Desarrollo post-embrionario, fecundidad y consumo de alimento de Dichroplus exilis (Orthoptera: Acrididae bajo condiciones controladas

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Christian Bardi

2011-12-01

Full Text Available La Subfamilia Melanoplinae tiene una relevancia central dentro de la acridiofauna Argentina. Varias especies suelen ser numéricamente dominantes en las comunidades de acridios del país y algunas constituyen serias plagas. El objetivo de este trabajo fue conocer el ciclo de vida postembrionario, la fecundidad y supervivencia de las hembras y el consumo de alimento de Dichruplus exilis bajo condiciones controladas (30°C; 40%HR y 14L-10O. Para ello se realizó el seguimiento de tres cohortes de 16, 17 y 20 individuos. El tiempo de incubación fue de 14.4±1.08 días. La duración del desarrollo ninfal fue 41.38; 0.71 días (I 8.73; 0.20, II 6.38; 0.24, III 5.64; 0.33, IV 7.15; 0.43, V 9.76; 0.54; IV 7.85; 0.95; la fecundidad promedio fue de 381.84, 38.54huevos/hembra. El consumo registrado fue de 9.89; 1.08 (mg/ind./día para las ninfas de IV, 18.04; 0.73 (mg/ind./día para las de V y IV, mientras que el consumo promedio de los adultos, sin diferenciar sexo y estado reproductivo, fue de 16.41; 4.32mg/día. Estos parámetros, al ser comparados con los de otras especies afines, indican que D. exilis exhibe atributos biológicos que condicen con los de otros melanoplinos considerados plaga.Postembryonic development, fecundity and food consumption of Dichroplus exilis (Orthoptera: Acrididae under controlled conditions. Dichroplus exilis is a widely distributed species in Southern South America. Although there have been reports of D. exilis as an agricultural pest, some recent observations suggest that the damage attributed to D. elongatus may actually have been caused by D. exilis. This study was conducted to determine the postembryonic life cycle stages, fertility and food consumption of this species under controlled conditions (30°C, 14L-10D, 40% RH.Individuals employed belong to the laboratory-hatched first generation (F1, from adults (n=64, ♀=28, ♂=36 collected in natural grasslands near Rafaela, Santa Fe province in North- Eastern

Preventing desert locust plagues: optimizing management interventions

NARCIS (Netherlands)

Huis, van A.; Cressman, K.; Magor, J.I.

2007-01-01

Solitarious desert locusts, Schistocerca gregaria (Forskål) (Orthoptera: Acrididae), inhabit the central, arid, and semi-arid parts of the species¿ invasion area in Africa, the Middle East, and South-West Asia. Their annual migration circuit takes them downwind to breed sequentially where winter,

Adaptive colour polymorphism of Acrida ungarica H. (Orthoptera: Acrididae) in a spatially heterogeneous environment

Science.gov (United States)

Pellissier, Loïc; Wassef, Jérôme; Bilat, Julia; Brazzola, Gregory; Buri, Pierrick; Colliard, Caroline; Fournier, Bertrand; Hausser, Jacques; Yannic, Glenn; Perrin, Nicolas

2011-03-01

Intra-specific colour polymorphism provides a cryptic camouflage from predators in heterogeneous habitats. The orthoptera species, Acrida ungarica (Herbst, 1786) possess two well-distinguished colour morphs: brown and green and displays several disruptive colouration patterns within each morph to improve the crypsis. This study focused on how the features of the background environment relate to the proportion of the two morphs and to the intensity of disruptive colouration patterns in A. ungarica. As the two sexes are very distinct with respect to mass and length, we also distinctively tested the relationship for each sex. In accordance with the background matching hypothesis, we found that, for both sexes, the brown morph was in higher proportion at sites with a brown-dominant environment, and green morphs were in higher proportion in green-dominant environments. Globally, individuals in drier sites and in the drier year also had more intense disruptive colouration patterns, and brown morphs and females were also more striped. Colour patterns differed largely between populations and were significantly correlated with relevant environmental features. Even if A. ungarica is a polymorphic specialist, disruptive colouration still appears to provide strong benefits, particularly in some habitats. Moreover, because females are larger, they are less able to flee, which might explain the difference between sexes.

Monograph of the Afrotropical species of Scelio Latreille (Hymenoptera, Platygastridae), egg parasitoids of acridid grasshoppers (Orthoptera, Acrididae).

Science.gov (United States)

Yoder, Matthew J; Valerio, Alejandro A; Polaszek, Andrew; van Noort, Simon; Masner, Lubomír; Johnson, Norman F

2014-01-01

The genus Scelio is a cosmopolitan and speciose group of solitary parasitoids of the eggs of short-horned grasshoppers (Orthoptera: Acrididae). A number of these hosts are important pests, including plague locusts of the genus Schistocerca. Species of Scelio are recognized as potentially important biological control agents, but this possibility has yet to be fully realized, in part because the species-level taxonomy is still incompletely developed. The species of the pulchripennis group have been recently revised. As a continuation of this effort, here we revise the Afrotropical species of Scelio, excluding the pulchripennis species group. Sixty two (62) species are treated, 48 of which are new. Species are classified into the following species groups: ernstii (12 species, 9 new), howardi (23 species, 19 new), ipomeae (6 species, 5 new), irwini (4 species, 3 new), simoni (3 new species) and walkeri (12 species, 9 new). Keys to species groups and to the species within each group are provided. New species described are: S. albatus Yoder, sp. n., S. aphares Yoder, sp. n., S. apospastos Yoder, sp. n., S. ardelio Yoder, sp. n., S. aurantium Yoder, sp. n., S. balo Valerio & Yoder, sp. n., S. bayanga Yoder, sp. n., S. bubulo Yoder, sp. n., S. cano Yoder, sp. n., S. clypeatus Yoder, sp. n., S. concavus Yoder, sp. n., S. copelandi Yoder, sp. n., S. crepo Yoder, sp. n., S. destico Yoder, sp. n., S. dupondi Yoder, sp. n., S. effervesco Yoder, sp. n., S. erugatus Yoder, sp. n., S. exophthalmus Yoder, sp. n., S. fremo Valerio & Yoder, sp. n., S. gemo Yoder, sp. n., S. grunnio Yoder, sp. n., S. harinhalai Yoder, sp. n., S. igland Yoder, sp. n., S. impostor Yoder, sp. n., S. irwini Yoder, sp. n., S. janseni Yoder, sp. n., S. latro Yoder, sp. n., S. memorabilis Yoder, sp. n., S. modulus Yoder, sp. n., S. mutio Yoder, sp. n., S. ntchisii Yoder, sp. n., S. parkeri Yoder, sp. n., S. phaeoprora Yoder, sp. n., S. pilosilatus Yoder, sp. n., S. pipilo Yoder, sp. n., S. quasiclypeatus

Sciences & Nature - Vol 5, No 2 (2008)

African Journals Online (AJOL)

Impact des doses sublétales de fénitrothion sur l\\'ovogenèse et la capacité de ponte du criquet pèlerin Schistocera gregaria (Orthoptera : Acrididae) · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. SW Ouali-N'Goran, KH Koua, MA D'Almeida, K Fouabi, 177-189.

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African Journals Online (AJOL)

Koua, KH. Vol 5, No 2 (2008) - Articles Impact des doses sublétales de fénitrothion sur l\\'ovogenèse et la capacité de ponte du criquet pèlerin Schistocera gregaria (Orthoptera : Acrididae) Abstract PDF. ISSN: 1812-0741. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors ...

Bioaccumulation of some natural radionuclides in short-antenna grasshoppers (Acrididae family, class Ortoptera)

International Nuclear Information System (INIS)

Dimitrova, M.; Markova, E.; Bogdanova, V.

1996-01-01

The seasonal accumulation of radioactive elements of the uranium-radium order in representatives of larva stages of different species of of Acrididae family has been examined. The monitoring sites are typical of the region and gave a relevant information about the natural background radiation. The process begins in the end of spring when Acrididae enter on the most intensive phase of their functional development and accumulate lots of radioisotopes not only by food but also through respiratory system and whole-body surface. Among the radioisotopes radium has an average biological absorbability, uranium - a very slight one. This fact explains the high values of radium in the ecosystems examined. Despite its low absorbability coefficient 238 U is found to a considerable extent in the investigated organisms. Because of it high mobility in soil compared to Ra 226, uranium 238 accumulates in plants by water and through trophic chain passes into the living organisms. It is found also that Acrididae accumulate later, during autumn and Bi 214. So they are a reliable bio-indicator for the radionuclides U 238, Ra 226, Pb 214 and Bi 214. It has been found that the ionizing radiation at the natural biocenoses is not only an individual irritant but also has an effect of a radioecological factor of the environment. The examinations show redistribution of the natural radionuclides as a result of economic activities

The effect of discontinuous gas exchange on respiratory water loss in grasshoppers (Orthoptera: Acrididae) varies across an aridity gradient.

Science.gov (United States)

Huang, Shu-Ping; Talal, Stav; Ayali, Amir; Gefen, Eran

2015-08-01

The significance of discontinuous gas-exchange cycles (DGC) in reducing respiratory water loss (RWL) in insects is contentious. Results from single-species studies are equivocal in their support of the classic 'hygric hypothesis' for the evolution of DGC, whereas comparative analyses generally support a link between DGC and water balance. In this study, we investigated DGC prevalence and characteristics and RWL in three grasshopper species (Acrididae, subfamily Pamphaginae) across an aridity gradient in Israel. In order to determine whether DGC contributes to a reduction in RWL, we compared the DGC characteristics and RWL associated with CO2 release (transpiration ratio, i.e. the molar ratio of RWL to CO2 emission rates) among these species. Transpiration ratios of DGC and continuous breathers were also compared intraspecifically. Our data show that DGC characteristics, DGC prevalence and the transpiration ratios correlate well with habitat aridity. The xeric-adapted Tmethis pulchripennis exhibited a significantly shorter burst period and lower transpiration ratio compared with the other two mesic species, Ocneropsis bethlemita and Ocneropsis lividipes. However, DGC resulted in significant water savings compared with continuous exchange in T. pulchripennis only. These unique DGC characteristics for T. pulchripennis were correlated with its significantly higher mass-specific tracheal volume. Our data suggest that the origin of DGC may not be adaptive, but rather that evolved modulation of cycle characteristics confers a fitness advantage under stressful conditions. This modulation may result from morphological and/or physiological modifications. © 2015. Published by The Company of Biologists Ltd.

Nitrogen limitation and life history adaptation in the grasshopper "Omocestus viridulus"

OpenAIRE

Berner, Daniel

2005-01-01

The role of plant-mediated constraints to herbivore populations in terrestrial ecosystems remains relatively poorly understood. One aim of this study was therefore to explore the effects of low host plant nitrogen (N) content on herbivore performance and feeding behaviour, and thereby to evaluate the utility of the N limitation and nutrient balance concepts. The grass-feeding grasshopper Omocestus viridulus (Orthoptera: Acrididae) provided a well-suited model system as the species exhibits hi...

ORTHOPTERA FAUNA OF SĂLAJ COUNTY, ROMANIA

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Gellért Puskás

2017-07-01

Full Text Available : Orthoptera fauna of Sălaj County, NW Romania is reviewed based on new and literature data. 63 species were collected during field investigations in 2014-2015, thus the known Orthoptera species in the region are 74 (30 Acridoidea, 3 Tetrigoidea, 1 Tridactyloidea, 7 Grylloidea, 33 Tettigonioidea. 9 species are recorded in the county for the first time (Chorthippus mollis, Ch. montanus, Ch. vagans, Euchorthippus pulvinatus, Stenobothrus stigmaticus, Tetrix tuerki, Isophya kraussii, Metrioptera brachyptera, Pholidoptera frivaldszkyi. Isophya kraussii kraussii is a new subspecies for the fauna of Romania. Correct original spelling of the name of Ph. frivaldszkyi (Herman, 1871 is fixed.

Microsatellite organization in the grasshopper Abracris flavolineata (Orthoptera: Acrididae revealed by FISH mapping: remarkable spreading in the A and B chromosomes.

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Diogo Milani

Full Text Available With the aim of acquiring deeper knowledge about repetitive DNAs chromosomal organization in grasshoppers, we used fluorescent in situ hybridization (FISH to map the distribution of 16 microsatellite repeats, including mono-, di-, tri- and tetra-nucleotides, in the chromosomes of the species Abracris flavolineata (Acrididae, which harbors B chromosome. FISH revealed two main patterns: (i exclusively scattered signals, and (ii scattered and specific signals, forming evident blocks. The enrichment was observed in both euchromatic and heterochromatic areas and only the motif (C30 was absent in heterochromatin. The A and B chromosomes were enriched with all the elements that were mapped, being observed in the B chromosome more distinctive blocks for (GA15 and (GAG10. For A complement distinctive blocks were noticed for (A30, (CA15, (CG15, (GA15, (CAC10, (CAA10, (CGG10, (GAA10, (GAC10 and (GATA8. These results revealed an intense spreading of microsatellites in the A. flavolineata genome that was independent of the A+T or G+C enrichment in the repeats. The data indicate that the microsatellites compose the B chromosome and could be involved in the evolution of this element in this species, although no specific relationship with any A chromosome was observed to discuss about its origin. The systematic analysis presented here contributes to the knowledge of repetitive DNA chromosomal organization among grasshoppers including the B chromosomes.

Desarrollo de tecnologías para el control biológico de la langosta de los llanos orientales

OpenAIRE

A. Cotes

1998-01-01

La langosta de los Llanos Orientales de Colombia Rhammatocerus schistocercoides (Rehn) (Orthoptera: Acrididae), es una especie nativa del continente americano. Esta plaga ha sido registrada en años anteriores en el Brasil y aunque según versiones de los agricultores había sido observada en Colombia en poblaciones bajas, desde 1994 por su alta densidad poblacional y comportamiento gregario, se ha convertido en uno de los insectos más importantes de la entomofauna en la altillanura colombiana, ...

Desarrollo de tecnologías para el control biológico de la langosta de los llanos orientales

OpenAIRE

A. Cotes

2012-01-01

La langosta de los Llanos Orientales de Colombia Rhammatocerus schistocercoides (Rehn) (Orthoptera: Acrididae), es una especie nativa del continente americano. Esta plaga ha sido registrada en años anteriores en el Brasil y aunque según versiones de los agricultores había sido observada en Colombia en poblaciones bajas, desde 1994 por su alta densidad poblacional y comportamiento gregario, se ha convertido en uno de los insectos más importantes de la entomofauna en la altillanura colombiana, ...

Use of large-scale acoustic monitoring to assess anthropogenic pressures on Orthoptera communities.

Science.gov (United States)

Penone, Caterina; Le Viol, Isabelle; Pellissier, Vincent; Julien, Jean-François; Bas, Yves; Kerbiriou, Christian

2013-10-01

Biodiversity monitoring at large spatial and temporal scales is greatly needed in the context of global changes. Although insects are a species-rich group and are important for ecosystem functioning, they have been largely neglected in conservation studies and policies, mainly due to technical and methodological constraints. Sound detection, a nondestructive method, is easily applied within a citizen-science framework and could be an interesting solution for insect monitoring. However, it has not yet been tested at a large scale. We assessed the value of a citizen-science program in which Orthoptera species (Tettigoniidae) were monitored acoustically along roads. We used Bayesian model-averaging analyses to test whether we could detect widely known patterns of anthropogenic effects on insects, such as the negative effects of urbanization or intensive agriculture on Orthoptera populations and communities. We also examined site-abundance correlations between years and estimated the biases in species detection to evaluate and improve the protocol. Urbanization and intensive agricultural landscapes negatively affected Orthoptera species richness, diversity, and abundance. This finding is consistent with results of previous studies of Orthoptera, vertebrates, carabids, and butterflies. The average mass of communities decreased as urbanization increased. The dispersal ability of communities increased as the percentage of agricultural land and, to a lesser extent, urban area increased. Despite changes in abundances over time, we found significant correlations between yearly abundances. We identified biases linked to the protocol (e.g., car speed or temperature) that can be accounted for ease in analyses. We argue that acoustic monitoring of Orthoptera along roads offers several advantages for assessing Orthoptera biodiversity at large spatial and temporal extents, particularly in a citizen science framework. © 2013 Society for Conservation Biology.

Agile Walker.

Science.gov (United States)

Katz, Reuven

2015-01-01

The goal of the Agile Walker is to improve the outdoor mobility of healthy elderly people with some mobility limitations. It is a newly developed, all-terrain walker, equipped with an electric drive system and speed control that can assists elderly people to walk outdoors or to hike. The walker has a unique product design with an attractive look that will appeal to "active-agers" population. This paper describes product design requirements and the development process of the Agile Walker, its features and some preliminary testing results.

The Orthoptera species (Insecta from Danube Delta Biosphere Reserve (Romania

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LUPU Gabriel

2012-09-01

Full Text Available The investigations that were made in the last 10 years and the review of scientific literature who relived studies made on grasshoppers, cricket and bush cricket species from Romania and especially from Danube Delta Biosphere Reserve (D.D.B.R. territory indicate the presence of 80 taxa belonging to Orthoptera order (ClassInsecta, an important number from a total of 187 taxa at national level. In the same time D.D.B.R. is characterized by some interesting elements of orthoptera fauna – one endemic species [Isophya dobrogensis (Kis 1994] on Popina Island, one new species for this territory [Metrioptera (Zeuneriana amplipennis (Brunner von Wattenwyl, 1882] and two species (Isophya dobrogensis (Kis, 1994 and Saga pedo (Pallas, 1771 from Red List of plant and animal species from D.D.B.R. Over 40% orthoptera species from Romania characterize through their presence Danube Delta Biosphere Reserve having a diverse geographical spreading, fact that is correlated with the diversity of dobroudjean climate. This is characterized by unique elements in Romania being an interface area between different types of climate.

Disentangling the role of management, vegetation structure, and plant quality for Orthoptera in lowland meadows.

Science.gov (United States)

Schirmel, Jens; Gerlach, Rebekka; Buhk, Constanze

2017-08-17

Seminatural grasslands provide habitats for various species and are important for biodiversity conservation. The understanding of the diverse responses of species and traits to different grassland management methods is therefore urgently needed. We disentangled the role of grassland management (fertilization and irrigation), vegetation structure (biomass, sward height) and plant quality (protein and fiber content) for Orthoptera communities in lowland hay meadows in Germany. We found vegetation structure to be the most important environmental category in explaining community structure of Orthoptera (species richness, total individuals, functional diversity and species composition). Intensively used meadows (fertilized, irrigated, high plant biomass) were characterized by assemblages with few species, low functional diversity, and low conservation value. Thereby, the relatively moderate fertilizer inputs in our study system of up to ∼75 kg N/ha/year reduced functional diversity of Orthoptera, while this negative effect of fertilization was not detectable when solely considering taxonomic aspects. We found strong support for a prominent role of plant quality in shaping Orthoptera communities and especially the trait composition. Our findings demonstrate the usefulness of considering both taxonomic and functional components (functional diversity) in biodiversity research and we suggest a stronger involvement of plant quality measures in Orthoptera studies. © 2017 Institute of Zoology, Chinese Academy of Sciences.

Temporal-spatial dynamics in orthoptera in relation to nutrient availability and plant species richness.

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Rob J J Hendriks

Full Text Available Nutrient availability in ecosystems has increased dramatically over the last century. Excess reactive nitrogen deposition is known to negatively impact plant communities, e.g. by changing species composition, biomass and vegetation structure. In contrast, little is known on how such impacts propagate to higher trophic levels. To evaluate how nitrogen deposition affects plants and herbivore communities through time, we used extensive databases of spatially explicit historical records of Dutch plant species and Orthoptera (grasshoppers and crickets, a group of animals that are particularly susceptible to changes in the C:N ratio of their resources. We use robust methods that deal with the unstandardized nature of historical databases to test whether nitrogen deposition levels and plant richness changes influence the patterns of richness change of Orthoptera, taking into account Orthoptera species functional traits. Our findings show that effects indeed also propagate to higher trophic levels. Differences in functional traits affected the temporal-spatial dynamics of assemblages of Orthoptera. While nitrogen deposition affected plant diversity, contrary to our expectations, we could not find a strong significant effect of food related traits. However we found that species with low habitat specificity, limited dispersal capacity and egg deposition in the soil were more negativly affected by nitrogen deposition levels. Despite the lack of significant effect of plant richness or food related traits on Orthoptera, the negative effects of nitrogen detected within certain trait groups (e.g. groups with limited disperse ability could be related to subtle changes in plant abundance and plant quality. Our results, however, suggest that the changes in soil conditions (where many Orthoptera species lay their eggs or other habitat changes driven by nitrogen have a stronger influence than food related traits. To fully evaluate the negative effects of nitrogen

Vicious random walkers in the limit of a large number of walkers

International Nuclear Information System (INIS)

Forrester, P.J.

1989-01-01

The vicious random walker problem on a line is studied in the limit of a large number of walkers. The multidimensional integral representing the probability that the p walkers will survive a time t (denoted P t (p) ) is shown to be analogous to the partition function of a particular one-component Coulomb gas. By assuming the existence of the thermodynamic limit for the Coulomb gas, one can deduce asymptotic formulas for P t (p) in the large-p, large-t limit. A straightforward analysis gives rigorous asymptotic formulas for the probability that after a time t the walkers are in their initial configuration (this event is termed a reunion). Consequently, asymptotic formulas for the conditional probability of a reunion, given that all walkers survive, are derived. Also, an asymptotic formula for the conditional probability density that any walker will arrive at a particular point in time t, given that all p walkers survive, is calculated in the limit t >> p

Carnivorous and omnivorous species of Orthoptera order recorded in the Danube Delta Biosphere Reserve

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LUPU N. Gabriel

2007-10-01

Full Text Available Generally known like have a diet exclusively composed from vegetable, the orthoptera species still surprising by few species whereon the type of the track is different. Some species prefer an omnivorous food regime, which have combination between vegetables and animal protein, other have an exclusively carnivorousfood regime, some species manifesting even cannibalism phenomena. For Danube Delta Biosphere Reservation it was find much more orthoptera species even genre that have an food regime other then one exclusively vegetable.

Revisión del género Covasacris (Orthoptera: Acrididae: Acridinae: Hyalopterygini Revision of genus Covasacris (Orthoptera: Acrididae: Acridinae: Hyalopterygini

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Mariano Donato

2003-12-01

Full Text Available Se llevó a cabo la revisión del género monotípico Covasacris Liebermann. A partir del estudio detallado de la morfología externa e interna en ambos sexos y de la comparación con los restantes integrantes de la tribu, se propone que las especies Covasacris albitarsis Liebermann, Parorphula pallidinota Bruner y Parorphula strigata Bruner son la misma entidad, por ello se establece aquí la nueva combinación Covasacris pallidinota (Bruner.The revision of the monotypic genus Covasacris Liebermann was carried out. Based on the detailed study of the external and internal morphology in both sexes and the comparison with the remaining members of the tribe, the synonymy of the species Covasacris albitarsis Liebermann, Parorphula pallidinota Bruner and Parorphula strigata Bruner is proposed. Therefore, the new combination Covasacris pallidinota (Bruner is established.

Vondst van het schavertje Stenobothrus stigmaticus in Zeeland (Orthoptera)

NARCIS (Netherlands)

Bouwman, J.

2005-01-01

Discovery of a population of the lesser mottled grasshopper Stenobothrus stigmaticus on the Dutch coast (Orthoptera) During an inventory of the nature reserve De Vroongronden between the towns of Renesse and Burg-Haamstede (province of Zeeland) the first population of the lesser mottled grasshopper

Studies on taxonomy and distribution of Acridoidea (Orthoptera of Bihar, India

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M.K. Usmani

2012-10-01

Full Text Available Thirty seven species of locusts and grasshoppers representing 26 genera, four tribes and 12 subfamilies belonging to the families Pyrgomorphidae, Catantopidae and Acrididae are reported from different localities of Bihar. Their distinguishing characters and bio-ecological data are provided along with keys to tribes and subfamilies. This paper comprising of distribution and field observation along with taxonomy of Acridoid fauna is the first of its kind from the state.

Antennal sensilla of grasshoppers (Orthoptera: Acrididae) in relation ...

Indian Academy of Sciences (India)

Unknown

number of antennal sensillae varied among different sexes, subfamilies, ... Males showed significantly more sensillae than females, due to presence of more short basiconic and ..... were conducted to the primary olfactory center of the brain,.

Water Budgets of the Walker River Basin and Walker Lake, California and Nevada

Science.gov (United States)

Lopes, Thomas J.; Allander, Kip K.

2009-01-01

The Walker River is the main source of inflow to Walker Lake, a closed-basin lake in west-central Nevada. The only outflow from Walker Lake is evaporation from the lake surface. Between 1882 and 2008, upstream agricultural diversions resulted in a lake-level decline of more than 150 feet and storage loss of 7,400,000 acre-feet. Evaporative concentration increased dissolved solids from 2,500 to 17,000 milligrams per liter. The increase in salinity threatens the survival of the Lahontan cutthroat trout, a native species listed as threatened under the Endangered Species Act. This report describes streamflow in the Walker River basin and an updated water budget of Walker Lake with emphasis on the lower Walker River basin downstream from Wabuska, Nevada. Water budgets are based on average annual flows for a 30-year period (1971-2000). Total surface-water inflow to the upper Walker River basin upstream from Wabuska was estimated to be 387,000 acre-feet per year (acre-ft/yr). About 223,000 acre-ft/yr (58 percent) is from the West Fork of the Walker River; 145,000 acre-ft/yr (37 percent) is from the East Fork of the Walker River; 17,000 acre-ft/yr (4 percent) is from the Sweetwater Range; and 2,000 acre-ft/yr (less than 1 percent) is from the Bodie Mountains, Pine Grove Hills, and western Wassuk Range. Outflow from the upper Walker River basin is 138,000 acre-ft/yr at Wabuska. About 249,000 acre-ft/yr (64 percent) of inflow is diverted for irrigation, transpired by riparian vegetation, evaporates from lakes and reservoirs, and recharges alluvial aquifers. Stream losses in Antelope, Smith, and Bridgeport Valleys are due to evaporation from reservoirs and agricultural diversions with negligible stream infiltration or riparian evapotranspiration. Diversion rates in Antelope and Smith Valleys were estimated to be 3.0 feet per year (ft/yr) in each valley. Irrigated fields receive an additional 0.8 ft of precipitation, groundwater pumpage, or both for a total applied-water rate

Genetics Home Reference: Dandy-Walker malformation

Science.gov (United States)

... Twitter Home Health Conditions Dandy-Walker malformation Dandy-Walker malformation Printable PDF Open All Close All Enable ... to view the expand/collapse boxes. Description Dandy-Walker malformation affects brain development, primarily development of the ...

Polymorphism of the grasshopper Rhammatocerus schistocercoides populations revealed by RAPD Polimorfismo em populações do gafanhoto Rhammatocerus schistocercoides revelado por marcadores RAPD

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João Batista Tavares da Silva

2002-11-01

Full Text Available The objective of this work was to study the genetic variability of the grasshopper Rhammatocerus schistocercoides (Orthoptera: Acrididae using RAPD analysis among individuals from three populations, one from Colombia and two from Brazil (Goiás and Mato Grosso States. Ninety scorable binary markers were obtained by fingerprinting with 11 oligonucleotide primers. Most of the polymorphism was attributed to 42 markers with variable frequency among the different populations. Although the existence of significant difference among populations (PO objetivo deste trabalho foi estudar a variabilidade genética do gafanhoto Rhammatocerus schistocercoides (Orthoptera: Acrididae por meio da análise de RAPD entre indivíduos de três populações, uma da Colômbia e duas do Brasil (Goiás e Mato Grosso. Noventa marcadores binários foram selecionados através de análise de polimorfismo com o uso de 11 oligonucleotídeos. A maior parte do polimorfismo observado foi atribuída a 42 marcadores com freqüência variável entre as diferentes populações. Apesar da existência de diferença significativa interpopulacional (P<0,0001, grande proporção da variabilidade genética foi detectada dentro das populações (87,7% da variação total. As distâncias entre as populações colombianas e brasileiras foram 0,12 (P<0,0001 e 0,18 (P<0,0001 para Goiás e Mato Grosso, respectivamente. A distância obtida entre Goiás e Mato Grosso foi 0,06 (P<0,0001. Estes dados indicam que as diferenças fenotípicas entre populações estão associadas principalmente às distâncias geográficas entre as populações do Brasil e a da Colômbia.

Desarrollo postembrionario de Ronderosia bergi (Orthoptera: Acrididae: Melanoplinae bajo condiciones controladas Postembryonic development of Ronderosia bergi (Orthoptera: Acrididae: Melanoplinae under controlled conditions

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Yanina Mariottini

2006-07-01

Full Text Available Mediante el seguimiento de cohortes correspondientes a la primera generación de bioterio, provenientes de ejemplares capturados en el sudeste de la provincia de San Luis, se registraron algunos parámetros biológicos fundamentales del acridio Ronderosia bergi (Stål bajo condiciones controladas (30 ° C, 40% HR; 14hs. luz, 10 hs. oscuridad. La duración total del desarrollo postembrionario fue de 213 días, de los cuales 30 correspondieron a los cinco estadios del desarrollo ninfal. El número promedio de huevos por postura fue de 16,8, y la madurez sexual fue alcanzada dentro de los 4-5 días después del ingreso a imago. Las diferencias con los escasos datos provenientes de estudios previos, obedecerían a las distintas condiciones de crianza o a una alta variabilidad intraespecífica.First generation cohorts obtained in the laboratory from field collected (southeast of San Luis province individuals of the grasshopper Ronderosia bergi (Stål, were used to measure some developmental parameters of the species under controlled conditions (30 ° C, 40% RH, 14 hs. L: 10 hs. D. The total duration of the postembryonic development was 213 days, of which thirty were devoted to the five instars of nymphal development. The mean number of eggs per eggpod was 16.8, and sexual maturity was reached 4-5 days after the last molt. Differences with data coming from other studies may be due to the different conditions used or the high intraspecific variability of R. bergi.

Sir Gilbert Thomas Walker

Indian Academy of Sciences (India)

He was educated at St Paul's School and later at the. Trinity College ... Walker spent the next 21 years doing research on monsoon ... J Bjerknes in 1969, 11 years after Walker's death. ... water-colours of landscapes at the Shimla Art Exhibition.

Vicious walkers in a potential

International Nuclear Information System (INIS)

Bray, Alan J; Winkler, Karen

2004-01-01

We consider N vicious walkers moving in one dimension in a one-body potential v(x). Using the backward Fokker-Planck equation we derive exact results for the asymptotic form of the survival probability Q(x, t) of vicious walkers initially located at (x 1 , ..., x N ) = x, when v(x) is an arbitrary attractive potential. Explicit results are given for a square-well potential with absorbing or reflecting boundary conditions at the walls, and for a harmonic potential with an absorbing or reflecting boundary at the origin and the walkers starting on the positive half line. By mapping the problem of N vicious walkers in zero potential onto the harmonic potential problem, we rederive the results by Fisher (1984 J. Stat. Phys. 34 667) and Krattenthaler et al (2000 J. Phys. A: Math. Gen. 33 8835) respectively for vicious walkers on an infinite line and on a semi-infinite line with an absorbing wall at the origin. This mapping also gives a new result for vicious walkers on a semi-infinite line with a reflecting boundary at the origin: Q(x,t) ∼ t N(N-1)/2

Three friendly walkers

Science.gov (United States)

Jensen, Iwan

2017-01-01

More than 15 years ago Guttmann and Vöge (2002 J. Stat. Plan. Inference 101 107), introduced a model of friendly walkers. Since then it has remained unsolved. In this paper we provide the exact solution to a closely allied model which essentially only differs in the boundary conditions. The exact solution is expressed in terms of the reciprocal of the generating function for vicious walkers which is a D-finite function. However, ratios of D-finite functions are inherently not D-finite and in this case we prove that the friendly walkers generating function is the solution to a non-linear differential equation with polynomial coefficients, it is in other words D-algebraic. We find using numerically exact calculations a conjectured expression for the generating function of the original model as a ratio of a D-finite function and the generating function for vicious walkers. We obtain an expression for this D-finite function in terms of a {{}2}{{F}1} hypergeometric function with a rational pullback and its first and second derivatives. Dedicated to Tony Guttmann on the occasion of his 70th birthday.

Curvature properties of four-dimensional Walker metrics

International Nuclear Information System (INIS)

Chaichi, M; Garcia-Rio, E; Matsushita, Y

2005-01-01

A Walker n-manifold is a semi-Riemannian manifold, which admits a field of parallel null r-planes, r ≤ n/2. In the present paper we study curvature properties of a Walker 4-manifold (M, g) which admits a field of parallel null 2-planes. The metric g is necessarily of neutral signature (+ + - -). Such a Walker 4-manifold is the lowest dimensional example not of Lorentz type. There are three functions of coordinates which define a Walker metric. Some recent work shows that a Walker 4-manifold of restricted type whose metric is characterized by two functions exhibits a large variety of symplectic structures, Hermitian structures, Kaehler structures, etc. For such a restricted Walker 4-manifold, we shall study mainly curvature properties, e.g., conditions for a Walker metric to be Einstein, Osserman, or locally conformally flat, etc. One of our main results is the exact solutions to the Einstein equations for a restricted Walker 4-manifold

Why is walker-assisted gait metabolically expensive?

Science.gov (United States)

Priebe, Jonathon R; Kram, Rodger

2011-06-01

Walker-assisted gait is reported to be ∼200% more metabolically expensive than normal bipedal walking. However, previous studies compared different walking speeds. Here, we compared the metabolic power consumption and basic stride temporal-spatial parameters for 10 young, healthy adults walking without assistance and using 2-wheeled (2W), 4-wheeled (4W) and 4-footed (4F) walker devices, all at the same speed, 0.30m/s. We also measured the metabolic power demand for walking without any assistive device using a step-to gait at 0.30m/s, walking normally at 1.25m/s, and for repeated lifting of the 4F walker mimicking the lifting pattern used during 4F walker-assisted gait. Similar to previous studies, we found that the cost per distance walked was 217% greater with a 4F walker at 0.30m/s compared to unassisted, bipedal walking at 1.25m/s. Compared at the same speed, 0.30m/s, using a 4F walker was still 82%, 74%, and 55% energetically more expensive than walking unassisted, with a 4W walker and a 2W walker respectively. The sum of the metabolic cost of step-to walking plus the cost of lifting itself was equivalent to the cost of walking with a 4F walker. Thus, we deduce that the high cost of 4F walker assisted gait is due to three factors: the slow walking speed, the step-to gait pattern and the repeated lifting of the walker. Copyright © 2011 Elsevier B.V. All rights reserved.

Een nieuwe vondst van het locomotiefje Chorthippus apricarius in Nederland (Orthoptera)

NARCIS (Netherlands)

Groenendijk, D.; Groenendijk, M.

1999-01-01

A new record of Chorthippus apricarius in the Netherlands (Orthoptera) Chorthippus apricarius is a very rare grasshopper in The Netherlands. Only three, very widely separated sites are known. In 1998 a small new population has been found in a roadside verge, 2 km southwest of the southernmost site

A walker with a device of partial suspension for patients with gait disturbance: body weight supported walker.

Science.gov (United States)

Ochi, Mitsuhiro; Makino, Kenichiro; Wada, Futoshi; Saeki, Satoru; Hachisuka, Kenji

2009-09-01

We developed a walker, the Body Weight Supported (BWS) Walker, with a device of partial suspension for patients with gait disturbance. It consists of a light frame with casters, a harness, and a winch system. One therapist alone can perform gait training safely with the BWS Walker without any additional physical load, even if a patient has severe gait disturbance, and the therapist can concentrate on evaluating and improving the patient' s standing balance and gait pattern. Because the BWS Walker is less expensive, simpler, and easier to operate than other BWS systems, we believe the BWS Walker can be widely applicable in training for patients with severe and moderate gait disturbance.

Diversity of Orthoptera (Insecta fauna of Achanakmar Wildlife Sanctuary, Bilaspur, Chhattisgarh, India

Directory of Open Access Journals (Sweden)

Sunil Kumar Gupta

2017-03-01

Full Text Available The paper presents the distributional record of the Orthoptera fauna of Achanakmar Wildlife Sanctuary, Bilaspur, Chhattisgarh, India. Thirty-three species pertaining to 30 genera under five families are reported. The habitus photographs and map is provided for the first time.

Fibreglass Total Contact Casting, Removable Cast Walkers, and Irremovable Cast Walkers to Treat Diabetic Neuropathic Foot Ulcers: A Health Technology Assessment

Science.gov (United States)

Costa, Vania; Tu, Hong Anh; Wells, David; Weir, Mark; Holubowich, Corinne; Walter, Melissa

2017-01-01

Background Diabetic neuropathic foot ulcers are a risk factor for lower leg amputation. Many experts recommend offloading with fibreglass total contact casting, removable cast walkers, and irremovable cast walkers as a way to treat these ulcers. Methods We completed a health technology assessment, which included an evaluation of clinical benefits and harms, value for money, and patient preferences for offloading devices. We performed a systematic literature search on August 17, 2016, to identify randomized controlled trials that compared fibreglass total contact casting, removable cast walkers, and irremovable cast walkers with other treatments (offloading or non-offloading) in patients with diabetic neuropathic foot ulcers. We developed a decision-analytic model to assess the cost-effectiveness of fibreglass total contact casting, removable cast walkers, and irremovable cast walkers, and we conducted a 5-year budget impact analysis. Finally, we interviewed people with diabetes who had lived experience with foot ulcers, asking them about the different offloading devices and the factors that influenced their treatment choices. Results We identified 13 randomized controlled trials. The evidence suggests that total contact casting, removable cast walkers, and irremovable cast walkers are beneficial in the treatment of neuropathic, noninfected foot ulcers in patients with diabetes but without severe peripheral arterial disease. Compared to removable cast walkers, ulcer healing was improved with total contact casting (moderate quality evidence; risk difference 0.17 [95% confidence interval 0.00–0.33]) and irremovable cast walkers (low quality evidence; risk difference 0.21 [95% confidence interval 0.01–0.40]). We found no difference in ulcer healing between total contact casting and irremovable cast walkers (low quality evidence; risk difference 0.02 [95% confidence interval −0.11–0.14]). The economic analysis showed that total contact casting and irremovable

Families of vicious walkers

International Nuclear Information System (INIS)

Cardy, John; Katori, Makoto

2003-01-01

We consider a generalization of the vicious walker problem in which N random walkers in R d are grouped into p families. Using field-theoretic renormalization group methods we calculate the asymptotic behaviour of the probability that no pairs of walkers from different families have met up to time t. For d > 2, this is constant, but for d -α , which we compute to O(ε 2 ) in an expansion in ε = 2 - d. The second-order term depends on the ratios of the diffusivities of the different families. In two dimensions, we find a logarithmic decay (ln t) -α-bar and compute α-bar exactly

Recent progress on DNA based walkers.

Science.gov (United States)

Pan, Jing; Li, Feiran; Cha, Tae-Gon; Chen, Haorong; Choi, Jong Hyun

2015-08-01

DNA based synthetic molecular walkers are reminiscent of biological protein motors. They are powered by hybridization with fuel strands, environment induced conformational transitions, and covalent chemistry of oligonucleotides. Recent developments in experimental techniques enable direct observation of individual walkers with high temporal and spatial resolution. The functionalities of state-of-the-art DNA walker systems can thus be analyzed for various applications. Herein we review recent progress on DNA walker principles and characterization methods, and evaluate various aspects of their functions for future applications. Copyright © 2014 Elsevier Ltd. All rights reserved.

Baby walkers--health visitors' current practice, attitudes and knowledge.

Science.gov (United States)

Kendrick, Denise; Illingworth, Rachel; Hapgood, Rhydian; Woods, Amanda J; Collier, Jacqueline

2003-09-01

Baby walkers are a commonly used item of nursery equipment. Between 12% and 50% of parents whose infant uses a walker report that their child has suffered a walker-related injury. Health visitors' knowledge, attitudes and practice with regard to walkers and related health education has not been explored so far. The aim of the study was to describe health visitors' knowledge of walkers and walker-related injuries, their attitudes towards walkers and current practice with regard to walker health education, and to examine the relationship between knowledge and attitudes and knowledge and practice. A survey was carried out with 64 health visitors prior to participation in a randomized controlled trial assessing the effectiveness of an educational package in reducing baby walker use. The response rate was 95%. Half of the health visitors always discussed walkers postnatally, most frequently at the 6-9 month check. Most did not usually discuss the frequency of walker-related injuries. Most had negative attitudes towards walkers, but believed that parents hold positive attitudes to them and that it is hard to persuade parents not to use them. Health visitors had a limited knowledge of walker use and walker-related injuries. Those giving advice on walkers most often had higher knowledge scores than those giving advice less often (P = 0.03). Those with higher knowledge scores held more negative attitudes towards walkers (rs = 0.29, P = 0.023) and believed parents to have more positive attitudes towards walkers (rs = -0.49, P negotiating alternatives to their use. The provision of audio-visual aids for discussing walkers might also be helpful.

21 CFR 890.3825 - Mechanical walker.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Mechanical walker. 890.3825 Section 890.3825 Food... DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3825 Mechanical walker. (a) Identification. A mechanical walker is a four-legged device with a metal frame intended for medical purposes to...

Sir Gilbert Thomas Walker

Indian Academy of Sciences (India)

playa fundamental role in the variability of the earth's climate. Walker noted a tendency of ... Walker was however not able to ascertain the physical mechanism governing these oscillations. In the first two ... In 1927, he made the follow- ing prophetic statement: "There is, to-day, always a risk that specialists in two subjects,.

Aging in mortal superdiffusive Lévy walkers

Science.gov (United States)

Stage, Helena

2017-12-01

A growing body of literature examines the effects of superdiffusive subballistic movement premeasurement (aging or time lag) on observations arising from single-particle tracking. A neglected aspect is the finite lifetime of these Lévy walkers, be they proteins, cells, or larger structures. We examine the effects of aging on the motility of mortal walkers, and discuss the means by which permanent stopping of walkers may be categorized as arising from "natural" death or experimental artifacts such as low photostability or radiation damage. This is done by comparison of the walkers' mean squared displacement (MSD) with the front velocity of propagation of a group of walkers, which is found to be invariant under time lags. For any running time distribution of a mortal random walker, the MSD is tempered by the stopping rate θ . This provides a physical interpretation for truncated heavy-tailed diffusion processes and serves as a tool by which to better classify the underlying running time distributions of random walkers. Tempering of aged MSDs raises the issue of misinterpreting superdiffusive motion which appears Brownian or subdiffusive over certain time scales.

Aging in mortal superdiffusive Lévy walkers.

Science.gov (United States)

Stage, Helena

2017-12-01

A growing body of literature examines the effects of superdiffusive subballistic movement premeasurement (aging or time lag) on observations arising from single-particle tracking. A neglected aspect is the finite lifetime of these Lévy walkers, be they proteins, cells, or larger structures. We examine the effects of aging on the motility of mortal walkers, and discuss the means by which permanent stopping of walkers may be categorized as arising from "natural" death or experimental artifacts such as low photostability or radiation damage. This is done by comparison of the walkers' mean squared displacement (MSD) with the front velocity of propagation of a group of walkers, which is found to be invariant under time lags. For any running time distribution of a mortal random walker, the MSD is tempered by the stopping rate θ. This provides a physical interpretation for truncated heavy-tailed diffusion processes and serves as a tool by which to better classify the underlying running time distributions of random walkers. Tempering of aged MSDs raises the issue of misinterpreting superdiffusive motion which appears Brownian or subdiffusive over certain time scales.

Salvadoracris e Caruaruacris, novos gêneros de gafanhotos sul-americanos (Orthoptera, Acrididae Salvadoracris and Caruaruacris, new South American genera of grasshopper (Orthoptera, Acrididae

Directory of Open Access Journals (Sweden)

Maria Kátia Matiotti da Costa

2006-03-01

Full Text Available Salvadoracris gen. nov. com S. nigritus sp. nov. (espécie-tipo, do Peru (Cuzco e Caruaruacris gen. nov. com C. bivittatus sp. nov. (espécie-tipo, do Brasil, Pernambuco, são descritos e ilustrados.Salvadoracris gen. nov. with S. nigritus sp. nov. (type species from Peru, Cuzco, and Caruaruacris gen. nov. with C. bivittatus sp. nov. (type species, from Brazil, Pernambuco, are described and illustrated.

Dandy-Walker variant in Coffin-Siris syndrome.

Science.gov (United States)

Imai, T; Hattori, H; Miyazaki, M; Higuchi, Y; Adachi, S; Nakahata, T

2001-04-22

We describe a five-month-old male infant with Coffin-Siris syndrome, the so-called Dandy-Walker variant (hypoplasia of the cerebellar vermis with cystic dilatation of the fourth ventricle, but without enlargement of the posterior fossa), and partial agenesis of the corpus callosum. Dandy-Walker malformation and mega cisterna magna, but not Dandy-Walker variant, have been reported in Coffin-Siris syndrome. The presence of Dandy-Walker variant in the infant we described confirms that the full continuum of the Dandy-Walker complex can occur in Coffin-Siris syndrome. The yet unidentified gene(s) for the syndrome may be related to the development of the hindbrain. Copyright 2001 Wiley-Liss, Inc.

Fall prevention walker during rehabilitation

Science.gov (United States)

Tee, Kian Sek; E, Chun Zhi; Saim, Hashim; Zakaria, Wan Nurshazwani Wan; Khialdin, Safinaz Binti Mohd; Isa, Hazlita; Awad, M. I.; Soon, Chin Fhong

2017-09-01

This paper proposes on the design of a walker for the prevention of falling among elderlies or patients during rehabilitation whenever they use a walker to assist them. Fall happens due to impaired balance or gait problem. The assistive device is designed by applying stability concept and an accelerometric fall detection system is included. The accelerometric fall detection system acts as an alerting device that acquires body accelerometric data and detect fall. Recorded accelerometric data could be useful for further assessment. Structural strength of the walker was verified via iterations of simulation using finite element analysis, before being fabricated. Experiments were conducted to identify the fall patterns using accelerometric data. The design process and detection of fall pattern demonstrates the design of a walker that could support the user without fail and alerts the helper, thus salvaging the users from injuries due to fall and unattended situation.

Prima segnalazione di Saga pedo (Pallas, 1771) per la Toscana (Orthoptera: Tettigoniidae)

OpenAIRE

Vergari, Sebastiano; Vergari, Simone; Dondini, Gianna; Carotti, Giovanni

2017-01-01

First record of Saga pedo (Pallas, 1771) for Tuscany (Orthoptera: Tettigoniidae). The presence in Tuscany of the katydid Saga pedo (Pallas, 1771) is recorded for the first time. Saga pedo is considered a vulnerable species in the EU and it is included in Annex IV of Council Directive 92/43/EEC.

Vicious walkers and hook Young tableaux

International Nuclear Information System (INIS)

Hikami, Kazuhiro; Imamura, Takashi

2003-01-01

We consider a generalization of the vicious walker model. Using a bijection map between the path configuration of the non-intersecting random walkers and the hook Young diagram, we compute the probability concerning the number of movements of the walker. Applying the saddle point method, we reveal that the scaling limit gives the Tracy-Widom distribution, which is the same with the limit distribution of the largest eigenvalues of the Gaussian unitary ensemble

Quincke random walkers

Science.gov (United States)

Pradillo, Gerardo; Heintz, Aneesh; Vlahovska, Petia

2017-11-01

The spontaneous rotation of a sphere in an applied uniform DC electric field (Quincke effect) has been utilized to engineer self-propelled particles: if the sphere is initially resting on a surface, it rolls. The Quincke rollers have been widely used as a model system to study collective behavior in ``active'' suspensions. If the applied field is DC, an isolated Quincke roller follows a straight line trajectory. In this talk, we discuss the design of a Quincke roller that executes a random-walk-like behavior. We utilize AC field - upon reversal of the field direction a fluctuation in the axis of rotation (which is degenerate in the plane perpendicular to the field and parallel to the surface) introduces randomness in the direction of motion. The MSD of an isolated Quincke walker depends on frequency, amplitude, and waveform of the electric field. Experiment and theory are compared. We also investigate the collective behavior of Quincke walkers,the transport of inert particles in a bath of Quincke walkers, and the spontaneous motion of a drop containing Quincke active particle. supported by NSF Grant CBET 1437545.

Waarnemingen van de veenmol Gryllotalpa gryllotalpa in de duinen van Noord-Holland (Orthoptera).

NARCIS (Netherlands)

Kerkhof, W.

2007-01-01

The mole cricket Gryllotalpa gryllotalpa in de Dutch dunes (Orthoptera) In recent years mole crickets Gryllotalpa gryllotalpa were found at 37 sites in the Dutch dunes. Conservation measures to create moist dune valleys seem to play a positive role for mole crickets. Half of the new records stemmed

75 FR 38833 - Walker River Basin Acquisition Program

Science.gov (United States)

2010-07-06

... DEPARTMENT OF THE INTERIOR Bureau of Reclamation Walker River Basin Acquisition Program AGENCY... (Reclamation) is canceling work on the Environmental Impact Statement (EIS) for the Walker River Basin... Walker River, primarily for irrigated agriculture, have resulted in a steadily declining surface...

A review of the functionalities of smart walkers.

Science.gov (United States)

Martins, Maria; Santos, Cristina; Frizera, Anselmo; Ceres, Ramón

2015-10-01

There is a need to conceptualize and improve the investigation and developments in assistive devices, focusing on the design and effectiveness of walkers in the user's rehabilitation process and functional compensation. This review surveys the importance of smart walkers in maintaining mobility and discusses their potential in rehabilitation and their demands as assistive devices. It also presents related research in addressing and quantifying the smart walker's efficiency and influence on gait. Besides, it discusses smart walkers focusing on studies related to the concept of autonomous and shared-control and manual guidance, the use of smart walkers as personal helpers to sit-to-stand and diagnostic tools for patients' rehabilitation through the evaluation of their gait. Copyright © 2015 IPEM. Published by Elsevier Ltd. All rights reserved.

Random walk on a population of random walkers

International Nuclear Information System (INIS)

Agliari, E; Burioni, R; Cassi, D; Neri, F M

2008-01-01

We consider a population of N labelled random walkers moving on a substrate, and an excitation jumping among the walkers upon contact. The label X(t) of the walker carrying the excitation at time t can be viewed as a stochastic process, where the transition probabilities are a stochastic process themselves. Upon mapping onto two simpler processes, the quantities characterizing X(t) can be calculated in the limit of long times and low walkers density. The results are compared with numerical simulations. Several different topologies for the substrate underlying diffusion are considered

Pediatricians' attitude about the use of infant walkers.

Science.gov (United States)

Kara, Semra; Yilmaz, Ayşe Esra; Gümüş Dogan, Derya; Bilici, Meki; Turkay, Sadi; Akca, Halise; Catal, Ferhat

2013-12-01

Infant walkers are still very popular even though their use might cause injuries. A survey was carried out to obtain information about attitudes and pediatricians' approach regarding the use of infant walkers. Two hundred and forty seven pediatricians who attended the 44th Turkish Congress of Pediatrics and Europediatrics (2008) were invited to reply to a questionnaire prepared by the authors. Two hundred and twenty six questionnaires replied in full were included. The median age of participants (119 women) was 39 years old (range: 29-58 years old). Out of the total, 4% recommended the use of a walker; 32.2% left the decision to parents' judgment, and 63.7% did not recommend its use. A hundred and five had previously treated an infant who had an injury associated to the use of the walker; out of them, 73.3% did not recommend its use and 57.1% stated that there should be a ban on the sale and manufacture of walkers. Out of the total number of surveyed pediatricians, 4% recommend the use of infant walkers and over 30% leave this decision to parents. Those pediatricians who took care of babies who had an injury associated to the use of a walker were less prone to recommending it.

Using walker during walking: a pilot study for health elder.

Science.gov (United States)

Po-Chan, Yeh; Cherng-Yee, Leung

2012-01-01

Walker operation completely relies on the walker handle, however most marketed walkers possess two horizontal handles. Several researchers have suggested that horizontal handles might lead to wrist injury. Therefore, the purpose of this study is to assess the relevant design aspects of walker for elderly people. 28 elders participated in this study; when the experiment was started, subject walked on the tile for 3 meter distance twice by using walker. Data for analysis were selected at the corresponding wrist deviation and vertical force. The results showed that during walker using, the mean wrist deviation was greater than zero. The largest vertical force is significantly larger than the smallest one, and different wrist deviation occurred at three phases, the largest wrist deviation while raising walker is larger than the smallest one, however, no significant different was found between the largest and smallest wrist deviation while pressing walker. No significant correlation occurred between weight and wrist deviation. The correlation between weight and vertical force was significantly positive. With wrist deviation walker use may cause injury to upper-limb, however wrists remain in a neutral position during hand movement to prevent damage. The findings of this study should improve the design of walker handles to reduce the wrist deviations of users.

Desarrollo de tecnologías para el control biológico de la langosta de los llanos orientales

Directory of Open Access Journals (Sweden)

A. Cotes

1998-01-01

Full Text Available La langosta de los Llanos Orientales de Colombia Rhammatocerus schistocercoides (Rehn (Orthoptera: Acrididae, es una especie nativa del continente americano. Esta plaga ha sido registrada en años anteriores en el Brasil y aunque según versiones de los agricultores había sido observada en Colombia en poblaciones bajas, desde 1994 por su alta densidad poblacional y comportamiento gregario, se ha convertido en uno de los insectos más importantes de la entomofauna en la altillanura colombiana, ya que afecta extensas áreas de sabana nativa, pastos mejorados. Este insecto además representa un riesgo potencial para cultivos de importancia econ6mica como son el arroz, el maíz, la caña de azúcar y el sorgo.

Realization of Robertson-Walker spacetimes as affine hypersurfaces

International Nuclear Information System (INIS)

Chen Bangyen

2007-01-01

Due to the growing interest in embeddings of spacetimes in higher dimensional spaces, we consider a special type of embedding. We prove that Robertson-Walker spacetimes can be embedded as centroaffine hypersurfaces and graph hypersurfaces in some affine spaces in such a way that the induced relative metrics are exactly the Lorentzian metrics on the Robertson-Walker spacetimes. Such realizations allow us to view Robertson-Walker spacetimes and their submanifolds as affine submanifolds in a natural way. Consequently, our realizations make it possible to apply the tools of affine differential geometry to study Robertson-Walker spacetimes and their submanifolds

Variante de Dandy Walker: relato de caso = Dandy Walker variant: a case report

Directory of Open Access Journals (Sweden)

Khan, Richard Lester

2009-01-01

Conclusões: este artigo procura caracterizar a variante de Dandy Walker, que é uma malformação congênita do sistema nervoso central e é o tipo mais comum da Síndrome de Dandy Walker. Seu fenótipo é variável, devendo-se sempre pesquisar malformações tanto intra quanto extracranianas, visto que o risco de mortalidade pós-natal aumenta quando existe esta associação. O tratamento envolve equipe multidisciplinar e o prognóstico é reservado, variando conforme o fenótipo

Biomimetic Molecular Signaling using DNA Walkers on Microparticles.

Science.gov (United States)

Damase, Tulsi Ram; Spencer, Adam; Samuel, Bamidele; Allen, Peter B

2017-06-22

We report the release of catalytic DNA walkers from hydrogel microparticles and the detection of those walkers by substrate-coated microparticles. This might be considered a synthetic biology analog of molecular signal release and reception. One type of particles was coated with components of a DNA one-step strand displacement (OSD) reaction to release the walker. A second type of particle was coated with substrate (or "track") for the molecular walker. We distinguish these particle types using fluorescence barcoding: we synthesized and distinguished multiple particle types with multicolor fluorescence microscopy and automated image analysis software. This represents a step toward amplified, multiplex, and microscopically localized detection based on DNA nanotechnology.

Dandy-Walker Syndrome

Science.gov (United States)

... treatment options. Other research indicates that mothers with diabetes and those with rubella (German measles) during pregnancy are more likely to have a child with Dandy-Walker syndrome. × What research is being ...

Dandy Walker malformation

African Journals Online (AJOL)

PROF. EZECHUKWU

2014-10-01

- tion of Dandy walker syndrome to enhance early diagnosis, prompt intervention and better outcome ... tion of the central nervous system. It results from a .... Other predisposing factors include first trimester exposure to rubella ...

Beliefs about the use of baby walkers.

Science.gov (United States)

Chagas, Paula S C; Mancini, Marisa C; Tirado, Marcella G A; Megale, Luiz; Sampaio, Rosana F

2011-01-01

To understand the opinion of the parents about the baby walker and compare the age of gait acquisition between infants that used a walker and those that did not. In this quali-quantitative study, an interview involving a semi-structured questionnaire was carried out with 26 parents, 14 of whose infants used the equipment (BWG) and 12 of whose infants did not (NBWG) prior to gait acquisition. After extensive content analysis, categories for interpreting the results emerged. For data triangulation, the age of gait acquisition was documented by weekly telephone contact. Student's t-test was used for comparison between groups with a significance level of α=0.05. The following categories were identified in the parents' reports: a) information about the baby walker; b) doubt/decision to use it vs. certainty about not using it; c) beliefs about the use of a baby-walker; and d) benefits and harm from use. The age of independent gait acquisition did not differ between groups (p=0.837): BWG initiated gait at 376.17 (SD=32.62) days and NBWG did so at 378.75 (SD=27.99) days. The beliefs and feelings that permeate the decision to use a baby walker illustrate the different rationales adopted by parents about the role of this equipment in the child's development of gait and autonomy. The use of a baby walker did not influence the age of gait acquisition. The results broaden the understanding of choices that influence child-rearing practices prior to gait acquisition.

Singular perturbations of empty Robertson-Walker cosmologies

International Nuclear Information System (INIS)

Newman, R.P.A.C.

1979-02-01

An investigation is presented which concerns a class of cosmological models defined by McVittie (1931): the universe is envisaged as a set of galaxies, idealised as point particles, which provide singular perturbations of Robertson-Walker cosmologies. The perturbations are considered only to first order in the gravitational coupling constant (8πG)/c 2 . Attention will only be given to such perturbations of empty Robertson-Walker cosmologies. Chapter 1 summarises the observational support for the type of model employed and for the smallness of the quantities to be used as perturbation coefficients. Chapter 2 provides the prerequisite analysis of Robertson-Walker cosmologies. Perturbations of empty Robertson-Walker cosmologies of non-vanishing cosmical constant are considered in general in Chapter 3. The structure of McVittie's singularly perturbed Robertson-Walker cosmologies are considered in detail in Chapter 4. The remaining chapters seek to investigate them further by way of their optical properties. Chapter 5 provides the necessary theory of geometric optics with particular regard to the intensity and distortion of a beam of light, and Chapter 6 applies this theory to the McVittie cosmologies. Chapter 7 sees the definition of an averaging procedure which leads to expressions for the intensity and distortion of a typical beam of light from a point source. (author)

The role of walkers' needs and expectations in supporting maintenance of attendance at walking groups: a longitudinal multi-perspective study of walkers and walk group leaders.

Science.gov (United States)

Kassavou, Aikaterini; Turner, Andrew; French, David P

2015-01-01

There is good evidence that when people's needs and expectations regarding behaviour change are met, they are satisfied with that change, and maintain those changes. Despite this, there is a dearth of research on needs and expectations of walkers when initially attending walking groups and whether and how these needs and expectations have been satisfied after a period of attendance. Equally, there is an absence of research on how people who lead these groups understand walkers' needs and walk leaders' actions to address them. The present study was aimed at addressing both of these gaps in the research. Two preliminary thematic analyses were conducted on face-to-face interviews with (a) eight walkers when they joined walking groups, five of whom were interviewed three months later, and (b) eight walk leaders. A multi-perspective analysis building upon these preliminary analyses identified similarities and differences within the themes that emerged from the interviews with walkers and walk leaders. Walkers indicated that their main needs and expectations when joining walking groups were achieving long-term social and health benefits. At the follow up interviews, walkers indicated that satisfaction with meeting similar others within the groups was the main reason for continued attendance. Their main source of dissatisfaction was not feeling integrated in the existing walking groups. Walk leaders often acknowledged the same reasons for walkers joining and maintaining attendance at walking. However, they tended to attribute dissatisfaction and drop out to uncontrollable environmental factors and/or walkers' personalities. Walk leaders reported a lack of efficacy to effectively address walkers' needs. Interventions to increase retention of walkers should train walk leaders with the skills to help them modify the underlying psychological factors affecting walkers' maintenance at walking groups. This should result in greater retention of walkers in walking groups, thereby

The role of walkers' needs and expectations in supporting maintenance of attendance at walking groups: a longitudinal multi-perspective study of walkers and walk group leaders.

Directory of Open Access Journals (Sweden)

Aikaterini Kassavou

Full Text Available There is good evidence that when people's needs and expectations regarding behaviour change are met, they are satisfied with that change, and maintain those changes. Despite this, there is a dearth of research on needs and expectations of walkers when initially attending walking groups and whether and how these needs and expectations have been satisfied after a period of attendance. Equally, there is an absence of research on how people who lead these groups understand walkers' needs and walk leaders' actions to address them. The present study was aimed at addressing both of these gaps in the research.Two preliminary thematic analyses were conducted on face-to-face interviews with (a eight walkers when they joined walking groups, five of whom were interviewed three months later, and (b eight walk leaders. A multi-perspective analysis building upon these preliminary analyses identified similarities and differences within the themes that emerged from the interviews with walkers and walk leaders.Walkers indicated that their main needs and expectations when joining walking groups were achieving long-term social and health benefits. At the follow up interviews, walkers indicated that satisfaction with meeting similar others within the groups was the main reason for continued attendance. Their main source of dissatisfaction was not feeling integrated in the existing walking groups. Walk leaders often acknowledged the same reasons for walkers joining and maintaining attendance at walking. However, they tended to attribute dissatisfaction and drop out to uncontrollable environmental factors and/or walkers' personalities. Walk leaders reported a lack of efficacy to effectively address walkers' needs.Interventions to increase retention of walkers should train walk leaders with the skills to help them modify the underlying psychological factors affecting walkers' maintenance at walking groups. This should result in greater retention of walkers in walking

Intelligent control of a smart walker and its performance evaluation.

Science.gov (United States)

Grondin, Simon L; Li, Qingguo

2013-06-01

Recent technological advances have allowed the development of force-dependent, intelligently controlled smart walkers that are able to provide users with enhanced mobility, support and gait assistance. The purpose of this study was to develop an intelligent rule-based controller for a smart walker to achieve a smooth interaction between the user and the walker. This study developed a rule-based mapping between the interaction force, measured by a load cell attached to the walker handle, and the acceleration of the walker. Ten young, healthy subjects were used to evaluate the performance of the proposed controller compared to a well-known admittance-based control system. There were no significant differences between the two control systems concerning their user experience, velocity profiles or average cost of transportation. However, the admittance-based control system required a 1.2N lower average interaction force to maintain the 1m/s target speed (p = 0.002). Metabolic data also indicated that smart walker-assisted gait could considerably reduce the metabolic demand of walking with a four-legged walker.

Insect pests of Eucalyptus and their control

Energy Technology Data Exchange (ETDEWEB)

Sen-Sarma, P K; Thakur, M L

1983-12-01

In India, about sixty odd species of insects have so far been recorded to be associated with Eucalyptus. Important pests are some xylophagous insects, sap suckers, defoliators and termites. Of these, stem and root borer, Celostrna scabrator Fabr, and some species of termites have been recognised as key pests, whereas Apogonia coriaces Waterhouse, Mimeta mundissima Walker (Coleoptera: Scarabaeidae), Agrotis ipsilon Hufnagel (Lepidoptera: Noctuidae), Brachytrypus portenosus Lichtenstein and Gymmogryllus humeralis Walker (Orthoptera: Gryllidae) are likely to become potential pests in Eucalyptus nurseries. In this paper available information on insect pests of Eucalyptus, their bioecology and control measures have been presented.

Hydrogel Walkers with Electro-Driven Motility for Cargo Transport.

Science.gov (United States)

Yang, Chao; Wang, Wei; Yao, Chen; Xie, Rui; Ju, Xiao-Jie; Liu, Zhuang; Chu, Liang-Yin

2015-08-28

In this study, soft hydrogel walkers with electro-driven motility for cargo transport have been developed via a facile mould-assisted strategy. The hydrogel walkers consisting of polyanionic poly(2-acrylamido-2-methylpropanesulfonic acid-co-acrylamide) exhibit an arc looper-like shape with two "legs" for walking. The hydrogel walkers can reversibly bend and stretch via repeated "on/off" electro-triggers in electrolyte solution. Based on such bending/stretching behaviors, the hydrogel walkers can move their two "legs" to achieve one-directional walking motion on a rough surface via repeated "on/off" electro-triggering cycles. Moreover, the hydrogel walkers loaded with very heavy cargo also exhibit excellent walking motion for cargo transport. Such hydrogel systems create new opportunities for developing electro-controlled soft systems with simple design/fabrication strategies in the soft robotic field for remote manipulation and transportation.

Perceiving Direction of a Walker: Effect of Body Appearance

Directory of Open Access Journals (Sweden)

Kazuya Ono

2011-05-01

Full Text Available Human can perceive others' walking direction accurately even with 117ms observation (Sato, et al., ECVP2008. We aimed to see whether appearance of walker's body affects the accuracy of perceiving direction of the walker. Thus, we employed three different appearances: realistic human computer-graphics body (CG-human, nonrealistic cylinder-assembled body (Cylinders, and point-light walker (Points. We made a three-dimensional model of an adult-size walker who walked at a place. CG-human stimuli were generated by rendering the model with smooth shading. We made Cylinders stimuli by replacing body parts such as arms, legs, head, and hands with cylinders. Points stimuli were made by tracking 18 positions (mostly joints of the body like biological motion. One of walkers was presented for 117, 250, 500 or 1000ms while its direction was randomly varied by 3deg steps to 21deg left or right. Observers judged whether the walker was walking toward them (hit or not (miss, and self-range was measured in terms of the standard deviation for hit distributions. The perceived self-range was narrowed with long duration, and with CG-human stimulus. It is suggested that the accuracy of perceiving walker's direction depends on body appearance, and it is higher for human-like body than nonhuman body.

A new species of Ormocerus Walker (Hymenoptera: Pteromalidae) from North America and a range expansion for Ormocerus latus Walker

Science.gov (United States)

Ormocerus dirigoius, n. sp. is described and compared to the North American O. americanus Dzhanokmen and Grissell and European species O. latus Walker and O. vernalis Walker. A range expansion into the Nearctic is reported for O. latus, previously only known from the Palearctic. Specimens were colle...

78 FR 48301 - Establishment of Class E Airspace; Walker, MN

Science.gov (United States)

2013-08-08

...-0266; Airspace Docket No. 13-AGL-11] Establishment of Class E Airspace; Walker, MN AGENCY: Federal... at Walker, MN. Controlled airspace is necessary to accommodate new Area Navigation (RNAV) Standard Instrument Approach Procedures at Walker Municipal Airport. The FAA is taking this action to enhance the...

A walker used as a lifting device.

Science.gov (United States)

Glimskär, Bo; Hjalmarson, Jenny; Lundberg, Stefan; Larsson, Tore

2014-05-01

To develop assistive technology that would help an older person to arise from a kneeling position to a standing one. Developing a prototype, based on an inclusive design and then testing the prototype to verify the approach. The prototype was subsequently tested by a panel of 20 elderly users. These tests were observed and filmed. Participants' experiences of being lifted with the elevation seat were registered with the VIDAR ergonomic assessment system. None of the 20 participants used a walker at that time. In response to a question of whether, assuming they might have to use a walker in the future, they thought that a walker with an elevating seat would be helpful, 18 said that it would. Two of the participants did not believe that they would ever have to use a walker. A simple assistive technology such as a walker equipped with an elevating seat would in many of these cases simplify matters and reduce the distress of people who fall often. In addition, such a device can allow people who fall often to live in their homes longer. For caregivers dealing frequently with people who fall, this assistive device can contribute to decreasing occupational injuries. Development of a lifting device that can help people raise themselves up entirely on their own, or with minimal assistance, would be a revolutionary step for the individual. Lifting devices in use today requires much more extensive assistance from home helpers or others and due to the risk of injuries it is a great value for the helpers that easy to use devices develops. A walker equipped with an elevating seat could even provide a potential for people to stay in their homes longer.

Dandy-Walker syndrome together with occipital encephalocele.

Science.gov (United States)

Cakmak, A; Zeyrek, D; Cekin, A; Karazeybek, H

2008-08-01

Dandy-Walker malformation is an anomaly characterized by dysgenesis of the foramina of Magendie and Lushka in the upper 4(th) ventricle, hypoplasia of the cerebellar vermis and agenesis of the corpus callosum. Encephalocele is diagnosed from the calvarium defect, cerebrospinal fluid (CSF) and herniation of the meninges. It is the rarest neural tube defect. A 7 x 9 cm encephalocele was found on physical examination of a 6-day old baby boy patient. From cranial magnetic resonance, it was seen that the posterior fossa was enlarged with cysts and there was agenesis of the vermis. A connection was established between the ventricle and the development of cysts on the posterior fossa. These findings were evaluated as significant from the aspect of Dandy-Walker malformation. The extension of the bone defect in the left occipital area towards the posterior, and the cranio-caudal diameter reaching 9 cm was seen to be in accordance with encephalocele. It is rare for Dandy-Walker syndrome to occur together with occipital encephalocele. The authors present a case of Dandy-Walker syndrome together with occipital encephalocele.

Madame Kara Walker, notre artiste

Directory of Open Access Journals (Sweden)

Riché Deianne Richardson

2008-01-01

Full Text Available « Mon Ennemi, Mon Frère, Mon Bourreau, Mon Amour, » the epic exhibition at ARC/ Musée d’art moderne de la ville de Paris running from 20 June to 9 September, reveals the creative genius and vision of the artist Kara Walker, who was born in Stockton, California in 1969. The show is her most comprehensive one yet in Europe and includes the form that Walker has uniquely developed and for which she is best known, cut-out black silhouettes that are sometimes small and at other times gigantic and r...

Multiple Walkers in the Wang-Landau Algorithm

Energy Technology Data Exchange (ETDEWEB)

Brown, G

2005-12-28

The mean cost for converging an estimated density of states using the Wang-Landau algorithm is measured for the Ising and Heisenberg models. The cost increases in a power-law fashion with the number of spins, with an exponent near 3 for one-dimensional models, and closer to 2.4 for two-dimensional models. The effect of multiple, simultaneous walkers on the cost is also measured. For the one-dimensional Ising model the cost can increase with the number of walkers for large systems. For both the Ising and Heisenberg models in two-dimensions, no adverse impact on the cost is observed. Thus multiple walkers is a strategy that should scale well in a parallel computing environment for many models of magnetic materials.

Dandy-Walker Malformation

African Journals Online (AJOL)

rme

Dandy-Walker malformation is a rare congenital malformation and involves the cerebellum and fourth ventricle. The condition is characterized by agenesis or hypoplasia of the cerebellar vermis, cystic dilatation of the fourth ventricle, and enlargement of the posterior fossa. A large number of concomitant problems may be ...

Spatial autocorrelation in farmland grasshopper assemblages (Orthoptera: Acrididae) in western France.

Science.gov (United States)

Badenhausser, I; Gouat, M; Goarant, A; Cornulier, T; Bretagnolle, V

2012-10-01

Agricultural intensification in western Europe has caused a dramatic loss of grassland surfaces in farmlands, which have resulted in strong declines in grassland invertebrates, leading to cascade effects at higher trophic levels among consumers of invertebrates. Grasshoppers are important components of grassland invertebrate assemblages in European agricultural ecosystems, particularly as prey for bird species. Understanding how grasshopper populations are distributed in fragmented landscapes with low grassland availability is critical for both studies in biodiversity conservation and insect management. We assessed the range and strength of spatial autocorrelation for two grasshopper taxa (Gomphocerinae subfamily and Calliptamus italicus L.) across an intensive farmland in western France. Data from surveys carried out over 8 yr in 1,715 grassland fields were analyzed using geostatistics. Weak spatial patterns were observed at small spatial scales, suggesting important local effects of management practices on grasshopper densities. Spatial autocorrelation patterns for both grasshopper taxa were only detected at intermediate scales. For Gomphocerinae, the range of spatial autocorrelation varied from 802 to 2,613 m according to the year, depending both on grasshopper density and on grassland surfaces in the study site, whereas spatial patterns for the Italian locust were more variable and not related to grasshopper density or grassland surfaces. Spatial patterns in the distribution of Gomphocerinae supported our hypothesis that habitat availability was a major driver of grasshopper distribution in the landscape, and suggested it was related to density-dependent processes such as dispersal.

Desarrollo postembrionario de Ronderosia bergi (Orthoptera: Acrididae: Melanoplinae bajo condiciones controladas

Directory of Open Access Journals (Sweden)

Yanina MARIOTTINI

2006-01-01

Full Text Available Mediante el seguimiento de cohortes correspondientes a la primera generación de bioterio, provenientes de ejemplares capturados en el sudeste de la provincia de San Luis, se registraron algunos parámetros biológicos fundamentales del acridio Ronderosia bergi (Stål bajo condiciones controladas (30°C, 40% HR; 14hs. luz, 10 hs. oscuridad. La duración total del desarrollo postembrionario fue de 213 días, de los cuales 30 correspondieron a los cinco estadios del desarrollo ninfal. El número promedio de huevos por postura fue de 16,8, y la madurez sexual fue alcanzada dentro de los 4-5 días después del ingreso a imago. Las diferencias con los escasos datos provenientes de estudios previos, obedecerían a las distintas condiciones de crianza o a una alta variabilidad intraespecífica.

Obituary: Robert Mowbray Walker, 1929-2004

Science.gov (United States)

Schoenherr, Neil T.

2004-12-01

Robert M. Walker, PhD, Professor of Physics in Arts & Sciences and a faculty fellow of the McDonnell Center for the Space Sciences, died of stomach cancer Thursday, 12 February 2004, in Brussels, Belgium. He was 75. Walker worked on the frontiers of space research for more than four decades. Robert Walker was born in Philadelphia on 6 February 1929. His mother was Dorothy Potter and he considered Roger Potter his father though he was not his biological father. His early years were spent in New York City and in upstate New York. He attended the Bronx High School of Science, earned his BS in physics from Union College and in 1954, he received his PhD in particle physics from Yale University. He subsequently joined the General Electric Laboratory in Schenectady, New York where he studied the radiation effects in solids. His work on defects in irradiated copper is still regarded as the definitive work on the topic. In the early 1960s, Walker's discovery of fossil nuclear particle tracks in minerals was instrumental to new developments in geo-chronology and cosmic ray physics. In particular, his discovery of tracks from nuclei heavier than iron opened a new frontier of cosmic ray physics. He subsequently pioneered the use of plastics to detect and count such nuclei in cosmic ray balloon flights. Beginning in 1966, when he moved to Washington University and became the first McDonnell Professor of Physics, his research interests turned more toward space physics. He was the inaugural director of the McDonnell Center, which was established in 1975 by a gift from aerospace pioneer James S. McDonnell. Walker was a member of the NASA committee that allocated samples of the first returned lunar materials, and his laboratory led the way in deciphering their record of lunar, solar system and galactic evolution. Together with Ghislaine Crozaz and other colleagues, Walker made path breaking laboratory studies of the first moon rocks revealing the history of solar radiation and

Interacting walkers on the Cayley tree, and polymer statistics

International Nuclear Information System (INIS)

Priezzhev, V.B.

1986-01-01

We obtain the generating function for an ensemble of random walkers on the Cayley tree of coordination number z. The pair interaction between walkers is taken into account. This forbids two walkers to occupy the same lattice point after an equal number of steps. Interacting polymer statistics results from this model if one associates time (or the number of steps) with an additional space coordinate. The limiting free energy appears in a form that corresponds to the phase transition of ''3/2 order.''

Different levels of shade on population of grasshoppers and its oviposition preference on heliconias

Directory of Open Access Journals (Sweden)

Ana Cristina Bittar

2018-02-01

Full Text Available ABSTRACT: Grasshoppers of the families Acrididae and Romaleidae (Orthoptera are among the insects that defoliate heliconias and have been gaining status as pests of commercial crops of these plants in Brazil. The objectives of the present study were to identify the grasshopper defoliating heliconias in the municipality of Santo Antônio de Pádua, RJ (Brazil, to evaluate the effect of different levels of shade on the population of this grasshopper and the production parameters of heliconias, and to determine if this grasshopper has an oviposition preference among the heliconias evaluated. The experiment was in a completely randomized block design, in subdivided plots (four levels of shade in the plot, 0%, 30%, 50% and 80%, and four species of Heliconia: H. psittacorum, H. stricta, H. wagneriana and H. psittacorum x H. spathocircinata ‘Golden Torch’ in the subplot, with four replications. The grasshopper was identified as Cornops frenatum frenatum (Acrididae. An increase in shade resulted in a decrease in the number of oviposition holes from the grasshopper and the number of lateral buds. Shade did not influence the number of C. f. frenatum nymphs and adults and the number of flower stems. H. wagneriana was the most preferred species for oviposition by C. f. frenatum. Results suggested using screens to shade heliconia plants can help control C. f. frenatum populations, however, the light requirements of the heliconias should be considered to guarantee productivity.

Designing instrumented walker to measure upper-extremity's efforts: A case study.

Science.gov (United States)

Khodadadi, Mohammad; Baniasad, Mina Arab; Arazpour, Mokhtar; Farahmand, Farzam; Zohoor, Hassan

2018-02-26

The high prevalence of shoulder pain in using walkers in patients who have spinal cord injury (SCI). Also, the limited options available to economically measure grip forces in walkers, which drove the need to create one. This article describes a method to obtain upper-extremities' forces and moments in a person with SCI by designing an appropriate instrumented walker. First, since the commercial multidirectional loadcells are too expensive, custom loadcells are fabricated. Ultimately, a complete gait analysis by means of VICON motion analysis and using inverse dynamic method has been held to measure upper-extremities' efforts. The results for a person with SCI using a two-wheel walker in low and high heights and a basic walker show that there are higher shoulder and elbow flexion-extension moments and also higher shoulder forces in superior-inferior direction and higher elbow and wrist forces in anterior-posterior directions. The results are not much different in using two different types of walker. By using the proposed method, upper-extremities' forces and moments were obtained and the results were compared to each other in using two different walkers.

Invertebrates of The H.J. Andrews Experimental Forest, Western Cascades, Oregon: III. The Orthoptera (Grasshoppers and Crickets).

Science.gov (United States)

David C. Lightfoot

1986-01-01

An inventory of Orthoptera (grasshoppers and crickets) at the H.J. Andrews Experimental Forest, near Blue River, Oregon, was conducted to determine the species present and ecological relationships. A key for identification and an annotated list are presented. From qualitative assessments of successional habitat relationships, generalized species associations of forest...

78 FR 25234 - Proposed Establishment of Class E Airspace; Walker, MN

Science.gov (United States)

2013-04-30

...-0266; Airspace Docket No. 13-AGL-11] Proposed Establishment of Class E Airspace; Walker, MN AGENCY... action proposes to establish Class E airspace at Walker, MN. Controlled airspace is necessary to accommodate new Standard Instrument Approach Procedures (SIAP) at Walker Municipal Airport. The FAA is taking...

Human-robot interaction strategies for walker-assisted locomotion

CERN Document Server

Cifuentes, Carlos A

2016-01-01

This book presents the development of a new multimodal human-robot interface for testing and validating control strategies applied to robotic walkers for assisting human mobility and gait rehabilitation. The aim is to achieve a closer interaction between the robotic device and the individual, empowering the rehabilitation potential of such devices in clinical applications. A new multimodal human-robot interface for testing and validating control strategies applied to robotic walkers for assisting human mobility and gait rehabilitation is presented. Trends and opportunities for future advances in the field of assistive locomotion via the development of hybrid solutions based on the combination of smart walkers and biomechatronic exoskeletons are also discussed. .

Anthropometric characteristics of top-class Olympic race walkers.

Science.gov (United States)

Gomez-Ezeiza, Josu; Tam, Nicholas; Torres-Unda, Jon; Granados, Cristina; Santos-Concejero, Jordan

2018-04-20

Typical training programmes in elite race walkers involve high training volumes at low and moderate intensities, which have been reported to induce functional and structural adaptations at an anthropometric level. Since anthropometrical variables are closely related to movement efficiency and performance in endurance events, the aim of this study was to describe the anthropometric profile of world-class race walkers. Twenty-nine world-class race walkers (21 men & 8 women) participated in this study. Anthropometric characteristics, including height, body mass, eight skinfolds, five girths and four bone breadths were measured. Body composition, somatotype, somatotype dispersion mean, somatotype attitudinal mean and height to weight ratio, as well as skinfolds extremity to trunk ratio were also calculated. Mean height, body mass and body mass index were 177.1 ± 7.1 cm, 66.4 ± 5.8 kg, and21.2±1.3kg·m2 formenand165.6±4.5cm,53.6±3.7kg,and19.6±1.6kg·m2for women, respectively. Women presented greater body fat content (6.7 ± 0.6 vs. 12.2 ± 0.8%; very large effect), less muscle mass (65.6 ± 4.6 vs. 61.6 ± 2.6 kg; large effect), and were more endomorphic (large effect) than men. Men specialists in 20-km showed greater muscle mass (66.7 ± 4.9 vs. 64.4 ± 4.3 kg; moderate effect), and slightly higher skinfolds, girths, body fat content and were more mesomorphic than 50-km specialists (moderate effect). The present study expands the limited knowledge on the anthropometric characteristics and somatotype elements of elite top-class race walkers. The characterisation of the morphology of elite race walkers provides coaches a reference values to control the training development of the race walker, as well as providing reference values to improve talent identification.

Grasshoppers (Orthoptera: Caelifera and crickets (Orthoptera: Ensifera from slopes of Macošská stráň and Vilémovická stráň (Moravský kras Protected landscape area, Czech Republic

Directory of Open Access Journals (Sweden)

Jana Niedobová

2011-01-01

Full Text Available In 2008 we found 21 species of grasshoppers and crickets on Macošská stráň slope and 18 species on Vilémovická stráň slope. Both slopes are located in the northern part of the Moravský kras Protected landscape area and have xerothermic character. Both slopes are influenced by pasture management. For the most comprehensive picture of Orthoptera we used a standard method (sweeping of vegetation and nonstandard methods (pitfall traps and Möricke yellow cups. Termophilous species of Orthoptera on Macošská stráň (47% were dominating. On Vilémovická stráň mezophilous species (46% were dominating. The most common species were Stenobothrus lineatus (Panzer, 1796 on Macošská stráň slope and Chorthippus parallelus (Zetterstedt, 1821, Stenobothrus lineatus, Chorthippus bigutulus (Linné, 1758 and Chorthippus dorsatus (Zetterstedt, 1821 on Vilémovická stráň slope. Rare species of this assemblage were Stenobothrus nigromaculatus (Herrich-Schaffer, 1840 which was on Macošská stráň slope only and Tetrix bipunctata (Linnaeus, 1758 which has much bigger abundances also on Macošská stráň slope.

Four-wheeled walker related injuries in older adults in the Netherlands.

Science.gov (United States)

van Riel, K M M; Hartholt, K A; Panneman, M J M; Patka, P; van Beeck, E F; van der Cammen, T J M

2014-02-01

With ageing populations worldwide, mobility devices are used more than ever. In the current literature there is no consensus whether the available mobility devices safely improve the mobility of their users. Also, evidence is lacking concerning the risks and types of injuries sustained while using a four-wheeled walker. To assess injury risks and injury patterns in older adults (≥65 years) who presented at Emergency Departments (ED) in the Netherlands with an injury due to using a four-wheeled walker. In this study, the Dutch Injury Surveillance System was used to obtain a national representative sample of annual ED visits in the Netherlands in the adult population (≥65 years) sustaining an injury while using a four-wheeled walker. The numbers of four-wheeled walker users in the Netherlands were obtained from the national insurance board. The numbers of ED visits were divided by the numbers of four-wheeled walker users to calculate age- and sex-specific injury risks. Annually 1869 older adults visited an ED after sustaining an injury while using a four-wheeled walker. Falls were the main cause of injury (96%). The injury risk was 3.1 per 100 users of four-wheeled walkers. Women (3.5 per 100 users) had a higher risk than men (2.0 per 100 users). Injury risk was the highest in women aged 85 years and older (6.2 per 100 users). The majority of injuries were fractures (60%) with hip fracture (25%) being the most common injury. Nearly half of all four-wheeled walker related injuries required hospitalisation, mostly due to hip fractures. Healthcare costs per injury were approximately €12 000. This study presents evidence that older adults experiencing a fall while using a four-wheeled walker are at high risk to suffer severe injuries.

21 CFR 890.3790 - Cane, crutch, and walker tips and pads.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cane, crutch, and walker tips and pads. 890.3790 Section 890.3790 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES..., crutch, and walker tips and pads. (a) Identification. Cane, crutch, and walker tips and pads are rubber...

Species composition of grasshoppers (Orthoptera) in open plots and farmlands in calabar metropolis, southern Nigeria.

Science.gov (United States)

Oku, E E; Arong, G A; Bassey, D A

2011-04-15

The grasshoppers are strategic in the welfare of man and may constitute a major threat when its population is not checked. A study on the distribution of grasshoppers in open plots and farmlands was carried out within Calabar Metropolis between August to November, 2010. A total of 295 grasshoppers belonging to 11 species grouped under 3 families (Tettigoniidae, Acrididae and Pyrgomorphidae) were collected from 8 study locations. Grasshoppers were collected weekly from all study sites using sweep nets between 11 a.m. to 4 p.m. The collection was done using sweep nets between 11 a.m. to 4 p.m. when grasshoppers baked themselves under the sun. The percentage abundance of these species were Spathosterrium pygmaeum (16.27%), Tettigonia viridissima (11.86%), Catantops spissus (11.19%) Acridaturita sp. (10.17%), Gastrimargus acrididae (9.83%), Schistocerca nitens (9.49%), Tylopsis sp. (7.46%), Zonocerus variegatus (6.78%), Omocestus viridulus (6.10%), Scudderia mexicana (5.76%) and Zonocerus elegans (5.08%). Tettigonia viridissima and Acridaturita sp. were largely distributed as it occurred in 7 of 8 study sites while Scudderia mexicana was the least distributed, as it was reported in 3 sites only. The dominant grasshopper species in open plot was Spathosterrium pygmaeum (19%) in relative abundance and the least was Zonocerus variegatus (0.64%). Zonocerus variegatus was the dominant species in farmland (14%) in relative abundance and the least was Schistocerca nitens (4%). Chi-square test showed a high significant difference between the distribution of grasshoppers in open plots and farmlands (p grasshopper species composition were attributed to lizard predation and management practices such as grass cutting, fertilizer and pesticide applications. It was therefore concluded that species abundance and population of grasshoppers could be enhanced by minimizing human activities that interfere with land use.

Interaction of two walkers: wave-mediated energy and force.

Science.gov (United States)

Borghesi, Christian; Moukhtar, Julien; Labousse, Matthieu; Eddi, Antonin; Fort, Emmanuel; Couder, Yves

2014-12-01

A bouncing droplet, self-propelled by its interaction with the waves it generates, forms a classical wave-particle association called a "walker." Previous works have demonstrated that the dynamics of a single walker is driven by its global surface wave field that retains information on its past trajectory. Here we investigate the energy stored in this wave field for two coupled walkers and how it conveys an interaction between them. For this purpose, we characterize experimentally the "promenade modes" where two walkers are bound and propagate together. Their possible binding distances take discrete values, and the velocity of the pair depends on their mutual binding. The mean parallel motion can be either rectilinear or oscillating. The experimental results are recovered analytically with a simple theoretical framework. A relation between the kinetic energy of the droplets and the total energy of the standing waves is established.

Effects of walker gender and observer gender on biological motion walking direction discrimination.

Science.gov (United States)

Yang, Xiaoying; Cai, Peng; Jiang, Yi

2014-09-01

The ability to recognize the movements of other biological entities, such as whether a person is walking toward you, is essential for survival and social interaction. Previous studies have shown that the visual system is particularly sensitive to approaching biological motion. In this study, we examined whether the gender of walkers and observers influenced the walking direction discrimination of approaching point-light walkers in fine granularity. The observers were presented a walker who walked in different directions and were asked to quickly judge the walking direction (left or right). The results showed that the observers demonstrated worse direction discrimination when the walker was depicted as male than when the walker was depicted as female, probably because the observers tended to perceive the male walkers as walking straight ahead. Intriguingly, male observers performed better than female observers at judging the walking directions of female walkers but not those of male walkers, a result indicating perceptual advantage with evolutionary significance. These findings provide strong evidence that the gender of walkers and observers modulates biological motion perception and that an adaptive perceptual mechanism exists in the visual system to facilitate the survival of social organisms. © 2014 The Institute of Psychology, Chinese Academy of Sciences and Wiley Publishing Asia Pty Ltd.

Beliefs about the use of baby walkers

OpenAIRE

Chagas,Paula S. C.; Mancini,Marisa C.; Tirado,Marcella G. A.; Megale,Luiz; Sampaio,Rosana F.

2011-01-01

OBJECTIVES: To understand the opinion of the parents about the baby walker and compare the age of gait acquisition between infants that used a walker and those that did not. METHODS: In this quali-quantitative study, an interview involving a semi-structured questionnaire was carried out with 26 parents, 14 of whose infants used the equipment (BWG) and 12 of whose infants did not (NBWG) prior to gait acquisition. After extensive content analysis, categories for interpreting the results emerged...

Mechanical efficiency of a champion walker | Wyndham | South ...

African Journals Online (AJOL)

Oxygen consumptions were measured on a champion walker, while walking at between 6·4 and 16·9 km / hand while running at between 11.3 and 17.7 km/h. Above 9.7 km /h the curve of oxygen consumption against speed for walking was almost twice as steep as that for running, indicating that even champion walkers are ...

[Active and safe with wheeled walkers : Pilot study on feasibility of mobility exercises for wheeled walker users].

Science.gov (United States)

Pflaum, Marina; Lang, Frieder R; Freiberger, Ellen

2016-07-01

The number of older people with mobility impairments using wheeled walkers is increasing; however, the handling of these walking aids is often ineffective. Moreover, age-associated functional loss, environmental demands and fear of falling may additionally challenge mobility. The new training program "Active and safe with wheeled walkers" aims to enhance skills and to improve mobility. The present pilot study was carried out to assess the feasibility of the training as well as to identify training effects and methodological insights for further research. The study was carried out with 28 wheeled walker users (age 68-91 years) in assisted living facilities using a pre-post design. Of the participants 13 persons were trained for 10 weeks (90 min, twice a week) and 15 persons served as a control group. Data were collected on functional mobility, hand strength, leg strength, balance, walker handling and fear of falling. The drop-out rate for the training was 38 % due to health concerns (n = 2), lack of time (n = 1) and changes in health status independent of training (n = 3). Medium to large effects were detected. Data regarding the recruitment strategy and the acceptance of individual exercises are available. The results indicate a good feasibility and effectiveness of the training. The simple accessibility of the training was conducive for the regular participation. The everyday relevance of the results and the lack of comparable interventions suggest that further research efforts be carried out. Recruitment strategies, training requirements and data collection methods need to be optimized.

A stochastic DNA walker that traverses a microparticle surface

Science.gov (United States)

Jung, C.; Allen, P. B.; Ellington, A. D.

2016-02-01

Molecular machines have previously been designed that are propelled by DNAzymes, protein enzymes and strand displacement. These engineered machines typically move along precisely defined one- and two-dimensional tracks. Here, we report a DNA walker that uses hybridization to drive walking on DNA-coated microparticle surfaces. Through purely DNA:DNA hybridization reactions, the nanoscale movements of the walker can lead to the generation of a single-stranded product and the subsequent immobilization of fluorescent labels on the microparticle surface. This suggests that the system could be of use in analytical and diagnostic applications, similar to how strand exchange reactions in solution have been used for transducing and quantifying signals from isothermal molecular amplification assays. The walking behaviour is robust and the walker can take more than 30 continuous steps. The traversal of an unprogrammed, inhomogeneous surface is also due entirely to autonomous decisions made by the walker, behaviour analogous to amorphous chemical reaction network computations, which have been shown to lead to pattern formation.

Effects of a fluorescent lamp to embryo growth of Gryllodes sigillatus (Orthoptera:Gryllidae)

OpenAIRE

新井, 哲夫

2016-01-01

The influence of a fluorescent lighting on embryo growth in a cricket, Gryllodes sigillatus (Orthoptera:Gryllidae) was observed. The experiment was carried out using an incubator of 25°C(±1°C), and using a 10-watt fluorescent lamp. Eggs were placed at 10-, 20-, and 30cm distances from a fluorescent lamp. Eggs were transferred from continuous light(LL)(various periods) to continuous darkness(DD)(or vice versa), it was examined hatching rate and egg period. All eggs died regardless of the dista...

Spacetime emergence of the robertson-walker universe from a matrix model.

Science.gov (United States)

Erdmenger, Johanna; Meyer, René; Park, Jeong-Hyuck

2007-06-29

Using a novel, string theory-inspired formalism based on a Hamiltonian constraint, we obtain a conformal mechanical system for the spatially flat four-dimensional Robertson-Walker Universe. Depending on parameter choices, this system describes either a relativistic particle in the Robertson-Walker background or metric fluctuations of the Robertson-Walker geometry. Moreover, we derive a tree-level M theory matrix model in this time-dependent background. Imposing the Hamiltonian constraint forces the spacetime geometry to be fuzzy near the big bang, while the classical Robertson-Walker geometry emerges as the Universe expands. From our approach, we also derive the temperature of the Universe interpolating between the radiation and matter dominated eras.

Effects of aging on identifying emotions conveyed by point-light walkers.

Science.gov (United States)

Spencer, Justine M Y; Sekuler, Allison B; Bennett, Patrick J; Giese, Martin A; Pilz, Karin S

2016-02-01

The visual system is able to recognize human motion simply from point lights attached to the major joints of an actor. Moreover, it has been shown that younger adults are able to recognize emotions from such dynamic point-light displays. Previous research has suggested that the ability to perceive emotional stimuli changes with age. For example, it has been shown that older adults are impaired in recognizing emotional expressions from static faces. In addition, it has been shown that older adults have difficulties perceiving visual motion, which might be helpful to recognize emotions from point-light displays. In the current study, 4 experiments were completed in which older and younger adults were asked to identify 3 emotions (happy, sad, and angry) displayed by 4 types of point-light walkers: upright and inverted normal walkers, which contained both local motion and global form information; upright scrambled walkers, which contained only local motion information; and upright random-position walkers, which contained only global form information. Overall, emotion discrimination accuracy was lower in older participants compared with younger participants, specifically when identifying sad and angry point-light walkers. In addition, observers in both age groups were able to recognize emotions from all types of point-light walkers, suggesting that both older and younger adults are able to recognize emotions from point-light walkers on the basis of local motion or global form. (c) 2016 APA, all rights reserved).

Development of the SORRI-BAURU Posterior Walker.

Science.gov (United States)

Nicholl, Anthony R J; Busnardo, Renato G; da Silva, Luciana M; Rodrigues, Ana Cláudia T; Luz, Fernanda R C; Bentim, Claudia C G; Medola, Fausto O; Paschoarelli, Luis C

2015-01-01

This study aimed to report on the design and development of a low cost Reverse Walker through a participative development cycle with people undergoing rehabilitation. The creation and fundamentals of the concept are described, as well as the development of prototypes and their provision to subjects with mobility problems. The Reverse Walker benefits the user by promoting a more upright posture and favoring the development of postural balance. Enhancing the mobility of people with disabilities may benefit their independence, social participation and quality of life.

Binema bonaerensis n. sp. (Oxyurida: Thelastomatidae) parasite of Neocurtilla claraziana Saussure (Orthoptera: Gryllotalpidae) in Argentina.

Science.gov (United States)

Camino, N B; Reboredo, G R

1999-01-01

The nematode Binema bonaerensis n. sp. (Oxyurida: Thelastomatidae) is described from the intestine of the mole cricket of Neocurtilla claraziana Saussure (Orthoptera: Gryllotalpidae) from Buenos Aires Province, Argentina. It is distinguished mainly by having a conical tail; three sclerotized arches in the buccal cavity; an excretory pore immediately posterior to the base of the esophagus and the presence of five pairs of male genital papillae with one pair preanal and four pairs postanal.

Influence of temperature on current-induced domain wall motion and its Walker breakdown

International Nuclear Information System (INIS)

Fan, Lvchao; Hu, Jingguo; Su, Yuanchang; Zhu, Jinrong

2016-01-01

The current-driven domain wall propagation along a thin ferromagnetic strip with thermal field is studied by means of micromagnetic simulations. The results show that the velocity of domain wall is almost independent of temperature until Walker breakdown happened. However the thermal field can suppress Walker breakdown and makes domain wall move faster. Further analysis indicates that the thermal field tends to keep the out-of-plane magnetic moment of the domain wall stay in high value, which can promote domain wall motion and suppress the Walker breakdown by breaking the period of domain wall transformation. - Highlights: • Influences of temperature on the displacement and the velocity of DW are shown. • The suppression of Walker breakdown by temperature is given. • The reason for suppressing Walker breakdown is analyzed. • The breaking transformation period of Walker breakdown by temperature is given.

Dynamics of unvisited sites in the presence of mutually repulsive random walkers

International Nuclear Information System (INIS)

Das, Pratap Kumar; Dasgupta, Subinay; Sen, Parongama

2007-01-01

We have considered the persistence of unvisited sites of a lattice, i.e., the probability S(t) that a site remains unvisited till time t in the presence of mutually repulsive random walkers in one dimension. The dynamics of this system has direct correspondence to that of the domain walls in a certain system of Ising spins where the number of domain walls becomes fixed following a zero-temperature quench. Here we get the result that S(t) ∼ exp(-αt β ) where β is close to 0.5 and α a function of the density of the walkers ρ. The fraction of persistent sites in the presence of independent walkers of density ρ' is known to be S'(t) = exp(-2√(2/π ρ't 1/2 ). We show that a mapping of the interacting walkers' problem to the independent walkers' problem is possible with ρ' = ρ/(1 - ρ) provided ρ' and ρ are small. We also discuss some other intricate results obtained in the interacting walkers' case

Can use of walkers or canes impede lateral compensatory stepping movements?

Science.gov (United States)

Bateni, Hamid; Heung, Evelyn; Zettel, John; McLlroy, William E; Maki, Brian E

2004-08-01

Although assistive devices, such as walkers and canes are often prescribed to aid in balance control, recent studies have suggested that such devices may actually increase risk of falling. In this study, we investigated one possible mechanism: the potential for walkers or canes to interfere with, or constrain, lateral movement of the feet and thereby impede execution of compensatory stepping reactions during lateral loss of balance. Lateral stepping reactions were evoked, in 10 healthy young adults (ages 22-27 years), by means of sudden unpredictable medio-lateral support surface translation. Subjects were tested while holding and loading a standard pickup walker or single-tip cane or while using no assistive device (hands free or holding an object). Results supported the hypothesis that using a walker or cane can interfere with compensatory stepping. Collisions between the swing-foot and mobility aid were remarkably frequent when using the walker (60% of stepping reactions) and also occurred in cane trials (11% of stepping reactions). Furthermore, such collisions were associated with a significant reduction (26-37%) in lateral step length. It appeared that subjects were sometimes able to avoid collision by increasing the forward or backward displacement of the swing-foot or by moving the cane; however, attempts to lift the walker out of the way occurred rarely and were usually impeded due to collision between the contralateral walker post and stance foot. The fact that compensatory stepping behavior was altered significantly in such a healthy cohort clearly demonstrates some of the safety limitations inherent to these assistive devices, as currently designed. Copyright 2003 Elsevier B.V.

Robertson-Walker solutions for various types of energy-momentum tensor

International Nuclear Information System (INIS)

Lukacs, B.

1976-01-01

Robertson-Walker solutions are important in general relativity as universe solutions. This paper contains a number of Robertson-Walker-type solutions for certain cases, namely, for noncharged massless scalar meson fields, viscous fluids, Hookean elastic mediums, and Kelvin-Voigt viscoelastic systems. (author)

Cephalobellus lobulata n. sp. (Oxyurida:Thelastomatidae) A parasite of Neocurtilla claraziana Saussure (Orthoptera: gryllotalpidae) from Argentina.

Science.gov (United States)

Camino, N B; Reboredo, G R

2000-01-01

Cephalobellus lobulata n. sp. (Oxyurida: Thelastomatidae) a parasite of the mole cricket Neocurtilla claraziana Saussure (Orthoptera: Gryllotalpidae) found in Argentina is described and illustrated. It is characterized by a short buccal cavity armed with three teeth, a striated cuticle with the first annule wide with four lobes and the second annule divided in twelve lobes. The male have three pairs of preanal papillae and two pairs of postanal papillae.

Experimental detection of domain wall propagation above the Walker field

International Nuclear Information System (INIS)

Kondou, Kouta; Chiba, Daichi; Kobayashi, Kensuke; Ono, Teruo; Ohshima, Norikazu; Kasai, Shinya

2012-01-01

The domain wall (DW) velocity above the Walker field drops abruptly with increasing magnetic field, because of the so-called Walker breakdown, where the DW moves with a precessional mode. On applying the higher field, the DW velocity again starts to increase gradually. We report the DW propagation around this local minimum regime in detail, investigated through the time-resolved electrical detection technique, with a magnetic tunnel junction. Just above the Walker field, we succeeded in detecting the precessional motion of the DW in a real-time regime, while a different mode appeared around the local minimum of the DW velocity. (paper)

Maximum distance between the Leader and the Laggard for three Brownian walkers

International Nuclear Information System (INIS)

Majumdar, Satya N; Bray, Alan J

2010-01-01

We consider three independent Brownian walkers moving on a line. The process terminates when the leftmost walker (the 'Leader') meets either of the other two walkers. For arbitrary values of the diffusion constants D 1 (the Leader), D 2 and D 3 of the three walkers, we compute the probability distribution P(m|y 2 , y 3 ) of the maximum distance m between the Leader and the current rightmost particle (the 'Laggard') during the process, where y 2 and y 3 are the initial distances between the Leader and the other two walkers. The result has, for large m, the form P(m|y 2 , y 3 ) ∼ A(y 2 , y 3 )m −δ , where δ = (2π − θ)/(π − θ) and θ= cos -1 (D 1 /√((D 1 +D 2 )(D 1 +D 3 ))). The amplitude A(y 2 , y 3 ) is also determined exactly

Supercooling capacity and cold hardiness of band-winged grasshopper eggs (Orthoptera: Acrididae).

Science.gov (United States)

Pang, Bao-Ping; Li, Na; Zhou, Xiao-Rong

2014-01-01

The band-winged grasshopper, Oedaleus asiaticus Bei-Bienko, is one of the most dominant and economically important grasshopper species in the steppe grasslands and farming-pastoral ecotone in northern China. It is a univoltine species and overwinters as eggs in soil. The cold hardiness of its eggs was examined in the laboratory. Water content in soil significantly affected the supercooling points (SCPs), water content and fat content of prediapause eggs. With the increase of water content in soil, the SCP, and water content of prediapause eggs rose whereas the fat content declined. There was a significant relationship between the SCP and water content or fat content of prediapause eggs. The SCPs of prediapause and diapause eggs varied from -7.6 to -28.4°C and the SCPs of eggs 30 d after oviposition could be divided into two groups. The means of high SCP group (-11.0 to -11.9°C) were much higher than those of low SCP group (-21.8 to -21.9°C), and the majority belonged to the latter (90.48-93.33%). The SCPs of prediapause eggs and early-diapause eggs 30 d after oviposition were significantly higher than those of deep-diapause eggs 60 d after oviposition. The survival rates of diapause eggs were significantly different among different temperature treatments. The survival rate was higher than 88% at greater than -20°C and declined significantly to 57% at -25°C, and suddenly dropped to zero at -30°C. The lower lethal temperature (Ltemp50) for 12 h exposure was -25.3°C and the lower lethal time (Ltime50) at -20°C was 32.8 d. As the mean SCPs of diapause eggs were similar to their Ltemp50, the SCP of eggs can be considered as a good indicator of cold hardiness for O. asiaticus and that this grasshopper is a freeze-intolerant insect. © The Author 2014. Published by Oxford University Press on behalf of the Entomological Society of America.

Diet alters performance and transcription patterns in Oedaleus asiaticus (Orthoptera: Acrididae) grasshoppers.

Science.gov (United States)

Huang, Xunbing; Whitman, Douglas W; Ma, Jingchuan; McNeill, Mark Richard; Zhang, Zehua

2017-01-01

We reared Oedaleus asiaticus grasshoppers under four different single-plant diets to examine the relationships among diet, performance, stress, and transcription patterns. Grasshoppers fed only Artemisia frigida (Asteraceae) were stressed, as indicated by their lower growth, size, development, and survival, in comparison to grasshoppers fed on any of three grasses, Cleistogenes squarrosa, Leymus chinensis, or Stipa krylovii (all Poaceae). We then used transcriptome analysis to examine how gene expression levels in O. asiaticus were altered by feeding on these diets. Nymphs fed A. frigida had the largest variation in gene expression profiles with a total of 299 genes significantly up- or down-regulated compared to those feeding on the three grasses: down-regulated genes included those involved in cuticle biosynthesis, DNA replication, biosynthesis and metabolism of nutrition. The up-regulated genes included stress-resistant and detoxifying enzymes. GO and KEGG enrichment analysis also showed that feeding on A. frigida could down-regulate biosynthesis and metabolism related pathways, and up-regulate stress-resistant and detoxification terms and pathways. Our results show that diet significantly altered gene-expression, and that unfavorable, stressful diets induce more transcriptional changes than favorable diets. Altered gene-expression represents phenotypic plasticity, and many such changes appear to be evolved, adaptive responses. The ease and regularity by which individuals shift phenotypes via altered transcription suggests that populations consist not of similar, fixed phenotypes, but of a collection of ever-changing, divergent phenotypes.

Biomasa de Cornops aquaticum (Orthoptera: Acrididae en humedales del nordeste de Argentina

Directory of Open Access Journals (Sweden)

Luciana Irene Gallardo

2015-03-01

Full Text Available La estimación de la biomasa en las poblaciones de insectos, es un factor clave para cuantificar los recursos disponibles y los flujos de energía en las redes tróficas de los ecosistemas. Cornops aquaticum es un herbívoro común en las plantas de Eichhornia en los humedales del nordeste de Argentina. Nuestro objetivo fue analizar la variación de su biomasa en relación a las distintas categorías de edades de la población de este acridio, en dos plantas huésped: Eichhornia azurea y Eichhornia crassipes. Para ello, se realizaron muestreos estándar de las poblaciones de C. aquaticum con una red entomológica de 70cm de diámetro, en dos humedales con E. azurea y E. crassipes en las provincias de Corrientes y Chaco; además, se obtuvo el peso seco de los individuos (de manera directa e indirecta y, se propuso un modelo de regresión para estimar la biomasa de C. aquaticum de manera indirecta a partir de una medida de dimensión lineal (longitud del fémur posterior. Un total de 2 307 individuos fueron recolectados y separados en distintas categorías de edades; se obtuvo su abundancia y distintas medidas de dimensión lineal. El modelo propuesto fue lnPS=lna+b*lnH (donde PS=peso seco, a y b son constantes y H=longitud del fémur posterior (R²=0.97. Las variaciones en la biomasa de las poblaciones de C. aquaticum se debieron a la abundancia relativa de cada categoría de edad y al peso seco individual de estos acridios. No hubo diferencias significativas entre la biomasa de las poblaciones de C. aquaticum obtenida por los métodos directo e indirecto en las praderas flotantes de E. azurea y E. crassipes. Este modelo facilita el cálculo de la biomasa individual y poblacional de C. aquaticum y acelera el procesamiento de un gran número de muestras. Finalmente, los valores altos de biomasa poblacional e individual de las categorías de edades (especialmente en adultos enfatizan la importancia de C. aquaticum como consumidor y como recurso para los depredadores en las redes alimenticias de las praderas flotantes de Eichhornia.

Generalized Friedmann-Robertson-Walker metric and redundancy in the generalized Einstein equations

International Nuclear Information System (INIS)

Kao, W.F.; Pen, U.

1991-01-01

A nontrivial redundancy relation, due to the differential structure of the gravitational Bianchi identity as well as the symmetry of the Friedmann-Robertson-Walker metric, in the gravitational field equation is clarified. A generalized Friedmann-Robertson-Walker metric is introduced in order to properly define a one-dimensional reduced problem which offers an alternative approach to obtain the gravitational field equations on Friedmann-Robertson-Walker spaces

Cephalobellus lobulata n. sp. (Oxyurida:Thelastomatidae a parasite of Neocurtilla claraziana Saussure (Orthoptera: Gryllotalpidae from Argentina

Directory of Open Access Journals (Sweden)

Camino Nora B

2000-01-01

Full Text Available Cephalobellus lobulata n. sp. (Oxyurida: Thelastomatidae a parasite of the mole cricket Neocurtilla claraziana Saussure (Orthoptera: Gryllotalpidae found in Argentina is described and illustrated. It is characterized by a short buccal cavity armed with three teeth, a striated cuticle with the first annule wide with four lobes and the second annule divided in twelve lobes. The male have three pairs of preanal papillae and two pairs of postanal papillae.

Twentieth century Walker Circulation change: data analysis and model experiments

Energy Technology Data Exchange (ETDEWEB)

Meng, Qingjia [Leibniz-Institut fuer Meereswissenschaften, Kiel (Germany); Chinese Research Academy of Environmental Sciences, River and Coastal Environment Research Center, Beijing (China); Chinese Academy of Sciences, Key Laboratory of Ocean Circulation and Waves, Institute of Oceanology, Qingdao (China); Latif, Mojib; Park, Wonsun; Keenlyside, Noel S.; Martin, Thomas [Leibniz-Institut fuer Meereswissenschaften, Kiel (Germany); Semenov, Vladimir A. [Leibniz-Institut fuer Meereswissenschaften, Kiel (Germany); A.M. Obukhov Institute of Atmospheric Physics, Russian Academy of Sciences, Moscow (Russian Federation)

2012-05-15

Recent studies indicate a weakening of the Walker Circulation during the twentieth century. Here, we present evidence from an atmospheric general circulation model (AGCM) forced by the history of observed sea surface temperature (SST) that the Walker Circulation may have intensified rather than weakened. Observed Equatorial Indo-Pacific Sector SST since 1870 exhibited a zonally asymmetric evolution: While the eastern part of the Equatorial Pacific showed only a weak warming, or even cooling in one SST dataset, the western part and the Equatorial Indian Ocean exhibited a rather strong warming. This has resulted in an increase of the SST gradient between the Maritime Continent and the eastern part of the Equatorial Pacific, one driving force of the Walker Circulation. The ensemble experiments with the AGCM, with and without time-varying external forcing, suggest that the enhancement of the SST gradient drove an anomalous atmospheric circulation, with an enhancement of both Walker and Hadley Circulation. Anomalously strong precipitation is simulated over the Indian Ocean and anomalously weak precipitation over the western Pacific, with corresponding changes in the surface wind pattern. Some sensitivity to the forcing SST, however, is noticed. The analysis of twentieth century integrations with global climate models driven with observed radiative forcing obtained from the Coupled Model Intercomparison Project (CMIP) database support the link between the SST gradient and Walker Circulation strength. Furthermore, control integrations with the CMIP models indicate the existence of strong internal variability on centennial timescales. The results suggest that a radiatively forced signal in the Walker Circulation during the twentieth century may have been too weak to be detectable. (orig.)

Additions and corrections to the cadastre of Orthoptera insects of Samarskaya Luka, on the basis of analysis of acoustic signals of males

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Alexander А. Benediktov

2017-08-01

Full Text Available For the territory of Samarskaya Luka, at the village Bakhilova Polyana (I.I. Sprygin Zhiguli State Natural Biosphere Reserve, 25 species of Orthoptera were found in mid-July 2016. These species were identified basically by the analysis of male acoustic signals. This is 44% of the total species composition of Samarskaya Luka Orthoptera, specified in the Cadastre of invertebrates of Samarskaya Luka. The specimens belonging to the grasshopper Platychleis albopunctata (= P. intermedia auct. are clarified. The cricket Melanogryllus desertus and the locust Chorthippus dorsatus were found for the first time in the Samarskaya Luka. The species composition of the cryptic taxa of the «Chorthippus biguttulus group» of the Middle Volga region is discussed. Based on the unstable amplitude-time structure of the signals of the supposed Ch. biguttulus males from Malaya Bahilova Mountain, it is assumed that they may have a hybrid origin.

Análisis morfológico del sistema reproductor femenino de Baeacris punctulatus (Orthoptera: Acrididae: Melanoplinae) Morphological analysis of the female reproductive system in Baeacris punctulatus (Orthoptera, Acrididae, Melanoplinae)

OpenAIRE

Adriana A. Michel; Héctor R. Terán

2005-01-01

RESUMEN. Baeacris punctulatus (Thunberg) es una especie de importancia económica, de amplia distribución en Sudamérica. En el presente trabajo se realiza un estudio anatomo-histológico de los órganos reproductivos internos, en hembras silvestres y obtenidas en cámara de cría. El estudio permitió determinar particularidades histomorfológicas, en ovarios, glándulas accesorias, oviductos laterales y oviducto medio, relacionadas con la génesis y transferencia de las gametas y la ovoposición. Se c...

Revalidation of Ceresa terminalis walker and its placement in Stictocephala Stål (Hemiptera, Membracidae Revalidação de Ceresa terminalis walker e sua alocação em Stictocephala Stål (Hemiptera, Membracidae

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Gabriel S. de Andrade

2005-12-01

Full Text Available Ceresa terminalis Walker, 1851 is reinstated and transferred to Stictocephala Stål, 1869: Stictocephala terminalis (Walker, 1851 sp. rev., comb. nov.Ceresa terminalis Walker, 1851 é revalidada e transferida para Stictocephala Stål, 1869: Stictocephala terminalis (Walker, 1851 sp. rev., comb. nov.

Integral constraints on perturbations of Robertson-Walker cosmologies

International Nuclear Information System (INIS)

Ellis, G.F.R.; Jaklitsch, M.J.

1989-01-01

Integral constraints occur in the case of spherically symmetric inhomogeneities in Robertson-Walker universes, and (according to Traschen) in the case of general perturbations of these models. It is shown that these constraints are the same in the case of spherical symmetry, and they are interpreted as 'fitting conditions', that is, as constraints on the background Robertson-Walker model rather than on the nature of inhomogeneities. These integral constraints significantly affect the interpretation of anisotropies in the cosmic microwave background radiation. 22 refs

Design and Control of JAIST Active Robotic Walker

OpenAIRE

Lee, Geunho; Ohnuma, Takanori; Chong, Nak Young

2010-01-01

This paper presents the design and control of a novel assistive robotic walker that we call “JAIST activerobotic walker (JARoW)”. JARoW is developed to providepotential users with sufficient ambulatory capability in anefficient、 cost-effective way. Specifically、 our focus is placed on how to allow easier maneuverability by creating a natural interface between the user and JARoW. For the purpose、 we develop a rotating infrared sensor to detect the user’s lower limb movement. The implementation...

A new walker with upper trunk suspension system for severely disabled patients.

Science.gov (United States)

Scoppetta, C; Scoppetta, M

2013-10-01

We have recently designed a new type of walker for those severely disabled patients who cannot walk with commonly used medical walkers. A drawing and the description of this new walker is reported in order to permit the worldwide companies as well as artisans to develop and produce it for the people affected from severe motor problems. This walker supposes the patient wearing either a modified climbing harness or equipped clothes and being suspended to the walking frame. It consists in two series of bands suspending the patient from the frame; the upper one suspends him for the upper part of his trunk, the lower one by his pelvis. This walker is suggested for patients belonging to three principal groups: (1) Persons who have no trunk control (e.g.: patients affected by severe stroke or ataxias). (2) Persons whose walk is allowed only if they achieve a significant reduction (up to 30-40%) of the their body weight charging on trunk, spine, and lower limbs. (3) Persons who need a differentiated reduction of the body weight either among anterior and posterior side or among their right and left part of the body (hemiparesis, Parkinson disease, scoliosis, kyphosis). Creating this walker is easy; producing costs are low; there are no maintenance costs.

Ordering statistics of four random walkers on a line

Science.gov (United States)

Helenbrook, Brian; ben-Avraham, Daniel

2018-05-01

We study the ordering statistics of four random walkers on the line, obtaining a much improved estimate for the long-time decay exponent of the probability that a particle leads to time t , Plead(t ) ˜t-0.91287850 , and that a particle lags to time t (never assumes the lead), Plag(t ) ˜t-0.30763604 . Exponents of several other ordering statistics for N =4 walkers are obtained to eight-digit accuracy as well. The subtle correlations between n walkers that lag jointly, out of a field of N , are discussed: for N =3 there are no correlations and Plead(t ) ˜Plag(t) 2 . In contrast, our results rule out the possibility that Plead(t ) ˜Plag(t) 3 for N =4 , although the correlations in this borderline case are tiny.

Racial Stereotypes and the Art of Kara Walker Stéréotypes raciaux dans l’art de Kara Walker

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Monika Seidl

2009-07-01

Full Text Available L’artiste afro-américaine Kara Walker (1969- travaille principalement sur les silhouettes découpées, forme d’art des XVIIIe et XIXe siècles qui était alors utilisée pour les portraits, les caricatures et la décoration. Un grand nombre de critiques d’art, tout particulièrement Howardena Pindell, accuse Walker de renforcer les stéréotypes raciaux et de ne pas réussir à mettre le présent en relation avec le passé dans son travail. Cet article considère l’aspect humoristique du travail de Walker et défend l’idée que le rire est une pratique spatiale, en tant qu’expérience vécue, qui occupe une partie seulement de l’espace se trouvant entre les stéréotypes raciaux et la vie. Offrir une perspective ludique est une stratégie clé dans un contexte de recherche d’un espace à partir duquel il est possible de critiquer et d’analyser des imaginaires sociaux irréconciliables. La distorsion gênante de Walker se situe dans son insistance à aplanir les corps et donc à leur retirer tout espace, tout en les étalant littéralement en tant que projections sur une surface plane, accentuant de ce fait le coté dramatique du blanc et du noir. A première vue, les silhouettes de Walker semblent perpétuer un code dichotomique de la différence culturelle. Cependant, cet article montre que le troisième espace, celui du rire, exerce une force perturbatrice qui commente la politique de la représentation à partir des stéréotypes eux-mêmes. Cet argument est illustré par son panneau Safety Curtain I qui servit de rideau à l’Opéra de Vienne pendant l’hiver 1998-1999.

Development and evaluation of low-cost walker with trunk support for senior citizen.

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Poier, Paloma Hohmann; Godke, Francisco; Foggiatto, José Aguiomar; Ulbricht, Leandra

2017-10-09

Develop and evaluate a low-cost walker with trunk support for senior citizens. Two-stage descriptive study: development of a walker with trunk support and evaluation with fourth age senior citizens. Twenty-three fourth age senior citizens were selected. The evaluated criteria were the immediate influence of the walker on the static stabilometry with baropodometer and the evaluation of gait with accelerometers monitoring time and amplitude of the hip movement. There was a significant decrease in the body oscillation of senior citizens with the use of the developed walker, and there were changes in the joint amplitudes of the hip, but they were not significant. Using low-cost materials, it was possible to develop and equipment that met resistance and effectiveness requirements. The walker interfered in the balance of the senior citizens, reducing significantly the static body oscillation.

States of low energy on Robertson-Walker spacetimes

International Nuclear Information System (INIS)

Olbermann, Heiner

2007-01-01

We construct a new class of physical states of the free Klein-Gordon field in Robertson-Walker spacetimes. This is done by minimizing the expectation value of smeared stress-energy. We get an explicit expression for the state depending on the smearing function. We call it a state of low energy. States of low energy are an improvement of the concept of adiabatic vacua on Robertson-Walker spacetimes. The latter are approximations of the former. It is shown that states of low energy are Hadamard states

Auditory perception of a human walker.

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Cottrell, David; Campbell, Megan E J

2014-01-01

When one hears footsteps in the hall, one is able to instantly recognise it as a person: this is an everyday example of auditory biological motion perception. Despite the familiarity of this experience, research into this phenomenon is in its infancy compared with visual biological motion perception. Here, two experiments explored sensitivity to, and recognition of, auditory stimuli of biological and nonbiological origin. We hypothesised that the cadence of a walker gives rise to a temporal pattern of impact sounds that facilitates the recognition of human motion from auditory stimuli alone. First a series of detection tasks compared sensitivity with three carefully matched impact sounds: footsteps, a ball bouncing, and drumbeats. Unexpectedly, participants were no more sensitive to footsteps than to impact sounds of nonbiological origin. In the second experiment participants made discriminations between pairs of the same stimuli, in a series of recognition tasks in which the temporal pattern of impact sounds was manipulated to be either that of a walker or the pattern more typical of the source event (a ball bouncing or a drumbeat). Under these conditions, there was evidence that both temporal and nontemporal cues were important in recognising theses stimuli. It is proposed that the interval between footsteps, which reflects a walker's cadence, is a cue for the recognition of the sounds of a human walking.

Infinitesimal conformal closed transformations of de Sitter and Robertson-Walker cosmological spaces

International Nuclear Information System (INIS)

Sakoto, Moussa

1976-01-01

The infinitesimal conformal closed transfromations of de Sitter and Robertson-Walker cosmological spaces are determined and an interesting property of the current lines for Robertson-Walker spaces is given [fr

Asymptotic shape of the region visited by an Eulerian walker.

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Kapri, Rajeev; Dhar, Deepak

2009-11-01

We study an Eulerian walker on a square lattice, starting from an initial randomly oriented background using Monte Carlo simulations. We present evidence that, for a large number of steps N , the asymptotic shape of the set of sites visited by the walker is a perfect circle. The radius of the circle increases as N1/3, for large N , and the width of the boundary region grows as Nalpha/3, with alpha=0.40+/-0.06 . If we introduce stochasticity in the evolution rules, the mean-square displacement of the walker, approximately approximately N2nu, shows a crossover from the Eulerian (nu=1/3) to a simple random-walk (nu=1/2) behavior.

LCP method for a planar passive dynamic walker based on an event-driven scheme

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Zheng, Xu-Dong; Wang, Qi

2018-06-01

The main purpose of this paper is to present a linear complementarity problem (LCP) method for a planar passive dynamic walker with round feet based on an event-driven scheme. The passive dynamic walker is treated as a planar multi-rigid-body system. The dynamic equations of the passive dynamic walker are obtained by using Lagrange's equations of the second kind. The normal forces and frictional forces acting on the feet of the passive walker are described based on a modified Hertz contact model and Coulomb's law of dry friction. The state transition problem of stick-slip between feet and floor is formulated as an LCP, which is solved with an event-driven scheme. Finally, to validate the methodology, four gaits of the walker are simulated: the stance leg neither slips nor bounces; the stance leg slips without bouncing; the stance leg bounces without slipping; the walker stands after walking several steps.

Helen M. Walker: Influential in 1929 and Still Cited Today.

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Rice, Marti H.; Stallings, William M.

Helen M. Walker contributed to the field of educational research and statistics during a 55-year career. Born in Iowa in 1891, Walker earned a bachelor's degree from Iowa Wesleyan College and taught high school mathematics for nine years. She then taught at the University of Kansas while doing graduate work. One source noted that she was the first…

Patterns in Orthoptera biodiversity. I. Adaptations in ecological and evolutionary contexts

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Claudio J. Bidau

2014-10-01

Full Text Available The Orthoptera have inhabited the Earth for ca 300 million years and today include about 25,000 described species. Although orthopterans are mainly known to the general public by their most conspicuous species such as rangeland grasshoppers, locusts, katydids and crickets, they include an amazing diversity of forms and life-styles. In this review, I bring together a series of facts about orthopteran biology that demonstrate their enormous biodiversity, concentrating on ecological and evolutionary characteristics such as habitat variation, modes of feeding, defense mechanisms and phase transformation. In a second part of this review I will consider subjects of more direct human interest as their use as food, their importance in folk medicine and their role as entertainment.

Assistive devices alter gait patterns in Parkinson disease: advantages of the four-wheeled walker.

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Kegelmeyer, Deb A; Parthasarathy, Sowmya; Kostyk, Sandra K; White, Susan E; Kloos, Anne D

2013-05-01

Gait abnormalities are a hallmark of Parkinson's disease (PD) and contribute to fall risk. Therapy and exercise are often encouraged to increase mobility and decrease falls. As disease symptoms progress, assistive devices are often prescribed. There are no guidelines for choosing appropriate ambulatory devices. This unique study systematically examined the impact of a broad range of assistive devices on gait measures during walking in both a straight path and around obstacles in individuals with PD. Quantitative gait measures, including velocity, stride length, percent swing and double support time, and coefficients of variation were assessed in 27 individuals with PD with or without one of six different devices including canes, standard and wheeled walkers (two, four or U-Step). Data were collected using the GAITRite and on a figure-of-eight course. All devices, with the exception of four-wheeled and U-Step walkers significantly decreased gait velocity. The four-wheeled walker resulted in less variability in gait measures and had less impact on spontaneous unassisted gait patterns. The U-Step walker exhibited the highest variability across all parameters followed by the two-wheeled and standard walkers. Higher variability has been correlated with increased falls. Though subjects performed better on a figure-of-eight course using either the four-wheeled or the U-Step walker, the four-wheeled walker resulted in the most consistent improvement in overall gait variables. Laser light use on a U-Step walker did not improve gait measures or safety in figure-of-eight compared to other devices. Of the devices tested, the four-wheeled-walker offered the most consistent advantages for improving mobility and safety. Copyright © 2012 Elsevier B.V. All rights reserved.

78 FR 37706 - Safety Standards for Infant Walkers and Infant Swings

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2013-06-24

... test procedure that is needed for testing certain style walkers; Two references to federal regulations... a new step to the test procedure that enables test laboratories to test certain styles of walkers... direct final rule. Although the Administrative Procedure Act (APA) generally requires notice and comment...

On the existence of perturbed Robertson-Walker universes

International Nuclear Information System (INIS)

D'Eath, P.D.

1976-01-01

Solutions of the full nonlinear field equations of general relativity near the Robertson-Walker universes are examined, together with their relation to linearized perturbations. A method due to Choquet-Bruhat and Deser is used to prove existence theorems for solutions near Robertson-Walker constraint data of the constraint equations on a spacelike hypersurface. These theorems allow one to regard the matter fluctuations as independent quantities, ranging over certain function spaces. In the k=-1 case the existence theory describes perturbations which may vary within uniform bounds throughout space. When k=+1 a modification of the method leads to a theorem which clarifies some unusual features of these constraint perturbations. The k=0 existence theorem refers only to perturbations which die away at large distances. The connection between linearized constraint solutions and solutions of the full constraints is discussed. For k= +- 1 backgrounds, solutions of the linearized constraints are analyzed using transverse-traceless decompositions of symmetric tensors. Finally the time-evolution of perturbed constraint data and the validity of linearized perturbation theory for Robertson-Walker universes are considered

Terrain Interaction With The Quarter Scale Beam Walker

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Chun, Wendell H.; Price, R. S.; Spiessbach, Andrew J.

1990-03-01

Frame walkers are a class of mobile robots that are robust and capable mobility platforms. Variations of the frame walker robot are in commercial use today. Komatsu Ltd. of Japan developed the Remotely Controlled Underwater Surveyor (ReCUS) and Normed Shipyards of France developed the Marine Robot (RM3). Both applications of the frame walker concept satisfied robotic mobility requirements that could not be met by a wheeled or tracked design. One vehicle design concept that falls within this class of mobile robots is the walking beam. A one-quarter scale prototype of the walking beam was built by Martin Marietta to evaluate the potential merits of utilizing the vehicle as a planetary rover. The initial phase of prototype rover testing was structured to evaluate the mobility performance aspects of the vehicle. Performance parameters such as vehicle power, speed, and attitude control were evaluated as a function of the environment in which the prototype vehicle was tested. Subsequent testing phases will address the integrated performance of the vehicle and a local navigation system.

Terrain interaction with the quarter scale beam walker

Science.gov (United States)

Chun, Wendell H.; Price, S.; Spiessbach, A.

1990-01-01

Frame walkers are a class of mobile robots that are robust and capable mobility platforms. Variations of the frame walker robot are in commercial use today. Komatsu Ltd. of Japan developed the Remotely Controlled Underwater Surveyor (ReCUS) and Normed Shipyards of France developed the Marine Robot (RM3). Both applications of the frame walker concept satisfied robotic mobility requirements that could not be met by a wheeled or tracked design. One vehicle design concept that falls within this class of mobile robots is the walking beam. A one-quarter scale prototype of the walking beam was built by Martin Marietta to evaluate the potential merits of utilizing the vehicle as a planetary rover. The initial phase of prototype rover testing was structured to evaluate the mobility performance aspects of the vehicle. Performance parameters such as vehicle power, speed, and attitude control were evaluated as a function of the environment in which the prototype vehicle was tested. Subsequent testing phases will address the integrated performance of the vehicle and a local navigation system.

Vacuum quantum effect for curved boundaries in static Robertson-Walker space-time

International Nuclear Information System (INIS)

Setare, M.R.; Sadeghi, J.

2009-01-01

The energy-momentum tensor for a massless conformally coupled scalar field in the region between two curved boundaries in k=-1 static Robertson-Walker space-time is investigated. We assume that the scalar field satisfies the Dirichlet boundary condition on the boundaries. k=-1 Robertson-Walker space is conformally related to the Rindler space, as a result we can obtain vacuum expectation values of energy-momentum tensor for conformally invariant field in Robertson-Walker space from the corresponding Rindler counterpart by the conformal transformation.

Dandy walker variant and bipolar I disorder with graphomania.

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Can, Serdar Suleyman; Karakaş Uğurlu, Görkem; Cakmak, Selcen

2014-07-01

Cerebellum is known to play an important role in coordination and motor functions. In some resent studies it is also considered to be involved in modulation of mood, cognition and psychiatric disorders. Dandy Walker Malformation is a congenital malformation that is characterized by hypoplasia or aplasia of the cerebellar vermis, cystic dilatation of the fourth ventricle and enlargement of the posterior fossa. When the volume of posterior fossa is normal, the malformation is called Dandy Walker Variant. Case is a 32 year old male with a 12 year history of Bipolar I Disorder presented with manic and depresive symptoms, including dysphoric and depressive affect, anhedonia, suicidal thoughts and behaviours, thoughts of fear about future, overtalkativeness and graphomania, increased energy, irregular sleep, loss of appetite, increased immersion in projects, irritability, agressive behavior, impulsivity. Cranial Magnetic Resonance Imaging was compatible to the morphological features of Dandy Walker Variant.

Network formation determined by the diffusion process of random walkers

International Nuclear Information System (INIS)

Ikeda, Nobutoshi

2008-01-01

We studied the diffusion process of random walkers in networks formed by their traces. This model considers the rise and fall of links determined by the frequency of transports of random walkers. In order to examine the relation between the formed network and the diffusion process, a situation in which multiple random walkers start from the same vertex is investigated. The difference in diffusion rate of random walkers according to the difference in dimension of the initial lattice is very important for determining the time evolution of the networks. For example, complete subgraphs can be formed on a one-dimensional lattice while a graph with a power-law vertex degree distribution is formed on a two-dimensional lattice. We derived some formulae for predicting network changes for the 1D case, such as the time evolution of the size of nearly complete subgraphs and conditions for their collapse. The networks formed on the 2D lattice are characterized by the existence of clusters of highly connected vertices and their life time. As the life time of such clusters tends to be small, the exponent of the power-law distribution changes from γ ≅ 1-2 to γ ≅ 3

CommWalker: correctly evaluating modules in molecular networks in light of annotation bias.

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Luecken, M D; Page, M J T; Crosby, A J; Mason, S; Reinert, G; Deane, C M

2018-03-15

Detecting novel functional modules in molecular networks is an important step in biological research. In the absence of gold standard functional modules, functional annotations are often used to verify whether detected modules/communities have biological meaning. However, as we show, the uneven distribution of functional annotations means that such evaluation methods favor communities of well-studied proteins. We propose a novel framework for the evaluation of communities as functional modules. Our proposed framework, CommWalker, takes communities as inputs and evaluates them in their local network environment by performing short random walks. We test CommWalker's ability to overcome annotation bias using input communities from four community detection methods on two protein interaction networks. We find that modules accepted by CommWalker are similarly co-expressed as those accepted by current methods. Crucially, CommWalker performs well not only in well-annotated regions, but also in regions otherwise obscured by poor annotation. CommWalker community prioritization both faithfully captures well-validated communities and identifies functional modules that may correspond to more novel biology. The CommWalker algorithm is freely available at opig.stats.ox.ac.uk/resources or as a docker image on the Docker Hub at hub.docker.com/r/lueckenmd/commwalker/. deane@stats.ox.ac.uk. Supplementary data are available at Bioinformatics online.

A note on the new species of the genus Isopsera (Orthoptera: Phaneropteridae: Phaneropterinae) from India.

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Nagar, Rajendra; Mal, Jhabar; Swaminathan, R

2015-05-29

A new species of the genus, Isopsera: Isopsera arcuata Nagar, Mal, Swaminathan sp. nov. (Orthoptera:Phaneropteridae Burmeister, 1838; Phaneropterinae Burmeister, 1838) is described. The holotype (♂) was collected from South India: Coimbatore (Tamil Nadu). The geographical location had the following specifications: 12⁰58 N 77⁰35E 930MSL South India. The described species differs from the two closely related species, I. caligula Ingrisch and I. spinosa Ingrisch, based on the structure of the male sub-genital plate, cerci and stridulatory file on the left tegmen.

A New Controller for a Smart Walker Based on Human-Robot Formation.

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Valadão, Carlos; Caldeira, Eliete; Bastos-Filho, Teodiano; Frizera-Neto, Anselmo; Carelli, Ricardo

2016-07-19

This paper presents the development of a smart walker that uses a formation controller in its displacements. Encoders, a laser range finder and ultrasound are the sensors used in the walker. The control actions are based on the user (human) location, who is the actual formation leader. There is neither a sensor attached to the user's body nor force sensors attached to the arm supports of the walker, and thus, the control algorithm projects the measurements taken from the laser sensor into the user reference and, then, calculates the linear and angular walker's velocity to keep the formation (distance and angle) in relation to the user. An algorithm was developed to detect the user's legs, whose distances from the laser sensor provide the information necessary to the controller. The controller was theoretically analyzed regarding its stability, simulated and validated with real users, showing accurate performance in all experiments. In addition, safety rules are used to check both the user and the device conditions, in order to guarantee that the user will not have any risks when using the smart walker. The applicability of this device is for helping people with lower limb mobility impairments.

Presencia de Malameba locustae (Protozoa: Rhizopoda en acridios (Orthoptera: Acrididae de la provincia de Misiones, Argentina Presence of Malameba locustae (Protozoa: Rhizopoda in grasshoppers (Orthoptera: Acrididae of Misiones province, Argentina

Directory of Open Access Journals (Sweden)

Carlos E. Lange

2004-07-01

Full Text Available La ameba patógena Malameba locustae King y Taylor fue detectada parasitando ejemplares del acridio Ronderosia bergi (Stal recolectados en las cercanías del Parque Nacional Iguazú, Misiones. El hallazgo constituye el segundo registro de M. locustae para acridios sudamericanos.Individuals of the grasshopper Ronderosia bergi (Stal collected in the surroundings of Iguazú National Park, Misiones, were found to be parasitized by the pathogenic amoeba Malameba locustae King & Taylor. The finding constitutes the second record of M. locustae for southamerican grasshoppers.

Vertical force and wrist deviation angle when using a walker to stand up and sit down.

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Leung, Cherng-Yee; Yeh, Po-Chan

2011-08-01

Research investigating walkers suggests that safety and assistance for the elderly with weak lower limbs were important. However, the relationship between the use of a walker and the upper limbs has received little investigation. Standing up and sitting down are important daily activities. Therefore, the aim of this study was to explore wrist deviation and vertical force among elderly individuals using a walker for assistance to stand up and sit down. In total, 64 elderly volunteers (M age = 80.22, SD = 9.36) were enrolled. Data were obtained from four load cells and a twin-axis wrist goniometer. Wrist deviation and vertical force were examined when participants used a walker with horizontal handles to assist in standing up and sitting down. Significant wrist angle deviation occurred with the use of a walker, with dorsiflexion of the right hand greater than that of the left. Males exerted significantly greater vertical force. In the sitting position, greater ulnar deviation was seen among experienced walker users, whereas during standing, experienced users exhibited greater dorsiflexion. The horizontal handles of most marketed walkers may cause user wrist deviations, suggesting researchers should pursue improvements in walker design.

Dataset reporting the perceiver identification rates of basic emotions expressed by male, female and ambiguous gendered walkers in full-light, point-light and synthetically modelled point-light walkers.

Science.gov (United States)

Halovic, Shaun; Kroos, Christian

2017-12-01

This data set describes the experimental data collected and reported in the research article "Walking my way? Walker gender and display format confounds the perception of specific emotions" (Halovic and Kroos, in press) [1]. The data set represent perceiver identification rates for different emotions (happiness, sadness, anger, fear and neutral), as displayed by full-light, point-light and synthetic point-light walkers. The perceiver identification scores have been transformed into H t rates, which represent proportions/percentages of correct identifications above what would be expected by chance. This data set also provides H t rates separately for male, female and ambiguously gendered walkers.

Walking my way? Walker gender and display format Confounds the perception of specific emotions.

Science.gov (United States)

Halovic, Shaun; Kroos, Christian

2018-02-01

Previous evidence has shown that males and females display different gait kinematics which may influence the perception of emotions displayed through the same walking gait. We therefore investigated the influence of walker gender on the perception of happiness, sadness, anger and fear displayed through walking movements. Full-light (FL), point-light (PL) and synthetically modelled point-light walkers (SW) of both genders were shown to perceivers over three experiments. Additionally, gender ambiguous synthetic walkers were shown to control for the influence of form, gender stereotypes and idiosyncratic gait movements on emotional gait perception. Each emotion was identified above chance level for both walker genders and in all display conditions though significantly less in PL and SW than in FL. The gender of the walker did not influence the pattern of identifications in FL walkers (Fear > Sad > Happy > Anger > Neutral), but did influence the identification patterns in PL (Female: [Happy = Sad = Fear = Anger] > Neutral; Male: Fear = Sad = [Happy > Anger] > Neutral) and SWs (Female: Happy = Sad = Anger = Fear = Neutral; Male: [Happy = Sad = Anger] > [Fear = Neutral]; Ambiguous: [[Happy = Sad = Anger] > Fear] = Neutral). The gender of the walker and format in which they are displayed influenced the perception of different basic emotions. The constructed SW stimuli also displayed happiness, sadness and anger with equivalent intensity in female, male and gender ambiguous walkers thus untangling the perception-expression entanglement that has plagued previous emotion perception research. Crown Copyright © 2017. Published by Elsevier B.V. All rights reserved.

[Effect of abducens orthosis combined with walker on developmental dysplasia of the hip].

Science.gov (United States)

Hu, Zhiyong; Xu, Yongqiang; Liang, Jieyu; Li, Kanghua; Liao, Qiande

2009-07-01

To evaluate the effect of abducens orthosis combined with walker on developmental dysplasia of the hip (DDH). A total of 126 patients (224 hips) with DDH aged 6-36 months in Xiangya Hospital was randomly divided into 2 groups: an orthosis combined with walker group and an improved hip frog cast fixation group. Seventy patients (130 hips) were treated by the orthosis combined with walker and 56 patients (94 hips) were treated by the improved hip frog cast fixation. We compared the effect and complications of the 2 groups. The fineness rates of the orthosis combined with walker group and the improved hip frog cast fixation group were 89.2% and 90.4%, respectively, with no significant difference (P>0.05). The rate of femoral head osteonecrosis in the orthosis combined with walker group was significantly lower than that in the improved hip frog cast fixation group (1.5% vs. 5.3%,Pwalker has a lower proportion of femoral head osteonecrosis, but a higher proportion of re-dislocation.

Simulation of the Lower Walker River Basin hydrologic system, west-central Nevada, using PRMS and MODFLOW models

Science.gov (United States)

Allander, Kip K.; Niswonger, Richard G.; Jeton, Anne E.

2014-01-01

Walker Lake is a terminal lake in west-central Nevada with almost all outflow occurring through evaporation. Diversions from Walker River since the early 1900s have contributed to a substantial reduction in flow entering Walker Lake. As a result, the lake is receding, and salt concentrations have increased to a level in which Oncorhynchus clarkii henshawi (Lahontan Cutthroat trout) are no longer present, and the lake ecosystem is threatened. Consequently, there is a concerted effort to restore the Walker Lake ecosystem and fishery to a level that is more sustainable. However, Walker Lake is interlinked with the lower Walker River and adjacent groundwater system which makes it difficult to understand the full effect of upstream water-management actions on the overall hydrologic system including the lake level, volume, and dissolved-solids concentrations of Walker Lake. To understand the effects of water-management actions on the lower Walker River Basin hydrologic system, a watershed model and groundwater flow model have been developed by the U.S. Geological Survey in cooperation with the Bureau of Reclamation and the National Fish and Wildlife Foundation.

Walker Branch Watershed Vegetation Inventory, 1967-1997

Data.gov (United States)

National Aeronautics and Space Administration — ABSTRACT: The original objectives of the long-term vegetation survey of Walker Branch Watershed in eastern Tennessee (WBW; Curlin and Nelson 1968) was to quantify...

Grasshoppers, crickets (Orthoptera and earwigs (Dermaptera of Tovačov gravel pit (central Moravia, Czech Republic: New locality for several thermophilous species in anthropogenic secondary habitat

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Trnka Filip

2015-12-01

Full Text Available Study of Orthoptera and earwigs was conducted in Tovačov gravel pit in 2014. We have recorded 18 species of Orthoptera and 3 species of earwigs. The most significant recorded species are Cepero’s ground-hopper (Tetrix ceperoi, pygmy mole cricket (Xya variegata, Italian tree cricket (Oecanthus pellucens and riparian earwig (Labidura riparia. Tovačov gravel pit poses the northernmost locality of T. ceperoi and X. variegata in the Czech Republic and the northernmost known locality in Moravia for O. pellucens. For the L. riparia, we present a founding from Tovačov together with another finding from Olomouc vicinity, which is currently the northernmost locality within Moravia. Our findings display recent spatial expansion of some thermophilous species. Moreover, we emphasize importance of (post-industrial areas as secondary habitats for specialised endangered species.

Usher syndrome associated with a variant of Dandy-Walker malformation.

Science.gov (United States)

Simsek, Tulay; Ozdamar, Yasemin; Simsek, Enver; Men, Gamze

2010-05-21

Three cases of Usher syndrome associated with a variant of Dandy-Walker malformation in three siblings from consanguineous Turkish parents are described. The siblings had retinitis pigmentosa and hearing loss. Two of the siblings also had mental retardation, which is not a constant finding in Usher syndrome. Dandy-Walker malformation might have contributed to the mental retardation in two of these patients and might be a coincidental finding with Usher syndrome. Copyright 2010, SLACK Incorporated.

Casimir densities for a boundary in Robertson-Walker spacetime

Energy Technology Data Exchange (ETDEWEB)

Saharian, A.A., E-mail: saharian@ictp.i [Department of Physics, Yerevan State University, 1 Alex Manoogian Street, 0025 Yerevan (Armenia); Setare, M.R., E-mail: rezakord@ipm.i [Department of Science of Bijar, University of Kurdistan, Bijar (Iran, Islamic Republic of)

2010-04-12

For scalar and electromagnetic fields we evaluate the vacuum expectation value of the energy-momentum tensor induced by a curved boundary in the Robertson-Walker spacetime with negative spatial curvature. In order to generate the vacuum densities we use the conformal relation between the Robertson-Walker and Rindler spacetimes and the corresponding results for a plate moving by uniform proper acceleration through the Fulling-Rindler vacuum. For the general case of the scale factor the vacuum energy-momentum tensor is presented as the sum of the boundary free and boundary induced parts.

Casimir densities for a boundary in Robertson-Walker spacetime

International Nuclear Information System (INIS)

Saharian, A.A.; Setare, M.R.

2010-01-01

For scalar and electromagnetic fields we evaluate the vacuum expectation value of the energy-momentum tensor induced by a curved boundary in the Robertson-Walker spacetime with negative spatial curvature. In order to generate the vacuum densities we use the conformal relation between the Robertson-Walker and Rindler spacetimes and the corresponding results for a plate moving by uniform proper acceleration through the Fulling-Rindler vacuum. For the general case of the scale factor the vacuum energy-momentum tensor is presented as the sum of the boundary free and boundary induced parts.

Pengelolaan Lingkungan dalam Rangka Mengantisipasi Perkembangan Hama Belalang Nomadacris succincta Linnaeus (Orthoptera: Acrididae

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Sri Suharni Siwi

2005-12-01

Full Text Available Swarming grasshopper Nomadacris succincta (Linnaeus, sinonim: Patanga succincta (L. was one of the dominant species attacked corn and soybean plantations at Jeneponto District, South Sulawesi in early 2005. The species has been identified for a long time occurred in that environment, although has never been reported before as pest of farmer's crops. For a basis of the capability in controlling the swarm grasshopper in the field, changed of increasing population hould be monitored regularly to prevent future outbreak. Information on taxonomic and ecology research of N. succincta are needed for environmental management efforts, such as change in morphology, physiology and behavior, change in host's preferences of gregarious adult, and environmental conditions i.e. climate, cultural techniques, and the death of natural enemies in the field.

Oviposition site selection by the grasshoppers Melanoplus borealis and M. sanguinipes (Orthoptera: Acrididae)

Science.gov (United States)

Female grasshoppers can affect the fitness of their offspring through their selection of oviposition sites. Successful embryological development depends on suitable temperature and moisture levels, factors which may vary considerably on a fine scale in natural environments where grasshoppers occur. ...

Biological half-life of radiophosphorus in desert locust, Schistocerca gregaria Forskal (orthoptera:acrididae)

International Nuclear Information System (INIS)

Ulagaraj, S.M.; Singh, K.M.; Sethi, G.R.

1975-01-01

Adult desert locust, Schistocerca gregaria Forskal were fed with cabbage leaves, painted with carrier free 32 P 1mCi/ml. Radioactivity of five adults of both sexes and of feces was measured daily for 28 days. The amount of radioactivity appearing in the feces of males was consistently below that found in female locusts. The mean biological half-life of 32 P for males and females were 35.04 and 15.01 days, respectively. (author)

Aleuas uruguayensis Carbonell (Orthoptera, Acrididae, Copiocerinae: novel occurrence in the Paranaense biogeographic province

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Alberto TAFFAREL

2014-01-01

Full Text Available El género neotropical Aleuas Stål 1878 está constituido por nueve es - pecies distribuidas a lo largo de América del Sur. Este género se encuentra cer - canamente relacionado con Adimantus Stål 1878, Zygoclistron Rehn 1905 y Epis - copotettix Rehn 1903 (Copiocerinae. Únicamente cuatro especies de Aleuas fue - ron descriptas en distintas provincias fitogeográficas en Argentina: A. gracilis Stål 1878, A. lineatus Stål 1878, A. paranensis Carbonell 2008 y A. vitticollis Stål 1878. En este trabajo proporcionamos nuevos registros de A. uruguayensis y brindamos un mapa de distribución geográfica actualizado, incluyendo las localidades conocidas en las que se encuentra esta especie. Confirmamos la presencia de A. uruguayensis por primera vez en Argentina, en cuatro localidades distantes a 450 kilómetros al noroeste del único registro conocido. De esta manera, ampliamos el rango de distribución de la especie y realizamos un aporte al conocimiento general de la diversidad de ortópteros de Argentina.

Behavioral responses of Schistocerca americana (Orthoptera: Acrididae) to Azadirex (neem)-treated host plants.

Science.gov (United States)

Capinera, John L; Froeba, Jason G

2007-02-01

Azadirex (azadirachtin and other biologically active extracts from neem trees) has been shown to have considerable potential to be used in integrated pest management systems based on its growth regulator/insecticide properties. Less well known are the antifeedant properties. The feeding-deterrent properties of a commercial azadirex formulation (Azatrol EC) were evaluated using both no-choice and choice tests, the American grasshopper, Schistocerca americana (Drury), and four host plants [savoy cabbage, Brassica oleracea variety capitata L.; cos (romaine) lettuce, Lactuca sativa variety longifolia Lam.; sweet orange, Citrus sinensis variety Hamlin L.; and peregrina, Jatropha integerrima Jacq.]. These studies demonstrated that azadirex application can significantly affect the feeding behavior of grasshoppers. Some degree of protection can be afforded to plants that differ markedly in their innate attractiveness to the insect, although the level of protection varies among hosts. The tendency of grasshoppers to sometimes feed on azadirex-treated foliage suggests that it will be difficult to prevent damage from occurring at all times, on all hosts. No evidence of rapid habituation to azadirex was detected. Rapid loss of efficacy was observed under field conditions, suggesting that daily retreatment might be necessary to maintain protection of plants from feeding.

Neutral signature Walker-VSI metrics

International Nuclear Information System (INIS)

Coley, A; McNutt, D; Musoke, N; Brooks, D; Hervik, S

2014-01-01

We will construct explicit examples of four-dimensional neutral signature Walker (but not necessarily degenerate Kundt) spaces for which all of the polynomial scalar curvature invariants vanish. We then investigate the properties of some particular subclasses of Ricci flat spaces. We also briefly describe some four-dimensional neutral signature Einstein spaces for which all of the polynomial scalar curvature invariants are constant. (paper)

A new species of Thelastomathidae (Nematoda) a parasite of Neocurtilla claraziana Saussure (Orthoptera, Gryllotalpidae) in Argentina.

Science.gov (United States)

Camino, Nora B; Maiztegui, Bárbara

2002-07-01

Gryllophila cephalobulata n. sp. (Nematoda, Thelastomatidae) a parasite of the mole cricket Neocurtilla claraziana (Orthoptera, Gryllotalpidae) isolated in Buenos Aires Province, is described and illustrated. It is characterized by cuticle annulated all along the length of the body; the first ring has 4 lobules, the second one has 14 lobules, the others rings are simple, the stoma is short and has 4 small teeth, the genital papillae are arranged in 5 pairs, of which 3 pairs are preanal and 2 pairs are postanal. The tail appendage of the male is long and filiform.

Anterior or posterior walkers for children with cerebral palsy? A systematic review.

Science.gov (United States)

Poole, Marilyn; Simkiss, Doug; Rose, Alice; Li, François-Xavier

2018-05-01

To review the literature comparing use of anterior and posterior walkers (PW's) by children with cerebral palsy (CP) to determine which walker type is preferable. Electronic databases were searched using pre-defined terms by two independent reviewers. Reference lists of included studies were hand searched. Studies published between 1985 and 2016 comparing use of anterior and PW's by children with CP were included. All study designs and outcomes were accepted. Risk of bias was assessed using the "Quality assessment standard for a cross-over study". Quality of evidence was evaluated using GRADE. Six studies were analysed. All studies had small sample sizes. A total of 4/6 studies were randomized. A total of 4/6 had high risk of bias. Outcomes included velocity, pelvic tilt, hip flexion, knee flexion, step length, stride length, cadence, double stance time, oxygen cost and participant/parental preference. Velocity, trunk flexion/pelvic tilt, and stability may be improved by using a PW, however, GRADE quality was very low for all outcomes and there was heterogeneity between studies. The majority of participants and parents preferred the PW. Heterogeneity and low quality of existing evidence prevented recommendation of one walker type. Well-designed studies with adequate power are needed to inform clinical recommendations. Implications for rehabilitation Clinical recommendations cannot be made for whether anterior or posterior walkers are preferable for children with cerebral palsy based on the existing evidence. Velocity, trunk flexion/pelvic tilt, and stability may be improved by using a posterior walker. The majority of walking aid users and their parents preferred posterior walkers. Adequately powered studies designed to minimize bias are needed.

The fire-walker's high: affect and physiological responses in an extreme collective ritual.

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Ronald Fischer

Full Text Available How do people feel during extreme collective rituals? Despite longstanding speculation, few studies have attempted to quantify ritual experiences. Using a novel pre/post design, we quantified physiological fluctuations (heart rates and self-reported affective states from a collective fire-walking ritual in a Mauritian Hindu community. Specifically, we compared changes in levels of happiness, fatigue, and heart rate reactivity among high-ordeal participants (fire-walkers, low-ordeal participants (non-fire-walking participants with familial bonds to fire-walkers and spectators (unrelated/unknown to the fire-walkers. We observed that fire-walkers experienced the highest increase in heart rate and reported greater happiness post-ritual compared to low-ordeal participants and spectators. Low-ordeal participants reported increased fatigue after the ritual compared to both fire-walkers and spectators, suggesting empathetic identification effects. Thus, witnessing the ritualistic suffering of loved ones may be more exhausting than experiencing suffering oneself. The findings demonstrate that the level of ritual involvement is important for shaping affective responses to collective rituals. Enduring a ritual ordeal is associated with greater happiness, whereas observing a loved-one endure a ritual ordeal is associated with greater fatigue post-ritual.

Corrections to the Walker-Thompson estimate of the cascade volume

International Nuclear Information System (INIS)

Swaminarayan, S.; Nastasi, M.

2009-01-01

Sigmund [P. Sigmund, Appl. Phys. Lett. 25 (1974) 169] analytically predicted that the ratio of cascade volume to energy distribution volume should follow a universal curve that is sigmoidal in shape. Subsequent Monte Carlo simulations by Walker and Thompson [R.S. Walker, D.A. Thompson, Radiat. Eff. 37 (1978) 113] showed that although this curve is sigmoidal in shape, the curve is different for different materials with large deviations from Sigmund's prediction at high M 2 /M 1 . Our analysis of the Walker and Thompson approach has revealed an error in the analytical equations used. A correct analysis of volume ratios using a different set of equations is presented. Analysis of data produced by SRIM [J.F. Ziegler, J.P. Biersack, U. Littmark, in: The Stopping and Range of Ions in solids, Pergamon, New York, 1985] (Monte Carlo) simulations gives results that are in good agreement with Sigmund's predictions.

Does the Walker Lane extend through the Nevada test site region?

International Nuclear Information System (INIS)

Fridrich, C.; O'Leary, D.

1993-01-01

The southeastern terminus of the Walker Lane is poorly defined and poorly understood. Recent work in and around the Nevada Test Site (NTS) suggests the presence of a structural zone that may be an extension of the Walker Lane, and that may be continuous with the Las Vegas valley shear zone farther to the southeast. Unlike the Walker Lane, large through-going strike-slip faults have not been found in the NTS zone. Instead, the strike-slip faults present are few, are relatively short, commonly consist of diffuse fault zones, are interconnected poorly if at all, and largely appear to represent zones of accommodation between domains in which extension occurred at different times and to different degrees. However, the majority of these right-slip and left-slip faults are northwest-trending and northeast-trending, respectively, suggesting that plate motions may have played a role in the creation of these accommodation zones. An obstacle to understanding the NTS zone is that major ignimbrite sheets and calderas of the southwestern Nevada volcanic field (SNVF) formed in this zone at the height of late Tertiary tectonic activity, possibly burying much of the structural evidence. The NTS zone could represent an intersection of the Walker Lane with another major structural feature, a significant bend in the Walker Lane, or a transtensional tear that localized accommodation structures as well as the prominent late Miocene calderas of the SNVF. Ongoing field work is aimed at determining which of these and competing interpretations is best

Agamermis (Nematoda: Mermithidae) Infection in South Carolina Agricultural Pests.

Science.gov (United States)

Stubbins, Francesca L; Agudelo, Paula; Reay-Jones, Francis P F; Greene, Jeremy K

2016-12-01

Native and invasive stink bugs (Hemiptera: Pentatomidae) and the closely related invasive Megacopta cribraria (Hemiptera: Plataspidae) are agricultural pests in the southeastern United States. Natural enemies, from various phyla, parasitize these pests and contribute to population regulation. We specifically investigated Nematoda infections in pentatomid and plataspid pests in one soybean field in South Carolina in 2015. Nematodes were identified through molecular and morphological methods and assigned to family Mermithidae, genus Agamermis . This study reports mermithid nematode infection in immature M. cribraria for the first time and provides the first mermithid host record for the stink bugs Chinavia hilaris , Euschistus servus , and another Euschistus species, and a grasshopper (Orthoptera: Acrididae) in South Carolina. The same Agamermis species infected all hosts. The broad host range and prevalence suggests that Agamermis may be an important contributor to natural mortality of pentatomid and plataspid pests. Previous mermithid host records for the Pentatomidae and Plataspidae worldwide are summarized. Further work is needed to assess the impact of infection on populations over a broader range of agricultural fields and geographic localities.

Cochlear implantation in patient with Dandy-walker syndrome.

Science.gov (United States)

de Oliveira, Adriana Kosma Pires; Hamerschmidt, Rogerio; Mocelin, Marcos; Rezende, Rodrigo K

2012-07-01

 Dandy Walker Syndrome is a congenital abnormality in the central nervous system, characterized by a deficiency in the development of middle cerebelar structures, cystic dilatation of the posterior pit communicating with the fourth ventricle and upward shift of the transverse sinuses, tentorium and dyes. Among the clinical signs are occipital protuberances, a progressive increase of the skull, bowing before the fontanels, papilledema, ataxia, gait disturbances, nystagmus, and intellectual impairment.  To describe a case of female patient, 13 years old with a diagnosis of this syndrome and bilateral hearing loss underwent cochlear implant surgery under local anesthesia and sedation.  CGS, 13 years old female was referred to the Otolaryngological Department of Otolaryngology Institute of Parana with a diagnosis of "Dandy-Walker syndrome" for Otolaryngological evaluation for bilateral hearing loss with no response to the use of hearing aids. Final Comments: The field of cochlear implants is growing rapidly. We believe that the presence of Dandy-Walker syndrome cannot be considered a contraindication to the performance of cochlear implant surgery, and there were no surgical complications due to neurological disorders with very favorable results for the patient who exhibits excellent discrimination. It has less need for lip reading with improvement in speech quality.

Cochlear implantation in patient with Dandy-walker syndrome

Directory of Open Access Journals (Sweden)

Oliveira, Adriana Kosma Pires de

2012-01-01

Full Text Available Introduction: Dandy Walker Syndrome is a congenital abnormality in the central nervous system, characterized by a deficiency in the development of middle cerebelar structures, cystic dilatation of the posterior pit communicating with the fourth ventricle and upward shift of the transverse sinuses, tentorium and dyes. Among the clinical signs are occipital protuberances, a progressive increase of the skull, bowing before the fontanels, papilledema, ataxia, gait disturbances, nystagmus, and intellectual impairment. Objectives: To describe a case of female patient, 13 years old with a diagnosis of this syndrome and bilateral hearing loss underwent cochlear implant surgery under local anesthesia and sedation. Case Report: CGS, 13 years old female was referred to the Otolaryngological Department of Otolaryngology Institute of Parana with a diagnosis of "Dandy-Walker syndrome" for Otolaryngological evaluation for bilateral hearing loss with no response to the use of hearing aids. Final Comments: The field of cochlear implants is growing rapidly. We believe that the presence of Dandy-Walker syndrome cannot be considered a contraindication to the performance of cochlear implant surgery, and there were no surgical complications due to neurological disorders with very favorable results for the patient who exhibits excellent discrimination. It has less need for lip reading with improvement in speech quality.

Bistability and biasing effects in the perception of ambiguous point-light walkers.

Science.gov (United States)

Vanrie, Jan; Dekeyser, Mathias; Verfaillie, Karl

2004-01-01

The perceptually bistable character of point-light walkers has been examined in three experiments. A point-light figure without explicit depth cues constitutes a perfectly ambiguous stimulus: from all viewpoints, multiple interpretations are possible concerning the depth orientation of the figure. In the first experiment, it is shown that non-lateral views of the walker are indeed interpreted in two orientations, either as facing towards the viewer or as facing away from the viewer, but that the interpretation in which the walker is oriented towards the viewer is reported more frequently. In the second experiment the point-light figure was walking backwards, making the global orientation of the point-light figure opposite to the direction of global motion. The interpretation in which the walker was facing the viewer was again reported more frequently. The robustness of these findings was examined in the final experiment, in which the effects of disambiguating the stimulus by introducing a local depth cue (occlusion) or a more global depth cue (applying perspective projection) were explored.

Compliant walker

Science.gov (United States)

Kerley, James J. (Inventor); Eklund, Wayne D. (Inventor); Crane, J. Allen (Inventor)

1992-01-01

A compliant walker is provided for humans having limited use of their legs and lower back. It includes an upright wheel frame which at least partially surrounds an upright user wearing a partial body harness. It is attached to the frame by means of cable compliant apparatus consisting of sets of cable segments and angle bracket members connected between opposite side members of the frame and adjacent side portions of the harness. Novelty is believed to exist in the combination of a wheeled frame including a side support structure, a body harness, and compliance means connecting the body harness to the side support structure for flexibility holding and supporting a person in a substantially upright position when the user sags in the frame when taking weight off the lower extremities.

[Needs, uses, cons-pros, good practices and opportunities about walker in elderly with loss of autonomy].

Science.gov (United States)

Mézière, Anthony; Schonheit, Claire; Moreau, Caroline; Baudry, Elodie; Monié, Marguerite; Piette, François; Curtis, Valentine; Pasqui, Viviane

2015-01-01

Non-use of the walker may be secondary to an initial inappropriate prescribing, a lack of adequate training, a lack of monitoring and side effects of using. Improving both stability and mobility in users is due to several biomechanical mechanisms. The benefits of walker are: general physiological effects, more confidence, better social life and decrease in the burden of care. The disadvantages of walker are: technical or practical aspects criticized by users, musculoskeletal disorders, delayed reaction time, fall risk and stigma. Few scientific data evaluating the interest of the walker concerning mobility exist, thus recommendations are low grade and are often taken from professional clinical experiences. The choice of technical walking assistance depends on the pathology and biomechanical mechanism. The walker robots are few distributed. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Effect of uphill and downhill walking on walking performance in geriatric patients using a wheeled walker.

Science.gov (United States)

Lindemann, Ulrich; Schwenk, Michael; Schmitt, Syn; Weyrich, Michael; Schlicht, Wolfgang; Becker, Clemens

2017-08-01

Wheeled walkers are recommended to improve walking performance in older persons and to encourage and assist participation in daily life. Nevertheless, using a wheeled walker can cause serious problems in the natural environment. This study aimed to compare uphill and downhill walking with walking level in geriatric patients using a wheeled walker. Furthermore, we investigated the effect of using a wheeled walker with respect to dual tasking when walking level. A total of 20 geriatric patients (median age 84.5 years) walked 10 m at their habitual pace along a level surface, uphill and downhill, with and without a standard wheeled walker. Gait speed, stride length and cadence were assessed by wearable sensors and the walk ratio was calculated. When using a wheeled walker while walking level the walk ratio improved (0.58 m/[steps/min] versus 0.57 m/[steps/min], p = 0.023) but gait speed decreased (1.07 m/s versus 1.12 m/s, p = 0.020) when compared to not using a wheeled walker. With respect to the walk ratio, uphill and downhill walking with a wheeled walker decreased walking performance when compared to level walking (0.54 m/[steps/min] versus 0.58 m/[steps/min], p = 0.023 and 0.55 m/[steps/min] versus 0.58 m/[steps/min], p = 0.001, respectively). At the same time, gait speed decreased (0.079 m/s versus 1.07 m/s, p walker improved the quality of level walking but the performance of uphill and downhill walking was worse compared to walking level when using a wheeled walker.

Influence of an infant walker on onset and quality of walking pattern of locomotion:an electromyographic investigation.

Science.gov (United States)

Kauffman, I B; Ridenour, M

1977-12-01

Acquisition of bipedal locomotor skill in human infants was studied electromyographically with regard to the deprivation or enrichment behavior resulting from the frequent and regular use of an infant walker. Subjects were six sets of male, fraternal twins. One randomly selected sibling from each set underwent a training program, commencing at the age of 300 days, spending a total of 2 hr. per day in a walker. Siblings not included in this group were subjected to no special training. EMG recordings were taken of all subjects at specified intervals in order to establish a model of the typical motor pattern at various stages of skill development. These data were then contrasted with EMG data similarly obtained from the walker-trained subjects. Use of an infant walker modified the mechanics of the infant's locomotion in a number of important ways. It was shown that use of the walker enables an infant to commit substantial mechanical errors yet succeed in bipedal locomotion. Inasmuch as the mechanics of walker-assisted and non-assisted bipedal locomotion are dissimilar in so many important ways, positive transfer from walker-training appears questionable.

Directional transport of colloids inside a bath of self-propelling walkers.

Science.gov (United States)

Merlitz, Holger; Wu, Chenxu; Sommer, Jens-Uwe

2017-05-24

We present a setup in which passive colloids inside a solvent are moved to the boundaries of the container. The directional transport is facilitated by self-propelling microparticles ("walkers") with an activity gradient, which reduces their propulsion in the vicinity of bounding walls. An attractive interaction leads to the adsorption of walkers onto the colloid-surfaces in regions of low walker activity. It is shown that the activity gradient generates a free energy gradient which in turn acts as a driving force on the passive colloids. We carry out molecular dynamics simulations and present approaches to a theoretical description of the involved processes. Although the simulation data are not reproduced on a fully quantitative level, their qualitative features are covered by the model. The effect described here may be applied to facilitate a directional transport of drugs or to eliminate pollutants.

76 FR 13665 - Arcelor Mittal, Formerly Known as Mittal Steel Walker Wire, a Subsidiary of Arcelor Mittal...

Science.gov (United States)

2011-03-14

... Known as Mittal Steel Walker Wire, a Subsidiary of Arcelor Mittal--Montreal, Including On-Site Leased... Steel Walker Wire, a subsidiary of Arcelor Mittal-- Montreal, including on-site leased workers from... Walker Wire, Inc., Ferndale, Michigan, separated from employment on or after July 23, 2006 through August...

Averaging Robertson-Walker cosmologies

International Nuclear Information System (INIS)

Brown, Iain A.; Robbers, Georg; Behrend, Juliane

2009-01-01

The cosmological backreaction arises when one directly averages the Einstein equations to recover an effective Robertson-Walker cosmology, rather than assuming a background a priori. While usually discussed in the context of dark energy, strictly speaking any cosmological model should be recovered from such a procedure. We apply the scalar spatial averaging formalism for the first time to linear Robertson-Walker universes containing matter, radiation and dark energy. The formalism employed is general and incorporates systems of multiple fluids with ease, allowing us to consider quantitatively the universe from deep radiation domination up to the present day in a natural, unified manner. Employing modified Boltzmann codes we evaluate numerically the discrepancies between the assumed and the averaged behaviour arising from the quadratic terms, finding the largest deviations for an Einstein-de Sitter universe, increasing rapidly with Hubble rate to a 0.01% effect for h = 0.701. For the ΛCDM concordance model, the backreaction is of the order of Ω eff 0 ≈ 4 × 10 −6 , with those for dark energy models being within a factor of two or three. The impacts at recombination are of the order of 10 −8 and those in deep radiation domination asymptote to a constant value. While the effective equations of state of the backreactions in Einstein-de Sitter, concordance and quintessence models are generally dust-like, a backreaction with an equation of state w eff < −1/3 can be found for strongly phantom models

Future null infinity of Robertson-Walker spacetimes

International Nuclear Information System (INIS)

Moreschi, O.M.

1988-08-01

The future null infinity for all non-contracting Robertson-Walker space time is studied systematically. A theorem is proved which establishes the expected relation between the nature of J + and the appearance or absence of cosmic event horizons. (author). 7 refs, 1 tab

Measuring cortical motor hemodynamics during assisted stepping - An fNIRS feasibility study of using a walker.

Science.gov (United States)

de Lima-Pardini, Andrea Cristina; Zimeo Morais, Guilherme A; Balardin, Joana Bisol; Coelho, Daniel Boari; Azzi, Nametala Maia; Teixeira, Luis Augusto; Sato, João Ricardo

2017-07-01

Walkers are commonly prescribed worldwide to individuals unable to walk independently. Walker usage leads to improved postural control and voluntary movement during step. In the present study, we aimed to provide a concept-proof on the feasibility of an event-related protocol integrating the analyses of biomechanical variables of step initiation and functional near-infrared spectroscopy (fNIRS) to measure activation of the supplementary motor area (SMA) while using a walker. Healthy young participants were tested while stepping with versus without the use of the walker. Behavioral analysis showed that anticipatory postural adjustments (APA) decreased when supporting the body weight on the walker. Delta (without-with) of activation magnitude of the muscle tibialis anterior was positively correlated to the delta of deoxyhemoglobin concentration changes in the SMA. The novelty of this study is the development of a protocol to assess brain function together with biomechanical analysis during the use of a walker. The method sheds light to the potential utility of combining fNIRS and biomechanical assessment during assistive step initiation, which can represent a new opportunity to study populations with mobility deficits. Copyright © 2017 Elsevier B.V. All rights reserved.

Robust Redundant Input Reliable Tracking Control for Omnidirectional Rehabilitative Training Walker

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Ping Sun

2014-01-01

Full Text Available The problem of robust reliable tracking control on the omnidirectional rehabilitative training walker is examined. The new nonlinear redundant input method is proposed when one wheel actuator fault occurs. The aim of the study is to design an asymptotically stable controller that can guarantee the safety of the user and ensure tracking on a training path planned by a physical therapist. The redundant degrees of freedom safety control and the asymptotically zero state detectable concept of the walker are presented, the model of redundant degree is constructed, and the property of center of gravity constant shift is obtained. A controller that can satisfy asymptotic stability is obtained using a common Lyapunov function for admissible uncertainties resulting from an actuator fault. Simulation results confirm the effectiveness of the proposed method and verify that the walker can provide safe sequential motion when one wheel actuator is at fault.

Novel and deviant Walker A ATP-binding motifs in bacteriophage large terminase-DNA packaging proteins

International Nuclear Information System (INIS)

Mitchell, Michael S.; Rao, Venigalla B.

2004-01-01

Bacteriophage terminases constitute a very interesting class of viral-coded multifunctional ATPase 'motors' that apparently drive directional translocation of DNA into an empty viral capsid. A common Walker A motif and other conserved signatures of a critical ATPase catalytic center are identified in the N-terminal half of numerous large terminase proteins. However, several terminases, including the well-characterized λ and SPP1 terminases, seem to lack the classic Walker A in the N-terminus. Using sequence alignment approaches, we discovered the presence of deviant Walker A motifs in these and many other phage terminases. One deviation, the presence of a lysine at the beginning of P-loop, may represent a 3D equivalent of the universally conserved lysine in the Walker A GKT/S signature. This and other novel putative Walker A motifs that first came to light through this study help define the ATPase centers of phage and viral terminases as well as elicit important insights into the molecular functioning of this fundamental motif in biological systems

MECHANICAL EFFICIENCY OF A CHAMPION WALKER* • • • • .o •

African Journals Online (AJOL)

Oxygen consumplions were measured on a champion walker, while walking at between 6·4 and 16·9 km / hand while running at between lJ·] and 17-7 km/h. Above. 9-7 km / h the curve of oxygen consumption against speed for walking was almost twice as steep as that for rlInning, indicating that el'en champion walkers are ...

Quantum Tunneling and Chaos in Classical Scale Walkers

Science.gov (United States)

Su, Jenny; Dijksman, Joshua; Ward, Jeremy; Behringer, Robert

2014-03-01

We study the behavior of `walkers' small droplets bouncing on a fluid layer vibrated at amplitudes just below the onset of Faraday instability. It was shown recently that despite their macroscopic size, the droplet dynamics are stochastic in nature and reminiscent of the dual particle-wave dynamics in the realm of quantum mechanics (Couder PRL 2006). We use these walkers to study how chaos, which is macroscopically unpredictable, will manifest in a quantum setting. Pecora showed in 2011 that tunneling for particles that have a chaotic ground state is different from tunneling for particles with a regular ground state (PRE 2011). In the experiment we gather data that illustrates the particle trajectory and tunneling behavior as particles transition across the barrier in the double well system with both integrable and chaotic shapes.

Longevity and fecundity of Dichroplus maculipennis (Orthoptera, Acrididae at non-outbreaking and outbreaking situations Longevidade e fecundidade de Dichroplus maculipennis (Orthoptera: Acrididae: Melanoplinae em situações de "non-outbreaking" e "outbreaking"

Directory of Open Access Journals (Sweden)

Yanina Mariottini

2011-09-01

Full Text Available Dichroplus maculipennis is one of the most characteristic and damaging grasshopper species of Argentina, mainly in areas of the Pampas and Patagonia regions. We estimated and compared the longevity and fecundity of adult female D. maculipennis under controlled conditions (30ºC, 14L:10D, 40% RH from individuals collected as last instar nymphs (VI in the field and with a known recent history of low and high density conditions. Densities of D. maculipennis at the collecting sites were 0.95 individuals per m² in 2006 and 46 ind/m² in 2009, representing non-outbreaking and outbreaking situations, respectively. Adult female longevity in 2006 (67.96 ± 3.2 days was significantly higher (p 0.05. The fecundity curves showed that the highest values were at weeks 11 and 13 for the 2006 females, and at week 6 for those of 2009. Since the daily oviposition rate at low and high densities was not significantly different, the diminished fecundity rate at high density is attributable to their reduced longevity.O gafanhoto Dichroplus maculipennis é um dos mais característicos e prejudiciales da Argentina, principalmente nas regiões das Pampas e da Patagonia. O objetivo deste estudo foi estimar e comparar a longevidade e fecundidade das fêmeas adultas do D. maculipennis sob condições controladas (30ºC, 14 luz: 10 obscuridad, 40% RH a partir do indivíduos coletados em campo como ultimo estadio ninfal (VI e con historia recente conocida de baixas e altas densidades. As densidades de D. maculipennis nos locais de coleta foram de 0.95 indivíduos por m² em 2006 e 46 indivíduos/m² em 2009, representando situações de "non-outbreaking" e "outbreaking", respectivamente. A longevidade das fêmeas adultas em 2006 (67.96 ± 3.2 dias foi significamente maior (p 0.05. No entanto, as baixas taxas de fecundidade das fêmeas em densidades elevadas, se devem, provavelmente à longevidade reduzida.

A Motion Control of a Robotic Walker for Continuous Assistance during Standing, Walking and Seating Operation

OpenAIRE

Chugo, Daisuke; Takase, Kunikatsu

2010-01-01

In this paper, we develop an active walker system for standing, walking and seating operation continuously which cooperates the developed standing assistance system with safety and stability. For realizing these conditions, our walker coordinates the assisting position cooperating the standing assistance manipulator according to the posture of the patient. Furthermore, our walker adjusts a seating position when the patient sit down which has high risk for falling down. Using our proposed syst...

[Upper extremity kinetics and energy expenditure during walker-assisted gait in children with cerebral palsy].

Science.gov (United States)

Konop, Katherine A; Strifling, Kelly M B; Wang, Mei; Cao, Kevin; Eastwood, Daniel; Jackson, Scott; Ackman, Jeffrey; Altiok, Haluk; Schwab, Jeffrey; Harris, Gerald F

2009-01-01

We evaluated the relationships between upper extremity (UE) kinetics and the energy expenditure index during anterior and posterior walker-assisted gait in children with spastic diplegic cerebral palsy (CP). Ten children (3 boys, 7 girls; mean age 12.1 years; range 8 to 18 years) with spastic diplegic CP, who ambulated with a walker underwent gait analyses that included UE kinematics and kinetics. Upper extremity kinetics were obtained using instrumented walker handles. Energy expenditure index was obtained using the heart rate method (EEIHR) by subtracting resting heart rate from walking heart rate, and dividing by the walking speed. Correlations were sought between the kinetic variables and the EEIHR and temporal and stride parameters. In general, anterior walker use was associated with a higher EEIHR. Several kinetic variables correlated well with temporal and stride parameters, as well as the EEIHR. All of the significant correlations (r>0.80; pwalker use and involved joint reaction forces (JRF) rather than moments. Some variables showed multiple strong correlations during anterior walker use, including the medial JRF in the wrist, the posterior JRF in the elbow, and the inferior and superior JRFs in the shoulder. The observed correlations may indicate a relationship between the force used to advance the body forward within the walker frame and an increased EEIHR. More work is needed to refine the correlations, and to explore relationships with other variables, including the joint kinematics.

Hydrologic data for the Walker River Basin, Nevada and California, water years 2010–14

Science.gov (United States)

Pavelko, Michael T.; Orozco, Erin L.

2015-12-10

Walker Lake is a threatened and federally protected desert terminal lake in western Nevada. To help protect the desert terminal lake and the surrounding watershed, the Bureau of Reclamation and U.S. Geological Survey have been studying the hydrology of the Walker River Basin in Nevada and California since 2004. Hydrologic data collected for this study during water years 2010 through 2014 included groundwater levels, surface-water discharge, water chemistry, and meteorological data. Groundwater levels were measured in wells, and surface-water discharge was measured in streams, canals, and ditches. Water samples for chemical analyses were collected from wells, streams, springs, and Walker Lake. Chemical analyses included determining physical properties; the concentrations of major ions, nutrients, trace metals, dissolved gases, and radionuclides; and ratios of the stable isotopes of hydrogen and oxygen. Walker Lake water properties and meteorological parameters were monitored from a floating platform on the lake. Data collection methods followed established U.S. Geological Survey guidelines, and all data are stored in the National Water Information System database. All of the data are presented in this report and accessible on the internet, except multiple-depth Walker Lake water-chemistry data, which are available only in this report.

The RBE of Fractionated Fast Neutron on Walker 256 Carcinosarcoma with KCCH-Cyclotron

International Nuclear Information System (INIS)

Yoo, Seong Yul; Koh, Kyoung Hwan; Cho, Chul Koo; Park, Charn Il; Kang, Wee Saing

1987-01-01

For evaluation of biological effect of p+(50.5 MeV) Be neutron beam produced by Korea Cancer Center Hospital(KCCH) cyclotron the RBE had been measured in experimental tumor Walker 256 carcinosarcoma as well as normal tissue, mouse intestine and bone marrow, in single and fractionated irradiation. As pilot study, the RBE had been measured for the mouse jejunal crypt cells in single whole body irradiation of which the result was 2.8. The obtained RBE values of TCD 50 of Walker 256 tumor, bone marrow and intestine in single irradiation were 1.9, 1.9 and 1.5 respectively. In fractionated irradiation, the RBE value of tumor Walker 256 was decreased as increasing of fraction number and increased as increasing of fraction size

Test pilots 1962 - Armstrong, Walker, Dana, Peterson, McKay, Thompson, Butchart

Science.gov (United States)

1962-01-01

The research pilots at what in 1962 was called the Flight Research Center standing in front of the X-1E. They are (left to right) Neil Armstrong, Joe Walker, Bill Dana, Bruce Peterson, Jack McKay, Milt Thompson, and Stan Butchart. of the group, Armstrong, Walker, Dana, McKay and Thompson all flew the X-15. Bruce Peterson flew the M2-F2 and HL-10 lifting bodies, while Stan Butchart was the B-29 drop plane pilot for many of the D-558-II and X-1 series research aircraft.

Cloning, purification and crystallization of a Walker-type Pyrococcus abyssi ATPase family member

International Nuclear Information System (INIS)

Uhring, Muriel; Bey, Gilbert; Lecompte, Odile; Cavarelli, Jean; Moras, Dino; Poch, Olivier

2005-01-01

The Walker-type ATPase PABY2304 of P. abyssi has been cloned, overexpressed, purified and crystallized. X-ray diffraction data from selenomethionine-derivative crystals have been collected to 2.6 Å. The structure has been solved by MAD techniques. Several ATPase proteins play essential roles in the initiation of chromosomal DNA replication in archaea. Walker-type ATPases are defined by their conserved Walker A and B motifs, which are associated with nucleotide binding and ATP hydrolysis. A family of 28 ATPase proteins with non-canonical Walker A sequences has been identified by a bioinformatics study of comparative genomics in Pyrococcus genomes. A high-throughput structural study on P. abyssi has been started in order to establish the structure of these proteins. 16 genes have been cloned and characterized. Six out of the seven soluble constructs were purified in Escherichia coli and one of them, PABY2304, has been crystallized. X-ray diffraction data were collected from selenomethionine-derivative crystals using synchrotron radiation. The crystals belong to the orthorhombic space group C2, with unit-cell parameters a = 79.41, b = 48.63, c = 108.77 Å, and diffract to beyond 2.6 Å resolution

Cloning, purification and crystallization of a Walker-type Pyrococcus abyssi ATPase family member

Energy Technology Data Exchange (ETDEWEB)

Uhring, Muriel; Bey, Gilbert; Lecompte, Odile; Cavarelli, Jean; Moras, Dino; Poch, Olivier, E-mail: poch@igbmc.u-strasbg.fr [Département de Biologie et Génomiques Structurales, UMR 7104, Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS/INSERM/ULP Strasbourg, 1 Rue Laurent Fries, 64404 Illkirch (France)

2005-10-01

The Walker-type ATPase PABY2304 of P. abyssi has been cloned, overexpressed, purified and crystallized. X-ray diffraction data from selenomethionine-derivative crystals have been collected to 2.6 Å. The structure has been solved by MAD techniques. Several ATPase proteins play essential roles in the initiation of chromosomal DNA replication in archaea. Walker-type ATPases are defined by their conserved Walker A and B motifs, which are associated with nucleotide binding and ATP hydrolysis. A family of 28 ATPase proteins with non-canonical Walker A sequences has been identified by a bioinformatics study of comparative genomics in Pyrococcus genomes. A high-throughput structural study on P. abyssi has been started in order to establish the structure of these proteins. 16 genes have been cloned and characterized. Six out of the seven soluble constructs were purified in Escherichia coli and one of them, PABY2304, has been crystallized. X-ray diffraction data were collected from selenomethionine-derivative crystals using synchrotron radiation. The crystals belong to the orthorhombic space group C2, with unit-cell parameters a = 79.41, b = 48.63, c = 108.77 Å, and diffract to beyond 2.6 Å resolution.

Effects of no mating female adults and embryonic development of Schistocerca gregaria (Orthoptera: Acrididae)

Czech Academy of Sciences Publication Activity Database

Wang, F. H.; Sehnal, František

2013-01-01

Roč. 58, č. 26 (2013), s. 3244-3247 ISSN 1001-6538 R&D Projects: GA ČR GA522/98/0773 Grant - others:National Natural Science Foundation of China(CN) 39870475; National Natural Science Foundation of China(CN) 31171844; Natural Science Foundation of Guangdong Province(CN) S2011010001353 Institutional support: RVO:60077344 Keywords : Schistocerca gregaria Subject RIV: ED - Physiology Impact factor: 1.365, year: 2013 http://link.springer.com/article/10.1007%2Fs11434-013-5867-2#

Mechanical Vectors Enhance Fungal Entomopathogen Reduction of the Grasshopper Pest Camnula pellucida (Orthoptera: Acrididae).

Science.gov (United States)

Kistner, Erica J; Saums, Marielle; Belovsky, Gary E

2015-02-01

Mounting scientific evidence indicates that pathogens can regulate insect populations. However, limited dispersal and sensitivity to abiotic conditions often restricts pathogen regulation of host populations. While it is well established that arthropod biological vectors increase pathogen incidence in host populations, few studies have examined whether arthropod mechanical vectors (an organism that transmits pathogens but is not essential to the life cycle of the pathogen) influence host-pathogen dynamics. The importance of mechanical dispersal by ant scavengers, Formica fusca (L.), in a grasshopper-fungal entomopathogen system was investigated. We examined the ability of ants to mechanically disperse and transmit the pathogen, Entomophaga grylli (Fresenius) pathotype 1, to its host, the pest grasshopper Camnula pellucida (Scudder), in a series of laboratory experiments. Fungal spores were dispersed either externally on the ant's body surface or internally through fecal deposition. In addition, a third of all grasshoppers housed with fungal-inoculated ants became infected, indicating that ants can act as mechanical vectors of E. grylli. The effect of ant mechanical vectors on E. grylli incidence was also examined in a field experiment. Ant access to pathogen-exposed experimental grasshopper populations was restricted using organic ant repellent, thereby allowing us to directly compare mechanical and natural transmission. Ants increased grasshopper pathogen mortality by 58%, which led to greater pathogen reductions of grasshopper survival than natural transmission. Taken together, our results indicate that ants enhance E. grylli reduction of grasshopper pest numbers. Therefore, mechanical transmission of pathogens may be an important overlooking component of this grasshopper-fungal pathogen system. © The Author 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Longevity and fecundity of Dichroplus maculipennis (Orthoptera, Acrididae at non-outbreaking and outbreaking situations

Directory of Open Access Journals (Sweden)

Yanina Mariottini

2011-09-01

Full Text Available Dichroplus maculipennis is one of the most characteristic and damaging grasshopper species of Argentina, mainly in areas of the Pampas and Patagonia regions. We estimated and compared the longevity and fecundity of adult female D. maculipennis under controlled conditions (30ºC, 14L:10D, 40% RH from individuals collected as last instar nymphs (VI in the field and with a known recent history of low and high density conditions. Densities of D. maculipennis at the collecting sites were 0.95 individuals per m² in 2006 and 46 ind/m² in 2009, representing non-outbreaking and outbreaking situations, respectively. Adult female longevity in 2006 (67.96 ± 3.2 days was significantly higher (p 0.05. The fecundity curves showed that the highest values were at weeks 11 and 13 for the 2006 females, and at week 6 for those of 2009. Since the daily oviposition rate at low and high densities was not significantly different, the diminished fecundity rate at high density is attributable to their reduced longevity.

Population Dynamics and Transcriptomic Responses of Chorthippus albonemus (Orthoptera: Acrididae to Herbivore Grazing Intensity

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Xinghu Qin

2017-11-01

Full Text Available Livestock grazing can trigger outbreaks of insect pests in steppe ecosystems of Inner Mongolia in China. However, the physiological responses of the grasshopper Chorthippus albonemus to grazing are not well-understood. Here we investigated the effects of sheep grazing on the population dynamics and transcriptomic response of C. albonemus. We collected the insects three times (about 20 days apart in 1.33-ha plots in which there were no grazing, light grazing, moderate grazing, heavy grazing, or overgrazing. Our results showed that continuous grazing significantly decreased plant biomass and influenced plant succession. Total insect species diversity significantly declined along the grazing intensity gradient and over time. Results of the first two collections of C. albonemus indicated that moderate grazing significantly increased the abundance of C. albonemus. However, abundance was significantly decreased in plots that were overgrazed, possibly because of food stress and environmental pressures. Under moderate grazing, betA and CHDH genes were significantly upregulated in C. albonemus. In response to higher grazing intensity, upregulated genes included those involved in serine-type peptidase activity, anatomical structure development, and sensory organ development; downregulated genes included those involved in the structural constituents of the ribosome and ribosome processes. Genes strongly upregulated in response to heavy grazing pressure included adaptive genes such as those encoding ankyrin repeat domain-containing protein and HSP. These findings improve our understanding of the role of the transcriptome in C. albonemus population response to livestock grazing and may provide useful targets for grasshopper control.

REVISION OF THE SOUTH AMERICAN GENERA ALLOTRUXALIS REHN AND EUTRYXALIS BRUNER (ORTHOPTERA: ACRIDIDAE: HYALOPTERYGINI

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DONATO MARIANO

2003-12-01

Full Text Available En este estudio se redescriben los géneros Allotruxalis y Eutryxalis con base encaracteres de la morfología externa y la genitalia. El género Allotruxalis constaba dedos especies: A. gracilis y A. strigata, las cuales eran separadas con base en caracteresde la morfología externa. El análisis llevado a cabo en este estudio mostró quelos caracteres de la morfología externa no permiten separar estas dos especies.Caracteres derivados de la genitalia interna son decisivos para postular a A. strigatacomo sinónimo de A. gracilis. El género Eutryxalis poseía a la especie E. filata ytres subespecies: E. f. filata, E. f. minor, y E. f. bellula, las cuales estaban descritascon base en caracteres de la morfología externa. Se llevó a cabo un análisismultivariado y se demuestra que los caracteres utilizados no permiten distinguir lastres entidades. Por lo tanto, se postula que las anteriores subespecies son sinónimosde E. filata.

New species of Poecilocloeus Bruner, 1910 (Orthoptera: Acrididae: Proctolabinae) from Paraná State, Brazil.

Science.gov (United States)

DA Costa, Maria Kátia Matiotti; Fianco, Marcos; Martins, Fernando DE Farias; Prasniewski, Victor Mateus; Szinwelski, Neucir; Zefa, Edison

2017-10-30

In this study, we describe a new species of the genus Poecilocloeus from Renascença municipality, Paraná State, Brazil. Poecilocloeus renascensis n. sp. inhabits the Atlantic Semideciduous Forest edges of Renascença and adjacent areas, and our study is the first record of this genus from southern Brazil. The species belongs to the group bullatus (Rehn, 1908), and the descriptions are based on morphological characters, mainly from male genitalia. Morphological descriptions are provided together with illustrations emphasizing the most significant diagnostic features of external morphology and male genitalia. Information is given about type specimens, examined material and geographic distribution.

Race walking gait and its influence on race walking economy in world-class race walkers.

Science.gov (United States)

Gomez-Ezeiza, Josu; Torres-Unda, Jon; Tam, Nicholas; Irazusta, Jon; Granados, Cristina; Santos-Concejero, Jordan

2018-03-06

The aim of this study was to determine the relationships between biomechanical parameters of the gait cycle and race walking economy in world-class Olympic race walkers. Twenty-One world-class race walkers possessing the Olympic qualifying standard participated in this study. Participants completed an incremental race walking test starting at 10 km·h -1 , where race walking economy (ml·kg -1 ·km -1 ) and spatiotemporal gait variables were analysed at different speeds. 20-km race walking performance was related to race walking economy, being the fastest race walkers those displaying reduced oxygen cost at a given speed (R = 0.760, p < 0.001). Longer ground contact times, shorter flight times, longer midstance sub-phase and shorter propulsive sub-phase during stance were related to a better race walking economy (moderate effect, p < 0.05). According to the results of this study, the fastest race walkers were more economi cal than the lesser performers. Similarly, shorter flight times are associated with a more efficient race walking economy. Coaches and race walkers should avoid modifying their race walking style by increasing flight times, as it may not only impair economy, but also lead to disqualification.

Análise cladística e biogeográfica dos gêneros do grupo Sitalces (Orthoptera, Acrididae, Abracrini Cladistic and biogeographic analysis of the genera of the group Sitalces (Orthoptera, Acrididae, Abracrini

Directory of Open Access Journals (Sweden)

Maria Kátia Matiotti da Costa

2007-12-01

Full Text Available Uma análise cladística do relacionamento entre as espécies sul-americanas do grupo Sitalces (Sitalces Stål, 1878, Eusitalces Bruner, 1911, Parasitalces Bruner, 1911, Psilocirtus Bruner, 1911, Liebermannacris Costa & Carvalho, 2006, Robustusacris Costa & Carvalho, 2006, Arimacris Costa & Carvalho, 2006, Salvadoracris Costa & Carvalho, 2006 e Caruaruacris Costa & Carvalho, 2006 é apresentada. A análise incluiu 14 espécies com três grupos-externos e 34 caracteres morfológicos. A monofilia do grupo é suportada por três sinapomorfias com índices de consistência e retenção de 100%: prozona maior que a metazona, borda posterior do pronoto não angulada e placa supranal mais curta em relação aos cercos. A análise resultou em um único cladograma: (P. olivaceus (E. vittatus (L. dorsualis; L. punctifrons (R. balzapambae (A. trinitatis (S. nigritus; C. bivittatus (S. volxemi (P. vulneratus; P. sexnotata. Comentários biogeográficos são apresentados e relacionados com padrões pré-estabelecidos.A cladistic analysis of the relationships among the species of the South American genera of the group Sitalces (Sitalces Stål, 1878, Eusitalces Bruner, 1911, Parasitalces Bruner, 1911, Psilocirtus Bruner, 1911, Liebermannacris Costa & Carvalho, 2006, Robustusacris Costa & Carvalho, 2006, Arimacris Costa & Carvalho, 2006, Salvadoracris Costa & Carvalho, 2006 and Caruaruacris Costa & Carvalho, 2006 is presented. The analysis included 14 species with three outgroups and 34 morphological characters. The monophyly of the group is supported by three sinapomorphies with 100% consistency and retention indices: prozona larger than the metazona, posterior border of the pronotum not angulated and supranal plate shorter than cerci. The analysis resulted in a single cladogram: (P. olivaceus (E. vittatus (L. dorsualis; L. punctifrons (R. balzapambae (A. trinitatis (S. nigritus; C. bivittatus (S. volxemi (P. vulneratus; P. sexnotata. Biogeographic comments are presented and related with pre-established standards.

Circular orbits in cosmic string and Schwarzschild-AdS spacetime with Fermi-Walker transport

International Nuclear Information System (INIS)

Bakke, K.; Furtado, C.; Carvalho, A.M. de

2009-01-01

In this paper we discuss the Fermi-Walker transport of vectors along orbits in cosmic string and Schwarzschild-AdS spacetimes. We analyze the influence of acceleration on these holonomies. An effect similar to Thomas precession is observed within the process of Fermi-Walker transport along these circular orbits which are studied in the limit of vanishing cosmological constant in Schwarzschild-AdS case; also we obtain Fermi-Walker transport in a Schwarzschild background. In the case of a Schwarzschild spacetime, we analyze the quantized band holonomy invariance. In the limit of zero acceleration we recover the well-known results for holonomy matrix obtained by parallel transport in all these spacetimes. (orig.)

Bioaccumulation of some natural radionuclides in short-antenna grasshoppers (Acrididae family, class Ortoptera)

International Nuclear Information System (INIS)

Dimitrova, M.; Markova, E.

1996-01-01

The seasonal accumulation of radioactive elements of uranium-radium line in representatives of larval stages of different species of Acrididae family has been examined. This group of invertebrates is a good bioindicator of radionuclides accumulation and could be used successfully as an ecological evaluation. The monitoring sites are typical for the region of Etropole (where the uranium mine 'Elatsite' is situated) and offer information about the natural radiation background as well as about an eventual radiation pollution. Two years examination has been carried out during spring, summer and autumn on natural grass ecosystem (one of them just above the mentioned uranium mine). The gamma-spectrometric analysis of seventeen samples have shown the presence of U-238, Ra-226, Pb-214 and Bi-214. The minimal detectable activity of these radionuclides was calculated, resp. 0.25Bq, 0.49Bq, 0.07Bq and 0.12Bq. All experimental data for the four radionuclides are reliable considering Currie criterion. The meadow close to the uranium mine has shown maximal radiation background, while the control samples from nearby region have shown no presence of radionuclides. The accumulation of the radionuclides from U-Ra line is seasonal, more expressed in autumn. This fact could be explained by the biological maturity of this species in the end of summer. It has been found that the ionizing radiation in the natural biocenoses is not only an individual irritant, but also has an effect of a radioecological factor of the environment. The examinations show a redistribution of the natural radionuclides resulting from economic activities. 17 refs., 3 tabs., 3 figs

La tribu Pycnopalpini n. trib. (Orthoptera, Tettigonioidea, Phaneropteridae): segunda contribución a la organización supragenérica de los faneropterinos neotropicales

OpenAIRE

Cadena–Castañeda, O. J.

2014-01-01

The tribe Pycnopalpini n. trib. (Orthoptera, Tettigonioidea, Phaneropteridae): second contribution to neotropical Phaneropterinae The new tribe Pycnopalpini is proposed, based on morphological similarity among the genera Hetaira, Pycnopalpa, Topana (Pycnopalpina n. subtr.), Dolichocercus, Oxyprorella, Theia, and TheiellaTheia unicolor, Theia bifurcata n. sp., Theiella amazonica n. sp., Theiella andina n. sp., and D. santanderensis n. sp. from Colombia, and D. costaricensis n. sp. from Cost...

Extraction of user's navigation commands from upper body force interaction in walker assisted gait.

Science.gov (United States)

Frizera Neto, Anselmo; Gallego, Juan A; Rocon, Eduardo; Pons, José L; Ceres, Ramón

2010-08-05

The advances in technology make possible the incorporation of sensors and actuators in rollators, building safer robots and extending the use of walkers to a more diverse population. This paper presents a new method for the extraction of navigation related components from upper-body force interaction data in walker assisted gait. A filtering architecture is designed to cancel: (i) the high-frequency noise caused by vibrations on the walker's structure due to irregularities on the terrain or walker's wheels and (ii) the cadence related force components caused by user's trunk oscillations during gait. As a result, a third component related to user's navigation commands is distinguished. For the cancelation of high-frequency noise, a Benedict-Bordner g-h filter was designed presenting very low values for Kinematic Tracking Error ((2.035 +/- 0.358).10(-2) kgf) and delay ((1.897 +/- 0.3697).10(1)ms). A Fourier Linear Combiner filtering architecture was implemented for the adaptive attenuation of about 80% of the cadence related components' energy from force data. This was done without compromising the information contained in the frequencies close to such notch filters. The presented methodology offers an effective cancelation of the undesired components from force data, allowing the system to extract in real-time voluntary user's navigation commands. Based on this real-time identification of voluntary user's commands, a classical approach to the control architecture of the robotic walker is being developed, in order to obtain stable and safe user assisted locomotion.

Philip Glass, Scott Walker ja Sigur Ros! / Immo Mihkelson

Index Scriptorium Estoniae

Mihkelson, Immo, 1959-

2007-01-01

Pimedate Ööde 11. filmifestivali muusikafilme - Austraalia "Glass: Philipi portree 12 osas" (rež. Scott Hicks), Islandi "Sigur Ros kodus" (rež. Dean DeBois), Suurbritannia "Scott Walker: 30 Century Man" (rež. Stephen Kijak)

Quantum centipedes: collective dynamics of interacting quantum walkers

International Nuclear Information System (INIS)

Krapivsky, P L; Luck, J M; Mallick, K

2016-01-01

We consider the quantum centipede made of N fermionic quantum walkers on the one-dimensional lattice interacting by means of the simplest of all hard-bound constraints: the distance between two consecutive fermions is either one or two lattice spacings. This composite quantum walker spreads ballistically, just as the simple quantum walk. However, because of the interactions between the internal degrees of freedom, the distribution of its center-of-mass velocity displays numerous ballistic fronts in the long-time limit, corresponding to singularities in the empirical velocity distribution. The spectrum of the centipede and the corresponding group velocities are analyzed by direct means for the first few values of N . Some analytical results are obtained for arbitrary N by exploiting an exact mapping of the problem onto a free-fermion system. We thus derive the maximal velocity describing the ballistic spreading of the two extremal fronts of the centipede wavefunction, including its non-trivial value in the large- N limit. (paper)

Galilean generalized Robertson-Walker spacetimes: A new family of Galilean geometrical models

Science.gov (United States)

de la Fuente, Daniel; Rubio, Rafael M.

2018-02-01

We introduce a new family of Galilean spacetimes, the Galilean generalized Robertson-Walker spacetimes. This new family is relevant in the context of a generalized Newton-Cartan theory. We study its geometrical structure and analyse the completeness of its inextensible free falling observers. This sort of spacetimes constitutes the local geometric model of a much wider family of spacetimes admitting certain conformal symmetry. Moreover, we find some sufficient geometric conditions which guarantee a global splitting of a Galilean spacetime as a Galilean generalized Robertson-Walker spacetime.

75 FR 24753 - The Walker Auto Group, Inc., Miamisburg, OH; Notice of Negative Determination Regarding...

Science.gov (United States)

2010-05-05

... DEPARTMENT OF LABOR Employment and Training Administration [TA-W-72,471] The Walker Auto Group... Auto Group, Inc., Miamisburg, Ohio, was based on the finding that the subject firm did not shift abroad... of the subject firm should be eligible for TAA because the Walker Auto Group, Inc., Miamisburg, Ohio...

Walker use, but not falls, is associated with lower physical functioning and health of residents in an assisted-living environment.

Science.gov (United States)

Andersen, Daniel A; Roos, Bernard A; Stanziano, Damian C; Gonzalez, Natasha M; Signorile, Joseph F

2007-01-01

The relationship between perceived health and walker use has seldom been addressed. Concerns over falls and falls risk are precursors to walker use. We compared the SF-36 scores of 26 women and 14 men, mean age 86.8 +/- 6.0 years based on walker use and faller status. An analysis of covariance (ANCOVA) with age as the covariate, compared groups for the SF-36 constructs and totals score. Significant differences were noted between walker users and nonusers in physical functioning, role limitations due to physical problems, general health, and the total SF-36 score. Pairwise comparisons favored nonusers, while no differences were seen due to faller status. Walker use is associated with lower self-perceptions of physical functioning, role limitations due to physical problems, and general health in assisted-living residents. Faller status is not associated with self-perceived health status. Although walker use aids mobility and lowers the probability of falls, further research is needed to determine if the prescription of assistive devices has a more negative impact on self-perceived health than does falling. This possibility could be explained, in part, by the greater activity levels of those individuals who do not depend on walkers.

Differences in the Limits of Stability Between Older Rolling Walker Users and Older Single-Tip-Cane Users - A Preliminary Study.

Science.gov (United States)

Liu, Hao Howe; Quiben, Myles; Holmes, Clayton; Connors, Michael; Salem, Yasser

To identify the differences in the limits of stability (LOS) between older rolling walker and single-tip-cane users. This was a matched paired t-test design with repeated measure. Eighteen older subjects were matched based on age, gender, and functional level. The subjects were assessed using the multidirectional reach test initially and 5-month later in four directions: forward, backward, leftward, and rightward. Initially, there were no differences between cane users and rolling walker users in the LOS in all directions. However, 5-month later, the cane users who held their canes in their right hand had significantly better stability in forward and rightward reach than the walker users (p walker users demonstrated significantly decreased functional reach in forward reach (p walker users in the forward direction and in the direction toward the side holding the cane. This study may provide guide for clinicians including nurses for selecting appropriate rehabilitative interventions for older adults using walkers and canes.

Dandy-Walker malformation | Hamid | Egyptian Journal of Medical ...

African Journals Online (AJOL)

Dandy-Walker malformation is a rare congenital malformation and involves the cerebellum and fourth ventricle. The condition is characterized by agenesis or hypoplasia of the cerebellar vermis, cystic dilatation of the fourth ventricle, and enlargement of the posterior fossa. A large number of concomitant problems may be ...

DNA damage in grasshopper Chorthippus brunneus (Orthoptera) hatchlings following paraquat exposure.

Science.gov (United States)

Augustyniak, M; Nocoń, Ł; Kędziorski, A; Łaszczyca, P; Sawczyn, T; Tarnawska, M; Zawisza-Raszka, A

2015-04-01

Comet assay was applied to study genotoxic damage induced by paraquat (PQ) in brain cells of Chorthippus brunneus (Insecta: Orthoptera) hatchlings. Percentage of the comet fluorescence in the tail (TDNA), length of the comet tail (TL) and Olive tail moment (OTM) were used for quantitative assessment of the DNA damage. Multiple regression analysis supplemented standard statistical elaboration of the results. Increasing PQ concentrations applied either directly to the brain cells suspension (10, 50, and 250 μM PQ final concentration--in vitro protocol) or indirectly (50, 250, and 1250 μM PQ final concentration--in vivo protocol) provoked significant increase of oxidative damage to DNA (higher median TDNA and OTM values). The damage increased with time of exposure (0, 5, 15, and 30 min) following in vitro application, but decreased in longer interval (3 vs 24 h) after in vivo administration of paraquat. On contrary, median TL values did not correlate with paraquat concentration irrespectively of the exposure protocol. Possible reason of this discrepancy in light of paraquat toxicity is discussed. Copyright © 2015 Elsevier Ltd. All rights reserved.

Deterministic and Probabilistic Serviceability Assessment of Footbridge Vibrations due to a Single Walker Crossing

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Cristoforo Demartino

2018-01-01

Full Text Available This paper presents a numerical study on the deterministic and probabilistic serviceability assessment of footbridge vibrations due to a single walker crossing. The dynamic response of the footbridge is analyzed by means of modal analysis, considering only the first lateral and vertical modes. Single span footbridges with uniform mass distribution are considered, with different values of the span length, natural frequencies, mass, and structural damping and with different support conditions. The load induced by a single walker crossing the footbridge is modeled as a moving sinusoidal force either in the lateral or in the vertical direction. The variability of the characteristics of the load induced by walkers is modeled using probability distributions taken from the literature defining a Standard Population of walkers. Deterministic and probabilistic approaches were adopted to assess the peak response. Based on the results of the simulations, deterministic and probabilistic vibration serviceability assessment methods are proposed, not requiring numerical analyses. Finally, an example of the application of the proposed method to a truss steel footbridge is presented. The results highlight the advantages of the probabilistic procedure in terms of reliability quantification.

Variability in energy cost and walking gait during race walking in competitive race walkers.

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Brisswalter, J; Fougeron, B; Legros, P

1998-09-01

The aim of this study was to examine the variability of energy cost (Cw) and race walking gait after a 3-h walk at the competition pace in race walkers of the same performance level. Nine competitive race walkers were studied. In the same week, after a first test of VO2max determination, each subject completed two submaximal treadmill walks (6 min length, 0% grade, 12 km X h(-1) speed) before and after a 3-h overground test completed at the individual competition speed of the race walker. During the two submaximal tests, subjects were filmed between the 2nd and the 4th min, and physiological parameters were recorded between the 4th and the 6th min. Results showed two trends. On the one hand, we observed a significant and systematic increase in energy cost of walking (mean deltaCw = 8.4%), whereas no variation in the gait kinematics prescribed by the rules of race walking was recorded. On the other hand, this increase in metabolic energy demand was accompanied by variations of different magnitude and direction of stride length, of the excursion of the heel and of the maximal ankle flexion at toe-off among the race walkers. These results indicated that competitive race walkers are able to maintain their walking gait with exercise duration apart from a systematic increase in energy cost. Moreover, in this form of locomotion the effect of fatigue on the gait variability seems to be an individual function of the race walk constraints and the constraints of the performer.

Ground reaction force and 3D biomechanical characteristics of walking in short-leg walkers.

Science.gov (United States)

Zhang, Songning; Clowers, Kurt G; Powell, Douglas

2006-12-01

Short-leg walking boots offer several advantages over traditional casts. However, their effects on ground reaction forces (GRF) and three-dimensional (3D) biomechanics are not fully understood. The purpose of the study was to examine 3D lower extremity kinematics and joint dynamics during walking in two different short-leg walking boots. Eleven (five females and six males) healthy subjects performed five level walking trials in each of three conditions: two testing boot conditions, Gait Walker (DeRoyal Industries, Inc.) and Equalizer (Royce Medical Co.), and one pair of laboratory shoes (Noveto, Adidas). A force platform and a 6-camera Vicon motion analysis system were used to collect GRFs and 3D kinematic data during the testing session. A one-way repeated measures analysis of variance (ANOVA) was used to evaluate selected kinematic, GRF, and joint kinetic variables (p<0.05). The results revealed that both short-leg walking boots were effective in minimizing ankle eversion and hip adduction. Neither walker increased the bimodal vertical GRF peaks typically observed in normal walking. However, they did impose a small initial peak (<1BW) earlier in the stance phase. The Gait Walker also exhibited a slightly increased vertical GRF during midstance. These characteristics may be related to the sole materials/design, the restriction of ankle movements, and/or the elevated heel heights of the tested walkers. Both walkers appeared to increase the demand on the knee extensors while they decreased the demand of the knee and hip abductors based on the joint kinetic results.

Extraction of user's navigation commands from upper body force interaction in walker assisted gait

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Pons José L

2010-08-01

Full Text Available Abstract Background The advances in technology make possible the incorporation of sensors and actuators in rollators, building safer robots and extending the use of walkers to a more diverse population. This paper presents a new method for the extraction of navigation related components from upper-body force interaction data in walker assisted gait. A filtering architecture is designed to cancel: (i the high-frequency noise caused by vibrations on the walker's structure due to irregularities on the terrain or walker's wheels and (ii the cadence related force components caused by user's trunk oscillations during gait. As a result, a third component related to user's navigation commands is distinguished. Results For the cancelation of high-frequency noise, a Benedict-Bordner g-h filter was designed presenting very low values for Kinematic Tracking Error ((2.035 ± 0.358·10-2 kgf and delay ((1.897 ± 0.3697·101ms. A Fourier Linear Combiner filtering architecture was implemented for the adaptive attenuation of about 80% of the cadence related components' energy from force data. This was done without compromising the information contained in the frequencies close to such notch filters. Conclusions The presented methodology offers an effective cancelation of the undesired components from force data, allowing the system to extract in real-time voluntary user's navigation commands. Based on this real-time identification of voluntary user's commands, a classical approach to the control architecture of the robotic walker is being developed, in order to obtain stable and safe user assisted locomotion.

Where Are They Now: Nathalie Walker Moves from Science to Activism and Art Communications | Poster

Science.gov (United States)

Whether it’s in a flowerbed or an art gallery, former Werner H. Kirsten (WHK) student intern Nathalie Walker can’t help but to cause a buzz. Since completing her WHK internship in the summer of 2015, Walker has been attending Loyola University Maryland, where she is striving to make a positive impact on campus.

Quantization of Robertson-Walker geometry coupled to fermionic matter

International Nuclear Information System (INIS)

Christodoulakis, T.; Zanelli, J.

1983-06-01

A Robertson-Walker universe coupled to a spin 1/2 Dirac field is quantized following Dirac's formalism for constrained Hamiltonian systems. It is found that in nearly all cases it can be asserted that the universe avoids the collapse. (author)

Exact solution of two interacting run-and-tumble random walkers with finite tumble duration

International Nuclear Information System (INIS)

Slowman, A B; Evans, M R; Blythe, R A

2017-01-01

We study a model of interacting run-and-tumble random walkers operating under mutual hardcore exclusion on a one-dimensional lattice with periodic boundary conditions. We incorporate a finite, poisson-distributed, tumble duration so that a particle remains stationary whilst tumbling, thus generalising the persistent random walker model. We present the exact solution for the nonequilibrium stationary state of this system in the case of two random walkers. We find this to be characterised by two lengthscales, one arising from the jamming of approaching particles, and the other from one particle moving when the other is tumbling. The first of these lengthscales vanishes in a scaling limit where the continuous-space dynamics is recovered whilst the second remains finite. Thus the nonequilibrium stationary state reveals a rich structure of attractive, jammed and extended pieces. (paper)

Catalogue of type specimens of the Collection of Invertebrates of Instituto Nacional de Pesquisas da Amazônia, Manaus, Brazil. III. Hexapoda: Isoptera, Mantodea, Mecoptera, Orthoptera, Plecoptera, Trichoptera and Zoraptera Catálogo dos espécimes-tipo de invertebrados da coleção do Instituto Nacional de Pesquisas da Amazônia, Manaus, Brasil. III. Hexapoda: Isoptera, Mantodea, Mecoptera, Orthoptera, Plecoptera, Trichoptera e Zoraptera

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José Moacir Ferreira Ribeiro

2009-01-01

Full Text Available A catalogue of the type specimens of Isoptera, Mantodea, Mecoptera, Orthoptera, Plecoptera, Trichoptera, and Zoraptera deposited in the Invertebrate Collection of the Instituto Nacional de Pesquisas da Amazônia (INPA, Manaus, Brazil, is presented and updated to December, 2007. A total of eight holotypes and seven lots of paratypes of nine species of Isoptera; three holotypes and one paratype of three species of Mantodea; five holotypes and five lots of paratypes of five species of Mecoptera; eight holotypes and five lots of paratypes of eleven species of Orthoptera; three holotypes, three neotypes and two lots of paratypes of seven species of Plecoptera; six holotypes and seven lots of paratypes of ten species of Trichoptera; and two holotypes and three lots of paratypes of three species of Zoraptera, are listed. Specific names are listed alphabetically within the family, followed by bibliographic citation, original genus name, status of type, collection number, locality data and remarks when appropriate.É apresentado o catálogo dos espécimes-tipo de Isoptera, Mantodea, Orthoptera, Plecoptera, Trichoptera e Zoraptera depositados na Coleção de Invertebrados do Instituto Nacional de Pesquisas da Amazônia (INPA, Manaus, Brasil, atualizado até dezembro de 2007. É relacionado um total de sete holótipos e sete lotes de parátipos de nove espécies de Isoptera; três holótipos e um parátipo de três espécies de Mantodea; cinco holótipos e cinco lotes de parátipos de cinco espécies de Mecoptera; oito holótipos e cinco lotes de parátipos de 11 espécies de Orthoptera; três holótipos, três neótipos e dois lotes de parátipos de sete espécies de Plecoptera; seis holótipos e sete lotes de parátipos de dez espécies de Trichoptera; e dois holótipos e três lotes de parátipos de três espécies de Zoraptera. São listados alfabeticamente em cada família os nomes das espécies, seguidos da citação bibliográfica, nome original do

Distribution of Grasshoppers (Insecta: Orthoptera among different host plants and habitats in two districts of Tamil Nadu, India

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M.G. Paulraj

2009-04-01

Full Text Available In a survey of grasshoppers in nine localities of northeastern Tamil Nadu, carried out from August 2004 to December 2006, 33 grasshopper species grouped under four families were recorded. Family Acrididae was found to be the predominant group of grasshoppers represented by 21 species, which was 63.6% of the total species collected. The acridids collected can be classified under seven subfamilies and 15 genera. Family Tettigoniidae was the second largest group represented by six species falling under five genera and three subfamilies, and this family contributed 18.2% to the total grasshopper species recorded in this study. Among the different habitats, grasses supported the highest number of 18 species (54.6% while 11 species were surface grasshoppers. The painted grasshopper Poekilocerus pictus (Fab. was collected from many plants viz., Calotropis, curry leaf, grass, groundnut, okra, and on ground. The maximum number of species was recorded from Manimangalam in Kancheepuram District during the entire study period.

Motor properties from persistence: a linear molecular walker lacking spatial and temporal asymmetry

International Nuclear Information System (INIS)

Zuckermann, Martin J; Forde, Nancy R; Angstmann, Christopher N; Schmitt, Regina; Linke, Heiner; Blab, Gerhard A; Bromley, Elizabeth HC; Curmi, Paul MG

2015-01-01

The stepping direction of linear molecular motors is usually defined by a spatial asymmetry of the motor, its track, or both. Here we present a model for a molecular walker that undergoes biased directional motion along a symmetric track in the presence of a temporally symmetric chemical cycle. Instead of using asymmetry, directionality is achieved by persistence. At small load force the walker can take on average thousands of steps in a given direction until it stochastically reverses direction. We discuss a specific experimental implementation of a synthetic motor based on this design and find, using Langevin and Monte Carlo simulations, that a realistic walker can work against load forces on the order of picoNewtons with an efficiency of ∼18%, comparable to that of kinesin. In principle, the walker can be turned into a permanent motor by externally monitoring the walker’s momentary direction of motion, and using feedback to adjust the direction of a load force. We calculate the thermodynamic cost of using feedback to enhance motor performance in terms of the Shannon entropy, and find that it reduces the efficiency of a realistic motor only marginally. We discuss the implications for natural protein motor performance in the context of the strong performance of this design based only on a thermal ratchet. (paper)

La tribu Insarini (Orthoptera, Tettigoniidae, Phaneropteridae: tercera contribución a la organización supragenérica de los faneropterinos neotropicales

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Cadena–Castañeda, O. J.

2014-12-01

Full Text Available The tribe Insarini (Orthoptera, Tettigoniidae, Phaneropteridae: third contribution to the supra–generic organization of neotropical Phaneropterinae The tribe Insarini is delimited in this contribution to four genera: Arethaea, Brachyinsara, Insara and Psilinsara. A table to separate these genera is provided. The generic boundaries are not well delimited in this tribe. The genus Callinsara n. syn. is synonymized under Sictuna, which in in turn is moved to the group Plagiopleurae. The tribal boundaries of Insarini and Pycnopalpini are discussed.

Phenotypic disparity in Iberian short-horned grasshoppers (Acrididae): the role of ecology and phylogeny.

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García-Navas, Vicente; Noguerales, Víctor; Cordero, Pedro J; Ortego, Joaquín

2017-05-04

The combination of model-based comparative techniques, disparity analyses and ecomorphological correlations constitutes a powerful method to gain insight into the evolutionary mechanisms that shape morphological variation and speciation processes. In this study, we used a time-calibrated phylogeny of 70 Iberian species of short-horned grasshoppers (Acrididae) to test for patterns of morphological disparity in relation to their ecology and phylogenetic history. Specifically, we examined the role of substrate type and level of ecological specialization in driving different aspects of morphological evolution (locomotory traits, chemosensitive organs and cranial morphology) in this recent radiation. We found a bimodal distribution of locomotory attributes corresponding to the two main substrate type guilds (plant vs. ground); plant-perching species tend to exhibit larger wings and thicker femora than those that remain on the ground. This suggests that life form (i.e., substrate type) is an important driving force in the evolution of morphological traits in short-horned grasshoppers, irrespective of ancestry. Substrate type and ecological specialization had no significant influence on head shape, a trait that showed a strong phylogenetic conservatism. Finally, we also found a marginal significant association between the length of antennae and the level of ecological specialization, suggesting that the development of sensory organs may be favored in specialist species. Our results provide evidence that even in taxonomic groups showing limited morphological and ecological disparity, natural selection seems to play a more important role than genetic drift in driving the speciation process. Overall, this study suggests that morphostatic radiations should not necessarily be considered as "non-adaptive" and that the speciation process can bind both adaptive divergence mechanisms and neutral speciation processes related with allopatric and/or reproductive isolation.

Unintentional fall injuries associated with walkers and canes in older adults treated in U.S. emergency departments.

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Stevens, Judy A; Thomas, Karen; Teh, Leesia; Greenspan, Arlene I

2009-08-01

To characterize nonfatal, unintentional, fall-related injuries associated with walkers and canes in older adults. Surveillance data of injuries treated in hospital emergency departments (EDs), January 1, 2001, to December 31, 2006. The National Electronic Injury Surveillance System All Injury Program, which collects data from a nationally representative stratified probability sample of 66 U.S. hospital EDs. People aged 65 and older treated in EDs for 3,932 nonfatal unintentional fall injuries and whose records indicated that a cane or a walker was involved in the fall. Sex, age, whether the fall involved a cane or walker, primary diagnosis, part of the body injured, disposition, and location and circumstances of the fall. An estimated 47,312 older adult fall injuries associated with walking aids were treated annually in U.S. EDs: 87.3% with walkers, 12.3% with canes, and 0.4% with both. Walkers were associated with seven times as many injuries as canes. Women's injury rates exceeded those for men (rate ratios=2.6 for walkers, 1.4 for canes.) The most prevalent injuries were fractures and contusions or abrasions. Approximately one-third of subjects were hospitalized for their injuries. Injuries and hospital admissions for falls associated with walking aids were frequent in this highly vulnerable population. The results suggest that more research is needed to improve the design of walking aids. More information also is needed about the circumstances preceding falls, both to better understand the contributing fall risk factors and to develop specific and effective fall prevention strategies.

Nonintegrated Host Association of Myrmecophilus tetramorii, a Specialist Myrmecophilous Ant Cricket (Orthoptera: Myrmecophilidae

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Takashi Komatsu

2013-01-01

Full Text Available Myrmecophilus ant crickets (Orthoptera: Myrmecophilidae are typical ant guests. In Japan, about 10 species are recognized on the basis of morphological and molecular phylogenetic frameworks. Some of these species have restricted host ranges and behave intimately toward their host ant species (i.e., they are host specialist. We focused on one species, M. tetramorii, which uses the myrmicine ant Tetramorium tsushimae as its main host. All but one M. tetramorii individuals were collected specifically from nests of T. tsushimae in the field. However, behavioral observation showed that all individuals used in the experiment received hostile reactions from the host ants. There were no signs of intimate behaviors such as grooming of hosts or receipt of mouth-to-mouth feeding from hosts, which are seen in some host-specialist Myrmecophilus species among obligate host-ant species. Therefore, it may be that M. tetramorii is the species that is specialized to exploit the host by means other than chemical integration.

Walker-type velocity oscillations of magnetic domain walls

International Nuclear Information System (INIS)

Vella-Coleiro, G.P.

1976-01-01

We report stroboscopic observations of the radial motion of a magnetic bubble domain wall in an epitaxial LuGdAl iron garnet film. At high drive fields, initial velocities up to 9500 cm/sec were measured, and the domain wall was observed to move backwards during the field pulse, in agreement with calculations based on the Walker model

Finding the Right Formula: Edwin H. Walker Jr

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Keels, Crystal L.

2005-01-01

Edwin H. Walker Jr earned his doctorate in chemistry at age 27 and has barely looked back. With 13 publications under his belt before coming out of graduate school, he has also given more than 20 poster presentations in national venues, most recently at the American Chemical Society. He can also include securing a half-million-dollar National…

77 FR 67811 - Porter-Walker LLC; Supplemental Notice That Initial Market-Based Rate Filing Includes Request for...

Science.gov (United States)

2012-11-14

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. ER13-327-000] Porter-Walker LLC; Supplemental Notice That Initial Market-Based Rate Filing Includes Request for Blanket Section 204 Authorization This is a supplemental notice in the above-referenced proceeding of Porter-Walker...

SYMMETRY AS CONCEPTUAL METAPHOR IN WALKER'S THE COLOR PURPLE

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Elena Tapia

2003-05-01

Full Text Available The author analyzes three types of the conceptual metaphor of embodied symmetry in Alice Walker's novel, The color purple (1982. These metaphorical projections, perceived as equilibrium and its breakage in abstract phenomena, enable readers to reexamine issues of race, non-traditional families, and gender roles. The dis/equilibrium emerges in the novel's epistolary structure. Biological equilibrium breaks in incidents of rape and incest. Walker creates characters in the novel through default-concept opposites of black/white, submissive/dominant, male/female and others. These contraries foreground issues of race and gender. The novel's asymmetries engage readers, leading them to rethink individual character histories and motives. The removal of objects (e.g., rape, mothers deprived of children suggests conceptual asymmetry and alerts readers to parallel themes of sexual and racial oppression. Subjugation sometimes subtle, sometimes blatant- manifests in simple oppositions. In epistemological terms, readers seek causal explanations for the asymmetries of the narrative, interpreting each to recover its history.

Mary Edwards Walker, M.D.: a feminist physician a century ahead of her time.

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Spiegel, A D; Suskind, P B

1996-06-01

In her teens, Mary Edwards Walker already wore the "bloomer" outfit began to campaign for reforming the "unhygienic" clothing of women. Assertively, she attended medical school and earned her M.D. degree. Due to prejudice, her practice did not flourish and she moved to Washington to offer her medical services to the Union as the Civil War began. Rebuffed by the male medical bureaucrats, she volunteered her services anyway. Eventually, she was awarded the Congressional Medal of Honor, the only women to ever gain such distinction. After the war, Walker became a journalist, an author of two sensational books, a political lobbyist, a suffrage campaigner, a professional and public lecturer, an ardent dress reformer, a peace activist, a Utopianist and a women's right advocate. Light-years ahead of her times, Dr. Walker was an intelligent, independent, irrepressible and indefatigable proponent for a host of worthy causes.

The type specimen and generic placement of Tridactylus galla Saussure, 1895 (Orthoptera: Caelifera: Tridactylidae).

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Heads, Sam W; Hollier, John

2016-11-15

Tridactylus galla was described by Henri de Saussure (1895) on the basis of a single adult female collected during Vittorio Bottego's first expedition to the Horn of Africa in 1892 and 1893. The species appears in lists compiled by Fenizia (1896), Lucas (1898) and Kirby (1906), but aside from a brief mention by Günther (1995), is entirely overlooked by subsequent authors and is absent from Otte's (1997) catalogue. During the course of compiling an annotated catalogue of the Orthoptera described by Saussure (Hollier and Heads, 2012) we were able to relocate the type of Tridactylus galla in the collection of the Museo Civico di Storia Naturale "Giacomo Doria" in Genova, Italy. Our examination of the specimen confirmed Günther's (1995) assertion that its placement in Tridactylus Olivier, 1789 is erroneous, and the species is herein formally transferred to the genus Xya Latreille, 1809.

Gut Transcriptome Analysis Shows Different Food Utilization Efficiency by the Grasshopper Oedaleous asiaticus (Orthoptera: Acrididae).

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Huang, Xunbing; McNeill, Mark Richard; Ma, Jingchuan; Qin, Xinghu; Tu, Xiongbing; Cao, Guangchun; Wang, Guangjun; Nong, Xiangqun; Zhang, Zehua

2017-08-01

Oedaleus asiaticus B. Bienko is a persistent pest occurring in north Asian grasslands. We found that O. asiaticus feeding on Stipa krylovii Roshev. had higher approximate digestibility (AD), efficiency of conversion of ingested food (ECI), and efficiency of conversion of digested food (ECD), compared with cohorts feeding on Leymus chinensis (Trin.) Tzvel, Artemisia frigida Willd., or Cleistogenes squarrosa (Trin.) Keng. Although this indicated high food utilization efficiency for S. krylovii, the physiological processes and molecular mechanisms underlying these biological observations are not well understood. Transcriptome analysis was used to examine how gene expression levels in O. asiaticus gut are altered by feeding on the four plant species. Nymphs (fifth-instar female) that fed on S. krylovii had the largest variation in gene expression profiles, with a total of 88 genes significantly upregulated compared with those feeding on the other three plants, mainly including nutrition digestive genes of protein, carbohydrate, and lipid digestion. GO and KEGG enrichment also showed that feeding S. krylovii could upregulate the nutrition digestion-related molecular function, biological process, and pathways. These changes in transcripts levels indicate that the physiological processes of activating nutrition digestive enzymes and metabolism pathways can well explain the high food utilization of S. krylovii by O. asiaticus. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

A hierarchy of factors influence discontinuous gas exchange in the grasshopper Paracinema tricolor (Orthoptera: Acrididae).

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Groenewald, Berlizé; Chown, Steven L; Terblanche, John S

2014-10-01

The evolutionary origin and maintenance of discontinuous gas exchange (DGE) in tracheate arthropods are poorly understood and highly controversial. We investigated prioritization of abiotic factors in the gas exchange control cascade by examining oxygen, water and haemolymph pH regulation in the grasshopper Paracinema tricolor. Using a full-factorial design, grasshoppers were acclimated to hypoxic or hyperoxic (5% O2, 40% O2) gas conditions, or dehydrated or hydrated, whereafter their CO2 release was measured under a range of O2 and relative humidity (RH) conditions (5%, 21%, 40% O2 and 5%, 60%, 90% RH). DGE was significantly less common in grasshoppers acclimated to dehydrating conditions compared with the other acclimations (hypoxia, 98%; hyperoxia, 100%; hydrated, 100%; dehydrated, 67%). Acclimation to dehydrating conditions resulted in a significant decrease in haemolymph pH from 7.0±0.3 to 6.6±0.1 (mean ± s.d., P=0.018) and also significantly increased the open (O)-phase duration under 5% O2 treatment conditions (5% O2, 44.1±29.3 min; 40% O2, 15.8±8.0 min; 5% RH, 17.8±1.3 min; 60% RH, 24.0±9.7 min; 90% RH, 20.6±8.9 min). The observed acidosis could potentially explain the extension of the O-phase under low RH conditions, when it would perhaps seem more useful to reduce the O-phase to lower respiratory water loss. The results confirm that DGE occurrence and modulation are affected by multiple abiotic factors. A hierarchical framework for abiotic factors influencing DGE is proposed in which the following stressors are prioritized in decreasing order of importance: oxygen supply, CO2 excretion and pH modulation, oxidative damage protection and water savings. © 2014. Published by The Company of Biologists Ltd.

Embryonic development rates of northern grasshoppers (Orthoptera: Acrididae): implications for climate change and habitat management

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Temperature-dependent rates of embryonic development are a primary determinant of the life cycle of many species of grasshoppers which, in cold climates, spend two winters in the egg stage. Knowledge of embryonic developmental rates is important for an assessment of the effects of climate change and...

Populations of the northern grasshopper, Melanoplus borealis (Orthoptera: Acrididae), in Alaska are rarely food limited.

Science.gov (United States)

Fielding, Dennis J; Zhang, Mingchu

2011-06-01

In some systems, grasshoppers appear to be food limited in most years, whereas in other systems top down forces, for example, predators, are more often implicated in population regulation. Sustainable strategies to manage grasshopper populations through habitat management require knowledge of the forces that regulate grasshopper populations. This experiment was undertaken to determine whether populations of Melanoplus borealis (Fieber), a common pest species in Alaska, are food-limited in Alaska. Cages were set up in a fallow field near Delta Junction, AK, in 3 yr (2007-2009). In 2007 and 2008, fertilizer was added to half the plots to increase primary production, and, in all years, cages within each plot were stocked with 0, 5, 9, or 13 fourth-instar M. borealis (equivalent to 0, 20, 36, or 52 grasshoppers/m(2)). Grasshoppers in each cage were counted weekly. Near the end of the growing season, surviving female grasshoppers (≈40% of the original number) were collected. Femur length was taken as a measure of adult size, and functional ovarioles were counted as a measure of current fecundity. If the grasshoppers were food limited, we expected to see significant effects of either density or fertilizer on grasshopper survival, size, or fecundity. The fertilizer treatment greatly increased primary production in both years. Neither fertilizer treatment nor grasshopper density had consistent effects on survival, size, or potential fecundity, leading us to conclude that food is seldom limiting to populations in the interior of Alaska at densities <50 m(-2).

Nursery Pest Management of Phytolyma lata Walker (Scott) Attack ...

African Journals Online (AJOL)

The establishment of plantations of Milicia excelsa has been constrained by the gall-forming psyllid Phytolyma lata Walker (Scott) that causes extensive damage to young plants. We present findings of an experiment aimed at preventing Phytolyma attack on Milicia seedlings in the nursery using chemical control and ...

Hidden marker position estimation during sit-to-stand with walker.

Science.gov (United States)

Yoon, Sang Ho; Jun, Hong Gul; Dan, Byung Ju; Jo, Byeong Rim; Min, Byung Hoon

2012-01-01

Motion capture analysis of sit-to-stand task with assistive device is hard to achieve due to obstruction on reflective makers. Previously developed robotic system, Smart Mobile Walker, is used as an assistive device to perform motion capture analysis in sit-to-stand task. All lower limb markers except hip markers are invisible through whole session. The link-segment and regression method is applied to estimate the marker position during sit-to-stand. Applying a new method, the lost marker positions are restored and the biomechanical evaluation of the sit-to-stand movement with a Smart Mobile Walker could be carried out. The accuracy of the marker position estimation is verified with normal sit-to-stand data from more than 30 clinical trials. Moreover, further research on improving the link segment and regression method is addressed.

Dynamic optimization of walker-assisted FES-activated paraplegic walking: simulation and experimental studies.

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Nekoukar, Vahab; Erfanian, Abbas

2013-11-01

In this paper, we propose a musculoskeletal model of walker-assisted FES-activated paraplegic walking for the generation of muscle stimulation patterns and characterization of the causal relationships between muscle excitations, multi-joint movement, and handle reaction force (HRF). The model consists of the lower extremities, trunk, hands, and a walker. The simulation of walking is performed using particle swarm optimization to minimize the tracking errors from the desired trajectories for the lower extremity joints, to reduce the stimulations of the muscle groups acting around the hip, knee, and ankle joints, and to minimize the HRF. The results of the simulation studies using data recorded from healthy subjects performing walker-assisted walking indicate that the model-generated muscle stimulation patterns are in agreement with the EMG patterns that have been reported in the literature. The experimental results on two paraplegic subjects demonstrate that the proposed methodology can improve walking performance, reduce HRF, and increase walking speed when compared to the conventional FES-activated paraplegic walking. Copyright © 2013 IPEM. Published by Elsevier Ltd. All rights reserved.

Construction of calibration pads facility, Walker Field, Grand Junction, Colorado

International Nuclear Information System (INIS)

Ward, D.L.

1978-08-01

A gamma-ray spectrometer facility was completed at Walker Field Airport, Grand Junction, Colorado, in November 1976. This report describes spectrometers and their calibration, the construction of the spectrometer facility, the radioelement concentrations, procedures for using the facilites, and environmental considerations

A gait stability investigation into FES-assisted paraplegic walking based on the walker tipping index.

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Ming, Dong; Bai, Yanru; Liu, Xiuyun; Qi, Hongzhi; Cheng, Longlong; Wan, Baikun; Hu, Yong; Wong, Yatwa; Luk, Keith D K; Leong, John C Y

2009-12-01

The gait outcome measures used in clinical trials of paraplegic locomotor training determine the effectiveness of improved walking function assisted by the functional electrical stimulation (FES) system. Focused on kinematic, kinetic or physiological changes of paraplegic patients, traditional methods cannot quantify the walking stability or identify the unstable factors of gait in real time. Up until now, the published studies on dynamic gait stability for the effective use of FES have been limited. In this paper, the walker tipping index (WTI) was used to analyze and process gait stability in FES-assisted paraplegic walking. The main instrument was a specialized walker dynamometer system based on a multi-channel strain-gauge bridge network fixed on the frame of the walker. This system collected force information for the handle reaction vector between the patient's upper extremities and the walker during the walking process; the information was then converted into walker tipping index data, which is an evaluation indicator of the patient's walking stability. To demonstrate the potential usefulness of WTI in gait analysis, a preliminary clinical trial was conducted with seven paraplegic patients who were undergoing FES-assisted walking training and seven normal control subjects. The gait stability levels were quantified for these patients under different stimulation patterns and controls under normal walking with knee-immobilization through WTI analysis. The results showed that the walking stability in the FES-assisted paraplegic group was worse than that in the control subject group, with the primary concern being in the anterior-posterior plane. This new technique is practical for distinguishing useful gait information from the viewpoint of stability, and may be further applied in FES-assisted paraplegic walking rehabilitation.

A gait stability investigation into FES-assisted paraplegic walking based on the walker tipping index

Science.gov (United States)

Ming, Dong; Bai, Yanru; Liu, Xiuyun; Qi, Hongzhi; Cheng, Longlong; Wan, Baikun; Hu, Yong; Wong, Yatwa; Luk, Keith D. K.; Leong, John C. Y.

2009-12-01

The gait outcome measures used in clinical trials of paraplegic locomotor training determine the effectiveness of improved walking function assisted by the functional electrical stimulation (FES) system. Focused on kinematic, kinetic or physiological changes of paraplegic patients, traditional methods cannot quantify the walking stability or identify the unstable factors of gait in real time. Up until now, the published studies on dynamic gait stability for the effective use of FES have been limited. In this paper, the walker tipping index (WTI) was used to analyze and process gait stability in FES-assisted paraplegic walking. The main instrument was a specialized walker dynamometer system based on a multi-channel strain-gauge bridge network fixed on the frame of the walker. This system collected force information for the handle reaction vector between the patient's upper extremities and the walker during the walking process; the information was then converted into walker tipping index data, which is an evaluation indicator of the patient's walking stability. To demonstrate the potential usefulness of WTI in gait analysis, a preliminary clinical trial was conducted with seven paraplegic patients who were undergoing FES-assisted walking training and seven normal control subjects. The gait stability levels were quantified for these patients under different stimulation patterns and controls under normal walking with knee-immobilization through WTI analysis. The results showed that the walking stability in the FES-assisted paraplegic group was worse than that in the control subject group, with the primary concern being in the anterior-posterior plane. This new technique is practical for distinguishing useful gait information from the viewpoint of stability, and may be further applied in FES-assisted paraplegic walking rehabilitation.

Walking on the edge: meanings of living in an ageing body and using a walker in everyday life - a phenomenological hermeneutic study.

Science.gov (United States)

Brännström, Helene; Bäckman, Margit; Santamäki Fischer, Regina

2013-05-01

In order to maintain one's state of health whilst growing older, the ability to walk is essential. The aim of this study was to illuminate the meanings of the lived experience of living in an ageing body and using a walker in daily life. Narrative interviews were performed with seven older persons aged 79-95 years. The transcribed text was analysed using a phenomenological hermeneutic method. The key finding of the study was that the lived experience of living in an ageing body and using a walker in daily life was interpreted as 'walking on the edge' based on the themes 'Being vulnerable and dependent' and 'Being confident and independent'. The results highlight the importance of reflecting on this phenomenon as a health care professional while meeting the care needs of older persons who use walkers. Nurses need to consider the walker as a personal and valued possession of the individual and handle the walker in agreement with the older person, placing the walker close at hand with the brakes locked to give secure support. © 2012 Blackwell Publishing Ltd.

“Ancestors We Didn’t Even Know We Had”: Alice Walker, Asian Religion, and Ethnic Authenticity

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Kyle Garton-Gundling

2015-03-01

Full Text Available Recent debates about the ethics of identity in a global age have dealt with how to prioritize conflicting local and global allegiances. Guided by these concerns, the fiction of Alice Walker develops a distinctive view of how local cultures and global movements can fruitfully interact. This vision depends on concepts from Asian religions, a major influence that critics of Walker have largely overlooked. Walker promotes Hindu and Buddhist meditation in a context of widespread African American skepticism toward Asian religions. According to widespread notions of cultural authenticity, Asian religions cannot nourish an African American connection to ethnic roots. In response to this challenge, Alice Walker’s fiction portrays Hindu and Buddhist mystics as African Americans’ ancestors, thus positioning these faiths as authentically black. By creatively enfolding Asian religions into her sense of African American heritage, Walker builds a spiritual cosmopolitanism that relies on claims of ancestral affiliation even when these claims are not literal. This strategy is Walker’s effort to create a new paradigm of cultural authenticity, one that allows individuals and groups to choose their ancestors. Walker’s approach seeks to incorporate disparate global influences while still valorizing the figure of the ancestor. This innovative approach places Walker at the forefront of a growing number of African American artists and intellectuals who promote Asian religions to American minorities. Walker’s work vividly dramatizes larger concerns in transnational American Studies: Eastern philosophy’s relevance to identity politics, the tensions between universal ideals and cultural specifics, and the ethics of cross-cultural appropriation.

Radio-telemetric evidence of migration in the gregarious but not the solitary morph of the Mormon cricket (Anabrus simplex: Orthoptera: Tettigoniidae)

Science.gov (United States)

Lorch, Patrick D.; Gwynne, D. T.

The Mormon cricket, Anabrus simplex, is one of just a few species of katydids (or bushcrickets, Orthoptera: Tettigoniidae) that, like migratory locusts, appear to have solitary and migratory morphs. Using radio telemetry we studied movements of individuals of two morphs of this flightless species. Individuals within each migratory band had similar rates of movements along similar directional headings whereas solitary individuals moved little and showed little evidence of directionality in movement. Our results also add to other recent radio-telemetry studies showing that flightless insects of 1-2g in mass can be tracked successfully using these methods.

Pedestrian Dharma: Slowness and Seeing in Tsai Ming-Liang’s Walker

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Teng-Kuan Ng

2018-06-01

Full Text Available This paper studies the ways that Walker, a short film by the Malaysian-Taiwanese auteur Tsai Ming-Liang, visualizes the relationship between Buddhism and modernity. Via detailed film analysis as well as attention to sources in premodern Buddhist traditions, this paper argues that its filmic performance of Zen walking meditation serves two functions: To present slowness and simplicity as prophetic counterpoints against the dizzying excesses of the contemporary metropolis; and to offer contemplative attentiveness as a therapeutic resource for life in the modern world. By instantiating and cultivating critical shifts in viewerly perspective in the manner of Buddhist ritual practice, Walker invites us to envision how a place of frenetic distraction or pedestrian mundaneness might be transfigured into a site of beauty, wonder, and liberation.

Anisotropic evolution of 5D Friedmann-Robertson-Walker spacetime

International Nuclear Information System (INIS)

Middleton, Chad A.; Stanley, Ethan

2011-01-01

We examine the time evolution of the five-dimensional Einstein field equations subjected to a flat, anisotropic Robertson-Walker metric, where the 3D and higher-dimensional scale factors are allowed to dynamically evolve at different rates. By adopting equations of state relating the 3D and higher-dimensional pressures to the density, we obtain an exact expression relating the higher-dimensional scale factor to a function of the 3D scale factor. This relation allows us to write the Friedmann-Robertson-Walker field equations exclusively in terms of the 3D scale factor, thus yielding a set of 4D effective Friedmann-Robertson-Walker field equations. We examine the effective field equations in the general case and obtain an exact expression relating a function of the 3D scale factor to the time. This expression involves a hypergeometric function and cannot, in general, be inverted to yield an analytical expression for the 3D scale factor as a function of time. When the hypergeometric function is expanded for small and large arguments, we obtain a generalized treatment of the dynamical compactification scenario of Mohammedi [Phys. Rev. D 65, 104018 (2002)] and the 5D vacuum solution of Chodos and Detweiler [Phys. Rev. D 21, 2167 (1980)], respectively. By expanding the hypergeometric function near a branch point, we obtain the perturbative solution for the 3D scale factor in the small time regime. This solution exhibits accelerated expansion, which, remarkably, is independent of the value of the 4D equation of state parameter w. This early-time epoch of accelerated expansion arises naturally out of the anisotropic evolution of 5D spacetime when the pressure in the extra dimension is negative and offers a possible alternative to scalar field inflationary theory.

Spacelike Hypersurfaces in Weighted Generalized Robertson-Walker Space-Times

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Ximin Liu

2018-01-01

Full Text Available Applying generalized maximum principle and weak maximum principle, we obtain several uniqueness results for spacelike hypersurfaces immersed in a weighted generalized Robertson-Walker (GRW space-time under suitable geometric assumptions. Furthermore, we also study the special case when the ambient space is static and provide some results by using Bochner’s formula.

Digestive morphophysiology of Gryllodes sigillatus (Orthoptera: Gryllidae).

Science.gov (United States)

Biagio, Fernanda P; Tamaki, Fabio K; Terra, Walter R; Ribeiro, Alberto F

2009-12-01

The evolution of the digestive system in the Order Orthoptera is disclosed from the study of the morphophysiology of the digestive process in its major taxa. This paper deals with a cricket representing the less known suborder Ensifera. Most amylase and trypsin activities occur in crop and caeca, respectively. Maltase and aminopeptidase are found in soluble and membrane-bound forms in caeca, with aminopeptidase also occurring in ventriculus. Amaranth was orally fed to Gryllodes sigillatus adults or injected into their haemolymph. The experiments were performed with starving and feeding insects with identical results. Following feeding of the dye the luminal side of the most anterior ventriculus (and in lesser amounts the midgut caeca) became heavily stained. In injected insects, the haemal side of the most posterior ventriculus was stained. This suggested that the anterior ventriculus is the main site of water absorption (the caeca is a secondary one), whereas the posterior ventriculus secretes water into the gut. Thus, a putative counter-current flux of fluid from posterior to anterior ventriculus may propel digestive enzyme recycling. This was confirmed by the finding that digestive enzymes are excreted at a low rate. The fine structure of midgut caeca and ventriculus cells revealed that they have morphological features that may be related to their involvement in secretion (movement from cell to lumen) and absorption (movement from lumen to cell) of fluids. Furthermore, morphological data showed that both merocrine and apocrine secretory mechanisms occur in midgut cells. The results showed that cricket digestion differs from that in grasshopper in having: (1) more membrane-bound digestive enzymes; (2) protein digestion slightly displaced toward the ventriculus; (3) midgut fluxes, and hence digestive enzyme recycling, in both starved and fed insects.

Can intermittent long-range jumps of a random walker compensate for lethargy?

International Nuclear Information System (INIS)

Bologna, Mauro; Ahat, Yasin; Grigolini, Paolo; West, Bruce J

2011-01-01

We study the dynamics of a lazy random walker who is inactive for extended times and tries to make up for her laziness with very large jumps. She remains in a condition of rest for a time τ derived from a waiting-time distribution ψ(τ)∝1/τ μ W , with μ W μ ξ , with μ ξ > 1. The most convenient choice to make up for the random walker laziness would be to select μ ξ W > 2 would produce Levy flights with scaling δ = 1/(μ ξ - 1) and consequently super-diffusion. According to the Sparre Andersen theorem, the distribution density of the first times to go from x A to x B > x A has the inverse power law form f(t)∝1/(t μ FPT ) with μ FPT = μ SA = 1.5. We find the surprising result that there exists a region of the phase space (μ ξ , μ W ) with μ W FPT > μ SA and the lazy walker compensates for her laziness. There also exists an extended region breaking the Sparre Andersen theorem, where the lazy runner cannot compensate for her laziness. We make conjectures concerning the possible relevance of this mathematical prediction, supported by numerical calculations, for the problem of animal foraging. (fast track communication)

Experimental Studies of Wheelchair and Walker Users Passing Through Doors with Different Opening Force.

Science.gov (United States)

Nersveen, Jonny

2016-01-01

Users of walkers and users of different categories of wheelchairs tested doors with different opening force, aiming to reveal the limit that these groups of people could manage on an everyday basis. 94.7% of the wheelchair users reported that a door opening force of 30 N was acceptable, while as 92.1% of this group described 40 N as acceptable. Similarly, 100% of the walker users reported that a door opening force of 30 N was acceptable, while as 87,5% of this group described 40 N as acceptable.

A preliminary mitochondrial genome phylogeny of Orthoptera (Insecta) and approaches to maximizing phylogenetic signal found within mitochondrial genome data.

Science.gov (United States)

Fenn, J Daniel; Song, Hojun; Cameron, Stephen L; Whiting, Michael F

2008-10-01

The phylogenetic utility of mitochondrial genomes (mtgenomes) is examined using the framework of a preliminary phylogeny of Orthoptera. This study presents five newly sequenced genomes from four orthopteran families. While all ensiferan and polyneopteran taxa retain the ancestral gene order, all caeliferan lineages including the newly sequenced caeliferan species contain a tRNA rearrangement from the insect ground plan tRNA(Lys)(K)-tRNA(Asp)(D) swapping to tRNA(Asp) (D)-tRNA(Lys) (K) confirming that this rearrangement is a possible molecular synapomorphy for this suborder. The phylogenetic signal in mtgenomes is rigorously examined under the analytical regimens of parsimony, maximum likelihood and Bayesian inference, along with how gene inclusion/exclusion, data recoding, gap coding, and different partitioning schemes influence the phylogenetic reconstruction. When all available data are analyzed simultaneously, the monophyly of Orthoptera and its two suborders, Caelifera and Ensifera, are consistently recovered in the context of our taxon sampling, regardless of the optimality criteria. When protein-coding genes are analyzed as a single partition, nearly identical topology to the combined analyses is recovered, suggesting that much of the signals of the mtgenome come from the protein-coding genes. Transfer and ribosomal RNAs perform poorly when analyzed individually, but contribute signal when analyzed in combination with the protein-coding genes. Inclusion of third codon position of the protein-coding genes does not negatively affect the phylogenetic reconstruction when all genes are analyzed together, whereas recoding of the protein-coding genes into amino acid sequences introduces artificial resolution. Over-partitioning in a Bayesian framework appears to have a negative effect in achieving convergence. Our findings suggest that the best phylogenetic inferences are made when all available nucleotide data from the mtgenome are analyzed simultaneously, and that

Food supply (Orthoptera, Mantodea, Rodentia and Eulipotyphla and food preferences of the red-footed falcon (Falco vespertinus in Slovakia

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Krištín Anton

2017-12-01

Full Text Available Food supply in the nesting territories of species has a key role to the species diet composition and their breeding success. Red-footed falcon (Falco vespertinus preys predominantly on larger insect species with a supplementary portion of smaller vertebrates. In the breeding periods 2014 and 2016 their food supply, focusing on Orthoptera, Mantodea, Rodentia and Eulipotyphla, was analysed at five historical nesting sites of the species in Slovakia. Preference for these prey groups in the diet was also studied at the last active nesting site in this country. Overall we recorded 45 Orthoptera species (of which 23 species are known as the food of the red-footed falcon, one species of Mantodea, 10 species of Rodentia (of which 2 species are known as the food of the red-footed falcon and 5 species of the Eulipotyphla order in the food supply. With regard to the availability of the falcons' preferred food, in both years the most suitable was the Tvrdošovce site, which continuously showed the greatest range and abundance of particular species. In the interannual comparison the insects showed lower variability in abundance than the small mammals. In 2014 the growth of the common vole (Microtus arvalis population culminated and with the exception of a single site (Bodza a slump in abundance was recorded in 2016. In comparing the diet composition with the food supply at the last Slovak breeding site Rusovce (Special Protection Area Sysľovské polia, we recorded significant preference for grasshopper Caliptamus italicus (in 2014, common vole (in 2016 and cricket Tettigonia viridissima (in both years in the falcons' diet. They did not prey on the Apodemus sylvaticus species belonging among the abundant small mammal species in that locality. Conservation measures in the agricultural landscape are discussed in relation to homogeneous red-footed falcon breeding territories.

Empowering and Assisting Natural Empowering and Assisting Natural Human Mobility: The Simbiosis Walker

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Anselmo Frizera-Neto

2011-08-01

Full Text Available This paper presents the complete development of the Simbiosis Smart Walker. The device is equipped with a set of sensor subsystems to acquire user-machine interaction forces and the temporal evolution of user's feet during gait. The authors present an adaptive filtering technique used for the identification and separation of different components found on the human-machine interaction forces. This technique allowed isolating the components related with the navigational commands and developing a Fuzzy logic controller to guide the device. The Smart Walker was clinically validated at the Spinal Cord Injury Hospital of Toledo - Spain, presenting great acceptability by spinal chord injury patients and clinical staff.

Separation of massive field equation of arbitrary spin in Robertson-Walker space-time

International Nuclear Information System (INIS)

Zecca, A.

2006-01-01

The massive spin-(3/2) field equation is explicitly integrated in the Robertson-Walker space-time by the Newman Penrose formalism. The solution is obtained by extending a separation procedure previously used to solve the spin-1 equation. The separated time dependence results in two coupled equations depending on the cosmological background evolution. The separated angular equations are explicitly integrated and the eigenvalues determined. The separated radial equations are integrated in the flat space-time case. The separation method of solution is then generalized, by induction, to prove the main result, that is the separability of the massive field equations of arbitrary spin in the Robertson-Walker space-time

75 FR 49517 - Notice of Intent To Prepare an Environmental Impact Statement for the Walker Ridge Wind Project...

Science.gov (United States)

2010-08-13

...] Notice of Intent To Prepare an Environmental Impact Statement for the Walker Ridge Wind Project, Lake and...: You may submit comments related to the Walker Ridge Wind Project by any of the following methods: Web... CONTACT: For further information and/or to have your name added to our mailing list, contact Bethney...

Experience in the management of Dandy-Walker syndrome in an ...

African Journals Online (AJOL)

Dandy-Walker Syndrome (DWS) is a congenital brain malformation involving the cerebellum and the fluid spaces around it. There is atresia of foramenofMagendie and Lushka resulting in a complete absence of the part of the brain located between the two cerebellar hemispheres (cerebellarvermis) and cystic dilatation of ...

Monocoque structure for the SKITTER three-legged walker

Science.gov (United States)

Bansek, Robert N.; Booth, Andrew J.; Daneman, Steven A.; Dresser, James A.; Haney, Todd G.; Johnson, Gregory R.; Lindzen, Eric C.; Montgomery, Robert C.; Warren, Andrew L.

1988-01-01

The SKITTER 2 design is a monocoque version of the proposed lunar three-legged walker. By the definition of monocoque, the body and legs are a shell with no internal ribbing or supports added for absorbing stresses. The purpose of the monocoque is to encase the elements used for power transmission, power supply, and control of the motion. The material for the structure is a vinyl ester resin, Derakane 8084. This material is easily formable and locally obtainable. The body consists of a hexagonally shaped cylinder with truncated hexagonal pyramids on the top and botton. The legs are eight inch diameter cylinders. The legs are comprised of a tibia section and a femur section. The SKITTER 2 is powered by six actuators which provide linear forces that are transformed into rotary torques by a series of chains and sprockets. The joints connect the femur to the body and the tibia to the femur. Surrounding the joints are flexible rubber hoses that fully encase the chains and sprockets. The SKITTER 2 is capable of walking upside down, righting itself after being overturned, and has the ability to perform in many environments. Applications for this walker include lunar transport or drilling, undersea exploration, and operation in severe surroundings such as arctic temperatures or high radiation.

Walker use, but not falls, is associated with lower physical functioning and health of residents in an assisted-living environment

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Daniel A Andersen

2007-04-01

Full Text Available Daniel A Andersen1,5, Bernard A Roos1–4, Damian C Stanziano1,3, Natasha M Gonzalez3, Joseph F Signorile1–31Stein Gerontological Institute, Miami, FL; 2Geriatric Research, Education, and Clinical Center, Veterans Affairs Medical Center, Miami, FL; 3Department of Exercise and Sport Sciences, University of Miami, Coral Gables, FL; 4Departments of Medicine and Neurology, University of Miami Miller School of Medicine, Miami, FL; 5Department of Epidemiology and Public Health, University of Miami School of Medicine, Miami, FL, USAAbstract: The relationship between perceived health and walker use has seldom been addressed. Concerns over falls and falls risk are precursors to walker use. We compared the SF-36 scores of 26 women and 14 men, mean age 86.8 ± 6.0 years based on walker use and faller status. An analysis of covariance (ANCOVA with age as the covariate, compared groups for the SF-36 constructs and totals score. Significant differences were noted between walker users and nonusers in physical functioning, role limitations due to physical problems, general health, and the total SF-36 score. Pairwise comparisons favored nonusers, while no differences were seen due to faller status. Walker use is associated with lower self-perceptions of physical functioning, role limitations due to physical problems, and general health in assisted-living residents. Faller status is not associated with self-perceived health status. Although walker use aids mobility and lowers the probability of falls, further research is needed to determine if the prescription of assistive devices has a more negative impact on self-perceived health than does falling. This possibility could be explained, in part, by the greater activity levels of those individuals who do not depend on walkers.Keywords: physical function, threshold, walking aid, elderly, perceived health

Three new species of the genus Ripipteryx from Colombia (Orthoptera, Ripipterygidae).

Science.gov (United States)

Baena-Bejarano, Nathalie; Heads, Sam W

2015-01-01

Three new species of Ripipteryx Newman (Orthoptera: Tridactyloidea: Ripipterygidae) are described from Colombia; namely Ripipteryxdiegoi sp. n. (Forceps Group) and Ripipteryxguacharoensis sp. n. (Marginipennis Group) from Parque Nacional Natural Cueva de los Guacharos in Huila, and Ripipteryxgorgonaensis sp. n. (Crassicornis Group) from Parque Nacional Natural Gorgona in Cauca. Ripipteryxdiegoi sp. n. is characterized by the antennae black with white spots on flagellomeres 3-7, male subgenital plate with median ridge forming a bilobed setose process, epiproct produced laterally near its base and phallic complex with virga thickened distally and not reaching beyond the membrane. Ripipteryxguacharoensis sp. n. is characterized by the antennae thick with white spots present dorsally on flagellomeres 1-4 and 8, epiproct narrow and triangular, uncus reduced and lacking a distal hook, phallic complex with a concave ventral plate and a dorsal elevation in the middle extended to the virga, and the virga itself with two small projections basally. Ripipteryxgorgonaensis sp. n. is characterized by the epiproct with a lateral notch, antennae with a white dorsal spot on flagellomere 1 and flagellomeres 4-7 entirely white. The antennal color pattern of Ripipteryxgorgonaensis sp. n. strongly resembles that of Ripipteryxatra but differs from the latter in the absence of any significant morphological modification of the flagellomeres.

Revisiting adaptations of neotropical katydids (Orthoptera: Tettigoniidae) to gleaning bat predation.

Science.gov (United States)

Ter Hofstede, Hannah; Voigt-Heucke, Silke; Lang, Alexander; Römer, Heinrich; Page, Rachel; Faure, Paul; Dechmann, Dina

2017-01-01

All animals have defenses against predators, but assessing the effectiveness of such traits is challenging. Neotropical katydids (Orthoptera: Tettigoniidae) are an abundant, ubiquitous, and diverse group of large insects eaten by a variety of predators, including substrate-gleaning bats. Gleaning bats capture food from surfaces and usually use prey-generated sounds to detect and locate prey. A number of Neotropical katydid signaling traits, such as the emission of ultrasonic frequencies, substrate vibration communication, infrequent calling, and ultrasound-evoked song cessation are thought to have evolved as defenses against substrate-gleaning bats. We collected insect remains from hairy big-eared bat ( Micronycteris hirsuta ) roosts in Panama. We identified insect remains to order, species, or genus and quantified the proportion of prey with defenses against predatory bats based on defenses described in the literature. Most remains were from katydids and half of those were from species with documented defenses against substrate-gleaning bats. Many culled remains were from insects that do not emit mate-calling songs (e.g. beetles, dragonflies, cockroaches, and female katydids), indicating that eavesdropping on prey signals is not the only prey-finding strategy used by this bat. Our results show that substrate-gleaning bats can occasionally overcome katydid defenses.

Quantum features derived from the classical model of a bouncer-walker coupled to a zero-point field

International Nuclear Information System (INIS)

Schwabl, H; Mesa Pascasio, J; Fussy, S; Grössing, G

2012-01-01

In our bouncer-walker model a quantum is a nonequilibrium steady-state maintained by a permanent throughput of energy. Specifically, we consider a 'particle' as a bouncer whose oscillations are phase-locked with those of the energy-momentum reservoir of the zero-point field (ZPF), and we combine this with the random-walk model of the walker, again driven by the ZPF. Starting with this classical toy model of the bouncer-walker we were able to derive fundamental elements of quantum theory. Here this toy model is revisited with special emphasis on the mechanism of emergence. Especially the derivation of the total energy hω o and the coupling to the ZPF are clarified. For this we make use of a sub-quantum equipartition theorem. It can further be shown that the couplings of both bouncer and walker to the ZPF are identical. Then we follow this path in accordance with Ref. [2], expanding the view from the particle in its rest frame to a particle in motion. The basic features of ballistic diffusion are derived, especially the diffusion constant D, thus providing a missing link between the different approaches of our previous works.

Spruce aphid (Elatobium abietinum Walker) (Hemiptera: Aphididae) [Chapter XXIV

Science.gov (United States)

Ann M. Lynch

2014-01-01

Elatobium abietinum Walker is a spruce-feeding aphid that in Europe is referred to as the green spruce aphid (Day et al., 1998a) (Fig. 1). However, in North America E. abietinum is known simply as the spruce aphid, while the common name "green spruce aphid" refers to a different species, Cinara fornacula Hottes (Hemiptera: Aphididae) (http://www.entsoc.org/...

Short-Term Dynamics of Behavioral Thermoregulation by Adults of the Grasshopper Melanoplus sanguinipes

Science.gov (United States)

O'Neill, Kevin M.; Rolston, Marni G.

2007-01-01

The short-term behavioral responses of adult grasshoppers, Melanoplus sanguinipes (F.) (Orthoptera: Acrididae), were examined after they experienced changes in microclimate when beingforced to change positions in their habitat. It was also determined if and when behavioral tactics allowed adults to achieve body temperatures within their preferred range. The preferred or set-point range, here taken as the interquartile range of temperatures selected on a laboratory thermal gradient, was estimated to be 37.4–40.5°C. In the field, adults progressed through a relatively consistent daily sequence of behaviors, basking on the soil early in the day, but moving onto vegetation as temperatures increased. Although basking allowed grasshoppers to maximize body temperature within the available range, as much as 7°C in excess of air temperature, they could not attain preferred body temperatures until soil surface temperatures reach about 35°C. Basking was more effective in grazed than ungrazed pastures due to a lower degree of shading of the soil surface. As soil surface temperatures exceeded 35°C, grasshoppers could achieve body temperatures within the preferred range by moving to the appropriate height on vegetation. These results illustrate the advantage of assessing behavior in the field in relation to preferred body temperatures determined in the laboratory. PMID:20302531

Morphology, Diet Composition, Distribution and Nesting Biology of Four Lark Species in Mongolia

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Galbadrakh Mainjargal

2013-12-01

Full Text Available We aimed to enhance existing knowledge of four lark species (Mongolian lark , Horned lark, Eurasian skylark, and Lesser short-toed lark, with respect to nesting biology, distribution, and diet, using long-term dataset collected during 2000–2012. Nest and egg measurements substantially varied among species. For pooled data across species, the clutch size averaged 3.72 ± 1.13 eggs and did not differ among larks. Body mass of nestlings increased signi fi cantly with age at weighing. Daily increase in body mass of lark nestlings ranged between 3.09 and 3.89 gram per day. Unsurprisingly, the majority of lark locations occurred in steppe ecosystems, followed by human created systems; whereas only 1.8% of the pooled locations across species were observed in forest ecosystem. Diet composition did not vary among species in the proportions of major food categories consumed. The most commonly occurring food items were invertebrates and frequently consumed were being beetles (e.g. Coleoptera: Carabidae, Scarabaeidae, and Curculionidae and grasshoppers (e.g. Orthoptera: Acrididae, and their occurrences accounted for 63.7% of insect related food items. Among the fi ve morphological traits we measured, there were signi fi cant differences in wing span, body mass, bill, and tarsus; however tail lengths did not differ across four species.

Swing-Leg Retraction for Limit Cycle Walkers Improves Disturbance Rejection

NARCIS (Netherlands)

Hobbelen, D.G.E.; Wisse, M.

2008-01-01

Limit cycle walkers are bipeds that exhibit a stable cyclic gaitwithout requiring local controllability at all times during gait. A well-known example of limit cycle walking is McGeer’s “passive dynamic walking,” but the concept expands to actuated bipeds as involved in this study. One of the

VarWalker: personalized mutation network analysis of putative cancer genes from next-generation sequencing data.

Science.gov (United States)

Jia, Peilin; Zhao, Zhongming

2014-02-01

A major challenge in interpreting the large volume of mutation data identified by next-generation sequencing (NGS) is to distinguish driver mutations from neutral passenger mutations to facilitate the identification of targetable genes and new drugs. Current approaches are primarily based on mutation frequencies of single-genes, which lack the power to detect infrequently mutated driver genes and ignore functional interconnection and regulation among cancer genes. We propose a novel mutation network method, VarWalker, to prioritize driver genes in large scale cancer mutation data. VarWalker fits generalized additive models for each sample based on sample-specific mutation profiles and builds on the joint frequency of both mutation genes and their close interactors. These interactors are selected and optimized using the Random Walk with Restart algorithm in a protein-protein interaction network. We applied the method in >300 tumor genomes in two large-scale NGS benchmark datasets: 183 lung adenocarcinoma samples and 121 melanoma samples. In each cancer, we derived a consensus mutation subnetwork containing significantly enriched consensus cancer genes and cancer-related functional pathways. These cancer-specific mutation networks were then validated using independent datasets for each cancer. Importantly, VarWalker prioritizes well-known, infrequently mutated genes, which are shown to interact with highly recurrently mutated genes yet have been ignored by conventional single-gene-based approaches. Utilizing VarWalker, we demonstrated that network-assisted approaches can be effectively adapted to facilitate the detection of cancer driver genes in NGS data.

The Dirac equation and the normalization of its solutions in a closed Friedmann- Robertson-Walker universe

Energy Technology Data Exchange (ETDEWEB)

Finster, Felix [NWF I-Mathematik, Universitaet Regensburg, D-93040 Regensburg (Germany); Reintjes, Moritz, E-mail: Felix.Finster@mathematik.uni-regensburg.d, E-mail: moritz@math.ucdavis.ed [Mathematics Department, University of California, Davis, CA 95616 (United States)

2009-05-21

We set up the Dirac equation in a Friedmann-Robertson-Walker geometry and separate the spatial and time variables. In the case of a closed universe, the spatial dependence is solved explicitly, giving rise to a discrete set of solutions. We compute the probability integral and analyze a spacetime normalization integral. This analysis allows us to introduce the fermionic projector in a closed Friedmann-Robertson-Walker geometry and to specify its global normalization as well as its local form.

The Dirac equation and the normalization of its solutions in a closed Friedmann- Robertson-Walker universe

International Nuclear Information System (INIS)

Finster, Felix; Reintjes, Moritz

2009-01-01

We set up the Dirac equation in a Friedmann-Robertson-Walker geometry and separate the spatial and time variables. In the case of a closed universe, the spatial dependence is solved explicitly, giving rise to a discrete set of solutions. We compute the probability integral and analyze a spacetime normalization integral. This analysis allows us to introduce the fermionic projector in a closed Friedmann-Robertson-Walker geometry and to specify its global normalization as well as its local form.

Henri Cartier-Bresson / Walker Evans : Photographier l’Amérique (1929-1947

Directory of Open Access Journals (Sweden)

François Brunet

2009-08-01

Full Text Available Dans un mot adressé en 2001 à Peter Galassi, conservateur de la photographie au MOMA, Henri Cartier-Bresson, alors âgé de quatre-vingt-treize ans, écrivait plaisamment — mais non pas complaisamment : « If it had not been for the challenge of the work of Walker Evans, I don’t think I would have remained a fotographer » (« sans le défi constitué par le travail de Walker Evans, je ne crois pas que je serais resté fotographe ». Pour fêter le centenaire de Cartier-Bresson, c’est ce défi — plutôt ...

Massive bosons interacting with gravity: No standard solutions in Robertson-Walker space-time

International Nuclear Information System (INIS)

Zecca, A.

2009-01-01

The problem of the interaction of boson and gravitational field is formulated in the Robertson-Walker space-time. It consist the simultaneous solution of the boson and of the Einstein field equation whose source is the energy momentum tensor of the boson field. By direct verification it is shown that the problem does not admit solutions in the class of massive standard solutions, previously determined, of the boson field equation. Also there cannot be solutions, in case of massive interacting boson, that are superpositions of standard solutions. The case of massless boson field is left open. The result is essentially due to the very special form of the Einstein tensor in Robertson-Walker metric.

Ketertarikan Anaxipha longipennis Serville (Orthoptera: Gryllidae terhadap Beberapa Jenis Gulma di Sawah sebagai Tempat Bertelur

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Sri Karindah

2015-09-01

Full Text Available Anaxipha longipennis Serville (Orthoptera: Gryllidae is one of the generalist predator in rice habitat that has a potential as a biological control agents of rice leaf folder eggs and small insects such as rice hoppers. Females insert their eggs in plant tissue. The female’s oviposition site is important for the subsequent distribution of the cricket. Oviposition preference on 17 weeds species from rice habitat were tested in a free choice experiment in the laboratory. There was strong evidence to conclude that the cricket preferred certain plant for laying eggs. In free choice experiment nine species of weeds were preferred by A. longipennis for laying their eggs instead of rice. The preferred species were ranked as follows: rice, Monochoria vaginalis, Cyperus rotundus, C. iria, Echinochloa colonum, E. crusgalli, Eleusine indica, Fimbristylis miliacea, Imperata cylindrica, and Limnocharis flava. Whereas Ageratum conyzoides, Alternanthera sessilis, Commelina diffusa, Leersia hexandra, Leptochloa chinensis, Ludwigia adscendens, Panicum repens, and Sonchus arvensis were not preferred in free-choice test.

75 FR 35265 - Safety Standard for Infant Walkers: Final Rule

Science.gov (United States)

2010-06-21

... are walking (usually 6 to 15 months old). ASTM F 977-07 defines ``walker'' as ``a mobile unit that... attached to rigid trays. The trays are fastened to bases that have wheels or casters to make them mobile.../jumping. Occupant retention--intended to prevent entrapment by setting requirements for leg openings. The...

Effects of aquatic walking exercise using a walker in a chronic stroke patient.

Science.gov (United States)

Matsuda, Tadashi; Akezaki, Yoshiteru

2017-07-01

[Purpose] The aim of this study was to examine the usefulness of aquatic walking exercise using a walker for chronic stroke patients. We also examined the psychological effects on the study subject and the primary caregiver before and after aquatic walking exercise. [Subject and Methods] The subject was a 60-year-old male with bilateral paralysis after a cerebrovascular accident. The Fugl-Meyer Assessment (FMA) total score was 116 on the right and 115 on the left. The intervention combined aquatic and land walking exercise. A U-shaped walker was used for both water and land exercise. Continuous walking distance was the measure used to evaluate land walking ability. The psychological effects on the study subject and the primary caregiver were examined with the questionnaire. [Results] In aquatic walking, the mean time to walk 5 m showed an increase from the intervention after two months. After the aquatic walking and land walking combination, continuous walking distance also showed a prolonged trend. In the survey given to the main caregivers, improvements were observed. [Conclusion] Aquatic walking practice using a walker improved motivation in a chronic stroke patient, leading to improved walking ability, with a positive psychological influence on the participant and family caregiver.

Simple autonomous Mars walker

Science.gov (United States)

Larimer, Stanley J.; Lisec, Thomas R.; Spiessbach, Andrew J.

1989-01-01

Under a contract with NASA's Jet Propulsion Laboratory, Martin Marietta has developed several alternative rover concepts for unmanned exploration of the planet Mars. One of those concepts, the 'Walking Beam', is the subject of this paper. This concept was developed with the goal of achieving many of the capabilities of more sophisticated articulated-leg walkers with a much simpler, more robust, less computationally demanding and more power efficient design. It consists of two large-base tripods nested one within the other which alternately translate with respect to each other along a 5-meter beam to propel the vehicle. The semiautonomous navigation system relies on terrain geometry sensors and tacticle feedback from each foot to autonomously select a path which avoids hazards along a route designated from earth. Both mobility and navigation features of this concept are discussed including a top-level description of the vehicle's physical characteristics, deployment strategy, mobility elements, sensor suite, theory of operation, navigation and control processes, and estimated performance.

Women in History--Madame C. J. Walker 1867-1919

Science.gov (United States)

Huber, Germaine W.

2009-01-01

This article profiles Madame C. J. Walker. Sarah Breedlove was born on December 23, 1867, the fifth of six children of Owen and Minerva Breedlove. Sarah was the first of the Breedlove children to be born after the end of slavery. Her parents died when she was six or seven years of age. At age fourteen she married Moses McWilliams, who also died in…

Upper-Ocean Heat Balance Processes and the Walker Circulation in CMIP5 Model Projections

Science.gov (United States)

Robertson, F. R.; Roberts, J. B.; Funk, C.; Lyon, B.; Ricciardulli, L.

2012-01-01

Considerable uncertainty remains as to the importance of mechanisms governing decadal and longer variability of the Walker Circulation, its connection to the tropical climate system, and prospects for tropical climate change in the face of anthropogenic forcing. Most contemporary climate models suggest that in response to elevated CO2 and a warmer but more stratified atmosphere, the required upward mass flux in tropical convection will diminish along with the Walker component of the tropical mean circulation as well. Alternatively, there is also evidence to suggest that the shoaling and increased vertical stratification of the thermocline in the eastern Pacific will enable a muted SST increase there-- preserving or even enhancing some of the dynamical forcing for the Walker cell flow. Over the past decade there have been observational indications of an acceleration in near-surface easterlies, a strengthened Pacific zonal SST gradient, and globally-teleconnected dislocations in precipitation. But is this evidence in support of an ocean dynamical thermostat process posited to accompany anthropogenic forcing, or just residual decadal fluctuations associated with variations in warm and cold ENSO events and other stochastic forcing? From a modeling perspective we try to make headway on this question by examining zonal variations in surface energy fluxes and dynamics governing tropical upper ocean heat content evolution in the WCRP CMIP5 model projections. There is some diversity among model simulations; for example, the CCSM4 indicates net ocean warming over the IndoPacific region while the CSIRO model concentrates separate warming responses over the central Pacific and Indian Ocean regions. The models, as with observations, demonstrate strong local coupling between variations in column water vapor, downward surface longwave radiation and SST; but the spatial patterns of changes in the sign of this relationship differ among models and, for models as a whole, with

Lightweight Biometric Sensing for Walker Classification Using Narrowband RF Links

Directory of Open Access Journals (Sweden)

Tong Liu

2017-12-01

Full Text Available This article proposes a lightweight biometric sensing system using ubiquitous narrowband radio frequency (RF links for path-dependent walker classification. The fluctuated received signal strength (RSS sequence generated by human motion is used for feature representation. To capture the most discriminative characteristics of individuals, a three-layer RF sensing network is organized for building multiple sampling links at the most common heights of upper limbs, thighs, and lower legs. The optimal parameters of sensing configuration, such as the height of link location and number of fused links, are investigated to improve sensory data distinctions among subjects, and the experimental results suggest that the synergistic sensing by using multiple links can contribute a better performance. This is the new consideration of using RF links in building a biometric sensing system. In addition, two types of classification methods involving vector quantization (VQ and hidden Markov models (HMMs are developed and compared for closed-set walker recognition and verification. Experimental studies in indoor line-of-sight (LOS and non-line-of-sight (NLOS scenarios are conducted to validate the proposed method.

Lightweight Biometric Sensing for Walker Classification Using Narrowband RF Links.

Science.gov (United States)

Liu, Tong; Liang, Zhuo-Qian

2017-12-05

This article proposes a lightweight biometric sensing system using ubiquitous narrowband radio frequency (RF) links for path-dependent walker classification. The fluctuated received signal strength (RSS) sequence generated by human motion is used for feature representation. To capture the most discriminative characteristics of individuals, a three-layer RF sensing network is organized for building multiple sampling links at the most common heights of upper limbs, thighs, and lower legs. The optimal parameters of sensing configuration, such as the height of link location and number of fused links, are investigated to improve sensory data distinctions among subjects, and the experimental results suggest that the synergistic sensing by using multiple links can contribute a better performance. This is the new consideration of using RF links in building a biometric sensing system. In addition, two types of classification methods involving vector quantization (VQ) and hidden Markov models (HMMs) are developed and compared for closed-set walker recognition and verification. Experimental studies in indoor line-of-sight (LOS) and non-line-of-sight (NLOS) scenarios are conducted to validate the proposed method.

Lightweight Biometric Sensing for Walker Classification Using Narrowband RF Links

Science.gov (United States)

Liang, Zhuo-qian

2017-01-01

This article proposes a lightweight biometric sensing system using ubiquitous narrowband radio frequency (RF) links for path-dependent walker classification. The fluctuated received signal strength (RSS) sequence generated by human motion is used for feature representation. To capture the most discriminative characteristics of individuals, a three-layer RF sensing network is organized for building multiple sampling links at the most common heights of upper limbs, thighs, and lower legs. The optimal parameters of sensing configuration, such as the height of link location and number of fused links, are investigated to improve sensory data distinctions among subjects, and the experimental results suggest that the synergistic sensing by using multiple links can contribute a better performance. This is the new consideration of using RF links in building a biometric sensing system. In addition, two types of classification methods involving vector quantization (VQ) and hidden Markov models (HMMs) are developed and compared for closed-set walker recognition and verification. Experimental studies in indoor line-of-sight (LOS) and non-line-of-sight (NLOS) scenarios are conducted to validate the proposed method. PMID:29206188

Sex ratios in juveniles and adults of Dichroplus maculipennis (Blanchard and Borellia bruneri (Rehn (Orthoptera: Acrididae

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Yanina Mariottini

2015-06-01

Full Text Available Dichroplus maculipennis and Borellia bruneri are two of the 18 grasshopper species of actual or potential economic relevance as pests in Argentina. The objective of this study was to estimate the sex ratios for adults and older nymphs of D. maculipennis and B. bruneri in the field, and analyze possible temporal variations. The study was conducted during seven seasons (2005-06 to 2011-12 in representative plant communities of the southern Pampas region. A total of 4536 individuals of D. maculipennis, and 6038 individuals of B. bruneri were collected. The sex ratio registered in older nymphs for D. maculipennis and B. bruneri did not deviate from a 1:1 ratio (p > 0.05, suggesting that these species have such a primary sex ratio. However, a significant bias in sex composition in adults of both species was observed (p < 0.05. The sex ratio in adults of D. maculipennis was different in five of the 18 sampling dates carried out. In three sampling dates it was biased toward males, while in the other two it was biased toward females. Taking into account the sex ratio by sampling season, significant differences were recorded in two seasons. In 2007-08 the sex ratio was biased toward males (1 F:2.26 M, while in 2008-09 it was biased toward females (1.35 F:1 M. The sex ratio in adults of B. bruneri was always biased toward males (p < 0.05. We conclude that results obtained in this study indicate that various factors like differential survival, dispersion, predation, among others, could have modified the primary sex ratio in these species.

Microsatellite Markers for the Chameleon Grasshopper (Kosciuscola tristis (Orthoptera: Acrididae, an Australian Alpine Specialist

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Ange-Marie Risterucci

2012-09-01

Full Text Available A set of polymorphic loci was characterised using an enrichment library for the Australian alpine specialist, the chameleon grasshopper (Kosciuscola tristis, an atypical grasshopper known for its remarkable temperature-controlled colour change. The number of alleles per locus ranged from three to 20 and observed heterozygosity from 0.16 to 0.76. These are the first microsatellite markers for a non-endangered Australian alpine animal and will inform questions of gene flow across the sky islands of this unique and threatened region.

Análisis morfológico del sistema reproductor femenino de Baeacris punctulatus (Orthoptera: Acrididae: Melanoplinae)

OpenAIRE

Adriana A. MICHEL; Héctor R. TERÁN

2005-01-01

Baeacris punctulatus (Thunberg) es una especie de importancia económica, de amplia distribución en Sudamérica. En el presente trabajo se realiza un estudio anatomo-histológico de los órganos reproductivos internos, en hembras silvestres y obtenidas en cámara de cría. El estudio permitió determinar particularidades histomorfológicas, en ovarios, glándulas accesorias, oviductos laterales y oviducto medio, relacionadas con la génesis y transferencia de las gametas y la ovoposición. Se caracteriz...

Age structure and feeding of the neotropical grasshopper Cornops aquaticum (Bruner) (Orthoptera: Acrididae) on water hyacinth.

Science.gov (United States)

Franceschini, M C; de Wysiecki, M L; Poi, A

2013-08-01

We aimed to evaluate the variation in the age structure of Cornops aquaticum (Bruner) population and its relation to the host plant biomass and the feeding of the different age classes of this grasshopper on the water hyacinth Eichhornia crassipes along 2 years, in a Paraná River floodplain lake (Chaco, Argentina). Individuals of C. aquaticum were captured with a 70-cm diameter sweep and separated in nymphs A (instars I and II), nymphs B (instars III to VI), adult females, and adult males; host plant biomass was sampled using a ring with a 0.30-m(2) diameter. Relative daily feeding of C. aquaticum population was calculated by multiplying the number of individuals captured per minute by the daily consumption by individual obtained in each age classes. We found that the age structure and the relative daily feeding of C. aquaticum varied between seasons and years. The highest values of grasshopper abundance, leaf biomass, and relative daily feeding of C. aquaticum population were observed in summer 2006. Plant biomass was directly correlated with nymph abundance and not correlated with adult abundance. Plant biomass available as refuge (leaves), food (laminas), and oviposition site (petioles) to C. aquaticum represented up to 62% of the total plant biomass. The results obtained in C. aquaticum show the importance of considering total plant biomass and plant biomass available for herbivores separately. Our study highlights the need to find an adequate method to estimate the density of C. aquaticum and other semiaquatic grasshoppers in the Paraná River floodplain involving different seasons, years, and water phases (rising and falling).

Desarrollo post-embrionario, fecundidad y consumo de alimento de Dichroplus exilis (Orthoptera: Acrididae bajo condiciones controladas

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Christian Bardi

2011-12-01

Full Text Available La Subfamilia Melanoplinae tiene una relevancia central dentro de la acridiofauna Argentina. Varias especies suelen ser numéricamente dominantes en las comunidades de acridios del país y algunas constituyen serias plagas. El objetivo de este trabajo fue conocer el ciclo de vida postembrionario, la fecundidad y supervivencia de las hembras y el consumo de alimento de Dichruplus exilis bajo condiciones controladas (30°C; 40%HR y 14L-10O. Para ello se realizó el seguimiento de tres cohortes de 16, 17 y 20 individuos. El tiempo de incubación fue de 14.4±1.08 días. La duración del desarrollo ninfal fue 41.38; 0.71 días (I 8.73; 0.20, II 6.38; 0.24, III 5.64; 0.33, IV 7.15; 0.43, V 9.76; 0.54; IV 7.85; 0.95; la fecundidad promedio fue de 381.84, 38.54huevos/hembra. El consumo registrado fue de 9.89; 1.08 (mg/ind./día para las ninfas de IV, 18.04; 0.73 (mg/ind./día para las de V y IV, mientras que el consumo promedio de los adultos, sin diferenciar sexo y estado reproductivo, fue de 16.41; 4.32mg/día. Estos parámetros, al ser comparados con los de otras especies afines, indican que D. exilis exhibe atributos biológicos que condicen con los de otros melanoplinos considerados plaga.

Biomonitoring of genotoxicity of industrial fertilizer pollutants in Aiolopus thalassinus (Orthoptera: Acrididae) using alkaline comet assay.

Science.gov (United States)

Abdelfattah, Eman A; Augustyniak, Maria; Yousef, Hesham A

2017-09-01

Phosphate fertilizer industry is considered as one of the main sources of environmental pollutants. Besides solid waste products, e.g. phosphates, sulphates, and heavy metals, also atmospheric pollutants, such as hydrofluoric acid fumes (HF), sulphur dioxide (SO 2 ), nitrogen oxides (NO 2 ), and particulate matter with diameter up to 10 μm (PM 10 ) can be dangerous. Genotoxic effect of these pollutants was monitored by assessing the DNA damage using alkaline comet assay on cells from brain, thoracic muscles and gut of Aiolopus thalassinus collected at three sites (A-C) located at 1, 3, and 6 km away from Abu-Zaabal Company for Fertilizers and Chemical Industries. Control site was established 32 km from the source of pollution, at the Cairo University Campus. The level of the DNA damage was significantly higher in insects from polluted sites comparing to that from the control site. A strong negative correlation between percentage of cells with visible DNA damage (% of severed cells) and the distance of the sites from Abu-Zaabal Company was found. The best parameter for monitoring of fertilizer pollutants is % of severed cells. Possible impact of Abu-Zaabal Company (extremely high concentration of phosphates and sulphates in all the polluted sites) on DNA integrity in A. thalassinus tissues was discussed. The potential use of the comet assay as a biomonitoring method of the environmental pollution caused by fertilizer industry was proposed. Specific pollution resulting from the activity of the fertilizer industry can cause comparable adverse effects in the organisms inhabiting areas up to 6 km from the source of contamination. Copyright © 2017 Elsevier Ltd. All rights reserved.

Epiphanic Awakenings in Raymond Carver's "Cathedral" and Alice Walker's "Everyday Use"

Science.gov (United States)

Sadeq, Ala Eddin; Al-Badawi, Mohammed

2016-01-01

This paper explores how two short stories from very different backgrounds conclude in a significant epiphany for the characters. Raymond Carver's short story "Cathedral" and Alice Walker's "Everyday Use" are studied to see how the husband in Carver's work is blinder than his visually-impaired overnight guest, and the…

Dissipative Boltzmann-Robertson-Walker cosmologies

International Nuclear Information System (INIS)

Hiscock, W.A.; Salmonson, J.

1991-01-01

The equations governing a flat Robertson-Walker cosmological model containing a dissipative Boltzmann gas are integrated numerically. The bulk viscous stress is modeled using the Eckart and Israel-Stewart theories of dissipative relativistic fluids; the resulting cosmologies are compared and contrasted. The Eckart models are shown to always differ in a significant quantitative way from the Israel-Stewart models. It thus appears inappropriate to use the pathological (nonhyperbolic) Eckart theory for cosmological applications. For large bulk viscosities, both cosmological models approach asymptotic nonequilibrium states; in the Eckart model the total pressure is negative, while in the Israel-Stewart model the total pressure is asymptotically zero. The Eckart model also expands more rapidly than the Israel-Stewart models. These results suggest that ''bulk-viscous'' inflation may be an artifact of using a pathological fluid theory such as the Eckart theory

Three new species of the genus Ripipteryx from Colombia (Orthoptera, Ripipterygidae

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Nathalie Baena-Bejarano

2015-05-01

Full Text Available Three new species of Ripipteryx Newman (Orthoptera: Tridactyloidea: Ripipterygidae are described from Colombia; namely R. diegoi sp. n. (Forceps Group and R. guacharoensis sp. n. (Marginipennis Group from Parque Nacional Natural Cueva de los Guacharos in Huila, and R. gorgonaensis sp. n. (Crassicornis Group from Parque Nacional Natural Gorgona in Cauca. Ripipteryx diegoi sp. n. is characterized by the antennae black with white spots on flagellomeres 3–7, male subgenital plate with median ridge forming a bilobed setose process, epiproct produced laterally near its base and phallic complex with virga thickened distally and not reaching beyond the membrane. Ripipteryx guacharoensis sp. n. is characterized by the antennae thick with white spots present dorsally on flagellomeres 1–4 and 8, epiproct narrow and triangular, uncus reduced and lacking a distal hook, phallic complex with a concave ventral plate and a dorsal elevation in the middle extended to the virga, and the virga itself with two small projections basally. Ripipteryx gorgonaensis sp. n. is characterized by the epiproct with a lateral notch, antennae with a white dorsal spot on flagellomere 1 and flagellomeres 4–7 entirely white. The antennal color pattern of R. gorgonaensis sp. n. strongly resembles that of R. atra but differs from the latter in the absence of any significant morphological modification of the flagellomeres.

Phylogeography and systematics of the westernmost Italian Dolichopoda species (Orthoptera, Rhaphidophoridae)

Science.gov (United States)

Allegrucci, Giuliana; Rampini, Mauro; Di Russo, Claudio; Lana, Enrico; Cocchi, Sara; Sbordoni, Valerio

2014-01-01

Abstract The genus Dolichopoda (Orthoptera; Rhaphidopohoridae) is present in Italy with 9 species distributed from northwestern Italy (Piedmont and Liguria) to the southernmost Apennines (Calabria), occurring also in the Tyrrhenian coastal areas and in Sardinia. Three morphologically very close taxa have been described in Piedmont and Liguria, i.e., D. ligustica ligustica, D. ligustica septentrionalis and D. azami azami. To investigate the delimitation of the northwestern species of Dolichopoda, we performed both morphological and molecular analyses. Morphological analysis was carried out by considering diagnostic characters generally used to distinguish different taxa, as the shape of epiphallus in males and the subgenital fig in females. Molecular analysis was performed by sequencing three mitochondrial genes, 12S rRNA, 16S rRNA, partially sequenced and the entire gene of COI. Results from both morphological and molecular analyses highlighted a very homogeneous group of populations, although genetically structured. Three haplogroups geographically distributed could be distinguished and based on these results we suggest a new taxonomic arrangement. All populations, due to the priority of description, should be assigned to D. azami azami Saulcy, 1893 and to preserve the names ligustica and septentrionalis, corresponding to different genetic haplogroups, we assign them to D. azami ligustica stat. n. Baccetti & Capra, 1959 and to D. azami septentrionalis stat. n. Baccetti & Capra, 1959. PMID:25197209

Morphology and fine organization of the spermatheca of Haplotropis brunneriana (Orthoptera: Pamphagidae

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Ke Li

2017-10-01

Full Text Available We investigated the morphology and structure of spermatheca in Haplotropis brunneriana (Orthoptera: Pamphagidae by light and electronic microscopy. The spermatheca can be subdivided into a tubular seminal receptacle and a multiple-coiled spermathecal tube, both of which are composed of cuticular intima, epithelium layer, basal lamina and muscle layer, from inside to outside. The cuticular intima is made up of a heterogeneous endocuticle, a homogeneous exocuticle and an epicuticle, but the proportion of exocuticle in intima of the seminal receptacle is larger than that of the spermathecal tube. The epithelium layer comprises epithelial cells, gland cells and duct cells. The ultrastructural features of the epithelial cells indicated that its function potentially includes support, secretion and absorption. The gland cells potentially fulfil a secretory role indicative of the abundance of mitochondria and microvilli. In gland cells, an extracellular cavity, showing region differences in the seminal receptacle and the spermathecal tube, was lined with microvillus border. The role of duct cell is responsible for forming the secretory ductules, which connect the extracellular cavity with the lumen of the spermatheca through the cuticular intima. These new data contribute to our understanding of the function of the spermatheca of H. brunneriana. Keywords: Ultrastructure, Seminal receptacle, Spermathecal tube

Morphology and fine organization of the spermatheca of Haplotropis brunneriana (Orthoptera: Pamphagidae

Directory of Open Access Journals (Sweden)

Ke Li

Full Text Available Abstract We investigated the morphology and structure of spermatheca in Haplotropis brunneriana (Orthoptera: Pamphagidae by light and electronic microscopy. The spermatheca can be subdivided into a tubular seminal receptacle and a multiple-coiled spermathecal tube, both of which are composed of cuticular intima, epithelium layer, basal lamina and muscle layer, from inside to outside. The cuticular intima is made up of a heterogeneous endocuticle, a homogeneous exocuticle and an epicuticle, but the proportion of exocuticle in intima of the seminal receptacle is larger than that of the spermathecal tube. The epithelium layer comprises epithelial cells, gland cells and duct cells. The ultrastructural features of the epithelial cells indicated that its function potentially includes support, secretion and absorption. The gland cells potentially fulfil a secretory role indicative of the abundance of mitochondria and microvilli. In gland cells, an extracellular cavity, showing region differences in the seminal receptacle and the spermathecal tube, was lined with microvillus border. The role of duct cell is responsible for forming the secretory ductules, which connect the extracellular cavity with the lumen of the spermatheca through the cuticular intima. These new data contribute to our understanding of the function of the spermatheca of H. brunneriana.

The Dirac equation and the normalization of its solutions in a closed Friedmann- Robertson-Walker universe

Science.gov (United States)

Finster, Felix; Reintjes, Moritz

2009-05-01

We set up the Dirac equation in a Friedmann-Robertson-Walker geometry and separate the spatial and time variables. In the case of a closed universe, the spatial dependence is solved explicitly, giving rise to a discrete set of solutions. We compute the probability integral and analyze a spacetime normalization integral. This analysis allows us to introduce the fermionic projector in a closed Friedmann-Robertson-Walker geometry and to specify its global normalization as well as its local form. First author supported in part by the Deutsche Forschungsgemeinschaft.

Draft Title V Operating Permit: Andeavor Field Services, LLC - Walker Hollow Compressor Station

Science.gov (United States)

Draft Operating Permit (Permit Number: V-UO-000979-2017.00), statement of basis, public notice bulletin, and the administrative permit docket (application and other supporting documents) for the Andeavor Walker Hollow Compressor Station.

Prenatal diagnosis of the Dandy-Walker syndrome by sonography and computed tomography

International Nuclear Information System (INIS)

Toelly, E.; Ebner, F.; Oberbauer, R.W.

1984-01-01

A case of Dandy-Walker-syndrome is presented, comparing the value of sonography and CT in intrauterine diagnosis. Together with a review of the literature of the subject, pathogenesis, morphology and prognosis in regard to the psychomotoric development are discussed. (orig.) [de

ARG-walker: inference of individual specific strengths of meiotic recombination hotspots by population genomics analysis.

Science.gov (United States)

Chen, Hao; Yang, Peng; Guo, Jing; Kwoh, Chee Keong; Przytycka, Teresa M; Zheng, Jie

2015-01-01

Meiotic recombination hotspots play important roles in various aspects of genomics, but the underlying mechanisms for regulating the locations and strengths of recombination hotspots are not yet fully revealed. Most existing algorithms for estimating recombination rates from sequence polymorphism data can only output average recombination rates of a population, although there is evidence for the heterogeneity in recombination rates among individuals. For genome-wide association studies (GWAS) of recombination hotspots, an efficient algorithm that estimates the individualized strengths of recombination hotspots is highly desirable. In this work, we propose a novel graph mining algorithm named ARG-walker, based on random walks on ancestral recombination graphs (ARG), to estimate individual-specific recombination hotspot strengths. Extensive simulations demonstrate that ARG-walker is able to distinguish the hot allele of a recombination hotspot from the cold allele. Integrated with output of ARG-walker, we performed GWAS on the phased haplotype data of the 22 autosome chromosomes of the HapMap Asian population samples of Chinese and Japanese (JPT+CHB). Significant cis-regulatory signals have been detected, which is corroborated by the enrichment of the well-known 13-mer motif CCNCCNTNNCCNC of PRDM9 protein. Moreover, two new DNA motifs have been identified in the flanking regions of the significantly associated SNPs (single nucleotide polymorphisms), which are likely to be new cis-regulatory elements of meiotic recombination hotspots of the human genome. Our results on both simulated and real data suggest that ARG-walker is a promising new method for estimating the individual recombination variations. In the future, it could be used to uncover the mechanisms of recombination regulation and human diseases related with recombination hotspots.

Draft Title V Operating Permit: Andeavor Field Services, LLC - Walker Hollow Compressor Station

Science.gov (United States)

Draft Title V Operating Permit, statement of basis, public notice bulletin, and the administrative permit docket (application and other supporting documents) for the Draft Part 71 Permit for Andeavor Field Services, LLC - Walker Hollow CS.

Walker-Warburg syndrome

Directory of Open Access Journals (Sweden)

Schachter Harry

2006-08-01

Full Text Available Abstract Walker-Warburg Syndrome (WWS is a rare form of autosomal recessive congenital muscular dystrophy associated with brain and eye abnormalities. WWS has a worldwide distribution. The overall incidence is unknown but a survey in North-eastern Italy has reported an incidence rate of 1.2 per 100,000 live births. It is the most severe form of congenital muscular dystrophy with most children dying before the age of three years. WWS presents at birth with generalized hypotonia, muscle weakness, developmental delay with mental retardation and occasional seizures. It is associated with type II cobblestone lissencephaly, hydrocephalus, cerebellar malformations, eye abnormalities and congenital muscular dystrophy characterized by hypoglycosylation of α-dystroglycan. Several genes have been implicated in the etiology of WWS, and others are as yet unknown. Several mutations were found in the Protein O-Mannosyltransferase 1 and 2 (POMT1 and POMT2 genes, and one mutation was found in each of the fukutin and fukutin-related protein (FKRP genes. Laboratory investigations usually show elevated creatine kinase, myopathic/dystrophic muscle pathology and altered α-dystroglycan. Antenatal diagnosis is possible in families with known mutations. Prenatal ultrasound may be helpful for diagnosis in families where the molecular defect is unknown. No specific treatment is available. Management is only supportive and preventive.

The Deep Semantics of Imagery in Alice Walker's The Color Purple ...

African Journals Online (AJOL)

Hinged on this theoretical framework, the paper assesses the deep semantics of imagery in Walker's The Color Purple and highlights the salient non-ostensive references of the text and the new world it proposes. The analysis reveals the key to a deeper and broader perception of God, the imperativeness of equality of ...

The key role of ozone depleting substances in weakening the Walker Circulation over the second half of the 20th Century

Science.gov (United States)

Bellomo, K.; Polvani, L. M.

2017-12-01

It is widely believed that the Walker Circulation will weaken in response to increasing greenhouse gases (GHG) by the end of the 21st century. But over the 20th century, the existence of a statistical significant weakening trends in the observations remains unclear. We here present new modelling evidence showing that Ozone Depleting Substances (ODS) may have significantly contributed to the weakening of the Walker Circulation over the years 1955-2005. While the primary impact of increasing ODS has been the formation of the ozone hole, it is perhaps not as widely appreciated that ODS are also powerful greenhouse gases. Using an ensemble of integrations with the the Whole Atmosphere Chemistry Climate Model, we show that the surface warming caused by increasing ODS over the second half of the 20th century causes a statistically significant weakening of the Walker Circulation in the model. In fact, we find that the increase of the other well-mixed GHG alone leads to a strengthening, not a weakening of the Walker Circulation, over that period in our model. When ODS concentrations are held fixed at 1950's levels, the effect of the other GHG is not sufficient, and a warming delay in the eastern tropical Pacific SST leads to an increase in the east-west SST gradient which is accompanied by a strengthening of the Walker Circulation. But, when the forcing from ODS is added in, the additional radiative forcing causes the eastern Pacific to warm faster, and the trend in the Walker Circulation reverses sign and becomes negative over the second half of the 20th century.

Walkers' Perspectives on Nature Management Strategies: Nature Restoration in a National Park

NARCIS (Netherlands)

Marwijk, van R.B.M.

2008-01-01

Leisure practices and public space, third chapter. Ramona van Marwijk is part of a bigger research projecton time-space behavioural patterns in a landscape where nature development and recreational values are combined. She is interested in what walkers in the Dutch National Park Dwingelderveld think

Dandy–Walker malformation is a rare cause of syringomyelia in adults

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G. Yu. Evzikov

2017-01-01

Full Text Available Neural tube defects are the most common central nervous system malformation. Dandy–Walker malformation (DWM is a rare abnormality of the posterior cranial fossa, which is generally diagnosed in the prenatal period or early infancy.The paper describes a case of the late clinical manifestation of DWM, which has caused syringomyelia. All variants of pathological changes within the Dandy–Walker complex very rarely become a cause of syringomyelia. Only four cases of DWM, in which syringomyelia was found in adults, are known.The authors believe that formation of syringomyelia cysts in these patients is associated with the impaired circulation of normal cerebrospinal fluid between the superior cistern and the subarachnoid spaces of the spinal cord due to the caudal dislocation of the cyst formed in the fourth ventricle.Decompression of the craniovertebral junction, by resecting the caudal portion of the cyst in the foramen magnum, and repair of the free communication between the superior cistern and the cerebrospinal fluid spaces of the spinal cord, which is complemented by duroplasty, are pointed out to be an optimal treatment in these patients.

Accommodation of missing shear strain in the Central Walker Lane, western North America: Constraints from dense GPS measurements

Science.gov (United States)

Bormann, Jayne M.; Hammond, William C.; Kreemer, Corné; Blewitt, Geoffrey

2016-04-01

We present 264 new interseismic GPS velocities from the Mobile Array of GPS for Nevada Transtension (MAGNET) and continuous GPS networks that measure Pacific-North American plate boundary deformation in the Central Walker Lane. Relative to a North America-fixed reference frame, northwestward velocities increase smoothly from ∼4 mm/yr in the Basin and Range province to 12.2 mm/yr in the central Sierra Nevada resulting in a Central Walker Lane deformation budget of ∼8 mm/yr. We use an elastic block model to estimate fault slip and block rotation rates and patterns of deformation from the GPS velocities. Right-lateral shear is distributed throughout the Central Walker Lane with strike-slip rates generally Bodie Hills, Carson Domain, and Mina Deflection are between 1-4°/Myr, lower than published paleomagnetic rotation rates, suggesting that block rotation rates have decreased since the Late to Middle Miocene.

Risks of vaginal breech delivery at term compared with elective cesarean section - reply to comments by Walker and Powell, and Sholapurkar

NARCIS (Netherlands)

Vlemmix, Floortje; Mol, Ben Willem; Kok, Marjolein

2015-01-01

We thank both Walker and Powell (1), as well as Sholapurkar (2) for their interest in our work. Walker and Powell note that the risk of neonatal mortality for planned vaginal breech delivery (VBD) in our study is lower than the mortality reported in the term breech trial and comparable to the risk

Trans-sphenoidal encephalocele in association with Dandy-Walker complex and cardiovascular anomalies

Energy Technology Data Exchange (ETDEWEB)

Joy, H.M.; Barker, C.S. [Wessex Neurological Centre, Southampton (United Kingdom); Small, J.H. [Dept. of Radiology, Royal Bournemouth Hospital (United Kingdom); Armitage, M. [Bournemouth Diabetes and Endocrine Centre, Royal Bournemouth Hospital (United Kingdom)

2001-01-01

We present a case of trans-sphenoidal encephalomeningocele in association with a posterior cranial fossa malformation which fulfils the criteria for the Dandy-Walker complex. Congenital cardiovascular defects were also present. An abnormality of neural crest development may be responsible for the combined occurrence of these anomalies. (orig.)

Do Canes or Walkers Make Any Difference? NonUse and Fall Injuries.

Science.gov (United States)

Luz, Clare; Bush, Tamara; Shen, Xiaoxi

2017-04-01

Examine patterns of cane and walker use as related to falls and fall injuries. Among people who fall at home, most do not have an assistive device with them when they fall. Nonusers who fall sustain more severe injuries. This was a cross-sectional study using a self-administered written survey completed by 262 people aged 60 and older who were community dwelling, cognitively intact, and current cane/walker users with a history of falls. They were recruited through clinical practice sites, churches, and senior housing in central Michigan. Outcomes of interest included patterns of device use, reasons for nonuse, device use at time of fall, and fall-related injuries. Seventy-five percent of respondents who fell were not using their device at the time of fall despite stating that canes help prevent falls. Reasons for nonuse included believing it was not needed, forgetfulness, the device made them feel old, and inaccessibility. Perceived risk was not high enough to engage in self-protective behavior. However, nonuse led to a significantly higher proportion of falls resulting in surgery than among device users. Among respondents requiring surgery, 100% were nonusers. Most respondents never received a home safety evaluation (68%) and only 50% received training on proper device use. Providers must place increased emphasis on the importance of cane/walker use for injury prevention through patient education to promote personal relevance, proper fitting, and training. New strategies are needed to improve device acceptability and accessibility. © The Author 2015. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Tachyons in Robertson-Walker Cosmology

CERN Document Server

Tomaschitz, R

1998-01-01

Superluminal signal transfer is studied in the context of a preferred cosmic frame of reference provided by the galactic background. The receding galaxies constitute a frame of absolute rest, in which the energy of tachyons (faster-than-light particles) is unambiguously defined as a positive quantity. The causality violation which arises in relativistic tachyonic theories is avoided. We define interactions of particles and tachyons in terms of elastic head-on collisions and energy-momentum conservation. To compare the theory developed with existing relativistic theories, tachyons are studied at first in a Minkowski universe, and the causality of a superluminal communication process is analyzed. Then we discuss the dynamics of tachyons in a Robertson-Walker universe with linear expansion factor and negatively curved three-space. We point out the consequences that the space expansion has on tachyons, like a finite life-time in the frame of absolute rest, and multiple images in the rest frames of moving observer...

A 'water walkers' exercise program for the elderly.

Science.gov (United States)

Heyneman, C A; Premo, D E

1992-01-01

Recent studies have shown that older people, stereotyped as weak, frail, and inactive, demonstrate an equal capacity to reap the physical and psychological benefits of recreational exercise. A low cost aquatic exercise program is proposed that is geared towards those persons who, because of their physical limitations, are unable to participate in the more traditional walking or low-impact aerobics programs currently available for seniors. A water-based program would allow these people to gain all the advantages of land-based exercise with out stress or strain on arthritic joints. In addition, the use of water walkers (a buoyancy device which attaches easily around the waist) would allow total freedom of movement without fear of deep water. Those with various levels of disability could, therefore, participate at their own pace. Two programs, including transportation, would be provided twice a week for 8 weeks each. An individual 45-minute session would consist of a warm-up period with gentle stretching, a cardiovascular segment, a cool-down period, strength-training, and a final stretching time. All exercises would be conducted with participants wearing the water walkers, allowing total immersion to the shoulder. Free to move about the pool, they would be encouraged to interact socially with one another. The results of the program would be determined by measuring range of motion, cardiovascular endurance, and strength before and after each 8-week session. Participants' level of self confidence and life satisfaction will be estimated and any psychological improvement will be documented.

Contribution of radiosensitivity study for Walker 256 tumor in rats. Association of early immunization with action of ionized radiation

International Nuclear Information System (INIS)

Sakate, A.T.Y.

1979-01-01

The suspension of tumoral cells from Walker 256 were irradiated with doses of 2.500, 4.500, 5.000, 5.500 and 7.500 rad for determining the attenuation dose. The suspension of inactives tumoral cells were injected in rats for verifying the immunized effects in relation of active Walker tumor. After be certified the growth of tumor, the rats were irradiated with cobalt 60 and was verified the decrease of tumor. (author)

On the minimal vacuum definition for spin 1 massive fields in Robertson-Walker universes

International Nuclear Information System (INIS)

Castagnino, M.; Laciana, C.; Chimento, L.

1986-01-01

A definition of quantum vacuum is introduced for spin 1, massive, neutral fields, in spatially flat Robertson-Walker universes. For this definition all relevant observables turn out to be devoid of ultraviolet divergencies. (author)

Experimental model of ultrasound thermotherapy in rats inoculated with Walker-236 tumor Modelo experimental de termoterapia ultrassônica em ratos inoculados com tumor de Walker-236

Directory of Open Access Journals (Sweden)

José Antonio Carlos Otaviano David Morano

2011-01-01

Full Text Available PURPOSE: To develop a model to evaluate the effects of focal pulsed ultrasound (US waves as a source of heat for treatment of murine subcutaneous implanted Walker tumor. METHODS: An experimental, controlled, comparative study was conducted. Twenty male Wistar rats (160-300 g randomized in 2 equal groups (G-1: Control and G-2: Hyperthermia were inoculated with Walker-256 carcinosarcoma tumor. After 5 days G-2 rats were submitted to 45ºC hyperthermia. Heat was delivered directly to the tumor by an ultrasound (US equipment (3 MHz frequency, 1,5W/cm³. Tumor temperature reached 45º C in 3 minutes and was maintained at this level for 5 minutes. Tumor volume was measured on days 5, 8, 11, 14 e 17 post inoculation in both groups. Unpaired t-test was used for comparison. POBJETIVO: Desenvolver um modelo para avaliar os efeitos do ultra-som focal pulsado como fonte de calor para o tratamento de tumores de Walker subcutâneos implantados em ratos. MÉTODOS: Um estudo experimental, controlado, comparativo foi realizado. Vinte ratos Wistar machos (160-300 g divididos em dois grupos (G-1: Controle e G-2: hipertermia foram inoculados com tumor de Walker carcinossarcoma-256. Após cinco dias os ratos do grupo G-2 ratos foram submetidos a hipertermia (45ºC. O calor foi aplicado diretamente no tumor por um equipamento de ultrassonografia (3 MHz, 1,5 W/cm³. A temperatura no tumor atingiu 45ºC em 3 minutos e foi mantida nesse nível por 5 minutos. O volume do tumor foi medido nos dias 5, 8, 11, 14 e 17 após a inoculação, em ambos os grupos. Teste t não pareado foi utilizado para comparação. P <0,05 foi considerado significante. RESULTADOS: O volume do tumor foi significativamente maior no 5º dia e diminuiu nos dias 11, 14 e 17 nos ratos tratados. Animais submetidos à hipertermia sobreviveram mais tempo que os animais do grupo controle. No 29º dia após a inoculação do tumor, 40% dos ratos do grupo controle e 77,78% dos ratos tratados com

How do walkers behave when crossing the way of a mobile robot that replicates human interaction rules?

Science.gov (United States)

Vassallo, Christian; Olivier, Anne-Hélène; Souères, Philippe; Crétual, Armel; Stasse, Olivier; Pettré, Julien

2018-02-01

Previous studies showed the existence of implicit interaction rules shared by human walkers when crossing each other. Especially, each walker contributes to the collision avoidance task and the crossing order, as set at the beginning, is preserved along the interaction. This order determines the adaptation strategy: the first arrived increases his/her advance by slightly accelerating and changing his/her heading, whereas the second one slows down and moves in the opposite direction. In this study, we analyzed the behavior of human walkers crossing the trajectory of a mobile robot that was programmed to reproduce this human avoidance strategy. In contrast with a previous study, which showed that humans mostly prefer to give the way to a non-reactive robot, we observed similar behaviors between human-human avoidance and human-robot avoidance when the robot replicates the human interaction rules. We discuss this result in relation with the importance of controlling robots in a human-like way in order to ease their cohabitation with humans. Copyright © 2017 Elsevier B.V. All rights reserved.

Bubble merging in breathing DNA as a vicious walker problem in opposite potentials

DEFF Research Database (Denmark)

Pedersen, Jonas Nyvold; Hansen, Mikael Sonne; Novotny, Tomas

2009-01-01

on the problem of two vicious walkers in opposite potentials. We also present a discrete master equation approach to the bubble coalescence problem. Numerical evaluation and stochastic simulation of the master equation show excellent agreement with the results from the continuum approach. Given...

Fuzzy Random Walkers with Second Order Bounds: An Asymmetric Analysis

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Georgios Drakopoulos

2017-03-01

Full Text Available Edge-fuzzy graphs constitute an essential modeling paradigm across a broad spectrum of domains ranging from artificial intelligence to computational neuroscience and social network analysis. Under this model, fundamental graph properties such as edge length and graph diameter become stochastic and as such they are consequently expressed in probabilistic terms. Thus, algorithms for fuzzy graph analysis must rely on non-deterministic design principles. One such principle is Random Walker, which is based on a virtual entity and selects either edges or, like in this case, vertices of a fuzzy graph to visit. This allows the estimation of global graph properties through a long sequence of local decisions, making it a viable strategy candidate for graph processing software relying on native graph databases such as Neo4j. As a concrete example, Chebyshev Walktrap, a heuristic fuzzy community discovery algorithm relying on second order statistics and on the teleportation of the Random Walker, is proposed and its performance, expressed in terms of community coherence and number of vertex visits, is compared to the previously proposed algorithms of Markov Walktrap, Fuzzy Walktrap, and Fuzzy Newman–Girvan. In order to facilitate this comparison, a metric based on the asymmetric metrics of Tversky index and Kullback–Leibler divergence is used.

Ground reaction forces of Olympic and World Championship race walkers.

Science.gov (United States)

Hanley, Brian; Bissas, Athanassios

2016-01-01

Race walking is an Olympic event where no visible loss of contact should occur and the knee must be straightened until midstance. The purpose of this study was to analyse ground reaction forces of world-class race walkers and associate them with key spatiotemporal variables. Nineteen athletes race walked along an indoor track and made contact with two force plates (1000 Hz) while being filmed using high-speed videography (100 Hz). Race walking speed was correlated with flight time (r = .46, p = .049) and flight distance (r = .69, p = .001). The knee's movement from hyperextension to flexion during late stance meant the vertical push-off force that followed midstance was smaller than the earlier loading peak (p push-off forces (r = .60, p = .011). Lower fluctuations in speed during stance were associated with higher stride frequencies (r = .69, p = .001), and highlighted the importance of avoiding too much braking in early stance. The flattened trajectory and consequential decrease in vertical propulsion might help the race walker avoid visible loss of contact (although non-visible flight times were useful in increasing stride length), while a narrow stride width was important in reducing peak forces in all three directions and could improve movement efficiency.

A class of almost equilibrium states in Robertson-Walker spacetimes

Energy Technology Data Exchange (ETDEWEB)

Kueskue, Muharrem

2008-11-06

In quantum field theory in curved spacetimes the construction of the algebra of observables of linear fields is today well understood. However, it remains a non-trivial task to construct physically meaningful states on the algebra. For instance, we are in the unsatisfactory situation that there exist no examples of states suited to describe local thermal equilibrium in a non-stationary spacetime. In this thesis, we construct a class of states for the Klein-Gordon field in Robertson-Walker spacetimes, which seem to provide the first example of thermal states in a spacetime without time translation symmetry. More precisely, in the setting of real, linear, scalar fields in Robertson-Walker spacetimes we define on the set of homogeneous, isotropic, quasi-free states a free energy functional that is based on the averaged energy density measured by an isotropic observer along his worldline. This functional is well defined and lower bounded by a suitable quantum energy inequality. Subsequently, we minimize this functional and obtain states that we interpret as 'almost equilibrium states'. It turns out that the states of low energy are the ground states of the almost equilibrium states. Finally, we prove that the almost equilibrium states satisfy the Hadamard condition, which qualifies them as physically meaningful states. (orig.)

Third annual Walker Branch watershed research symposium: Programs and abstracts

International Nuclear Information System (INIS)

1992-03-01

The methods and concepts of watershed research, originally applied in an experimental or monitoring mode to relatively small catchments, are increasingly being used at larger scales and for specific applied problems. Research at Oak Ridge National Laboratory, the Tennessee Valley Authority, the US Forest Service, and other agencies and institutions participating in this symposium reflects research over a broad range of spatial scales. These research projects address the basic atmospheric, geophysical, biogeochemical, and biological processes that regulate the responses of forested ecosystems to natural environmental variation and anthropogenic stresses. Regional and global issues addressed by presentations include emissions of carbon dioxide, methane, and other hydrocarbons; deposition of sulfate, nitrate, and mercury; land-use changes; biological diversity; droughts; and water quality. The Department of Energy's local research site, Walker Branch Watershed, is a long-term ecosystem research project initiated on the Oak Ridge Reservation in 1967. Walker Branch provides a well-characterized site where many of these methods can be tested and applied.In addition, other large-scale experiments represented in this symposium include experiments on the effects of clearcutting and burning on forest structure and productivity associated with Coweeta Hydrologic Laboratory, and whole-tree ozone exposure chambers constructed by TVA and ORNL researchers

A class of almost equilibrium states in Robertson-Walker spacetimes

International Nuclear Information System (INIS)

Kueskue, Muharrem

2008-01-01

In quantum field theory in curved spacetimes the construction of the algebra of observables of linear fields is today well understood. However, it remains a non-trivial task to construct physically meaningful states on the algebra. For instance, we are in the unsatisfactory situation that there exist no examples of states suited to describe local thermal equilibrium in a non-stationary spacetime. In this thesis, we construct a class of states for the Klein-Gordon field in Robertson-Walker spacetimes, which seem to provide the first example of thermal states in a spacetime without time translation symmetry. More precisely, in the setting of real, linear, scalar fields in Robertson-Walker spacetimes we define on the set of homogeneous, isotropic, quasi-free states a free energy functional that is based on the averaged energy density measured by an isotropic observer along his worldline. This functional is well defined and lower bounded by a suitable quantum energy inequality. Subsequently, we minimize this functional and obtain states that we interpret as 'almost equilibrium states'. It turns out that the states of low energy are the ground states of the almost equilibrium states. Finally, we prove that the almost equilibrium states satisfy the Hadamard condition, which qualifies them as physically meaningful states. (orig.)

Effect of two dosages of Metarhizium anisopliae var. acridum against Rhammatocerus schistocercoides Rehn

Directory of Open Access Journals (Sweden)

Faria Marcos Rodrigues de

2002-01-01

Full Text Available The fungus Metarhizium anisopliae var. acridum, strain CG 423, was tested under field conditions against the gregarious grasshopper Rhammatocerus schistocercoides (Rehn (Orthoptera: Acrididae. Conidia formulated in a racemic mixture of soybean oil and kerosene were sprayed under field conditions using an ultralow-volume hand-held atomizer Ulva Plus adjusted to deliver 2.9 L/ha. Bands composed of 2nd instar nymphs were treated with either 5.0x10(12 or 1.0x10(13 viable conidia/ha. The number of insects in each band was estimated at day one following spraying and by the end of the field trial (15 to 16 days post-treatment. Reductions in population size reached, in average, 65.8% and 80.4% for bands treated with the higher and lower dosage, respectively. For both dosages, total mortality rates of insects collected at two days post-application, and kept in cages for 14 days under lab conditions, showed no significant differences as compared to that obtained with insects collected immediately after spraying. Healthy insects were fed to native grasses sprayed on the field with 1.0x10(13 viable conidia/ha. Mortality levels of the nymphs fed on grasses collected two and four days post-application were not affected when compared to nymphs fed on grasses collected immediately following application.

Collateral Damage: Veterans and Domestic Violence in Mari Sandoz's "The Tom-Walker"

Science.gov (United States)

Bahr, Kathy

2010-01-01

"The Tom-Walker" combines the best of Sandoz's realism with her worst attempts at moralizing. Unable to divine exactly what political configuration right-wing post-World War II sentiments might take, Sandoz nevertheless feared a fascist uprising in this country. Perhaps because these concerns dominated her thoughts at the time, she allowed her…

On Maximal Surfaces in Certain Non-Flat 3-Dimensional Robertson-Walker Spacetimes

Energy Technology Data Exchange (ETDEWEB)

Romero, Alfonso, E-mail: aromero@ugr.es [Universidad de Granada, Departamento de Geometria y Topologia (Spain); Rubio, Rafael M., E-mail: rmrubio@uco.es [Universidad de Cordoba, Departamento de Matematicas, Campus de Rabanales (Spain)

2012-09-15

An upper bound for the integral, on a geodesic disc, of the squared length of the gradient of a distinguished function on any maximal surface in certain non-flat 3-dimensional Robertson-Walker spacetimes is obtained. As an application, a new proof of a known Calabi-Bernstein's theorem is given.

Participation of the NO/cGMP/K+ATP pathway in the antinociception induced by Walker tumor bearing in rats

International Nuclear Information System (INIS)

Barbosa, A.L.R.; Pinheiro, C.A.; Oliveira, G.J.; Torres, J.N.L.; Moraes, M.O.; Ribeiro, R.A.; Vale, M.L.; Souza, M.H.L.P.

2012-01-01

Implantation of Walker 256 tumor decreases acute systemic inflammation in rats. Inflammatory hyperalgesia is one of the most important events of acute inflammation. The L-arginine/NO/cGMP/K + ATP pathway has been proposed as the mechanism of peripheral antinociception mediated by several drugs and physical exercise. The objective of this study was to investigate a possible involvement of the NO/cGMP/K + ATP pathway in antinociception induced in Walker 256 tumor-bearing male Wistar rats (180-220 g). The groups consisted of 5-6 animals. Mechanical inflammatory hypernociception was evaluated using an electronic version of the von Frey test. Walker tumor (4th and 7th day post-implantation) reduced prostaglandin E 2 - (PGE 2 , 400 ng/paw; 50 µL; intraplantar injection) and carrageenan-induced hypernociception (500 µg/paw; 100 µL; intraplantar injection). Walker tumor-induced analgesia was reversed (99.3% for carrageenan and 77.2% for PGE 2 ) by a selective inhibitor of nitric oxide synthase (L-NAME; 90 mg/kg, ip) and L-arginine (200 mg/kg, ip), which prevented (80% for carrageenan and 65% for PGE 2 ) the effect of L-NAME. Treatment with the soluble guanylyl cyclase inhibitor ODQ (100% for carrageenan and 95% for PGE 2 ; 8 µg/paw) and the ATP-sensitive K + channel (KATP) blocker glibenclamide (87.5% for carrageenan and 100% for PGE 2 ; 160 µg/paw) reversed the antinociceptive effect of tumor bearing in a statistically significant manner (P < 0.05). The present study confirmed an intrinsic peripheral antinociceptive effect of Walker tumor bearing in rats. This antinociceptive effect seemed to be mediated by activation of the NO/cGMP pathway followed by the opening of KATP channels

A new species of Blatticola Schwenk, 1926 (Oxyurida, Thelastomatidae a parasite of Anurogryllus muticus (De Geer, 1773 (Orthoptera, Gryllidae from Argentina

Directory of Open Access Journals (Sweden)

María Fernanda Achinelly

2007-01-01

Full Text Available Blatticola cristovata n. sp. (Oxyurida, Thelastomatidae a parasite of the cricket Anurogryllus muticus (De Geer, 1773 (Orthoptera, Gryllidae from Argentina, is described and illustrated. This is the first species of the genus Blatticola found parasitizing cricket. This new species is characterized in females by having the cuticle annulated through the body length, the mouth opening is subtriangular and surrounded by eight cephalic papillae, the stoma is short with three pairs placed in two rows of cuticular sclerotised plates, amphids in small pore shaped, oesophagus is divided into three parts, anterior cylindrical corpus, isthmus distinct, and basal bulb valved, the nerve ring is situated around the middle of corpus, the intestine is wide broad anteriorly, oval eggs, smooth shell, with a straight side, and the other side with a band running longitudinally. Males with one pair of preanal, one pair of adanal and two pairs of postanal papillae, and the tail appendage short, conical and pointed.Una nueva especie Blatticola cristovata n. sp. (Oxyurida, Thelastomatidae parásita del grillo Anurogryllus muticus (De Geer, 1773 (Orthoptera, Gryllidae en Argentina, se describe e ilustra. Esta es la primera especie del género Blatticola que se encontró parasitando a grillos. Esta nueva especie se caracteriza por tener las hembras la cutícula anillada a lo largo de todo el cuerpo, la abertura bucal triangular rodeada por ocho papilas cefálicas, el estoma corto con tres pares de placas esclerotizadas dispuestas en dos líneas, anfidios pequeños en forma de poro, esofago dividido en tres partes, una anterior con un corpus cilíndrico, un istmo distintivo, y un bulbo basal con valvas, el anillo nervioso situado rodeando el corpus, el intestino ensanchado anteriormente, huevos ovales, de cáscara lisa, con un lado recto y el otro con una cresta longitudinal. Macho con un par de papilas preanal, uno adanal y dos pares de papilas postanales, y ap

METALLOPROTEINS DURING DEVELOPMENT OF WALKER-256 CARCINOSARCOMA RESISTANT PHENOTYPE.

Science.gov (United States)

Chekhun, V F; Lozovska, Yu V; Burlaka, A P; Ganusevich, I I; Shvets, Yu V; Lukianova, N Yu; Todor, I M; Demash, D V; Pavlova, A A; Naleskina, L A

2015-01-01

The study was focused on the detection of changes in serum and tumor metal-containing proteins in animals during development ofdoxorubicin-resistant phenotype in malignant cells after 12 courses of chemotherapy. We found that on every stage of resistance development there was a significant increase in content of ferritin and transferrin proteins (which take part in iron traffick and storage) in Walker-256 carc'inosarcoma tissue. We observed decreased serumferritin levels at the beginning stage of the resistance development and significant elevation of this protein levels in the cases withfully developed resistance phenotype. Transferrin content showed changes opposite to that offerritin. During the development of resistance phenotype the tumor tissue also exhibited increased 'free iron' concentration that putatively correlate with elevation of ROS generation and levels of MMP-2 and MMP-9 active forms. The tumor non-protein thiol content increases gradually as well. The serum of animals with early stages of resistance phenotype development showed high ceruloplasmin activity and its significant reduction after loss of tumor sensitivity to doxorubicin. Therefore, the development of resistance phenotype in Walker-256 carcinosarcoma is accompanied by both the deregulation of metal-containing proteins in serum and tumor tissue and by the changes in activity of antioxidant defense system. Thus, the results of this study allow us to determine the spectrum of metal-containing proteins that are involved in the development of resistant tumor phenotype and that may be targeted for methods for doxorubicin sensitivity correction therapy.

FreeWalker: a smart insole for longitudinal gait analysis.

Science.gov (United States)

Wang, Baitong; Rajput, Kuldeep Singh; Tam, Wing-Kin; Tung, Anthony K H; Yang, Zhi

2015-08-01

Gait analysis is an important diagnostic measure to investigate the pattern of walking. Traditional gait analysis is generally carried out in a gait lab, with equipped force and body tracking sensors, which needs a trained medical professional to interpret the results. This procedure is tedious, expensive, and unreliable and makes it difficult to track the progress across multiple visits. In this paper, we present a smart insole called FreeWalker, which provides quantitative gait analysis outside the confinement of traditional lab, at low- cost. The insole consists of eight pressure sensors and two motion tracking sensors, i.e. 3-axis accelerometer and 3-axis gyroscope. This enables measurement of under-foot pressure distribution and motion sequences in real-time. The insole is enabled with onboard SD card as well as wireless data transmission, which help in continuous gait-cycle analysis. The data is then sent to a gateway, for analysis and interpretation of data, using a user interface where gait features are graphically displayed. We also present validation result of a subject's left foot, who was asked to perform a specific task. Experiment results show that we could achieve a data-sampling rate of over 1 KHz, transmitting data up to a distance of 20 meter and maintain a battery life of around 24 hours. Taking advantage of these features, FreeWalker can be used in various applications, like medical diagnosis, rehabilitation, sports and entertainment.

Phenology of Cornops aquaticum (Bruner) (Orthoptera: Acrididae) in Eichhornia azurea (Pontederiaceae) in the northern region of pantanal of Mato Grosso, Brazil; Fenologia de Cornops aquaticum (Bruner) (Orthoptera: Acrididae) em Eichhornia azurea (Pontederiaceae) no norte do pantanal de Mato Grosso

Energy Technology Data Exchange (ETDEWEB)

Silva, Fatima R.J da; Marques, Marinez I., E-mail: fateca@gmail.com.b, E-mail: marinez@ufmt.b [Universidade Federal de Mato Grosso (UFMT), Cuiaba, MT (Brazil). Programa de Pos-graduacao em Ecologia e Conservacao da Biodiversidade; Battirola, Leandro D., E-mail: ldbattirola@uol.com.b [Universidade Federal de Mato Grosso (UFMT), Sinop, MT (Brazil). Inst. de Ciencias Naturais, Humanas e Sociais; Lhano, Marcos G., E-mail: marcos@ufrb.edu.b [Universidade Federal do Reconcavo da Bahia, Cruz das Almas, BA (Brazil). Centro de Ciencias Agrarias, Ambientais e Biologicas

2010-07-15

Cornops aquaticum (Bruner) has Eichhornia crassipes, E. azurea, Pontederia cordata and P. lanceolata (Pontederiaceae) as the known host plants. This grasshopper species is cited as a possible agent of biological control for native aquatic macrophytes E. azurea and E. crassipes. This study, carried out from March, 2006 to February, 2007, aimed to evaluate the phenology and age structure of the population of C. aquaticum associated with E. azurea in Piuval bay, Pantanal of Pocone, MT, and to identify possible relationships of its life cycle to abiotic factors such as insolation, temperature and precipitation. Monthly collections of 50 individuals were carried out according to the protocol defined by the - Host - Insect Coevolution on Waterhyacinth - project. Adults and nymphs were separated and the females dissected in order to evaluate ovary maturation. The population presented adults and nymphs during the whole year, suggesting the occurrence of more than one reproductive period. The nymphs from the fi rst stage predominated in August 2006 and the adults in September and October 2006, synchronized with the dry period and beginning of the flooding period, respectively. The highest relative abundance of the females with mature ovaries occurred in July 2006 (50%), indicating that this may be a more propitious period for reproduction. The data suggest that C. aquaticum is a species in continual reproduction in Piuval bay and its cycle is associated with the environmental conditions guided by the flood pulse in the Pantanal of Mato Grosso. (author)

Optimal handgrip height of four-wheeled walker on various road conditions to reduce muscular load for elderly users with steady walking.

Science.gov (United States)

Takanokura, Masato

2010-03-22

A four-wheeled walker is a valuable tool for assisting elderly persons with walking. The handgrip height is one of the most important factor determining the usefulness of the walker. However, the optimal handgrip height for elderly users has not been considered from a biomechanical viewpoint. In this study, the handgrip height was optimized by a two-dimensional mechanical model to reduce muscular loads in the lower body as well as in the upper body with various road conditions during steady walking. A critical height of the handgrip existed at 48% of the body height for the user regardless of gender and body dimension. A lower handgrip relieved muscular load for stooping users with a lower standing height. The stooping user pushed the handgrip strongly in the perpendicular direction by leaning the upper body on the walker. However, upright users with a higher standing height should use a four-wheeled walker with a higher handgrip for maintaining his or her upright posture. For downhill movement, the optimal handgrip height depended on the slope angle and the friction coefficient between the road and the wheels of the walker. On a low-friction downhill such as asphalt with a steeper slope angle, the user was required to maintain an erect trunk with a higher handgrip and to press on the handgrip strongly in the perpendicular direction. Movement on a low-friction road was easier for users on a flat road and an uphill road, but it compelled distinct effort from users when moving downhill. Copyright (c) 2009 Elsevier Ltd. All rights reserved.

Decoherence induced by a chaotic enviroment: A quantum walker with a complex coin

International Nuclear Information System (INIS)

Ermann, Leonardo; Paz, Juan Pablo; Saraceno, Marcos

2006-01-01

We study the differences between the processes of decoherence induced by chaotic and regular environments. For this we analyze a family of simple models that contain both regular and chaotic environments. In all cases the system of interest is a ''quantum walker,'' i.e., a quantum particle that can move on a lattice with a finite number of sites. The walker interacts with an environment which has a D-dimensional Hilbert space. The results we obtain suggest that regular and chaotic environments are not distinguishable from each other in a (short) time scale t*, which scales with the dimensionality of the environment as t*∝log 2 (D). However, chaotic environments continue to be effective over exponentially longer time scales while regular environments tend to reach saturation much sooner. We present both numerical and analytical results supporting this conclusion. The family of chaotic evolutions we consider includes the so-called quantum multibaker map as a particular case

The captain class : the hidden force that creates the world's greatest teams / Sam Walker

Trove (Australia)

Walker, Sam

2017-01-01

... it is. It's not the coach. It's not the star. It's not chemistry. It's not a strategy. It's something else entirely. Several years ago, Sam Walker set out to answer one of the most hotly debated questions in sports ...

Difficulties with Prenatal Diagnosis of the Walker-Warburg Syndrome

International Nuclear Information System (INIS)

Low, A.S.C.; Lee, S.L.; Tan, A.S.A.; Chan, D.K.L.; Chan, L.L.

2005-01-01

We describe a postnatally diagnosed case of Walker-Warburg syndrome - a form of congenital muscular dystrophy with lissencephaly and eye abnormalities. We reviewed the literature to highlight its clinico-radiological diagnostic features and discuss the difficulties encountered with prenatal diagnosis, especially in cases with no positive family history. An increased awareness of this rare but lethal condition, and a high index of suspicion during routine antenatal ultrasound, could prompt further advanced fetal ultrasonography and magnetic resonance imaging, and aid in timely prenatal diagnosis, management, and counseling. Brain/brainstem, congenital, magnetic resonance imaging, obstetrics, pediatrics, ultrasound

Difficulties with Prenatal Diagnosis of the Walker-Warburg Syndrome

Energy Technology Data Exchange (ETDEWEB)

Low, A.S.C.; Lee, S.L.; Tan, A.S.A.; Chan, D.K.L.; Chan, L.L. [Singapore General Hospital (Singapore). Depts. of Diagnostic Radiology, Obstetrics and Gynecology and Neonatology

2005-10-01

We describe a postnatally diagnosed case of Walker-Warburg syndrome - a form of congenital muscular dystrophy with lissencephaly and eye abnormalities. We reviewed the literature to highlight its clinico-radiological diagnostic features and discuss the difficulties encountered with prenatal diagnosis, especially in cases with no positive family history. An increased awareness of this rare but lethal condition, and a high index of suspicion during routine antenatal ultrasound, could prompt further advanced fetal ultrasonography and magnetic resonance imaging, and aid in timely prenatal diagnosis, management, and counseling. Brain/brainstem, congenital, magnetic resonance imaging, obstetrics, pediatrics, ultrasound.

Dandy-Walker syndrome in adult mimicking myasthenia gravis Síndrome de Dandy-Walker em adulto simulando miastenia gravis

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Juliana Cardoso

2007-03-01

Full Text Available The Dandy-Walker syndrome (DWS is a rare posterior fossa malformation. The DWS can occur associated with other brain or systemic malformations, but ocular abnormalities in this disease are rare and clinical findings mimicking myasthenia gravis have not been described to date. We report a 23-year-old woman who presented mild limitation of the ocular movements with progressive palpebral ptosis, which changed in intensity during the day. The investigation showed negative anti-acetylcholine receptor antibody, repetitive nerve stimulation and "Tensilon test", but the brain magnetic resonance image reveals DWS with hydrocephalus associated with calosal dysgenesis. The characteristic of disease, clinical manifestations and pathologic features, specially the clinical evaluation of ocular abnormalities in suspicion of DWS, including the MG in differential diagnosis are discussed.A síndrome de Dandy-Walker (DWS é uma rara malformação da fossa posterior que pode ocorrer associada com outras malformações cerebrais ou sistêmicas. As alterações oculares são raras e as manifestações clínicas, simulando miastenia gravis (MG, não foram descritas até o momento. Descrevemos uma mulher de 23 anos apresentando discreta limitação da movimentação ocular com progressiva ptose palpebral que mudava de intensidade durante o dia. A investigação mostrou negativos o anticorpo anti-receptor de acetilcolina, a estimulação nervosa repetitiva e o "teste do Tensilon", porém a ressonância magnética de crânio revelou DWS com hidrocefalia associada à disgenesia de corpo caloso. As características da doença, manifestações clínicas e patológicas, especialmente a avaliação clínica de anormalidade ocular na suspeita de DWS serão discutidas, incluindo a MG no diagnóstico diferencial.

Estágios imaturos de Spodoptera cosmioides (Walker (Lepidoptera, Noctuidae Immature stages of Spodoptera cosmioides (Walker (Lepidoptera, Noctuidae

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Maurício M. Zenker

2007-03-01

Full Text Available O gênero Spodoptera Guenée, 1852 é composto por trinta espécies de distribuição cosmopolita, encontradas com maior freqüência em locais de clima mais quente. Quinze espécies são pragas agrícolas, apresentando alto grau de polifitofagia, alimentando-se de importantes culturas como soja, milho, arroz e batata inglesa. A morfologia dos estágios imaturos dos representantes deste gênero é pouco conhecida, sendo que um terço das espécies não possui descrição de seus estágios imaturos. Entre as espécies ocorrentes no Brasil, sem tais informações, destaca-se Spodoptera cosmioides (Walker, 1858. Este trabalho caracterizou detalhadamente seus principais aspectos morfológicos, passíveis de serem utilizados na identificação taxonômica dos estágios imaturos; contém dados referentes à morfologia, destacando-se a área micropilar dos ovos, quetotaxia, fiandeira e coloração da fase de lagarta e disposição dos apêndices e aberturas naturais nas pupas.There are 30 species in the genus Spodoptera Guenée, 1852 worldwide distributed, occurring mainly in the warm regions. Fifteen species are considered plagues feeding on several important agricultural crops as soybean, corn, rice and potato. The immature stages morphology of this genus is not well known. In about one third of the most economically relevant species, the caterpillar is not described and, also, few information related to the chrysalis and the eggs are available. Spodoptera cosmioides (Walker, 1858 is one of the most important pest among the noctuids occurring in Brazil with no information about its immature stages. Detailed morphological descriptions and illustrations of the immature stages of S. cosmioides, as micropilar area of the egg, chaetotaxy, spinneret, caterpillar ground color, arrangement of the appendages and natural openings of the pupa, are presented for the first time. Taxonomic remarks are also provided.

New Analytical Solution of the Equilibrium Ampere's Law Using the Walker's Method: a Didactic Example

Science.gov (United States)

Sousa, A. N. Laurindo; Ojeda-González, A.; Prestes, A.; Klausner, V.; Caritá, L. A.

2018-02-01

This work aims to demonstrate the analytical solution of the Grad-Shafranov (GS) equation or generalized Ampere's law, which is important in the studies of self-consistent 2.5-D solution for current sheet structures. A detailed mathematical development is presented to obtain the generating function as shown by Walker (RSPSA 91, 410, 1915). Therefore, we study the general solution of the GS equation in terms of the Walker's generating function in details without omitting any step. The Walker's generating function g( ζ) is written in a new way as the tangent of an unspecified function K( ζ). In this trend, the general solution of the GS equation is expressed as exp(- 2Ψ) = 4| K '( ζ)|2/cos2[ K( ζ) - K( ζ ∗)]. In order to investigate whether our proposal would simplify the mathematical effort to find new generating functions, we use Harris's solution as a test, in this case K( ζ) = arctan(exp( i ζ)). In summary, one of the article purposes is to present a review of the Harris's solution. In an attempt to find a simplified solution, we propose a new way to write the GS solution using g( ζ) = tan( K( ζ)). We also present a new analytical solution to the equilibrium Ampere's law using g( ζ) = cosh( b ζ), which includes a generalization of the Harris model and presents isolated magnetic islands.

A Linguistic Analysis of Rhetorical Strategies in Selected Narratives of Alice Walker

Science.gov (United States)

Matunda, Robert Stephen Mokaya

2009-01-01

The objective of this investigation was to analyze rhetorical strategies of Alice Walker in four narratives, namely, "The Color Purple, In Search of Our Mother's Gardens, Possessing the Secret of Joy, and Now Is the Time To Open Your Heart". As such, this study helps to expand the body of investigation relating linguistics to literature and medium…

Hybridization between multi-objective genetic algorithm and support vector machine for feature selection in walker-assisted gait.

Science.gov (United States)

Martins, Maria; Costa, Lino; Frizera, Anselmo; Ceres, Ramón; Santos, Cristina

2014-03-01

Walker devices are often prescribed incorrectly to patients, leading to the increase of dissatisfaction and occurrence of several problems, such as, discomfort and pain. Thus, it is necessary to objectively evaluate the effects that assisted gait can have on the gait patterns of walker users, comparatively to a non-assisted gait. A gait analysis, focusing on spatiotemporal and kinematics parameters, will be issued for this purpose. However, gait analysis yields redundant information that often is difficult to interpret. This study addresses the problem of selecting the most relevant gait features required to differentiate between assisted and non-assisted gait. For that purpose, it is presented an efficient approach that combines evolutionary techniques, based on genetic algorithms, and support vector machine algorithms, to discriminate differences between assisted and non-assisted gait with a walker with forearm supports. For comparison purposes, other classification algorithms are verified. Results with healthy subjects show that the main differences are characterized by balance and joints excursion in the sagittal plane. These results, confirmed by clinical evidence, allow concluding that this technique is an efficient feature selection approach. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Dissemination of Walker 256 carcinoma cells to rat skeletal muscle

International Nuclear Information System (INIS)

Ueoka, H.; Hayashi, K.; Namba, T.; Grob, D.

1986-01-01

After injection of 10 6 Walker 256 carcinoma cells labelled with 125 I-5-iodo-2'-deoxyuridine into the tail vein, peak concentration in skeletal muscle was 46 cells/g at 60 minutes, which was lower than 169202, 1665, 555, 198 and 133 cells/g, respectively, at 30 or 60 minutes in lung, liver, spleen, kidney and heart. Because skeletal muscle constitutes 37.4% of body weight, the total number of tumor cells was 2323 cells, which was much greater than in spleen, kidney and heart with 238, 271, and 85 cells, respectively, and only less than in lung and liver, at 222857 and 11700 cells, respectively. The total number in skeletal muscle became greater than in liver at 4 hours and than in lung at 24 hours. Ten minutes after injection of 7.5 x 10 6 Walker 256 carcinoma cells into the abdominal aorta of rats, a mean of 31 colony-forming cells were recovered from the gastrocnemius, while 106 cells were recovered from the lung after injection into the tail vein. These results indicate that a large number of viable tumor cells can be arrested in skeletal muscle through circulation. The rare remote metastasis of malignancies into skeletal muscle despite constantly circulating tumor cells does not appear to be due to poor dissemination of tumor cells into muscle but due to unhospitable environment of skeletal muscle

ACADEMIC TRAINING (R.P. Walker)

CERN Multimedia

Françoise Benz

2002-01-01

15, 16, 17 May LECTURE SERIES from 11.00 to 12.00 hrs - Council room, bldg. 503 on 15 May, Auditorium, bldg. 500 on 16 and 17 May Introduction to free electron lasers by R.P. Walker / Rutherford Laboratory, UK The Free-electron laser (FEL) is a source of coherent electromagnetic radiation based on a relativistic electron beam. First operated 25 years ago, the FEL has now reached a stage of maturity for operation in the infra-red region of the spectrum and several facilities provide intense FEL radiation beams for research covering a wide range of disciplines. Several projects both underway and proposed aim at pushing the minimum wavelength from its present limit around 100 nm progressively down to the 1 Angstrom region where the X-ray FEL would open up many new and exciting research possibilities. Other developments aim at increasing power levels to the 10's of kW level. In this series of lectures we give an introduction to the basic principles of FELs and their different modes of operation, and summarise the...

Sex Differences in Moral Reasoning: Response to Walker's (1984) Conclusion That There Are None.

Science.gov (United States)

Baumrind, Diana

1986-01-01

Takes issue with Lawrence Walker's literature review on developmental and individual differences in moral reasoning which found no consistent evidence for sex differences in moral development. Argues instead that the source and specific nature of these differences have yet to be established. (HOD)

Green's functions for a scalar fields in a class of Robertson-Walker space-times

International Nuclear Information System (INIS)

Mankin, Romi; Ainsaar, Ain

1997-01-01

The retarded and advanced Green's functions for a massless non conformally-coupled scalar field in a class of Robertson-Walker space-times are calculated analytically. The results are applied to the calculation of the Hadamard fundamental solutions in some special cases. (author)

Male responses to conspecific advertisement signals in the field cricket Gryllus rubens (Orthoptera: Gryllidae).

Science.gov (United States)

Jang, Yikweon

2011-01-20

In many species males aggregate and produce long-range advertisement signals to attract conspecific females. The majority of the receivers of these signals are probably other males most of the time, and male responses to competitors' signals can structure the spatial and temporal organization of the breeding aggregation and affect male mating tactics. I quantified male responses to a conspecific advertisement stimulus repeatedly over three age classes in Gryllus rubens (Orthoptera: Gryllidae) in order to estimate the type and frequency of male responses to the broadcast stimulus and to determine the factors affecting them. Factors tested included body size, wing dimorphism, age, and intensity of the broadcast stimulus. Overall, males employed acoustic response more often than positive phonotactic response. As males aged, the frequency of positive phonotactic response decreased but that of the acoustic response increased. That is, males may use positive phonotaxis in the early stages of their adult lives, possibly to find suitable calling sites or parasitize calling males, and then later in life switch to acoustic responses in response to conspecific advertisement signals. Males with smaller body size more frequently exhibited acoustic responses. This study suggests that individual variation, more than any factors measured, is critical for age-dependent male responses to conspecific advertisement signals.

Walker occupancy has an impact on changing airborne bacterial communities in an underground pedestrian space, as small-dust particles increased with raising both temperature and humidity.

Science.gov (United States)

Okubo, Torahiko; Osaki, Takako; Nozaki, Eriko; Uemura, Akira; Sakai, Kouhei; Matushita, Mizue; Matsuo, Junji; Nakamura, Shinji; Kamiya, Shigeru; Yamaguchi, Hiroyuki

2017-01-01

Although human occupancy is a source of airborne bacteria, the role of walkers on bacterial communities in built environments is poorly understood. Therefore, we visualized the impact of walker occupancy combined with other factors (temperature, humidity, atmospheric pressure, dust particles) on airborne bacterial features in the Sapporo underground pedestrian space in Sapporo, Japan. Air samples (n = 18; 4,800L/each sample) were collected at 8:00 h to 20:00 h on 3 days (regular sampling) and at early morning / late night (5:50 h to 7:50 h / 22:15 h to 24:45 h) on a day (baseline sampling), and the number of CFUs (colony forming units) OTUs (operational taxonomic units) and other factors were determined. The results revealed that temperature, humidity, and atmospheric pressure changed with weather. The number of walkers increased greatly in the morning and evening on each regular sampling day, although total walker numbers did not differ significantly among regular sampling days. A slight increase in small dust particles (0.3-0.5μm) was observed on the days with higher temperature regardless of regular or baseline sampling. At the period on regular sampling, CFU levels varied irregularly among days, and the OTUs of 22-phylum types were observed, with the majority being from Firmicutes or Proteobacteria (γ-), including Staphylococcus sp. derived from human individuals. The data obtained from regular samplings reveled that although no direct interaction of walker occupancy and airborne CFU and OTU features was observed upon Pearson's correlation analysis, cluster analysis indicated an obvious lineage consisting of walker occupancy, CFU numbers, OTU types, small dust particles, and seasonal factors (including temperature and humidity). Meanwhile, at the period on baseline sampling both walker and CFU numbers were similarly minimal. Taken together, the results revealed a positive correlation of walker occupancy with airborne bacteria that increased with increases in

Phylogeography and systematics of the westernmost Italian Dolichopoda species (Orthoptera, Rhaphidophoridae

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Giuliana Allegrucci

2014-08-01

Full Text Available The genus Dolichopoda (Orthoptera; Rhaphidopohoridae is present in Italy with 9 species distributed from northwestern Italy (Piedmont and Liguria to the southernmost Apennines (Calabria, occurring also in the Tyrrhenian coastal areas and in Sardinia. Three morphologically very close taxa have been described in Piedmont and Liguria, i.e., D. ligustica ligustica, D. ligustica septentrionalis and D. azami azami.To investigate the delimitation of the northwestern species of Dolichopoda, we performed both morphological and molecular analyses. Morphological analysis was carried out by considering diagnostic characters generally used to distinguish different taxa, as the shape of epiphallus in males and the subgenital plate in females. Molecular analysis was performed by sequencing three mitochondrial genes, 12S rRNA, 16S rRNA, partially sequenced and the entire gene of COI.Results from both morphological and molecular analyses highlighted a very homogeneous group of populations, although genetically structured. Three haplogroups geographically distributed could be distinguished and based on these results we suggest a new taxonomic arrangement. All populations, due to the priority of description, should be assigned to D. azami azami Saulcy, 1893 and to preserve the names ligustica and septentrionalis, corresponding to different genetic haplogroups, we assign them to D. azami ligustica Baccetti & Capra, 1959, stat. n. and to D. azami septentrionalis Baccetti & Capra, 1959, stat. n.

Solutions to the maximal spacelike hypersurface equation in generalized Robertson-Walker spacetimes

Directory of Open Access Journals (Sweden)

Henrique F. de Lima

2018-03-01

Full Text Available We apply some generalized maximum principles for establishing uniqueness and nonexistence results concerning maximal spacelike hypersurfaces immersed in a generalized Robertson-Walker (GRW spacetime, which is supposed to obey the so-called timelike convergence condition (TCC. As application, we study the uniqueness and nonexistence of entire solutions of a suitable maximal spacelike hypersurface equation in GRW spacetimes obeying the TCC.

Metalloproteins during development of Walker-256 carcinosarcoma resistant phenotype

Directory of Open Access Journals (Sweden)

V. F. Chekhun

2015-04-01

Full Text Available The study was focused on the detection of changes in serum and tumor metal-containing proteins in animals during development of doxorubicin-resistant phenotype in malignant cells after 12 courses of chemotherapy. We found that on every stage of resistance development there was a significant increase in content of ferritin and transferrin proteins (which take part in iron traffick and storage in Walker-256 carcinosarcoma tissue. We observed decreased serum ferritin levels at the beginning stage of the resistance development and significant elevation of this protein levels in the cases with fully developed resistance phenotype. Transferrin content showed changes opposite to that of ferritin. During the development of resistance phenotype the tumor tissue also exhibited increased ‘free iron’ concentration that putatively correlate with elevation of ROS generation and levels of MMP-2 and MMP-9 active forms. The tumor non-protein thiol content increases gradually as well. The serum of animals with early stages of resistance phenotype development showed high ceruloplasmin activity and its significant reduction after loss of tumor sensitivity to doxorubicin. Therefore, the development of resistance phenotype in Walker-256 carcinosarcoma is accompanied by both the deregulation of metal-containing proteins in serum and tumor tissue and by the changes in activity of antioxidant defense system. Thus, the results of this study allow us to determine the spectrum of metal-containing proteins that are involved in the development of resistant tumor phenotype and that may be targeted for methods for doxorubicin sensitivity correction therapy.

Public and private space curvature in Robertson-Walker universes.

Science.gov (United States)

Rindler, W.

1981-05-01

The question is asked: what space curvature would a fundamental observer in an ideal Robertson-Walker universe obtain by direct local spatial measurements, i.e., without reference to the motion pattern of the other galaxies? The answer is that he obtains the curvatureK of his “private” space generated by all the geodesics orthogonal to his world line at the moment in question, and that ˜K is related to the usual curvatureK=k/R 2 of the “public” space of galaxies byK=K+H 2/c2, whereH is Hubble's parameter.

Inverse curvature flows in asymptotically Robertson Walker spaces

Science.gov (United States)

Kröner, Heiko

2018-04-01

In this paper we consider inverse curvature flows in a Lorentzian manifold N which is the topological product of the real numbers with a closed Riemannian manifold and equipped with a Lorentzian metric having a future singularity so that N is asymptotically Robertson Walker. The flow speeds are future directed and given by 1 / F where F is a homogeneous degree one curvature function of class (K*) of the principal curvatures, i.e. the n-th root of the Gauss curvature. We prove longtime existence of these flows and that the flow hypersurfaces converge to smooth functions when they are rescaled with a proper factor which results from the asymptotics of the metric.

Field screening of water quality, bottom sediment, and biota associated with irrigation drainage in and near Walker River Indian Reservation, Nevada 1994-95

Science.gov (United States)

Thodal, Carl E.; Tuttle, Peter L.

1996-01-01

A study was begun in 1994 to determine whether the quality of irrigation drainage from the Walker River Indian Reservation, Nevada, has caused or has potential to cause harmful effects on human health or on fish and wildlife, or may adversely affect the suitability of the Walker River for other beneficial uses. Samples of water, bottom sediment, and biota were collected during June-August 1994 (during a drought year) from sites upstream from and on the Walker River Indian Reservation for analyses of trace elements. Other analyses included physical characteristics, major dissolved constituents, selected species of water-soluble nitrogen and phosphorus, and selected pesticides in bottom sediment. Water samples were collected again from four sites on the Reservation in August 1995 (during a wetterthan- average year) to provide data for comparing extreme climatic conditions. Water samples collected from the Walker River Indian Reservation in 1994 equaled or exceeded the Nevada water-quality standard or level of concern for at least one of the following: water temperature, pH, dissolved solids, unionized ammonia, phosphate, arsenic, boron, chromium, lead, and molybdenum; in 1995, only a single sample from one site exceeded a Nevada water-quality standard for molybdenum. Levels of concern for trace elements in bottom sediment collected in 1994 were equaled or exceeded for arsenic, iron, manganese, and zinc. Concentrations of organochiorine pesticide residues in bottom sediment were below analytical reporting limits. Levels of concern for trace-elements in samples of biota were equaled or exceeded for arsenic, boron, copper, and mercury. Results of toxicity testing indicate that only water samples from Walker Lake caused a toxic response in test bacteria. Arsenic and boron concentrations in water, bottom sediment, and biological tissue exceeded levels of concern throughout the Walker River Basin, but most commonly in the lower Walker River Basin. Mercury also was elevated

The Legal Dimension of RTI--Confusion Confirmed: A Response to Walker and Daves

Science.gov (United States)

Zirkel, Perry A.

2012-01-01

In this issue of "Learning Disability Quarterly" (LDQ), Professors Daves and Walker reply to my earlier LDQ article on confusion in the cases and commentary about the legal dimension of RTI. In this brief rejoinder, I show that their reply confirms rather than resolves the confusion in their original commentary in 2010. This persistent…

Dandy Walker Syndrome with Unusual Associated Findings in a Fetal Autopsy Study

OpenAIRE

Surekha U Arakeri; Himanshu Mulay

2015-01-01

Dandy Walker Syndrome (DWS) is a congenital brain malformation characterized by hypoplasia or absence of cerebellar vermis, cystic dilatation of fourth ventricle and hydrocephalus. It is frequently associated with other congenital anomalies. Associated central nervous system anomalies such as agenesis of corpus callosum and vermis are associated with poor prognosis. Association of DWS with congenital absence of spleen is life threatening condition and has been reported...

A preliminary study of murine walker-256 tumor hypoxia detected by blood oxygen level dependent-MR

International Nuclear Information System (INIS)

Zhang Shengjian; Mao Jian; Wu Bin; Peng Weijun

2013-01-01

Objective: To establish Walker-256 transplantation tumor model in SD Rats. To study of R_2"* signal changes on murine Walker-256 tumor after inhaling Carbogen by blood oxygen level dependent (BOLD)-MR, and to explore the feasibility of BOLD-MRI on detecting tumor hypoxia. Methods: Walker-256 tumor cell implanted subcutaneously in right lower abdomen of 95 female SD rats. MR was performed on the tumor-forming rats when the maximum diameter of tumor reached 1-3 cm, using a 3.0 T MR scanner equipped with a 3 inch animal surface coil. BOLD-MRI was done by using a multiecho SPGR sequence during inhaling air and at 10 minute after inhaling Carbogen, respectively. All images were transferred to GE ADW 4.3 workstation, then a baseline R_2"* (R_2"* a) and R_2"* (R_2"* b) after inhaling Carbogen of tumor was calculated using R_2 Star analysis software and ΔR_2"* was calculated through ΔR_2"* = R_2"* b -R_2"* a", meanwhile the volume of tumor were calculated as well. The difference of R_2"* signal pre and post-inhaling of Carbogen was compared with a paired t test, Pearson correlation was calculated between R_2"* a, ΔR_2"* and the volume of tumor, respectively. The correlation between ΔR_2"* and R_2"* a was also assessed by Pearson correlation. Results: Sixty-eight of ninety-five female SD rats formed the tumor (71.6%). The volume of tumor was from 352 to 13 173 mm"3. Mean ΔR_2"* decreased significantly (-2.26 ± 3.90) s"-"1 from (41.18 ± 22.29) s"-"1 during breathing air to (38.91 ± 21.35) s"-"1 10 min after inhaling Carbogen (t = 4.01, P 0.05). Conclusions: BOLD-MRI can detect the R_2"* signal change of murine Walker-256 tumor pre-and post-inhaling of Carbogen. The R_2"* signal showed significant decrease after inhaling Carbogen, however, the individual variation was remarkable. (authors)

Grain-size data from four cores from Walker Lake, Nevada

International Nuclear Information System (INIS)

Yount, J.C.; Quimby, M.F.

1990-01-01

A number of cores, taken from within and near Walker Lake, Nevada are being studied by various investigators in order to evaluate the late-Pleistocene paleoclimate of the west-central Great Basin. In particular, the cores provide records that can be interpreted in terms of past climate and compared to proposed numerical models of the region's climate. All of these studies are being carried out as part of an evaluation of the regional paleoclimatic setting of a proposed high-level nuclear waste storage facility at Yucca Mountain, Nevada. Changes in past climate often manifest themselves in changes in sedimentary processes or in changes in the volume of sediment transported by those processes. One fundamental sediment property that can be related to depositional processes is grain size. Grain size effects other physical properties of sediment such as porosity and permeability which, in turn, affect the movement and chemistry of fluids. The purposes of this report are: (1) to document procedures of sample preparation and analysis, and (2) to summarize grain-size statistics for 659 samples from Walker Lake cores 84-4, 84-5, 84-8 and 85-2. Plots of mean particle diameter, percent sand, and the ratio of silt to clay are illustrated for various depth intervals within each core. Summary plots of mean grain size, sorting, and skewness parameters allow comparison of textural data between each core. 15 refs., 8 figs., 3 tabs

A summary of eight traits of Coleoptera, Hemiptera, Orthoptera and Araneae, occurring in grasslands in Germany

Science.gov (United States)

Gossner, Martin M.; Simons, Nadja K.; Achtziger, Roland; Blick, Theo; Dorow, Wolfgang H. O.; Dziock, Frank; Köhler, Frank; Rabitsch, Wolfgang; Weisser, Wolfgang W.

2015-03-01

Analyses of species traits have increased our understanding of how environmental drivers such as disturbances affect the composition of arthropod communities and related processes. There are, however, few studies on which traits in the arthropod community are affected by environmental changes and which traits affect ecosystem functioning. The assembly of arthropod traits of several taxa is difficult because of the large number of species, limited availability of trait databases and differences in available traits. We sampled arthropod species data from a total of 150 managed grassland plots in three regions of Germany. These plots represent the spectrum from extensively used pastures to mown pastures to intensively managed and fertilized meadows. In this paper, we summarize information on body size, dispersal ability, feeding guild and specialization (within herbivores), feeding mode, feeding tissue (within herbivorous suckers), plant part (within herbivorous chewers), endophagous lifestyle (within herbivores), and vertical stratum use for 1,230 species of Coleoptera, Hemiptera (Heteroptera, Auchenorrhyncha), Orthoptera (Saltatoria: Ensifera, Caelifera), and Araneae, sampled by sweep-netting between 2008 and 2012. We compiled traits from various literature sources and complemented data from reliable internet sources and the authors’ experience.

Low carbohydrate, high fat diet impairs exercise economy and negates the performance benefit from intensified training in elite race walkers

Science.gov (United States)

Ross, Megan L.; Garvican‐Lewis, Laura A.; Welvaert, Marijke; Heikura, Ida A.; Forbes, Sara G.; Mirtschin, Joanne G.; Cato, Louise E.; Strobel, Nicki; Sharma, Avish P.; Hawley, John A.

2017-01-01

Key points Three weeks of intensified training and mild energy deficit in elite race walkers increases peak aerobic capacity independent of dietary support.Adaptation to a ketogenic low carbohydrate, high fat (LCHF) diet markedly increases rates of whole‐body fat oxidation during exercise in race walkers over a range of exercise intensities.The increased rates of fat oxidation result in reduced economy (increased oxygen demand for a given speed) at velocities that translate to real‐life race performance in elite race walkers.In contrast to training with diets providing chronic or periodised high carbohydrate availability, adaptation to an LCHF diet impairs performance in elite endurance athletes despite a significant improvement in peak aerobic capacity. Abstract We investigated the effects of adaptation to a ketogenic low carbohydrate (CHO), high fat diet (LCHF) during 3 weeks of intensified training on metabolism and performance of world‐class endurance athletes. We controlled three isoenergetic diets in elite race walkers: high CHO availability (g kg−1 day−1: 8.6 CHO, 2.1 protein, 1.2 fat) consumed before, during and after training (HCHO, n = 9); identical macronutrient intake, periodised within or between days to alternate between low and high CHO availability (PCHO, n = 10); LCHF (diets providing chronic or periodised high‐CHO availability, and despite a significant improvement in V˙O2 peak , adaptation to the topical LCHF diet negated performance benefits in elite endurance athletes, in part due to reduced exercise economy. PMID:28012184

If the Song Sounds the Same Check for Static: A Reply to Walker and Frimer

Science.gov (United States)

Sherblom, Stephen A.

2009-01-01

The "care challenge" is shown to be both broader and more successful than Walker and Frimer's (this issue, pp. 53-68) critique allows. The main philosophical and psychological tenets of the care challenge foreshadowed the direction of twenty-first century moral psychology.

A review of the New World Atteva Walker moths (Yponomeutidae, Attevinae Resenha das mariposas do gênero Atteva Walker do Novo Mundo (Yponomeutidae, Attevinae

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Vitor O. Becker

2009-01-01

Full Text Available The New World species of Atteva Walker are reviewed and illustrated in colour. One name: A. pustulella (Fabricius, nom. rev. and three species: A. aurea (Fitch, sp. rev., A. floridana (Neumoegen, sp. rev. and A. gemmata (Grote, sp. rev. are reinstated; five names are synonymised under A. aurea: Poeciloptera compta Clemens, syn. n., A. edithella Busck, syn. n., A. exquisita Busck, syn. n., A. ergatica Walsingham, syn. n. and A. microsticta Walsingham, syn. n.; four new species are described: A. rawlinsi sp. n., from the Dominican Republic, A. sidereoides sp. n., from Jamaica, A. entermedia sp. n., from Antigua, and A. zebrina sp. n., from Brazil; lectotypes for A. floridana and A. glaucopidella (Guenée (=fulviguttata are also designated.As species de Atteva Walker são revistas e ilustradas em cores. Um nome: A. pustulella (Fabricius, nom. rev. e três espécies: A. aurea (Fitch, sp. rev., A. floridana (Neumoegen, sp. rev. and A. gemmata (Grote, sp. rev. são restabelecidos; cinco nomes são considerados sinônimos recentes de A.aurea: Poeciloptera compta Clemens, syn. n., A. edithella Busck, syn. n., A. exquisita Busck, syn. n., A. ergatica Walsingham, syn. n. e A. microsticta Walsingham, syn. n.; quatro espécies novas são descritas: A. rawlinsi sp. n., da República Dominica, A. sidereoides sp. n., da Jamaica, A. entermedia sp. n., de Antigua, e A. zebrina sp. n., do Brazil; são designados lectótipos para A. floridana e A. glaucopidella (Guenée (=fulviguttata.

Thomas James Walker (1835-1916): Surgeon and general practitioner.

Science.gov (United States)

Thomas, Martyn

2018-02-01

Thomas James Walker was a surgeon and general practitioner who worked in the city of Peterborough at a time when there were changes and innovations in the practice of medicine. After training in medicine and surgery at Edinburgh University, he qualified in London in 1857. He was a pioneer of laryngoscopy. He played an important role in introducing antiseptic surgery to the Peterborough Infirmary and was instrumental in the development of the operating theatre which opened in 1894. He was a philanthropist and collector of Roman and Saxon artefacts. In 1915, he was recognized as an outstanding member of the Peterborough community when he was offered the Freedom of the City.

The navel orangeworm, Amyelois transtilla (Walker) (Lepidoptera: Pyralidae) discovered in northeastern Mexico feeding on Sapindaceae

Science.gov (United States)

Amyelois transitella (Walker) (Lepidoptera: Pyralidae), the navel orangeworm, is an important pest of a wide variety fruits and their seeds. We discovered and report for the first time A. transitella feeding on Sapindaceae in wild populations of U. speciosa (Endl.) in northeastern Mexico. We provid...

Precipitation Change and Soil Leaching: Field Results and Simulations from Walker Branch Watershed, Tennessee

Science.gov (United States)

D.W. Johnson; P.J. Hanson; D.E. Todd; R.B. Susfalk; Carl C. Trettin

1998-01-01

Abstract. To investigate the potential effects of changing precipitation on a deciduous forest ecosystem, an experiment was established on Walker Branch Watershed, Tennessee that modified the amount of throughfall at 4 -33 %. ambient (no change), and +33 % using a system of rain gutters and sprinklers. We hypothesized that the drier treatments would...

Beyond the Friedmann—Lemaître—Robertson—Walker Big Bang Singularity

International Nuclear Information System (INIS)

Stoica, Cristi

2012-01-01

Einstein's equation, in its standard form, breaks down at the Big Bang singularity. A new version, equivalent to Einstein's whenever the latter is defined, but applicable in wider situations, is proposed. The new equation remains smooth at the Big Bang singularity of the Friedmann—Lemaître—Robertson—Walker model. It is a tensor equation defined in terms of the Ricci part of the Riemann curvature. It is obtained by taking the Kulkarni—Nomizu product between Einstein's equation and the metric tensor.

Automatic detection of lift-off and touch-down of a pick-up walker using 3D kinematics.

Science.gov (United States)

Grootveld, L; Thies, S B; Ogden, D; Howard, D; Kenney, L P J

2014-02-01

Walking aids have been associated with falls and it is believed that incorrect use limits their usefulness. Measures are therefore needed that characterize their stable use and the classification of key events in walking aid movement is the first step in their development. This study presents an automated algorithm for detection of lift-off (LO) and touch-down (TD) events of a pick-up walker. For algorithm design and initial testing, a single user performed trials for which the four individual walker feet lifted off the ground and touched down again in various sequences, and for different amounts of frame loading (Dataset_1). For further validation, ten healthy young subjects walked with the pick-up walker on flat ground (Dataset_2a) and on a narrow beam (Dataset_2b), to challenge balance. One 88-year-old walking frame user was also assessed. Kinematic data were collected with a 3D optoelectronic camera system. The algorithm detected over 93% of events (Dataset_1), and 95% and 92% in Dataset_2a and b, respectively. Of the various LO/TD sequences, those associated with natural progression resulted in up to 100% correctly identified events. For the 88-year-old walking frame user, 96% of LO events and 93% of TD events were detected, demonstrating the potential of the approach. Copyright © 2013 IPEM. Published by Elsevier Ltd. All rights reserved.

Creatine supplementation prevents hyperhomocysteinemia, oxidative stress and cancer-induced cachexia progression in Walker-256 tumor-bearing rats.

Science.gov (United States)

Deminice, Rafael; Cella, Paola Sanches; Padilha, Camila S; Borges, Fernando H; da Silva, Lilian Eslaine Costa Mendes; Campos-Ferraz, Patrícia L; Jordao, Alceu Afonso; Robinson, Jason Lorne; Bertolo, Robert F; Cecchini, Rubens; Guarnier, Flávia Alessandra

2016-08-01

The purpose of this study was to investigate (1) the impact of tumor growth on homocysteine (Hcy) metabolism, liver oxidative stress and cancer cachexia and, (2) the potential benefits of creatine supplementation in Walker-256 tumor-bearing rats. Three experiments were conducted. First, rats were killed on days 5 (D5), 10 (D10) and 14 (D14) after tumor implantation. In experiment 2, rats were randomly assigned to three groups designated as control (C), tumor-bearing (T) and tumor-bearing supplemented with creatine (TCr). A life span experiment was conducted as the third experiment. Creatine was supplied in drinking water for 21 days (8 g/L) in all cases. Tumor implantation consisted of a suspension of Walker-256 cells (8.0 × 10(7) cells in 0.5 mL of PBS). The progressive increase (P creatine supplementation promoted a 28 % reduction of tumor weight (P Creatine supplementation was unable to decrease Hcy concentration and to increase SAM/SAH ratio in tumor tissue. These data suggest that creatine effects on hepatic impaired Hcy metabolism promoted by tumor cell inoculation are responsible to decrease plasma Hcy in tumor-bearing rats. In conclusion, Walker-256 tumor growth is associated with progressive hyperhomocysteinemia, body weight loss and liver oxidative stress in rats. Creatine supplementation, however, prevented these tumor-associated perturbations.

Anestesia em criança com síndrome de Walker-Warburg

Directory of Open Access Journals (Sweden)

Emine Arzu Kose

2014-04-01

Full Text Available Justificativa e objetivos: A síndrome de Walker-Warburg é uma distrofia muscular autossômica recessiva congênita rara, manifestada pelo sistema nervoso central com malformações oculares e possível envolvimento de vários sistemas. O diagnóstico é estabelecido pela presença de quatro critérios: distrofia muscular congênita, lisencefalia tipo II, malformação cerebelar e malformação da retina. A maioria das crianças com a síndrome morre nos primeiros três anos de vida por causa de insuficiência respiratória, pneumonia, convulsões, hipertermia e fibrilação ventricular. Relato de caso: É discutida a conduta anestésica em uma criança do sexo masculino, de dois meses, programada para cirurgia eletiva de derivação ventrículo-peritoneal. Conclusões: Uma abordagem anestésica cuidadosa é necessária por causa do envolvimento de vários sistemas. Relatamos a conduta anestésica em uma criança do sexo masculino de dois meses com síndrome de Walker-Warburg, que foi programada para cirurgia eletiva de derivação ventrículo-peritoneal.

Climatic changes inferred fron analyses of lake-sediment cores, Walker Lake, Nevada

International Nuclear Information System (INIS)

Yang, In Che.

1989-01-01

Organic and inorganic fractions of sediment collected from the bottom of Walker Lake, Nevada, have been dated by carbon-14 techniques. Sedimentation rates and the organic-carbon content of the sediment were correlated with climatic change. The cold climate between 25,000 and 21,000 years ago caused little runoff, snow accumulation on the mountains, and rapid substantial glacial advances; this period of cold climate resulted in a slow sedimentation rate (0.20 millimeter per year) and in a small organic-carbon content in the sediment. Also, organic-carbon accumulation rates in the lake during this period were slow. The most recent period of slow sedimentation rate and small organic-carbon content occurred between 10,000 and 5500 years ago, indicative of low lake stage and dry climatic conditions. This period of dry climate also was evidenced by dry conditions for Lake Lahontan in Nevada and Searles Lake in California, as cited in the literature. Walker Lake filled rapidly with water between 5500 and 4500 years ago. The data published in this report was not produced under an approved Site Investigation Plan (SIP) or Study Plan (SP) and will not be used in the licensing process. 10 refs., 3 figs., 2 tabs

Celecoxib and Ibuprofen Restore the ATP Content and the Gluconeogenesis Activity in the Liver of Walker-256 Tumor-Bearing Rats

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Camila Oliveira de Souza

2015-07-01

Full Text Available Background/Aims: The main purpose of this study was to investigate the effects of celecoxib and ibuprofen, both non-steroidal anti-inflammatory drugs (NSAIDs, on the decreased gluconeogenesis observed in liver of Walker-256 tumor-bearing rats. Methods: Celecoxib and ibuprofen (both at 25 mg/Kg were orally administered for 12 days, beginning on the same day when the rats were inoculated with Walker-256 tumor cells. Results: Celecoxib and ibuprofen treatment reversed the reduced production of glucose, pyruvate, lactate and urea from alanine as well as the reduced production of glucose from pyruvate and lactate in perfused liver from tumor-bearing rats. Besides, celecoxib and ibuprofen treatment restored the decreased ATP content, increased triacylglycerol levels and reduced mRNA expression of carnitine palmitoyl transferase 1 (CPT1, while ibuprofen treatment restored the reduced mRNA expression of peroxisome proliferator-activated receptor alpha (PPARα in the liver of tumor-bearing rats. Both treatments tended to decrease TNFα, IL6 and IL10 in the liver of tumor-bearing rats. Finally, the treatment with celecoxib, but not with ibuprofen, reduced the growth of Walker-256 tumor. Conclusion: Celecoxib and ibuprofen restored the decreased gluconeogenesis in the liver of Walker-256 tumor-bearing rats. These effects did not involve changes in tumor growth and probably occurred by anti-inflammatory properties of these NSAIDs, which increased expression of genes associated with fatty acid oxidation (PPARα and CPT1 and consequently the ATP production, normalizing the energy status in the liver of tumor-bearing rats.

Laboratory Trials of Metarhizium anisopliae var. acridum (Green Muscle® Against the Saxaul Locust, Dericorys albidula Serville (Orthoptera: Dericorythidae Ensayos de Laboratorio de Metarhizium anisopliae var. acridum (Green muscle® contra la Langosta de Saxaul, Dericorys albidula Serville (Orthoptera: Dericorythidae

Directory of Open Access Journals (Sweden)

Heydar Valizadeh

2011-12-01

Full Text Available The saxaul locust, Dericorys albidula Serville (Orthoptera: Dericorythidae is a major pest of saxaul plants in Qom province of Iran. During 2005-2006, different nymphal instars of bands of D. albidula were treated by aerial spraying of Metarhizium anisopliae var. acridum (Green Muscle®. The gasoline formulation of M. anisopliae var. acridum isolate IMI 330189 was applied in different conidial concentrations (10(6, 10(7, 10(8, 10(9, 10(10 and 10(13 spores mL-1 that were prepared in sterile distilled gasoline. Results showed that various concentrations significantly affected the 2nd, 3rd, 4th and 5th nymphal instars of D. albidula compared to control. In addition, there were no differences in the effects of the different concentrations in 2005, but the differences were significant in 2006. Concentration 10(10 killed 100% of tested insects 15 d after treatment. Comparing the results of the two years showed that the susceptibility of nymphs in the second year (2006 was higher than in the first year (2005. In conclusion, the results of this study indicated that the fungal insecticide M. anisopliae var. acridum, diluted in gasoline, was efficacious with the nymphal instars of locust D. albidula in 2005 and 2006.La langosta del saxaul, Dericorys albidula Serville (Orthoptera: Dericorythidae, es la principal plaga de plantas de saxaul de las provincias Qom, Irán. Durante 2005-2006, diferentes instars ninfales de D. albidula se asperjaron con Metarhizium anisopliae var. acridum (Green Muscle®. La formulación de gasolina de M. anisopliae var. acridum aislamiento IMI 330189 se aplicó en diferentes concentraciones conidiales (10(6, 10(7, 10(8, 10(9, 10(10 and 10(13 esporas mL-1 preparadas en gasolina destilada estéril. Los resultados demostraron que varias concentraciones afectaron significativamente los nstars ninfales de D. albidula comparado con el control. Además el efecto de concentraciones no fue diferente en 2005 pero sí significativamente en

Determining the Walker exponent and developing a modified Smith-Watson-Topper parameter model

Energy Technology Data Exchange (ETDEWEB)

Lv, Zhiqiang; Huang, Hong Zhong; Wang, Hai Kun; Gao, Huiying; Zuo, Fang Jun [University of Electronic Science and Technology of China, Chengdu (China)

2016-03-15

Mean stress effects significantly influence the fatigue life of components. In general, tensile mean stresses are known to reduce the fatigue life of components, whereas compressive mean stresses are known to increase it. To date, various methods that account for mean stress effects have been studied. In this research, considering the high accuracy of mean stress correction and the difficulty in obtaining the material parameter of the Walker method, a practical method is proposed to describe the material parameter of this method. The test data of various materials are then used to verify the proposed practical method. Furthermore, by applying the Walker material parameter and the Smith-Watson-Topper (SWT) parameter, a modified strain-life model is developed to consider sensitivity to mean stress of materials. In addition, three sets of experimental fatigue data from super alloy GH4133, aluminum alloy 7075-T651, and carbon steel are used to estimate the accuracy of the proposed model. A comparison is also made between the SWT parameter method and the proposed strainlife model. The proposed strain-life model provides more accurate life prediction results than the SWT parameter method.

Quantum field theory in flat Robertson-Walker space-time functional Schrodinger picture

International Nuclear Information System (INIS)

Pi, S.Y.

1990-01-01

Quantum field theory in Robertson-Walker space-time is intrinsically time-dependent and the functional Schrodinger picture provides a useful description. This paper discusses free and self-interacting bosonic quantum field theories: Schrodinger picture quantization, time-dependent Gaussian approximations based on variational principles describing time evolution of pure and mixed states, and renormalizability of the Schrodinger picture. The technique introduced can be used to study various dynamical questions in early universe processes

Quantum field theory in flat Robertson-Walker space-time functional Schroedinger picture

International Nuclear Information System (INIS)

Pi, S.Y.

1989-01-01

Quantum field theory in Robertson-Walker space-time is intrinsically time-dependent and the functional Schroedinger picture provides a useful description. We discuss free and self-interacting bosonic quantum field theories: Schroedinger picture quantization, time-dependent Gaussian approximations based on variational principles describing time evolution of pure and mixed states, and renormalizability of the Schroedinger picture. The techniques introduced can be used to study various dynamical questions in early universe processes. (author)

Beliefs about the use of baby walkers Crenças sobre o uso do andador infantil

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Paula S. C. Chagas

2011-08-01

Full Text Available OBJECTIVES: To understand the opinion of the parents about the baby walker and compare the age of gait acquisition between infants that used a walker and those that did not. METHODS: In this quali-quantitative study, an interview involving a semi-structured questionnaire was carried out with 26 parents, 14 of whose infants used the equipment (BWG and 12 of whose infants did not (NBWG prior to gait acquisition. After extensive content analysis, categories for interpreting the results emerged. For data triangulation, the age of gait acquisition was documented by weekly telephone contact. Student's t-test was used for comparison between groups with a significance level of α=0.05. RESULTS: The following categories were identified in the parents' reports: a information about the baby walker; b doubt/decision to use it vs. certainty about not using it; c beliefs about the use of a baby-walker; and d benefits and harm from use. The age of independent gait acquisition did not differ between groups (p=0.837: BWG initiated gait at 376.17 (SD=32.62 days and NBWG did so at 378.75 (SD=27.99 days. CONCLUSIONS: The beliefs and feelings that permeate the decision to use a baby walker illustrate the different rationales adopted by parents about the role of this equipment in the child's development of gait and autonomy. The use of a baby walker did not influence the age of gait acquisition. The results broaden the understanding of choices that influence child-rearing practices prior to gait acquisition.OBJETIVOS: Conhecer a opinião dos pais sobre o uso do andador infantil e comparar a idade de aquisição da marcha independente entre os lactentes que usaram e os que não usaram o andador. MÉTODOS: Neste estudo qualiquantitativo, realizou-se entrevista com questionário semiestruturado com 26 pais, 14 de lactentes que usaram (GUAI e 12 dos que não usaram o equipamento (GNUAI antes da aquisição da marcha. Empregou-se análise de conteúdo, a partir da qual

Conformal Killing vectors in Robertson-Walker spacetimes

International Nuclear Information System (INIS)

Maartens, R.; Maharaj, S.d.

1986-01-01

It is well known that Robertson-Walker spacetimes admit a conformal Killingl vector normal to the spacelike homogeneous hypersurfaces. Because these spacetimes are conformally flat, there are a further eight conformal Killing vectors, which are neither normal nor tangent to the homogeneous hypersurfaces. The authors find these further conformal Killing vectors and the Lie algebra of the full G 15 of conformal motions. Conditions on the metric scale factor are determined which reduce some of the conformal Killing vectors to homothetic Killing vectors or Killing vectors, allowing one to regain in a unified way the known special geometries. The non-normal conformal Killing vectors provide a counter-example to show that conformal motions do not, in general, map a fluid flow conformally. These non-normal vectors are also used to find the general solution of the null geodesic equation and photon Liouville equation. (author)

Transcriptome profiling of ontogeny in the acridid grasshopper Chorthippus biguttulus.

Science.gov (United States)

Berdan, Emma L; Finck, Jonas; Johnston, Paul R; Waurick, Isabelle; Mazzoni, Camila J; Mayer, Frieder

2017-01-01

Acridid grasshoppers (Orthoptera:Acrididae) are widely used model organisms for developmental, evolutionary, and neurobiological research. Although there has been recent influx of orthopteran transcriptomic resources, many use pooled ontogenetic stages obscuring information about changes in gene expression during development. Here we developed a de novo transcriptome spanning 7 stages in the life cycle of the acridid grasshopper Chorthippus biguttulus. Samples from different stages encompassing embryonic development through adults were used for transcriptomic profiling, revealing patterns of differential gene expression that highlight processes in the different life stages. These patterns were validated with semi-quantitative RT-PCR. Embryonic development showed a strongly differentiated expression pattern compared to all of the other stages and genes upregulated in this stage were involved in signaling, cellular differentiation, and organ development. Our study is one of the first to examine gene expression during post-embryonic development in a hemimetabolous insect and we found that only the fourth and fifth instars had clusters of genes upregulated during these stages. These genes are involved in various processes ranging from synthesis of biogenic amines to chitin binding. These observations indicate that post-embryonic ontogeny is not a continuous process and that some instars are differentiated. Finally, genes upregulated in the imago were generally involved in aging and immunity. Our study highlights the importance of looking at ontogeny as a whole and indicates promising directions for future research in orthopteran development.

Micro-Evolution in Grasshoppers Mediated by Polymorphic Robertsonian Translocations

Science.gov (United States)

Colombo, Pablo C.

2013-01-01

This review focuses on grasshoppers that are polymorphic for Robertsonian translocations because in these organisms the clarity of meiotic figures allows the study of both chiasma distribution and the orientation of trivalents and multivalents in metaphase I. Only five species of such grasshoppers were found in the literature, and all of them were from the New World: Oedaleonotus enigma (Scudder) (Orthoptera: Acrididae), Leptysma argentina Bruner, Dichroplus pratensis Bruner, Sinipta dalmani Stål, and Cornops aquaticum Bruner. A general feature of these species (except O. enigma) is that fusion carriers suffer a marked reduction of proximal and interstitial (with respect to the centromere) chiasma frequency; this fact, along with the reduction in the number of linkage groups with the consequent loss of independent segregation, produces a marked decrease of recombination in fusion carriers. This reduction in recombination has led to the conclusion that Robertsonian polymorphic grasshopper species share some properties with inversion polymorphic species of Drosophila, such as the central-marginal pattern (marginal populations are monomorphic, central populations are highly polymorphic). This pattern might be present in D. pratensis, which is certainly the most complex Robertsonian polymorphism system in the present study. However, L. argentina and C. aquaticum do not display this pattern. This issue is open to further research. Since C. aquaticum is soon to be released in South Africa as a biological control, the latitudinal pattern found in South America may repeat there. This experiment's outcome is open and deserves to be followed. PMID:23909914

Prospective evidence for independent nitrogen and phosphorus limitation of grasshopper (Chorthippus curtipennis) growth in a tallgrass prairie.

Science.gov (United States)

Rode, Madison; Lemoine, Nathan P; Smith, Melinda D

2017-01-01

Insect herbivores play a pivotal role in regulating plant production and community composition, and their role in terrestrial ecosystems is partly determined by their feeding behavior and performance among plants of differing nutritional quality. Historically, nitrogen (N) has been considered the primary limiting nutrient of herbivorous insects, but N is only one of many potential nutrients important to insect performance. Of these nutrients, phosphorus (P) is perhaps the most important because somatic growth depends upon P-rich ribosomal RNA. Yet relatively few studies have assessed the strength of P-limitation for terrestrial insects and even fewer have simultaneously manipulated both N and P to assess the relative strengths of N- and P-limitation. Here, we tested for potential N and P limitation, as well as N:P co-limitation, on Chorthippis curtipennis (Orthoptera, Acrididae), an abundant member of arthropod communities of central US prairies. Our results demonstrate weak evidence for both N and P limitation of C. curtipennis growth rates in laboratory feeding assays. Importantly, P-limitation was just as strong as N-limitation, but we found no evidence for NP co-limitation in our study. Furthermore, nutrient limitation was not apparent in field studies, suggesting that insect growth rates may be predominately controlled by other factors, including temperature and predation. Our results suggest that P should be jointly considered, along with N, as a primary determinant of herbivore feeding behavior under both current and future climate conditions.

Comparative study of two female African-American Writers in 20 Centu-ry-Alice Walker VS. Toni Morriso

Institute of Scientific and Technical Information of China (English)

桂生义

2013-01-01

Toni Morrison and Alice Walker are among the most outstanding female African-American writers in Contemporary American Literature. Their works have been popular since 1960s to now. Although Walker and Morrison grew up under differ⁃ent family environments, they had the same experience of witnessing African-American women’s movements in last Century;therefore, they reached an agreement on writing thoughts and contents. For instance, they both referred to Racism, Sexism and“Womanism”in many of their works. This dissertation studies about the two authors’difference and sameness descriptions on Af⁃rican-American women’s identities, social status, rights, powers and fates,and to express their self-consciousness and bright prospection after experiencing the most painful encounters through comparative study on two of their short stories—Everyday Use and Recitatif.

On the spectrum of particles created in a Robertson-Walker universe

International Nuclear Information System (INIS)

Azuma, T.

1983-01-01

Created particle spectra are calculated in Robertson-Walker universes and discussed with a special emphasis on their dependence upon the initial and final times at which a WKB-like positive frequency conditions should be imposed. It is shown that the obtained spectra are very sensitive to these times if the WKB approximation for the field equation is not valid in their neighborhood. It is also shown that the total number density of created particles remains finite if the final time is set to be finite. (author)

Multiple phases and vicious walkers in a wedge

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Gesualdo Delfino

2015-12-01

Full Text Available We consider a statistical system in a planar wedge, for values of the bulk parameters corresponding to a first order phase transition and with boundary conditions inducing phase separation. Our previous exact field theoretical solution for the case of a single interface is extended to a class of systems, including the Blume–Capel model as the simplest representative, allowing for the appearance of an intermediate layer of a third phase. We show that the interfaces separating the different phases behave as trajectories of vicious walkers, and determine their passage probabilities. We also show how the theory leads to a remarkable form of wedge covariance, i.e. a relation between properties in the wedge and in the half plane, which involves the appearance of self-Fourier functions.

Metabolic changes during development of Walker-256 carcinosarcoma resistance to doxorubicin.

Science.gov (United States)

Todor, I N; Lukyanova, N Yu; Shvets, Yu V; Lozovska, Yu V; Chekhun, V F

2015-03-01

To study indices of energy metabolism, content of K(+) and Mg(++) both in peripheral blood and in Walker-256 carcinosarcoma during development of resistance to doxorubicin. Resistance of Walker-256 carcinosarcoma to doxorubicin has been developed through 12 subsequent transplantations of tumor after the chemotherapy. Parental strain was inhibited by drug by 65%, while transitional resistant substrains - by 30% and 2%, respectively. Determination of biochemical indices in blood serum and homogenates of tumor tissue, level of potassium, magnesium, lactate, glucose, activities of lactate dehydrogenase and glucose-6-phosphate dehydrogenase was performed with the help of biochemical and immune-enzyme analyzer GBG ChemWell 2990 (USA) using standard kits. Polarography was used to determine indices of mitochondrial oxidative phosphorylation. Study of mitochondrial membrane potential was carried out on flow cytometer Beckman Coulter Epics XL using dye JC-1. It has been determined that development of drug resistance causes the decrease of K(+), Mg(++), glucose content in blood serum and increase of these indices in tumor tissue. At the same time, gradual tumor's loss of sensitivity is characterized by decrease of glycolysis activity in it and activation of mitochondrial oxidative phosphorylation and pentose phosphate pathway of glucose degradation, which causes more intensive formation of NADPH. Development of drug resistance of tumor causes certain metabolic changes in organism and tumor. Further study of such changes will make possible to determine tumor and extratumor markers of resistance.

Computation of Partially Invariant Solutions for the Einstein Walker Manifolds' Identifying Equations

OpenAIRE

Nadjafikhah, Mehdi; Jafari, Mehdi

2014-01-01

In this paper, partially invariant solutions (PISs) method is applied in order to obtain new four-dimensional Einstein Walker manifolds. This method is based on subgroup classification for the symmetry group of partial differential equations (PDEs) and can be regarded as the generalization of the similarity reduction method. For this purpose, those cases of PISs which have the defect structure delta=1 and are resulted from two-dimensional subalgebras are considered in the present paper. Also ...

Walker devices and microswitch technology to enhance assisted indoor ambulation by persons with multiple disabilities: three single-case studies.

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Lancioni, Giulio E; Singh, Nirbhay N; O'Reilly, Mark F; Sigafoos, Jeff; Oliva, Doretta; Campodonico, Francesca; Buono, Serafino

2013-07-01

These three single-case studies assessed the use of walker devices and microswitch technology for promoting ambulation behavior among persons with multiple disabilities. The walker devices were equipped with support and weight lifting features. The microswitch technology ensured that brief stimulation followed the participants' ambulation responses. The participants were two children (i.e., Study I and Study II) and one man (i.e., Study III) with poor ambulation performance. The ambulation efforts of the child in Study I involved regular steps, while those of the child in Study II involved pushing responses (i.e., he pushed himself forward with both feet while sitting on the walker's saddle). The man involved in Study III combined his poor ambulation performance with problem behavior, such as shouting or slapping his face. The results were positive for all three participants. The first two participants had a large increase in the number of steps/pushes performed during the ambulation events provided and in the percentages of those events that they completed independently. The third participant improved his ambulation performance as well as his general behavior (i.e., had a decline in problem behavior and an increase in indices of happiness). The wide-ranging implications of the results are discussed. Copyright © 2013 Elsevier Ltd. All rights reserved.

Action of tacrolimus on Wistar rat kidneys implanted with Walker 256 carcinosarcoma Estudo da ação do tacrolimus em rins de ratos Wistar implantados com carcinossarcoma de Walker

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Cristiano Machado Inácio

2010-02-01

Full Text Available PURPOSE: To evaluate the development of Walker 256 tumor in male Wistar rats treated with tacrolimus using an experimental kidney tumor model. METHODS: 40 male Wistar rats were divided into four groups: Tumor group (TU (n=10, Tacrolimus-Tumor group (TT (n=10, Tacrolimus group (TC (n=10 and Control group (C (n=10. Treatment with tacrolimus was performed in groups TT and TC. Under anesthesia, the right kidney of each animal of TU and TT was accessed through a supraumbilical incision and inoculated with a 0.1mL solution containing 2x10(6 tumor cells (Walker 256 carcinosarcoma tumor cells. Group TC was treated with a saline solution. All the animals of groups TC and TT were treated with tacrolimus (5mg/kg/day by gavage for 15 days. TU group animals received saline by gavage for 15 days. On the 15th postoperative day, all animals were submitted to euthanasia and blood sampling for analysis of serum creatinine (Cr and blood urea nitrogen (BUN. Abdominal gross examination was performed, the right kidney removed and prepared for histological analysis by hematoxylin-eosin staining. The resulting data were submitted to statistical analysis by ANOVA. RESULTS: Statistical significance was found when comparing creatinine level between groups TU, TT and TC -TT group culminated with a marked increased in creatinine levels (Cr=1.013 ± 0.3028 mg/mL, TU group (Cr=0.5670 ± 0.03536 mg/dL P=0.00256, TC group (Cr =0.711 ± 0.1653 mg/mL P= 0.02832. Statistical significance was found when comparing BUN levels in TT group (71.32 ± 17.14 mg/mL, compared with TU group (45.83 ± 5.046 mg/dL, P=0.000318. There were no statistically significant differences between groups TT and TC (61.23 ± 9.503 mg/mL P=0.7242. Histological analysis showed a poor evolution in TT group with multiple foci of hemorrhage and cortical invasion by the Walker tumor. CONCLUSION: The Tacrolimus-treated group developed a more aggressive tumor and a drug-related nephrotoxic effect.OBJETIVO: Avaliar

Fenologia de Cornops aquaticum (Orthoptera: Acrididae associado a Eichhornia crassipes (Pontederiaceae em um Lago de Várzea na Amazônia Central, Brasil Phenology of Cornops aquaticum (Orthoptera: Acrididae associated with Eichhornia crassipes (Pontederiaceae in a Floodplain Lake in Central Amazonia, Brazil

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Carlos Elias Braga

2011-12-01

Full Text Available O gafanhoto Neotropical Cornops aquaticum (Bruner vive associado às macrófitas da família Pontederiaceae da qual se alimenta. Nos lagos da Amazônia Central, Eichhornia crassipes (Mart. Solms (mururé ou aguapé é considerada a planta hospedeira de maior importante para este gafanhoto. Esse trabalho teve o objetivo de realizar um estudo fenológico de adultos e ninfas desse gafanhoto em associação a sua planta hospedeira, frente ao regime hidrológico da Amazônia Central. Tal estudo foi realizado entre os meses de abril de 2006 a agosto de 2007 no Lago Camaleão (03º17'05"S 60º11'11"W, na várzea da Amazônia Central. Para isso, utilizou-se uma rede entomológica (70 cm de diâmetro adaptada para a captura dos gafanhotos. Onde foram capturados 850 exemplares (296 adultos e 554 ninfas. Observou-se que a abundância e a biomassa de adultos e de ninfas de C. aquaticum, bem como de sua macrófita hospedeira, estão relacionados com a oscilação sazonal do nível do rio (pulso de inundação.La tucura Neotropical, Cornops aquaticum (Bruner, vive asociada a las macrófitas de la familia Pontederiaceae, de las cuales se alimenta. En los lagos de la Amazonia Central, Eichhornia crassipes (Mart. Solms (camalote o aguape constituye la planta huésped más importante de esta tucura. El objetivo de este trabajo fue estudiar la fenología de los adultos y las ninfas de C. aquaticum en los camalotales de E. crassipes, en relación al régimen hidrológico de la Amazonia Central. Los muestreos se realizaron entre los meses de abril de 2006 a agosto de 2007, en el Lago Camaleón (03º17'05"S 60º 11 '11 "O en la Várzea de la Amazonia Central. Los individuos fueron capturados desde una embarcación a motor, utilizando una red entomológica de 70 cm de diámetro. Durante este estudio, se capturaron un total de 850 ejemplares (296 adultos y 554 ninfas. Se observó que la abundancia y la biomasa de los adultos y de las ninfas de C. aquaticum, así como la planta huésped, están estrechamente relacionados con la oscilación estacional del nivel del río (pulso de inundación.The Neotropical grasshopper Cornops aquaticum (Bruner lives associated with the macrophytes of the family Pontederiaceae from which it feeds. In the lakes of Central Amazon, Eichhornia crassipes (Mart. Solms (water hyacinth or Mururé is considered the most important host plant for this grasshopper. This study aimed to perform a phenological study of adults and nymphs of grasshopper in association with its host plant, compared to the hydrological regime of the Central Amazon. This study was undertaken between April 2006 and August 2007 at the Chameleon Lake (03 17'05"S, 60 11'11"W in the Central Amazon floodplain. An entomological net adapted for catching grasshoppers was used. 850 individuals (296 adults and 554 nymphs were captured. It was observed that the abundance and biomass of adults and nymphs of C. aquaticum, as well as their macrophyte host are related to the "flood pulse", ie. to the seasonal oscillations of the Amazonian rivers.

Diagnosis of Van den Ende-Gupta syndrome: Approach to the Marden-Walker-like spectrum of disorders.

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Niederhoffer, Karen Y; Fahiminiya, Somayyeh; Eydoux, Patrice; Mawson, John; Nishimura, Gen; Jerome-Majewska, Loydie A; Patel, Millan S

2016-09-01

Marden-Walker syndrome is challenging to diagnose, as there is significant overlap with other multi-system congenital contracture syndromes including Beals congenital contractural arachnodactyly, D4ST1-Deficient Ehlers-Danlos syndrome (adducted thumb-clubfoot syndrome), Schwartz-Jampel syndrome, Freeman-Sheldon syndrome, Cerebro-oculo-facio-skeletal syndrome, and Van den Ende-Gupta syndrome. We discuss this differential diagnosis in the context of a boy from a consanguineous union with Van den Ende-Gupta syndrome, a diagnosis initially confused by the atypical presence of intellectual disability. SNP microarray and whole exome sequencing identified a homozygous frameshift mutation (p.L870V) in SCARF2 and predicted damaging mutations in several genes, most notably DGCR2 (p.P75L) and NCAM2 (p.S147G), both possible candidates for this child's intellectual disability. We review distinguishing features for each Marden-Walker-like syndrome and propose a clinical algorithm for diagnosis among this spectrum of disorders. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

The influence of septal lesions on sodium and water retention induced by Walker 256 tumor

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F. Guimarães

1999-03-01

Full Text Available In the course of studies on the effects of septal area lesions on neuroimmunomodulation and Walker 256 tumor development, it was observed that tumor-induced sodium and water retention was less marked in lesioned than in non-lesioned rats. In the present study possible mechanisms involved in this phenomenon were investigated. The experiments were performed in septal-lesioned (LW; N = 15 and sham-operated (SW; N = 7 8-week-old male Wistar rats, which received multifocal simultaneous subcutaneous (sc inoculations of Walker 256 tumor cells about 30 days after the stereotaxic surgery. Control groups (no tumor, sham-operated food-restricted (SFR, N = 7 and lesioned food-restricted (LFR, N = 10 were subjected to a feeding pattern similar to that observed in tumor-bearing animals. Multifocal inoculation of Walker 256 tumor rapidly induces anorexia, which is paradoxically accompanied by an increase in body weight, as a result of renal Na+ and fluid retention. These effects of the tumor were also seen in LW rats, although the rise in fractional sodium balance during the early clinical period was significantly smaller than in SW rats (day 4: SW = 47.6 ± 6.4% and LW = 13.8 ± 5.2%; day 5: SW = 57.5 ± 3.5% and LW = 25.7 ± 4.8%; day 6: SW = 54.4 ± 3.8% and LW = 32.1 ± 4.4%; P<0.05, suggesting a temporary reduction in tumor-induced sodium retention. In contrast, urine output was significantly reduced in SW rats and increased in LW rats (LW up to -0.85 and SW up to 4.5 ml/100 g body weight, with no change in osmolar excretion. These temporary changes in the tumor's effects on LW rats may reflect a "reversal" of the secondary central antidiuretic response induced by the tumor (from antidiuretic to diuretic.

Parenchymal neurocutaneous melanosis in association with intraventricular dermoid and Dandy-walker variant: a case report

Energy Technology Data Exchange (ETDEWEB)

Kim, Young Joo; Won, Yoo Dong; Kim, Ki Tae; Chang, Eun Deok; Huh, Pil Woo [The Catholic University of Korea, College of Medicine, Uijongbu (Korea, Republic of)

2006-06-15

Neurocutaneous melanosis (NCM) is a rare congenital disease that is characterized by the presence of large or multiple congenital melanocytic nevi and melanotic lesions of the central nervous system. We report here on the CT and MR imaging findings of an unusual case of NCM that was associated with intraventricular dermoid and Dandy-Walker malformation.

Neimark-Sacker bifurcations and evidence of chaos in a discrete dynamical model of walkers

International Nuclear Information System (INIS)

Rahman, Aminur; Blackmore, Denis

2016-01-01

Bouncing droplets on a vibrating fluid bath can exhibit wave-particle behavior, such as being propelled by interacting with its own wave field. These droplets seem to walk across the bath, and thus are dubbed walkers. Experiments have shown that walkers can exhibit exotic dynamical behavior indicative of chaos. While the integro-differential models developed for these systems agree well with the experiments, they are difficult to analyze mathematically. In recent years, simpler discrete dynamical models have been derived and studied numerically. The numerical simulations of these models show evidence of exotic dynamics such as period doubling bifurcations, Neimark–Sacker (N–S) bifurcations, and even chaos. For example, in [1], based on simulations Gilet conjectured the existence of a supercritical N-S bifurcation as the damping factor in his one- dimensional path model. We prove Gilet’s conjecture and more; in fact, both supercritical and subcritical (N-S) bifurcations are produced by separately varying the damping factor and wave-particle coupling for all eigenmode shapes. Then we compare our theoretical results with some previous and new numerical simulations, and find complete qualitative agreement. Furthermore, evidence of chaos is shown by numerically studying a global bifurcation.

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

Science.gov (United States)

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

Extraction and radioimmunological detection of parathormone from the hypercalcaemic Walker carcinosarcoma 256 of the rat

International Nuclear Information System (INIS)

Schieber, P.

1978-01-01

Out of 1.5 kg solid Walker carcionosarcoma 256, 1682 mg extract were obtained by a specific parathormone extraction technique. This extract was analyzed radioimmunologically with a bovine parathormone standard for comparison. The radioimmunological analysis showed a comparable immunoreactivity in tumour extract and bovine parathormone. This can be seen in the small difference in the rise of regression lines. (orig.) [de

"It's Not so Much a Job but a Relationship": A Response to Romer and Walker

Science.gov (United States)

O'Brien, John

2013-01-01

Romer and Walker's "Appreciative Inquiry," which obtained input from 16 capable personal assistants, challenges some influential assumptions about personal assistance and opens a way to think about the demanding work of developing capable and committed personal assistants. Attempts to depersonalize the relationship between people…

Computation of partially invariant solutions for the Einstein Walker manifolds' identifying equations

Science.gov (United States)

Nadjafikhah, Mehdi; Jafari, Mehdi

2013-12-01

In this paper, partially invariant solutions (PISs) method is applied in order to obtain new four-dimensional Einstein Walker manifolds. This method is based on subgroup classification for the symmetry group of partial differential equations (PDEs) and can be regarded as the generalization of the similarity reduction method. For this purpose, those cases of PISs which have the defect structure δ=1 and are resulted from two-dimensional subalgebras are considered in the present paper. Also it is shown that the obtained PISs are distinct from the invariant solutions that obtained by similarity reduction method.

C. Walker-Said and J. D. Kelly (eds), Corporate Social Responsibility? Human Rights in the New Global Economy (Chicago, IL: The University of Chicago Press, 2015), 392 pp

DEFF Research Database (Denmark)

Whelan, Glen

2017-01-01

Book review of: Charlotte Walker-Said and John D. Kelly (eds), Corporate Social Responsibility? Human Rights in the New Global Economy (Chicago, IL: The University of Chicago Press, 2015), 392 pp.......Book review of: Charlotte Walker-Said and John D. Kelly (eds), Corporate Social Responsibility? Human Rights in the New Global Economy (Chicago, IL: The University of Chicago Press, 2015), 392 pp....

Decorin is one of the proteoglycans expressed in Walker 256 rat mammary carcinoma

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S.M. Oba-Shinjo

2003-08-01

Full Text Available Proteoglycan and glycosaminoglycan content was analyzed in a model of rat mammary carcinoma to study the roles of these compounds in tumorigenesis. Hyaluronic acid and proteoglycans bearing chondroitin and/or dermatan sulfate chains were detected in solid tumors obtained after subcutaneous inoculation of Walker 256 rat carcinoma cells. About 10% of sulfated glycosaminoglycan chains corresponded to heparan sulfate. The small leucine-rich proteoglycan, decorin, was identified as one of the proteoglycans, in addition to others of higher molecular weight, by cross-reaction with an antiserum raised against pig laryngeal decorin and by N-terminal amino acid sequencing. Decorin was separated from other proteoglycans by hydrophobic chromatography and its complete structure was determined. It has a molecular weight of about 85 kDa and a dermatan chain of 45 kDa with 4-sulfated disaccharides. After degradation of the glycosaminoglycan chain, three core proteins of different molecular weight (36, 46 and 56 kDa were identified. The presence of hyaluronic acid and decorin has been reported in a variety of tumors and tumor cells. In the Walker 256 mammary carcinoma model, hyaluronic acid may play an important role in tumor progression, since it provides a more hydrated extracellular matrix. On the other hand, decorin, which is expressed by stromal cells, represents a host defense response to tumor growth.

La tribu Pycnopalpini n. trib. (Orthoptera, Tettigonioidea, Phaneropteridae: segunda contribución a la organización supragenérica de los faneropterinos neotropicales

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Cadena–Castañeda, O. J.

2014-12-01

Full Text Available The tribe Pycnopalpini n. trib. (Orthoptera, Tettigonioidea, Phaneropteridae: second contribution to neotropical Phaneropterinae The new tribe Pycnopalpini is proposed, based on morphological similarity among the genera Hetaira, Pycnopalpa, Topana (Pycnopalpina n. subtr., Dolichocercus, Oxyprorella, Theia, and TheiellaTheia unicolor, Theia bifurcata n. sp., Theiella amazonica n. sp., Theiella andina n. sp., and D. santanderensis n. sp. from Colombia, and D. costaricensis n. sp. from Costa Rica. Hetaira (Atopana morona and Hetaira (Atopana varia are recorded from the Colombian Amazon, where both species seem to occur sympatrically. Theia peruviana n. comb. is also recorded from the Colombian Amazon, where it seems to occur sympatrically with T. bifurcata. The paper contains additional new combinations, and Oxyprorella gregoirea syn. n. is a new synonym for Insara bolivari. This contribution reconsiders the neotropical subfamily Phaneropterinae, aiming to establish the limits of the tribes and genera of this subfamily.

Autoregressive-moving-average hidden Markov model for vision-based fall prediction-An application for walker robot.

Science.gov (United States)

Taghvaei, Sajjad; Jahanandish, Mohammad Hasan; Kosuge, Kazuhiro

2017-01-01

Population aging of the societies requires providing the elderly with safe and dependable assistive technologies in daily life activities. Improving the fall detection algorithms can play a major role in achieving this goal. This article proposes a real-time fall prediction algorithm based on the acquired visual data of a user with walking assistive system from a depth sensor. In the lack of a coupled dynamic model of the human and the assistive walker a hybrid "system identification-machine learning" approach is used. An autoregressive-moving-average (ARMA) model is fitted on the time-series walking data to forecast the upcoming states, and a hidden Markov model (HMM) based classifier is built on the top of the ARMA model to predict falling in the upcoming time frames. The performance of the algorithm is evaluated through experiments with four subjects including an experienced physiotherapist while using a walker robot in five different falling scenarios; namely, fall forward, fall down, fall back, fall left, and fall right. The algorithm successfully predicts the fall with a rate of 84.72%.

POMT1-associated walker-warburg syndrome: a disorder of dendritic development of neocortical neurons.

Science.gov (United States)

Judas, M; Sedmak, G; Rados, M; Sarnavka, V; Fumić, K; Willer, T; Gross, C; Hehr, U; Strahl, S; Cuk, M; Barić, I

2009-02-01

We have analyzed the morphology and dendritic development of neocortical neurons in a 2.5-month-old infant with Walker-Warburg syndrome homozygotic for a novel POMT1 gene mutation, by Golgi methods. We found that pyramidal neurons frequently displayed abnormal (oblique, horizontal, or inverted) orientation. A novel finding of this study is that members of the same population of pyramidal neurons display different stages of development of their dendritic arborizations: some neurons had poorly developed dendrites and thus resembled pyramidal neurons of the late fetal cortex; for some neurons, the level of differentiation corresponded to that in the newborn cortex; finally, some neurons had quite elaborate dendritic trees as expected for the cortex of 2.5-month-old infant. In addition, apical dendrites of many pyramidal neurons were conspiciously bent to one side, irrespective to the general orientation of the pyramidal neuron. These findings suggest that Walker-Warburg lissencephaly is characterized by two hitherto unnoticed pathogenetic changes in the cerebral cortex: (a) heterochronic decoupling of dendritic maturation within the same neuronal population (with some members significantly lagging behind the normal maturational schedule) and (b) anisotropically distorted shaping of dendritic trees, probably caused by patchy displacement of molecular guidance cues for dendrites in the malformed cortex. Copyright Georg Thieme Verlag KG Stuttgart New York.

DO INFANTS USING BABY WALKERS SUFFER DEVELOPMENTAL DELAYS IN ACQUISITION OF MOTOR SKILLS?

OpenAIRE

A. Talebian; A. Honarpishe; A. Taghavi; E. Fakharian; M. Parsa; GA. Mousavi

2008-01-01

 AbstractObjectiveDevelopment is a complex process, completed over a specific period of time, through the maturation of the nervous system. It is affected by genetic, ethnic, nutritional, social, and economic factors; one of the environmental factors affecting the acquisition of motor skills in infants is the use of baby walkers. Since this device is very commonly used for infants in our country, we conducted this study to evaluate its effects on the acquisition of motor skills in this age gr...

Effects of aquatic walking exercise using a walker in a chronic stroke patient

OpenAIRE

Matsuda, Tadashi; Akezaki, Yoshiteru

2017-01-01

[Purpose] The aim of this study was to examine the usefulness of aquatic walking exercise using a walker for chronic stroke patients. We also examined the psychological effects on the study subject and the primary caregiver before and after aquatic walking exercise. [Subject and Methods] The subject was a 60-year-old male with bilateral paralysis after a cerebrovascular accident. The Fugl-Meyer Assessment (FMA) total score was 116 on the right and 115 on the left. The intervention combined aq...

Effects Of Walker 256 Carcinoma On Metabolic Alterations During The Evolution Of Pregnancy.

OpenAIRE

Cintra-Gomes M.C.; Cury L.; Parreira M.R.; Elias C.F.; Areas M.A.

1990-01-01

The control of pregnant cancer patients is difficult because it involves both mother and fetus, and the metabolic alterations in the cancer host induce a massive mobilization of nutrients diverted to the neoplastic cells. The purpose of the present study was to determine the evolution of the Walker 256 carcinoma in pregnant rats and its consequences on fetal development. The results showed that the tumors displayed a very rapid rate of growth and induced a reduction in fetal weights in the pr...

WATER TEMPERATURE and other data from USS WALKER from 1991-07-01 to 1991-07-10 (NODC Accession 9100147)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The data in this accession were collected from ship WALKER between July 1, 1991 to July 10, 1991. The real time data of water temperature at varying depth...

Neuropsychological and Behavioural Phenotype of Dandy-Walker Variant Presenting in Chromosome 22 Trisomy: A Case Study

Science.gov (United States)

Searson, Ruth; Hare, Dougal Julian; Sridharan, Sridhar

2013-01-01

In this study, a case of Dandy-Walker variant syndrome associated with trisomy 22 in a 17-year-old man is described. This is the first account of this combination in a person surviving into adulthood, and the neuropsychological and behavioural presentation is described in detail and a clinical formulation is presented for the benefit of…

Changes in Central Walker Lane Strain Accommodation near Bridgeport, California; as told by the Stanislaus Group

Science.gov (United States)

Carlson, C. W.; Pluhar, C. J.; Glen, J. M.; Farner, M. J.

2012-12-01

Accommodating ~20-25% of the dextral-motion between the Pacific and North American plates the Walker Lane is represented as an elongate, NW oriented, region of active tectonics positioned between the northwesterly-translating Sierra Nevada microplate and the east-west extension of the Basin and Range. This region of transtension is being variably accommodated on regional-scale systems of predominantly strike-slip faulting. At the western edge of the central Walker Lane (ca. 38°-39°N latitude) is a region of crustal-scale blocks bounded by wedge-shaped depositional-basins and normal-fault systems, here defined as the west-central Walker Lane (WCWL). Devoid of obvious strike-slip faulting, the presence of tectonic-block vertical-axis rotations in the WCWL represents unrecognized components of dextral-shearing and/or changes of strain-accommodation over time. We use paleomagnetic reference directions for Eureka Valley Tuff (EVT) members of the late Miocene Stanislaus Group as spatial and temporal markers for documentation of tectonic-block vertical-axis rotations near Bridgeport, CA. Study-site rotations revealed discrete rotational domains of mean vertical-axis rotation ranging from ~10°-30° with heterogeneous regional distribution. Additionally, the highest measured magnitudes of vertical-axis rotation (~50°-60° CW) define a 'Region of High Strain' that includes the wedge-shaped Bridgeport Valley (Basin). This study revealed previously-unrecognized tectonic rotation of reference direction sites from prior studies for two (By-Day and Upper) of the three members of the EVT, resulting in under-estimates of regional strain accommodation by these studies. Mean remanent directions and virtual geomagnetic poles utilized in our study yielded a recalculated reference direction for the By-Day member of: Dec.=353.2°; Inc.= 43.7°; α95=10.1, in agreement with new measurements in the stable Sierra Nevada. This recalculated direction confirmed the presence of previously

Stability of geodesic imcompleteness for Robertson-Walker space-times

International Nuclear Information System (INIS)

Beem, J.K.

1981-01-01

Let (M,g) be a Lorentzian warped product space-time M = (a, b) X H,g = -dt 2 x fh, where -infinity -infinity and (H,h) is homogeneous, then the past incompleteness of every timelike geodesic of (M,g) is stable under small C 0 perturbations in the space Lor(M) of Lorentzian metrics for M. Also it is shown that if (H,h) is isotropic and (M,g) contains a past-inextendible, past-incomplete null geodesic, then the past incompleteness of all null geodesics is stable under small C 1 perturbations in Lor(M). Given either the isotropy or homogeneity of the Riemannian factor, the background space-time (M,g) is globally hyperbolic. The results of this paper, in particular, answer a question raised by D. Lerner for big bang Robertson-Walker cosmological models affirmatively. (author)

Review of the North American species of Marimatha Walker with descriptions of three new species (Lepidoptera, Noctuidae, Eustrotiinae and the description of Pseudomarimatha flava (Noctuinae, Elaphriini, a new genus and species confused with Marimatha

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Clifford Ferris

2010-03-01

Full Text Available Seven species of Marimatha Walker are examined, five of which occur in North America. In addition to the existing species M. nigrofimbria (Guenee, M. tripuncta (Moschler is reported from North America for the first time and three new species are described from southwestern North America: M. piscimala, M. squala, and M. quadrata. Marimatha alboflava (Walker, M. botyoides (Guenee, and M. dinumeratalis (Walker are discussed in terms of the generic name Marimatha, and M. aurifera (Walker is discussed in relation to the identity of M. tripuncta. A generic diagnosis, key to species, descriptions, and illustrations of adults and genitalia are included. A new genus and species is proposed for a species currently placed as an undescribed species of Marimatha, but tympanal and genital characters and mtDNA suggest an association with the subfamily Noctuinae, tribe Elaphriini.

A test of the thermal melanism hypothesis in the wingless grasshopper Phaulacridium vittatum.

Science.gov (United States)

Harris, Rebecca M; McQuillan, Peter; Hughes, Lesley

2013-01-01

Altitudinal clines in melanism are generally assumed to reflect the fitness benefits resulting from thermal differences between colour morphs, yet differences in thermal quality are not always discernible. The intra-specific application of the thermal melanism hypothesis was tested in the wingless grasshopper Phaulacridium vittatum (Sjöstedt) (Orthoptera: Acrididae) first by measuring the thermal properties of the different colour morphs in the laboratory, and second by testing for differences in average reflectance and spectral characteristics of populations along 14 altitudinal gradients. Correlations between reflectance, body size, and climatic variables were also tested to investigate the underlying causes of clines in melanism. Melanism in P. vittatum represents a gradation in colour rather than distinct colour morphs, with reflectance ranging from 2.49 to 5.65%. In unstriped grasshoppers, darker morphs warmed more rapidly than lighter morphs and reached a higher maximum temperature (lower temperature excess). In contrast, significant differences in thermal quality were not found between the colour morphs of striped grasshoppers. In support of the thermal melanism hypothesis, grasshoppers were, on average, darker at higher altitudes, there were differences in the spectral properties of brightness and chroma between high and low altitudes, and temperature variables were significant influences on the average reflectance of female grasshoppers. However, altitudinal gradients do not represent predictable variation in temperature, and the relationship between melanism and altitude was not consistent across all gradients. Grasshoppers generally became darker at altitudes above 800 m a.s.l., but on several gradients reflectance declined with altitude and then increased at the highest altitude.

Genetic variation and geographic differentiation among populations of the nonmigratory agricultural pest Oedaleus infernalis (Orthoptera: Acridoidea) in China.

Science.gov (United States)

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, θ(II), 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. © The Author 2015. Published by Oxford University Press on behalf of the Entomological Society of America.

Comparing Arc-shaped Feet and Rigid Ankles with Flat Feet and Compliant Ankles for a Dynamic Walker

DEFF Research Database (Denmark)

Kuhlemann, Ilyas; Matthias Braun, Jan; Wörgötter, Florentin

2014-01-01

In this paper we show that exchanging curved feet and rigid ankles by at feet and compliant ankles improves the range of gait parameters for a bipedal dynamic walker. The new lower legs were designed such that they t to the old set-up, allowing for a direct and quantitative comparison. The dynamic...

Dandy Walker Syndrome with Unusual Associated Findings in a Fetal Autopsy Study

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Surekha U Arakeri

2015-01-01

Full Text Available Dandy Walker Syndrome (DWS is a congenital brain malformation characterized by hypoplasia or absence of cerebellar vermis, cystic dilatation of fourth ventricle and hydrocephalus. It is frequently associated with other congenital anomalies. Associated central nervous system anomalies such as agenesis of corpus callosum and vermis are associated with poor prognosis. Association of DWS with congenital absence of spleen is life threatening condition and has been reported very rarely. Autopsy findings of DWS with association of congenital absence of corpus callosum, vermis and spleen are reported in a stillborn fetus of 28 weeks gestation and review of relevant literature was done

[Diversity and distribution of grasshoppers (Orthoptera: Acridoidea) in grasslands of the Southern Pampas region, Argentina].

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Mariottini, Yanina; De Wysiecki, María Laura; Lange, Carlos Ernesto

2013-03-01

In Argentina, the grasslands of Pampas region comprise approximately 15% of the country. As in other grasslands of the world, grasshoppers are among the most important native herbivores. Their economic importance has been recognized in Argentina since the mid to late nineteenth century, since outbreaks of different species have become recurrent phenomena. Therefore, the main objective of this work was to study their diversity and distribution in grasslands of the Southern Pampas region (Laprida county, Buenos Aires province), as one of the most affected areas. The study was conducted during five seasons (2005-10). Sampling sites were represented by the most common plant communities in this area, classified in four categories: native grasslands, disturbed grasslands, implanted pastures and halophilous grasslands. The samplings were conducted from mid-spring to early autumn, with five or six samples per season. We estimated the following population descriptors: species richness (S), eveness (E), dominance (J), and diversity index (H'). In order to evaluate the similitude of the grasshopper communities present in the different plant communities, we used qualitative and quantitative coefficients of similitude. A total of 22 species of grasshoppers were collected, of which 21 belong to the family Acrididae. The subfamily Melanoplinae was the most diverse with eight species. The largest species richness was recorded in native grasslands (18). The different communities of grasshoppers had similar indices of evenness and dominance (p>0.05). Considering all plant communities, the average value of Shannon-Wiener index was 1.58+/-0.075. There was a positive correlation between evenness index and species richness (pgrasshoppers species richness, and diversity of grasshoppers. According to the qualitative indices applied, the similitude between different grasshopper communities was higher than 60%. In general, the species that had a higher frequency of occurrence showed greater

Anandan quantum phase for a neutral particle with Fermi-Walker reference frame in the cosmic string background

International Nuclear Information System (INIS)

Bakke, Knut; Furtado, C.

2010-01-01

We study geometric quantum phases in the relativistic and non-relativistic quantum dynamics of a neutral particle with a permanent magnetic dipole moment interacting with two distinct field configurations in a cosmic string spacetime. We consider the local reference frames of the observers are transported via Fermi-Walker transport and study the influence of the non-inertial effects on the phase shift of the wave function of the neutral particle due to the choice of this local frame. We show that the wave function of the neutral particle acquires non-dispersive relativistic and non-relativistic quantum geometric phases due to the topology of the spacetime, the interaction between the magnetic dipole moment with external fields and the spin-rotation coupling. However, due to the Fermi-Walker reference frame, no phase shift associated to the Sagnac effect appears in the quantum dynamics of a neutral particle. We show that in the absence of topological defect, the contribution to the quantum phase due to the spin-rotation coupling is equivalent to the Mashhoon effect in non-relativistic dynamics. (orig.)

Finite-temperature effects in the φ4-model in a Robertson-Walker universe

International Nuclear Information System (INIS)

Kundu, P.K.

1987-01-01

The computation of the one-loop trace anomaly in a massless, conformally coupled φ 4 -model displaying spontaneous symmetry breaking in a spatially flat Robertson-Walker universe investigated in a previous paper, is extended to the case in which the physical system is in a state of thermal equilibrium. It is found that due to a nonperturbative nature of this effect the anomalous trace exhibits a rather nontrivial temperature dependence and cannot be expressed as a sum of contributions from the vacuum state and an ideal black-body radiation gas

Biological aspects of Periga circumstans Walker, 1855 (Lepidoptera: Saturniidae: Hemileucinae with larvae reared on khaki and mate-plant leaves

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A. Specht

Full Text Available The goal of the present study was to investigate biological aspects of Periga circumstans Walker, 1855 (Lepidoptera: Saturniidae: Hemileucinae whose larvae were fed on leaves of khaki-plant (Diospyros khaki Linnaeus - Ebenaceae and Mate-plant (Ilex paraguariensis Saint Hilaire - Aquifoliaceae leaves. The biological parameters were obtained from specimens kept under controlled conditions: temperature of 25 ± 1 °C, relative humidity of 70 ± 10%, and photoperiod of 12 hours. For each developmental stage, morphological and ethological parameters are described. The larvae passed through six instars with a growth average rate of 1.4 for each instar. The host plants influenced significantly only the total duration of the larval phase, which was prolonged for larvae fed on khaki-plant leaves. Several aspects related to the morphology and the ethology of P. circumstans are similar to those described for Lonomia obliqua Walker, 1855.

Effects of field interactions upon particle creation in Robertson-Walker universes

International Nuclear Information System (INIS)

Birrell, N.D.; Davies, P.C.W.; Ford, L.H.

1980-01-01

Particle creation due to field interactions in an expanding Robertson-Walker universe is investigated. A model in which pseudoscalar mesons and photons are created as a result of their mutual interaction is considered, and the energy density of created particles is calculated in model universes which undergo a bounce at some maximum curvature. The free-field creation of non-conformally coupled scalar particles and of gravitons is calculated in the same space-times. It is found that if the bounce occurs at a sufficiently early time the interacting particle creation will dominate. This result may be traced to the fact that the model interaction chosen introduces a length scale which is much larger than the Planck length. (author)

Dandy-walker malformation and the contribution of radioisotopic studies of cerebral spinal fluid dynamics to its diagnosis

International Nuclear Information System (INIS)

Palma, A.; Nazar, N.; Castro, M.; Olea, E.; Guzmann, G.

1982-01-01

On case of Dandy-Walker malformation is described. The diagnosis was mainly reached by dynamic isotope studies of CSF, and was confirmed by axial computerized tomography. The importance of these examinations is discussed, not only as a means of understanding the aetiopathology, but especially because of the functional information they give and the therapeutic consequences they have. (Author)

Rapid Communication. Tamarixia monesus (Walker (Hym.: Eulophidae parasitoid of Bactericera tremblayi (Wagner, 1961 (Hemiptera: Triozidae in Iran

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Lotfalizadeh Hossein

2016-08-01

Full Text Available Bactericera tremblayi (Wagner, 1961 (Hemiptera: Triozidae is reported on Brassica oleracea var. capitata (Brassicaceae in northwestern Iran. Tamarixia monesus (Walker (Hymenoptera: Chalcidoidea, Eulophidae was reared for the first time on B. tremblayi, and compared with Tamarixia tremblayi, another parasitoid of B. tremblayi. This is a new record of T. monesus from the Middle East.

Irradiation of solid Walker carcino-sarcomas after synchronisation with hydroxyurea

International Nuclear Information System (INIS)

Wayss, K.; Mattern, J.; Volm, M.

1980-01-01

Sprague-Dawley rats with solid Walker carcino-sarcomas were synchronized with hydroxyurea (HU; 6 x 50 mg and 1 x 300 mg HU/kg body weight) and then irradiated at different time points ( 60 Co). The synchronized tumors showed a significant delay of growth when irradiation was applied in the late G1 phase, at the transition G1/S and in the early S phase. The remaining phases of the cell cycle, especially the S phase showed the same sensitivity as the non-synchronized controls. Improvement of therapy by irradiation after HU application was largely due to the synchronization of tumor cells. Only the increased therapeutic effect of irradiation shortly after application of HU can be explained also by combination of both HU and irradiation. (orig.) 891 MG/orig. 892 MKO [de

Case 3724 - Metochus abbreviatus Scott, 1874 (Insecta, Heteroptera): proposed precedence over Rhyparochromus erosus Walker, 1872 (currently Metochus erosus)

Science.gov (United States)

The purpose of this application, under Article 23.9.3 of the Code, is to conserve the widely used specific name Metochus abbreviatus Scott, 1874, for a species of rhyparochromid bugs from East Asia. The name is threatened by the senior subjective synonym Metochus erosus (Walker, 1872), which has bee...

75 FR 19880 - Safety Zone; BW PIONEER at Walker Ridge 249, Outer Continental Shelf FPSO, Gulf of Mexico

Science.gov (United States)

2010-04-16

... BW PIONEER, a Floating Production, Storage and Offloading (FPSO) system, at Walker Ridge 249 in the Outer Continental Shelf. The purpose of the safety zone is to protect the FPSO from vessels operating... reduces the threat of allisions, oil spills, and releases of natural gas, and thereby protects the safety...

The role of the host-specific grasshopper Cornops aquaticum (Orthoptera: Acrididae) as consumer of native Eichhornia crassipes (Pontederiaceae) floating meadows.

Science.gov (United States)

Franceschini, María Celeste; De Wysiecki, María Laura; Poi de Neiff, Alicia; Galassi, María Eugenia; Martínez Fedra, Solange

2011-09-01

Cornops aquaticum is a widely distributed semiaquatic grasshopper in the Neotropics. The development, feeding and oviposition of C. aquaticum take place on Pontederiaceae, especially on species of Eichhornia. Several aspects of the feeding of C. aquaticum are studied because is one of the most important herbivores of the highly invasive floating Eichhornia crassipes in native areas. The aims of this paper were: (1) to quantify the amount of E. crassipes consumed by C. aquaticum, (2) to determine the growth rate and the conversion efficiency of food ingested by this grasshopper, and (3) to determine the possible effect of consumption on E. crassipes productivity. Thirty individuals from each specific age class were used in the experiment: nymphs A, nymphs B, adult males and adult females. Insects were individually confined in plastic pots with a leaf of E. crassipes. We estimated feeding by individual, consumption index (CI), relative growth rate (GR) and efficiency of conversion of ingested food to body substance (ECI). The impact of C. aquaticum consumption on E. crassipes floating meadows was assessed with the abundance of the grasshopper, and the available data on primary production of the host plant at the study site. Food intake of C. aquaticum was 11.23% of plant productivity. Food consumption, growth rate and food conversion efficiency of this grasshopper varied according to the specific age classes. Damage caused by C. aquaticum is high in comparison with the damage caused by other semiaquatic and grassland grasshoppers, however it is not enough to prevent the growth and coverage of native E. crassipes floating meadows because abundance of grasshoppers are realtively low and the growth rate and productivity of the host plant is high.

New species of Zygoclistron Rehn, 1905 (Insecta: Orthoptera: Acrididae: Copiocerinae) in the central corridor of the Atlantic Forest biome.

Science.gov (United States)

Silva, Daniela Santos Martins; Pereira, Marcelo Ribeiro; Domenico, Fernando Campos De; Sperber, Carlos Frankl

2016-06-17

Herein we describe a new species of Copiocerinae, Zygoclistron ruschii Silva n. sp., from Atlantic Forest remnants in southeastern Brazil, collected from the Reserva Biológica Augusto Ruschi in the Santa Teresa municipality, Espírito Santo state, Brazil. The diagnosis of this new species is based on phallic complex and terminalia characters.

The role of the host-specific grasshopper Cornops aquaticum (Orthoptera: Acrididae as consumer of native Eichhornia crassipes (Pontederiaceae floating meadows

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María Celeste Franceschini

2011-09-01

Full Text Available Cornops aquaticum is a widely distributed semiaquatic grasshopper in the Neotropics. The development, feeding and oviposition of C. aquaticum take place on Pontederiaceae, especially on species of Eichhornia. Several aspects of the feeding of C. aquaticum are studied because is one of the most important herbivores of the highly invasive floating Eichhornia crassipes in native areas. The aims of this paper were: (1 to quantify the amount of E. crassipes consumed by C. aquaticum, (2 to determine the growth rate and the conversion efficiency of food ingested by this grasshopper, and (3 to determine the possible effect of consumption on E. crassipes productivity. Thirty individuals from each specific age class were used in the experiment: nymphs A, nymphs B, adult males and adult females. Insects were individually confined in plastic pots with a leaf of E. crassipes. We estimated feeding by individual, consumption index (CI, relative growth rate (GR and efficiency of conversion of ingested food to body substance (ECI. The impact of C. aquaticum consumption on E. crassipes floating meadows was assessed with the abundance of the grasshopper, and the available data on primary production of the host plant at the study site. Food intake of C. aquaticum was 11.23% of plant productivity. Food consumption, growth rate and food conversion efficiency of this grasshopper varied according to the specific age classes. Damage caused by C. aquaticum is high in comparison with the damage caused by other semiaquatic and grassland grasshoppers, however it is not enough to prevent the growth and coverage of native E. crassipes floating meadows because abundance of grasshoppers are realtively low and the growth rate and productivity of the host plant is high. Rev. Biol. Trop. 59 (3: 1407-1418. Epub 2011 September 01.Cornops aquaticum es una tucura semiacuática Neotropical que vive asociada a las Pontederiaceae y constituye uno de los más importantes herbívoros de Eichhornia crassipes en áreas nativas. Los objetivos de este trabajo son: (1 cuantificar el consumo de C. aquaticum (2 determinar la tasa de crecimiento y la eficiencia de conversión del alimento ingerido de esta tucura, y (3 determinar el efecto del consumo en la productividad de E. crassipes. De cada categoría de edades de la población se utilizaron 30 individuos: ninfas A, ninfas B, adultos machos y hembras. Los insectos fueron confinados individualmente en recipientes con hojas de E. crassipes. Luego, se estimó el consumo por individuo, la tasa de consumo (CI, tasa de crecimiento (GR y la eficiencia de conversión del alimento (ECI. La abundancia de C. aquaticum se determinó en verano y con los datos de productividad de la planta se calculó el efecto del consumo sobre E. crassipes. La tasa de consumo, tasa de crecimiento y la eficiencia de conversión del alimento varió entre las distintas categorías de edades de la población. C. aquaticum consume el 11% de la productividad primaria de E. crassipes. Si bien el consumo es alto, el daño no produce mermas importantes en los camalotales debido a la abundancia relativamente baja de C. aquaticum y la alta productividad de la planta huésped.

Vaidya--Patel solution with Robertson--Walker metric as a rotating inflationary scenario

International Nuclear Information System (INIS)

Groen, O.; Soleng, H.H.

1988-01-01

The Vaidya--Patel solution of a rotating homogeneous fluid in the presence of a Maxwellian source-free electromagnetic field is interpretated as an inflationary scenario with a gauge field with local U(1) symmetry, a vacuum energy, and a rotating perfect fluid. An explicit solution is found to be expressible in terms of known solutions representing the radiation filled Robertson--Walker universe with a cosmological term. In the case that the rotating fluid is radiation, the discussion of the model is considerably simplified. How the time scale of transition into a pseudo-de Sitter stage, as observed by an observer following the rotating fluid, is affected by vorticity is also studied

Changes in Energy Cost and Total External Work of Muscles in Elite Race Walkers Walking at Different Speeds

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Chwała Wiesław

2014-12-01

Full Text Available The aim of the study was to assess energy cost and total external work (total energy depending on the speed of race walking. Another objective was to determine the contribution of external work to total energy cost of walking at technical, threshold and racing speed in elite competitive race walkers.

Alterations caused by physical training in pulmonary edema and loss of muscle mass in rats with Walker-256 tumor Alterações promovidas pelo treinamento físico no edema pulmonar e perda de massa muscular em ratos portadores de tumor Walker-256

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Rubens Cecchini

2008-10-01

Full Text Available Walker-256 tumor is a fast-growing tumor and has been studied under several metabolic aspects associated or not to cachexia. It was observed in our laboratory that animals with Walker-256 tumor, after spontaneous death (usually around the fifteenth day, showed significant pulmonary edema with fluid in the pleural cavity. Some studies have suggested that physical training improves the survival of animals with tumor and minimizes the effects of cachexia. The purpose of our work was to assess the pulmonary edema index as well as the cardiac and skeletal muscle mass, besides the survival of rats with Walker-256 tumor submitted previously to physical training through swimming (N. For this study male Wistar rats (200 to 220 g were used, submitted to physical training through swimming (1 hour; 5 days a week, four weeks. One day after the training, sedentary rats (C or trained ones (N were submitted to inoculation on the right flank of 8 x 107 Walker-256 tumor cells (T. Immediately after spontaneous death of these animals, the pulmonary edema index (PEI, cardiac and skeletal muscle mass (gastrocnemius and soleus were evaluated. Pulmonary edema was evaluated through the index calculated by the relation between lung and body weights of each animal, and multiplied by 100 (PP/PC x 100 (LEE et al., 2001. Muscle mass (MM index was calculated similarly. In normal animals the PEI is equal to 0,53±0,02 (n=20. In tumor-bearing rats after spontaneous death the PEI was significantly higher (2,62±0,31, n=18. After the physical training in rats without tumor, the PEI was 0,55±0,03 (n=5. Whereas in tumor-bearing rats previously trained, it was obtained a pulmonary edema index lower than that of the control group with tumor (1,46±0,16, n=5; pO tumor Walker-256 é um carcinoma de crescimento rápido e tem sido estudado sob vários aspectos metabólicos, associados ou não, à caquexia. Foi observado, em nosso laboratório, que em animais portadores de tumor Walker

Organic geochemistry and brine composition in Great Salt, Mono, and Walker Lakes

Science.gov (United States)

Domagalski, Joseph L.; Orem, W.H.; Eugster, H.P.

1989-01-01

Samples of Recent sediments, representing up to 1000 years of accumulation, were collected from three closed basin lakes (Mono Lake, CA, Walker Lake, NV, and Great Salt Lake, UT) to assess the effects of brine composition on the accumulation of total organic carbon, the concentration of dissolved organic carbon, humic acid structure and diagenesis, and trace metal complexation. The Great Salt Lake water column is a stratified Na-Mg-Cl-SO4 brine with low alkalinity. Algal debris is entrained in the high density (1.132-1.190 g/cc) bottom brines, and in this region maximum organic matter decomposition occurs by anaerobic processes, with sulfate ion as the terminal electron acceptor. Organic matter, below 5 cm of the sediment-water interface, degrades at a very slow rate in spite of very high pore-fluid sulfate levels. The organic carbon concentration stabilizes at 1.1 wt%. Mono Lake is an alkaline (Na-CO3-Cl-SO4) system. The water column is stratified, but the bottom brines are of lower density relative to the Great Salt Lake, and sedimentation of algal debris is rapid. Depletion of pore-fluid sulfate, near l m of core, results in a much higher accumulation of organic carbon, approximately 6 wt%. Walker Lake is also an alkaline system. The water column is not stratified, and decomposition of organic matter occurs by aerobic processes at the sediment-water interface and by anaerobic processes below. Total organic carbon and dissolved organic carbon concentrations in Walker Lake sediments vary with location and depth due to changes in input and pore-fluid sulfate concentrations. Nuclear magnetic resonance studies (13C) of humic substances and dissolved organic carbon provide information on the source of the Recent sedimentary organic carbon (aquatic vs. terrestrial), its relative state of decomposition, and its chemical structure. The spectra suggest an algal origin with little terrestrial signature at all three lakes. This is indicated by the ratio of aliphatic to

Energy-momentum tensor and definition of particle states for Robertson-Walker space-time

International Nuclear Information System (INIS)

Brown, M.R.; Dutton, C.R.

1978-01-01

A new regularization scheme is developed for calculating expectation values of the energy-momentum tensor of a quantized scalar field in Robertson-Walker space-times. Using this regularized stress tensor we consider a definition for the vacuum state of the scalar field on any initial hypersurface. Asymptotic methods are developed to investigate the structure of both the divergent and finite terms of the stress tensor when evaluated in this state. The conformal anomaly is discussed in the context of this model. It does not naturally enter into the analysis and we argue that its inclusion is unnecessary

Lonomia obliqua Walker (Lepidoptera: Saturniidae: hemostasis implications

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Silviane Maggi

2015-06-01

Full Text Available Summary In southern Brazil, since 1989, several cases of accidents produced by unwilling contact with the body of poisonous caterpillars of the moth species Lonomia obliqua Walker, 1855 (Lepidoptera: Saturniidae, were described. L. obliqua caterpillars have gregarious behavior and feed on leaves of host trees during the night, staying grouped in the trunk during the day, which favors the occurrence of accidents with the species. This caterpillar has the body covered with bristles that on contact with the skin of individuals, breaks and release their contents, inoculating the venom into the victim. The basic constitution of the venom is protein and its components produce physiological changes in the victim, which include disturbances in hemostasis. Hemorrhagic syndrome associated with consumption coagulopathy, intravascular hemolysis and acute renal failure are some of the possible clinical manifestations related to poisoning by L. obliqua. Specific laboratory tests for diagnosis of poisoning have not been described previously. The diagnosis of poisoning is made based on the patient's medical history, clinical manifestations, erythrocyte levels, and, primarily, parameters that evaluate blood coagulation. Treatment is performed with the use of supportive care and the administration of specific hyperimmune antivenom. Poisoning can be serious and even fatal.

Effect of Walker A mutation (K86M) on oligomerization and surface targeting of the multidrug resistance transporter ABCG2

DEFF Research Database (Denmark)

Henriksen, Ulla Birk; Gether, Ulrik; Litman, Thomas

2005-01-01

The ATP binding cassette (ABC) half-transporter ABCG2 (MXR/BCRP/ABCP) is associated with mitoxantrone resistance accompanied by cross-resistance to a broad spectrum of cytotoxic drugs. Here we investigate the functional consequences of mutating a highly conserved lysine in the Walker A motif...

Neurodevelopment in preschool idiopathic toe-walkers.

Science.gov (United States)

Martín-Casas, P; Ballestero-Pérez, R; Meneses-Monroy, A; Beneit-Montesinos, J V; Atín-Arratibel, M A; Portellano-Pérez, J A

2017-09-01

Idiopathic toe walking, a differential diagnosis for neurological and orthopaedic disorders, has been associated with neurodevelopmental alterations. Neurodevelopmental assessment at early ages using specific tests may improve management and follow-up of these patients. The aim of our study is to analyse the neurodevelopmental characteristics of preschool idiopathic toe-walkers (ITW) by comparing them to a control group. Our descriptive cross-sectional study compared possible risk factors, neurodevelopmental characteristics, and scores on the Child Neuropsychological Maturity Questionnaire (CUMANIN) between a group of 56 ITWs aged 3 to 6 and a control group including 40 children. The proportion of males was significantly higher in the ITW group (P=.008). The percentage of patients with a family history (P=.000) and biological risk factors during the perinatal period (P=.032) was also higher in this group. According to the parents' reports, motor coordination in ITWs was significantly poorer (59%; P=.009). ITWs scored significantly lower on CUMANIN subscales of psychomotricity (=0,001) and memory (P=.001), as well as in verbal development (P=.000), non-verbal development (P=.026), and overall development (P=.004). Foot preference was less marked in the ITW group (P=.047). The neurodevelopmental characteristics of our sample suggest that idiopathic toe walking is a marker of neurodevelopmental impairment. However, further studies are necessary to confirm these findings. Copyright © 2016 Sociedad Española de Neurología. Publicado por Elsevier España, S.L.U. All rights reserved.

Comments on the Dirac field in Friedmann-Robertson-Walker spacetime

International Nuclear Information System (INIS)

Khanal, U.

2006-12-01

Some further consequences about the massive Dirac field in Friedmann-Robertson-Walker universe are drawn. The comoving momenta of the particles in a closed universe are found to be quantized in units of half-integer, half being the contribution of the spin. This suggests that a gravitationally trapped fermion will have its momentum quantized. Both the comoving particle number and energy density are found not to be conserved in any finite volume of the universe. There exists a finite current that tends to enhance the density contrast. A series solution for the temporal part is used to show this effect. The particles distribute themselves in such a way as to resemble that required for the flattened rotation curves of galaxies. Although the total energy current grows with r, it is found that the current density, through unit area, goes down after attaining a peak. (author)

Laminin beta 2 chain and adhalin deficiency in the skeletal muscle of Walker-Warburg syndrome (cerebro-ocular dysplasia-muscular dystrophy)

DEFF Research Database (Denmark)

Wewer, U M; Durkin, M E; Zhang, X

1995-01-01

Muscular dystrophy may be caused by disturbances in a number of muscle proteins that appear to be part of a chain of interacting molecules that includes cytoskeletal, cell membrane, and basement membrane components. We found that the skeletal muscle cells in two cases of Walker-Warburg syndrome w...

¿La práctica de la siembra directa en cultivos de soja favorece las poblaciones de acridios (Orthoptera: Acrididae en el partido de Benito Juárez? Does the direct tillage practice in soybean crops favour grasshopper populations (Orthoptera: Acrididae, in Benito Juárez county?

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Daniel Scuffi

2012-12-01

Full Text Available Considerando el desarrollo del cultivo de soja en siembra directa en el partido de Benito Juárez, y que algunos autores sostienen que esta práctica favorece los acridios, se evaluó la riqueza de especies y la abundancia en soja con siembra directa y convencional. Se registraron siete especies (Aleuas lineatus Stål, Covasacris pallidinota (Bruner, Baeacris pseudopunctulatus (Ronderos, Dichroplus elongatus Giglio-Tos, Dichroplus maculipennis (Blanchard, Dichroplus pratensis Bruner y Scotussa lemniscata (Stål. La riqueza de especies acumulada en los diferentes cultivos fue similar (p> 0,05. En soja de primera con siembra directa, se registraron 2,3 ± 0,19 especies, en soja de primera con siembra convencional 1,45 ± 0,15 especies y en soja de segunda con siembra directa 2,25 ± 0,28 especies. Dichroplus elongatus fue la especie más abundante en todos los cultivos y en todos los momentos. Las restantes presentaron baja abundancia y se registraron en algunos momentos. No existió diferencia (p> 0,05 en la abundancia de tucuras entre los cultivos y en las diferentes fechas de muestreo. La baja riqueza de especies registrada estaría relacionada con la baja diversidad vegetal de los cultivos. Este estudio no mostró diferencias en la abundancia y riqueza de especies de acuerdo a la labranza utilizada.Considering the development of the soybean crops using direct tillage in Benito Juárez county, and taking into account that for some authors this practice favours the grasshopper populations, the abundance and species richness in soybean with direct and conventional tillage were evaluated. Seven species were registered (Aleuas lineatus Stål, Covasacris pallidinota (Bruner, Baeacris pseudopunctulatus (Ronderos, Dichroplus elongatus Giglio-Tos, Dichroplus maculipennis (Blanchard, Dichroplus pratensis Bruner and Scotussa lemniscata (Stål. The accumulated richness was similar (p> 0.05, along the different crops; 2.3 ± 0.19 species were registered in soybean crops first seedtime with direct tillage, 1.45 ± 0.15 species in soybean with conventional tillage and 2.25 ± 0.28 species in soybean second seedtime with direct tillage. Dichroplus elongatus was the most abundant grasshopper in all crops and at every sampling moment. The remaining species had low abundance and were recorded in some samples. There was no difference (p> 0.05, in the grasshoppers abundance in the different soybean crops at the different sampling times. The low grasshopper species richness registered could be related to the low vegetal diversity of the crops. The results of this study showed no differences in abundance and species richness among different systems of tillage of the soybeans crops.

Overground walking training with the i-Walker, a robotic servo-assistive device, enhances balance in patients with subacute stroke: a randomized controlled trial.

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Morone, Giovanni; Annicchiarico, Roberta; Iosa, Marco; Federici, Alessia; Paolucci, Stefano; Cortés, Ulises; Caltagirone, Carlo

2016-05-26

Patients affected by mild stroke benefit more from physiological overground walking training than walking-like training performed in place using specific devices. The aim of the study was to evaluate the effects of overground robotic walking training performed with the servo-assistive robotic rollator (i-Walker) on walking, balance, gait stability and falls in a community setting in patients with mild subacute stroke. Forty-four patients were randomly assigned to two different groups that received the same therapy in two daily 40-min sessions 5 days a week for 4 weeks. Twenty sessions of standard therapy were performed by both groups. In the other 20 sessions the subjects enrolled in the i-Walker-Group (iWG) performed with the i-Walker and the Control-Group patients (CG) performed the same amount of conventional walking oriented therapy. Clinical and instrumented gait assessments were made pre- and post-treatment. The follow-up observation consisted of recording the number of fallers in the community setting after 6 months. Treatment effectiveness was higher in the iWG group in terms of balance improvement (Tinetti: 68.4 ± 27.6 % vs. 48.1 ± 33.9 %, p = 0.033) and 10-m and 6-min timed walking tests (significant interaction between group and time: F(1,40) = 14.252, p = 0.001; and F(1,40) = 7.883, p = 0.008, respectively). When measured, latero-lateral upper body accelerations were reduced in iWG (F = 4.727, p = 0.036), suggesting increased gait stability, which was supported by a reduced number of falls at home. A robotic servo-assisted i-Walker improved walking performance and balance in patients affected by mild/moderate stroke, leading to increased gait stability and reduced falls in the community. This study was registered on anzctr.org.au (July 1, 2015; ACTRN12615000681550 ).

Comparison of range of motion and function of subjects with reverse anatomy Bayley-Walker shoulder replacement with those of normal subjects.

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Masjedi, Milad; Lovell, Cara; Johnson, Garth R

2011-12-01

Patients with rotator cuff tear and degenerative shoulder joint disease commonly experience severe pain and reduced performance during activities of daily living. A popular way to treat these patients is by means of reverse anatomy shoulder prosthesis. Studying the kinematics of subjects with reverse anatomy implant would be useful in order to gain knowledge about functionality of different designs. It is hypothesized that the kinematics of these subjects, in the absence of rotator cuff muscles, differs from that of normal subjects. In this study the upper limb kinematics of 12 subjects with a Bayley-Walker reverse anatomy shoulder prosthesis while performing tasks common in everyday activities and those that represent the range of motion was analyzed and compared to that of 12 normal subjects. Each patient also completed an Oxford Shoulder Score. Substantial reduction in the Bayley-Walker subjects' ranges of motion was observed compared to normal subjects. The mean abduction angle decreased from 109° (±20) for normal subjects to 64° (±25). A similar trend was observed during flexion and axial rotation tasks. Furthermore, the normal group showed less variable ranges of motion performing the standard tasks, whereas for the prosthetic group this varied greatly, which is likely to be dependent on muscle strength. Although the decreased range of motion was prominent, subjects were able to complete most of the tasks by compensating with their elbow and trunk. The most challenging task for Bayley-Walker subjects was lifting an object to head height. Copyright © 2010 Elsevier B.V. All rights reserved.

Combined therapy of the Walker-256 carcinosarcoma with X-rays and ICRF-159

International Nuclear Information System (INIS)

Schaphaus, A.

1974-01-01

The radiosensitivity of the Walker-256 carcinosarcoma of the rat under the influence of the tumour-inhibiting bisdioxopiperazine ICRF-159 was studied in collectives of 11-16 animals with tumours. In the combined radio- and chemotherapy, the animals received a daily i.p. injection of 30 mg/kg K.G. of the bisdioxopiperazine ICRF-159 in 1.0 ml NaCl solution containing carboxyl methyl cellulose. The tumour inhibition was determined by multidimensional measurements of the increase in tumour size with the aid of a slide gange. The combined therapy had a better inhibiting effect on tumour growth than radiotherapy alone. (orig./AK) [de

Description of a new species and subspecies of Idalus Walker from Costa Rica, Honduras and Guatemala (Lepidoptera, Erebidae, Arctiinae, Arctiini)

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Espinoza, Bernardo A.; Janzen, Daniel H.; Winnie Hallwachs;  J. Bolling Sullivan

2013-01-01

Abstract A new species and subspecies of Idalus Walker are described from Costa Rica, Honduras and Guatemala. Images of males and females and their genitalia are provided. Locality information and distribution maps for Costa Rica and for Guatemala are included. The biology and phylogeny of Idalus are discussed. PMID:23730178

Detection of Spiroplasma and Wolbachia in the bacterial gonad community of Chorthippus parallelus.

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Martínez-Rodríguez, P; Hernández-Pérez, M; Bella, J L

2013-07-01

We have recently detected the endosymbiont Wolbachia in multiple individuals and populations of the grasshopper Chorthippus parallelus (Orthoptera: acrididae). This bacterium induces reproductive anomalies, including cytoplasmic incompatibility. Such incompatibilities may help explain the maintenance of two distinct subspecies of this grasshopper, C. parallelus parallelus and C. parallelus erythropus, which are involved in a Pyrenean hybrid zone that has been extensively studied for the past 20 years, becoming a model system for the study of genetic divergence and speciation. To evaluate whether Wolbachia is the sole bacterial infection that might induce reproductive anomalies, the gonadal bacterial community of individuals from 13 distinct populations of C. parallelus was determined by denaturing gradient gel electrophoresis analysis of bacterial 16S rRNA gene fragments and sequencing. The study revealed low bacterial diversity in the gonads: a persistent bacterial trio consistent with Spiroplasma sp. and the two previously described supergroups of Wolbachia (B and F) dominated the gonad microbiota. A further evaluation of the composition of the gonad bacterial communities was carried out by whole cell hybridization. Our results confirm previous studies of the cytological distribution of Wolbachia in C. parallelus gonads and show a homogeneous infection by Spiroplasma. Spiroplasma and Wolbachia cooccurred in some individuals, but there was no significant association of Spiroplasma with a grasshopper's sex or with Wolbachia infection, although subtle trends might be detected with a larger sample size. This information, together with previous experimental crosses of this grasshopper, suggests that Spiroplasma is unlikely to contribute to sex-specific reproductive anomalies; instead, they implicate Wolbachia as the agent of the observed anomalies in C. parallelus.

Effect of electromagnetic fields on the creation of scalar particles in a flat Robertson-Walker space-time

International Nuclear Information System (INIS)

Haouat, S.; Chekireb, R.

2012-01-01

The influence of electromagnetic fields on the creation of scalar particles from vacuum in a flat Robertson-Walker space-time is studied. The Klein-Gordon equation with varying electric field and constant magnetic one is solved. The Bogoliubov transformation method is applied to calculate the pair creation probability and the number density of created particles. It is shown that the electric field amplifies the creation of scalar particles while the magnetic field minimizes it. (orig.)

Étude de la toxicité des extraits foliaires d’Euphorbia guyoniana Boiss. et Reut. (Euphorbiaceae chez Schistocerca gregaria (Forskål, 1775 (Orthoptera-Acrididea

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A. KEMASSI

2013-03-01

Full Text Available Study of the toxicity of the crude acetone leaf extract of Euphorbia guyoniana Boiss. and Reut. (Euphorbiaceae in Schistocerca gregaria (Forskål, 1775 (Orthoptera-Acrididea Abstract-This study examines the effect by ingestion of leaf cabbage sprayed with crude acetone extract of Euphorbia guyoniana leaves harvested in the Algerian Sahara on some biological parameters of larvae L5 and adult of desert locusts. The ingestion of cabbage leaves soaked in acetone extract of this Saharan plant generates a 100% mortality in larvae L5 and 66,67% for adult. A significant reduction in food intake was observed in the treated population compared to the control population. It results in a loss of exceptional weight ranging from 26,93% in larvae L5 to 33,09% in adults. Difficulties and anomalies are observed in moulting 16,66% of larvae L5 fed with cabbage leaves soaked in leaf extract of E. guyoniana. Dissection of adult females of the lot processing allows the observation of body regression demonstrating the depressant action of this extract on ovocyte cycle in the desert locust.

Phenology of Cornops aquaticum (Bruner) (Orthoptera: Acrididae) in Eichhornia azurea (Pontederiaceae) in the northern region of pantanal of Mato Grosso, Brazil

International Nuclear Information System (INIS)

Silva, Fatima R.J da; Marques, Marinez I.; Battirola, Leandro D.; Lhano, Marcos G.

2010-01-01

Cornops aquaticum (Bruner) has Eichhornia crassipes, E. azurea, Pontederia cordata and P. lanceolata (Pontederiaceae) as the known host plants. This grasshopper species is cited as a possible agent of biological control for native aquatic macrophytes E. azurea and E. crassipes. This study, carried out from March, 2006 to February, 2007, aimed to evaluate the phenology and age structure of the population of C. aquaticum associated with E. azurea in Piuval bay, Pantanal of Pocone, MT, and to identify possible relationships of its life cycle to abiotic factors such as insolation, temperature and precipitation. Monthly collections of 50 individuals were carried out according to the protocol defined by the - Host - Insect Coevolution on Waterhyacinth - project. Adults and nymphs were separated and the females dissected in order to evaluate ovary maturation. The population presented adults and nymphs during the whole year, suggesting the occurrence of more than one reproductive period. The nymphs from the fi rst stage predominated in August 2006 and the adults in September and October 2006, synchronized with the dry period and beginning of the flooding period, respectively. The highest relative abundance of the females with mature ovaries occurred in July 2006 (50%), indicating that this may be a more propitious period for reproduction. The data suggest that C. aquaticum is a species in continual reproduction in Piuval bay and its cycle is associated with the environmental conditions guided by the flood pulse in the Pantanal of Mato Grosso. (author)

Comparison of reproductive traits of regular and irradiated male desert locust Schistocerca gregaria (Orthoptera: Acrididae: Evidence of last-male sperm precedence

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Severin Dushimirimana

2012-02-01

The sterile insect technique (SIT is increasingly used to control pest insect populations. The success of SIT control programs depends on the ability to release sterile males and on the capacity of sterile males to compete with wild males to inseminate wild females. In this study, we evaluated the mating performance of Schistocerca gregaria (Försk. males irradiated with 4 Gray. We compared reproductive traits, such as duration of precopulation time, mating duration, quantity of sperm stored by females after copulation, number of females mated successively and postmating competition of irradiated males with non-irradiated males. Irradiated males were able to mate but the resulting number of offspring was dramatically reduced compared to the average number of offspring observed during a regular mating. During a single copulation, irradiated males transferred fewer sperm than regular males but, theoretically, this quantity is enough to fertilize all the eggs produced by a female during its reproductive life. Irradiated males also had the ability to remove sperm from a previous mating with unirraditated males. This new information on the mating strategies helps explain the post-copulation guarding behaviour of S. gregaria.

Autecology, feeding preferences and reproductive biology of Chorthippus (Glyptobothrus) vagans (Eversmann, 1848) (Orthoptera: Gomphocerinae) in Mediterranean ecosystems.

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Cárdenas, A M; Gallardo, P; Moyano, L; Presa, J J

2017-02-01

Chorthippus vagans is a common species of Gomphocerinae (Orthoptera) on the Iberian Peninsula. It is endangered in Central Europe where information about its ecological requirements is available; however, aspects of its biology are almost unknown in Mediterranean ecosystems, where it is widespread and common. The focus of this study was to determine how C. vagans adjusts its biology to environmental features of this ecosystem and to interpret how it may be affected by the ecological changes related to the re-vegetation programme linked to the construction of the Breña dam (SW Spain). The research parameters included the autoecology, feeding response and some aspects of reproduction of this species in the Southern Iberian Peninsula. To determine the local distribution and phenology of C. vagans, monthly samplings were conducted (2007-2010) in 12 sampling plots. For the food selection tests, ten nymphs and ten adults were placed individually in insectaries under controlled conditions. Grasses (Lolium sp.) and shrubs (Cistus sp.) were supplied ad libitum in two types of tests, monospecific and mixed diet. The reproductive biology was analysed by both observations of anatomical structures (integument, bristles, tibial spines, tarsal claws and mandibles) and ovarian dissections of 29 females and in laboratory rearing experiments with 15 pairs of adults. The results indicate that C. vagans shows an extended activity period which peaks at the end of summer. It is a polyphagous grasshopper, although adults show a slight preference for grasses. In addition, it is a univoltine species with spring-summer breeding activity.

Leucine-rich diet alters the 1H-NMR based metabolomic profile without changing the Walker-256 tumour mass in rats.

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Viana, Laís Rosa; Canevarolo, Rafael; Luiz, Anna Caroline Perina; Soares, Raquel Frias; Lubaczeuski, Camila; Zeri, Ana Carolina de Mattos; Gomes-Marcondes, Maria Cristina Cintra

2016-10-03

Cachexia is one of the most important causes of cancer-related death. Supplementation with branched-chain amino acids, particularly leucine, has been used to minimise loss of muscle tissue, although few studies have examined the effect of this type of nutritional supplementation on the metabolism of the tumour-bearing host. Therefore, the present study evaluated whether a leucine-rich diet affects metabolomic derangements in serum and tumour tissues in tumour-bearing Walker-256 rats (providing an experimental model of cachexia). After 21 days feeding Wistar female rats a leucine-rich diet, distributed in L-leucine and LW-leucine Walker-256 tumour-bearing groups, we examined the metabolomic profile of serum and tumour tissue samples and compared them with samples from tumour-bearing rats fed a normal protein diet (C - control; W - tumour-bearing groups). We utilised 1 H-NMR as a means to study the serum and tumour metabolomic profile, tumour proliferation and tumour protein synthesis pathway. Among the 58 serum metabolites examined, we found that 12 were altered in the tumour-bearing group, reflecting an increase in activity of some metabolic pathways related to energy production, which diverted many nutrients toward tumour growth. Despite displaying increased tumour cell activity (i.e., higher Ki-67 and mTOR expression), there were no differences in tumour mass associated with changes in 23 metabolites (resulting from valine, leucine and isoleucine synthesis and degradation, and from the synthesis and degradation of ketone bodies) in the leucine-tumour group. This result suggests that the majority of nutrients were used for host maintenance. A leucine rich-diet, largely used to prevent skeletal muscle loss, did not affect Walker 256 tumour growth and led to metabolomic alterations that may partially explain the positive effects of leucine for the whole tumour-bearing host.

Problems of older persons using a wheeled walker.

Science.gov (United States)

Lindemann, Ulrich; Schwenk, Michael; Klenk, Jochen; Kessler, Max; Weyrich, Michael; Kurz, Franziska; Becker, Clemens

2016-04-01

Wheeled walkers (WWs) are used to improve mobility and for fall prevention in older persons, but not all users are satisfied with the usability of WWs. Intelligent WWs are being developed to improve the usability. The aim of this study was to support the development of intelligent WWs by investigating possible problems of using a WW. This study investigated 22 geriatric in-patients (median age 82 years) with and without their WW while opening a door against the direction of walking and passing through. Other possible problems when using WWs were identified by interview. Walking through the door was faster without than with using the WW (8.71 versus 12.86 s, p < 0.001), while interference between door and WW was documented in 41 of 44 (93 %) cases. Backward walking performance was better when using a WW with regard to gait speed, step width and walk ratio (all p < 0.002). Most referred problems when using a WW were walking downhill (83 %) and uphill (77 %) and obstacle crossing in general (77 %). Problems with opening a door against the direction of walking and the optimization of downhill and uphill walking as well as obstacle crossing should be regarded when developing an intelligent WW.

X-derived marker chromosome in patient with mosaic Turner syndrome and Dandy-Walker syndrome: a case report

OpenAIRE

Telepova, Alena S.; Romanenko, Svetlana A.; Lemskaya, Natalya A.; Maksimova, Yulia V.; Shorina, Asia R.; Yudkin, Dmitry V.

2017-01-01

Background Small supernumerary marker chromosomes can be derived from autosomes and sex chromosomes and can accompany chromosome pathologies, such as Turner syndrome. Case presentation Here, we present a case report of a patient with mosaic Turner syndrome and Dandy-Walker syndrome carrying a marker chromosome. We showed the presence of the marker chromosome in 33.8% of blood cells. FISH of the probe derived from the marker chromosome by microdissection revealed that it originated from the ce...

Shrinking wings for ultrasonic pitch production: hyperintense ultra-short-wavelength calls in a new genus of neotropical katydids (Orthoptera: Tettigoniidae.

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Fabio A Sarria-S

Full Text Available This article reports the discovery of a new genus and three species of predaceous katydid (Insecta: Orthoptera from Colombia and Ecuador in which males produce the highest frequency ultrasonic calling songs so far recorded from an arthropod. Male katydids sing by rubbing their wings together to attract distant females. Their song frequencies usually range from audio (5 kHz to low ultrasonic (30 kHz. However, males of Supersonus spp. call females at 115 kHz, 125 kHz, and 150 kHz. Exceeding the human hearing range (50 Hz-20 kHz by an order of magnitude, these insects also emit their ultrasound at unusually elevated sound pressure levels (SPL. In all three species these calls exceed 110 dB SPL rms re 20 µPa (at 15 cm. Males of Supersonus spp. have unusually reduced forewings (<0.5 mm(2. Only the right wing radiates appreciable sound, the left bears the file and does not show a particular resonance. In contrast to most katydids, males of Supersonus spp. position and move their wings during sound production so that the concave aspect of the right wing, underlain by the insect dorsum, forms a contained cavity with sharp resonance. The observed high SPL at extreme carrier frequencies can be explained by wing anatomy, a resonant cavity with a membrane, and cuticle deformation.

GPS Imaging suggests links between climate, magmatism, seismicity, and tectonics in the Sierra Nevada-Long Valley Caldera-Walker Lane system, western United States

Science.gov (United States)

Hammond, W. C.; Blewitt, G.; Kreemer, C.; Smith, K.

2017-12-01

The Walker Lane is a region of complex active crustal transtension in the western Great Basin of the western United States, accommodating about 20% of the 50 mm/yr relative motion between the Pacific and North American plates. The Long Valley caldera lies in the central Walker Lane in eastern California, adjacent to the eastern boundary of the Sierra Nevada/Great Valley microplate, and experiences intermittent inflation, uplift, and volcanic unrest from the magma chamber that resides at middle crustal depths. Normal and transform faults accommodating regional tectonic transtension pass by and through the caldera, complicating the interpretation of the GPS-measured strain rate field, estimates of fault slip rates, and seismic hazard. Several dozen continuously recording GPS stations measure strain and uplift in the area with mm precision. They observe that the most recent episode of uplift at Long Valley began in mid-2011, continuing until late 2016, raising the surface by 100 mm in 6 years. The timing of the initiation of uplift coincides with the beginning of severe drought in California. Furthermore, the timing of a recent pause in uplift coincides with the very wet 2016-2017 winter, which saw approximately double normal snow pack. In prior studies, we showed that the timing of changes in geodetically measured uplift rate of the Sierra Nevada coincides with the timing of drought conditions in California, suggesting a link between hydrological loading and Sierra Nevada elevation. Here we take the analysis three steps further to show that changes in Sierra Nevada uplift rate coincide in time with 1) enhanced inflation at the Long Valley caldera, 2) shifts in the patterns and rates of horizontal tensor strain rate, and 3) seismicity patterns in the central Walker Lane. We use GPS solutions from the Nevada Geodetic Laboratory and the new GPS Imaging technique to produce robust animations of the time variable strain and uplift fields. The goals of this work are to

Prissy’s Quittin’ Time: The Black Camp Aesthetics of Kara Walker

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Stephens Brian

2017-12-01

Full Text Available Through a close reading of Walker’s first silhouette instalment-the audaciously titled Gone, An Historical Romance of a Civil War as it Occurred Between the Dusky Thighs of One Young Negress and Her Heart (1994-this article examines how Walker utilises black camp to undermine both white supremacist and restrictive black uplift discourse. To be sure, the article is not an attempt to conflate these two, for the former is powerfully worse than the latter. However, it is necessary to explore how both discourses reinforce essentialist articulations of blackness and also to examine how black camp is a provocative analytic for their simultaneous disruption. Camp is usually understood as a queer-derived cultural practice that inflates identity to expose the constructed nature of gender. However, this article shows that black articulations of camp inflate identity to demonstrate the fiction of race as well.

Lanczos potentials and a definition of gravitational entropy for perturbed Friedman-Lemaitre-Robertson-Walker spacetimes

International Nuclear Information System (INIS)

Mena, Filipe C; Tod, Paul

2007-01-01

We give a prescription for constructing a Lanczos potential for a cosmological model which is a purely gravitational perturbation of a Friedman-Lemaitre-Robertson-Walker spacetime. For the radiation equation of state, we find the Lanczos potential explicitly via Fourier transforms. As an application, we follow up a suggestion of Penrose (1979 Singularities and time-asymmetry General Relativity: An Einstein Centenary Survey ed S W Hawking and W Israel (Cambridge: Cambridge University Press)) and propose a definition of gravitational entropy for these cosmologies. With this definition, the gravitational entropy initially is finite if and only if the initial Weyl tensor is finite

Rates and timing of vertical-axis block rotations across the Sierra Nevada-Walker Lane transition in the Bodie Hills

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Rood, D. H.; Herman, S.; Burbank, D.; Bogue, S.

2008-12-01

We use paleomagnetic data from Tertiary volcanic rocks to address the rates and timing of vertical-axis block rotation across the Sierra Nevada-Walker Lane transition in the Bodie Hills, California/Nevada. In zones of continental deformation, block rotations are an important mechanism for permanent stain accommodation, and thus may be crucial to testing geodetic block models and resolving geologic-geodetic slip discrepancies. In our study, data included in the paleomagetic site means are high quality AF demagnetization results (least squared fits that generally include 5-7 points with MAD values less than 1). Thermal demagnetization results match the AF directions, and both thermal demag and rockmag results indicate strong ChRM, mostly carried by single domain magnetite. The site means used to calculate the VGPs all have a95 values less than 10 (mostly 2-5) and include 6-11 sites each. Each site (and thus site mean) has a reasonably well-known structural correction. The VGP scatter values range from 12 to 16 degrees, indicating that they include appropriate secular variation. The mean declinations and 95 percent confidence limits for each VGP timeslice are statistically distinct from one another (71 ± 9, 39 ± 13, and 11 ± 11 degrees). The slope of a linear regression fit to the age versus declination data gives a rate of vertical axis block rotation of approximately 3-4 degrees/Myr. Fitting two separate lines to the age vs. declination data would indicate an increase in the rates of rotation since ~10 Ma. Two possible interpretations of the data are: (1) the rotations began during or before the Middle Miocene, or (2) rates of rotation were high initially (e.g. ~10 Ma) and decelerated until the Pliocene. These data have implications for the (1) timing and spatial extent of distributed strain accumulation related to the initiation of the San Andreas Fault-Eastern California Shear Zone-Walker Lane transform plate boundary, (2) transfer of transform plate boundary

Bound states for a neutral particle analogous to a quantum dot induced by the non-inertial effects of the Fermi-Walker reference frame

International Nuclear Information System (INIS)

Bakke, Knut

2010-01-01

We study the appearance of bound states analogous to a quantum dot, proposed by Tan and Inkson (1996) , in the non-relativistic quantum dynamics of a neutral particle with permanent magnetic dipole moment induced by the non-inertial effects of the Fermi-Walker reference frame.

Corrected entropy of Friedmann-Robertson-Walker universe in tunneling method

International Nuclear Information System (INIS)

Zhu, Tao; Ren, Ji-Rong; Li, Ming-Fan

2009-01-01

In this paper, we study the thermodynamic quantities of Friedmann-Robertson-Walker (FRW) universe by using the tunneling formalism beyond semiclassical approximation developed by Banerjee and Majhi [25]. For this we first calculate the corrected Hawking-like temperature on apparent horizon by considering both scalar particle and fermion tunneling. With this corrected Hawking-like temperature, the explicit expressions of the corrected entropy of apparent horizon for various gravity theories including Einstein gravity, Gauss-Bonnet gravity, Lovelock gravity, f(R) gravity and scalar-tensor gravity, are computed. Our results show that the corrected entropy formula for different gravity theories can be written into a general expression (4.39) of a same form. It is also shown that this expression is also valid for black holes. This might imply that the expression for the corrected entropy derived from tunneling method is independent of gravity theory, spacetime and dimension of the spacetime. Moreover, it is concluded that the basic thermodynamical property that the corrected entropy on apparent horizon is a state function is satisfied by the FRW universe

Olfactory signaling of aggressive intent in male-male contests of cave crickets (Troglophilus neglectus; Orthoptera: Rhaphidophoridae.

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Nataša Stritih

Full Text Available In animal contests, communicating aggressive motivation is most often mediated by visual or acoustic signals, while chemical signals are not expected to serve such a function since they are less able to be modulated by the sender during the changing behavioral context. We describe a rare example of ephemeral olfactory signals in terrestrial animals, signals that are emitted via protrusive scent glands in male cave crickets Troglophilus neglectus (Orthoptera, Rhaphidophoridae to reflect the state of the signaler's aggression. We correlate the intensity of behaviorally expressed aggression of the individuals in dyadic contests with the frequency and extent of their gland tissue protrusion, the latter serving as an indication of the amount of released odor. We detected large amounts of odor release during brief gland protrusions, and the absence of its release during gland retraction. Males protruded the glands during and after encountering a rival, with the degree of protrusion increasing with the intensity of the signalers' aggression. During the encounters, the degree of gland protrusion increased most strongly with the occurrence of the elevated body posture, directly preceding the attack. This degree was significantly higher in encounter winners than in losers displaying such posture, suggesting the highly important role of the released odor for contest resolution. After the encounters, glands were protruded almost exclusively by winners, apparently announcing victory. We tested for the function of the olfactory signals also directly, by preventing gland tissue protrusion in symmetric and asymmetric treatments of the contestants. Treating only the dominant individuals decreased the percentage of encounters they won by over 60%, while treating both contestants elicited a significant increase in the frequency and duration of fights. During contests, the olfactory signals of T. neglectus apparently function as a highly effective threat, which

Neuronal Regression of Internal Leg Vibroreceptor Organs in a Cave-Dwelling Insect (Orthoptera: Rhaphidophoridae: Dolichopoda araneiformis).

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Strauß, Johannes; Stritih, Nataša

2017-01-01

Animals' adaptations to cave habitats generally include elaboration of extraoptic senses, and in insects the receptor structures located on the legs are supposed to become more prominent in response to constant darkness. The receptors for detecting substrate vibrations are often highly sensitive scolopidial sensilla localized within the legs or the body. For troglobitic insects the evolutionary changes in vibroreceptor organs have not been studied. Since rock is an extremely unfavorable medium for vibration transmission, selection on vibration receptors may be weakened in caves, and these sensory organs may undergo regressive evolution. We investigated the anatomy of the most elaborate internal vibration detection system in orthopteroid insects, the scolopidial subgenual organ complex in the cave cricket Dolichopoda araneiformis (Orthoptera: Ensifera: Rhaphidophoridae). This is a suitable model species which shows high levels of adaptation to cave life in terms of both phenotypic and life cycle characteristics. We compared our data with data on the anatomy and physiology of the subgenual organ complex from the related troglophilic species Troglophilus neglectus. In D. araneiformis, the subgenual organ complex contains three scolopidial organs: the subgenual organ, the intermediate organ, and the accessory organ. The presence of individual organs and their innervation pattern are identical to those found in T. neglectus, while the subgenual organ and the accessory organ of D. araneiformis contain about 50% fewer scolopidial sensilla than in T. neglectus. This suggests neuronal regression of these organs in D. araneiformis, which may reflect a relaxed selection pressure for vibration detection in caves. At the same time, a high level of overall neuroanatomical conservation of the intermediate organ in this species suggests persistence of the selection pressure maintaining this particular organ. While regressive evolution of chordotonal organs has been documented for

Characterization of the damage of Spodoptera eridania (Cramer) and Spodoptera cosmioides (Walker) (Lepidoptera: Noctuidae) to structures of cotton plants

OpenAIRE

Santos, Karen B dos; Meneguim, Ana M; Santos, Walter J dos; Neves, Pedro M O J; Santos, Rachel B dos

2010-01-01

The cotton plant, Gossypium hirsutum, hosts various pests that damage different structures. Among these pests, Spodoptera cosmioides (Walker) and Spodoptera eridania (Cramer) (Lepidoptera: Noctuidae) are considered important. The objectives of this study were to characterize and to quantify the potential damage of S. eridania and S. cosmioides feeding on different structures of cotton plants. For this purpose, newly-hatched larvae were reared on the following plant parts: leaf and flower bud;...

Review of the East Palaearctic and North Oriental Psyttalia Walker, with the description of three new species (Hymenoptera, Braconidae, Opiinae).

Science.gov (United States)

Wu, Qiong; van Achterberg, Cornelis; Tan, Jiang-Li; Chen, Xue-Xin

2016-01-01

The East Palaearctic and North Oriental species of the genus Psyttalia Walker (Hymenoptera, Braconidae, Opiinae) are reviewed. Three new species are described and illustrated: Psyttalia latinervis Wu & van Achterberg, sp. n . and Psyttalia majocellata Wu & van Achterberg, sp. n . from China, and Psyttalia spectabilis van Achterberg, sp. n. from Japan. Coeloreuteus formosanus Watanabe, 1934, Opius (Lissosema) proclivis Papp, 1981, Opius (Psyttalia) subcyclogaster Tobias, 1998, Opius (Psyttalia) darasunicus Tobias, 1998, Opius (Psyttalia) cyclogastroides Tobias, 1998, Psyttalia extensa Weng & Chen, 2001, and Rhogadopsis longicaudifera Li & van Achterberg, 2013, are new synonyms of Psyttalia cyclogaster (Thomson, 1895); Opius (Psyttalia) ophthalmicus Tobias, 1977, and Opius (Psyttalia) brevitemporalis Tobias, 1998, of Psyttalia carinata (Thomson, 1895) and both Opius (Psyttalia) vacuus Tobias, 1998, and Opius (Lissosema) longurius Chen & Weng, 1995, of Rhogadopsis mediocarinata (Fischer, 1963). Phaedrotoma daghestanicum (Telenga, 1950), Rhogadopsis mediocarinata (Fischer, 1963) and Rhogadopsis mystica (Fischer, 1963) are new combinations. New records are Psyttalia carinata (Thomson, 1895) from The Netherlands and Norway, and Psyttalia cyclogaster (Thomson, 1895) from Japan. A lectotype is designated for Psyttalia carinata (Thomson, 1895) and Psyttalia cyclogaster (Thomson, 1895). A key to the East Palaearctic and North Oriental species of the genus Psyttalia Walker is included.

Review of the East Palaearctic and North Oriental Psyttalia Walker, with the description of three new species (Hymenoptera, Braconidae, Opiinae

Directory of Open Access Journals (Sweden)

Qiong Wu

2016-11-01

Full Text Available The East Palaearctic and North Oriental species of the genus Psyttalia Walker (Hymenoptera, Braconidae, Opiinae are reviewed. Three new species are described and illustrated: P. latinervis Wu & van Achterberg, sp. n. and P. majocellata Wu & van Achterberg, sp. n. from China, and P. spectabilis van Achterberg, sp. n. from Japan. Coeloreuteus formosanus Watanabe, 1934, Opius (Lissosema proclivis Papp, 1981, O. (Psyttalia subcyclogaster Tobias, 1998, O. (P. darasunicus Tobias, 1998, O. (P. cyclogastroides Tobias, 1998, Psyttalia extensa Weng & Chen, 2001, and Rhogadopsis longicaudifera Li & van Achterberg, 2013, are new synonyms of Psyttalia cyclogaster (Thomson, 1895; Opius (Psyttalia ophthalmicus Tobias, 1977, and O. (P. brevitemporalis Tobias, 1998, of Psyttalia carinata (Thomson, 1895 and both O. (P. vacuus Tobias, 1998, and O. (Lissosema longurius Chen & Weng, 1995, of Rhogadopsis mediocarinata (Fischer, 1963. Phaedrotoma daghestanicum (Telenga, 1950, Rhogadopsis mediocarinata (Fischer, 1963 and R. mystica (Fischer, 1963 are new combinations. New records are Psyttalia carinata (Thomson, 1895 from The Netherlands and Norway, and P. cyclogaster (Thomson, 1895 from Japan. A lectotype is designated for Psyttalia carinata (Thomson, 1895 and P. cyclogaster (Thomson, 1895. A key to the East Palaearctic and North Oriental species of the genus Psyttalia Walker is included.

From precocious fame to mature obscurity: David Walker (1837-1917) MD, LRCSI, surgeon and naturalist to the Fox Arctic Expedition of 1857-59.

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Froggatt, Peter; Walker, Brian M

2012-11-01

The Belfast-born David Walker was the 19-year-old surgeon and naturalist on the epic Fox Arctic Expedition (1857-59) that established the fate of Sir John Franklin's unsuccessful (1845) search for the North-West Passage. On return the crew were fêted as heroes and decorated, and shared in a £5000 government bounty: Walker was also received by the Queen and (in Ireland) by the Lord Lieutenant, was honoured by the principal British and Irish natural history societies and his portrait was exhibited in the National Portrait Gallery, London. This paper describes his adventurous life, including the Fox Expedition, which from 1862 was spent abroad and included time in the Cariboo gold fields, service in the United States Army, practice in a notorious Californian frontier town and, in later life, the comparative quiet of general and occupational medical practice in Portland, Oregon. Once a household name, his death went unrecorded in the British and Irish medical and lay press.

Scanning Electron Microscopy Study of the Antennal Sensilla of Monema flavescens Walker (Lepidoptera: Limacodidae).

Science.gov (United States)

Yang, S; Liu, H; Zhang, J T; Liu, J; Zheng, H; Ren, Y

2017-04-01

Monema flavescens Walker (Lepidoptera: Limacodidae) is a serious polyphagous defoliator. Using scanning electron microscopy, the external morphology of the antennal sensilla of this pest was examined for a better understanding of the mechanisms of insect-insect and insect-plant chemical communications. The antennae of M. flavescens were filiform in shape, and 11 morphological types of sensilla were found in both sexes. Six types of likely chemosensory sensilla were identified: uniporous sensilla chaetica, multiporous sensilla trichodea, and four types of multiporous sensilla basiconica. The sensilla identified as likely mechanoreceptors included two subtypes of aporous sensilla chaetica, aporous sensilla coeloconica, aporous sensilla styloconica, and Böhm's bristles, whereas the position of the antennae was monitored by Böhm's bristles.

On defects of the volume and curvature of the Robertson-Walker metric and construction of cosmological models

International Nuclear Information System (INIS)

Gackstatter, F.

1987-01-01

For the Robertson-Walker metric (RWM) normal coordinates are constructed and the Riemann curvature tensor is determined. Then results on the defects of the volume and curvature, derived formerly, are applied to the RWM and to cosmological models. Finally cosmological models are constructed, they describe different states of the development of the cosmos: p ∼ 0, 1/3u, 2/3u, in a unified form. A Laurent expansion of the density of energy u and pressure p is used to solve the Friedmann equations. (author)

Planning and Execution of a Marine Methane Hydrate Pressure Coring Program for the Walker Ridge and Green Canyon Areas of the Gulf of Mexico

Energy Technology Data Exchange (ETDEWEB)

Humphrey, Gary [Fugro Geoconsulting Inc., Houston, TX (United States)

2015-09-14

The objective of this project (and report) is to produce a guide to developing scientific, operational, and logistical plans for a future methane hydrate-focused offshore pressure coring program. This report focuses primarily on a potential coring program in the Walker Ridge 313 and Green Canyon 955 blocks where previous investigations were undertaken as part of the 2009 Department of Energy JIP Leg II expedition, however, the approach to designing a pressure coring program that was utilized for this project may also serve as a useful model for planning pressure coring programs for hydrates in other areas. The initial portion of the report provides a brief overview of prior investigations related to gas hydrates in general and at the Walker Ridge 313 and Green Canyon 955 blocks in particular. The main content of the report provides guidance for various criteria that will come into play when designing a pressure coring program.

Disparate requirements for the Walker A and B ATPase motifs ofhuman RAD51D in homologous recombination

Energy Technology Data Exchange (ETDEWEB)

Wiese, Claudia; Hinz, John M.; Tebbs, Robert S.; Nham, Peter B.; Urbin, Salustra S.; Collins, David W.; Thompson, Larry H.; Schild, David

2006-04-21

In vertebrates, homologous recombinational repair (HRR) requires RAD51 and five RAD51 paralogs (XRCC2, XRCC3, RAD51B, RAD51C, and RAD51D) that all contain conserved Walker A and B ATPase motifs. In human RAD51D we examined the requirement for these motifs in interactions with XRCC2 and RAD51C, and for survival of cells in response to DNA interstrand crosslinks. Ectopic expression of wild type human RAD51D or mutants having a non-functional A or B motif was used to test for complementation of a rad51d knockout hamster CHO cell line. Although A-motif mutants complement very efficiently, B-motif mutants do not. Consistent with these results, experiments using the yeast two- and three-hybrid systems show that the interactions between RAD51D and its XRCC2 and RAD51C partners also require a functional RAD51D B motif, but not motif A. Similarly, hamster Xrcc2 is unable to bind to the non-complementing human RAD51D B-motif mutants in co-immunoprecipitation assays. We conclude that a functional Walker B motif, but not A motif, is necessary for RAD51D's interactions with other paralogs and for efficient HRR. We present a model in which ATPase sites are formed in a bipartite manner between RAD51D and other RAD51 paralogs.

New data on morphometrics, distribution and ecology of Mioscirtus wagneri (Kittary, 1849 (Orthoptera, Acrididae in Spain: is maghrebi a well defined subespecies?

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Aparicio, J. M.

2007-06-01

Full Text Available We studied different populations of Mioscirtus wagneri (Kittary, 1859 in Spain assigned to subspecies maghrebi by Fernandes (1968 and obtained some new records for the species. To see if maghrebi is a consistent taxon for the Iberian populations, we performed a morphometric analysis involving 53 individuals from different origins considering body size (front of the head to tip of the abdomen; the shape of pronotum and presence of a second anterior notch or sulcus; length of the antennae and epiphallum, according to the characters used to define subspecies maghrebi. If maghrebi is consistent, we would expect intermediate sizes between wagneri and rogenhoferi, the other two well separated subspecies considered for M.w. However, in our measurements we obtained that body size is not intermediate between M. w. wagneri and M. w. rogenhoferi contrary to expectations if assuming the existence of maghrebi. Body size is similar to wagneri and further, we recorded some of the smallest individuals described so far. Also, the pronotum varied widely across and within populations showing different phenotypes that formerly were used to separate maghrebi and wagneri. Taking into account body size, pronotum, length of antenna and epiphallum, we think that differences between the studied Spanish populations and wagneri form are not enough to assign the studied populations to maghrebi. In the studied area, M.w. shows a narrow ecological niche inhabiting shores or proximities of hipersaline lagoons wherever Suaeda vera (Forsskål 1791, Chenopodiacea is present, M.w. uses this plant as refuge and food. The species also inhabits bare saline low grounds with scattered S vera. It presents a markedly discontinuous and patchy distribution in Spain, showing up punctually, where the microhabitat is appropriate. We obtained a morphometric variability with a significant association between body size and locality, and between body size and the colour of posterior wings in males. Because of its wide range disjunction, its discontinuous regional distribution and morphological variability, we believe that M.w. is an interesting species to investigate possible substructuring of populations in which we probably may recognize ecological forms or varieties that deserve deeper and further study.Estudiamos distintas poblaciones de Mioscirtus wagneri (Kittary, 1859, considerado como M. w. maghrebi por Fernandes (1968 en España, con algunas nuevas citas para la especie. Para dilucidar si el taxón maghrebi es consistente en nuestras poblaciones, realizamos un análisis morfométrico de 53 ejemplares considerando los mismos caracteres utilizados para establecer dicha subespecie, a citar: tamaño del cuerpo, relieve y forma del pronoto, longitud de la antena y forma del epifalo. El tamaño de los individuos de nuestras poblaciones no es intermedio entre las formas conocidas de M. w. wagneri y M. w. rogenhoferi Saussuare, 1888, como cabría esperar asumiendo la existencia de maghrebi. Nuestras poblaciones no se apartan del tamaño de wagneri e incluso encontramos las menores tallas descritas para este taxón. El relieve del pronoto, y en particular la presencia de un segundo surco, el anterior, es muy variable abarcando en una misma población fenotipos dispares utilizados anteriormente para separar las formas maghrebi y wagneri. Las diferencias entre el tamaño del cuerpo, el pronoto, la longitud de la antena y la forma del epifalo no nos parecen suficientes para asignar como maghrebi al conjunto de las poblaciones estudiadas y separarlas de la subespecie nominada wagneri. M.w. es una especie de requerimientos ecológicos muy restringidos. La hemos encontrado a orillas de lagunas hipersalinas y siempre dependiendo de Suaeda vera (Forsskål, 1791 Chenopodiacea que utiliza como refugio y alimento, en particular en suelos desnudos y salitrosos donde predominan manchas de esa planta. Su distribución regional es marcadamente discontinua y muy puntual, presentándose allí donde el hábitat le es propicio. Aunque el análisis es preliminar, encontramos una variabilidad morfométrica y una asociación del tamaño corporal con la localidad, y del tamaño corporal con la coloración de las alas posteriores en los machos. Debido a su distribución geográfica disjunta, localmente discontinua, y a la variabilidad morfométrica encontrada en sus poblaciones, creemos que M. w. es una especie interesante para investigar la posible subestructuración de sus poblaciones en las cuales es posible se reconozcan diversas formas o variedades ecológicas lo que merece mayor investigación.

Divergent Host Plant Adaptation Drives the Evolution of Sexual Isolation in the Grasshopper Hesperotettix viridis (Orthoptera: Acrididae) in the Absence of Reinforcement

Science.gov (United States)

The beginning stages of lineage divergence can be difficult to detect, as correlations between altered genotypic and phenotypic attributes are often weak early in the process. Shifts in host plant use and divergence in mating signals can lead to sexual isolation and ultimately speciation. To underst...

Distribución geográfica, prevalencia e intensidad de las infecciones de Gregarina ronderosi (Eugregarinorida: Gregarinidae en Dichroplus elongatus (Orthoptera: Acrididae

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Christian Bardi

2016-01-01

Full Text Available regarina ronderosi es un parásito obligado del tracto digestivo del acrídido plaga Dichroplus elongatus y una de las únicas dos eugregarinas de acrídidos argentinos descriptas con su ciclo de vida completo. Dada la falta de conocimiento acerca de aspectos epizootiológicos fundamentales de las infecci- ones causadas por eugregarinas en acrídidos de Argentina, el objetivo de esta contribución es iniciar el registro de la distribución geográfica de G. ronderosi en la región Pampeana, su prevalencia natural y la intensidad de las infecciones en condiciones naturales. Para ello, se colectaron ejemplares de D. elongatus (2008 – 2012 en distintos puntos de la región Pampeana. Se obtuvieron y analizaron un total de 4084 ejemplares provenientes de cuarenta y dos localidades. La prevalen- cia promedio de G. ronderosi para el total de localidades con presencia (diecisiete localidades fue de 29,7 ± EE 6,6% (n = 1071. El total de individuos infectados (n = 396 fue categorizado respecto de la intensidad de las infecciones: tres (0,8% presentaron infecciones muy fuertes, ochenta (20% fuerte, doscientos diez (53% moderadas y ciento tres (26% infecciones leves. Se ha ampliado la distribución ge- ográfica conocida, se han registrado prevalencias elevadas que sugieren la ocur - rencia de epizootias y se han registrado por primera vez en condiciones naturales infecciones de G. ronderosi categorizadas como Fuertes y Muy Fuertes.

Genetic variation for parental effects on the propensity to gregarise in Locusta migratoria

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Foucart Antoine

2008-02-01

Full Text Available Abstract Background Environmental parental effects can have important ecological and evolutionary consequences, yet little is known about genetic variation among populations in the plastic responses of offspring phenotypes to parental environmental conditions. This type of variation may lead to rapid phenotypic divergence among populations and facilitate speciation. With respect to density-dependent phenotypic plasticity, locust species (Orthoptera: family Acrididae, exhibit spectacular developmental and behavioural shifts in response to population density, called phase change. Given the significance of phase change in locust outbreaks and control, its triggering processes have been widely investigated. Whereas crowding within the lifetime of both offspring and parents has emerged as a primary causal factor of phase change, less is known about intraspecific genetic variation in the expression of phase change, and in particular in response to the parental environment. We conducted a laboratory experiment that explicitly controlled for the environmental effects of parental rearing density. This design enabled us to compare the parental effects on offspring expression of phase-related traits between two naturally-occurring, genetically distinct populations of Locusta migratoria that differed in their historical patterns of high population density outbreak events. Results We found that locusts from a historically outbreaking population of L. migratoria expressed parentally-inherited density-dependent phase changes to a greater degree than those from a historically non-outbreaking population. Conclusion Because locusts from both populations were raised in a common environment during our experiment, a genetically-based process must be responsible for the observed variation in the propensity to express phase change. This result emphasizes the importance of genetic factors in the expression of phase traits and calls for further investigations on density

Growth, development, and nutritional physiology of grasshoppers from subarctic and temperate regions.

Science.gov (United States)

Fielding, Dennis J; Defoliart, Linda S

2007-01-01

Despite the importance of developmental rate, growth rate, and size at maturity in the life history of poikliotherms, the trade-offs among these traits and selection pressures involved in the evolution of these traits are not well understood. This study compared these traits in a grasshopper, Melanoplus sanguinipes F. (Orthoptera: Acrididae), from two contrasting geographical regions, subarctic Alaska and temperate Idaho. The growing season in the interior of Alaska is about 80 d shorter than at low-elevation sites in Idaho. We hypothesized that the Alaskan grasshoppers would show more rapid growth and development than grasshoppers from Idaho, at the cost of greater sensitivity to food quality. On a diet of lettuce and wheat bran, grasshoppers from Alaska developed from egg hatch to adult more rapidly than those from Idaho at each of three different temperature regimes. Averaged over all temperature treatments, the weight of the Alaskan grasshoppers was about 5% less than that of the Idaho grasshoppers at the adult molt. Feeding and digestive efficiencies were determined for the final two instars using two meridic diets: one with a high concentration of nutrients and the other with the same formulation but diluted with cellulose. Alaskan grasshoppers again developed more rapidly, weighed less, and had faster growth rates than those from Idaho. Alaskan grasshoppers supported their more rapid growth by increasing postingestive efficiencies; that is, they had higher conversion rates of digested matter to biomass on the high-quality diet, greater assimilation of food on the low-quality diet, and greater efficiency of nitrogen assimilation or retention on both diets. There was no evidence that performance of Alaskan grasshoppers suffered any more than that of the Idaho grasshoppers on the low-quality diet.

An Architect Cicada in Brazilian Rainforest: Guyalna chlorogena (Walker).

Science.gov (United States)

Béguin, C F

2017-04-01

To study the noteworthy nest building behavior of the nymph of the Brazilian Rainforest cicada Guyalna chlorogena (Walker) during the last year of its underground life, we monitored a large number of edifices, consisting of a vertical well (up to 1 m deep) with a turret (20 to 40 cm tall) on top, and we also performed experiments. We have shown that the buildings are occupied by a single nymph, male or female, which increases the height of its turret each night by about 3 cm, during a short active growing phase. The nymph softens and reshapes the apex by pushing upwards a lump of freshly mixed soaked clay, without any opening present, i. e., without ever exposing itself to the outside. We also established that the nymph is very active once its building is achieved. For example, it restores the height of the turret to its original value when shortening and opens the top of its building in case of variation of environmental parameters. Finally, we have shown how the nymph opens its edifice to reach the outside for molting into an adult stage (imago). With this work, we contributed to a better understanding of the nesting behavior of Amazon cicadas.

A ratiometric electrochemical biosensor for the exosomal microRNAs detection based on bipedal DNA walkers propelled by locked nucleic acid modified toehold mediate strand displacement reaction.

Science.gov (United States)

Zhang, Jing; Wang, Liang-Liang; Hou, Mei-Feng; Xia, Yao-Kun; He, Wen-Hui; Yan, An; Weng, Yun-Ping; Zeng, Lu-Peng; Chen, Jing-Hua

2018-04-15

Sensitive and selective detection of microRNAs (miRNAs) in cancer cells derived exosomes have attracted rapidly growing interest owing to their potential in diagnostic and prognostic applications. Here, we design a ratiometric electrochemical biosensor based on bipedal DNA walkers for the attomolar detection of exosomal miR-21. In the presence of miR-21, DNA walkers are activated to walk continuously along DNA tracks, resulting in conformational changes as well as considerable increases of the signal ratio produced by target-respond and target-independent reporters. With the signal cascade amplification of DNA walkers, the biosensor exhibits ultrahigh sensitivity with the limit of detection (LOD) down to 67 aM. Furthermore, owing to the background-correcting function of target-independent reporters termed as reference reporters, the biosensor is robust and stable enough to be applied in the detection of exosomal miR-21 extracted from breast cancer cell lines and serums. In addition, because locked nucleic acid (LNA) modified toehold mediate strand displacement reaction (TMSDR) has extraordinary discriminative ability, the biosensor displays excellent selectivity even against the single-base-mismatched target. It is worth mentioning that our sensor is regenerative and stable for at least 5 cycles without diminution in sensitivity. In brief, the high sensitivity, selectivity and reproducibility, together with cheap, make the proposed biosensor a promising approach for exosomal miRNAs detection, in conjunction with early point-of-care testing (POCT) of cancer. Copyright © 2017 Elsevier B.V. All rights reserved.

Monitoring of insects with public participation (MIPP; EU LIFE project 11 NAT/IT/000252: overview on a citizen science initiative and a monitoring programme (Insecta: Coleoptera; Lepidoptera; Orthoptera

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Franco Mason

2015-06-01

Full Text Available The LIFE project “MIPP” - Monitoring of Insects with Public Participation (11 NAT/IT/000252 is focused on selected insect species (five Coleoptera, three Lepidoptera, one Orthoptera, all included in the annexes II and IV of the Habitats Directive (HD 92/43/EEC. One important aim is a citizen science initiative where every person may become a citizen scientist and collect faunistic data on the above species throughout Italy. Another objective of the project MIPP is the development of standard methods for monitoring the conserva- tion status of the five target beetle species. One innovative method employed is a sniffer-dog (“Osmodog”, trained to find the rare and endangered hermit beetle, Osmoderma eremita, which lives in veteran, hollow trees. The dog detects the strong smell of mature peach produced by adult males and an odor produced by the larvae. Another objective of the project MIPP is the dissemination of topics such as HD, Natura 2000, importance of dead-wood, Life projects, insect monitoring and conservation.

Die Silhouette in der zeitgenössischen Kunst: Vergegenwärtigung und Bewältigung in Kara Walkers "Slavery! Slavery!"

OpenAIRE

Haarer, Andrea

2012-01-01

Lotte Reinigers Silhouettenfilme nutzten mediale Eigenschaften von Abstraktion und Imagination sowie kulturelle Kodes als visuelle Strategie, um bekannte Geschichten bildlich zu kommentieren und andersartig zu erzählen. Kara Walker setzt diese Strategie bildlichen Erzählens in der zeitgenössischen Kunst fruchtbar fort. Ihre großformatigen Silhouetten machen in "Slavery! Slavery!" (1997) die Schwierigkeit sichtbar, eine afroamerikanische Geschichte zu erzählen, die nicht von Mythen und Stereot...

Prof. John Wood, Chief Executive Designate, Dr Gordon Walker, Directorate, Chief Executive, Prof. Ken J. Peach, Head of the Particle Physics Department, CLRC Rutherford Appleton Laboratory, United Kingdom

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Patrice Loïez

2001-01-01

L. to. r.: Dr. Ian Wilson, CLIC Deputy Study Leader, Prof. Ken J. Peach, Head of the Particle Physics Department, Prof. John Wood, Chief Executive Designate, Dr. Gordon Walker, Directorate, Chief Executive

A Kinematic Model for Vertical Axis Rotation within the Mina Deflection of the Walker Lane

Science.gov (United States)

Gledhill, T.; Pluhar, C. J.; Johnson, S. A.; Lindeman, J. R.; Petronis, M. S.

2016-12-01

The Mina Deflection, at the boundary between the Central and Southern Walker Lane, spans the California-Nevada border and includes a heavily-faulted Pliocene volcanic field overlying Miocene ignimbrites. The dextral Walker Lane accommodates 25% of relative Pacific-North America plate motion and steps right across the sinistral Mina deflection. Ours and previous work shows that the Mina Deflection partially accommodates deformation by vertical-axis rotation of up to 99.9o ± 6.1o rotation since 11 Ma. This rotation is evident in latite ignimbrite of Gilbert et al. (1971), which we have formalized as three members of Tuff of Huntoon Creek (THC). The welded, basal, normal-polarity Huntoon Valley Member of THC is overlain by the unwelded to partially-welded, reversed-polarity Adobe Hills Mbr. This member includes internal breaks suggesting multiple eruptive phases, but the paleomagnetic results from each are statistically indistinguishable, meaning that they were likely erupted in rapid succession (within a few centuries of one another). THC ends with a welded member exhibiting very shallow inclination and south declination that we call Excursional Mbr. One of the upper members has been dated at 11.17 ± 0.04 Ma. These Miocene units are overlain by Pliocene basalts, Quaternary alluvium, and lacustrine deposits. Our paleomagnetic results show a gradient between the zero rotation domain and high rotation across a 20km baseline. A micropolar model, based on 25 years of earthquake data from the Northern and Southern California Seismic Network, suggest the Mina Deflection is currently experiencing transpressional seismogenic deformation (Unruh et al., 2003). Accepting Unruh's model and assuming continuous rotation since 11 Ma, we propose a kinematic model for the western Mina Deflection that accommodates 90o of vertical axis rotation from N-S to ENE-WSW oriented blocks.

Kinetic analysis of the function of the upper body for elite race walkers during official men 20 km walking race.

Science.gov (United States)

Hoga-Miura, Koji; Ae, Michiyoshi; Fujii, Norihisa; Yokozawa, Toshiharu

2016-10-01

This study investigated the function of the upper extremities of elite race walkers during official 20 km races, focusing on the angular momentum about the vertical axis and other parameters of the upper extremities. Sixteen walkers were analysed using the three-dimensional direct linear transformation method during three official men's 20 km walking races. The subjects, included participants at the Olympics and World Championships, who finished without disqualification and had not been disqualified during the two years prior to or following the races analysed in the present study. The angular momenta of the upper and lower body were counterbalanced as in running and normal walking. The momentum of the upper body was mainly generated by the upper extremities. The joint force moment of the right shoulder and the joint torque at the left shoulder just before right toe-off were significantly correlated with the walking speed. These were counterbalanced by other moments and torques to the torso torque, which worked to obtain a large mechanical energy flow from the recovery leg to the support leg in the final phase of the support phase. Therefore, a function of the shoulder torque was to counterbalance the torso torque to gain a fast walking speed with substantial mechanical energy flow.

Interactions of ozone and antineoplastic drugs on rat lung fibroblasts and Walker rat carcinoma cells

International Nuclear Information System (INIS)

Wenzel, D.G.; Morgan, D.L.

1983-01-01

Cultured rat lung fibroblasts (F-cells) and Walker rat carcinoma cells (WRC-cells) labeled with 51 Cr were exposed to the following antitumor drugs alone or with O 3 : carmustine (BCNU), doxorubicin (Dox), cisplatin (CPt), mitomycin C (Mit C) or vitamin K 3 (Vit K). Release of 51 Cr (cell injury) was greater for F-cells than WRC-cells with any single treatment. Pretreatment with any drug (400 microM), except for Vit K with WRC-cells, did not significantly increase O 3 -induced loss of 51 Cr. Co-exposure of F-cells to drugs and O 3 resulted in a marked potentiation of O 3 -induced injury with Vit K, and an inhibition with Dox

NMR images of non-communicating hydrocephalus associated with Dandy-Walker variant and achondroplasia

International Nuclear Information System (INIS)

Sato, Masaharu; Kuroda, Ryotaro; Watanabe, Masaru; Nakatani, Jiro; Ioku, Masahiko; Irisawa, Minoru; Hamada, Tatsumi; Ishida, Osamu

1988-01-01

Two cases of non-communicating hydrocephalus caused by a relatively rare etiology were reported. They were both diagnosed by means of nuclear magnetic resonance (NMR). The first patient, a 4-month-old boy, had Dandy-Walker variant, showing hypoplasia of the corpus callosum and the inferior vermis, and a large cyst behind the vermis, communicating with the subarachnoid space, as well as hydrocephalus; the fourth ventricle was partially reserved. The second patient, also a 4-month-old boy, had achondroplasia, resulting in a narrow foramen magnum; the disturbance of the outflow of the cerebro-spinal fluid around the cisterna magna was thought to be the cause of hydrocephalus in his case. The validity of NMR was demonstrated in the diagnoses of these conditions, for a high resolution was needed in examining the complicated structure of the posterior fossa. (author)

NMR images of non-communicating hydrocephalus associated with Dandy-Walker variant and achondroplasia

Energy Technology Data Exchange (ETDEWEB)

Sato, Masaharu; Kuroda, Ryotaro; Watanabe, Masaru; Nakatani, Jiro; Ioku, Masahiko; Irisawa, Minoru; Hamada, Tatsumi; Ishida, Osamu

1988-06-01

Two cases of non-communicating hydrocephalus caused by a relatively rare etiology were reported. They were both diagnosed by means of nuclear magnetic resonance (NMR). The first patient, a 4-month-old boy, had Dandy-Walker variant, showing hypoplasia of the corpus callosum and the inferior vermis, and a large cyst behind the vermis, communicating with the subarachnoid space, as well as hydrocephalus; the fourth ventricle was partially reserved. The second patient, also a 4-month-old boy, had achondroplasia, resulting in a narrow foramen magnum; the disturbance of the outflow of the cerebro-spinal fluid around the cisterna magna was thought to be the cause of hydrocephalus in his case. The validity of NMR was demonstrated in the diagnoses of these conditions, for a high resolution was needed in examining the complicated structure of the posterior fossa.

Effects of Walker 256 carcinoma on metabolic alterations during the evolution of pregnancy.

Science.gov (United States)

Cintra-Gomes, M C; Cury, L; Parreira, M R; Elias, C F; Areas, M A

1990-01-01

The control of pregnant cancer patients is difficult because it involves both mother and fetus, and the metabolic alterations in the cancer host induce a massive mobilization of nutrients diverted to the neoplastic cells. The purpose of the present study was to determine the evolution of the Walker 256 carcinoma in pregnant rats and its consequences on fetal development. The results showed that the tumors displayed a very rapid rate of growth and induced a reduction in fetal weights in the pregnant tumor-bearing rats. The tumor-bearing and pregnant tumor-bearing groups showed a decrease in blood glucose and total serum protein, suggesting an increase in energy utilization of these substrates and synthetic activity by the tumoral cells. An imbalance between protein synthesis and catabolism may occur in the tumor-bearing rats which may be related to the degree of nutritional depletion.

Morphology-Controlled 9,10-Diphenylanthracene Nanoblocks as Electrochemiluminescence Emitters for MicroRNA Detection with One-Step DNA Walker Amplification.

Science.gov (United States)

Liu, Jia-Li; Tang, Zhi-Ling; Zhang, Jia-Qi; Chai, Ya-Qin; Zhuo, Ying; Yuan, Ruo

2018-04-17

The electrochemiluminescence (ECL) properties of polycyclic aromatic hydrocarbons (PAHs) are excellent on account of the high photoluminescence quantum yield. However, the poor solubility and radical instability of PAHs in the aqueous solution severely restricted further biological application. Here 9,10-diphenylanthracene (DPA) nanoblocks (NBs) with good dispersibility and stability in aqueous solution were prepared according to morphology-controlled technology employing water-soluble polymers as a protectant. Furthermore, an ECL "off-on" switch biosensor was developed based on a novel ECL ternary system with DPA NBs as luminophore, dissolved O 2 as coreactant, and Pt-Ag alloy nanoflowers as the coreaction accelerator, which achieved a high-intense initial ECL signal. Subsequently, the Fc-DNA as ECL signal quencher was assembled on the electrode surface to quench the initial ECL signal for a "signal-off" state. Meanwhile, DNA swing arm was modified on the electrode surface for one-step DNA walker amplification. Interestingly, in the presence of miRNA-141 and T7 Exo, the one-step DNA walker amplification was executed to recover a strong ECL signal as a "signal-on" state by the digestion of Fc-DNA. Thus the developed ECL "off-on" switch biosensor possesses a detection limit down to 29.5 aM for ultrasensitive detection of miRNA-141, which is expected to be applicable to the detection of miRNA in clinic tumor cells.

Dispersion, Topological Scattering, and Self-Interference in Multiply Connected Robertson-Walker Cosmologies

CERN Document Server

Tomaschitz, R

1994-01-01

We investigate scattering effects in open Robertson-Walker cosmologies whose spacelike slices are multiply connected hyperbolic manifolds. We work out an example in which the 3-space is infinite and has the topology of a solid torus. The world-lines in these cosmologies are unstable, and classical probability densities evolving under the horospherical geodesic flow show dispersion, as do the densities of scalar wave packets. The rate of dispersion depends crucially on the expansion factor, and we calculate the time evolution of their widths. We find that the cosmic expansion can confine dispersion: The diameter of the domain of chaoticity in the 3-manifold provides the natural, time-dependent length unit in an infinite, multiply connected universe. In a toroidal 3-space manifold this diameter is just the length of the limit cycle. On this scale we find that the densities take a finite limit width in the late stage of the expansion. In the early stage classical densities and conformally coupled fields approach...

Disparate requirements for the Walker A and B ATPase motifs of human RAD51D in homologous recombination.

Science.gov (United States)

Wiese, Claudia; Hinz, John M; Tebbs, Robert S; Nham, Peter B; Urbin, Salustra S; Collins, David W; Thompson, Larry H; Schild, David

2006-01-01

In vertebrates, homologous recombinational repair (HRR) requires RAD51 and five RAD51 paralogs (XRCC2, XRCC3, RAD51B, RAD51C and RAD51D) that all contain conserved Walker A and B ATPase motifs. In human RAD51D we examined the requirement for these motifs in interactions with XRCC2 and RAD51C, and for survival of cells in response to DNA interstrand crosslinks (ICLs). Ectopic expression of wild-type human RAD51D or mutants having a non-functional A or B motif was used to test for complementation of a rad51d knockout hamster CHO cell line. Although A-motif mutants complement very efficiently, B-motif mutants do not. Consistent with these results, experiments using the yeast two- and three-hybrid systems show that the interactions between RAD51D and its XRCC2 and RAD51C partners also require a functional RAD51D B motif, but not motif A. Similarly, hamster Xrcc2 is unable to bind to the non-complementing human RAD51D B-motif mutants in co-immunoprecipitation assays. We conclude that a functional Walker B motif, but not A motif, is necessary for RAD51D's interactions with other paralogs and for efficient HRR. We present a model in which ATPase sites are formed in a bipartite manner between RAD51D and other RAD51 paralogs.

Global bifurcation of solutions of the mean curvature spacelike equation in certain Friedmann-Lemaître-Robertson-Walker spacetimes

Science.gov (United States)

Dai, Guowei; Romero, Alfonso; Torres, Pedro J.

2018-06-01

We study the existence of spacelike graphs for the prescribed mean curvature equation in the Friedmann-Lemaître-Robertson-Walker (FLRW) spacetime. By using a conformal change of variable, this problem is translated into an equivalent problem in the Lorentz-Minkowski spacetime. Then, by using Rabinowitz's global bifurcation method, we obtain the existence and multiplicity of positive solutions for this equation with 0-Dirichlet boundary condition on a ball. Moreover, the global structure of the positive solution set is studied.

The influence of whole-body and local irradiation modified by hyperglycemia on metastatic Walker carcinosarcoma 256 in rats

International Nuclear Information System (INIS)

Kutlimuratov, A.B.; Ivashkin, A.V.; Zakirkhodzhaev, U.D.

1990-01-01

It has been shown that the local radiation therapy, and also radiation therapy modified by the short-term hyperglycemia really increase the life-span of rats with Walker 256 carcinosarcoma. At the same time the metastatic process also increases, especially after the modified radiation therapy. The total irradiation of experimental animals in a dose of 50 sGy before the modified radiation therapy considerably decreases the frequency of metastatic process. A conclusion is drawn that the total irradiation has a prophylactic influence on metastases under conditions of modified radiation therapy

Comparative management of Chilo suppressalis (Walker) (Lepidoptera: Crambidae) by convenient pesticides and non-chemical practices in a double rice cropping system

OpenAIRE

M. N. Poor Amiri; Faramarz Alinia; Sohrab Imani, et al.

2017-01-01

The inclination of rice growers towards double cropping system in north of Iran has raised new concerns about the excessive release of broad-spectrum pesticides, particularly organophosphates, in the environment. In this study, the efficiency of three insecticides and an integrated pest management (IPM) program for management of the striped rice stem borer, Chilo suppressalis (Walker) (Lep: Crambidae), in double cropping system was investigated under field condition. According to the results,...