals, to test whether drift may be driving divergence of their signals. Signal distances were highly correlated with genetic distances, even after controlling for geographic distances, suggesting that drift alone is sufficient to explain geographic variation in electric signals. Significant differences at smaller geographic scales (within drainages) showed, however, that electric signals may evolve at a faster rate than expected under drift, raising the possibility that additional adaptive forces may be contributing to their evolution. Overall, our data point to stochastic forces as main drivers of signal evolution in this species and extend the role of drift in the evolution of communication systems to fish and electrocommunication. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.

Gain control in the sonar of odontocetes.

PubMed

Ya Supin, Alexander; Nachtigall, Paul E

2013-06-01

The sonar of odontocetes processes echo-signals within a wide range of echo levels. The level of echoes varies widely by tens of decibels depending on the level of the emitted sonar pulse, the target strength, the distance to the target, and the sound absorption by the water media. The auditory system of odontocetes must be capable of effective perception, analysis, and discrimination of echo-signals within all this variability. The sonar of odontocetes has several mechanisms to compensate for the echo-level variation (gain control). To date, several mechanisms of the biosonar gain control have been revealed in odontocetes: (1) adjustment of emitted sonar pulse levels (the longer the distance to the target, the higher the level of the emitted pulse), (2) short-term variation of hearing sensitivity based on forward masking of the echo by the preceding self-heard emitted pulse and subsequent release from the masking, and (3) active long-term control of hearing sensitivity. Recent investigations with the use of the auditory evoked-potential technique have demonstrated that these mechanisms effectively minimize the variation of the response to the echo when either the emitted sonar pulse level, or the target distance, or both vary within a wide range. A short review of these data is presented herein.

A laboratory study for assessing speech privacy in a simulated open-plan office.

PubMed

Lee, P J; Jeon, J Y

2014-06-01

The aim of this study is to assess speech privacy in open-plan office using two recently introduced single-number quantities: the spatial decay rate of speech, DL(2,S) [dB], and the A-weighted sound pressure level of speech at a distance of 4 m, L(p,A,S,4) m [dB]. Open-plan offices were modeled using a DL(2,S) of 4, 8, and 12 dB, and L(p,A,S,4) m was changed in three steps, from 43 to 57 dB.Auditory experiments were conducted at three locations with source–receiver distances of 8, 16, and 24 m, while background noise level was fixed at 30 dBA.A total of 20 subjects were asked to rate the speech intelligibility and listening difficulty of 240 Korean sentences in such surroundings. The speech intelligibility scores were not affected by DL(2,S) or L(p,A,S,4) m at a source–receiver distance of 8 m; however, listening difficulty ratings were significantly changed with increasing DL(2,S) and L(p,A,S,4) m values. At other locations, the influences of DL(2,S) and L(p,A,S,4) m on speech intelligibility and listening difficulty ratings were significant. It was also found that the speech intelligibility scores and listening difficulty ratings were considerably changed with increasing the distraction distance (r(D)). Furthermore, listening difficulty is more sensitive to variations in DL(2,S) and L(p,A,S,4) m than intelligibility scores for sound fields with high speech transmission performances. The recently introduced single-number quantities in the ISO standard, based on the spatial distribution of sound pressure level, were associated with speech privacy in an open-plan office. The results support single-number quantities being suitable to assess speech privacy, mainly at large distances. This new information can be considered when designing open-plan offices and making acoustic guidelines of open-plan offices.

Classification and conservation priority of five Deccani sheep ecotypes of Maharashtra, India

PubMed Central

Arora, Reena; Jain, Anand

2017-01-01

Characterization of Indian livestock breeds has mostly been limited to single breed/population focused on either physical description of traditionally recognized breeds/populations or to their genetic description. Usually, morphological and genetic characterization has taken place in isolation. A parallel morphological characterization of genetically identified breeds or genetic characterization of morphologically described breeds is mostly missing, and their conservation priorities have largely been based on solely considering degree of endangerment. This study uses parallel approach based on morphometric and genetic differentiation for classification of five sheep ecotypes of Maharashtra state, and sets their conservation priority using threat parameters, current utilities/merits and contribution to genetic diversity. A total of 1101 animals were described for 7 body measurements for morphometric characterization. From this sample set, 456 animals were genotyped for 25 microsatellite markers for genetic characterization. Conservation priorities were assessed combining genetic and non-genetic factors. All studied traits varied significantly among ecotypes (p<0.05). All morphometric traits exhibited substantial sexual dimorphism except ear length. Males were 42% heavier than females. Madgyal sheep were the largest amongst the five ecotypes. In the stepwise discriminant analysis, all measured traits were significant and were found to have potential discriminatory power. Tail length was the most discriminatory trait. The Mahalanobis distance of the morphological traits between Kolhapuri and Madgyal was maximum (12.07) while the least differentiation was observed between Madgyal and Solapuri (1.50). Discriminant analysis showed that 68.12% sheep were classified into their source population. The Sangamneri sheep showed least assignment error (22%) whilst Solapuri exhibited maximum error level (41%). A total of 407 alleles were observed, with an average of 16.28 alleles per locus. Sufficient levels of genetic diversity were observed in all the ecotypes with observed heterozygosity values exceeding 0.47 and gene diversity values exceeding 0.76. About 6% of the total genetic variation was explained by population differences (FST = 0.059). Pairwise FST values indicated least differentiation between Solapuri and Madgyal (0.025). In terms of genetic distances, Kolhapuri and Lonand were most closely related (Ds = 0.177). The most probable structure clustering of the five studied populations was at K = 5. The study showed a fair congruence between the dendrogram constructed on the basis of Mahalanobis distances and Nei’s as well as Reynolds genetic distances. The findings gave highest conservation priority to Lonand and least to Solapuri ecotype. PMID:28910329

Management of osteoarthritis (OA) with the pharma-standard supplement FlexiQule (Boswellia): a 12-week registry.

PubMed

Belcaro, G; Dugall, M; Luzzi, R; Ledda, A; Pellegrini, L; Hu, S; Ippolito, E

2015-10-22

This registry study assessed the pharma-standard supplement FlexiQule (Boswellia extract in capsules) in the management of symptoms associated to osteoarthritis (OA) also managed with the 'standard management' (SM) in comparison with a group of patients managed only with SM. The 12- week registry included patients with symptomatic knee arthrosis. They were able to walk on a treadmill for a walking test and to complete the WOMAC questionnaire. 32 patients used the supplement and 34 acted as controls (SM). No safety problems were observed. At 12 weeks, the Karnofsky scale was significantly improved in both groups: the variation was higher (p<0.05) in the supplement group. The WOMAC score was decreased significantly more in the supplement+SM group in comparison with controls considering pain, stiffness and physical functions (p<0.05). For social and emotional functions the decrease in score was also more evident in the supplement group (p<0.05). Both groups improved in pain-free and total walking distance at 12 weeks. Pain-free walking distance (treadmill) was higher (p<0.05) with the supplement (from 93.4;11.6 m to 271.3;19.3 m) than in controls (from 90.5;13.5 m to 158.3;22.3)(p<0.05). The improvement in total walking distance was also higher in the supplement group (p<0.05) (from 164.3;23.2 to 322.3;22.3 m) in comparison with the SM- only group ( from 158.3;18,4 to 240.2;19.3 m). The need for concomitant drugs and medical attention during the registry was reduced more in the supplement group (p<0.05). In conclusion the difference between SM and the Flexiqule+SM was in favor of the management with the supplement for all target measurements. The product is safe and well tolerated.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yi, B; Chung, H; Mutaf, Y

Purpose: To test a novel total body irradiation (TBI) system using conformal partial arc with patient lying on the stationary couch which is biologically equivalent to a moving couch TBI. This improves the scanning field TBI, which is previously presented. Methods: The Uniform MU Modulated arc Segments TBI or UMMS-TBI scans the treatment plane with a constant machine dose rate and a constant gantry rotation speed. A dynamic MLC pattern which moves while gantry rotates has been designed so that the treatment field moves same distance at the treatment plane per each gantry angle, while maintaining same treatment field sizemore » (34cm) at the plane. Dose across the plane varies due to the geometric differences including the distance from the source to a point of interest and the different attenuation from the slanted depth which changes the effective depth. Beam intensity is modulated to correct the dose variation across the plane by assigning the number of gantry angles inversely proportional to the uncorrected dose. Results: Measured dose and calculated dose matched within 1 % for central axis and 3% for off axis for various patient scenarios. Dose from different distance does not follow the inverse square relation as it is predicted from calculation. Dose uniformity better than 5% across 180 cm at 10cm depth is achieved by moving the gantry from −55 to +55 deg. Total treatment time for 2 Gy AP/PA fields is 40–50 minutes excluding patient set up time, at the machine dose rate of 200 MU/min. Conclusion: This novel technique, yet accurate but easy to implement enables TBI treatment in a small treatment room with less program development preparation than other techniques. The VMAT function of treatment delivery is not required to modulate beams. One delivery pattern can be used for different patients by changing the monitor units.« less

Effect of environmental parameters on biodiversity of the fungal component in lithic Antarctic communities.

PubMed

Selbmann, Laura; Onofri, Silvano; Coleine, Claudia; Buzzini, Pietro; Canini, Fabiana; Zucconi, Laura

2017-11-01

A wide sampling of rocks, colonized by microbial epi-endolithic communities, was performed along an altitudinal gradient from sea level to 3600 m asl and sea distance from the coast to 100 km inland along the Victoria Land Coast, Antarctica. Seventy-two rock samples of different typology, representative of the entire survey, were selected and studied using denaturing gradient gel electrophoresis to compare variation in fungal diversity according to environmental conditions along this altitudinal and sea distance transect. Lichenized fungi were largely predominant in all the samples studied and the biodiversity was heavily influenced even by minimal local variations. The n-MDS analysis showed that altitude and sea distance affect fungal biodiversity, while sandstone allows the communities to maintain high biodiversity indices. The Pareto-Lorenz curves indicate that all the communities analyzed are highly adapted to extreme conditions but scarcely resilient, so any external perturbation may have irreversible effects on these fragile ecosystems.

Method and system for homogenizing diode laser pump arrays

DOEpatents

Bayramian, Andrew James

2016-05-03

An optical amplifier system includes a diode pump array including a plurality of semiconductor diode laser bars disposed in an array configuration and characterized by a periodic distance between adjacent semiconductor diode laser bars. The periodic distance is measured in a first direction perpendicular to each of the plurality of semiconductor diode laser bars. The diode pump array provides a pump output propagating along an optical path and characterized by a first intensity profile measured as a function of the first direction and having a variation greater than 10%. The optical amplifier system also includes a diffractive optic disposed along the optical path. The diffractive optic includes a photo-thermo-refractive glass member. The optical amplifier system further includes an amplifier slab having an input face and position along the optical path and separated from the diffractive optic by a predetermined distance. A second intensity profile measured at the input face of the amplifier slab as a function of the first direction has a variation less than 10%.

Method and system for homogenizing diode laser pump arrays

DOEpatents

Bayramian, Andy J

2013-10-01

An optical amplifier system includes a diode pump array including a plurality of semiconductor diode laser bars disposed in an array configuration and characterized by a periodic distance between adjacent semiconductor diode laser bars. The periodic distance is measured in a first direction perpendicular to each of the plurality of semiconductor diode laser bars. The diode pump array provides a pump output propagating along an optical path and characterized by a first intensity profile measured as a function of the first direction and having a variation greater than 10%. The optical amplifier system also includes a diffractive optic disposed along the optical path. The diffractive optic includes a photo-thermo-refractive glass member. The optical amplifier system further includes an amplifier slab having an input face and position along the optical path and separated from the diffractive optic by a predetermined distance. A second intensity profile measured at the input face of the amplifier slab as a function of the first direction has a variation less than 10%.

Local topography shapes fine-scale spatial genetic structure in the Arkansas Valley evening primrose, Oenothera harringtonii (Onagraceae).

PubMed

Rhodes, Matthew K; Fant, Jeremie B; Skogen, Krissa A

2014-01-01

Identifying factors that shape the spatial distribution of genetic variation is crucial to understanding many population- and landscape-level processes. In this study, we explore fine-scale spatial genetic structure in Oenothera harringtonii (Onagraceae), an insect-pollinated, gravity-dispersed herb endemic to the grasslands of south-central and southeastern Colorado, USA. We genotyped 315 individuals with 11 microsatellite markers and utilized a combination of spatial autocorrelation analyses and landscape genetic models to relate life history traits and landscape features to dispersal processes. Spatial genetic structure was consistent with theoretical expectations of isolation by distance, but this pattern was weak (Sp = 0.00374). Anisotropic analyses indicated that spatial genetic structure was markedly directional, in this case consistent with increased dispersal along prominent slopes. Landscape genetic models subsequently confirmed that spatial genetic variation was significantly influenced by local topographic heterogeneity, specifically that geographic distance, elevation and aspect were important predictors of spatial genetic structure. Among these variables, geographic distance was ~68% more important than elevation in describing spatial genetic variation, and elevation was ~42% more important than aspect after removing the effect of geographic distance. From these results, we infer a mechanism of hydrochorous seed dispersal along major drainages aided by seasonal monsoon rains. Our findings suggest that landscape features may shape microevolutionary processes at much finer spatial scales than typically considered, and stress the importance of considering how particular dispersal vectors are influenced by their environmental context. © The American Genetic Association 2014. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Spatial Variations in Vitreous Oxygen Consumption

PubMed Central

Murali, Karthik; Kang, Dongyang; Nazari, Hossein; Scianmarello, Nicholas; Cadenas, Enrique; Tai, Yu-Chong; Kashani, Amir; Humayun, Mark

2016-01-01

We investigated the spatial variation of vitreous oxygen consumption in enucleated porcine eyes. A custom made oxygen source was fabricated that could be localized to either the mid or posterior vitreous cavity and steady state vitreous oxygen tension was measured as a function of distance from the source using a commercially available probe. The reaction rate constant of ascorbate oxidation was estimated ex vivo by measuring the change in oxygen tension over time using vitreous harvested from porcine eyes. Vitreous ascorbate from mid and posterior vitreous was measured spectrophotometrically. When the oxygen source was placed in either the mid-vitreous (N = 6) or the posterior vitreous (N = 6), we measured a statistically significant decrease in vitreous oxygen tension as a function of distance from the oxygen source when compared to control experiments without an oxygen source; (p<0.005 for mid-vitreous and p<0.018 for posterior vitreous at all distances). The mid-vitreous oxygen tension change was significantly different from the posterior vitreous oxygen tension change at 2 and 3mm distances from the respective oxygen source (p<0.001). We also found a statistically significant lower concentration of ascorbate in the mid-vitreous as compared to posterior vitreous (p = 0.02). We determined the reaction rate constant, k = 1.61 M-1s-1 ± 0.708 M-1s-1 (SE), of the oxidation of ascorbate which was modeled following a second order rate equation. Our data demonstrates that vitreous oxygen consumption is higher in the posterior vitreous compared to the mid-vitreous. We also show spatial variations in vitreous ascorbate concentration. PMID:26930281

Spatial Variations in Vitreous Oxygen Consumption.

PubMed

Murali, Karthik; Kang, Dongyang; Nazari, Hossein; Scianmarello, Nicholas; Cadenas, Enrique; Tai, Yu-Chong; Kashani, Amir; Humayun, Mark

2016-01-01

We investigated the spatial variation of vitreous oxygen consumption in enucleated porcine eyes. A custom made oxygen source was fabricated that could be localized to either the mid or posterior vitreous cavity and steady state vitreous oxygen tension was measured as a function of distance from the source using a commercially available probe. The reaction rate constant of ascorbate oxidation was estimated ex vivo by measuring the change in oxygen tension over time using vitreous harvested from porcine eyes. Vitreous ascorbate from mid and posterior vitreous was measured spectrophotometrically. When the oxygen source was placed in either the mid-vitreous (N = 6) or the posterior vitreous (N = 6), we measured a statistically significant decrease in vitreous oxygen tension as a function of distance from the oxygen source when compared to control experiments without an oxygen source; (p<0.005 for mid-vitreous and p<0.018 for posterior vitreous at all distances). The mid-vitreous oxygen tension change was significantly different from the posterior vitreous oxygen tension change at 2 and 3mm distances from the respective oxygen source (p<0.001). We also found a statistically significant lower concentration of ascorbate in the mid-vitreous as compared to posterior vitreous (p = 0.02). We determined the reaction rate constant, k = 1.61 M(-1) s(-1) ± 0.708 M(-1) s(-1) (SE), of the oxidation of ascorbate which was modeled following a second order rate equation. Our data demonstrates that vitreous oxygen consumption is higher in the posterior vitreous compared to the mid-vitreous. We also show spatial variations in vitreous ascorbate concentration.

On the security of compressed encryption with partial unitary sensing matrices embedding a secret keystream

NASA Astrophysics Data System (ADS)

Yu, Nam Yul

2017-12-01

The principle of compressed sensing (CS) can be applied in a cryptosystem by providing the notion of security. In this paper, we study the computational security of a CS-based cryptosystem that encrypts a plaintext with a partial unitary sensing matrix embedding a secret keystream. The keystream is obtained by a keystream generator of stream ciphers, where the initial seed becomes the secret key of the CS-based cryptosystem. For security analysis, the total variation distance, bounded by the relative entropy and the Hellinger distance, is examined as a security measure for the indistinguishability. By developing upper bounds on the distance measures, we show that the CS-based cryptosystem can be computationally secure in terms of the indistinguishability, as long as the keystream length for each encryption is sufficiently large with low compression and sparsity ratios. In addition, we consider a potential chosen plaintext attack (CPA) from an adversary, which attempts to recover the key of the CS-based cryptosystem. Associated with the key recovery attack, we show that the computational security of our CS-based cryptosystem is brought by the mathematical intractability of a constrained integer least-squares (ILS) problem. For a sub-optimal, but feasible key recovery attack, we consider a successive approximate maximum-likelihood detection (SAMD) and investigate the performance by developing an upper bound on the success probability. Through theoretical and numerical analyses, we demonstrate that our CS-based cryptosystem can be secure against the key recovery attack through the SAMD.

Determination of Spatial Chromium Contamination of the Environment around Industrial Zones.

PubMed

Homa, Dereje; Haile, Ermias; Washe, Alemayehu P

2016-01-01

This study was conducted to determine the spatial levels of chromium contamination of water, agricultural soil, and vegetables in the leather tanning industrial areas using spectrophotometric methods. The results showed elevated accumulation of total Cr ranging from 10.85 ± 0.885 mg/L to 39.696 ± 0.326 mg/L, 16.225 ± 0.12 mg/Kg to 1581.667 ± 0.122 mg/Kg, and 1.0758 ± 0.05348 mg/Kg to 11.75 ± 0.206 mg/Kg in water, agricultural soil, and vegetable samples, respectively. The highest levels of chromium (VI) found from the speciation study were 2.23 ± 0.032 mg/Kg and 0.322 ± 0.07 mg/L in soil and water samples, respectively, which decreased with distance from the tannery. Among the vegetables, the highest load of Cr(VI) was detected in onion root (0.048 ± 0.065 mg/Kg) and the lowest (0.004 ± 0.007 mg/Kg) in fruit of green pepper. The detected levels of Cr in all of the suggested samples were above the WHO permissible limits. The variations of the levels Cr(III) and Cr(VI) contamination of the environment with distance from the tannery were statistically significant ( p = 0.05). Similarly, significant difference in the levels of Cr among the tested vegetables was recorded. The levels increased with decreasing distance from the effluent channel.

The reliability and validity of a soccer-specific nonmotorised treadmill simulation (intermittent soccer performance test).

PubMed

Aldous, Jeffrey W F; Akubat, Ibrahim; Chrismas, Bryna C R; Watkins, Samuel L; Mauger, Alexis R; Midgley, Adrian W; Abt, Grant; Taylor, Lee

2014-07-01

This study investigated the reliability and validity of a novel nonmotorised treadmill (NMT)-based soccer simulation using a novel activity category called a "variable run" to quantify fatigue during high-speed running. Twelve male University soccer players completed 3 familiarization sessions and 1 peak speed assessment before completing the intermittent soccer performance test (iSPT) twice. The 2 iSPTs were separated by 6-10 days. The total distance, sprint distance, and high-speed running distance (HSD) were 8,968 ± 430 m, 980 ± 75 m and 2,122 ± 140 m, respectively. No significant difference (p > 0.05) was found between repeated trials of the iSPT for all physiological and performance variables. Reliability measures between iSPT1 and iSPT2 showed good agreement (coefficient of variation: <4.6%; intraclass correlation coefficient: >0.80). Furthermore, the variable run phase showed HSD significantly decreased (p ≤ 0.05) in the last 15 minutes (89 ± 6 m) compared with the first 15 minutes (85 ± 7 m), quantifying decrements in high-speed exercise compared with the previous literature. This study validates the iSPT as a NMT-based soccer simulation compared with the previous match-play data and is a reliable tool for assessing and monitoring physiological and performance variables in soccer players. The iSPT could be used in a number of ways including player rehabilitation, understanding the efficacy of nutritional interventions, and also the quantification of environmentally mediated decrements on soccer-specific performance.

Estimating Brownian motion dispersal rate, longevity and population density from spatially explicit mark-recapture data on tropical butterflies.

PubMed

Tufto, Jarle; Lande, Russell; Ringsby, Thor-Harald; Engen, Steinar; Saether, Bernt-Erik; Walla, Thomas R; DeVries, Philip J

2012-07-01

1. We develop a Bayesian method for analysing mark-recapture data in continuous habitat using a model in which individuals movement paths are Brownian motions, life spans are exponentially distributed and capture events occur at given instants in time if individuals are within a certain attractive distance of the traps. 2. The joint posterior distribution of the dispersal rate, longevity, trap attraction distances and a number of latent variables representing the unobserved movement paths and time of death of all individuals is computed using Gibbs sampling. 3. An estimate of absolute local population density is obtained simply by dividing the Poisson counts of individuals captured at given points in time by the estimated total attraction area of all traps. Our approach for estimating population density in continuous habitat avoids the need to define an arbitrary effective trapping area that characterized previous mark-recapture methods in continuous habitat. 4. We applied our method to estimate spatial demography parameters in nine species of neotropical butterflies. Path analysis of interspecific variation in demographic parameters and mean wing length revealed a simple network of strong causation. Larger wing length increases dispersal rate, which in turn increases trap attraction distance. However, higher dispersal rate also decreases longevity, thus explaining the surprising observation of a negative correlation between wing length and longevity. © 2012 The Authors. Journal of Animal Ecology © 2012 British Ecological Society.

Entangling mobility and interactions in social media.

PubMed

Grabowicz, Przemyslaw A; Ramasco, José J; Gonçalves, Bruno; Eguíluz, Víctor M

2014-01-01

Daily interactions naturally define social circles. Individuals tend to be friends with the people they spend time with and they choose to spend time with their friends, inextricably entangling physical location and social relationships. As a result, it is possible to predict not only someone's location from their friends' locations but also friendship from spatial and temporal co-occurrence. While several models have been developed to separately describe mobility and the evolution of social networks, there is a lack of studies coupling social interactions and mobility. In this work, we introduce a model that bridges this gap by explicitly considering the feedback of mobility on the formation of social ties. Data coming from three online social networks (Twitter, Gowalla and Brightkite) is used for validation. Our model reproduces various topological and physical properties of the networks not captured by models uncoupling mobility and social interactions such as: i) the total size of the connected components, ii) the distance distribution between connected users, iii) the dependence of the reciprocity on the distance, iv) the variation of the social overlap and the clustering with the distance. Besides numerical simulations, a mean-field approach is also used to study analytically the main statistical features of the networks generated by a simplified version of our model. The robustness of the results to changes in the model parameters is explored, finding that a balance between friend visits and long-range random connections is essential to reproduce the geographical features of the empirical networks.

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

PubMed

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 driver for the geographic variation in the advertisement calls of M. fissipes.

Hippocampal “Time Cells”: Time versus Path Integration

PubMed Central

Kraus, Benjamin J.; Robinson, Robert J.; White, John A.; Eichenbaum, Howard; Hasselmo, Michael E.

2014-01-01

SUMMARY Recent studies have reported the existence of hippocampal “time cells,” neurons that fire at particular moments during periods when behavior and location are relatively constant. However, an alternative explanation of apparent time coding is that hippocampal neurons “path integrate” to encode the distance an animal has traveled. Here, we examined hippocampal neuronal firing patterns as rats ran in place on a treadmill, thus “clamping” behavior and location, while we varied the treadmill speed to distinguish time elapsed from distance traveled. Hippocampal neurons were strongly influenced by time and distance, and less so by minor variations in location. Furthermore, the activity of different neurons reflected integration over time and distance to varying extents, with most neurons strongly influenced by both factors and some significantly influenced by only time or distance. Thus, hippocampal neuronal networks captured both the organization of time and distance in a situation where these dimensions dominated an ongoing experience. PMID:23707613

A Cepheid Distance to NGC 4603 in the Centaurus Cluster

NASA Technical Reports Server (NTRS)

Madore, B.; Newman, J.; Zepf, S.; Davis, M.; Freedman, W.; Madore, B.; Stetson, P.; Silbermann, N.; Phelps, R.

1999-01-01

In an attempt to use Cepheid variables to determine the distance to the Centaurus cluster, we have obtained images of NGC 4603 with the Hubble Space Telescope for 9 epochs (totalling 24 orbits) over 14 months in the F555W filter and 2 epochs (totalling 6 orbits) in the F814W filter.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jones, M. L.; McLaughlin, M. A.; Lam, M. T.

We analyze dispersion measure (DM) variations of 37 millisecond pulsars in the nine-year North American Nanohertz Observatory for Gravitational Waves (NANOGrav) data release and constrain the sources of these variations. DM variations can result from a changing distance between Earth and the pulsar, inhomogeneities in the interstellar medium, and solar effects. Variations are significant for nearly all pulsars, with characteristic timescales comparable to or even shorter than the average spacing between observations. Five pulsars have periodic annual variations, 14 pulsars have monotonically increasing or decreasing trends, and 14 pulsars show both effects. Of the four pulsars with linear trends thatmore » have line-of-sight velocity measurements, three are consistent with a changing distance and require an overdensity of free electrons local to the pulsar. Several pulsars show correlations between DM excesses and lines of sight that pass close to the Sun. Mapping of the DM variations as a function of the pulsar trajectory can identify localized interstellar medium features and, in one case, an upper limit to the size of the dispersing region of 4 au. Four pulsars show roughly Kolmogorov structure functions (SFs), and another four show SFs less steep than Kolmogorov. One pulsar has too large an uncertainty to allow comparisons. We discuss explanations for apparent departures from a Kolmogorov-like spectrum, and we show that the presence of other trends and localized features or gradients in the interstellar medium is the most likely cause.« less

The Nanograv Nine-Year Data Set: Measurement and Analysis of Variations in Dispersion Measures

NASA Technical Reports Server (NTRS)

Jones, M. L.; McLaughlin, M. A.; Lam, M. T.; Cordes, J. M.; Levin, L.; Chatterjee, S.; Arzoumanian, Z.; Crowter, K.; Demorest, P. B.; Dolch, T.;

Annual and Seasonal Global Variation in Total Ozone and Layer-Mean Ozone, 1958-1987 (1991)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Angell, J. K.; Korshover, J.; Planet, W. G.

For 1958 through 1987, this data base presents total ozone variations and layer mean ozone variations expressed as percent deviations from the 1958 to 1977 mean. The total ozone variations were derived from mean monthly ozone values published in Ozone Data for the World by the Atmospheric Environment Service in cooperation with the World Meteorological Organization. The layer mean ozone variations are derived from ozonesonde and Umkehr observations. The data records include year, seasonal and annual total ozone variations, and seasonal and annual layer mean ozone variations. The total ozone data are for four regions (Soviet Union, Europe, North America,more » and Asia); five climatic zones (north and south polar, north and south temperate, and tropical); both hemispheres; and the world. Layer mean ozone data are for four climatic zones (north and south temperate and north and south polar) and for the stratosphere, troposphere, and tropopause layers. The data are in two files [seasonal and year-average total ozone (13.4 kB) and layer mean ozone variations (24.2 kB)].« less

An Estimate of Changes in the Sun's Total Irradiance Caused by UV Irradiance Variations from 1874 to 1988

NASA Technical Reports Server (NTRS)

Lean, J.

1990-01-01

Enhanced emission from bright solar faculae is a source of significant variation in the sun's total irradiance. Relative to the emission from the quiet sun, facular emission is known to be considerably greater at UV wavelengths than at visible wavelengths. Determining the spectral dependence of facular emission is of interest for the physical insight this may provide to the origin of the sun's irradiance variations. It is also of interest because solar radiation at lambda less than 300 nm is almost totally absorbed in the Earth's atmosphere. Depending on the magnitude of the UV irradiance variations, changes in the sun's irradiance that penetrates to the Earth's surface may not be equivalent to total irradiance variations measured above the Earth's atmosphere. Using an empirical model of total irradiance variations which accounts separately for changes caused by bright faculae from those associated with dark sunspots, the contribution of UV irradiance variations to changes in the sun's total irradiance is estimated during solar cycles 12 to 21.

Seed harvesting by a generalist consumer is context-dependent: Interactive effects across multiple spatial scales

USGS Publications Warehouse

Ostoja, Steven M.; Schupp, Eugene W.; Klinger, Rob

2013-01-01

Granivore foraging decisions affect consumer success and determine the quantity and spatial pattern of seed survival. These decisions are influenced by environmental variation at spatial scales ranging from landscapes to local foraging patches. In a field experiment, the effects of seed patch variation across three spatial scales on seed removal by western harvester ants Pogonomyrmex occidentalis were evaluated. At the largest scale we assessed harvesting in different plant communities, at the intermediate scale we assessed harvesting at different distances from ant mounds, and at the smallest scale we assessed the effects of interactions among seed species in local seed neighborhoods on seed harvesting (i.e. resource–consumer interface). Selected seed species were presented alone (monospecific treatment) and in mixture with Bromus tectorum (cheatgrass; mixture treatment) at four distances from P. occidentalis mounds in adjacent intact sagebrush and non-native cheatgrass-dominated communities in the Great Basin, Utah, USA. Seed species differed in harvest, with B. tectorum being least preferred. Large and intermediate scale variation influenced harvest. More seeds were harvested in sagebrush than in cheatgrass-dominated communities (largest scale), and the quantity of seed harvested varied with distance from mounds (intermediate-scale), although the form of the distance effect differed between plant communities. At the smallest scale, seed neighborhood affected harvest, but the patterns differed among seed species considered. Ants harvested fewer seeds from mixed-seed neighborhoods than from monospecific neighborhoods, suggesting context dependence and potential associational resistance. Further, the effects of plant community and distance from mound on seed harvest in mixtures differed from their effects in monospecific treatments. Beyond the local seed neighborhood, selection of seed resources is better understood by simultaneously evaluating removal at multiple scales. Associational effects provide a useful theoretical basis for better understanding harvester ant foraging decisions. These results demonstrate the importance of ecological context for seed removal, which has implications for seed pools, plant populations and communities.

Amplitude variations during SIDs in 10.2 and 13.6 kHz waves propagating long distances in the subionospheric waveguide - Theoretical interpretation

NASA Astrophysics Data System (ADS)

Charcosset, G.; Tixier, M.

1981-12-01

During sudden ionospheric disturbances (SIDs), vertical electric field amplitude variations of waves emitted at 10.2 and 13.6 kHz in Norway and Liberia and observed in France were found to result in a regular decrease at the former wavelength and more complex behavior at the latter, where amplitude behavior depends on the importance of the SID. A theoretical interpretation employing a waveguide mode hypothesis of long distance wave propagation is presented, in which it is assumed that the D-region ionization enhancement produced by the solar X-ray flux during SID can be represented by a decrease of the waveguide height in which the shape of the density profile remains unchanged.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miller, James Christopher; Rennie, John Alan; Toevs, James Waldo

The introduction points out that radiation backgrounds fluctuate across very short distances: factors include geology, soil composition, altitude, building structures, topography, and other manmade structures; and asphalt and concrete can vary significantly over short distances. Brief descriptions are given of the detection system, experimental setup, and background variation measurements. It is concluded that positive and negative gradients can greatly reduce the detection sensitivity of an MDS: negative gradients create opportunities for false negatives (nondetection), and positive gradients create a potentially unacceptable FAR (above 1%); the location of use for mobile detection is important to understand; spectroscopic systems provide more informationmore » for screening out false alarms and may be preferred for mobile use; and mobile monitor testing at LANL accounts for expected variations in the background.« less

Genetic variation within and between strains of outbred Swiss mice.

PubMed

Cui, S; Chesson, C; Hope, R

1993-04-01

The aim of this survey was to measure levels of genetic variation within and between 5 different strains of outbred Swiss mice. Ten to 15 animals from each strain (NIH, Q(S), ARC, IMVS and STUD) were typed, using allozyme electrophoresis, at 10 gene loci: Mod-1, Idh-1, Gpi-I, Es-1, Es-3, Hbb, Pep-3, Gr-1, Got-2 and Pgm-1. Polymorphic variation in at least one of the 5 strains was detected at all 10 loci. The proportion of polymorphic loci ranged from 0.3 (NIH) to 0.8 (IMVS) with a mean of 0.52. Average expected heterozygosities ranged from 0.08 (NIH) to 0.37 (IMVS) with a mean of 0.21. The inbred strain SWR was, as expected, homozygous at all 10 loci. The amount of allelic substitution between pairs of strains was quantified using Nei's genetic distance, and a dendrogram based on these genetic distances showed a close overall similarity in its branching pattern to the known genealogy of the strains. This survey showed that a considerable degree of genetic variation persists in the 5 strains examined, a level of variation similar to that previously detected by Rice and O'Brien (1980) in 3 other outbred Swiss strains.

Match Physical Performance of Elite Female Soccer Players During International Competition.

PubMed

Datson, Naomi; Drust, Barry; Weston, Matthew; Jarman, Ian H; Lisboa, Paulo J; Gregson, Warren

2017-09-01

Datson, N, Drust, B, Weston, M, Jarman, IH, Lisboa, P, and Gregson, W. Match physical performance of elite female soccer players during international competition. J Strength Cond Res 31(9): 2379-2387, 2017-The purpose of this study was to provide a detailed analysis of the physical demands of competitive international female soccer match play. A total of 148 individual match observations were undertaken on 107 outfield players competing in competitive international matches during the 2011-2012 and 2012-2013 seasons, using a computerized tracking system (Prozone Sports Ltd., Leeds, England). Total distance and total high-speed running distances were influenced by playing position, with central midfielders completing the highest (10,985 ± 706 m and 2,882 ± 500 m) and central defenders the lowest (9,489 ± 562 m and 1,901 ± 268 m) distances, respectively. Greater total very high-speed running distances were completed when a team was without (399 ± 143 m) compared to with (313 ± 210 m) possession of the ball. Most sprints were over short distances with 76% and 95% being less than 5 and 10 m, respectively. Between half reductions in physical performance were present for all variables, independent of playing position. This study provides novel findings regarding the physical demands of different playing positions in competitive international female match play and provides important insights for physical coaches preparing elite female players for competition.

Space use of a dominant Arctic vertebrate: Effects of prey, sea ice, and land on Pacific walrus resource selection

USGS Publications Warehouse

Beatty, William; Jay, Chadwick V.; Fischbach, Anthony S.; Grebmeier, Jacqueline M.; Taylor, Rebecca L.; Blanchard, Arny L.; Jewett, Stephen C.

2016-01-01

Sea ice dominates marine ecosystems in the Arctic, and recent reductions in sea ice may alter food webs throughout the region. Sea ice loss may also stress Pacific walruses (Odobenus rosmarus divergens), which feed on benthic macroinvertebrates in the Bering and Chukchi seas. However, no studies have examined the effects of sea ice on foraging Pacific walrus space use patterns. We tested a series of hypotheses that examined walrus foraging resource selection as a function of proximity to resting substrates and prey biomass. We quantified walrus prey biomass with 17 benthic invertebrate families, which included bivalves, polychaetes, amphipods, tunicates, and sipunculids. We included covariates for distance to sea ice and distance to land, and systematically developed a series of candidate models to examine interactions among benthic prey biomass and resting substrates. We ranked candidate models with Bayesian Information Criterion and made inferences on walrus resource selection based on the top-ranked model. Based on the top model, biomass of the bivalve family Tellinidae, distance to ice, distance to land, and the interaction of distances to ice and land all positively influenced walrus foraging resource selection. Standardized model coefficients indicated that distance to ice explained the most variation in walrus foraging resource selection followed by Tellinidae biomass. Distance to land and the interaction of distances to ice and land accounted for similar levels of variation. Tellinidae biomass likely represented an index of overall bivalve biomass, indicating walruses focused foraging in areas with elevated levels of bivalve and tellinid biomass. Our results also emphasize the importance of sea ice to walruses. Projected sea ice loss will increase the duration of the open water season in the Chukchi Sea, altering the spatial distribution of resting sites relative to current foraging areas and possibly affecting the spatial structure of benthic communities.

Consistent individual differences in seed disperser quality in a seed-eating fish.

PubMed

Pollux, Bart J A

2017-01-01

Animal-mediated seed dispersal (zoochory) is considered to be an important mechanism regulating biological processes at larger spatial scales. To date, intra-specific variation in seed disperser quality within seed-dispersing animals has not been studied. Here, I employed seed feeding trials to quantify individual differences in disperser quality within the common carp (Cyprinus carpio) using seeds of two aquatic plants: unbranched bur-reed (Sparganium emersum, Sparganiaceae) and arrowhead (Sagittaria sagittifolia, Alismataceae). I found substantial variation among carp individuals in their propensity to ingest seeds and their ability to digest them, resulting in up to 31-fold differences in the probability of seed dispersal. In addition, there were significant differences in the time that seeds are retained in their digestive systems, generating a twofold difference in the maximum distance over which they can potentially disperse seeds. I propose that seed-eating animal species consist of individuals that display continuous variation in disperser quality, with at one end of the continuum individuals that are likely to eat seeds, pass them unharmed through their digestive tract and transport them over large distances to new locations (i.e. high-quality seed dispersers) and at the other end individuals that rarely eat seeds, destroy most of the ones they ingest and transport the few surviving seeds over relatively short distances (low-quality seed dispersers). Although individual differences in seed dispersal quality could be the result of a variety of factors, these results underline the ecological and evolutionary potential of such variation for both plants and animals.

Mate-finding as an overlooked critical determinant of dispersal variation in sexually-reproducing animals.

PubMed

Gilroy, James J; Lockwood, Julie L

2012-01-01

Dispersal is a critically important process in ecology, but robust predictive models of animal dispersal remain elusive. We identify a potentially ubiquitous component of variation in animal dispersal that has been largely overlooked until now: the influence of mate encounters on settlement probability. We use an individual-based model to simulate dispersal in sexually-reproducing organisms that follow a simple set of movement rules based on conspecific encounters, within an environment lacking spatial habitat heterogeneity. We show that dispersal distances vary dramatically with fluctuations in population density in such a model, even in the absence of variation in dispersive traits between individuals. In a simple random-walk model with promiscuous mating, dispersal distributions become increasingly 'fat-tailed' at low population densities due to the increasing scarcity of mates. Similar variation arises in models incorporating territoriality. In a model with polygynous mating, we show that patterns of sex-biased dispersal can even be reversed across a gradient of population density, despite underlying dispersal mechanisms remaining unchanged. We show that some widespread dispersal patterns found in nature (e.g. fat tailed distributions) can arise as a result of demographic variability in the absence of heterogeneity in dispersive traits across the population. This implies that models in which individual dispersal distances are considered to be fixed traits might be unrealistic, as dispersal distances vary widely under a single dispersal mechanism when settlement is influenced by mate encounters. Mechanistic models offer a promising means of advancing our understanding of dispersal in sexually-reproducing organisms.

Speckle reduction in optical coherence tomography by adaptive total variation method

NASA Astrophysics Data System (ADS)

Wu, Tong; Shi, Yaoyao; Liu, Youwen; He, Chongjun

2015-12-01

An adaptive total variation method based on the combination of speckle statistics and total variation restoration is proposed and developed for reducing speckle noise in optical coherence tomography (OCT) images. The statistical distribution of the speckle noise in OCT image is investigated and measured. With the measured parameters such as the mean value and variance of the speckle noise, the OCT image is restored by the adaptive total variation restoration method. The adaptive total variation restoration algorithm was applied to the OCT images of a volunteer's hand skin, which showed effective speckle noise reduction and image quality improvement. For image quality comparison, the commonly used median filtering method was also applied to the same images to reduce the speckle noise. The measured results demonstrate the superior performance of the adaptive total variation restoration method in terms of image signal-to-noise ratio, equivalent number of looks, contrast-to-noise ratio, and mean square error.

Genetic linkage map construction and QTL mapping of seedling height, basal diameter and crown width of Taxodium 'Zhongshanshan 302' × T. mucronatum.

PubMed

Wang, Ziyang; Cheng, Yanli; Yin, Yunlong; Yu, Chaoguang; Yang, Ying; Shi, Qin; Hao, Ziyuan; Li, Huogen

2016-01-01

Taxodium is a genus renowned for its fast growth, good form and tolerance of flooding, salt, alkalinity, disease and strong winds. In this study, a genetic linkage map was constructed using sequence-related amplified polymorphism (SRAP) and simple sequence repeat (SSR) markers based on an F1 population containing 148 individuals generated from a cross between T. 'Zhongshanshan 302' and T. mucronatum. The map has a total length of 976.5 cM, with a mean distance of 7.0 cM between markers, and contains 34 linkage groups with 179 markers (171 SRAPs and 8 SSRs). Quantitative trait loci (QTLs) affecting growth traits, such as seedling height, basal diameter and crown width, were detected based on the constructed linkage map. Four significant QTLs were identified, three of which, namely qtSH-1 for seedling height, qtBD-1 for basal diameter and qtCW-1 for crown width, were located at 2.659 cM of LG7 with logarithm odds values of 3.72, 3.49 and 3.93, respectively, and explained 24.9, 27.0 and 21.7 % of the total variation of the three grown traits, respectively. Another QTL for crown width (qtCW-2) was detected at 1.0 cM on LG13, with a logarithm of odds value of 3.15, and explained 31.7 % of the total variation of crown width. This is the first report on the construction of a genetic linkage map and QTL analysis in Taxodium, laying the groundwork for the construction of a high-density genetic map and QTL mapping in the genus Taxodium.

Measurement and comparison of skin dose using OneDose MOSFET and Mobile MOSFET for patients with acute lymphoblastic leukemia

PubMed Central

Mattar, Essam H.; Hammad, Lina F.; Al-Mohammed, Huda I.

2011-01-01

Summary Background Total body irradiation is a protocol used to treat acute lymphoblastic leukemia in patients prior to bone marrow transplant. It is involved in the treatment of the whole body using a large radiation field with extended source-skin distance. Therefore measuring and monitoring the skin dose during the treatment is important. Two kinds of metal oxide semiconductor field effect transistor (OneDose MOSFET and mobile MOSEFT) dosimeter are used during the treatment delivery to measure the skin dose to specific points and compare it with the target prescribed dose. The objective of this study was to compare the variation of skin dose in patients with acute lymphatic leukemia (ALL) treated with total body irradiation (TBI) using OneDose MOSFET detectors and Mobile MOSFET, and then compare both results with the target prescribed dose. Material/Methods The measurements involved 32 patient’s (16 males, 16 females), aged between 14–30 years, with an average age of 22.41 years. One-Dose MOSFET and Mobile MOSFET dosimetry were performed at 10 different anatomical sites on every patient. Results The results showed there was no variation between skin dose measured with OneDose MOSFET and Mobile MOSFET in all patients. Furthermore, the results showed for every anatomical site selected there was no significant difference in the dose delivered using either OneDose MOSFET detector or Mobile MOSFET as compared to the prescribed dose. Conclusions The study concludes that One-Dose MOSFET detectors and Mobile MOSFET both give a direct read-out immediately after the treatment; therefore both detectors are suitable options when measuring skin dose for total body irradiation treatment. PMID:21709641

Measurement and comparison of skin dose using OneDose MOSFET and Mobile MOSFET for patients with acute lymphoblastic leukemia.

PubMed

Mattar, Essam H; Hammad, Lina F; Al-Mohammed, Huda I

2011-07-01

Total body irradiation is a protocol used to treat acute lymphoblastic leukemia in patients prior to bone marrow transplant. It is involved in the treatment of the whole body using a large radiation field with extended source-skin distance. Therefore measuring and monitoring the skin dose during the treatment is important. Two kinds of metal oxide semiconductor field effect transistor (OneDose MOSFET and mobile MOSEFT) dosimeter are used during the treatment delivery to measure the skin dose to specific points and compare it with the target prescribed dose. The objective of this study was to compare the variation of skin dose in patients with acute lymphatic leukemia (ALL) treated with total body irradiation (TBI) using OneDose MOSFET detectors and Mobile MOSFET, and then compare both results with the target prescribed dose. The measurements involved 32 patient's (16 males, 16 females), aged between 14-30 years, with an average age of 22.41 years. One-Dose MOSFET and Mobile MOSFET dosimetry were performed at 10 different anatomical sites on every patient. The results showed there was no variation between skin dose measured with OneDose MOSFET and Mobile MOSFET in all patients. Furthermore, the results showed for every anatomical site selected there was no significant difference in the dose delivered using either OneDose MOSFET detector or Mobile MOSFET as compared to the prescribed dose. The study concludes that One-Dose MOSFET detectors and Mobile MOSFET both give a direct read-out immediately after the treatment; therefore both detectors are suitable options when measuring skin dose for total body irradiation treatment.

Statistical analysis of the ionospheric ion density recorded by DEMETER in the epicenter areas of earthquakes as well as in their magnetically conjugate point areas

NASA Astrophysics Data System (ADS)

Li, Mei; Parrot, Michel

2018-02-01

Results of a statistical variation of total ion density observed in the vicinity of epicenters as well as around magnetically conjugated points of earthquakes are presented in this paper. Two data sets are used: the ion density measured by DEMETER during about 6.5 years and the list of strong earthquakes (MW ≥ 4.8) occurring globally during this period (14,764 earthquakes in total). First of all, ionospheric perturbations with 23-120 s observation time corresponding to spatial scales of 160-840 km are automatically detected by a software (64,287 anomalies in total). Second, it is checked if a perturbation could be associated either with the epicenter of an earthquake or with its magnetically conjugated point (distance < 1500 km and time < 15 days before the earthquake). The index Kp < 3 is also considered in order to reduce the effect of the geomagnetic activity on the ionosphere during this period. The results show that it is possible to detect variations of the ionospheric parameters above the epicenter areas as well as above their conjugated points. About one third of the earthquakes are detected with ionospheric influence on both sides of the Earth. There is a trend showing that the perturbation length increases as the magnitude of the detected EQs but it is more obvious for large magnitude. The probability that a perturbation appears is higher on the day of the earthquake and then gradually decreases when the time before the earthquake increases. The spatial distribution of perturbations shows that the probability of perturbations appearing southeast of the epicenter before an earthquake is a little bit higher and that there is an obvious trend because perturbations appear west of the conjugated point of an earthquake.

Assessment of resuspended matter and redistribution of macronutrient elements produced by boat disturbance in a eutrophic lagoon.

PubMed

Lenzi, Mauro; Finoia, Maria Grazia; Gennaro, Paola; Mercatali, Isabel; Persia, Emma; Solari, Jacopo; Porrello, Salvatore

2013-07-15

Harvesting of macroalgae by specially equipped boats in a shallow eutrophic lagoon produces evident sediment resuspension. To outline the environmental effects of this disturbance, we examined the quantity of fall-out and the distances travelled by sediment and macronutrients from the source of boat disturbance. Resuspended sediment fall-out (RSFO) was trapped at different distances from the boat path to determine total dry weight, total nitrogen (TN), total carbon (TC), total organic carbon (TOC), total sulphur (TS) and total phosphorus (TP). The data was analysed by principal components analysis (PCA) and linear discriminant analysis (LDA) on PCA factors. Fall-out of C, N, S and P from the plume of resuspended sediment indicated significant re-arrangement of these nutrients: RSFO dry weight and S content decreased with distance from the boat path, whereas TP increased and was the variable responsible for most discrimination at 100 m. The mass of resuspended matter was relatively large, indicating that the boats considerably reshuffle lagoon sediment. Copyright © 2013 Elsevier Ltd. All rights reserved.

Genetic structure of wild boar (Sus scrofa) populations from East Asia based on microsatellite loci analyses

PubMed Central

2014-01-01

Background Wild boar, Sus scrofa, is an extant wild ancestor of the domestic pig as an agro-economically important mammal. Wild boar has a worldwide distribution with its geographic origin in Southeast Asia, but genetic diversity and genetic structure of wild boar in East Asia are poorly understood. To characterize the pattern and amount of genetic variation and population structure of wild boar in East Asia, we genotyped and analyzed microsatellite loci for a total of 238 wild boar specimens from ten locations across six countries in East and Southeast Asia. Results Our data indicated that wild boar populations in East Asia are genetically diverse and structured, showing a significant correlation of genetic distance with geographic distance and implying a low level of gene flow at a regional scale. Bayesian-based clustering analysis was indicative of seven inferred genetic clusters in which wild boars in East Asia are geographically structured. The level of genetic diversity was relatively high in wild boars from Southeast Asia, compared with those from Northeast Asia. This gradient pattern of genetic diversity is consistent with an assumed ancestral population of wild boar in Southeast Asia. Genetic evidences from a relationship tree and structure analysis suggest that wild boar in Jeju Island, South Korea have a distinct genetic background from those in mainland Korea. Conclusions Our results reveal a diverse pattern of genetic diversity and the existence of genetic differentiation among wild boar populations inhabiting East Asia. This study highlights the potential contribution of genetic variation of wild boar to the high genetic diversity of local domestic pigs during domestication in East Asia. PMID:25034725

Categorizing natural history trajectories of ambulatory function measured by the 6-minute walk distance in patients with Duchenne muscular dystrophy.

PubMed

Mercuri, Eugenio; Signorovitch, James Edward; Swallow, Elyse; Song, Jinlin; Ward, Susan J

2016-09-01

High variability in patients' changes in 6 minute walk distance (6MWD) over time has complicated clinical trials of treatment efficacy in Duchenne muscular dystrophy (DMD). We assessed whether boys with DMD could be grouped into classes that shared similar ambulatory function trajectories as measured by 6MWD. Ambulatory boys aged 5 years or older with genetically confirmed DMD who were enrolled in a natural history study at 11 care centers throughout Italy were included. For each boy, standardized assessments of 6MWD were available at annual intervals spanning 3 years. Trajectories of 6MWD vs. age and trajectories of 6MWD vs. time from enrollment were examined using latent class analysis. A total of 96 boys were included. At enrollment, the mean age was 8.3 years (mean 6MWD: 374 meters). After accounting for age, baseline 6MWD, and steroid use, four latent trajectory classes were identified as explaining 3-year 6MWD outcomes significantly better than a single average trajectory. Patient trajectories of 6MWD change from enrollment were categorized as having fast decline (n = 25), moderate decline (n = 19), stable function (n = 37), and improving function (n = 15) during the 3-year follow-up. After accounting for trajectory classes, the standard deviation of variation in 6MWD was reduced by approximately 40%. The natural history of ambulatory function in DMD may be composed of distinct trajectory classes. The extent to which trajectories are associated with novel and established prognostic factors warrants further study. Reducing unexplained variation in patient outcomes could help to further improve DMD clinical trial design and analysis. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Generous to whom? The influence of oxytocin on social discounting.

PubMed

Pornpattananangkul, Narun; Zhang, Junfeng; Chen, Qiaoyu; Kok, Bing Cai; Yu, Rongjun

2017-05-01

Oxytocin is thought to play an essential role in pro-social behaviors, such as generosity and altruism, in humans. Yet, most research in humans that demonstrated the pro-social effect of oxytocin had participants interact with partners who were total strangers to them. In real life, however, people often interact with others varying in social relatedness with them (a concept known as social distance), ranging from their parents to total strangers. Here we employed the social-discounting framework to investigate whether the effect of oxytocin on prosociality depends on the social distance between the participants and their interaction partners. In a double-blind, placebo-controlled experiment (n=172 participants), we measured the amount of money participants were willing to forgo to another person as a function of social distance. We found that oxytocin administration selectively enhanced amount of money forgone toward total strangers, as opposed to someone closer to participants, suggesting that social distance constrained the pro-social effect of oxytocin. Copyright © 2017 Elsevier Ltd. All rights reserved.

Same items, different order: effects of temporal variability on infant categorization.

PubMed

Mather, Emily; Plunkett, Kim

2011-06-01

How does variability between members of a category influence infants' category learning? We explore the impact of the order in which different items are sampled on category formation. Two groups of 10-months-olds were presented with a series of exemplars to be organized into a single category. In a low distance group, the order of presentation minimized the perceptual distance between consecutive exemplars. In a high distance group, the order of presentation maximized the distance between successive exemplars. At test, only infants in the High Distance condition reliably discriminated between the category prototype and an atypical exemplar. Hence, the order in which infants learnt about the exemplars impacted their categorization performance. Our findings demonstrate the importance of moment-to-moment variations in similarity during infants' category learning. Copyright © 2011 Elsevier B.V. All rights reserved.

The Mysterious Bar of the Large Magellanic Cloud: What Is It?

NASA Astrophysics Data System (ADS)

Subramaniam, Annapurni; Subramanian, Smitha

2009-09-01

The bar of the Large Magellanic Cloud (LMC) is one of the prominent, but controversial, features regarding its location with respect to the disk of the LMC. In order to study the relative location of the bar with respect to the disk, we present the high-resolution map of the structure across the LMC. We used the reddening corrected mean magnitudes (I 0) of red clump (RC) stars from the OGLE III catalog to map the relative variation in distance (vertical structure) or variation in RC population across the LMC. The bar does not appear as an identifiable vertical feature in the map, as there is no difference in I 0 values between the bar and the disk regions. We conclude that the LMC bar is very much part of the disk (within 0.02 mag), located in the plane of the disk and not a separate component. We identify warps or variation in RC population with increase in radial distance.

Individualized Internal and External Training Load Relationships in Elite Wheelchair Rugby Players.

PubMed

Paulson, Thomas A W; Mason, Barry; Rhodes, James; Goosey-Tolfrey, Victoria L

2015-01-01

The quantification and longitudinal monitoring of athlete training load (TL) provides a scientific explanation for changes in performance and helps manage injury/illness risk. Therefore, accurate and reliable monitoring tools are essential for the optimization of athletic performance. The aim of the present study was to establish the relationship between measures of internal [heart rate (HR) and session RPE (sRPE)] and external TL specific to wheelchair rugby (WR). Fourteen international WR athletes (age = 29 ± 7 years; body mass = 58.9 ± 10.9 kg) were monitored during 18 training sessions over a 3 month period during the competitive phase of the season. Activity profiles were collected during each training session using a radio-frequency based indoor tracking system (ITS). External TL was quantified by total distance (m) covered as well as time spent and distance covered in a range of classification-specific arbitrary speed zones. Banister's TRIMP, Edwards's summated HR zone (SHRZ), and Lucia's TRIMP methods were used to quantify physiological internal TL. sRPE was calculated as the product of session duration multiplied by perceived exertion using the Borg CR10 scale. Relationships between external and internal TL were examined using correlation coefficients and the 90% confidence intervals (90% CI). sRPE (r = 0.59) and all HR-based (r > 0.80) methods showed large and very large relationships with the total distance covered during training sessions, respectively. Large and very large correlations (r = 0.56 - 0.82) were also observed between all measures of internal TL and times spent and distances covered in low and moderate intensity speed zones. HR-based methods showed very large relationships with time (r = 0.71-0.75) and distance (r = 0.70-0.73) in the very high speed zone and a large relationship with the number of high intensity activities (HIA) performed (r = 0.56-0.62). Weaker relationships (r = 0.32-0.35) were observed between sRPE and all measures of high intensity activity. A large variation of individual correlation co-efficient was observed between sRPE and all external TL measures. The current findings suggest that sRPE and HR-based internal TL measures provide a valid tool for quantifying volume of external TL during WR training but may underestimate HIA. It is recommended that both internal and external TL measures are employed for the monitoring of overall TL during court-based training in elite WR athletes.

Individualized Internal and External Training Load Relationships in Elite Wheelchair Rugby Players

PubMed Central

Paulson, Thomas A. W.; Mason, Barry; Rhodes, James; Goosey-Tolfrey, Victoria L.

2015-01-01

Aim: The quantification and longitudinal monitoring of athlete training load (TL) provides a scientific explanation for changes in performance and helps manage injury/illness risk. Therefore, accurate and reliable monitoring tools are essential for the optimization of athletic performance. The aim of the present study was to establish the relationship between measures of internal [heart rate (HR) and session RPE (sRPE)] and external TL specific to wheelchair rugby (WR). Methods: Fourteen international WR athletes (age = 29 ± 7 years; body mass = 58.9 ± 10.9 kg) were monitored during 18 training sessions over a 3 month period during the competitive phase of the season. Activity profiles were collected during each training session using a radio-frequency based indoor tracking system (ITS). External TL was quantified by total distance (m) covered as well as time spent and distance covered in a range of classification-specific arbitrary speed zones. Banister's TRIMP, Edwards's summated HR zone (SHRZ), and Lucia's TRIMP methods were used to quantify physiological internal TL. sRPE was calculated as the product of session duration multiplied by perceived exertion using the Borg CR10 scale. Relationships between external and internal TL were examined using correlation coefficients and the 90% confidence intervals (90% CI). Results: sRPE (r = 0.59) and all HR-based (r > 0.80) methods showed large and very large relationships with the total distance covered during training sessions, respectively. Large and very large correlations (r = 0.56 − 0.82) were also observed between all measures of internal TL and times spent and distances covered in low and moderate intensity speed zones. HR-based methods showed very large relationships with time (r = 0.71−0.75) and distance (r = 0.70−0.73) in the very high speed zone and a large relationship with the number of high intensity activities (HIA) performed (r = 0.56−0.62). Weaker relationships (r = 0.32−0.35) were observed between sRPE and all measures of high intensity activity. A large variation of individual correlation co-efficient was observed between sRPE and all external TL measures. Conclusion: The current findings suggest that sRPE and HR-based internal TL measures provide a valid tool for quantifying volume of external TL during WR training but may underestimate HIA. It is recommended that both internal and external TL measures are employed for the monitoring of overall TL during court-based training in elite WR athletes. PMID:26733881

Evaluating the Consistency of Current Mainstream Wearable Devices in Health Monitoring: A Comparison Under Free-Living Conditions.

PubMed

Wen, Dong; Zhang, Xingting; Liu, Xingyu; Lei, Jianbo

2017-03-07

Wearable devices are gaining increasing market attention; however, the monitoring accuracy and consistency of the devices remains unknown. The purpose of this study was to assess the consistency of the monitoring measurements of the latest wearable devices in the state of normal activities to provide advice to the industry and support to consumers in making purchasing choices. Ten pieces of representative wearable devices (2 smart watches, 4 smart bracelets of Chinese brands or foreign brands, and 4 mobile phone apps) were selected, and 5 subjects were employed to simultaneously use all the devices and the apps. From these devices, intact health monitoring data were acquired for 5 consecutive days and analyzed on the degree of differences and the relationships of the monitoring measurements ​​by the different devices. The daily measurements by the different devices fluctuated greatly, and the coefficient of variation (CV) fluctuated in the range of 2-38% for the number of steps, 5-30% for distance, 19-112% for activity duration, .1-17% for total energy expenditure (EE), 22-100% for activity EE, 2-44% for sleep duration, and 35-117% for deep sleep duration. After integrating the measurement data of 25 days among the devices, the measurements of the number of steps (intraclass correlation coefficient, ICC=.89) and distance (ICC=.84) displayed excellent consistencies, followed by those of activity duration (ICC=.59) and the total EE (ICC=.59) and activity EE (ICC=.57). However, the measurements for sleep duration (ICC=.30) and deep sleep duration (ICC=.27) were poor. For most devices, there was a strong correlation between the number of steps and distance measurements (R 2 >.95), and for some devices, there was a strong correlation between activity duration measurements and EE measurements (R 2 >.7). A strong correlation was observed in the measurements of steps, distance and EE from smart watches and mobile phones of the same brand, Apple or Samsung (r>.88). Although wearable devices are developing rapidly, the current mainstream devices are only reliable in measuring the number of steps and distance, which can be used as health assessment indicators. However, the measurement consistencies of activity duration, EE, sleep quality, and so on, are still inadequate, which require further investigation and improved algorithms. ©Dong Wen, Xingting Zhang, Xingyu Liu, Jianbo Lei. Originally published in the Journal of Medical Internet Research (http://www.jmir.org), 07.03.2017.

Comparative analyses of the bacterial community of hydrothermal deposits and seafloor sediments across Okinawa Trough

NASA Astrophysics Data System (ADS)

Wang, Long; Yu, Min; Liu, Yan; Liu, Jiwen; Wu, Yonghua; Li, Li; Liu, Jihua; Wang, Min; Zhang, Xiao-Hua

2018-04-01

As an ideal place to study back-arc basins and hydrothermal eco-system, Okinawa Trough has attracted the interests of scientists for decades. However, there are still no in-depth studies targeting the bacterial community of the seafloor sediments and hydrothermal deposits in Okinawa Trough. In the present study, we reported the bacterial community of the surface deposits of a newly found hydrothermal field in the southern Okinawa Trough, and the horizontal and vertical variation of bacterial communities in the sediments of the northern Okinawa Trough. The hydrothermal deposits had a relatively high 16S rRNA gene abundance but low bacterial richness and diversity. Epsilonproteobacteria and Bacteroidetes were predominant in hydrothermal deposits whereas Deltaproteobacteria, Gammaproteobacteria and Chloroflexi were abundant across all samples. The bacterial distribution in the seafloor of Okinawa Trough was significantly correlated to the content of total nitrogen, and had consistent relationship with total carbon. Gradual changes of sulfur-oxidizing bacteria were found with the distance away from hydrothermal fields, while the hydrothermal activity did not influence the distribution of the major clades of sulfate-reducing bacteria. Higher abundance of the sulfur cycle related genes (aprA and dsrB), and lower abundance of the bacterial ammonia-oxidizing related gene (amoA) were quantified in hydrothermal deposits. In addition, the present study also compared the inter-field variation of Epsilonproteobacteria among multi-types of hydrothermal vents, revealing that the proportion and diversity of this clade were quite various.

Comparison of microsatellite variations between Red Junglefowl and a commercial chicken gene pool.

PubMed

Tadano, R; Kinoshita, K; Mizutani, M; Tsudzuki, M

2014-02-01

It is assumed that Red Junglefowl (Gallus gallus) is one of the main ancestors of domestic chickens (Gallus gallus domesticus). Differences in microsatellite polymorphisms between Red Junglefowl and modern commercial chickens, which are used for egg and meat production, have not been fully reported. A total of 361 individuals from 1 Red Junglefowl population that has been maintained as a closed flock, 5 final cross-bred commercial layer populations (white-, tinted-, and brown-egg layers), and 2 final cross-bred commercial broiler populations were genotyped for 40 autosomal microsatellite loci. We compared microsatellite variations in Red Junglefowl with those in a commercial chicken gene pool. The contribution of each population to the genetic diversity was also estimated based on the molecular coancestry. In total, 302 distinct alleles were detected in 1 Red Junglefowl and 7 commercial chicken populations, of which 31 alleles (10.3%) were unique to Red Junglefowl, most of which occurred at a high frequency. The genetic differentiation between Red Junglefowl and commercial chickens (pairwise FST) ranged from 0.32 to 0.47. According to the neighbor-joining tree based on the modified Cavalli-Sforza chord distances and the Bayesian clustering analysis, Red Junglefowl was genetically distant from the commercial chicken gene pool tested. In all of the populations analyzed, Red Junglefowl made the highest contribution to genetic diversity. These results suggest that Red Junglefowl has a distinct distribution of microsatellite alleles and that there is a high level of genetic divergence between Red Junglefowl and commercial chickens.

Adaptive neuro fuzzy system for modelling and prediction of distance pantograph catenary in railway transportation

NASA Astrophysics Data System (ADS)

Panoiu, M.; Panoiu, C.; Lihaciu, I. L.

2018-01-01

This research presents an adaptive neuro-fuzzy system which is used in the prediction of the distance between the pantograph and contact line of the electrical locomotives used in railway transportation. In railway transportation any incident that occurs in the electrical system can have major negative effects: traffic interrupts, equipment destroying. Therefore, a prediction as good as possible of such situations is very useful. In the paper was analyzing the possibility of modeling and prediction the variation of the distance between the pantograph and the contact line using intelligent techniques

Combined adductor canal block with periarticular infiltration versus periarticular infiltration for analgesia after total knee arthroplasty.

PubMed

Ma, Jinhui; Gao, Fuqiang; Sun, Wei; Guo, Wanshou; Li, Zirong; Wang, Weiguo

2016-12-01

Both adductor canal block (ACB) and periarticular infiltration (PI) have been shown to reduce pain after total knee arthroplasty (TKA) without the motor blockade. However, the efficacy and safety of combined ACB with PI (ACB + PI) as compared to PI alone for analgesia after TKA remains controversial. We therefore performed a meta-analysis to compare the effects of ACB + PI with PI alone on pain controll after TKA. PubMed, Medline, Embase, Web of Science, and the Cochrane Library were searched to identify studies comparing ACB + PI with PI alone for TKA patients. The primary outcomes included pain score with rest or activity and morphine consumption. Secondary outcomes were distance walked, length of hospital stay, and postoperative complications. Relevant data were analyzed using RevMan v5.3. Three studies involving 337 patients were included. Combined ACB with PI was associated with longer distances walked than PI alone (MD = 7.27, 95% CI: 0.43-14.12, P = 0.04) on postoperative day 1. The outcomes of pain, morphine consumption, length of hospital stay, and postoperative complications were not statistically different between the 2 groups (P > 0.05). Our meta-analysis suggests that combined ACB with PI may achieve earlier ambulation for patients after TKA without a reduction in analgesia when compared to PI alone in the early postoperative period. There were no significant differences in morphine consumption, length of hospital stay, and postoperative complications between the 2 groups. However, owing to the variation of included studies, no firm conclusions can be drawn.

Extralaryngeal division of the recurrent laryngeal nerve: A common and asymmetric anatomical variant

PubMed Central

Uludağ, Mehmet; Yetkin, Gürkan; Oran, Ebru Şen; Aygün, Nurcihan; Celayir, Fevzi; İşgör, Adnan

2017-01-01

Objective Recognition of extralaryngeal branching of the recurrent laryngeal nerve is crucial because prevention of vocal cord paralysis requires preservation of all branches of the recurrent laryngeal nerve. We assessed the prevalence of extralaryngeal branching of the recurrent laryngeal nerve and the median branching distance from the point of bifurcation to the entry point of the nerve into the larynx. Material and Methods Prospective operative data on recurrent laryngeal nerve branching were collected from 94 patients who underwent thyroid or parathyroid surgery between September 2011 and May 2012. Results A total of 161 recurrent laryngeal nerves were examined (82 right, 79 left). Overall, 77 (47.8%) of 161 recurrent laryngeal nerves were bifurcated before entering the larynx. There were 36 (43.9%) branching nerves on the right and 41 (51.9%) branching nerves on the left, and there was no significant difference between the sides in terms of branching (p=0.471). Among 67 patients who underwent bilateral exploration, 28.4% were found to have bilateral branching, 40.3% had unilateral branching, and the remaining 31.3% had no branching. The median branching distance was 15 mm (5–60mm). Conclusion Extralaryngeal division of recurrent laryngeal nerve is a common and asymmetric anatomical variant. These variations can be easily recognized if the recurrent laryngeal nerve is identified at the level of the inferior thyroid artery and then dissected totally to the entry point of the larynx. Inadvertent division of a branch may lead to vocal cord palsy postoperatively, even when the surgeon believes the integrity of the nerve has been preserved. PMID:28944327

Extralaryngeal division of the recurrent laryngeal nerve: A common and asymmetric anatomical variant.

PubMed

Uludağ, Mehmet; Yetkin, Gürkan; Oran, Ebru Şen; Aygün, Nurcihan; Celayir, Fevzi; İşgör, Adnan

2017-01-01

Recognition of extralaryngeal branching of the recurrent laryngeal nerve is crucial because prevention of vocal cord paralysis requires preservation of all branches of the recurrent laryngeal nerve. We assessed the prevalence of extralaryngeal branching of the recurrent laryngeal nerve and the median branching distance from the point of bifurcation to the entry point of the nerve into the larynx. Prospective operative data on recurrent laryngeal nerve branching were collected from 94 patients who underwent thyroid or parathyroid surgery between September 2011 and May 2012. A total of 161 recurrent laryngeal nerves were examined (82 right, 79 left). Overall, 77 (47.8%) of 161 recurrent laryngeal nerves were bifurcated before entering the larynx. There were 36 (43.9%) branching nerves on the right and 41 (51.9%) branching nerves on the left, and there was no significant difference between the sides in terms of branching (p=0.471). Among 67 patients who underwent bilateral exploration, 28.4% were found to have bilateral branching, 40.3% had unilateral branching, and the remaining 31.3% had no branching. The median branching distance was 15 mm (5-60mm). Extralaryngeal division of recurrent laryngeal nerve is a common and asymmetric anatomical variant. These variations can be easily recognized if the recurrent laryngeal nerve is identified at the level of the inferior thyroid artery and then dissected totally to the entry point of the larynx. Inadvertent division of a branch may lead to vocal cord palsy postoperatively, even when the surgeon believes the integrity of the nerve has been preserved.

Efficient distribution of toy products using ant colony optimization algorithm

NASA Astrophysics Data System (ADS)

Hidayat, S.; Nurpraja, C. A.

2017-12-01

CV Atham Toys (CVAT) produces wooden toys and furniture, comprises 13 small and medium industries. CVAT always attempt to deliver customer orders on time but delivery costs are high. This is because of inadequate infrastructure such that delivery routes are long, car maintenance costs are high, while fuel subsidy by the government is still temporary. This study seeks to minimize the cost of product distribution based on the shortest route using one of five Ant Colony Optimization (ACO) algorithms to solve the Vehicle Routing Problem (VRP). This study concludes that the best of the five is the Ant Colony System (ACS) algorithm. The best route in 1st week gave a total distance of 124.11 km at a cost of Rp 66,703.75. The 2nd week route gave a total distance of 132.27 km at a cost of Rp 71,095.13. The 3rd week best route gave a total distance of 122.70 km with a cost of Rp 65,951.25. While the 4th week gave a total distance of 132.27 km at a cost of Rp 74,083.63. Prior to this study there was no effort to calculate these figures.

Size-dependent characterization of embedded Ge nanocrystals: Structural and thermal properties

NASA Astrophysics Data System (ADS)

Araujo, L. L.; Giulian, R.; Sprouster, D. J.; Schnohr, C. S.; Llewellyn, D. J.; Kluth, P.; Cookson, D. J.; Foran, G. J.; Ridgway, M. C.

2008-09-01

A combination of conventional and synchrotron-based techniques has been used to characterize the size-dependent structural and thermal properties of Ge nanocrystals (NCs) embedded in a silica (a-SiO2) matrix. Ge NC size distributions with four different diameters ranging from 4.0 to 9.0 nm were produced by ion implantation and thermal annealing as characterized with small-angle x-ray scattering and transmission electron microscopy. The NCs were well represented by the superposition of bulklike crystalline and amorphous environments, suggesting the formation of an amorphous layer separating the crystalline NC core and the a-SiO2 matrix. The amorphous fraction was quantified with x-ray-absorption near-edge spectroscopy and increased as the NC diameter decreased, consistent with the increase in surface-to-volume ratio. The structural parameters of the first three nearest-neighbor shells were determined with extended x-ray-absorption fine-structure (EXAFS) spectroscopy and evolved linearly with inverse NC diameter. Specifically, increases in total disorder, interatomic distance, and the asymmetry in the distribution of distances were observed as the NC size decreased, demonstrating that finite-size effects govern the structural properties of embedded Ge NCs. Temperature-dependent EXAFS measurements in the range of 15-300 K were employed to probe the mean vibrational frequency and the variation of the interatomic distance distribution (mean value, variance, and asymmetry) with temperature for all NC distributions. A clear trend of increased stiffness (higher vibrational frequency) and decreased thermal expansion with decreasing NC size was evident, confirming the close relationship between the variation of structural and thermal/vibrational properties with size for embedded Ge NCs. The increase in surface-to-volume ratio and the presence of an amorphous Ge layer separating the matrix and crystalline NC core are identified as the main factors responsible for the observed behavior, with the surrounding a-SiO2 matrix also contributing to a lesser extent. Such results are compared to previous reports and discussed in terms of the influence of the surface-to-volume ratio in objects of nanometer dimensions.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Qian, S.-B.; Zhu, L.-Y.; Dai, Z.-B.

We report here the tentative discovery of a Jovian planet in orbit around the rapidly pulsating subdwarf B-type (sdB-type) eclipsing binary NY Vir. By using newly determined eclipse times together with those collected from the literature, we detect that the observed-calculated (O - C) curve of NY Vir shows a small-amplitude cyclic variation with a period of 7.9 yr and a semiamplitude of 6.1 s, while it undergoes a downward parabolic change (revealing a period decrease at a rate of P-dot = -9.2 x 10{sup -12}). The periodic variation was analyzed for the light-travel-time effect via the presence of amore » third body. The mass of the tertiary companion was determined to be M{sub 3}sin i' = 2.3({+-} 0.3)M{sub Jupiter} when a total mass of 0.60 M{sub Sun} for NY Vir is adopted. This suggests that it is most probably a giant circumbinary planet orbiting NY Vir at a distance of about 3.3 astronomical units (AU). Since the rate of period decrease cannot be explained by true angular momentum loss caused by gravitational radiation or/and magnetic braking, the observed downward parabolic change in the O - C diagram may be only a part of a long-period (longer than 15 years) cyclic variation, which may reveal the presence of another Jovian planet ({approx}2.5 M{sub Jupiter}) in the system.« less

DDT_jcernich_10: Time Variability of Thermal Molecular Line Emission in IRC+10216 (4th Epoch)

NASA Astrophysics Data System (ADS)

Cernicharo, J.

2013-04-01

We have found during our GT line survey of IRC+10216 and the search for hydrides (OT1 proposal) that some molecular lines present a strong intensity variation with time due to the role of infrared pumping. For some lines the intensity change in six months reaches a factor 3 (CCH). We have checked that the effect is not instrumental and than it arises from physical processes ignored so far in the radiative transfer models. We propose to observe the CCH and HNC lines within bands 1a-5b of HIFI every four months (three observing slots) to allow a detailed study of the variation of thermal molecular emission, and dust emission, in this prototype of AGB C-rich object. The settings will also provide, as a bonus, many lines of SiO, SiS, CS, HCN, CO and 13CO for which intensity variations of up to 30% have been found. In addition, a few specificc settings for HCN and CO will complete the observations. SPIRE and PACS observations will complement, with lower spectral resolution, the whole spectrum of each of these molecules and will provide a global view of the total intensity change of these lines with time. A crude estimate of the distance could be also obtained from the observed time lags between the blue and red parts of the line profiles observed with HIFI.

OT2_jcernich_9: Time Variability of Thermal Molecular Line Emission in IRC+10216

NASA Astrophysics Data System (ADS)

Cernicharo, J.

2011-09-01

We have found during our GT line survey of IRC+10216 and the search for hydrides (OT1 proposal) that some molecular lines present a strong intensity variation with time due to the role of infrared pumping. For some lines the intensity change in six months reaches a factor 3 (CCH). We have checked that the effect is not instrumental and than it arises from physical processes ignored so far in the radiative transfer models. We propose to observe the CCH and HNC lines within bands 1a-5b of HIFI every four months (three observing slots) to allow a detailed study of the variation of thermal molecular emission, and dust emission, in this prototype of AGB C-rich object. The settings will also provide, as a bonus, many lines of SiO, SiS, CS, HCN, CO and 13CO for which intensity variations of up to 30% have been found. In addition, a few specificc settings for HCN and CO will complete the observations. SPIRE and PACS observations will complement, with lower spectral resolution, the whole spectrum of each of these molecules and will provide a global view of the total intensity change of these lines with time. A crude estimate of the distance could be also obtained from the observed time lags between the blue and red parts of the line profiles observed with HIFI.

Spatial and temporal variations of chemicals in the TSP aerosols simultaneously collected at three islands in Okinawa, Japan

NASA Astrophysics Data System (ADS)

Arakaki, Takemitsu; Azechi, Sotaro; Somada, Yuka; Ijyu, Moriaki; Nakaema, Fumiya; Hitomi, Yuya; Handa, Daishi; Oshiro, Yoshito; Miyagi, Youichi; Tsuhako, Ai; Murayama, Hitomi; Higaonna, Yumi; Tanahara, Akira; Itoh, Akihide; Fukushima, Soko; Higashi, Kazuaki; Henza, Yui; Nishikawa, Rin; Shinjo, Hibiki; Wang, Hongyan

2014-11-01

East Asia's rapid economic growth has led to concerns about the emission of air pollutants. We collected total suspended particle (TSP) aerosol samples simultaneously at three islands in Okinawa, Japan, which are downwind of East Asia, during the Asian dust season, to examine the spatial and temporal variations and chemical transformations of major chemicals in the aerosols. Weekly samples were collected from July 2008 to June 2010, and the concentrations of water-soluble cations, anions, and organic carbon (WSOC) were determined (n = 303). Spatial distribution analysis showed that monthly mean concentrations of non-sea-salt (nss)-SO42- in the spring (Asian dust season) decreased with increasing distance from Asia, while the trend for NO3- was less evident, suggesting that chemical transformation affected the long-range transport of certain chemicals. Temporal variation analysis showed that concentrations of nss-SO42-, NO3-, and WSOC during the spring were about 2.0, 2.4, and 1.8 times those in the summer (cleaner air mass from the Pacific Ocean), respectively. This study demonstrated that air pollutants were transported from the Asian continent to the Okinawa islands and affected the air quality in the region. There may also be impacts on ecosystems, because increased concentrations of particulate NO3- could increase nutrient levels around the Okinawa islands.

Circumbinary Planets Orbiting the Rapidly Pulsating Subdwarf B-type Binary NY Vir

NASA Astrophysics Data System (ADS)

Qian, S.-B.; Zhu, L.-Y.; Dai, Z.-B.; Fernández-Lajús, E.; Xiang, F.-Y.; He, J.-J.

2012-02-01

We report here the tentative discovery of a Jovian planet in orbit around the rapidly pulsating subdwarf B-type (sdB-type) eclipsing binary NY Vir. By using newly determined eclipse times together with those collected from the literature, we detect that the observed-calculated (O - C) curve of NY Vir shows a small-amplitude cyclic variation with a period of 7.9 yr and a semiamplitude of 6.1 s, while it undergoes a downward parabolic change (revealing a period decrease at a rate of \\dot{P}=-9.2\\times {10^{-12}}). The periodic variation was analyzed for the light-travel-time effect via the presence of a third body. The mass of the tertiary companion was determined to be M 3sin i' = 2.3(± 0.3)M Jupiter when a total mass of 0.60 M ⊙ for NY Vir is adopted. This suggests that it is most probably a giant circumbinary planet orbiting NY Vir at a distance of about 3.3 astronomical units (AU). Since the rate of period decrease cannot be explained by true angular momentum loss caused by gravitational radiation or/and magnetic braking, the observed downward parabolic change in the O - C diagram may be only a part of a long-period (longer than 15 years) cyclic variation, which may reveal the presence of another Jovian planet (~2.5 M Jupiter) in the system.

Dispersal Ability Determines the Role of Environmental, Spatial and Temporal Drivers of Metacommunity Structure

PubMed Central

Padial, André A.; Ceschin, Fernanda; Declerck, Steven A. J.; De Meester, Luc; Bonecker, Cláudia C.; Lansac-Tôha, Fabio A.; Rodrigues, Liliana; Rodrigues, Luzia C.; Train, Sueli; Velho, Luiz F. M.; Bini, Luis M.

2014-01-01

Recently, community ecologists are focusing on the relative importance of local environmental factors and proxies to dispersal limitation to explain spatial variation in community structure. Albeit less explored, temporal processes may also be important in explaining species composition variation in metacommunities occupying dynamic systems. We aimed to evaluate the relative role of environmental, spatial and temporal variables on the metacommunity structure of different organism groups in the Upper Paraná River floodplain (Brazil). We used data on macrophytes, fish, benthic macroinvertebrates, zooplankton, periphyton, and phytoplankton collected in up to 36 habitats during a total of eight sampling campaigns over two years. According to variation partitioning results, the importance of predictors varied among biological groups. Spatial predictors were particularly important for organisms with comparatively lower dispersal ability, such as aquatic macrophytes and fish. On the other hand, environmental predictors were particularly important for organisms with high dispersal ability, such as microalgae, indicating the importance of species sorting processes in shaping the community structure of these organisms. The importance of watercourse distances increased when spatial variables were the main predictors of metacommunity structure. The contribution of temporal predictors was low. Our results emphasize the strength of a trait-based analysis and of better defining spatial variables. More importantly, they supported the view that “all-or- nothing” interpretations on the mechanisms structuring metacommunities are rather the exception than the rule. PMID:25340577

The Link between Microbial Diversity and Nitrogen Cycling in Marine Sediments Is Modulated by Macrofaunal Bioturbation

PubMed Central

Yazdani Foshtomi, Maryam; Braeckman, Ulrike; Derycke, Sofie; Sapp, Melanie; Van Gansbeke, Dirk; Sabbe, Koen; Willems, Anne; Vincx, Magda; Vanaverbeke, Jan

2015-01-01

Objectives The marine benthic nitrogen cycle is affected by both the presence and activity of macrofauna and the diversity of N-cycling microbes. However, integrated research simultaneously investigating macrofauna, microbes and N-cycling is lacking. We investigated spatio-temporal patterns in microbial community composition and diversity, macrofaunal abundance and their sediment reworking activity, and N-cycling in seven subtidal stations in the Southern North Sea. Spatio-Temporal Patterns of the Microbial Communities Our results indicated that bacteria (total and β-AOB) showed more spatio-temporal variation than archaea (total and AOA) as sedimentation of organic matter and the subsequent changes in the environment had a stronger impact on their community composition and diversity indices in our study area. However, spatio-temporal patterns of total bacterial and β-AOB communities were different and related to the availability of ammonium for the autotrophic β-AOB. Highest bacterial richness and diversity were observed in June at the timing of the phytoplankton bloom deposition, while richness of β-AOB as well as AOA peaked in September. Total archaeal community showed no temporal variation in diversity indices. Macrofauna, Microbes and the Benthic N-Cycle Distance based linear models revealed that, independent from the effect of grain size and the quality and quantity of sediment organic matter, nitrification and N-mineralization were affected by respectively the diversity of metabolically active β-AOB and AOA, and the total bacteria, near the sediment-water interface. Separate models demonstrated a significant and independent effect of macrofaunal activities on community composition and richness of total bacteria, and diversity indices of metabolically active AOA. Diversity of β-AOB was significantly affected by macrofaunal abundance. Our results support the link between microbial biodiversity and ecosystem functioning in marine sediments, and provided broad correlative support for the hypothesis that this relationship is modulated by macrofaunal activity. We hypothesized that the latter effect can be explained by their bioturbating and bio-irrigating activities, increasing the spatial complexity of the biogeochemical environment. PMID:26102286

MCNP simulations of material exposure experiments (u)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Temple, Brian A

2010-12-08

Simulations of proposed material exposure experiments were performed using MCNP6. The experiments will expose ampules containing different materials of interest with radiation to observe the chemical breakdown of the materials. Simulations were performed to map out dose in materials as a function of distance from the source, dose variation between materials, dose variation due to ampule orientation, and dose variation due to different source energy. This write up is an overview of the simulations and will provide guidance on how to use the data in the spreadsheet.

Detection of memory loss of symmetry in the blockage of a turbulent flow within a duct

NASA Astrophysics Data System (ADS)

Santos, F. Rodrigues; da Silva Costa, G.; da Cunha Lima, A. T.; de Almeida, M. P.; da Cunha Lima, I. C.

This paper aims to detect memory loss of the symmetry of blockades in ducts and how far the information on the asymmetry of the obstacles travels in the turbulent flow from computational simulations with OpenFOAM. From a practical point of view, it seeks alternatives to detect the formation of obstructions in pipelines. The numerical solutions of the Navier-Stokes equations were obtained through the solver PisoFOAM of the OpenFOAM library, using the large Eddy simulation (LES) for the turbulent model. Obstructions were placed near the duct inlet and, keeping the blockade ratio fixed, five combinations for the obstacles sizes were adopted. The results show that the information about the symmetry is preserved for a larger distance near the ducts wall than in mid-channel. For an inlet velocity of 5m/s near the walls the memory is kept up to distance 40 times the duct width, while in mid-channel this distance is reduced almost by half. The maximum distance in which the symmetry breaking memory is preserved shows sensitivity to Reynolds number variations in regions near the duct walls, while in the mid channel that variations do not cause relevant effects to the velocity distribution.

An acoustic thermometer for air refractive index estimation in long distance interferometric measurements

NASA Astrophysics Data System (ADS)

Pisani, Marco; Astrua, Milena; Zucco, Massimo

2018-02-01

We present a method to measure the temperature along the path of an optical interferometer based on the propagation of acoustic waves. It exploits the high sensitivity of the speed of sound to air temperature. In particular, it takes advantage of a technique where the generation of acoustic waves is synchronous with the amplitude modulation of a laser source. A photodetector converts the laser light into an electronic signal used as a reference, while the incoming acoustic waves are focused on a microphone and generate the measuring signal. Under this condition, the phase difference between the two signals substantially depends on the temperature of the air volume interposed between the sources and the receivers. A comparison with traditional temperature sensors highlighted the limit of the latter in the case of fast temperature variations and the advantage of a measurement integrated along the optical path instead of a sampling measurement. The capability of the acoustic method to compensate for the interferometric distance measurements due to air temperature variations has been demonstrated to the level of 0.1 °C corresponding to 10-7 on the refractive index of air. We applied the method indoor for distances up to 27 m, outdoor at 78 m and finally tested the acoustic thermometer over a distance of 182 m.

Life on the edge: carnivore body size variation is all over the place

PubMed Central

Meiri, Shai; Dayan, Tamar; Simberloff, Daniel; Grenyer, Richard

2009-01-01

Evolutionary biologists have long been fascinated by both the ways in which species respond to ecological conditions at the edges of their geographic ranges and the way that species' body sizes evolve across their ranges. Surprisingly, though, the relationship between these two phenomena is rarely studied. Here, we examine whether carnivore body size changes from the interior of their geographic range towards the range edges. We find that within species, body size often varies strongly with distance from the range edge. However, there is no general tendency across species for size to be either larger or smaller towards the edge. There is some evidence that the smallest guild members increase in size towards their range edges, but results for the largest guild members are equivocal. Whether individuals vary in relation to the distance from the range edges often depends on the way edge and interior are defined. Neither geographic range size nor absolute body size influences the tendency of size to vary with distance from the range edge. Therefore, we suggest that the frequent significant association between body size and the position of individuals along the edge-core continuum reflects the prevalence of geographic size variation and that the distance to range edge per se does not influence size evolution in a consistent way. PMID:19324818

Cranial measures and ancient DNA both show greater similarity of Neandertals to recent modern Eurasians than to recent modern sub-Saharan Africans.

PubMed

Relethford, John H; Smith, Fred H

2018-05-01

Ancient DNA analysis has shown that present-day humans of Eurasian ancestry are more similar to Neandertals than are present-day humans of sub-Saharan African ancestry, reflecting interbreeding after modern humans first left Africa. We use craniometric data to test the hypothesis that the crania of recent modern humans show the same pattern. We computed Mahalanobis squared distances between a published Neandertal centroid based on 37 craniometric traits and each of 2,413 recent modern humans from the Howells global data set (N = 373 sub-Saharan Africans, N = 2,040 individuals of Eurasian descent). The average distance to the Neandertal centroid is significantly lower for Eurasian crania than for sub-Saharan African crania as expected from the findings of ancient DNA (p < 0.001). This result holds when examining distances for separate geographic regions of humans of Eurasian descent (Europeans, Asians, Australasians, Native Americans, and Pacific Islanders). Most of these results are also seen when examining distances partitioning size and shape variation. Our results show that the genetic difference in Neandertal ancestry seen in the DNA of present-day sub-Saharan Africans and Eurasians is also found in patterns of recent modern human craniometric variation. © 2018 Wiley Periodicals, Inc.

An comprehensive time-distance measurement of deep meridional flow and its temporal variation

NASA Astrophysics Data System (ADS)

Chen, Ruizhu; Zhao, Junwei

2016-10-01

We report our latest results on the Sun's deep solar meridional-flow measurements by time-distance helioseismology technique using 6 years of SDO/HMI Doppler-velocity data. Determination of the meridional flow by time-distance helioseismology depends on a precise measurement of the flow-induced travel-time shifts of acoustic waves traveling in the solar interior. To resolve the weak travel-time-shift signals due to deep meridional flow, we need a high signal-to-noise ratio and a robust removal of the center-to-limb (CtoL) effect, which dominates the travel-time shifts. Here we perform an ultimately comprehensive measurement that tracks acoustic waves between any two points on solar surface. The travel-time shifts are composed of CtoL effect, which is a function of disk-centric distances, and contribution from the flow component parallel to wave traveling direction, which is a function of latitude and orientation. Assuming these two effects are independent, we can derive the CtoL effect and meridional-flow contributions by solving a set of linear equations in a least-square sense. We show the solved CtoL effect and the inversion results for the solar meridional flow, and analyze the annual variation of meridional flow from May 2010 to Apr 2016.

Spectral distances on the doubled Moyal plane using Dirac eigenspinors

NASA Astrophysics Data System (ADS)

Kumar, Kaushlendra; Chakraborty, Biswajit

2018-04-01

We present here a novel method for computing spectral distances in the doubled Moyal plane in a noncommutative geometrical framework using Dirac eigenspinors, while solving the Lipschitz ball condition explicitly through matrices. The standard results of longitudinal, transverse, and hypotenuse distances between different pairs of pure states have been computed and the Pythagorean equality between them has been reproduced. The issue of the nonunital nature of the Moyal plane algebra is taken care of through a sequence of projection operators constructed from Dirac eigenspinors, which plays a crucial role throughout this paper. At the end, a toy model for a "Higgs field" has been constructed by fluctuating the Dirac operator and the variation on the transverse distance has been demonstrated, through an explicit computation.

Solar wind velocity and temperature in the outer heliosphere

NASA Technical Reports Server (NTRS)

Gazis, P. R.; Barnes, A.; Mihalov, J. D.; Lazarus, A. J.

1994-01-01

At the end of 1992, the Pioneer 10, Pioneer 11, and Voyager 2 spacecraft were at heliocentric distances of 56.0, 37.3, and 39.0 AU and heliographic latitudes of 3.3 deg N, 17.4 deg N, and 8.6 deg S, respectively. Pioneer 11 and Voyager 2 are at similar celestial longitudes, while Pioneer 10 is on the opposite side of the Sun. All three spacecraft have working plasma analyzers, so intercomparison of data from these spacecraft provides important information about the global character of the solar wind in the outer heliosphere. The averaged solar wind speed continued to exhibit its well-known variation with solar cycle: Even at heliocentric distances greater than 50 AU, the average speed is highest during the declining phase of the solar cycle and lowest near solar minimum. There was a strong latitudinal gradient in solar wind speed between 3 deg and 17 deg N during the last solar minimum, but this gradient has since disappeared. The solar wind temperature declined with increasing heliocentric distance out to a heliocentric distance of at least 20 AU; this decline appeared to continue at larger heliocentric distances, but temperatures in the outer heliosphere were suprisingly high. While Pioneer 10 and Voyager 2 observed comparable solar wind temperatures, the temperature at Pioneer 11 was significantly higher, which suggests the existence of a large-scale variation of temperature with heliographic longitude. There was also some suggestion that solar wind temperatures were higher near solar minimum.

Slip parameters on major thrusts at a convergent plate boundary: regional heterogeneity of potential slip distance at the shallow portion of the subducting plate

NASA Astrophysics Data System (ADS)

Mukoyoshi, Hideki; Kaneki, Shunya; Hirono, Tetsuro

2018-03-01

Understanding variations of slip distance along major thrust systems at convergent margins is an important issue for evaluation of near-trench slip and the potential generation of large tsunamis. We derived quantitative estimates of slip along ancient subduction fault systems by using the maturity of carbonaceous material (CM) of discrete slip zones as a proxy for temperature. We first obtained the Raman spectra of CM in ultracataclasite and pseudotachylyte layers in discrete slip zones at depths below the seafloor of 1-4 km and 2.5-5.5 km, respectively. By comparing the area-under-the-peak ratios of graphitic and disordered bands in those Raman spectra with spectra of experimentally heated CM from surrounding rocks, we determined that the ultracataclasite and pseudotachylyte layers had been heated to temperatures of up to 700 and 1300 °C, respectively. Numerical simulation of the thermal history of CM extracted from rocks near the two slip zones, taking into consideration these temperature constraints, indicated that slip distances in the ultracataclasite and pseudotachylyte layers were more than 3 and 7 m, respectively. Thus, potential distance of coseismic slip along the subduction-zone fault system could have regional variations even at shallow depth (≤ 5.5 km). The slip distances we determined probably represent minimum slips for subduction-zone thrusts and thus provide an important contribution to earthquake preparedness plans in coastal areas facing the Nankai and Sagami Troughs.

Particulate Matter deposition on Quercus ilex leaves in an industrial city of central Italy.

PubMed

Sgrigna, G; Sæbø, A; Gawronski, S; Popek, R; Calfapietra, C

2015-02-01

A number of studies have focused on urban trees to understand their mitigation capacity of air pollution. In this study particulate matter (PM) deposition on Quercus ilex leaves was quantitatively analyzed in four districts of the City of Terni (Italy) for three periods of the year. Fine (between 0.2 and 2.5 μm) and Large (between 2.5 and 10 μm) PM fractions were analyzed. Mean PM deposition value on Quercus ilex leaves was 20.6 μg cm(-2). Variations in PM deposition correlated with distance to main roads and downwind position relatively to industrial area. Epicuticular waxes were measured and related to accumulated PM. For Fine PM deposited in waxes we observed a higher value (40% of total Fine PM) than Large PM (4% of total Large PM). Results from this study allow to increase our understanding about air pollution interactions with urban vegetation and could be hopefully taken into account when guidelines for local urban green management are realized. Copyright © 2014 Elsevier Ltd. All rights reserved.

QTL Mapping of Genome Regions Controlling Manganese Uptake in Lentil Seed.

PubMed

Ates, Duygu; Aldemir, Secil; Yagmur, Bulent; Kahraman, Abdullah; Ozkan, Hakan; Vandenberg, Albert; Tanyolac, Muhammed Bahattin

2018-05-04

This study evaluated Mn concentration in the seeds of 120 RILs of lentil developed from the cross "CDC Redberry" × "ILL7502". Micronutrient analysis using atomic absorption spectrometry indicated mean seed manganese (Mn) concentrations ranging from 8.5 to 26.8 mg/kg, based on replicated field trials grown at three locations in Turkey in 2012 and 2013. A linkage map of lentil was constructed and consisted of seven linkage groups with 5,385 DNA markers. The total map length was 973.1 cM, with an average distance between markers of 0.18 cM. A total of 6 QTL for Mn concentration were identified using composite interval mapping (CIM). All QTL were statistically significant and explained 15.3-24.1% of the phenotypic variation, with LOD scores ranging from 3.00 to 4.42. The high-density genetic map reported in this study will increase fundamental knowledge of the genome structure of lentil, and will be the basis for the development of micronutrient-enriched lentil genotypes to support biofortification efforts. Copyright © 2018 Ates et al.

Covalent bonds are created by the drive of electron waves to lower their kinetic energy through expansion

PubMed Central

Schmidt, Michael W.; Ivanic, Joseph; Ruedenberg, Klaus

2014-01-01

An analysis based on the variation principle shows that in the molecules H2+, H2, B2, C2, N2, O2, F2, covalent bonding is driven by the attenuation of the kinetic energy that results from the delocalization of the electronic wave function. For molecular geometries around the equilibrium distance, two features of the wave function contribute to this delocalization: (i) Superposition of atomic orbitals extends the electronic wave function from one atom to two or more atoms; (ii) intra-atomic contraction of the atomic orbitals further increases the inter-atomic delocalization. The inter-atomic kinetic energy lowering that (perhaps counter-intuitively) is a consequence of the intra-atomic contractions drives these contractions (which per se would increase the energy). Since the contractions necessarily encompass both, the intra-atomic kinetic and potential energy changes (which add to a positive total), the fact that the intra-atomic potential energy change renders the total potential binding energy negative does not alter the fact that it is the kinetic delocalization energy that drives the bond formation. PMID:24880263

Covalent bonds are created by the drive of electron waves to lower their kinetic energy through expansion.

PubMed

Schmidt, Michael W; Ivanic, Joseph; Ruedenberg, Klaus

2014-05-28

An analysis based on the variation principle shows that in the molecules H2 (+), H2, B2, C2, N2, O2, F2, covalent bonding is driven by the attenuation of the kinetic energy that results from the delocalization of the electronic wave function. For molecular geometries around the equilibrium distance, two features of the wave function contribute to this delocalization: (i) Superposition of atomic orbitals extends the electronic wave function from one atom to two or more atoms; (ii) intra-atomic contraction of the atomic orbitals further increases the inter-atomic delocalization. The inter-atomic kinetic energy lowering that (perhaps counter-intuitively) is a consequence of the intra-atomic contractions drives these contractions (which per se would increase the energy). Since the contractions necessarily encompass both, the intra-atomic kinetic and potential energy changes (which add to a positive total), the fact that the intra-atomic potential energy change renders the total potential binding energy negative does not alter the fact that it is the kinetic delocalization energy that drives the bond formation.

Species divergence and phylogenetic variation of ecophysiological traits in lianas and trees.

PubMed

Rios, Rodrigo S; Salgado-Luarte, Cristian; Gianoli, Ernesto

2014-01-01

The climbing habit is an evolutionary key innovation in plants because it is associated with enhanced clade diversification. We tested whether patterns of species divergence and variation of three ecophysiological traits that are fundamental for plant adaptation to light environments (maximum photosynthetic rate [A(max)], dark respiration rate [R(d)], and specific leaf area [SLA]) are consistent with this key innovation. Using data reported from four tropical forests and three temperate forests, we compared phylogenetic distance among species as well as the evolutionary rate, phylogenetic distance and phylogenetic signal of those traits in lianas and trees. Estimates of evolutionary rates showed that R(d) evolved faster in lianas, while SLA evolved faster in trees. The mean phylogenetic distance was 1.2 times greater among liana species than among tree species. Likewise, estimates of phylogenetic distance indicated that lianas were less related than by chance alone (phylogenetic evenness across 63 species), and trees were more related than expected by chance (phylogenetic clustering across 71 species). Lianas showed evenness for R(d), while trees showed phylogenetic clustering for this trait. In contrast, for SLA, lianas exhibited phylogenetic clustering and trees showed phylogenetic evenness. Lianas and trees showed patterns of ecophysiological trait variation among species that were independent of phylogenetic relatedness. We found support for the expected pattern of greater species divergence in lianas, but did not find consistent patterns regarding ecophysiological trait evolution and divergence. R(d) followed the species-level pattern, i.e., greater divergence/evolution in lianas compared to trees, while the opposite occurred for SLA and no pattern was detected for A(max). R(d) may have driven lianas' divergence across forest environments, and might contribute to diversification in climber clades.

Statistics of strain rates and surface density function in a flame-resolved high-fidelity simulation of a turbulent premixed bluff body burner

NASA Astrophysics Data System (ADS)

Sandeep, Anurag; Proch, Fabian; Kempf, Andreas M.; Chakraborty, Nilanjan

2018-06-01

The statistical behavior of the surface density function (SDF, the magnitude of the reaction progress variable gradient) and the strain rates, which govern the evolution of the SDF, have been analyzed using a three-dimensional flame-resolved simulation database of a turbulent lean premixed methane-air flame in a bluff-body configuration. It has been found that the turbulence intensity increases with the distance from the burner, changing the flame curvature distribution and increasing the probability of the negative curvature in the downstream direction. The curvature dependences of dilatation rate ∇ṡu → and displacement speed Sd give rise to variations of these quantities in the axial direction. These variations affect the nature of the alignment between the progress variable gradient and the local principal strain rates, which in turn affects the mean flame normal strain rate, which assumes positive values close to the burner but increasingly becomes negative as the effect of turbulence increases with the axial distance from the burner exit. The axial distance dependences of the curvature and displacement speed also induce a considerable variation in the mean value of the curvature stretch. The axial distance dependences of the dilatation rate and flame normal strain rate govern the behavior of the flame tangential strain rate, and its mean value increases in the downstream direction. The current analysis indicates that the statistical behaviors of different strain rates and displacement speed and their curvature dependences need to be included in the modeling of flame surface density and scalar dissipation rate in order to accurately capture their local behaviors.

Species Divergence and Phylogenetic Variation of Ecophysiological Traits in Lianas and Trees

PubMed Central

Rios, Rodrigo S.; Salgado-Luarte, Cristian; Gianoli, Ernesto

2014-01-01

The climbing habit is an evolutionary key innovation in plants because it is associated with enhanced clade diversification. We tested whether patterns of species divergence and variation of three ecophysiological traits that are fundamental for plant adaptation to light environments (maximum photosynthetic rate [Amax], dark respiration rate [Rd], and specific leaf area [SLA]) are consistent with this key innovation. Using data reported from four tropical forests and three temperate forests, we compared phylogenetic distance among species as well as the evolutionary rate, phylogenetic distance and phylogenetic signal of those traits in lianas and trees. Estimates of evolutionary rates showed that Rd evolved faster in lianas, while SLA evolved faster in trees. The mean phylogenetic distance was 1.2 times greater among liana species than among tree species. Likewise, estimates of phylogenetic distance indicated that lianas were less related than by chance alone (phylogenetic evenness across 63 species), and trees were more related than expected by chance (phylogenetic clustering across 71 species). Lianas showed evenness for Rd, while trees showed phylogenetic clustering for this trait. In contrast, for SLA, lianas exhibited phylogenetic clustering and trees showed phylogenetic evenness. Lianas and trees showed patterns of ecophysiological trait variation among species that were independent of phylogenetic relatedness. We found support for the expected pattern of greater species divergence in lianas, but did not find consistent patterns regarding ecophysiological trait evolution and divergence. Rd followed the species-level pattern, i.e., greater divergence/evolution in lianas compared to trees, while the opposite occurred for SLA and no pattern was detected for Amax. Rd may have driven lianas' divergence across forest environments, and might contribute to diversification in climber clades. PMID:24914958

Population-based geographic access to endocrinologists in the United States, 2012.

PubMed

Lu, Hua; Holt, James B; Cheng, Yiling J; Zhang, Xingyou; Onufrak, Stephen; Croft, Janet B

2015-12-07

Increases in population and life expectancy of Americans may result in shortages of endocrinologists by 2020. This study aims to assess variations in geographic accessibility to endocrinologists in the US, by age group at state and county levels, and by urban/rural status, and distance. We used the 2012 National Provider Identifier Registry to obtain office locations of all adult and pediatric endocrinologists in the US. The population with geographic access to an endocrinologist within a series of 6 distance radii, centered on endocrinologist practice locations, was estimated using the US Census 2010 block-level population. We assumed that persons living within the same circular buffer zone of an endocrinologist location have the same geographic accessibility to that endocrinologist. The geographic accessibility (the percentage of the population with geographic access to at least one endocrinologist) and the population-to-endocrinologist ratio for each geographic area were estimated. By using 20 miles as the distance radius, geographic accessibility to at least one pediatric/adult endocrinologist for age groups 0-17, 18-64, and ≥ 65 years was 64.1%, 85.4%, and 82.1%. The overall population-to-endocrinologist ratio within 20 miles was 39,492:1 for children, 29,887:1 for adults aged 18-64 years, and 6,194:1 for adults aged ≥ 65 years. These ratios varied considerably by state, county, urban/rural status, and distance. This study demonstrates that there are geographic variations of accessibility to endocrinologists in the US. The areas with poorer geographic accessibility warrant further study of the effect of these variations on disease prevention, detection, and management of endocrine diseases in the US population. Our findings of geographic access to endocrinologists also may provide valuable information for medical education and health resources allocation.

Rapid Plateau border size variations expected in three simple experiments on 2D liquid foams.

PubMed

Gay, C; Rognon, P; Reinelt, D; Molino, F

2011-01-01

Up to a global scaling, the geometry of foams squeezed between two solid plates (2D GG foams) essentially depends on two independent parameters: the liquid volume fraction and the degree of squeezing (bubble thickness to diameter ratio). We describe it in two main asymptotic regimes: fully dry floor tiles, where the Plateau border radius is smaller than the distance between the solid plates, and dry pancakes, where it is larger. We predict a rapid variation of the Plateau border radius in one part of the pancake regime, namely when the Plateau border radius is larger than the inter-plate distance but smaller than the geometric mean of that distance and the bubble perimeter. This rapid variation is not related to any topological change in the foam: in all the regimes we consider, the bubbles remain in mutual lateral contact through films located at mid-height between both plates. We provide asymptotic predictions in different types of experiments on such 2D GG foams: when foam is being progressively dried or wetted, when it is being squeezed further or stretched, when it coarsens through film breakage or through inter-bubble gas diffusion. Our analysis is restricted to configurations close to equilibrium, as we do not include stresses resulting from bulk viscous flow or from non-homogeneous surfactant concentrations. We also assume that the inter-plate distance is sufficiently small for gravity to be negligible. The present work does not provide a method for measuring small Plateau border radii experimentally, but it indicates that large (and easily observable) Plateau borders should appear or disappear rather suddenly in some types of experiments with small inter-plate gaps. It also gives expected orders of magnitude that should be helpful for designing experiments on 2D GG foams.

Variation among Populations of Belonolaimus longicaudatus.

PubMed

Robbins, R T; Hirschmann, H

1974-04-01

Three North Carolina populations of Belonolairnus longicaudatus differed significantly from three Georgia populations in stylet measurements, the c ratio, the distance of the excretory pore from the anterior end for both sexes; the a ratio for females only; and the total body length, tail length, and spicule length for males only. The Georgia nematodes were stouter, and the females possessed sclerotized vaginal pieces. The distal portion of the spicules of North Carolina males had an indentation and hump lacking in those of the Georgia males. The haploid number of chromosomes was eight for males from all populations of B. longicaudatus and a North Carolina population of B. maritimus. Interpopulation matings of the Tarboro, N.C. and Tifton, Ga. populations indicated that the offspring produced were infertile. Morphological differences and reproductive isolation suggest that the North Carolina and the Georgia populations belong to different species.

Genetic similarity between Taenia solium cysticerci collected from the two distant endemic areas in North and North East India.

PubMed

Sharma, Monika; Devi, Kangjam Rekha; Sehgal, Rakesh; Narain, Kanwar; Mahanta, Jagadish; Malla, Nancy

2014-01-01

Taenia solium taeniasis/cysticercosis is a major public health problem in developing countries. This study reports genotypic analysis of T. solium cysticerci collected from two different endemic areas of North (Chandigarh) and North East India (Dibrugarh) by the sequencing of mitochondrial cytochrome c oxidase subunit 1 (cox1) gene. The variation in cox1 sequences of samples collected from these two different geographical regions located at a distance of 2585 km was minimal. Alignment of the nucleotide sequences with different species of Taenia showed the similarity with Asian genotype of T. solium. Among 50 isolates, 6 variant nucleotide positions (0.37% of total length) were detected. These results suggest that population in these geographical areas are homogenous. Copyright © 2013 Elsevier B.V. All rights reserved.

Genetic variation and seed transfer guidelines for ponderosa pine in central Oregon.

Treesearch

Frank C. Sorensen

1994-01-01

Adaptive genetic variation in seed and seedling traits for ponderosa pine from the east slopes of the Cascade Range in Oregon was analyzed by using 307 families from 227 locations. Factor scores from three principal components based on seed and seedling traits were related by multiple regression to latitude, distance from the Cascade crest, elevation, slope, and...

Genetic variation and seed transfer guidelines for lodgepole pine in central Oregon.

Treesearch

Frank C. Sorensen

1992-01-01

Cones were collected from 272 trees at 189 locations uniformly distributed over the east slopes of the Oregon Cascade Range and Warner Mountains. Variation in seed and seedling traits was related to (1) seed source latitude, distance from the Cascade crest, elevation, slope, and aspect in multiple regression analyses; and (2) seed zone and elevation band in...

Human phoneme recognition depending on speech-intrinsic variability.

PubMed

Meyer, Bernd T; Jürgens, Tim; Wesker, Thorsten; Brand, Thomas; Kollmeier, Birger

2010-11-01

The influence of different sources of speech-intrinsic variation (speaking rate, effort, style and dialect or accent) on human speech perception was investigated. In listening experiments with 16 listeners, confusions of consonant-vowel-consonant (CVC) and vowel-consonant-vowel (VCV) sounds in speech-weighted noise were analyzed. Experiments were based on the OLLO logatome speech database, which was designed for a man-machine comparison. It contains utterances spoken by 50 speakers from five dialect/accent regions and covers several intrinsic variations. By comparing results depending on intrinsic and extrinsic variations (i.e., different levels of masking noise), the degradation induced by variabilities can be expressed in terms of the SNR. The spectral level distance between the respective speech segment and the long-term spectrum of the masking noise was found to be a good predictor for recognition rates, while phoneme confusions were influenced by the distance to spectrally close phonemes. An analysis based on transmitted information of articulatory features showed that voicing and manner of articulation are comparatively robust cues in the presence of intrinsic variations, whereas the coding of place is more degraded. The database and detailed results have been made available for comparisons between human speech recognition (HSR) and automatic speech recognizers (ASR).

Population structure and cultural geography of a folktale in Europe

PubMed Central

Ross, Robert M.; Greenhill, Simon J.; Atkinson, Quentin D.

2013-01-01

Despite a burgeoning science of cultural evolution, relatively little work has focused on the population structure of human cultural variation. By contrast, studies in human population genetics use a suite of tools to quantify and analyse spatial and temporal patterns of genetic variation within and between populations. Human genetic diversity can be explained largely as a result of migration and drift giving rise to gradual genetic clines, together with some discontinuities arising from geographical and cultural barriers to gene flow. Here, we adapt theory and methods from population genetics to quantify the influence of geography and ethnolinguistic boundaries on the distribution of 700 variants of a folktale in 31 European ethnolinguistic populations. We find that geographical distance and ethnolinguistic affiliation exert significant independent effects on folktale diversity and that variation between populations supports a clustering concordant with European geography. This pattern of geographical clines and clusters parallels the pattern of human genetic diversity in Europe, although the effects of geographical distance and ethnolinguistic boundaries are stronger for folktales than genes. Our findings highlight the importance of geography and population boundaries in models of human cultural variation and point to key similarities and differences between evolutionary processes operating on human genes and culture. PMID:23390109

Effects of variables upon pyrotechnically induced shock response spectra

NASA Technical Reports Server (NTRS)

Smith, J. L.

1986-01-01

Throughout the aerospace industry, large variations of 50 percent (6 dB) or more are continually noted for linear shaped charge (LSC) generated shock response spectra (SRS) from flight data (from the exact same location on different flights) and from plate tests (side by side measurements on the same test). A research program was developed to investigate causes of these large SRS variations. A series of ball drop calibration tests to verify calibration of accelerometers and a series of plate tests to investigate charge and assembly variables were performed. The resulting data were analyzed to determine if and to what degree manufacturing and assembly variables, distance from the shock source, data acquisition instrumentation, and shock energy propagation affect the SRS. LSC variables consisted of coreload, standoff, and apex angle. The assembly variable was the torque on the LSC holder. Other variables were distance from source of accelerometers, accelerometer mounting methods, and joint effects. Results indicated that LSC variables did not affect SRS as long as the plate was severed. Accelerometers mounted on mounting blocks showed significantly lower levels above 5000 Hz. Lap joints did not affect SRS levels. The test plate was mounted in an almost free-free state; therefore, distance from the source did not affect the SRS. Several varieties and brands of accelerometers were used, and all but one demonstrated very large variations in SRS.

Welding induced residual stress evaluation using laser-generated Rayleigh waves

NASA Astrophysics Data System (ADS)

Ye, Chong; Zhou, Yuanlai; Reddy, Vishnu V. B.; Mebane, Aaron; Ume, I. Charles

2018-04-01

Welding induced residual stress could affect the dimensional stability, fatigue life, and chemical resistance of the weld joints. Ultrasonic method serves as an important non-destructive tool for the residual stress evaluation due to its easy implementation, low cost and wide application to different materials. Residual stress would result in the ultrasonic wave velocity variation, which is the so called acoustoelastic effect. In this paper, Laser/EMAT ultrasonic technique was proposed to experimentally study the relative velocity variation ΔV/V of Rayleigh wave, which has the potential to evaluate surface/subsurface longitudinal residual stress developed during the Gas Metal Arc Welding process. Broad band ultrasonic waves were excited by pulsed Q-Switched Nd: YAG laser. An electromagnetic acoustic transducer (EMAT) attached to the welded plates was used to capture the Rayleigh wave signals propagating along the weld seam direction. Different time of flight measurements were conducted by varying the distance between the weld seam and Rayleigh wave propagating path in the range of 0 to 45 mm. The maximum relative velocity difference was found on the weld seam. With the increasing distance away from the weld seam, the relative velocity difference sharply decreased to negative value. With further increase in distance, the relative velocity difference slowly increased and approached zero. The distribution of relative velocity variations indicates that tensile stress appears in the melted zone as it becomes compressive near the heat-affected zone.

Self-potential response to periodic pumping test: a numerical study

NASA Astrophysics Data System (ADS)

Konosavsky, Pavel; Maineult, Alexis; Narbut, Mikhail; Titov, Konstantin

2017-09-01

We numerically model self-potential responses associated with periodic pumping test experiments by sequential calculation of the hydraulic response and the coupled electrical potential. We assume the pumping test experiments with a fully saturated confined aquifer. Application of different excitation functions leads to quasi-linear trends in electrical records whose direction and intensity depend on the form of the excitation function. The hydraulic response is phase shifted compared to the excitation function; the phase shift increases quasi-linearly with the distance from the pumping well. For the electrical signals, we investigated separately the cases of conducting and insulating casings of the pumping well. For the conducting casing the electrical signals are larger in magnitude than that for the insulating casing; they reproduce the drawdown signals in the pumping well at any distance from the well and exhibit any phase shift with the increased distance. For the insulating casing, the electrical signals are phase shifted and their shape depends on the distance from the pumping well. Three characteristic regimes were found for the phase shift, φ, with the increased distance and for various hydraulic diffusivity values. At small distances φ increases quasi-linearly; at intermediate distances φ attends the value of π/2 and stay about this value (for relatively small diffusivity values); and at large distances φ attends the value of π and, stay about this value at larger distances. This behaviour of the electrical signals can be explained by two electrical sources of reverse polarity. They are (i) linear, time independent, and located at the pumping interval of the well; and (ii) volumetric, time dependent, with maximum value located in the aquifer at the distance corresponding to maximum variation of the hydraulic head magnitude with time. We also model the variation of the amplitude and phase of the hydraulic and electrical signals with increased excitation function period, and we show the characteristic periods corresponding to transition of the periodic pumping test regime to the classical pumping test regime, when the excitation function is considered as the step-function. This transition depends on the distance from the pumping well and the hydraulic diffusivity value of aquifer. Finally, with this modelling of saturated flow we reproduced in sufficient details the field data previously obtained by Maineult et al.

Establishing an efficient way to utilize the drought resistance germplasm population in wheat.

PubMed

Wang, Jiancheng; Guan, Yajing; Wang, Yang; Zhu, Liwei; Wang, Qitian; Hu, Qijuan; Hu, Jin

2013-01-01

Drought resistance breeding provides a hopeful way to improve yield and quality of wheat in arid and semiarid regions. Constructing core collection is an efficient way to evaluate and utilize drought-resistant germplasm resources in wheat. In the present research, 1,683 wheat varieties were divided into five germplasm groups (high resistant, HR; resistant, R; moderate resistant, MR; susceptible, S; and high susceptible, HS). The least distance stepwise sampling (LDSS) method was adopted to select core accessions. Six commonly used genetic distances (Euclidean distance, Euclid; Standardized Euclidean distance, Seuclid; Mahalanobis distance, Mahal; Manhattan distance, Manhat; Cosine distance, Cosine; and Correlation distance, Correlation) were used to assess genetic distances among accessions. Unweighted pair-group average (UPGMA) method was used to perform hierarchical cluster analysis. Coincidence rate of range (CR) and variable rate of coefficient of variation (VR) were adopted to evaluate the representativeness of the core collection. A method for selecting the ideal constructing strategy was suggested in the present research. A wheat core collection for the drought resistance breeding programs was constructed by the strategy selected in the present research. The principal component analysis showed that the genetic diversity was well preserved in that core collection.

Drivers shaping the diversity and biogeography of total and active bacterial communities in the South China Sea

PubMed Central

Zhang, Yao; Zhao, Zihao; Dai, Minhan; Jiao, Nianzhi; Herndl, Gerhard J

2014-01-01

To test the hypothesis that different drivers shape the diversity and biogeography of the total and active bacterial community, we examined the bacterial community composition along two transects, one from the inner Pearl River estuary to the open waters of the South China Sea (SCS) and the other from the Luzon Strait to the SCS basin, using 454 pyrosequencing of the 16S rRNA and 16S rRNA gene (V1-3 regions) and thereby characterizing the active and total bacterial community, respectively. The diversity and biogeographic patterns differed substantially between the active and total bacterial communities. Although the composition of both the total and active bacterial community was strongly correlated with environmental factors and weakly correlated with geographic distance, the active bacterial community displayed higher environmental sensitivity than the total community and particularly a greater distance effect largely caused by the active assemblage from deep waters. The 16S rRNA vs. rDNA relationships indicated that the active bacteria were low in relative abundance in the SCS. This might be due to a high competition between active bacterial taxa as indicated by our community network models. Based on these analyses, we speculate that high competition could cause some dispersal limitation of the active bacterial community resulting in a distinct distance-decay relationship. Altogether, our results indicated that the biogeographic distribution of bacteria in the SCS is the result of both environmental control and distance decay. PMID:24684298

Distance-Based Functional Diversity Measures and Their Decomposition: A Framework Based on Hill Numbers

PubMed Central

Chiu, Chun-Huo; Chao, Anne

2014-01-01

Hill numbers (or the “effective number of species”) are increasingly used to characterize species diversity of an assemblage. This work extends Hill numbers to incorporate species pairwise functional distances calculated from species traits. We derive a parametric class of functional Hill numbers, which quantify “the effective number of equally abundant and (functionally) equally distinct species” in an assemblage. We also propose a class of mean functional diversity (per species), which quantifies the effective sum of functional distances between a fixed species to all other species. The product of the functional Hill number and the mean functional diversity thus quantifies the (total) functional diversity, i.e., the effective total distance between species of the assemblage. The three measures (functional Hill numbers, mean functional diversity and total functional diversity) quantify different aspects of species trait space, and all are based on species abundance and species pairwise functional distances. When all species are equally distinct, our functional Hill numbers reduce to ordinary Hill numbers. When species abundances are not considered or species are equally abundant, our total functional diversity reduces to the sum of all pairwise distances between species of an assemblage. The functional Hill numbers and the mean functional diversity both satisfy a replication principle, implying the total functional diversity satisfies a quadratic replication principle. When there are multiple assemblages defined by the investigator, each of the three measures of the pooled assemblage (gamma) can be multiplicatively decomposed into alpha and beta components, and the two components are independent. The resulting beta component measures pure functional differentiation among assemblages and can be further transformed to obtain several classes of normalized functional similarity (or differentiation) measures, including N-assemblage functional generalizations of the classic Jaccard, Sørensen, Horn and Morisita-Horn similarity indices. The proposed measures are applied to artificial and real data for illustration. PMID:25000299

Distance-based functional diversity measures and their decomposition: a framework based on Hill numbers.

PubMed

Chiu, Chun-Huo; Chao, Anne

2014-01-01

Hill numbers (or the "effective number of species") are increasingly used to characterize species diversity of an assemblage. This work extends Hill numbers to incorporate species pairwise functional distances calculated from species traits. We derive a parametric class of functional Hill numbers, which quantify "the effective number of equally abundant and (functionally) equally distinct species" in an assemblage. We also propose a class of mean functional diversity (per species), which quantifies the effective sum of functional distances between a fixed species to all other species. The product of the functional Hill number and the mean functional diversity thus quantifies the (total) functional diversity, i.e., the effective total distance between species of the assemblage. The three measures (functional Hill numbers, mean functional diversity and total functional diversity) quantify different aspects of species trait space, and all are based on species abundance and species pairwise functional distances. When all species are equally distinct, our functional Hill numbers reduce to ordinary Hill numbers. When species abundances are not considered or species are equally abundant, our total functional diversity reduces to the sum of all pairwise distances between species of an assemblage. The functional Hill numbers and the mean functional diversity both satisfy a replication principle, implying the total functional diversity satisfies a quadratic replication principle. When there are multiple assemblages defined by the investigator, each of the three measures of the pooled assemblage (gamma) can be multiplicatively decomposed into alpha and beta components, and the two components are independent. The resulting beta component measures pure functional differentiation among assemblages and can be further transformed to obtain several classes of normalized functional similarity (or differentiation) measures, including N-assemblage functional generalizations of the classic Jaccard, Sørensen, Horn and Morisita-Horn similarity indices. The proposed measures are applied to artificial and real data for illustration.

The metabolic power and energetic demands of elite Gaelic football match play.

PubMed

Malone, Shane; Solan, Barry; Collins, Kieran; Doran, Dominic

2017-05-01

Metabolic power has not yet been investigated within elite Gaelic football. The aim of the current investigation was to compare the metabolic power demands between positional groups and examine the temporal profile of elite Gaelic football match play. Global positional satellite system (GPS) data were collected from 50 elite Gaelic football players from 4 inter-county teams during 35 elite competitive matches over a three season period. A total of 351 complete match samples were obtained for final analysis. Players were categorized based on positional groups; full-back, half-back, midfield, half-forward and full-forward. Instantaneous raw velocity data was obtained from the GPS and exported to a customized spreadsheet which provided estimations of both speed based, derived metabolic power and energy expenditure variables (total distance, high speed distance, average metabolic power, high power distance and total energy expenditure). Match mean distance was 9222±1588 m, reflective of an average metabolic power of 9.5-12.5 W·kg-1, with an average energy expenditure of 58-70 Kj·kg-1 depending on position. There were significant differences between positional groups for both speed-based and metabolic power indices. Midfielders covered more total and high-speed distance, as well as greater average and overall energy expenditure compared to other positions (P<0.001). A reduction in total, high-speed, and high-power distance, as well as average metabolic power throughout the match (P<0.001) was observed. Positional differences exist for both metabolic power and traditional running based variables. The middle three positions (midfield, half-back and half-forward) possess greater activity profiles when compared to other positional groups. The reduction in metabolic power and traditional running based variables are comparable across match play. The current study demonstrates that metabolic power may contribute to our understanding of Gaelic football match-play.

Quantitative social dialectology: explaining linguistic variation geographically and socially.

PubMed

Wieling, Martijn; Nerbonne, John; Baayen, R Harald

2011-01-01

In this study we examine linguistic variation and its dependence on both social and geographic factors. We follow dialectometry in applying a quantitative methodology and focusing on dialect distances, and social dialectology in the choice of factors we examine in building a model to predict word pronunciation distances from the standard Dutch language to 424 Dutch dialects. We combine linear mixed-effects regression modeling with generalized additive modeling to predict the pronunciation distance of 559 words. Although geographical position is the dominant predictor, several other factors emerged as significant. The model predicts a greater distance from the standard for smaller communities, for communities with a higher average age, for nouns (as contrasted with verbs and adjectives), for more frequent words, and for words with relatively many vowels. The impact of the demographic variables, however, varied from word to word. For a majority of words, larger, richer and younger communities are moving towards the standard. For a smaller minority of words, larger, richer and younger communities emerge as driving a change away from the standard. Similarly, the strength of the effects of word frequency and word category varied geographically. The peripheral areas of the Netherlands showed a greater distance from the standard for nouns (as opposed to verbs and adjectives) as well as for high-frequency words, compared to the more central areas. Our findings indicate that changes in pronunciation have been spreading (in particular for low-frequency words) from the Hollandic center of economic power to the peripheral areas of the country, meeting resistance that is stronger wherever, for well-documented historical reasons, the political influence of Holland was reduced. Our results are also consistent with the theory of lexical diffusion, in that distances from the Hollandic norm vary systematically and predictably on a word by word basis.

Incompleteness and limit of security theory of quantum key distribution

NASA Astrophysics Data System (ADS)

Hirota, Osamu; Murakami, Dan; Kato, Kentaro; Futami, Fumio

2012-10-01

It is claimed in the many papers that a trace distance: d guarantees the universal composition security in quantum key distribution (QKD) like BB84 protocol. In this introduction paper, at first, it is explicitly explained what is the main misconception in the claim of the unconditional security for QKD theory. In general terms, the cause of the misunderstanding on the security claim is the Lemma in the paper of Renner. It suggests that the generation of the perfect random key is assured by the probability (1-d), and its failure probability is d. Thus, it concludes that the generated key provides the perfect random key sequence when the protocol is success. So the QKD provides perfect secrecy to the one time pad. This is the reason for the composition claim. However, the quantity of the trace distance (or variational distance) is not the probability for such an event. If d is not small enough, always the generated key sequence is not uniform. Now one needs the reconstruction of the evaluation of the trace distance if one wants to use it. One should first go back to the indistinguishability theory in the computational complexity based, and to clarify the meaning of the value of the variational distance. In addition, the same analysis for the information theoretic case is necessary. The recent serial papers by H.P.Yuen have given the answer on such questions. In this paper, we show more concise description of Yuen's theory, and clarify that the upper bound theories for the trace distance by Tomamichel et al and Hayashi et al are constructed by the wrong reasoning of Renner and it is unsuitable as the security analysis. Finally, we introduce a new macroscopic quantum communication to replace Q-bit QKD.

Quantitative Social Dialectology: Explaining Linguistic Variation Geographically and Socially

PubMed Central

Wieling, Martijn; Nerbonne, John; Baayen, R. Harald

2011-01-01

In this study we examine linguistic variation and its dependence on both social and geographic factors. We follow dialectometry in applying a quantitative methodology and focusing on dialect distances, and social dialectology in the choice of factors we examine in building a model to predict word pronunciation distances from the standard Dutch language to 424 Dutch dialects. We combine linear mixed-effects regression modeling with generalized additive modeling to predict the pronunciation distance of 559 words. Although geographical position is the dominant predictor, several other factors emerged as significant. The model predicts a greater distance from the standard for smaller communities, for communities with a higher average age, for nouns (as contrasted with verbs and adjectives), for more frequent words, and for words with relatively many vowels. The impact of the demographic variables, however, varied from word to word. For a majority of words, larger, richer and younger communities are moving towards the standard. For a smaller minority of words, larger, richer and younger communities emerge as driving a change away from the standard. Similarly, the strength of the effects of word frequency and word category varied geographically. The peripheral areas of the Netherlands showed a greater distance from the standard for nouns (as opposed to verbs and adjectives) as well as for high-frequency words, compared to the more central areas. Our findings indicate that changes in pronunciation have been spreading (in particular for low-frequency words) from the Hollandic center of economic power to the peripheral areas of the country, meeting resistance that is stronger wherever, for well-documented historical reasons, the political influence of Holland was reduced. Our results are also consistent with the theory of lexical diffusion, in that distances from the Hollandic norm vary systematically and predictably on a word by word basis. PMID:21912639

[Changes in the distance between carina and orotracheal tube during open or videolaparoscopic bariatric surgery].

PubMed

de Figueiredo Locks, Giovani; Simões de Almeida, Maria Cristina; Sperotto Ceccon, Maurício; Campos Pastório, Karen Adriana

2015-01-01

To examine whether there are changes in the distance between the orotracheal tubeand carina induced by orthostatic retractor placement or by pneumoperitoneum insufflation in obese patients undergoing gastroplasty. 60 patients undergoing bariatric surgery by two techniques: open (G1) or videola-paroscopic (G2) gastroplasty were studied. After tracheal intubation, adequate ventilation of both hemitoraxes was confirmed by lung auscultation. The distance orotracheal tube-carina was estimated with the use of a fiber bronchoscope before and after installation of orthostatic retractors in G1 or before and after insufflation of pneumoperitoneum in patients in G2. G1 was composed of 22 and G2 of 38 patients. No cases of endobronchial intubationwere detected in either group. The mean orotracheal tube-carina distance variation was estimated in -0.03 cm (95% CI 0.06 to -0.13) in the group of patients undergoing open gastroplastyand in -0.42 cm (95% CI -0.56 to -1.4) in the group of patients undergoing videolaparoscopic gastroplasty. The extremes of variation in each group were: 0.5 cm to -1.6 cm in patients under-going open surgery and 0.1 cm to -2.2 cm in patients undergoing videolaparoscopic surgery. There was no significant change in orotracheal tube-CA distance after placementof orthostatic retractors in patients undergoing open gastroplasty. There was a reduction inorotracheal tube-CA distance after insufflation of pneumoperitoneum in patients undergoing videolaparoscopic gastroplasty. We recommend attention to lung auscultation and to signals of ventilation monitoring and reevaluation of orotracheal tube placement after peritoneal insufflation. Copyright © 2014 Sociedade Brasileira de Anestesiologia. Publicado por Elsevier Editora Ltda. All rights reserved.

Changes in the distance between carina and orotracheal tube during open or videolaparoscopic bariatric surgery.

PubMed

de Figueiredo Locks, Giovani; Simões de Almeida, Maria Cristina; Sperotto Ceccon, Maurício; Campos Pastório, Karen Adriana

2015-01-01

To examine whether there are changes in the distance between the orotracheal tube and carina induced by orthostatic retractor placement or by pneumoperitoneum insufflation in obese patients undergoing gastroplasty. 60 patients undergoing bariatric surgery by two techniques: open (G1) or videolaparoscopic (G2) gastroplasty were studied. After tracheal intubation, adequate ventilation of both hemitoraxes was confirmed by lung auscultation. The distance orotracheal tube-carina was estimated with the use of a fiber bronchoscope before and after installation of orthostatic retractors in G1 or before and after insufflation of pneumoperitoneum in patients in G2. G1 was composed of 22 and G2 of 38 patients. No cases of endobronchial intubation were detected in either group. The mean orotracheal tube-carina distance variation was estimated in -0.03cm (95% CI 0.06 to -0.13) in the group of patients undergoing open gastroplasty and in -0.42cm (95% CI -0.56 to -1.4) in the group of patients undergoing videolaparoscopic gastroplasty. The extremes of variation in each group were: 0.5cm to -1.6cm in patients undergoing open surgery and 0.1cm to -2.2cm in patients undergoing videolaparoscopic surgery. There was no significant change in orotracheal tube-CA distance after placement of orthostatic retractors in patients undergoing open gastroplasty. There was a reduction in orotracheal tube-CA distance after insufflation of pneumoperitoneum in patients undergoing videolaparoscopic gastroplasty. We recommend attention to lung auscultation and to signals of ventilation monitoring and reevaluation of orotracheal tube placement after peritoneal insufflation. Copyright © 2014 Sociedade Brasileira de Anestesiologia. Published by Elsevier Editora Ltda. All rights reserved.

A spatial analysis of variations in health access: linking geography, socio-economic status and access perceptions

PubMed Central

2011-01-01

Background This paper analyses the relationship between public perceptions of access to general practitioners (GPs) surgeries and hospitals against health status, car ownership and geographic distance. In so doing it explores the different dimensions associated with facility access and accessibility. Methods Data on difficulties experienced in accessing health services, respondent health status and car ownership were collected through an attitudes survey. Road distances to the nearest service were calculated for each respondent using a GIS. Difficulty was related to geographic distance, health status and car ownership using logistic generalized linear models. A Geographically Weighted Regression (GWR) was used to explore the spatial non-stationarity in the results. Results Respondent long term illness, reported bad health and non-car ownership were found to be significant predictors of difficulty in accessing GPs and hospitals. Geographic distance was not a significant predictor of difficulty in accessing hospitals but was for GPs. GWR identified the spatial (local) variation in these global relationships indicating locations where the predictive strength of the independent variables was higher or lower than the global trend. The impacts of bad health and non-car ownership on the difficulties experienced in accessing health services varied spatially across the study area, whilst the impacts of geographic distance did not. Conclusions Difficulty in accessing different health facilities was found to be significantly related to health status and car ownership, whilst the impact of geographic distance depends on the service in question. GWR showed how these relationships were varied across the study area. This study demonstrates that the notion of access is a multi-dimensional concept, whose composition varies with location, according to the facility being considered and the health and socio-economic status of the individual concerned. PMID:21787394

Novel device (AirWave) to assess endotracheal tube migration: a pilot study.

PubMed

Nacheli, Gustavo Cumbo; Sharma, Manish; Wang, Xiaofeng; Gupta, Amit; Guzman, Jorge A; Tonelli, Adriano R

2013-08-01

Little is known about endotracheal tube (ETT) migration during routine care among critically ill patients. AirWave is a novel device that uses sonar waves to measure ETT migration and obstructions in real time. The aim of the present study is to assess the accuracy of the AirWave to evaluate ETT migration. In addition, we determined the degree of variation in ETT position and tested whether more pronounced migration occurs in specific clinical scenarios. After institutional review board approval, we included mechanically ventilated patients from February 2012 to May 2012. A chest radiography (CXR) was obtained at baseline and 24 hours when clinically indicated. The ETT distance at the lips was recorded at baseline and every 4 hours. The AirWave system continuously recorded ETT position changes from baseline, and luminal obstructions. A total of 42 patients (age: 61 [SD ±13] years, men: 52%) were recruited. A total of 19 patients had measurements of ETT migration at 24 hours by the 3 methodologies used in this study. The mean (SD) of the ETT migration at 24 hours was +0.04 (1.2), -0.42 (0.7) and +0.34 (1.81) cm when measured by portable CXR, ETT distance at the teeth and AirWave device, respectively. Bland-Altman analysis of tube migration at 24 hours comparing the AirWave with CXR readings showed a bias of 0.1 cm with 95% limit of agreement of -3.8 and +4.3 cm. Comparison of tube migration at 24 hours determined by AirWave with ETT distance at the lips revealed a bias of -0.4 with 95% limit of agreement -3.7 to +3 cm, similar to the values observed between CXR and ETT distance at the lips (bias of -0.3 cm, 95% limit of agreement of -3.4 to +2.8 cm). Factors associated with ETT migration at 24 hours were ETT size and initial measurement from ETT tip to carina by portable CXR. AirWave detected in eight patients some degree of ETT obstruction (30% ± 9.6%) that resolved with prompt ETT catheter suction. The AirWave may provide useful information regarding ETT migration and obstruction in real time. Copyright © 2013 Elsevier Inc. All rights reserved.

Structural covariance of brain region volumes is associated with both structural connectivity and transcriptomic similarity.

PubMed

Yee, Yohan; Fernandes, Darren J; French, Leon; Ellegood, Jacob; Cahill, Lindsay S; Vousden, Dulcie A; Spencer Noakes, Leigh; Scholz, Jan; van Eede, Matthijs C; Nieman, Brian J; Sled, John G; Lerch, Jason P

2018-05-18

An organizational pattern seen in the brain, termed structural covariance, is the statistical association of pairs of brain regions in their anatomical properties. These associations, measured across a population as covariances or correlations usually in cortical thickness or volume, are thought to reflect genetic and environmental underpinnings. Here, we examine the biological basis of structural volume covariance in the mouse brain. We first examined large scale associations between brain region volumes using an atlas-based approach that parcellated the entire mouse brain into 318 regions over which correlations in volume were assessed, for volumes obtained from 153 mouse brain images via high-resolution MRI. We then used a seed-based approach and determined, for 108 different seed regions across the brain and using mouse gene expression and connectivity data from the Allen Institute for Brain Science, the variation in structural covariance data that could be explained by distance to seed, transcriptomic similarity to seed, and connectivity to seed. We found that overall, correlations in structure volumes hierarchically clustered into distinct anatomical systems, similar to findings from other studies and similar to other types of networks in the brain, including structural connectivity and transcriptomic similarity networks. Across seeds, this structural covariance was significantly explained by distance (17% of the variation, up to a maximum of 49% for structural covariance to the visceral area of the cortex), transcriptomic similarity (13% of the variation, up to maximum of 28% for structural covariance to the primary visual area) and connectivity (15% of the variation, up to a maximum of 36% for structural covariance to the intermediate reticular nucleus in the medulla) of covarying structures. Together, distance, connectivity, and transcriptomic similarity explained 37% of structural covariance, up to a maximum of 63% for structural covariance to the visceral area. Additionally, this pattern of explained variation differed spatially across the brain, with transcriptomic similarity playing a larger role in the cortex than subcortex, while connectivity explains structural covariance best in parts of the cortex, midbrain, and hindbrain. These results suggest that both gene expression and connectivity underlie structural volume covariance, albeit to different extents depending on brain region, and this relationship is modulated by distance. Copyright © 2018. Published by Elsevier Inc.

Phylogeography and conservation genetics of Hygrophila pogonocalyx (Acanthaceae) based on atpB-rbcL noncoding spacer cpDNA.

PubMed

Huang, Jao-Ching; Wang, Wei-Kuang; Peng, Ching-I; Chiang, Tzen-Yuh

2005-02-01

Genetic variation in the atpB-rbcL intergenic spacer region of chloroplast DNA (cpDNA) was investigated in Hygrophila pogonocalyx Hayata (Acanthaceae), an endangered and endemic species in Taiwan. In this aquatic species, seed dispersal from capsules via elasticity is constrained by gravity and is thereby confined within populations, resulting in limited gene flow between populations. In this study, a total of 849 bp of the cpDNA atpB-rbcL spacer were sequenced from eight populations of H. pogonocalyx. Nucleotide diversity in the cpDNA is low (theta = 0.00343+/-0.00041). The distribution of genetic variation among populations agrees with an "isolation-by-distance" model. Two geographically correlated groups, the western and eastern regions, were identified in a neighbor-joining tree and a minimum-spanning network. Phylogeographical analyses based on the cpDNA network suggest that the present-day differentiation between western and eastern groups of H. pogonocalyx resulted from past fragmentation. The differentiation between eastern and western populations may be ascribed to isolation since the formation of the Central Mountain Range about 5 million years ago, which is consistent with the rate estimates based on a molecular clock of cpDNA.

Essential oil variation among natural populations of Lavandula multifida L. (Lamiaceae).

PubMed

Chograni, Hnia; Zaouali, Yosr; Rajeb, Chayma; Boussaid, Mohamed

2010-04-01

Volatiles from twelve wild Tunisian populations of Lavandula multifida L. growing in different bioclimatic zones were assessed by GC (RI) and GC/MS. Thirty-six constituents, representing 83.48% of the total oil were identified. The major components at the species level were carvacrol (31.81%), beta-bisabolene (14.89%), and acrylic acid dodecyl ester (11.43%). These volatiles, together with alpha-pinene, were also the main compounds discriminating the populations. According to these dominant compounds, one chemotype was revealed, a carvacrol/beta-bisabolene/acrylic acid dodecyl ester chemotype. However, a significant variation among the populations was observed for the majority of the constituents. A high chemical-population structure, estimated both by principal component analysis (PCA) and unweighted pair group method with averaging (UPGMA) cluster analysis based on Euclidean distances, was observed. Both methods allowed separation of the populations in three groups defined rather by minor than by major compounds. The population groups were not strictly concordant with their bioclimatic or geographic location. Conservation strategies should concern all populations, because of their low size and their high level of destruction. Populations exhibiting particular compounds other than the major ones should be protected first.

Sequence Polymorphisms and Structural Variations among Four Grapevine (Vitis vinifera L.) Cultivars Representing Sardinian Agriculture

PubMed Central

Mercenaro, Luca; Nieddu, Giovanni; Porceddu, Andrea; Pezzotti, Mario; Camiolo, Salvatore

2017-01-01

The genetic diversity among grapevine (Vitis vinifera L.) cultivars that underlies differences in agronomic performance and wine quality reflects the accumulation of single nucleotide polymorphisms (SNPs) and small indels as well as larger genomic variations. A combination of high throughput sequencing and mapping against the grapevine reference genome allows the creation of comprehensive sequence variation maps. We used next generation sequencing and bioinformatics to generate an inventory of SNPs and small indels in four widely cultivated Sardinian grape cultivars (Bovale sardo, Cannonau, Carignano and Vermentino). More than 3,200,000 SNPs were identified with high statistical confidence. Some of the SNPs caused the appearance of premature stop codons and thus identified putative pseudogenes. The analysis of SNP distribution along chromosomes led to the identification of large genomic regions with uninterrupted series of homozygous SNPs. We used a digital comparative genomic hybridization approach to identify 6526 genomic regions with significant differences in copy number among the four cultivars compared to the reference sequence, including 81 regions shared between all four cultivars and 4953 specific to single cultivars (representing 1.2 and 75.9% of total copy number variation, respectively). Reads mapping at a distance that was not compatible with the insert size were used to identify a dataset of putative large deletions with cultivar Cannonau revealing the highest number. The analysis of genes mapping to these regions provided a list of candidates that may explain some of the phenotypic differences among the Bovale sardo, Cannonau, Carignano and Vermentino cultivars. PMID:28775732

Genetic variation and evolution of Polaskia chichipe (Cactaceae) under domestication in the Tehuacán Valley, central Mexico.

PubMed

Otero-Arnaiz, Adriana; Casas, Alejandro; Hamrick, James L; Cruse-Sanders, Jennifer

2005-05-01

Polaskia chichipe is a columnar cactus under artificial selection in central Mexico because of its edible fruits. Our study explored the effect of human manipulation on levels and distribution of genetic variation in wild, silviculturally managed and cultivated sympatric populations. Total genetic variation, estimated in nine populations with five microsatellite loci, was H(T) = 0.658 +/- 0.026 SE, which was mainly distributed within populations (H(S) = 0.646) with low differentiation among them (F(ST) = 0.015). Fixation index (F(IS)) in all populations was positive, indicating a deficit of heterozygous individuals with respect to Hardy-Weinberg expectations. When populations were pooled by management type, the highest expected heterozygosity (H(E) = 0.631 +/- 0.031 SE) and the lowest fixation index (F(IS) = 0.07) were observed in wild populations, followed by cultivated populations (H(E) = 0.56 +/- 0.03 SE, F(IS) = 0.14), whereas the lowest variation was found in silviculturally managed populations (H(E) = 0.51 +/- 0.05 SE, F(IS) = 0.17). Low differentiation among populations under different management types (F(ST) 0.005, P < 0.04) was observed. A pattern of migration among neighbouring populations, suggested from isolation by distance (r2 = 0.314, P < 0.01), may have contributed to homogenizing populations and counteracting the effects of artificial selection. P. chichipe, used and managed for at least 700 generations, shows morphological differentiation, changes in breeding system and seed germination patterns associated with human management, with only slight genetic differences detected by neutral markers.

The density of cometary protons upstream of Comet Halley's bow shock

NASA Astrophysics Data System (ADS)

Neugebauer, M.; Goldstein, B. E.; Balsiger, H.; Neubauer, F. M.; Schwenn, R.; Shelley, E. G.

1989-02-01

Cometary protons picked up by the solar wind were detected by the high energy range spectrometer of the Giotto ion mass spectrometer starting at a cometocentric distance of about 12 million km. On the average, the density of cometary protons varied approximately as the inverse square of the cometocentric distance, reaching a value of 0.11/cu cm just outside the bow shock. The data can be successfully fit to models that include substantial amounts of both slow (1 km/s) and fast (8 km/s or greater) H atoms beyond the bow shock. Large local variations in the density of picked-up protons can be explained on the basis of variations in the direction of the interplanetary magnetic field in upstream regions where pitch angle scattering was weak.

Finding Semirigid Domains in Biomolecules by Clustering Pair-Distance Variations

PubMed Central

Schreiner, Wolfgang

2014-01-01

Dynamic variations in the distances between pairs of atoms are used for clustering subdomains of biomolecules. We draw on a well-known target function for clustering and first show mathematically that the assignment of atoms to clusters has to be crisp, not fuzzy, as hitherto assumed. This reduces the computational load of clustering drastically, and we demonstrate results for several biomolecules relevant in immunoinformatics. Results are evaluated regarding the number of clusters, cluster size, cluster stability, and the evolution of clusters over time. Crisp clustering lends itself as an efficient tool to locate semirigid domains in the simulation of biomolecules. Such domains seem crucial for an optimum performance of subsequent statistical analyses, aiming at detecting minute motional patterns related to antigen recognition and signal transduction. PMID:24959586

Integrating Compact Constraint and Distance Regularization with Level Set for Hepatocellular Carcinoma (HCC) Segmentation on Computed Tomography (CT) Images

NASA Astrophysics Data System (ADS)

Gui, Luying; He, Jian; Qiu, Yudong; Yang, Xiaoping

2017-01-01

This paper presents a variational level set approach to segment lesions with compact shapes on medical images. In this study, we investigate to address the problem of segmentation for hepatocellular carcinoma which are usually of various shapes, variable intensities, and weak boundaries. An efficient constraint which is called the isoperimetric constraint to describe the compactness of shapes is applied in this method. In addition, in order to ensure the precise segmentation and stable movement of the level set, a distance regularization is also implemented in the proposed variational framework. Our method is applied to segment various hepatocellular carcinoma regions on Computed Tomography images with promising results. Comparison results also prove that the proposed method is more accurate than other two approaches.

Maternal effects on anogenital distance in a wild marmot population.

PubMed

Fouqueray, Timothée D; Blumstein, Daniel T; Monclús, Raquel; Martin, Julien G A

2014-01-01

In mammals, prenatal exposure to sex steroid hormones may have profound effects on later behavior and fitness and have been reported under both laboratory and field conditions. Anogenital distance is a non-invasive measure of prenatal exposure to sex steroid hormones. While we know that intra-uterine position and litter sex ratio influence anogenital distance, there are other, heretofore unstudied, factors that could influence anogenital distance, including maternal effects. We capitalized on a long-term study of wild yellow-bellied marmots (Marmota flaviventris) to study the importance of maternal effects on explaining variation in anogenital distance and found significant effects. The strength of these effects varied annually. Taken together, our data highlights the strong variability due to environmental effects, and illustrates the importance of additive genetic and maternal genetic effects on neonatal anogenital distance. We suspect that, as others apply recently popularised quantitative genetic techniques to study free-living populations, such effects will be identified in other systems.

Maternal Effects on Anogenital Distance in a Wild Marmot Population

PubMed Central

Fouqueray, Timothée D.; Blumstein, Daniel T.; Monclús, Raquel; Martin, Julien G. A.

2014-01-01

In mammals, prenatal exposure to sex steroid hormones may have profound effects on later behavior and fitness and have been reported under both laboratory and field conditions. Anogenital distance is a non-invasive measure of prenatal exposure to sex steroid hormones. While we know that intra-uterine position and litter sex ratio influence anogenital distance, there are other, heretofore unstudied, factors that could influence anogenital distance, including maternal effects. We capitalized on a long-term study of wild yellow-bellied marmots (Marmota flaviventris) to study the importance of maternal effects on explaining variation in anogenital distance and found significant effects. The strength of these effects varied annually. Taken together, our data highlights the strong variability due to environmental effects, and illustrates the importance of additive genetic and maternal genetic effects on neonatal anogenital distance. We suspect that, as others apply recently popularised quantitative genetic techniques to study free-living populations, such effects will be identified in other systems. PMID:24651864

Estimating plant distance in maize using Unmanned Aerial Vehicle (UAV).

PubMed

Zhang, Jinshui; Basso, Bruno; Price, Richard F; Putman, Gregory; Shuai, Guanyuan

2018-01-01

Distance between rows and plants are essential parameters that affect the final grain yield in row crops. This paper presents the results of research intended to develop a novel method to quantify the distance between maize plants at field scale using an Unmanned Aerial Vehicle (UAV). Using this method, we can recognize maize plants as objects and calculate the distance between plants. We initially developed our method by training an algorithm in an indoor facility with plastic corn plants. Then, the method was scaled up and tested in a farmer's field with maize plant spacing that exhibited natural variation. The results of this study demonstrate that it is possible to precisely quantify the distance between maize plants. We found that accuracy of the measurement of the distance between maize plants depended on the height above ground level at which UAV imagery was taken. This study provides an innovative approach to quantify plant-to-plant variability and, thereby final crop yield estimates.

Variation of distances from mid-urethra to the obturator foramen: an MRI study

PubMed Central

Doumouchtsis, Stergios K.; Berger, Mitchell B.; DeLancey, John O.

2013-01-01

Introduction and hypothesis To estimate distances from the mid-urethra to the obturator foramina and to explore correlations between pelvic dimensions and body height. Methods This is a secondary analysis of a parent case–control study on the mechanisms of stress urinary incontinence. We measured pelvic dimensions on magnetic resonance images of women with (cases, n=50) and without (controls, n=50) stress urinary incontinence. Results The mean distance from mid-urethra to the obturator membrane among cases is 31.8 mm (left) and 32.1 mm (right), with a range from 25.9 to 42.0 mm. There were no significant differences in these distances when comparing left with right, or cases with controls. Weak correlation was found between the urethra-to-obturator foramina distances and heights only in the case subjects. Conclusion There is high variability in the distance from mid-urethra to the obturator foramina. Height should not be used as a predictor of dimensions in the lesser pelvis. PMID:22543545

Species-distance relation for birds of the Solomon Archipelago, and the paradox of the great speciators

PubMed Central

Diamond, Jared M.; Gilpin, Michael E.; Mayr, Ernst

1976-01-01

For scattered remote islands and for likely forms of immigration and extinction curves, the equilibrium theory of island biogeography leads to the prediction [unk]2 log S/[unk]A[unk]D > 0, where S is the number of species on an island, A island area, and D island distance from the colonization source. This prediction is confirmed for birds of the Solomon Archipelago. Bird species can be classified into three types according to how distance affects their distributions: non-water-crossers, which are stopped completely (usually for psychological reasons) by water gaps of even 1 mile; short-distance colonists, successful at colonizing close but not remote islands; and long-distance colonists, successful at colonizing remote as well as close islands. Almost all of the “great speciators”, the species for whose inter-island geographic variation the Solomons are famous, prove to be short-distance colonists. Lack's interpretation of the decrease in S with D is shown to rest on incorrect assumptions. PMID:16592328

Variations in plasma wave intensity with distance along the electron foreshock boundary at Venus

NASA Technical Reports Server (NTRS)

Crawford, G. K.; Strangeway, R. J.; Russell, C. T.

1991-01-01

Plasma waves are observed in the solar wind upstream of the Venus bow shock by the Pioneer Venus Orbiter. These wave signatures occur during periods when the interplanetary magnetic field through the spacecraft position intersects the bow shock, thereby placing the spacecraft in the foreshock region. Wave intensity is analyzed as a function of distance along the electron foreshock boundary. It is found that the peak wave intensity may increase along the foreshock boundary from the tangent point to a maximum value at several Venus radii, then decrease in intensity with subsequent increase in distance. These observations could be associated with the instability process: the instability of the distribution function increasing with distance from the tangent point to saturation at the peak. Thermalization of the beam for distances beyond this point could reduce the distribution function instability resulting in weaker wave signatures.

Farfield inflight measurements of high-speed turboprop noise

NASA Technical Reports Server (NTRS)

Balombin, J. R.; Loeffler, I. J.

1983-01-01

A flight program was carried out to determine the variation of noise level with distance from a model high-speed propeller. Noise measurements were obtained at different distances from a SR-3 propeller mounted on a JetStar aircraft, with the test instrumentation mounted on a Learjet flown in formation. The propeller was operated at 0.8 m flight Mach number, 1.12 helical tip Mach number and at 0.7 flight Mach number, 1.0 helical tip Mach number. The instantaneous pressure from individual blades was observed to rise faster at the 0.8 flight speed, than at the 0.7 M flight speed. The measured levels appeared to decrease in good agreement with a 6 dB/doubling of distance decay, over the measurement range of approximately 16 m to 100 m distance. Further extrapolation, to the distances represented by a community, would suggest that the propagated levels during cruise would not cause a serious community annoyance.

Invertebrate Metacommunity Structure and Dynamics in an Andean Glacial Stream Network Facing Climate Change

PubMed Central

Cauvy-Fraunié, Sophie; Espinosa, Rodrigo; Andino, Patricio; Jacobsen, Dean; Dangles, Olivier

2015-01-01

Under the ongoing climate change, understanding the mechanisms structuring the spatial distribution of aquatic species in glacial stream networks is of critical importance to predict the response of aquatic biodiversity in the face of glacier melting. In this study, we propose to use metacommunity theory as a conceptual framework to better understand how river network structure influences the spatial organization of aquatic communities in glacierized catchments. At 51 stream sites in an Andean glacierized catchment (Ecuador), we sampled benthic macroinvertebrates, measured physico-chemical and food resource conditions, and calculated geographical, altitudinal and glaciality distances among all sites. Using partial redundancy analysis, we partitioned community variation to evaluate the relative strength of environmental conditions (e.g., glaciality, food resource) vs. spatial processes (e.g., overland, watercourse, and downstream directional dispersal) in organizing the aquatic metacommunity. Results revealed that both environmental and spatial variables significantly explained community variation among sites. Among all environmental variables, the glacial influence component best explained community variation. Overland spatial variables based on geographical and altitudinal distances significantly affected community variation. Watercourse spatial variables based on glaciality distances had a unique significant effect on community variation. Within alpine catchment, glacial meltwater affects macroinvertebrate metacommunity structure in many ways. Indeed, the harsh environmental conditions characterizing glacial influence not only constitute the primary environmental filter but also, limit water-borne macroinvertebrate dispersal. Therefore, glacier runoff acts as an aquatic dispersal barrier, isolating species in headwater streams, and preventing non-adapted species to colonize throughout the entire stream network. Under a scenario of glacier runoff decrease, we expect a reduction in both environmental filtering and dispersal limitation, inducing a taxonomic homogenization of the aquatic fauna in glacierized catchments as well as the extinction of specialized species in headwater groundwater and glacier-fed streams, and consequently an irreversible reduction in regional diversity. PMID:26308853

Advances in Time-Distance Helioseismology

NASA Technical Reports Server (NTRS)

Duvall, Thomas L., Jr.; Beck, John G.; Gizon, Laurent; Kosovichev, Alexander F.; Oegerle, William (Technical Monitor)

2002-01-01

Time-distance helioseismology is a way to measure travel times between surface locations for waves traversing the solar interior. Coupling the travel with an extensive modeling effort has proven to be a powerful tool for measuring flows and other wave speed inhomogeneities in the solar interior. Problems receiving current attention include studying the time variation of the meridional circulation and torsional oscillation and active region emergence and evolution, current results on these topics will be presented.

Selection of a DNA barcode for Nectriaceae from fungal whole-genomes.

PubMed

Zeng, Zhaoqing; Zhao, Peng; Luo, Jing; Zhuang, Wenying; Yu, Zhihe

2012-01-01

A DNA barcode is a short segment of sequence that is able to distinguish species. A barcode must ideally contain enough variation to distinguish every individual species and be easily obtained. Fungi of Nectriaceae are economically important and show high species diversity. To establish a standard DNA barcode for this group of fungi, the genomes of Neurospora crassa and 30 other filamentous fungi were compared. The expect value was treated as a criterion to recognize homologous sequences. Four candidate markers, Hsp90, AAC, CDC48, and EF3, were tested for their feasibility as barcodes in the identification of 34 well-established species belonging to 13 genera of Nectriaceae. Two hundred and fifteen sequences were analyzed. Intra- and inter-specific variations and the success rate of PCR amplification and sequencing were considered as important criteria for estimation of the candidate markers. Ultimately, the partial EF3 gene met the requirements for a good DNA barcode: No overlap was found between the intra- and inter-specific pairwise distances. The smallest inter-specific distance of EF3 gene was 3.19%, while the largest intra-specific distance was 1.79%. In addition, there was a high success rate in PCR and sequencing for this gene (96.3%). CDC48 showed sufficiently high sequence variation among species, but the PCR and sequencing success rate was 84% using a single pair of primers. Although the Hsp90 and AAC genes had higher PCR and sequencing success rates (96.3% and 97.5%, respectively), overlapping occurred between the intra- and inter-specific variations, which could lead to misidentification. Therefore, we propose the EF3 gene as a possible DNA barcode for the nectriaceous fungi.

The Farther the Better: Effects of Multiple Environmental Variables on Reef Fish Assemblages along a Distance Gradient from River Influences.

PubMed

Neves, Leonardo M; Teixeira-Neves, Tatiana P; Pereira-Filho, Guilherme H; Araújo, Francisco G

2016-01-01

The conservation and management of site-attached assemblages of coastal reefs are particularly challenging because of the tremendous environmental variation that exists at small spatial scales. In this sense, understanding the primary sources of variation in spatial patterns of the biota is fundamental for designing effective conservation policies. We investigated spatial variation in fish assemblages around the windward and leeward sides of coastal islands situated across a gradient of riverine influence (13 km in length). Specifically, relationships between rocky reef fish assemblages and benthic, topographic and physical predictors were assessed. We hypothesized that river induced disturbances may overcome local habitat features in modeling spatial patterns of fish distribution. Fish assemblages varied primarily due to the strong directional gradient of riverine influence (22.6% of the estimated components of variation), followed by topographic complexity (15%), wave exposure (9.9%), and benthic cover (8%). The trophic structure of fish assemblages changed from having a high abundance of invertebrate feeders in macroalgae-dominated reefs close to river mouths to a high proportion of herbivores, planktivores and invertebrate feeder species in reefs with large boulders covered by epilithic algal matrices, as the distance from rivers increased. This gradient led to an increase of 4.5-fold in fish richness and fish trophic group diversity, 11-fold in fish biomass and 10-fold in fish abundance. Our results have implications for the conservation and monitoring of assemblages patchily distributed at small spatial scales. The major role of distance from river influences on fish assemblages rather than benthic cover and topographic complexity suggest that managing land-based activities should be a conservation priority toward reef restoration.

The Farther the Better: Effects of Multiple Environmental Variables on Reef Fish Assemblages along a Distance Gradient from River Influences

PubMed Central

Neves, Leonardo M.; Teixeira-Neves, Tatiana P.; Pereira-Filho, Guilherme H.; Araújo, Francisco G.

2016-01-01

The conservation and management of site-attached assemblages of coastal reefs are particularly challenging because of the tremendous environmental variation that exists at small spatial scales. In this sense, understanding the primary sources of variation in spatial patterns of the biota is fundamental for designing effective conservation policies. We investigated spatial variation in fish assemblages around the windward and leeward sides of coastal islands situated across a gradient of riverine influence (13 km in length). Specifically, relationships between rocky reef fish assemblages and benthic, topographic and physical predictors were assessed. We hypothesized that river induced disturbances may overcome local habitat features in modeling spatial patterns of fish distribution. Fish assemblages varied primarily due to the strong directional gradient of riverine influence (22.6% of the estimated components of variation), followed by topographic complexity (15%), wave exposure (9.9%), and benthic cover (8%). The trophic structure of fish assemblages changed from having a high abundance of invertebrate feeders in macroalgae-dominated reefs close to river mouths to a high proportion of herbivores, planktivores and invertebrate feeder species in reefs with large boulders covered by epilithic algal matrices, as the distance from rivers increased. This gradient led to an increase of 4.5-fold in fish richness and fish trophic group diversity, 11-fold in fish biomass and 10-fold in fish abundance. Our results have implications for the conservation and monitoring of assemblages patchily distributed at small spatial scales. The major role of distance from river influences on fish assemblages rather than benthic cover and topographic complexity suggest that managing land-based activities should be a conservation priority toward reef restoration. PMID:27907017

The use of anaphoric pronouns by French children in narrative: evidence from constrained text production.

PubMed

Millogo, Victor Emmanuel

2005-05-01

This paper describes the acquisition of the 3rd person pronoun 'il/elle' (he, she, it) in seven to twelve-year-old French children (N = 58), in written production. An experiment was conducted to examine the relationship between the use of this anaphoric pronoun and the accessibility of the memory-trace of the corresponding referent in the texts. Referential accessibility in short texts was varied according to three factors: referential distance, thematization of the agent role (first sentence subject), and discourse focus. We found that the children were sensitive to the distance factor as early as 7;0, i.e. they used fewer personal pronouns when the referential distance increased. However, children of different ages differed in their weighting of the discourse focus factor and the thematization factor: the seven-year-olds (N = 18) and the eleven-year-olds (N = 20) were sensitive to variation of the discourse focus but not the thematization factor, while for the nine-year-olds (N = 20) it was the reverse. The main results suggest: (a) when seven and nine-year-olds use the pronoun 'il/elle', they do not comply with the constraints associated with the accessibility of the memory-trace of the referent; (b) memory constraints have an effect from the age of 7;0, but only when the discourse focus is maintained. It was concluded that the discourse management of the French personal pronoun 'il/elle' is not totally mastered at 11;0: children cannot operationally integrate the whole array of constraints implied in anaphoric management.

The food retail environment and area deprivation in Glasgow City, UK

PubMed Central

Macdonald, Laura; Ellaway, Anne; Macintyre, Sally

2009-01-01

It has previously been suggested that deprived neighbourhoods within modern cities have poor access to general amenities, for example, fewer food retail outlets. Here we examine the distribution of food retailers by deprivation in the City of Glasgow, UK. We obtained a list of 934 food retailers in Glasgow, UK, in 2007, and mapped these at address level. We categorised small areas (data zones) into quintiles of area deprivation using the 2006 Scottish Index of Multiple Deprivation Income sub-domain score. We computed mean number of retailers per 1000 residents per data zone, and mean network distance to nearest outlet from data zone centroid, for all retailers combined and for each of seven categories of retailer separately (i.e. bakers, butchers, fruit and vegetable sellers, fishmongers, convenience stores, supermarkets and delicatessens). The most deprived quintile (of areas) had the greatest mean number of total food retailers per 1000 residents while quintile 1 (least deprived) had the least, and this difference was statistically significant (Chi-square p < 0.01). The closest mean distance to the nearest food retailer was within quintile 3 while the furthest distance was within quintile 1, and this was also statistically significant (Chi-square p < 0.01). There was variation in the distribution of the seven different types of food retailers, and access to amenities depended upon the type of food retailer studied and whether proximity or density was measured. Overall the findings suggested that deprived neighbourhoods within the City of Glasgow did not necessarily have fewer food retail outlets. PMID:19660114

The food retail environment and area deprivation in Glasgow City, UK.

PubMed

Macdonald, Laura; Ellaway, Anne; Macintyre, Sally

2009-08-06

It has previously been suggested that deprived neighbourhoods within modern cities have poor access to general amenities, for example, fewer food retail outlets. Here we examine the distribution of food retailers by deprivation in the City of Glasgow, UK.We obtained a list of 934 food retailers in Glasgow, UK, in 2007, and mapped these at address level. We categorised small areas (data zones) into quintiles of area deprivation using the 2006 Scottish Index of Multiple Deprivation Income sub-domain score. We computed mean number of retailers per 1000 residents per data zone, and mean network distance to nearest outlet from data zone centroid, for all retailers combined and for each of seven categories of retailer separately (i.e. bakers, butchers, fruit and vegetable sellers, fishmongers, convenience stores, supermarkets and delicatessens).The most deprived quintile (of areas) had the greatest mean number of total food retailers per 1000 residents while quintile 1 (least deprived) had the least, and this difference was statistically significant (Chi-square p < 0.01). The closest mean distance to the nearest food retailer was within quintile 3 while the furthest distance was within quintile 1, and this was also statistically significant (Chi-square p < 0.01). There was variation in the distribution of the seven different types of food retailers, and access to amenities depended upon the type of food retailer studied and whether proximity or density was measured. Overall the findings suggested that deprived neighbourhoods within the City of Glasgow did not necessarily have fewer food retail outlets.

Significance of localization of mandibular foramen in an inferior alveolar nerve block

PubMed Central

Thangavelu, K.; Kannan, R.; Kumar, N. Senthil; Rethish, E.; Sabitha, S.; SayeeGanesh, N.

2012-01-01

Background: The mandibular foramen (MF) is an opening on the internal surface of the ramus for divisions of the mandibular vessels and nerve to pass. The aim of this study is to determine the position of the MF from various anatomical landmarks in several dry adult mandibles. Materials and Methods: A total of 102 human dry mandibles were examined, of which 93 were of dentulous and 9 were of edentulous. The measurements were taken from the anterior border of the ramus (coronoid notch) to the midportion of the MF and then from the midportion of the MF to the other landmarks such as internal oblique ridge, inferior border, sigmoid notch, and condyle were measured and recorded. Results: The data were compared using Student's t-test. The MF is positioned at a mean distance of 19 mm (with SD 2.34) from coronoid notch of the anterior border of the ramus. Superio-inferiorly from the condyle to the inferior border MF is situated 5 mm inferior to the midpoint of condyle to the inferior border distance (ramus height). Conclusion: We conclude that failures in the anesthesia of the inferior alveolar nerve are due to the operator error and not due to the anatomical variation. PMID:23225978

Temporal genetic population structure and interannual variation in migration behavior of Pacific Lamprey Entosphenus tridentatus

USGS Publications Warehouse

Clemens, Benjamin J.; Wyss, Lance A.; McCoun, Rebecca; Courter, Ian; Schwabe, Lawrence; Peery, Christopher; Schreck, Carl B.; Spice, Erin K.; Docker, Margaret F.

2017-01-01

Studies using neutral loci suggest that Pacific lamprey, Entosphenus tridentatus, lack strong spatial genetic population structure. However, it is unknown whether temporal genetic population structure exists. We tested whether adult Pacific lamprey: (1) show temporal genetic population structure; and (2) migrate different distances between years. We non-lethally sampled lamprey for DNA in 2009 and 2010 and used eight microsatellite loci to test for genetic population structure. We used telemetry to record the migration behaviors of these fish. Lamprey were assignable to three moderately differentiated genetic clusters (FST = 0.16–0.24 for all pairwise comparisons): one cluster was composed of individuals from 2009, and the other two contained individuals from 2010. The FST value between years was 0.13 and between genetic clusters within 2010 was 0.20. A total of 372 (72.5%) fish were detected multiple times during their migrations. Most fish (69.9%) remained in the mainstem Willamette River; the remaining 30.1% migrated into tributaries. Eighty-two lamprey exhibited multiple back-and-forth movements among tributaries and the mainstem, which may indicate searching behaviors. All migration distances were significantly greater in 2010, when the amplitude of river discharge was greater. Our data suggest genetic structuring between and within years that may reflect different cohorts.

Recognition and characterization of migratory movements of Australian plague locusts, Chortoicetes terminifera, with an insect monitoring radar

NASA Astrophysics Data System (ADS)

Drake, V. Alistair; Wang, Haikou

2013-01-01

Two special purpose insect-detecting radar units have operated in inland eastern Australia, in the region where nocturnal migratory movements of Australian plague locusts Chortoicetes terminifera occur, for over 10 years. The fully automatic radars detect individual insects as they fly directly overhead and "interrogate" them to obtain information about their characters (size, shape, and wing beating) and trajectory (speed, direction, and orientation). The character data allow locusts to be distinguished from most other migrant species. A locust index, calculated from the total count of locust-like targets for a night, provides a simple indication of migration intensity. For nights of heavy migration, the variation of numbers, directions, and speeds with both height and time can be examined. Emigration and immigration events can be distinguished, as can "transmigration," the passage overhead of populations originating elsewhere. Movement distances can be inferred, and broad source and (more tentatively) destination regions are identified. Movements were typically over distances of up to 400 km. Interpretation of radar observations requires judgment, and the present two units provide only partial coverage of the locust infestation area, but their capacity to detect major population movements promptly, and to provide information between necessarily infrequent surveys, has proved valuable.

What drives patient mobility across Italian regions? Evidence from hospital discharge data.

PubMed

Balia, Silvia; Brau, Rinaldo; Marrocu, Emanuela

2014-01-01

This chapter examines patient mobility across Italian regions using data on hospital discharges that occurred in 2008. The econometric analysis is based on Origin-Destination (OD) flow data. Since patient mobility is a crucial phenomenon in contexts of hospital competition based on quality and driven by patient choice, as is the case in Italy, it is crucial to understand its determinants. What makes the Italian case more interesting is the decentralization of the National Health Service that yields large regional variation in patient flows in favor of Centre-Northern regions, which typically are 'net exporters' of hospital treatments. We present results from gravity models estimated using count data estimators, for total and specific types of flows (ordinary admissions, surgical DRGs and medical DRGs). We model cross-section dependence by specifically including features other than geographical distance for OD pairs, such as past migration flows and the share of surgical DRGs. Most of the explanatory variables exhibit the expected effect, with distance and GDP per capita at origin showing a negative impact on patient outflows. Past migrations and indicators of performance at destination are effective determinants of patient mobility. Moreover, we find evidence of regional externalities due to spatial proximity effects at both origin and destination.

Genetic variability of natural populations of trematodes of the genus Lecithochirium parasites of eels.

PubMed

Vilas, R; Sanmartín, M L; Paniagua, E

2004-08-01

Allozyme variation within and among populations of 3 species of the genus Lecithochirium (Trematoda: Hemiuridae) was studied by starch gel electrophoresis. In total, 19 loci were analysed in 7 populations. The level of genetic variability was relatively high in all populations. The percentage of polymorphic loci (0.95 criterion) observed per population varied from 21.0% to 55.5%, and expected heterozygosity levels varied from 0.082 to 0.197. All populations showed significant heterozygote deficiencies. In Lecithochirium fusiforme most of the deviations from Hardy-Weinberg proportions were within the populations and this species showed moderate population structuring (F(IS)=0.486, F(ST)=0.142, Nm= 1.51) and accordingly low intraspecific genetic distances (D=0.003 to 0.027). A significant lack of heterozygotes for several polymorphic loci was revealed in Lecithochirium rufoviride and Lecithochirium musculus. The most probable cause of the population genetic subdivision in L. rufoviride is the presence of at least 1 cryptic species in the populations studied. Although the lowest percentage of fixed genetic differences was that between L. fusiforme and L. musculus, two different algorithms for the construction of evolutionary trees on a matrix of genetic distances confirmed that L. fusiforme and L. rufoviride are phenetically the most closely related species.

Multilevel assessment of fish species traits to evaluate habitat degradation in streams of the upper midwest

USGS Publications Warehouse

Goldstein, R.M.; Meador, M.R.

2005-01-01

We used species traits to examine the variation in fish assemblages for 21 streams in the Northern Lakes and Forests Ecoregion along a gradient of habitat disturbance. Fish species were classified based on five species trait-classes (trophic ecology, substrate preference, geomorphic preference, locomotion morphology, and reproductive strategy) and 29 categories within those classes. We used a habitat quality index to define a reference stream and then calculated Euclidean distances between the reference and each of the other sites for the five traits. Three levels of species trait analyses were conducted: (1) a composite measure (the sum of Euclidean distances across all five species traits), (2) Euclidean distances for the five individual species trait-classes, and (3) frequencies of occurrence of individual trait categories. The composite Euclidean distance was significantly correlated to the habitat index (r = -0.81; P = 0.001), as were the Euclidean distances for four of the five individual species traits (substrate preference: r = -0.70, P = 0.001; geomorphic preference: r = -0.69, P = 0.001; trophic ecology: r = -0.73, P = 0.001; and reproductive strategy: r = -0.64, P = 0.002). Although Euclidean distances for locomotion morphology were not significantly correlated to habitat index scores (r = -0.21; P = 0.368), analysis of variance and principal components analysis indicated that Euclidean distances for locomotion morphology contributed to significant variation in the fish assemblages among sites. Examination of trait categories indicated that low habitat index scores (degraded streams) were associated with changes in frequency of occurrence within the categories of all five of the species traits. Though the objectives and spatial scale of a study will dictate the level of species trait information required, our results suggest that species traits can provide critical information at multiple levels of data analysis. ?? Copyright by the American Fisheries Society 2005.

The spatial distribution and temporal variation of desert riparian forests and their influencing factors in the downstream Heihe River basin, China

NASA Astrophysics Data System (ADS)

Ding, Jingyi; Zhao, Wenwu; Daryanto, Stefani; Wang, Lixin; Fan, Hao; Feng, Qiang; Wang, Yaping

2017-05-01

Desert riparian forests are the main restored vegetation community in Heihe River basin. They provide critical habitats and a variety of ecosystem services in this arid environment. Since desert riparian forests are also sensitive to disturbance, examining the spatial distribution and temporal variation of these forests and their influencing factors is important to determine the limiting factors of vegetation recovery after long-term restoration. In this study, field experiment and remote sensing data were used to determine the spatial distribution and temporal variation of desert riparian forests and their relationship with the environmental factors. We classified five types of vegetation communities at different distances from the river channel. Community coverage and diversity formed a bimodal pattern, peaking at the distances of 1000 and 3000 m from the river channel. In general, the temporal normalized difference vegetation index (NDVI) trend from 2000 to 2014 was positive at different distances from the river channel, except for the region closest to the river bank (i.e. within 500 m from the river channel), which had been undergoing degradation since 2011. The spatial distribution of desert riparian forests was mainly influenced by the spatial heterogeneity of soil properties (e.g. soil moisture, bulk density and soil particle composition). Meanwhile, while the temporal variation of vegetation was affected by both the spatial heterogeneity of soil properties (e.g. soil moisture and soil particle composition) and to a lesser extent, the temporal variation of water availability (e.g. annual average and variability of groundwater, soil moisture and runoff). Since surface (0-30 cm) and deep (100-200 cm) soil moisture, bulk density and the annual average of soil moisture at 100 cm obtained from the remote sensing data were regarded as major determining factors of community distribution and temporal variation, conservation measures that protect the soil structure and prevent soil moisture depletion (e.g. artificial soil cover and water conveyance channels) were suggested to better protect desert riparian forests under climate change and intensive human disturbance.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jang, Junhwan; Hwang, Sungui; Park, Kyihwan, E-mail: khpark@gist.ac.kr

To utilize a time-of-flight-based laser scanner as a distance measurement sensor, the measurable distance and accuracy are the most important performance parameters to consider. For these purposes, the optical system and electronic signal processing of the laser scanner should be optimally designed in order to reduce a distance error caused by the optical crosstalk and wide dynamic range input. Optical system design for removing optical crosstalk problem is proposed in this work. Intensity control is also considered to solve the problem of a phase-shift variation in the signal processing circuit caused by object reflectivity. The experimental results for optical systemmore » and signal processing design are performed using 3D measurements.« less

Estimated metabolic and mechanical demands during different small-sided games in elite soccer players.

PubMed

Gaudino, Paolo; Alberti, Giampietro; Iaia, F Marcello

2014-08-01

The present study examined the extent to which game format (possession play, SSG-P and game with regular goals and goalkeepers, SSG-G) and the number of players (5, 7 and 10 a-side) influence the physical demands of small-sided soccer games (SSGs) in elite soccer players. Training data were collected during the in-season period from 26 English Premier League outfield players using global positioning system technology. Total distance covered, distance at different speed categories and maximal speed were calculated. In addition, we focused on changes in velocity by reporting the number of accelerations and decelerations carried out during the SSGs (divided in two categories: moderate and high) and the absolute maximal values of acceleration and deceleration achieved. By taking into account these parameters besides speed and distance values, estimated energy expenditure and average metabolic power and distance covered at different metabolic power categories were calculated. All variables were normalized by time (i.e., 4min). The main findings were that the total distance, distances run at high speed (>14.4kmh(-1)) as well as absolute maximum velocity, maximum acceleration and maximum deceleration increased with pitch size (10v10>7v7>5v5; p<.05). Furthermore, total distance, very high (19.8-25.2kmh(-1)) and maximal (>25.2kmh(-1)) speed distances, absolute maximal velocity and maximum acceleration and deceleration were higher in SSG-G than in SSG-P (p<.001). On the other hand, the number of moderate (2-3ms(-2)) accelerations and decelerations as well as the total number of changes in velocity were greater as the pitch dimensions decreased (i.e., 5v5>7v7>10v10; p<.001) in both SSG-G and SSG-P. In addition, predicted energy cost, average metabolic power and distance covered at every metabolic power categories were higher in SSG-P compared to SSG-G and in big than in small pitch areas (p<.05). A detailed analysis of these drills is pivotal in contemporary football as it enables an in depth understanding of the workload imposed on each player which consequently has practical implications for the prescription of the adequate type and amount of stimulus during exercise training. Copyright © 2014 Elsevier B.V. All rights reserved.

Behavioral and environmental influences on fishing rewards and the outcomes of alternative management scenarios for large tropical rivers.

PubMed

Hallwass, Gustavo; Lopes, Priscila F M; Juras, Anastácio A; Silvano, Renato A M

2013-10-15

Identifying the factors that influence the amount of fish caught, and thus the fishers' income, is important for proposing or improving management plans. Some of these factors influencing fishing rewards may be related to fishers' behavior, which is driven by economic motivations. Therefore, those management rules that have less of an impact on fishers' income could achieve better acceptance and compliance from fishers. We analyzed the relative influence of environmental and socioeconomic factors on fish catches (biomass) in fishing communities of a large tropical river. We then used the results from this analysis to propose alternative management scenarios in which we predicted potential fishers' compliance (high, moderate and low) based on the extent to which management proposals would affect fish catches and fishers' income. We used a General Linear Model (GLM) to analyze the influence of environmental (fishing community, season and habitat) and socioeconomic factors (number of fishers in the crew, time spent fishing, fishing gear used, type of canoe, distance traveled to fishing grounds) on fish catches (dependent variable) in 572 fishing trips by small-scale fishers in the Lower Tocantins River, Brazilian Amazon. According to the GLM, all factors together accounted for 43% of the variation in the biomass of the fish that were caught. The behaviors of fishers' that are linked to fishing effort, such as time spent fishing (42% of the total explained by GLM), distance traveled to the fishing ground (12%) and number of fishers (10%), were all positively related to the biomass of fish caught and could explain most of the variation on it. The environmental factor of the fishing habitat accounted for 10% of the variation in fish caught. These results, when applied to management scenarios, indicated that some combinations of the management measures, such as selected lakes as no-take areas, restrictions on the use of gillnets (especially during the high-water season) and individual quotas larger than fishers' usual catches, would most likely have less impact on fishers' income. The proposed scenarios help to identify feasible management options, which could promote the conservation of fish, potentially achieving higher fishers' compliance. Copyright © 2013 Elsevier Ltd. All rights reserved.

Predicting pathologic tumor response to chemoradiotherapy with histogram distances characterizing longitudinal changes in 18F-FDG uptake patterns

PubMed Central

Tan, Shan; Zhang, Hao; Zhang, Yongxue; Chen, Wengen; D’Souza, Warren D.; Lu, Wei

2013-01-01

Purpose: A family of fluorine-18 (18F)-fluorodeoxyglucose (18F-FDG) positron-emission tomography (PET) features based on histogram distances is proposed for predicting pathologic tumor response to neoadjuvant chemoradiotherapy (CRT). These features describe the longitudinal change of FDG uptake distribution within a tumor. Methods: Twenty patients with esophageal cancer treated with CRT plus surgery were included in this study. All patients underwent PET/CT scans before (pre-) and after (post-) CRT. The two scans were first rigidly registered, and the original tumor sites were then manually delineated on the pre-PET/CT by an experienced nuclear medicine physician. Two histograms representing the FDG uptake distribution were extracted from the pre- and the registered post-PET images, respectively, both within the delineated tumor. Distances between the two histograms quantify longitudinal changes in FDG uptake distribution resulting from CRT, and thus are potential predictors of tumor response. A total of 19 histogram distances were examined and compared to both traditional PET response measures and Haralick texture features. Receiver operating characteristic analyses and Mann-Whitney U test were performed to assess their predictive ability. Results: Among all tested histogram distances, seven bin-to-bin and seven crossbin distances outperformed traditional PET response measures using maximum standardized uptake value (AUC = 0.70) or total lesion glycolysis (AUC = 0.80). The seven bin-to-bin distances were: L2 distance (AUC = 0.84), χ2 distance (AUC = 0.83), intersection distance (AUC = 0.82), cosine distance (AUC = 0.83), squared Euclidean distance (AUC = 0.83), L1 distance (AUC = 0.82), and Jeffrey distance (AUC = 0.82). The seven crossbin distances were: quadratic-chi distance (AUC = 0.89), earth mover distance (AUC = 0.86), fast earth mover distance (AUC = 0.86), diffusion distance (AUC = 0.88), Kolmogorov-Smirnov distance (AUC = 0.88), quadratic form distance (AUC = 0.87), and match distance (AUC = 0.84). These crossbin histogram distance features showed slightly higher prediction accuracy than texture features on post-PET images. Conclusions: The results suggest that longitudinal patterns in 18F-FDG uptake characterized using histogram distances provide useful information for predicting the pathologic response of esophageal cancer to CRT. PMID:24089897

Development of an Elliptical Trainer Physical Fitness Test

DTIC Science & Technology

2006-04-02

have demonstrated caloric expenditures and ratings of perceived exertion (RPE) similar to those measured during treadmill running (Clay, 2000...elliptical trainer calculates and displays total caloric expenditure and distance for each workout session. Distance is a function of the force phase of the...total caloric expenditure will be the performance measure. Bout duration will be 12 min to make the exercise bout similar to Cooper’s 12-minute run

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hidalgo, Sebastian L.; Aparicio, Antonio; MartInez-Delgado, David

We present the star formation history (SFH) and its variations with galactocentric distance for the Local Group dwarf galaxy of Phoenix. They have been derived from a (F555W, F814W) color-magnitude diagram obtained from WFPC2-HST data, which reaches the oldest main-sequence turnoffs. The IAC-star and IAC-pop codes and the MinnIAC suite have been used to obtain the star formation rate as a function of time and metallicity, psi(t, z). We find that Phoenix has had ongoing but gradually decreasing star formation over nearly a Hubble time. The highest level of star formation occurred from the formation of the galaxy till 10.5more » Gyr ago, when 50% of the total star formation had already taken place. From that moment, star formation continues at a significant level until 6 Gyr ago (an additional 35% of the stars are formed in this time interval), and at a very low level till the present time. The chemical enrichment law shows a trend of slowly increasing metallicity as a function of time until 6-8 Gyr ago, when metallicity starts to increase steeply to the current value. We have paid particular attention to the study of the variations of the SFH as a function of radius. Young stars are found in the inner region of the galaxy only, but intermediate-age and old stars can be found at all galactocentric distances. The distribution of mass density in alive stars and its evolution with time has been studied. This study shows that star formation started at all galactocentric distances in Phoenix at an early epoch. If stars form in situ in Phoenix, the star formation onset took place all over the galaxy (up to a distance of about 400 pc from the center), but preferentially out of center regions. After that, our results are compatible with a scenario in which the star formation region envelope slowly shrinks as time goes on, possibly as a natural result of pressure support reduction as gas supply diminishes. As a consequence, the star formation stopped first (about 7-8 Gyr ago) in outer regions and the scale length of the stellar mass density distribution decreased with time. Finally, no traces of a true, old halo are apparent in Phoenix either in its stellar age distribution or in the stellar mass density distribution, at least out to 0.5 kpc (about 2.5 scale length) from the center.« less

Organic geochemistry in Pennsylvanian tidally influenced sediments from SW Indiana

USGS Publications Warehouse

Mastalerz, Maria; Kvale, E.P.; Stankiewicz, B.A.; Portle, K.

1999-01-01

Tidal rhythmites are vertically stacked small-scale sedimentary structures that record daily variations in tidal current energy and are known to overlie some low-sulfur coals in the Illinois Basin. Tidal rhythmites from the Pennsylvanian Brazil Formation in Indiana have been analyzed sedimentologically, petrographically, and geochemically in order to understand the character and distribution of organic matter (OM) preserved in an environment of daily interactions between marine and fresh waters. The concentration of organic matter (TOC) ranges from traces to 6.9% and sulfur rarely exceeds 0.1% in individual laminae. Angular vitrinite is the major organic matter type, accounting for 50-90% of total OM. The C/S ratio decreases as the verfical distance from the underlying coal increases. A decreasing C/S ratio coupled with decreases in Pr/Ph, Pr/n-C17, Ph/n-C18 ratios and a shift of carbon isotopic composition towards less negative values suggest an increase in salinity from freshwater in the mudflat tidal rhythmite facies close to the coal to brackish/marine in the sandflat tidal rhythmite facies further above from the coal. Within an interval spanning one year of deposition, TOC and S values show monthly variability. On a daily scale, TOC and S oscillations are still detectable but they are of lower magnitude than on a monthly scale. These small-scale variations are believed to reflect oscillations in water salinity related to tidal cycles.Tidal rhythmites are vertically stacked small-scale sedimentary structures that record daily variations in tidal current energy and are known to overlie some low-sulfur coals in the Illinois Basin. Tidal rhythmites from the Pennsylvanian Brazil Formation in Indiana have been analyzed sedimentologically, petrographically, and geochemically in order to understand the character and distribution of organic matter (OM) preserved in an environment of daily interactions between marine and fresh waters. The concentration of organic matter (TOC) ranges from traces to 6.9% and sulfur rarely exceeds 0.1% in individual laminae. Angular vitrinite is the major organic matter type, accounting for 50-90% of total OM. The C/S ratio decreases as the vertical distance from the underlying coal increases. A decreasing C/S ratio coupled with decreases in Pr/Ph, Pr/n-C17, Ph/n-C18 ratios and a shift of carbon isotopic composition towards less negative values suggest an increase in salinity from freshwater in the mudflat tidal rhythmite facies close to the coal to brackish/marine in the sandflat tidal rhythmite facies further above from the coal. Within an interval spanning one year of deposition, TOC and S values show monthly variability. On a daily scale, TOC and S oscillations are still detectable but they are of lower magnitude than on a monthly scale. These small-scale variations are believed to reflect oscillations in water salinity related to tidal cycles.

A High-Density Integrated DArTseq SNP-Based Genetic Map of Pisum fulvum and Identification of QTLs Controlling Rust Resistance

PubMed Central

Barilli, Eleonora; Cobos, María J.; Carrillo, Estefanía; Kilian, Andrzej; Carling, Jason; Rubiales, Diego

2018-01-01

Pisum fulvum, a wild relative of pea is an important source of allelic diversity to improve the genetic resistance of cultivated species against fungal diseases of economic importance like the pea rust caused by Uromyces pisi. To unravel the genetic control underlying resistance to this fungal disease, a recombinant inbred line (RIL) population was generated from a cross between two P. fulvum accessions, IFPI3260 and IFPI3251, and genotyped using Diversity Arrays Technology. A total of 9,569 high-quality DArT-Seq and 8,514 SNPs markers were generated. Finally, a total of 12,058 markers were assembled into seven linkage groups, equivalent to the number of haploid chromosomes of P. fulvum and P. sativum. The newly constructed integrated genetic linkage map of P. fulvum covered an accumulated distance of 1,877.45 cM, an average density of 1.19 markers cM−1 and an average distance between adjacent markers of 1.85 cM. The composite interval mapping revealed three QTLs distributed over two linkage groups that were associated with the percentage of rust disease severity (DS%). QTLs UpDSII and UpDSIV were located in the LGs II and IV respectively and were consistently identified both in adult plants over 3 years at the field (Córdoba, Spain) and in seedling plants under controlled conditions. Whenever they were detected, their contribution to the total phenotypic variance varied between 19.8 and 29.2. A third QTL (UpDSIV.2) was also located in the LGIVand was environmentally specific as was only detected for DS % in seedlings under controlled conditions. It accounted more than 14% of the phenotypic variation studied. Taking together the data obtained in the study, it could be concluded that the expression of resistance to fungal diseases in P. fulvum originates from the resistant parent IFPI3260. PMID:29497430

Comparison of different interpolation methods for spatial distribution of soil organic carbon and some soil properties in the Black Sea backward region of Turkey

NASA Astrophysics Data System (ADS)

Göl, Ceyhun; Bulut, Sinan; Bolat, Ferhat

2017-10-01

The purpose of this research is to compare the spatial variability of soil organic carbon (SOC) in four adjacent land uses including the cultivated area, the grassland area, the plantation area and the natural forest area in the semi - arid region of Black Sea backward region of Turkey. Some of the soil properties, including total nitrogen, SOC, soil organic matter, and bulk density were measured on a grid with a 50 m sampling distance on the top soil (0-15 cm depth). Accordingly, a total of 120 samples were taken from the four adjacent land uses. Data was analyzed using geostatistical methods. The methods used were: Block kriging (BK), co - kriging (CK) with organic matter, total nitrogen and bulk density as auxiliary variables and inverse distance weighting (IDW) methods with the power of 1, 2 and 4. The methods were compared using a performance criteria that included root mean square error (RMSE), mean absolute error (MAE) and the coefficient of correlation (r). The one - way ANOVA test showed that differences between the natural (0.6653 ± 0.2901) - plantation forest (0.7109 ± 0.2729) areas and the grassland (1.3964 ± 0.6828) - cultivated areas (1.5851 ± 0.5541) were statistically significant at 0.05 level (F = 28.462). The best model for describing spatially variation of SOC was CK with the lowest error criteria (RMSE = 0.3342, MAE = 0.2292) and the highest coefficient of correlation (r = 0.84). The spatial structure of SOC could be well described by the spherical model. The nugget effect indicated that SOC was moderately dependent on the study area. The error distributions of the model showed that the improved model was unbiased in predicting the spatial distribution of SOC. This study's results revealed that an explanatory variable linked SOC increased success of spatial interpolation methods. In subsequent studies, this case should be taken into account for reaching more accurate outputs.

Assessment of Technical Skills in Young Soccer Goalkeepers: Reliability and Validity of Two Goalkeeper-Specific Tests.

PubMed

Rebelo-Gonçalves, Ricardo; Figueiredo, António J; Coelho-E-Silva, Manuel J; Tessitore, Antonio

2016-09-01

The purpose of this study was to evaluate the reproducibility and validity of two new tests designed to examine goalkeeper-specific technique. Twenty-six goalkeepers (14.49 ± 2.52 years old) completed two trial sessions, each separated by one week, to evaluate the reproducibility of the Sprint-Keeper Test (S-Keeper) and the Lateral Shuffle-Keeper Test (LS-Keeper). Construct validity was assessed among forty goalkeepers (14.49 ± 1.71 years old) by competitive level (elite versus non-elite), after controlling for chronological age. All participants were examined in vertical jump (CMJ and CMJ-free arms), acceleration (5-m and 10-m sprint) and goalkeeper-specific technique. The S-Keeper requires the goalkeeper to accelerate during 3 m and dive over a stationary ball after performing a change of direction in a total distance of 10 m. The LS-Keeper involves three changes of direction and a diving save over a stationary ball, in a total distance of 12.55 m. Performance was respectively measured as total time for the right and left sides in each protocol. Bivariate correlations between repeated measures were high and significant (r = 0.835 - 0.912). Test-retest results for the S-Keeper and LS-Keeper showed good reliability (reliability coefficients > 0.88, intra-class correlation coefficient > 0.908 and coefficients of variation < 4.37%), even though participants tended to improve performance when diving to their right side (p < 0.05). Both tests were able to detect significant differences between elite and non-elite goalkeepers, particularly to the left side (p < 0.05). These findings suggest that the S-Keeper and LS-Keeper are reliable and valid tests for assessing goalkeeper-specific technique. Both protocols can be used as a practical tool to provide relevant information about the influence of several components of performance in the overall execution of a diving save, particularly movement patterns, take-off movements and possible asymmetries.