Rediscovering digitules in Aphidomorpha and the question of homology among Sternorrhyncha (Insecta, Hemiptera

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Mark A. Metz

2017-07-01

Full Text Available We explore and expand on the morphological term digitule. The term was originally proposed for toe-like setae on a species of Phylloxera Boyer de Fonscolombe, 1834 (Hemiptera, Sternorrhyncha, Aphidomorpha by Henry Shimer, an American naturalist. While it is standard terminology in scale systematics (Hemiptera, Sternorrhyncha, Coccidomorpha, the term digitule was ignored by aphid specialists despite being the original taxon for which the term was described. Similar setae occur on many arthropod groups, so the homology is poorly understood even within any superfamily of Hemiptera. We provide the etymology of the term, a proposed explanation for why it was used among scale taxonomists and not aphid taxonomists, and discuss briefly options to progress beyond the confusion between terminology for morphology and homology in Sternorrhyncha.

Host Range Specificity of Scymnus camptodromus (Coleoptera: Coccinellidae), A Predator of Hemlock Woolly Adelgid (Hemiptera: Adelgidae).

Science.gov (United States)

Limbu, Samita; Cassidy, Katie; Keena, Melody; Tobin, Patrick; Hoover, Kelli

2016-02-01

Scymnus (Neopullus) camptodromus Yu and Liu (Coleoptera: Coccinellidae) was brought to the United States from China as a potential biological control agent for hemlock woolly adelgid (Adelges tsugae Annand) (Hemiptera: Adelgidae). Scymnus camptodromus phenology is closely synchronized with that of A. tsugae and has several characteristics of a promising biological control agent. As a prerequisite to field release, S. camptodromus was evaluated for potential nontarget impacts. In host range studies, the predator was given the choice of sympatric adelgid and nonadelgid prey items. Nontarget testing showed that S. camptodromus will feed to some degree on other adelgid species, but highly prefers A. tsugae. We also evaluated larval development of S. camptodromus on pine bark adelgid (Pineus strobi (Hartig)) (Hemiptera: Adelgidae) and larch adelgid (Adelges laricis Vallot) (Hemiptera: Adelgidae); a small proportion of predator larvae was able to develop to adulthood on P. strobi or A. laricis alone. Scymnus camptodromus showed no interest in feeding on woolly alder aphid (Paraprociphilus tessellatus Fitch) (Hemiptera: Aphididae) or woolly apple aphid (Eriosoma lanigerum (Hausmann)) (Hemiptera: Aphididae), and minimal interest in cotton aphid (Aphis gossypii Glover) (Hemiptera: Aphididae) in choice and no-choice experiments. Scymnus camptodromus females did not oviposit on any host material other than A. tsugae-infested hemlock. Under the circumstances of the study, S. camptodromus appears to be a specific predator of A. tsugae, with minimal risk to nontarget species. Although the predator can develop on P. strobi, the likelihood that S. camptodromus would oviposit on pine hosts of this adelgid is small.

Application of RNA-seq for mitogenome reconstruction, and reconsideration of long-branch artifacts in Hemiptera phylogeny

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Song, Nan; An, Shiheng; Yin, Xinming; Cai, Wanzhi; Li, Hu

2016-01-01

Hemiptera make up the largest nonholometabolan insect assemblage. Despite previous efforts to elucidate phylogeny within this group, relationships among the major sub-lineages remain uncertain. In particular, mitochondrial genome (mitogenome) data are still sparse for many important hemipteran insect groups. Recent mitogenomic analyses of Hemiptera have usually included no more than 50 species, with conflicting hypotheses presented. Here, we determined the nearly complete nucleotide sequence of the mitogenome for the aphid species of Rhopalosiphum padi using RNA-seq plus gap filling. The 15,205 bp mitogenome included all mitochondrial genes except for trnF. The mitogenome organization and size for R. padi are similar to previously reported aphid species. In addition, the phylogenetic relationships for Hemiptera were examined using a mitogenomic dataset which included sequences from 103 ingroup species and 19 outgroup species. Our results showed that the seven species representing the Aleyrodidae exhibit extremely long branches, and always cluster with long-branched outgroups. This lead to the failure of recovering a monophyletic Hemiptera in most analyses. The data treatment of Degen-coding for protein-coding genes and the site-heterogeneous CAT model show improved suppression of the long-branch effect. Under these conditions, the Sternorrhyncha was often recovered as the most basal clade in Hemiptera. PMID:27633117

Preliminary Observations on Zelus obscuridorsis (Stål (Hemiptera: Reduviidae as Predator of the Corn Leafhopper (Hemiptera: Cicadellidae in Argentina

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Eduardo G. Virla

2015-06-01

Full Text Available The corn leafhopper Dalbulus maidis (Hemiptera: Cicadellidae, is an important corn pest in most of tropical and subtropical America. This leafhopper has a rich natural enemy complex of which parasitoids and pathogens are the most studied; knowledge on its predators is limited. We noted the presence of the native assassin bug Zelus obscuridorsis (Hemiptera: Reduviidae predating diverse motile insects, including the corn leafhopper, on corn plants cultivated in household vegetable gardens in San Miguel de Tucumán (Argentina; in order to verify its predatory actions, we exposed lab-bred individuals of D. maidis to adults of Z. obscuridorsis. The predators were starved for 24 h before trials in which the corn leafhopper in different developmental stages were exposed. Zelus obscuridorsis is highly skilled in catching specimens in motion, but it was not able to prey on eggs. The predator was capable to catch and prey on nymphs and adults.

A new species of Enchenopa (Hemiptera: Membracidae from the Brazilian Atlantic Forest

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Frederico Lencioni-Neto

2015-06-01

Full Text Available Enchenopa luizae sp. nov. (holotype female from Brazil, State of São Paulo, municipality of São José dos Campos, Parque Natural Municipal Augusto Ruschi at 23°04'05°S", 45°56'22"W, 06.VIII.2011, R. La Rosa leg. deposited in DZUP is described and diagnosed from the Atlantic Forest Vale do Paraíba, São Paulo, Brazil. The new species is very similar to Enchenopa monoceros (Germar, 1821 in overall aspects but much larger and with inconspicuous lateral secondary carinae. The fourth instar nymph is also briefly characterized.

Random walk on random walks

NARCIS (Netherlands)

Hilário, M.; Hollander, den W.Th.F.; Sidoravicius, V.; Soares dos Santos, R.; Teixeira, A.

2014-01-01

In this paper we study a random walk in a one-dimensional dynamic random environment consisting of a collection of independent particles performing simple symmetric random walks in a Poisson equilibrium with density ¿¿(0,8). At each step the random walk performs a nearest-neighbour jump, moving to

Relation between random walks and quantum walks

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Boettcher, Stefan; Falkner, Stefan; Portugal, Renato

2015-05-01

Based on studies of four specific networks, we conjecture a general relation between the walk dimensions dw of discrete-time random walks and quantum walks with the (self-inverse) Grover coin. In each case, we find that dw of the quantum walk takes on exactly half the value found for the classical random walk on the same geometry. Since walks on homogeneous lattices satisfy this relation trivially, our results for heterogeneous networks suggest that such a relation holds irrespective of whether translational invariance is maintained or not. To develop our results, we extend the renormalization-group analysis (RG) of the stochastic master equation to one with a unitary propagator. As in the classical case, the solution ρ (x ,t ) in space and time of this quantum-walk equation exhibits a scaling collapse for a variable xdw/t in the weak limit, which defines dw and illuminates fundamental aspects of the walk dynamics, e.g., its mean-square displacement. We confirm the collapse for ρ (x ,t ) in each case with extensive numerical simulation. The exact values for dw themselves demonstrate that RG is a powerful complementary approach to study the asymptotics of quantum walks that weak-limit theorems have not been able to access, such as for systems lacking translational symmetries beyond simple trees.

Essential oils as fumigants for bed bugs (Hemiptera: Cimicidae)

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In Petri dish assays, fumigation of a pyrethroid-susceptible strain of bed bugs Cimex lectularius L. (Hemiptera: Cimicidae) with various essential oils resulted in mortality that approached or equaled 100%, after 5 days. However, when bed bugs were exposed to the same essential oils in sealed, comme...

Fire-Walking

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Willey, David

2010-01-01

This article gives a brief history of fire-walking and then deals with the physics behind fire-walking. The author has performed approximately 50 fire-walks, took the data for the world's hottest fire-walk and was, at one time, a world record holder for the longest fire-walk (www.dwilley.com/HDATLTW/Record_Making_Firewalks.html). He currently…

Randomized random walk on a random walk

International Nuclear Information System (INIS)

Lee, P.A.

1983-06-01

This paper discusses generalizations of the model introduced by Kehr and Kunter of the random walk of a particle on a one-dimensional chain which in turn has been constructed by a random walk procedure. The superimposed random walk is randomised in time according to the occurrences of a stochastic point process. The probability of finding the particle in a particular position at a certain instant is obtained explicitly in the transform domain. It is found that the asymptotic behaviour for large time of the mean-square displacement of the particle depends critically on the assumed structure of the basic random walk, giving a diffusion-like term for an asymmetric walk or a square root law if the walk is symmetric. Many results are obtained in closed form for the Poisson process case, and these agree with those given previously by Kehr and Kunter. (author)

Nine Walks

DEFF Research Database (Denmark)

2013-01-01

Based on studies of, among others, the Situationists and their theories regarding walks as an artistic method and expression nine master students from “Studio Constructing an Archive”, Aarhus School of Architecture, Denmark performed nine walks as part of the exhibition. These walks relate...... to the students’ individual mappings of Behind the Green Door, its structure and content. They highlight a number of motifs found in the exhibition which are of particular interest to the students. The walks represented reflections on the walk as an artistic method and expression. Each walk is an individual...

Verde plant bug, Creontiades signatus (Hemiptera: Miridae) effects of insect density and bloom period of infestation on cotton damage and yield

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The verde plant bug, Creontiades signatus Distant (Hemiptera: Miridae), has emerged as a threat to cotton in South Texas, causing boll damage similar to boll-feeding stink bugs (Hemiptera: Pentatomidae). Verde plant bugs were released into caged cotton for a one-week period to characterize the effec...

Walk Score(TM), Perceived Neighborhood Walkability, and walking in the US.

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Tuckel, Peter; Milczarski, William

2015-03-01

To investigate both the Walk Score(TM) and a self-reported measure of neighborhood walkability ("Perceived Neighborhood Walkability") as estimators of transport and recreational walking among Americans. The study is based upon a survey of a nationally-representative sample of 1224 American adults. The survey gauged walking for both transport and recreation and included a self-reported measure of neighborhood walkability and each respondent's Walk Score(TM). Binary logistic and linear regression analyses were performed on the data. The Walk Score(TM) is associated with walking for transport, but not recreational walking nor total walking. Perceived Neighborhood Walkability is associated with transport, recreational and total walking. Perceived Neighborhood Walkability captures the experiential nature of walking more than the Walk Score(TM).

Development of DNA barcodes of genus Lygus Hahn (Hemiptera: Miridae)

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The genus Lygus (Hemiptera: Miridae) is an important group of insects that contains 43 known species worldwide. Some species within this genus are important agricultural pests in North America. Annual economic impacts in cotton, Gossypium hirsutum L., from Lygus spp. due to yield losses and control ...

Preparing soft-bodied arthropods for microscope examination: Whiteflies (Insecta: Hemiptera: Alyrodidae)

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Proper identification of whiteflies (Hemiptera:Alyrodidae) requires preparation of the specimen on a microscope slide. This training video provides visual instruction on how to prepare whitefly specimens on microscope slides for examination and identification. Steps ranging from collection, specimen...

Walking pattern classification and walking distance estimation algorithms using gait phase information.

Science.gov (United States)

Wang, Jeen-Shing; Lin, Che-Wei; Yang, Ya-Ting C; Ho, Yu-Jen

2012-10-01

This paper presents a walking pattern classification and a walking distance estimation algorithm using gait phase information. A gait phase information retrieval algorithm was developed to analyze the duration of the phases in a gait cycle (i.e., stance, push-off, swing, and heel-strike phases). Based on the gait phase information, a decision tree based on the relations between gait phases was constructed for classifying three different walking patterns (level walking, walking upstairs, and walking downstairs). Gait phase information was also used for developing a walking distance estimation algorithm. The walking distance estimation algorithm consists of the processes of step count and step length estimation. The proposed walking pattern classification and walking distance estimation algorithm have been validated by a series of experiments. The accuracy of the proposed walking pattern classification was 98.87%, 95.45%, and 95.00% for level walking, walking upstairs, and walking downstairs, respectively. The accuracy of the proposed walking distance estimation algorithm was 96.42% over a walking distance.

Genetic variation in social influence on mate preferences

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Rebar, Darren; Rodríguez, Rafael L.

2013-01-01

Patterns of phenotypic variation arise in part from plasticity owing to social interactions, and these patterns contribute, in turn, to the form of selection that shapes the variation we observe in natural populations. This proximate–ultimate dynamic brings genetic variation in social environments to the forefront of evolutionary theory. However, the extent of this variation remains largely unknown. Here, we use a member of the Enchenopa binotata species complex of treehoppers (Hemiptera: Membracidae) to assess how mate preferences are influenced by genetic variation in the social environment. We used full-sibling split-families as ‘treatment’ social environments, and reared focal females alongside each treatment family, describing the mate preferences of the focal females. With this method, we detected substantial genetic variation in social influence on mate preferences. The mate preferences of focal females varied according to the treatment families along with which they grew up. We discuss the evolutionary implications of the presence of such genetic variation in social influence on mate preferences, including potential contributions to the maintenance of genetic variation, the promotion of divergence, and the adaptive evolution of social effects on fitness-related traits. PMID:23698010

Temporal and Directional Patterns of Nymphal Halyomorpha halys (Hemiptera: Pentatomidae) Movement on the Trunk of Selected Wild and Fruit Tree Hosts in the Mid-Atlantic Region.

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Acebes-Doria, Angelita L; Leskey, Tracy C; Bergh, J Christopher

2017-04-01

Halyomorpha halys (Stål) (Hemiptera: Pentatomidae) is an invasive and polyphagous herbivore that has been problematic in Mid-Atlantic fruit orchards, many of which are adjacent to woodlands containing its wild hosts. Our tree census in woodlands bordering 15 Mid-Atlantic apple orchards revealed 47 species of deciduous trees and shrubs, 76.6% of which were recorded hosts of H. halys. Tree of heaven was most common and abundant overall. Halyomorpha halys nymphs have a substantial walking dispersal capacity, and their fitness is enhanced by feeding on multiple hosts. Directional and temporal patterns of nymphal H. halys movement on selected wild hosts and apple and peach trees at the orchard-woodland interface were monitored in 2014 and 2015 using passive traps to capture nymphs walking up and down tree trunks. Weekly captures from mid-May to late September or mid-October were compared among hosts across both seasons. Despite higher total nymphal captures in 2014 than 2015, the seasonal trends for both years were similar and indicated bivoltine H. halys populations. In both years, more nymphs were intercepted while walking up than down and captures of upward- and downward-walking nymphs varied significantly among the hosts. All instars were captured, but captures of second instars predominated. Captures reflected seasonal changes in instar distribution and consisted predominantly of younger and older nymphs, early and later in the season, respectively. Results are discussed in relation to host and seasonal effects on the movement of nymphs at the orchard-woodland interface, and the implications for H. halys management. © 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.

Preparing soft-bodied arthropods for microscope examination: Aphids (Insecta: Hemiptera: Aphididae)

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Proper identification of aphids (Hemiptera: Aphididae) require preparation of the specimen on a microscope slide. This training video provides visual instruction on how to prepare aphid specimens on microscope slides for examination and indentification. Steps ranging from collection, specimen clear...

Catalog of the adelgids of the world (Hemiptera, Adelgidae)

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Colin Favret; Nathan P. Havill; Gary L. Miller; Masakazu Sano; Benjamin Victor

2015-01-01

A taxonomic and nomenclatural Catalogue of the adelgids (Hemiptera: Adelgidae) is presented. Six family-group names are listed, five being synonyms of Adelgidae. Twenty-two genus-group names, of which nine are subjectively valid and in use, are presented with their type species, etymology, and grammatical gender. One hundred and six species-group names are listed, of...

The complete mitochondrial genome sequence of Diaphorina citri (Hemiptera: Psyllidae)

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The first complete mitochondrial genome (mitogenome) sequence of Asian citrus psyllid, Diaphorina citri (Hemiptera: Psyllidae), from Guangzhou, China is presented. The circular mitogenome is 14,996 bp in length with an A+T content of 74.5%, and contains 13 protein-coding genes (PCGs), 22 tRNA genes ...

Who walks? Factors associated with walking behavior in disabled older women with and without self-reported walking difficulty.

Science.gov (United States)

Simonsick, E M; Guralnik, J M; Fried, L P

1999-06-01

To determine how severity of walking difficulty and sociodemographic, psychosocial, and health-related factors influence walking behavior in disabled older women. Cross-sectional analyses of baseline data from the Women's Health and Aging Study (WHAS). An urban community encompassing 12 contiguous zip code areas in the eastern portion of Baltimore City and part of Baltimore County, Maryland. A total of 920 moderately to severely disabled community-resident women, aged 65 years and older, identified from an age-stratified random sample of Medicare beneficiaries. Walking behavior was defined as minutes walked for exercise and total blocks walked per week. Independent variables included self-reported walking difficulty, sociodemographic factors, psychological status (depression, mastery, anxiety, and cognition), and health-related factors (falls and fear of falling, fatigue, vision and balance problems, weight, smoking, and cane use). Walking at least 8 blocks per week was strongly negatively related to severity of walking difficulty. Independent of difficulty level, older age, black race, fatigue, obesity, and cane use were also negatively associated with walking; living alone and high mastery had a positive association with walking. Even among functionally limited women, sociocultural, psychological, and health-related factors were independently associated with walking behavior. Thus, programs aimed at improving walking ability need to address these factors in addition to walking difficulties to maximize participation and compliance.

“Candidatus Phytoplasma pyri” affects behavior of Cacopsylla pyricola (Hemiptera: Psyllidae)

Science.gov (United States)

Pear psylla, Cacopsylla pyricola (Hemiptera: Psyllidae), is a key pest of pear and is a vector of "Candidatus Phytoplasma pyri", the pathogen associated with pear decline disease. Although commercial pear trees are grafted to Phytoplasma-resistant rootstock, a recent report indicated that many C. p...

Observations on some species of the genus Lyramorpha Westw. (Hemiptera Heteroptera)

NARCIS (Netherlands)

Schouteden, H.

1908-01-01

1. Lyramorpha pallida Westwood and L. rosea Westwood. In his »Catalogue of Hemiptera in the Collection of the Rev. W. F. Hope”, part I, London 1837, Westwood founded the genus Lyramorpha, with two species, L. rosea and L. pallida, both from New Holland.

First report and morphological redescription of Teleonemia morio (Stål (Hemiptera, Tingidae in Annona squamosa L. (Annonaceae in Brazil

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Sônia M. F. Broglio

2012-03-01

Full Text Available First report and morphological redescription of Teleonemia morio (Stål (Hemiptera, Tingidae in Annona squamosa L. (Annonaceae in Brazil. This is the first report of a severe attack of Teleonemia morio (Stål, 1855 (Hemiptera, Heteroptera, Tingidae on Annona squamosa L. (custard apple, causing up to 80% of losses of infested trees. In order to facilitate the identification of this insect pest, the adult female of T. morio is redescribed based on specimens collected in Palmeira dos Índios, Alagoas, Brazil.Primeiro registro e redescrição morfológica de Teleonemia morio (Stål (Hemiptera, Tingidae em Annona squamosa L. (Annonaceae no Brazil. Este é o primeiro registro de um ataque severo de Teleonemia morio (Stål, 1855 (Hemiptera, Heteroptera, Tingidae em árvores de Annona squamosa L. (pinheira ou fruta-do-conde, resultando em perdas de aproximadamente 80% das plantas infestadas. Com o objetivo de facilitar a identificação deste inseto-praga, foi feita a redescrição da fêmea adulta de T. morio com base em espécimes coletados em Palmeira dos Índios, Alagoas, Brasil.

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/...

Shared and task-specific muscle synergies of Nordic walking and conventional walking.

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Boccia, G; Zoppirolli, C; Bortolan, L; Schena, F; Pellegrini, B

2018-03-01

Nordic walking is a form of walking that includes a poling action, and therefore an additional subtask, with respect to conventional walking. The aim of this study was to assess whether Nordic walking required a task-specific muscle coordination with respect to conventional walking. We compared the electromyographic (EMG) activity of 15 upper- and lower-limb muscles of 9 Nordic walking instructors, while executing Nordic walking and conventional walking at 1.3 ms -1 on a treadmill. Non-negative matrix factorization method was applied to identify muscle synergies, representing the spatial and temporal organization of muscle coordination. The number of muscle synergies was not different between Nordic walking (5.2 ± 0.4) and conventional walking (5.0 ± 0.7, P = .423). Five muscle synergies accounted for 91.2 ± 1.1% and 92.9 ± 1.2% of total EMG variance in Nordic walking and conventional walking, respectively. Similarity and cross-reconstruction analyses showed that 4 muscle synergies, mainly involving lower-limb and trunk muscles, are shared between Nordic walking and conventional walking. One synergy acting during upper limb propulsion is specific to Nordic walking, modifying the spatial organization and the magnitude of activation of upper limb muscles compared to conventional walking. The inclusion of the poling action in Nordic walking does not increase the complexity of movement control and does not change the coordination of lower limb muscles. This makes Nordic walking a physical activity suitable also for people with low motor skill. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Rhizoecus colombiensis Ramos & Caballero, a new species of hypogeal mealybug (Hemiptera: Coccomor.

Science.gov (United States)

Ramos-Portilla, Andrea Amalia; Caballero, Alejandro

2016-03-14

A new species belonging to Rhizoecus Künckel d'Herculais (Hemiptera: Coccomorpha: Rhizoecidae) is described, with hosts and distribution data in the New World. A dichotomous and illustrated key for the twelve species of Rhizoecus recorded from Colombia is presented.

Preparing soft-bodied arthropods for microscope examination: Soft Scales (Insecta: Hemiptera: Coccidae)

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Proper identification of soft scales (Hemiptera:Coccidae) requires preparation of the specimen on a microscope slide. This training video provides visual instruction on how to prepare soft scale specimens on microscope slides for examination and identification. Steps ranging from collection, speci...

Instar- and stage-specific photoperiodic diapause response of Lygus hesperus (Hemiptera: Miridae)

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The western tarnished plant bug (Lygus hesperus Knight)(Hemiptera:Miridae) is a polyphagous pest of numerous western crops. This pest overwinters in a relatively short duration adult diapause, but many details regarding diapause induction and maintenance remain unstudied. Instar-specific responses t...

Effects of the Trophobiont Herbivore Calloconophora pugionata (Hemiptera on Ant Fauna Associated with Myrcia obovata (Myrtaceae in a Montane Tropical Forest

Directory of Open Access Journals (Sweden)

Roberth Fagundes

2012-01-01

Full Text Available Many studies have investigated the mechanisms behind the structure of arboreal ant assemblages. In this study, the objective was to evaluate the effect of availability of honeydew-producing colonies of Calloconophora pugionata (Membracidae on the structure of ant assemblages associated with the host plant Myrcia obovata (Myrtaceae in an Atlantic forest of Minas Gerais (Brazil. Our experiment consisted in a gradual exclusion of hemipteran colonies out of the host plant crown and further record of the ant assemblage response (species richness, composition, and occurrence to the presence and density of treehopper colonies. The hypothesis was that an increase in the number of trophobiont herbivores results in an increase in tending ant occurrence but a reduction in ant species diversity. Results corroborated our main hypothesis: membracids had a positive effect on the occurrence of ants but negative on species richness. Overall insect occurrence was also reduced with increasing in C. pugionata colonies, probably due to strengthening dominant ant species territory sizes and intensification of patrolling.

Preparing sternorrhynchous insects (Insecta: Hemiptera: Sternorrhyncha) for microscope examination: Hoyer’s mounting medium

Science.gov (United States)

Proper identification of aphids, scale insects, psyllids, and whitefles (Hemiptera: Sternorrhyncha) require preparation of the specimen on a microscope slide. This training video provides visual instruction on how to prepare sternorrhynchous specimens on microscope slides for examination and identi...

Preparing soft-bodied arthropods for arthropods for microscope examination: Mealybugs (Insects: Hemiptera: Pseudococcidae)

Science.gov (United States)

Proper identification of mealybugs (Hemiptera: Pseudococcidae) require preparation of the specimen on a microscope slide. This training video provides visual instruction on how to prepare mealybug specimens on microscope slides for examination and identification. Steps ranging from collection, spec...

KidsWalk-to-School: A Guide To Promote Walking to School.

Science.gov (United States)

Center for Chronic Disease Prevention and Health Promotion (DHHS/CDC), Atlanta, GA.

This guide encourages people to create safe walking and biking routes to school, promoting four issues: physically active travel, safe and walkable routes to school, crime prevention, and health environments. The chapters include: "KidsWalk-to-School: A Guide to Promote Walking to School" (Is there a solution? Why is walking to school important?…

Walking training with cueing of cadence improves walking speed and stride length after stroke more than walking training alone: a systematic review.

Science.gov (United States)

Nascimento, Lucas R; de Oliveira, Camila Quel; Ada, Louise; Michaelsen, Stella M; Teixeira-Salmela, Luci F

2015-01-01

After stroke, is walking training with cueing of cadence superior to walking training alone in improving walking speed, stride length, cadence and symmetry? Systematic review with meta-analysis of randomised or controlled trials. Adults who have had a stroke. Walking training with cueing of cadence. Four walking outcomes were of interest: walking speed, stride length, cadence and symmetry. This review included seven trials involving 211 participants. Because one trial caused substantial statistical heterogeneity, meta-analyses were conducted with and without this trial. Walking training with cueing of cadence improved walking speed by 0.23 m/s (95% CI 0.18 to 0.27, I(2)=0%), stride length by 0.21 m (95% CI 0.14 to 0.28, I(2)=18%), cadence by 19 steps/minute (95% CI 14 to 23, I(2)=40%), and symmetry by 15% (95% CI 3 to 26, random effects) more than walking training alone. This review provides evidence that walking training with cueing of cadence improves walking speed and stride length more than walking training alone. It may also produce benefits in terms of cadence and symmetry of walking. The evidence appears strong enough to recommend the addition of 30 minutes of cueing of cadence to walking training, four times a week for 4 weeks, in order to improve walking in moderately disabled individuals with stroke. PROSPERO (CRD42013005873). Copyright © 2014 Australian Physiotherapy Association. Published by Elsevier B.V. All rights reserved.

Complementarity and quantum walks

International Nuclear Information System (INIS)

Kendon, Viv; Sanders, Barry C.

2005-01-01

We show that quantum walks interpolate between a coherent 'wave walk' and a random walk depending on how strongly the walker's coin state is measured; i.e., the quantum walk exhibits the quintessentially quantum property of complementarity, which is manifested as a tradeoff between knowledge of which path the walker takes vs the sharpness of the interference pattern. A physical implementation of a quantum walk (the quantum quincunx) should thus have an identifiable walker and the capacity to demonstrate the interpolation between wave walk and random walk depending on the strength of measurement

Physiological aspect walking and Nordic walking as adequate kinetic activities.

OpenAIRE

BENEŠ, Václav

2010-01-01

This bachelor thesis on the topic of The Physiological Aspect of Walking and Nordic Walking as an adequate physical activity focuses on chosen physiological changes of an organism during a five-month training cycle. In the theoretical part I describe the physiological changes of organism during a regularly repeated strain, and also the technique of walking, Nordic walking and health benefits of these activities are defined here. The research part of the thesis describes the measurement method...

Walking Beliefs in Women With Fibromyalgia: Clinical Profile and Impact on Walking Behavior.

Science.gov (United States)

Peñacoba, Cecilia; Pastor, María-Ángeles; López-Roig, Sofía; Velasco, Lilian; Lledo, Ana

2017-10-01

Although exercise is essential for the treatment of fibromyalgia, adherence is low. Walking, as a form of physical exercise, has significant advantages. The aim of this article is to describe, in 920 women with fibromyalgia, the prevalence of certain walking beliefs and analyze their effects both on the walking behavior itself and on the associated symptoms when patients walk according to a clinically recommended way. The results highlight the high prevalence of beliefs related to pain and fatigue as walking-inhibitors. In the whole sample, beliefs are associated with an increased perception that comorbidity prevents walking, and with higher levels of pain and fatigue. In patients who walk regularly, beliefs are only associated with the perception that comorbidity prevents them from walking. It is necessary to promote walking according to the established way (including breaks to prevent fatigue) and to implement interventions on the most prevalent beliefs that inhibit walking.

Hemiptera Mitochondrial Control Region: New Sights into the Structural Organization, Phylogenetic Utility, and Roles of Tandem Repetitions of the Noncoding Segment

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Kui Li

2018-04-01

Full Text Available As a major noncoding fragment, the control region (CR of mtDNA is responsible for the initiation of mitogenome transcription and replication. Several structural features of CR sequences have been reported in many insects. However, comprehensive analyses on the structural organization and phylogenetic utility, as well as the role of tandem replications (TRs on length variation, high A+T content, and shift of base skew of CR sequences are poorly investigated in hemipteran insects. In this study, we conducted a series of comparative analyses, using 116 samples covering all 11 infraorders of the five currently recognized monophyletic groups in the Hemiptera. Several structural elements (mononucleotide stretches containing conserved sequence blocks (CSBs, TRs, and GA-rich region were identified in the mitochondrial control region in hemipteran insects, without showing a consistent location. The presence and absence of certain specific structural elements in CR sequences show the various structural organizations of that segment among the five monophyletic groups, which indicates the diversification of the control region’s structural organization in Hemiptera. Among the many groups within Hemiptera, eight monophyletic groups and three consistent phylogenetic trees were recovered, using CSBs datasets by maximum likelihood and Bayesian methods, which suggests the possible utility of CR sequences for phylogenetic reconstruction in certain groups of Hemiptera. Statistical analyses showed that TRs may contribute to the length variation, high AT content, and the shift of base skewing of CR sequences toward high AT content in the Hemiptera. Our findings enrich the knowledge of structural organization, phylogenetic utility, and roles of tandem replication of hemipteran CR, and provide a possible framework for mitochondrial control region analyses in hemimetabolous insects.

Scymnus camptodromus (Coleoptera: Coccinellidae) larval development and predation of hemlock woolly adelgid (Hemiptera: Adelgidae)

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Samita Limbu; Melody A. Keena; David Long; Nancy Ostiguy; Kelli. Hoover

2015-01-01

Development time and prey consumption of Scymnus (Neopullus) camptodromus Yu and Liu (Coleoptera: Coccinellidae) larvae by instar, strain, and temperature were evaluated. S. camptodromus, a specialist predator of hemlock woolly adelgid Adelges tsugae (Annand) (Hemiptera:...

Effects of Nordic walking and walking on spatiotemporal gait parameters and ground reaction force.

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Park, Seung Kyu; Yang, Dae Jung; Kang, Yang Hun; Kim, Je Ho; Uhm, Yo Han; Lee, Yong Seon

2015-09-01

[Purpose] The purpose of this study was to investigate the effects of Nordic walking and walking on spatiotemporal gait parameters and ground reaction force. [Subjects] The subjects of this study were 30 young adult males, who were divided into a Nordic walking group of 15 subjects and a walking group of 15 subjects. [Methods] To analyze the spatiotemporal parameters and ground reaction force during walking in the two groups, the six-camera Vicon MX motion analysis system was used. The subjects were asked to walk 12 meters using the more comfortable walking method for them between Nordic walking and walking. After they walked 12 meters more than 10 times, their most natural walking patterns were chosen three times and analyzed. To determine the pole for Nordic walking, each subject's height was multiplied by 0.68. We then measured the spatiotemporal gait parameters and ground reaction force. [Results] Compared with the walking group, the Nordic walking group showed an increase in cadence, stride length, and step length, and a decrease in stride time, step time, and vertical ground reaction force. [Conclusion] The results of this study indicate that Nordic walking increases the stride and can be considered as helping patients with diseases affecting their gait. This demonstrates that Nordic walking is more effective in improving functional capabilities by promoting effective energy use and reducing the lower limb load, because the weight of the upper and lower limbs is dispersed during Nordic walking.

Walking drawings and walking ability in children with cerebral palsy.

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Chong, Jimmy; Mackey, Anna H; Stott, N Susan; Broadbent, Elizabeth

2013-06-01

To investigate whether drawings of the self walking by children with cerebral palsy (CP) were associated with walking ability and illness perceptions. This was an exploratory study in 52 children with CP (M:F = 28:24), mean age 11.1 years (range 5-18), who were attending tertiary level outpatient clinics. Children were asked to draw a picture of themselves walking. Drawing size and content was used to investigate associations with clinical walk tests and children's own perceptions of their CP assessed using a CP version of the Brief Illness Perception Questionnaire. Larger drawings of the self were associated with less distance traveled, higher emotional responses to CP, and lower perceptions of pain or discomfort, independent of age. A larger self-to-overall drawing height ratio was related to walking less distance. Drawings of the self confined within buildings and the absence of other figures were also associated with reduced walking ability. Drawing size and content can reflect walking ability, as well as symptom perceptions and distress. Drawings may be useful for clinicians to use with children with cerebral palsy to aid discussion about their condition. PsycINFO Database Record (c) 2013 APA, all rights reserved.

Walking performance: correlation between energy cost of walking and walking participation. new statistical approach concerning outcome measurement.

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Marco Franceschini

Full Text Available Walking ability, though important for quality of life and participation in social and economic activities, can be adversely affected by neurological disorders, such as Spinal Cord Injury, Stroke, Multiple Sclerosis or Traumatic Brain Injury. The aim of this study is to evaluate if the energy cost of walking (CW, in a mixed group of chronic patients with neurological diseases almost 6 months after discharge from rehabilitation wards, can predict the walking performance and any walking restriction on community activities, as indicated by Walking Handicap Scale categories (WHS. One hundred and seven subjects were included in the study, 31 suffering from Stroke, 26 from Spinal Cord Injury and 50 from Multiple Sclerosis. The multivariable binary logistical regression analysis has produced a statistical model with good characteristics of fit and good predictability. This model generated a cut-off value of.40, which enabled us to classify correctly the cases with a percentage of 85.0%. Our research reveal that, in our subjects, CW is the only predictor of the walking performance of in the community, to be compared with the score of WHS. We have been also identifying a cut-off value of CW cost, which makes a distinction between those who can walk in the community and those who cannot do it. In particular, these values could be used to predict the ability to walk in the community when discharged from the rehabilitation units, and to adjust the rehabilitative treatment to improve the performance.

New species of Braggia (Hemiptera: Aphididae) on buckwheat in western North America

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K. S. Pike; G. Graf; R. G. Foottit; H. E. L. Maw; P. Stary; R. Hammon; D. G. Miller

2009-01-01

Species of Braggia Gillette and Palmer (Hemiptera: Aphididae: Aphidinae: Aphidini) feed on various buckwheat, Eriogonum Michx. (Polygonaceae), species in western North America. Two new species, Braggia columbiana Pike n. sp. from Washington and Oregon and Braggia longicauda Pike n. sp. from Washington, Oregon, and northern California, are proposed. Descriptions,...

Gut content analysis of a phloem-feeding insect, Bactericera cockerelli (Sulc) (Hemiptera: Triozidae)

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Potato psyllid, Bactericera cockerelli (Šulc) (Hemiptera: Triozidae) is a key pest of potato (Solanum tuberosum L., Solanales: Solanaceae) and a vector of "Candidatus Liberibacter solanacearum," the pathogen associated with zebra chip disease. In addition to its presence on cultivated crops, the p...

Nordic walking versus walking without poles for rehabilitation with cardiovascular disease: Randomized controlled trial.

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Girold, Sébastien; Rousseau, Jérome; Le Gal, Magalie; Coudeyre, Emmanuel; Le Henaff, Jacqueline

2017-07-01

With Nordic walking, or walking with poles, one can travel a greater distance and at a higher rate than with walking without poles, but whether the activity is beneficial for patients with cardiovascular disease is unknown. This randomized controlled trial was undertaken to determine whether Nordic walking was more effective than walking without poles on walk distance to support rehabilitation training for patients with acute coronary syndrome (ACS) and peripheral arterial occlusive disease (PAOD). Patients were recruited in a private specialized rehabilitation centre for cardiovascular diseases. The entire protocol, including patient recruitment, took place over 2 months, from September to October 2013. We divided patients into 2 groups: Nordic Walking Group (NWG, n=21) and Walking Group without poles (WG, n=21). All patients followed the same program over 4 weeks, except for the walk performed with or without poles. The main outcome was walk distance on the 6-min walk test. Secondary outcomes were maximum heart rate during exercise and walk distance and power output on a treadmill stress test. We included 42 patients (35 men; mean age 57.2±11 years and BMI 26.5±4.5kg/m 2 ). At the end of the training period, both groups showed improved walk distance on the 6-min walk test and treatment stress test as well as power on the treadmill stress test (PNordic walking training appeared more efficient than training without poles for increasing walk distance on the 6-min walk test for patients with ACS and PAOD. Copyright © 2017. Published by Elsevier Masson SAS.

Distribution and Abundance of Adelges tsugae (Hemiptera: Adelgidae) Within Hemlock Trees

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S.V. Joseph; J.L. Hanula; S.K. Braman

2011-01-01

We studied the distribution of hemlock woolly adelgid, Adelges tsugae Annand (Hemiptera: Adelgidae), within hemlock trees for three summer (progrediens) and two winter (sistens) generations in northern Georgia. Eastern hemlock, Tsuga canadensis (L.) Carrie` re, trees were treated with 0, 10, or 25% of 1.5 g of imidacloprid per 2.5 cm of tree diameter at breast height...

Alzheimer random walk

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Odagaki, Takashi; Kasuya, Keisuke

2017-09-01

Using the Monte Carlo simulation, we investigate a memory-impaired self-avoiding walk on a square lattice in which a random walker marks each of sites visited with a given probability p and makes a random walk avoiding the marked sites. Namely, p = 0 and p = 1 correspond to the simple random walk and the self-avoiding walk, respectively. When p> 0, there is a finite probability that the walker is trapped. We show that the trap time distribution can well be fitted by Stacy's Weibull distribution b(a/b){a+1}/{b}[Γ({a+1}/{b})]-1x^a\\exp(-a/bx^b)} where a and b are fitting parameters depending on p. We also find that the mean trap time diverges at p = 0 as p- α with α = 1.89. In order to produce sufficient number of long walks, we exploit the pivot algorithm and obtain the mean square displacement and its Flory exponent ν(p) as functions of p. We find that the exponent determined for 1000 step walks interpolates both limits ν(0) for the simple random walk and ν(1) for the self-avoiding walk as [ ν(p) - ν(0) ] / [ ν(1) - ν(0) ] = pβ with β = 0.388 when p ≪ 0.1 and β = 0.0822 when p ≫ 0.1. Contribution to the Topical Issue "Continuous Time Random Walk Still Trendy: Fifty-year History, Current State and Outlook", edited by Ryszard Kutner and Jaume Masoliver.

Effects of fertilizer and low rates of Imidacloprid on Adelges tsugae (Hemiptera: Adelgidae).

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S. V. Joseph; James Hanula; S. K. Braman; F. J. Byrne

2011-01-01

Healthy hemlock trees, Tsuga canadensis (L.) Carriere, and hemlock woolly adelgid, Adelges tsugae Annand (Hemiptera: Adelgidae), populations should favor retention and population growth of adelgid predators such as Laricobius nigrinus Fender (Coleoptera: Derodontidae) and Sasajiscymnus tsugae (Sasaji&McClure) (Coleoptera: Coccinellidae). Eastern hemlock trees...

System overview and walking dynamics of a passive dynamic walking robot with flat feet

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Xinyu Liu

2015-12-01

Full Text Available The concept of “passive dynamic walking robot” refers to the robot that can walk down a shallow slope stably without any actuation and control which shows a limit cycle during walking. By adding actuation at some joints, the passive dynamic walking robot can walk stably on level ground and exhibit more versatile gaits than fully passive robot, namely, the “limit cycle walker.” In this article, we present the mechanical structures and control system design for a passive dynamic walking robot with series elastic actuators at hip joint and ankle joints. We built a walking model that consisted of an upper body, knee joints, and flat feet and derived its walking dynamics that involve double stance phases in a walking cycle based on virtual power principle. The instant just before impact was chosen as the start of one step to reduce the number of independent state variables. A numerical simulation was implemented by using MATLAB, in which the proposed passive dynamic walking model could walk stably down a shallow slope, which proves that the derived walking dynamics are correct. A physical passive robot prototype was built finally, and the experiment results show that by only simple control scheme the passive dynamic robot could walk stably on level ground.

Revisional notes on the genus Melucha (Hemiptera, Heteroptera, Coreidae

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Harry Brailovsky

2014-05-01

Full Text Available Melucha grandicula sp. n. and M. perampla sp. n., (Hemiptera: Heteroptera: Coreidae: Coreinae: Nematopodini are described from Bolivia, Colombia, Paraguay and Peru. Melucha quadrivittis Stål, 1862, stat. restit., is resurrected from synonymy under M. phyllocnemis (Burmeister, 1835. Melucha ruficornis Breddin, 1903, syn. n., is synonymized under M. lineatella (Fabricius, 1803. An identification key for the known species of Melucha Amyot & Serville, 1843 is given. New distributional records for some previously known species are added.

First report and morphological redescription of Teleonemia morio (Stål (Hemiptera, Tingidae in Annona squamosa L. (Annonaceae in Brazil

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Sônia M. F. Broglio

2012-03-01

Full Text Available First report and morphological redescription of Teleonemia morio (Stål (Hemiptera, Tingidae in Annona squamosa L. (Annonaceae in Brazil. This is the first report of a severe attack of Teleonemia morio (Stål, 1855 (Hemiptera, Heteroptera, Tingidae on Annona squamosa L. (custard apple, causing up to 80% of losses of infested trees. In order to facilitate the identification of this insect pest, the adult female of T. morio is redescribed based on specimens collected in Palmeira dos Índios, Alagoas, Brazil.

Walking modality, but not task difficulty, influences the control of dual-task walking.

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Wrightson, J G; Smeeton, N J

2017-10-01

During dual-task gait, changes in the stride-to-stride variability of stride time (STV) are suggested to represent the allocation of cognitive control to walking [1]. However, contrasting effects have been reported for overground and treadmill walking, which may be due to differences in the relative difficulty of the dual task. Here we compared the effect of overground and treadmill dual-task walking on STV in 18 healthy adults. Participants walked overground and on a treadmill for 120s during single-task (walking only) and dual-task (walking whilst performing serial subtractions in sevens) conditions. Dual-task effects on STV, cognitive task (serial subtraction) performance and perceived task difficulty were compared between walking modalities. STV was increased during overground dual-task walking, but was unchanged during treadmill dual-task walking. There were no differences in cognitive task performance or perceived task difficulty. These results show that gait is controlled differently during overground and treadmill dual-task walking. However, these differences are not solely due to differences in task difficulty, and may instead represent modality dependent control strategies. Copyright © 2017 Elsevier B.V. All rights reserved.

Biomechanical analysis of rollator walking

DEFF Research Database (Denmark)

Alkjaer, T; Larsen, Peter K; Pedersen, Gitte

2006-01-01

The rollator is a very popular walking aid. However, knowledge about how a rollator affects the walking patterns is limited. Thus, the purpose of the study was to investigate the biomechanical effects of walking with and without a rollator on the walking pattern in healthy subjects.......The rollator is a very popular walking aid. However, knowledge about how a rollator affects the walking patterns is limited. Thus, the purpose of the study was to investigate the biomechanical effects of walking with and without a rollator on the walking pattern in healthy subjects....

Identification of a new species of Aphis (Hemiptera: Aphididae) based on distinct morphology

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Aphis elena Lagos-Kutz and Voegtlin, sp. nov. (Hemiptera: Aphididae), is described from specimens collected in Illinois, USA, on the North American native plant, Pycnanthemum virginianum (L.) T. Dur. & B.D. Jacks. ex B.L. Rob. & Fernald (Family: Lamiaceae). Both apterous and alate viviparae are desc...

Descriptions of two new species of Sphenorhina (Hemiptera, Cercopidae, Tomaspidinae from the Neotropical region

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Andressa Paladini

2013-06-01

Full Text Available Description of two new species of Sphenorhina (Hemiptera, Cercopidae, Tomaspidinae from the Neotropical region. Two new species of Sphenorhina Amyot & Serville, S. pseudoboliviana SP. NOV: from Bolivia and S. plata SP. NOV: from Argentina are described and illustrated.

Preparing soft-bodied arthropods for arthropods for microscope examination: Armored Scales (Insects: Hemiptera: Diaspididae)

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Proper identification of armored scales (Hemiptera: Diaspididae) requires preparation of the specimen on a microscope slide. This training video provides visual instruction on how to prepare armored scales specimens on microscope slides for examination and identification. Steps ranging from collect...

Lévy walks

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Zaburdaev, V.; Denisov, S.; Klafter, J.

2015-04-01

Random walk is a fundamental concept with applications ranging from quantum physics to econometrics. Remarkably, one specific model of random walks appears to be ubiquitous across many fields as a tool to analyze transport phenomena in which the dispersal process is faster than dictated by Brownian diffusion. The Lévy-walk model combines two key features, the ability to generate anomalously fast diffusion and a finite velocity of a random walker. Recent results in optics, Hamiltonian chaos, cold atom dynamics, biophysics, and behavioral science demonstrate that this particular type of random walk provides significant insight into complex transport phenomena. This review gives a self-consistent introduction to Lévy walks, surveys their existing applications, including latest advances, and outlines further perspectives.

Mitochondrial phylogenomics of Hemiptera reveals adaptive innovations driving the diversification of true bugs

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Li, Hu; Leavengood, John M.; Chapman, Eric G.; Burkhardt, Daniel; Song, Fan; Jiang, Pei; Liu, Jinpeng; Cai, Wanzhi

2017-01-01

Hemiptera, the largest non-holometabolous order of insects, represents approximately 7% of metazoan diversity. With extraordinary life histories and highly specialized morphological adaptations, hemipterans have exploited diverse habitats and food sources through approximately 300 Myr of evolution. To elucidate the phylogeny and evolutionary history of Hemiptera, we carried out the most comprehensive mitogenomics analysis on the richest taxon sampling to date covering all the suborders and infraorders, including 34 newly sequenced and 94 published mitogenomes. With optimized branch length and sequence heterogeneity, Bayesian analyses using a site-heterogeneous mixture model resolved the higher-level hemipteran phylogeny as (Sternorrhyncha, (Auchenorrhyncha, (Coleorrhyncha, Heteroptera))). Ancestral character state reconstruction and divergence time estimation suggest that the success of true bugs (Heteroptera) is probably due to angiosperm coevolution, but key adaptive innovations (e.g. prognathous mouthpart, predatory behaviour, and haemelytron) facilitated multiple independent shifts among diverse feeding habits and multiple independent colonizations of aquatic habitats. PMID:28878063

Adults' Daily Walking for Travel and Leisure: Interaction Between Attitude Toward Walking and the Neighborhood Environment.

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Yang, Yong; Diez-Roux, Ana V

2017-09-01

Studies on how the interaction of psychological and environmental characteristics influences walking are limited, and the results are inconsistent. Our aim is to examine how the attitude toward walking and neighborhood environments interacts to influence walking. Cross-sectional phone and mail survey. Participants randomly sampled from 6 study sites including Los Angeles, Chicago, Baltimore, Minneapolis, Manhattan, and Bronx Counties in New York City, and Forsyth and Davidson Counties in North Carolina. The final sample consisted of 2621 persons from 2011 to 2012. Total minutes of walking for travel or leisure, attitude toward walking, and perceptions of the neighborhood environments were self-reported. Street Smart (SS) Walk Score (a measure of walkability derived from a variety of geographic data) was obtained for each residential location. Linear regression models adjusting for age, gender, race/ethnicity, education, and income. Attitude toward walking was positively associated with walking for both purposes. Walking for travel was significantly associated with SS Walk Score, whereas walking for leisure was not. The SS Walk Score and selected perceived environment characteristics were associated with walking in people with a very positive attitude toward walking but were not associated with walking in people with a less positive attitude. Attitudes toward walking and neighborhood environments interact to affect walking behavior.

Hemiptera community and species responses to grassland sward islets

OpenAIRE

Helden, Alvin J.; Dittrich, Alex D. K.

2016-01-01

Sward islet is a term that has been used to describe a patch of longer vegetation in a pasture produced by a reduction in cattle grazing around their dung. They are known to affect the abundance and distribution of grassland arthropods. Hemiptera, like other groups, are found in higher densities within islets than the surrounding sward. Does this modify the community composition or is there just a density effect? Evidence from a paired (islets, non-islets) study at an Irish cattle-grazed site...

Morphometrics of the Southern Green Stink Bug [Nezara viridula (L.) (Hemiptera: Pentatomidae)] Stylet Bundle

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The southern green stink bug, Nezara viridula (L.) (Hemiptera: Pentatomidae), is a cosmopolitan pest of high-value cash crops, including cotton (Gossypium hirsutum L.; Malvales: Malvaceae). The pest can ingest and transmit disease-causing bacterial and fungal pathogens of cotton. We hypothesized t...

Fooling the harlequin bug (Hemiptera: Pentatomidae) using synthetic volatiles to alter host plant choice

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Harlequin bug, Murgantia histrionica (Hahn) (Hemiptera: Pentatomidae), is a widespread invasive pest that feeds on a variety of brassicaceous crops and other plants. To understand olfactory cues which mediate host-finding, and possible utility in pest management, we deployed aggregation pheromone (m...

Attraction of stink bug (Hemiptera: Pentatomidae) nymphs to Euschistus aggregation pheromone in the field

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Phytophagous stink bugs (Hemiptera: Pentatomidae) are primary pests in most fruit, vegetable, grain, and row crops worldwide. Pheromones have been identified and synthesized for several species of economically important stink bug pests. When yellow pyramid traps are baited with lures containing thes...

Walking, sustainability and health: findings from a study of a Walking for Health group.

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Grant, Gordon; Machaczek, Kasia; Pollard, Nick; Allmark, Peter

2017-05-01

Not only is it tacitly understood that walking is good for health and well-being but there is also now robust evidence to support this link. There is also growing evidence that regular short walks can be a protective factor for a range of long-term health conditions. Walking in the countryside can bring additional benefits, but access to the countryside brings complexities, especially for people with poorer material resources and from different ethnic communities. Reasons for people taking up walking as a physical activity are reasonably well understood, but factors linked to sustained walking, and therefore sustained benefit, are not. Based on an ethnographic study of a Walking for Health group in Lincolnshire, UK, this paper considers the motivations and rewards of group walks for older people. Nineteen members of the walking group, almost all with long-term conditions, took part in tape-recorded interviews about the personal benefits of walking. The paper provides insights into the links between walking as a sustainable activity and health, and why a combination of personal adaptive capacities, design elements of the walks and relational achievements of the walking group are important to this understanding. The paper concludes with some observations about the need to reframe conventional thinking about adherence to physical activity programmes. © 2017 John Wiley & Sons Ltd.

Phylogenetic divergences of the true bugs (Insecta: Hemiptera: Heteroptera), with emphasis on the aquatic lineages

DEFF Research Database (Denmark)

Wang, Yan-hui; Cui, Ying; Rédei, Dávid

2016-01-01

Heteroptera are among the most diverse hemimetabolous insects. Seven infraorders have been recognized within this suborder of Hemiptera. Apart from the well-established sister-group relationship between Cimicomorpha and Pentatomomorpha (= Terheteroptera), the two terminal lineages, the relationsh...

Quantum walk computation

International Nuclear Information System (INIS)

Kendon, Viv

2014-01-01

Quantum versions of random walks have diverse applications that are motivating experimental implementations as well as theoretical studies. Recent results showing quantum walks are “universal for quantum computation” relate to algorithms, to be run on quantum computers. We consider whether an experimental implementation of a quantum walk could provide useful computation before we have a universal quantum computer

Walking to health.

Science.gov (United States)

Morris, J N; Hardman, A E

1997-05-01

Walking is a rhythmic, dynamic, aerobic activity of large skeletal muscles that confers the multifarious benefits of this with minimal adverse effects. Walking, faster than customary, and regularly in sufficient quantity into the 'training zone' of over 70% of maximal heart rate, develops and sustains physical fitness: the cardiovascular capacity and endurance (stamina) for bodily work and movement in everyday life that also provides reserves for meeting exceptional demands. Muscles of the legs, limb girdle and lower trunk are strengthened and the flexibility of their cardinal joints preserved; posture and carriage may improve. Any amount of walking, and at any pace, expends energy. Hence the potential, long term, of walking for weight control. Dynamic aerobic exercise, as in walking, enhances a multitude of bodily processes that are inherent in skeletal muscle activity, including the metabolism of high density lipoproteins and insulin/glucose dynamics. Walking is also the most common weight-bearing activity, and there are indications at all ages of an increase in related bone strength. The pleasurable and therapeutic, psychological and social dimensions of walking, whilst evident, have been surprisingly little studied. Nor has an economic assessment of the benefits and costs of walking been attempted. Walking is beneficial through engendering improved fitness and/or greater physiological activity and energy turnover. Two main modes of such action are distinguished as: (i) acute, short term effects of the exercise; and (ii) chronic, cumulative adaptations depending on habitual activity over weeks and months. Walking is often included in studies of exercise in relation to disease but it has seldom been specifically tested. There is, nevertheless, growing evidence of gains in the prevention of heart attack and reduction of total death rates, in the treatment of hypertension, intermittent claudication and musculoskeletal disorders, and in rehabilitation after heart

Increasing Walking in the Hartsfield-Jackson Atlanta International Airport: The Walk to Fly Study.

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Fulton, Janet E; Frederick, Ginny M; Paul, Prabasaj; Omura, John D; Carlson, Susan A; Dorn, Joan M

2017-07-01

To test the effectiveness of a point-of-decision intervention to prompt walking, versus motorized transport, in a large metropolitan airport. We installed point-of-decision prompt signage at 4 locations in the airport transportation mall at Hartsfield-Jackson Atlanta International Airport (Atlanta, GA) at the connecting corridor between airport concourses. Six ceiling-mounted infrared sensors counted travelers entering and exiting the study location. We collected traveler counts from June 2013 to May 2016 when construction was present and absent (preintervention period: June 2013-September 2014; postintervention period: September 2014-May 2016). We used a model that incorporated weekly walking variation to estimate the intervention effect on walking. There was an 11.0% to 16.7% relative increase in walking in the absence of airport construction where 580 to 810 more travelers per day chose to walk. Through May 2016, travelers completed 390 000 additional walking trips. The Walk to Fly study demonstrated a significant and sustained increase in the number of airport travelers choosing to walk. Providing signage about options to walk in busy locations where reasonable walking options are available may improve population levels of physical activity and therefore improve public health.

Association of Verde plant bug, Creontiades signatus (Hemiptera: Miridae), with cotton boll rot

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Cotton along the Gulf Coast of south Texas has experienced loss from cotton boll rot especially during the last 10 to 15 years, and stink bugs and plant bugs (Hemiptera: Pentatomidae and Miridae) that feed on cotton bolls have been suspected in introducing the disease. A replicated grower field surv...

Walk Score® and Transit Score® and Walking in the Multi-Ethnic Study of Atherosclerosis

Science.gov (United States)

Hirsch, Jana A.; Moore, Kari A.; Evenson, Kelly R.; Rodriguez, Daniel A; Diez Roux, Ana V.

2013-01-01

Background Walk Score® and Transit Score® are open-source measures of the neighborhood built environment to support walking (“walkability”) and access to transportation. Purpose To investigate associations of Street Smart Walk Score and Transit Score with self-reported transport and leisure walking using data from a large multi-city and diverse population-based sample of adults. Methods Data from a sample of 4552 residents of Baltimore MD; Chicago IL; Forsyth County NC; Los Angeles CA; New York NY; and St. Paul MN from the Multi-Ethnic Study of Atherosclerosis (2010–2012) were linked to Walk Score and Transit Score (collected in 2012). Logistic and linear regression models estimated ORs of not walking and mean differences in minutes walked, respectively, associated with continuous and categoric Walk Score and Transit Score. All analyses were conducted in 2012. Results After adjustment for site, key sociodemographic, and health variables, a higher Walk Score was associated with lower odds of not walking for transport and more minutes/week of transport walking. Compared to those in a “walker’s paradise,” lower categories of Walk Score were associated with a linear increase in odds of not transport walking and a decline in minutes of leisure walking. An increase in Transit Score was associated with lower odds of not transport walking or leisure walking, and additional minutes/week of leisure walking. Conclusions Walk Score and Transit Score appear to be useful as measures of walkability in analyses of neighborhood effects. PMID:23867022

Effects of walking and strength training on walking capacity in individuals with claudication: meta-analysis

Directory of Open Access Journals (Sweden)

Alessandra de Souza Miranda

2013-06-01

Full Text Available CONTEXT: Over the past few years, several clinical trials have been performed to analyze the effects of exercise training on walking ability in patients with intermittent claudication (IC. However, it remains unclear which type of physical exercise provides the maximum benefits in terms of walking ability. OBJECTIVE: To analyze, by means of a meta-analysis, the effects of walking and strength training on the walking capacity in patients with IC. METHODS: Papers analyzing the effects of walking and strength training programs in patients with IC were browsed on the Medline, Lilacs, and Cochrane databases. Randomized clinical trials scoring >4 on the Physiotherapy Evidence Database (PEDro scale and assessing claudication distance (CD and total walking distance (TWD were included in the review. RESULTS: Walking and strength training yielded increases in CD and TWD (P < 0.05. However, walking training yielded greater increases than strength training (P = 0.02. CONCLUSION: Walking and strength training improve walking capacity in patients with IC. However, greater improvements in TWD are obtained with walking training.

Stylet bundle morphology and trophically related enzymes of the hemlock woolly adelgid (Hemiptera: Adelgidae)

Science.gov (United States)

Kelly L.F. Oten; Allen C. Cohen; Fred P. Hain

2014-01-01

The hemlock woolly adelgid, Adelges tsugae Annand (Hemiptera: Adelgidae), is a pest of eastern and Carolina hemlocks (Tsuga canadensis (L.) Carriere and Tsuga caroliniana Engelmann, respectively) in the eastern United States and has already caused catastrophic changes to eastern forests. As one of the significant...

Walking economy during cued versus non-cued self-selected treadmill walking in persons with Parkinson's disease.

Science.gov (United States)

Gallo, Paul M; McIsaac, Tara L; Garber, Carol Ewing

2014-01-01

Gait impairments related to Parkinson's disease (PD) include variable step length and decreased walking velocity, which may result in poorer walking economy. Auditory cueing is a common method used to improve gait mechanics in PD that has been shown to worsen walking economy at set treadmill walking speeds. It is unknown if auditory cueing has the same effects on walking economy at self-selected treadmill walking speeds. To determine if auditory cueing will affect walking economy at self-selected treadmill walking speeds and at speeds slightly faster and slower than self-selected. Twenty-two participants with moderate PD performed three, 6-minute bouts of treadmill walking at three speeds (self-selected and ± 0.22 m·sec-1). One session used cueing and the other without cueing. Energy expenditure was measured and walking economy was calculated (energy expenditure/power). Poorer walking economy and higher energy expenditure occurred during cued walking at a self-selected and a slightly faster walking speed, but there was no apparent difference at the slightly slower speed. These results suggest that potential gait benefits of auditory cueing may come at an energy cost and poorer walking economy for persons with PD at least at some treadmill walking speeds.

Biomechanical parameters in lower limbs during natural walking and Nordic walking at different speeds.

Science.gov (United States)

Dziuba, Alicja K; Żurek, Grzegorz; Garrard, Ian; Wierzbicka-Damska, Iwona

2015-01-01

Nordic Walking (NW) is a sport that has a number of benefits as a rehabilitation method. It is performed with specially designed poles and has been often recommended as a physical activity that helps reduce the load to limbs. However, some studies have suggested that these findings might be erroneous. The aim of this paper was to compare the kinematic, kinetic and dynamic parameters of lower limbs between Natural Walking (W) and Nordic Walking (NW) at both low and high walking speeds. The study used a registration system, BTS Smart software and Kistler platform. Eleven subjects walked along a 15-metre path at low (below 2 m⋅s-1) and high (over 2 m⋅s-1) walking speeds. The Davis model was employed for calculations of kinematic, kinetic and dynamic parameters of lower limbs. With constant speed, the support given by Nordic Walking poles does not make the stroke longer and there is no change in pelvic rotation either. The only change observed was much bigger pelvic anteversion in the sagittal plane during fast NW. There were no changes in forces, power and muscle torques in lower limbs. The study found no differences in kinematic, kinetic and dynamic parameters between Natural Walking (W) and Nordic Walking (NW). Higher speeds generate greater ground reaction forces and muscle torques in lower limbs. Gait parameters depend on walking speed rather than on walking style.

An overview on the ecology of Triatominae (Hemiptera:Reduviidae).

Science.gov (United States)

Galvão, Cleber; Justi, Silvia A

2015-11-01

Chagas disease, the American trypanosomiasis, is an important neglected tropical illness caused by the flagellate protozoan Trypanosoma cruzi (Kinetoplastida, Trypanosomatidae) and transmitted by insects of the subfamily Triatominae (Hemiptera: Reduviidae). Here we provide an overview on the current knowledge about Triatominae ecology, its association with human, T. cruzi infection and the immediate consequences of habitat fragmentation. We also discuss the geographic distribution of the species and the importance of predicting their distributions to control programs. Copyright © 2015 Elsevier B.V. All rights reserved.

Toe Walking in Children

Science.gov (United States)

... prone to damage and weaken over time. This diagnosis might be more likely if your child initially walked normally before starting to toe walk. Autism. Toe walking has been linked to autism spectrum ...

Relative Abundance of Carsonella ruddii (Gamma Proteobacterium) in Females and Males of Cacopsylla pyricola (Hemiptera: Psyllidae) and Bactericera cockerelli (Hemiptera: Triozidae)

Science.gov (United States)

Cooper, W. Rodney; Garczynski, Stephen F.; Horton, David R.

2015-01-01

Carsonella ruddii (Gamma Proteobacterium) is an obligate bacterial endosymbiont of psyllids that produces essential amino acids that are lacking in the insect’s diet. Accurate estimations of Carsonella populations are important to studies of Carsonella-psyllid interactions and to developing ways to target Carsonella for control of psyllid pests including pear psylla, Cacopsylla pyricola (Förster) (Hemiptera: Psyllidae) and potato psyllid, Bactericera cockerelli (Šulc) (Hemiptera: Triozidae). We used two methods, namely fluorescence in situ hybridization and quantitative polymerase chain reaction (qPCR), to estimate relative abundance of Carsonella in bacteriocytes and whole bodies of psyllids, respectively. Using these two methods, we compared Carsonella populations between female and male insects. Estimations using fluorescence in situ hybridization indicated that Carsonella was more abundant in bacteriocytes of female C. pyricola than in those of males, but Carsonella abundance in bacteriocytes did not differ between sexes of B. cockerelli. Analyses by qPCR using whole-body specimens indicated Carsonella was more abundant in females than in males of both psyllids. Neither fluorescence in situ hybridization nor qPCR indicated that Carsonella populations differed in abundance among adults of different ages (0–3 wk after adult eclosion). Using fluorescence in situ hybridization, Carsonella was observed in ovarioles of newly emerged females and formed an aggregation in the posterior end of mature oocytes. Results of our study indicate that female psyllids harbor greater populations of Carsonella than do males and that sex should be controlled for in studies which require estimations of Carsonella populations. PMID:26056318

Allozyme Variation in Hemlock Woolly Adelgid (Hemiptera: Adelgidae) from the United States and China

Science.gov (United States)

V. S& #225; nchez; M.A. Keena; M.A. Keena

2009-01-01

The hemlock woolly adelgid, Adelges tsugae Annand (Hemiptera: Adelgidae), is a major introduced pest of eastern hemlock, Tsuga canadensis (L.) Carriere. Hemlock woolly adelgid in the United States is anholocyclic and an obligate parthenogen, because no suitable primary host (on which sexual reproduction occurs in Asia) is...

Talk the Walk: Does Socio-Cognitive Resource Reallocation Facilitate the Development of Walking?

Science.gov (United States)

Geva, Ronny; Orr, Edna

2016-01-01

Walking is of interest to psychology, robotics, zoology, neuroscience and medicine. Human's ability to walk on two feet is considered to be one of the defining characteristics of hominoid evolution. Evolutionary science propses that it emerged in response to limited environmental resources; yet the processes supporting its emergence are not fully understood. Developmental psychology research suggests that walking elicits cognitive advancements. We postulate that the relationship between cognitive development and walking is a bi-directional one; and further suggest that the initiation of novel capacities, such as walking, is related to internal socio-cognitive resource reallocation. We shed light on these notions by exploring infants' cognitive and socio-communicative outputs prospectively from 6-18 months of age. Structured bi/tri weekly evaluations of symbolic and verbal development were employed in an urban cohort (N = 9) for 12 months, during the transition from crawling to walking. Results show links between preemptive cognitive changes in socio-communicative output, symbolic-cognitive tool-use processes, and the age of emergence of walking. Plots of use rates of lower symbolic play levels before and after emergence of new skills illustrate reductions in use of previously attained key behaviors prior to emergence of higher symbolic play, language and walking. Further, individual differences in age of walking initiation were strongly related to the degree of reductions in complexity of object-use (r = .832, p developments, form an integrated adaptable composite, which possibly enables proactive internal resource reallocation, designed to support the emergence of new developmental milestones, such as walking.

Allegheny County Walk Scores

Data.gov (United States)

Allegheny County / City of Pittsburgh / Western PA Regional Data Center — Walk Score measures the walkability of any address using a patented system developed by the Walk Score company. For each 2010 Census Tract centroid, Walk Score...

Talk the Walk: Does Socio-Cognitive Resource Reallocation Facilitate the Development of Walking?

Directory of Open Access Journals (Sweden)

Ronny Geva

Full Text Available Walking is of interest to psychology, robotics, zoology, neuroscience and medicine. Human's ability to walk on two feet is considered to be one of the defining characteristics of hominoid evolution. Evolutionary science propses that it emerged in response to limited environmental resources; yet the processes supporting its emergence are not fully understood. Developmental psychology research suggests that walking elicits cognitive advancements. We postulate that the relationship between cognitive development and walking is a bi-directional one; and further suggest that the initiation of novel capacities, such as walking, is related to internal socio-cognitive resource reallocation. We shed light on these notions by exploring infants' cognitive and socio-communicative outputs prospectively from 6-18 months of age. Structured bi/tri weekly evaluations of symbolic and verbal development were employed in an urban cohort (N = 9 for 12 months, during the transition from crawling to walking. Results show links between preemptive cognitive changes in socio-communicative output, symbolic-cognitive tool-use processes, and the age of emergence of walking. Plots of use rates of lower symbolic play levels before and after emergence of new skills illustrate reductions in use of previously attained key behaviors prior to emergence of higher symbolic play, language and walking. Further, individual differences in age of walking initiation were strongly related to the degree of reductions in complexity of object-use (r = .832, p < .005, along with increases, counter to the general reduction trend, in skills that serve recruitment of external resources [socio-communication bids before speech (r = -.696, p < .01, and speech bids before walking; r = .729, p < .01]. Integration of these proactive changes using a computational approach yielded an even stronger link, underscoring internal resource reallocation as a facilitator of walking initiation (r = .901, p<0

Kineziologická charakteristika Nordic Walking

OpenAIRE

Pospíšilová, Petra

2009-01-01

Title: Functional a physiological characteristics of Nordic Walking Purposes: The aim of the thesis is to describe and summarize current knowledge about Nordic Walking Methods: Literature analysis Key words: Nordic Walking, free bipedal walk, health benefits, functional indicator changes

First record of Acizzia jamatonica (Hemiptera: Psyllidae) in North America: friend or foe?

Science.gov (United States)

Michael D. Ulyshen; Douglass Miller

2007-01-01

Acizzia jamatonica (Kuwayama) (Hemiptera: Sternorrhyncha: Psyllidae) is reported for the first time in North America. Because the species is thought to feed exclusively on Albizia, it may prove to be an effective biocontrol agent against the invasive Albizia julibrissin Durazzini in the southeastern United States. Because A. julibrissin is also an ornamental plant of...

Effects of founder population size on the performance of Orius laevigatus (Hemiptera: Anthocoridae) colonies

NARCIS (Netherlands)

Castañe, C.; Bueno, V.H.P.; Carvalho, L.M.; Lenteren, van J.C.

2014-01-01

Orius laevigatus (Hemiptera: Anthocoridae) is a key predator of thrips and is mass reared in large numbers for use in biological control. The aim of this study was to evaluate the effect of founder population size on the biological and behavioral performance of O. laevigatus over time. Laboratory

The genus Alphocoris in the Indomalaya (Hemiptera: Heteroptera: Scutelleridae).

Science.gov (United States)

RÉdei, DÁvid; Tsai, Jing-Fu; Jindra, ZdenĚk

2018-02-21

The Indomalayan species of the genus Alphocoris Germar, 1839 (Hemiptera: Heteroptera: Scutelleridae: Odontotarsinae: Odontotarsini) are revised. Three species, A. caudatus Rédei, Tsai Jindra, sp. nov. (India: Maharashtra), A. naso Rédei Tsai, sp. nov. (India: Goa), and A. asper Rédei, Tsai Jindra, sp. nov. (India: Goa and Maharashtra), are recognized. The type material of A. lixoides Germar, 1839 (type locality: Senegal) is documented; previous records of this species from India and Pakistan are considered as based on misidentifications, the species is restricted to the Afrotropical Region.

Diaspididae (Hemiptera, Coccoidea in sori of two fern species

Directory of Open Access Journals (Sweden)

Marcelo Santos

2015-12-01

Duas Espécies de Cochonilhas (Hemiptera: Diaspididae Associadas com Soros de Samambaias Resumo. A presente comunicação relata a presença de duas espécies de cochonilhas Hemiberlesia palmae (Cockerell e Pinnaspis strachani (Cooley (Coccoidea, Diaspididae, associadas respectivamente com Asplenium serratum L. (Aspleniaceae e Niphidium crassifolium (L. Lellinger (Polypodiaceae. É o primeiro registro de uma samambaia como planta hospedeira de Hemiberlesia palmae.  Nas duas espécies de samambaias, os diaspidídeos encontravam-se concentrados principalmente ao redor dos soros.

Quantum walks with entangled coins

International Nuclear Information System (INIS)

Venegas-Andraca, S E; Ball, J L; Burnett, K; Bose, S

2005-01-01

We present a mathematical formalism for the description of un- restricted quantum walks with entangled coins and one walker. The numerical behaviour of such walks is examined when using a Bell state as the initial coin state, with two different coin operators, two different shift operators, and one walker. We compare and contrast the performance of these quantum walks with that of a classical random walk consisting of one walker and two maximally correlated coins as well as quantum walks with coins sharing different degrees of entanglement. We illustrate that the behaviour of our walk with entangled coins can be very different in comparison to the usual quantum walk with a single coin. We also demonstrate that simply by changing the shift operator, we can generate widely different distributions. We also compare the behaviour of quantum walks with maximally entangled coins with that of quantum walks with non-entangled coins. Finally, we show that the use of different shift operators on two and three qubit coins leads to different position probability distributions in one- and two-dimensional graphs

Mating disruption of Homalodisca vitripennis (Germar) (Hemiptera: Cicadellidae) by playback of vibrational signals in vineyard trellis

Science.gov (United States)

BACKGROUND: Glassy-winged sharpshooter (GWSS), Homalodisca vitripennis (Germar) (Hemiptera: Cicadellidae), is an important vector of the bacterium Xylella fastidiosa, the causal agent of Pierce’s disease of grapevine. Area-wide applications of neonicotinoid insecticides have suppressed GWSS populati...

Walking for Well-Being: Are Group Walks in Certain Types of Natural Environments Better for Well-Being than Group Walks in Urban Environments?

Directory of Open Access Journals (Sweden)

Sara L. Warber

2013-10-01

Full Text Available The benefits of walking in natural environments for well-being are increasingly understood. However, less well known are the impacts different types of natural environments have on psychological and emotional well-being. This cross-sectional study investigated whether group walks in specific types of natural environments were associated with greater psychological and emotional well-being compared to group walks in urban environments. Individuals who frequently attended a walking group once a week or more (n = 708 were surveyed on mental well-being (Warwick Edinburgh Mental Well-being Scale, depression (Major Depressive Inventory, perceived stress (Perceived Stress Scale and emotional well-being (Positive and Negative Affect Schedule. Compared to group walks in urban environments, group walks in farmland were significantly associated with less perceived stress and negative affect, and greater mental well-being. Group walks in green corridors were significantly associated with less perceived stress and negative affect. There were no significant differences between the effect of any environment types on depression or positive affect. Outdoor walking group programs could be endorsed through “green prescriptions” to improve psychological and emotional well-being, as well as physical activity.

The cicada genus Karenia Distant, 1888 (Hemiptera: Cicadidae), with description of a new species.

Science.gov (United States)

Pham, Hong-Thai; Constant, Jerome

2014-08-19

The cicadas of the genus Karenia are reviewed, and Karenia tibetensis sp.nov. (Hemiptera: Cicadidae) is described from Tibet, China. Pictures of the male adult and illustrations of the male genitalia are provided. A key to the species of Karenia is presented and the distribution of the Karenia species is discussed.

Beam walking can detect differences in walking balance proficiency across a range of sensorimotor abilities.

Science.gov (United States)

Sawers, Andrew; Ting, Lena H

2015-02-01

The ability to quantify differences in walking balance proficiency is critical to curbing the rising health and financial costs of falls. Current laboratory-based approaches typically focus on successful recovery of balance while clinical instruments often pose little difficulty for all but the most impaired patients. Rarely do they test motor behaviors of sufficient difficulty to evoke failures in balance control limiting their ability to quantify balance proficiency. Our objective was to test whether a simple beam-walking task could quantify differences in walking balance proficiency across a range of sensorimotor abilities. Ten experts, ten novices, and five individuals with transtibial limb loss performed six walking trials across three different width beams. Walking balance proficiency was quantified as the ratio of distance walked to total possible distance. Balance proficiency was not significantly different between cohorts on the wide-beam, but clear differences between cohorts on the mid and narrow-beams were identified. Experts walked a greater distance than novices on the mid-beam (average of 3.63±0.04m verus 2.70±0.21m out of 3.66m; p=0.009), and novices walked further than amputees (1.52±0.20m; p=0.03). Amputees were unable to walk on the narrow-beam, while experts walked further (3.07±0.14m) than novices (1.55±0.26m; p=0.0005). A simple beam-walking task and an easily collected measure of distance traveled detected differences in walking balance proficiency across sensorimotor abilities. This approach provides a means to safely study and evaluate successes and failures in walking balance in the clinic or lab. It may prove useful in identifying mechanisms underlying falls versus fall recoveries. Copyright © 2015 Elsevier B.V. All rights reserved.

Walking on high heels changes muscle activity and the dynamics of human walking significantly

DEFF Research Database (Denmark)

Simonsen, Erik B; Svendsen, Morten Bo Søndergaard; Nørreslet, Andreas

2012-01-01

The aim of the study was to investigate the distribution of net joint moments in the lower extremities during walking on high-heeled shoes compared with barefooted walking at identical speed. Fourteen female subjects walked at 4 km/h across three force platforms while they were filmed by five...... digital video cameras operating at 50 frames/second. Both barefooted walking and walking on high-heeled shoes (heel height: 9 cm) were recorded. Net joint moments were calculated by 3D inverse dynamics. EMG was recorded from eight leg muscles. The knee extensor moment peak in the first half of the stance...... phase was doubled when walking on high heels. The knee joint angle showed that high-heeled walking caused the subjects to flex the knee joint significantly more in the first half of the stance phase. In the frontal plane a significant increase was observed in the knee joint abductor moment and the hip...

Minimal Walking Technicolor

DEFF Research Database (Denmark)

Foadi, Roshan; Frandsen, Mads Toudal; A. Ryttov, T.

2007-01-01

Different theoretical and phenomenological aspects of the Minimal and Nonminimal Walking Technicolor theories have recently been studied. The goal here is to make the models ready for collider phenomenology. We do this by constructing the low energy effective theory containing scalars......, pseudoscalars, vector mesons and other fields predicted by the minimal walking theory. We construct their self-interactions and interactions with standard model fields. Using the Weinberg sum rules, opportunely modified to take into account the walking behavior of the underlying gauge theory, we find...... interesting relations for the spin-one spectrum. We derive the electroweak parameters using the newly constructed effective theory and compare the results with the underlying gauge theory. Our analysis is sufficiently general such that the resulting model can be used to represent a generic walking technicolor...

Walking - Sensing - Participation

DEFF Research Database (Denmark)

Bødker, Mads; Meinhardt, Nina Dam; Browning, David

2014-01-01

Building on ethnographic research and social theory in the field of ‘mobilities’, this workshop paper suggests that field work based on simply walking with people entails a form of embodied participation that informs technological interventions by creating a space within which to address a wider ...... set of experiential or ‘felt’ qualities of living with mobile technologies. Moving from reflections on the value of walking with people, the paper outlines some affordances of a smartphone application built to capture place experiences through walking.......Building on ethnographic research and social theory in the field of ‘mobilities’, this workshop paper suggests that field work based on simply walking with people entails a form of embodied participation that informs technological interventions by creating a space within which to address a wider...

Field evaluation of potential pheromone lures for Lygus lineolaris (Hemiptera: Miridae) in the Mid-South

Science.gov (United States)

Plant bugs (Hemiptera: Miridae) are phytophagous pests of cultivated plants around the world. In the mid-South region of the United States, Lygus lineolaris is a primary pest of cotton, and causes economic damage. Previously published research about the volatiles produced by members of the genus Lyg...

The Effects of Walking or Walking-with-Poles Training on Tissue Oxygenation in Patients with Peripheral Arterial Disease

Directory of Open Access Journals (Sweden)

Eileen G. Collins

2012-01-01

Full Text Available This randomized trial proposed to determine if there were differences in calf muscle StO2 parameters in patients before and after 12 weeks of a traditional walking or walking-with-poles exercise program. Data were collected on 85 patients who were randomized to a traditional walking program ( or walking-with-poles program ( of exercise training. Patients walked for 3 times weekly for 12 weeks. Seventy-one patients completed both the baseline and the 12-week follow-up progressive treadmill tests ( traditional walking and walking-with-poles. Using the near-infrared spectroscopy measures, StO2 was measured prior to, during, and after exercise. At baseline, calf muscle oxygenation decreased from % prior to the treadmill test to % at peak exercise. The time elapsed prior to reaching nadir StO2 values increased more in the traditional walking group when compared to the walking-with-poles group. Likewise, absolute walking time increased more in the traditional walking group than in the walking-with-poles group. Tissue oxygenation decline during treadmill testing was less for patients assigned to a 12-week traditional walking program when compared to those assigned to a 12-week walking-with-poles program. In conclusion, the 12-week traditional walking program was superior to walking-with-poles in improving tissue deoxygenation in patients with PAD.

A Study of Effect of Walking Pole on the Walking Exercise

OpenAIRE

加藤, 麻樹; 下平, 佳江; 佐藤, 健

2010-01-01

So-called metabolic syndrome is one of the medical problems in our country, because many of people have difficulty at lack of exercises. Ministry of Health, Labor and Welfare suggest healthy life by exercise and moderate foods. Walking is one of the effective exercises to keep health in everyday life. Walking with poles, the exercise method of cross country skiing, is noticed as the effective exercise nowadays. Some studies show the effect of the pole walking exercise from view points of c...

Two pests overlap: Drosophila suzukii (Diptera: Drosophilidae) use of fruit exposed to Halyomorpha halys (Hemiptera: Pentatomidae)

Science.gov (United States)

Spotted wing drosophila, Drosophila suzukii (Matsumura) (Diptera: Drosophilidae), and brown marmorated stink bug, Halyomorpha halys (Stål) (Hemiptera: Pentatomidae) are global economic pests. Both pests may co-occur on small fruits, and we investigated whether fruit recently exposed to H. halys woul...

Molecular and morphological identification of the mealybug pest species, Phenacoccus solani Ferris (Hemiptera: Pseudococcidae), in Egypt

Science.gov (United States)

During the summer and autumn of 2016, heavy infestations of the mealybug, Phenacoccus solani Ferris (Hemiptera: Pseudococcidae), were observed on pumpkins, Cucurbita spp. (Cucurbitaceae). This was the first record of the species in Egypt. Several populations have been collected in various pumpkin fr...

Effects of atmospheric pressure trends on calling, mate-seeking, and phototaxis of Diaphorina citri (Hemiptera: Liviidae)

Science.gov (United States)

Insects and other animals sometimes modify behavior in response to changes in atmospheric pressure, an environmental cue that can provide warning of potentially injurious windy and rainy weather. To determine if Diaphorina citri (Hemiptera: Liviidae) calling, mate-seeking, and phototaxis behaviors w...

Two new planthopper species (Hemiptera, Fulgoroidea, Caliscelidae) collected in pitfall traps in Zambia.

Science.gov (United States)

Chmurova, Lucia; Webb, Michael D

2016-08-22

Two new species of planthoppers in the family Caliscelidae (Hemiptera: Fulgoroidea) are described from Zambia, i.e., Afronaso spinosa sp. n. and Calampocus zambiaensis sp. n. All specimens are flightless males and nearly all were collected from baited pitfall traps (except for one specimen collected from a yellow pan trap), suggesting that they live near to or on the ground.

Walking the Everyday

Directory of Open Access Journals (Sweden)

Matthew Bissen

2014-11-01

Full Text Available Since 2010, @matthewalking (Bissen, 2013 has published real-time public texts of walks in the city. This text-based Twitter feed has developed a narrative of a particular everyday life and developed a space of interface with others that represents a centering of perspective within an urban landscape. Walking the city provides a spatial, tactile, social, and embodied knowledge of the environment as each of us emerges into a space, orients ourselves, and determines a path that is highly localized, but is in connection with distant spaces and cultures. According to Ben Jacks in “Walking the City: Manhattan Projects,” “for urban dwellers and designers, walking is a fundamental tool for laying claim to, understanding, and shaping a livable city. Walking yields bodily knowing, recovers place memory, creates narrative, prioritizes human scale, and reconnects people to places” (75. @matthewalking’s walks, at times for as long as 5 hours, attempt to center an experience of an urban existence in a spatial narrative of the city that at once prioritizes a connection to place, but also is projected outward into a mediated relationship with others. The project is a series of unbounded walks, or dérives (drift, through the city that are logged on Twitter and traced to create an archive map of a set of particular urban experiences. The dérive concept as outlined in “The Theory of the Dérive,” by Guy Debord is when “one or more persons during a certain period drop their relations, their work and leisure activities, and all their other usual motives for movement and action, and let themselves be drawn by the attractions of the terrain and the encounters they find there” (62.

Dog ownership, dog walking, and leisure-time walking among Taiwanese metropolitan and nonmetropolitan older adults.

Science.gov (United States)

Liao, Yung; Huang, Pin-Hsuan; Chen, Yi-Ling; Hsueh, Ming-Chun; Chang, Shao-Hsi

2018-04-04

This study examined the prevalence of dog ownership and dog walking and its association with leisure-time walking among metropolitan and nonmetropolitan older adults. A telephone-based cross-sectional survey targeting Taiwanese older adults was conducted in November 2016. Data related to dog ownership, time spent dog walking (categorized as non-dog owner, non-dog walkers, and dog walkers), and sociodemographic variables were obtained from 1074 older adults. Adjusted binary logistic regression was then performed. In this sample, 12% of Taiwanese older adults owned a dog and 31% of them walked their dogs for an average of 232.13 min over 5.9 days/week (standard deviation = 2.03). Older adults living in nonmetropolitan areas were more likely to own a dog (14.7% vs. 9.1%) but less likely to walk their dog (25.9% vs. 39.6%) than were those living in metropolitan areas. Compared with non-dog owners, only older adults living in nonmetropolitan areas who were dog walkers achieved 150 min of leisure-time walking (odds ratio: 3.03, 95% confidence interval: 1.05-8.77), after adjustment for potential confounders. Older Taiwanese adults living in nonmetropolitan areas who owned and walked their dogs were more likely to achieve health-enhancing levels of leisure-time walking. Tailored physical activity interventions for promoting dog walking should be developed for older adults who are dog owners living in nonmetropolitan areas and who do not engage in dog walking.

Complete DNA sequence of the mitochondrial genome of the treehopper Leptobelus gazella (Membracoidea: Hemiptera).

Science.gov (United States)

Zhao, Xing; Liang, Ai-Ping

2016-09-01

The first complete DNA sequence of the mitochondrial genome (mitogenome) of Leptobelus gazelle (Membracoidea: Hemiptera) is determined in this study. The circular molecule is 16,007 bp in its full length, which encodes a set of 37 genes, including 13 proteins, 2 ribosomal RNAs, 22 transfer RNAs, and contains an A + T-rich region (CR). The gene numbers, content, and organization of L. gazelle are similar to other typical metazoan mitogenomes. Twelve of the 13 PCGs are initiated with ATR methionine or ATT isoleucine codons, except the atp8 gene that uses the ATC isoleucine as start signal. Ten of the 13 PCGs have complete termination codons, either TAA (nine genes) or TAG (cytb). The remaining 3 PCGs (cox1, cox2 and nad5) have incomplete termination codons T (AA). All of the 22 tRNAs can be folded in the form of a typical clover-leaf structure. The complete mitogenome sequence data of L. gazelle is useful for the phylogenetic and biogeographic studies of the Membracoidea and Hemiptera.

Aerobic treadmill plus Bobath walking training improves walking in subacute stroke: a randomized controlled trial.

Science.gov (United States)

Eich, H-J; Mach, H; Werner, C; Hesse, S

2004-09-01

To evaluate the immediate and long-term effects of aerobic treadmill plus Bobath walking training in subacute stroke survivors compared with Bobath walking training alone. Randomized controlled trial. Rehabilitation unit. Fifty patients, first-time supratentorial stroke, stroke interval less than six weeks, Barthel Index (0-100) from 50 to 80, able to walk a minimum distance of 12 m with either intermittent help or stand-by while walking, cardiovascular stable, minimum 50 W in the bicycle ergometry, randomly allocated to two groups, A and B. Group A 30 min of treadmill training, harness secured and minimally supported according to patients' needs, and 30 min of physiotherapy, every workday for six weeks, speed and inclination of the treadmill were adjusted to achieve a heart rate of HR: (Hrmax-HRrest)*0.6+HRrest; in group B 60 min of daily physiotherapy for six weeks. Primary outcome variables were the absolute improvement of walking velocity (m/s) and capacity (m), secondary were gross motor function including walking ability (score out of 13) and walking quality (score out of 41), blindly assessed before and after the intervention, and at follow-up three months later. Patients tolerated the aerobic training well with no side-effects, significantly greater improvement of walking velocity and capacity both at study end (p =0.001 versus p =0.002) and at follow-up (p Bobath walking training in moderately affected stroke patients was better than Bobath walking training alone with respect to the improvement of walking velocity and capacity. The treatment approach is recommended in patients meeting the inclusion criteria. A multicentre trial should follow to strengthen the evidence.

Influence of the swing ankle angle on walking stability for a passive dynamic walking robot with flat feet

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Xizhe Zang

2016-03-01

Full Text Available To achieve high walking stability for a passive dynamic walking robot is not easy. In this article, we aim to investigate whether the walking performance for a passive dynamic walking robot can be improved by just simply changing the swing ankle angle before impact. To validate this idea, a passive bipedal walking model with two straight legs, two flat feet, a hip joint, and two ankle joints was built in this study. The walking dynamics that contains double stance phase was derived. By numerical simulation of the walking in MATLAB, we found that the walking performance can be adjusted effectively by only simply changing the swing ankle angle before impact. A bigger swing ankle angle in a reasonable range will lead to a higher walking stability and a lower initial walking speed of the next step. A bigger swing ankle angle before impact leads to a bigger amount of energy lost during impact for the quasi-passive dynamic walking robot which will influence the walking stability of the next step.

The Walking Renaissance: A Longitudinal Analysis of Walking Travel in the Greater Los Angeles Area, USA

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Kenneth Joh

2015-07-01

Full Text Available Promoting walking travel is considered important for reducing automobile use and improving public health. Recent U.S. transportation policy has incentivized investments in alternative, more sustainable transportation modes such as walking, bicycling and transit in auto-oriented cities such as Los Angeles. Although many past studies have analyzed changes in walking travel across the U.S., there is little clarity on the drivers of change. We address this gap by conducting a longitudinal analysis of walking travel in the greater Los Angeles area from 2001 to 2009. We use travel diary and household data from regional and national surveys to analyze changes in walking trip shares and rates across our study area. Results show that walking has significantly increased across most of Los Angeles, and that increases in walking trips generally correspond with increases in population, employment, and transit service densities. Estimates from fixed-effects regression analysis generally suggest a positive association between population density and walking, and that higher increases in transit stop density are correlated with increased walking trips to and from transit stops. These findings illustrate how regional planning efforts to pursue a coordinated land use-transit planning strategy can help promote walking in auto-oriented or vehicle adopting cities.

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.

Time course study of feeding damage to pin head cotton squares by Lygus hesperus (Hemiptera: Miridae)

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Lygus hesperus (Hemiptera: Miridae) is an economically important pest affecting cotton crops in California. Lygus feeding causes abscission of cotton squares, with damage severity dependent on size of the square and life stage of the insect. Fifth instar nymphs are the most damaging stage; however, ...

[Objective evaluation of arterial intermittent claudication by the walking tolerance test. Comparative study of physiological walking and walking on a conveyor belt (author's transl)].

Science.gov (United States)

Bouchet, J Y; Franco, A; Morzol, B; Beani, J C

1980-01-01

Two methods are used to evaluate the walking distance: physiological walking along a standard path (0% - 6 mk/h) and walking on a tread mill (10% - 3 km/h). In both tests, four data are checked: -- initial trouble distance, -- cramp or walking-distance, -- localisation of pain, -- recovery time. These tests are dependable for the diagnosis of arterial claudication, reproducible and well tolerated. Their results have been compared: there is no correlation between the initial trouble distance and the cramp distance. However there is a correlation between the cramp distance by physiological walking and on treadmill. Recovery time, if long, is a criteria of gravity. Interests of both methods are discussed.

Biology of Leptoypha hospita (Hemiptera: Tingidae), a Potential Biological Control Agent of Chinese Privet

Science.gov (United States)

Yanzhuo Zhang; James L. Hanula; Scott Horn; Kristine Braman; Jianghua Sun

2011-01-01

The biology of Leptoypha hospita Drake et Poor (Hemiptera: Tingidae), a potential biological control agent from China for Chinese privet, Ligustrum sinense Lour., was studied in quarantine in the United States. Both nymphs and adults feed on Chinese privet mesophyll cells that lead to a bleached appearance of leaves and dieback of branch tips. L. hospita has five...

Contributions to the knowledge of Banasa Stål (Hemiptera, Heteroptera, Pentatomidae: Banasa chaca Thomas

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Thereza de Almeida Garbelotto

2011-09-01

Full Text Available Contributions to the knowledge of Banasa Stål (Hemiptera, Heteroptera, Pentatomidae: Banasa chaca Thomas. The male of Banasa chaca Thomas is described with emphasis on external and internal genitalia and the female internal genitalia is described. Banasa chaca is newly recorded from Buenos Aires Province (Argentina.

Insects associated with tropical foliage produced in the coffee growing region of Colombia

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Luis F. Aristizábal

2013-09-01

Full Text Available We conducted a survey of insects and pest management practices on 34 farms growing ornamental tropical foliage plants in the central coffee region of Colombia over two years. Tropical foliage provided habitat for a diverse range of insects. In total, phytophagous or detritivorous insects from six orders, 40 families and 62 genera were collected. The most common were Hemiptera (29 genera from 16 families, followed by Coleoptera (17 genera from 4 families, Diptera (5 genera from 5 families, Lepidoptera (5 genera from 4 families, Hymenoptera (3 genera from 2 families and Orthoptera (2 genera from 2 families. The most common phytophagous species were leaf cutting ants (Atta and Acromyrmex spp., leaf beetles (Chrysomelidae, leafhoppers (Cicadellidae, stinkbugs (Pentatomidae, squash bugs (Coreidae, tree hoppers (Membracidae and plant hoppers (Fulgoridae. Beneficial insects identified from tropical foliage included predators and parasitoids amongst 5 orders, 12 families and 22 genera. The most abundant were predators among the Coccinellidae, Chrysopidae, Reduviidae, Lycidae and Formicidae but only low numbers of parasitoids (Ichneumonidae, Braconidae and Tachinidae were collected. A pest management questionnaire given to growers revealed a preponderance of reliance on broad spectrum insecticides with a smaller number of growers (approximately one third also using some biological control methods. Our survey contributes basic information regarding diversity of Neotropical insects associated with ornamental foliage plants.

Random walks and diffusion on networks

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Masuda, Naoki; Porter, Mason A.; Lambiotte, Renaud

2017-11-01

Random walks are ubiquitous in the sciences, and they are interesting from both theoretical and practical perspectives. They are one of the most fundamental types of stochastic processes; can be used to model numerous phenomena, including diffusion, interactions, and opinions among humans and animals; and can be used to extract information about important entities or dense groups of entities in a network. Random walks have been studied for many decades on both regular lattices and (especially in the last couple of decades) on networks with a variety of structures. In the present article, we survey the theory and applications of random walks on networks, restricting ourselves to simple cases of single and non-adaptive random walkers. We distinguish three main types of random walks: discrete-time random walks, node-centric continuous-time random walks, and edge-centric continuous-time random walks. We first briefly survey random walks on a line, and then we consider random walks on various types of networks. We extensively discuss applications of random walks, including ranking of nodes (e.g., PageRank), community detection, respondent-driven sampling, and opinion models such as voter models.

A comparison of at-home walking and 10-meter walking test parameters of individuals with post-stroke hemiparesis.

Science.gov (United States)

Nagano, Katsuhito; Hori, Hideaki; Muramatsu, Ken

2015-02-01

[Purpose] The purpose of this study was to clarify the difference in gait parameters of at-home walking and the 10-meter walking test results of individuals with hemiparesis. [Subjects] A total of 14 hemiparetic stroke recovery patients participated in this study. Inclusion criteria were: living at home, the ability to walk independently, and demonstrated low extremity on recovery stages III-V on the Brunnstrom Approach. The average age of the subjects was 66 years. [Methods] We used video surveillance and the inked footprint technique to record usual walking speed and maximum speed patterns both in subjects' homes and during the 10-meter walking test. From these methods, walking speed, stride length, and step rate were calculated. [Results] While both usual and maximum walking speeds of the 10-meter walking test correlated with stride length and step rate, at-home walking speeds only significantly correlated with stride length. [Conclusion] Walking patterns of the 10-meter walking test are quantifiably distinct from those demonstrated in patients' homes, and this difference is mainly characterized by stride length. In order to enhance in-home walking ability, exercises that improve length of stride rather than step rate should be recommended.

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.

Non-Markovian decoherent quantum walks

International Nuclear Information System (INIS)

Xue Peng; Zhang Yong-Sheng

2013-01-01

Quantum walks act in obviously different ways from their classical counterparts, but decoherence will lessen and close this gap between them. To understand this process, it is necessary to investigate the evolution of quantum walks under different decoherence situations. In this article, we study a non-Markovian decoherent quantum walk on a line. In a short time regime, the behavior of the walk deviates from both ideal quantum walks and classical random walks. The position variance as a measure of the quantum walk collapses and revives for a short time, and tends to have a linear relation with time. That is, the walker's behavior shows a diffusive spread over a long time limit, which is caused by non-Markovian dephasing affecting the quantum correlations between the quantum walker and his coin. We also study both quantum discord and measurement-induced disturbance as measures of the quantum correlations, and observe both collapse and revival in the short time regime, and the tendency to be zero in the long time limit. Therefore, quantum walks with non-Markovian decoherence tend to have diffusive spreading behavior over long time limits, while in the short time regime they oscillate between ballistic and diffusive spreading behavior, and the quantum correlation collapses and revives due to the memory effect

A NEW SPECIES OF BEAMERANA YOUNG, 1952 (HEMIPTERA: CICADELLIDAE: TYPHLOCYBINAE FROM SOUTHEASTERN BRAZIL

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Luci Boa Nova Coelho

2014-05-01

Full Text Available A new species of the Neotropical leafhopper genus Beamerana Young, 1952 (Hemiptera: Cicadellidae: Typhlocybinae is described and illustrated based on the specimens from Minas Gerais, southeastern Brazil. Beamerana boomerang sp. nov. differs from its congeners by the fore wing venation and the male genitalia. A key to the species of Beamerana is provided. The genus is recorded for Brazil for the first time.

Neuromorphic walking gait control.

Science.gov (United States)

Still, Susanne; Hepp, Klaus; Douglas, Rodney J

2006-03-01

We present a neuromorphic pattern generator for controlling the walking gaits of four-legged robots which is inspired by central pattern generators found in the nervous system and which is implemented as a very large scale integrated (VLSI) chip. The chip contains oscillator circuits that mimic the output of motor neurons in a strongly simplified way. We show that four coupled oscillators can produce rhythmic patterns with phase relationships that are appropriate to generate all four-legged animal walking gaits. These phase relationships together with frequency and duty cycle of the oscillators determine the walking behavior of a robot driven by the chip, and they depend on a small set of stationary bias voltages. We give analytic expressions for these dependencies. This chip reduces the complex, dynamic inter-leg control problem associated with walking gait generation to the problem of setting a few stationary parameters. It provides a compact and low power solution for walking gait control in robots.

Human H-reflexes are smaller in difficult beam walking than in normal treadmill walking.

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Llewellyn, M; Yang, J F; Prochazka, A

1990-01-01

Hoffman (H) reflexes were elicited from the soleus (SOL) muscle while subjects walked on a treadmill and on a narrow beam (3.5 cm wide, raised 34 cm from the floor). The speed of walking on the treadmill was selected for each subject to match the background activation level of their SOL muscle during beam walking. The normal reciprocal activation pattern of the tibialis anterior and SOL muscles in treadmill walking was replaced by a pattern dominated by co-contraction on the beam. In addition, the step cycle duration was more variable and the time spent in the swing phase was reduced on the beam. The H-reflexes were highly modulated in both tasks, the amplitude being high in the stance phase and low in the swing phase. The H-reflex amplitude was on average 40% lower during beam walking than treadmill walking. The relationship between the H-reflex amplitude and the SOL EMG level was quantified by a regression line relating the two variables. The slope of this line was on average 41% lower in beam walking than treadmill walking. The lower H-reflex gain observed in this study and the high level of fusimotor drive observed in cats performing similar tasks suggest that the two mechanisms which control the excitability of this reflex pathway (i.e. fusimotor action and control of transmission at the muscle spindle to moto-neuron synapse) may be controlled independently.

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.

Walking and child pedestrian injury: a systematic review of built environment correlates of safe walking.

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Rothman, Linda; Buliung, Ron; Macarthur, Colin; To, Teresa; Howard, Andrew

2014-02-01

The child active transportation literature has focused on walking, with little attention to risk associated with increased traffic exposure. This paper reviews the literature related to built environment correlates of walking and pedestrian injury in children together, to broaden the current conceptualization of walkability to include injury prevention. Two independent searches were conducted focused on walking in children and child pedestrian injury within nine electronic databases until March, 2012. Studies were included which: 1) were quantitative 2) set in motorized countries 3) were either urban or suburban 4) investigated specific built environment risk factors 5) had outcomes of either walking in children and/or child pedestrian roadway collisions (ages 0-12). Built environment features were categorized according to those related to density, land use diversity or roadway design. Results were cross-tabulated to identify how built environment features associate with walking and injury. Fifty walking and 35 child pedestrian injury studies were identified. Only traffic calming and presence of playgrounds/recreation areas were consistently associated with more walking and less pedestrian injury. Several built environment features were associated with more walking, but with increased injury. Many features had inconsistent results or had not been investigated for either outcome. The findings emphasise the importance of incorporating safety into the conversation about creating more walkable cities.

Walking and Sensing Mobile Lives

DEFF Research Database (Denmark)

Bødker, Mads; Meinhardt, Nina Dam

In this position paper, we discuss how mindful walking with people allow us to explore sensory aspects of mobile lives that are typically absent from research. We present an app that aids researchers collect impressions from a walk.......In this position paper, we discuss how mindful walking with people allow us to explore sensory aspects of mobile lives that are typically absent from research. We present an app that aids researchers collect impressions from a walk....

Primeiro registro de ocorrência do parasitóide Brasema sp. (hymenoptera: eupelmidae em ovos de Leptoglossus zonatus (Dallas, 1852 (hemiptera: coreidae no Brasil First record of occurrence of the parasitoid Brasema sp. (hymenoptera: eupelmidae in eggs of Leptoglossus zonatus (Dallas, 1852 (hemiptera: coreidae in Brazil

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Carlos Henrique Marchiori

2002-12-01

Full Text Available Este trabalho registra a primeira ocorrência do parasitóide Brasema sp. (Hymenoptera: Eupelmidae parasitando ovos de Leptoglossus zonatus (Hemiptera: Coreidae em cultivar de milho em Itumbiara, GO. A porcentagem de parasitismo foi de 4,8%. Brasema sp. constitue-se em ectoparasitóide de larvas de coleópteros e de outros hospedeiros no interior de tecidos de plantas.This work reports, for the first time, of parasitoid Brasema sp. (Hymenoptera: Eupelmidae parasitizinf eggs of Leptoglossus zonatus (Hemiptera: Coreidae in maize cultivate in Itumbiara, GO, Brazil. The percentage of parasitizing was 4,8%. Brasema sp. constitutes ectoparasitoid of beetle larvae and other hosts concealed in plant tissue.

Human treadmill walking needs attention

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Daniel Olivier

2006-08-01

Full Text Available Abstract Background The aim of the study was to assess the attentional requirements of steady state treadmill walking in human subjects using a dual task paradigm. The extent of decrement of a secondary (cognitive RT task provides a measure of the attentional resources required to maintain performance of the primary (locomotor task. Varying the level of difficulty of the reaction time (RT task is used to verify the priority of allocation of attentional resources. Methods 11 healthy adult subjects were required to walk while simultaneously performing a RT task. Participants were instructed to bite a pressure transducer placed in the mouth as quickly as possible in response to an unpredictable electrical stimulation applied on the back of the neck. Each subject was tested under five different experimental conditions: simple RT task alone and while walking, recognition RT task alone and while walking, walking alone. A foot switch system composed of a pressure sensitive sensor was placed under the heel and forefoot of each foot to determine the gait cycle duration. Results Gait cycle duration was unchanged (p > 0.05 by the addition of the RT task. Regardless of the level of difficulty of the RT task, the RTs were longer during treadmill walking than in sitting conditions (p 0.05 was found between the attentional demand of the walking task and the decrement of performance found in the RT task under varying levels of difficulty. This finding suggests that the healthy subjects prioritized the control of walking at the expense of cognitive performance. Conclusion We conclude that treadmill walking in young adults is not a purely automatic task. The methodology and outcome measures used in this study provide an assessment of the attentional resources required by walking on the treadmill at a steady state.

'It was not just a walking experience': reflections on the role of care in dog-walking.

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Degeling, Chris; Rock, Melanie

2013-09-01

Research into physical activity and human health has recently begun to attend to dog-walking. This study extends the literature on dog-walking as a health behaviour by conceptualizing dog-walking as a caring practice. It centres on qualitative interviews with 11 Canadian dog-owners. All participants resided in urban neighbourhoods identified through previous quantitative research as conducive to dog-walking. Canine characteristics, including breed and age, were found to influence people's physical activity. The health of the dog and its position in the life-course influenced patterns of dog-walking. Frequency, duration and spatial patterns of dog-walking all depended on relationships and people's capacity to tap into resources. In foregrounding networks of care, inclusive of pets and public spaces, a relational conceptualization of dog-walking as a practice of caring helps to make sense of heterogeneity in patterns of physical activity among dog-owners.

Pedestrian Walking Behavior Revealed through a Random Walk Model

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Hui Xiong

2012-01-01

Full Text Available This paper applies method of continuous-time random walks for pedestrian flow simulation. In the model, pedestrians can walk forward or backward and turn left or right if there is no block. Velocities of pedestrian flow moving forward or diffusing are dominated by coefficients. The waiting time preceding each jump is assumed to follow an exponential distribution. To solve the model, a second-order two-dimensional partial differential equation, a high-order compact scheme with the alternating direction implicit method, is employed. In the numerical experiments, the walking domain of the first one is two-dimensional with two entrances and one exit, and that of the second one is two-dimensional with one entrance and one exit. The flows in both scenarios are one way. Numerical results show that the model can be used for pedestrian flow simulation.

Exploring Muscle Activation during Nordic Walking: A Comparison between Conventional and Uphill Walking.

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Barbara Pellegrini

Full Text Available Nordic Walking (NW owes much of its popularity to the benefits of greater energy expenditure and upper body engagement than found in conventional walking (W. Muscle activation during NW is still understudied, however. The aim of the present study was to assess differences in muscle activation and physiological responses between NW and W in level and uphill walking conditions. Nine expert Nordic Walkers (mean age 36.8±11.9 years; BMI 24.2±1.8 kg/m2 performed 5-minute treadmill trials of W and NW at 4 km/h on inclines of 0% and 15%. The electromyographic activity of seven upper body and five leg muscles and oxygen consumption (VO2 were recorded and pole force during NW was measured. VO2 during NW was 22.3% higher at 0% and only 6.9% higher at 15% than during W, while upper body muscle activation was 2- to 15-fold higher under both conditions. Lower body muscle activation was similarly increased during NW and W in the uphill condition, whereas the increase in erector spinae muscle activity was lower during NW than W. The lack of a significant increase in pole force during uphill walking may explain the lower extra energy expenditure of NW, indicating less upper body muscle activation to lift the body against gravity. NW seemed to reduce lower back muscle contraction in the uphill condition, suggesting that walking with poles may reduce effort to control trunk oscillations and could contribute to work production during NW. Although the difference in extra energy expenditure between NW and W was smaller in the uphill walking condition, the increased upper body muscle involvement during exercising with NW may confer additional benefit compared to conventional walking also on uphill terrains. Furthermore, people with low back pain may gain benefit from pole use when walking uphill.

Exploring Muscle Activation during Nordic Walking: A Comparison between Conventional and Uphill Walking.

Science.gov (United States)

Pellegrini, Barbara; Peyré-Tartaruga, Leonardo Alexandre; Zoppirolli, Chiara; Bortolan, Lorenzo; Bacchi, Elisabetta; Figard-Fabre, Hélène; Schena, Federico

2015-01-01

Nordic Walking (NW) owes much of its popularity to the benefits of greater energy expenditure and upper body engagement than found in conventional walking (W). Muscle activation during NW is still understudied, however. The aim of the present study was to assess differences in muscle activation and physiological responses between NW and W in level and uphill walking conditions. Nine expert Nordic Walkers (mean age 36.8±11.9 years; BMI 24.2±1.8 kg/m2) performed 5-minute treadmill trials of W and NW at 4 km/h on inclines of 0% and 15%. The electromyographic activity of seven upper body and five leg muscles and oxygen consumption (VO2) were recorded and pole force during NW was measured. VO2 during NW was 22.3% higher at 0% and only 6.9% higher at 15% than during W, while upper body muscle activation was 2- to 15-fold higher under both conditions. Lower body muscle activation was similarly increased during NW and W in the uphill condition, whereas the increase in erector spinae muscle activity was lower during NW than W. The lack of a significant increase in pole force during uphill walking may explain the lower extra energy expenditure of NW, indicating less upper body muscle activation to lift the body against gravity. NW seemed to reduce lower back muscle contraction in the uphill condition, suggesting that walking with poles may reduce effort to control trunk oscillations and could contribute to work production during NW. Although the difference in extra energy expenditure between NW and W was smaller in the uphill walking condition, the increased upper body muscle involvement during exercising with NW may confer additional benefit compared to conventional walking also on uphill terrains. Furthermore, people with low back pain may gain benefit from pole use when walking uphill.

Quantum walks based on an interferometric analogy

International Nuclear Information System (INIS)

Hillery, Mark; Bergou, Janos; Feldman, Edgar

2003-01-01

There are presently two models for quantum walks on graphs. The ''coined'' walk uses discrete-time steps, and contains, besides the particle making the walk, a second quantum system, the coin, that determines the direction in which the particle will move. The continuous walk operates with continuous time. Here a third model for quantum walks is proposed, which is based on an analogy to optical interferometers. It is a discrete-time model, and the unitary operator that advances the walk one step depends only on the local structure of the graph on which the walk is taking place. This type of walk also allows us to introduce elements, such as phase shifters, that have no counterpart in classical random walks. Several examples are discussed

First record in Argentina of Drepanosiphum oregonense Granovsky (Hemiptera: Aphididae) found on maples (Sapindaceae)

OpenAIRE

Ortego, Jaime; Olave, Anabel; Mier Durante, Milagros Pilar

2014-01-01

Se informa del hallazgo del áfido Drepanosiphum oregonense Granovsky (Hemiptera: Aphididae) sobre árboles de Acer pseudoplatanus y A. campestre (Sapindaceae) en Argentina lo que constituye el primer registro de la especie y del género Drepanosiphum Koch en Argentina y el segundo en Sudamérica. The finding in Argentina of the aphid Drepanosiphum oregonense on "maple tree" Acer pseudoplatanus ...

Occurrence of lace bug Vatiga illudens and Vatiga manihotae (Hemiptera: Tingidae in Mato Grosso do Sul, midwestern Brazil

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Patrícia P. Bellon

2012-09-01

Full Text Available Nymphs and adults of the lace bug (Hemiptera: Tingidae have been found in cassava crops (Manihot esculenta in Mato Grosso do Sul State, Brazil. The insects were collected in the field and taken to the laboratory where they were identified based on some morphological traits of the species Vatiga manihotae (Drake and V. illudens (Drake, which are first reported in the aforementioned state.Ninfas e adultos do percevejo-de-renda (Hemiptera: Tingidae foram encontrados em lavouras de mandioca (Manihot esculenta no Estado do Mato Grosso do Sul, Brasil. Os insetos foram coletados em campo e levados ao laboratório, onde foram identificados com base em algumas características morfológicas nas espécies Vatiga manihotae (Drake e V. illudens (Drake, os quais são registrados pela primeira vez no Estado mencionado.

Equivalence of Szegedy's and coined quantum walks

Science.gov (United States)

Wong, Thomas G.

2017-09-01

Szegedy's quantum walk is a quantization of a classical random walk or Markov chain, where the walk occurs on the edges of the bipartite double cover of the original graph. To search, one can simply quantize a Markov chain with absorbing vertices. Recently, Santos proposed two alternative search algorithms that instead utilize the sign-flip oracle in Grover's algorithm rather than absorbing vertices. In this paper, we show that these two algorithms are exactly equivalent to two algorithms involving coined quantum walks, which are walks on the vertices of the original graph with an internal degree of freedom. The first scheme is equivalent to a coined quantum walk with one walk step per query of Grover's oracle, and the second is equivalent to a coined quantum walk with two walk steps per query of Grover's oracle. These equivalences lie outside the previously known equivalence of Szegedy's quantum walk with absorbing vertices and the coined quantum walk with the negative identity operator as the coin for marked vertices, whose precise relationships we also investigate.

Predation of Apiomerus pilipes (Fabricius (Hemiptera, Reduviidae, Harpactorinae, Apiomerini over Meliponinae bees (Hymenoptera, Apidae, in the State of Amazonas, Brazil

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Alexandre Coletto da Silva

2004-12-01

Full Text Available The present work shows the occurrence of an intense predatory activity on adults working Meliponinae bees (Hymenoptera, Apidae, by Apiomerus pilipes (Fabricius, 1787 (Hemiptera, Reduviidae, Harpactorinae, Apiomerini at a meliponary in the Instituto Nacional de Pesquisas da Amazônia (INPA, Manaus, Amazonas State, Brazil.O presente trabalho registra a ocorrência de intensa atividade predatória de Apiomerus pilipes (Fabricius, 1787 (Hemiptera, Reduviidae, Harpactorini, Apiomerini sobre operárias adultas de meliponíneos (Hymenoptera, Apidae, no meliponário experimental do Instituto Nacional de Pesquisas da Amazônia (INPA, Manaus, Estado do Amazonas, Brasil. O meliponário se encontra num fragmento de vegetação secundária no próprio INPA.

Evaluation of hemlock (Tsuga) species and hybrids for resistance to Adelges tsugae (Hemiptera: Adelgidae) using artificial infestation

Science.gov (United States)

Michael E. Montgomery; S.E. Bentz; Richard T. Olsen

2009-01-01

Hemlock (Tsuga) species and hybrids were evaluated for resistance to the hemlock woolly adelgid, Adelges tsugae Annand (Hemiptera: Adelgidae). The adelgid was accidentally introduced from Asia to the eastern United States, where it is causing widespread mortality of the native hemlocks, Tsuga canadensis (L.)...

Pheromone of the banana-spotting bug, amblypelta lutescens lutescens Distant (Hemiptera: Coreidae): identification, synthesis and field bioassay

Science.gov (United States)

The banana spotting bug Amblypelta lutescens lutescens Distant (Hemiptera: Coreidae) is one of the principal pests of tree fruits and nuts across northern and eastern Australia. Apart from damage assessments in orchards, there are currently no other methods for monitoring bug activity to aid manage...

Potential transmission of Pantoea spp. and Serratia marcescens (Enterobacteriales: Enterobacteriaceae) to plants by Lygus hesperus (Hemiptera: Miridae)

Science.gov (United States)

Lygus hesperus Knight (Hemiptera: Miridae) is a key agricultural pest in the western United States. In a recent study, proteins from Pantoea ananatis and Serratia marcescens (Enterobacteriales: Enterobacteriaceae) were identified in diet that was stylet-probed and fed upon by L. hesperus adults. P...

Rhythmic walking interactions with auditory feedback

DEFF Research Database (Denmark)

Jylhä, Antti; Serafin, Stefania; Erkut, Cumhur

2012-01-01

of interactions based on varying the temporal characteristics of the output, using the sound of human walking as the input. The system either provides a direct synthesis of a walking sound based on the detected amplitude envelope of the user's footstep sounds, or provides a continuous synthetic walking sound...... as a stimulus for the walking human, either with a fixed tempo or a tempo adapting to the human gait. In a pilot experiment, the different interaction modes are studied with respect to their effect on the walking tempo and the experience of the subjects. The results tentatively outline different user profiles......Walking is a natural rhythmic activity that has become of interest as a means of interacting with software systems such as computer games. Therefore, designing multimodal walking interactions calls for further examination. This exploratory study presents a system capable of different kinds...

First record of Sesbania punicea (Fabales: Fabaceae) as a host plant for Chinavia hilaris (Hemiptera: Pentatomidae)

Science.gov (United States)

The green stink bug, Chinavia hilaris (Say) (Hemiptera: Pentatomidae), is an economic pest of cotton, Gossypium hirsutum L. Numerous known non-crop hosts of C. hilaris that exist in field edges bordering cotton are sources of this stink bug in this crop. Sesbania punicea plants in a field border su...

Consumer preference in ranking walking function utilizing the walking index for spinal cord injury II.

Science.gov (United States)

Patrick, M; Ditunno, P; Ditunno, J F; Marino, R J; Scivoletto, G; Lam, T; Loffree, J; Tamburella, F; Leiby, B

2011-12-01

Blinded rank ordering. To determine consumer preference in walking function utilizing the walking Index for spinal cord injury II (WISCI II) in individuals with spinal cord injury (SCI)from the Canada, the Italy and the United States of America. In all, 42 consumers with incomplete SCI (25 cervical, 12 thoracic, 5 lumbar) from Canada (12/42), Italy (14/42) and the United States of America (16/42) ranked the 20 levels of the WISCI II scale by their individual preference for walking. Subjects were blinded to the original ranking of the WISCI II scale by clinical scientists. Photographs of each WISCI II level used in a previous pilot study were randomly shuffled and rank ordered. Percentile, conjoint/cluster and graphic analyses were performed. All three analyses illustrated consumer ranking followed a bimodal distribution. Ranking for two levels with physical assistance and two levels with a walker were bimodal with a difference of five to six ranks between consumer subgroups (quartile analysis). The larger cluster (N=20) showed preference for walking with assistance over the smaller cluster (N=12), whose preference was walking without assistance and more devices. In all, 64% (27/42) of consumers ranked WISCI II level with no devices or braces and 1 person assistance higher than multiple levels of the WISCI II requiring no assistance. These results were unexpected, as the hypothesis was that consumers would rank independent walking higher than walking with assistance. Consumer preference for walking function should be considered in addition to objective measures in designing SCI trials that use significant improvement in walking function as an outcome measure.

Quantum walks on quotient graphs

International Nuclear Information System (INIS)

Krovi, Hari; Brun, Todd A.

2007-01-01

A discrete-time quantum walk on a graph Γ is the repeated application of a unitary evolution operator to a Hilbert space corresponding to the graph. If this unitary evolution operator has an associated group of symmetries, then for certain initial states the walk will be confined to a subspace of the original Hilbert space. Symmetries of the original graph, given by its automorphism group, can be inherited by the evolution operator. We show that a quantum walk confined to the subspace corresponding to this symmetry group can be seen as a different quantum walk on a smaller quotient graph. We give an explicit construction of the quotient graph for any subgroup H of the automorphism group and illustrate it with examples. The automorphisms of the quotient graph which are inherited from the original graph are the original automorphism group modulo the subgroup H used to construct it. The quotient graph is constructed by removing the symmetries of the subgroup H from the original graph. We then analyze the behavior of hitting times on quotient graphs. Hitting time is the average time it takes a walk to reach a given final vertex from a given initial vertex. It has been shown in earlier work [Phys. Rev. A 74, 042334 (2006)] that the hitting time for certain initial states of a quantum walks can be infinite, in contrast to classical random walks. We give a condition which determines whether the quotient graph has infinite hitting times given that they exist in the original graph. We apply this condition for the examples discussed and determine which quotient graphs have infinite hitting times. All known examples of quantum walks with hitting times which are short compared to classical random walks correspond to systems with quotient graphs much smaller than the original graph; we conjecture that the existence of a small quotient graph with finite hitting times is necessary for a walk to exhibit a quantum speedup

Quantum walks with infinite hitting times

International Nuclear Information System (INIS)

Krovi, Hari; Brun, Todd A.

2006-01-01

Hitting times are the average time it takes a walk to reach a given final vertex from a given starting vertex. The hitting time for a classical random walk on a connected graph will always be finite. We show that, by contrast, quantum walks can have infinite hitting times for some initial states. We seek criteria to determine if a given walk on a graph will have infinite hitting times, and find a sufficient condition, which for discrete time quantum walks is that the degeneracy of the evolution operator be greater than the degree of the graph. The set of initial states which give an infinite hitting time form a subspace. The phenomenon of infinite hitting times is in general a consequence of the symmetry of the graph and its automorphism group. Using the irreducible representations of the automorphism group, we derive conditions such that quantum walks defined on this graph must have infinite hitting times for some initial states. In the case of the discrete walk, if this condition is satisfied the walk will have infinite hitting times for any choice of a coin operator, and we give a class of graphs with infinite hitting times for any choice of coin. Hitting times are not very well defined for continuous time quantum walks, but we show that the idea of infinite hitting-time walks naturally extends to the continuous time case as well

Optimal speeds for walking and running, and walking on a moving walkway.

Science.gov (United States)

Srinivasan, Manoj

2009-06-01

Many aspects of steady human locomotion are thought to be constrained by a tendency to minimize the expenditure of metabolic cost. This paper has three parts related to the theme of energetic optimality: (1) a brief review of energetic optimality in legged locomotion, (2) an examination of the notion of optimal locomotion speed, and (3) an analysis of walking on moving walkways, such as those found in some airports. First, I describe two possible connotations of the term "optimal locomotion speed:" that which minimizes the total metabolic cost per unit distance and that which minimizes the net cost per unit distance (total minus resting cost). Minimizing the total cost per distance gives the maximum range speed and is a much better predictor of the speeds at which people and horses prefer to walk naturally. Minimizing the net cost per distance is equivalent to minimizing the total daily energy intake given an idealized modern lifestyle that requires one to walk a given distance every day--but it is not a good predictor of animals' walking speeds. Next, I critique the notion that there is no energy-optimal speed for running, making use of some recent experiments and a review of past literature. Finally, I consider the problem of predicting the speeds at which people walk on moving walkways--such as those found in some airports. I present two substantially different theories to make predictions. The first theory, minimizing total energy per distance, predicts that for a range of low walkway speeds, the optimal absolute speed of travel will be greater--but the speed relative to the walkway smaller--than the optimal walking speed on stationary ground. At higher walkway speeds, this theory predicts that the person will stand still. The second theory is based on the assumption that the human optimally reconciles the sensory conflict between the forward speed that the eye sees and the walking speed that the legs feel and tries to equate the best estimate of the forward

High on walking

DEFF Research Database (Denmark)

Woythal, Bente Martinsen; Haahr, Anita; Dreyer, Pia

2018-01-01

a leg, and people who live with Parkinson’s disease. The analysis of the data is inspired by Paul Ricoeur’s philosophy of interpretation. Four themes were identified: (a) I feel high in two ways; (b) Walking has to be automatic; (c) Every Monday, I walk with the girls in the park; and (d) I dream...

Disorder and decoherence in coined quantum walks

International Nuclear Information System (INIS)

Zhang Rong; Qin Hao; Tang Bao; Xue Peng

2013-01-01

This article aims to provide a review on quantum walks. Starting form a basic idea of discrete-time quantum walks, we will review the impact of disorder and decoherence on the properties of quantum walks. The evolution of the standard quantum walks is deterministic and disorder introduces randomness to the whole system and change interference pattern leading to the localization effect. Whereas, decoherence plays the role of transmitting quantum walks to classical random walks. (topical review - quantum information)

Populations of predators and parasitoids of Bemisia tabaci (Hemiptera: Aleyrodidae) after the application of eight biorational insecticides in vegetable crops.

Science.gov (United States)

Simmons, Alvin M; Shaaban, Abd-Rabou

2011-08-01

The sweetpotato whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), is an important pest of vegetables and many other crops worldwide. Eight biorational insecticides (based on oil, plant derivatives, insect growth regulator and fungus) were evaluated in the field for their influence on populations of six natural enemies of B. tabaci. Natural populations of two predators [Chrysoperla carnea Stephen (Neuroptera: Chrysopidae) and Orius spp. (Hemiptera: Anthocoridae)] and two genera of parasitoids [Encarsia spp. and Eretmocerus spp. (Hymenoptera: Aphelinidae)] were evaluated in eggplant (Solanum melongena L.). Also, augmented field populations of three predators [C. carnea, Coccinella undecimpunctata L. (Coleoptera: Coccinellidae) and Macrolophus caliginosus (Wagner) (Hemiptera: Miridae)] were evaluated in cabbage (Brassica oleracea var. capitata L.), cucumber (Cucumis sativus L.) and squash (Cucurbita pepo L.). Regardless of natural enemy or crop, jojoba oil, Biovar and Neemix had the least effect on abundance of the natural enemies in comparison with the other insecticides during a 14 day evaluation period. Conversely, Admiral, KZ oil, Mesrona oil, Mesrona oil + sulfur and natural oil had a high detrimental effect on abundance of the natural enemies. These results demonstrate the differential effects of biorational insecticides for whitefly control on predators and parasitoids in the field. This article is a US Government work and is in the public domain in the USA. Published 2011 by John Wiley & Sons, Ltd.

Neighborhood Walking and Social Capital: The Correlation between Walking Experience and Individual Perception of Social Capital

Directory of Open Access Journals (Sweden)

Heechul Kim

2017-04-01

Full Text Available The purpose of this study was to analyze the relationship between people’s actual walking experience and their social capital levels in order to examine the possibility of restoring weakened social functions of streets and public spaces in a walking-friendly urban environment. Based on the survey data of 591 residents of Seoul, we empirically analyzed the relationship between walking experience for various purposes and individual perceptions of social capital using one-way ANOVA and OLS regression models. As a result of the analysis, we found that the levels of neighborly trust and networking of people who experienced leisure walking were higher than those of people who did not, while there was no difference in the level of social capital according to walking experiences for other purposes. This result is significant in that it shows the basis for the restoration of the social function of neighborhoods through social capital formation of people as an effect of walking. Hence, it is important to create a walking environment that supports leisure activities.

Walking on four limbs: A systematic review of Nordic Walking in Parkinson disease.

Science.gov (United States)

Bombieri, Federica; Schena, Federico; Pellegrini, Barbara; Barone, Paolo; Tinazzi, Michele; Erro, Roberto

2017-05-01

Nordic Walking is a relatively high intensity activity that is becoming increasingly popular. It involves marching using poles adapted from cross-country skiing poles in order to activate upper body muscles that would not be used during normal walking. Several studies have been performed using this technique in Parkinson disease patients with contradictory results. Thus, we reviewed here all studies using this technique in Parkinson disease patients and further performed a meta-analysis of RCTs where Nordic Walking was evaluated against standard medical care or other types of physical exercise. Nine studies including four RCTs were reviewed for a total of 127 patients who were assigned to the Nordic Walking program. The majority of studies reported beneficial effects of Nordic Walking on either motor or non-motor variables, but many limitations were observed that hamper drawing definitive conclusions and it is largely unclear whether the benefits persist over time. It would appear that little baseline disability is the strongest predictor of response. The meta-analysis of the 4 RCTs yielded a statistically significant reduction of the UPDRS-3 score, but its value of less than 1 point does not appear to be clinically meaningful. Well-designed, large RCTs should be performed both against standard medical care and other types of physical exercise to definitively address whether Nordic Walking can be beneficial in PD. Copyright © 2017. Published by Elsevier Ltd.

"Four legs instead of two"--perspectives on a Nordic walking-based walking programme among people with arthritis.

Science.gov (United States)

O'Donovan, Rhona; Kennedy, Norelee

2015-01-01

Nordic Walking (NW) is growing in popularity among people with arthritis. The aim of this study was to explore the perspectives of participants with arthritis on a NW-based walking programme including factors contributing to sustained participation in the programme. Three semi-structured focus groups were conducted with a total of 27 participants with various types of arthritis. The groups consisted of participants who completed a NW-based walking programme in the previous 4 years. Only participants who had sustained involvement in the walking group were included. Groups were audio-recorded, transcribed verbatim and thematic analysis was performed. Participants reported that the walking programme offered numerous benefits. Two distinct themes emerged: (1) "four legs instead of two legs" and (2) "a support group". Theme 1 incorporates the physical, psychological and educational benefits that stem from involvement in a walking group while Theme 2 incorporates the benefits of social support in group-based activity. Several benefits of a NW-based walking programme from the perspectives of individuals with arthritis who engage in group-based walking programmes were identified. The benefits may encourage sustained participation and justify the promotion of NW as an intervention for people with arthritis. Considering how to sustain exercise participation is important to ensure continued benefits from physical activity participation. A community-based Nordic walking-based walking programme for people with arthritis improved exercise knowledge and confidence to exercise. Group exercise is valuable in providing support and motivation to continue exercising.

Comparison of fecundity and survival of hemlock woolly adelgid (Hemiptera: Adelgidae) in northern and southern populations

Science.gov (United States)

Artemis Roehrig; Joseph. Elkinton

2011-01-01

The hemlock woolly adelgid (HWA), Adelges tsugae Annand (Hemiptera: Adelgidae), is an introduced species first reported in the eastern United States in 1951. The infestation has since spread in all directions from its initial sighting in Virginia, to its current range from northern Georgia, to southern Maine, and westward into Tennessee, causing...

Mitigating trans-boundary movement of Bemisia tabaci (Hemiptera: Aleyrodidae) on Mentha sp. by pre-shipping treaments of biopesticides

Science.gov (United States)

Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is a major pest of several important crops including vegetables, cereals, fruits, and ornamentals grown worldwide. One important mode of its dispersal is through the trans-boundary movement of infested plant materials. In order to prevent the sprea...

Walking on fractals: diffusion and self-avoiding walks on percolation clusters

International Nuclear Information System (INIS)

Blavatska, V; Janke, W

2009-01-01

We consider random walks (RWs) and self-avoiding walks (SAWs) on disordered lattices directly at the percolation threshold. Applying numerical simulations, we study the scaling behavior of the models on the incipient percolation cluster in space dimensions d = 2, 3, 4. Our analysis yields estimates of universal exponents, governing the scaling laws for configurational properties of RWs and SAWs

Physical implementation of quantum walks

CERN Document Server

Manouchehri, Kia

2013-01-01

Given the extensive application of random walks in virtually every science related discipline, we may be at the threshold of yet another problem solving paradigm with the advent of quantum walks. Over the past decade, quantum walks have been explored for their non-intuitive dynamics, which may hold the key to radically new quantum algorithms. This growing interest has been paralleled by a flurry of research into how one can implement quantum walks in laboratories. This book presents numerous proposals as well as actual experiments for such a physical realization, underpinned by a wide range of

CHEMICAL COMPOSITION AND TOXICITY OF CITRUS ESSENTIAL OILS ON Dysmicoccus brevipes (HEMIPTERA: PSEUDOCOCCIDAE)

OpenAIRE

MARTINS, GISELE DOS SANTOS OLIVEIRA; ZAGO, HUGO BOLSONI; COSTA, ADILSON VIDAL; ARAUJO JUNIOR, LUIS MOREIRA DE; CARVALHO, JOSÉ ROMÁRIO DE

2017-01-01

ABSTRACT The insect Dysmicoccus brevipes (Hemiptera: Pseudococcidae) has been reported as an important pest for several crops, especially coffee. The citrus essential oils can be obtained as by-products of the citrus-processing industry and have been tested as an alternative to control different insect groups. Therefore, the objective of this work was to determine the chemical composition and evaluate the toxicity of commercial sweet orange (Citrus sinensis), bitter orange (Citrus aurantium) ...

Treadmill walking with body weight support

OpenAIRE

Aaslund, Mona Kristin

2012-01-01

Background: Rehabilitating walking in patients post-stroke with safe, task-specific, intensive training of sufficient duration, can be challenging. Body weight supported treadmill training (BWSTT) has been proposed as an effective method to meet these challenges and may therefore have benefits over training overground walking. However, walking characteristics should not be aggravated during BWSTT or require a long familiarisation time compared to overground walking. Objectives: To investi...

Interlimb coordination during forward walking is largely preserved in backward walking in children with cerebral palsy

NARCIS (Netherlands)

Meyns, P.; Molenaers, G.; Desloovere, K.; Duysens, J.E.J.

2014-01-01

OBJECTIVE: Limb kinematics in backward walking (BW) are essentially those of forward walking (FW) in reverse. It has been argued that subcortical mechanisms could underlie both walking modes. METHODS: Therefore, we tested whether participants with supraspinal/cortical deficits (i.e. cerebral palsy)

More Adults Are Walking

Centers for Disease Control (CDC) Podcasts

This podcast is based on the August 2012 CDC Vital Signs report. While more adults are walking, only half get the recommended amount of physical activity. Listen to learn how communities, employers, and individuals may help increase walking.

A Passive Dynamic Walking Model Based on Knee-Bend Behaviour: Stability and Adaptability for Walking down Steep Slopes

Directory of Open Access Journals (Sweden)

Kang An

2013-10-01

Full Text Available This paper presents a passive dynamic walking model based on knee-bend behaviour, which is inspired by the way human beings walk. The length and mass parameters of human beings are used in the walking model. The knee-bend mechanism of the stance leg is designed in the phase between knee-strike and heel-strike. q* which is the angular difference of the stance leg between the two events, knee-strike and knee-bend, is adjusted in order to find a stable walking motion. The results show that the stable periodic walking motion on a slope of r <0.4 can be found by adjusting q*. Furthermore, with a particular q* in the range of 0.12walk down more steps before falling down on an arbitrary slope. The walking motion is more stable and adaptable than the conventional walking motion, especially for steep slopes.

Quantum walk on a chimera graph

Science.gov (United States)

Xu, Shu; Sun, Xiangxiang; Wu, Jizhou; Zhang, Wei-Wei; Arshed, Nigum; Sanders, Barry C.

2018-05-01

We analyse a continuous-time quantum walk on a chimera graph, which is a graph of choice for designing quantum annealers, and we discover beautiful quantum walk features such as localization that starkly distinguishes classical from quantum behaviour. Motivated by technological thrusts, we study continuous-time quantum walk on enhanced variants of the chimera graph and on diminished chimera graph with a random removal of vertices. We explain the quantum walk by constructing a generating set for a suitable subgroup of graph isomorphisms and corresponding symmetry operators that commute with the quantum walk Hamiltonian; the Hamiltonian and these symmetry operators provide a complete set of labels for the spectrum and the stationary states. Our quantum walk characterization of the chimera graph and its variants yields valuable insights into graphs used for designing quantum-annealers.

Description of a new coccid (Hemiptera, Coccidae on avocado (Persea americana Mill. from Colombia, South America

Directory of Open Access Journals (Sweden)

Takumasa Kondo

2010-04-01

Full Text Available A new soft scale insect, Bombacoccus aguacatae Kondo, gen. n. and sp. n. (Hemiptera: Coccidae collected on the branches and twigs of avocado, Persea americana Mill. (Lauraceae in Colombia, is described and illustrated based on the adult female. An updated taxonomic key to closely related genera of the Toumeyella-group is provided.

Establishing the Range of Perceptually Natural Visual Walking Speeds for Virtual Walking-In-Place Locomotion

DEFF Research Database (Denmark)

Nilsson, Niels Christian; Serafin, Stefania; Nordahl, Rolf

2014-01-01

to virtual motion. This paper describes two within-subjects studies performed with the intention of establishing the range of perceptually natural walking speeds for WIP locomotion. In both studies, subjects performed a series of virtual walks while exposed to visual gains (optic flow multipliers) ranging...... from 1.0 to 3.0. Thus, the slowest speed was equal to an estimate of the subjects normal walking speed, while the highest speed was three times greater. The perceived naturalness of the visual speed was assessed using self-reports. The first study compared four different types of movement, namely...... proportional to the degree of underestimation of the virtual speeds for both treadmill-mediated virtual walking and WIP locomotion. Combined, the results constitute a first attempt at establishing a set of guidelines specifying what virtual walking speeds WIP gestures should produce in order to facilitate...

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

Science.gov (United States)

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.

Motor modules in robot-aided walking

Directory of Open Access Journals (Sweden)

Gizzi Leonardo

2012-10-01

Full Text Available Abstract Background It is hypothesized that locomotion is achieved by means of rhythm generating networks (central pattern generators and muscle activation generating networks. This modular organization can be partly identified from the analysis of the muscular activity by means of factorization algorithms. The activity of rhythm generating networks is described by activation signals whilst the muscle intervention generating network is represented by motor modules (muscle synergies. In this study, we extend the analysis of modular organization of walking to the case of robot-aided locomotion, at varying speed and body weight support level. Methods Non Negative Matrix Factorization was applied on surface electromyographic signals of 8 lower limb muscles of healthy subjects walking in gait robotic trainer at different walking velocities (1 to 3km/h and levels of body weight support (0 to 30%. Results The muscular activity of volunteers could be described by low dimensionality (4 modules, as for overground walking. Moreover, the activation signals during robot-aided walking were bursts of activation timed at specific phases of the gait cycle, underlying an impulsive controller, as also observed in overground walking. This modular organization was consistent across the investigated speeds, body weight support level, and subjects. Conclusions These results indicate that walking in a Lokomat robotic trainer is achieved by similar motor modules and activation signals as overground walking and thus supports the use of robotic training for re-establishing natural walking patterns.

Walking Behavior of Zoo Elephants: Associations between GPS-Measured Daily Walking Distances and Environmental Factors, Social Factors, and Welfare Indicators.

Directory of Open Access Journals (Sweden)

Matthew R Holdgate

Full Text Available Research with humans and other animals suggests that walking benefits physical health. Perhaps because these links have been demonstrated in other species, it has been suggested that walking is important to elephant welfare, and that zoo elephant exhibits should be designed to allow for more walking. Our study is the first to address this suggestion empirically by measuring the mean daily walking distance of elephants in North American zoos, determining the factors that are associated with variations in walking distance, and testing for associations between walking and welfare indicators. We used anklets equipped with GPS data loggers to measure outdoor daily walking distance in 56 adult female African (n = 33 and Asian (n = 23 elephants housed in 30 North American zoos. We collected 259 days of data and determined associations between distance walked and social, housing, management, and demographic factors. Elephants walked an average of 5.3 km/day with no significant difference between species. In our multivariable model, more diverse feeding regimens were correlated with increased walking, and elephants who were fed on a temporally unpredictable feeding schedule walked 1.29 km/day more than elephants fed on a predictable schedule. Distance walked was also positively correlated with an increase in the number of social groupings and negatively correlated with age. We found a small but significant negative correlation between distance walked and nighttime Space Experience, but no other associations between walking distances and exhibit size were found. Finally, distance walked was not related to health or behavioral outcomes including foot health, joint health, body condition, and the performance of stereotypic behavior, suggesting that more research is necessary to determine explicitly how differences in walking may impact elephant welfare.

Walking Behavior of Zoo Elephants: Associations between GPS-Measured Daily Walking Distances and Environmental Factors, Social Factors, and Welfare Indicators.

Science.gov (United States)

Holdgate, Matthew R; Meehan, Cheryl L; Hogan, Jennifer N; Miller, Lance J; Soltis, Joseph; Andrews, Jeff; Shepherdson, David J

2016-01-01

Research with humans and other animals suggests that walking benefits physical health. Perhaps because these links have been demonstrated in other species, it has been suggested that walking is important to elephant welfare, and that zoo elephant exhibits should be designed to allow for more walking. Our study is the first to address this suggestion empirically by measuring the mean daily walking distance of elephants in North American zoos, determining the factors that are associated with variations in walking distance, and testing for associations between walking and welfare indicators. We used anklets equipped with GPS data loggers to measure outdoor daily walking distance in 56 adult female African (n = 33) and Asian (n = 23) elephants housed in 30 North American zoos. We collected 259 days of data and determined associations between distance walked and social, housing, management, and demographic factors. Elephants walked an average of 5.3 km/day with no significant difference between species. In our multivariable model, more diverse feeding regimens were correlated with increased walking, and elephants who were fed on a temporally unpredictable feeding schedule walked 1.29 km/day more than elephants fed on a predictable schedule. Distance walked was also positively correlated with an increase in the number of social groupings and negatively correlated with age. We found a small but significant negative correlation between distance walked and nighttime Space Experience, but no other associations between walking distances and exhibit size were found. Finally, distance walked was not related to health or behavioral outcomes including foot health, joint health, body condition, and the performance of stereotypic behavior, suggesting that more research is necessary to determine explicitly how differences in walking may impact elephant welfare.

Quantum walks, quantum gates, and quantum computers

International Nuclear Information System (INIS)

Hines, Andrew P.; Stamp, P. C. E.

2007-01-01

The physics of quantum walks on graphs is formulated in Hamiltonian language, both for simple quantum walks and for composite walks, where extra discrete degrees of freedom live at each node of the graph. It is shown how to map between quantum walk Hamiltonians and Hamiltonians for qubit systems and quantum circuits; this is done for both single-excitation and multiexcitation encodings. Specific examples of spin chains, as well as static and dynamic systems of qubits, are mapped to quantum walks, and walks on hyperlattices and hypercubes are mapped to various gate systems. We also show how to map a quantum circuit performing the quantum Fourier transform, the key element of Shor's algorithm, to a quantum walk system doing the same. The results herein are an essential preliminary to a Hamiltonian formulation of quantum walks in which coupling to a dynamic quantum environment is included

Asociaciones áfido-parasitoide (Hemiptera: Aphididae; Hymenoptera: Braconidae, Aphidiinae en cultivos hortícolas orgánicos en Los Cardales, Buenos Aires, Argentina Aphid-parasitoid associations (Hemiptera: Aphididae; Hymenoptera: Braconidae, Aphidiinae on organic vegetable crops in Los Cardales, Buenos Aires, Argentina

Directory of Open Access Journals (Sweden)

Andrea V. Andorno

2007-07-01

Full Text Available Diez especies de áfidos (Hemiptera: Aphididae se hallaron parasitados por siete especies de parasitoides (Hymenoptera: Braconidae, Aphidiinae en cultivos hortícolas orgánicos. Myzus persicae (Sulzer fue el áfido más frecuentemente encontrado sobre una amplia variedad de cultivos, y con mayor diversidad de parasitoides asociados. Aphidius colemani Viereck fue el afidiino más usual, que ataca varias especies de áfidos. Ocho asociaciones tritróficas, involucrando Aphidius matricariae Haliday, han sido registradas por primera vez para la Argentina.Ten aphid species (Hemiptera: Aphididae were found parasitized by seven aphid parasitoid species (Hymenoptera: Braconidae, Aphidiinae on organic vegetable crops. Myzus persicae (Sulzer was the most frequent aphid found on a wide variety of crops, with the largest parasitoid diversity associated. Aphidius colemani Viereck was the most frequent aphidiine attacking several species of aphids. Eight tritrophic associations involving Aphidius matricariae Haliday are reported for the first time for Argentina.

The Act of Walking

DEFF Research Database (Denmark)

Vestergaard, Maria Quvang Harck; Olesen, Mette; Helmer, Pernille Falborg

2014-01-01

’ of mobility (Jensen 2013:111) such as the urban environment, and the infrastructures. Walking has indeed also a ‘software dimension’ as an embodied performance that trigger the human senses (Jensen 2013) and which is closely related to the habitus and identity of the individual (Halprin 1963). The individual......The ability to walk in an area is, in the existing literature, often explained by the physical structures like building density and the presence of facilities in an area, and it is often termed ‘walkability’ (Patton 2007; Forsyth and Southworth 2008; Krizek, Handy and Forsyth 2009; Johnson 2003......; Frumkin 2002). The term ‘walkability’ focuses on how the physical structures in the urban environment can promote walking, and how this potentially eases issues of public health and liveability in our cities (Krizek et al. 2009). However, the study of walking should not be reduced merely to the ‘hardware...

Effects of Intermittent Versus Continuous Walking on Distance Walked and Fatigue in Persons With Multiple Sclerosis: A Randomized Crossover Trial.

Science.gov (United States)

Karpatkin, Herb; Cohen, Evan T; Rzetelny, Adam; Parrott, J Scott; Breismeister, Breanne; Hartman, Ryan; Luu, Ronald; Napolione, Danielle

2015-07-01

Fatigue is a common, disabling symptom experienced by persons with multiple sclerosis (MS). Evidence shows that intermittent exercise is associated in improved performance and negligible fatigue. The purpose of this study was to examine whether subjects with MS walk greater distances with less fatigue under intermittent (INT) or continuous (CONT) walking condition. Twenty-seven subjects with MS (median Extended Disability Severity Scale 3.5, interquartile range 1.6) walked in the CONT (ie, 6 uninterrupted minutes) and INT (ie, three 2-minute walking bouts) conditions in a randomized crossover. Distance was measured for the entire 6-minute walking period and each 2-minute increment. Fatigue was measured as the difference in a visual analog scale of fatigue (ΔVAS-F) immediately preceding and following each trial. Participants walked greater distances in the INT condition compared to the CONT condition (P = 0.005). There was a significant interaction of walking condition and time (P walked in the INT condition changed across time. ΔVAS-F was significantly lower in the INT condition than in the CONT condition (P = 0.036). Subjects with MS walked farther, and with less fatigue, when walking intermittently rather than continuously. Persons with MS may be able to tolerate a greater dose of walking training if the walking bouts are intermittent. Further study to determine the benefits of a walking exercise program using intermittent walking is recommended.Video Abstract available for additional insights from the authors (Supplemental Digital Content 1, http://links.lww.com/JNPT/A103).

Influence of trap color on collection of the recently introduced Bean Plataspid, Megacopta cribraria (Hemiptera: Plataspidae).

Science.gov (United States)

Scott Horn; James Hanula

2011-01-01

Large numbers of the exotic bean plataspid, Megacopta cribraria (F.) (Hemiptera: Plataspidae). were first collected from several northeast Georgia counties beginning in October 2009 (Suiter and Ames 2009, Statewide Pest Alert). How this insect arrived in the United States and where it came from is still not known. The native range of M. cribraria is reported to be...

Spotted alfalfa aphid, Therioaphis trifolii (Monell) (Hemiptera: Aphididae): Pest on alfalfa in Serbia

OpenAIRE

Jovičić, Ivana; Radonjić, Anđa; Petrović-Obradović, Olivera

2017-01-01

Spotted alfalfa aphid Therioaphis trifolii (Monell) (Hemiptera, Aphididae) is one of the most important alfalfa pest on the world. Also, it is the most abundant alfalfa aphid in Serbia. This aphid cause damage to alfalfa directly by feeding and indirectly by vectoring plant-pathogenic viruses. Some notes of morphology, host plants, damage, biology, vector role and distribution of spotted alfalfa aphid are given. Abundance of this aphid on alfalfa, influence of climates changes on its abundanc...

Walking during body-weight-supported treadmill training and acute responses to varying walking speed and body-weight support in ambulatory patients post-stroke.

Science.gov (United States)

Aaslund, Mona Kristin; Helbostad, Jorunn Lægdheim; Moe-Nilssen, Rolf

2013-05-01

Rehabilitating walking in ambulatory patients post-stroke, with training that is safe, task-specific, intensive, and of sufficient duration, can be challenging. Some challenges can be met by using body-weight-supported treadmill training (BWSTT). However, it is not known to what degree walking characteristics are similar during BWSTT and overground walking. In addition, important questions regarding the training protocol of BWSTT remain unanswered, such as how proportion of body-weight support (BWS) and walking speed affect walking characteristics during training. The objective was therefore to investigate if and how kinematic walking characteristics are different between overground walking and treadmill walking with BWS in ambulatory patients post-stroke, and the acute response of altering walking speed and percent BWS during treadmill walking with BWS. A cross-sectional repeated-measures design was used. Ambulating patients post-stroke walked in slow, preferred, and fast walking speed overground and at comparable speeds on the treadmill with 20% and 40% BWS. Kinematic walking characteristics were obtained using a kinematic sensor attached over the lower back. Forty-four patients completed the protocol. Kinematic walking characteristics were similar during treadmill walking with BWS, compared to walking overground. During treadmill walking, choice of walking speed had greater impact on kinematic walking characteristics than proportion of BWS. Faster walking speeds tended to affect the kinematic walking characteristics positively. This implies that in order to train safely and with sufficient intensity and duration, therapists may choose to include BWSTT in walking rehabilitation also for ambulatory patients post-stroke without aggravating gait pattern during training.

Quantum walks and search algorithms

CERN Document Server

Portugal, Renato

2013-01-01

This book addresses an interesting area of quantum computation called quantum walks, which play an important role in building quantum algorithms, in particular search algorithms. Quantum walks are the quantum analogue of classical random walks. It is known that quantum computers have great power for searching unsorted databases. This power extends to many kinds of searches, particularly to the problem of finding a specific location in a spatial layout, which can be modeled by a graph. The goal is to find a specific node knowing that the particle uses the edges to jump from one node to the next. This book is self-contained with main topics that include: Grover's algorithm, describing its geometrical interpretation and evolution by means of the spectral decomposition of the evolution operater Analytical solutions of quantum walks on important graphs like line, cycles, two-dimensional lattices, and hypercubes using Fourier transforms Quantum walks on generic graphs, describing methods to calculate the limiting d...

Generalized atmospheric sampling of self-avoiding walks

International Nuclear Information System (INIS)

Van Rensburg, E J Janse; Rechnitzer, A

2009-01-01

In this paper, we introduce a new Monte Carlo method for sampling lattice self-avoiding walks. The method, which we call 'GAS' (generalized atmospheric sampling), samples walks along weighted sequences by implementing elementary moves generated by the positive, negative and neutral atmospheric statistics of the walks. A realized sequence is weighted such that the average weight of states of length n is proportional to the number of self-avoiding walks from the origin c n . In addition, the method also self-tunes to sample from uniform distributions over walks of lengths in an interval [0, n max ]. We show how to implement GAS using both generalized and endpoint atmospheres of walks and analyse our data to obtain estimates of the growth constant and entropic exponent of self-avoiding walks in the square and cubic lattices.

Nordic walking and chronic low back pain

DEFF Research Database (Denmark)

Morsø, Lars; Hartvigsen, Jan; Puggaard, Lis

2006-01-01

activity provide similar benefits. Nordic Walking is a popular and fast growing type of exercise in Northern Europe. Initial studies have demonstrated that persons performing Nordic Walking are able to exercise longer and harder compared to normal walking thereby increasing their cardiovascular metabolism....... Until now no studies have been performed to investigate whether Nordic Walking has beneficial effects in relation to low back pain. The primary aim of this study is to investigate whether supervised Nordic Walking can reduce pain and improve function in a population of chronic low back pain patients...... when compared to unsupervised Nordic Walking and advice to stay active. In addition we investigate whether there is an increase in the cardiovascular metabolism in persons performing supervised Nordic Walking compared to persons who are advised to stay active. Finally, we investigate whether...

Prevalence of Walking-Related Motor Fatigue in Persons With Multiple Sclerosis: Decline in Walking Distance Induced by the 6-Minute Walk Test.

Science.gov (United States)

Leone, Carmela; Severijns, Deborah; Doležalová, Vendula; Baert, Ilse; Dalgas, Ulrik; Romberg, Anders; Bethoux, Francois; Gebara, Benoit; Santoyo Medina, Carmen; Maamâgi, Heigo; Rasova, Kamila; Maertens de Noordhout, Benoît; Knuts, Kathy; Skjerbaek, Anders; Jensen, Ellen; Wagner, Joanne M; Feys, Peter

2016-05-01

To investigate the individual occurrence of walking-related motor fatigue in persons with multiple sclerosis (PwMS), according to disability level and disease phenotype.Study design This was a cross-sectional, multinational study.Participants They were 208 PwMS from 11 centers with Expanded Disability Status Scale (EDSS) scores up to 6.5. The percentage change in distance walked (distance walked index, DWI) was calculated between minute 6 and 1 (DWI(6-1)) of the 6-Minute Walk Test (6MWT). Its magnitude was used to classify participants into 4 subgroups: (1) DWI(6-1)[≥5%], (2) DWI(6-1)[5%; -5%], (3) DWI(6-1)[-5%; > -15%], and (4) DWI(6-1)[≤-15%]. The latter group was labeled as having walking-related motor fatigue. PwMS were stratified into 5 subgroups based on the EDSS (0-2.5, 3-4, 4.5-5.5, 6, 6.5) and 3 subgroups based on MS phenotype (relapsing remitting [RR], primary progressive [PP], and secondary progressive [SP]). The DWI6-1was ≥5% in 16 PwMS (7.7%), between 5% and -5% in 70 PwMS (33.6%), between -5% and -15% in 58 PwMS (24%), and ≤-15% in 64 PwMS (30.8%). The prevalence of walking-related motor fatigue (DWI(6-1)[≤-15%]) was significantly higher among the progressive phenotype (PP = 50% and SP = 39%; RR = 15.6%) and PwMS with higher disability level (EDSS 4.5-5.5 = 48.3%, 6 = 46.3% and 6.5 = 51.5%, compared with EDSS 0-2.5 = 7.8% and 3-4 = 16.7%;P< .05). Stepwise multiple regression analysis indicated that EDSS, but not MS phenotype, explained a significant part of the variance in DWI(6-1)(R(2)= 0.086;P< .001). More than one-third of PwMS showed walking-related motor fatigue during the 6MWT, with its prevalence greatest in more disabled persons (up to 51%) and in those with progressive MS phenotype (up to 50%). Identification of walking-related motor fatigue may lead to better-tailored interventions. © The Author(s) 2015.

Pengaruh Jenis Mangsa dan Suhu pada Perkembangan Menochilus sexmaculatus Fabricius (Coleoptera: Coccinellidae dan Peranannya dalam Pengendalian Diaphorina citri Kuwayama (Hemiptera: Psyllidae

Directory of Open Access Journals (Sweden)

Tris Haris Ramadhan

2008-07-01

Full Text Available Diaphorina citri Kuwayama (Hemiptera: Psyllidae is the vector of citrus greening (Huanglongbing bacterium and the most serious impediment to citrus culture. Classical biological control of this psyllid vector should contribute to suppress their population. This research was conducted to determine the performance of Menochilus sexmaculatus Fabricius (Coleoptera: Coccinellidae when they were fed with D. citri. The larval performance index of M. sexmaculatus on D. citri compared with Aphis craccivora Koch (Hemiptera: Aphididae diet was 1.3.M. sexmaculatus fed with D. citri had lower fitness than those fed with A. craccivora as shown by longer larval stadium, lower adult dry weight, less number of egg produced and lower percentage of egg hatched. M. sexmaculatus grew best at the temperature of 27oC. Employing the exclusion procedure under field condition,M. sexmaculatus could reduce the population of D. citri up to 90%. These findings showed that theM. sexmaculatus could be a potential predator in reducing D. citri, particularly when the more preferred prey A. craccivora was not present.   Diaphorina citri Kuwayama (Hemiptera: Psyllidae merupakan kelompok Psyllid yang menularkan penyebab penyakit Huanglongbing yang sangat berbahaya pada tanaman jeruk. Pengendalian hayati klasik telah banyak memberikan kontribusi dalam pengendalian di lapangan. Penelitian ini dilakukan untuk melihat penampilan Menochilus sexmaculatus Fabricius (Coleoptera: Coccinellidae dengan pakan D. citri. Indeks penampilan larva M. sexmaculatus dengan pakan D. citri dibandingkan dengan Aphis craccivora Koch (Hemiptera: Aphididae adalah 1,3. M. sexmaculatus yang diberi pakan D. citri menunjukkan penurunan kebugaran dibandingkan jika diberi pakan A. craccivora seperti yang ditunjukkan dengan stadium larva lebih lama, penurunan berat kering serangga dewasa, telur yang dihasilkan lebih sedikit, dan penurunan jumlah telur yang menetas. Menggunakan metode eksklusi pada kondisi

Analysis of absorbing times of quantum walks

International Nuclear Information System (INIS)

Yamasaki, Tomohiro; Kobayashi, Hirotada; Imai, Hiroshi

2003-01-01

Quantum walks are expected to provide useful algorithmic tools for quantum computation. This paper introduces absorbing probability and time of quantum walks and gives both numerical simulation results and theoretical analyses on Hadamard walks on the line and symmetric walks on the hypercube from the viewpoint of absorbing probability and time

Random walk through fractal environments

International Nuclear Information System (INIS)

Isliker, H.; Vlahos, L.

2003-01-01

We analyze random walk through fractal environments, embedded in three-dimensional, permeable space. Particles travel freely and are scattered off into random directions when they hit the fractal. The statistical distribution of the flight increments (i.e., of the displacements between two consecutive hittings) is analytically derived from a common, practical definition of fractal dimension, and it turns out to approximate quite well a power-law in the case where the dimension D F of the fractal is less than 2, there is though, always a finite rate of unaffected escape. Random walks through fractal sets with D F ≤2 can thus be considered as defective Levy walks. The distribution of jump increments for D F >2 is decaying exponentially. The diffusive behavior of the random walk is analyzed in the frame of continuous time random walk, which we generalize to include the case of defective distributions of walk increments. It is shown that the particles undergo anomalous, enhanced diffusion for D F F >2 is normal for large times, enhanced though for small and intermediate times. In particular, it follows that fractals generated by a particular class of self-organized criticality models give rise to enhanced diffusion. The analytical results are illustrated by Monte Carlo simulations

Nine walks (photo series / web page)

OpenAIRE

Robinson, Andrew

2015-01-01

'Nine Walks' is a body of work resulting from my engagement with the Media Arts Research Walking Group at Sheffield Hallam University who are exploring the role of walking in as a social, developmental and production space for the creative arts. / My participation in the walking group is an extension of my investigation of the journey as a creative, conceptual and contemplative space for photography which in turn reflects an interest in the role of the accident, instinct and intuition and the...

Host range of the exotic brown marmorated stink bug, Halyomorpha halys, (Hemiptera: Pentatomidae), implications for future distribution

Science.gov (United States)

Gary Bernon; Karen M. Bernhard; Anne L. Nielsen; James F. Stimmel; E. Richard Hoebeke; Maureen E. Carter

2007-01-01

Halyomorpha halys, (Hemiptera: Pentatomidae), is a pest in eastern Asia on soybeans and woody plants, including broadleaved trees and fruit trees. A population was discovered in Allentown, PA in 2001. H. halys is also a nuisance pest as it overwinters in homes and other buildings. Based on earlier reports to the Lehigh County...

Demand response to improved walking infrastructure: A study into the economics of walking and health behaviour change.

Science.gov (United States)

Longo, Alberto; Hutchinson, W George; Hunter, Ruth F; Tully, Mark A; Kee, Frank

2015-10-01

Walking is the most common form of moderate-intensity physical activity among adults, is widely accessible and especially appealing to obese people. Most often policy makers are interested in valuing the effect on walking of changes in some characteristics of a neighbourhood, the demand response for walking, of infrastructure changes. A positive demand response to improvements in the walking environment could help meet the public health target of 150 min of at least moderate-intensity physical activity per week. We model walking in an individual's local neighbourhood as a 'weak complement' to the characteristics of the neighbourhood itself. Walking is affected by neighbourhood characteristics, substitutes, and individual's characteristics, including their opportunity cost of time. Using compensating variation, we assess the economic benefits of walking and how walking behaviour is affected by improvements to the neighbourhood. Using a sample of 1209 respondents surveyed over a 12 month period (Feb 2010-Jan 2011) in East Belfast, United Kingdom, we find that a policy that increased walkability and people's perception of access to shops and facilities would lead to an increase in walking of about 36 min/person/week, valued at £13.65/person/week. When focussing on inactive residents, a policy that improved the walkability of the area would lead to guidelines for physical activity being reached by only 12.8% of the population who are currently inactive. Additional interventions would therefore be needed to encourage inactive residents to achieve the recommended levels of physical activity, as it appears that interventions that improve the walkability of an area are particularly effective in increasing walking among already active citizens, and, among the inactive ones, the best response is found among healthier, younger and wealthier citizens. Copyright © 2015 Elsevier Ltd. All rights reserved.

Development of independent walking in toddlers

NARCIS (Netherlands)

Ivanenko, Yuri P; Dominici, Nadia; Lacquaniti, Francesco

Surprisingly, despite millions of years of bipedal walking evolution, the gravity-related pendulum mechanism of walking does not seem to be implemented at the onset of independent walking, requiring each toddler to develop it. We discuss the precursor of the mature locomotor pattern in infants as an

Energy cost of walking: solving the paradox of steady state in the presence of variable walking speed.

Science.gov (United States)

Plasschaert, Frank; Jones, Kim; Forward, Malcolm

2009-02-01

Measurement of the energy cost of walking in children with cerebral palsy is used for baseline and outcome assessment. However, such testing relies on the establishment of steady state that is deemed present when oxygen consumption is stable. This is often assumed when walking speed is constant but in practice, speed can and does vary naturally. Whilst constant speed is achievable on a treadmill, this is often impractical clinically, thus rendering an energy cost test to an element of subjectivity. This paper attempts to address this issue by presenting a new method for calculating energy cost of walking that automatically applies a mathematically defined threshold for steady state within a (non-treadmill) walking trial and then strips out all of the non-steady state events within that trial. The method is compared with a generic approach that does not remove non-steady state data but rather uses an average value over a complete walking trial as is often used in the clinical environment. Both methods were applied to the calculation of several energy cost of walking parameters of self-selected walking speed in a cohort of unimpaired subjects and children with cerebral palsy. The results revealed that both methods were strongly correlated for each parameter but showed systematic significant differences. It is suggested that these differences are introduced by the rejection of non-steady state data that would otherwise have incorrectly been incorporated into the calculation of the energy cost of walking indices during self-selected walking with its inherent speed variation.

Population Dynamics of Empoasca fabae (Hemiptera: Cicadellidae) in Central Iowa Alfalfa Fields

Science.gov (United States)

Weiser Erlandson, L. A.; Obrycki, J. J.

2015-01-01

Adults and nymphs of Empoasca fabae Harris (Hemiptera: Cicadellidae) and adults of predatory species in the families Coccinellidae, Anthocoridae, Nabidae, Chrysopidae, and Hemerobiidae were sampled in Iowa alfalfa fields from June to September in 1999 and 2000. The relationship between each predatory taxa and E. fabae was examined using regression analysis. In 2000, all predators were found to be positively correlated with the presence of E. fabae during all periods sampled and most likely contributed to mortality. Orius insidiosus (Say) (Hemiptera: Anthoridae) was the most numerous insect predatory species; population numbers ranged from 0 to 1 and 0.1 to 3.7 adults per 0.25 m2 in 1999 and 2000, respectively. Partial life tables were constructed for E. fabae nymphs for two alfalfa-growing periods. Nymphs were grouped into three age intervals: first and second, third and fourth, and fifth instars. For the first alfalfa growing period examined, E. fabae nymphal mortality was 70% in 1999 and 49% in 2000. During the last growing period of each season (August–September), total nymphal mortality was relatively low (<25%). Adult E. fabae density ranged from 5.4 to 25.6 and 1.4–9.2 per 0.25 m2 in 1999 and 2000, respectively. E. fabae population peaks were similar for each age interval in all growing periods. This study provides further information on the population dynamics of E. fabae and its relationship with select predatory species in Iowa alfalfa fields. PMID:26320260

To Walk or Not to Walk?: The Hierarchy of Walking Needs

Science.gov (United States)

Alfonzo, Mariela

2005-01-01

The multitude of quality of life problems associated with declining walking rates has impelled researchers from various disciplines to identify factors related to this behavior change. Currently, this body of research is in need of a transdisciplinary, multilevel theoretical model that can help explain how individual, group, regional, and…

Prey suitability and phenology of Leucopis spp. (Diptera: Chamaemyiidae) associated with hemlock woolly adelgid (Hemiptera: Adelgidae) in the Pacific Northwest

Science.gov (United States)

Sarah M. Grubin; Darrell W. Ross; Kimberly F. Wallin

2011-01-01

Leucopis spp. (Diptera: Chamaemyiidae) from the Pacific Northwest previously were identified as potential biological control agents for the hemlock woolly adelgid, Adelges tsugae Annand (Hemiptera: Adelgidae), in the eastern United States. We collected Leucopis spp. larvae from A. tsugae...

Monitoring of brown stink bug (Hemiptera: Pentatomidae) population dynamics in corn to predict its abundance using weather data

Science.gov (United States)

The brown stink bug (BSB), Euschistus servus (Say) (Hemiptera: Pentatomidae), is a serious economic pest of corn production in the Southeastern U. S. The BSB population dynamics was monitored for 17 wks from tasseling to pre-harvest of corn plants (i.e., late May to mid-September) using pheromone ...

Walks on SPR neighborhoods.

Science.gov (United States)

Caceres, Alan Joseph J; Castillo, Juan; Lee, Jinnie; St John, Katherine

2013-01-01

A nearest-neighbor-interchange (NNI)-walk is a sequence of unrooted phylogenetic trees, T1, T2, . . . , T(k) where each consecutive pair of trees differs by a single NNI move. We give tight bounds on the length of the shortest NNI-walks that visit all trees in a subtree-prune-and-regraft (SPR) neighborhood of a given tree. For any unrooted, binary tree, T, on n leaves, the shortest walk takes Θ(n²) additional steps more than the number of trees in the SPR neighborhood. This answers Bryant’s Second Combinatorial Challenge from the Phylogenetics Challenges List, the Isaac Newton Institute, 2011, and the Penny Ante Problem List, 2009.

James Watt's Leicester Walk

OpenAIRE

Bell, Kathleen

2016-01-01

a poem in which James Watt, inventor of the separate condenser, walks through contemporary Leicester (his route is from Bonners Lane and alongside the canal, taking in the Statue of Liberty on its traffic island near Sage Road). It is derived from the exercise of taking a character for a walk,

Effect of Body Composition on Walking Economy

Directory of Open Access Journals (Sweden)

Maciejczyk Marcin

2016-12-01

Full Text Available Purpose. The aim of the study was to evaluate walking economy and physiological responses at two walking speeds in males with similar absolute body mass but different body composition. Methods. The study involved 22 young men with similar absolute body mass, BMI, aerobic performance, calf and thigh circumference. The participants differed in body composition: body fat (HBF group and lean body mass (HLBM group. In the graded test, maximal oxygen uptake (VO2max and maximal heart rate were measured. Walking economy was evaluated during two walks performed at two different speeds (4.8 and 6.0 km ‧ h-1. Results. The VO2max was similar in both groups, as were the physiological responses during slow walking. The absolute oxygen uptake or oxygen uptake relative to body mass did not significantly differentiate the studied groups. The only indicator significantly differentiating the two groups was oxygen uptake relative to LBM. Conclusions. Body composition does not significantly affect walking economy at low speed, while during brisk walking, the economy is better in the HLBM vs. HBF group, provided that walking economy is presented as oxygen uptake relative to LBM. For this reason, we recommend this manner of oxygen uptake normalization in the evaluation of walking economy.

Identification of a sex pheromone of the chrysanthemum lace bug Corythucha marmorata (Hemiptera: Tingidae)

OpenAIRE

Watanabe, Kisaki; Shimizu, Nobuhiro

2017-01-01

Although the nymphs of Corythucha marmorata form clusters on the undersides of host plant leaves, as frequently observed for Hemiptera, the adults are scattered in the vicinity of the nymph population. By investigating the biological activities of volatile secretions from the adult, we found that the secretions activated male mounting behaviour. A chemical analysis revealed that borneol was a common component of the secretions from both sexes. The absolute configuration of the natural product...

Relationship between quantum walks and relativistic quantum mechanics

International Nuclear Information System (INIS)

Chandrashekar, C. M.; Banerjee, Subhashish; Srikanth, R.

2010-01-01

Quantum walk models have been used as an algorithmic tool for quantum computation and to describe various physical processes. This article revisits the relationship between relativistic quantum mechanics and the quantum walks. We show the similarities of the mathematical structure of the decoupled and coupled forms of the discrete-time quantum walk to that of the Klein-Gordon and Dirac equations, respectively. In the latter case, the coin emerges as an analog of the spinor degree of freedom. Discrete-time quantum walk as a coupled form of the continuous-time quantum walk is also shown by transforming the decoupled form of the discrete-time quantum walk to the Schroedinger form. By showing the coin to be a means to make the walk reversible and that the Dirac-like structure is a consequence of the coin use, our work suggests that the relativistic causal structure is a consequence of conservation of information. However, decoherence (modeled by projective measurements on position space) generates entropy that increases with time, making the walk irreversible and thereby producing an arrow of time. The Lieb-Robinson bound is used to highlight the causal structure of the quantum walk to put in perspective the relativistic structure of the quantum walk, the maximum speed of walk propagation, and earlier findings related to the finite spread of the walk probability distribution. We also present a two-dimensional quantum walk model on a two-state system to which the study can be extended.

Quantum Walks on the Line with Phase Parameters

Science.gov (United States)

Villagra, Marcos; Nakanishi, Masaki; Yamashita, Shigeru; Nakashima, Yasuhiko

In this paper, a study on discrete-time coined quantum walks on the line is presented. Clear mathematical foundations are still lacking for this quantum walk model. As a step toward this objective, the following question is being addressed: Given a graph, what is the probability that a quantum walk arrives at a given vertex after some number of steps? This is a very natural question, and for random walks it can be answered by several different combinatorial arguments. For quantum walks this is a highly non-trivial task. Furthermore, this was only achieved before for one specific coin operator (Hadamard operator) for walks on the line. Even considering only walks on lines, generalizing these computations to a general SU(2) coin operator is a complex task. The main contribution is a closed-form formula for the amplitudes of the state of the walk (which includes the question above) for a general symmetric SU(2) operator for walks on the line. To this end, a coin operator with parameters that alters the phase of the state of the walk is defined. Then, closed-form solutions are computed by means of Fourier analysis and asymptotic approximation methods. We also present some basic properties of the walk which can be deducted using weak convergence theorems for quantum walks. In particular, the support of the induced probability distribution of the walk is calculated. Then, it is shown how changing the parameters in the coin operator affects the resulting probability distribution.

Biological parameters and thermal requirements of the parasitoid Praon volucre (Hymenoptera: Braconidae) with Macrosiphum euphorbiae (Hemiptera: Aphididae) as host

NARCIS (Netherlands)

Conti, De B.F.; Bueno, V.H.P.; Sampaio, M.V.; Lenteren, van J.C.

2011-01-01

The effect of temperature on the biology of Praon volucre (Haliday, 1833) (Hymenoptera: Braconidae) in Macrosiphum euphorbiae (Thomas, 1878) (Hemiptera: Aphididae) hosts was studied and the thermal requirements of the parasitoid were determined. Experiments were carried out at 16, 19, 22, 25, and 28

Brochosome influence on parasitisation efficiency of Homalodisca coagulata (Say) (Hemiptera: Cicadellidae) egg masses by Gonatocerus ashmeadi Girault (Hymenoptera : Mymaridae)

NARCIS (Netherlands)

Velema, H.P.; Hemerik, L.; Hoddle, M.S.; Luck, R.F.

2005-01-01

1. Many cicadellid females in the tribe Proconiini (Hemiptera: Cicadellidae) cover their egg masses with specialised, usually rod-shaped, brochosomes as the eggs are being laid. The brochosomes are produced in Golgi complexes in the Malpighian tubules of Cicadellidae. In contrast to the gravid

Cognitive Resource Demands of Redirected Walking.

Science.gov (United States)

Bruder, Gerd; Lubas, Paul; Steinicke, Frank

2015-04-01

Redirected walking allows users to walk through a large-scale immersive virtual environment (IVE) while physically remaining in a reasonably small workspace. Therefore, manipulations are applied to virtual camera motions so that the user's self-motion in the virtual world differs from movements in the real world. Previous work found that the human perceptual system tolerates a certain amount of inconsistency between proprioceptive, vestibular and visual sensation in IVEs, and even compensates for slight discrepancies with recalibrated motor commands. Experiments showed that users are not able to detect an inconsistency if their physical path is bent with a radius of at least 22 meters during virtual straightforward movements. If redirected walking is applied in a smaller workspace, manipulations become noticeable, but users are still able to move through a potentially infinitely large virtual world by walking. For this semi-natural form of locomotion, the question arises if such manipulations impose cognitive demands on the user, which may compete with other tasks in IVEs for finite cognitive resources. In this article we present an experiment in which we analyze the mutual influence between redirected walking and verbal as well as spatial working memory tasks using a dual-tasking method. The results show an influence of redirected walking on verbal as well as spatial working memory tasks, and we also found an effect of cognitive tasks on walking behavior. We discuss the implications and provide guidelines for using redirected walking in virtual reality laboratories.

Occurrence of the Tamarix Leafhopper, Opsius stactogalus Fieber (Hemiptera: Cicadellidae), in Argentina.

Science.gov (United States)

Virla, Eduardo G; Logarzo, Guillermo A; Paradell, Susana L

2010-01-01

The paleartic tamarix leafhopper, Opsius stactogalus Fieber (Hemiptera: Cicadellidae), can reduce the growth of tamarisk due to the aggregate feeding imposed by their populations. The species was mentioned for Argentina in Metcalf's catalogue (1967) without locality or region reference, and the contributions on Cicadellidae published by many authors after Metcalf omitted this distributional data. Populations of O. stactogalus on Tamarix sp. were found in 12 sites between 28 degrees 48' to 39 degrees 17' S and 64 degrees 06' to 70 degrees 04' W, located in both the Neotropical and Andean biogeographic regions.

Positive messaging promotes walking in older adults.

Science.gov (United States)

Notthoff, Nanna; Carstensen, Laura L

2014-06-01

Walking is among the most cost-effective and accessible means of exercise. Mounting evidence suggests that walking may help to maintain physical and cognitive independence in old age by preventing a variety of health problems. However, older Americans fall far short of meeting the daily recommendations for walking. In 2 studies, we examined whether considering older adults' preferential attention to positive information may effectively enhance interventions aimed at promoting walking. In Study 1, we compared the effectiveness of positive, negative, and neutral messages to encourage walking (as measured with pedometers). Older adults who were informed about the benefits of walking walked more than those who were informed about the negative consequences of failing to walk, whereas younger adults were unaffected by framing valence. In Study 2, we examined within-person change in walking in older adults in response to positively- or negatively-framed messages over a 28-day period. Once again, positively-framed messages more effectively promoted walking than negatively-framed messages, and the effect was sustained across the intervention period. Together, these studies suggest that consideration of age-related changes in preferences for positive and negative information may inform the design of effective interventions to promote healthy lifestyles. Future research is needed to examine the mechanisms underlying the greater effectiveness of positively- as opposed to negatively-framed messages and the generalizability of findings to other intervention targets and other subpopulations of older adults. PsycINFO Database Record (c) 2014 APA, all rights reserved.

Treadmill walking of the pneumatic biped Lucy: Walking at different speeds and step-lengths

Science.gov (United States)

Vanderborght, B.; Verrelst, B.; Van Ham, R.; Van Damme, M.; Versluys, R.; Lefeber, D.

2008-07-01

Actuators with adaptable compliance are gaining interest in the field of legged robotics due to their capability to store motion energy and to exploit the natural dynamics of the system to reduce energy consumption while walking and running. To perform research on compliant actuators we have built the planar biped Lucy. The robot has six actuated joints, the ankle, knee and hip of both legs with each joint powered by two pleated pneumatic artificial muscles in an antagonistic setup. This makes it possible to control both the torque and the stiffness of the joint. Such compliant actuators are used in passive walkers to overcome friction when walking over level ground and to improve stability. Typically, this kind of robots is only designed to walk with a constant walking speed and step-length, determined by the mechanical design of the mechanism and the properties of the ground. In this paper, we show that by an appropriate control, the robot Lucy is able to walk at different speeds and step-lengths and that adding and releasing weights does not affect the stability of the robot. To perform these experiments, an automated treadmill was built

A review of Chinese tribe Achilini (Hemiptera: Fulgoromorpha: Achilidae), with descriptions of Paracatonidia webbeda gen. & sp. nov.

Science.gov (United States)

Long, Jian-Kun; Yang, Lin; Chen, Xiang-Sheng

2015-12-02

Planthoppers of the tribe Achilini (Hemiptera: Fulgoromorpha: Achilidae) from China, are reviewed. A key to the three genera of Chinese Achilini is given. A new genus and species of the tribe from southwestern China: Paracatonidia webbeda gen. & sp. nov., is described. A new genus and species record for China, Cixidia kasparyani Anufriev, is also given.

Complex of primary and secondary parasitoids (Hymenoptera: Encyrtidae and Signiphoridae) of Hypogeoccoccus spp. mealybugs (Hemiptera: Pseudococcidae) in the New World

Science.gov (United States)

Parasitoids, both primary and secondary (hyperparasitoids), of Hypogeococcus spp. mealybugs (Hemiptera: Pseudococcidae) are reviewed to report results of the surveys in the New World conducted during 2009–2017 for perspective natural enemies of the Harrisia cactus mealybug, Hypogeococcus sp., which ...

Population fluctuation of Empoasca sp. (Hemiptera: Cicadellidae in a physic nut crop in Mato Grosso do Sul

Directory of Open Access Journals (Sweden)

Denisar Paggioli de Carvalho

2016-01-01

Full Text Available Physic nut (Jatropha curcas L. is an oilseed, semi-evergreen shrub or small tree of the Euphorbiaceae family, whose seeds contain oil that can be processed into a high quality biofuel. However, there have been reports of arthropods feeding from its leaves, including the green leafhopper Empoasca sp. (Hemiptera: Cicadellidae. The large numbers of this insect, observed in certain periods of the year in many regions of Brazil, are causing damage to the oilseed crops. This study aims at evaluating the fluctuation in green leafhopper population in a physic nut crop in Dourados, Mato Grosso do Sul, to assess possible correlations with rainfall, maximum, average and minimum temperatures. This evaluation was conducted between March 2011 and July 2012. The largest Empoasca sp. populations were recorded in May and June, 2011, and between February and May, 2012. No significant correlation was observed between the weather parameters analyzed and the fluctuation in the Hemiptera population, but there was a trend toward higher population density during the warmer and rainier months.

Full revivals in 2D quantum walks

International Nuclear Information System (INIS)

Stefanak, M; Jex, I; Kollar, B; Kiss, T

2010-01-01

Recurrence of a random walk is described by the Polya number. For quantum walks, recurrence is understood as the return of the walker to the origin, rather than the full revival of its quantum state. Localization for two-dimensional quantum walks is known to exist in the sense of non-vanishing probability distribution in the asymptotic limit. We show, on the example of the 2D Grover walk, that one can exploit the effect of localization to construct stationary solutions. Moreover, we find full revivals of a quantum state with a period of two steps. We prove that there cannot be longer cycles for a four-state quantum walk. Stationary states and revivals result from interference, which has no counterpart in classical random walks.

Exploring topological phases with quantum walks

International Nuclear Information System (INIS)

Kitagawa, Takuya; Rudner, Mark S.; Berg, Erez; Demler, Eugene

2010-01-01

The quantum walk was originally proposed as a quantum-mechanical analog of the classical random walk, and has since become a powerful tool in quantum information science. In this paper, we show that discrete-time quantum walks provide a versatile platform for studying topological phases, which are currently the subject of intense theoretical and experimental investigations. In particular, we demonstrate that recent experimental realizations of quantum walks with cold atoms, photons, and ions simulate a nontrivial one-dimensional topological phase. With simple modifications, the quantum walk can be engineered to realize all of the topological phases, which have been classified in one and two dimensions. We further discuss the existence of robust edge modes at phase boundaries, which provide experimental signatures for the nontrivial topological character of the system.

Walking in Place Through Virtual Worlds

DEFF Research Database (Denmark)

Nilsson, Niels Chr.; Serafin, Stefania; Nordahl, Rolf

2016-01-01

Immersive virtual reality (IVR) is seemingly on the verge of entering the homes of consumers. Enabling users to walk through virtual worlds in a limited physical space presents a challenge. With an outset in a taxonomy of virtual travel techniques, we argue that Walking-in-Place (WIP) techniques...... constitute a promising approach to virtual walking in relation to consumer IVR. Subsequently we review existing approaches to WIP locomotion and highlight the need for a more explicit focus on the perceived naturalness of WIP techniques; i.e., the degree to which WIP locomotion feels like real walking....... Finally, we summarize work we have performed in order to produce more natural WIP locomotion and present unexplored topics which need to be address if WIP techniques are to provide perceptually natural walking experiences....

Self-Trapping Self-Repelling Random Walks

Science.gov (United States)

Grassberger, Peter

2017-10-01

Although the title seems self-contradictory, it does not contain a misprint. The model we study is a seemingly minor modification of the "true self-avoiding walk" model of Amit, Parisi, and Peliti in two dimensions. The walks in it are self-repelling up to a characteristic time T* (which depends on various parameters), but spontaneously (i.e., without changing any control parameter) become self-trapping after that. For free walks, T* is astronomically large, but on finite lattices the transition is easily observable. In the self-trapped regime, walks are subdiffusive and intermittent, spending longer and longer times in small areas until they escape and move rapidly to a new area. In spite of this, these walks are extremely efficient in covering finite lattices, as measured by average cover times.

Membracidae Colombianae

Directory of Open Access Journals (Sweden)

Richter Leopold

1954-12-01

Full Text Available El  trabajo  sobre una de las familias más interesantes de insectos, cuya publicación se inicia en el presente  número, ha sido compuesto lejos de toda literatura y de los laboratorios, en el  medio natural de los insectos, es decir : en los páramos de los Andes colombianos y de las selvas del Amazonas y Orinoco hasta las costas de  los océanos Atlántico y Pacífico.  No fue descrito insecto alguno que el autor no haya observado y estudiado en su propio ambiente natural. Puesto que en todos estos distintos ambientes se plantearon problemas diferentes. los cuales no podían ser concebidos y reconocidos ordenadamente y dentro de sus debidas relaciones, algo de esto se notará en el presente ensayo.

Membracidae peruanae

Directory of Open Access Journals (Sweden)

Richter Leopoldo

1958-09-01

Full Text Available La separación por especies de las pequeñas formas del género Membracis, se puede verificar únicamente según el dibujo del apéndice pronotal. Porque todos los demás caracteres usados por autores son inconstantes y solamente podrían ser usados como caracteres después de varios días de vida del adulto y si se cuenta con las influencias ambientales.  Los insectos coleccionados, sin ser minuciosamente limpiados y sin conocer su edad, no deben usarse para fijar ciertos caracteres como sistemáticos. Así, casi todas las formas del género Enchenopa pueden alimentarse de distintas especies de Vismia o de Eupatorium.  La primera planta, Vismia, esta cubierta por secreciones granulosas de color rojizo.

Effects of fertilization of four hemlock species on Adelges tsugae (Hemiptera: Adelgidae) growth and feeding preference of predators.

Science.gov (United States)

S.V. Joseph; James Hanula

2011-01-01

Understanding how fertilization affects host resistance to hemlock woolly adelgid, Adelges tsugae Annand (Hemiptera:Adelgidae), is important because fertilizers are often used to grow resistant selections to a suitable size for testing. We evaluated four hemlock species (Tsuga) under three different fertilizer regimes to assess whether fertility affected resistance to...

A new species of Tamarixia Mercet (Hymenoptera, Eulophidae, parasitoid of Trioza aguacate Hollis & Martin (Hemiptera, Triozidae in Mexico

Directory of Open Access Journals (Sweden)

Zoya Yefremova

2014-01-01

Full Text Available Tamarixia aguacatensis Yefremova, sp. n. (Hymenoptera: Eulophidae: Tetrastichinae is described from Mexico as a parasitoid of the avocado psyllid, Trioza aguacate Hollis & Martin (Hemiptera: Triozidae. Trioza aguacate is a serious pest of avocado, Persea americana Miller. A key to the species of Tamarixia Mercet in Mexico is given.

Walking dreams in congenital and acquired paraplegia.

Science.gov (United States)

Saurat, Marie-Thérèse; Agbakou, Maité; Attigui, Patricia; Golmard, Jean-Louis; Arnulf, Isabelle

2011-12-01

To test if dreams contain remote or never-experienced motor skills, we collected during 6 weeks dream reports from 15 paraplegics and 15 healthy subjects. In 9/10 subjects with spinal cord injury and in 5/5 with congenital paraplegia, voluntary leg movements were reported during dream, including feelings of walking (46%), running (8.6%), dancing (8%), standing up (6.3%), bicycling (6.3%), and practicing sports (skiing, playing basketball, swimming). Paraplegia patients experienced walking dreams (38.2%) just as often as controls (28.7%). There was no correlation between the frequency of walking dreams and the duration of paraplegia. In contrast, patients were rarely paraplegic in dreams. Subjects who had never walked or stopped walking 4-64 years prior to this study still experience walking in their dreams, suggesting that a cerebral walking program, either genetic or more probably developed via mirror neurons (activated when observing others performing an action) is reactivated during sleep. Copyright © 2011 Elsevier Inc. All rights reserved.

Quantum snake walk on graphs

International Nuclear Information System (INIS)

Rosmanis, Ansis

2011-01-01

I introduce a continuous-time quantum walk on graphs called the quantum snake walk, the basis states of which are fixed-length paths (snakes) in the underlying graph. First, I analyze the quantum snake walk on the line, and I show that, even though most states stay localized throughout the evolution, there are specific states that most likely move on the line as wave packets with momentum inversely proportional to the length of the snake. Next, I discuss how an algorithm based on the quantum snake walk might potentially be able to solve an extended version of the glued trees problem, which asks to find a path connecting both roots of the glued trees graph. To the best of my knowledge, no efficient quantum algorithm solving this problem is known yet.

Limited predation potential by adult and larval lady beetles (Coleoptera: Coccinellidae) on Nezara viridula (Hemiptera: Pentatomidae) eggs and nymphs

Science.gov (United States)

The Coccinellidae (Coleoptera) co-occur in many habitats with many arthropods that are of suitable size as prey. The Pentatomidae (Hemiptera) are one such group of insects with eggs and early instars that could be susceptible to predation by Coccinellidae. The objective of this laboratory study wa...

Rapid Communication. Tamarixia monesus (Walker (Hym.: Eulophidae parasitoid of Bactericera tremblayi (Wagner, 1961 (Hemiptera: Triozidae in Iran

Directory of Open Access Journals (Sweden)

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.

An unusual new species of Hallodapomimus Herczek, 2000 from the Eocene Baltic amber (Hemiptera, Heteroptera, Miridae, Phylinae

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Aleksander Herczek

2015-03-01

Full Text Available Hallodapomimus antennatus sp. n. (Hemiptera: Heteroptera, Miridae, Phylinae, Hallodapini is described from a macropterous female found in Eocene Baltic amber. The new species can be recognized readily from the other species of the genus, mainly due to its unusual second antennal segment. A key for the identification of all known fossil Hallodapini is presented.

Portanus Ball: descrição de uma espécie nova (Hemiptera, Cicadellidae, Xestocephalinae

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Adenomar Neves de Carvalho

2004-01-01

Full Text Available Portanus dubius sp. nov. é descrita e ilustrada a partir de espécimens que foram coletados com armadilha Malaise durante um levantamento entomológico no Estado do Paraná, Brasil (PROFAUPAR.Portanus Ball: description of a new species (Hemiptera, Cicadellidae, Xestocephalinae. Portanus dubius sp. nov. is described and illustrated. The specimens were collected with Malaise trap during an entomological inventory in Paraná State, Brazil (PROFAUPAR.

Scale insects (Hemiptera: Coccomorpha) on sugarcane in Colombia, with description of a new species of Tillancoccus Ben-Dov (Coccidae).

Science.gov (United States)

Caballero, Alejandro; Ramos-Portilla, Andrea Amalia; Kondo, Takumasa

2017-05-02

Herein we describe a new species, Tillancoccus koreguajae Caballero & Ramos, sp. n. (Hemiptera: Coccidae) from Colombia collected on sugarcane. Pinnaspis strachani (Cooley) is also recorded on sugarcane for the first time worldwide. An updated list of seven species of Coccomorpha on sugarcane in Colombia is provided, including information on its distribution, biology, and mutualistic ants for each species. Seven species of scale insects (Hemiptera: Coccomorpha) have been recorded previously on sugarcane, Saccharum officinarum L. (Poaceae) in Colombia: Pseudococcidae: Dysmicoccus boninsis (Kuwana), D. brevipes (Cockerell), Pseudococcus calceolariae (Maskell), Saccharicoccus sacchari (Cockerell); Coccidae: Pulvinaria elongata Newstead; Diaspididae: Duplachionaspis divergens (Green) and Serenaspis minima (Maskell). However, the record of S. minima in Colombia is considered doubtful as there are no voucher specimens from Colombia and because the distribution of this species is currently limited to the Australasian region. Pseudococcus calceolariae is present in Colombia but its record on sugarcane is also doubtful. A taxonomic key for the identification of scale insects on sugarcane in Colombia is provided.

More Adults Are Walking

Centers for Disease Control (CDC) Podcasts

2012-07-31

This podcast is based on the August 2012 CDC Vital Signs report. While more adults are walking, only half get the recommended amount of physical activity. Listen to learn how communities, employers, and individuals may help increase walking.  Created: 7/31/2012 by Centers for Disease Control and Prevention (CDC).   Date Released: 8/7/2012.

Minnesota Walk-In Access Sites

Data.gov (United States)

Minnesota Department of Natural Resources — The Minnesota Walk-In Access site (WIA) GIS data represents areas of private land that have been made open to the public for the purpose of walk-in (foot travel)...

Let's Walk Outdoors! Self-Paced Walking Outdoors Improves Future Intention to Exercise in Women With Obesity.

Science.gov (United States)

Krinski, Kleverton; Machado, Daniel G S; Lirani, Luciana S; DaSilva, Sergio G; Costa, Eduardo C; Hardcastle, Sarah J; Elsangedy, Hassan M

2017-04-01

In order to examine whether environmental settings influence psychological and physiological responses of women with obesity during self-paced walking, 38 women performed two exercise sessions (treadmill and outdoors) for 30 min, where oxygen uptake, heart rate, ratings of perceived exertion, affect, attentional focus, enjoyment, and future intentions to walk were analyzed. Physiological responses were similar during both sessions. However, during outdoor exercise, participants displayed higher externally focused attention, positive affect, and lower ratings of perceived exertion, followed by greater enjoyment and future intention to participate in outdoor walking. The more externally focused attention predicted greater future intentions to participate in walking. Therefore, women with obesity self-selected an appropriate exercise intensity to improve fitness and health in both environmental settings. Also, self-paced outdoor walking presented improved psychological responses. Health care professionals should consider promoting outdoor forms of exercise to maximize psychological benefits and promote long-term adherence to a physically active lifestyle.

Lower limb joint moment during walking in water.

Science.gov (United States)

Miyoshi, Tasuku; Shirota, Takashi; Yamamoto, Shin-Ichiro; Nakazawa, Kimitaka; Akai, Masami

2003-11-04

Walking in water is a widely used rehabilitation method for patients with orthopedic disorders or arthritis, based on the belief that the reduction of weight in water makes it a safer medium and prevents secondary injuries of the lower-limb joints. To our knowledge, however, no experimental data on lower-limb joint moment during walking in water is available. The aim of this study was to quantify the joint moments of the ankle, knee, and hip during walking in water in comparison with those on land. Eight healthy volunteers walked on land and in water at a speed comfortable for them. A video-motion analysis system and waterproof force platform were used to obtain kinematic data and to calculate the joint moments. The hip joint moment was shown to be an extension moment almost throughout the stance phase during walking in water, while it changed from an extension- to flexion-direction during walking on land. The knee joint moment had two extension peaks during walking on land, whereas it had only one extension peak, a late one, during walking in water. The ankle joint moment during walking in water was considerably reduced but in the same direction, plantarflexion, as that during walking on land. The joint moments of the hip, knee, and ankle were not merely reduced during walking in water; rather, inter-joint coordination was totally changed.

Thlastocoris laetus Mayr, 1866 (hemiptera: coreidae: acanthocerini) nueva plaga de la piña

OpenAIRE

Couturier,G.; Brailovsky,H.; Zucchi,R.A.

1993-01-01

Thlastocoris laetus (Hemiptera: Coreidae) es por primera vez señalado como plaga de la piña para la Amazonia brasileña y peruana comentando los daños que ocasiona. Se presenta la caracterización morfológica de esta especie, comparandola con Lybindus dichrous que también es reconocido como plaga de la piña en el Brasil. La distribución geográfica de ambas especies es citada.

Continuous-time quantum walks on star graphs

International Nuclear Information System (INIS)

Salimi, S.

2009-01-01

In this paper, we investigate continuous-time quantum walk on star graphs. It is shown that quantum central limit theorem for a continuous-time quantum walk on star graphs for N-fold star power graph, which are invariant under the quantum component of adjacency matrix, converges to continuous-time quantum walk on K 2 graphs (complete graph with two vertices) and the probability of observing walk tends to the uniform distribution.

Walk well: a randomised controlled trial of a walking intervention for adults with intellectual disabilities: study protocol

Science.gov (United States)

2013-01-01

Background Walking interventions have been shown to have a positive impact on physical activity (PA) levels, health and wellbeing for adult and older adult populations. There has been very little work carried out to explore the effectiveness of walking interventions for adults with intellectual disabilities. This paper will provide details of the Walk Well intervention, designed for adults with intellectual disabilities, and a randomised controlled trial (RCT) to test its effectiveness. Methods/design This study will adopt a RCT design, with participants allocated to the walking intervention group or a waiting list control group. The intervention consists of three PA consultations (baseline, six weeks and 12 weeks) and an individualised 12 week walking programme. A range of measures will be completed by participants at baseline, post intervention (three months from baseline) and at follow up (three months post intervention and six months from baseline). All outcome measures will be collected by a researcher who will be blinded to the study groups. The primary outcome will be steps walked per day, measured using accelerometers. Secondary outcome measures will include time spent in PA per day (across various intensity levels), time spent in sedentary behaviour per day, quality of life, self-efficacy and anthropometric measures to monitor weight change. Discussion Since there are currently no published RCTs of walking interventions for adults with intellectual disabilities, this RCT will examine if a walking intervention can successfully increase PA, health and wellbeing of adults with intellectual disabilities. Trial registration ISRCTN: ISRCTN50494254 PMID:23816316

Fractional scaling of quantum walks on percolation lattices

International Nuclear Information System (INIS)

Kendon, Viv; Knott, Paul; Leung, Godfrey; Bailey, Joe

2011-01-01

Quantum walks can be used to model processes such as transport in spin chains and bio-molecules. The enhanced spreading and mixing properties of quantum walks compared with their classical counterparts have been well-studied on regular structures and also shown to be sensitive to defects and imperfections. Using numerical simulation, we study the spreading properties of quantum walks on percolation lattices for both bond and site percolation. The randomly missing edges or sites provide a controlled amount of disorder in the regular Cartesian lattice. In one dimension (the line) we introduce a simple model of quantum tunneling to allow the walk to proceed past the missing edges or sites. This allows the quantum walk to spread faster than a classical random walk for short times, but at longer times the disorder localises the quantum walk. In two dimensions, we observe fractional scaling of the spreading with the number of steps of the walk. For percolation above the 85% level, we obtain faster spreading than classical random walks on the full lattice.

Mechanical design of walking machines.

Science.gov (United States)

Arikawa, Keisuke; Hirose, Shigeo

2007-01-15

The performance of existing actuators, such as electric motors, is very limited, be it power-weight ratio or energy efficiency. In this paper, we discuss the method to design a practical walking machine under this severe constraint with focus on two concepts, the gravitationally decoupled actuation (GDA) and the coupled drive. The GDA decouples the driving system against the gravitational field to suppress generation of negative power and improve energy efficiency. On the other hand, the coupled drive couples the driving system to distribute the output power equally among actuators and maximize the utilization of installed actuator power. First, we depict the GDA and coupled drive in detail. Then, we present actual machines, TITAN-III and VIII, quadruped walking machines designed on the basis of the GDA, and NINJA-I and II, quadruped wall walking machines designed on the basis of the coupled drive. Finally, we discuss walking machines that travel on three-dimensional terrain (3D terrain), which includes the ground, walls and ceiling. Then, we demonstrate with computer simulation that we can selectively leverage GDA and coupled drive by walking posture control.

Thermodynamics and entanglements of walks under stress

International Nuclear Information System (INIS)

Janse van Rensburg, E J; Orlandini, E; Tesi, M C; Whittington, S G

2009-01-01

We use rigorous arguments and Monte Carlo simulations to study the thermodynamics and the topological properties of self-avoiding walks on the cubic lattice subjected to an external force f. The walks are anchored at one or both endpoints to an impenetrable plane at Z = 0 and the force is applied in the Z-direction. If a force is applied to the free endpoint of an anchored walk, then a model of pulled walks is obtained. If the walk is confined to a slab and a force is applied to the top bounding plane, then a model of stretched walks is obtained. For both models we prove the existence of the limiting free energy for any value of the force and we show that, for compressive forces, the thermodynamic properties of the two models differ substantially. For pulled walks we prove the existence of a phase transition that, by numerical simulation, we estimate to be second order and located at f = 0. By using a pattern theorem for large positive forces we show that almost all sufficiently long stretched walks are knotted. We examine the entanglement complexity of stretched and pulled walks; our numerical results show a sharp reduction with increasing pulling and stretching forces. Finally, we also examine models of pulled and stretched loops. We prove the existence of limiting free energies in these models and consider the knot probability numerically as a function of the applied pulling or stretching force

Walking, running, and resting under time, distance, and average speed constraints: optimality of walk-run-rest mixtures.

Science.gov (United States)

Long, Leroy L; Srinivasan, Manoj

2013-04-06

On a treadmill, humans switch from walking to running beyond a characteristic transition speed. Here, we study human choice between walking and running in a more ecological (non-treadmill) setting. We asked subjects to travel a given distance overground in a given allowed time duration. During this task, the subjects carried, and could look at, a stopwatch that counted down to zero. As expected, if the total time available were large, humans walk the whole distance. If the time available were small, humans mostly run. For an intermediate total time, humans often use a mixture of walking at a slow speed and running at a higher speed. With analytical and computational optimization, we show that using a walk-run mixture at intermediate speeds and a walk-rest mixture at the lowest average speeds is predicted by metabolic energy minimization, even with costs for transients-a consequence of non-convex energy curves. Thus, sometimes, steady locomotion may not be energy optimal, and not preferred, even in the absence of fatigue. Assuming similar non-convex energy curves, we conjecture that similar walk-run mixtures may be energetically beneficial to children following a parent and animals on long leashes. Humans and other animals might also benefit energetically from alternating between moving forward and standing still on a slow and sufficiently long treadmill.

Walking training associated with virtual reality-based training increases walking speed of individuals with chronic stroke: systematic review with meta-analysis

OpenAIRE

Juliana M. Rodrigues-Baroni; Lucas R. Nascimento; Louise Ada; Luci F. Teixeira-Salmela

2014-01-01

OBJECTIVE: To systematically review the available evidence on the efficacy of walking training associated with virtual reality-based training in patients with stroke. The specific questions were: Is walking training associated with virtual reality-based training effective in increasing walking speed after stroke? Is this type of intervention more effective in increasing walking speed, than non-virtual reality-based walking interventions? METHOD: A systematic review with meta-analysis of rando...

Neighborhood preference, walkability and walking in overweight/obese men.

Science.gov (United States)

Norman, Gregory J; Carlson, Jordan A; O'Mara, Stephanie; Sallis, James F; Patrick, Kevin; Frank, Lawrence D; Godbole, Suneeta V

2013-03-01

To investigate whether self-selection moderated the effects of walkability on walking in overweight and obese men. 240 overweight and obese men completed measures on importance of walkability when choosing a neighborhood (selection) and preference for walkable features in general (preference). IPAQ measured walking. A walkbility index was derived from geographic information systems (GIS). Walkability was associated with walking for transportation (p = .027) and neighborhood selection was associated with walking for transportation (p = .002) and total walking (p = .001). Preference was associated with leisure walking (p = .045) and preference moderated the relationship between walkability and total walking (p = .059). Walkability and self-selection are both important to walking behavior.

First report of Idiopterus nephrelepidis Davis, 1909 (Hemiptera: Aphididae from Bulgaria

Directory of Open Access Journals (Sweden)

Elena Tasheva-Terzieva

2011-11-01

Full Text Available Idiopterus nephrelepidis (Hemiptera: Aphididae is reported for the first time in Bulgaria on ornamental ferns in four greenhouses in Sofia and Varna. Dense colonies of apterous viviparous females and larvae were observed. The established host plants are Nephrolepis exaltata, Asplenium nidus and Pteris cretica. Infested ferns exhibit leaf deformation. The aphids were reared in laboratory conditions for four months. A morphometric study of apterae was carried out. Taking into account the presence of host plants of I. nephrelepidis in Bulgaria which are native to the local flora and the reports of the aphid from the Balkan area, it may spread in the country outdoors.

Nordic Walking Practice Might Improve Plantar Pressure Distribution

Science.gov (United States)

Perez-Soriano, Pedro; Llana-Belloch, Salvador; Martinez-Nova, Alfonso; Morey-Klapsing, G.; Encarnacion-Martinez, Alberto

2011-01-01

Nordic walking (NW), characterized by the use of two walking poles, is becoming increasingly popular (Morgulec-Adamowicz, Marszalek, & Jagustyn, 2011). We studied walking pressure patterns of 20 experienced and 30 beginner Nordic walkers. Plantar pressures from nine foot zones were measured during trials performed at two walking speeds (preferred…

Design with the feet: walking methods and participatory design

DEFF Research Database (Denmark)

Kanstrup, Anne Marie; Bertelsen, Pernille; Madsen, Jacob Østergaard

2014-01-01

This paper presents an analysis of walking methods and their relation to participatory design (PD). The paper includes a study of walking methods found in the literature and an empirical study of transect walks in a PD project. From this analysis, we identify central attributes of, and challenges...... to, PD walks. Walking with people in the context of design is a natural activity for the participatory designer, who acknowledges the importance of immersion and relationships in design. However, the various intentions of walking approaches indicate an underacknowledged awareness of walking methods...

Does getting a dog increase recreational walking?

Directory of Open Access Journals (Sweden)

Knuiman Matthew W

2008-03-01

Full Text Available Abstract Background This study examines changes in socio-demographic, environmental and intrapersonal factors associated with dog acquisition in non-dog owners at baseline to 12-months follow-up and the effect of dog acquisition on minutes per week of recreational walking. Methods RESIDE study participants completed self-administered questionnaires (baseline and 12-months follow-up measuring physical activity, dog ownership, dog walking behavior as well as environmental, intrapersonal and socio-demographic factors. Analysis was restricted to 'Continuing non-owners' (i.e., non-owners at both baseline and follow-up; n = 681 and 'New dog owners' (i.e., non-owners who acquired a dog by follow-up; n = 92. Results Overall, 12% of baseline non-owners had acquired a dog at follow-up. Dog acquisition was associated with working and having children at home. Those who changed from single to couple marital status were also more likely to acquire a dog. The increase in minutes of walking for recreation within the neighborhood from baseline to follow-up was 48 minutes/week for new dog owners compared with 12 minutes/week for continuing non-owners (p p p > 0.05 after further adjustment for change in baseline to follow-up variables. Increase in intention to walk was the main factor contributing to attenuation of the effect of dog acquisition on recreational walking. Conclusion This study used a large representative sample of non-owners to examine the relationship between dog acquisition and recreational walking and provides evidence to suggest that dog acquisition leads to an increase in walking. The most likely mechanism through which dog acquisition facilitates increased physical activity is through behavioral intention via the dog's positive effect on owner's cognitive beliefs about walking, and through the provision of motivation and social support for walking. The results suggest that behavioral intention mediates the relationship between dog acquisition

Probability distributions for Markov chain based quantum walks

Science.gov (United States)

Balu, Radhakrishnan; Liu, Chaobin; Venegas-Andraca, Salvador E.

2018-01-01

We analyze the probability distributions of the quantum walks induced from Markov chains by Szegedy (2004). The first part of this paper is devoted to the quantum walks induced from finite state Markov chains. It is shown that the probability distribution on the states of the underlying Markov chain is always convergent in the Cesaro sense. In particular, we deduce that the limiting distribution is uniform if the transition matrix is symmetric. In the case of a non-symmetric Markov chain, we exemplify that the limiting distribution of the quantum walk is not necessarily identical with the stationary distribution of the underlying irreducible Markov chain. The Szegedy scheme can be extended to infinite state Markov chains (random walks). In the second part, we formulate the quantum walk induced from a lazy random walk on the line. We then obtain the weak limit of the quantum walk. It is noted that the current quantum walk appears to spread faster than its counterpart-quantum walk on the line driven by the Grover coin discussed in literature. The paper closes with an outlook on possible future directions.

Flight Muscle Dimorphism and Heterogeneity in Flight Initiation of Field-Collected Triatoma infestans (Hemiptera: Reduviidae)

OpenAIRE

Gurevitz, Juan M.; Kitron, Uriel; Gürtler, Ricardo E.

2007-01-01

Recent experiments demonstrated that most field-collected Triatoma infestans (Klug) (Hemiptera: Reduviidae) adults from northern Argentina either never initiated flight or did so repeatedly in both sexes. This pattern could not be explained by sex, adult age, weight, weight-to-length ratio (W/L), or chance. We examined whether bugs that never initiated flight possessed developed flight muscles, and whether flight muscle mass relative to total body mass (FMR) was related to the probability of ...

A new species in the genus Crisicoccus Ferris (Hemiptera: Coccomorpha: Pseudococcidae), with a key to Chinese species.

Science.gov (United States)

Zhang, Jiang-Tao; Wu, San-An

2016-06-01

A new mealybug, Crisicoccus ziziphus sp. nov. (Hemiptera: Coccomorpha: Pseudococcidae), collected on the leaves and twigs of Ziziphus jujuba (Rhamnaceae), is described from China. All the female developmental stages (adult, third-instar, second-instar and first-instar nymphs) are described and illustrated. Keys are provided to separate the female instars and to identify adult females of Crisicoccus species from China.

Review of the genus Neotetricodes Zhang et Chen (Hemiptera: Fulgoromorpha: Issidae) with description of two new species.

Science.gov (United States)

Chang, Zhi-Min; Yang, Lin; Zhang, Zheng-Guang; Chen, Xiang-Sheng

2015-12-11

Two new species of the issid genus Neotetricodes Zhang et Chen (Hemiptera: Fulgoromorpha: Issidae): Neotetricodes longispinus Chang et Chen sp. nov. (China: Yunnan) and Neotetricodes xiphoideus Chang et Chen sp. nov. (China: Yunnan) are described and illustrated. The generic characteristic is redefined. A checklist and key to the species of the genus are provided. The female genitalia of the genus are firstly described.

Rearing and Release of Megamelus scutellaris Berg (Hemiptera: Delphacidae) for Biological Control of Water hyacinth in 2015

Science.gov (United States)

2017-06-01

Hemiptera: Delphacidae) for Biological Control of Waterhyacinth in 2015 by Jan Freedman and Nathan Harms PURPOSE: Waterhyacinth biological control ... control agents. Three insects were released in the United States for biological control of waterhyacinth during the 1970s; two weevils, Neochetina...content) and competitive interactions with other biological control agents (e.g., Neochetina spp.), though their consideration in other biological

Walking around to grasp interaction

DEFF Research Database (Denmark)

Lykke, Marianne; Jantzen, Christian

2013-01-01

The paper presents experiences from a study using walk-alongs to provide insight into museum visitors’ experience with interactive features of sound art installations. The overall goal of the study was to learn about the participants’ opinions and feelings about the possibility of interaction...... with the sound installations. The aim was to gain an understanding of the role of the in-teraction, if interaction makes a difference for the understanding of the sound art. 30 walking interviews were carried out at ZKM, Karlsruhe with a total of 57 museum guests, individuals or groups. During the walk......-alongs the research-ers acted as facilitators and partners in the engagement with the sound installa-tions. The study provided good insight into advantages and challenges with the walk-along method, for instance the importance of shared, embodied sensing of space for the understanding of the experience. The common...

Cell phones change the way we walk.

Science.gov (United States)

Lamberg, Eric M; Muratori, Lisa M

2012-04-01

Cell phone use among pedestrians leads to increased cognitive distraction, reduced situation awareness and increases in unsafe behavior. Performing a dual-task, such as talking or texting with a cell phone while walking, may interfere with working memory and result in walking errors. At baseline, thirty-three participants visually located a target 8m ahead; then vision was occluded and they were instructed to walk to the remembered target. One week later participants were assigned to either walk, walk while talking on a cell phone, or walk while texting on a cell phone toward the target with vision occluded. Duration and final location of the heel were noted. Linear distance traveled, lateral angular deviation from the start line, and gait velocity were derived. Changes from baseline to testing were analyzed with paired t-tests. Participants engaged in cell phone use presented with significant reductions in gait velocity (texting: 33% reduction, p=0.01; talking: 16% reduction, p=0.02). Moreover, participants who were texting while walking demonstrated a 61% increase in lateral deviation (p=0.04) and 13% increase in linear distance traveled (p=0.03). These results suggest that the dual-task of walking while using a cell phone impacts executive function and working memory and influences gait to such a degree that it may compromise safety. Importantly, comparison of the two cell phone conditions demonstrates texting creates a significantly greater interference effect on walking than talking on a cell phone. Copyright © 2011 Elsevier B.V. All rights reserved.

Urban walking: Perspectives of locals and tourists

Directory of Open Access Journals (Sweden)

Farkić Jelena

2015-01-01

Full Text Available Urban planners and architects have done extensive research on walk ability: what it means and how it correlates with urban design and quality of life of the locals, however, it has been hitherto neglected from the aspect of tourism studies. Many cities worldwide are or tend to be walkable as this leads to more sustainable and prosperous communities. In addition, walking-friendly environments greatly cater for leisure and tourism, as in many cities, walking is an integral part of tourist experience. Therefore, tourism industry can be of tremendous help for the city authorities in understanding walkers' needs and experiences. Taking into account both the locals and tourists, this research sought to: (1 determine the most frequently utilized modes of transportation in Novi Sad in Serbia and Koper in Slovenia; (2 assess thier reasons for walking and perception of the quality of pedestrian infrastructure; and (3 evaluate the psychometric properties of the questionnaire designed for the purpose of this study. The results show that the great majority of respondents walk in these two cities. The locals walk primarily to achieve physical fitness, whereas tourists walk primarily to explore the urban spaces. This makes more space for tourism as it combines a competitive supply able to meet visitors' expectations with a positive contribution to the sustainable development of cities and well-being of their residents. Furthermore, this study contributes to emphasizing walking as a sustainable form of mobility in urban environment and can be the impetus for profiling Novi Sad and Koper as walking-friendly cities.

Occurrence of the Tamarix Leafhopper, Opsius stactogalus Fieber (Hemiptera: Cicadellidae), in Argentina

Science.gov (United States)

Virla, Eduardo G.; Logarzo, Guillermo A.; Paradell, Susana L.

2010-01-01

The paleartic tamarix leafhopper, Opsius stactogalus Fieber (Hemiptera: Cicadellidae), can reduce the growth of tamarisk due to the aggregate feeding imposed by their populations. The species was mentioned for Argentina in Metcalf's catalogue (1967) without locality or region reference, and the contributions on Cicadellidae published by many authors after Metcalf omitted this distributional data. Populations of O. stactogalus on Tamarix sp. were found in 12 sites between 28° 48′ to 39° 17′ S and 64° 06′ to 70° 04′ W, located in both the Neotropical and Andean biogeographic regions. PMID:20578887

PRIMER REPORTE DE LA PRESENCIA DE Diaphorina citri (HEMIPTERA: LIVIIDAE EN MANABÍ

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José Bernardo Navarrete Cedeño

2016-12-01

Full Text Available Diaphorina citri (Hemiptera: Liviidae, conocido como el psílido asiático de los cítricos, es considerada una plaga clave de la citricultura mundial, debido a que es vector de la bacteria “Candidatus Liberibacter”, agente causal de la enfermedad “Huanglongbing”, que tiene efectos letales sobre vegetales dentro de la familia Rutaceae. En este documento se reporta la presencia de D. citri infestando Murraya spp., un arbusto de la familia Rutaceae, en la zona urbana del cantón Portoviejo. Este es el primer reporte de la plaga en la provincia de Manabí-Ecuador

Dopluise (Hemiptera: Coccoidea geassosieer met die wipstertmier, Crematogaster peringueyi Emery (Hymenoptera: Formicidae

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Johannes H. Giliomee

2015-02-01

Full Text Available Neste van die wipstertmier, Crematogaster peringueyi (Hymenoptera: Formicidae, is op verskeie plekke langs die kus van die Wes-Kaap versamel. Die doel was om vas te stel watter dopluisagtiges (Hemiptera: Coccoidea in die neste in assosiasie met hierdie miere leef. Dopluise van drie families, naamlik die Pseudococcidae (witluise, Coccidae (sagtedopluise en Kerriidae (lakdopluise is in die neste gevind, almal bekend daarvoor dat hulle heuningdou afskei. Hierdie mutualistiese verhouding tussen die miere en dopluise, bekend as mirmekofilie, is fakultatief van aard. Die wipstertmier blyk ook nie spesifiek te wees wat betref die plant waarop hulle nes maak nie.

Description of a new genus, Galgoria gen. nov. (Hemiptera: Cicadidae: Cicadinae: Leptopsaltriini: Leptopsaltriina).

Science.gov (United States)

Lee, Young June

2016-05-10

A new cicada genus, Galgoria gen. nov., is described with Tanna herzbergi Schmidt, 1932 (from southern China) as its type species, which is placed in the subtribe Leptopsaltriina Moulton, 1923 of the tribe Leptopsaltriini Moulton, 1923 in the subfamily Cicadinae Latreille, 1802 (Hemiptera: Cicadidae). Tanna herzbergi Schmidt, 1932 is transferred from Tanna Distant, 1905 to Galgoria gen. nov. to become Galgoria herzbergi (Schmidt, 1932) comb. nov. Tanna apicalis Chen, 1940 syn. nov. and Tanna pseudocalis Lei & Chou, 1997 syn. nov. are synonymized here with Galgoria herzbergi (Schmidt, 1932) comb. nov.

Fungal flora of the digestive tract of Triatoma infestans (Hemiptera: Reduviidae from Argentina Flora fúngica de tractos digestivos en Triatoma infestans (Hemiptera: Reduviidae en Argentina

Directory of Open Access Journals (Sweden)

G. A. Marti

Full Text Available A survey of the fungal microbiota of the digestive tract of Triatoma infestans (Klug (Hemiptera: Reduviidae adults was carried out. Insects captured in the field from different provinces in Argentina, as well as individuals reared in artificial colonies, were used for dissection. Axenic cultures of the fungal species were identified and were deposited with mycological collections at La Plata , Argentina. A total of 33 fungal species, with the exception of three that were mycelia sterilia, belonging to 11 genera were identified. Thirty two species belonged to Ascomycota (Eurotiomycetes and Sordariomycetes and one to Zygomycota (Zygomycetes. The genera with the greatest number of species were Penicillium (15, Aspergillus (5, and Cladosporium (2. Among the isolated fungi, some of the species were entomopathogenic or pathogens of humans and other animals.En el presente estudio se realizó un relevamiento de la flora fúngica microbiana en tractos digestivos de adultos de Triatoma infestans (Klug (Hemiptera: Reduviidae. Se disecaron insectos capturados del campo en diferentes provincias Argentinas, así como también se utilizaron individuos de una colonia artificial. Fueron realizados cultivos axénicos de las especies fúngicas aisladas, los que fueron identificados y luego depositados en las colecciones de hongos entomopatógenos del CEPAVE La Plata , Argentina. Fueron identificadas 33 especies fúngicas perteneciente a 11 géneros. Treinta y dos especies pertenecen a Ascomycota (Eurotiomycetes y Sordariomycetes y una a Zygomycota (Zygomycetes. Los géneros con mayor número de especies fueron Penicillium (15, Aspergillus (5, y Cladosporium (2. Entre los aislamientos fúngicos, algunas de las especies encontradas son entomopatogénicas o patógenas de humanos y otros animales.

Lévy Walks Suboptimal under Predation Risk.

Directory of Open Access Journals (Sweden)

Masato S Abe

2015-11-01

Full Text Available A key challenge in movement ecology is to understand how animals move in nature. Previous studies have predicted that animals should perform a special class of random walks, called Lévy walk, to obtain more targets. However, some empirical studies did not support this hypothesis, and the relationship between search strategy and ecological factors is still unclear. We focused on ecological factors, such as predation risk, and analyzed whether Lévy walk may not be favored. It was remarkable that the ecological factors often altered an optimal search strategy from Lévy walk to Brownian walk, depending on the speed of the predator's movement, density of predators, etc. This occurred because higher target encounter rates simultaneously led searchers to higher predation risks. Our findings indicate that animals may not perform Lévy walks often, and we suggest that it is crucial to consider the ecological context for evaluating the search strategy performed by animals in the field.

Lévy Walks Suboptimal under Predation Risk

Science.gov (United States)

Abe, Masato S.; Shimada, Masakazu

2015-01-01

A key challenge in movement ecology is to understand how animals move in nature. Previous studies have predicted that animals should perform a special class of random walks, called Lévy walk, to obtain more targets. However, some empirical studies did not support this hypothesis, and the relationship between search strategy and ecological factors is still unclear. We focused on ecological factors, such as predation risk, and analyzed whether Lévy walk may not be favored. It was remarkable that the ecological factors often altered an optimal search strategy from Lévy walk to Brownian walk, depending on the speed of the predator’s movement, density of predators, etc. This occurred because higher target encounter rates simultaneously led searchers to higher predation risks. Our findings indicate that animals may not perform Lévy walks often, and we suggest that it is crucial to consider the ecological context for evaluating the search strategy performed by animals in the field. PMID:26544687

Scaling of the atmosphere of self-avoiding walks

Energy Technology Data Exchange (ETDEWEB)

Owczarek, A L [Department of Mathematics and Statistics, The University of Melbourne, Victoria 3010 (Australia); Prellberg, T [School of Mathematical Sciences, Queen Mary, University of London, Mile End Road, London E1 4NS (United Kingdom)], E-mail: a.owczarek@ms.unimelb.edu.au, E-mail: t.prellberg@qmul.ac.uk

2008-09-19

The number of free sites next to the end of a self-avoiding walk is known as the atmosphere of the walk. The average atmosphere can be related to the number of configurations. Here we study the distribution of atmospheres as a function of length and how the number of walks of fixed atmosphere scale. Certain bounds on these numbers can be proved. We use Monte Carlo estimates to verify our conjectures in two dimensions. Of particular interest are walks that have zero atmosphere, which are known as trapped. We demonstrate that these walks scale in the same way as the full set of self-avoiding walks, barring an overall constant factor.

Robust and efficient walking with spring-like legs

Energy Technology Data Exchange (ETDEWEB)

Rummel, J; Blum, Y; Seyfarth, A, E-mail: juergen.rummel@uni-jena.d, E-mail: andre.seyfarth@uni-jena.d [Lauflabor Locomotion Laboratory, University of Jena, Dornburger Strasse 23, 07743 Jena (Germany)

2010-12-15

The development of bipedal walking robots is inspired by human walking. A way of implementing walking could be performed by mimicking human leg dynamics. A fundamental model, representing human leg dynamics during walking and running, is the bipedal spring-mass model which is the basis for this paper. The aim of this study is the identification of leg parameters leading to a compromise between robustness and energy efficiency in walking. It is found that, compared to asymmetric walking, symmetric walking with flatter angles of attack reveals such a compromise. With increasing leg stiffness, energy efficiency increases continuously. However, robustness is the maximum at moderate leg stiffness and decreases slightly with increasing stiffness. Hence, an adjustable leg compliance would be preferred, which is adaptable to the environment. If the ground is even, a high leg stiffness leads to energy efficient walking. However, if external perturbations are expected, e.g. when the robot walks on uneven terrain, the leg should be softer and the angle of attack flatter. In the case of underactuated robots with constant physical springs, the leg stiffness should be larger than k-tilde = 14 in order to use the most robust gait. Soft legs, however, lack in both robustness and efficiency.

Robust and efficient walking with spring-like legs

International Nuclear Information System (INIS)

Rummel, J; Blum, Y; Seyfarth, A

2010-01-01

The development of bipedal walking robots is inspired by human walking. A way of implementing walking could be performed by mimicking human leg dynamics. A fundamental model, representing human leg dynamics during walking and running, is the bipedal spring-mass model which is the basis for this paper. The aim of this study is the identification of leg parameters leading to a compromise between robustness and energy efficiency in walking. It is found that, compared to asymmetric walking, symmetric walking with flatter angles of attack reveals such a compromise. With increasing leg stiffness, energy efficiency increases continuously. However, robustness is the maximum at moderate leg stiffness and decreases slightly with increasing stiffness. Hence, an adjustable leg compliance would be preferred, which is adaptable to the environment. If the ground is even, a high leg stiffness leads to energy efficient walking. However, if external perturbations are expected, e.g. when the robot walks on uneven terrain, the leg should be softer and the angle of attack flatter. In the case of underactuated robots with constant physical springs, the leg stiffness should be larger than k-tilde = 14 in order to use the most robust gait. Soft legs, however, lack in both robustness and efficiency.

Locally Perturbed Random Walks with Unbounded Jumps

OpenAIRE

Paulin, Daniel; Szász, Domokos

2010-01-01

In \\cite{SzT}, D. Sz\\'asz and A. Telcs have shown that for the diffusively scaled, simple symmetric random walk, weak convergence to the Brownian motion holds even in the case of local impurities if $d \\ge 2$. The extension of their result to finite range random walks is straightforward. Here, however, we are interested in the situation when the random walk has unbounded range. Concretely we generalize the statement of \\cite{SzT} to unbounded random walks whose jump distribution belongs to th...

The identity and distribution of Fiorinia phantasma (Cockerell & Robinson) (Hemiptera: Coccomorpha: Diaspididae), with a new synonym.

Science.gov (United States)

Watson, Gillian W; Williams, Douglas J; Miller, Douglass R

2015-11-25

The morphologies of Fiorinia phantasma (Cockerell & Robinson) (Hemiptera: Coccomorpha: Diaspididae) and F. coronata Williams & Watson are reviewed, and the name F. coronata is placed as a junior synonym of the name F. phantasma syn. n. The known geographical distribution and host range of F. phantasma is documented and discussed. An identification key to 12 of the 16 species of Fiorinia known from the Australasian, Nearctic and Neotropical Regions is provided.

Kinematic evaluation of virtual walking trajectories.

Science.gov (United States)

Cirio, Gabriel; Olivier, Anne-Hélène; Marchal, Maud; Pettré, Julien

2013-04-01

Virtual walking, a fundamental task in Virtual Reality (VR), is greatly influenced by the locomotion interface being used, by the specificities of input and output devices, and by the way the virtual environment is represented. No matter how virtual walking is controlled, the generation of realistic virtual trajectories is absolutely required for some applications, especially those dedicated to the study of walking behaviors in VR, navigation through virtual places for architecture, rehabilitation and training. Previous studies focused on evaluating the realism of locomotion trajectories have mostly considered the result of the locomotion task (efficiency, accuracy) and its subjective perception (presence, cybersickness). Few focused on the locomotion trajectory itself, but in situation of geometrically constrained task. In this paper, we study the realism of unconstrained trajectories produced during virtual walking by addressing the following question: did the user reach his destination by virtually walking along a trajectory he would have followed in similar real conditions? To this end, we propose a comprehensive evaluation framework consisting on a set of trajectographical criteria and a locomotion model to generate reference trajectories. We consider a simple locomotion task where users walk between two oriented points in space. The travel path is analyzed both geometrically and temporally in comparison to simulated reference trajectories. In addition, we demonstrate the framework over a user study which considered an initial set of common and frequent virtual walking conditions, namely different input devices, output display devices, control laws, and visualization modalities. The study provides insight into the relative contributions of each condition to the overall realism of the resulting virtual trajectories.

Fermionic entanglement via quantum walks in quantum dots

Science.gov (United States)

Melnikov, Alexey A.; Fedichkin, Leonid E.

2018-02-01

Quantum walks are fundamentally different from random walks due to the quantum superposition property of quantum objects. Quantum walk process was found to be very useful for quantum information and quantum computation applications. In this paper we demonstrate how to use quantum walks as a tool to generate high-dimensional two-particle fermionic entanglement. The generated entanglement can survive longer in the presence of depolorazing noise due to the periodicity of quantum walk dynamics. The possibility to create two distinguishable qudits in a system of tunnel-coupled semiconductor quantum dots is discussed.

Scale Insects (Hemiptera: Coccoidea) on Myrciaria dubia (Myrtaceae) in Brazil.

Science.gov (United States)

Wolff, V R S; Kondo, T; Peronti, A L B G; Noronha, A C S

2016-06-01

Commercial cultivation of the fruit tree Myrciaria dubia (Myrtaceae) is being developed in Brazil but phytophagous insects, including scale insects (Hemiptera: Coccoidea), can become pests in plantations. The coccids Ceroplastes jamaicensis White, Coccus viridis (Green), Parasaissetia nigra (Nietner), Pseudokermes vitreus (Cockerell) (Coccidae), and the diaspidid Pseudaonidia trilobitiformis (Green) were collected on M. dubia in the municipality of Belém and Tomé-Açu, state of Pará (PA), metropolitan and Northeast Pará mesoregions, Brazil. A key to species of Coccoidea recorded on M. dubia, based on adult females, is provided. Photographs for all scale insects reported on M. dubia are provided. Ceroplastes jamaicensis is recorded for the first time for Brazil and is herein reported for the first time associated with this host.

Cardiovascular Responses Associated with Daily Walking in Subacute Stroke

Directory of Open Access Journals (Sweden)

Sanjay K. Prajapati

2013-01-01

Full Text Available Despite the importance of regaining independent ambulation after stroke, the amount of daily walking completed during in-patient rehabilitation is low. The purpose of this study is to determine if (1 walking-related heart rate responses reached the minimum intensity necessary for therapeutic aerobic exercise (40%–60% heart rate reserve or (2 heart rate responses during bouts of walking revealed excessive workload that may limit walking (>80% heart rate reserve. Eight individuals with subacute stroke attending in-patient rehabilitation were recruited. Participants wore heart rate monitors and accelerometers during a typical rehabilitation day. Walking-related changes in heart rate and walking bout duration were determined. Patients did not meet the minimum cumulative requirements of walking intensity (>40% heart rate reserve and duration (>10 minutes continuously necessary for cardiorespiratory benefit. Only one patient exceeded 80% heart rate reserve. The absence of significant increases in heart rate associated with walking reveals that patients chose to walk at speeds well below a level that has meaningful cardiorespiratory health benefits. Additionally, cardiorespiratory workload is unlikely to limit participation in walking. Measurement of heart rate and walking during in-patient rehabilitation may be a useful approach to encourage patients to increase the overall physical activity and to help facilitate recovery.

Transit-Related Walking to Work in Promoting Physical Activity.

Science.gov (United States)

Yu, Chia-Yuan; Lin, Hsien-Chang

2015-04-01

Transit-related walking to work is a potential strategy for incorporating physical activity into daily life and promoting health benefits. This study estimated the transit-related walking time for work trips on the journey to and from work and examined the predictors of transit users who walked to/from transit and the workplace and those who walked 30 minutes or more per day. This study used the 2009 National Household Travel Survey and identified 772 subjects who took transit to/from work, 355 subjects who walked to/from transit and the workplace, and 145 subjects who walked 30 minutes or more per day among the 40,659 workers. Weighted logistic regressions were used for the analysis. Of the people who walked to/from transit and the workplace, 40.9% walked 30 minutes or more per day. The weighted logistic regressions revealed that low-income groups and workers living in high population density areas were more likely to walk to/from transit and the workplace. Workers living in high population density areas were more likely to walk 30 minutes or more per day. Transit-related walking to work provides an opportunity to increase physical activity levels and to meet the physical activity recommendations.

Influence of neuromuscular noise and walking speed on fall risk and dynamic stability in a 3D dynamic walking model.

Science.gov (United States)

Roos, Paulien E; Dingwell, Jonathan B

2013-06-21

Older adults and those with increased fall risk tend to walk slower. They may do this voluntarily to reduce their fall risk. However, both slower and faster walking speeds can predict increased risk of different types of falls. The mechanisms that contribute to fall risk across speeds are not well known. Faster walking requires greater forward propulsion, generated by larger muscle forces. However, greater muscle activation induces increased signal-dependent neuromuscular noise. These speed-related increases in neuromuscular noise may contribute to the increased fall risk observed at faster walking speeds. Using a 3D dynamic walking model, we systematically varied walking speed without and with physiologically-appropriate neuromuscular noise. We quantified how actual fall risk changed with gait speed, how neuromuscular noise affected speed-related changes in fall risk, and how well orbital and local dynamic stability measures predicted changes in fall risk across speeds. When we included physiologically-appropriate noise to the 'push-off' force in our model, fall risk increased with increasing walking speed. Changes in kinematic variability, orbital, and local dynamic stability did not predict these speed-related changes in fall risk. Thus, the increased neuromuscular variability that results from increased signal-dependent noise that is necessitated by the greater muscular force requirements of faster walking may contribute to the increased fall risk observed at faster walking speeds. The lower fall risk observed at slower speeds supports experimental evidence that slowing down can be an effective strategy to reduce fall risk. This may help explain the slower walking speeds observed in older adults and others. Copyright © 2013 Elsevier Ltd. All rights reserved.

Self-avoiding polygons and walks in slits

International Nuclear Information System (INIS)

Alvarez, J; Whittington, S G; Rensburg, E J Janse van; Soteros, C E

2008-01-01

A polymer in a confined geometry may be modeled by a self-avoiding walk or a self-avoiding polygon confined between two parallel walls. In two dimensions, this model involves self-avoiding walks or self-avoiding polygons in the square lattice between two parallel confining lines. Interactions of the polymer with the confining walls are introduced by energy terms associated with edges in the walk or polygon which are at or near the confining lines. We use transfer-matrix methods to investigate the forces between the walk or polygon and the confining lines, as well as to investigate the effects of the confining slit's width and of the energy terms on the thermodynamic properties of the walks or polygons in several models. The phase diagram found for the self-avoiding walk models is qualitatively similar to the phase diagram of a directed walk model confined between two parallel lines, as was previously conjectured. However, the phase diagram of one of our polygon models is found to be significantly different and we present numerical data to support this. For that particular model we prove that, for any finite values of the energy terms, there are an infinite number of slit widths where a polygon will induce a steric repulsion between the confining lines

New corological and biological data of the Red Gum Lerp Psyllid, Glycaspis brimblecombei Moore, 1964 in Italy (Hemiptera, Psyllidae

Directory of Open Access Journals (Sweden)

Ricardo Jiménez-Peydró

2011-03-01

Full Text Available Glycaspis brimblecombei Moore, 1964 is a psyllid (Hemiptera: Psyllidae pest of Eucalyptus, native toAustralia and first recorded in Europe: Spain in 2008 and more recently (2010 in Italy. The present paper dealswith recent research, carried out in central Italy, with new data on the distribution and biology of this species.

Distracted walking: Examining the extent to pedestrian safety problems

Directory of Open Access Journals (Sweden)

Judith Mwakalonge

2015-10-01

Full Text Available Pedestrians, much like drivers, have always been engaged in multi-tasking like using hand-held devices, listening to music, snacking, or reading while walking. The effects are similar to those experienced by distracted drivers. However, distracted walking has not received similar policies and effective interventions as distracted driving to improve pedestrian safety. This study reviewed the state-of-practice on policies, campaigns, available data, identified research needs, and opportunities pertaining to distracted walking. A comprehensive review of literature revealed that some of the agencies/organizations disseminate useful information about certain distracting activities that pedestrians should avoid while walking to improve their safety. Various walking safety rules/tips have been given, such as not wearing headphones or talking on a cell phone while crossing a street, keeping the volume down, hanging up the phone while walking, being aware of traffic, and avoiding distractions like walking with texting. The majority of the past observational-based and experimental-based studies reviewed in this study on distracted walking is in agreement that there is a positive correlation between distraction and unsafe walking behavior. However, limitations of the existing crash data suggest that distracted walking may not be a severe threat to the public health. Current pedestrian crash data provide insufficient information for researchers to examine the extent to which distracted walking causes and/or contributes to actual pedestrian safety problems.

I Walk My Dog Because It Makes Me Happy: A Qualitative Study to Understand Why Dogs Motivate Walking and Improved Health.

Science.gov (United States)

Westgarth, Carri; Christley, Robert M; Marvin, Garry; Perkins, Elizabeth

2017-08-19

Dog walking is a popular everyday physical activity. Dog owners are generally more active than non-owners, but some rarely walk with their dog. The strength of the dog-owner relationship is known to be correlated with dog walking, and this qualitative study investigates why. Twenty-six interviews were combined with autoethnography of dog walking experiences. Dog walking was constructed as "for the dog", however, owners represented their dog's needs in a way which aligned with their own. Central to the construction of need was perceptions of dog personality and behaviour. Owners reported deriving positive outcomes from dog walking, most notably, feelings of "happiness", but these were "contingent" on the perception that their dogs were enjoying the experience. Owner physical activity and social interaction were secondary bonuses but rarely motivating. Perceptions and beliefs of owners about dog walking were continually negotiated, depending on how the needs of the owner and dog were constructed at that time. Complex social interactions with the "significant other" of a pet can strongly motivate human health behaviour. Potential interventions to promote dog walking need to account for this complexity and the effect of the dog-owner relationship on owner mental wellbeing.

Characterization of a recombinant Cathepsin B-Like cysteine peptidase from Diaphorina citri Kuwayama (Hemiptera: Liviidae): A putative target control of citrus huanglongbing

Science.gov (United States)

Huanglongbing (HLB) is one of the most destructive disease affecting citrus plants. The causal agent is associated with the phloem-limited bacterium Candidatus Liberibacter asiaticus (CLas) spread by the Asian citrus psyllid, Diaphorina citri (Hemiptera: Liviidae). Among the control strategies for H...

Occurrence of lace bug Vatiga illudens and Vatiga manihotae (Hemiptera: Tingidae) in Mato Grosso do Sul, midwestern Brazil.

Science.gov (United States)

Bellon, Patrícia P; Wengrat, Ana P G S; Kassab, Samir O; Pietrowski, Vanda; Loureiro, Elisângela S

2012-09-01

Nymphs and adults of the lace bug (Hemiptera: Tingidae) have been found in cassava crops (Manihot esculenta) in Mato Grosso do Sul State, Brazil. The insects were collected in the field and taken to the laboratory where they were identified based on some morphological traits of the species Vatiga manihotae (Drake) and V. illudens (Drake), which are first reported in the aforementioned state.

Running for exercise mitigates age-related deterioration of walking economy.

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Justus D Ortega

Full Text Available Impaired walking performance is a key predictor of morbidity among older adults. A distinctive characteristic of impaired walking performance among older adults is a greater metabolic cost (worse economy compared to young adults. However, older adults who consistently run have been shown to retain a similar running economy as young runners. Unfortunately, those running studies did not measure the metabolic cost of walking. Thus, it is unclear if running exercise can prevent the deterioration of walking economy.To determine if and how regular walking vs. running exercise affects the economy of locomotion in older adults.15 older adults (69 ± 3 years who walk ≥ 30 min, 3x/week for exercise, "walkers" and 15 older adults (69 ± 5 years who run ≥ 30 min, 3x/week, "runners" walked on a force-instrumented treadmill at three speeds (0.75, 1.25, and 1.75 m/s. We determined walking economy using expired gas analysis and walking mechanics via ground reaction forces during the last 2 minutes of each 5 minute trial. We compared walking economy between the two groups and to non-aerobically trained young and older adults from a prior study.Older runners had a 7-10% better walking economy than older walkers over the range of speeds tested (p = .016 and had walking economy similar to young sedentary adults over a similar range of speeds (p =  .237. We found no substantial biomechanical differences between older walkers and runners. In contrast to older runners, older walkers had similar walking economy as older sedentary adults (p =  .461 and ∼ 26% worse walking economy than young adults (p<.0001.Running mitigates the age-related deterioration of walking economy whereas walking for exercise appears to have minimal effect on the age-related deterioration in walking economy.

[Walking abnormalities in children].

Science.gov (United States)

Segawa, Masaya

2010-11-01

Walking is a spontaneous movement termed locomotion that is promoted by activation of antigravity muscles by serotonergic (5HT) neurons. Development of antigravity activity follows 3 developmental epochs of the sleep-wake (S-W) cycle and is modulated by particular 5HT neurons in each epoch. Activation of antigravity activities occurs in the first epoch (around the age of 3 to 4 months) as restriction of atonia in rapid eye movement (REM) stage and development of circadian S-W cycle. These activities strengthen in the second epoch, with modulation of day-time sleep and induction of crawling around the age of 8 months and induction of walking by 1 year. Around the age of 1 year 6 months, absence of guarded walking and interlimb cordination is observed along with modulation of day-time sleep to once in the afternoon. Bipedal walking in upright position occurs in the third epoch, with development of a biphasic S-W cycle by the age of 4-5 years. Patients with infantile autism (IA), Rett syndrome (RTT), or Tourette syndrome (TS) show failure in the development of the first, second, or third epoch, respectively. Patients with IA fail to develop interlimb coordination; those with RTT, crawling and walking; and those with TS, walking in upright posture. Basic pathophysiology underlying these condition is failure in restricting atonia in REM stage; this induces dysfunction of the pedunculopontine nucleus and consequently dys- or hypofunction of the dopamine (DA) neurons. DA hypofunction in the developing brain, associated with compensatory upward regulation of the DA receptors causes psychobehavioral disorders in infancy (IA), failure in synaptogenesis in the frontal cortex and functional development of the motor and associate cortexes in late infancy through the basal ganglia (RTT), and failure in functional development of the prefrontal cortex through the basal ganglia (TS). Further, locomotion failure in early childhood causes failure in development of functional

Audio-haptic interaction in simulated walking experiences

DEFF Research Database (Denmark)

Serafin, Stefania

2011-01-01

and interchangeable use of the haptic and auditory modality in floor interfaces, and for the synergy of perception and action in capturing and guiding human walking. We describe the technology developed in the context of this project, together with some experiments performed to evaluate the role of auditory......In this paper an overview of the work conducted on audio-haptic physically based simulation and evaluation of walking is provided. This work has been performed in the context of the Natural Interactive Walking (NIW) project, whose goal is to investigate possibilities for the integrated...... and haptic feedback in walking tasks....

A case study of energy expenditure based on walking speed reduction during walking upstairs situation at a staircase in FKAAS, UTHM, Johor building

Science.gov (United States)

Abustan, M. S.; Ali, M. F. M.; Talib, S. H. A.

2018-04-01

Walking velocity is a vector quantity that can be determined by calculating the time taken and displacement of a moving objects. In Malaysia, there are very few researches that were done to determine the walking velocity of citizens to be compared with other countries such as the study about walking upstairs during evacuation process is important when emergency case happen, if there are people in underground garages, they have to walk upstairs for exits and look for shelter and the walking velocity of pedestrian in such cases are necessary to be analysed. Therefore, the objective of this study is to determine the walking speed of pedestrian during walking upstairs situation, finding the relationship between pedestrian walking speed and the characteristics of the pedestrian as well as analysing the energy reduction by comparing the walking speed of pedestrian at the beginning and at the end of staircase. In this case study, an experiment was done to determine the average walking speed of pedestrian. The pedestrian has been selected from different gender, physical character, and age. Based on the data collected, the average normal walking speed of male pedestrian was 1.03 m/s while female was 1.08 m/s. During walking upstairs, the walking speed of pedestrian decreased as the number of floor increased. The average speed for the first stairwell was 0.90 m/s and the number decreased to 0.73 m/s for the second stairwell. From the reduction of speed, the energy used has been calculated and the average kinetic energy used was 1.69 J. Hence, the data collected can be used for further research of staircase design and plan of evacuation process.

Rodolia cardinalis (Mulsant) (Coleoptera: Coccinellidae), a new predator of Crypticerya multicicatrices Kondo and Unruh (Hemiptera: Monophlebidae)

OpenAIRE

Pinchao, Ever Camilo; Kondo, Takumasa; González F., Guillermo

2016-01-01

The Colombian fluted scale (CFS), Crypticerya multicicatrices Kondo & Unruh (Hemiptera: Monophlebidae) is a polyphagous scale insect which affects about 100 species of plants. Between 2010–2013, the species was reported as an invasive pest on the islands of San Andres and Old Providence, Colombian territory in the Caribbean sea. Currently, populations of the CFS also have increased in the city of Cali, Valle del Cauca State, mainland Colombia, affecting different host plants, especially l...

Walking Tips for Older Adults

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... you can continue your walking program. Don’t let a cane or walker stop you It’s OK to use your cane or walker if you already have one. These can improve your balance and help take the load off painful joints. Aim for the right pace Try to walk as fast as you ...

Design of wheel-type walking-assist device

International Nuclear Information System (INIS)

Jung, Seung Ho; Kim, Seung Ho; Kim, Chang Hoi; Seo, Yong Chil; Jung, Kyung Min; Lee, Sung Uk

2006-03-01

In this research, a outdoor wheel-type walking-assist device is developed to help an elder having a poor muscular strength at legs for walking, sitting and standing up easily at outdoors, and also for going and downing stairs. In conceptually designing, the environments of an elder's activity, the size of an elder's body and a necessary function of helping an elder are considered. This device has 4 wheels for stability. When an elder walks in incline plane with the proposed device, a rear-wing is rotated to keep the supporting device horizontal, regardless of an angle of inclination. A height-controlling device, which can control the height of the supporting device for adjusting an elder's height, is varied vertically to help an elder to sit and stand-up easily. Moreover, a outdoor wheel-type walking-assist device is conceptually designed and is made. In order to design it, the preview research is investigated firstly. On the basis of the proposed walking-assist device, the outdoor walking-assist device is designed and made. The outdoor wheel-type walking-assist device can go and down stairs automatically. This device go up and down the stair of having maximum 20cm height and an angle of 25 degrees with maximum 4 sec/stairs speed, and move at flatland with 60cm/sec speed

Searching via walking: How to find a marked clique of a complete graph using quantum walks

International Nuclear Information System (INIS)

Hillery, Mark; Reitzner, Daniel; Buzek, Vladimir

2010-01-01

We show how a quantum walk can be used to find a marked edge or a marked complete subgraph of a complete graph. We employ a version of a quantum walk, the scattering walk, which lends itself to experimental implementation. The edges are marked by adding elements to them that impart a specific phase shift to the particle as it enters or leaves the edge. If the complete graph has N vertices and the subgraph has K vertices, the particle becomes localized on the subgraph in O(N/K) steps. This leads to a quantum search that is quadratically faster than a corresponding classical search. We show how to implement the quantum walk using a quantum circuit and a quantum oracle, which allows us to specify the resources needed for a quantitative comparison of the efficiency of classical and quantum searches--the number of oracle calls.

Ways of Walking

DEFF Research Database (Denmark)

Eslambolchilar, Parisa; Bødker, Mads; Chamberlain, Alan

2016-01-01

It seems logical to argue that mobile computing technologies are intended for use "on-the-go." However, on closer inspection, the use of mobile technologies pose a number of challenges for users who are mobile, particularly moving around on foot. In engaging with such mobile technologies and thei......It seems logical to argue that mobile computing technologies are intended for use "on-the-go." However, on closer inspection, the use of mobile technologies pose a number of challenges for users who are mobile, particularly moving around on foot. In engaging with such mobile technologies...... and their envisaged development, we argue that interaction designers must increasingly consider a multitude of perspectives that relate to walking in order to frame design problems appropriately. In this paper, we consider a number of perspectives on walking, and we discuss how these may inspire the design of mobile...... technologies. Drawing on insights from non-representational theory, we develop a partial vocabulary with which to engage with qualities of pedestrian mobility, and we outline how taking more mindful approaches to walking may enrich and inform the design space of handheld technologies....

Can environmental improvement change the population distribution of walking?

Science.gov (United States)

Panter, Jenna; Ogilvie, David

2017-06-01

Few studies have explored the impact of environmental change on walking using controlled comparisons. Even fewer have examined whose behaviour changes and how. In a natural experimental study of new walking and cycling infrastructure, we explored changes in walking, identified groups who changed in similar ways and assessed whether exposure to the infrastructure was associated with trajectories of walking. 1257 adults completed annual surveys assessing walking, sociodemographic and health characteristics and use of the infrastructure (2010-2012). Residential proximity to the new routes was assessed objectively. We used latent growth curve models to assess change in total walking, walking for recreation and for transport, used simple descriptive analysis and latent class analysis (LCA) to identify groups who changed in similar ways and examined factors associated with group membership using multinomial regression. LCA identified five trajectories, characterised by consistently low levels; consistently high levels; decreases; short-lived increases; and sustained increases. Those with lower levels of education and lower incomes were more likely to show both short-lived and sustained increases in walking for transport. However, those with lower levels of education were less likely to take up walking. Proximity to the intervention was associated with both uptake of and short-lived increases in walking for transport. Environmental improvement encouraged the less active to take up walking for transport, as well as encouraging those who were already active to walk more. Further research should disentangle the role of socioeconomic characteristics in determining use of new environments and changes in walking. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Hypotensive response after water-walking and land-walking exercise sessions in healthy trained and untrained women

Directory of Open Access Journals (Sweden)

Bocalini DS

2011-08-01

Full Text Available Daniel Rodriguez1, Valter Silva2, Jonato Prestes3, Roberta Luksevicius Rica4, Andrey Jorge Serra5, Danilo Sales Bocalini6, Francisco Luciano Pontes Junior71São Judas Tadeu University, São Paulo, SP, Brazil; 2College of Physical Education of Sorocaba, Sorocaba, SP, Brazil; 3Graduation Program in Physical Education, Catholic University of Brasilia, Brasilia-DF, Brazil; 4Department of Physical Education, Arbos College, São Bernardo do Campo, SP, Brazil; 5Department of Physical Education and Laboratory of Rehabilitation Science, Nove de Julho University, São Paulo, SP, Brazil; 6Department of Medicine, Federal University of São Paulo – Escola Paulista de Medicina, São Paulo, SP, Brazil; 7School of Arts, Sciences and Humanities, University of São Paulo, São Paulo, SP, BrazilBackground: The aim of this study was to compare post-exercise hypotension after acute sessions of water-walking and land-walking in healthy trained and untrained women.Methods: Twenty-three untrained (n = 12 and trained (n = 11 normotensive women performed two walking sessions in water and on land at 40% of peak VO2 for 45 minutes. Systolic and diastolic blood pressure and mean arterial pressure were measured 15, 30, 45, and 60 minutes after the exercise sessions.Results: No differences were found between the groups for age and anthropometric parameters, but peak VO2 for the trained women (45 ± 8 mL/kg/minute was higher than for the untrained women (31 ± 3 mL/kg/minute. No differences were found between the groups with regard to systolic and diastolic blood pressure and mean arterial pressure after water immersion. The heart rate in the trained group (62 ± 3 beats per minute [bpm] was significantly lower (P < 0.05 than in the untrained group (72 ± 4 bpm on land, and after water immersion, this difference disappeared (58 ± 5 bpm in the trained women and 66 ± 5 bpm in the untrained women. Sixty minutes after water-walking, systolic blood pressure (108 ± 8 mmHg vs

Compliant walking appears metabolically advantageous at extreme step lengths.

Science.gov (United States)

Kim, Jaehoon; Bertram, John E A

2018-05-19

Humans alter gait in response to unusual gait circumstances to accomplish the task of walking. For instance, subjects spontaneously increase leg compliance at a step length threshold as step length increases. Here we test the hypothesis that this transition occurs based on the level of energy expenditure, where compliant walking becomes less energetically demanding at long step lengths. To map and compare the metabolic cost of normal and compliant walking as step length increases. 10 healthy individuals walked on a treadmill using progressively increasing step lengths (100%, 120%, 140% and 160% of preferred step length), in both normal and compliant leg walking as energy expenditure was recorded via indirect calorimetry. Leg compliance was controlled by lowering the center-of-mass trajectory during stance, forcing the leg to flex and extend as the body moved over the foot contact. For normal step lengths, compliant leg walking was more costly than normal walking gait, but compliant leg walking energetic cost did not increase as rapidly for longer step lengths. This led to an intersection between normal and compliant walking cost curves at 114% relative step length (regression analysis; r 2  = 0.92 for normal walking; r 2  = 0.65 for compliant walking). Compliant leg walking is less energetically demanding at longer step lengths where a spontaneous shift to compliant walking has been observed, suggesting the human motor control system is sensitive to energetic requirements and will employ alternate movement patterns if advantageous strategies are available. The transition could be attributed to the interplay between (i) leg work controlling body travel during single stance and (ii) leg work to control energy loss in the step-to-step transition. Compliant leg walking requires more stance leg work at normal step lengths, but involves less energy loss at the step-to-step transition for very long steps. Copyright © 2018 Elsevier B.V. All rights reserved.

Running for exercise mitigates age-related deterioration of walking economy.

Science.gov (United States)

Ortega, Justus D; Beck, Owen N; Roby, Jaclyn M; Turney, Aria L; Kram, Rodger

2014-01-01

Impaired walking performance is a key predictor of morbidity among older adults. A distinctive characteristic of impaired walking performance among older adults is a greater metabolic cost (worse economy) compared to young adults. However, older adults who consistently run have been shown to retain a similar running economy as young runners. Unfortunately, those running studies did not measure the metabolic cost of walking. Thus, it is unclear if running exercise can prevent the deterioration of walking economy. To determine if and how regular walking vs. running exercise affects the economy of locomotion in older adults. 15 older adults (69 ± 3 years) who walk ≥ 30 min, 3x/week for exercise, "walkers" and 15 older adults (69 ± 5 years) who run ≥ 30 min, 3x/week, "runners" walked on a force-instrumented treadmill at three speeds (0.75, 1.25, and 1.75 m/s). We determined walking economy using expired gas analysis and walking mechanics via ground reaction forces during the last 2 minutes of each 5 minute trial. We compared walking economy between the two groups and to non-aerobically trained young and older adults from a prior study. Older runners had a 7-10% better walking economy than older walkers over the range of speeds tested (p = .016) and had walking economy similar to young sedentary adults over a similar range of speeds (p =  .237). We found no substantial biomechanical differences between older walkers and runners. In contrast to older runners, older walkers had similar walking economy as older sedentary adults (p =  .461) and ∼ 26% worse walking economy than young adults (peconomy whereas walking for exercise appears to have minimal effect on the age-related deterioration in walking economy.

Cavemen were better at depicting quadruped walking than modern artists: erroneous walking illustrations in the fine arts from prehistory to today.

Science.gov (United States)

Horvath, Gabor; Farkas, Etelka; Boncz, Ildiko; Blaho, Miklos; Kriska, Gyorgy

2012-01-01

The experts of animal locomotion well know the characteristics of quadruped walking since the pioneering work of Eadweard Muybridge in the 1880s. Most of the quadrupeds advance their legs in the same lateral sequence when walking, and only the timing of their supporting feet differ more or less. How did this scientific knowledge influence the correctness of quadruped walking depictions in the fine arts? Did the proportion of erroneous quadruped walking illustrations relative to their total number (i.e. error rate) decrease after Muybridge? How correctly have cavemen (upper palaeolithic Homo sapiens) illustrated the walking of their quadruped prey in prehistoric times? The aim of this work is to answer these questions. We have analyzed 1000 prehistoric and modern artistic quadruped walking depictions and determined whether they are correct or not in respect of the limb attitudes presented, assuming that the other aspects of depictions used to determine the animals gait are illustrated correctly. The error rate of modern pre-Muybridgean quadruped walking illustrations was 83.5%, much more than the error rate of 73.3% of mere chance. It decreased to 57.9% after 1887, that is in the post-Muybridgean period. Most surprisingly, the prehistoric quadruped walking depictions had the lowest error rate of 46.2%. All these differences were statistically significant. Thus, cavemen were more keenly aware of the slower motion of their prey animals and illustrated quadruped walking more precisely than later artists.

Cavemen were better at depicting quadruped walking than modern artists: erroneous walking illustrations in the fine arts from prehistory to today.

Directory of Open Access Journals (Sweden)

Gabor Horvath

Full Text Available The experts of animal locomotion well know the characteristics of quadruped walking since the pioneering work of Eadweard Muybridge in the 1880s. Most of the quadrupeds advance their legs in the same lateral sequence when walking, and only the timing of their supporting feet differ more or less. How did this scientific knowledge influence the correctness of quadruped walking depictions in the fine arts? Did the proportion of erroneous quadruped walking illustrations relative to their total number (i.e. error rate decrease after Muybridge? How correctly have cavemen (upper palaeolithic Homo sapiens illustrated the walking of their quadruped prey in prehistoric times? The aim of this work is to answer these questions. We have analyzed 1000 prehistoric and modern artistic quadruped walking depictions and determined whether they are correct or not in respect of the limb attitudes presented, assuming that the other aspects of depictions used to determine the animals gait are illustrated correctly. The error rate of modern pre-Muybridgean quadruped walking illustrations was 83.5%, much more than the error rate of 73.3% of mere chance. It decreased to 57.9% after 1887, that is in the post-Muybridgean period. Most surprisingly, the prehistoric quadruped walking depictions had the lowest error rate of 46.2%. All these differences were statistically significant. Thus, cavemen were more keenly aware of the slower motion of their prey animals and illustrated quadruped walking more precisely than later artists.

Duas espécies novas de membracídeos (Hemiptera, Membracidae da Mata Atlântica do Estado de São Paulo, Brasil Two new species of treehopper (Hemiptera, Membracidae from the Atlantic Forest of São Paulo State, Brazil

Directory of Open Access Journals (Sweden)

Albino M. Sakakibara

2009-01-01

Full Text Available Duas espécies são descritas da Mata Atlântica do Estado de São Paulo: uma pertencente ao gênero Antonae Stål (Smiliinae-Ceresini, Antonae brasiliensis sp. nov. e outra a Hypheodana Metcalf (Darninae-Darnini, Hypheodana gargionei sp. nov., ambas de Campos do Jordão, São Paulo. O gênero Antonae é registrado pela primeira vez no Brasil e Hypheodana, por outro lado, para a Mata Atlântica.Two species are described: one belonging to the genus Antonae Stål (Smiliinae, Ceresini, Antonae brasiliensis sp. nov., and another to Hypheodana Metcalf (Darninae-Darnini, Hypheodana gargionei sp. nov., both from Campos do Jordão, São Paulo. The genus Antonae Stål is recorded for the first time in Brazil, and Hypheodana, on the other hand, in the Atlantic Forest.

Biomechanical implications of walking with indigenous footwear.

Science.gov (United States)

Willems, Catherine; Stassijns, Gaetane; Cornelis, Wim; D'Août, Kristiaan

2017-04-01

This study investigates biomechanical implications of walking with indigenous "Kolhapuri" footwear compared to barefoot walking among a population of South Indians. Ten healthy adults from South India walked barefoot and indigenously shod at voluntary speed on an artificial substrate. The experiment was repeated outside, on a natural substrate. Data were collected from (1) a heel-mounted 3D-accelerometer recording peak impact at heel contact, (2) an ankle-mounted 3D-goniometer (plantar/dorsiflexion and inversion/eversion), and (3) sEMG electrodes at the m. tibialis anterior and the m. gastrocnemius medialis. Data show that the effect of indigenous footwear on the measured variables, compared to barefoot walking, is relatively small and consistent between substrates (even though subjects walked faster on the natural substrate). Walking barefoot, compared to shod walking yields higher impact accelerations, but the differences are small and only significant for the artificial substrate. The main rotations of the ankle joint are mostly similar between conditions. Only the shod condition shows a faster ankle rotation over the rapid eversion motion on the natural substrate. Maximal dorsiflexion in late stance differs between the footwear conditions on an artificial substrate, with the shod condition involving a less dorsiflexed ankle, and the plantar flexion at toe-off is more extreme when shod. Overall the activity pattern of the external foot muscles is similar. The indigenous footwear studied (Kolhapuri) seems to alter foot biomechanics only in a subtle way. While offering some degree of protection, walking in this type of footwear resembles barefoot gait and this type of indigenous footwear might be considered "minimal". © 2017 The Authors American Journal of Physical Anthropology Published by Wiley Periodicals, Inc.

I Walk My Dog Because It Makes Me Happy: A Qualitative Study to Understand Why Dogs Motivate Walking and Improved Health

Science.gov (United States)

Marvin, Garry; Perkins, Elizabeth

2017-01-01

Dog walking is a popular everyday physical activity. Dog owners are generally more active than non-owners, but some rarely walk with their dog. The strength of the dog–owner relationship is known to be correlated with dog walking, and this qualitative study investigates why. Twenty-six interviews were combined with autoethnography of dog walking experiences. Dog walking was constructed as “for the dog”, however, owners represented their dog’s needs in a way which aligned with their own. Central to the construction of need was perceptions of dog personality and behaviour. Owners reported deriving positive outcomes from dog walking, most notably, feelings of “happiness”, but these were “contingent” on the perception that their dogs were enjoying the experience. Owner physical activity and social interaction were secondary bonuses but rarely motivating. Perceptions and beliefs of owners about dog walking were continually negotiated, depending on how the needs of the owner and dog were constructed at that time. Complex social interactions with the “significant other” of a pet can strongly motivate human health behaviour. Potential interventions to promote dog walking need to account for this complexity and the effect of the dog-owner relationship on owner mental wellbeing. PMID:28825614

PCR-based gut content analysis to detect predation of Eriococcus ironsidei (Hemiptera: Eriococcidae) by Coccinellidae species in macadamia nut orchards in Hawaii

Science.gov (United States)

Macadamia felted coccid, Eriococcus ironsidei (Williams) (Hemiptera: Eriococcidae) was first found infesting macadamia trees in the island of Hawaii in 2005. Macadamia felted coccid infests all above-ground parts of trees to feed and reproduce. Their feeding activity distorts and stunts new growth w...

A new species of Dysmicoccus damaging lavender in French Provence (Hemiptera, Sternorrhyncha, Pseudococcidae).

Science.gov (United States)

Germain, J-F; Matile-Ferrero, D; Kaydan, M B; Malausa, T; Williams, D J

2015-07-01

Une nouvelle espèce de Dysmicoccus nuisible à la lavande en Provence (France) (Hemiptera, Sternorrhyncha, Pseudococcidae). Dysmicoccus lavandulae Germain, Matile-Ferrero & Williams n. sp. est décrite et illustrée. Ses séquences ADN sont présentées. L'espèce vit sur Lavandula x intermedia cultivée pour la production d'essence de lavande en Provence. La liste des espèces de pseudococcines vivant sur les lavandes spontanées en France est dressée. Le statut des 2 genres voisins Trionymus Berg et Dysmicoccus Ferris est discuté.

Generating random walks and polygons with stiffness in confinement

International Nuclear Information System (INIS)

Diao, Y; Ernst, C; Saarinen, S; Ziegler, U

2015-01-01

The purpose of this paper is to explore ways to generate random walks and polygons in confinement with a bias toward stiffness. Here the stiffness refers to the curvature angle between two consecutive edges along the random walk or polygon. The stiffer the walk (polygon), the smaller this angle on average. Thus random walks and polygons with an elevated stiffness have lower than expected curvatures. The authors introduced and studied several generation algorithms with a stiffness parameter s>0 that regulates the expected curvature angle at a given vertex in which the random walks and polygons are generated one edge at a time using conditional probability density functions. Our generating algorithms also allow the generation of unconfined random walks and polygons with any desired mean curvature angle. In the case of random walks and polygons confined in a sphere of fixed radius, we observe that, as expected, stiff random walks or polygons are more likely to be close to the confinement boundary. The methods developed here require that the random walks and random polygons be rooted at the center of the confinement sphere. (paper)

Walking Robots Dynamic Control Systems on an Uneven Terrain

Directory of Open Access Journals (Sweden)

MUNTEANU, M. S.

2010-05-01

Full Text Available The paper presents ZPM dynamic control of walking robots, developing an open architecture real time control multiprocessor system, in view of obtaining new capabilities for walking robots. The complexity of the movement mechanism of a walking robot was taken into account, being a repetitive tilting process with numerous instable movements and which can lead to its turnover on an uneven terrain. The control system architecture for the dynamic robot walking is presented in correlation with the control strategy which contains three main real time control loops: balance robot control using sensorial feedback, walking diagram control with periodic changes depending on the sensorial information during each walk cycle, predictable movement control based on a quick decision from the previous experimental data. The results obtained through simulation and experiments show an increase in mobility, stability in real conditions and obtaining of high performances related to the possibility of moving walking robots on terrains with a configuration as close as possible to real situations, respectively developing new technological capabilities of the walking robot control systems for slope movement and walking by overtaking or going around obstacles.

Quantum walk with one variable absorbing boundary

International Nuclear Information System (INIS)

Wang, Feiran; Zhang, Pei; Wang, Yunlong; Liu, Ruifeng; Gao, Hong; Li, Fuli

2017-01-01

Quantum walks constitute a promising ingredient in the research on quantum algorithms; consequently, exploring different types of quantum walks is of great significance for quantum information and quantum computation. In this study, we investigate the progress of quantum walks with a variable absorbing boundary and provide an analytical solution for the escape probability (the probability of a walker that is not absorbed by the boundary). We simulate the behavior of escape probability under different conditions, including the reflection coefficient, boundary location, and initial state. Moreover, it is also meaningful to extend our research to the situation of continuous-time and high-dimensional quantum walks. - Highlights: • A novel scheme about quantum walk with variable boundary is proposed. • The analytical results of the survival probability from the absorbing boundary. • The behavior of survival probability under different boundary conditions. • The influence of different initial coin states on the survival probability.

Two Legged Walking Robot

OpenAIRE

Kraus, V.

2015-01-01

The aim of this work is to construct a two-legged wirelessly controlled walking robot. This paper describes the construction of the robot, its control electronics, and the solution of the wireless control. The article also includes a description of the application to control the robot. The control electronics of the walking robot are built using the development kit Arduino Mega, which is enhanced with WiFi module allowing the wireless control, a set of ultrasonic sensors for detecting obstacl...

Efficient quantum circuit implementation of quantum walks

International Nuclear Information System (INIS)

Douglas, B. L.; Wang, J. B.

2009-01-01

Quantum walks, being the quantum analog of classical random walks, are expected to provide a fruitful source of quantum algorithms. A few such algorithms have already been developed, including the 'glued trees' algorithm, which provides an exponential speedup over classical methods, relative to a particular quantum oracle. Here, we discuss the possibility of a quantum walk algorithm yielding such an exponential speedup over possible classical algorithms, without the use of an oracle. We provide examples of some highly symmetric graphs on which efficient quantum circuits implementing quantum walks can be constructed and discuss potential applications to quantum search for marked vertices along these graphs.

On the physical realizability of quantum stochastic walks

Science.gov (United States)

Taketani, Bruno; Govia, Luke; Schuhmacher, Peter; Wilhelm, Frank

Quantum walks are a promising framework that can be used to both understand and implement quantum information processing tasks. The recently developed quantum stochastic walk combines the concepts of a quantum walk and a classical random walk through open system evolution of a quantum system, and have been shown to have applications in as far reaching fields as artificial intelligence. However, nature puts significant constraints on the kind of open system evolutions that can be realized in a physical experiment. In this work, we discuss the restrictions on the allowed open system evolution, and the physical assumptions underpinning them. We then introduce a way to circumvent some of these restrictions, and simulate a more general quantum stochastic walk on a quantum computer, using a technique we call quantum trajectories on a quantum computer. We finally describe a circuit QED approach to implement discrete time quantum stochastic walks.

Does walking strategy in older people change as a function of walking distance?

Science.gov (United States)

Najafi, Bijan; Helbostad, Jorunn L; Moe-Nilssen, Rolf; Zijlstra, Wiebren; Aminian, Kamiar

2009-02-01

This study investigates whether the spatio-temporal parameters of gait in the elderly vary as a function of walking distance. The gait pattern of older subjects (n=27) over both short (SWDLWD>20 m) walking was evaluated using an ambulatory device consisting of body-worn sensors (Physilog). The stride velocity (SV), gait cycle time (GCT), and inter-cycle variability of each parameter (CV) were evaluated for each subject. Analysis was undertaken after evaluating the errors and the test-retest reliability of the Physilog device compared with an electronic walkway system (GaitRite) over the SWD with different walking speeds. While both systems were highly reliable with respect to the SV and GCT parameters (ICC>0.82), agreement for the gait variability was poor. Interestingly, our data revealed that the measured gait parameters over SWD and LWD were significantly different. LWD trials had a mean increase of 5.2% (pLWD trials decreased by an average of 1% relative to the SWD case, the drop was not significant. Moreover, reliability for gait variability measures was poor, irrespective of the instrument and despite a moderate improvement for LWD trials. Taken together, our findings indicate that for valid and reliable comparisons, test and retest should be performed under identical distance conditions. Furthermore, our findings suggest that the older subjects may choose different walking strategies for SWD and LWD conditions.

More Adults Are Walking PSA (:60)

Centers for Disease Control (CDC) Podcasts

This 60 second PSA is based on the August 2012 CDC Vital Signs report. While more adults are walking, only half get the recommended amount of physical activity. Listen to learn how communities, employers, and individuals may help increase walking.

Rhythmic walking interaction with auditory feedback

DEFF Research Database (Denmark)

Maculewicz, Justyna; Jylhä, Antti; Serafin, Stefania

2015-01-01

We present an interactive auditory display for walking with sinusoidal tones or ecological, physically-based synthetic walking sounds. The feedback is either step-based or rhythmic, with constant or adaptive tempo. In a tempo-following experiment, we investigate different interaction modes...

Stride rate and walking intensity in healthy older adults.

Science.gov (United States)

Peacock, Leslie; Hewitt, Allan; Rowe, David A; Sutherland, Rona

2014-04-01

The study investigated (a) walking intensity (stride rate and energy expenditure) under three speed instructions; (b) associations between stride rate, age, height, and walking intensity; and (c) synchronization between stride rate and music tempo during overground walking in a population of healthy older adults. Twenty-nine participants completed 3 treadmill-walking trials and 3 overground-walking trials at 3 self-selected speeds. Treadmill VO2 was measured using indirect calorimetry. Stride rate and music tempo were recorded during overground-walking trials. Mean stride rate exceeded minimum thresholds for moderate to vigorous physical activity (MVPA) under slow (111.41 ± 11.93), medium (118.17 ± 11.43), and fast (123.79 ± 11.61) instructions. A multilevel model showed that stride rate, age, and height have a significant effect (p Music can be a useful way to guide walking cadence.

Continuous-time quantum random walks require discrete space

International Nuclear Information System (INIS)

Manouchehri, K; Wang, J B

2007-01-01

Quantum random walks are shown to have non-intuitive dynamics which makes them an attractive area of study for devising quantum algorithms for long-standing open problems as well as those arising in the field of quantum computing. In the case of continuous-time quantum random walks, such peculiar dynamics can arise from simple evolution operators closely resembling the quantum free-wave propagator. We investigate the divergence of quantum walk dynamics from the free-wave evolution and show that, in order for continuous-time quantum walks to display their characteristic propagation, the state space must be discrete. This behavior rules out many continuous quantum systems as possible candidates for implementing continuous-time quantum random walks

Continuous-time quantum random walks require discrete space

Science.gov (United States)

Manouchehri, K.; Wang, J. B.

2007-11-01

Quantum random walks are shown to have non-intuitive dynamics which makes them an attractive area of study for devising quantum algorithms for long-standing open problems as well as those arising in the field of quantum computing. In the case of continuous-time quantum random walks, such peculiar dynamics can arise from simple evolution operators closely resembling the quantum free-wave propagator. We investigate the divergence of quantum walk dynamics from the free-wave evolution and show that, in order for continuous-time quantum walks to display their characteristic propagation, the state space must be discrete. This behavior rules out many continuous quantum systems as possible candidates for implementing continuous-time quantum random walks.

Efficient quantum circuits for Szegedy quantum walks

International Nuclear Information System (INIS)

Loke, T.; Wang, J.B.

2017-01-01

A major advantage in using Szegedy’s formalism over discrete-time and continuous-time quantum walks lies in its ability to define a unitary quantum walk by quantizing a Markov chain on a directed or weighted graph. In this paper, we present a general scheme to construct efficient quantum circuits for Szegedy quantum walks that correspond to classical Markov chains possessing transformational symmetry in the columns of the transition matrix. In particular, the transformational symmetry criteria do not necessarily depend on the sparsity of the transition matrix, so this scheme can be applied to non-sparse Markov chains. Two classes of Markov chains that are amenable to this construction are cyclic permutations and complete bipartite graphs, for which we provide explicit efficient quantum circuit implementations. We also prove that our scheme can be applied to Markov chains formed by a tensor product. We also briefly discuss the implementation of Markov chains based on weighted interdependent networks. In addition, we apply this scheme to construct efficient quantum circuits simulating the Szegedy walks used in the quantum Pagerank algorithm for some classes of non-trivial graphs, providing a necessary tool for experimental demonstration of the quantum Pagerank algorithm. - Highlights: • A general theoretical framework for implementing Szegedy walks using quantum circuits. • Explicit efficient quantum circuit implementation of the Szegedy walk for several classes of graphs. • Efficient implementation of Szegedy walks for quantum page-ranking of a certain class of graphs.

Walking ability in patients with glioblastoma: prognostic value of the Berg Balance Scale and the 10 meter walk test.

Science.gov (United States)

Liljehult, Monique Mesot; Buus, Lise; Liljehult, Jacob; Rasmussen, Birthe Krogh

2017-11-01

Primary brain tumors frequently cause considerable functional impairments and the survival time when diagnosed with glioblastoma is 14.6 months. The aim of this study was to examine if baseline postural control and walking ability in patients with glioblastoma could predict long term walking ability and 1 year mortality. Data were gathered from prospective recordings in a brain cancer database supplemented by retrospective review of electronic patient records. We included 109 patients with glioblastoma, 47 women and 62 men with mean age 65 years. At admission 84 patients were tested with Berg Balance Scale and 57 were tested with 10 meter walk test. Binary logistic regression analysis showed no statistical significance in favour of the 10 meter walk test. Berg Balance Scale showed an ability to predict walking ability 4-8 months after admission. The risk of dying within a year was 6.9 times higher in patients who lost their ability to walk within 4-8 months of the first admission. This study showed that Berg Balance Scale has some ability to predict the loss of walking ability 4-8 months after admission. This could be an important indicator pin pointing patients most in need of more intensive specialized neurorehabilitation efforts early in the disease course.

Quantum random-walk search algorithm

International Nuclear Information System (INIS)

Shenvi, Neil; Whaley, K. Birgitta; Kempe, Julia

2003-01-01

Quantum random walks on graphs have been shown to display many interesting properties, including exponentially fast hitting times when compared with their classical counterparts. However, it is still unclear how to use these novel properties to gain an algorithmic speedup over classical algorithms. In this paper, we present a quantum search algorithm based on the quantum random-walk architecture that provides such a speedup. It will be shown that this algorithm performs an oracle search on a database of N items with O(√(N)) calls to the oracle, yielding a speedup similar to other quantum search algorithms. It appears that the quantum random-walk formulation has considerable flexibility, presenting interesting opportunities for development of other, possibly novel quantum algorithms

Neuromechanical adaptations during a robotic powered exoskeleton assisted walking session.

Science.gov (United States)

Ramanujam, Arvind; Cirnigliaro, Christopher M; Garbarini, Erica; Asselin, Pierre; Pilkar, Rakesh; Forrest, Gail F

2017-04-20

To evaluate gait parameters and neuromuscular profiles of exoskeleton-assisted walking under Max Assist condition during a single-session for; (i) able bodied (AB) individuals walking assisted with (EXO) and without (non-EXO) a powered exoskeleton, (ii) non-ambulatory SCI individuals walking assisted with a powered exoskeleton. Single-session. Motion analysis laboratory. Four AB individuals and four individuals with SCI. Powered lower extremity exoskeleton. Temporal-spatial parameters, kinematics, walking velocity and electromyography data. AB individuals in exoskeleton showed greater stance time and a significant reduction in walking velocity (P exoskeleton movements, they walked with an increased velocity and lowered stance time to resemble that of slow walking. For SCI individuals, mean percent stance time was higher and walking velocity was lower compared to all AB walking conditions (P exoskeleton and moreover with voluntary control there is a greater temporal-spatial response of the lower limbs. Also, there are neuromuscular phasic adaptions for both AB and SCI groups while walking in the exoskeleton that are inconsistent to non-EXO gait muscle activation.

Primer registro de Triatoma infestans (Klug (Hemiptera: Reduviidae asociado a nidos de loros barranqueros (Cyanoliseus patagonus (Aves: Psittacidae

Directory of Open Access Journals (Sweden)

María L. HERNÁNDEZ

2015-01-01

Full Text Available Triatoma infestans es el vector más importante de la enfermedad de Chagas de la Argentina. Se cita por primera vez la presencia de T. infestans (Klug (Hemiptera: Reduviidae asociado a nidos de loro barranquero Cyanoliseus patagonus (Psittasiformes: Psittacidae construidos en viviendas de adobe abandonadas. Se discuten las posibles implicancias de este hallazgo para la vigilancia entomológica del vector.

Dilemma Produced by Infinity of a Random Walk

International Nuclear Information System (INIS)

Li Jing-Hui

2015-01-01

We report a dilemma produced by the infinity of a random walk moving along a two-dimensional space sidestep. For this random walk, our investigation shows that using a different model can lead to a different diffusion coefficient of the random walk, which is produced by the infinity of the random walk. The result obtained by us in the present work can serve as a warning to us when we build the models to investigate the corresponding scientific problems. (paper)

Efficient quantum walk on a quantum processor

Science.gov (United States)

Qiang, Xiaogang; Loke, Thomas; Montanaro, Ashley; Aungskunsiri, Kanin; Zhou, Xiaoqi; O'Brien, Jeremy L.; Wang, Jingbo B.; Matthews, Jonathan C. F.

2016-01-01

The random walk formalism is used across a wide range of applications, from modelling share prices to predicting population genetics. Likewise, quantum walks have shown much potential as a framework for developing new quantum algorithms. Here we present explicit efficient quantum circuits for implementing continuous-time quantum walks on the circulant class of graphs. These circuits allow us to sample from the output probability distributions of quantum walks on circulant graphs efficiently. We also show that solving the same sampling problem for arbitrary circulant quantum circuits is intractable for a classical computer, assuming conjectures from computational complexity theory. This is a new link between continuous-time quantum walks and computational complexity theory and it indicates a family of tasks that could ultimately demonstrate quantum supremacy over classical computers. As a proof of principle, we experimentally implement the proposed quantum circuit on an example circulant graph using a two-qubit photonics quantum processor. PMID:27146471

Does parkland influence walking? The relationship between area of parkland and walking trips in Melbourne, Australia

Directory of Open Access Journals (Sweden)

King Tania L

2012-09-01

Full Text Available Abstract Background Using two different measures of park area, at three buffer distances, we sought to investigate the ways in which park area and proximity to parks, are related to the frequency of walking (for all purposes in Australian adults. Little previous research has been conducted in this area, and results of existing research have been mixed. Methods Residents of 50 urban areas in metropolitan Melbourne, Australia completed a physical activity survey (n = 2305. Respondents reported how often they walked for ≥10 minutes in the previous month. Walking frequency was dichotomised to ‘less than weekly’ (less than 1/week and ‘at least weekly’ (1/week or more. Using Geographic Information Systems, Euclidean buffers were created around each respondent’s home at three distances: 400metres (m, 800 m and 1200 m. Total area of parkland in each person’s buffer was calculated for the three buffers. Additionally, total area of ‘larger parks’, (park space ≥ park with Australian Rules Football oval (17,862 m2, was calculated for each set of buffers. Area of park was categorised into tertiles for area of all parks, and area of larger parks (the lowest tertile was used as the reference category. Multilevel logistic regression, with individuals nested within areas, was used to estimate the effect of area of parkland on walking frequency. Results No statistically significant associations were found between walking frequency and park area (total and large parks within 400 m of respondent’s homes. For total park area within 800 m, the odds of walking at least weekly were lower for those in the mid (OR 0.65, 95% CI 0.46-0.91 and highest (OR 0.65, 95% CI 0.44-0.95 tertile of park area compared to those living in areas with the least amount of park area. Similar results were observed for total park area in the 1200 m buffers. When only larger parks were investigated, again more frequent walking was less likely when respondents had

Population growth and within-plant distribution of the striped mealybug Ferrisia virgata (Cockerell (Hemiptera, Pseudococcidae on cotton

Directory of Open Access Journals (Sweden)

Martin D. Oliveira

2014-03-01

Full Text Available Population growth and within-plant distribution of the striped mealybug Ferrisia virgata (Cockerell (Hemiptera, Pseudococcidae on cotton. The striped mealybug, Ferrisia virgata (Cockerell (Hemiptera, Pseudococcidae, is a widely distributed and polyphagous pest species, which naturally occurs on cotton plants in Brazil. This study evaluated the establishment and population growth as well as the within-plant distribution of F. virgata on four cotton cultivars: CNPA 7H (white fibers, BRS Verde, BRS Safira, and BRS Rubi (colored fibers. The experiment was conducted in a complete randomized design with four treatments (cultivars and 18 replications of each. Thus, cotton plants of each cultivar were infested with 100 newly hatched nymphs of F. virgata. The number of adult female mealybugs and the total number of mealybugs per plant were quantified, respectively, at 25 and 50 days after infestation. The developmental and pre-reproductive periods were also determined. Furthermore, we verified the distribution of F. virgata on the plant parts at 25 and 50 days after infestation. Ferrisia virgata showed similar growth of 412-fold in the four cotton cultivars studied. Also, the nymphs were spread on infested leaves; the secondgeneration nymphs were spread and established in all plant parts. Our results characterize F. virgata as having much potential as an important cotton pest in Brazil.

Biomechanics of stair walking and jumping.

Science.gov (United States)

Loy, D J; Voloshin, A S

1991-01-01

Physical activities such as stair walking and jumping result in increased dynamic loading on the human musculoskeletal system. Use of light weight, externally attached accelerometers allows for in-vivo monitoring of the shock waves invading the human musculoskeletal system during those activities. Shock waves were measured in four subjects performing stair walking up and down, jumping in place and jumping off a fixed elevation. The results obtained show that walking down a staircase induced shock waves with amplitude of 130% of that observed in walking up stairs and 250% of the shock waves experienced in level gait. The jumping test revealed levels of the shock waves nearly eight times higher than that in level walking. It was also shown that the shock waves invading the human musculoskeletal system may be generated not only by the heel strike, but also by the metatarsal strike. To moderate the risk of degenerative joint disorders four types of viscoelastic insoles were utilized to reduce the impact generated shock waves. The insoles investigated were able to reduce the amplitude of the shock wave by between 9% and 41% depending on the insole type and particular physical activity. The insoles were more effective in the reduction of the heel strike impacts than in the reduction of the metatarsal strike impacts. In all instances, the shock attenuation capacities of the insoles tested were greater in the jumping trials than in the stair walking studies. The insoles were ranked in three groups on the basis of their shock absorbing capacity.

Walking adaptability after a stroke and its assessment in clinical settings.

Science.gov (United States)

Balasubramanian, Chitralakshmi K; Clark, David J; Fox, Emily J

2014-01-01

Control of walking has been described by a tripartite model consisting of stepping, equilibrium, and adaptability. This review focuses on walking adaptability, which is defined as the ability to modify walking to meet task goals and environmental demands. Walking adaptability is crucial to safe ambulation in the home and community environments and is often severely compromised after a stroke. Yet quantification of walking adaptability after stroke has received relatively little attention in the clinical setting. The objectives of this review were to examine the conceptual challenges for clinical measurement of walking adaptability and summarize the current state of clinical assessment for walking adaptability. We created nine domains of walking adaptability from dimensions of community mobility to address the conceptual challenges in measurement and reviewed performance-based clinical assessments of walking to determine if the assessments measure walking adaptability in these domains. Our literature review suggests the lack of a comprehensive well-tested clinical assessment tool for measuring walking adaptability. Accordingly, recommendations for the development of a comprehensive clinical assessment of walking adaptability after stroke have been presented. Such a clinical assessment will be essential for gauging recovery of walking adaptability with rehabilitation and for motivating novel strategies to enhance recovery of walking adaptability after stroke.

Walking with Students To Increase Satisfaction and Retention.

Science.gov (United States)

Steinhaus, Carol s.

1999-01-01

Describes "walking office hours," an activity in which students (n=64) in introductory health topics and human resources management classes each took a one-half hour walk with the professor around the campus. In both classes students unanimously reported higher "comfort levels" with the instructor following the walk. (DB)

Daily intermittent hypoxia enhances walking after chronic spinal cord injury

Science.gov (United States)

Hayes, Heather B.; Jayaraman, Arun; Herrmann, Megan; Mitchell, Gordon S.; Rymer, William Z.

2014-01-01

Objectives: To test the hypothesis that daily acute intermittent hypoxia (dAIH) and dAIH combined with overground walking improve walking speed and endurance in persons with chronic incomplete spinal cord injury (iSCI). Methods: Nineteen subjects completed the randomized, double-blind, placebo-controlled, crossover study. Participants received 15, 90-second hypoxic exposures (dAIH, fraction of inspired oxygen [Fio2] = 0.09) or daily normoxia (dSHAM, Fio2 = 0.21) at 60-second normoxic intervals on 5 consecutive days; dAIH was given alone or combined with 30 minutes of overground walking 1 hour later. Walking speed and endurance were quantified using 10-Meter and 6-Minute Walk Tests. The trial is registered at ClinicalTrials.gov (NCT01272349). Results: dAIH improved walking speed and endurance. Ten-Meter Walk time improved with dAIH vs dSHAM after 1 day (mean difference [MD] 3.8 seconds, 95% confidence interval [CI] 1.1–6.5 seconds, p = 0.006) and 2 weeks (MD 3.8 seconds, 95% CI 0.9–6.7 seconds, p = 0.010). Six-Minute Walk distance increased with combined dAIH + walking vs dSHAM + walking after 5 days (MD 94.4 m, 95% CI 17.5–171.3 m, p = 0.017) and 1-week follow-up (MD 97.0 m, 95% CI 20.1–173.9 m, p = 0.014). dAIH + walking increased walking distance more than dAIH after 1 day (MD 67.7 m, 95% CI 1.3–134.1 m, p = 0.046), 5 days (MD 107.0 m, 95% CI 40.6–173.4 m, p = 0.002), and 1-week follow-up (MD 136.0 m, 95% CI 65.3–206.6 m, p walking improved walking speed and distance in persons with chronic iSCI. The impact of dAIH is enhanced by combination with walking, demonstrating that combinatorial therapies may promote greater functional benefits in persons with iSCI. Classification of evidence: This study provides Class I evidence that transient hypoxia (through measured breathing treatments), along with overground walking training, improves walking speed and endurance after iSCI. PMID:24285617

Brownian Optimal Stopping and Random Walks

International Nuclear Information System (INIS)

Lamberton, D.

2002-01-01

One way to compute the value function of an optimal stopping problem along Brownian paths consists of approximating Brownian motion by a random walk. We derive error estimates for this type of approximation under various assumptions on the distribution of the approximating random walk

Pseudo-Hermitian continuous-time quantum walks

Energy Technology Data Exchange (ETDEWEB)

Salimi, S; Sorouri, A, E-mail: shsalimi@uok.ac.i, E-mail: a.sorouri@uok.ac.i [Department of Physics, University of Kurdistan, PO Box 66177-15175, Sanandaj (Iran, Islamic Republic of)

2010-07-09

In this paper we present a model exhibiting a new type of continuous-time quantum walk (as a quantum-mechanical transport process) on networks, which is described by a non-Hermitian Hamiltonian possessing a real spectrum. We call it pseudo-Hermitian continuous-time quantum walk. We introduce a method to obtain the probability distribution of walk on any vertex and then study a specific system. We observe that the probability distribution on certain vertices increases compared to that of the Hermitian case. This formalism makes the transport process faster and can be useful for search algorithms.

Walking on a moving surface: energy-optimal walking motions on a shaky bridge and a shaking treadmill can reduce energy costs below normal.

Science.gov (United States)

Joshi, Varun; Srinivasan, Manoj

2015-02-08

Understanding how humans walk on a surface that can move might provide insights into, for instance, whether walking humans prioritize energy use or stability. Here, motivated by the famous human-driven oscillations observed in the London Millennium Bridge, we introduce a minimal mathematical model of a biped, walking on a platform (bridge or treadmill) capable of lateral movement. This biped model consists of a point-mass upper body with legs that can exert force and perform mechanical work on the upper body. Using numerical optimization, we obtain energy-optimal walking motions for this biped, deriving the periodic body and platform motions that minimize a simple metabolic energy cost. When the platform has an externally imposed sinusoidal displacement of appropriate frequency and amplitude, we predict that body motion entrained to platform motion consumes less energy than walking on a fixed surface. When the platform has finite inertia, a mass- spring-damper with similar parameters to the Millennium Bridge, we show that the optimal biped walking motion sustains a large lateral platform oscillation when sufficiently many people walk on the bridge. Here, the biped model reduces walking metabolic cost by storing and recovering energy from the platform, demonstrating energy benefits for two features observed for walking on the Millennium Bridge: crowd synchrony and large lateral oscillations.

The influence of incline walking on joint mechanics.

Science.gov (United States)

Haggerty, Mason; Dickin, D Clark; Popp, Jennifer; Wang, Henry

2014-04-01

Walking is a popular form of exercise and is associated with many health benefits; however, frontal-plane knee joint loading brought about by a large internal knee-abduction moment and cyclic loading could lead to cartilage degeneration over time. Therefore, knee joint mechanics during an alternative walking exercise needs to be analyzed. The purpose of this study was to examine the lower-extremity joint mechanics in the frontal and sagittal planes during incline walking. Fifteen healthy males walked on a treadmill at five gradients (0%, 5%, 10%, 15%, and 20%) at 1.34m/s, and lower-extremity joint mechanics in the frontal and sagittal planes were quantified. The peak internal knee-abduction moment significantly decreased from the level walking condition at all gradients except 5%. Also, a negative relationship between the internal knee-abduction moment and the treadmill gradient was found to exist in 10% increments (0-10%, 5-15%, and 10-20%). The decrease in the internal knee-abduction moment during incline walking could have positive effects on knee joint health such as potentially reducing cartilage degeneration of the knee joint, reducing pain, and decreasing the rate of development of medial tibiofemoral osteoarthritis. This would be beneficial for a knee surgery patient, obese persons, and older adults who are using incline walking for rehabilitation and exercise protocols. Findings from the current study can provide guidance for the development of rehabilitation and exercise prescriptions incorporating incline walking. Copyright © 2014 Elsevier B.V. All rights reserved.

Fitness Club / Nordic Walking

CERN Multimedia

Fitness Club

2011-01-01

Nordic Walking at CERN Enrollments are open for Nordic Walking courses and outings at CERN. Classes will be on Tuesdays as of 20 September, and outings for the more experienced will be on Thursdays as of 15 September. We meet at the CERN Club barracks car park (near entrance A). • 18:00 to 19:00 on 20 & 27 September, as well as 4 & 11 October. Check out our schedule and rates and enroll at: http://cern.ch/club-fitness Hope to see you among us! CERN Fitness Club fitness.club@cern.ch  

Description of the immature stages of the planthopper Lacertinella australis (Hemiptera: Delphacidae)

Science.gov (United States)

Batiz, M. F. Rossi; Marino de Remes Lenicov, A. M.; Hagedorn, Henry

2014-01-01

Abstract The five immature stages of the planthopper Lacertinella australis (Remes Lenicov and Rossi Batiz) (Hemiptera: Delphacidae: Saccharosydnini) are described and illustrated. The main characters that allowed us to distinguish the various stages were body size, number of tarsomeres and metatibial spines, and number of teeth on the spur. New biological data based on laboratory rearing and field observations showed that L. australis can carry out its biological cycle successfully on the graminaceous pampas grass ( Cortaderia spp. Stapf (Poales: Poaceae)). In addition, the efficient rearing in captivity, the high survivorship registered, and overwintering only on this host plant suggests that L. australis is a potential biocontrol agent of this invasive graminaceous weed. This study provides information about the immature stages , including a key for their identification, based on laboratory reared specimens and field observations. Resumen Se describen e ilustran las cinco etapas inmaduras de la especie de Saccharisydnini Lacertinella australis (Remes Lenicov and Rossi Batiz) (Hemiptera: Delphacidae). Los principales caracteres que permitieron distinguir las diferentes etapas fueron: tamaño corporal, número de espinas en los tarsómeros y metatibia y número de dientes en el espolón tibial. Nuevos datos biológicos, basados en la cría de laboratorio y observaciones de campo, mostraron que L. australis puede realizar su ciclo biológico exitosamente en la graminácea cortadera ( Cortaderia spp. Stapf (Poales: Poaceae)). Además, la eficiente crianza en cautive-rio y la alta supervivencia registrada en esta planta hospedera, sugieren que L. australis podría ser usada como un potencial agente de control biológico de esta maleza invasora. Este estudio proporciona informa-ción sobre las etapas inmaduras, incluyendo una clave para su identificación, basada en individuos provenientes de la cría de laboratorio y de campo. PMID:25199992

A severity rating system for evaluating stand-level balsam woolly adelgid (Hemiptera: Adelgidae) damage in two Abies species in western North America

Science.gov (United States)

Kathryn H. Hrinkevich; Robert A. Progar; David C. Shaw

2016-01-01

Severity rating systems are fundamental to understanding the impacts of disturbance agents in forest stands. The balsam woolly adelgid (BWA), Adelges piceae (Ratzeburg) (Hemiptera: Adelgidae), is an invasive forest pest in North America that infests and causes mortality in true fir, Abies spp. There is currently no single...

Male Enchenopa treehoppers (Hemiptera: Membracidae) vary mate-searching behavior but not signaling behavior in response to spider silk

Science.gov (United States)

Fowler-Finn, Kasey D.; Al-Wathiqui, Nooria; Cruz, Daniel; Al-Wathiqui, Mishal; Rodríguez, Rafael L.

2014-03-01

Finding and attracting mates can impose costs on males in terms of increased encounters with, and attraction of, predators. To decrease the likelihood of predation, males may modify mate-acquisition efforts in two main ways: they may reduce mate-searching efforts or they may reduce mate-attraction efforts. The specific behavior that males change in the presence of predator cues should depend upon the nature of risk imposed by the type of predator present in the environment. For example, sit-and-wait predators impose greater costs to males moving in search of mates. Here, we test whether cues of the presence of a sit-and-wait predator lead to a reduction in mate-searching but not mate-acquisition behavior. We used a member of the Enchenopa binotata complex of treehoppers—a clade of vibrationally communicating insects in which males fly in search of mates and produce mate-attraction signals when they land on plant stems. We tested for changes in mate-searching and signaling behaviors when silk from a web-building spider was present or absent. We found that males delayed flight when spider silk was present but only if they were actively searching for mates. These results suggest that males have been selected to reduce predation risk by adjusting how they move about their environment according to the cues of sit-and-wait predators.

Using built environment characteristics to predict walking for exercise

Directory of Open Access Journals (Sweden)

Siscovick David S

2008-02-01

Full Text Available Abstract Background Environments conducive to walking may help people avoid sedentary lifestyles and associated diseases. Recent studies developed walkability models combining several built environment characteristics to optimally predict walking. Developing and testing such models with the same data could lead to overestimating one's ability to predict walking in an independent sample of the population. More accurate estimates of model fit can be obtained by splitting a single study population into training and validation sets (holdout approach or through developing and evaluating models in different populations. We used these two approaches to test whether built environment characteristics near the home predict walking for exercise. Study participants lived in western Washington State and were adult members of a health maintenance organization. The physical activity data used in this study were collected by telephone interview and were selected for their relevance to cardiovascular disease. In order to limit confounding by prior health conditions, the sample was restricted to participants in good self-reported health and without a documented history of cardiovascular disease. Results For 1,608 participants meeting the inclusion criteria, the mean age was 64 years, 90 percent were white, 37 percent had a college degree, and 62 percent of participants reported that they walked for exercise. Single built environment characteristics, such as residential density or connectivity, did not significantly predict walking for exercise. Regression models using multiple built environment characteristics to predict walking were not successful at predicting walking for exercise in an independent population sample. In the validation set, none of the logistic models had a C-statistic confidence interval excluding the null value of 0.5, and none of the linear models explained more than one percent of the variance in time spent walking for exercise. We did not

Skyrmion burst and multiple quantum walk in thin ferromagnetic films

International Nuclear Information System (INIS)

Ezawa, Motohiko

2011-01-01

We propose a new type of quantum walk in thin ferromagnetic films. A giant Skyrmion collapses to a singular point in a thin ferromagnetic film, emitting spin waves, when external magnetic field is increased beyond the critical one. After the collapse the remnant is a quantum walker carrying spin S. We determine its time evolution and show the diffusion process is a continuous-time quantum walk. We also analyze an interference of two quantum walkers after two Skyrmion bursts. The system presents a new type of quantum walk for S>1/2, where a quantum walker breaks into 2S quantum walkers. -- Highlights: → A giant Skyrmion collapses to a singular point by applying strong magnetic field. → Quantum walk is realized in thin ferromagnetic films by Skyrmion collapsing. → Quantum walks for S=1/2 and 1 are exact solvable, where S represents the spin. → Quantum walks for >1/2 presents a new type of quantum walks, i.e., 'multiple quantum walks'. → Skyrmion bursts which occur simultaneously exhibit an interference as a manifestation of quantum walk.

Human-like Walking with Compliant Legs

NARCIS (Netherlands)

Visser, L.C.; de Geus, Wouter; Stramigioli, Stefano; Carloni, Raffaella

2011-01-01

This work presents a novel approach to robotic bipedal walking. Based on the bipedal spring-mass model, which is known to closely describe human-like walking behavior, a robot has been designed that approaches the ideal model as closely as possible. The compliance of the springs is controllable by

Learning to walk changes infants' social interactions.

Science.gov (United States)

Clearfield, Melissa W

2011-02-01

The onset of crawling marks a motor, cognitive and social milestone. The present study investigated whether independent walking marks a second milestone for social behaviors. In Experiment 1, the social and exploratory behaviors of crawling infants were observed while crawling and in a baby-walker, resulting in no differences based on posture. In Experiment 2, the social behaviors of independently walking infants were compared to age-matched crawling infants in a baby-walker. Independently walking infants spent significantly more time interacting with the toys and with their mothers, and also made more vocalizations and more directed gestures compared to infants in the walker. Experiment 3 tracked infants' social behaviors longitudinally across the transition from crawling and walking. Even when controlled for age, the transition to independent walking marked increased interaction time with mothers, as well as more sophisticated interactions, including directing mothers' attention to particular objects. The results suggest a developmental progression linking social interactions with milestones in locomotor development. Copyright © 2010 Elsevier Inc. All rights reserved.

Effects of a 6-month exercise program pilot study on walking economy, peak physiological characteristics, and walking performance in patients with peripheral arterial disease

Directory of Open Access Journals (Sweden)

Crowther RG

2012-04-01

Full Text Available Robert G Crowther1, Anthony S Leicht1, Warwick L Spinks1, Kunwarjit Sangla2, Frank Quigley2, Jonathan Golledge2,31Institute of Sport and Exercise Science, James Cook University, Townsville, Queensland, Australia; 2Townsville Hospital, Townsville, Queensland, Australia; 3The Vascular Biology Unit, James Cook University, Townsville, Queensland, AustraliaAbstract : The purpose of this study was to examine the effects of a 6-month exercise program on submaximal walking economy in individuals with peripheral arterial disease and intermittent claudication (PAD-IC. Participants (n = 16 were randomly allocated to either a control PAD-IC group (CPAD-IC, n = 6 which received standard medical therapy, or a treatment PAD-IC group (TPAD-IC; n = 10 which took part in a supervised exercise program. During a graded treadmill test, physiological responses, including oxygen consumption, were assessed to calculate walking economy during submaximal and maximal walking performance. Differences between groups at baseline and post-intervention were analyzed via Kruskal–Wallis tests. At baseline, CPAD-IC and TPAD-IC groups demonstrated similar walking performance and physiological responses. Postintervention, TPAD-IC patients demonstrated significantly lower oxygen consumption during the graded exercise test, and greater maximal walking performance compared to CPAD-IC. These preliminary results indicate that 6 months of regular exercise improves both submaximal walking economy and maximal walking performance, without significant changes in maximal walking economy. Enhanced walking economy may contribute to physiological efficiency, which in turn may improve walking performance as demonstrated by PAD-IC patients following regular exercise programs.Keywords: vascular disease, peripheral vascular disease, walking economy

Iterated random walks with shape prior

DEFF Research Database (Denmark)

Pujadas, Esmeralda Ruiz; Kjer, Hans Martin; Piella, Gemma

2016-01-01

the parametric probability density function. Then, random walks is performed iteratively aligning the prior with the current segmentation in every iteration. We tested the proposed approach with natural and medical images and compared it with the latest techniques with random walks and shape priors......We propose a new framework for image segmentation using random walks where a distance shape prior is combined with a region term. The shape prior is weighted by a confidence map to reduce the influence of the prior in high gradient areas and the region term is computed with k-means to estimate....... The experiments suggest that this method gives promising results for medical and natural images....

Modeling Framework and Software Tools for Walking Robots

NARCIS (Netherlands)

Duindam, V.; Stramigioli, Stefano; Groen, F.N.J.

2005-01-01

In research on passive dynamic walking, the aim is to study and design robots that walk naturally, i.e., with little or no control effort. McGeer [1] and others (e.g. [2, 3]) have shown that, indeed, robots can walk down a shallow slope with no actuation, only powered by gravity. In this work, we

Comparison of functional ramp walk test and 6-min walk test in healthy volunteers: A new approach in functional capacity evaluation

Directory of Open Access Journals (Sweden)

Manivel Arumugam

2017-01-01

Full Text Available Objective: Inclined surfaces or ramps are the common obstacles faced by elderly and cardiopulmonary disabled in accessing public amenities. Ramp walking is one of the most common functional demands to be met by a common man in the industrialized world. To assess the functional (uphill walking capacity, we need a different functional stress test over the routinely used 6-min walk test (6MWT. Hence, a new 3-min steep ramp walk test (3MRWT was constructed to meet the demands similar to an uphill walk and to provide more functional stress than routinely used 6MWT. Methodology: The observational, crossover study design was adopted for this study. Fifteen healthy participants (8 males, 7 females performed both tests in a randomized order with a washout time of 6 h in between the tests. Walking distance to both ramp and ground, heart rate, blood pressure, saturation (SpO2, dyspnea, and fatigue with Borg exertion scale were compared prior and after the two walk tests. Results: The average distances covered in 6MWT were 510.5 ± 55.06 and 440.65 ± 25.08 meters and in 3MRWT were 270.18 ± 30.8, 230.05 ± 15.06 meters for male and female respectively. The difference between 3MRWT and 6MWT distances covered by the participants was statistically significant (t = 0.893. The mean difference between the heart rate, saturation and perceptions were highly significant (P < 0.001. Conclusion: The study results show that 3MRWT is valid over routinely administered 6MWT and may provide greater functional stress (uphill or ramp walk capacity in a shorter duration in healthy individuals in assessing the maximal functional capacity in a ramp or uphill walking.

Analysis of coined quantum walks with renormalization

Science.gov (United States)

Boettcher, Stefan; Li, Shanshan

2018-01-01

We introduce a framework to analyze quantum algorithms with the renormalization group (RG). To this end, we present a detailed analysis of the real-space RG for discrete-time quantum walks on fractal networks and show how deep insights into the analytic structure as well as generic results about the long-time behavior can be extracted. The RG flow for such a walk on a dual Sierpinski gasket and a Migdal-Kadanoff hierarchical network is obtained explicitly from elementary algebraic manipulations, after transforming the unitary evolution equation into Laplace space. Unlike for classical random walks, we find that the long-time asymptotics for the quantum walk requires consideration of a diverging number of Laplace poles, which we demonstrate exactly for the closed-form solution available for the walk on a one-dimensional loop. In particular, we calculate the probability of the walk to overlap with its starting position, which oscillates with a period that scales as NdwQ/df with system size N . While the largest Jacobian eigenvalue λ1 of the RG flow merely reproduces the fractal dimension, df=log2λ1 , the asymptotic analysis shows that the second Jacobian eigenvalue λ2 becomes essential to determine the dimension of the quantum walk via dwQ=log2√{λ1λ2 } . We trace this fact to delicate cancellations caused by unitarity. We obtain identical relations for other networks, although the details of the RG analysis may exhibit surprisingly distinct features. Thus, our conclusions—which trivially reproduce those for regular lattices with translational invariance with df=d and dwQ=1 —appear to be quite general and likely apply to networks beyond those studied here.

Primeiro Registro de Afídeos (Hemiptera: Aphidoidea) em Carambola (Averrhoa carambola L.) no Brasil

OpenAIRE

Cunha, Suzan Beatriz Zambon da; Sousa e Silva, Carlos Roberto

2016-01-01

A carambola (Averrhoa carambola L.) árvore de origem Asiática foi introduzida no Brasil em 1817, desde então vem aumentando sua área de cultivo no país. A planta é atacada por poucos insetos como as moscas e percevejos. Este trabalho relata a presença de Aphis gossypii Glover em A. carambola pela primeira vez no Brasil. First Record of Aphids (Hemiptera: Aphididae) on Starfruit (Averrhoa carambola L.) in Brazil Abstract. The starfruit (Averrhoa carambola L.) has origin Asiatic an...

Walking: Paths of a political and artistic practice

Directory of Open Access Journals (Sweden)

Sergio Martínez Luna

2016-11-01

Full Text Available Walking is a practice that involves issues related to body, landscape, nature and city. The article provides a historical overview of some of these practices from English Romanticism to contemporary art. Within this historical framework walking is approached as a political and aesthetic practice that questions the logics of economic efficiency, as well as the parallel processes of privatization of public space. The different modalities of walking (alone, in group, around the city, through natural landscapes come together as different poetics and politics. Walking is to make a public discourse that stablishes a dialectic between traces and presences.

Scaling Argument of Anisotropic Random Walk

International Nuclear Information System (INIS)

Xu Bingzhen; Jin Guojun; Wang Feifeng

2005-01-01

In this paper, we analytically discuss the scaling properties of the average square end-to-end distance (R 2 ) for anisotropic random walk in D-dimensional space (D≥2), and the returning probability P n (r 0 ) for the walker into a certain neighborhood of the origin. We will not only give the calculating formula for (R 2 ) and P n (r 0 ), but also point out that if there is a symmetric axis for the distribution of the probability density of a single step displacement, we always obtain (R p erpendicular n 2 )∼n, where perpendicular refers to the projections of the displacement perpendicular to each symmetric axes of the walk; in D-dimensional space with D symmetric axes perpendicular to each other, we always have (R n 2 )∼n and the random walk will be like a purely random motion; if the number of inter-perpendicular symmetric axis is smaller than the dimensions of the space, we must have (R n 2 )∼n 2 for very large n and the walk will be like a ballistic motion. It is worth while to point out that unlike the isotropic random walk in one and two dimensions, which is certain to return into the neighborhood of the origin, generally there is only a nonzero probability for the anisotropic random walker in two dimensions to return to the neighborhood.

Four new species of the genus Mongoliana Distant (Hemiptera: Fulgoromorpha: Issidae) from southern China.

Science.gov (United States)

Meng, Rui; Wang, Yinglun; Qin, Daozheng

2016-01-05

Four new species in the planthopper genus Mongoliana Distant from southern China (Hemiptera: Fulgoromorpha: Issidae) are reported. Three of them, M. bistriata sp. nov., M. latistriata sp. nov. and M. albimaculata sp. nov., are described and illustrated; the fourth new one, M. arcuata sp. nov., is briefly described for M. triangularis Chen, Zhang & Chang which was a misidentification of M. triangularis Che, Wang & Chou. M. recurrens (Butler, 1875) is re-described and remarks for its current status is given. A key to all known species of Mongoliana is provided. The distribution and morphological peculiarities of the genus are briefly discussed.

Cardiorespiratory Responses to Pool Floor Walking in People Poststroke.

Science.gov (United States)

Jeng, Brenda; Fujii, Takuto; Lim, Hyosok; Vrongistinos, Konstantinos; Jung, Taeyou

2018-03-01

To compare cardiorespiratory responses between pool floor walking and overground walking (OW) in people poststroke. Cross-sectional study. University-based therapeutic exercise facility. Participants (N=28) were comprised of 14 community-dwelling individuals poststroke (5.57±3.57y poststroke) and 14 age- and sex-matched healthy adults (mean age, 58.00±15.51y; male/female ratio, 9:5). Not applicable. A telemetric metabolic system was used to collect cardiorespiratory variables, including oxygen consumption (V˙o 2 ), energy expenditure (EE), and expired volume per unit time (V˙e), during 6-minute walking sessions in chest-depth water and on land at a matched speed, determined by average of maximum walking speed in water. Individuals poststroke elicited no significant differences in cardiorespiratory responses between pool floor walking and OW. However, healthy controls showed significant increases in mean V˙o 2 values by 94%, EE values by 109%, and V˙e values by 94% (all Pstroke group did not. Our results indicate that people poststroke, unlike healthy adults, do not increase EE while walking in water compared with on land. Unlike stationary walking on an aquatic treadmill, forward locomotion during pool floor walking at faster speeds may have increased drag force, which requires greater EE from healthy adults. Without demanding excessive EE, walking in water may offer a naturally supportive environment for gait training in the early stages of rehabilitation. Copyright © 2017 American Congress of Rehabilitation Medicine. All rights reserved.

Studies on idiocerine leafhoppers with descriptions of Chinaocerus gen. nov. and three new species from China (Hemiptera: Cicadomorpha: Cicadellidae).

Science.gov (United States)

Dang, Li-Hong; Zhang, Bin; Li, Zi-Zhong

2016-03-08

A new leafhopper genus of the tribe Idiocerini (Hemiptera: Cicadomorpha: Cicadellidae), Chinaocerus, is described from the southwest China together with three new species, C. kangdingensis Zhang & Li sp. nov. (Sichuan Province), C. bispinatus Zhang & Li sp. nov. (Yunnan Province) and C. shii Zhang & Li sp. nov. (Sichuan Province). Descriptions and illustrations of these three new species are provided, and a key for their separation is also given.

Treadmill training and body weight support for walking after stroke.

Science.gov (United States)

Mehrholz, Jan; Thomas, Simone; Elsner, Bernhard

2017-08-17

Treadmill training, with or without body weight support using a harness, is used in rehabilitation and might help to improve walking after stroke. This is an update of the Cochrane review first published in 2003 and updated in 2005 and 2014. To determine if treadmill training and body weight support, individually or in combination, improve walking ability, quality of life, activities of daily living, dependency or death, and institutionalisation or death, compared with other physiotherapy gait-training interventions after stroke. The secondary objective was to determine the safety and acceptability of this method of gait training. We searched the Cochrane Stroke Group Trials Register (last searched 14 February 2017), the Cochrane Central Register of Controlled Trials (CENTRAL) and the Database of Reviews of Effects (DARE) (the Cochrane Library 2017, Issue 2), MEDLINE (1966 to 14 February 2017), Embase (1980 to 14 February 2017), CINAHL (1982 to 14 February 2017), AMED (1985 to 14 February 2017) and SPORTDiscus (1949 to 14 February 2017). We also handsearched relevant conference proceedings and ongoing trials and research registers, screened reference lists, and contacted trialists to identify further trials. Randomised or quasi-randomised controlled and cross-over trials of treadmill training and body weight support, individually or in combination, for the treatment of walking after stroke. Two review authors independently selected trials, extracted data, and assessed risk of bias and methodological quality. The primary outcomes investigated were walking speed, endurance, and dependency. We included 56 trials with 3105 participants in this updated review. The average age of the participants was 60 years, and the studies were carried out in both inpatient and outpatient settings. All participants had at least some walking difficulties and many could not walk without assistance. Overall, the use of treadmill training did not increase the chances of walking

The "Interval Walking in Colorectal Cancer" (I-WALK-CRC) study: Design, methods and recruitment results of a randomized controlled feasibility trial.

Science.gov (United States)

Banck-Petersen, Anna; Olsen, Cecilie K; Djurhuus, Sissal S; Herrstedt, Anita; Thorsen-Streit, Sarah; Ried-Larsen, Mathias; Østerlind, Kell; Osterkamp, Jens; Krarup, Peter-Martin; Vistisen, Kirsten; Mosgaard, Camilla S; Pedersen, Bente K; Højman, Pernille; Christensen, Jesper F

2018-03-01

Low physical activity level is associated with poor prognosis in patients with colorectal cancer (CRC). To increase physical activity, technology-based platforms are emerging and provide intriguing opportunities to prescribe and monitor active lifestyle interventions. The "Interval Walking in Colorectal Cancer"(I-WALK-CRC) study explores the feasibility and efficacy a home-based interval-walking intervention delivered by a smart-phone application in order to improve cardio-metabolic health profile among CRC survivors. The aim of the present report is to describe the design, methods and recruitment results of the I-WALK-CRC study.Methods/Results: The I-WALK-CRC study is a randomized controlled trial designed to evaluate the feasibility and efficacy of a home-based interval walking intervention compared to a waiting-list control group for physiological and patient-reported outcomes. Patients who had completed surgery for local stage disease and patients who had completed surgery and any adjuvant chemotherapy for locally advanced stage disease were eligible for inclusion. Between October 1st , 2015, and February 1st , 2017, 136 inquiries were recorded; 83 patients were eligible for enrollment, and 42 patients accepted participation. Age and employment status were associated with participation, as participants were significantly younger (60.5 vs 70.8 years, P CRC survivors was feasible but we aim to better the recruitment rate in future studies. Further, the study clearly favored younger participants. The I-WALK-CRC study will provide important information regarding feasibility and efficacy of a home-based walking exercise program in CRC survivors.

Hopeless love and other lattice walks

NARCIS (Netherlands)

Verhoeff, T.; Verhoeff, Koos; Swart, David; Séquin, Carlo H.; Fenyvesi, Kristóf

The Hopeless Love theme arose from observations about chess bishops and their walks on the chessboard. In chess, there are two types of bishops: one confined to the white squares and the other to the black squares. If two bishops of opposite type fall in love, then they can walk around each other,

Does dynamic stability govern propulsive force generation in human walking?

Science.gov (United States)

Browne, Michael G; Franz, Jason R

2017-11-01

Before succumbing to slower speeds, older adults may walk with a diminished push-off to prioritize stability over mobility. However, direct evidence for trade-offs between push-off intensity and balance control in human walking, independent of changes in speed, has remained elusive. As a critical first step, we conducted two experiments to investigate: (i) the independent effects of walking speed and propulsive force ( F P ) generation on dynamic stability in young adults, and (ii) the extent to which young adults prioritize dynamic stability in selecting their preferred combination of walking speed and F P generation. Subjects walked on a force-measuring treadmill across a range of speeds as well as at constant speeds while modulating their F P according to a visual biofeedback paradigm based on real-time force measurements. In contrast to improvements when walking slower, walking with a diminished push-off worsened dynamic stability by up to 32%. Rather, we find that young adults adopt an F P at their preferred walking speed that maximizes dynamic stability. One implication of these findings is that the onset of a diminished push-off in old age may independently contribute to poorer balance control and precipitate slower walking speeds.

Do Scaphoideus titanus (Hemiptera: Cicadellidae) nymphs use vibrational communication?

Science.gov (United States)

Chuche, Julien; Thiéry, Denis; Mazzoni, Valerio

2011-07-01

Small Auchenorrhyncha use substrate-borne vibrations to communicate. Although this behaviour is well known in adult leafhoppers, so far no studies have been published on nymphs. Here we checked the occurrence of vibrational communication in Scaphoideus titanus (Hemiptera: Cicadellidae) nymphs as a possible explanation of their aggregative distributions on host plants. We studied possible vibratory emissions of isolated and grouped nymphs, as well as their behavioural responses to vibration stimuli that simulated presence of conspecifics, to disturbance noise, white noise and predator spiders. None of our synthetic stimuli or pre-recorded substrate vibrations from nymphs elicited specific vibration responses and only those due to grooming or mechanical contacts of the insect with the leaf were recorded. Thus, S. titanus nymphs showed to not use species-specific vibrations neither for intra- nor interspecific communication and also did not produce alarm vibrations when facing potential predators. We conclude that their aggregative behaviour is independent from a vibrational communication.

Inheritance of sterility in Dysdercus koenigii F. (Hemiptera: Pyrrhocoridae)

International Nuclear Information System (INIS)

Harwalkar, M.R.; Rahalkar, G.W.

1979-01-01

It has been suggested that for the control of Lepidopterous populations, release of fully competitive partially sterile males would be more advantageous than the release of completely sterile males. This suggestion is based on the fact, elucidated in many studies, that partially sterilized males mated to normal females produce totally sterile or partially sterile progeny. In Hemiptera too, F 1 progeny of partially sterile males has been shown to inherit sterility. Individual impact of sterility inherited by either sex of the F 1 progeny on population growth has been studied in an hemipteran insect Dysdercus koenigii. A dose of 7 krad induces near-complete sterility in males. When males irradiated with substerilizing doses of 1,2 and 3 krad were crossed with normal females, F 1 progeny of both sexes was partially sterile : the female being more sterile than the males. When the F 1 progeny was intercrossed, there was enhanced reduction in progeny production. (auth.)

Changes in resting and walking energy expenditure and walking speed during pregnancy in obese women.

Science.gov (United States)

Byrne, Nuala M; Groves, Ainsley M; McIntyre, H David; Callaway, Leonie K

2011-09-01

Energy-conserving processes reported in undernourished women during pregnancy are a recognized strategy for providing the energy required to support fetal development. Women who are obese before conceiving arguably have sufficient fat stores to support the energy demands of pregnancy without the need to provoke energy-conserving mechanisms. We tested the hypothesis that obese women would show behavioral adaptation [ie, a decrease in self-selected walking (SSW) speed] but not metabolic compensation [ie, a decrease in resting metabolic rate (RMR) or the metabolic cost of walking] during gestation. RMR, SSW speed, metabolic cost of walking, and anthropometric variables were measured in 23 women aged 31 ± 4 y with a BMI (in kg/m(2)) of 33.6 ± 2.5 (mean ± SD) at ≈15 and 30 wk of gestation. RMR was also measured in 2 cohorts of nonpregnant control subjects matched for the age, weight, and height of the pregnant cohort at 15 (n = 23) and 30 (n = 23) wk. Gestational weight gain varied widely (11.3 ± 5.4 kg), and 52% of the women gained more weight than is recommended. RMR increased significantly by an average of 177 ± 176 kcal/d (11 ± 12%; P 80% of the cohort, the net oxygen cost of walking decreased in the same proportion of women. Although the increase in RMR was greater than that explained by weight gain, evidence of both behavioral and biological compensation in the metabolic cost of walking was observed in obese women during gestation. The trial is registered with the Australian Clinical Trials Registry as ACTRN012606000271505.

A new species of Klabonosa Bouček (Hymenoptera: Pteromalidae) reared from eggs of Endochus sp. (Hemiptera: Reduviidae) from India.

Science.gov (United States)

Gupta, Ankita; Yeshwanth, H M; Sureshan, P M

2018-04-23

The genus Klabonosa Bouček (Hymenoptera: Pteromalidae) is recorded for the first time from the Oriental region, with both sexes of K. indica Gupta, Sureshan Yeshwanth sp. n. reared from eggs of the assassin bug Endochus sp. (Hemiptera: Reduviidae) on Artocarpus heterophyllus Lam. (Moraceae). The male is formally described and illustrated for the first time for the genus.

Elements of random walk and diffusion processes

CERN Document Server

Ibe, Oliver C

2013-01-01

Presents an important and unique introduction to random walk theory Random walk is a stochastic process that has proven to be a useful model in understanding discrete-state discrete-time processes across a wide spectrum of scientific disciplines. Elements of Random Walk and Diffusion Processes provides an interdisciplinary approach by including numerous practical examples and exercises with real-world applications in operations research, economics, engineering, and physics. Featuring an introduction to powerful and general techniques that are used in the application of physical and dynamic

Use of the entomopathogenic fungi Metarhizium anisopliae, Cordyceps bassiana and Isaria fumosorosea to control Diaphorina citri (Hemiptera: Psylidae) in Persian lime under field conditions

Science.gov (United States)

The Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Psyllidae), is a destructive insect pest in the citriculture, because it is an efficient vector of the proteobacteria, ‘Candidatus Liberibacter asiaticus’ (Las), ‘Ca. L. Africanus’ (Laf), and ‘Ca. L. Americanus’ (Lam). These bacteria c...

Random Walks with Anti-Correlated Steps

OpenAIRE

Wagner, Dirk; Noga, John

2005-01-01

We conjecture the expected value of random walks with anti-correlated steps to be exactly 1. We support this conjecture with 2 plausibility arguments and experimental data. The experimental analysis includes the computation of the expected values of random walks for steps up to 22. The result shows the expected value asymptotically converging to 1.

A new species in the indigenous New Zealand soft scale insect genus Kalasiris Henderson & Hodgson (Hemiptera: Sternorrhyncha: Coccomorpha: Coccidae) on Gahnia setifolia (Cyperaceae).

Science.gov (United States)

Hodgson, Chris J; Gunawardana, D N; Richmond, J E

2016-03-14

The genus Kalasiris Henderson & Hodgson (Hemiptera: Sternorrhyncha: Coccomorpha: Coccidae) is currently only known from New Zealand. The adult female and pupa of a new species, K. martini Hodgson & Richmond are described and illustrated below and the possible taxonomic relationships of the genus to other New Zealand genera are discussed.

Potential use of the fungus Beauveria bassiana against the western flower thrips Frankliniella occidentalis without reducing the effectiveness of its natural predator Orius sauteri (Hemiptera: Anthocoridae)

Science.gov (United States)

Orius sauteri (Poppius) (Hemiptera: Anthocoridae) is an important predator of western flower thrips, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae). Orius sauteri would be directly exposed to the entomopathogenic fungus Beauveria bassiana (Bals.) Vuillemin in the field should the fu...

Mall Walking Program Environments, Features, and Participants: A Scoping Review.

Science.gov (United States)

Farren, Laura; Belza, Basia; Allen, Peg; Brolliar, Sarah; Brown, David R; Cormier, Marc L; Janicek, Sarah; Jones, Dina L; King, Diane K; Marquez, David X; Rosenberg, Dori E

2015-08-13

Walking is a preferred and recommended physical activity for middle-aged and older adults, but many barriers exist, including concerns about safety (ie, personal security), falling, and inclement weather. Mall walking programs may overcome these barriers. The purpose of this study was to summarize the evidence on the health-related value of mall walking and mall walking programs. We conducted a scoping review of the literature to determine the features, environments, and benefits of mall walking programs using the RE-AIM framework (reach, effectiveness, adoption, implementation, and maintenance). The inclusion criteria were articles that involved adults aged 45 years or older who walked in indoor or outdoor shopping malls. Exclusion criteria were articles that used malls as laboratory settings or focused on the mechanics of walking. We included published research studies, dissertations, theses, conference abstracts, syntheses, nonresearch articles, theoretical papers, editorials, reports, policy briefs, standards and guidelines, and nonresearch conference abstracts and proposals. Websites and articles written in a language other than English were excluded. We located 254 articles on mall walking; 32 articles met our inclusion criteria. We found that malls provided safe, accessible, and affordable exercise environments for middle-aged and older adults. Programmatic features such as program leaders, blood pressure checks, and warm-up exercises facilitated participation. Individual benefits of mall walking programs included improvements in physical, social, and emotional well-being. Limited transportation to the mall was a barrier to participation. We found the potential for mall walking programs to be implemented in various communities as a health promotion measure. However, the research on mall walking programs is limited and has weak study designs. More rigorous research is needed to define best practices for mall walking programs' reach, effectiveness, adoption

Influence of Neuromuscular Noise and Walking Speed on Fall Risk and Dynamic Stability in a 3D Dynamic Walking Model

OpenAIRE

Roos, Paulien E.; Dingwell, Jonathan B.

2013-01-01

Older adults and those with increased fall risk tend to walk slower. They may do this voluntarily to reduce their fall risk. However, both slower and faster walking speeds can predict increased risk of different types of falls. The mechanisms that contribute to fall risk across speeds are not well known. Faster walking requires greater forward propulsion, generated by larger muscle forces. However, greater muscle activation induces increased signal-dependent neuromuscular noise. These speed-r...

Walking the history of healthcare.

Science.gov (United States)

Black, Nick

2007-12-01

The history of healthcare is complex, confusing and contested. In Walking London's medical history the story of how health services developed from medieval times to the present day is told through seven walks. The book also aims to help preserve our legacy, as increasingly former healthcare buildings are converted to other uses, and to enhance understanding of the current challenges we face in trying to improve healthcare in the 21st century. Each walk has a theme, ranging from the way hospitals merge or move and the development of primary care to how key healthcare trades became professions and the competition between the church, Crown and City for control of healthcare. While recognising the contributions of the 'great men of medicine', the book takes as much interest in the six ambulance stations built by the London County Council (1915) as the grandest teaching hospitals.

Single and Dual Task Walking

Directory of Open Access Journals (Sweden)

Natalie de Bruin

2010-01-01

Full Text Available This study explored the viability and efficacy of integrating cadence-matched, salient music into a walking intervention for patients with Parkinson's disease (PD. Twenty-two people with PD were randomised to a control (CTRL, n=11 or experimental (MUSIC, n=11 group. MUSIC subjects walked with an individualised music playlist three times a week for the intervention period. Playlists were designed to meet subject's musical preferences. In addition, the tempo of the music closely matched (±10–15 bpm the subject's preferred cadence. CTRL subjects continued with their regular activities during the intervention. The effects of training accompanied by “walking songs” were evaluated using objective measures of gait score. The MUSIC group improved gait velocity, stride time, cadence, and motor symptom severity following the intervention. This is the first study to demonstrate that music listening can be safely implemented amongst PD patients during home exercise.

Validity of the Nike+ device during walking and running.

Science.gov (United States)

Kane, N A; Simmons, M C; John, D; Thompson, D L; Bassett, D R; Basset, D R

2010-02-01

We determined the validity of the Nike+ device for estimating speed, distance, and energy expenditure (EE) during walking and running. Twenty trained individuals performed a maximal oxygen uptake test and underwent anthropometric and body composition testing. Each participant was outfitted with a Nike+ sensor inserted into the shoe and an Apple iPod nano. They performed eight 6-min stages on the treadmill, including level walking at 55, 82, and 107 m x min(-1), inclined walking (82 m x min(-1)) at 5 and 10% grades, and level running at 134, 161, and 188 m x min(-1). Speed was measured using a tachometer and EE was measured by indirect calorimetry. Results showed that the Nike+ device overestimated the speed of level walking at 55 m x min(-1) by 20%, underestimated the speed of level walking at 107 m x min(-1) by 12%, but closely estimated the speed of level walking at 82 m x min(-1), and level running at all speeds (pNike+ device overestimated the EE of level walking by 18-37%, but closely estimated the EE of level running (pNike+ in-shoe device provided reasonable estimates of speed and distance during level running at the three speeds tested in this study. However, it overestimated EE during level walking and it did not detect the increased cost of inclined locomotion.

Elastic coupling of limb joints enables faster bipedal walking

Science.gov (United States)

Dean, J.C.; Kuo, A.D.

2008-01-01

The passive dynamics of bipedal limbs alone are sufficient to produce a walking motion, without need for control. Humans augment these dynamics with muscles, actively coordinated to produce stable and economical walking. Present robots using passive dynamics walk much slower, perhaps because they lack elastic muscles that couple the joints. Elastic properties are well known to enhance running gaits, but their effect on walking has yet to be explored. Here we use a computational model of dynamic walking to show that elastic joint coupling can help to coordinate faster walking. In walking powered by trailing leg push-off, the model's speed is normally limited by a swing leg that moves too slowly to avoid stumbling. A uni-articular spring about the knee allows faster but uneconomical walking. A combination of uni-articular hip and knee springs can speed the legs for improved speed and economy, but not without the swing foot scuffing the ground. Bi-articular springs coupling the hips and knees can yield high economy and good ground clearance similar to humans. An important parameter is the knee-to-hip moment arm that greatly affects the existence and stability of gaits, and when selected appropriately can allow for a wide range of speeds. Elastic joint coupling may contribute to the economy and stability of human gait. PMID:18957360

Natural Walking in Virtual Reality: A Review

DEFF Research Database (Denmark)

Nilsson, Niels Chr.; Serafin, Stefania; Steinicke, Franke

2018-01-01

Recent technological developments have finally brought virtual reality (VR) out of the laboratory and into the hands of developers and consumers. However, a number of challenges remain. Virtual travel is one of the most common and universal tasks performed inside virtual environments, yet enabling...... users to navigate virtual environments is not a trivial challenge—especially if the user is walking. In this article, we initially provide an overview of the numerous virtual travel techniques that have been proposed prior to the commercialization of VR. Then we turn to the mode of travel...... that is the most difficult to facilitate, that is, walking. The challenge of providing users with natural walking experiences in VR can be divided into two separate, albeit related, challenges: (1) enabling unconstrained walking in virtual worlds that are larger than the tracked physical space and (2) providing...

Measuring Oscillating Walking Paths with a LIDAR

Directory of Open Access Journals (Sweden)

Jordi Palacín

2011-05-01

Full Text Available This work describes the analysis of different walking paths registered using a Light Detection And Ranging (LIDAR laser range sensor in order to measure oscillating trajectories during unsupervised walking. The estimate of the gait and trajectory parameters were obtained with a terrestrial LIDAR placed 100 mm above the ground with the scanning plane parallel to the floor to measure the trajectory of the legs without attaching any markers or modifying the floor. Three different large walking experiments were performed to test the proposed measurement system with straight and oscillating trajectories. The main advantages of the proposed system are the possibility to measure several steps and obtain average gait parameters and the minimum infrastructure required. This measurement system enables the development of new ambulatory applications based on the analysis of the gait and the trajectory during a walk.

Minimum dose method for walking-path planning of nuclear facilities

International Nuclear Information System (INIS)

Liu, Yong-kuo; Li, Meng-kun; Xie, Chun-li; Peng, Min-jun; Wang, Shuang-yu; Chao, Nan; Liu, Zhong-kun

2015-01-01

Highlights: • For radiation environment, the environment model is proposed. • For the least dose walking path problem, a path-planning method is designed. • The path-planning virtual–real mixed simulation program is developed. • The program can plan walking path and simulate. - Abstract: A minimum dose method based on staff walking road network model was proposed for the walking-path planning in nuclear facilities. A virtual–reality simulation program was developed using C# programming language and Direct X engine. The simulation program was used in simulations dealing with virtual nuclear facilities. Simulation results indicated that the walking-path planning method was effective in providing safety for people walking in nuclear facilities

Assessment of Feeding Acceptance and Injury of Kerman Pistachios, Pistacia vera, by Brown Marmorated Stink Bug (Hemiptera: Pentatomidae)

OpenAIRE

Lara, Jesús R; Kamiyama, Matthew T; Hernandez, Gabriel; Nay, Justin; Hoddle, Mark S

2017-01-01

Abstract In the United States, California (CA) is the primary commercial producer of pistachio nuts, Pistacia vera L. (Anacardiaceae). The brown marmorated stink bug (BMSB), Halyomorpha halys (Stål) (Hemiptera: Pentatomidae), an invasive and polyphagous insect pest from Asia, has established in urban areas in several pistachio-growing counties in CA. Breeding BMSB populations have not been detected in commercial pistachio acreage. However, the detection of BMSB in Kern and Fresno counties, ma...

Effect of the walking speed to the lower limb joint angular displacements, joint moments and ground reaction forces during walking in water.

Science.gov (United States)

Miyoshi, Tasuku; Shirota, Takashi; Yamamoto, Shin-ichiro; Nakazawa, Kimitaka; Akai, Masami

2004-06-17

The purpose of this study was to compare the changes in ground reaction forces (GRF), joint angular displacements (JAD), joint moments (JM) and electromyographic (EMG) activities that occur during walking at various speeds in water and on land. Fifteen healthy adults participated in this study. In the water experiments, the water depth was adjusted so that body weight was reduced by 80%. A video-motion analysis system and waterproof force platform was used to obtain kinematics and kinetics data and to calculate the JMs. Results revealed that (1) the anterior-posterior GRF patterns differed between walking in water and walking on land, whereas the medio-lateral GRF patterns were similar, (2) the JAD patterns of the hip and ankle were similar between water- and land-walking, whereas the range of motion at the knee joint was lower in water than on land, (3) the JMs in all three joints were lower in water than on land throughout the stance phase, and (4) the hip joint extension moment and hip extensor muscle EMG activity were increased as walking speed increase during walking in water. Rehabilitative water-walking exercise could be designed to incorporate large-muscle activities, especially of the lower-limb extensor muscles, through full joint range of motion and minimization of joint moments.

Health benefits of Nordic walking: a systematic review.

Science.gov (United States)

Tschentscher, Marcus; Niederseer, David; Niebauer, Josef

2013-01-01

Modern lifestyle, with its lack of everyday physical activity and exercise training, predisposes people to chronic diseases such as diabetes mellitus, obesity, hypertension, and coronary artery diseases. Brisk walking as a simple and safe form of exercise is undisputedly an effective measure to counteract sedentary lifestyle risks even in the most unfit and could lead to a reduction of the prevalence of chronic diseases in all populations. The purpose of this review is to systematically summarize, analyze, and interpret the health benefits of Nordic walking (walking with poles), and to compare it to brisk walking and jogging. A systematic and comprehensive literature search was performed between November 2010 and May 2012. Data were analyzed between April 2011 and May 2012. Sixteen RCTs with a total of 1062 patients and 11 observational studies with 831 patients were identified. The current analysis revealed that with regard to short- and long-term effects on heart rate, oxygen consumption, quality of life, and other measures, Nordic walking is superior to brisk walking without poles and in some endpoints to jogging. Nordic walking exerts beneficial effects on resting heart rate, blood pressure, exercise capacity, maximal oxygen consumption, and quality of life in patients with various diseases and can thus be recommended to a wide range of people as primary and secondary prevention. Copyright © 2013 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.

walk over ℤ

Directory of Open Access Journals (Sweden)

Philippe Leroux

2005-01-01

walk over ℤ can be described from a coassociative coalgebra. Relationships between this coalgebra and the set of periodic orbits of the classical chaotic system x↦2x mod⁡1, x∈[0,1], are also given.

The environmental benefits of bicycling and walking.

Science.gov (United States)

1993-01-01

Bicycling and walking are the two major non-fuel-consuming, non-polluting : forms of transportation in the United States. Millions of Americans ride : bicycles and/or walk for a wide variety of purposes --- commuting to work, as : part of their job, ...

Quantum walk on a line with two entangled particles

International Nuclear Information System (INIS)

Omar, Y.; Paunkovic, N.; Sheridan, L.; Bose, S.; Mateus, P.

2005-01-01

Full text: We introduce the concept of a quantum walk with two particles and study it for the case of a discrete time walk on a line. A quantum walk with more than one particle may contain entanglement, thus offering a resource unavailable in the classical scenario and which can present interesting advantages. In this work, we show how the entanglement and the relative phase between the states describing the coin degree of freedom of each particle will influence the evolution of the quantum walk. In particular, the probability to find at least one particle in a certain position after N steps of the walk, as well as the average distance between the two particles, can be larger or smaller than the case of two unentangled particles, depending on the initial conditions we choose. This resource can then be tuned according to our needs, in particular to enhance a given application (algorithmic or other) based on a quantum walk. Experimental implementations are briefly discussed. (author)

Quantum random walks and their convergence to Evans–Hudson ...

Indian Academy of Sciences (India)

Quantum dynamical semigroup; Evans–Hudson flow; quantum random walk. 1. Introduction. The aim of this article is to investigate convergence of random walks on von Neumann algebra to Evans–Hudson flows. Here the random walks and Evans–Hudson flows are gene- ralizations of classical Markov chains and Markov ...

CDC Vital Signs: More People Walk to Better Health

Science.gov (United States)

... problems such as snow, rocks, trash, and fallen tree limbs. Promote walking paths with signs that are easy to read, and route maps that the public can easily find and use. Employers can Create and support walking programs for employees. Identify walking paths around or near the work place ...

Effects of Progressive Body Weight Support Treadmill Forward and Backward Walking Training on Stroke Patients' Affected Side Lower Extremity's Walking Ability.

Science.gov (United States)

Kim, Kyunghoon; Lee, Sukmin; Lee, Kyoungbo

2014-12-01

[Purpose] The purpose of the present study was to examine the effects of progressive body weight supported treadmill forward and backward walking training (PBWSTFBWT), progressive body weight supported treadmill forward walking training (PBWSTFWT), progressive body weight supported treadmill backward walking training (PBWSTBWT), on stroke patients' affected side lower extremity's walking ability. [Subjects and Methods] A total of 36 chronic stroke patients were divided into three groups with 12 subjects in each group. Each of the groups performed one of the progressive body weight supported treadmill training methods for 30 minute, six times per week for three weeks, and then received general physical therapy without any other intervention until the follow-up tests. For the assessment of the affected side lower extremity's walking ability, step length of the affected side, stance phase of the affected side, swing phase of the affected side, single support of the affected side, and step time of the affected side were measured using optogait and the symmetry index. [Results] In the within group comparisons, all the three groups showed significant differences between before and after the intervention and in the comparison of the three groups, the PBWSTFBWT group showed more significant differences in all of the assessed items than the other two groups. [Conclusion] In the present study progressive body weight supported treadmill training was performed in an environment in which the subjects were actually walked, and PBWSTFBWT was more effective at efficiently training stroke patients' affected side lower extremity's walking ability.

Velocity and Dispersion for a Two-Dimensional Random Walk

International Nuclear Information System (INIS)

Li Jinghui

2009-01-01

In the paper, we consider the transport of a two-dimensional random walk. The velocity and the dispersion of this two-dimensional random walk are derived. It mainly show that: (i) by controlling the values of the transition rates, the direction of the random walk can be reversed; (ii) for some suitably selected transition rates, our two-dimensional random walk can be efficient in comparison with the one-dimensional random walk. Our work is motivated in part by the challenge to explain the unidirectional transport of motor proteins. When the motor proteins move at the turn points of their tracks (i.e., the cytoskeleton filaments and the DNA molecular tubes), some of our results in this paper can be used to deal with the problem. (general)

Probability of walking in children with cerebral palsy in Europe

DEFF Research Database (Denmark)

Beckung, E.; Hagberg, G.; Uldall, P.

2008-01-01

cerebral palsy, as well as to IQ level, active epilepsy, and severe visual and hearing impairment. Severe cerebral palsy, defined as both the inability to walk and an IQ of ...OBJECTIVES: The purpose of this work was to describe walking ability in children with cerebral palsy from the Surveillance of Cerebral Palsy in Europe common database through 21 years and to examine the association between walking ability and predicting factors. PATIENTS AND METHODS: Anonymous data...... on 10042 children with cerebral palsy born between 1976 and 1996 were gathered from 14 European centers; 9012 patients were eligible for the analyses. RESULTS: Unaided walking as the primary way of walking at 5 years of age was reported for 54%, walking with assistive devices was reported for 16...

Nano-formulation enhances insecticidal activity of natural pyrethrins against Aphis gossypii (Hemiptera: Aphididae) and retains their harmless effect to non-target predators.

Science.gov (United States)

Papanikolaou, Nikos E; Kalaitzaki, Argyro; Karamaouna, Filitsa; Michaelakis, Antonios; Papadimitriou, Vassiliki; Dourtoglou, Vassilis; Papachristos, Dimitrios P

2018-04-01

The insecticidal activity of a new nano-formulated natural pyrethrin was examined on the cotton aphid, Aphis gossypii Glover (Hemiptera: Aphididae), and the predators Coccinella septempunctata L. (Coleoptera: Coccinellidae) and Macrolophus pygmaeus Rambur (Hemiptera: Miridae), in respect with the nano-scale potential to create more effective and environmentally responsible pesticides. Pyrethrin was nano-formulated in two water-in-oil micro-emulsions based on safe biocompatible materials, i.e., lemon oil terpenes as dispersant, polysorbates as stabilizers, and mixtures of water with glycerol as the dispersed aqueous phase. Laboratory bioassays showed a superior insecticidal effect of the pyrethrin micro-emulsions compared to two commercial suspension concentrates of natural pyrethrins against the aphid. The nano-formulated pyrethrins were harmless, in terms of caused mortality and survival time, to L3 larvae and four-instar nymphs of the predators C. septempunctata and M. pygmaeus, respectively. We expect that these results can contribute to the application of nano-technology in optimization of pesticide formulation, with further opportunities in the development of effective plant protection products compatible with integrated pest management practices.

A Walk in the Semantic Park

DEFF Research Database (Denmark)

Danvy, Olivier; Johannsen, Jacob; Zerny, Ian

2011-01-01

To celebrate the 20th anniversary of PEPM, we are inviting you to a walk in the semantic park and to inter-derive reduction-based and reduction-free negational normalization functions.......To celebrate the 20th anniversary of PEPM, we are inviting you to a walk in the semantic park and to inter-derive reduction-based and reduction-free negational normalization functions....

More Adults Are Walking PSA (:60)

Centers for Disease Control (CDC) Podcasts

2012-07-31

This 60 second PSA is based on the August 2012 CDC Vital Signs report. While more adults are walking, only half get the recommended amount of physical activity. Listen to learn how communities, employers, and individuals may help increase walking.  Created: 7/31/2012 by Centers for Disease Control and Prevention (CDC).   Date Released: 8/7/2012.

Identifying particular places through experimental walking

Directory of Open Access Journals (Sweden)

Henrik Schultz

2016-11-01

Full Text Available Experimental walking can be used to identify particular places, design strategies and spatial visions for urban landscapes. Walking designers can explore sites and, in particular, their temporal dynamics and atmospheric particularities – both essential elements in making particular places. This article illustrates the benefits of this method, using the changing German city of Freiburg as an example.

A randomized trial of functional electrical stimulation for walking in incomplete spinal cord injury: Effects on walking competency.

Science.gov (United States)

Kapadia, Naaz; Masani, Kei; Catharine Craven, B; Giangregorio, Lora M; Hitzig, Sander L; Richards, Kieva; Popovic, Milos R

2014-09-01

Multi-channel surface functional electrical stimulation (FES) for walking has been used to improve voluntary walking and balance in individuals with spinal cord injury (SCI). To investigate short- and long-term benefits of 16 weeks of thrice-weekly FES-assisted walking program, while ambulating on a body weight support treadmill and harness system, versus a non-FES exercise program, on improvements in gait and balance in individuals with chronic incomplete traumatic SCI, in a randomized controlled trial design. Individuals with traumatic and chronic (≥18 months) motor incomplete SCI (level C2 to T12, American Spinal Cord Injury Association Impairment Scale C or D) were recruited from an outpatient SCI rehabilitation hospital, and randomized to FES-assisted walking therapy (intervention group) or aerobic and resistance training program (control group). Outcomes were assessed at baseline, and after 4, 6, and 12 months. Gait, balance, spasticity, and functional measures were collected. Spinal cord independence measure (SCIM) mobility sub-score improved over time in the intervention group compared with the control group (baseline/12 months: 17.27/21.33 vs. 19.09/17.36, respectively). On all other outcome measures the intervention and control groups had similar improvements. Irrespective of group allocation walking speed, endurance, and balance during ambulation all improved upon completion of therapy, and majority of participants retained these gains at long-term follow-ups. Task-oriented training improves walking ability in individuals with incomplete SCI, even in the chronic stage. Further randomized controlled trials, involving a large number of participants are needed, to verify if FES-assisted treadmill training is superior to aerobic and strength training.

The random walk model of intrafraction movement

International Nuclear Information System (INIS)

Ballhausen, H; Reiner, M; Kantz, S; Belka, C; Söhn, M

2013-01-01

The purpose of this paper is to understand intrafraction movement as a stochastic process driven by random external forces. The hypothetically proposed three-dimensional random walk model has significant impact on optimal PTV margins and offers a quantitatively correct explanation of experimental findings. Properties of the random walk are calculated from first principles, in particular fraction-average population density distributions for displacements along the principal axes. When substituted into the established optimal margin recipes these fraction-average distributions yield safety margins about 30% smaller as compared to the suggested values from end-of-fraction Gaussian fits. Stylized facts of a random walk are identified in clinical data, such as the increase of the standard deviation of displacements with the square root of time. Least squares errors in the comparison to experimental results are reduced by about 50% when accounting for non-Gaussian corrections from the random walk model. (paper)

The random walk model of intrafraction movement.

Science.gov (United States)

Ballhausen, H; Reiner, M; Kantz, S; Belka, C; Söhn, M

2013-04-07

The purpose of this paper is to understand intrafraction movement as a stochastic process driven by random external forces. The hypothetically proposed three-dimensional random walk model has significant impact on optimal PTV margins and offers a quantitatively correct explanation of experimental findings. Properties of the random walk are calculated from first principles, in particular fraction-average population density distributions for displacements along the principal axes. When substituted into the established optimal margin recipes these fraction-average distributions yield safety margins about 30% smaller as compared to the suggested values from end-of-fraction gaussian fits. Stylized facts of a random walk are identified in clinical data, such as the increase of the standard deviation of displacements with the square root of time. Least squares errors in the comparison to experimental results are reduced by about 50% when accounting for non-gaussian corrections from the random walk model.

Alternate two-dimensional quantum walk with a single-qubit coin

International Nuclear Information System (INIS)

Di Franco, C.; Busch, Th.; Mc Gettrick, M.; Machida, T.

2011-01-01

We have recently proposed a two-dimensional quantum walk where the requirement of a higher dimensionality of the coin space is substituted with the alternance of the directions in which the walker can move [C. Di Franco, M. Mc Gettrick, and Th. Busch, Phys. Rev. Lett. 106, 080502 (2011)]. For a particular initial state of the coin, this walk is able to perfectly reproduce the spatial probability distribution of the nonlocalized case of the Grover walk. Here, we present a more detailed proof of this equivalence. We also extend the analysis to other initial states in order to provide a more complete picture of our walk. We show that this scheme outperforms the Grover walk in the generation of x-y spatial entanglement for any initial condition, with the maximum entanglement obtained in the case of the particular aforementioned state. Finally, the equivalence is generalized to wider classes of quantum walks and a limit theorem for the alternate walk in this context is presented.

ImWalkMF: Joint matrix factorization and implicit walk integrative learning for recommendation

KAUST Repository

Zhang, Chuxu

2018-01-15

Data sparsity and cold-start problems are prevalent in recommender systems. To address such problems, both the observable explicit social information (e.g., user-user trust connections) and the inferable implicit correlations (e.g., implicit neighbors computed by similarity measurement) have been introduced to complement user-item ratings data for improving the performances of traditional model-based recommendation algorithms such as matrix factorization. Although effective, (1) the utilization of the explicit user-user social relationships suffers from the weakness of unavailability in real systems such as Netflix or the issue of sparse observable content like 0.03% trust density in Epinions, thus there is no or little explicit social information that can be employed to improve baseline model in real applications; (2) the current similarity measurement approaches focus on inferring implicit correlations between a user (item) and their direct neighbors or top-k similar neighbors based on user-item ratings bipartite network, so that they fail to comprehensively unfold the indirect potential relationships among users and items. To solve these issues regarding both explicit/implicit social recommendation algorithms, we design a joint model of matrix factorization and implicit walk integrative learning, i.e., ImWalkMF, which only uses explicit ratings information yet models both direct rating feedbacks and multiple direct/indirect implicit correlations among users and items from a random walk perspective. We further propose a combined strategy for training two independent components in the proposed model based on sampling. The experimental results on two real-world sparse datasets demonstrate that ImWalkMF outperforms the traditional regularized/probabilistic matrix factorization models as well as other competitive baselines that utilize explicit/implicit social information.

Stair-Walking Performance in Adolescents with Intellectual Disabilities

Directory of Open Access Journals (Sweden)

Wann-Yun Shieh

2016-07-01

Full Text Available Most individuals with intellectual disabilities (ID demonstrate problems in learning and movement coordination. Consequently, they usually have difficulties in activities such as standing, walking, and stair climbing. To monitor the physical impairments of these children, regular gross motor evaluation is crucial. Straight-line level walking is the most frequently used test of their mobility. However, numerous studies have found that unless the children have multiple disabilities, no significant differences can be found between the children with ID and typically-developed children in this test. Stair climbing presents more challenges than level walking because it is associated with numerous physical factors, including lower extremity strength, cardiopulmonary endurance, vision, balance, and fear of falling. Limited ability in those factors is one of the most vital markers for children with ID. In this paper, we propose a sensor-based approach for measuring stair-walking performance, both upstairs and downstairs, for adolescents with ID. Particularly, we address the problem of sensor calibration to ensure measurement accuracy. In total, 62 participants aged 15 to 21 years, namely 32 typically-developed (TD adolescents, 20 adolescents with ID, and 10 adolescents with multiple disabilities (MD, participated. The experimental results showed that stair-walking is more sensitive than straight-line level walking in capturing gait characteristics for adolescents with ID.

How edge-reinforced random walk arises naturally

NARCIS (Netherlands)

Rolles, S.W.W.

2003-01-01

We give a characterization of a modified edge-reinforced random walk in terms of certain partially exchangeable sequences. In particular, we obtain a characterization of an edge-reinforced random walk (introduced by Coppersmith and Diaconis) on a 2-edge-connected graph. Modifying the notion of

Walking to transit.

Science.gov (United States)

2011-12-01

Using a real-life setting, WalkBostons project focused on developing and testing techniques to broaden the scope and range of public participation in transportation planning in a large neighborhood in Boston. The team explored methods of seeking o...

On your feet: protocol for a randomized controlled trial to compare the effects of pole walking and regular walking on physical and psychosocial health in older adults.

Science.gov (United States)

Fritschi, Juliette O; Brown, Wendy J; van Uffelen, Jannique G Z

2014-04-17

Physical activity is associated with better physical and mental health in older adults. Pole walking is a form of walking which may have additional health benefits in older adults, because of the addition of hand held poles, and consequent upper limb involvement. However, few studies have examined the potential additional effects of pole walking on physical and psychosocial health in older adults compared with walking. The aim of this study is to compare the effect of a pole walking program with the effects of a walking program, on physical and psychosocial wellbeing, in older adults in assisted living facilities. Sixty men and women from assisted living communities over 65 years will be recruited from senior retirement facilities and randomized into a group based, pole walking program, or walking program. The pole walking group will use the Exerstrider method of pole walking. Total duration of the programs is 12 weeks, with three sessions per week, building from 20 minute to 30 minute sessions.The primary outcome is physical function, as measured by items from the Seniors Fitness Test and hand grip strength. Secondary outcomes include, physical activity levels, sedentary behaviour, joint pain, and quality of life. All outcomes will be assessed before and after the programs, using valid and reliable measures. The study will add to the evidence base for the effects of pole walking, compared with walking, on physical and psychosocial health and physical function, in healthy older adults. This will improve understanding about the feasibility of pole walking programs and its specific benefits in this population. Australian New Zealand Clinical Trials Registry ACTRN12612001127897.

Tempo and walking speed with music in the urban context.

Science.gov (United States)

Franěk, Marek; van Noorden, Leon; Režný, Lukáš

2014-01-01

The study explored the effect of music on the temporal aspects of walking behavior in a real outdoor urban setting. First, spontaneous synchronization between the beat of the music and step tempo was explored. The effect of motivational and non-motivational music (Karageorghis et al., 1999) on the walking speed was also studied. Finally, we investigated whether music can mask the effects of visual aspects of the walking route environment, which involve fluctuation of walking speed as a response to particular environmental settings. In two experiments, we asked participants to walk around an urban route that was 1.8 km in length through various environments in the downtown area of Hradec Králové. In Experiment 1, the participants listened to a musical track consisting of world pop music with a clear beat. In Experiment 2, participants were walking either with motivational music, which had a fast tempo and a strong rhythm, or with non-motivational music, which was slower, nice music, but with no strong implication to movement. Musical beat, as well as the sonic character of the music listened to while walking, influenced walking speed but did not lead to precise synchronization. It was found that many subjects did not spontaneously synchronize with the beat of the music at all, and some subjects synchronized only part of the time. The fast, energetic music increases the speed of the walking tempo, while slower, relaxing music makes the walking tempo slower. Further, it was found that listening to music with headphones while walking can mask the influence of the surrounding environment to some extent. Both motivational music and non-motivational music had a larger effect than the world pop music from Experiment 1. Individual differences in responses to the music listened to while walking that were linked to extraversion and neuroticism were also observed. The findings described here could be useful in rhythmic stimulation for enhancing or recovering the features of

Tempo and walking speed with music in the urban context

Directory of Open Access Journals (Sweden)

Marek eFranek

2014-12-01

Full Text Available The study explored the effect of music on the temporal aspects of walking behavior in a real outdoor urban setting. First, spontaneous synchronization between the beat of the music and step tempo was explored. The effect of motivational and non-motivational music (Karageorghis et al. 1999 on the walking speed was also studied. Finally, we investigated whether music can mask the effects of visual aspects of the walking route environment, which involve fluctuation of walking speed as a response to particular environmental settings. In two experiments, we asked participants to walk around an urban route through various environments in the downtown area of Hradec Králové. In Experiment 1, the participants listened to a musical track consisting of world pop music with a clear beat. In Experiment 2, participants were walking either with motivational music, which had a fast tempo and a strong rhythm, or with non-motivational music, which was slower, nice music, but with no strong implication to movement. Musical beat, as well as the sonic character of the music listened to while walking, influenced walking speed but did not lead to precise synchronization. It was found that many subjects did not spontaneously synchronize with the beat of the music at all, and some subjects synchronized only part of the time. The fast, energetic music increases the speed of the walking tempo, while slower, relaxing music makes the walking tempo slower. Further, it was found that listening to music with headphones while walking can mask the influence of the surrounding environment to some extent. Both motivational music and non-motivational music had a larger effect than the music from Experiment 1. Individual differences in responses to the music listened to while walking that were linked to extraversion and neuroticism were also observed. The findings described here could be useful in rhythmic stimulation for enhancing or recovering the features of movement

Tempo and walking speed with music in the urban context

Science.gov (United States)

Franěk, Marek; van Noorden, Leon; Režný, Lukáš

2014-01-01

The study explored the effect of music on the temporal aspects of walking behavior in a real outdoor urban setting. First, spontaneous synchronization between the beat of the music and step tempo was explored. The effect of motivational and non-motivational music (Karageorghis et al., 1999) on the walking speed was also studied. Finally, we investigated whether music can mask the effects of visual aspects of the walking route environment, which involve fluctuation of walking speed as a response to particular environmental settings. In two experiments, we asked participants to walk around an urban route that was 1.8 km in length through various environments in the downtown area of Hradec Králové. In Experiment 1, the participants listened to a musical track consisting of world pop music with a clear beat. In Experiment 2, participants were walking either with motivational music, which had a fast tempo and a strong rhythm, or with non-motivational music, which was slower, nice music, but with no strong implication to movement. Musical beat, as well as the sonic character of the music listened to while walking, influenced walking speed but did not lead to precise synchronization. It was found that many subjects did not spontaneously synchronize with the beat of the music at all, and some subjects synchronized only part of the time. The fast, energetic music increases the speed of the walking tempo, while slower, relaxing music makes the walking tempo slower. Further, it was found that listening to music with headphones while walking can mask the influence of the surrounding environment to some extent. Both motivational music and non-motivational music had a larger effect than the world pop music from Experiment 1. Individual differences in responses to the music listened to while walking that were linked to extraversion and neuroticism were also observed. The findings described here could be useful in rhythmic stimulation for enhancing or recovering the features of

Foot trajectory approximation using the pendulum model of walking.

Science.gov (United States)

Fang, Juan; Vuckovic, Aleksandra; Galen, Sujay; Conway, Bernard A; Hunt, Kenneth J

2014-01-01

Generating a natural foot trajectory is an important objective in robotic systems for rehabilitation of walking. Human walking has pendular properties, so the pendulum model of walking has been used in bipedal robots which produce rhythmic gait patterns. Whether natural foot trajectories can be produced by the pendulum model needs to be addressed as a first step towards applying the pendulum concept in gait orthosis design. This study investigated circle approximation of the foot trajectories, with focus on the geometry of the pendulum model of walking. Three able-bodied subjects walked overground at various speeds, and foot trajectories relative to the hip were analysed. Four circle approximation approaches were developed, and best-fit circle algorithms were derived to fit the trajectories of the ankle, heel and toe. The study confirmed that the ankle and heel trajectories during stance and the toe trajectory in both the stance and the swing phases during walking at various speeds could be well modelled by a rigid pendulum. All the pendulum models were centred around the hip with pendular lengths approximately equal to the segment distances from the hip. This observation provides a new approach for using the pendulum model of walking in gait orthosis design.

Preferred step frequency minimizes veering during natural human walking

NARCIS (Netherlands)

Uematsu, Azusa; Inoue, Koh; Hobara, Hiroaki; Kobayashi, Hirofumi; Iwamoto, Yuki; Hortobagyi, Tibor; Suzuki, Shuji

2011-01-01

In the absence of visual information, humans cannot maintain a straight walking path. We examined the hypothesis that step frequency during walking affects the magnitude of veering in healthy adults. Subject walked at a preferred (1.77 +/- 0.18 Hz), low (0.8 x preferred, 1.41 +/- 0.15 Hz), and high

Mealybugs (Hemiptera: Coccomorpha: Pseudococcidae) attacking Hibiscus rosa-sinensis L. in Malaysia, with two new country records

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Sartiami, Dewi; Watson, Gillian W.; Mohamad Roff, M. N.; Idris, A. B.

2016-11-01

A survey of mealybugs (Hemiptera: Coccomorpha: Pseudococcidae) attacking the national flower of Malaysia, Hibiscus rosa-sisnensis L. and Hibiscus spp. (Malvaceae) was conducted in Selangor and Kuala Lumpur, Malaysia, from January to March 2016. Adult females were mounted on microscope slides in Canada balsam. The five species identified were Ferrisia dasylirii (Cockerell), Maconellicoccus hirsutus (Green), Paracoccus marginatus Williams and Granara de Willink, Phenacoccus solenopsis (Tinsley) and Pseudococcus jackbeardsleyi Gimpel & Miller. Two of these, the invasive species Ferrisia dasylirii and P. solenopsis were introduced and first recorded in Malaysia.

Walking adaptability therapy after stroke: study protocol for a randomized controlled trial.

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Timmermans, Celine; Roerdink, Melvyn; van Ooijen, Marielle W; Meskers, Carel G; Janssen, Thomas W; Beek, Peter J

2016-08-26

Walking in everyday life requires the ability to adapt walking to the environment. This adaptability is often impaired after stroke, and this might contribute to the increased fall risk after stroke. To improve safe community ambulation, walking adaptability training might be beneficial after stroke. This study is designed to compare the effects of two interventions for improving walking speed and walking adaptability: treadmill-based C-Mill therapy (therapy with augmented reality) and the overground FALLS program (a conventional therapy program). We hypothesize that C-Mill therapy will result in better outcomes than the FALLS program, owing to its expected greater amount of walking practice. This is a single-center parallel group randomized controlled trial with pre-intervention, post-intervention, retention, and follow-up tests. Forty persons after stroke (≥3 months) with deficits in walking or balance will be included. Participants will be randomly allocated to either C-Mill therapy or the overground FALLS program for 5 weeks. Both interventions will incorporate practice of walking adaptability and will be matched in terms of frequency, duration, and therapist attention. Walking speed, as determined by the 10 Meter Walking Test, will be the primary outcome measure. Secondary outcome measures will pertain to walking adaptability (10 Meter Walking Test with context or cognitive dual-task and Interactive Walkway assessments). Furthermore, commonly used clinical measures to determine walking ability (Timed Up-and-Go test), walking independence (Functional Ambulation Category), balance (Berg Balance Scale), and balance confidence (Activities-specific Balance Confidence scale) will be used, as well as a complementary set of walking-related assessments. The amount of walking practice (the number of steps taken per session) will be registered using the treadmill's inbuilt step counter (C-Mill therapy) and video recordings (FALLS program). This process measure will

Walking Adaptability after a Stroke and Its Assessment in Clinical Settings

OpenAIRE

Balasubramanian, Chitralakshmi K.; Clark, David J.; Fox, Emily J.

2014-01-01

Control of walking has been described by a tripartite model consisting of stepping, equilibrium, and adaptability. This review focuses on walking adaptability, which is defined as the ability to modify walking to meet task goals and environmental demands. Walking adaptability is crucial to safe ambulation in the home and community environments and is often severely compromised after a stroke. Yet quantification of walking adaptability after stroke has received relatively little attention in t...

Dynamic Simulation and Analysis of Human Walking Mechanism

Science.gov (United States)

Azahari, Athirah; Siswanto, W. A.; Ngali, M. Z.; Salleh, S. Md.; Yusup, Eliza M.

2017-01-01

Behaviour such as gait or posture may affect a person with the physiological condition during daily activities. The characteristic of human gait cycle phase is one of the important parameter which used to described the human movement whether it is in normal gait or abnormal gait. This research investigates four types of crouch walking (upright, interpolated, crouched and severe) by simulation approach. The assessment are conducting by looking the parameters of hamstring muscle joint, knee joint and ankle joint. The analysis results show that based on gait analysis approach, the crouch walking have a weak pattern of walking and postures. Short hamstring and knee joint is the most influence factor contributing to the crouch walking due to excessive hip flexion that typically accompanies knee flexion.

Mealybugs (Hemiptera: Coccomorpha: Pseudococcidae) with oral rim ducts; description of a new genus and species from Turkey, and discussion of their higher classification within the Pseudococcidae.

Science.gov (United States)

Kaydan, Mehmet Bora; Szita, Éva

2017-02-03

A new monotypic mealybug genus with oral rim ducts, Bromusicoccus Kaydan gen. n. (Hemiptera: Pseudococcidae: Pseudococcinae), is described from Turkey. The higher classification of mealybug genera with oral rim tubular ducts worldwide is discussed and a key is provided to separate them.

Random walk with memory enhancement and decay

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Tan, Zhi-Jie; Zou, Xian-Wu; Huang, Sheng-You; Zhang, Wei; Jin, Zhun-Zhi

2002-04-01

A model of random walk with memory enhancement and decay was presented on the basis of the characteristics of the biological intelligent walks. In this model, the movement of the walker is determined by the difference between the remaining information at the jumping-out site and jumping-in site. The amount of the memory information si(t) at a site i is enhanced with the increment of visiting times to that site, and decays with time t by the rate e-βt, where β is the memory decay exponent. When β=0, there exists a transition from Brownian motion (BM) to the compact growth of walking trajectory with the density of information energy u increasing. But for β>0, this transition does not appear and the walk with memory enhancement and decay can be considered as the BM of the mass center of the cluster composed of remembered sites in the late stage.

Effects of virtual reality training using Nintendo Wii and treadmill walking exercise on balance and walking for stroke patients.

Science.gov (United States)

Bang, Yo-Soon; Son, Kyung Hyun; Kim, Hyun Jin

2016-11-01

[Purpose] The purpose of this study is to investigate the effects of virtual reality training using Nintendo Wii on balance and walking for stroke patients. [Subjects and Methods] Forty stroke patients with stroke were randomly divided into two exercise program groups: virtual reality training (n=20) and treadmill (n=20). The subjects underwent their 40-minute exercise program three times a week for eight weeks. Their balance and walking were measured before and after the complete program. We measured the left/right weight-bearing and the anterior/posterior weight-bearing for balance, as well as stance phase, swing phase, and cadence for walking. [Results] For balance, both groups showed significant differences in the left/right and anterior/posterior weight-bearing, with significant post-program differences between the groups. For walking, there were significant differences in the stance phase, swing phase, and cadence of the virtual reality training group. [Conclusion] The results of this study suggest that virtual reality training providing visual feedback may enable stroke patients to directly adjust their incorrect weight center and shift visually. Virtual reality training may be appropriate for patients who need improved balance and walking ability by inducing their interest for them to perform planned exercises on a consistent basis.

Public open spaces and walking for recreation: moderation by attributes of pedestrian environments.

Science.gov (United States)

Sugiyama, Takemi; Paquet, Catherine; Howard, Natasha J; Coffee, Neil T; Taylor, Anne W; Adams, Robert J; Daniel, Mark

2014-05-01

This study examined whether attributes of pedestrian environments moderate the relationships between access to public open spaces (POS) and adults' recreational walking. Data were collected from participants of the North West Adelaide Health Study in 2007. Recreational walking was determined using self-reported walking frequency. Measures of POS access (presence, count, and distance to the nearest POS) were assessed using a Geographic Information System. Pedestrian environmental attributes included aesthetics, walking infrastructure, barrier/traffic, crime concern, intersection density, and access to walking trails. Regression analyses examined whether associations between POS access and recreational walking were moderated by pedestrian environmental attributes. The sample included 1574 participants (45% men, mean age: 55). POS access measures were not associated with recreational walking. However, aesthetics, walking infrastructure, and access to walking trail were found to moderate the POS-walking relationships. The presence of POS was associated with walking among participants with aesthetically pleasing pedestrian environments. Counter-intuitively, better access to POS was associated with recreational walking for those with poorer walking infrastructure or no access to walking trails. Local pedestrian environments moderate the relationships between access to POS and recreational walking. Our findings suggest the presence of complex relationships between POS availability and pedestrian environments. Copyright © 2014 Elsevier Inc. All rights reserved.

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

Partition-based discrete-time quantum walks

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Konno, Norio; Portugal, Renato; Sato, Iwao; Segawa, Etsuo

2018-04-01

We introduce a family of discrete-time quantum walks, called two-partition model, based on two equivalence-class partitions of the computational basis, which establish the notion of local dynamics. This family encompasses most versions of unitary discrete-time quantum walks driven by two local operators studied in literature, such as the coined model, Szegedy's model, and the 2-tessellable staggered model. We also analyze the connection of those models with the two-step coined model, which is driven by the square of the evolution operator of the standard discrete-time coined walk. We prove formally that the two-step coined model, an extension of Szegedy model for multigraphs, and the two-tessellable staggered model are unitarily equivalent. Then, selecting one specific model among those families is a matter of taste not generality.

Using wireless technology in clinical practice: does feedback of daily walking activity improve walking outcomes of individuals receiving rehabilitation post-stroke? Study protocol for a randomized controlled trial

Science.gov (United States)

2013-01-01

Background Regaining independent ambulation is the top priority for individuals recovering from stroke. Thus, physical rehabilitation post-stroke should focus on improving walking function and endurance. However, the amount of walking completed by individuals with stroke attending rehabilitation is far below that required for independent community ambulation. There has been increased interest in accelerometer-based monitoring of walking post-stroke. Walking monitoring could be integrated within the goal-setting process for those with ambulation goals in rehabilitation. The feedback from these devices can be downloaded to a computer to produce reports. The purpose of this study is to determine the effect of accelerometer-based feedback of daily walking activity during rehabilitation on the frequency and duration of walking post-stroke. Methods Participants will be randomly assigned to one of two groups: feedback or no feedback. Participants will wear accelerometers daily during in- and out-patient rehabilitation and, for participants in the feedback group, the participants’ treating physiotherapist will receive regular reports of walking activity. The primary outcome measures are the amount of daily walking completed, as measured using the accelerometers, and spatio-temporal characteristics of walking (e.g. walking speed). We will also examine goal attainment, satisfaction with progress towards goals, stroke self-efficacy, and community-integration. Discussion Increased walking activity during rehabilitation is expected to improve walking function and community re-integration following discharge. In addition, a focus on altering walking behaviour within the rehabilitation setting may lead to altered behaviour and increased activity patterns after discharge. Trial registration ClinicalTrials.gov NCT01521234 PMID:23865593

Adaptive random walks on the class of Web graphs

Science.gov (United States)

Tadić, B.

2001-09-01

We study random walk with adaptive move strategies on a class of directed graphs with variable wiring diagram. The graphs are grown from the evolution rules compatible with the dynamics of the world-wide Web [B. Tadić, Physica A 293, 273 (2001)], and are characterized by a pair of power-law distributions of out- and in-degree for each value of the parameter β, which measures the degree of rewiring in the graph. The walker adapts its move strategy according to locally available information both on out-degree of the visited node and in-degree of target node. A standard random walk, on the other hand, uses the out-degree only. We compute the distribution of connected subgraphs visited by an ensemble of walkers, the average access time and survival probability of the walks. We discuss these properties of the walk dynamics relative to the changes in the global graph structure when the control parameter β is varied. For β≥ 3, corresponding to the world-wide Web, the access time of the walk to a given level of hierarchy on the graph is much shorter compared to the standard random walk on the same graph. By reducing the amount of rewiring towards rigidity limit β↦βc≲ 0.1, corresponding to the range of naturally occurring biochemical networks, the survival probability of adaptive and standard random walk become increasingly similar. The adaptive random walk can be used as an efficient message-passing algorithm on this class of graphs for large degree of rewiring.

The role of series ankle elasticity in bipedal walking.

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Zelik, Karl E; Huang, Tzu-Wei P; Adamczyk, Peter G; Kuo, Arthur D

2014-04-07

The elastic stretch-shortening cycle of the Achilles tendon during walking can reduce the active work demands on the plantarflexor muscles in series. However, this does not explain why or when this ankle work, whether by muscle or tendon, needs to be performed during gait. We therefore employ a simple bipedal walking model to investigate how ankle work and series elasticity impact economical locomotion. Our model shows that ankle elasticity can use passive dynamics to aid push-off late in single support, redirecting the body's center-of-mass (COM) motion upward. An appropriately timed, elastic push-off helps to reduce dissipative collision losses at contralateral heelstrike, and therefore the positive work needed to offset those losses and power steady walking. Thus, the model demonstrates how elastic ankle work can reduce the total energetic demands of walking, including work required from more proximal knee and hip muscles. We found that the key requirement for using ankle elasticity to achieve economical gait is the proper ratio of ankle stiffness to foot length. Optimal combination of these parameters ensures proper timing of elastic energy release prior to contralateral heelstrike, and sufficient energy storage to redirect the COM velocity. In fact, there exist parameter combinations that theoretically yield collision-free walking, thus requiring zero active work, albeit with relatively high ankle torques. Ankle elasticity also allows the hip to power economical walking by contributing indirectly to push-off. Whether walking is powered by the ankle or hip, ankle elasticity may aid walking economy by reducing collision losses. Copyright © 2013 Elsevier Ltd. All rights reserved.

Joint forces and torques when walking in shallow water.

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Orselli, Maria Isabel Veras; Duarte, Marcos

2011-04-07

This study reports for the first time an estimation of the internal net joint forces and torques on adults' lower limbs and pelvis when walking in shallow water, taking into account the drag forces generated by the movement of their bodies in the water and the equivalent data when they walk on land. A force plate and a video camera were used to perform a two-dimensional gait analysis at the sagittal plane of 10 healthy young adults walking at comfortable speeds on land and in water at a chest-high level. We estimated the drag force on each body segment and the joint forces and torques at the ankle, knee, and hip of the right side of their bodies using inverse dynamics. The observed subjects' apparent weight in water was about 35% of their weight on land and they were about 2.7 times slower when walking in water. When the subjects walked in water compared with walking on land, there were no differences in the angular displacements but there was a significant reduction in the joint torques which was related to the water's depth. The greatest reduction was observed for the ankle and then the knee and no reduction was observed for the hip. All joint powers were significantly reduced in water. The compressive and shear joint forces were on average about three times lower during walking in water than on land. These quantitative results substantiate the use of water as a safe environment for practicing low-impact exercises, particularly walking. Copyright © 2011 Elsevier Ltd. All rights reserved.

Does Dog Walking Predict Physical Activity Participation: Results From a National Survey.

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Richards, Elizabeth A

2016-05-01

The purpose of this study is to: (1) identify characteristics associated with dog owners who walk their dog, (2) describe the frequency and duration of walking the dog, and (3) determine whether dog owners who walk their dog participate in more physical activity than dog owners who do not walk their dog and non-dog owners. A cross-sectional study design was used. The study setting was nationwide. Adults (n = 4010) participating in the 2005 ConsumerStyles mail-panel survey were the study subjects. Measures used were demographic, physical activity, dog ownership, and dog walking questions from the 2005 ConsumerStyles mail-panel survey. Chi-square tests and analyses of variance were conducted to examine participant characteristics associated with dog walking and to describe the frequency and duration of dog walking. Analysis of covariance was used to determine whether dog owners who walk their dog participate in more physical activity than dog owners who do not walk their dog and non-dog owners. Among dog owners, 42% reported some dog walking in a typical week. Dog owners walked their dog an average 4.3 ± 0.1 times and 128.8 ± 5.6 minutes per week. There were no significant differences in weekly minutes of moderate or vigorous physical activity across the dog-ownership and dog walking groups. Most dog owners did not walk their dog. Dog owners were not more active than non-dog owners, except when considering the activity obtained via dog walking. © The Author(s) 2016.

Quality of Public Open Spaces and Recreational Walking.

Science.gov (United States)

Sugiyama, Takemi; Gunn, Lucy D; Christian, Hayley; Francis, Jacinta; Foster, Sarah; Hooper, Paula; Owen, Neville; Giles-Corti, Billie

2015-12-01

We examined associations between specific public open space (POS) attributes and recreational walking to local POS. Between October 2004 and December 2006, 1465 adults of the RESIDential Environments Project, conducted in Perth, Australia, reported whether they walk to a POS for recreation. For each participant, we identified all open spaces larger than 0.8 hectares within 1.6 kilometers from home. On the basis of field audit data, we created 3 scores (presence, count, size-weighted presence) for 19 specific open space attributes. With logistic regression analyses, we found that walking to a POS was associated with the presence of gardens, grassed areas, walking paths, water features, wildlife, amenities, dog-related facilities, and off-leash areas for dogs. It was also associated with the highest number of these attributes in a single open space, but not with the total number of attributes in all POSs within 1.6 kilometers of home. Building 1 high-quality local park may be more effective in promoting recreational walking than is providing many average-quality parks.

Stylet biogenesis in Bactericera cockerelli (Hemiptera: Triozidae).

Science.gov (United States)

Cicero, Joseph M

2017-07-01

The discovery of 'Ca. Liberibacter solanacearum', causal agent of certain solanaceous and apiaceous crop diseases, inside the functional (intrastadial) and pharate stylet anatomy of the potato psyllid prompted elucidation of the mechanism of stylet replacement as a novel exit portal in the transmission pathway. In Hemiptera, presumptive (formative) stylets, secreted during consecutive pharate instars, replace functional stylets lost with the exuviae. In potato psyllids, each functional stylet has a hollow core filled with a cytology that extends out of the core to form a hemispherical aggregate of cells, the 'end-cap', somewhat resembling a golf ball on a tee. A tightly folded mass of extremely thin cells, the 'matrix', occurs inside the end-cap. Micrograph interpretations indicate that during the pharate stage, the end-cap apolyses from the core and 'deconstructs' to release and expand the matrix into a long, coiled tube, the 'atrium'. Cells that were in contact with the inner walls of the functional stylet core maintain their position at the apex of the tube, and secrete a new stylet, apex first, the growing length of which descends into the tube until completed. They then despool from the coils into their functional position as the exuviae is shed. Copyright © 2016 Elsevier Ltd. All rights reserved.

Adaptive evolutionary walks require neutral intermediates in RNA fitness landscapes.

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Rendel, Mark D

2011-01-01

In RNA fitness landscapes with interconnected networks of neutral mutations, neutral precursor mutations can play an important role in facilitating the accessibility of epistatic adaptive mutant combinations. I use an exhaustively surveyed fitness landscape model based on short sequence RNA genotypes (and their secondary structure phenotypes) to calculate the minimum rate at which mutants initially appearing as neutral are incorporated into an adaptive evolutionary walk. I show first, that incorporating neutral mutations significantly increases the number of point mutations in a given evolutionary walk when compared to estimates from previous adaptive walk models. Second, that incorporating neutral mutants into such a walk significantly increases the final fitness encountered on that walk - indeed evolutionary walks including neutral steps often reach the global optimum in this model. Third, and perhaps most importantly, evolutionary paths of this kind are often extremely winding in their nature and have the potential to undergo multiple mutations at a given sequence position within a single walk; the potential of these winding paths to mislead phylogenetic reconstruction is briefly considered. Copyright © 2010 Elsevier Inc. All rights reserved.

What is my walking neighbourhood? A pilot study of English adults' definitions of their local walking neighbourhoods

Directory of Open Access Journals (Sweden)

Davey Rachel

2010-05-01

Full Text Available Abstract Background Existing measures of perceptions of the environment associated with walking commonly rely on providing a definition of 'neighbourhood', e.g. 1 mile area around the home. We have little understanding of how these examples relate with adults' own geographical definitions of their neighbourhood area. Our pilot study examined the congruence between definitions used in environmental questionnaires and adults' own definitions of neighbourhood. Methods We conducted 58 face-to-face interviews with participants randomly selected from 10 areas of Stoke-on-Trent, England. Participants were shown printed maps showing their local area with road names and places of interest (e.g. shops, services, green space and were asked: (i to recall usual walking destinations (from their home; (ii to draw their 'neighbourhood walking area' on the map. Annotated maps were scanned back into GIS for analysis. Results When asked to draw their 'neighbourhood' boundary, the resulting area drawn by participants on average represented only 16 ± 20% of the commonly used total straight-line buffer of 1 mile (or 1.6 km with a range of 0.3% to 111%. Even when repeated using a network buffer (rather than straight-line the same comparison resulted in a mean of 36% (± 47% and a range of 0.6 to 245%. Conclusions We found that adults' interpretation of their neighbourhood area does not appear to relate accurately to the definitions typically used in research into environmental perceptions and walking. This mis-match warrants further investigation as definitions used in existing measures may be consistently misclassifying perceived local walking neighbourhoods.

Pedagogies of the Walking Dead

Directory of Open Access Journals (Sweden)

Michael A. Peters

2016-04-01

Full Text Available This paper investigates the trope of the zombie and the recent upsurge in popular culture surrounding the figure of the zombie described as the “walking dead”. We investigate this trope and figure as a means of analyzing the “pedagogy of the walking dead” with particular attention to the crisis of education in the era of neoliberal capitalism. In particular we examine the professionalization and responsibilization of teachers in the new regulative environment and ask whether there is any room left for the project of critical education.

Random walks in the quarter-plane: invariant measures and performance bounds

NARCIS (Netherlands)

Chen, Y.

2015-01-01

This monograph focuses on random walks in the quarter-plane. Such random walks are frequently used to model queueing systems and the invariant measure of a random walk is of major importance in studying the performance of these systems. In special cases the invariant measure of a random walk can be

Nordic Walking improves daily physical activities in COPD: a randomised controlled trial

Directory of Open Access Journals (Sweden)

Breyer Marie-Kathrin

2010-08-01

Full Text Available Abstract Background In patients with COPD progressive dyspnoea leads to a sedentary lifestyle. To date, no studies exist investigating the effects of Nordic Walking in patients with COPD. Therefore, the aim was to determine the feasibility of Nordic Walking in COPD patients at different disease stages. Furthermore we aimed to determine the short- and long-term effects of Nordic Walking on COPD patients' daily physical activity pattern as well as on patients exercise capacity. Methods Sixty COPD patients were randomised to either Nordic Walking or to a control group. Patients of the Nordic Walking group (n = 30; age: 62 ± 9 years; FEV1: 48 ± 19% predicted underwent a three-month outdoor Nordic Walking exercise program consisting of one hour walking at 75% of their initial maximum heart rate three times per week, whereas controls had no exercise intervention. Primary endpoint: daily physical activities (measured by a validated tri-axial accelerometer; secondary endpoint: functional exercise capacity (measured by the six-minute walking distance; 6MWD. Assessment time points in both groups: baseline, after three, six and nine months. Results After three month training period, in the Nordic Walking group time spent walking and standing as well as intensity of walking increased (Δ walking time: +14.9 ± 1.9 min/day; Δ standing time: +129 ± 26 min/day; Δ movement intensity: +0.40 ± 0.14 m/s2 while time spent sitting decreased (Δ sitting time: -128 ± 15 min/day compared to baseline (all: p Conclusions Nordic Walking is a feasible, simple and effective physical training modality in COPD. In addition, Nordic Walking has proven to positively impact the daily physical activity pattern of COPD patients under short- and long-term observation. Clinical trial registration Nordic Walking improves daily physical activities in COPD: a randomised controlled trial - ISRCTN31525632

Women with fibromyalgia walk with an altered muscle synergy.

Science.gov (United States)

Pierrynowski, Michael R; Tiidus, Peter M; Galea, Victoria

2005-11-01

Most individuals can use different movement and muscle recruitment patterns to perform a stated task but often only one pattern is selected which optimizes an unknown global objective given the individual's neuromusculoskeletal characteristics. Patients with fibromyalgia syndrome (FS), characterized by their chronic pain, reduced physical work capacity and muscular fatigue, could exhibit a different control signature compared to asymptomatic control volunteers (CV). To test this proposal, 22 women with FS, and 11 CV, were assessed in a gait analysis laboratory. Each subject walked repeatedly at self-selected slow, comfortable, and fast walking speeds. The gait analysis provided, for each walk, each subject's stride time, length, and velocity, and ground reaction force, and lower extremity joint kinematics, moments and powers. The data were then anthropometrically scaled and velocity normalized to reduce the influence of subject mass, leg length, and walking speed on the measured gait outcomes. Similarities and differences in the two groups' scaled and normalized gait patterns were then determined. Results show that FS and CV walk with externally similar stride lengths, times, and velocities, and joint angles and ground reaction forces but they use internally different muscle recruitment patterns. Specifically, FS preferentially power gait using their hip flexors instead of their ankle plantarflexors. Interestingly, CV use a similar muscle fatiguing recruitment pattern to walk fast which parallels the common complaint of fatigue reported by FS walking at comfortable speed.

Experimental two-dimensional quantum walk on a photonic chip.

Science.gov (United States)

Tang, Hao; Lin, Xiao-Feng; Feng, Zhen; Chen, Jing-Yuan; Gao, Jun; Sun, Ke; Wang, Chao-Yue; Lai, Peng-Cheng; Xu, Xiao-Yun; Wang, Yao; Qiao, Lu-Feng; Yang, Ai-Lin; Jin, Xian-Min

2018-05-01

Quantum walks, in virtue of the coherent superposition and quantum interference, have exponential superiority over their classical counterpart in applications of quantum searching and quantum simulation. The quantum-enhanced power is highly related to the state space of quantum walks, which can be expanded by enlarging the photon number and/or the dimensions of the evolution network, but the former is considerably challenging due to probabilistic generation of single photons and multiplicative loss. We demonstrate a two-dimensional continuous-time quantum walk by using the external geometry of photonic waveguide arrays, rather than the inner degree of freedoms of photons. Using femtosecond laser direct writing, we construct a large-scale three-dimensional structure that forms a two-dimensional lattice with up to 49 × 49 nodes on a photonic chip. We demonstrate spatial two-dimensional quantum walks using heralded single photons and single photon-level imaging. We analyze the quantum transport properties via observing the ballistic evolution pattern and the variance profile, which agree well with simulation results. We further reveal the transient nature that is the unique feature for quantum walks of beyond one dimension. An architecture that allows a quantum walk to freely evolve in all directions and at a large scale, combining with defect and disorder control, may bring up powerful and versatile quantum walk machines for classically intractable problems.

Go Naked: Diapers Affect Infant Walking

OpenAIRE

Cole, Whitney G.; Lingeman, Jesse M.; Adolph, Karen E.

2012-01-01

In light of cross-cultural and experimental research highlighting effects of childrearing practices on infant motor skill, we asked whether wearing diapers, a seemingly innocuous childrearing practice, affects infant walking. Diapers introduce bulk between the legs, potentially exacerbating infants’ poor balance and wide stance. We show that walking is adversely affected by old-fashioned cloth diapers, and that even modern disposable diapers—habitually worn by most infants in the sample—incur...

Feedforward neural control of toe walking in humans.

Science.gov (United States)

Lorentzen, Jakob; Willerslev-Olsen, Maria; Hüche Larsen, Helle; Svane, Christian; Forman, Christian; Frisk, Rasmus; Farmer, Simon Francis; Kersting, Uwe; Nielsen, Jens Bo

2018-03-23

Activation of ankle muscles at ground contact during toe walking is unaltered when sensory feedback is blocked or the ground is suddenly dropped. Responses in the soleus muscle to transcranial magnetic stimulation, but not peripheral nerve stimulation, are facilitated at ground contact during toe walking. We argue that toe walking is supported by feedforward control at ground contact. Toe walking requires careful control of the ankle muscles in order to absorb the impact of ground contact and maintain a stable position of the joint. The present study aimed to clarify the peripheral and central neural mechanisms involved. Fifteen healthy adults walked on a treadmill (3.0 km h -1 ). Tibialis anterior (TA) and soleus (Sol) EMG, knee and ankle joint angles, and gastrocnemius-soleus muscle fascicle lengths were recorded. Peripheral and central contributions to the EMG activity were assessed by afferent blockade, H-reflex testing, transcranial magnetic brain stimulation (TMS) and sudden unloading of the planter flexor muscle-tendon complex. Sol EMG activity started prior to ground contact and remained high throughout stance. TA EMG activity, which is normally seen around ground contact during heel strike walking, was absent. Although stretch of the Achilles tendon-muscle complex was observed after ground contact, this was not associated with lengthening of the ankle plantar flexor muscle fascicles. Sol EMG around ground contact was not affected by ischaemic blockade of large-diameter sensory afferents, or the sudden removal of ground support shortly after toe contact. Soleus motor-evoked potentials elicited by TMS were facilitated immediately after ground contact, whereas Sol H-reflexes were not. These findings indicate that at the crucial time of ankle stabilization following ground contact, toe walking is governed by centrally mediated motor drive rather than sensory driven reflex mechanisms. These findings have implications for our understanding of the control of

Responses of Neomegalotomus parvus (Hemiptera: Alydidae to color and male-lured traps

Directory of Open Access Journals (Sweden)

Maurício Ursi Ventura

2004-08-01

Full Text Available In 1998, the relative responses of Neomegalotomus parvus (Westwood (Hemiptera: Alydidae to colors in traps were assessed in the field. Colors were printed in white alkaline paper and covered with transparent plastic. Printed colors were black, green, yellow, red and blue. Treatments also included white paper and aluminum foil. Green traps captured more bugs than the other traps (except yellow. Yellow traps caught significantly more N. parvus males than blue, black and aluminum traps. White, red and blue traps captured significantly more N. parvus males than black traps. In 1999, the same treatments were used and additionally included the factor presence (X absence of males in cages in the traps. Four males were confined in the cages together with pigeon pea seeds and water. Control traps received only pigeon pea seeds and water. No responses were found for color comparisons. Male-lured traps captured significantly more males than control traps.Em 1998, as respostas relativas de Neomegalotomus parvus (Westwood (Hemiptera: Alydidae a cores em armadilhas foram avaliadas no campo. As cores foram impressas (preto, verde, amarelo, vermelho e azul, em papel alcalino branco e coberto com plástico transparente. Também se incluiu papel branco e folha de alumínio, como tratamentos. Armadilhas verdes capturaram mais insetos que outras armadilhas (exceto amarelo. Armadilhas amarelas capturaram significativamente mais machos de N. parvus do que armadilhas azuis, pretas e alumínio. Armadilhas brancas, vermelhas e azuis capturaram significativamente mais machos de N. parvus do que armadilhas pretas. Em 1999, os mesmos tratamentos foram usados e também se incluiu fator presença (X ausência de machos em gaiolas nas armadilhas. Quatro machos foram confinados nas gaiolas junto com sementes de guandu e água. Testemunhas receberam somente sementes de guandu e água. Não foram obtidas respostas significativas à cores. Armadilhas com machos capturaram

The Walking Classroom: Active Learning Is Just Steps Away!

Science.gov (United States)

Becker, Kelly Mancini

2016-01-01

Walking is a viable and valuable form of exercise for young children that has both physical and mental health benefits. There is much evidence showing that school-age children are not getting the recommended 60 minutes of daily exercise. A school-wide walking program can be a great way to encourage walking in and out of school, can be aligned with…

Biology of Maconellicoccus hirsutus (Hemiptera: Pseudococcidae on Hibiscus rosa-sinensis = Biologia de Maconellicoccus hirsutus (Hemiptera: Pseudococcidae em Hibiscus rosa-sinensis

Directory of Open Access Journals (Sweden)

Marcelo Negrini

2017-10-01

Full Text Available Maconellicoccus hirsutus Green, 1908 (Hemiptera: Pseudococcidae is an introduced pest that threatens fruit and ornamental plant production in Brazil. Reported in Brazil for the first time in 2010, in the state of Roraima, M. hirsutus, has spread rapidly to other regions of the country. The objective of this study was to investigate the biology of M. hirsutus on Hibiscus rosa-sinensis L. (Malvaceae leaves in laboratory conditions with climatic parameters similar to those of the Brazilian North and Northeast (27 ± 1 °C, 60 ± 10% relative humidity and 12 hours light and 12 hours dark. Eighty M. hirsutus nymphs were individualized on rooted H. rosa-sinensis leaves and their survival, mortality, sex ratio, and egg numbers per female emerged were recorded. Maconellicoccus hirsutus can have up to nine generations per year, taking 6.5 days to double its population size. The female numbers of this pest are about three times higher than those for its male counterparts, with 98 eggs per female and 97% viability. The survival curve of the species is type I, that is, mortality rates are higher in adulthood. Maconellicoccus hirsutus, especially, a pest of fruit trees and ornamental plants, presents great potential for population growth in Brazilian tropical conditions. = Maconellicoccus hirsutus Green, 1908 (Hemiptera: Pseudococcidae é uma praga introduzida que ameaça a produção de frutas e plantas ornamentais no Brasil. Registrada no Brasil pela primeira vez em 2010, no estado de Roraima, M. hirsutus se espalhou rapidamente para outras regiões do país. O objetivo deste estudo foi investigar a biologia de M. hirsutus em folhas de Hibiscus rosa-sinensis L. (Malvaceae, em condições de laboratório com parâmetros climáticos semelhantes aos das regiões Norte e Nordeste do Brasil (27 ± 1 °C, 60 ± 10 % de umidade relativa e 12 h de luz e 12 h de escuro. Oitenta ninfas de M. hirsutus foram individualizadas em folhas enraizadas de H. rosa-sinensis e

Inferring Lévy walks from curved trajectories: A rescaling method

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Tromer, R. M.; Barbosa, M. B.; Bartumeus, F.; Catalan, J.; da Luz, M. G. E.; Raposo, E. P.; Viswanathan, G. M.

2015-08-01

An important problem in the study of anomalous diffusion and transport concerns the proper analysis of trajectory data. The analysis and inference of Lévy walk patterns from empirical or simulated trajectories of particles in two and three-dimensional spaces (2D and 3D) is much more difficult than in 1D because path curvature is nonexistent in 1D but quite common in higher dimensions. Recently, a new method for detecting Lévy walks, which considers 1D projections of 2D or 3D trajectory data, has been proposed by Humphries et al. The key new idea is to exploit the fact that the 1D projection of a high-dimensional Lévy walk is itself a Lévy walk. Here, we ask whether or not this projection method is powerful enough to cleanly distinguish 2D Lévy walk with added curvature from a simple Markovian correlated random walk. We study the especially challenging case in which both 2D walks have exactly identical probability density functions (pdf) of step sizes as well as of turning angles between successive steps. Our approach extends the original projection method by introducing a rescaling of the projected data. Upon projection and coarse-graining, the renormalized pdf for the travel distances between successive turnings is seen to possess a fat tail when there is an underlying Lévy process. We exploit this effect to infer a Lévy walk process in the original high-dimensional curved trajectory. In contrast, no fat tail appears when a (Markovian) correlated random walk is analyzed in this way. We show that this procedure works extremely well in clearly identifying a Lévy walk even when there is noise from curvature. The present protocol may be useful in realistic contexts involving ongoing debates on the presence (or not) of Lévy walks related to animal movement on land (2D) and in air and oceans (3D).

Predictive neuromechanical simulations indicate why walking performance declines with ageing.

Science.gov (United States)

Song, Seungmoon; Geyer, Hartmut

2018-04-01

Although the natural decline in walking performance with ageing affects the quality of life of a growing elderly population, its physiological origins remain unknown. By using predictive neuromechanical simulations of human walking with age-related neuro-musculo-skeletal changes, we find evidence that the loss of muscle strength and muscle contraction speed dominantly contribute to the reduced walking economy and speed. The findings imply that focusing on recovering these muscular changes may be the only effective way to improve performance in elderly walking. More generally, the work is of interest for investigating the physiological causes of altered gait due to age, injury and disorders. Healthy elderly people walk slower and energetically less efficiently than young adults. This decline in walking performance lowers the quality of life for a growing ageing population, and understanding its physiological origin is critical for devising interventions that can delay or revert it. However, the origin of the decline in walking performance remains unknown, as ageing produces a range of physiological changes whose individual effects on gait are difficult to separate in experiments with human subjects. Here we use a predictive neuromechanical model to separately address the effects of common age-related changes to the skeletal, muscular and nervous systems. We find in computer simulations of this model that the combined changes produce gait consistent with elderly walking and that mainly the loss of muscle strength and mass reduces energy efficiency. In addition, we find that the slower preferred walking speed of elderly people emerges in the simulations when adapting to muscle fatigue, again mainly caused by muscle-related changes. The results suggest that a focus on recovering these muscular changes may be the only effective way to improve performance in elderly walking. © 2018 The Authors. The Journal of Physiology © 2018 The Physiological Society.

15 Years of Research on Redirected Walking in Immersive Virtual Environments

DEFF Research Database (Denmark)

Nilsson, Niels Chr.; Peck, Tabitha; Bruder, Gerd

2018-01-01

Virtual reality users wearing head-mounted displays can experience the illusion of walking in any direction for infinite distance while, in reality, they are walking a curvilinear path in physical space. This is accomplished by introducing unnoticeable rotations to the virtual environment—a techn......—a technique called redirected walking. This paper gives an overview of the research that has been performed since redirected walking was first practically demonstrated 15 years ago.......Virtual reality users wearing head-mounted displays can experience the illusion of walking in any direction for infinite distance while, in reality, they are walking a curvilinear path in physical space. This is accomplished by introducing unnoticeable rotations to the virtual environment...

Spin lattices of walking droplets

Science.gov (United States)

Saenz, Pedro; Pucci, Giuseppe; Goujon, Alexis; Dunkel, Jorn; Bush, John

2017-11-01

We present the results of an experimental investigation of the spontaneous emergence of collective behavior in spin lattice of droplets walking on a vibrating fluid bath. The bottom topography consists of relatively deep circular wells that encourage the walking droplets to follow circular trajectories centered at the lattice sites, in one direction or the other. Wave-mediated interactions between neighboring drops are enabled through a thin fluid layer between the wells. The sense of rotation of the walking droplets may thus become globally coupled. When the coupling is sufficiently strong, interactions with neighboring droplets may result in switches in spin that lead to preferred global arrangements, including correlated (all drops rotating in the same direction) or anti-correlated (neighboring drops rotating in opposite directions) states. Analogies with ferromagnetism and anti-ferromagnetism are drawn. Different spatial arrangements are presented in 1D and 2D lattices to illustrate the effects of topological frustration. This work was supported by the US National Science Foundation through Grants CMMI-1333242 and DMS-1614043.

Movement Behavior of High-Heeled Walking

DEFF Research Database (Denmark)

Alkjær, Tine; Raffalt, Peter Christian; Petersen, Nicolas Caesar

2012-01-01

The human locomotor system is flexible and enables humans to move without falling even under less than optimal conditions. Walking with high-heeled shoes constitutes an unstable condition and here we ask how the nervous system controls the ankle joint in this situation? We investigated the movement...... behavior of high-heeled and barefooted walking in eleven female subjects. The movement variability was quantified by calculation of approximate entropy (ApEn) in the ankle joint angle and the standard deviation (SD) of the stride time intervals. Electromyography (EMG) of the soleus (SO) and tibialis...... anterior (TA) muscles and the soleus Hoffmann (H-) reflex were measured at 4.0 km/h on a motor driven treadmill to reveal the underlying motor strategies in each walking condition. The ApEn of the ankle joint angle was significantly higher (p...

Predicting the walking speed of pedestrians on stairs

OpenAIRE

Fujiyama, T.; Tyler, N.

2010-01-01

In this paper, we propose a framework in which the behaviour of a pedestrian is predicted based on the characteristics of both the pedestrian and the facility the pedestrian uses. As an example of its application, we develop a model to predict the walking speed of a pedestrian on stairs. We examine the physiology and biomechanics of walking on stairs, and then develop a model that predicts walking speed based on the weight and leg extensor power of the pedestrian, and the gradient of the stai...

Description of a new species of Hemiberlesia Cockerell (Hemiptera: Coccomorpha: Diaspididae) from China, with a key to Hemiberlesia species known from China.

Science.gov (United States)

Liu, Di; Feng, Jinian

2018-03-06

The diagnostic characters of the genus Hemiberlesia Cockerell (Hemiptera: Coccoidea: Diaspididae) are reviewed. The adult female, adult male and all immature stages (except the male prepupa and pupa) of a new species, H. serrulata Liu Feng sp. n., collected from Henan Province, China, are described and illustrated. A key is provided to identify the Hemiberlesia species known to occur in China.

The Social Relations of a Health Walk Group: An Ethnographic Study.

Science.gov (United States)

Grant, Gordon; Pollard, Nick; Allmark, Peter; Machaczek, Kasia; Ramcharan, Paul

2017-09-01

It is already well established that regular walks are conducive to health and well-being. This article considers the production of social relations of regular, organized weekly group walks for older people. It is based on an ethnographic study of a Walking for Health group in a rural area of the United Kingdom. Different types of social relations are identified arising from the walk experience. The social relations generated are seen to be shaped by organizational factors that are constitutive of the walks; the resulting culture having implications for the sustainability of the experience. As there appears to be no single uniting theory linking group walk experiences to the production of social relations at this time, the findings are considered against therapeutic landscape, therapeutic mobility, and social capital theorizing. Finally, implications for the continuance of walking schemes for older people and for further research are considered.

Walking football as sustainable exercise for older adults - A pilot investigation.

Science.gov (United States)

Reddy, Peter; Dias, Irundika; Holland, Carol; Campbell, Niyah; Nagar, Iaysha; Connolly, Luke; Krustrup, Peter; Hubball, Harry

2017-06-01

The health benefits of playing football and the importance of exercise and social contact for healthy ageing are well established, but few older adults in the UK take enough exercise. Football is popular, flexible in format and draws players into engrossing, effortful and social exercise, but the physical demands of play at full speed may make it unsustainable for some older adults. Restricted to walking pace, will play still be engaging? Will health benefits be retained? Will physical demands remain manageable? This pilot study aims to investigate: (1) the experience of older adults playing walking football every week, is it sustainable and rewarding, (2) the intensity and locomotor pattern of walking football, (3) the scale and nature of walking football health benefits and (4) possible cognitive benefits of playing walking football through measures of processing speed, selective and divided attention and updating and inhibition components of executive function.
 'Walking football' and 'waiting list' groups were compared before and after 12 weeks of one-hour per week football. Walking football was found to be engaging, sustainable for older adults and moderately intensive; however, selective health and cognitive benefits were not found from this brief intervention. Highlights Walking football is a lower impact but authentic form of football that enables older players to extend their active participation. Walking football is enjoyable and moderately demanding and may be a sustainable form of exercise for older adults. Health and cognitive benefits to playing walking football were not found.

Functional roles of lower-limb joint moments while walking in water.

Science.gov (United States)

Miyoshi, Tasuku; Shirota, Takashi; Yamamoto, Shin-Ichiro; Nakazawa, Kimitaka; Akai, Masami

2005-02-01

To clarify the functional roles of lower-limb joint moments and their contribution to support and propulsion tasks while walking in water compared with that on land. Sixteen healthy, young subjects walked on land and in water at several different speeds with and without additional loads. Walking in water is a major rehabilitation therapy for patients with orthopedic disorders. However, the functional role of lower-limb joint moments while walking in water is still unclear. Kinematics, electromyographic activities in biceps femoris and gluteus maximums, and ground reaction forces were measured under the following conditions: walking on land and in water at a self-determined pace, slow walking on land, and fast walking in water with or without additional loads (8 kg). The hip, knee, and ankle joint moments were calculated by inverse dynamics. The contribution of the walking speed increased the hip extension moment, and the additional weight increased the ankle plantar flexion and knee extension moment. The major functional role was different in each lower-limb joint muscle. That of the muscle group in the ankle is to support the body against gravity, and that of the muscle group involved in hip extension is to contribute to propulsion. In addition, walking in water not only reduced the joint moments but also completely changed the inter-joint coordination. It is of value for clinicians to be aware that the greater the viscosity of water produces a greater load on the hip joint when fast walking in water.

[Walking in Crustacea: motor program and peripheral regulation (author's transl)].

Science.gov (United States)

Clarac, F; Ayers, J

1977-01-01

1. Rock lobsters can walk in all directions. In the present study, we report the organization of the motor output of the three muscles which control the mero-carpopodite joint (M-C): the extensor E, the flexor F and the accuracy flexor FA, during unrestrained locomotion (fig. 1). 2. During lateral walking, movements of the M-C joint provide most of the propulsive force, whereas during forward and backward walking this joint function more as a strut (fig. 2). Corresponding differences are observed in the motor discharge in the different walking modes. During lateral walking, discharge in the M-C extensor and M-C flexor alternates, whereas during forward and backward walking these antagonists are coactivated (fig. 3 and 4). 3. We have also examined the effects of alterations of proprioceptive feedback: the FA tendon has been cut to eliminate MCO afferents during walking. This ablation does not modify the burst period and the temporal structure of the output pattern is largely unaffected (fig. 5, 6 and 7). MCO may influence the motor output of a given muscle depending upon whether it participates in the return stroke or the power stroke.

Technology-related distracted walking behaviours in Manhattan's most dangerous intersections.

Science.gov (United States)

Basch, Corey H; Ethan, Danna; Rajan, Sonali; Basch, Charles E

2014-10-01

Use of mobile devices has been cited as a distraction while driving, and more recently, among pedestrians crossing urban streets. In 2010, over half of New York City traffic fatalities were pedestrians. The aim of this study was to estimate the prevalence of distracted walking due to pedestrians' use of headphones, mobile phones, or both. Data were gathered by direct observations at the 10 intersections in Manhattan with the highest frequency of pedestrian-motor vehicle collisions. More than 1 in 4 of the >3500 pedestrians observed were distracted by mobile electronic devices while crossing during the 'walk' (28.8%) and 'don't walk' (26.3%) signals. Poisson regression analyses established there was a significant difference in individuals talking on a mobile device during the 'walk' signal versus the 'don't walk' signal; however, no other significant differences in other distracted walking behaviours were observed. This study contributes to the emerging literature on distracted walking behaviour by pedestrians in busy urban areas and can help to inform pedestrian-focused safety efforts. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Walking solitons in quadratic nonlinear media

OpenAIRE

Torner Sabata, Lluís; Mazilu, D; Mihalache, Dumitru

1996-01-01

We study self-action of light in parametric wave interactions in nonlinear quadratic media. We show the existence of stationary solitons in the presence of Poynting vector beam walk-off or different group velocities between the waves. We discover that the new solitons constitute a two-parameter family, and they exist for different wave intensities and transverse velocities. We discuss the properties of the walking solitons and their experimental implications. Peer Reviewed

Quantum walk on the line as an interference phenomenon

International Nuclear Information System (INIS)

Knight, Peter L.; Roldan, Eugenio; Sipe, J. E.

2003-01-01

We show that the coined quantum walk on a line can be understood as an interference phenomenon, can be classically implemented, and indeed already has been. The walk is essentially two independent walks associated with the different coin sides, coupled only at initiation. There is a simple analogy between the evolution of walker positions and the propagation of light in a dispersive optical fiber

The immediate effects of robot-assistance on energy consumption and cardiorespiratory load during walking compared to walking without robot-assistance: a systematic review.

Science.gov (United States)

Lefeber, Nina; Swinnen, Eva; Kerckhofs, Eric

2017-10-01

The integration of sufficient cardiovascular stress into robot-assisted gait (RAG) training could combine the benefits of both RAG and aerobic training. The aim was to summarize literature data on the immediate effects of RAG compared to walking without robot-assistance on metabolic-, cardiorespiratory- and fatigue-related parameters. PubMed and Web of Science were searched for eligible articles till February 2016. Means, SDs and significance values were extracted. Effect sizes were calculated. Fourteen studies were included, concerning 155 participants (85 healthy subjects, 39 stroke and 31 spinal cord injury patients), 9 robots (2 end-effectors, 1 treadmill-based and 6 wearable exoskeletons), and 7 outcome parameters (mostly oxygen consumption and heart rate). Overall, metabolic and cardiorespiratory parameters were lower during RAG compared to walking without robot-assistance (moderate to large effect sizes). In healthy subjects, when no body-weight support (BWS) was provided, RAG with an end-effector device was more energy demanding than walking overground (p > .05, large effect sizes). Generally, results suggest that RAG is less energy-consuming and cardiorespiratory stressful than walking without robot-assistance, but results depend on factors such as robot type, walking speed, BWS and effort. Additional research is needed to draw firm conclusions. Implications for Rehabilitation Awareness of the energy consumption and cardiorespiratory load of robot-assisted gait (RAG) training is important in the rehabilitation of (neurological) patients with impaired cardiorespiratory fitness and patients who are at risk of cardiovascular diseases. On the other hand, the integration of sufficient cardiometabolic stress in RAG training could combine the effects of both RAG and aerobic training. Energy consumption and cardiorespiratory load during walking with robot-assistance seems to depend on factors such as robot type, walking speed, body-weight support or amount of

The average inter-crossing number of equilateral random walks and polygons

International Nuclear Information System (INIS)

Diao, Y; Dobay, A; Stasiak, A

2005-01-01

In this paper, we study the average inter-crossing number between two random walks and two random polygons in the three-dimensional space. The random walks and polygons in this paper are the so-called equilateral random walks and polygons in which each segment of the walk or polygon is of unit length. We show that the mean average inter-crossing number ICN between two equilateral random walks of the same length n is approximately linear in terms of n and we were able to determine the prefactor of the linear term, which is a = 3ln2/8 ∼ 0.2599. In the case of two random polygons of length n, the mean average inter-crossing number ICN is also linear, but the prefactor of the linear term is different from that of the random walks. These approximations apply when the starting points of the random walks and polygons are of a distance ρ apart and ρ is small compared to n. We propose a fitting model that would capture the theoretical asymptotic behaviour of the mean average ICN for large values of ρ. Our simulation result shows that the model in fact works very well for the entire range of ρ. We also study the mean ICN between two equilateral random walks and polygons of different lengths. An interesting result is that even if one random walk (polygon) has a fixed length, the mean average ICN between the two random walks (polygons) would still approach infinity if the length of the other random walk (polygon) approached infinity. The data provided by our simulations match our theoretical predictions very well

Does the aggressiveness of the prey modify the attack behavior of the predator Supputius cincticeps (Stål (Hemiptera, Pentatomidae? A agressividade da presa altera o comportamento de ataque do predador Supputius cincticeps (Stål (Hemiptera, Pentatomidae?

Directory of Open Access Journals (Sweden)

Rafael Braga da Silva

2012-06-01

Full Text Available Does the aggressiveness of the prey modify the attack behavior of the predator Supputius cincticeps (Stål (Hemiptera, Pentatomidae? The stink bug Supputius cincticeps (Stål (Hemiptera, Pentatomidae is a predator found in several Brazilian regions, which possesses desirable attributes as a natural control agent and in biological control programs. The aim of this study was to test if the attack behavior and predation success of S. cincticeps were affected by prey species. Larvae of Tenebrio molitor (L. (Coleoptera, Tenebrionidae, Spodoptera frugiperda (J. E. Smith (Lepidoptera, Noctuidae, and Thyrinteina arnobia (Stoll (Lepidoptera, Geometridae were offered to S. cincticeps in laboratory bioassays where predatory attack and prey defensive behaviors were observed for 2-hour periods. The attack behavior of S. cincticeps changed with the prey species offered. More than 25% of T. molitor and S. frugiperda larvae were immediately attacked, but T. arnobia was not immediately attacked by S. cincticeps. Successful attack (i.e., successful insertion of the predator stylets into the prey depends on the region of the body attacked, with a greater proportion of successful attacks in the anterior than in the median or posterior regions. Larvae of T. arnobia and S. frugiperda displayed a sequence of abrupt head and body movements in response to S. cincticeps attack. Attempts of predation were more successful on T. molitor and S. frugiperda than on T. arnobia. Information about the differential attack behavior of S. cincticeps on different prey species is important for designing successful biological control programs using this hemipteran predator.A agressividade da presa altera o comportamento de ataque do predador Supputius cincticeps (Stål (Hemiptera, Pentatomidae? O percevejo Supputius cincticeps (Stål (Hemiptera, Pentatomidae é um predador encontrado em várias regiões brasileiras, que possui atributos desejáveis como agente de controle natural ou em

Port-Based Modeling and Control for Efficient Bipedal Walking Robots

NARCIS (Netherlands)

Duindam, V.

2006-01-01

Research on walking robots has shown that the process of walking, in itself, requires little energy. Indeed, many robots have been built that walk with high efficiency. General analysis and control tools for such efficient walkers, however, are lacking, and many results are based on engineering

Navigation by anomalous random walks on complex networks.

Science.gov (United States)

Weng, Tongfeng; Zhang, Jie; Khajehnejad, Moein; Small, Michael; Zheng, Rui; Hui, Pan

2016-11-23

Anomalous random walks having long-range jumps are a critical branch of dynamical processes on networks, which can model a number of search and transport processes. However, traditional measurements based on mean first passage time are not useful as they fail to characterize the cost associated with each jump. Here we introduce a new concept of mean first traverse distance (MFTD) to characterize anomalous random walks that represents the expected traverse distance taken by walkers searching from source node to target node, and we provide a procedure for calculating the MFTD between two nodes. We use Lévy walks on networks as an example, and demonstrate that the proposed approach can unravel the interplay between diffusion dynamics of Lévy walks and the underlying network structure. Moreover, applying our framework to the famous PageRank search, we show how to inform the optimality of the PageRank search. The framework for analyzing anomalous random walks on complex networks offers a useful new paradigm to understand the dynamics of anomalous diffusion processes, and provides a unified scheme to characterize search and transport processes on networks.

Navigation by anomalous random walks on complex networks

Science.gov (United States)

Weng, Tongfeng; Zhang, Jie; Khajehnejad, Moein; Small, Michael; Zheng, Rui; Hui, Pan

2016-11-01

Anomalous random walks having long-range jumps are a critical branch of dynamical processes on networks, which can model a number of search and transport processes. However, traditional measurements based on mean first passage time are not useful as they fail to characterize the cost associated with each jump. Here we introduce a new concept of mean first traverse distance (MFTD) to characterize anomalous random walks that represents the expected traverse distance taken by walkers searching from source node to target node, and we provide a procedure for calculating the MFTD between two nodes. We use Lévy walks on networks as an example, and demonstrate that the proposed approach can unravel the interplay between diffusion dynamics of Lévy walks and the underlying network structure. Moreover, applying our framework to the famous PageRank search, we show how to inform the optimality of the PageRank search. The framework for analyzing anomalous random walks on complex networks offers a useful new paradigm to understand the dynamics of anomalous diffusion processes, and provides a unified scheme to characterize search and transport processes on networks.

Design, Modeling and Control of a Biped Line-Walking Robot

Directory of Open Access Journals (Sweden)

Ludan Wang

2010-12-01

Full Text Available The subject of this paper is the design and analysis of a biped line walking robot for inspection of power transmission lines. With a novel mechanism the centroid of the robot can be concentrated on the axis of hip joint to minimize the drive torque of the hip joint. The mechanical structure of the robot is discussed, as well as forward kinematics. Dynamic model is established in this paper to analyze the inverse kinematics for motion planning. The line-walking cycle of the line-walking robot is composed of a single-support phase and a double-support phase. Locomotion of the line-walking robot is discussed in details and the obstacle-navigation process is planed according to the structure of power transmission line. To fulfill the demands of line-walking, a control system and trajectories generation method are designed for the prototype of the line-walking robot. The feasibility of this concept is then confirmed by performing experiments with a simulated line environment.

Stepping forward together: Could walking facilitate interpersonal conflict resolution?

Science.gov (United States)

Webb, Christine E; Rossignac-Milon, Maya; Higgins, E Tory

2017-01-01

Walking has myriad benefits for the mind, most of which have traditionally been explored and explained at the individual level of analysis. Much less empirical work has examined how walking with a partner might benefit social processes. One such process is conflict resolution-a field of psychology in which movement is inherent not only in recent theory and research, but also in colloquial language (e.g., "moving on"). In this article, we unify work from various fields pointing to the idea that walking together can facilitate both the intra- and interpersonal pathways to conflict resolution. Intrapersonally, walking supports various psychological mechanisms for reconciliation, including creativity, locomotion motivation, and embodied notions of forward progress. Both alone and in combination with its effects on mood and stress, walking can encourage individual mindsets conducive to resolving conflict (e.g., divergent thinking). Interpersonally, walking can allow partners to reap the cognitive, affective, and behavioral advantages of synchronous movement, such as increased positive rapport, empathy, and prosociality. Walking partners naturally adopt cooperative (as opposed to competitive) postural stances, experience shared attention, and can benefit from discussions in novel environments. Overall, despite its prevalence in conflict resolution theory, little is known about how movement influences conflict resolution practice. Such knowledge has direct implications for a range of psychological questions and approaches within negotiation and alternative mediation techniques, clinical settings, and the study of close relationships. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Parrondo's game using a discrete-time quantum walk

International Nuclear Information System (INIS)

Chandrashekar, C.M.; Banerjee, Subhashish

2011-01-01

We present a new form of a Parrondo game using discrete-time quantum walk on a line. The two players A and B with different quantum coins operators, individually losing the game can develop a strategy to emerge as joint winners by using their coins alternatively, or in combination for each step of the quantum walk evolution. We also present a strategy for a player A (B) to have a winning probability more than player B (A). Significance of the game strategy in information theory and physical applications are also discussed. - Highlights: → Novel form of Parrondo's game on a single particle discrete-time quantum walk. → Strategies for players to emerge as individual winners or as joint winners. → General framework for controlling and using quantum walk with multiple coins. → Strategies can be used in algorithms and situations involving directed motion.