Epidemiologic characterization of Colorado backyard bird flocks.

Science.gov (United States)

Smith, Emily I; Reif, John S; Hill, Ashley E; Slota, Katharine E; Miller, Ryan S; Bjork, Kathe E; Pabilonia, Kristy L

2012-06-01

Backyard gallinaceous bird flocks may play an important role in the spread of infectious diseases within poultry populations as well as the transmission of zoonotic diseases to humans. An epidemiologic characterization was conducted of Colorado backyard flocks to gather information on general flock characteristics, human movement of birds, human-bird interaction, biosecurity practices, and flock health. Our results suggest that backyard poultry flocks in Colorado are small-sized flocks (68.6% of flocks had meat or egg) production for the family (86.44%) or as pet or hobby birds (42.27%). The backyard flock environment may promote bird-to-bird transmission as well as bird-to-human transmission of infectious disease. Birds are primarily housed with free access to the outside (96.85%), and many are moved from the home premises (46.06% within 1 yr). Human contact with backyard flocks is high, biosecurity practices are minimal, and bird health is negatively impacted by increased movement events. Increased knowledge of backyard bird characteristics and associated management practices can provide guidelines for the development of measures to decrease disease transmission between bird populations, decrease disease transmission from birds to humans, and increase the overall health of backyard birds.

Density distributions and depth in flocks

Science.gov (United States)

Lewis, J. M.; Turner, M. S.

2017-12-01

Recent experimental evidence suggests that interactions in flocks of birds do not involve a characteristic length scale. Bird flocks have also been revealed to have an inhomogeneous density distribution, with the density of birds near the border greater than near the centre. We introduce a strictly metric-free model for collective behaviour that incorporates a distributed motional bias, providing control of the density distribution. A simple version of this model is then able to provide a good fit to published data for the density variation across flocks of Starlings. We find that it is necessary for individuals on the edge of the flock to have an inward motional bias but that birds in the interior of the flock instead must have an outward bias. We discuss the ability of individuals to determine their depth within a flock and show how this might be achieved by relatively simple analysis of their visual environment.

Flocking regimes in a simple lattice model.

Science.gov (United States)

Raymond, J R; Evans, M R

2006-03-01

We study a one-dimensional lattice flocking model incorporating all three of the flocking criteria proposed by Reynolds [Computer Graphics 21, 4 (1987)]: alignment, centering, and separation. The model generalizes that introduced by O. J. O'Loan and M. R. Evans [J. Phys. A. 32, L99 (1999)]. We motivate the dynamical rules by microscopic sampling considerations. The model exhibits various flocking regimes: the alternating flock, the homogeneous flock, and dipole structures. We investigate these regimes numerically and within a continuum mean-field theory.

Analysis of factors important for the occurrence of Campylobacter in Danish broiler flocks

DEFF Research Database (Denmark)

Sommer, Helle Mølgaard; Heuer, Ole Eske; Sørensen, Anna Irene Vedel

2013-01-01

a multivariate analysis including all 43 variables. A multivariate analysis was conducted using a generalized linear model, and the correlations between the houses from the same farms were accounted for by adding a variance structure to the model. The procedures for analyses included backward elimination...... of positive flocks/total number of flocks delivered over the 2-year period).The following factors were found to be significantly associated with the occurrence of Campylobacter in the broiler flocks: old broiler houses, late introduction of whole wheat in the feed, relatively high broiler age at slaughter...

Flocking through disorder

Science.gov (United States)

Morin, Alexandre; Desreumaux, Nicolas; Caussin, Jean-Baptiste; Bartolo, Denis

How do flocks, herds and swarms proceed through disordered environments? This question is not only crucial to animal groups in the wild, but also to virtually all applications of collective robotics, and active materials composed of synthetic motile units. In stark contrast, appart from very rare exceptions, our physical understanding of flocking has been hitherto limited to homogeneous media. Here we explain how collective motion survives to geometrical disorder. To do so, we combine experiments on motile colloids cruising through random microfabricated obstacles, and analytical theory. We explain how disorder and bending elasticity compete to channel the flow of polar flocks along sparse river networks akin those found beyond plastic depinning in driven condensed matter. Further increasing disorder, we demonstrate that collective motion is suppressed in the form of a first-order phase transition generic to all polar active materials.

An index for quantifying flocking behavior.

Science.gov (United States)

Quera, Vicenç; Herrando, Salvador; Beltran, Francesc S; Salas, Laura; Miñano, Meritxell

2007-12-01

One of the classic research topics in adaptive behavior is the collective displacement of groups of organisms such as flocks of birds, schools of fish, herds of mammals, and crowds of people. However, most agent-based simulations of group behavior do not provide a quantitative index for determining the point at which the flock emerges. An index was developed of the aggregation of moving individuals in a flock and an example was provided of how it can be used to quantify the degree to which a group of moving individuals actually forms a flock.

Design of Connectivity Preserving Flocking Using Control Lyapunov Function

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Bayu Erfianto

2016-01-01

Full Text Available This paper investigates cooperative flocking control design with connectivity preserving mechanism. During flocking, interagent distance is measured to determine communication topology of the flocks. Then, cooperative flocking motion is built based on cooperative artificial potential field with connectivity preserving mechanism to achieve the common flocking objective. The flocking control input is then obtained by deriving cooperative artificial potential field using control Lyapunov function. As a result, we prove that our flocking protocol establishes group stabilization and the communication topology of multiagent flocking is always connected.

Feather-pecking and injurious pecking in organic laying hens in 107 flocks from eight European countries

DEFF Research Database (Denmark)

Bestman, M.; Verwer, Cynthia; Brenninkmeyer, Christine

2017-01-01

Feather-pecking and cannibalism may reduce the potential of organic husbandry to enhance the welfare of laying hens. We report risk factors for these issues based on a large survey of 107 commercial flocks in eight European countries. Information was collected regarding housing, management...... and flock characteristics (age, genotype). Near the end of lay, 50 hens per flock were assessed for plumage condition and wounds. Potential influencing factors were screened and submitted to a multivariate model. The majority of the flocks (81%) consisted of brown genotypes and were found in six countries...

A Flocking Based algorithm for Document Clustering Analysis

Energy Technology Data Exchange (ETDEWEB)

Cui, Xiaohui [ORNL; Gao, Jinzhu [ORNL; Potok, Thomas E [ORNL

2006-01-01

Social animals or insects in nature often exhibit a form of emergent collective behavior known as flocking. In this paper, we present a novel Flocking based approach for document clustering analysis. Our Flocking clustering algorithm uses stochastic and heuristic principles discovered from observing bird flocks or fish schools. Unlike other partition clustering algorithm such as K-means, the Flocking based algorithm does not require initial partitional seeds. The algorithm generates a clustering of a given set of data through the embedding of the high-dimensional data items on a two-dimensional grid for easy clustering result retrieval and visualization. Inspired by the self-organized behavior of bird flocks, we represent each document object with a flock boid. The simple local rules followed by each flock boid result in the entire document flock generating complex global behaviors, which eventually result in a clustering of the documents. We evaluate the efficiency of our algorithm with both a synthetic dataset and a real document collection that includes 100 news articles collected from the Internet. Our results show that the Flocking clustering algorithm achieves better performance compared to the K- means and the Ant clustering algorithm for real document clustering.

Prevalence and risk factors for Salmonella spp. colonization in broiler flocks in Shiraz, southern Iran

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Maryam Ansari-Lari

2014-04-01

Full Text Available Salmonella spp. are important food borne pathogens worldwide that frequently infect poultry flocks. This cross-sectional study was conducted to determine the prevalence of Salmonella spp. colonization in broiler flocks in Shiraz (southern Iran and to find the possible association of infection status with some potential risk factors including vaccination program and use of antibiotics. During October 2009 to April 2010, a total of 40 broiler flocks were selected in slaughterhouse and 20 cloacae contents were collected from each flock. Every five cloacae contents were pooled and investigated for Salmonella spp. using appropriate culture methods. The flock was considered positive if any of the pooled samples turned positive in culture. Statistical analysis was performed using multiple logistic regression. Nine out of 40 flocks (22.50%, 95% CI: 9-36 were positive for Salmonella spp. colonization. Nearly 75.00% of flock owners reported that they used antibiotics during production period, more frequently fluoroquinolones, combination of trimethoprim-sulfonamides (TMP/SU and tetracycline. Nearly 60.00% of the flocks which had used TMP/SU were positive for Salmonella spp. compared with 10.00% of the flocks which did not use this antibiotic (p = 0.006. Increasing flock age was associated with a decreased chance of Salmonella spp. detection (p = 0.003. In flocks which received infectious bronchitis vaccine, 36.00% were positive for Salmonella spp. whereas this was 15.00% for flocks which did not receive this vaccine (p = 0.08. Careful monitoring of antibiotics use and further studies to determine the most appropriate vaccination program in the field is recommended.

Design of Connectivity Preserving Flocking Using Control Lyapunov Function

OpenAIRE

Erfianto, Bayu; Bambang, Riyanto T.; Hindersah, Hilwadi; Muchtadi-Alamsyah, Intan

2016-01-01

This paper investigates cooperative flocking control design with connectivity preserving mechanism. During flocking, interagent distance is measured to determine communication topology of the flocks. Then, cooperative flocking motion is built based on cooperative artificial potential field with connectivity preserving mechanism to achieve the common flocking objective. The flocking control input is then obtained by deriving cooperative artificial potential field using control Lyapunov functio...

Statistical mechanics for natural flocks of birds

Science.gov (United States)

Bialek, William; Cavagna, Andrea; Giardina, Irene; Mora, Thierry; Silvestri, Edmondo; Viale, Massimiliano; Walczak, Aleksandra M.

2012-01-01

Flocking is a typical example of emergent collective behavior, where interactions between individuals produce collective patterns on the large scale. Here we show how a quantitative microscopic theory for directional ordering in a flock can be derived directly from field data. We construct the minimally structured (maximum entropy) model consistent with experimental correlations in large flocks of starlings. The maximum entropy model shows that local, pairwise interactions between birds are sufficient to correctly predict the propagation of order throughout entire flocks of starlings, with no free parameters. We also find that the number of interacting neighbors is independent of flock density, confirming that interactions are ruled by topological rather than metric distance. Finally, by comparing flocks of different sizes, the model correctly accounts for the observed scale invariance of long-range correlations among the fluctuations in flight direction. PMID:22427355

Influence of flock coating on bending rigidity of woven fabrics

Science.gov (United States)

Ozdemir, O.; Kesimci, M. O.

2017-10-01

This work presents the preliminary results of our efforts that focused on the effect of the flock coating on the bending rigidity of woven fabrics. For this objective, a laboratory scale flocking unit is designed and flocked samples of controlled flock density are produced. Bending rigidity of the samples with different flock densities are measured on both flocked and unflocked sides. It is shown that the bending rigidity depends on both flock density and whether the side to be measured is flocked or not. Adhesive layer thickness on the bending rigidity is shown to be dramatic. And at higher basis weights, flock density gets less effective on bending rigidity.

Research on an Infectious Disease Transmission by Flocking Birds

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Mingsheng Tang

2013-01-01

Full Text Available The swarm intelligence is becoming a hot topic. The flocking of birds is a natural phenomenon, which is formed and organized without central or external controls for some benefits (e.g., reduction of energy consummation. However, the flocking also has some negative effects on the human, as the infectious disease H7N9 will easily be transmited from the denser flocking birds to the human. Zombie-city model has been proposed to help analyzing and modeling the flocking birds and the artificial society. This paper focuses on the H7N9 virus transmission in the flocking birds and from the flocking birds to the human. And some interesting results have been shown: (1 only some simple rules could result in an emergence such as the flocking; (2 the minimum distance between birds could affect H7N9 virus transmission in the flocking birds and even affect the virus transmissions from the flocking birds to the human.

Research on an infectious disease transmission by flocking birds.

Science.gov (United States)

Tang, Mingsheng; Mao, Xinjun; Guessoum, Zahia

2013-01-01

The swarm intelligence is becoming a hot topic. The flocking of birds is a natural phenomenon, which is formed and organized without central or external controls for some benefits (e.g., reduction of energy consummation). However, the flocking also has some negative effects on the human, as the infectious disease H7N9 will easily be transmited from the denser flocking birds to the human. Zombie-city model has been proposed to help analyzing and modeling the flocking birds and the artificial society. This paper focuses on the H7N9 virus transmission in the flocking birds and from the flocking birds to the human. And some interesting results have been shown: (1) only some simple rules could result in an emergence such as the flocking; (2) the minimum distance between birds could affect H7N9 virus transmission in the flocking birds and even affect the virus transmissions from the flocking birds to the human.

Reduced flocking by birds on islands with relaxed predation.

Science.gov (United States)

Beauchamp, Guy

2004-05-22

Adaptive hypotheses for the evolution of flocking in birds have usually focused on predation avoidance or foraging enhancement. It still remains unclear to what extent each factor has contributed to the evolution of flocking. If predation avoidance were the sole factor involved, flocking should not be prevalent when predation is relaxed. I examined flocking tendencies along with mean and maximum flock size in species living on islands where predation risk is either absent or negligible and then compared these results with matched counterparts on the mainland. The dataset consisted of 46 pairs of species from 22 different islands across the world. The tendency to flock was retained on islands in most species, but in pairs with dissimilar flocking tendencies, island species were less likely to flock. Mean and maximum flock size were smaller on islands than on the mainland. Potential confounding factors such as population density, nest predation, habitat type, food type and body mass failed to account for the results. The results suggest that predation is a significant factor in the evolution of flocking in birds. Nevertheless, predation and other factors, such as foraging enhancement, probably act together to maintain the trait in most species.

The influence of age on the exploitation period in broiler ...

African Journals Online (AJOL)

These investigations were intended to identify the influence of parental flock age at heavy hybrid Ross 308 (usage period) on more important reproductive capabilities (carrying eggs intensity of brood eggs, egg mass, one day old chick mass, relative chick mass share in complete egg mass) and consumption of food per ...

Nitrogen emissions from broilers measured by mass balance over eighteen consecutive flocks.

Science.gov (United States)

Coufal, C D; Chavez, C; Niemeyer, P R; Carey, J B

2006-03-01

Emission of nitrogen in the form of ammonia from poultry rearing facilities has been an important topic for the poultry industry because of concerns regarding the effects of ammonia on the environment. Sound scientific data is needed to accurately estimate air emissions from poultry operations. Many factors, such as season of the year, ambient temperature and humidity, bird health, and management practices can influence ammonia volatilization from broiler rearing facilities. Precise results are often difficult to attain from commercial facilities, particularly over long periods of time. Therefore, an experiment was conducted to determine nitrogen loss from broilers in a research facility under conditions simulating commercial production for 18 consecutive flocks. Broilers were reared to 40 to 42 d of age and fed diets obtained from a commercial broiler integrator. New rice hulls were used for litter for the first flock, and the same litter was recycled for all subsequent flocks with caked litter removed between flocks. All birds, feeds, and litter materials entering and leaving the facility were quantified, sampled, and analyzed for total nitrogen content. Nitrogen loss was calculated by the mass balance method in which loss was equal to the difference between the nitrogen inputs and the nitrogen outputs. Nitrogen partitioning as a percentage of inputs averaged 15.29, 6.84, 55.52, 1.27, and 21.08% for litter, caked litter, broiler carcasses, mortalities, and nitrogen loss, respectively, over all eighteen flocks. During the production of 18 flocks of broilers on the same recycled litter, the average nitrogen emission rate was calculated to range from 4.13 to 19.74 g of N/ kg of marketed broiler (grams of nitrogen per kilogram) and averaged 11.07 g of N/kg. Nitrogen loss was significantly (P broiler grow-out facilities varies significantly on a flock-to-flock basis.

A discontinuous Galerkin method on kinetic flocking models

OpenAIRE

Tan, Changhui

2014-01-01

We study kinetic representations of flocking models. They arise from agent-based models for self-organized dynamics, such as Cucker-Smale and Motsch-Tadmor models. We prove flocking behavior for the kinetic descriptions of flocking systems, which indicates a concentration in velocity variable in infinite time. We propose a discontinuous Galerkin method to treat the asymptotic $\\delta$-singularity, and construct high order positive preserving scheme to solve kinetic flocking systems.

Self-Organized Fission Control for Flocking System

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Mingyong Liu

2015-01-01

Full Text Available This paper studies the self-organized fission control problem for flocking system. Motivated by the fission behavior of biological flocks, information coupling degree (ICD is firstly designed to represent the interaction intensity between individuals. Then, from the information transfer perspective, a “maximum-ICD” based pairwise interaction rule is proposed to realize the directional information propagation within the flock. Together with the “separation/alignment/cohesion” rules, a self-organized fission control algorithm is established that achieves the spontaneous splitting of flocking system under conflict external stimuli. Finally, numerical simulations are provided to demonstrate the effectiveness of the proposed algorithm.

From particle to kinetic and hydrodynamic descriptions of flocking

OpenAIRE

Ha, Seung-Yeal; Tadmor, Eitan

2008-01-01

We discuss the Cucker-Smale's (C-S) particle model for flocking, deriving precise conditions for flocking to occur when pairwise interactions are sufficiently strong long range. We then derive a Vlasov-type kinetic model for the C-S particle model and prove it exhibits time-asymptotic flocking behavior for arbitrary compactly supported initial data. Finally, we introduce a hydrodynamic description of flocking based on the C-S Vlasov-type kinetic model and prove flocking behavior \\emph{without...

Perceptions of aging among middle-aged offspring of traumatized parents: the effects of parental Holocaust-related communication and secondary traumatization.

Science.gov (United States)

Shrira, Amit

2016-01-01

Traumatized parents may transmit anxieties of physical deterioration and demise to their offspring. These anxieties can amplify negative perceptions of the aging process when the offspring enter old age. The current study examined how middle-aged offspring of Holocaust survivors (OHS) recount trauma-related communication by their parents, and how these reports are related to offspring's perceptions of their aging process. The study included 450 respondents at the age range of 50-67 (mean age = 57.5, SD = 4.6): 300 OHS and 150 comparisons. Participants reported parental communication of the Holocaust, completed measures of subjective successful aging, aging and death anxieties, and reported secondary traumatization assessing symptoms, developed as a result of a close and continuous relationship with a traumatized parent. Latent profile analysis identified two profiles of parental Holocaust-related communication: intrusive and informative. Offspring who reported intrusive parental communication about the Holocaust perceived themselves as aging less successfully and were more anxious of aging and death than comparisons. Offspring who reported informative parental communication and comparisons did not differ in perceptions of aging. Secondary traumatization mediated these group differences, meaning, intrusive parental communication was related to higher secondary traumatization, which in turn was related to less favorable perceptions of aging. These findings allude to the possibility that secondary traumatization mold negative perceptions of the aging process among middle-aged offspring of traumatized parents. Mental health practitioners may help OHS process fragmented and intrusive remnants of parental trauma, thereby diminishing secondary traumatization, and promoting more adaptive perceptions of aging.

Clinical and pathomorphological diagnostics of mycotoxicosis in parent poultry flock caused by T-2 trychotecene

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Kapetanov Miloš C.

2013-01-01

Full Text Available The most relevant mycotoxin from the trychotecene group, T-2, causes prominent citotoxic effects. The toxin is a secondary product of fungi from the genus Fusarium that contaminates feed. Oraly intaken, T-2 is absorbed fast in the upper digestive system and within only 3 to 4 hours later reaches liver, kidneys and muscle tissue. Clinical and pathological changes are sometimes not obvious. The case of mycotoxicosis in a breeder flock of chickens, here presented, is aimed to underline the significance of clinical and pathological diagnosis supported with laboratory analysis that gave an objective causative diagnosis. On the farm, the disease occurred suddenly and with total cessation of feed consumption. First cases were recorded in the flock at the age of 42 weeks. Grouping, intensive breathing and lying with overstretched legs and extended neck were symptoms observed in birds. Evident necrosis of beak tips and painful multi-focal necrosis in oral cavity were recorded during the clinical examination. On section, dark unclothed blood was first observed. Other postmortem findings included: filled gizzard with mucosal erosions and easy-removable cuticle, enlarged congested liver with multi-focal necrosis and subcapsulary bleeding. The mortality rate increased by 4%, and the drop of laying rate was by about 18%. The fertility rate decreased by 22%. There was the increased number of rejected hatching eggs, 12%. Culture of the complete diet resulted in approximately 150000 colonies per 1g of Fusarium. T-2 was detected by using ELISA in concentration of 480 μg/kg, which corresponded to the upper limit of maximum permitted concentrations for chickens, according to national legislations. This bylaw interpretation of “tolerable” concentrations of mycotoxins provokes controversy among experts and public. [Projekat Ministarstva nauke Republike Srbije, br. TR 31071

Mixed species flocking of tits (Parus spp.): a field experiment.

Science.gov (United States)

Székely, T; Szép, T; Juhász, T

1989-03-01

We tested two general models of flocking behaviour, namely the antipredation model and foraging efficiency model on mixed-species tit flocks (Parus spp.). After food addition the size of mixed-species flocks was significantly less than in the control samples. In the presence of extra food significantly more birds were observed either in monospecific flocks or solitary, than during the control observations. In the presence of a living predator the birds foraged in larger mixed-specifies flocks than during the control observations. In addition, the social behaviour of Great Spotted Woodpecker, Middle Spotted Woodpecker and Nuthatch shifted to mixed-specific flocking. The size of monospecific flocks was independent of both treatments. The density of birds increased significantly after food addition, while in the predator presence the birds tended to leave the forest. These results support the view that both the antipredation model and foraging efficiency model seem to be valid for mixed-species flocking. However, in the case of monospecific flocks, the territory maintenance could be the most important factor.

Sources of salmonellae in an uninfected commercially-processed broiler flock.

Science.gov (United States)

Rigby, C E; Pettit, J R; Baker, M F; Bentley, A H; Salomons, M O; Lior, H

1980-07-01

Cultural monitoring was used to study the incidence and sources of salmonellae in a 4160 bird broiler flock during the growing period, transport and processing in a commercial plant. No salmonellae were isolated from any of 132 litter samples of 189 chickens cultured during the seven-week growing period, even though nest litter samples from four of the eight parent flocks yielded salmonellae and Salmonella worthington was isolated from the meat meal component of the grower ration. On arrival at the plant, 2/23 birds sampled carried S. infantis on their feathers, although intestinal cultures failed to yield salmonellae. Three of 18 processed carcasses samples yielded salmonellae (S. infantis, S. heidelberg, S. typhimurium var copenhagen). The most likely source of these salmonellae was the plastic transport crates, since 15/107 sampled before the birds were loaded yielded salmonellae (S. infantis, S. typhimurium). The crate washer at the plant did not reduce the incidence of Salmonella-contaminated crates, since 16/116 sampled after washing yielded salmonellae (S. infantis, S. typhimurium, S. heidelberg, S. schwarzengrund, S. albany).

Some causes of the variable shape of flocks of birds.

Directory of Open Access Journals (Sweden)

Charlotte K Hemelrijk

Full Text Available Flocks of birds are highly variable in shape in all contexts (while travelling, avoiding predation, wheeling above the roost. Particularly amazing in this respect are the aerial displays of huge flocks of starlings (Sturnus vulgaris above the sleeping site at dawn. The causes of this variability are hardly known, however. Here we hypothesise that variability of shape increases when there are larger local differences in movement behaviour in the flock. We investigate this hypothesis with the help of a model of the self-organisation of travelling groups, called StarDisplay, since such a model has also increased our understanding of what causes the oblong shape of schools of fish. The flocking patterns in the model prove to resemble those of real birds, in particular of starlings and rock doves. As to shape, we measure the relative proportions of the flock in several ways, which either depend on the direction of movement or do not. We confirm that flock shape is usually more variable when local differences in movement in the flock are larger. This happens when a flock size is larger, b interacting partners are fewer, c the flock turnings are stronger, and d individuals roll into the turn. In contrast to our expectations, when variability of speed in the flock is higher, flock shape and the positions of members in the flock are more static. We explain this and indicate the adaptive value of low variability of speed and spatial restriction of interaction and develop testable hypotheses.

Modeling the flocking propensity of passerine birds in two Neotropical habitats.

Science.gov (United States)

Pomara, Lars Y; Cooper, Robert J; Petit, Lisa J

2007-08-01

We examined the importance of mixed-species flock abundance, individual bird home range size, foraging height, and foraging patch characteristics in predicting the propensity for five Neotropical passerine bird species (Slaty Antwren, Myrmotherula schisticolor; Golden-crowned Warbler, Basileuterus culicivorus; Slate-throated Redstart, Myioborus miniatus; Wilson's Warbler, Wilsonia pusilla; and Black-and-white Warbler, Mniotilta varia) to forage within flocks, rather than solitarily. We used study plots in primary mid-elevation forest and in shade coffee fields in western Panama. We expected that all species would spend as much time as possible flocking, but that the social and environmental factors listed above would limit compatibility between flock movements and individual bird movements, explaining variability in flocking propensity both within and among species. Flocking propensity was well predicted by home range size and flock abundance together, for four of the five species. While flock abundance was uniform across plots, home range sizes varied among species and plots, so that home range size appeared to be the principle factor limiting flocking propensity. Estimates of flock abundance were still required, however, for calculating flocking propensity values. Foraging height and patch characteristics slightly improved predictive ability for the remaining species, M. miniatus. In general, individual birds tended to join flocks whenever one was available inside their home range, regardless of a flock's specific location within the home range. Flocking propensities of individual species were lower in shade coffee fields than in forests, and probably vary across landscapes with variations in habitat. This variability affects the stability and species composition of flocks, and may affect survival rates of individual species.

Parental Identity and Its Relation to Parenting and Psychological Functioning in Middle Age

Science.gov (United States)

Fadjukoff, Päivi; Pulkkinen, Lea; Lyyra, Anna-Liisa; Kokko, Katja

2016-01-01

SYNOPSIS Objective. This article focuses on identity as a parent in relation to parenting and psychological functioning in middle age. Design. Drawn from the Jyväskylä Longitudinal Study of Personality and Social Development, 162 participants (53% females) with children (age 36), represented the Finnish age-cohort born in 1959. Parental identity was assessed at ages 36, 42, and 50. Results. In both women and men, parental identity achievement increased from age 36 to 42 and remained stable to 50. The level of parental identity achievement was higher in women than in men. Achievement was typical for women and foreclosure for men. Participants’ education, occupational status, and number of offspring were not related to parental identity status. As expected, parental identity achievement was associated with authoritative (indicated by higher nurturance and parental knowledge about the child’s activities) parenting style. No significant associations emerged between parental identity foreclosure and restrictiveness as an indicator of authoritarian parenting style. The diffused men outscored others in parental stress. Achieved parental identity was related to generativity in both genders and to higher psychological and social well-being in men. Conclusions. At present, many parenting programs are targeted to young parents. This study highlighted the importance of a later parenting phase at around age 40, when for many, the children are approaching puberty. Therefore, parenting programs and support should also be designed for middle-aged parents. Specifically men may need additional support for their active consideration and engagement in the fathering role. © Päivi Fadjukoff, Lea Pulkkinen, Anna-Liisa Lyyra, and Katja Kokko This is an Open Access article distributed under the terms of the Creative Commons Attribution-NonCommercial-No Derivatives License (http://creativecommons.org/licenses/by-nc-nd/4.0/), which permits non-commercial re-use, distribution, and

Parental Identity and Its Relation to Parenting and Psychological Functioning in Middle Age.

Science.gov (United States)

Fadjukoff, Päivi; Pulkkinen, Lea; Lyyra, Anna-Liisa; Kokko, Katja

2016-04-02

Objective. This article focuses on identity as a parent in relation to parenting and psychological functioning in middle age. Design. Drawn from the Jyväskylä Longitudinal Study of Personality and Social Development, 162 participants (53% females) with children (age 36), represented the Finnish age-cohort born in 1959. Parental identity was assessed at ages 36, 42, and 50. Results. In both women and men, parental identity achievement increased from age 36 to 42 and remained stable to 50. The level of parental identity achievement was higher in women than in men. Achievement was typical for women and foreclosure for men. Participants' education, occupational status, and number of offspring were not related to parental identity status. As expected, parental identity achievement was associated with authoritative (indicated by higher nurturance and parental knowledge about the child's activities) parenting style. No significant associations emerged between parental identity foreclosure and restrictiveness as an indicator of authoritarian parenting style. The diffused men outscored others in parental stress. Achieved parental identity was related to generativity in both genders and to higher psychological and social well-being in men. Conclusions. At present, many parenting programs are targeted to young parents. This study highlighted the importance of a later parenting phase at around age 40, when for many, the children are approaching puberty. Therefore, parenting programs and support should also be designed for middle-aged parents. Specifically men may need additional support for their active consideration and engagement in the fathering role. © Päivi Fadjukoff, Lea Pulkkinen, Anna-Liisa Lyyra, and Katja Kokko This is an Open Access article distributed under the terms of the Creative Commons Attribution-NonCommercial-No Derivatives License (http://creativecommons.org/licenses/by-nc-nd/4.0/), which permits non-commercial re-use, distribution, and reproduction in

Ranging Behaviour of Commercial Free-Range Broiler Chickens 1: Factors Related to Flock Variability.

Science.gov (United States)

Taylor, Peta S; Hemsworth, Paul H; Groves, Peter J; Gebhardt-Henrich, Sabine G; Rault, Jean-Loup

2017-07-20

Little is known about the ranging behaviour of chickens. Understanding ranging behaviour is required to improve management and shed and range design to ensure optimal ranging opportunities. Using Radio Frequency Identification technology, we tracked 300 individual broiler chickens in each of four mixed sex ROSS 308 flocks on one commercial farm across two seasons. Ranging behaviour was tracked from the first day of range access (21 days of age) until 35 days of age in winter and 44 days of age in summer. Range use was higher than previously reported from scan sampling studies. More chickens accessed the range in summer (81%) than winter (32%; p range use was greater in summer flocks (4.4 ± 0.1 visits for a total of 26.3 ± 0.8 min/day) than winter flocks (3.2 ± 0.2 visits for a total of 7.9 ± 1.0 min/day). Seasonal differences were only marginally explained by weather conditions and may reflect the reduction in range exposure between seasons (number of days, hours per day, and time of day). Specific times of the day ( p ranging and external factors that may explain ranging preferences.

Rubin H. Flocks and Colloidal Gold Treatments for Prostate Cancer

Directory of Open Access Journals (Sweden)

Henry M. Rosevear

2011-01-01

Full Text Available In the early 1950s, Rubin H. Flocks of the University of Iowa began to treat prostate cancer patients with colloidal gold (Au198 therapy, evolving his technique over nearly 25 years in 1515 patients. We reviewed the long-term outcomes of Flocks' prostate cancer patients as compared to those patients treated by other methods at the University of Iowa before Flocks' chairmanship. We reviewed archived patient records, Flocks' published data, and long-term survival data from the Iowa Tumor Registry to determine short- and long-term outcomes of Flocks' work with colloidal gold. We also reviewed the literature of Flocks' time to compare his outcomes against those of his contemporaries. The use of colloidal gold, either as primary or adjunctive therapy, provided short- and long-term survival benefit for the majority of Flocks' patients as compared to historical treatment options (p < 0.001. Flocks' use of colloidal gold for the treatment of locally advanced prostate cancer offered short- and long-term survival benefits compared to other contemporary treatments.

Flock worker's lung: chronic interstitial lung disease in the nylon flocking industry.

Science.gov (United States)

Kern, D G; Crausman, R S; Durand, K T; Nayer, A; Kuhn, C

1998-08-15

Two young men working at a nylon flocking plant in Rhode Island developed interstitial lung disease of unknown cause. Similar clusters at the same company's Canadian plant were reported previously. To define the extent, clinicopathologic features, and potential causes of the apparent disease outbreak. Case-finding survey and retrospective cohort study. Academic occupational medicine program. All workers employed at the Rhode Island plant on or after 15 June 1990. Symptomatic employees had chest radiography, pulmonary function tests, high-resolution computed tomography, and serologic testing. Those with unexplained radiographic or pulmonary function abnormalities underwent bronchoalveolar lavage, lung biopsy, or both. The case definition of "flock worker's lung" required histologic evidence of interstitial lung disease (or lavage evidence of lung inflammation) not explained by another condition. Eight cases of flock worker's lung were identified at the Rhode Island plant. Three cases were characterized by a high proportion of eosinophils (25% to 40%) in lavage fluid. Six of the seven patients who had biopsy had histologic findings of nonspecific interstitial pneumonia, and the seventh had bronchiolitis obliterans organizing pneumonia. All seven of these patients had peribronchovascular interstitial lymphoid nodules, usually with germinal centers, and most had lymphocytic bronchiolitis and interstitial fibrosis. All improved after leaving work. Review of the Canadian tissue specimens showed many similar histologic findings. Among the 165-member study cohort, a 48-fold or greater increase was seen in the sex-adjusted incidence rate of all interstitial lung disease. Work in the nylon flocking industry poses substantial risk for a previously unrecognized occupational interstitial lung disease. Nylon fiber is the suspected cause of this condition.

Impulsive Flocking of Dynamical Multiagent Systems with External Disturbances

Directory of Open Access Journals (Sweden)

Fujun Han

2017-01-01

Full Text Available Flocking motion of multiagent systems is influenced by various external disturbances in complex environment. By applying disturbance observer, flocking of multiagent systems with exogenous disturbances is studied. Based on the robust features of impulsive control, a distributed impulsive control protocol is presented with disturbance observer, and flocking motion of multiagent systems is analyzed. Moreover, a sufficient condition is obtained to ensure the flocking motion of multiagent systems following a leader. Finally, simulation results show the validity of the theoretical conclusion.

Environmental study of nylon flocking process.

Science.gov (United States)

Burkhart, J; Piacitelli, C; Schwegler-Berry, D; Jones, W

1999-05-14

Environmental measurements for a variety of gas, particulate, and microbiological agents have been made in order to characterize exposures associated with the nylon flocking process. Of all agents measured, particulate is the predominant exposure. Levels of total particulate ranged from O.1 to 240 mg/m3 (x = 11.4 mg/m3). Average respirable particulate was 2.2 mg/m3, ranging from 0.5 to 39.9 mg/m3. Highest levels of particulates were found in the flocking room, and direct reading dust measurements indicate that the highest peak exposures are associated with "blowdown" (a cleaning procedure used between flocking runs). The nature of the airborne particles was investigated using polarized light and scanning electron microscopy. Air samples were found to contain flock particles (fibers nominally 10-15 microm in diameter by about 1000 microm in length) and a variety of respirable particles types, several of which were linked directly to the process. Of special interest were elongated respirable particles, which by microscopic analysis, complemented with melting-point determination, were found to be shreds of nylon.

Spontaneous flocking in human groups.

Science.gov (United States)

Belz, Michael; Pyritz, Lennart W; Boos, Margarete

2013-01-01

Flocking behaviour, as a type of self-organised collective behaviour, is described as the spatial formation of groups without global control and explicit inter-individual recruitment signals. It can be observed in many animals, such as bird flocks, shoals or herds of ungulates. Spatial attraction between humans as the central component of flocking behaviour has been simulated in a number of seminal models but it has not been detected experimentally in human groups so far. The two other sub-processes of this self-organised collective movement - collision avoidance and alignment - are excluded or held constant respectively in this study. We created a computer-based, multi-agent game where human players, represented as black dots, moved on a virtual playground. The participants were deprived of social cues about each other and could neither communicate verbally nor nonverbally. They played two games: (1) Single Game, where other players were invisible, and (2) Joint Game, where each player could see players' positions in a local radius around himself/herself. We found that individuals approached their neighbours spontaneously if their positions were visible, leading to less spatial dispersion of the whole group compared to moving alone. We conclude that human groups show the basic component of flocking behaviour without being explicitly instructed or rewarded to do so. Copyright © 2012 Elsevier B.V. All rights reserved.

Boundary information inflow enhances correlation in flocking.

Science.gov (United States)

Cavagna, Andrea; Giardina, Irene; Ginelli, Francesco

2013-04-19

The most conspicuous trait of collective animal behavior is the emergence of highly ordered structures. Less obvious to the eye, but perhaps more profound a signature of self-organization, is the presence of long-range spatial correlations. Experimental data on starling flocks in 3D show that the exponent ruling the decay of the velocity correlation function, C(r)~1/r(γ), is extremely small, γflocks. The effect of the dynamical field is to create an information inflow from border to bulk that triggers long-range spin-wave modes, thus giving rise to an anomalously long-ranged correlation. The biological origin of this phenomenon can be either exogenous-information produced by environmental perturbations is transferred from boundary to bulk of the flock-or endogenous-the flock keeps itself in a constant state of dynamical excitation that is beneficial to correlation and collective response.

Risk factors and likelihood of Campylobacter colonization in broiler flocks

Directory of Open Access Journals (Sweden)

SL Kuana

2007-09-01

Full Text Available Campylobacter was investigated in cecal droppings, feces, and cloacal swabs of 22 flocks of 3 to 5 week-old broilers. Risk factors and the likelihood of the presence of this agent in these flocks were determined. Management practices, such as cleaning and disinfection, feeding, drinkers, and litter treatments, were assessed. Results were evaluated using Odds Ratio (OR test, and their significance was tested by Fisher's test (p<0.05. A Campylobacter prevalence of 81.8% was found in the broiler flocks (18/22, and within positive flocks, it varied between 85 and 100%. Campylobacter incidence among sample types was homogenous, being 81.8% in cecal droppings, 80.9% in feces, and 80.4% in cloacal swabs (230. Flocks fed by automatic feeding systems presented higher incidence of Campylobacter as compared to those fed by tube feeders. Litter was reused in 63.6% of the farm, and, despite the lack of statistical significance, there was higher likelihood of Campylobacter incidence when litter was reused. Foot bath was not used in 45.5% of the flocks, whereas the use of foot bath associated to deficient lime management increased the number of positive flocks, although with no statiscal significance. The evaluated parameters were not significantly associated with Campylobacter colonization in the assessed broiler flocks.

Parental age in relation to severity of clefting

DEFF Research Database (Denmark)

Hermann, Nuno Vibe; Darvann, Tron Andre; Kreiborg, Sven

2016-01-01

Lip and/or Palate (IC). Wilcoxon Rank-Sum test (5% significance level) was applied in order to test for group differences. Standard logistic regression was used in order to estimate the risk of developing CC relative to IC. Results. In the group with CC mean paternal age was 29.5+/-4.5 (1SD) years...... parental ages in the group with IC did not differ from normative population values during the same time period. Logistic regression showed for paternal age OR=1.1[1.04,1.16](Wald confidence limits); for maternal age 1.08[1.01,1.15]. Conclusions. The hypothesis was rejected. Parental age was significantly...... of cleft individuals, as well as to compare parental age in the cleft population with normative values of parental age. It was hypothesized that there was no difference in parental age between the cleft groups with incomplete and complete clefts, respectively. Methods/Descriptions. The consecutive non...

Flocking and invariance of velocity angles.

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Liu, Le; Huang, Lihong; Wu, Jianhong

2016-04-01

Motsch and Tadmor considered an extended Cucker-Smale model to investigate the flocking behavior of self-organized systems of interacting species. In this extended model, a cone of the vision was introduced so that outside the cone the influence of one agent on the other is lost and hence the corresponding influence function takes the value zero. This creates a problem to apply the Motsch-Tadmor and Cucker-Smale method to prove the flocking property of the system. Here, we examine the variation of the velocity angles between two arbitrary agents, and obtain a monotonicity property for the maximum cone of velocity angles. This monotonicity permits us to utilize existing arguments to show the flocking property of the system under consideration, when the initial velocity angles satisfy some minor technical constraints.

A model for an economically optimal replacement of a breeder flock

NARCIS (Netherlands)

Yassin, H.; Velthuis, A.G.J.; Giesen, G.W.J.; Oude Lansink, A.G.J.M.

2012-01-01

A deterministic model is developed to support the tactical and operational replacement decisions at broiler breeder farms. The marginal net revenue approach is applied to determine the optimal replacement age of a flock. The objective function of the model maximizes the annual gross margin over the

Facial attractiveness judgements reflect learning of parental age characteristics.

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Perrett, David I; Penton-Voak, Ian S; Little, Anthony C; Tiddeman, Bernard P; Burt, D Michael; Schmidt, Natalie; Oxley, Roz; Kinloch, Nicholas; Barrett, Louise

2002-05-07

Mate preferences are shaped by infant experience of parental characteristics in a wide variety of species. Similar processes in humans may lead to physical similarity between parents and mates, yet this possibility has received little attention. The age of parents is one salient physical characteristic that offspring may attend to. The current study used computer-graphic faces to examine how preferences for age in faces were influenced by parental age. We found that women born to 'old' parents (over 30) were less impressed by youth, and more attracted to age cues in male faces than women with 'young' parents (under 30). For men, preferences for female faces were influenced by their mother's age and not their father's age, but only for long-term relationships. These data indicate that judgements of facial attractiveness in humans reflect the learning of parental characteristics.

Prevalence and risk factors for Salmonella spp. and Campylobacter spp. caecal colonization in broiler chicken and turkey flocks slaughtered in Quebec, Canada.

Science.gov (United States)

Arsenault, Julie; Letellier, Ann; Quessy, Sylvain; Normand, Valérie; Boulianne, Martine

2007-10-16

We conducted an observational study to estimate prevalence and risk factors for Salmonella spp. and Campylobacter spp. caecal colonization in poultry. Eighty-one broiler chicken and 59 turkey flocks selected among flocks slaughtered in the province of Quebec, Canada, were included in the study. Flock status was evaluated by culturing pooled caecal contents from about 30 birds per flock. Exposure to potential risk factors was evaluated with a questionnaire. Odds ratios were computed using multivariable logistic regression. The prevalence of Salmonella-positive flocks was 50% (95% CI: 37, 64) for chickens and 54% (95% CI: 39, 70) for turkeys, respectively. Odds of Salmonella colonization were 2.6 times greater for chicken flocks which failed to lock the chicken house permanently. In turkeys, odds of Salmonella colonization were 4.8-7.7 times greater for flocks which failed to be raised by hatchery. The prevalence of Campylobacter-positive flocks was 35% (95% CI: 22, 49) for chickens and 46% (95% CI: 30, 62) for turkeys. Odds of colonization were 4.1 times higher for chicken flocks raised on farms with professional rodent control and 5.2 times higher for flocks with manure heap >200m from the poultry house, and also increased with the number of birds raised per year on the farm and with the age at slaughter. For turkeys, odds of Campylobacter flock colonization were 3.2 times greater in flocks having a manure heap at flocks drinking unchlorinated water.

Diffusion of individual birds in starling flocks

Science.gov (United States)

Cavagna, A.; Queirós, S. M. Duarte; Giardina, I.; Stefanini, F.; Viale, M.

2013-01-01

Flocking is a paradigmatic example of collective animal behaviour, where global order emerges out of self-organization. Each individual has a tendency to align its flight direction with those of neighbours, and such a simple form of interaction produces a state of collective motion of the group. When compared with other cases of collective ordering, a crucial feature of animal groups is that the interaction network is not fixed in time, as each individual moves and continuously changes its neighbours. The possibility to exchange neighbours strongly enhances the stability of global ordering and the way information is propagated through the group. Here, we assess the relevance of this mechanism in large flocks of starlings (Sturnus vulgaris). We find that birds move faster than Brownian walkers both with respect to the centre of mass of the flock, and with respect to each other. Moreover, this behaviour is strongly anisotropic with respect to the direction of motion of the flock. We also measure the amount of neighbours reshuffling and find that neighbours change in time exclusively as a consequence of the random fluctuations in the individual motion, so that no specific mechanism to keep one's neighbours seems to be enforced. On the contrary, our findings suggest that a more complex dynamical process occurs at the border of the flock. PMID:23407827

The experience of parents implementing authoritarian parenting for their school-age children.

Science.gov (United States)

Benga Olla, Marice; Catharina Daulima, Novy Helena; Eka Putri, Yossie Susanti

2018-02-01

To explore families' experiences who use an authoritarian parenting style in caring for school-age children. This was a qualitative study employing a phenomenological approach. The sampling method was to interview parents of school-age children living in the Central Maluku district in Indonesia. The findings of this study generated the following themes: (1) parents strictly controlled their children to achieve the parental values and expectations, (2) children failed to meet the parental values and expectations, and (3) problems experienced by the children were the results of the parenting style. This study suggested nursing professionals provide adequate information for parents with respect to parenting styles that may facilitate the optimal growth and development of the children. Future studies pertinent to cultural factors associated with authoritarian parenting were also suggested to better understand the cultural context of this parenting style. Copyright © 2018 Elsevier España, S.L.U. All rights reserved.

Composition and foraging behaviour of mixed-species flocks in two ...

African Journals Online (AJOL)

Enlarged flock size resulted from a general increase in flocking tendency of all species. At the species level, the Long-billed Crombec Sylvietta rufescens and the Chinspot Batis Batis molitor showed clear feeding benefits within flocks, whereas tits obtained no feeding benefit. Crombecs and batises also changed foraging ...

Local equilibrium in bird flocks

Science.gov (United States)

Mora, Thierry; Walczak, Aleksandra M.; Del Castello, Lorenzo; Ginelli, Francesco; Melillo, Stefania; Parisi, Leonardo; Viale, Massimiliano; Cavagna, Andrea; Giardina, Irene

2016-12-01

The correlated motion of flocks is an example of global order emerging from local interactions. An essential difference with respect to analogous ferromagnetic systems is that flocks are active: animals move relative to each other, dynamically rearranging their interaction network. This non-equilibrium characteristic has been studied theoretically, but its impact on actual animal groups remains to be fully explored experimentally. Here, we introduce a novel dynamical inference technique, based on the principle of maximum entropy, which accommodates network rearrangements and overcomes the problem of slow experimental sampling rates. We use this method to infer the strength and range of alignment forces from data of starling flocks. We find that local bird alignment occurs on a much faster timescale than neighbour rearrangement. Accordingly, equilibrium inference, which assumes a fixed interaction network, gives results consistent with dynamical inference. We conclude that bird orientations are in a state of local quasi-equilibrium over the interaction length scale, providing firm ground for the applicability of statistical physics in certain active systems.

Prevalence and antimicrobial susceptibility of thermophilic Campylobacter in organic and conventional broiler flocks

DEFF Research Database (Denmark)

Heuer, Ole Eske; Pedersen, Karl; Andersen, J.S.

2001-01-01

Aims: To determine the flock prevalence and to estimate the within flock prevalence of Campylobacter in broiler flocks from different rearing systems, and to determine the antimicrobial susceptibility of Campylobacter isolates to selected antimicrobial substances. Methods and Results: One hundred...... and sixty broiler flocks originating from organic, conventional and extensive indoor production farms were investigated for the presence of Campylobacter at the time of slaughter. Campylobacter isolates from a subsample of positive flocks were subjected to susceptibility testing. Campylobacter spp. were...... isolated from 100% of organic broiler flocks, from 36.7% of conventional broiler flocks and from 49.2% of extensive indoor broiler flocks. Six of 62 Campylobacter isolates were resistant to one or more of the antimicrobials tested. Conclusions: These results indicate that the special characteristics...

Switching hierarchical leadership mechanism in homing flight of pigeon flocks

Science.gov (United States)

Chen, Duxin; Vicsek, Tamás; Liu, Xiaolu; Zhou, Tao; Zhang, Hai-Tao

2016-06-01

To explore the fascinating inter-individual interaction mechanism governing the abundant biological grouping behaviors, more and more efforts have been devoted to collective motion investigation in recent years. Therein, bird flocking is one of the most intensively studied behaviors. A previous study (Nagy M. et al., Nature, 464 (2010) 890.) claims the existence of a well-defined hierarchical structure in pigeon flocks, which implies that a multi-layer leadership network leads to the occurrence of highly coordinated pigeon flock movements. However, in this study, by using high-resolution GPS data of homing flight of pigeon flocks, we reveal an explicit switching hierarchical mechanism underlying the group motions of pigeons. That is, a pigeon flock has a long-term leader for smooth moving trajectories, whereas the leading tenure passes to a temporary one upon sudden turns or zigzags. Therefore, the present observation helps explore more deeply into the principle of a huge volume of bird flocking dynamics. Meanwhile, from the engineering point of view, it may shed some light onto industrial multi-robot coordination and unmanned air vehicle formation control.

Outdoor flocking of quadcopter drones with decentralized model predictive control.

Science.gov (United States)

Yuan, Quan; Zhan, Jingyuan; Li, Xiang

2017-11-01

In this paper, we present a multi-drone system featured with a decentralized model predictive control (DMPC) flocking algorithm. The drones gather localized information from neighbors and update their velocities using the DMPC flocking algorithm. In the multi-drone system, data packages are transmitted through XBee ® wireless modules in broadcast mode, yielding such an anonymous and decentralized system where all the calculations and controls are completed on an onboard minicomputer of each drone. Each drone is a double-layered agent system with the coordination layer running multi-drone flocking algorithms and the flight control layer navigating the drone, and the final formation of the flock relies on both the communication range and the desired inter-drone distance. We give both numerical simulations and field tests with a flock of five drones, showing that the DMPC flocking algorithm performs well on the presented multi-drone system in both the convergence rate and the ability of tracking a desired path. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

Campylobacter spp. contamination of chicken carcasses during processing in relation to flock colonisation.

Science.gov (United States)

Allen, V M; Bull, S A; Corry, J E L; Domingue, G; Jørgensen, F; Frost, J A; Whyte, R; Gonzalez, A; Elviss, N; Humphrey, T J

2007-01-01

The presence and numbers of campylobacters on chicken carcasses from 26 slaughter groups, originating from 22 single-house flocks and processed in four UK plants, were studied in relation to the level of flock colonisation determined by examining the caecal contents of at least ten birds per group. The prevalence of campylobacters on carcasses from five campylobacter-negative flocks processed just after other negative flocks was low (8.0 log(10) cfu) than carcasses originating from low prevalence flocks (average of 2.3 log(10) cfu; range: defeathering and evisceration areas but not in the chillers. This was the case even when campylobacters were not isolated from the target flock. Campylobacters on carcasses from two partly colonised flocks were either the same subtype, as determined by speciation, Multi-Locus Sequence Typing (MLST) and flaA Restricted Fragment Length Polymorphism (RFLP) typing, as those in the fully colonised flocks processed previously, although not necessarily the most prevalent ones; or were the same subtypes as those found in the caeca of the flock itself. The prevalences of the different campylobacter subtypes found on carcasses from two fully colonised flocks did not closely reflect those found in the caeca. MLST combined with flaA RFLP provided a good method for ascertaining the relatedness of strains isolated from carcasses and caecal contents. This study showed that carcass contamination is related to the within-flock prevalence of campylobacter colonisation, but that contamination from previously processed flocks was also significant, especially on carcasses from low prevalence flocks. Forced dry air cooling of carcasses reduced contamination levels.

Starling flock networks manage uncertainty in consensus at low cost.

Directory of Open Access Journals (Sweden)

George F Young

Full Text Available Flocks of starlings exhibit a remarkable ability to maintain cohesion as a group in highly uncertain environments and with limited, noisy information. Recent work demonstrated that individual starlings within large flocks respond to a fixed number of nearest neighbors, but until now it was not understood why this number is seven. We analyze robustness to uncertainty of consensus in empirical data from multiple starling flocks and show that the flock interaction networks with six or seven neighbors optimize the trade-off between group cohesion and individual effort. We can distinguish these numbers of neighbors from fewer or greater numbers using our systems-theoretic approach to measuring robustness of interaction networks as a function of the network structure, i.e., who is sensing whom. The metric quantifies the disagreement within the network due to disturbances and noise during consensus behavior and can be evaluated over a parameterized family of hypothesized sensing strategies (here the parameter is number of neighbors. We use this approach to further show that for the range of flocks studied the optimal number of neighbors does not depend on the number of birds within a flock; rather, it depends on the shape, notably the thickness, of the flock. The results suggest that robustness to uncertainty may have been a factor in the evolution of flocking for starlings. More generally, our results elucidate the role of the interaction network on uncertainty management in collective behavior, and motivate the application of our approach to other biological networks.

Starling Flock Networks Manage Uncertainty in Consensus at Low Cost

Science.gov (United States)

Young, George F.; Scardovi, Luca; Cavagna, Andrea; Giardina, Irene; Leonard, Naomi E.

2013-01-01

Flocks of starlings exhibit a remarkable ability to maintain cohesion as a group in highly uncertain environments and with limited, noisy information. Recent work demonstrated that individual starlings within large flocks respond to a fixed number of nearest neighbors, but until now it was not understood why this number is seven. We analyze robustness to uncertainty of consensus in empirical data from multiple starling flocks and show that the flock interaction networks with six or seven neighbors optimize the trade-off between group cohesion and individual effort. We can distinguish these numbers of neighbors from fewer or greater numbers using our systems-theoretic approach to measuring robustness of interaction networks as a function of the network structure, i.e., who is sensing whom. The metric quantifies the disagreement within the network due to disturbances and noise during consensus behavior and can be evaluated over a parameterized family of hypothesized sensing strategies (here the parameter is number of neighbors). We use this approach to further show that for the range of flocks studied the optimal number of neighbors does not depend on the number of birds within a flock; rather, it depends on the shape, notably the thickness, of the flock. The results suggest that robustness to uncertainty may have been a factor in the evolution of flocking for starlings. More generally, our results elucidate the role of the interaction network on uncertainty management in collective behavior, and motivate the application of our approach to other biological networks. PMID:23382667

A retrospective study on salmonella infection in Danish broiler flocks

DEFF Research Database (Denmark)

Angen, Øystein; Skov, M. N.; Chriél, Mariann

1996-01-01

-year period from 1992 to 1993 in Denmark. The AM database contains information collected by the ante-mortem veterinarians, from the slaughterhouses, and from the salmonella examinations carried out at the National Veterinary Laboratory. The epidemiological unit was the individual broiler flock....... The salmonella status of the flock was determined by examining the caecal tonsils from 16 3-week-old chickens from each flock. This procedure would detect a salmonella-infected flock, with a probability above 95%, if the prevalence is above 20%. Furthermore, the structure and quality of the collected data have...... been evaluated. Fourteen variables were selected for analysis by multivariable logistic regression. An increased risk of salmonella infection in the broiler Becks was associated with the biggest hatcheries and feedmill, with an increasing number of houses on the farm, if the preceding flock...

Flock sizes and sex ratios of canvasbacks in Chesapeake Bay and North Carolina

Science.gov (United States)

Haramis, G.M.; Derleth, E.L.; Link, W.A.

1994-01-01

Knowledge of the distribution, size, and sex ratios of flocks of wintering canvasbacks (Aythya valisineria) is fundamental to understanding the species' winter ecology and providing guidelines for management. Consequently, in winter 1986-87, we conducted 4 monthly aerial photographic surveys to investigate temporal changes in distribution, size, and sex ratios of canvasback flocks in traditional wintering areas of Chesapeake Bay and coastal North Carolina. Surveys yielded 35mm imagery of 194,664 canvasbacks in 842 flocks. Models revealed monthly patterns of flock size in North Carolina and Virginia, but no pattern of change in Maryland. A stepwise analysis of flock size and sex ratio fit a common positive slope (increasing proportion male) for all state-month datasets, except for North Carolina in February where the slope was larger (P lt 0.001). State and month effects on intercepts were significant (P lt 0.001) and confirmed a previously identified latitudinal gradient in sex ratio in the survey region. There was no relationship between flock purity (% canvasbacks vs. other species) and flock size except in North Carolina in January, February, and March when flock purity was related to flock size. Contrasting characteristics in North Carolina with regard to flock size (larger flocks) and flock purity suggested that proximate factors were reinforcing flocking behavior and possibly species fidelity there. Of possible factors, the need to locate foraging sites within this large, open-water environment was hypothesized to be of primary importance. Comparison of January 1981 and 1987 sex ratios indicated no change in Maryland, but lower (P lt 0.05) canvasback sex ratios (proportion male) in Virginia and North Carolina.

Flocking of quad-rotor UAVs with fuzzy control.

Science.gov (United States)

Mao, Xiang; Zhang, Hongbin; Wang, Yanhui

2018-03-01

This paper investigates the flocking problem of quad-rotor UAVs. Considering the actual situations, we derived a new simplified quad-rotor UAV model which is more reasonable. Based on the model, the T-S fuzzy model of attitude dynamic equation and the corresponding T-S fuzzy feedback controller are discussed. By introducing a double-loop control construction, we adjust its attitude to realize the position control. Then a flocking algorithm is proposed to achieve the flocking of the quad-rotor UAVs. Compared with the flocking algorithm of the mass point model, we dealt with the collision problem of the quad-rotor UAVs. In order to improve the airspace utilization, a more compact configuration called quasi e-lattice is constructed to guarantee the compact flight of the quad-rotor UAVs. Finally, numerical simulations are provided to illustrate the effectiveness of the obtained theoretical results. Copyright © 2018 ISA. Published by Elsevier Ltd. All rights reserved.

AD HOC TEAMWORK BEHAVIORS FOR INFLUENCING A FLOCK

Directory of Open Access Journals (Sweden)

Katie Genter

2016-02-01

Full Text Available Ad hoc teamwork refers to the challenge of designing agents that can influence the behavior of a team, without prior coordination with its teammates. This paper considers influencing a flock of simple robotic agents to adopt a desired behavior within the context of ad hoc teamwork. Specifically, we examine how the ad hoc agents should behave in order to orient a flock towards a target heading as quickly as possible when given knowledge of, but no direct control over, the behavior of the flock. We introduce three algorithms which the ad hoc agents can use to influence the flock, and we examine the relative importance of coordinating the ad hoc agents versus planning farther ahead when given fixed computational resources. We present detailed experimental results for each of these algorithms, concluding that in this setting, inter-agent coordination and deeper lookahead planning are no more beneficial than short-term lookahead planning.

Flocking and rendezvous in distributed robotics

CERN Document Server

Francis, Bruce A

2016-01-01

This brief describes the coordinated control of groups of robots using only sensory input – and no direct external commands. Furthermore, each robot employs the same local strategy, i.e., there are no leaders, and the text also deals with decentralized control, allowing for cases in which no single robot can sense all the others. One can get intuition for the problem from the natural world, for example, flocking birds. How do they achieve and maintain their flying formation? Recognizing their importance as the most basic coordination tasks for mobile robot networks, the brief details flocking and rendezvous. They are shown to be physical illustrations of emergent behaviors with global consensus arising from local interactions. The authors extend the consideration of these fundamental ideas to describe their operation in flying robots and prompt readers to pursue further research in the field.  Flocking and Rendezvous in Distributed Robotics will provide graduate students a firm grounding in the subject, w...

Pigeon interaction mode switch-based UAV distributed flocking control under obstacle environments.

Science.gov (United States)

Qiu, Huaxin; Duan, Haibin

2017-11-01

Unmanned aerial vehicle (UAV) flocking control is a serious and challenging problem due to local interactions and changing environments. In this paper, a pigeon flocking model and a pigeon coordinated obstacle-avoiding model are proposed based on a behavior that pigeon flocks will switch between hierarchical and egalitarian interaction mode at different flight phases. Owning to the similarity between bird flocks and UAV swarms in essence, a distributed flocking control algorithm based on the proposed pigeon flocking and coordinated obstacle-avoiding models is designed to coordinate a heterogeneous UAV swarm to fly though obstacle environments with few informed individuals. The comparative simulation results are elaborated to show the feasibility, validity and superiority of our proposed algorithm. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

Field estimation of the flock-level diagnostic specificity of an enzyme-linked immunosorbent assay for Avian metapneumovirus antibodies in turkeys.

Science.gov (United States)

Muñoz-Zanzi, Claudia; Trampel, Darrell; Hanson, Tim; Harrison, Kristen; Goyal, Sagar; Cortinas, Roberto; Lauer, Dale

2009-03-01

Routine serologic testing for Avian metapneumovirus (AMPV) infection of turkey flocks at slaughter is currently being used to monitor changes in the occurrence of AMPV infection in endemic areas and can also be used to detect the emergence of infection in currently unaffected areas. Because of the costs associated with false-positive results, particularly in areas that are free of AMPV infection, there is a need to obtain improved estimates of flock-level specificity (SP). The objective of this study was to estimate flock-level SP of a program to monitor AMPV infection in turkey flocks at processing using a standard enzyme-linked immunosorbent assay (ELISA). A study was carried out in which 37 AMPV-free flocks from 7 Midwest operations were followed serologically. Six percent, 3%, and 0.2% of total samples tested AMPV positive at 8 weeks, 12 weeks, and at processing, respectively. Overall, flock-level SP increased as the cutoff increased and as age increased. Flock-level SP at processing was 97%, if a cutoff of 1 was used (the flock was classified as positive if at least 1 sample tested positive), and 100%, if any other cutoff was used. Administration of antibiotics (P = 0.02) and vaccination for Bordetella avium (P = 0.08) were positively associated with the probability of (false) positive test results. These findings suggest possible cross-reactions with other infections and highlight the need to consider variable diagnostic performance depending on farm conditions.

Pilot trial of an age-paced parenting newsletter.

Science.gov (United States)

Keane, Brigid; Waterston, Tony; McConachie, Helen; Towner, Elizabeth; Cook, Margaret; Birks, Eileen

2005-10-01

Supporting parents in the first three years of a child's life has the potential to produce successful outcomes. Present government initiatives such as Sure Start focus on this age group. An American educational intervention, in the style of a monthly newsletter, was adapted for use in the UK for parents of young children. Topics were presented in an easy-to-read format and focused on infant emotional development, parent interaction and play. Newsletters, called Baby Express were posted at monthly intervals to the family home providing age-paced information which could meet the specific needs of parents at that stage of their child's life. The aim of the study was to determine the applicability of the newsletter to UK parents and evaluate their satisfaction. Sixty home-based interviews were conducted and 95 per cent of mothers reported reading all or part of the newsletter. Changes in parenting style were spontaneously reported by 28 per cent of mothers. This study found that an aged-paced parenting newsletter was an acceptable and useful method of supporting parents in the early months of a child's life and promotes positive changes in parenting behaviour.

Prevalence of Campylobacter jejuni in poultry breeder flocks

Directory of Open Access Journals (Sweden)

Ludovico Dipineto

2010-01-01

Full Text Available The aim of this work is to present the preliminary results of a study about the prevalence of Campylobacter jejuni in poultry breeder flocks. It was examined three different breeder flocks of Bojano in Molise region. A total of 360 cloacal swabs and 80 enviromental swabs was collected. Of the 3 flocks studied, 6.9% tested were positive for Campylobacter spp. The most-prevalent isolated species is C. jejuni (8.2%. Only 3 of the 360 cloacal swabs samples examined were associated with C. coli. The environmental swabs resulted negative. This results confirms again that poultry is a reservoir of this germ.

Acute coenurosis of dairy sheep from 11 flocks in Greece.

Science.gov (United States)

Giadinis, N D; Psychas, V; Polizopoulou, Z; Papadopoulos, E; Papaioannou, N; Komnenou, A Th; Thomas, A-L; Petridou, E J; Kritsepi-Konstantinou, M; Lafi, S Q; Brellou, G D

2012-07-01

A syndrome of acute neurological dysfunction with increased mortality was observed in lambs of 10 dairy sheep flocks and adult animals in one flock in Central and Northern Greece. Each farmer completed a questionnaire regarding the management and feeding of their flocks. In seven of the 11 flocks the affected animals were grazing pasture, while in the remaining four flocks (5, 8, 9, 10) the animals were fed alfalfa hay (Medicago sativa) and concentrates indoors. A follow-up study of the affected flocks was conducted during the next 12 months. Of 42 sheep with acute coenurosis that were examined, the most prominent neurological abnormalities were ataxia, depression, blindness, scoliosis, coma and dysmetria. Except for the four sheep that were comatose, all other animals had normal body temperatures and their appetites remained normal or were slightly decreased. Haematological findings of 15 examined sheep were within normal limits. The affected sheep were subject to euthanasia. A histopathological examination was performed in 13 cases. Faecal samples from dogs associated with these flocks were negative for taeniid infections. During the following 12 months cases of chronic coenurosis in these flocks were observed. In the 42 animals that were necropsied, the main gross findings were cystic formations between 0.5-1 cm in diameter with translucent walls that were seen lying free on the leptomeninges or partly penetrating the brain tissue, sterile microabscecess and brain necrosis. Histopathological evaluation of tissue sections of 13 brains showed multifocal purulent or pyogranulomatous meningoencephalitis, accompanied by eosinophilic infiltrations. No bacteria were isolated following bacterial culture of brain tissue Parasitological examination of the cysts from five cases revealed whitish specks on the transparent cyst wall and germination membrane representing the scolices. Acute coenurosis was diagnosed in all cases studied. Acute coenurosis can be one of the

Emergence of the scale-invariant proportion in a flock from the metric-topological interaction.

Science.gov (United States)

Niizato, Takayuki; Murakami, Hisashi; Gunji, Yukio-Pegio

2014-05-01

Recently, it has become possible to more precisely analyze flocking behavior. Such research has prompted a reconsideration of the notion of neighborhoods in the theoretical model. Flocking based on topological distance is one such result. In a topological flocking model, a bird does not interact with its neighbors on the basis of a fixed-size neighborhood (i.e., on the basis of metric distance), but instead interacts with its nearest seven neighbors. Cavagna et al., moreover, found a new phenomenon in flocks that can be explained by neither metric distance nor topological distance: they found that correlated domains in a flock were larger than the metric and topological distance and that these domains were proportional to the total flock size. However, the role of scale-free correlation is still unclear. In a previous study, we constructed a metric-topological interaction model on three-dimensional spaces and showed that this model exhibited scale-free correlation. In this study, we found that scale-free correlation in a two-dimensional flock was more robust than in a three-dimensional flock for the threshold parameter. Furthermore, we also found a qualitative difference in behavior from using the fluctuation coherence, which we observed on three-dimensional flocking behavior. Our study suggests that two-dimensional flocks try to maintain a balance between the flock size and flock mobility by breaking into several smaller flocks. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Clusterflock: a flocking algorithm for isolating congruent phylogenomic datasets.

Science.gov (United States)

Narechania, Apurva; Baker, Richard; DeSalle, Rob; Mathema, Barun; Kolokotronis, Sergios-Orestis; Kreiswirth, Barry; Planet, Paul J

2016-10-24

Collective animal behavior, such as the flocking of birds or the shoaling of fish, has inspired a class of algorithms designed to optimize distance-based clusters in various applications, including document analysis and DNA microarrays. In a flocking model, individual agents respond only to their immediate environment and move according to a few simple rules. After several iterations the agents self-organize, and clusters emerge without the need for partitional seeds. In addition to its unsupervised nature, flocking offers several computational advantages, including the potential to reduce the number of required comparisons. In the tool presented here, Clusterflock, we have implemented a flocking algorithm designed to locate groups (flocks) of orthologous gene families (OGFs) that share an evolutionary history. Pairwise distances that measure phylogenetic incongruence between OGFs guide flock formation. We tested this approach on several simulated datasets by varying the number of underlying topologies, the proportion of missing data, and evolutionary rates, and show that in datasets containing high levels of missing data and rate heterogeneity, Clusterflock outperforms other well-established clustering techniques. We also verified its utility on a known, large-scale recombination event in Staphylococcus aureus. By isolating sets of OGFs with divergent phylogenetic signals, we were able to pinpoint the recombined region without forcing a pre-determined number of groupings or defining a pre-determined incongruence threshold. Clusterflock is an open-source tool that can be used to discover horizontally transferred genes, recombined areas of chromosomes, and the phylogenetic 'core' of a genome. Although we used it here in an evolutionary context, it is generalizable to any clustering problem. Users can write extensions to calculate any distance metric on the unit interval, and can use these distances to 'flock' any type of data.

Flocking dynamics and roosting behaviour of Meyer's parrot ...

African Journals Online (AJOL)

For most of the year, Meyer's parrots in the Okavango Delta do not form large feeding flocks, and groups larger than two or three are probably the result of opportunistic aggregation at favoured food items after dispersion from communal roosts. Communal roosting likely does not facilitate flocking unless the food resources ...

Semi-flocking algorithm for motion control of mobile sensors in large-scale surveillance systems.

Science.gov (United States)

Semnani, Samaneh Hosseini; Basir, Otman A

2015-01-01

The ability of sensors to self-organize is an important asset in surveillance sensor networks. Self-organize implies self-control at the sensor level and coordination at the network level. Biologically inspired approaches have recently gained significant attention as a tool to address the issue of sensor control and coordination in sensor networks. These approaches are exemplified by the two well-known algorithms, namely, the Flocking algorithm and the Anti-Flocking algorithm. Generally speaking, although these two biologically inspired algorithms have demonstrated promising performance, they expose deficiencies when it comes to their ability to maintain simultaneous robust dynamic area coverage and target coverage. These two coverage performance objectives are inherently conflicting. This paper presents Semi-Flocking, a biologically inspired algorithm that benefits from key characteristics of both the Flocking and Anti-Flocking algorithms. The Semi-Flocking algorithm approaches the problem by assigning a small flock of sensors to each target, while at the same time leaving some sensors free to explore the environment. This allows the algorithm to strike balance between robust area coverage and target coverage. Such balance is facilitated via flock-sensor coordination. The performance of the proposed Semi-Flocking algorithm is examined and compared with other two flocking-based algorithms once using randomly moving targets and once using a standard walking pedestrian dataset. The results of both experiments show that the Semi-Flocking algorithm outperforms both the Flocking algorithm and the Anti-Flocking algorithm with respect to the area of coverage and the target coverage objectives. Furthermore, the results show that the proposed algorithm demonstrates shorter target detection time and fewer undetected targets than the other two flocking-based algorithms.

Flocking ferromagnetic colloids.

Science.gov (United States)

Kaiser, Andreas; Snezhko, Alexey; Aranson, Igor S

2017-02-01

Assemblages of microscopic colloidal particles exhibit fascinating collective motion when energized by electric or magnetic fields. The behaviors range from coherent vortical motion to phase separation and dynamic self-assembly. Although colloidal systems are relatively simple, understanding their collective response, especially under out-of-equilibrium conditions, remains elusive. We report on the emergence of flocking and global rotation in the system of rolling ferromagnetic microparticles energized by a vertical alternating magnetic field. By combing experiments and discrete particle simulations, we have identified primary physical mechanisms, leading to the emergence of large-scale collective motion: spontaneous symmetry breaking of the clockwise/counterclockwise particle rotation, collisional alignment of particle velocities, and random particle reorientations due to shape imperfections. We have also shown that hydrodynamic interactions between the particles do not have a qualitative effect on the collective dynamics. Our findings shed light on the onset of spatial and temporal coherence in a large class of active systems, both synthetic (colloids, swarms of robots, and biopolymers) and living (suspensions of bacteria, cell colonies, and bird flocks).

Characteristics of positive-interaction parenting style among primiparous teenage, optimal age, and advanced age mothers in Canada.

Science.gov (United States)

Kim, Theresa H M; Connolly, Jennifer A; Rotondi, Michael; Tamim, Hala

2018-01-08

Positive-interaction parenting early in childhood is encouraged due to its association with behavioural development later in life. The objective of this study was to examine if the level of positive-interaction parenting style differs among teen, optimal age, and advanced age mothers in Canada, and to identify the characteristics associated with positive-interaction parenting style separately for each age group. This was a cross-sectional secondary analysis of the National Longitudinal Survey of Children and Youth. First-time mothers with children 0-23 months were grouped into: teen (15-19 years, N = 53,409), optimal age (20-34 years, N = 790,960), and advanced age (35 years and older, N = 106,536). The outcome was positive-interaction parenting style (Parenting Practices Scale); maternal socio-demographics, health, social, and child characteristics were considered for backward stepwise multiple linear regression modeling, stratified for each of the age groups. Teen, optimal age, and advanced age mothers reported similar levels of positive- interaction parenting style. Covariates differed across the three age groups. Among optimal age mothers, being an ever-landed immigrant, childcare use, and being devoted to religion were found to decrease positive-interaction parenting style, whereas, higher education was found to increase positive-interaction parenting style. Teen mothers were not found to have any characteristics uniquely associated with positive-interaction parenting. Among advanced age mothers, social support was uniquely associated with an increase in positive-interaction parenting. Very good/excellent health was found to be positively associated with parenting in teens but negatively associated with parenting in advanced age mothers. Characteristics associated with positive-interaction parenting varied among the three age groups. Findings may have public health implications through information dissemination to first-time mothers, clinicians

Effect of aluminum sulfate on litter composition and ammonia emission in a single flock of broilers up to 42 days of age.

Science.gov (United States)

Madrid, J; López, M J; Orengo, J; Martínez, S; Valverde, M; Megías, M D; Hernández, F

2012-08-01

New alternatives are necessary if the environmental impact linked to intensive poultry production is to be reduced, and different litter handling methods should be explored. Among these, acidifying amendments added to poultry litters has been suggested as a management practice to help reduce the potential environmental effect involved in multiple flock cycles. There have been several studies on the use of aluminum sulfate (alum) and its benefits, but almost no data are available under farm conditions in Europe. An experiment with Ross 308 broilers from 1 to 42 days of age was conducted to evaluate the effect of alum on litter composition, the solubility of some mineral elements and NH3 emission during a single flock-rearing period in commercial houses located in southeast Spain. Broilers were placed on clean wood shavings in four commercial houses, containing 20 000 broilers each. Before filling, alum was applied at a rate of 0.25 kg/m2 to the wood shavings of two poultry houses, whereas the remaining two were used as control. Litter from each poultry house was sampled every 3 to 5 days. Ammonia emissions from the poultry houses were monitored from 37 to 42 days of age. In comparison with the control group, alum treatment significantly reduced the pH level of the litter (P litter showed, on average, a higher electrical conductivity than the control litter (5.52 v. 3.63 dS/m). The dry matter (DM) and total N and P contents did not show differences between the treatments (P > 0.05). Regarding the NH4 +-N content, alum-treated litter showed a higher value than the untreated litter, with an average difference of 0.16 ± 0.07% (on a DM basis). On average, alum-treated litter had lower water-soluble P, Zn and Cu contents than the untreated litter. Alum noticeably reduced the in-house ammonia concentration (P litter, with a corresponding positive effect on the building environment and poultry health. For these reasons, litter amendment with alum could be recommended as a

Risk factors for Campylobacter spp. infection in Senegalese broiler-chicken flocks.

Science.gov (United States)

Cardinale, E; Tall, F; Guèye, E F; Cisse, M; Salvat, G

2004-06-10

Our objective was to identify the risk factors for Campylobacter infection in Senegalese broiler flocks. Seventy broiler farms were studied around Dakar from January 2000 to December 2001 around Dakar. A questionnaire was administered to the farmers, and samples of fresh droppings were taken to assess the flocks' Campylobacter status. About 63% of the flocks were infected by Campylobacter spp.; Campylobacter jejuni was the most-prevalent species (P hatchery to the farm as feed plates (rather than specifically designed feed plates). Alternatively, thorough cleaning and disinfection of poultry-house surroundings and manure disposal outside the farm were associated with decreased flock risk.

Tracers as invisible evidence - The transfer and persistence of flock fibres during a car exchange.

Science.gov (United States)

Slot, Ana; van der Weerd, Jaap; Roos, Martin; Baiker, Martin; Stoel, Reinoud D; Zuidberg, Matthijs C

2017-06-01

This study assessed the recovery of flock fibres used as a tracer in a car exchange scenario. Flock fibres were deposited onto a car seat (or model thereof) and their transfer and persistence was investigated after a real or simulated car exchange. The overall aim of this study was to achieve an optimal use of flock fibres as tracers, i.e. to be able to select a fit-for-purpose flock fibre, to be able to predict the amount of flock fibres to be recovered from crime related items, and to be able to use these numbers to exclude accidental uptake. The effect of a number of variables on the transfer and persistence of flock fibres was studied, including flock fibre length, car upholstery, and trousers material. Laboratory based experiments were undertaken first, followed by realistic field based experiments. The flock fibres were captured in a non-destructive manner through fluorescence photography. A Matlab algorithm enabled fast automated counting of flock fibres on the images. Results indicate that an initial rapid loss of flock fibres from garments may be expected as a result of moderate movement. Although the amount of flock fibres to be recovered is affected by the flock fibre length, the type of car upholstery, and the type of trousers materials (if frictional force is taken into consideration), large numbers of flock fibres have been recovered from all target materials throughout the transfer route. These numbers are higher than the amount of flock fibres recovered due to accidental uptake. In conclusion, flock fibres can serve as invisible evidence to reconstruct a series of events. Copyright © 2017 Elsevier B.V. All rights reserved.

Cucker-Smale Flocking with Bounded Cohesive and Repulsive Forces

Directory of Open Access Journals (Sweden)

Qiang Song

2013-01-01

Full Text Available This paper proposes two Cucker-Smale-type flocking models by introducing both cohesive and repulsive forces to second-order multiagent systems. Under some mild conditions on the initial state of the flocking system, it is shown that the velocity consensus of the agents can be reached independent of the parameter which describes the decay of communication rates. In particular, the collision between any two agents can always be avoided by designing an appropriate bounded repulsive function based on the initial energy of the flock. Numerical examples are given to demonstrate the effectiveness of the theoretical analysis.

The confusion effect when attacking simulated three-dimensional starling flocks.

Science.gov (United States)

Hogan, Benedict G; Hildenbrandt, Hanno; Scott-Samuel, Nicholas E; Cuthill, Innes C; Hemelrijk, Charlotte K

2017-01-01

The confusion effect describes the phenomenon of decreasing predator attack success with increasing prey group size. However, there is a paucity of research into the influence of this effect in coherent groups, such as flocks of European starlings ( Sturnus vulgaris ). Here, for the first time, we use a computer game style experiment to investigate the confusion effect in three dimensions. To date, computerized studies on the confusion effect have used two-dimensional simulations with simplistic prey movement and dynamics. Our experiment is the first investigation of the effects of flock size and density on the ability of a (human) predator to track and capture a target starling in a realistically simulated three-dimensional flock of starlings. In line with the predictions of the confusion effect, modelled starlings appear to be safer from predation in larger and denser flocks. This finding lends credence to previous suggestions that starling flocks have anti-predator benefits and, more generally, it suggests that active increases in density in animal groups in response to predation may increase the effectiveness of the confusion effect.

Topological Sound and Flocking on Curved Surfaces

Science.gov (United States)

Shankar, Suraj; Bowick, Mark J.; Marchetti, M. Cristina

2017-07-01

Active systems on curved geometries are ubiquitous in the living world. In the presence of curvature, orientationally ordered polar flocks are forced to be inhomogeneous, often requiring the presence of topological defects even in the steady state because of the constraints imposed by the topology of the underlying surface. In the presence of spontaneous flow, the system additionally supports long-wavelength propagating sound modes that get gapped by the curvature of the underlying substrate. We analytically compute the steady-state profile of an active polar flock on a two-sphere and a catenoid, and show that curvature and active flow together result in symmetry-protected topological modes that get localized to special geodesics on the surface (the equator or the neck, respectively). These modes are the analogue of edge states in electronic quantum Hall systems and provide unidirectional channels for information transport in the flock, robust against disorder and backscattering.

Prevalence of Coxiella burnetii in clinically healthy German sheep flocks

Directory of Open Access Journals (Sweden)

Hilbert Angela

2012-03-01

Full Text Available Abstract Background Current epidemiological data on the situation of Coxiella (C. burnetii infections in sheep are missing, making risk assessment and the implementation of counteractive measures difficult. Using the German state of Thuringia as a model example, the estimated sero-, and antigen prevalence of C. burnetii (10% and 25%, respectively was assessed at flock level in 39/252 randomly selected clinically healthy sheep flocks with more than 100 ewes and unknown abortion rate. Results The CHECKIT™ Q-fever Test Kit identified 11 (28% antibody positive herds, whereas real-time PCR revealed the presence of C. burnetii DNA in 2 (5% of the flocks. Multiple-locus variable number of tandem repeats analysis of 9 isolates obtained from one flock revealed identical profiles. All isolates contained the plasmid QpH1. Conclusions The results demonstrate that C. burnetii is present in clinically inconspicuous sheep flocks and sporadic flare-ups do occur as the notifications to the German animal disease reporting system show. Although C. burnetii infections are not a primary veterinary concern due to the lack of significant clinical impact on animal health (with the exception of goats, the eminent zoonotic risk for humans should not be underestimated. Therefore, strategies combining the interests of public and veterinary public health should include monitoring of flocks, the identification and culling of shedders as well as the administration of protective vaccines.

Stability of model flocks in turbulent-like flow

International Nuclear Information System (INIS)

Khurana, Nidhi; Ouellette, Nicholas T

2013-01-01

We report numerical simulations of a simple model of flocking particles in the presence of an uncertain background environment. We consider two types of environmental perturbations: random noise applied separately to each particle, and spatiotemporally correlated ‘noise’ provided by a turbulent-like flow field. The effects of these two types of noise are very different; surprisingly, the applied flow field tends to destroy the global order of the flocking model even for vanishingly small flow amplitudes. Local order, however, is preserved in smaller sub-flocks, although their composition changes dynamically. Our results suggest that realistic perturbations must be considered in assessing the stability of models of collective animal behavior, and that random noise is not a sufficient proxy. (paper)

Flock-based surveillance for lowpathogenic avian influenza virus in ...

African Journals Online (AJOL)

Flock-based surveillance for lowpathogenic avian influenza virus in commercial breeders and layers, southwest Nigeria. ... African Journal of Infectious Diseases ... Background: Flock surveillance systems for avian influenza (AI) virus play a critical role in countries where vaccination is not practiced so as to establish the ...

Aging Parents' Daily Support Exchanges With Adult Children Suffering Problems.

Science.gov (United States)

Huo, Meng; Graham, Jamie L; Kim, Kyungmin; Birditt, Kira S; Fingerman, Karen L

2017-06-17

When adult children incur life problems (e.g., divorce, job loss, health problems), aging parents generally report providing more frequent support and experiencing poorer well-being. Yet, it is unclear how adult children's problems may influence aging parents' daily support exchanges with these children or the parents' daily mood. Aging parents from the Family Exchanges Study Wave 2 (N = 207, Mage = 79.86) reported providing and receiving emotional support, practical support, and advice from each adult child each day for 7 days. Parents also rated daily positive and negative mood. Multilevel models showed that aging parents were more likely to provide emotional and practical support to adult children incurring life problems than children not suffering problems. Parents were also more likely to receive emotional support and advice from these children with problems. Further, parents reported less negative mood on days when providing practical support to children with problems. Examining daily support exchanges adds to our understanding of how children's problems influence parent-child ties in late life. Prior research suggests that children's problems upset parents. In this study, however, it appears that supporting adult children who suffer problems may alleviate aging parents' distress regarding such children. © The Author 2017. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Age Differences in Children's Strategies for Influencing Parents' Purchases.

Science.gov (United States)

Fuehrer, Ann; And Others

The specific purposes of this study were to examine (1) age differences in the sophistication of influence strategies children use to affect parents' consumption decisions, and (2) whether or not parents differentially reinforce such strategies according to the child's age. Data were gathered by observing the interactions of 145 parent-child dyads…

Composition of Mix Species Foraging Flocks of Birds in Riverstan of Montane Region, Sri Lanka

Directory of Open Access Journals (Sweden)

W.G.D.D.M. Shermila

2013-04-01

Full Text Available Montane zone mixed-species bird flock system is distinct from that of low-land wet zone of SriLanka, although some species are present in both systems. The present study identified the mixed speciesflocks of birds in Riverstan at Knuckles Region, Sri Lanka. Monthly transect counts and opportunisticobservations were made between January and May, 2012. A total of 78 flocks and 27 bird species wereencountered at Riverstan during the study period. The flock size varied between 2 to 13 species and 4 to58 individuals. The mean number of species per flock was 6.03 ± 2.25 and the mean number ofindividuals in a flock was 18.41±9.87. The flock size was positively correlated with the number of speciespresent (r = 0.756, P <0.05. Grey-headed Canary Flycatcher was the most abundant species (mean2.68±1.02 birds per flocks while Sri Lanka White-eye was the most frequent species (mean 5.69±3.92birds per flocks. Grey-headed Canary Flycatcher and Sri Lanka Scimitar-babbler were the nuclear speciesin Riverstan. The leading species were Sri Lanka white-eye and Sri Lanka Yellow-eared Bulbul. Differentbird species used different heights within flocks.Keywords: Mixed-species flock, Nuclear species, Abundance, Foraging flocks

Parental age at delivery and a man's semen quality

DEFF Research Database (Denmark)

Priskorn, Lærke; Jensen, Tina K; Lindahl-Jacobsen, Rune

2014-01-01

STUDY QUESTION: Is parental age at delivery associated with a man's semen quality? SUMMARY ANSWER: In this large register-based study both mother's and father's age are found to have minimal effects on semen quality in men. WHAT IS KNOWN ALREADY: Both maternal and paternal age have been associated...... with a range of adverse health effects in the offspring. Given the varied health effects of parental age upon offspring, and the sensitivity of genital development to external factors, it is plausible that the age of a man's mother and father at conception may impact his reproductive health. To our knowledge...... this is the first examination of the effects of parental age on semen quality. STUDY DESIGN, SIZE, DURATION: A retrospective cohort study of 10 965 men with semen data and parental data. PARTICIPANTS/MATERIALS, SETTING, METHODS: The study was based on Danish men referred to the Copenhagen Sperm Analysis Laboratory...

Comparison of strategies for substantiating freedom from scrapie in a sheep flock.

Science.gov (United States)

Durand, Benoit; Martinez, Marie-José; Calavas, Didier; Ducrot, Christian

2009-04-30

The public health threat represented by a potential circulation of bovine spongiform encephalopathy agent in sheep population has led European animal health authorities to launch large screening and genetic selection programmes. If demonstrated, such a circulation would have dramatic economic consequences for sheep breeding sector. In this context, it is important to evaluate the feasibility of qualification procedures that would allow sheep breeders demonstrating their flock is free from scrapie. Classical approaches, based on surveys designed to detect disease presence, do not account for scrapie specificities: the genetic variations of susceptibility and the absence of live diagnostic test routinely available. Adapting these approaches leads to a paradoxical situation in which a greater amount of testing is needed to substantiate disease freedom in genetically resistant flocks than in susceptible flocks, whereas probability of disease freedom is a priori higher in the former than in the latter. The goal of this study was to propose, evaluate and compare several qualification strategies for demonstrating a flock is free from scrapie. A probabilistic framework was defined that accounts for scrapie specificities and allows solving the preceding paradox. Six qualification strategies were defined that combine genotyping data, diagnostic tests results and flock pedigree. These were compared in two types of simulated flocks: resistant and susceptible flocks. Two strategies allowed demonstrating disease freedom in several years, for the majority of simulated flocks: a strategy in which all the flock animals are genotyped, and a strategy in which only founders animals are genotyped, the flock pedigree being known. In both cases, diagnostic tests are performed on culled animals. The less costly strategy varied according to the genetic context (resistant or susceptible) and to the relative costs of a genotyping exam and of a diagnostic test. This work demonstrates that

Topological Sound and Flocking on Curved Surfaces

Directory of Open Access Journals (Sweden)

Suraj Shankar

2017-09-01

Full Text Available Active systems on curved geometries are ubiquitous in the living world. In the presence of curvature, orientationally ordered polar flocks are forced to be inhomogeneous, often requiring the presence of topological defects even in the steady state because of the constraints imposed by the topology of the underlying surface. In the presence of spontaneous flow, the system additionally supports long-wavelength propagating sound modes that get gapped by the curvature of the underlying substrate. We analytically compute the steady-state profile of an active polar flock on a two-sphere and a catenoid, and show that curvature and active flow together result in symmetry-protected topological modes that get localized to special geodesics on the surface (the equator or the neck, respectively. These modes are the analogue of edge states in electronic quantum Hall systems and provide unidirectional channels for information transport in the flock, robust against disorder and backscattering.

Detection of antibodies against Chlamydophila abortus in Costa Rican sheep flocks

Directory of Open Access Journals (Sweden)

R. Villagra-Blanco

2015-09-01

Full Text Available A total of 359 sheep samples from 15 flocks were analyzed for the presence of antibodies against Chlamydophila abortus using a commercial Enzyme linked Immunosorbent Assay (ELISA. Antibodies were detected in 19 (5.29% sheep from 12 (80% flocks. Seropositive animals were found in all analyzed regions (Central, Chorotega, Atlantic Huetar, North Huetar and Central Pacific determining prevalence between 0.28% and 4.4%, and intra-flock positivity between 3.7% and 25.0%. The survey revealed two risk factors associated with seropositivity; introducing animals (males and females, embryos, or semen from other farms or from abroad without any sanitary certification, and flocks not having quarantine areas or separated boxes for diseased animals. No clinical signs of disease were observed in positive seroreactors. C. abortus seems to be present in Costa Rica in a very low prevalence in sheep flocks. Further studies, to isolate the bacteria are required. Finally, implementation of control measures to prevent the spread of C. abortus is recommended.

Detection of antibodies against Chlamydophila abortus in Costa Rican sheep flocks

Science.gov (United States)

Villagra-Blanco, R.; Dolz, G.; Montero-Caballero, D.; Romero-Zúñiga, J.J.

2015-01-01

A total of 359 sheep samples from 15 flocks were analyzed for the presence of antibodies against Chlamydophila abortus using a commercial Enzyme linked Immunosorbent Assay (ELISA). Antibodies were detected in 19 (5.29%) sheep from 12 (80%) flocks. Seropositive animals were found in all analyzed regions (Central, Chorotega, Atlantic Huetar, North Huetar and Central Pacific) determining prevalence between 0.28% and 4.4%, and intra-flock positivity between 3.7% and 25.0%. The survey revealed two risk factors associated with seropositivity; introducing animals (males and females), embryos, or semen from other farms or from abroad without any sanitary certification, and flocks not having quarantine areas or separated boxes for diseased animals. No clinical signs of disease were observed in positive seroreactors. C. abortus seems to be present in Costa Rica in a very low prevalence in sheep flocks. Further studies, to isolate the bacteria are required. Finally, implementation of control measures to prevent the spread of C. abortus is recommended. PMID:26623377

Viral Agents Associated with Poult Enteritis in Croatian Commercial Turkey Flocks

Directory of Open Access Journals (Sweden)

Ivana Lojkić

2010-01-01

Full Text Available From 2003 to 2006, samples of intestinal content and spleens from 10-day-old to 6-week-old fattening turkeys showing clinical signs of enteritis were analyzed by specific PCR and RT-PCRs for detection of haemorrhagic enteritis virus (HEV, avian reovirus (ARV, turkey astrovirus-2 (TastV-2, and turkey coronavirus (TCV. A total of 23 flocks from 6 farms were included in the study. Specific sequence for HEV hexon gene was present in 6 samples from turkeys younger than and in one turkey at 6 weeks of age. A product of TastV-2 capsid gene was detected in 17/23 intestinal content samples. A 626-bp band of sigma A (S2 encoding gene segment from avian reovirus was present in three samples, all from the same farm. Sequence analysis of 450 bp fragment of avian reovirus sigma A encoding gene sequence showed that our strain had the identity of 91.3% with the strains 138, 2408, 1733, 919, T6, and Os161. No TCV specific PCR band was found in any sample. Four flocks were positive simultaneously for HEV and TastV-2, and three flocks on TastV-2 and ARV. Severity of poult enteritis described in our study is caused by immunosuppressive TastV-2 in combination with HEV or ARV.

Carry-over of thermophilic Campylobacter spp. between sequential and adjacent poultry flocks.

Science.gov (United States)

Alter, Thomas; Weber, Rita Margarete; Hamedy, Ahmad; Glünder, Gerhard

2011-01-10

Nineteen flocks of four poultry species were monitored at a veterinary field station to investigate the distribution and spread of Campylobacter genotypes between sequential and adjacent flocks. Caecal and liver samples were obtained at frequent intervals from birds of all flocks and examined for Campylobacter. Amplified fragment length polymorphism (AFLP) analysis was performed to genotype Campylobacter isolates. Of the 1643 caecal and liver samples investigated, 452 (27.5%) caecal samples and 11 (0.7%) liver samples contained Campylobacter. Of the caecal isolates 76.3% were identified as Campylobacter jejuni and 23.7% were identified as Campylobacter coli. Poultry flocks were largely colonized by more than one AFLP type and an intense exchange of Campylobacter genotypes between different poultry flocks occurred. These findings indicate that multiple genotypes can constitute the Campylobacter population within single poultry flocks, hinting to different sources of exposure and/or genetic drifts within the Campylobacter population. Nevertheless, in most flocks single Campylobacter genotypes predominated. Some strains superseded others resulting in colonization by successive Campylobacter genotypes during the observation period. In conclusion, the data demonstrate that the large genetic diversity of Campylobacter must be considered in epidemiological evaluations and microbial risk assessments of Campylobacter in poultry. Copyright © 2010 Elsevier B.V. All rights reserved.

9 CFR 146.23 - Terminology and classification; flocks and products.

Science.gov (United States)

2010-01-01

... layers through routine serological surveillance of each participating commercial table-egg layer flock. A... SERVICE, DEPARTMENT OF AGRICULTURE LIVESTOCK IMPROVEMENT NATIONAL POULTRY IMPROVEMENT PLAN FOR COMMERCIAL POULTRY Special Provisions for Commercial Table-Egg Layer Flocks § 146.23 Terminology and classification...

Worm control practice against gastro-intestinal parasites in Norwegian sheep and goat flocks

Science.gov (United States)

2011-01-01

Background Anthelmintic treatment is the most common way of controlling nematode infections in ruminants. However, several countries have reported anthelmintic resistance (AR), representing a limitation for sustainable small ruminant production. The knowledge regarding worm control management represents a baseline to develop a guideline for preventing AR. The aim of the present study was therefore to improve our knowledge about the worm control practices in small ruminant flocks in Norway. Methods A questionnaire survey regarding worm control practices was performed in small ruminant flocks in Norway. Flocks were selected from the three main areas of small ruminant farming, i.e. the coastal, inland and northern areas. A total of 825 questionnaires, comprising 587 sheep flocks (return rate of 51.3%) and 238 goat flocks (52.6%) were included. Results The results indicated that visual appraisal of individual weight was the most common means of estimating the anthelmintic dose used in sheep (78.6%) and goat (85.1%) flocks. The mean yearly drenching rate in lambs and ewes were 2.5 ± 1.7 and 1.9 ± 1.1, respectively, whereas it was 1.0 (once a year) in goats. However, these figures were higher in sheep in the coastal area with a rate of 3.4 and 2.2 in lambs and ewes, respectively. Benzimidazoles were the predominant anthelmintic class used in sheep flocks (64.9% in 2007), whereas benzimidazoles and macrocyclic lactones were both equally used in dairy goat flocks. In the period of 2005-2007, 46.3% of the sheep flocks never changed the anthelmintic class. The dose and move strategy was practiced in 33.2% of the sheep flocks. Conclusions The present study showed that inaccurate weight calculation gives a risk of under-dosing in over 90% of the sheep and goat flocks in Norway. Taken together with a high treatment frequency in lambs, a lack of anthelmintic class rotation and the common use of a dose-and-move strategy, a real danger for development of anthelmintic resistance

Worm control practice against gastro-intestinal parasites in Norwegian sheep and goat flocks

Directory of Open Access Journals (Sweden)

Vatn Synnøve

2011-05-01

Full Text Available Abstract Background Anthelmintic treatment is the most common way of controlling nematode infections in ruminants. However, several countries have reported anthelmintic resistance (AR, representing a limitation for sustainable small ruminant production. The knowledge regarding worm control management represents a baseline to develop a guideline for preventing AR. The aim of the present study was therefore to improve our knowledge about the worm control practices in small ruminant flocks in Norway. Methods A questionnaire survey regarding worm control practices was performed in small ruminant flocks in Norway. Flocks were selected from the three main areas of small ruminant farming, i.e. the coastal, inland and northern areas. A total of 825 questionnaires, comprising 587 sheep flocks (return rate of 51.3% and 238 goat flocks (52.6% were included. Results The results indicated that visual appraisal of individual weight was the most common means of estimating the anthelmintic dose used in sheep (78.6% and goat (85.1% flocks. The mean yearly drenching rate in lambs and ewes were 2.5 ± 1.7 and 1.9 ± 1.1, respectively, whereas it was 1.0 (once a year in goats. However, these figures were higher in sheep in the coastal area with a rate of 3.4 and 2.2 in lambs and ewes, respectively. Benzimidazoles were the predominant anthelmintic class used in sheep flocks (64.9% in 2007, whereas benzimidazoles and macrocyclic lactones were both equally used in dairy goat flocks. In the period of 2005-2007, 46.3% of the sheep flocks never changed the anthelmintic class. The dose and move strategy was practiced in 33.2% of the sheep flocks. Conclusions The present study showed that inaccurate weight calculation gives a risk of under-dosing in over 90% of the sheep and goat flocks in Norway. Taken together with a high treatment frequency in lambs, a lack of anthelmintic class rotation and the common use of a dose-and-move strategy, a real danger for development of

Prevalence of and risk factors associated with ovine progressive pneumonia in Wyoming sheep flocks.

Science.gov (United States)

Gerstner, Shelley; Adamovicz, Jeffrey J; Duncan, John V; Laegreid, William W; Marshall, Katherine L; Logan, James R; Schumaker, Brant A

2015-10-15

To determine the prevalence of antibodies against small ruminant lentivirus (SRLV), the causative agent of ovine progressive pneumonia (OPP), and to identify risk factors associated with OPP in Wyoming sheep flocks. Cross-sectional study. 1,415 sheep from 54 flocks in Wyoming. Flocks were surveyed as part of the National Animal Health Monitoring System (NAHMS) 2011 sheep study. Serum samples obtained from sheep in Wyoming were analyzed for anti-SRLV antibodies by use of a competitive-inhibition ELISA. The prevalence of seropositive animals overall and within each flock was calculated. Respective associations between flock OPP status and various demographic and management variables were assessed. The estimated prevalence of sheep seropositive for anti-SRLV antibodies and OPP-infected flocks in Wyoming was 18.0% and 47.5%, respectively. Within OPP-infected flocks, the prevalence of seropositive sheep ranged from 3.9% to 96%. Flocks maintained on nonfenced range were more likely to be infected with OPP than were flocks maintained on fenced range (OR, 3.4; 95% confidence interval, 1.1 to 10.7). The estimated prevalence of OPP-infected flocks in Wyoming did not vary substantially from that at the regional or national level reported in the NAHMS 2001 sheep study. Compared with results of the NAHMS 2011 sheep study, Wyoming producers were more familiar with OPP than were other US sheep producers, but only 61% of Wyoming producers surveyed reported being very or somewhat familiar with the disease. Results indicated that OPP is prevalent in many Wyoming sheep flocks, which suggested that continued efforts are necessary to increase producer knowledge about the disease and investigate practices to minimize economic losses associated with OPP.

Flocking algorithm for autonomous flying robots.

Science.gov (United States)

Virágh, Csaba; Vásárhelyi, Gábor; Tarcai, Norbert; Szörényi, Tamás; Somorjai, Gergő; Nepusz, Tamás; Vicsek, Tamás

2014-06-01

Animal swarms displaying a variety of typical flocking patterns would not exist without the underlying safe, optimal and stable dynamics of the individuals. The emergence of these universal patterns can be efficiently reconstructed with agent-based models. If we want to reproduce these patterns with artificial systems, such as autonomous aerial robots, agent-based models can also be used in their control algorithms. However, finding the proper algorithms and thus understanding the essential characteristics of the emergent collective behaviour requires thorough and realistic modeling of the robot and also the environment. In this paper, we first present an abstract mathematical model of an autonomous flying robot. The model takes into account several realistic features, such as time delay and locality of communication, inaccuracy of the on-board sensors and inertial effects. We present two decentralized control algorithms. One is based on a simple self-propelled flocking model of animal collective motion, the other is a collective target tracking algorithm. Both algorithms contain a viscous friction-like term, which aligns the velocities of neighbouring agents parallel to each other. We show that this term can be essential for reducing the inherent instabilities of such a noisy and delayed realistic system. We discuss simulation results on the stability of the control algorithms, and perform real experiments to show the applicability of the algorithms on a group of autonomous quadcopters. In our case, bio-inspiration works in two ways. On the one hand, the whole idea of trying to build and control a swarm of robots comes from the observation that birds tend to flock to optimize their behaviour as a group. On the other hand, by using a realistic simulation framework and studying the group behaviour of autonomous robots we can learn about the major factors influencing the flight of bird flocks.

[Parenting style in Spanish parents with children aged 6 to 14].

Science.gov (United States)

Alonso-Geta, Petra María

2012-01-01

The aim of this paper was to establish which parenting style of Spanish families is associated with optimum children's outcomes. A random Spanish sample of 1,103 parents of children and teenagers from 6 to 14 years of age, of whom 47% were females, reported on their child-rearing practices. Families were classified into 1 of 4 groups (authoritative, authoritarian, indulgent, or neglectful) based on the parents' answers. Socialization outcomes were 6 indicators of interpersonal relationship quality, 9 indicators of psychological adjustment, 7 indicators of personal competence, and 12 indicators of behavior problems. Results showed that indulgent and authoritative parenting styles were associated with better outcomes than authoritarian and neglectful parenting. Overall, our results supported the idea that, in Spain, the optimum parenting style is the indulgent one, as scores in the four sets of socialization outcomes among children and teenagers from indulgent families were always equal to, or even better than, the authoritative parenting style.

An Improved Fast Flocking Algorithm with Obstacle Avoidance for Multiagent Dynamic Systems

Directory of Open Access Journals (Sweden)

Jialiang Wang

2014-01-01

Full Text Available Flocking behavior is a common phenomenon in nature, such as flocks of birds and groups of fish. In order to make the agents effectively avoid obstacles and fast form flocking towards the direction of destination point, this paper proposes a fast multiagent obstacle avoidance (FMOA algorithm. FMOA is illustrated based on the status of whether the flocking has formed. If flocking has not formed, agents should avoid the obstacles toward the direction of target. If otherwise, these agents have reached the state of lattice and then these agents only need to avoid the obstacles and ignore the direction of target. The experimental results show that the proposed FMOA algorithm has better performance in terms of flocking path length. Furthermore, the proposed FMOA algorithm is applied to the formation flying of quad-rotor helicopters. Compared with other technologies to perform the localization of quad-rotor helicopter, this paper innovatively constructs a smart environment by deploying some wireless sensor network (WSN nodes using the proposed localization algorithm. Finally, the proposed FMOA algorithm is used to conduct the formation flying of these quad-rotor helicopters in the smart environment.

Serotype and genotype diversity and hatchery transmission of Campylobacter jejuni in commercial poultry flocks

DEFF Research Database (Denmark)

Petersen, L.; Nielsen, E.M.; On, Stephen L.W.

2001-01-01

, 314 C jejuni and 32 C coli isolates from parent and broiler flocks and from the surroundings of broiler houses were typed by flagellin gene PCR/RFLP fla-typing), and selected isolates were also typed by serotyping and macrorestriction profiling using PFGE (MRP/PFGE). The combined typing results showed...... discriminated by fla-typing as well as by MRP/PFGE, except for a few cases where individual isolates belonging to two different clones were found to have altered fla-types. Similarly, one C coli clone showed pronounced fla-type variation. The present results lead to the conclusion that vertical transmission...

9 CFR 145.63 - Terminology and classification; flocks and products.

Science.gov (United States)

2010-01-01

... Terminology and classification; flocks and products. Participating flocks, and the eggs and baby poultry... examination monitoring program of hatcher debris or eggs for ostriches, emus, rheas, or cassowaries acceptable... made that can be traced to a source in that State, that uses a bacteriological examination monitoring...

How many dissenters does it take to disorder a flock?

Science.gov (United States)

Yllanes, D.; Leoni, M.; Marchetti, M. C.

2017-10-01

We consider the effect of introducing a small number of non-aligning agents in a well-formed flock. To this end, we modify a minimal model of active Brownian particles with purely repulsive (excluded volume) forces to introduce an alignment interaction that will be experienced by all the particles except for a small minority of ‘dissenters’. We find that even a very small fraction of dissenters disrupts the flocking state. Strikingly, these motile dissenters are much more effective than an equal number of static obstacles in breaking up the flock. For the studied system sizes we obtain clear evidence of scale invariance at the flocking-disorder transition point and the system can be effectively described with a finite-size scaling formalism. We develop a continuum model for the system which reveals that dissenters act like annealed noise on aligners, with a noise strength that grows with the persistence of the dissenters’ dynamics.

Parenting clinically anxious versus healthy control children aged 4-12 years

NARCIS (Netherlands)

van der Sluis, C.M.; van Steensel, F.J.A.; Bögels, S.M.

2015-01-01

This study investigated whether parenting behaviors differed between parents of 68 clinically anxious children and 106 healthy control children aged 4-12 years. The effects of parent gender, child gender and child age on parenting were explored. Mothers and fathers completed a questionnaire to

Graphics Processing Unit Enhanced Parallel Document Flocking Clustering

Energy Technology Data Exchange (ETDEWEB)

Cui, Xiaohui [ORNL; Potok, Thomas E [ORNL; ST Charles, Jesse Lee [ORNL

2010-01-01

Analyzing and clustering documents is a complex problem. One explored method of solving this problem borrows from nature, imitating the flocking behavior of birds. One limitation of this method of document clustering is its complexity O(n2). As the number of documents grows, it becomes increasingly difficult to generate results in a reasonable amount of time. In the last few years, the graphics processing unit (GPU) has received attention for its ability to solve highly-parallel and semi-parallel problems much faster than the traditional sequential processor. In this paper, we have conducted research to exploit this archi- tecture and apply its strengths to the flocking based document clustering problem. Using the CUDA platform from NVIDIA, we developed a doc- ument flocking implementation to be run on the NVIDIA GEFORCE GPU. Performance gains ranged from thirty-six to nearly sixty times improvement of the GPU over the CPU implementation.

Comparisons of Sampling Procedures and Time of Sampling for the Detection of Salmonella in Danish Infected Chicken Flocks Raised in Floor Systems

Directory of Open Access Journals (Sweden)

Madsen M

2002-03-01

Full Text Available Bacteriological follow-up samples were taken from 41 chicken (Gallus gallus flocks in floor systems, where Salmonella enterica (Salmonella had been detected either directly in bacteriological samples or indirectly by serological samples. Three types of follow-up samples were compared to each other within each flock: 1 5 pairs of socks, analysed as 5 samples, 2 2 pairs of socks, analysed as one sample, and 3 60 faecal samples, analysed as one pooled sample. Agreement between sampling methods was evaluated by the following statistical tests: 'Kappa', 'The adjusted rand', McNemar's test for marginal symmetry, Proportion of agreement P0, P+, P-, and Odds Ratio. The highest agreement was found between the 2 types of sock sampling, while the lowest agreement was found by comparing 60 faecal samples with 5 pairs of socks. Two pairs of socks analysed as one pool appeared to be just as effective in detecting S. enterica as the 60 faecal samples. In broiler flocks, 5 pairs of socks were used both in the routine samples taken at about 3 weeks of age for the establishment of infection of the flock, and as one of the follow-up samples taken shortly before slaughter age, which means that the only notable differences between the 2 sampling rounds were the age of the broilers and of their litter. S. enterica was detected more frequently in samples from broilers about 3 weeks old, than in similar samples taken from broilers a few days prior to slaughter at ca. 33–40 days of age.

Flocking with minimal cooperativity: the panic model.

Science.gov (United States)

Pilkiewicz, Kevin R; Eaves, Joel D

2014-01-01

We present a two-dimensional lattice model of self-propelled spins that can change direction only upon collision with another spin. We show that even with ballistic motion and minimal cooperativity, these spins display robust flocking behavior at nearly all densities, forming long bands of stripes. The structural transition in this system is not a thermodynamic phase transition, but it can still be characterized by an order parameter, and we demonstrate that if this parameter is studied as a dynamical variable rather than a steady-state observable, we can extract a detailed picture of how the flocking mechanism varies with density.

Parenting clinically anxious versus healthy control children aged 4-12 years.

Science.gov (United States)

van der Sluis, C M; van Steensel, F J A; Bögels, S M

2015-05-01

This study investigated whether parenting behaviors differed between parents of 68 clinically anxious children and 106 healthy control children aged 4-12 years. The effects of parent gender, child gender and child age on parenting were explored. Mothers and fathers completed a questionnaire to assess parenting behaviors in for children hypothetically anxious situations. Results showed that parents of clinically anxious children reported more anxiety-enhancing parenting (reinforcement of dependency and punishment) as well as more positive parenting (positive reinforcement). For the clinical sample, fathers reported using more modeling/reassurance than mothers, and parents reported using more force with their 4-7-year-olds than with their 8-12-year-olds. No interaction effects were found for child gender with child anxiety status on parenting. Results indicate that for intervention, it is important to measure parenting behaviors, and to take into account father and mother differences and the age of the child. Copyright © 2015 Elsevier Ltd. All rights reserved.

Leadership of Winter Mixed-Species Flocks by Tufted Titmice (Baeolophus bicolor: Are Titmice Passive Nuclear Species?

Directory of Open Access Journals (Sweden)

Thomas A. Contreras

2011-01-01

Full Text Available The tufted titmouse (Baeolophus bicolor, TUTI is a nuclear species in winter foraging flocks whose antipredator calls are used to manage predation risk by diverse heterospecifics. We hypothesized that satellite species in mixed flocks follow TUTI (not vice versa, thereby defining the role of TUTI as a “passive” nuclear species. We followed 20 winter mixed-species flocks in North-Central Florida and assessed angular-angular correlations between overall flock, TUTI, and satellite species movement directions. We observed significant correlations between overall flock movement directions and those of TUTI, confirming our central prediction. Within flocks, however, fine-scale movement directions of satellite species were often more highly correlated with those of other satellites than with TUTI movements. We conclude that TUTI are passive nuclear species whose movements define flock paths, but within flocks, TUTI movements may have less influence on satellite movements than do other factors.

Aging children of long-lived parents experience slower cognitive decline.

Science.gov (United States)

Dutta, Ambarish; Henley, William; Robine, Jean-Marie; Llewellyn, David; Langa, Kenneth M; Wallace, Robert B; Melzer, David

2014-10-01

Parental longevity confers lower risks for some age-related diseases in offspring. We tested the association between parental longevity and late-life cognitive decline or dementia. Data were from the Health and Retirement Study (HRS), a US national sample. Biennial cognitive assessment (Telephone Interview of Cognitive Status-Modified [TICS-m]) occurred for ages 64 years or older in 1996 through 2008 (maximum, 79 years), including physician-diagnosed memory disorder. Offspring were categorized into parental longevity groups based on gender-specific distributional cut points. Model covariates included race, respondents' education, and income status during childhood and adulthood. Offspring groups did not differ on TICS-m scores at baseline. During follow-up, offspring of two long-lived parents experienced 40% slower rates of TICS-m decline than those with no long-lived parents (95% confidence interval, 12-72; P=.003; n=4731). Increased parental longevity was also associated with lower risk of physician-diagnosed memory disorder. Estimates did not change after controlling for environmental variables. Parental longevity is associated inversely with cognitive decline and self-reported diagnosed memory disorders in aging offspring. Parental longevity may be a valuable trait for identifying early biomarkers for resistance to cognitive decline in aging. Copyright © 2014 The Alzheimer's Association. Published by Elsevier Inc. All rights reserved.

Parental support during young adulthood: Why does assistance decline with age?

OpenAIRE

Hartnett, Caroline Sten; Furstenberg, Frank; Birditt, Kira; Fingerman, Karen

2013-01-01

Previous research has found that financial transfers from parents to young adult children decline as children age and that age is one of the strongest predictors of support. Using data collected from young adults (ages 18 to 34) and their parents (ages 40 to 60; N=536 parent-child dyads), we explore the possibility that the relationship between age and financial support is mediated by offspring needs, acquisition of adult roles, or geographical and emotional closeness. We find that age-relate...

Prevalence and antimicrobial resistance among Escherichia coli and Salmonella in Ontario smallholder chicken flocks.

Science.gov (United States)

Lebert, L; Martz, S-L; Janecko, N; Deckert, A E; Agunos, A; Reid, A; Rubin, J E; Reid-Smith, R J; McEwen, S A

2018-02-01

Surveillance is an important component of an overall strategy to address antimicrobial resistant bacteria in food animals and the food chain. The poultry market has many points of entry into the Canadian food chain, and some production practices are underrepresented in terms of surveillance. For example, pathogen carriage and antimicrobial resistance surveillance data are limited in smallholder chicken flocks raised for slaughter at provincially inspected abattoirs. In Canada, antimicrobial resistance in Escherichia coli and Salmonella isolated from commercial broiler chicken flocks, slaughtered at federally inspected abattoirs, is monitored by the Canadian Integrated Program for Antimicrobial Resistance Surveillance (CIPARS). The objective of this study was to establish baseline information of antimicrobial resistance presence in E. coli and Salmonella isolated from smallholder flocks in Ontario, utilizing CIPARS collection and isolation methodologies, and to compare findings with CIPARS federally inspected abattoir data from Ontario, Canada. Five chickens per flock were sampled from 205 smallholder flocks. Of 1,025 samples, the E. coli prevalence was 99% (1,022/1,025), and 47% (483/1,022) of positive E. coli isolates were resistant to one or more of the 14 antimicrobials. Furthermore, as compared to results reported for the CIPARS commercial flocks, E. coli isolates from smallholder flocks had significantly lower resistance prevalence to six of 14 individual antimicrobials. Recovery of E. coli did not differ between federally inspected and provincially inspected flocks. Salmonella prevalence at the bird level in smallholder flocks was 0.3% (3/1,025), significantly lower (p ≪ 0.0001, 95% CI 0.080%-0.86%) than federally inspected commercial flocks. The overall differences found between the commercial and smallholder flocks may be explained by differences in poultry husbandry practices and hatchery sources. © 2017 Her Majesty the Queen in Right of Canada

Comparisons of sampling procedures and time of sampling for the detection of Salmonella in Danish infected chicken flocks raised in floor systems

DEFF Research Database (Denmark)

Gradel, K.O.; Andersen, J.; Madsen, M.

2002-01-01

other within each flock: 1) 5 pairs of socks, analysed as 5 samples, 2) 2 pairs of socks, analysed as one sample, and 3) 60 faecal samples, analysed as one pooled sample. Agreement between sampling methods was evaluated by the following statistical tests: 'Kappa', 'The adjusted rand', McNemar"s test...... in detecting S. enterica as the 60 faecal samples. In broiler flocks, 5 pairs of socks were used both in the routine samples taken at about 3 weeks of age for the establishment of infection of the flock, and as one of the follow-up samples taken shortly before slaughter age, which means that the only notable...... for marginal symmetry, Proportion of agreement P-0, P-, P-, and Odds Ratio. The highest agreement was found between the 2 types of sock sampling, while the lowest agreement was found by comparing 60 faecal samples with 5 pairs of socks. Two pairs of socks analysed as one pool appeared to be just as effective...

Time-asymptotic interactions of two ensembles of Cucker-Smale flocking particles

Science.gov (United States)

Ha, Seung-Yeal; Ko, Dongnam; Zhang, Xiongtao; Zhang, Yinglong

2017-07-01

We study the time-asymptotic interactions of two ensembles of Cucker-Smale flocking particles. For this, we use a coupled hydrodynamic Cucker-Smale system and discuss two frameworks, leading to mono-cluster and bi-cluster flockings asymptotically depending on initial configurations, coupling strengths, and the far-field decay property of communication weights. Under the proposed two frameworks, we show that mono-cluster and bi-cluster flockings emerge asymptotically exponentially fast and algebraically slow, respectively. Our asymptotic analysis uses the Lyapunov functional approach and a Lagrangian formulation of the coupled system.

Emergent behaviour of a generalized Viscek-type flocking model

International Nuclear Information System (INIS)

Ha, Seung-Yeal; Jeong, Eunhee; Kang, Moon-Jin

2010-01-01

We present a planar agent-based flocking model with a distance-dependent communication weight. We derive a sufficient condition for the asymptotic flocking in terms of the initial spatial and heading-angle diameters and a communication weight. For this, we employ differential inequalities for the spatial and phase diameters together with the Lyapunov functional approach. When the diameter of the agent's initial heading-angles is sufficiently small, we show that the diameter of the heading-angles converges to the average value of the initial heading-angles exponentially fast. As an application of flocking estimates, we also show that the Kuramoto model with a connected communication topology on the regular lattice Z d for identical oscillators exhibits a complete-phase-frequency synchronization, when coupled oscillators are initially distributed on the half circle

Hydrodynamic Equations for Flocking Models without Velocity Alignment

Science.gov (United States)

Peruani, Fernando

2017-10-01

The spontaneous emergence of collective motion patterns is usually associated with the presence of a velocity alignment mechanism that mediates the interactions among the moving individuals. Despite of this widespread view, it has been shown recently that several flocking behaviors can emerge in the absence of velocity alignment and as a result of short-range, position-based, attractive forces that act inside a vision cone. Here, we derive the corresponding hydrodynamic equations of a microscopic position-based flocking model, reviewing and extending previous reported results. In particular, we show that three distinct macroscopic collective behaviors can be observed: i) the coarsening of aggregates with no orientational order, ii) the emergence of static, elongated nematic bands, and iii) the formation of moving, locally polar structures, which we call worms. The derived hydrodynamic equations indicate that active particles interacting via position-based interactions belong to a distinct class of active systems fundamentally different from other active systems, including velocity-alignment-based flocking systems.

Educating Parents on Developmentally Age-Appropriate Learning in Preschool.

Science.gov (United States)

Brown, Mitzi C.

This practicum paper reports on a project undertaken to enhance the knowledge of age-appropriate learning for parents of 3-year-old preschoolers. The project implemented a variety of techniques and strategies to improve parent knowledge, including parent education classes, a monthly newsletter for parents that addressed current research on…

Foraging intention affects whether willow tits call to attract members of mixed-species flocks.

Science.gov (United States)

Suzuki, Toshitaka N; Kutsukake, Nobuyuki

2017-06-01

Understanding how individual behaviour influences the spatial and temporal distribution of other species is necessary to resolve the complex structure of species assemblages. Mixed-species bird flocks provide an ideal opportunity to investigate this issue, because members of the flocks are involved in a variety of behavioural interactions between species. Willow tits ( Poecile montanus ) often produce loud calls when visiting a new foraging patch to recruit other members of mixed-species flocks. The costs and benefits of flocking would differ with individual foraging behaviours (i.e. immediate consumption or caching); thus, willow tits may adjust the production of loud calls according to their foraging intention. In this study, we investigated the link between foraging decisions and calling behaviour in willow tits and tested its influence on the temporal cohesion with members of mixed-species flocks. Observations at experimental foraging patches showed that willow tits produced more calls when they consumed food items compared with when they cached them. Playback experiments revealed that these calls attracted flock members and helped to maintain their presence at foraging patches. Thus, willow tits adjusted calling behaviour according to their foraging intention, thereby coordinating the associations with members of mixed-species flocks. Our findings demonstrate the influence of individual decision-making on temporal cohesion with other species and highlight the importance of interspecific communication in mixed-species flocking dynamics.

Does mixed-species flocking influence how birds respond to a gradient of land-use intensity?

Science.gov (United States)

Mammides, Christos; Chen, Jin; Goodale, Uromi Manage; Kotagama, Sarath Wimalabandara; Sidhu, Swati; Goodale, Eben

2015-07-22

Conservation biology is increasingly concerned with preserving interactions among species such as mutualisms in landscapes facing anthropogenic change. We investigated how one kind of mutualism, mixed-species bird flocks, influences the way in which birds respond to different habitat types of varying land-use intensity. We use data from a well-replicated, large-scale study in Sri Lanka and the Western Ghats of India, in which flocks were observed inside forest reserves, in 'buffer zones' of degraded forest or timber plantations, and in areas of intensive agriculture. We find flocks affected the responses of birds in three ways: (i) species with high propensity to flock were more sensitive to land use; (ii) different flock types, dominated by different flock leaders, varied in their sensitivity to land use and because following species have distinct preferences for leaders, this can have a cascading effect on followers' habitat selection; and (iii) those forest-interior species that remain outside of forests were found more inside flocks than would be expected by chance, as they may use flocks more in suboptimal habitat. We conclude that designing policies to protect flocks and their leading species may be an effective way to conserve multiple bird species in mixed forest and agricultural landscapes. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

Flocking of the Motsch-Tadmor Model with a Cut-Off Interaction Function

Science.gov (United States)

Jin, Chunyin

2018-04-01

In this paper, we study the flocking behavior of the Motsch-Tadmor model with a cut-off interaction function. Our analysis shows that connectedness is important for flocking of this kind of model. Fortunately, we get a sufficient condition imposed only on the model parameters and initial data to guarantee the connectedness of the neighbor graph associated with the system. Then we present a theoretical analysis for flocking, and show that the system achieves consensus at an exponential rate.

Micro-flock patterns and macro-clusters in chiral active Brownian disks

Science.gov (United States)

Levis, Demian; Liebchen, Benno

2018-02-01

Chiral active particles (or self-propelled circle swimmers) feature a rich collective behavior, comprising rotating macro-clusters and micro-flock patterns which consist of phase-synchronized rotating clusters with a characteristic self-limited size. These patterns emerge from the competition of alignment interactions and rotations suggesting that they might occur generically in many chiral active matter systems. However, although excluded volume interactions occur naturally among typical circle swimmers, it is not yet clear if macro-clusters and micro-flock patterns survive their presence. The present work shows that both types of pattern do survive but feature strongly enhance fluctuations regarding the size and shape of the individual clusters. Despite these fluctuations, we find that the average micro-flock size still follows the same characteristic scaling law as in the absence of excluded volume interactions, i.e. micro-flock sizes scale linearly with the single-swimmer radius.

Foraging efficiency of a predator flock for randomly moving prey: A simulation study

Science.gov (United States)

Lee, Sang-Hee; Kwon, Ohsung

2016-03-01

Flocking behavior of animals is highly advantageous for taking food resources. The degree of the advantage is related to the ability of flock members to detect their prey and the mobility of prey individuals. In this study, to explore the relation, we constructed a model to simulate a predator flock and its randomly moving prey. The predator members have the prey detection ability, which was characterized as sensing distance, R, and a sensing angle, θ. The mobility of the prey individuals was characterized as the maximum traveling distance of an iteration time step, L. The relative flock foraging efficiency, ɛ, was defined as ɛ = 1 - (Td/Tup). Tup and Td represent the spent time for the flock to eat all prey individuals and to uptake the last remaining 10% prey, respectively. Simulation results showed that ɛ increased, maximized, and decreased with the increase of R, regardless of L. As the number of prey, N, increased, the tendency of the increasing and decreasing was diluted. The result was briefly discussed in relation to the flock foraging behavior and the development of the model toward applications for real ecosystems.

Footpad dermatitis in Dutch broiler flocks: Prevalence and factors of influence

NARCIS (Netherlands)

Jong, de I.C.; Harn, van J.; Gunnink, H.; Hindle, V.A.; Lourens, A.

2012-01-01

In some European countries, footpad dermatitis (FPD) is measured as an indicator of broiler welfare. Prevalence and seasonal variation of FPD was determined within broiler flocks (fast-growing breeds) in the Netherlands. Samples were taken from 386 Dutch flocks at 8 slaughterhouses during a period

Decay of interspecific avian flock networks along a disturbance gradient in Amazonia

Science.gov (United States)

Mokross, Karl; Ryder, Thomas B.; Côrtes, Marina Corrêa; Wolfe, Jared D.; Stouffer, Philip C

2014-01-01

Our understanding of how anthropogenic habitat change shapes species interactions is in its infancy. This is in large part because analytical approaches such as network theory have only recently been applied to characterize complex community dynamics. Network models are a powerful tool for quantifying how ecological interactions are affected by habitat modification because they provide metrics that quantify community structure and function. Here, we examine how large-scale habitat alteration has affected ecological interactions among mixed-species flocking birds in Amazonian rainforest. These flocks provide a model system for investigating how habitat heterogeneity influences non-trophic interactions and the subsequent social structure of forest-dependent mixed-species bird flocks. We analyse 21 flock interaction networks throughout a mosaic of primary forest, fragments of varying sizes and secondary forest (SF) at the Biological Dynamics of Forest Fragments Project in central Amazonian Brazil. Habitat type had a strong effect on network structure at the levels of both species and flock. Frequency of associations among species, as summarized by weighted degree, declined with increasing levels of forest fragmentation and SF. At the flock level, clustering coefficients and overall attendance positively correlated with mean vegetation height, indicating a strong effect of habitat structure on flock cohesion and stability. Prior research has shown that trophic interactions are often resilient to large-scale changes in habitat structure because species are ecologically redundant. By contrast, our results suggest that behavioural interactions and the structure of non-trophic networks are highly sensitive to environmental change. Thus, a more nuanced, system-by-system approach may be needed when thinking about the resiliency of ecological networks. PMID:24335983

9 CFR 147.21 - Flock sanitation.

Science.gov (United States)

2010-01-01

... allow the litter to be maintained in a dry condition. Frequent stirring of the litter may be necessary... status of both the flock and introduced birds should be evaluated. (h) In rearing broiler or replacement...

Corrosion resistance of tank material for flock storage in the Fukushima Daiichi Nuclear Power Plant

International Nuclear Information System (INIS)

Sano, Yuichi; Anbai, Hiromu; Takeuchi, Masayuki; Ogino, Hideki; Koizumi, Kenji

2014-01-01

The installation of the storage tank made of SS400 is under planning in the Fukushima Daiichi nuclear power plant for the flock which was generated in the coagulation process for radioactive contaminated water. The flock contains the seawater and has a possibility to make a crevice and local corrosion on the surface of the tank. Air agitation will be applied in the storage tank to prevent the accumulation of the flock and hydrogen generated by radiolysis, which will increase the diffusion of oxygen and the corrosion of SS400. In addition, the effect of radiation from the flock on the corrosion should be considered. In this study, we investigated the corrosion behavior of SS400 in the flock under the aeration-agitation condition with γ-ray irradiation. Based on the flock storage condition announced by Tokyo Electric Power Company (TEPCO), immersion tests were performed with SS400 coupons under several conditions and corrosion rates were estimated by the weight loss of the coupons. After the immersion tests, the surfaces of the coupons were observed by microscopy for evaluating the local corrosion. To evaluate corrosion mechanism in detail, electrochemical tests were also carried out. In all of these tests, the non-radioactive flock as a surrogate and artificial seawater were used. Corrosion rates of SS400 increased significantly with aeration flow rates in the seawater with/without the flock, but this tendency was weaker in the seawater with the flock, especially under the condition where coupons were buried in the flock. The electrochemical tests indicated the suppression of the cathodic reaction, i.e. dissolved oxygen reduction, in the seawater with the flock. The effect of γ-ray irradiation on the corrosion rates was not remarkable under the assumed dose rate. Microscopic analysis of the immersed coupons showed no severe corrosion including local corrosion occurred. The corrosion rate could be decreased effectively by suppressing the dissolved oxygen reduction

Effects of the level of early productivity on the lifespan of ewes in contrasting flock environments.

Science.gov (United States)

Douhard, F; Jopson, N B; Friggens, N C; Amer, P R

2016-12-01

Selection for high levels of prolificacy has allowed substantial improvements in the production efficiency of New Zealand (NZ) sheep farms, but the consequences on ewe lifetime performance are mostly unknown. In this study, the relationship between the level of prolificacy early in ewes' productive lives and their probability to survive later (i.e. stayability) was evaluated in two contrasting NZ flock environments. Records were obtained from 6605 ewes from four ram breeder flocks representing either a moderate (n=2) or a highly variable (n=2) nutritional environment. All ewes lambed for the first time at 2 years of age and were mated the following year. The number of lambs born during the first 2 years of productive life (NLB2-3) was used as a measure of early prolificacy. Effects of NLB2-3 on stayability to 4, 5, 6, 7 and 8 years old were analysed using logistic regression. Curvilinear effects (logit-transformed) were detected (Pewe stayability was reduced when the proportion of the litter that survived from birth to weaning (i.e. ewe rearing ability) was submaximal during the early productive life. High prolific ewes had a low rearing ability whatever the environment whereas the rearing ability of lowly prolific ewes was apparently more sensitive to the nutritional environment. The poor maternal performance of ewes with low levels of NLB2-3 led to a premature culling by breeders whereas the high early reproductive effort associated with high levels of NLB2-3 seemed to be at the cost of ewes' survival, even in the moderate flock environment. In conclusion, the flock environment influenced the level of early prolificacy beyond which ewe longevity was reduced. It is suggested that further selection for high and early prolificacy in NZ flocks is likely to impair ewes' lifetime productivity.

Advanced parental age and the risk of autism spectrum disorder.

Science.gov (United States)

Durkin, Maureen S; Maenner, Matthew J; Newschaffer, Craig J; Lee, Li-Ching; Cunniff, Christopher M; Daniels, Julie L; Kirby, Russell S; Leavitt, Lewis; Miller, Lisa; Zahorodny, Walter; Schieve, Laura A

2008-12-01

This study evaluated independent effects of maternal and paternal age on risk of autism spectrum disorder. A case-cohort design was implemented using data from 10 US study sites participating in the Centers for Disease Control and Prevention's Autism and Developmental Disabilities Monitoring Network. The 1994 birth cohort included 253,347 study-site births with complete parental age information. Cases included 1,251 children aged 8 years with complete parental age information from the same birth cohort and identified as having an autism spectrum disorder based on Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision criteria. After adjustment for the other parent's age, birth order, maternal education, and other covariates, both maternal and paternal age were independently associated with autism (adjusted odds ratio for maternal age > or =35 vs. 25-29 years = 1.3, 95% confidence interval: 1.1, 1.6; adjusted odds ratio for paternal age > or =40 years vs. 25-29 years = 1.4, 95% confidence interval: 1.1, 1.8). Firstborn offspring of 2 older parents were 3 times more likely to develop autism than were third- or later-born offspring of mothers aged 20-34 years and fathers aged autism risk with both maternal and paternal age has potential implications for public health planning and investigations of autism etiology.

Who Is Spreading Avian Influenza in the Moving Duck Flock Farming Network of Indonesia?

Directory of Open Access Journals (Sweden)

Joerg Henning

Full Text Available Duck populations are considered to be a reservoir of Highly pathogenic avian influenza (HPAI virus H5N1 in some agricultural production systems, as they are able to shed the virus for several days without clinical signs. Countries endemically affected with HPAI in Asia are characterised by production systems where ducks are fed on post-harvest spilled rice. During this scavenging process it is common for ducks to come into contact with other duck flocks or wild birds, thereby providing opportunities for virus spread. Effective risk management for HPAI has been significantly compromised by a limited understanding of management of moving duck flocks in these countries, despite of a small number of recent investigations. Here, for the first time, we described the management of moving duck flocks and the structure of the moving duck flock network in quantitative terms so that factors influencing the risk of HPAIV transmission can be identified. By following moving duck flock farmers over a period of 6 months in Java, Indonesia, we were able to describe the movement of flocks and to characterise the network of various types of actors associated with the production system. We used these data to estimate the basic reproductive number for HPAI virus spread. Our results suggest that focussing HPAI prevention measures on duck flocks alone will not be sufficient. Instead, the role of transporters of moving duck flocks, hatcheries and rice paddy owners, in the spread of the HPAI virus needs to be recognised.

Lighting during grow-out and Salmonella in broiler flocks

Directory of Open Access Journals (Sweden)

Bailey Richard H

2010-06-01

Full Text Available Abstract Background Lighting is used during conventional broiler grow-out to modify bird behaviour to reach the goals of production and improve bird welfare. The protocols for lighting intensity vary. In a field study, we evaluated if the lighting practices impact the burden of Salmonella in broiler flocks. Methods Conventional grow-out flocks reared in the states of Alabama, Mississippi and Texas, USA in 2003 to 2006 were sampled 1 week before harvest (n = 58 and upon arrival for processing (n = 56 by collecting feathered carcass rinsate, crop and one cecum from each of 30 birds, and during processing by collecting rinsate of 30 carcasses at pre-chilling (n = 56 and post-chilling points (n = 54. Litter samples and drag swabs of litter were collected from the grow-out houses after bird harvest (n = 56. Lighting practices for these flocks were obtained with a questionnaire completed by the growers. Associations between the lighting practices and the burden of Salmonella in the flocks were tested while accounting for variation between the grow-out farms, their production complexes and companies. Results Longer relative duration of reduced lights during the grow-out period was associated with reduced detection of Salmonella on the exterior of birds 1 week before harvest and on the broiler carcasses at the post-chilling point of processing. In addition, starting reduced lights for ≥18 hours per day later in the grow-out period was associated with decreased detection of Salmonella on the exterior of broilers arriving for processing and in the post-harvest drag swabs of litter from the grow-out house. Conclusions The results of this field study show that lighting practices implemented during broiler rearing can impact the burden of Salmonella in the flock. The underlying mechanisms are likely to be interactive.

Effect of climate and farm environment on Campylobacter spp. colonisation in Norwegian broiler flocks

DEFF Research Database (Denmark)

Jonsson, Malin E.; Chriél, Mariann; Norström, Madelaine

2012-01-01

of Campylobacter spp. in Norwegian broiler flocks and factors related to the climate and the farm environment. Data from 18,488 broiler flocks from 623 different farms during 2002–2007 were included in the study. A logistic regression analysis was conducted where Campylobacter spp. status of a broiler flock...... at the time of slaughter was defined as the dependent variable and farm was modelled as a random effect. The following factors were found to increase the probability for a broiler flock to test positive for Campylobacter spp.: daily mean temperature above 6°C during the rearing period, private water supply...

Boundary Information Inflow Enhances Correlation in Flocking

Science.gov (United States)

Cavagna, Andrea; Giardina, Irene; Ginelli, Francesco

2013-04-01

The most conspicuous trait of collective animal behavior is the emergence of highly ordered structures. Less obvious to the eye, but perhaps more profound a signature of self-organization, is the presence of long-range spatial correlations. Experimental data on starling flocks in 3D show that the exponent ruling the decay of the velocity correlation function, C(r)˜1/rγ, is extremely small, γ≪1. This result can neither be explained by equilibrium field theory nor by off-equilibrium theories and simulations of active systems. Here, by means of numerical simulations and theoretical calculations, we show that a dynamical field applied to the boundary of a set of Heisenberg spins on a 3D lattice gives rise to a vanishing exponent γ, as in starling flocks. The effect of the dynamical field is to create an information inflow from border to bulk that triggers long-range spin-wave modes, thus giving rise to an anomalously long-ranged correlation. The biological origin of this phenomenon can be either exogenous—information produced by environmental perturbations is transferred from boundary to bulk of the flock—or endogenous—the flock keeps itself in a constant state of dynamical excitation that is beneficial to correlation and collective response.

Characteristics of positive-interaction parenting style among primiparous teenage, optimal age, and advanced age mothers in Canada

OpenAIRE

Kim, Theresa H. M.; Connolly, Jennifer A.; Rotondi, Michael; Tamim, Hala

2018-01-01

Background Positive-interaction parenting early in childhood is encouraged due to its association with behavioural development later in life. The objective of this study was to examine if the level of positive-interaction parenting style differs among teen, optimal age, and advanced age mothers in Canada, and to identify the characteristics associated with positive-interaction parenting style separately for each age group. Methods This was a cross-sectional secondary analysis of the National ...

Mobile Sensing of Pedestrian Flocks in Indoor Environments using WiFi Signals

DEFF Research Database (Denmark)

Kjærgaard, Mikkel Baun; Wirz, Martin; Roggen, Daniel

2012-01-01

a cohesive whole - specifically flocks - with clustering approaches operating on three different feature sets derived from WiFi signals which are comparatively analysed. Automatic detection of flocks has several important applications, including social and psychological sensing and emergency research studies...

Spontaneous fluctuations in a zero-noise model of flocking

Science.gov (United States)

Chakraborty, Abhijit; Bhattacharya, Kunal

2016-11-01

Investigations into the complex structure and dynamics of collectively moving groups of living organisms have provided valuable insights. Understanding the emergent features, especially, the origin of fluctuations, appears to be challenging in the current scheme of models. It has been argued that flocks are poised at criticality. We present a two-dimensional self-propelled particle model where neighbourhoods and forces are defined through topology-based rules. The attractive forces are modeled in order to maintain cohesion in the flock in open-boundary conditions. We find that fluctuations occur spontaneously in the absence of any external noise. For certain values of the parameters the flock shows a high degree of order as well as scale-free decay of spatial correlations in velocity and speed. We characterize the dynamical behaviour of the system using the Lyapunov spectrum. Largest exponents being positive but small in magnitude suggest that the apparent high susceptibility may result from the system operating near the borderline of order and chaos.

Reductive Effect of Fly Screens on the Campylobacter Prevalence of Broiler Flocks in Summer

DEFF Research Database (Denmark)

Hald, B.; Sommer, Helle Mølgaard; Skovgård, H. S.

Flies act as vectors in the introduction of Campylobacter from the environment to broiler flocks. We conducted a case-control study to evaluate the effect of fly screens on the prevalence of Campylobacter in broiler flocks. Cases were 52 broiler flocks reared in 20 houses on 11 farms between June...... and November 2006, where houses were equipped with fly screens made of glass fibre mesh. The controls consisted of 70 broiler flocks reared in 25 matched houses on 13 farms without screens. Other bio-security and management routines were strictly as before the study. All broiler houses were ventilated through...... wall inlets and roof outlets. The broiler flocks were sampled at days 21, 28, and 35 and at slaughter (on day 35 to 42). Samples were tested for Campylobacter by PCR. Campylobacter prevalence data were analyzed using SAS (SAS Institute). In fly screened houses, the Campylobacter prevalence was 15.4% (8...

Flocking Transition in Confluent Tissues

Science.gov (United States)

Paoluzzi, Matteo; Giavazzi, Fabio; Macchi, Marta; Scita, Giorgio; Cerbino, Roberto; Manning, Lisa; Marchetti, Cristina

The emerging of collective migration in biological tissues plays a pivotal role in embryonic morphogenesis, wound healing and cancer invasion. While many aspects of single cell movements are well established, the mechanisms leading to coherent displacements of cohesive cell groups are still poorly understood. Some of us recently proposed a Self-Propelled Voronoi (SPV) model of dense tissues that combines self-propelled particle models and vertex models of confluent cell layers and exhibits a liquid-solid transition as a function of cell shape and cell motility. We now examine the role of cell polarization on collective cell dynamics by introducing an orientation mechanism that aligns cell polarization with local cell motility. The model predicts a density-independent flocking transition tuned by the strength of the aligning interaction, with both solid and liquid flocking states existing in different regions of parameter space. MP and MCM were supported by the Simons Foundation Targeted Grant in the Mathematical Modeling of Living Systems Number: 342354 and by the Syracuse Soft Matter Program.

To flock or fight: neurochemical signatures of divergent life histories in sparrows.

Science.gov (United States)

Goodson, James L; Wilson, Leah C; Schrock, Sara E

2012-06-26

Many bird species exhibit dramatic seasonal switches between territoriality and flocking, but whereas neuroendocrine mechanisms of territorial aggression have been extensively studied, those of seasonal flocking are unknown. We collected brains in spring and winter from male field sparrows (Spizella pusilla), which seasonally flock, and male song sparrows (Melospiza melodia), which are territorial year-round in much of their range. Spring collections were preceded by field-based assessments of aggression. Tissue series were immunofluorescently multilabeled for vasotocin, mesotocin (MT), corticotropin-releasing hormone (CRH), vasoactive intestinal polypeptide, tyrosine hydroxylase, and aromatase, and labeling densities were measured in many socially relevant brain areas. Extensive seasonal differences are shared by both species. Many measures correlate significantly with both individual and species differences in aggression, likely reflecting evolved mechanisms that differentiate the less aggressive field sparrow from the more aggressive song sparrow. Winter-specific species differences include a substantial increase of MT and CRH immunoreactivity in the dorsal lateral septum (LS) and medial amygdala of field sparrows but not song sparrows. These species differences likely relate to flocking rather than the suppression of winter aggression in field sparrows, because similar winter differences were found for two other emberizids that are not territorial in winter--dark-eyed juncos (Junco hyemalis), which seasonally flock, and eastern towhees (Pipilo erythropthalmus), which do not flock. MT signaling in the dorsal LS is also associated with year-round species differences in grouping in estrildid finches, suggesting that common mechanisms are targeted during the evolution of different life histories.

Anomalous behaviour of mutual information in finite flocks

Science.gov (United States)

Barnett, L.; Brown, J.; Bossomaier, T.

2017-11-01

The existing consensus is that flocks are poised at criticality, entailing long correlation lengths and a maximal value of Shannon mutual information in the large-system limit. We show, by contrast, that for finite flocks which do not truly break ergodicity in the long-observation-time limit, mutual information may not only fail to peak at criticality —as observed for other critical systems— but also diverge as noise tends to zero. This result carries implications for other finite-size, out-of-equilibrium systems, where observation times may vary widely compared to time scales of internal system dynamics; thus it may not be assumed that mutual information locates the phase transition.

Brucellosis outbreak in a flock of seventeen sheep in Zaria | Onoja ...

African Journals Online (AJOL)

This work is a case report of brucellosis in a flock of sheep in Zaria. The flock comprised of seventeen Yankasa sheep, 14 ewes and 3 rams, with history of 2 recent cases of abortion, a presented case of uterine prolapse and 3 cases of carpal hygroma (1st and 2nd sheep bilaterally and the 3rd sheep left unilaterally).

Within-Flock Population Dynamics of Dichelobacter nodosus

Directory of Open Access Journals (Sweden)

Laura E. Green

2017-04-01

Full Text Available Footrot causes 70–90% of lameness in sheep in Great Britain. With approximately 5% of 18 million adult sheep lame at any one time, it costs the UK sheep industry £24–84 million per year. The Gram-negative anaerobe Dichelobacter nodosus is the causative agent, with disease severity influenced by bacterial load, virulence, and climate. The aim of the current study was to characterize strains of D. nodosus isolated by culture of swabs from healthy and diseased feet of 99 ewes kept as a closed flock over a 10-month period and investigate persistence and transmission of strains within feet, sheep, and the flock. Overall 268 isolates were characterized into strains by serogroup, proline–glycine repeat (pgr status, and multi-locus variable number tandem repeat analysis (MLVA. The culture collection contained 87 unique MLVA profiles and two major MLVA complexes that persisted over time. A subset of 189 isolates tested for the virulence marker aprV2 were all positive. The two MLVA complexes (76 and 114 comprised 62 and 22 MLVA types and 237 and 28 isolates, respectively. Serogroups B, and I, and pgrB were associated with MLVA complex 76, whereas serogroups D and H were associated with MLVA complex 114. We conclude that within-flock D. nodosus evolution appeared to be driven by clonal diversification. There was no association (P > 0.05 between serogroup, pgr, or MLVA type and disease state of feet. Strains of D. nodosus clustered within sheep and were transmitted between ewes over time. D. nodosus was isolated at more than one time point from 21 feet, including 5 feet where the same strain was isolated on two occasions at an interval of 1–33 weeks. Collectively, our results indicate that D. nodosus strains persisted in the flock, spread between sheep, and possibly persisted on feet over time.

Cyclic and Coherent States in Flocks with Topological Distance

Science.gov (United States)

Bhattacherjee, Biplab; Bhattacharya, Kunal; Manna, Subhrangshu

2014-01-01

A simple model of the two dimensional collective motion of a group of mobile agents have been studied. Like birds, these agents travel in open free space where each of them interacts with the first n neighbors determined by the topological distance with a free boundary condition. Using the same prescription for interactions used in the Vicsek model with scalar noise it has been observed that the flock, in absence of the noise, arrives at a number of interesting stationary states. One of the two most prominent states is the `single sink state' where the entire flock travels along the same direction maintaining perfect cohesion and coherence. The other state is the `cyclic state' where every individual agent executes a uniform circular motion, and the correlation among the agents guarantees that the entire flock executes a pulsating dynamics i.e., expands and contracts periodically between a minimum and a maximum size of the flock. We have studied another limiting situation when refreshing rate of the interaction zone is the fastest. In this case the entire flock gets fragmented into smaller clusters of different sizes. On introduction of scalar noise a crossover is observed when the agents cross over from a ballistic motion to a diffusive motion. Expectedly the crossover time is dependent on the strength of the noise η and diverges as η → 0. An even more simpler version of this model has been studied by suppressing the translational degrees of freedom of the agents but retaining their angular motion. Here agents are the spins, placed at the sites of a square lattice with periodic boundary condition. Every spin interacts with its n = 2, 3 or 4 nearest neighbors. In the stationary state the entire spin pattern moves as a whole when interactions are anisotropic with n = 2 and 3; but it is completely frozen when the interaction is isotropic with n=4$. These spin configu

Cyclic and Coherent States in Flocks with Topological Distance

Directory of Open Access Journals (Sweden)

Biplab eBhattacherjee

2014-01-01

Full Text Available A simple model of the two dimensional collective motion of a group of mobile agents have been studied. Like birds, these agents travel in open free space where each of them interacts with the first $n$ neighbors determined by the topological distance with a free boundary condition. Using the same prescription for interactions used in the Vicsek model with scalar noise it has been observed that the flock, in absence of the noise, arrives at a number of interesting stationary states. One of the two most prominent states is the `single sink state' where the entire flock travels along the same direction maintaining perfect cohesion and coherence. The other state is the `cyclic state' where every individual agent executes a uniform circular motion, and the correlation among the agents guarantees that the entire flock executes a pulsating dynamics i.e., expands and contracts periodically between a minimum and a maximum size of the flock. We have studied another limiting situation when refreshing rate of the interaction zone is the fastest. In this case the entire flock gets fragmented into smaller clusters of different sizes. On introduction of scalar noise a crossover is observed when the agents cross over from a ballistic motion to a diffusive motion. Expectedly the crossover time is dependent on the strength of the noise $eta$ and diverges as $eta to 0$. An even more simpler version of this model has been studied by suppressing the translational degrees of freedom of the agents but retaining their angular motion. Here agents are the spins, placed at the sites of a square lattice with periodic boundary condition. Every spin interacts with its $n$ = 2, 3 or 4 nearest neighbors. In the stationary state the entire spin pattern moves as a whole when interactions are anisotropic with $n$ = 2 and 3; but it is completely frozen when the interaction is isotropic with $n=4$. These spin configu

Potential risk factors associated with contact dermatitis, lameness, negative emotional state, and fear of humans in broiler chicken flocks.

Science.gov (United States)

Bassler, A W; Arnould, C; Butterworth, A; Colin, L; De Jong, I C; Ferrante, V; Ferrari, P; Haslam, S; Wemelsfelder, F; Blokhuis, H J

2013-11-01

The objectives of this study were to 1) identify determinants of poor welfare in commercial broiler chicken flocks by studying the associations between selected resource-based measures (RBM, potential risk factors), such as litter quality and dark period, and animal-based welfare indicators (ABM), such as foot pad dermatitis and lameness, and 2) establish the breadth of effect of a risk factor by determining the range of animal welfare indicators associated with each of the risk factors (i.e., the number of ABM related to a specific RBM). Eighty-nine broiler flocks were inspected in 4 European countries (France, Italy, the United Kingdom, and the Netherlands) in a cross-sectional study. The ABM were contact dermatitis (measured using scores of foot-pad dermatitis and hock burn, respectively), lameness (measured as gait score), fear of humans (measured by the avoidance distance test and the touch test), and negative emotional state (measured using qualitative behavior assessment, QBA). In a first step, risk factors were identified by building a multiple linear regression model for each ABM. Litter quality was identified as a risk factor for contact dermatitis. Length of dark period at 3 wk old (DARK3) was a risk factor for the touch test result. DARK3 and flock age were risk factors for lameness, and the number of different stockmen and DARK3 were risk factors for QBA results. Next, the ABM were grouped according to risk factor and counted. Then, in a second step, associations between the ABM were investigated using common factor analysis. The breadth of a risk factor's effect was judged by combining the number (count) of ABM related to this factor and the strength of association between these ABM. Flock age and DARK3 appeared to affect several weakly correlated ABM, thus indicating a broad range of effects. Our findings suggest that manipulation of the predominant risk factors identified in this study (DARK3, litter quality, and slaughter age) could generate

Study of Adolescents Perceived Parenting Styles Based on their Gender and Age

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صادق تقی لو

2017-12-01

Full Text Available Parenting styles play a major role in determining the life styles of adolescents and that is why they share a special significance. The present study was done with the aim to investigate adolescents’ perceived parenting styles based on their gender and age. The study was conducted by a post-event method and with a sample size of 623 subjects (311 female and 312 male, who were selected by the multistage sampling method. Data were analyzed, after being collected by the Baumrind Parenting Styles Questionnaire, using multivariate analysis of variance. The results indicated that the main effects of gender and age are significant at 0.01 level. Parents’ interaction with boys is more authoritarian and with girls more authoritative; also compared with adolescents less than 17 years, they interact with adolescents 17 years old more permissively. The interaction effects of gender and age were significant at 0.05 level only in the permissive parenting style. This means that unlike the girls, parents use more and more the permissive parenting style along with increasing age of adolescent teenage boys. It was concluded that the interaction patterns of parents with children are not fixed and these patterns vary according to gender and age of the children.

Investigation of parenting attitudes of parents whose children are at preschool age

Directory of Open Access Journals (Sweden)

Erhan Alabay

2017-09-01

Full Text Available The purpose of this study is to examine parental attitudes of parents with children between 48-72 months old, depending upon different variables while they are raising their children. Out of quantitative research patterns, descriptive survey model was used in the research. As data collecting tool, Parental Attitude Scale (PAS, developed by Demir and Şendil (2008 and which consists of 46 items in total and determines democratic, authoritative, overprotective, and permissive attitudes of parents in raising children was used. The sample of the research was composed of 422 parents who were selected in accordance with random sampling method and residing in İstanbul Province, Pendik District. Within context of the research, gender of parents, educational background, average income, family structure, number of children, whether or not they joined a seminar on pediatric development, the amount of time they spend with their child and the gender of the child were determined as independent variables and it was examined, based on these independent variables, whether there is a significant difference in parental attitude points which are dependent variables. In the analysis of data obtained from the research, it was concluded that non-employed parents are relatively more protective than employed parents, the fact that parents joined a seminar on pediatric development decreased the authoritative and overprotective attitude average points and parents adopted a more authoritative manner towards boys compared to girls. Also, in line with research findings, a significant difference was detected on parental attitude scale sub-dimension points depending on the independent variables of parents’ ages, educational background, income level and number of children.

Organic Turkey Flocks: A Reservoir of Streptococcus gallolyticus subspecies gallolyticus.

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Jochen Schulz

Full Text Available Streptococcus gallolyticus subspecies gallolyticus (S. gallolyticus can colonise the gastrointestinal tract of humans and animals and is known to cause similar infections in both humans and animals. Data about the spread or prevalence in farm animals are missing. In this study, Trypton Soya Agar was modified to a selective medium enabling the isolation and quantification of S. gallolyticus from faecal samples. The bacterium was observed in 82 out of 91 faecal samples obtained from 18 different organic turkey flocks. The prevalence of shedding birds was estimated by the number of positive fresh droppings and reached up to 100% on most farms. Furthermore, for the first time S. gallolyticus was quantified in faeces from poultry flocks. The median of colony forming units (CFU per gramme faeces was 3.6 x 10(5 CFU/g. Typing of one isolate from each positive faecal sample by multilocus sequence typing delivered 24 sequence types (STs. Most of the isolates belonged to the clonal complex CC58. The same STs of this complex were detected in up to six different flocks. Partly, these flocks were located in various regions and stocked with varying breeding lines. Regarding the biochemical profiles of the same STs from different farms, the results did not contradict a spread of specific STs in the organic turkey production. Moreover, checking the pubMLST database revealed that STs found in this study were also found in other animal species and in humans. The high detection rate and the number of S. gallolyticus in turkey faeces indicate that this bacterium probably belongs to the common microbiota of the gastrointestinal tract of turkeys from organic flocks. Furthermore, the findings of this study support the suggestion of a possible interspecies transmission.

Prevalence and characterization of Campylobacter jejuni isolated from pasture flock poultry.

Science.gov (United States)

Hanning, Irene; Biswas, Debabrata; Herrera, Paul; Roesler, Mary; Ricke, Steven C

2010-09-01

The growing interest in organic and natural foods warrants a greater need for information on the food safety of these products. In this study, samples were taken from 2 pasture flock farms (N = 178; feed, water, drag swabs, and insect traps), pasture flock retail carcasses (N = 48) and 1 pasture flock processing facility (N = 16) over a period of 8 mo. A total of 105 Campylobacter isolates were obtained from 53 (30%), 36 (75%), and 16 (100%) samples from the farms, retail carcasses, and processing facility, respectively. Of the 105 isolates collected, 65 were C. jejuni, 31 were C. coli, and 9 were other Campylobacter spp. Using PCR, the C. jejuni isolates were further analyzed for virulence genes involved in colonization and survival (flaA, flaC, cadF, dnaJ, racR, cbrR), invasion (virB11, ciaB, pldA), protection against harsh conditions (sodB, htrA, clpA), toxin production (cdtA, cdtB, cdtC), siderophore transport (ceuE), and ganglioside mimicry (wlaN). In addition, the short variable region of the flaA locus (flaA SVR) was sequenced to determine the genetic diversity of the C. jejuni isolates. The flaA SVR diversity indices increased along the farm to carcass continuum. PCR-based analysis indicated a low prevalence of 5 genes involved in colonization (dnaJ, ciaB, pldA, racR, virB11). The results of this survey indicate that the prevalence of Campylobacter on organic retail carcasses is similar to prevalence reports of Campylobacter on conventional retail carcasses. However, the genetic diversity of the flaA SVR genotypes increased along the farm to carcass continuum that contrasted with conventional poultry studies. Campylobacter jejuni is a leading cause of foodborne illness with poultry and poultry products being leading sources of infection. Free-range and pasture flock chickens are becoming more popular; however, there is an inherent biosecurity risk that can increase the prevalence of foodborne pathogens in these flocks. This study aimed to determine sources

Functional Traits, Flocking Propensity, and Perceived Predation Risk in an Amazonian Understory Bird Community.

Science.gov (United States)

Martínez, Ari E; Gomez, Juan P; Ponciano, José Miguel; Robinson, Scott K

2016-05-01

Within a community, different species might share similar predation risks, and, thus, the ability of species to signal and interpret heterospecific threat information may determine species' associations. We combined observational, experimental, and phylogenetic approaches to determine the extent to which evolutionary history and functional traits determined flocking propensity and perceived predation risk (response to heterospecific alarm calls) in a lowland Amazonian bird community. We predicted that small birds that feed myopically and out in the open would have higher flocking propensities and account for a higher proportion of positive responses to alarms. Using generalized linear models and the incorporation of phylogeny on data from 56 species, our results suggest that phylogenetic relationships alongside body size, foraging height, vegetation density, and response to alarm calls influence flocking propensity. Conversely, phylogenetic relationships did not influence response to heterospecific alarm calls. Among functional traits, however, foraging strategy, foraging density, and flocking propensity partially explained responses to alarm calls. Our results suggest that flocking propensity and perceived predation risk are positively related and that functional ecological traits and evolutionary history may explain certain species' associations.

Role of batch depletion of broiler houses on the occurrence of Campylobacter spp. in chicken flocks

DEFF Research Database (Denmark)

Hald, Birthe; Rattenborg, Erik; Madsen, Mogens

2001-01-01

Aims: The effect of batch depletion of broiler houses for campylobacter occurrence in broiler flocks was estimated in 10 flocks, each comprising a separate female and male batch. Methods and Results: The chicks were sampled first bq; cloacal swabs in the broiler houses before the start...... that batch depletion of broiler houses increased the prevalence of Campylobacter spp.-infected broilers in the flocks, that the introduction occurred a hen catching the first batch, and that campylobacter spreads through the entire flock within a week. Significance and Impact of the Study: The results from...

Parenting style in childhood and mortality risk at older ages: a longitudinal cohort study.

Science.gov (United States)

Demakakos, Panayotes; Pillas, Demetris; Marmot, Michael; Steptoe, Andrew

2016-08-01

Parenting style is associated with offspring health, but whether it is associated with offspring mortality at older ages remains unknown. We examined whether childhood experiences of suboptimal parenting style are associated with increased risk of death at older ages. Longitudinal cohort study of 1964 community-dwelling adults aged 65-79 years. The association between parenting style and mortality was inverse and graded. Participants in the poorest parenting style score quartile had increased risk of death (hazard ratio (HR) = 1.72, 95% CI 1.20-2.48) compared with those in the optimal parenting style score quartile after adjustment for age and gender. Full adjustment for covariates partially explained this association (HR = 1.49, 95% CI 1.02-2.18). Parenting style was inversely associated with cancer and other mortality, but not cardiovascular mortality. Maternal and paternal parenting styles were individually associated with mortality. Experiences of suboptimal parenting in childhood are associated with increased risk of death at older ages. © The Royal College of Psychiatrists 2016.

SEROMONITORING OF AVIAN INFLUENZA H9 SUBTYPE IN BREEDERS AND COMMERCIAL LAYER FLOCKS

Directory of Open Access Journals (Sweden)

M. Numan, M. Siddique and M. S. Yousaf1

2005-07-01

Full Text Available A serological survey for detection of antibodies against avian influenza virus (AIV subtype H9 in vaccinated layer flocks was carried out. Serum samples were divided into age groups A, B, C, D (commercial layers and E, F, G, H (layer breeders. Haemagglutination inhibition (HI test was performed to determine serum antibodies against AIV-H9 subtype. Geometric mean titer (GMT values were calculated. Results showed the level of protection of vaccinated birds was satisfactory.

Estimation of the sensitivity of various environmental sampling methods for detection of Salmonella in duck flocks.

Science.gov (United States)

Arnold, Mark E; Mueller-Doblies, Doris; Gosling, Rebecca J; Martelli, Francesca; Davies, Robert H

2015-01-01

Reports of Salmonella in ducks in the UK currently rely upon voluntary submissions from the industry, and as there is no harmonized statutory monitoring and control programme, it is difficult to compare data from different years in order to evaluate any trends in Salmonella prevalence in relation to sampling methodology. Therefore, the aim of this project was to assess the sensitivity of a selection of environmental sampling methods, including the sampling of faeces, dust and water troughs or bowls for the detection of Salmonella in duck flocks, and a range of sampling methods were applied to 67 duck flocks. Bayesian methods in the absence of a gold standard were used to provide estimates of the sensitivity of each of the sampling methods relative to the within-flock prevalence. There was a large influence of the within-flock prevalence on the sensitivity of all sample types, with sensitivity reducing as the within-flock prevalence reduced. Boot swabs (individual and pool of four), swabs of faecally contaminated areas and whole house hand-held fabric swabs showed the overall highest sensitivity for low-prevalence flocks and are recommended for use to detect Salmonella in duck flocks. The sample type with the highest proportion positive was a pool of four hair nets used as boot swabs, but this was not the most sensitive sample for low-prevalence flocks. All the environmental sampling types (faeces swabs, litter pinches, drag swabs, water trough samples and dust) had higher sensitivity than individual faeces sampling. None of the methods consistently identified all the positive flocks, and at least 10 samples would be required for even the most sensitive method (pool of four boot swabs) to detect a 5% prevalence. The sampling of dust had a low sensitivity and is not recommended for ducks.

Distance Constrained Based Adaptive Flocking Control for Multiagent Networks with Time Delay

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Qing Zhang

2015-01-01

Full Text Available The flocking control of multiagent system is a new type of decentralized control method, which has aroused great attention. The paper includes a detailed research in terms of distance constrained based adaptive flocking control for multiagent system with time delay. Firstly, the program on the adaptive flocking with time delay of multiagent is proposed. Secondly, a kind of adaptive controllers and updating laws are presented. According to the Lyapunov stability theory, it is proved that the distance between agents can be larger than a constant during the motion evolution. What is more, velocities of each agent come to the same asymptotically. Finally, the analytical results can be verified by a numerical example.

Modeling and Flocking Consensus Analysis for Large-Scale UAV Swarms

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Li Bing

2013-01-01

Full Text Available Recently, distributed coordination control of the unmanned aerial vehicle (UAV swarms has been a particularly active topic in intelligent system field. In this paper, through understanding the emergent mechanism of the complex system, further research on the flocking and the dynamic characteristic of UAV swarms will be given. Firstly, this paper analyzes the current researches and existent problems of UAV swarms. Afterwards, by the theory of stochastic process and supplemented variables, a differential-integral model is established, converting the system model into Volterra integral equation. The existence and uniqueness of the solution of the system are discussed. Then the flocking control law is given based on artificial potential with system consensus. At last, we analyze the stability of the proposed flocking control algorithm based on the Lyapunov approach and prove that the system in a limited time can converge to the consensus direction of the velocity. Simulation results are provided to verify the conclusion.

The interaction between parenting and children's cortisol reactivity at age 3 predicts increases in children's internalizing and externalizing symptoms at age 6.

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Barrios, Chelsey S; Bufferd, Sara J; Klein, Daniel N; Dougherty, Lea R

2017-10-01

Little is known about the role of stress reactivity in the emergence of psychopathology across early childhood. In this longitudinal study, we tested the hypothesis that child cortisol reactivity at age 3 moderates associations between early parenting and children's internalizing and externalizing symptoms from age 3 to age 6. One hundred and sixty children were assessed at age 3, and 135 children were reassessed at age 6. At age 3, we exposed children to stress-inducing laboratory tasks, during which we obtained four salivary cortisol samples, and parental hostility was assessed using an observational parent-child interaction task. At ages 3 and 6, child psychiatric symptoms were assessed using a clinical interview with parents. The results indicated that the combination of high child cortisol reactivity and high observed parental hostility at age 3 was associated with greater concurrent externalizing symptoms at age 3 and predicted increases in internalizing and externalizing symptoms from age 3 to age 6. Findings highlight that increased stress reactivity, within the context of hostile parenting, plays a role in the emergence of psychopathology from preschool to school entry.

Child and parent predictors of picky eating from preschool to school age.

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Steinsbekk, Silje; Bonneville-Roussy, Arielle; Fildes, Alison; Llewellyn, Clare H; Wichstrøm, Lars

2017-07-06

Picky eating is prevalent in childhood. Because pickiness concerns parents and is associated with nutrient deficiency and psychological problems, the antecedents of pickiness need to be identified. We propose an etiological model of picky eating involving child temperament, sensory sensitivity and parent-child interaction. Two cohorts of 4-year olds (born 2003 or 2004) in Trondheim, Norway were invited to participate (97.2% attendance; 82.0% consent rate, n = 2475) and a screen-stratified subsample of 1250 children was recruited. We interviewed 997 parents about their child's pickiness and sensory sensitivity using the Preschool Age Psychiatric Assessment (PAPA). Two years later, 795 of the parents completed the interview. The Children's Behavior Questionnaire (CBQ) was used to assess children's temperament. Parent- child interactions were videotaped and parental sensitivity (i.e., parental awareness and appropriate responsiveness to children's verbal and nonverbal cues) and structuring were rated using the Emotional Availability Scales (EAS). At both measurement times, 26% of the children were categorized as picky eaters. Pickiness was moderately stable from preschool to school age (OR = 5.92, CI = 3.95, 8.86), and about half of those who displayed pickiness at age 4 were also picky eaters two years later. While accounting for pickiness at age 4, sensory sensitivity at age 4 predicted pickiness at age 6 (OR = 1.25, CI = 1.08, 2.23), whereas temperamental surgency (OR = 0.88, CI = 0.64, 1.22) and negative affectivity (OR = 1.17, CI = 0.75, 1.84) did not. Parental structuring was found to reduce the risk of children's picky eating two years later (OR = 0.90, CI = 0.82, 0.99), whereas parental sensitivity increased the odds for pickiness (OR = 1.10, CI = 1.00, 1.21). Although pickiness is stable from preschool to school age, children who are more sensory sensitive are at higher risk for pickiness two years later, as are children whose

High prevalence of turkey parvovirus in turkey flocks from Hungary experiencing enteric disease syndromes.

Science.gov (United States)

Palade, Elena Alina; Demeter, Zoltán; Hornyák, Akos; Nemes, Csaba; Kisary, János; Rusvai, Miklós

2011-09-01

Samples collected in 2008 and 2009, from 49 turkey flocks of 6 to 43 days in age and presenting clinical signs of enteric disease and high mortality, were tested by polymerase chain reaction and reverse transcription-polymerase chain reaction for the presence of viruses currently associated with enteric disease (ED) syndromes: astrovirus, reovirus, rotavirus, coronavirus, adenovirus, and parvovirus. Turkey astroviruses were found in 83.67% of the cases and turkey astrovirus 2 (TAst-2) in 26.53%. The investigations directly demonstrated the high prevalence of turkey parvovirus (TuPV) in 23 flocks (46.9%) experiencing signs of ED, making this pathogen the second most identified after astroviruses. Phylogenetic analysis on a 527 base pair-long region from the NS1 gene revealed two main clusters, a chicken parvovirus (ChPV) and a TuPV group, but also the presence of a divergent branch of tentatively named "TuPV-like ChPV" strains. The 23 Hungarian TuPV strains were separately positioned in two groups from the American origin sequences in the TuPV cluster. An Avail-based restriction fragment length polymorphism assay has also been developed for the quick differentiation of TuPV, ChPV, and divergent TuPV-like ChPV strains. As most detected enteric viruses have been directly demonstrated in healthy turkey flocks as well, the epidemiology of this disease complex remains unclear, suggesting that a certain combination of pathogens, environmental factors, or both are necessary for the development of clinical signs.

Quinolone- and ß-lactam-resistance in Escherichia coli from Danish and Italian broiler flocks

DEFF Research Database (Denmark)

Bortolaia, Valeria; Guardabassi, Luca; Bisgaard, Magne

/ml), ampicillin (32 µg/ml), cefotaxime (2 µg/ml) or ceftiofur (8 µg/ml). The ß-glucuronidase test was performed for verification of presumptive E. coli. The same methods were used to analyse sock samples collected from six Italian broiler flocks. PCR with primers for the CTX-M-type ESBLs was performed...... usage and none of the flocks was positive for cephalosporin-resistant E. coli. In Italy, resistance to ciprofloxacin was detected in all flocks and resistances to ceftiofur and cefotaxime were detected in five flocks. Primers specific for the CTX-M-type ESBLs generated PCR amplicons from isolates from...

Radiocaesium activity in sheep: variation within flocks and with time

International Nuclear Information System (INIS)

Pearce, J.; Moss, B.W.; Colgan, P.A.; Scully, B.J.

1990-01-01

The radiocaesium levels in sheep, assessed by in vivo monitoring, increased rapidly and in a parallel manner in both lambs and ewes grazing upland pasture in Ireland known to be contaminated with post-Chernobyl fallout for at least 10 weeks after the animals were moved on to this pasture. Considerable variability was noted in the individual animal radiocaesium values within all the flocks studied. A comparison of the radiocaesium contents of some flocks in 1987, 1988 and 1989 show similar values for the different years. (author)

Parental age and child growth and development: child health check-up data.

Science.gov (United States)

Iwayama, Mariko; Kira, Ryutaro; Kinukawa, Naoko; Sakai, Yasunari; Torisu, Hiroyuki; Sanefuji, Masafumi; Ishizaki, Yoshito; Nose, Yoshiaki; Matsumoto, Toshimichi; Hara, Toshiro

2011-10-01

The aim of the present study was to determine whether parental age has any influence on child health. Well-baby check-up data at 1 month and at 12 months of age were used. The trends of parental age in association with growth measurements, incidence of physical and developmental abnormalities, occurrence of low birthweight, and maternal history of spontaneous abortion were analyzed. Associations between increasing paternal age and incidence of psychomotor developmental delay at 12 months, increasing paternal and maternal age and increasing birthweight, and increasing parental age and higher incidence of history of spontaneous abortion were found. The incidence of low-birthweight infants was significantly decreased with increasing paternal age. Not only increasing maternal age but also increasing paternal age have influences on child development and growth in the general population. © 2011 The Authors. Pediatrics International © 2011 Japan Pediatric Society.

Fluctuation-driven flocking movement in three dimensions and scale-free correlation.

Science.gov (United States)

Niizato, Takayuki; Gunji, Yukio-Pegio

2012-01-01

Recent advances in the study of flocking behavior have permitted more sophisticated analyses than previously possible. The concepts of "topological distances" and "scale-free correlations" are important developments that have contributed to this improvement. These concepts require us to reconsider the notion of a neighborhood when applied to theoretical models. Previous work has assumed that individuals interact with neighbors within a certain radius (called the "metric distance"). However, other work has shown that, assuming topological interactions, starlings interact on average with the six or seven nearest neighbors within a flock. Accounting for this observation, we previously proposed a metric-topological interaction model in two dimensions. The goal of our model was to unite these two interaction components, the metric distance and the topological distance, into one rule. In our previous study, we demonstrated that the metric-topological interaction model could explain a real bird flocking phenomenon called scale-free correlation, which was first reported by Cavagna et al. In this study, we extended our model to three dimensions while also accounting for variations in speed. This three-dimensional metric-topological interaction model displayed scale-free correlation for velocity and orientation. Finally, we introduced an additional new feature of the model, namely, that a flock can store and release its fluctuations.

Fluctuation-driven flocking movement in three dimensions and scale-free correlation.

Directory of Open Access Journals (Sweden)

Takayuki Niizato

Full Text Available Recent advances in the study of flocking behavior have permitted more sophisticated analyses than previously possible. The concepts of "topological distances" and "scale-free correlations" are important developments that have contributed to this improvement. These concepts require us to reconsider the notion of a neighborhood when applied to theoretical models. Previous work has assumed that individuals interact with neighbors within a certain radius (called the "metric distance". However, other work has shown that, assuming topological interactions, starlings interact on average with the six or seven nearest neighbors within a flock. Accounting for this observation, we previously proposed a metric-topological interaction model in two dimensions. The goal of our model was to unite these two interaction components, the metric distance and the topological distance, into one rule. In our previous study, we demonstrated that the metric-topological interaction model could explain a real bird flocking phenomenon called scale-free correlation, which was first reported by Cavagna et al. In this study, we extended our model to three dimensions while also accounting for variations in speed. This three-dimensional metric-topological interaction model displayed scale-free correlation for velocity and orientation. Finally, we introduced an additional new feature of the model, namely, that a flock can store and release its fluctuations.

Parenting style in childhood and mortality risk at old age: a longitudinal cohort study

Science.gov (United States)

Demakakos, Panayotes; Pillas, Demetris; Marmot, Michael; Steptoe, Andrew

2018-01-01

Background Parenting style is associated with offspring health, but whether it is associated with offspring mortality at older ages remains unknown. Aims We examined whether childhood experiences of suboptimal parenting style are associated with increased risk of death at older ages. Method Longitudinal cohort study of 1,964 community-dwelling adults aged 65 to 79 years. Results The association between parenting style and mortality was inverse and graded. Participants in the poorest parenting style score quartile had increased risk of death (hazard ratio (HR) 1.72; 95% CI, 1.20-2.48) compared with those in the optimal parenting style score quartile after adjustment for age and sex. Full adjustment for covariates partially explained this association (HR 1.49; 95% CI, 1.02-2.18). Parenting style was inversely associated with cancer and other mortality, but not cardiovascular mortality. Maternal and paternal parenting styles were individually associated with mortality. Conclusions Experiences of suboptimal parenting in childhood are associated with increased risk of death at older ages. PMID:26941265

Effect of climate and farm environment on Campylobacter spp. colonisation in Norwegian broiler flocks.

Science.gov (United States)

Jonsson, Malin E; Chriél, Mariann; Norström, Madelaine; Hofshagen, Merete

2012-11-01

Campylobacteriosis is the most frequently reported zoonosis in the EU. A recent report states that between 50% and 80% of the human campylobacteriosis cases could be attributed to broiler as a reservoir. The current study was conducted to investigate associations between the presence of Campylobacter spp. in Norwegian broiler flocks and factors related to the climate and the farm environment. Data from 18,488 broiler flocks from 623 different farms during 2002-2007 were included in the study. A logistic regression analysis was conducted where Campylobacter spp. status of a broiler flock at the time of slaughter was defined as the dependent variable and farm was modelled as a random effect. The following factors were found to increase the probability for a broiler flock to test positive for Campylobacter spp.: daily mean temperature above 6°C during the rearing period, private water supply, presence of other livestock farms within a distance of 2 km, presence of other broiler farms within a distance of 4 km with flocks positive for Campylobacter spp. within 30 days prior to slaughter, heavy rainfall 11-30 days prior to slaughter, region and year. Daily mean temperature below 0°C reduced the probability. The study emphasises the importance of the farm environment and the climate for the occurrence of Campylobacter spp. in broiler flocks. The farm environment is probably a part of the Campylobacter spp. pathway into and between broiler flocks where farmyard run-off and humans or flies entering the houses might constitute vehicles transporting the organism. Fly activity is temperature-driven and flies might be a part of the explanation of the increased risk for Campylobacter spp. related to increased temperature demonstrated in the study. Copyright © 2012 Elsevier B.V. All rights reserved.

Conium maculatum (poison hemlock) toxicosis in a flock of range turkeys.

Science.gov (United States)

Frank, A A; Reed, W M

1987-01-01

Five 20-week-old tom turkeys from a flock of range turkeys were presented for examination; the flock had a history of salivation, tremors, paralysis, and increased mortality. Necropsy revealed numerous seeds identified as seeds from Conium maculatum (poison hemlock) within the crop, proventriculus, and gizzard. Histopathologic alterations were limited to catarrhal enteritis. Clinical signs of Conium maculatum toxicosis abated after the turkeys were removed from their range, which was infested with poison hemlock.

A flocking algorithm for multi-agent systems with connectivity preservation under hybrid metric-topological interactions.

Science.gov (United States)

He, Chenlong; Feng, Zuren; Ren, Zhigang

2018-01-01

In this paper, we propose a connectivity-preserving flocking algorithm for multi-agent systems in which the neighbor set of each agent is determined by the hybrid metric-topological distance so that the interaction topology can be represented as the range-limited Delaunay graph, which combines the properties of the commonly used disk graph and Delaunay graph. As a result, the proposed flocking algorithm has the following advantages over the existing ones. First, range-limited Delaunay graph is sparser than the disk graph so that the information exchange among agents is reduced significantly. Second, some links irrelevant to the connectivity can be dynamically deleted during the evolution of the system. Thus, the proposed flocking algorithm is more flexible than existing algorithms, where links are not allowed to be disconnected once they are created. Finally, the multi-agent system spontaneously generates a regular quasi-lattice formation without imposing the constraint on the ratio of the sensing range of the agent to the desired distance between two adjacent agents. With the interaction topology induced by the hybrid distance, the proposed flocking algorithm can still be implemented in a distributed manner. We prove that the proposed flocking algorithm can steer the multi-agent system to a stable flocking motion, provided the initial interaction topology of multi-agent systems is connected and the hysteresis in link addition is smaller than a derived upper bound. The correctness and effectiveness of the proposed algorithm are verified by extensive numerical simulations, where the flocking algorithms based on the disk and Delaunay graph are compared.

A flocking algorithm for multi-agent systems with connectivity preservation under hybrid metric-topological interactions.

Directory of Open Access Journals (Sweden)

Chenlong He

Full Text Available In this paper, we propose a connectivity-preserving flocking algorithm for multi-agent systems in which the neighbor set of each agent is determined by the hybrid metric-topological distance so that the interaction topology can be represented as the range-limited Delaunay graph, which combines the properties of the commonly used disk graph and Delaunay graph. As a result, the proposed flocking algorithm has the following advantages over the existing ones. First, range-limited Delaunay graph is sparser than the disk graph so that the information exchange among agents is reduced significantly. Second, some links irrelevant to the connectivity can be dynamically deleted during the evolution of the system. Thus, the proposed flocking algorithm is more flexible than existing algorithms, where links are not allowed to be disconnected once they are created. Finally, the multi-agent system spontaneously generates a regular quasi-lattice formation without imposing the constraint on the ratio of the sensing range of the agent to the desired distance between two adjacent agents. With the interaction topology induced by the hybrid distance, the proposed flocking algorithm can still be implemented in a distributed manner. We prove that the proposed flocking algorithm can steer the multi-agent system to a stable flocking motion, provided the initial interaction topology of multi-agent systems is connected and the hysteresis in link addition is smaller than a derived upper bound. The correctness and effectiveness of the proposed algorithm are verified by extensive numerical simulations, where the flocking algorithms based on the disk and Delaunay graph are compared.

Fixed-Wing UAVs Flock Control through Cohesion and Repulsion Behaviours Combined with a Leadership

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Cezary Kownacki

2016-02-01

Full Text Available The aim of this paper is to present a novel approach to swarm control of small fixed-wing UAVs, which combines only two flocking behaviours with a leadership feature. In the presented approach, two fundamental rules of Reynolds flocking are applied, i.e., cohesion and repulsion, as the base of a decentralized control of self-organization of the flock. These rules are combined with a leadership feature, which is responsible for a global behaviour of guidance, as in the case of animals. Such a bio-inspired combination allows the achievement of a coherent collective flight of a flock of fixed-wing UAVs without applying formal behaviours of migration and alignment. This highly simplifies an implementation of the algorithm. The presented results include both numerical simulations and experimental flights, which validate the hardware implementation of the approach.

Flocking multiple microparticles with automatically controlled optical tweezers: solutions and experiments.

Science.gov (United States)

Chen, Haoyao; Wang, Can; Lou, Yunjiang

2013-06-01

This paper presents an efficient approach to achieve microparticles flocking with robotics and optical tweezers technologies. All particles trapped by optical tweezers can be automatically moved toward a predefined region without collision. The main contribution of this paper lies in the proposal of several solutions to the flocking manipulation of microparticles in microenvironments. First, a simple flocking controller is proposed to generate the desired positions and velocities for particles' movement. Second, a velocity saturation method is implemented to prevent the desired velocities from exceeding a safe limit. Third, a two-layer control architecture is proposed for the motion control of optical tweezers. This architecture can help make many robotic manipulations achievable under microenvironments. The proposed approach with these solutions can be applied to many bioapplications especially in cell engineering and biomedicine. Experiments on yeast cells with a robot-tweezers system are finally performed to verify the effectiveness of the proposed approach.

The epizootiology of Eimeria infections in commercial broiler chickens where anticoccidial drug programs were employed in six successive flocks to control coccidiosis.

Science.gov (United States)

Chapman, H D; Barta, J R; Hafeez, M A; Matsler, P; Rathinam, T; Raccoursier, M

2016-08-01

The course of natural Eimeria infections in 6 successive broiler flocks at a commercial farm comprising 4 houses, where different anticoccidial drug programs were employed, was studied by counting the number of oocysts in the litter at weekly intervals. The course of infection in all flocks followed a bell shaped curve in which oocyst numbers, initially low, increased to a peak ranging from 36 × 10(3) to 74 × 10(3) oocysts/g (OPG) of litter around 3 to 4 wk of age. Numbers subsequently declined to 3 × 10(3) to 15 × 10(3) OPG. Oocysts could be detected between flocks when birds were not present. Species of Eimeria identified included E. acervulina, E. maxima, and E. tenella Despite the presence of large numbers of oocysts in the litter, coccidial lesions were not observed in the intestines of the birds. The performance of broilers at the study site was comparable to that of other farms in the area where birds from the same settlement were reared to a similar age using the same drug programs. The results indicate the ubiquitous nature of Eimeria spp. infections in commercial broilers despite prophylactic medication. © 2016 Poultry Science Association Inc.

Role conflict and ambivalence in the aged-parent-adult-child relationship

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Xinjia Yu

2017-06-01

Full Text Available Purpose – The parent-child relationship is important to the solidarity of families and the emotional well-being of family members. Since people are more dependent on their close social relationships as they age, understanding the quality of relationships between aged parents and their adult children is a critical topic. Previous research shows that this relationship is complicated with both kinship and ambivalence. However, there is little research on the causes of this complexity. This paper proposes a role model to explain this complexity by studying the leadership transition within a family as the child grows. Design/methodology/approach – In this paper, we proposed a novel perception to understand this transition process and explain related problems based on the analysis of the leader-follower relationship between the parents and their children. Findings – When a child is born, his/her parents become the leader of this family because of their abilities, responsibilities and the requirements of the infant. This leader-follower role structure will last a long time in this family. Decades later, when the parents become old and the child grows up, the inter-generational contracts within the family and the requirement of each members change. This transition weakens the foundation of the traditional leader-follower role structure within the family. If either the parent or the child does not want to accept their new roles, both of them will suffer and struggle in this relationship. This role conflict will cause ambivalence in the relationship between aged parents and their adult children. Originality/value – Based on the quantitative study model provided in this paper, we can moderate the relationships between aged parents and their adult children. This effort is meaningful in enhancing the quality of life and emotional wellbeing for senior citizens.

Prevalence and risk factors for Listeria monocytogenes in broiler flocks in Shiraz, southern Iran.

Science.gov (United States)

Hosseinzadeh, Saeid; Shekarforoush, Seyed Shahram; Ansari-Lari, Maryam; EsalatPanah-Fard Jahromi, Mehdi; Berizi, Enayat; Abdollahi, Mostafa

2012-06-01

Listeria monocytogenes has been identified as an important foodborne pathogen in recent years. In humans, it most commonly affects pregnant women, neonates, children, elderly people, and persons with a suppressed immune system. It could contaminate both raw and cooked meat and poultry products. Studies regarding prevalence and risk factors of L. monocytogenes in broilers flocks are limited. Therefore, the present study was conducted to determine the prevalence and risk factors for L. monocytogenes in poultry flocks in Shiraz, southern Iran. During August to September 2009, in total, 100 broiler flocks were selected at slaughter, and 21 specimens were collected from cloacal samples from each flock. Polymerase chain reaction (PCR) was performed on the samples enriched in buffered Listeria enrichment broth (BLEB), using specific primers. Furthermore, enriched samples in BLEB and/or BLEB treated with 5% KOH were subcultured on Palcam medium. Data about farm and flocks were collected using a structured questionnaire. The prevalence of L. monocytogenes was 7% (95% CI, 2-12%) and 1% using PCR and culture, respectively. Results showed that using antibiotics during rearing period was dramatically reduced the rate of isolation (odds ratio [OR]=0.07, p=0.03), whereas house capacity of more than 10,000 birds (OR=24.03, p=0.04) and number of houses (OR=2, p=0.02) significantly increased the prevalence. The correlation between poor management of large poultry flocks and increasing the risk of contamination was more likely due to the recontamination of cooked poultry/undercooking or cross-contamination of other ready-to-eat foods.

Antimicrobial use surveillance in broiler chicken flocks in Canada, 2013-2015.

Science.gov (United States)

Agunos, Agnes; Léger, David F; Carson, Carolee A; Gow, Sheryl P; Bosman, Angelina; Irwin, Rebecca J; Reid-Smith, Richard J

2017-01-01

Defined Daily Doses in animals using Canadian standards /1,000 chicken-days at risk (nDDDvetCA/1,000 CD) the ranking was bacitracins (223 nDDDvetCA/1,000 CD), streptogramins (118 nDDDvetCA/1,000 CD), and trimethoprim-sulfonamides (87 nDDDvetCA/1,000 CD). The median animal treatment days in feed for one cycle (ATD/cycle) during the three-year study were 34 ATD/cycle; this was equal to the mean age of the flocks at pre-harvest sampling day (days at risk), indicating that the studied flocks except those that were raised without antibiotics and organic, were fed with medicated rations throughout the observation period. Overall, more than half (59%) of antimicrobials used in broiler chickens were in classes not used in human medicine, such as ionophores and chemical coccidiostats aimed to prevent coccidiosis. Compared to grower-finisher pigs and in production animal species (national sales data), the mg/PCU of antimicrobials used in broiler chickens was relatively lower. The findings of this paper highlighted the importance of farm-level AMU surveillance in measuring the impact of interventions to reduce antimicrobials in poultry.

Antimicrobial use surveillance in broiler chicken flocks in Canada, 2013-2015.

Directory of Open Access Journals (Sweden)

Agnes Agunos

of Defined Daily Doses in animals using Canadian standards /1,000 chicken-days at risk (nDDDvetCA/1,000 CD the ranking was bacitracins (223 nDDDvetCA/1,000 CD, streptogramins (118 nDDDvetCA/1,000 CD, and trimethoprim-sulfonamides (87 nDDDvetCA/1,000 CD. The median animal treatment days in feed for one cycle (ATD/cycle during the three-year study were 34 ATD/cycle; this was equal to the mean age of the flocks at pre-harvest sampling day (days at risk, indicating that the studied flocks except those that were raised without antibiotics and organic, were fed with medicated rations throughout the observation period. Overall, more than half (59% of antimicrobials used in broiler chickens were in classes not used in human medicine, such as ionophores and chemical coccidiostats aimed to prevent coccidiosis. Compared to grower-finisher pigs and in production animal species (national sales data, the mg/PCU of antimicrobials used in broiler chickens was relatively lower. The findings of this paper highlighted the importance of farm-level AMU surveillance in measuring the impact of interventions to reduce antimicrobials in poultry.

Flocking Control of Multiple Mobile Agents with the Rules of Avoiding Collision

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Hongtao Zhou

2015-01-01

Full Text Available This paper investigates the flocking and the coordinative control problems of multiple mobile agents with the rules of avoiding collision. We propose a set of control laws using hysteresis in adding new links and applying new potential function to guarantee that the fragmentation of the network can be avoided, under which all agents approach a common velocity vector, and asymptotically converge to a fixed value of interagent distances and collisions between agents can be avoided throughout the motion. Furthermore, we extend the flocking algorithm to solve the flocking situation of the group with a virtual leader agent. The laws can make all agents asymptotically approach the virtual leader and collisions can be avoided between agents in the motion evolution. Finally, some numerical simulations are showed to illustrate the theoretical results.

Birds, magnets, soap, and sandblasting: surprising connections in the theory of incompressible flocks

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Toner, John

In this talk I'll describe the hydrodynamic theory of the motion of incompressible flocks: that is, collections of self-propelled entities (birds\\x9D) that are packed so tightly together that their density cannot change as they move. In two dimensions, this problem can be mapped onto an equilibrium magnet with a peculiar constraint. This problem, in turn, can be shown to be equivalent to a 2d smectic (soap\\x9D), with the flow lines of the flock playing the role of the smectic layers. Finally, this smectic problem can be mapped onto the 1+1 dimensional KPZ equation, which describes the growth or corrosion (sandblasting\\x9D) of a one dimensional interface. The scaling properties of this last system, which have been known exactly for a long time, can thereby be used to determine those of incompressible 2d flocks. One important implication of the resulting scaling laws is that such flocks can exhibit long-ranged order in two dimensions, unlike their equilibrium counterparts.

On the duality between interaction responses and mutual positions in flocking and schooling.

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Perna, Andrea; Grégoire, Guillaume; Mann, Richard P

2014-01-01

Recent research in animal behaviour has contributed to determine how alignment, turning responses, and changes of speed mediate flocking and schooling interactions in different animal species. Here, we propose a complementary approach to the analysis of flocking phenomena, based on the idea that animals occupy preferential, anysotropic positions with respect to their neighbours, and devote a large amount of their interaction responses to maintaining their mutual positions. We test our approach by deriving the apparent alignment and attraction responses from simulated trajectories of animals moving side by side, or one in front of the other. We show that the anisotropic positioning of individuals, in combination with noise, is sufficient to reproduce several aspects of the movement responses observed in real animal groups. This anisotropy at the level of interactions should be considered explicitly in future models of flocking and schooling. By making a distinction between interaction responses involved in maintaining a preferred flock configuration, and interaction responses directed at changing it, our work provides a frame to discriminate movement interactions that signal directional conflict from interactions underlying consensual group motion.

Flocking-based Document Clustering on the Graphics Processing Unit

Energy Technology Data Exchange (ETDEWEB)

Cui, Xiaohui [ORNL; Potok, Thomas E [ORNL; Patton, Robert M [ORNL; ST Charles, Jesse Lee [ORNL

2008-01-01

Abstract?Analyzing and grouping documents by content is a complex problem. One explored method of solving this problem borrows from nature, imitating the flocking behavior of birds. Each bird represents a single document and flies toward other documents that are similar to it. One limitation of this method of document clustering is its complexity O(n2). As the number of documents grows, it becomes increasingly difficult to receive results in a reasonable amount of time. However, flocking behavior, along with most naturally inspired algorithms such as ant colony optimization and particle swarm optimization, are highly parallel and have found increased performance on expensive cluster computers. In the last few years, the graphics processing unit (GPU) has received attention for its ability to solve highly-parallel and semi-parallel problems much faster than the traditional sequential processor. Some applications see a huge increase in performance on this new platform. The cost of these high-performance devices is also marginal when compared with the price of cluster machines. In this paper, we have conducted research to exploit this architecture and apply its strengths to the document flocking problem. Our results highlight the potential benefit the GPU brings to all naturally inspired algorithms. Using the CUDA platform from NIVIDA? we developed a document flocking implementation to be run on the NIVIDA?GEFORCE 8800. Additionally, we developed a similar but sequential implementation of the same algorithm to be run on a desktop CPU. We tested the performance of each on groups of news articles ranging in size from 200 to 3000 documents. The results of these tests were very significant. Performance gains ranged from three to nearly five times improvement of the GPU over the CPU implementation. This dramatic improvement in runtime makes the GPU a potentially revolutionary platform for document clustering algorithms.

A Distributed Agent Implementation of Multiple Species Flocking Model for Document Partitioning Clustering

Energy Technology Data Exchange (ETDEWEB)

Cui, Xiaohui [ORNL; Potok, Thomas E [ORNL

2006-01-01

The Flocking model, first proposed by Craig Reynolds, is one of the first bio-inspired computational collective behavior models that has many popular applications, such as animation. Our early research has resulted in a flock clustering algorithm that can achieve better performance than the Kmeans or the Ant clustering algorithms for data clustering. This algorithm generates a clustering of a given set of data through the embedding of the highdimensional data items on a two-dimensional grid for efficient clustering result retrieval and visualization. In this paper, we propose a bio-inspired clustering model, the Multiple Species Flocking clustering model (MSF), and present a distributed multi-agent MSF approach for document clustering.

Speed Determines Leadership and Leadership Determines Learning during Pigeon Flocking.

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Pettit, Benjamin; Ákos, Zsuzsa; Vicsek, Tamás; Biro, Dora

2015-12-07

A key question in collective behavior is how individual differences structure animal groups, affect the flow of information, and give some group members greater weight in decisions. Depending on what factors contribute to leadership, despotic decisions could either improve decision accuracy or interfere with swarm intelligence. The mechanisms behind leadership are therefore important for understanding its functional significance. In this study, we compared pigeons' relative influence over flock direction to their solo flight characteristics. A pigeon's degree of leadership was predicted by its ground speeds from earlier solo flights, but not by the straightness of its previous solo route. By testing the birds individually after a series of flock flights, we found that leaders had learned straighter homing routes than followers, as we would expect if followers attended less to the landscape and more to conspecifics. We repeated the experiment from three homing sites using multiple independent flocks and found individual consistency in leadership and speed. Our results suggest that the leadership hierarchies observed in previous studies could arise from differences in the birds' typical speeds. Rather than reflecting social preferences that optimize group decisions, leadership may be an inevitable consequence of heterogeneous flight characteristics within self-organized flocks. We also found that leaders learn faster and become better navigators, even if leadership is not initially due to navigational ability. The roles that individuals fall into during collective motion might therefore have far-reaching effects on how they learn about the environment and use social information. Copyright © 2015 Elsevier Ltd. All rights reserved.

Parenting and feeding behaviors associated with school-aged African American and White children.

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Polfuss, Michele Lynn; Frenn, Marilyn

2012-08-01

Pediatric obesity is multifactorial and difficult to treat. Parenting and feeding behaviors have been shown to influence a child's weight status. Most prior studies have focused on preschool-aged White children. Additional complicating factors include parents' inability to accurately identify their child's abnormal weight status. Parenting and feeding behaviors used by 176 African American and White parents of school-age children were examined. Assessment included (a) identifying what behaviors were reported when parent expressed concern with child's weight and (b) the relationship of these behaviors on child's body mass index percentile (BMI%), considering ethnicity, socioeconomic status (SES), and parent's body mass index (BMI). Findings included African American parents and parents concerned about their child's weight exhibited increased controlling/authoritarian parenting and feeding behaviors. Parents were able to accurately identify their child's weight status. Parenting and feeding behaviors played a significant role in the children's BMI% even when controlling for ethnicity, SES, and parent's BMI.

The Advocacy Experiences of Parents of Elementary Age, Twice-Exceptional Children

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Besnoy, Kevin D.; Swoszowski, Nicole C.; Newman, Jane L.; Floyd, Amanda; Jones, Parrish; Byrne, Caitlin

2015-01-01

For many parents, successfully advocating for their twice-exceptional child can be intimidating and overwhelming. Using grounded theory, we conducted a study with parents (n = 8) of elementary age, twice-exceptional children to learn about their advocacy experiences. Findings revealed that parents simultaneously advocated for their child's…

Seeking a balance between employment and the care of an ageing parent.

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Eldh, Ann Catrine; Carlsson, Eva

2011-06-01

A growing number of middle-aged people are engaged in informal care of their parents while employed. To provide support as employers, co-workers or staff, health care professionals need insight into the experiences of people managing these responsibilities. To elucidate the experience of providing informal care to an ageing parent while managing the responsibilities of a working life. Narrative interviews were performed with 11 persons with experience of the phenomenon. Transcribed interviews were analysed with phenomenological hermeneutics. Informed consent was given prior to the interviews. The study was approved by a research ethics committee. Providing informal care to an ageing parent while also pursuing a working life implies seeking balance: a balance between providing support to the parent's needs and one's responsibilities at work. Being employed supports this balance as it provides both fulfilment and refuge. Being capable of managing both roles grants a sense of satisfaction, supporting one's sense of balance in life. The balance can be supported by sharing the responsibility of caring for the ageing parent with others. Despite perceived saturation and an effort to provide for the possibility to consider internal consistency, the findings should be considered as a contribution to the understanding of the phenomenon, as experienced by individuals in their life world. It is essential to recognise the impact that providing care for an ageing parent may have on the lives of a growing number of people, particularly if they have employment responsibilities. Acknowledgement by others supports one's ability to attain balance; as co-workers and managers, we can acknowledge the efforts of an informal caregiver and as health care staff recognise the valuable contribution made by people in mid-life who provide informal care for their ageing parents. © 2010 The Authors. Scandinavian Journal of Caring Sciences © 2010 Nordic College of Caring Science.

Implications for Welfare, Productivity and Sustainability of the Variation in Reported Levels of Mortality for Laying Hen Flocks Kept in Different Housing Systems: A Meta-Analysis of Ten Studies.

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Weeks, Claire A; Lambton, Sarah L; Williams, Adrian G

2016-01-01

Data from ten sources comprising 3,851 flocks were modelled to identify variation in levels of mortality in laying hens. The predicted increase with age was curvilinear with significant variation between the seven breed categories. Mortality was higher in loose housing systems than in cages and variable within system, confirming previous reports. Cumulative mortality (CM) was higher in flocks with intact beaks (χ2 = 6.03; df 1; p = 0.014) than in those with trimmed beaks. Most data were available for free-range systems (2,823 flocks), where producer recorded CM at 60-80 weeks of age averaged 10% but with a range from 0% to 69.3%. Life cycle assessment showed that the main effect of increased levels of hen mortality is to increase the relative contribution of breeding overheads, so increasing environmental burdens per unit of production. Reducing CM to levels currently achieved by the 1st quartile could reduce flock greenhouse gas emissions by as much as 25%. Concurrently this would enhance hen welfare and better meet the expectation of egg consumers. More research to understand the genetic x environment interaction and detailed records of the causes of mortality is required so that improved genotypes can be developed for different systems and different breeds can be better managed within systems.

Parental Post-traumatic Stress Disorder Symptoms Are Related to Successful Aging in Offspring of Holocaust Survivors

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Shrira, Amit; Ayalon, Liat; Bensimon, Moshe; Bodner, Ehud; Rosenbloom, Tova; Yadid, Gal

2017-01-01

A fascinating, yet underexplored, question is whether traumatic events experienced by previous generations affect the aging process of subsequent generations. This question is especially relevant for offspring of Holocaust survivors (OHS), who begin to face the aging process. Some preliminary findings point to greater physical dysfunction among middle-aged OHS, yet the mechanisms behind this dysfunction need further clarification. Therefore, the current studies assess aging OHS using the broad-scoped conceptualization of successful aging, while examining whether offspring successful aging relates to parental post-traumatic stress disorder (PTSD) symptoms and offspring’s secondary traumatization symptoms. In Study 1, 101 adult offspring (mean age = 62.31) completed measures of parental PTSD, secondary traumatization, as well as successful aging indices – objective (medical conditions, disability and somatic symptoms) and subjective (perceptions of one’s aging). Relative to comparisons and OHS who reported that none of their parents suffered from probable PTSD, OHS who reported that their parents suffered from probable PTSD had lower scores in objective and subjective measures of successful aging. Mediation analyses showed that higher level of secondary traumatization mediated the relationship between parental PTSD and less successful aging in the offspring. Study 2 included 154 dyads of parents (mean age = 81.86) and their adult offspring (mean age = 54.48). Parents reported PTSD symptoms and offspring reported secondary traumatization and completed measures of objective successful aging. Relative to comparisons, OHS whose parent had probable PTSD have aged less successfully. Once again, offspring secondary traumatization mediated the effect. The findings suggest that parental post-traumatic reactions assessed both by offspring (Study 1) and by parents themselves (Study 2) take part in shaping the aging of the subsequent generation via reactions of secondary

Parental Post-traumatic Stress Disorder Symptoms Are Related to Successful Aging in Offspring of Holocaust Survivors

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Amit Shrira

2017-06-01

Full Text Available A fascinating, yet underexplored, question is whether traumatic events experienced by previous generations affect the aging process of subsequent generations. This question is especially relevant for offspring of Holocaust survivors (OHS, who begin to face the aging process. Some preliminary findings point to greater physical dysfunction among middle-aged OHS, yet the mechanisms behind this dysfunction need further clarification. Therefore, the current studies assess aging OHS using the broad-scoped conceptualization of successful aging, while examining whether offspring successful aging relates to parental post-traumatic stress disorder (PTSD symptoms and offspring’s secondary traumatization symptoms. In Study 1, 101 adult offspring (mean age = 62.31 completed measures of parental PTSD, secondary traumatization, as well as successful aging indices – objective (medical conditions, disability and somatic symptoms and subjective (perceptions of one’s aging. Relative to comparisons and OHS who reported that none of their parents suffered from probable PTSD, OHS who reported that their parents suffered from probable PTSD had lower scores in objective and subjective measures of successful aging. Mediation analyses showed that higher level of secondary traumatization mediated the relationship between parental PTSD and less successful aging in the offspring. Study 2 included 154 dyads of parents (mean age = 81.86 and their adult offspring (mean age = 54.48. Parents reported PTSD symptoms and offspring reported secondary traumatization and completed measures of objective successful aging. Relative to comparisons, OHS whose parent had probable PTSD have aged less successfully. Once again, offspring secondary traumatization mediated the effect. The findings suggest that parental post-traumatic reactions assessed both by offspring (Study 1 and by parents themselves (Study 2 take part in shaping the aging of the subsequent generation via reactions of

[Parenting Stress in Mothers of Children with Down Syndrome in Preschool Age].

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Sarimski, Klaus

2017-11-01

Parenting Stress in Mothers of Children with Down Syndrome in Preschool Age Research suggests that parenting stress is elevated in parents of children with intellectual disabilities. However, data are inconsistent if this holds true for parents of children with Down syndrome. As part of the Heidelberg Down syndrome study, 52 mothers of children with Down syndrome (mean age: 5 years) completed the German adaptation of the Parenting Stress Index. These results show significantly elevated stress scores in scales measuring demanding and less acceptable behavior of the children (child characteristics). Scores in scales measuring parent characteristics do not differ significantly from the norms. Global stress scores are associated with the degree of behavioral problems (SDQ) and adaptive competence (VABS-II). A regression analysis points to optimism as a dispositional trait of the mother which makes a significant contribution to the prediction of parenting stress scores. The implications for early intervention are discussed.

Electrostatic flocking of chitosan fibres leads to highly porous, elastic and fully biodegradable anisotropic scaffolds.

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Gossla, Elke; Tonndorf, Robert; Bernhardt, Anne; Kirsten, Martin; Hund, Rolf-Dieter; Aibibu, Dilibar; Cherif, Chokri; Gelinsky, Michael

2016-10-15

Electrostatic flocking - a common textile technology which has been applied in industry for decades - is based on the deposition of short polymer fibres in a parallel aligned fashion on flat or curved substrates, covered with a layer of a suitable adhesive. Due to their highly anisotropic properties the resulting velvet-like structures can be utilised as scaffolds for tissue engineering applications in which the space between the fibres can be defined as pores. In the present study we have developed a fully resorbable compression elastic flock scaffold from a single material system based on chitosan. The fibres and the resulting scaffolds were analysed concerning their structural and mechanical properties and the biocompatibility was tested in vitro. The tensile strength and Young's modulus of the chitosan fibres were analysed as a function of the applied sterilisation technique (ethanol, supercritical carbon dioxide, γ-irradiation and autoclaving). All sterilisation methods decreased the Young's modulus (from 14GPa to 6-12GPa). The tensile strength was decreased after all treatments - except after the autoclaving of chitosan fibres submerged in water. Compressive strength of the highly porous flock scaffolds was 18±6kPa with a elastic modulus in the range of 50-100kPa. The flocked scaffolds did not show any cytotoxic effect during indirect or direct culture of human mesenchymal stem cells or the sarcoma osteogenic cell line Saos-2. Furthermore cell adhesion and proliferation of both cell types could be observed. This is the first demonstration of a fully biodegradable scaffold manufactured by electrostatic flocking. Most tissues possess anisotropic fibrous structures. In contrast, most of the commonly used scaffolds have an isotropic morphology. By utilising the textile technology of electrostatic flocking, highly porous and clearly anisotropic scaffolds can be manufactured. Flocking leads to parallel aligned short fibres, glued on the surface of a substrate

Outbreak of infectious laryngotracheitis in large multi-age egg layer chicken flocks in Minas Gerais, Brazil

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Ingred S. Preis

2013-05-01

Full Text Available A recent (November 2010 outbreak of infectious laryngotracheitis (ILT in a multi-age laying hen facility in Minas Gerais state, Brazil, is described. Previous ILT outbreak in laying hens was only notified in São Paulo state, Brazil, in 2002. In the outbreak described here, the affected population was approximately eight million hens, with flock sizes ranging from 100,000 to 2,900,000 chickens. The average mortality ranged from 1 to 6%, and morbidity was around 90% (most of the twenty seven farms of the area were positive for ILT virus. Three multi-age laying farms from one company were selected for this report. Clinical signs included prostration, dyspnea, conjunctivitis, occasional swelling of the paranasal sinuses and bloody mucous nasal discharge. Severely affected chickens presented with dyspnea, gasping and became cyanotic before death. At necropsy, these chickens had fibrinous exudate blocking the larynx and the lumen of cranial part of the trachea. In addition, conjunctivitis with intense hyperemia, edema and sinuses with caseous exudate were present. On histopathology, there were marked necrosis and desquamation of respiratory ephitelium and conjunctiva with numerous syncytial cells formation and fibrinous exudate. Moderate to marked non suppurative (especially lymphocytes and plasma cells infiltration in the lamina propria also was observed. Sixteen out of 20 examined chickens, eosinophilic intranuclear inclusion bodies were observed in the syncytial cells. The DNA extracted from larynx and trachea produced positive PCR results for ILT virus (ILTV DNA using formalin-fixed, paraffin embedded (FFPE samples. Amplicons from a small region of ICP4 gene were submitted to sequencing and showed 100% identity with ILTV EU104910.1 (USA strain, 99% with ILTV JN596963.1 (Australian strain and 91% with ILTV JN580316.1 (Gallid herpesvirus 1 CEO vaccine strain and JN580315.1 (Gallid herpesvirus 1 TCO vaccine strain.

Drug use and antimicrobial resistance among Escherichia coli and Enterococcus spp. isolates from chicken and turkey flocks slaughtered in Quebec, Canada.

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Boulianne, Martine; Arsenault, Julie; Daignault, Danielle; Archambault, Marie; Letellier, Ann; Dutil, Lucie

2016-01-01

An observational study was conducted of chicken and turkey flocks slaughtered at federal processing plants in the province of Quebec, Canada. The objectives were to estimate prevalence of drug use at hatchery and on farm and to identify antimicrobial resistance (AMR) in cecal Escherichia coli and Enterococcus spp. isolates and factors associated with AMR. Eighty-two chicken flocks and 59 turkey flocks were sampled. At the hatchery, the most used antimicrobial was ceftiofur in chickens (76% of flocks) and spectinomycin in turkeys (42% of flocks). Virginiamycin was the antimicrobial most frequently added to the feed in both chicken and turkey flocks. At least 1 E. coli isolate resistant to third-generation cephalosporins was present in all chicken flocks and in a third of turkey flocks. Resistance to tetracycline, streptomycin, and sulfisoxazole was detected in > 90% of flocks for E. coli isolates. Antimicrobial resistance (AMR) was observed to bacitracin, erythromycin, lincomycin, quinupristin-dalfopristin, and tetracycline in both chicken and turkey flocks for Enterococcus spp. isolates. No resistance to vancomycin was observed. The use of ceftiofur at hatchery was significantly associated with the proportion of ceftiofur-resistant E. coli isolates in chicken flocks. In turkey flocks, ceftiofur resistance was more frequent when turkeys were placed on litter previously used by chickens. Associations between drug use and resistance were observed with tetracycline (turkey) in E. coli isolates and with bacitracin (chicken and turkey), gentamicin (turkey), and tylosin (chicken) in Enterococcus spp. isolates. Further studies are needed to provide producers and veterinarians with alternative management practices and tools in order to reduce the use of antimicrobial feed additives in poultry.

Flocking at a distance in active granular matter

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Soni, Harsh; Kumar, Nitin; Ramaswamy, Sriram; Sood, Ajay

2014-03-01

Flocking, the self-organised motion of vast numbers of living creatures in a single direction, relies on organisms sensing each other's presence, orientation and direction of movement. We have attempted to emulate these properties in experiments of fore-aft asymmetric particles energised by a vertically vibrated horizontal surface, and validate and extend our results using computer simulations and a simple hydrodynamic theory. In these studies the asymmetric rods communicate their orientation and directed motion over several rod lengths through a medium of spherical beads. This results in a phase transition from an isotropic state to a coherently moving flock at exceptionally low rod concentrations, an observation reinforced by large-scale numerical simulations. Our findings include a phase diagram in the plane of rod and bead concentrations, power-law spatial correlations upon approaching the phase boundary, and insights into the underlying mechanisms.

Biosecurity Assessment and Seroprevalence of Respiratory Diseases in Backyard Poultry Flocks Located Close to and Far from Commercial Premises.

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Derksen, T; Lampron, R; Hauck, R; Pitesky, M; Gallardo, R A

2018-03-01

Raising backyard chickens is an ever-growing hobby in the United States. These flocks can be a substrate for respiratory disease amplification and transmission to commercial facilities. Five hundred fifty-four chickens from 41 backyard flocks were sampled in this study. ELISA kits were used to detect antibodies against avian influenza (AI), infectious laryngotracheitis (ILT), Newcastle disease (ND), infectious bronchitis (IB), Ornithobacterium rhinotracheale (ORT), Mycoplasma gallisepticum (MG), and Mycoplasma synoviae (MS). All visited flock owners answered a biosecurity questionnaire that assessed biosecurity measures. The questionnaire revealed that backyard poultry owners lack simple biosecurity measures such as use of dedicated shoes, their chicken sources are unreliable, and few of them benefit from veterinary oversight. Only one flock had a clear vaccination history against ND and IB. ORT, ND, IB, MS, MG, and ILT were the most seroprevalent in backyard poultry flocks with 97% (41/42), 77.5% (31/40), 75% (30/40), 73% (31/42), 69% (29/42), and 45% (19/42), respectively. The vaccinated flock was not considered in these calculations. When examining the distance between backyard flocks and the nearest commercial poultry facility, ND and MG were significantly more likely to be found in backyard flocks close to (4 miles) commercial poultry. Birds purchased directly from National Poultry Improvement Plan hatcheries showed a reduced ND, MG, and MS antibody prevalence. Wearing dedicated shoes decreased MS antibody-positive birds. Finally, history of wild bird contact had a clear effect on an increased seroprevalence of NDV and MG. Serological results suggest that backyard poultry flocks have the potential to serve as a reservoir or amplifier for poultry respiratory diseases. The information generated in this project should direct extension efforts toward emphasizing the importance of small flock biosecurity and chick acquisition sources.

Novel Textile Scaffolds Generated by Flock Technology for Tissue Engineering of Bone and Cartilage.

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Walther, Anja; Hoyer, Birgit; Springer, Armin; Mrozik, Birgit; Hanke, Thomas; Cherif, Chokri; Pompe, Wolfgang; Gelinsky, Michael

2012-03-22

Textile scaffolds can be found in a variety of application areas in regenerative medicine and tissue engineering. In the present study we used electrostatic flocking-a well-known textile technology-to produce scaffolds for tissue engineering of bone. Flock scaffolds stand out due to their unique structure: parallel arranged fibers that are aligned perpendicularly to a substrate, resulting in mechanically stable structures with a high porosity. In compression tests we demonstrated good mechanical properties of such scaffolds and in cell culture experiments we showed that flock scaffolds allow attachment and proliferation of human mesenchymal stem cells and support their osteogenic differentiation. These matrices represent promising scaffolds for tissue engineering.

From phase to microphase separation in flocking models: the essential role of nonequilibrium fluctuations.

Science.gov (United States)

Solon, Alexandre P; Chaté, Hugues; Tailleur, Julien

2015-02-13

We show that the flocking transition in the Vicsek model is best understood as a liquid-gas transition, rather than an order-disorder one. The full phase separation observed in flocking models with Z(2) rotational symmetry is, however, replaced by a microphase separation leading to a smectic arrangement of traveling ordered bands. Remarkably, continuous deterministic descriptions do not account for this difference, which is only recovered at the fluctuating hydrodynamics level. Scalar and vectorial order parameters indeed produce different types of number fluctuations, which we show to be essential in selecting the inhomogeneous patterns. This highlights an unexpected role of fluctuations in the selection of flock shapes.

Variations in parenting practices: gender- and age-related differences in African adolescents.

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Mboya, M M

1995-01-01

This study examines gender and age differences in parenting practices among African adolescents in South Africa. The Perceived Parent Behavior Inventory (PPBI) was administered to 274 students (14 through 18 years of age) in Standards 6 through 10 who attended one public coeducational high school in Cape Town. The results indicate that for the three scales of the PPBI, girls score higher than boys, and that on the total score and two of the PPBI scales, the level of perceived parental behaviors decreases with age. These findings support the hypotheses that competence in social interaction is a more significant factor for girls than for boys and that younger adolescents have a closer association with their parents than do their older counterparts. The findings have important implications for the study of adolescent development in an African context.

Aging Parents: 7 Warning Signs of Health Problems

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... a car or van service or hiring a driver. Consider home care services. You could hire someone ... 2017 Original article: http://www.mayoclinic.org/healthy-lifestyle/caregivers/in-depth/aging-parents/art-20044126 . Mayo ...

Radiocaesium variability in upland sheep flocks

Energy Technology Data Exchange (ETDEWEB)

Beresford, N.A

2002-07-01

Following the 1986 Chernobyl accident large areas of uplands in the United Kingdom were contaminated by radiocaesium. Consequently, the level of radiocaesium in the tissues of some sheep exceeded 1000 Bq kg{sup -1} fresh weight This is the limit adopted within the UK above which meat cannot enter the food chain. In 1986, restrictions were placed on the movement and slaughter of sheep in areas of west Cumbria, north Wales and Scotland. Whilst the number of farms under restriction has reduced considerably, some still remain restricted in 2002. Although a number of workers had noted considerable variability between the radiocaesium activities of individuals within sheep flocks there had been no analyses of causal effects. The work described here, combined studies on three upland farms within west Cumbria with controlled feeding experiments, to systematically assess the parameters which may contribute to such variability. Results from all three farms demonstrate a temporally consistent ranking of the {sup 137}Cs activity concentration of individual sheep within the study flocks. As there was also a correlation between the {sup 137}Cs activity concentration of ewes and their pre-weaned lambs it is likely that the same ewes are producing lambs in excess of the intervention limit in subsequent years. It is difficult to generalise as to which factors will contribute to {sup 137}Cs variability within a given upland flock; factors contributing to variation were not consistent between the study farms. However, the location grazed and/or vegetation selected by animals was a causal factor to the observed variability at all three farms. The transfer of radiocaesium from the diet to muscle of sheep was found to be determined by live-weight change and dry matter intake. Subsequent studies have suggested that protein turnover may be a potential mechanism for the relationship between dry matter intake and radiocaesium transfer. This hypothesis is supported by current understanding

Radiocaesium variability in upland sheep flocks

International Nuclear Information System (INIS)

Beresford, N.A.

2002-01-01

Following the 1986 Chernobyl accident large areas of uplands in the United Kingdom were contaminated by radiocaesium. Consequently, the level of radiocaesium in the tissues of some sheep exceeded 1000 Bq kg -1 fresh weight This is the limit adopted within the UK above which meat cannot enter the food chain. In 1986, restrictions were placed on the movement and slaughter of sheep in areas of west Cumbria, north Wales and Scotland. Whilst the number of farms under restriction has reduced considerably, some still remain restricted in 2002. Although a number of workers had noted considerable variability between the radiocaesium activities of individuals within sheep flocks there had been no analyses of causal effects. The work described here, combined studies on three upland farms within west Cumbria with controlled feeding experiments, to systematically assess the parameters which may contribute to such variability. Results from all three farms demonstrate a temporally consistent ranking of the 137 Cs activity concentration of individual sheep within the study flocks. As there was also a correlation between the 137 Cs activity concentration of ewes and their pre-weaned lambs it is likely that the same ewes are producing lambs in excess of the intervention limit in subsequent years. It is difficult to generalise as to which factors will contribute to 137 Cs variability within a given upland flock; factors contributing to variation were not consistent between the study farms. However, the location grazed and/or vegetation selected by animals was a causal factor to the observed variability at all three farms. The transfer of radiocaesium from the diet to muscle of sheep was found to be determined by live-weight change and dry matter intake. Subsequent studies have suggested that protein turnover may be a potential mechanism for the relationship between dry matter intake and radiocaesium transfer. This hypothesis is supported by current understanding of protein-dry matter

Flocking in Multi-Agent Systems with Multiple Virtual Leaders Based Only on Position Measurements

International Nuclear Information System (INIS)

Su Housheng

2012-01-01

Most existing flocking algorithms assume one single virtual leader and rely on information on both relative positions and relative velocities among neighboring agents. In this paper, the problem of controlling a flock of mobile autonomous agents to follow multiple virtual leaders is investigated by using only position information in the sense that agents with the same virtual leader asymptotically attain the same velocity and track the corresponding virtual leader based on only position measurements. A flocking algorithm is proposed under which every agent asymptotically attains its desired velocity, collision between agents can be avoided, and the final tight formation minimizes all agents' global potentials. A simulation example is presented to verify and illustrate the theoretical results. (general)

Isolation of Campylobacter from Brazilian broiler flocks using different culturing procedures.

Science.gov (United States)

Vaz, C S L; Voss-Rech, D; Pozza, J S; Coldebella, A; Silva, V S

2014-11-01

Conventional culturing methods enable the detection of Campylobacter in broiler flocks. However, laboratory culture of Campylobacter is laborious because of its fastidious behavior and the presence of competing nontarget bacteria. This study evaluated different protocols to isolate Campylobacter from broiler litter, feces, and cloacal and drag swabs. Samples taken from commercial Brazilian broiler flocks were directly streaked onto Preston agar (PA), Campy-Line agar (CLA), and modified charcoal cefoperazone deoxycholate agar (mCCDA) and also enriched in blood-free Bolton broth (bfBB) for 24 and 48 h followed by plating onto the different selective media. Higher numbers of Campylobacter-positive cloacal and drag swab samples were observed using either direct plating or enrichment for 24 h before plating onto PA, compared with enrichment for 48 h (P media. Together, these data showed that direct plating onto PA and onto either CLA or mCCDA as the second selective agar enabled the reliable isolation of thermophilic Campylobacter species from broiler samples. Finally, Campylobacter was detected in all broiler flocks sampled. ©2014 Poultry Science Association Inc.

Flocking small smart machines: An experiment in cooperative, multi-machine control

International Nuclear Information System (INIS)

Klarer, P.R.

1998-03-01

The intent and purpose of this work was to investigate and demonstrate cooperative behavior among a group of mobile robot machines. The specific goal of this work was to build a small swarm of identical machines and control them in such a way as to show a coordinated movement of the group in a flocking manner, similar to that observed in nature. Control of the swarm's individual members and its overall configuration is available to the human user via a graphic man-machine interface running on a base station control computer. Any robot may be designated as the nominal leader through the interface tool, which then may be commanded to proceed to a particular geographic destination. The remainder of the flock follows the leader by maintaining their relative positions in formation, as specified by the human controller through the interface. The formation's configuration can be altered manually through an interactive graphic-based tool. An alternative mode of control allows for teleoperation of one robot, with the flock following along as described above

Parental Predictors of Children's Shame and Guilt at Age 6 in a Multimethod, Longitudinal Study.

Science.gov (United States)

Parisette-Sparks, Alyssa; Bufferd, Sara J; Klein, Daniel N

2017-01-01

Shame and guilt are self-conscious emotions that begin to develop early in life and are associated with various forms of psychopathology. However, little is known about the factors that contribute to these emotions in young children. Specifically, no longitudinal studies to date have examined a range of parent factors that shape the expression of children's shame and guilt. The current multimethod, longitudinal study sought to determine whether parenting style, parental psychopathology, and parents' marital satisfaction assessed when children were age 3 predict expressions of shame and guilt in children at age 6. A large community sample of families (N = 446; 87.4% Caucasian) with 3-year-old children (45.7% female) was recruited through commercial mailing lists. Parent variables were assessed when children were age 3 with mother- and father-report questionnaires and a diagnostic interview. Children's expressions of shame and guilt were observed in the laboratory at age 6. Fathers', but not mothers', history of depression and permissive parenting assessed when children were age 3 predicted children's expressions of shame and guilt when children were age 6; parents' marital dissatisfaction also predicted children's shame and guilt. These findings suggest that parents, and fathers in particular, contribute to expressions of self-conscious emotions in children. These data on emotional development may be useful for better characterizing the risk and developmental pathways of psychopathology.

Implications for Welfare, Productivity and Sustainability of the Variation in Reported Levels of Mortality for Laying Hen Flocks Kept in Different Housing Systems: A Meta-Analysis of Ten Studies.

Directory of Open Access Journals (Sweden)

Claire A Weeks

Full Text Available Data from ten sources comprising 3,851 flocks were modelled to identify variation in levels of mortality in laying hens. The predicted increase with age was curvilinear with significant variation between the seven breed categories. Mortality was higher in loose housing systems than in cages and variable within system, confirming previous reports. Cumulative mortality (CM was higher in flocks with intact beaks (χ2 = 6.03; df 1; p = 0.014 than in those with trimmed beaks. Most data were available for free-range systems (2,823 flocks, where producer recorded CM at 60-80 weeks of age averaged 10% but with a range from 0% to 69.3%. Life cycle assessment showed that the main effect of increased levels of hen mortality is to increase the relative contribution of breeding overheads, so increasing environmental burdens per unit of production. Reducing CM to levels currently achieved by the 1st quartile could reduce flock greenhouse gas emissions by as much as 25%. Concurrently this would enhance hen welfare and better meet the expectation of egg consumers. More research to understand the genetic x environment interaction and detailed records of the causes of mortality is required so that improved genotypes can be developed for different systems and different breeds can be better managed within systems.

Patterns of Parental Rearing Styles and Child Behaviour Problems among Portuguese School-Aged Children

OpenAIRE

Pereira, Ana I. F.; Canavarro, Cristina; Cardoso, Margarida F.; Mendonça, Denisa

2008-01-01

The majority of studies investigating the effects of parental behaviour on the child’s adjustment have a dimensional approach. We identified the existence of various patterns in parental rearing styles and analysed the relationship between different parenting patterns and behavioural problems in a group of school-aged children. A longitudinal, multi-informant study was conducted. The sample consisted of 519 school-aged children from the Portuguese general population. Parental rearing styles w...

Identification and phylogenetic diversity of parvovirus circulating in commercial chicken and turkey flocks in Croatia.

Science.gov (United States)

Bidin, M; Lojkić, I; Bidin, Z; Tiljar, M; Majnarić, D

2011-12-01

Phylogenetic diversity of parvovirus detected in commercial chicken and turkey flocks is described. Nine chicken and six turkey flocks from Croatian farms were tested for parvovirus presence. Intestinal samples from one turkey and seven chicken flocks were found positive, and were sequenced. Natural parvovirus infection was more frequently detected in chickens than in turkeys examined in this study. Sequence analysis of 400 nucleotide fragments of the nonstructural gene (NS) showed that our sequences had more similarity with chicken parvovirus (ChPV) (92.3%-99.7%) than turkey parvovirus (TuPV) (89.5%-98.9%) strains. Phylogenetic analysis grouped our sequences in two clades. Also, the higher prevalence of ChPV than TuPV in tested flocks was defined. The necropsy findings suggested a malabsorption syndrome followed by a preascitic condition. Further research of parvovirus infection, pathogenesis, and the possibility of its association with poult enteritis and mortality syndrome (PEMS) and runting and stunting syndrome (RSS) is needed to clarify its significance as an agent of enteric disease.

Sheep farmer opinions on the current and future role of veterinarians in flock health management on sheep farms: A qualitative study

Science.gov (United States)

Kaler, Jasmeet; Green, L.E.

2013-01-01

A 2009 UK Government report on veterinary expertise in food animal production highlighted that there was insufficient herd health expertise among veterinarians and lack of appropriate business models to deliver veterinary services to the livestock sector. Approximately two thirds of sheep farmers only contact their veterinarian for emergencies and one fifth have all year round contact. The aim of the current study was to understand sheep farmers’ perception, the current and future role of veterinarians in flock health management using qualitative methodology. The eligibility criteria were male farmers with a flock size of at least 200 adult sheep. Seven focus groups of farmers (n = 45) stratified by three regions and two age groups (≤50 and >50) were conducted. Thematic analysis of the discussions indicated that most farmers considered and used their veterinarian as a fire-fighter, whilst other advice was gathered free of charge when the veterinarian was on the farm for other reasons (typically seeing cattle) or by telephone. A small group of farmers were using their veterinarian or a sheep consultant proactively with regular contact and found this financially beneficial. Farmers indicated that the key barriers to using a veterinarian proactively were inconsistent service, high turnover of veterinarians, lack of expertise of sheep farming among veterinarians and concern about independence of advice. Although economics was also mentioned as a key barrier to using veterinarians more proactively, most farmers did not know where they gained and lost income from their flock; there was heavy reliance on the single farm payment scheme (SPS) and very few farmers kept records from which they could investigate where there were inefficiencies in production. Overall sheep farmers considered sheep farming complex and that each farm was unique and that they themselves were the experts to manage their flock. We conclude that there is an impasse: veterinarians might need to

Overlooked potential: older-age parents in the era of ART.

Science.gov (United States)

Williams, Nathalie; Knodel, John; Kiry Kim, Sovan; Puch, Sina; Saengtienchai, Chanpen

2008-11-01

The advent of widespread ART provision in low- and middle-income countries requires not just medical attention, but also social and psychological support to encourage and monitor strict adherence to drug regimens. Developing innovative approaches to providing this broad support is a major challenge, especially within the financial constraints of resource-limited countries hardest hit by the epidemic. In this study, we examine the role of older-age parents in monitoring ART treatment and caring for their HIV-infected children and grandchildren in Cambodia. Our results are based on 25 open-ended interviews with older-age parents of people with AIDS (PWHA). A high level of co-residence when PWHA become ill and a sense of parental responsibility and emotional attachment facilitate high parental involvement in their children's and grandchildren's illness, care and treatment. Our interviews indicate that parents play an important role in encouraging their children to get tested and to access treatment if they test positive. They consistently monitor antiretroviral therapy (ART) adherence and opportunistic infections and remind PWHA to attend medical appointments and support-group meetings. Parents also provide for the nutrition and hygiene of PWHA essential to the success of ART treatments. We find that despite low levels of education, older parents were able to express clear, correct and detailed knowledge of complicated ART treatment regimens, nutrition and hygiene. Overall, our findings show that older parents play a pivotal role in care and treatment if they are provided with proper resources and training and have the ability to understand the necessity and details of ensuring strict adherence to medications. Based on these results, we suggest that explicitly including older parents in policy and programs for care and treatment would allow Cambodia and other countries to take advantage of this unique and effective but overlooked asset in AIDS care and treatment.

Flies and Campylobacter infection of broiler flocks

DEFF Research Database (Denmark)

Hald, Birthe; Skovgård, Henrik; Bang, Dang Duong

2004-01-01

A total of 8.2% of flies caught outside a broiler house in Denmark had the potential to transmit Campylobacter jejuni to chickens, and hundreds of flies per day passed through the ventilation system into the broiler house. Our study suggests that flies may be an important source of Campylobacter ...... infection of broiler flocks in summer....

Parental involvement in elementary school-aged child’s creativity

Science.gov (United States)

Suparmi; Suardiman, S. P.; Kumara, A.

2018-01-01

This study aims at describing the parental involvement in cultivating elementary school-aged child’s creativity. The qualitative research was designed with multidisciplinary study approach. Eight students and some parents from public elementary schools of Ngawen 4th of Gunungkidul, Yogyakarta, and 4 students from an elementary school in Sleman, Yogyakarta were involved in the process of collecting the data. In-depth interview, observation, and documentation were used simultaneously to collect the data. The results showed that: 1) the subject had a level of intelligence quotient; the intelligence of verbal creativity above the average level, and creative behaviour on average, 2) interaction of parents and child-related discussions, experiences, and plans, academic problems in school were needed to boost the students’ creativity, 3) interactions of parents and school-related participations in school were also encouraged to implant students’ social awareness, 4) interaction among parents communicated each other to have a better result of academic awareness, and 5) Parents should install family norms to cultivate children’s intelligence quotient.

Age of licensure and monitoring teenagers' driving: survey of parents of novice teenage drivers.

Science.gov (United States)

McCartt, Anne T; Hellinga, Laurie A; Haire, Emily R

2007-01-01

To assess parental decision making regarding the timing of teenagers initiating driving and monitoring teenagers' driving after licensure. About 300 parents were interviewed during spring 2006 in Minnesota, North Carolina, and Rhode Island, states with varying licensing provisions, while teenagers took their first on-road driving tests. States' differences in ages of obtaining learner's permits and licenses reflected different licensing laws, but most teenagers obtained permits and took road tests within the first few months after they became eligible. Common reasons for delaying obtaining permits were fulfilling driver education requirements and lack of readiness/immaturity. Insufficient practice driving most often delayed licensure. Among the parents interviewed, 33-49% believed the minimum licensure age should be 17 or older. Almost all parents planned to supervise teenagers' driving after licensure, and most wanted to know about speeding or distractions. When asked about in-vehicle devices to monitor teenagers' driving, 37-59% of parents had heard of them. Parents were least interested in using video cameras and about equally interested in computer chips and cell-phone-based GPS systems. Disinterest in monitoring devices most often was attributed to trusting teenagers or respecting their privacy. Licensing laws influence ages of initiating driving. Although many parents support licensing at 17 or older - higher than in all but one state - most teenagers initiate driving soon after reaching the minimum age. Parents plan to supervise teenagers' driving, and many say they are open to using in-vehicle monitoring devices. Many parents support a minimum licensing age of 17 or older and would consider in-vehicle devices to extend their supervision of teenager's driving.

Parent-child relationships and offspring's positive mental wellbeing from adolescence to early older age.

Science.gov (United States)

Stafford, Mai; Kuh, Diana L; Gale, Catharine R; Mishra, Gita; Richards, Marcus

2016-05-03

We examined parent-child relationship quality and positive mental well-being using Medical Research Council National Survey of Health and Development data. Well-being was measured at ages 13-15 (teacher-rated happiness), 36 (life satisfaction), 43 (satisfaction with home and family life) and 60-64 years (Diener Satisfaction With Life scale and Warwick Edinburgh Mental Well-being scale). The Parental Bonding Instrument captured perceived care and control from the father and mother to age 16, recalled by study members at age 43. Greater well-being was seen for offspring with higher combined parental care and lower combined parental psychological control ( p  < 0.05 at all ages). Controlling for maternal care and paternal and maternal behavioural and psychological control, childhood social class, parental separation, mother's neuroticism and study member's personality, higher well-being was consistently related to paternal care. This suggests that both mother-child and father-child relationships may have short and long-term consequences for positive mental well-being.

Parents' age and the risk of oral clefts

DEFF Research Database (Denmark)

Bille, C.; Skytthe, A.; Vach, W.

2005-01-01

BACKGROUND: Some malformations are clearly associated with older maternal age, but the effect of older age of the father is less certain. The aim of this study is to determine the degree to which maternal age and paternal age independently influence the risk of having a child with oral clefts....... In a joint analysis, both maternal and paternal ages were associated with the risk of cleft lip with or without cleft palate, but the contribution of each was dependent on the age of the other parent. In the analysis of cleft palate only, the effect of maternal age disappeared, leaving only paternal age...... as a risk factor. CONCLUSION: Both high maternal age and high paternal age were associated with cleft lip with or without cleft palate. Higher paternal age but not maternal age increased the risk of cleft palate only....

Fatal systemic cladosporiosis in a merino sheep flock.

Science.gov (United States)

Haligur, Mehmet; Ozmen, Ozlem; Dorrestein, Gerry M

2010-12-01

Systemic cladosporiosis is described in 25 merino sheep from a flock consisting 250 animals. The fungal pneumonia appeared after an intensive antibiotic treatment, because of a respiratory system disorder. The pen of the flock was humid and crowded, and animals had signs of respiratory distress, coughing, fever and anorexia. All of the ill animals died, and necropsy was performed on 10 sheep. The lesions were characterized by a multifocal pyogranulomatous pneumonia and an abomasitis. Severe hemorrhages were observed in the lungs. At the histopathological examination, severe vasculitis with thrombosis was observed in various organs, especially in the lungs and abomasums, suggestive for a hematogenous dissemination of the infection in these organs. Numerous PAS-positive fungal elements were seen in the pyogranulomatous foci. Dark green fungal colonies were seen in the blood agar and Sabouraud dextrose agar that were identified as Cladosporium cladosporioides. This report highlights that phaeohyphomycosis can cause a severe systemic and fatal disease in merino sheep under insufficient management conditions.

Atypical outbreak of acute coenurosis by Taenia multiceps in a sheep flock.

Science.gov (United States)

Pintus, Davide; Varcasia, Antonio; Dessì, Giorgia; Tamponi, Claudia; Manunta, Maria Lucia; Carboni, Giovanni Antonio; Cancedda, Maria Giovanna; Ligios, Ciriaco; Scala, Antonio

2018-06-01

Herein, we examined the brain of adult ewes and lambs less than 30 days old which were found affected by neurological signs in a flock located in Sardinia (Italy). Gross anatomo-pathological examination of all brains of the animals revealed multiple linear reddish-yellow foci of necrotic purulent inflammation due to oncosphere migration. Histologically, we confirmed a multifocal pyo-granulomatous meningo-encephalitis both in ewes and in lambs, confirming acute coenurosis. Morphological examination and DNA sequencing identified the Taenia multiceps we isolated as Tm1 strain. This report describes for the first time a natural acute coenurosis infection in suckling lambs under 30 days of age.

Parental Investment in Children with Chronic Disease: The Effect of Child's and Mother's Age

Directory of Open Access Journals (Sweden)

Sigal Tifferet

2007-10-01

Full Text Available Parents do not invest their resources in their children equally. Three factors which elicit differential parental investment are the parent's reproductive value, the child's reproductive value (RV, and the impact of the investment on the child (II. As the child matures, his RV increases while the II may decrease. This raises a question regarding the favored strategy of investment by child age. It was hypothesized that different categories of parental investment generate different age-based strategies. Emotional investment, such as maternal worrying for the child's health, was hypothesized to increase with the child's age, while direct care was hypothesized to decrease with the child's age. Both categories were hypothesized to increase with the mother's age at childbirth. 137 Israeli mothers of children with chronic neurological conditions reported levels of worrying for their child and levels of change in direct care. Maternal worrying about the child's health was positively associated with the child's age at diagnosis and the severity of his illness, and negatively associated with the time from diagnosis. An increase in direct care was positively associated with maternal age at childbirth and illness severity, and negatively associated with the time from diagnosis, and the duration of the marriage. Contrary to the hypothesis, the child's age had no effect on changes in direct care. It appears that in mothers of children with adverse neurological conditions, child and maternal age effect parental investment differently. While the child's age is related to maternal worrying about his health, the mother's age at childbirth is related to changes in direct care.

Effect of rearing factors on the prevalence of floor eggs, cloacal cannibalism and feather pecking in commercial flocks of loose housed laying hens.

Science.gov (United States)

Gunnarsson, S; Keeling, L J; Svedberg, J

1999-03-01

1. Effects of rearing conditions on behavioural problems were investigated in a cohort study of commercial flocks of laying hens housed in 2 different loose housing systems. The sample population was 120 385 laying hens from 59 flocks of various hybrids at 21 different farms. 2. Logistic regression modelling was used to test the effects of selected factors on floor eggs, cloacal cannibalism and feather pecking. In addition to early access to perches or litter, models included hybrid, stocking density, group size, housing system, age at delivery, identical housing system at the rearing farm and at the production farm and, in models for floor eggs and cloacal cannibalism, nest area per hen. Odds ratios were calculated from the results of the models to allow risk assessment. 3. No significant correlations were found between the prevalence of floor eggs, cloacal cannibalism and feather pecking. 4. Access to perches from not later than the 4th week of age decreased the prevalence of floor eggs during the period from start-of-lay until 35 weeks of age, odds ratio 0-30 (Pfeather pecking.

Relationship Quality with Parents: Implications for Own and Partner Well-Being in Middle-Aged Couples.

Science.gov (United States)

Polenick, Courtney A; Fredman, Steffany J; Birditt, Kira S; Zarit, Steven H

2018-03-01

Relationships with parents have significant implications for well-being throughout the lifespan. At midlife, these ties are situated within both developmental and family contexts that often involve the adult offspring's spouse. Yet, it is not known how ties with aging parents are related to psychological well-being within middle-aged couples. This study examined how middle-aged wives' and husbands' views of the current quality of relationships with their own parents (positive and negative) are linked to their own and their partner's psychological well-being. Using a sample of 132 middle-aged couples from Wave 1 of the Family Exchanges Study, we estimated actor-partner interdependence models to evaluate these dyadic associations while controlling for each spouse's marital satisfaction. Both actor and partner effects were observed. With respect to actor effects, wives who reported more negative relationship quality with their own parents had elevated depressive symptoms and lower life satisfaction. Husbands who reported more negative relationship quality with their own parents had lower life satisfaction. In terms of partner effects, husbands had lower depressive symptoms and greater life satisfaction when wives reported more positive relationship quality with their own parents. Finally, the link between wives' positive ties with parents and husbands' lower depressive symptoms was intensified when husbands had less positive relationships with their own parents. Findings suggest that relationship quality with wives' aging parents has implications for both spouses' well-being and may serve as a critical social resource for husbands. © 2016 Family Process Institute.

Flock size, diet composition, and habitat characteristics of the ...

African Journals Online (AJOL)

gla- cial history (Magin 2001). Some of the plant species endemic to SMNP are stonecrop. Rosularia simiensis and tussock grass Festuca gilbertiana. SMNP is home to 22 species. Flock size, diet composition, and habitat characteristics of ...

Serologic reactions against Salmonella in samples from broiler parent stock with and without preceding colibacillosis: A case-control study

DEFF Research Database (Denmark)

Gradel, K.O.; Feld, Niels Christian; Andersen, J. S.

2001-01-01

In the Danish Salmonella Control Program, eggs from broiler parent flocks are surveyed by serologic analysis every 4 wk for antibodies against Salmonella lipopolysaccharide O-antigens 1, 4, 5, 9, and 12 (Mix-enzyme-linked immunosorbent assay [ELISA]) and 6 and 7 (Infantis-ELISA). The antibody...... response is measured in percentage optical density (OD%) of a strong positive reaction, and the cutoff value has been determined to be 40 OD%. Two or more reactors above 40 OD% will place the parent flock under suspicion. There has been concern about possible cross-reactions between Salmonella spp....... and other Enterobacteriaceae, e.g., Escherichia coli, because a high specificity of a Salmonella antibody test is desirable. Moreover, false-positive Salmonella results have economic consequences and impede planning the production. A case-control study based on cases of clinical E. coli infections...

9 CFR 145.33 - Terminology and classification; flocks and products.

Science.gov (United States)

2010-01-01

... POULTRY Special Provisions for Multiplier Meat-Type Chicken Breeding Flocks and Products § 145.33... demonstrate pullorum or typhoid infection; (vii) All poultry, including exhibition, exotic, and game birds...

A farm-level study of risk factors associated with the colonization of broiler flocks with Campylobacter spp. in Iceland, 2001 – 2004

Directory of Open Access Journals (Sweden)

Berke Olaf

2007-07-01

Full Text Available Abstract Background Following increased rates of human campylobacteriosis in the late 1990's, and their apparent association with increased consumption of fresh chicken meat, a longitudinal study was conducted in Iceland to identify the means to decrease the frequency of broiler flock colonization with Campylobacter. Our objective in this study was to identify risk factors for flock colonization acting at the broiler farm level. Methods Between May 2001 and September 2004, pooled caecal samples were obtained from 1,425 flocks at slaughter and cultured for Campylobacter. Due to the strong seasonal variation in flock prevalence, analyses were restricted to a subset of 792 flocks raised during the four summer seasons. Flock results were collapsed to the farm level, such that the number of positive flocks and the total number of flocks raised were summed for each farm. Logistic regression models were fitted to the data using automated and manual selection methods. Variables of interest included manure management, water source and treatment, other poultry/livestock on farm, and farm size and management. Results The 792 flocks raised during the summer seasons originated from 83 houses on 33 farms, and of these, 217 (27.4% tested positive. The median number of flocks per farm was 14, and the median number of positive flocks per farm was three. Three farms did not have any positive flocks. In general, factors associated with an increased risk of Campylobacter were increasing median flock size on the farm (p ≤ 0.001, spreading manure on the farm (p = 0.004 to 0.035, and increasing the number of broiler houses on the farm (p = 0.008 to 0.038. Protective factors included the use of official (municipal (p = 0.004 to 0.051 or official treated (p = 0.006 to 0.032 water compared to the use of non-official untreated water, storing manure on the farm (p = 0.025 to 0.029, and the presence of other domestic livestock on the farm (p = 0.004 to 0.028. Conclusion

Effects of Parental Aging During Embryo Development and Adult Life: The Case of Nothobranchius furzeri.

Science.gov (United States)

Api, Martina; Biondi, Piera; Olivotto, Ike; Terzibasi, Eva; Cellerino, Alessandro; Carnevali, Oliana

2018-04-01

Studies on parental aging are a very attractive field, although it is poorly understood how parental age affects embryonic development and adult traits of the offspring. In this study, we used the turquoise killifish Nothobranchius furzeri, as is the vertebrate with shortest captive lifespan and an interesting model. The embryos of N. furzeri can follow two distinct developmental pathways either entering diapause or proceeding through direct development. Thus, this embryonic plasticity allows this model to be used to study different factors that could affect their embryonic development, including parental age. The first goal of the present study was to investigate whether parental aging could affect the embryo development. To do this, we collected F1 embryos from two breeder groups (old parents and young parents). We monitored the duration of embryonic development and analyzed genes involved in dorsalization process. The second goal was to investigate if embryonic developmental plasticity could be modulated by an epigenetic process. To this end, the expression of DNMTs genes was examined. Our data support the hypothesis that diapause, occurring more frequently in embryos from old parents, is associated with increased expression of DNMT3A and DNMT3B suggesting an epigenetic control. Finally, we analyzed whether parental age could affect metabolism and growth during adult life. Morphometric results and qPCR analysis of genes from IGF system showed a slower growth in adults from old breeders. Moreover, a gender-specificity effect on growth emerged. In conclusion, these results may contribute to the better understanding of the complex mechanism of aging.

34 CFR 300.520 - Transfer of parental rights at age of majority.

Science.gov (United States)

2010-07-01

... Children § 300.520 Transfer of parental rights at age of majority. (a) General. A State may provide that... (ii) All rights accorded to parents under Part B of the Act transfer to the child; (2) All rights... child and the parents of the transfer of rights. (b) Special rule. A State must establish procedures for...

Time-asymptotic interaction of flocking particles and an incompressible viscous fluid

International Nuclear Information System (INIS)

Bae, Hyeong-Ohk; Choi, Young-Pil; Ha, Seung-Yeal; Kang, Moon-Jin

2012-01-01

We present a new coupled kinetic-fluid model for the interactions between Cucker–Smale (C–S) flocking particles and incompressible fluid on the periodic spatial domain T d . Our coupled system consists of the kinetic C–S equation and the incompressible Navier–Stokes equations, and these two systems are coupled through the drag force. For the proposed model, we provide a global existence of weak solutions and a priori time-asymptotic exponential flocking estimates for any smooth flow, when the kinematic viscosity of the fluid is sufficiently large. The velocity of individual C–S particles and fluid velocity tend to the averaged time-dependent particle velocities exponentially fast

Schools, Schooling, and Children's Support of Their Aging Parents.

Science.gov (United States)

Brauner-Otto, Sarah R

2009-10-01

Intergenerational transfers play an important role in individuals' lives across the life course. In this paper I pull together theories on intergenerational transfers and social change to inform our understanding of how changes in the educational context influence children's support of their parents. By examining multiple aspects of a couple's educational context, including husbands' and wives' education and exposure to schools, this paper provides new information on the mechanisms through which changes in social context influence children's support of their parents. Using data from a rural Nepalese area I use multilevel logistic regression to estimate the relationship between schooling, exposure to schools, and the likelihood of couples giving to their parents. I find that both schooling and exposure to schools itself have separate, opposite effects on support of aging parents. Higher levels of schooling for husbands was associated with a higher likelihood of having given support to husbands' parents. On the other hand, increased exposure to schools for husbands and wives was associated with a lower likelihood of having given to wives' parents. Findings constitute evidence that multiple motivations for intergenerational support exist simultaneously and are related to social context through different mechanisms.

Fore-aft asymmetric flocking

Science.gov (United States)

Chen, Qiu-shi; Patelli, Aurelio; Chaté, Hugues; Ma, Yu-qiang; Shi, Xia-qing

2017-08-01

We show that fore-aft asymmetry, a generic feature of living organisms and some active matter systems, can have a strong influence on the collective properties of even the simplest flocking models. Specifically, an arbitrarily weak asymmetry favoring front neighbors changes qualitatively the phase diagram of the Vicsek model. A region where many sharp traveling band solutions coexist is present at low noise strength, below the Toner-Tu liquid, at odds with the phase-separation scenario well describing the usual isotropic model. Inside this region, a "banded-liquid" phase with algebraic density distribution coexists with band solutions. Linear stability analysis at the hydrodynamic level suggests that these results are generic and not specific to the Vicsek model.

[Effect of parental feeding behavior on eating behavior of children aged 1-3 years].

Science.gov (United States)

Liu, Hong-Hua; Chen, Jin-Jin

2014-06-01

To investigate the relationship between the eating behavior of children aged 1-3 years and parental feeding behavior and the effect of family status on feeding behavior. With stratified random sampling, 2 324 children aged 1-3 years were selected from Shanghai. Questionnaires were filled out by their parents or feeders to investigate the basic family information, parental feeding behavior, the eating behavior of children, and the basic information on children. The eating behavior of children was positively correlated with eating environment (r=0.223) and parental monitoring behavior (r=0.245) but negatively correlated with parental compulsive behavior (r=-0.264) (Pparental compulsive behavior (r=-0.569) but positively correlated with parental monitoring behavior (r=0.615) and eating environment (r=0.621). The emotional undereating of children was positively correlated with parental emotional feeding (r=0.259) and parental compulsive behavior (r=0.279). Parental monitoring behavior showed significant differences between different families (PParental feeding behavior is closely related to the eating behavior of children. Parental feeding behavior may vary across different family status.

Parenting stress and development of late preterm infants at 4 months corrected age.

Science.gov (United States)

Mughal, Muhammad K; Ginn, Carla S; Magill-Evans, Joyce; Benzies, Karen M

2017-10-01

Parenting stress has been linked to child development issues in early preterm infants, but less is known about its effects on development in infants born late preterm. We examined relationships between parenting stress of 108 mothers and 108 fathers and development of late preterm infants born at 34 0/7 to 36 6/7 weeks gestation. At 4 months corrected age, mothers and fathers completed the Parenting Stress Index (PSI-3); mothers were primary caregivers in almost all families and completed the Ages and Stages Questionnaire (ASQ-2) on child development. Mothers reported significantly more stress than fathers on the PSI-3 Parent Domain. PSI-3 subscale scores from the Child Domain were significant predictors of mother-reported infant development as measured by the ASQ-2 in regression models: Reinforces Parent predicted Gross Motor, Mood predicted Communication, and Acceptability predicted Communication, Fine Motor, Problem Solving, and Personal -Social development scale scores. Experiences of parenting stress differed for mothers and fathers. Further research is required on specific dimensions of parenting stress related to development of late preterm infants. © 2017 Wiley Periodicals, Inc.

Effect of vaccinating breeder chickens with a killed Salmonella vaccine on Salmonella prevalences and loads in breeder and broiler chicken flocks.

Science.gov (United States)

Berghaus, R D; Thayer, S G; Maurer, J J; Hofacre, C L

2011-05-01

The objective of this study was to evaluate the effect of vaccination of breeder chickens on Salmonella prevalences and loads in breeder and broiler chicken flocks. Chickens housed on six commercial breeder farms were vaccinated with a killed Salmonella vaccine containing Salmonella Typhimurium, Salmonella Enteritidis, and Salmonella Kentucky. Unvaccinated breeders placed on six additional farms served as controls. Eggs from vaccinated and unvaccinated breeder flocks were kept separately in the hatchery, and the resulting chicks were used to populate 58 commercial broiler flock houses by using a pair-matched design. Vaccinated breeder flocks had significantly higher Salmonella-specific antibody titers than did the unvaccinated breeder flocks, although they did not differ significantly with respect to environmental Salmonella prevalences or loads. Broiler flocks that were the progeny of vaccinated breeders had significantly lower Salmonella prevalences and loads than broiler flocks that were the progeny of unvaccinated breeders. After adjusting for sample type and clustering at the farm level, the odds of detecting Salmonella in samples collected from broiler flocks originating from vaccinated breeders were 62% lower (odds ratio [95% confidence interval] = 0.38 [0.21, 0.68]) than in flocks from unvaccinated breeders. In addition, the mean load of culture-positive samples was lower in broilers from vaccinated breeders by 0.30 log most probable number per sample (95% confidence interval of -0.51, -0.09; P = 0.004), corresponding to a 50% decrease in Salmonella loads. In summary, vaccination of broiler breeder pullets increased humoral immunity in the breeders and reduced Salmonella prevalences and loads in their broiler progeny, but did not significantly decrease Salmonella in the breeder farm environment.

A method for hardening or curing adhesives for flocking thermally sensitive substrata by means of an electron-beam

International Nuclear Information System (INIS)

Nablo, S.V.; Fussa, A.D.

1975-01-01

The invention relates to a method for hardening or curing adhesives for flocking thermally sensitive substrata by means of an electron-beam. That method consists in accurately adjusting the parameters of irradiation by an electron-beam and the beam velocity so as to obtain, a very rapid hardening of adhesives used for fixing flocking materials, or the like, to thermally sensitive substrate. That can be applied to hardening or curing adhesives for flocking thermally-sensitive substrata which normally restrict the hardening rate [fr

The interaction of birth order and parental age on sexual orientation: an examination in two samples.

Science.gov (United States)

Bogaert, Anthony F; Cairney, John

2004-01-01

A birth order and sexual orientation relationship has been demonstrated numerous times in men, but a related variable, parental age (i.e. age of parents when the participant was born), has been less studied and has demonstrated contradictory results. In this research, the relations among birth order, parental age and sexual orientation were examined in a national probability sample of the US (Kessler, 1994; Kessler et al., 1994) and in a Canadian sample of homosexual and heterosexual men closely matched on demographic characteristics (Blanchard & Bogaert, 1996a). In both studies, an interaction between birth order and parental age was observed in men, such that there was positive association between number of older siblings and the likelihood of homosexuality, but this association weakened with increasing parental age. No significant effects were observed for women. The results are discussed in relation to recent theories of the birth order/sexual orientation relationship.

Parental perspectives regarding primary-care weight-management strategies for school-age children.

Science.gov (United States)

Turer, Christy Boling; Mehta, Megha; Durante, Richard; Wazni, Fatima; Flores, Glenn

2016-04-01

To identify parental perspectives regarding weight-management strategies for school-age children, focus groups were conducted of parents of overweight and obese (body mass index ≥ 85th percentile) 6-12-year-old children recruited from primary-care clinics. Questions focused on the role of the primary-care provider, effective components of weight-management strategies and feasibility of specific dietary strategies. Focus groups were recorded, transcribed and analysed using margin coding and grounded theory. Six focus groups were held. The mean age (in years) for parents was 32, and for children, eight; 44% of participants were Latino, 33%, African-American and 23%, white. Parents' recommendations on the primary-care provider's role in weight management included monitoring weight, providing guidance regarding health risks and lifestyle changes, consistent follow-up and using discretion during weight discussions. Weight-management components identified as key included emphasising healthy lifestyles and enjoyment, small changes to routines and parental role modelling. Parents prefer guidance regarding healthy dietary practices rather than specific weight-loss diets, but identified principles that could enhance the acceptability of these diets. For dietary guidance to be feasible, parents recommended easy-to-follow instructions and emphasising servings over counting calories. Effective weight-management strategies identified by parents include primary-care provider engagement in weight management, simple instructions regarding healthy lifestyle changes, parental involvement and deemphasising specific weight-loss diets. These findings may prove useful in developing primary-care weight-management strategies for children that maximise parental acceptance. © 2014 John Wiley & Sons Ltd.

Chronic interstitial lung disease in nylon flocking industry workers--Rhode Island, 1992-1996.

Science.gov (United States)

1997-09-26

Interstitial lung disease (ILD) occurs infrequently; some cases are attributed to sarcoidosis, pulmonary hemorrhage syndromes, connective tissue diseases, hypersensitivity pneumonitis, drugs, radiation, and mineral dusts (e.g., silica or asbestos). However, most cases of ILD are of uncertain classification or etiology. This report describes preliminary findings of the investigation in Rhode Island of an outbreak of ILD among workers involved in the manufacture of finely cut nylon (flock) and flocked fabric (used for upholstery, clothing, and automobiles); the findings provide evidence of a newly recognized occupational illness.

Bidirectional sorting of flocking particles in the presence of asymmetric barriers.

Science.gov (United States)

Drocco, Jeffrey A; Olson Reichhardt, C J; Reichhardt, C

2012-05-01

We demonstrate numerically bidirectional sorting of flocking particles interacting with an array of V-shaped asymmetric barriers. Each particle aligns with the average swimming direction of its neighbors according to the Vicsek model and experiences additional steric interactions as well as repulsion from the fixed barriers. We show that particles preferentially localize to one side of the barrier array over time and that the direction of this rectification can be reversed by adjusting the particle-particle exclusion radius or the noise term in the equations of motion. These results provide a conceptual basis for isolation and sorting of single-cell and multicellular organisms that move collectively according to flocking-type interaction rules.

Broiler health status has a major negative impact on broiler flock contamination with Campylobacter spp. in Lithuania

DEFF Research Database (Denmark)

Legaudaite-Lydekaitiene, Viktorija; Serniene, Loreta; Vismantaite, Vaida

2017-01-01

analysed using the statistical package SPSS. Study revealed that 59.3% of the examined broiler flocks were contaminated with Campylobacter spp. Statistical analysis revealed that broiler flock contamination with Campylobacter was abattoir- and farm-dependent. Among a number of risk factors (e.g. the number...

The Effects of the Parenting Styles on Social Skills of Children Aged 5-6

Science.gov (United States)

Kol, Suat

2016-01-01

The purpose of this study is to determine the effects of the parenting styles on social skills of children aged 5-6. The problem sentence of the research is; Do the parenting styles' have any effects on social skills of children aged 5-6?. The sub-problems of the research are in the form as; Does the social skills of children aged 5-6 differs from…

Perceptions of parental smoking and sociodemographic factors associated with the adoption of home smoking bans among parents of school-aged children.

Science.gov (United States)

Chen, Yu-Ting; Chen, Ping-Ling

2014-08-01

Although public smoking restrictions have been implemented, children are still exposed to household smoking. Parental smoking is the main source of children's exposure to secondhand smoke. This study was conducted to examine the factors associated with parents' adoption of home smoking bans. A cross-sectional study was conducted using a self-administered questionnaire to collect data from 768 parents of school-aged children in Taiwan. The home smoking restriction status, parents' perceptions of smoking in the presence of children and its influences, and parents' sociodemographic characteristics were assessed. Hierarchical logistic regression analysis was used to determine the best-fit model. More than 80% of the parents agreed with home smoking bans, whereas only approximately 26% of the parents actually restricted smoking at home completely. The crude odds ratios showed that parents who perceived the influence of parental smoking on children to be negative were more likely to adopt home smoking bans. Hierarchical logistic regression revealed factors associated with the adoption of home smoking bans, including a higher education level and older age of parents, a family composed of nonparent adults, and opposition to parental smoking in the presence of children. Children's health is a major concern for parents considering home smoking bans. Helping parents clarify misunderstandings regarding parental smoking, emphasizing the adverse effects of children's exposure to parental smoking, suggesting healthy substitutes for smoking, and providing effective strategies for maintaining a smoke-free home can motivate families to adopt home smoking bans. © The Author 2014. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Influence of parenting styles on development of children aged three to six years old.

Science.gov (United States)

Nanthamongkolchai, Sutham; Ngaosusit, Chutima; Munsawaengsub, Chokchai

2007-05-01

To investigate the influences of parenting styles on development of children aged three to six years. A cross-sectional study was conducted in 360 children and their parents selected by multi-stage random sampling. The data were collected from July 24th to August 31st, 2004. The Denver II test kit and the scale by Baumrind D were used to test the child development and parenting styles respectively. A questionnaire was used to collect the family and child factors. Data were analyzed by frequency distribution and Multiple logistic regression with the significant level set at p-value of Parenting styles had significant influences on child development (p-value parenting style had a 1.9 times higher chance of having delayed development compared with those with democratic parenting style. In addition, significant family and child factors for explaining child development were family type, mother's education, father's occupation, relationship within the family, nutritional status and sex. Parenting styles had a significant influence on child development. The children raised with mixed parenting style had a 1.9 timds higher chance of having delayed development compared to those whose parents used democratic parenting style. Therefore, the parents should rear their children by using the democratic parenting style that leads to the age-appropriate development child

FLOCK cluster analysis of mast cell event clustering by high-sensitivity flow cytometry predicts systemic mastocytosis.

Science.gov (United States)

Dorfman, David M; LaPlante, Charlotte D; Pozdnyakova, Olga; Li, Betty

2015-11-01

In our high-sensitivity flow cytometric approach for systemic mastocytosis (SM), we identified mast cell event clustering as a new diagnostic criterion for the disease. To objectively characterize mast cell gated event distributions, we performed cluster analysis using FLOCK, a computational approach to identify cell subsets in multidimensional flow cytometry data in an unbiased, automated fashion. FLOCK identified discrete mast cell populations in most cases of SM (56/75 [75%]) but only a minority of non-SM cases (17/124 [14%]). FLOCK-identified mast cell populations accounted for 2.46% of total cells on average in SM cases and 0.09% of total cells on average in non-SM cases (P < .0001) and were predictive of SM, with a sensitivity of 75%, a specificity of 86%, a positive predictive value of 76%, and a negative predictive value of 85%. FLOCK analysis provides useful diagnostic information for evaluating patients with suspected SM, and may be useful for the analysis of other hematopoietic neoplasms. Copyright© by the American Society for Clinical Pathology.

Effects of habitat and time of day on flock size of Turkey Vultures in Cuba (Cathartes aura

Directory of Open Access Journals (Sweden)

Piotr Tryjanowski

2018-01-01

Full Text Available In agricultural landscapes, the Turkey Vulture Cathartes aura feeds mainly on carcases of domestic animals. In spring 2017, data on 214 flocks of Turkey vultures were collected in a road survey in Cuba (in total 2384 km. Turkey Vultures were found to be common accross Cuba, but flock size varied between habitats, reaching a maximum of 43 in valleys and 31 in agricultural landscapes with domestic animal farms. Vultures were active throughout the day, but the time of day did not significantly affect flock size. This study corroborates previous studies which suggested that carrion resources located in agricultural habitats and river valleys is crucial for the continued survival of this still abundant species. Changes in Cuba’s socio-political system in the near future will likely impact agricultural practices, and this in turn will likely affect Turkey Vultures. Our study may serve as a baseline against which future population changes and flocking behaviour of Turkey Vultures can be compared.

Parent-Reported Differences between School-Aged Girls and Boys on the Autism Spectrum

Science.gov (United States)

Sutherland, Rebecca; Hodge, Antoinette; Bruck, Susan; Costley, Debra; Klieve, Helen

2017-01-01

More boys than girls are diagnosed with autism spectrum disorder; however, there are conflicting findings about whether they differ in their presentation. This study involved a survey of parents of school-aged children on the autism spectrum (171 parents of girls and 163 parents of boys) that was distributed via social media. The surveys provided…

INITIAL VALIDATION OF THE ASSESSMENT OF PARENTING TOOL: A TASK- AND DOMAIN-LEVEL MEASURE OF PARENTING SELF-EFFICACY FOR PARENTS OF INFANTS FROM BIRTH TO 24 MONTHS OF AGE.

Science.gov (United States)

Moran, Tracy E; Polanin, Joshua R; Evenson, Amber L; Troutman, Beth R; Franklin, Christina L

2016-05-01

Parenting self-efficacy (PSE) includes parents' self-perceptions regarding their capabilities in performing the numerous and changing tasks associated with parenting a specific child (i.e., domain-specific PSE) as well as their self-perceptions in the parenting role overall (i.e., domain-general PSE). Prior literature has demonstrated PSE's relations with numerous constructs significant to mental health and the parent-infant relationship. Prior measures of PSE have been limited by focusing on only domain-specific or domain-general PSE, ignoring the importance of infant development to PSE, and other psychometric limitations. This article presents sound psychometric data for a new measure of PSE, the Assessment of Parenting Tool (APT). The APT includes task-level items on the Domain-Specific subscale (APT-DS) for each age-referenced version of the measure as well as a domain-general subscale that taps overall PSE within the first 24 months' postpartum. Initial construct validity of the measure is established, particularly for parents of infants aged 3 months and older. A stable, three-factor structure for the domain-general subscale includes "coping with being a parent," "attuned parenting," and "self-perceived model parenting." Future directions for the APT, including a revised checklist format for the domain-specific subscale, are included. © 2016 Michigan Association for Infant Mental Health.

Stress in parents of children born very preterm is predicted by child externalising behaviour and parent coping at age 7 years.

Science.gov (United States)

Linden, Mark A; Cepeda, Ivan L; Synnes, Anne; Grunau, Ruth E

2015-06-01

To examine factors which predict parenting stress in a longitudinal cohort of children born very preterm, and seen at age 7 years. We recruited 100 very preterm (≤32 weeks gestational age) child-parent dyads and a control group of 50 term-born dyads born between 2001 and 2004 with follow-up at 7 years. Parents completed the Parenting Stress Index, Ways of Coping Questionnaire, Child Behavior Check List, Beck Depression Inventory and the State Trait Anxiety Inventory questionnaires. Child IQ was assessed using the Wechsler Intelligence Scale-IV. After controlling for maternal education, parents of preterm children (95% CI 111.1 to 121.4) scored higher (p=0.027) on the Parenting Stress Index than term-born controls (95% CI 97.8 to 113.2). Regression analyses showed that child externalising behaviour, sex and parent escape/avoidance coping style, predicted higher parenting stress in the preterm group. Parents of preterm girls expressed higher levels of stress than those of boys. Maladaptive coping strategies contribute to greater stress in parents of very preterm children. Our findings suggest that these parents need support for many years after birth of a very preterm infant. 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.

Intergenerational Support and Marital Satisfaction: Implications of Beliefs About Helping Aging Parents

Science.gov (United States)

Polenick, Courtney A.; Zarit, Steven H.; Birditt, Kira S.; Bangerter, Lauren R.; Seidel, Amber J.; Fingerman, Karen L.

2016-01-01

Everyday support given to aging parents is a salient aspect of married life that may have implications for marital quality. Among 132 middle-aged couples drawn from Wave 1 of the Family Exchanges Study, we examined the moderating effects of each spouse’s normative and motivational beliefs about helping parents on associations between the frequency of everyday support that wives and husbands gave to their own parents and marital satisfaction. Husbands' more frequent provision of support was linked to wives' greater marital satisfaction when reports of personal rewards linked to helping parents were high for wives or low for husbands. Conversely, wives’ more frequent provision of support was linked to husbands’ lower marital satisfaction when reports of filial obligation were low for husbands or high for wives. Findings highlight the interdependence within couples, and indicate that both spouses' perceptions are important in understanding linkages between intergenerational support and marital satisfaction. PMID:28154427

Quantized flocking control for second-order multiple agents with obstacle avoidance

Directory of Open Access Journals (Sweden)

Chunguang Li

2016-01-01

Full Text Available A quantized flocking control for a group of second-order multiple agents with obstacle avoidance is proposed to address the problem of the exchange of information needed for quantification. With a reasonable assumption, a logarithmic or uniform quantizer is used for the exchange of relative position and velocity information between adjacent agents and the virtual leader, moving at a steady speed along a straight line, and a distributed flocking algorithm with obstacle avoidance capability is designed based on the quantitative information. The Lyapunov stability criterion of nonsmooth systems and the invariance principle are used to prove the stability of these systems. The simulations and experiments are presented to demonstrate the feasibility and effectiveness of the proposed approach.

Microbial ecology of Campylobacter jejuni in a United Kingdom chicken supply chain: intermittent common source, vertical transmission, and amplification by flock propagation.

OpenAIRE

Pearson, A D; Greenwood, M H; Feltham, R K; Healing, T D; Donaldson, J; Jones, D M; Colwell, R R

1996-01-01

A study of Campylobacter jejuni on a broiler chicken farm between 1989 and 1994 gave an estimated isolation rate of 27% (3,304 of 12,233) from a 0.9% sample of 1.44 million broiler chickens from six to eight sheds over 32 consecutive rearing flocks comprising 251 broiler shed flocks. During the study, C. jejuni was found in 35.5% of the 251 shed flocks but only 9.2% (23 of 251) had Campylobacter isolates in successive flocks, with 9 of those 23 sheds having the same serotype between consecuti...

House-level risk factors associated with the colonization of broiler flocks with Campylobacter spp. in Iceland, 2001 - 2004.

Science.gov (United States)

Guerin, Michele T; Martin, Wayne; Reiersen, Jarle; Berke, Olaf; McEwen, Scott A; Bisaillon, Jean-Robert; Lowman, Ruff

2007-11-12

The concurrent rise in consumption of fresh chicken meat and human campylobacteriosis in the late 1990's in Iceland led to a longitudinal study of the poultry industry to identify the means to decrease the frequency of broiler flock colonization with Campylobacter. Because horizontal transmission from the environment is thought to be the most likely source of Campylobacter to broilers, we aimed to identify broiler house characteristics and management practices associated with flock colonization. Between May 2001 and September 2004, pooled caecal samples were obtained from 1,425 flocks at slaughter and cultured for Campylobacter. Due to the strong seasonal variation in flock prevalence, analyses were restricted to a subset of 792 flocks raised during the four summer seasons. Logistic regression models with a farm random effect were used to analyse the association between flock Campylobacter status and house-level risk factors. A two-stage process was carried out. Variables were initially screened within major subsets: ventilation; roof and floor drainage; building quality, materials and repair; house structure; pest proofing; biosecurity; sanitation; and house size. Variables with p analyses were used in both the screening stage (i.e. within each subset) and in the comprehensive model. 217 out of 792 flocks (27.4%) tested positive. Four significant risk factors were identified. Campylobacter colonization was predicted to increase when the flock was raised in a house with vertical (OR = 2.7), or vertical and horizontal (OR = 3.2) ventilation shafts, when the producer's boots were cleaned and disinfected prior to entering the broiler house (OR = 2.2), and when the house was cleaned with geothermal water (OR = 3.3). The increased risk associated with vertical ventilation shafts might be related to the height of the vents and the potential for vectors such as flies to gain access to the house, or, increased difficulty in accessing the vents for proper cleaning and

TV parenting practices: is the same scale appropriate for parents of children of different ages?

OpenAIRE

Chen, Tzu-An; O?Connor, Teresia M; Hughes, Sheryl O; Frankel, Leslie; Baranowski, Janice; Mendoza, Jason A; Thompson, Debbe; Baranowski, Tom

2013-01-01

Purposes Use multidimensional polytomous item response modeling (MPIRM) to evaluate the psychometric properties of a television (TV) parenting practices (PP) instrument. Perform differential item functioning (DIF) analysis to test whether item parameter estimates differed across education, language, or age groups. Methods Secondary analyses of data from three studies that included 358 children between the ages of 3 and 12?years old in Houston, Texas. TV PP included 15 items with three subscal...

Factors contributing to radiocaesium variability in upland sheep flocks in west Cumbria (United Kingdom)

International Nuclear Information System (INIS)

Beresford, N.A.; Barnett, C.L.; Wright, S.M.; Howard, B.J.; Crout, N.M.J.

2007-01-01

Following the Chernobyl accident in 1986, restrictions were placed on the movement and slaughter of sheep within upland areas of the UK because radiocaesium activity concentrations in their meat exceeded 1000 Bq kg -1 fresh weight. Some farms remain under restriction in 2007. From 1991 to 1993 detailed studies were conducted on three sheep farms within the restricted area of west Cumbria to systematically assess the various parameters which may contribute to the observed variability in radiocaesium activity concentrations within sheep flocks. This paper reports the spatial variation in soil and vegetation activity concentrations across the grazed areas at these farms and determines the influence of grazing behaviour on variability in 137 Cs activity concentrations between individual sheep within the flocks. Together with previously reported results, these new data are used to draw conclusions on the factors determining variability within the three flocks. However, the factors are too site specific to be able to generalise the findings to other farms within the restricted areas of the UK

Long‐term trends in fall age ratios of black brant

Science.gov (United States)

Ward, David H.; Amundson, Courtney L.; Stehn, Robert A.; Dau, Christian P.

2018-01-01

Accurate estimates of the age composition of populations can inform past reproductive success and future population trajectories. We examined fall age ratios (juveniles:total birds) of black brant (Branta bernicla nigricans; brant) staging at Izembek National Wildlife Refuge near the tip of the Alaska Peninsula, southwest Alaska, USA, 1963 to 2015. We also investigated variation in fall age ratios associated with sampling location, an index of flock size, survey effort, day of season, observer, survey platform (boat‐ or land‐based) and tide stage. We analyzed data using logistic regression models implemented in a Bayesian framework. Mean predicted fall age ratio controlling for survey effort, day of year, and temporal and spatial variation was 0.24 (95% CL = 0.23, 0.25). Overall trend in age ratios was −0.6% per year (95% CL = −1.3%, 0.2%), resulting in an approximate 26% decline in the proportion of juveniles over the study period. We found evidence for variation across a range of variables implying that juveniles are not randomly distributed in space and time within Izembek Lagoon. Age ratios varied by location within the study area and were highly variable among years. They decreased with the number of birds aged (an index of flock size) and increased throughout September before leveling off in early October and declining in late October. Age ratios were similar among tide stages and observers and were lower during boat‐based (offshore) than land‐based (nearshore) surveys. Our results indicate surveys should be conducted annually during early to mid‐October to ensure the entire population is present and available for sampling, and throughout Izembek Lagoon to account for spatiotemporal variation in age ratios. Sampling should include a wide range of flock sizes representative of their distribution and occur in flocks located near and off shore. Further research evaluating the cause of declining age ratios in the fall population is necessary

Epidemiology of Mycoplasma agalactiae and Mycoplasma mycoides cluster in flocks of northeastern Brazil

Directory of Open Access Journals (Sweden)

Sandra Batista dos Santos

2018-04-01

Full Text Available ABSTRACT: The present study aimed to investigate contagious agalactia (CA in flocks from Pernambuco State. The study involved 225 goats and 63 ewes; 288 milk samples and 100 vaginal swabs were collected in total. The PCR assays were carried out using specific primers to Mycoplasma agalactiae and the Mycoplasma mycoides cluster. Among the goat’s milk samples,12.0% (27/225 were positive for Mycoplasma agalactiae DNA, while 5.3% (12/225 contained the Mycoplasma mycoides cluster. Of the vaginal swabs taken from goats, 15.4% (12/78 were positive for Mycoplasma agalactiae DNA and 3.8% (3/78 contained the Mycoplasma mycoides cluster. In the case of ewes, 4.3% (1/23 of the milk samples contained Mycoplasma agalactiae DNA, and 7.5% (3/40 were positive for the Mycoplasma mycoides cluster. Vaginal swabs taken from sheep´s were negative. Analysis of risk factors for mycoplasmosis, showed that goats and sheep flocks on the extensive breeding system are more likely to have mycoplasmosis than those on the intensive breeding system (odds ratio (OR 6.2; p=0.004; meat goat and sheep flocks are more likely to have infection compared to dairy flocks (OR 4.8; p=0.011; unclean animal housing increases the chances of infection (OR 5.0; p=0.031 and not performing quarantine increases the chances of mycoplasmosis (OR 4.6; p=0.042. Based on these findings we conclude that CA syndrome in the semiarid region of Pernambuco state can be associated with Mycoplasma agalactiae and Mycoplasma mycoides cluster.

Parental break-ups and stress: roles of age & family structure in 44 509 pre-adolescent children.

Science.gov (United States)

Dissing, Agnete S; Dich, Nadya; Andersen, Anne-Marie Nybo; Lund, Rikke; Rod, Naja H

2017-10-01

Parental break-up is wide spread, and the effects of parental break-up on children's well-being are known. The evidence regarding child age at break-up and subsequent family arrangements is inconclusive. Aim: to estimate the effects of parental break-up on stress in pre-adolescent children with a specific focus on age at break-up and post-breakup family arrangements. We used data from the Danish National Birth Cohort. Participants included 44 509 children followed from birth to age 11. Stress was self-reported by children at age 11, when the children also reported on parental break-up and post break-up family arrangements. Twenty-one percent of the children had experienced a parental break-up at age 11, and those who had experienced parental break-up showed a higher risk of stress (OR:1.72, 95%CI:1.55;1.91) regardless of the child's age at break-up. Children living in a new family with stepparents (OR = 1.63, 95%CI:1.38;1.92), or shared between the parents (OR = 1.48, 95%CI:1.26;1.75) reported higher stress than children of intact families. Single parent families reported markedly higher stress levels than children in intact families (OR = 2.18, 95%CI:1.90;2.50) and all other family types. Children who were satisfied with their living arrangements post-break-up reported the same stress level as children living in intact families (OR = 1.01, 95%CI:0.86;1.18). Children who experience parental break-up have higher stress levels, also many years after the break-up, and those living in a single parent household post break-up seem to be most vulnerable. Living arrangements post-breakup should be further investigated as a potential protective factor. © The Author 2017. Published by Oxford University Press on behalf of the European Public Health Association. All rights reserved.

Warm Parenting and Effortful Control in Toddlerhood: Independent and Interactive Predictors of School-Age Externalizing Behavior.

Science.gov (United States)

Reuben, Julia D; Shaw, Daniel S; Neiderhiser, Jenae M; Natsuaki, Misaki N; Reiss, David; Leve, Leslie D

2016-08-01

Externalizing symptoms, such as aggression, impulsivity, and inattention, represent the most common forms of childhood maladjustment (Campbell et al. Development and Psychopathology, 12, 467-488, 2000). Several dimensions of parenting behavior, including overreactive and warm parenting, have been linked to children's conduct problems. However, the majority of these studies involve biologically-related family members, thereby limiting understanding of the role of genetic and/or environmental underpinnings of parenting on child psychopathology. This study extends previous research by exploring associations between overreactive and warm parenting during toddlerhood and school-age externalizing problems, as well as the potential moderating effects of child effortful control (EC) on such associations using a longitudinal adoption design. The sample consisted of 225 adoption-linked families (adoptive parents, adopted child [124 male and 101 female] and birth parent[s]), thereby allowing for a more precise estimate of environmental influences on the association between parenting and child externalizing problems. Adoptive mothers' warm parenting at 27 months predicted lower levels of child externalizing problems at ages 6 and 7. Child EC moderated this association in relation to teacher reports of school-age externalizing problems. Findings corroborate prior research with biological families that was not designed to unpack genetic and environmental influences on associations between parenting and child externalizing problems during childhood, highlighting the important role of parental warmth as an environmental influence.

PRNP genetic variability and molecular typing of natural goat scrapie isolates in a high number of infected flocks

OpenAIRE

Fragkiadaki Eirini G; Vaccari Gabriele; Ekateriniadou Loukia V; Agrimi Umberto; Giadinis Nektarios D; Chiappini Barbara; Esposito Elena; Conte Michela; Nonno Romolo

2011-01-01

Abstract One hundred and four scrapie positive and 77 negative goats from 34 Greek mixed flocks were analysed by prion protein gene sequencing and 17 caprine scrapie isolates from 11 flocks were submitted to molecular isolate typing. For the first time, the protective S146 variant was reported in Greece, while the protective K222 variant was detected in negative but also in five scrapie positive goats from heavily infected flocks. By immunoblotting six isolates, including two goat flockmates ...

The role of litter beetles as potential reservoir for Salmonella enterica and thermophilic Campylobacter spp. between broiler flocks

DEFF Research Database (Denmark)

Skov, M.N.; Spencer, A.G.; Hald, Birthe

2004-01-01

broiler flocks in all) as well as beetles collected during both rotations of production and in the empty period (after cleaning and disinfection) between these flocks were monitored for the presence of salmonella. Examinations for the presence of campylobacter in the same sample materials were also...

Retraction and expansion of flock mobility in central asia: costs and ...

African Journals Online (AJOL)

Retraction and expansion of flock mobility in central asia: costs and consequences. Carol Kerven, Ilya Ilych Alimaev, Roy Behnke, Grant Davidson, Leen Franchois, Nurlan Malmakov, Erik Mathijs, Aidos Smailov, Sayat Temirbekov, Iain Wright ...

Parental age and offspring mortality: Negative effects of reproductive ageing may be counterbalanced by secular increases in longevity.

Science.gov (United States)

Barclay, Kieron; Myrskylä, Mikko

2018-07-01

As parental ages at birth continue to rise, concerns about the effects of fertility postponement on offspring are increasing. Due to reproductive ageing, advanced parental ages have been associated with negative health outcomes for offspring, including decreased longevity. The literature, however, has neglected to examine the potential benefits of being born at a later date. Secular declines in mortality mean that later birth cohorts are living longer. We analyse mortality over ages 30-74 among 1.9 million Swedish men and women born 1938-60, and use a sibling comparison design that accounts for all time-invariant factors shared by the siblings. When incorporating cohort improvements in mortality, we find that those born to older mothers do not suffer any significant mortality disadvantage, and that those born to older fathers have lower mortality. These findings are likely to be explained by secular declines in mortality counterbalancing the negative effects of reproductive ageing.

Relevance of metric-free interactions in flocking phenomena.

Science.gov (United States)

Ginelli, Francesco; Chaté, Hugues

2010-10-15

We show that the collective properties of self-propelled particles aligning with their topological (Voronoi) neighbors are qualitatively different from those of usual models where metric interaction ranges are used. This relevance of metric-free interactions, shown in a minimal setting, indicate that realistic models for the cohesive motion of cells, bird flocks, and fish schools may have to incorporate them, as suggested by recent observations.

Parental separation/divorce in childhood and partnership outcomes at age 30.

Science.gov (United States)

Fergusson, David M; McLeod, Geraldine F H; John Horwood, L

2014-04-01

Previous research has found that children exposed to separation/divorce may also experience relationship problems in adulthood. The aim of this investigation was to examine this issue in a birth cohort of over 900 New Zealand children studied to age 30. Data were gathered over the course of the Christchurch Health and Development Study (CHDS). The CHDS is a 30 year longitudinal study of a birth cohort of 1265 children born in Christchurch (NZ) in 1977. The data collected included the following: (a) timing and number of parental separations and divorces from birth to 15 years; (b) partnership outcomes (16-30 years) of the number of cohabiting/marriage partnerships; positive partner relations; negative partner relations; partner adjustment/conduct problems; and interpartner violence victimization and perpetration; and (c) potential covariate factors. Study findings showed the presence of significant associations between childhood parental separations/divorces and number of cohabiting/marriage partnerships (16-30 years) (p < .001), negative partner relations (p = .021), extent of partner adjustment/conduct problems (p < .001), and perpetration of interpartner violence (p = .018). Childhood parental separation/divorce explained less than 2.5% of the variance in partnership outcomes. These associations were explained statistically by a series of covariate factors associated with childhood parental separation/divorce including parental history of illicit drug use, childhood sexual abuse, childhood conduct problems (7-9 years), interparental conflict and violence, childhood physical punishment/maltreatment, family socio-economic status at the child's birth, and parental history of criminality. Tests of gender interaction showed that the effect of childhood parental separations/divorces may be the same for males and females. Analysis of the number of childhood parental separations/divorces experienced into three age groups (birth to 5, 5-10 years and 10-15�

Watermelons Not War! A Support Book for Parenting in the Nuclear Age.

Science.gov (United States)

Cloud, Kate; And Others

The Nuclear Education Project (NEP), a group of five women concerned about parenting in a nuclear age, developed this guide to help parents and others develop a sense of hope and promote a greater involvement in the democratic political process. Chapter I, "The Heart of the Matter," presents sections on answering possible questions children might…

Perceptions of parental behavior with regard to parents’ gender and respondents’ age and gender

Directory of Open Access Journals (Sweden)

Opsenica-Kostić Jelena

2010-01-01

Full Text Available The findings of the research into the perceived parental behavior provide contrasting data as to the existence and the nature of differences in the perception of parental behavior based on parents’ gender and respondents’ gender. The purpose of the present study is to examine the differences in the perceived parental behavior in adolescents with regard to parents’ gender and respondents’ age and gender. The study included 466 respondents (262 girls and 204 boys, in middle to late adolescence, divided into four sub-groups according to their age. The respondents were asked to fill in the Parental Bonding Instrument (PBI questionnaire which measures the care and overprotection in mothers and fathers respectively. The obtained findings show the existence of significant difference based on the parents’ gender for both subscales: both maternal care and maternal overprotection were estimated as higher. Observing the differences by respondents’ gender on the whole sample, only one significant difference is found: paternal overprotection was estimated as higher by girls. The differences by age as observed within gender groups are completely disparate for girl and boy groups. The best insight into the differences is obtained through analysis by gender, for groups relatively homogenous in terms of their age (for the first three groups the only significant difference appears in the paternal overprotection subscale; the difference disappears in the subgroup of the oldest respondents’, while the differences between the perception of maternal and paternal care are of significance here. One particularly important finding for future research into rearing behavior is the fact that the perception of parental behavior changes over the period of adolescence differently for boys and girls; therefore, the analysis including perceived parental behavior should be performed for subgroups by gender, which are as homogenous as possible in terms of their age.

Teacher Evaluations of Executive Functioning in Schoolchildren Aged 9-12 and the Influence of Age, Sex, Level of Parental Education.

Science.gov (United States)

van Tetering, Marleen A J; Jolles, Jelle

2017-01-01

Executive functions (EFs) develop over the period of early childhood and adolescence up until young adulthood. Individual children differ substantially in the pace at which their EFs develop, and characteristics such as sex and the level of parental education (LPE) are thought to contribute to these differences. In the present study, we assessed age-related changes in EFs as perceived and evaluated by teachers and parents as well as the influence of sex and LPE on their evaluations. We used a newly developed observer-report questionnaire, the Amsterdam Executive Function Inventory (AEFI). The AEFI assesses three important components of the executive aspects of daily life behavior in 13 questions: Attention; Self-control and Self-monitoring; and Planning and Initiative taking. Teachers and parents evaluated these aspects of executive functioning in 186 schoolchildren in grades 3-6 (age: 9-12 years). Age effects within grades and differences in social economic status between the four participating schools were controlled. Results showed a significant increase in teacher-perceived EFs from third to fourth grades and from fifth to sixth grades. This development was influenced both by the sex of the child and by the LPE. As perceived by teachers, the component self-control and self-monitoring was higher for girls than for boys, and planning abilities were higher for children from families with a higher LPE. Additional analyses showed that there is a systematic and statistically significant difference between the evaluations of the teachers and that of parents. Parents reported higher scores for planning, whereas teachers reported higher scores for self-control and self-monitoring. Evaluations by parents and teachers were different for girls, but not for boys. These findings are important because they imply that the development of EFs as perceived by parents and teachers is influenced by child-related factors. Second, there are clear differences in evaluations between

Measuring Parenting Practices among Parents of Elementary School-Age Youth

Science.gov (United States)

Randolph, Karen A.; Radey, Melissa

2011-01-01

Objectives: The objective of this study is to establish the factor structure of the Alabama Parenting Questionnaire (APQ), an instrument designed to measure parenting practices among parents of elementary school children. Methods: Exploratory (EFA) and confirmatory factor analytic (CFA) procedures are used to validate the APQ with 790 parents of…

PRNP genetic variability and molecular typing of natural goat scrapie isolates in a high number of infected flocks.

Science.gov (United States)

Fragkiadaki, Eirini G; Vaccari, Gabriele; Ekateriniadou, Loukia V; Agrimi, Umberto; Giadinis, Nektarios D; Chiappini, Barbara; Esposito, Elena; Conte, Michela; Nonno, Romolo

2011-09-30

One hundred and four scrapie positive and 77 negative goats from 34 Greek mixed flocks were analysed by prion protein gene sequencing and 17 caprine scrapie isolates from 11 flocks were submitted to molecular isolate typing. For the first time, the protective S146 variant was reported in Greece, while the protective K222 variant was detected in negative but also in five scrapie positive goats from heavily infected flocks. By immunoblotting six isolates, including two goat flockmates carrying the K222 variant, showed molecular features slightly different from all other Greek and Italian isolates co-analysed, possibly suggesting the presence of different scrapie strains in Greece.

PRNP genetic variability and molecular typing of natural goat scrapie isolates in a high number of infected flocks

Directory of Open Access Journals (Sweden)

Fragkiadaki Eirini G

2011-09-01

Full Text Available Abstract One hundred and four scrapie positive and 77 negative goats from 34 Greek mixed flocks were analysed by prion protein gene sequencing and 17 caprine scrapie isolates from 11 flocks were submitted to molecular isolate typing. For the first time, the protective S146 variant was reported in Greece, while the protective K222 variant was detected in negative but also in five scrapie positive goats from heavily infected flocks. By immunoblotting six isolates, including two goat flockmates carrying the K222 variant, showed molecular features slightly different from all other Greek and Italian isolates co-analysed, possibly suggesting the presence of different scrapie strains in Greece.

Parental age and birth order in Chinese children with congenital heart disease.

Science.gov (United States)

Tay, J S; Yip, W C; Joseph, R

1982-01-01

Parental age and birth order were studied in 100 Chinese children with congenital heart disease (proven by cardiac catheterisation) and in 100 controls. A higher incidence of congenital heart disease was present in the children with higher birth orders. No relationship was found between the incidence and the paternal or maternal ages. Using the method of multiple regression analysis this birth order effect was significant (p less than 0.01) and independent of parental age. This finding provides indirect evidence of environmental influence in the causation of congenital heart disease, which is known to be inherited in a multifactorial manner. Family planning to limit the size of the family may possibly contribute to the reduction of the incidence of congenital heart disease. PMID:7154041

Gifted Students' Perceptions of Parenting Styles: Associations with Cognitive Ability, Sex, Race, and Age

Science.gov (United States)

Rudasill, Kathleen Moritz; Adelson, Jill L.; Callahan, Carolyn M.; Houlihan, Deanna Vogt; Keizer, Benjamin M.

2013-01-01

Children whose parents are warm and responsive yet also set limits and have reasonable expectations for their children tend to have better outcomes than their peers whose parents show less warmth and responsiveness, have low expectations, or both. Parenting behavior is related to family race and children's sex, age, and cognitive ability. However,…

Study of Adolescents Perceived Parenting Styles Based on their Gender and Age

OpenAIRE

صادق تقی لو

2017-01-01

Parenting styles play a major role in determining the life styles of adolescents and that is why they share a special significance. The present study was done with the aim to investigate adolescents’ perceived parenting styles based on their gender and age. The study was conducted by a post-event method and with a sample size of 623 subjects (311 female and 312 male), who were selected by the multistage sampling method. Data were analyzed, after being collected by the Baumrind Parenting Style...

Production parameters for a commercial Dorper flock on extensive ...

African Journals Online (AJOL)

tion on initial records at 2 or 3 years suggested that selection in the current flock should be directed against barrenness or failure to rear at least one ... numbers in South Africa, while breeding stock have also been exported to other ..... tages over birth type as a selection criterion for increased. Table 3 Least squares means ...

Influencing the parents of children aged 9-13 years: findings from the VERB campaign.

Science.gov (United States)

Price, Simani M; Huhman, Marian; Potter, Lance D

2008-06-01

The CDC's VERB campaign was designed to increase physical activity among children aged 9-13 years (tweens). As part of the strategy to surround tweens with support to be physically active, VERB developed messages for parents, the secondary target audience, to encourage them to support their tween's physical activity. Multiple regression analyses were conducted to determine whether parent awareness of VERB was a significant predictor of seven factors that related to parental attitudes, beliefs, and supportive behaviors for tweens' physical activity using the Youth Media Campaign Longitudinal Survey (YMCLS). Parents (N=1946) of U.S. children aged 9-13 years. Advertising directed at tweens through paid television, radio, print, Internet, and schools was the primary VERB intervention; tween advertising could have been also seen by parents. Messages directed at parents encouraging their support of tweens' physical activity were delivered in English through mainly print and radio. In-language messages for Latino and Asian audiences were delivered through print, radio, television, and at events. Parents' awareness of VERB; parents' attitudes, beliefs, and support for their tweens' physical activities. Awareness increased each year of the campaign; more than 50% of parents were aware of VERB by the third year of the campaign. Parents reported that their main source of awareness was television, the main channel used to reach tweens. Awareness of VERB was predictive of positive attitudes about physical activity for all children, belief in the importance of physical activity for their own child, and the number of days parents were physically active with their child. Parents' awareness of VERB was associated with positive attitudes, beliefs, and behavior. Parents' awareness probably resulted from a combination of messages directed to parents and tweens. To maximize audience reach, social marketers who are developing health messages should consider the potential value of

Kinetic theory of flocking: derivation of hydrodynamic equations.

Science.gov (United States)

Ihle, Thomas

2011-03-01

It is shown how to explicitly coarse-grain the microscopic dynamics of the rule-based Vicsek model for self-propelled agents. The hydrodynamic equations are derived by means of an Enskog-type kinetic theory. Expressions for all transport coefficients are given. The transition from a disordered to a flocking state, which at large particle speeds appears to be a fluctuation-induced first-order phase transition, is studied numerically and analytically.

2D Hand Tracking Based on Flocking with Obstacle Avoidance

Directory of Open Access Journals (Sweden)

Zihong Chen

2014-02-01

Full Text Available Hand gesture-based interaction provides a natural and powerful means for human-computer interaction. It is also a good interface for human-robot interaction. However, most of the existing proposals are likely to fail when they meet some skin-coloured objects, especially the face region. In this paper, we present a novel hand tracking method which can track the features of the hand based on the obstacle avoidance flocking behaviour model to overcome skin-coloured distractions. It allows features to be split into two groups under severe distractions and merge later. The experiment results show that our method can track the hand in a cluttered background or when passing the face, while the Flocking of Features (FoF and the Mean Shift Embedded Particle Filter (MSEPF methods may fail. These results suggest that our method has better performance in comparison with the previous methods. It may therefore be helpful to promote the use of the hand gesture-based human-robot interaction method.

Evaluation of risk factors of prevalence of leptospirosis in sheep flocks

Directory of Open Access Journals (Sweden)

M Imandar

2012-02-01

Full Text Available Leptospirosis  is  a  worldwide  bacterial  zoonoses  that  its  main  source  are  wild animals  and  rodents  That  leptospirals  excrete  in  their  urine. This  disease  causes  fever, hemoglobinuria, jaundice, abortion, mastitis, reduced  milk  production, reproductive  disorders  and  death  in  cattle, that  major  complications  in  sheep  are  abortion  and  pyelonephritis. The  purpose  of  this  study  is the  evaluation  of   risk  factors  for  leptospirosis  disease  and  its  association  with  high  prevalence  of  infection  in  the  sheep  flocks. Accordingly, 260 serum samples were collected from 20 flocks of  sheep. Then  with  microscopic  agglutination  test (MAT using  6  live  antigen  Leptospira  interrogans  include  Pomona , canicola, icterohaemorrhagiae, gryppotyphoza, ballum  and  hardjo  was  studied. MAT  test  results  of  the  serum  samples  showed  the  contamination  was  28.46%. Most  contamination  of  the  samples  was  allocated  to  sheep  who  lived  in  swampy  areas, so  that  70.28%  of  positive   samples  were  included. 56.25%  of  positive  samples  among  the  samples  showed  positive  reaction  with  serotype canicola. On the other hand, 76.56%  of  the  positive  samples  belonged  to  animals  which  in  their  environment, rodents   in  very  large  numbers  were  observed. The  sheep  that  kept  in moist  and  wet  environment  to  be  had  60%  of  positive  samples , and  finally  the  highest frequency  of  positive  animals  were  ranged  among  ages  3  to  6  years  old, the  incidence  of  the  disease  increased  in  older  animals. By  attention  to  the  results, increasing  of  age, living  in  swampy  and  wet  bed, being  infectious  dogs  in  side  of  flocks and  also  very  large

Approaches used by parents to keep their children safe at home: a qualitative study to explore the perspectives of parents with children aged under five years.

Science.gov (United States)

Ablewhite, Joanne; McDaid, Lisa; Hawkins, Adrian; Peel, Isabel; Goodenough, Trudy; Deave, Toity; Stewart, Jane; Watson, Michael; Kendrick, Denise

2015-09-29

Childhood unintentional injury represents an important global health problem. Many unintentional injuries experienced by children aged under 5 years occur within the home and are preventable. The aim of this study was to explore the approaches used by parents of children under five in order to help prevent unintentional injuries in the home and the factors which influence their use. Understanding how parents approach risk-management in the home has important implications for injury practitioners. A multi-centre qualitative study using semi-structured interviews. A thematic approach was used to analyse the data. Sixty five parents of children aged under 5 years, from four study areas were interviewed: Bristol, Newcastle, Norwich and Nottingham. Three main injury prevention strategies used by parents were: a) Environmental such as removal of hazards, and use of safety equipment; b) parental supervision; and c) teaching, for example, teaching children about safety and use of rules and routine. Strategies were often used in combination due to their individual limitations. Parental assessment of injury risk, use of strategy and perceived effectiveness were fluid processes dependent on a child's character, developmental age and the prior experiences of both parent and child. Some parents were more proactive in their approach to home safety while others only reacted if their child demonstrated an interest in a particular object or activity perceived as being an injury risk. Parents' injury prevention practices encompass a range of strategies that are fluid in line with the child's age and stage of development; however, parents report that they still find it challenging to decide which strategy to use and when.

Parental and grandparental ages in the autistic spectrum disorders: a birth cohort study.

Science.gov (United States)

Golding, Jean; Steer, Colin; Pembrey, Marcus

2010-04-01

A number of studies have assessed ages of parents of children with autistic spectrum disorders (ASD), and reported both maternal and paternal age effects. Here we assess relationships with grandparental ages. We compared the parental and grandparental ages of children in the population-based Avon Longitudinal Study of Parents and Children (ALSPAC), according to their scores in regard to 4 autistic trait measures and whether they had been given a diagnosis of ASD. Mean maternal and paternal ages of ASD cases were raised, but this appears to be secondary to a maternal grandmother age effect (P = 0.006): OR = 1.66[95%CI 1.16, 2.37] for each 10-year increase in the grandmother's age at the birth of the mother. Trait measures also revealed an association between the maternal grandmother's age and the major autistic trait-the Coherence Scale (regression coefficient b = 0.142, [95%CI = 0.057, 0.228]P = 0.001). After allowing for confounders the effect size increased to b = 0.217[95%CI 0.125, 0.308](Pautistic trait was unexpected, there is some biological plausibility, for the maternal side at least, given that the timing of female meiosis I permits direct effects on the grandchild's genome during the grandmother's pregnancy. An alternative explanation is the meiotic mismatch methylation (3 M) hypothesis, presented here for the first time. Nevertheless the findings should be treated as hypothesis generating pending corroborative results from other studies.

Drug use and antimicrobial resistance among Escherichia coli and Enterococcus spp. isolates from chicken and turkey flocks slaughtered in Quebec, Canada

OpenAIRE

Boulianne, Martine; Arsenault, Julie; Daignault, Danielle; Archambault, Marie; Letellier, Ann; Dutil, Lucie

2016-01-01

An observational study was conducted of chicken and turkey flocks slaughtered at federal processing plants in the province of Quebec, Canada. The objectives were to estimate prevalence of drug use at hatchery and on farm and to identify antimicrobial resistance (AMR) in cecal Escherichia coli and Enterococcus spp. isolates and factors associated with AMR. Eighty-two chicken flocks and 59 turkey flocks were sampled. At the hatchery, the most used antimicrobial was ceftiofur in chickens (76% of...

Collective Behavior of Chiral Active Matter: Pattern Formation and Enhanced Flocking

Science.gov (United States)

Liebchen, Benno; Levis, Demian

2017-08-01

We generalize the Vicsek model to describe the collective behavior of polar circle swimmers with local alignment interactions. While the phase transition leading to collective motion in 2D (flocking) occurs at the same interaction to noise ratio as for linear swimmers, as we show, circular motion enhances the polarization in the ordered phase (enhanced flocking) and induces secondary instabilities leading to structure formation. Slow rotations promote macroscopic droplets with late time sizes proportional to the system size (indicating phase separation) whereas fast rotations generate patterns consisting of phase synchronized microflocks with a controllable characteristic size proportional to the average single-particle swimming radius. Our results defy the viewpoint that monofrequent rotations form a vapid extension of the Vicsek model and establish a generic route to pattern formation in chiral active matter with possible applications for understanding and designing rotating microflocks.

Anisotropic interaction rules in circular motions of pigeon flocks: An empirical study based on sparse Bayesian learning

Science.gov (United States)

Chen, Duxin; Xu, Bowen; Zhu, Tao; Zhou, Tao; Zhang, Hai-Tao

2017-08-01

Coordination shall be deemed to the result of interindividual interaction among natural gregarious animal groups. However, revealing the underlying interaction rules and decision-making strategies governing highly coordinated motion in bird flocks is still a long-standing challenge. Based on analysis of high spatial-temporal resolution GPS data of three pigeon flocks, we extract the hidden interaction principle by using a newly emerging machine learning method, namely the sparse Bayesian learning. It is observed that the interaction probability has an inflection point at pairwise distance of 3-4 m closer than the average maximum interindividual distance, after which it decays strictly with rising pairwise metric distances. Significantly, the density of spatial neighbor distribution is strongly anisotropic, with an evident lack of interactions along individual velocity. Thus, it is found that in small-sized bird flocks, individuals reciprocally cooperate with a variational number of neighbors in metric space and tend to interact with closer time-varying neighbors, rather than interacting with a fixed number of topological ones. Finally, extensive numerical investigation is conducted to verify both the revealed interaction and decision-making principle during circular flights of pigeon flocks.

Death of a child and parental wellbeing in old age: Evidence from Taiwan

OpenAIRE

Lee, Chioun; Glei, Dana A.; Weinstein, Maxine; Goldman, Noreen

2013-01-01

The death of a child is one of the most traumatic events that a parent can experience. The psychological and physical consequences of bereavement are well established, and the consequences are more severe for mothers than fathers. However, little is known about how the death of an adult child affects parental wellbeing in old age or how the deceased child’s sex may moderate the association. We use data from the Taiwanese Longitudinal Study of Aging (TLSA) to investigate how the death of a son...

Parenting Stress, Parental Reactions, and Externalizing Behavior From Ages 4 to 10.

Science.gov (United States)

Mackler, Jennifer S; Kelleher, Rachael T; Shanahan, Lilly; Calkins, Susan D; Keane, Susan P; O'Brien, Marion

2015-04-01

The association between parenting stress and child externalizing behavior, and the mediating role of parenting, has yielded inconsistent findings; however, the literature has typically been cross-sectional and unidirectional. In the current study the authors examined the longitudinal transactions among parenting stress, perceived negative parental reactions, and child externalizing at 4, 5, 7, and 10 years old. Models examining parent effects (parenting stress to child behavior), child effects (externalizing to parental reactions and stress), indirect effects of parental reactions, and the transactional associations among all variables, were compared. The transactional model best fit the data, and longitudinal reciprocal effects emerged between parenting stress and externalizing behavior. The mediating role of parental reactions was not supported; however, indirect effects suggest that parenting stress both is affected by and affects parent and child behavior. The complex associations among parent and child variables indicate the importance of interventions to improve the parent-child relationship and reducing parenting stress.

Fluctuating nonlinear hydrodynamics of flocking

Science.gov (United States)

Yadav, Sunil Kumar; Das, Shankar P.

2018-03-01

Starting from a microscopic model, the continuum field theoretic description of the dynamics of a system of active ingredients or "particles" is presented. The equations of motion for the respective collective densities of mass and momentum follow exactly from that of a single element in the flock. The single-particle dynamics has noise and anomalous momentum dependence in its frictional terms. The equations for the collective densities are averaged over a local equilibrium distribution to obtain the corresponding coarse grained equations of fluctuating nonlinear hydrodynamics (FNH). The latter are the equations used frequently for describing active systems on the basis of intuitive arguments. The transport coefficients which appear in the macroscopic FNH equations are determined in terms of the parameters of the microscopic dynamics.

Examining genotypic variation in autism spectrum disorder and its relationship to parental age and phenotype

Directory of Open Access Journals (Sweden)

Geier DA

2016-07-01

Full Text Available David A Geier,1,2 Janet K Kern,1,3 Lisa K Sykes,2 Mark R Geier1,2 1Research Department, The Institute of Chronic Illnesses, Inc, 2Research Department, CoMeD, Inc, Silver Spring, MD, 3Research Department, CONEM US Autism Research Group, Allen, TX, USA Background: Previous studies on genetic testing of chromosomal abnormalities in individuals diagnosed with autism spectrum disorder (ASD found that ~80% have negative genetic test results (NGTRs and ~20% have positive genetic test results (PGTRs, of which ~7% were probable de novo mutations (PDNMs. Research suggests that parental age is a risk factor for an ASD diagnosis. This study examined genotypic variation in ASD and its relationship to parental age and phenotype.Methods: Phenotype was derived from detailed clinical information, and genotype was derived from high-resolution blood chromosome and blood whole-genome copy number variant genetic testing on a consecutive cohort (born: 1983–2009 of subjects diagnosed with ASD (N=218.Results: Among the subjects examined, 80.3% had NGTRs and 19.7% had PGTRs, of which 6.9% had PDNMs. NGTR subjects were born more recently (the risk of PDNMs decreasing by 12% per more recent birth year and tended to have an increased male–female ratio compared to PDNM subjects. PDNM subjects had significantly increased mean parental age and paternal age at subject’s birth (the risk of a PDNM increasing by 7%–8% per year of parental or paternal age compared to NGTR subjects. PGTR and NGTR subjects showed significant improvements in speech/language/communication with increasing age. PGTR subjects showed significant improvements in sociability, a core feature of an ASD diagnosis, with increasing age, whereas NGTR subjects showed significant worsening in sociability with increasing age.Conclusion: This study helps to elucidate different phenotypic ASD subtypes and may even indicate the need for differential diagnostic classifications. Keywords: genotype, phenotype

Prevalence of parent-reported immediate hypersensitivity food allergy in Chilean school-aged children.

Science.gov (United States)

Hoyos-Bachiloglu, R; Ivanovic-Zuvic, D; Álvarez, J; Linn, K; Thöne, N; de los Ángeles Paul, M; Borzutzky, A

2014-01-01

Food allergies (FAs) affect 2-4% of school-aged children in developed countries and strongly impact their quality of life. The prevalence of FA in Chile remains unknown. Cross-sectional survey study of 488 parents of school-aged children from Santiago who were asked to complete a FA screening questionnaire. Parents who reported symptoms suggestive of FA were contacted to answer a second in-depth questionnaire to determine immediate hypersensitivity FA prevalence and clinical characteristics of school-aged Chilean children. A total of 455 parents answered the screening questionnaire: 13% reported recurrent symptoms to a particular food and 6% reported FA. Forty-three screening questionnaires (9%) were found to be suggestive of FA. Parents of 40 children answered the second questionnaire; 25 were considered by authors to have FA. FA rate was 5.5% (95% CI: 3.6-7.9). Foods reported to frequently cause FA included walnut, peanut, egg, chocolate, avocado, and banana. Children with FA had more asthma (20% vs. 7%, Phistory compatible with anaphylaxis. Of 13 children who sought medical attention, 70% were diagnosed with FA; none were advised to acquire an epinephrine autoinjector. Up to 5.5% of school-aged Chilean children may suffer from FA, most frequently to walnut and peanut. It is critical to raise awareness in Chile regarding FA and recognition of anaphylaxis, and promote epinephrine autoinjectors in affected children. Copyright © 2013 SEICAP. Published by Elsevier Espana. All rights reserved.

'Inconvenient biology:' advantages and disadvantages of first-time parenting after age 40 using in vitro fertilization.

Science.gov (United States)

Mac Dougall, K; Beyene, Y; Nachtigall, R D

2012-04-01

As ages at first birth have steadily risen in the industrial west over the last several decades, the phenomenon of 'delayed childbearing' has come under research scrutiny by demographers, medical specialists and social scientists. In this study, we specifically explore the perceived advantages and disadvantages of postponed conception as well as participants' retrospective opinions on the 'optimal age' for parenting. To this end, we examined a cohort purposely chosen to epitomize delayed childbearing, i.e. men and women who used IVF to conceive at the very end of their reproductive capability. In-depth qualitative interviews were conducted between 2009 and 2011 with 46 couples and 15 individual self-selected US women and men who had used IVF to conceive their first child when the woman was aged 40 or older at the time of delivery. Although the demographics of this cohort were consistent with others who use IVF in the USA, their median income was 3-4 times higher than that of the average US family, which may bias their largely positive parenting experiences. Most women and men believed that childbearing later in life resulted in advantages for themselves and their families. These included having established careers with financial security and career-time flexibility, enhanced emotional preparedness, committed co-parenting relationships and a positive overall family experience. The main disadvantage was the unexpected difficulty in conceiving that culminated in the use of IVF and resulted in a smaller family than desired, although many expressed feeling 'lucky' to have children at all. Other disadvantages were lack of energy for parenting, less available lifetime to spend with children and anticipated stigma as older parents. These disadvantages appear to have influenced conception and parenting experiences so that in hindsight the majority of participants identified the optimal age for first-time parenting as 5-10 years earlier than they had conceived. This age

Relationship between attention deficit hyperactive disorder symptoms and perceived parenting practices of school-age children.

Science.gov (United States)

Kim, Dong Hee; Yoo, Il Young

2013-04-01

To examine the relationship between the perception on parenting practices and attention deficit hyperactivity disorder (ADHD) symptoms in school-age children. Psychosocial attention deficit hyperactivity disorder intervention approaches emphasise environmental risk factors at the individual, family and community level. Parenting variables are strongly related to attention deficit hyperactivity disorder symptom severity. A cross-sectional questionnaire survey. The participants were 747 children and their parents in two elementary schools. The instruments used were Korean Conners Abbreviated Parent Questionnaire and Korean version Maternal Behavior Research Instrument (measuring four dimensions of parenting practices: affection, autonomy, rejection, control). Descriptive and logistic regression analyses were performed. The rejective parenting practice was statistically significant in logistic regression controlling gender and age of children, family structure, maternal education level and socio-economic status. The rejection parenting is associated with attention deficit hyperactivity disorder symptoms in children (OR=1.356). These results suggest the importance of specific parenting educational programmes for parents to prevent and decrease attention deficit hyperactivity disorder symptoms. It would be more effective rather than focusing only on the child's attention deficit hyperactivity disorder symptoms, developing educational programmes for parents to prevent rejection parenting practice and improve parenting skills in the family system. When developing a treatment programme for children with attention deficit hyperactivity disorder, healthcare providers should consider not only the child's attention deficit hyperactivity disorder symptoms, but also the parenting practices. Comprehensive interventions designed to prevent rejection and improve parenting skills may be helpful in mitigating attention deficit hyperactivity disorder symptoms. © 2012 Blackwell

A Q-Learning Approach to Flocking With UAVs in a Stochastic Environment.

Science.gov (United States)

Hung, Shao-Ming; Givigi, Sidney N

2017-01-01

In the past two decades, unmanned aerial vehicles (UAVs) have demonstrated their efficacy in supporting both military and civilian applications, where tasks can be dull, dirty, dangerous, or simply too costly with conventional methods. Many of the applications contain tasks that can be executed in parallel, hence the natural progression is to deploy multiple UAVs working together as a force multiplier. However, to do so requires autonomous coordination among the UAVs, similar to swarming behaviors seen in animals and insects. This paper looks at flocking with small fixed-wing UAVs in the context of a model-free reinforcement learning problem. In particular, Peng's Q(λ) with a variable learning rate is employed by the followers to learn a control policy that facilitates flocking in a leader-follower topology. The problem is structured as a Markov decision process, where the agents are modeled as small fixed-wing UAVs that experience stochasticity due to disturbances such as winds and control noises, as well as weight and balance issues. Learned policies are compared to ones solved using stochastic optimal control (i.e., dynamic programming) by evaluating the average cost incurred during flight according to a cost function. Simulation results demonstrate the feasibility of the proposed learning approach at enabling agents to learn how to flock in a leader-follower topology, while operating in a nonstationary stochastic environment.

Investigating the Relationship between Anxiety of School-age Children Undergoing Surgery and Parental State-trait Anxiety

OpenAIRE

Fatemeh Heshmati Nabavi; Malihe Shoja; Monir Ramezani; Azadeh Saki; Marjan Joodi

2017-01-01

Background: Surgery is a stressful experience for children, and preoperative anxiety in children could be affected by the level of parental anxiety. Aim: The aim of this study was to determine the relationship between anxiety in school-age children before surgery and parental state-trait anxiety. Method: This descriptive study was performed on 81 children within the age group of 6-12 years admitted for elective surgical operation and 128 parents in Doctor Sheikh Hospital, Mashhad, Iran, 2016....

Parental and grandparental ages in the autistic spectrum disorders: a birth cohort study.

Directory of Open Access Journals (Sweden)

Jean Golding

2010-04-01

Full Text Available A number of studies have assessed ages of parents of children with autistic spectrum disorders (ASD, and reported both maternal and paternal age effects. Here we assess relationships with grandparental ages.We compared the parental and grandparental ages of children in the population-based Avon Longitudinal Study of Parents and Children (ALSPAC, according to their scores in regard to 4 autistic trait measures and whether they had been given a diagnosis of ASD. Mean maternal and paternal ages of ASD cases were raised, but this appears to be secondary to a maternal grandmother age effect (P = 0.006: OR = 1.66[95%CI 1.16, 2.37] for each 10-year increase in the grandmother's age at the birth of the mother. Trait measures also revealed an association between the maternal grandmother's age and the major autistic trait-the Coherence Scale (regression coefficient b = 0.142, [95%CI = 0.057, 0.228]P = 0.001. After allowing for confounders the effect size increased to b = 0.217[95%CI 0.125, 0.308](P<0.001 for each 10 year increase in age.Although the relationship between maternal grandmother's age and ASD and a major autistic trait was unexpected, there is some biological plausibility, for the maternal side at least, given that the timing of female meiosis I permits direct effects on the grandchild's genome during the grandmother's pregnancy. An alternative explanation is the meiotic mismatch methylation (3 M hypothesis, presented here for the first time. Nevertheless the findings should be treated as hypothesis generating pending corroborative results from other studies.

Something for Everyone: Benefits of Mixed-Age Grouping for Children, Parents, and Teachers.

Science.gov (United States)

Theilheimer, Rachel

1993-01-01

Discusses the benefits of mixed-age grouping for children's social and cognitive development and reservations parents sometimes have about mixed-age groupings. Also discusses issues that teachers need to consider when implementing mixed-age groups: children's personal care routines; furnishings; children's language, motor, creative, and social…

House-level risk factors associated with the colonization of broiler flocks with Campylobacter spp. in Iceland, 2001 – 2004

Directory of Open Access Journals (Sweden)

Berke Olaf

2007-11-01

Full Text Available Abstract Background The concurrent rise in consumption of fresh chicken meat and human campylobacteriosis in the late 1990's in Iceland led to a longitudinal study of the poultry industry to identify the means to decrease the frequency of broiler flock colonization with Campylobacter. Because horizontal transmission from the environment is thought to be the most likely source of Campylobacter to broilers, we aimed to identify broiler house characteristics and management practices associated with flock colonization. Between May 2001 and September 2004, pooled caecal samples were obtained from 1,425 flocks at slaughter and cultured for Campylobacter. Due to the strong seasonal variation in flock prevalence, analyses were restricted to a subset of 792 flocks raised during the four summer seasons. Logistic regression models with a farm random effect were used to analyse the association between flock Campylobacter status and house-level risk factors. A two-stage process was carried out. Variables were initially screened within major subsets: ventilation; roof and floor drainage; building quality, materials and repair; house structure; pest proofing; biosecurity; sanitation; and house size. Variables with p ≤ 0.15 were then offered to a comprehensive model. Multivariable analyses were used in both the screening stage (i.e. within each subset and in the comprehensive model. Results 217 out of 792 flocks (27.4% tested positive. Four significant risk factors were identified. Campylobacter colonization was predicted to increase when the flock was raised in a house with vertical (OR = 2.7, or vertical and horizontal (OR = 3.2 ventilation shafts, when the producer's boots were cleaned and disinfected prior to entering the broiler house (OR = 2.2, and when the house was cleaned with geothermal water (OR = 3.3. Conclusion The increased risk associated with vertical ventilation shafts might be related to the height of the vents and the potential for vectors

Observing Interactions between Children and Adolescents and their Parents: The Effects of Anxiety Disorder and Age.

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Waite, Polly; Creswell, Cathy

2015-08-01

Parental behaviors, most notably overcontrol, lack of warmth and expressed anxiety, have been implicated in models of the development and maintenance of anxiety disorders in children and young people. Theories of normative development have proposed that different parental responses are required to support emotional development in childhood and adolescence, yet age has not typically been taken into account in studies of parenting and anxiety disorders. In order to identify whether associations between anxiety disorder status and parenting differ in children and adolescents, we compared observed behaviors of parents of children (7-10 years) and adolescents (13-16 years) with and without anxiety disorders (n = 120), while they undertook a series of mildly anxiety-provoking tasks. Parents of adolescents showed significantly lower levels of expressed anxiety, intrusiveness and warm engagement than parents of children. Furthermore, offspring age moderated the association between anxiety disorder status and parenting behaviors. Specifically, parents of adolescents with anxiety disorders showed higher intrusiveness and lower warm engagement than parents of non-anxious adolescents. A similar relationship between these parenting behaviors and anxiety disorder status was not observed among parents of children. The findings suggest that theoretical accounts of the role of parental behaviors in anxiety disorders in children and adolescents should distinguish between these different developmental periods. Further experimental research to establish causality, however, would be required before committing additional resources to targeting parenting factors within treatment.

Socialising adolescent volunteering: how important are parents and friends? Age dependent effects of parents and friends on adolescents' volunteering behaviours

NARCIS (Netherlands)

van Goethem, A.A.J.; van Hoof, A.; van Aken, M.A.G.; Orobio de Castro, B.; Raaijmakers, Q.A.W.

2014-01-01

This study examined the relative importance of best friend's and parents' volunteering and civic family orientation (combined with open family communication) in adolescent volunteering, and the moderating effect of age. Results, involving 698 adolescents (M age = 15.19; SD = 1.43), revealed that

Socialising adolescent volunteering : How important are parents and friends? Age dependent effects of parents and friends on adolescents' volunteering behaviours

NARCIS (Netherlands)

Van Goethem, Anne A J; van Hoof, Anne; van Aken, Marcel A G; Orobio de Castro, Bram; Raaijmakers, Quinten A W

2014-01-01

This study examined the relative importance of best friend's and parents' volunteering and civic family orientation (combined with open family communication) in adolescent volunteering, and the moderating effect of age. Results, involving 698 adolescents (M age. = 15.19; SD= 1.43), revealed that

The physics of flocking: Correlation as a compass from experiments to theory

Science.gov (United States)

Cavagna, Andrea; Giardina, Irene; Grigera, Tomás S.

2018-01-01

Collective behavior in biological systems is a complex topic, to say the least. It runs wildly across scales in both space and time, involving taxonomically vastly different organisms, from bacteria and cell clusters, to insect swarms and up to vertebrate groups. It entails concepts as diverse as coordination, emergence, interaction, information, cooperation, decision-making, and synchronization. Amid this jumble, however, we cannot help noting many similarities between collective behavior in biological systems and collective behavior in statistical physics, even though none of these organisms remotely looks like an Ising spin. Such similarities, though somewhat qualitative, are startling, and regard mostly the emergence of global dynamical patterns qualitatively different from individual behavior, and the development of system-level order from local interactions. It is therefore tempting to describe collective behavior in biology within the conceptual framework of statistical physics, in the hope to extend to this new fascinating field at least part of the great predictive power of theoretical physics. In this review we propose that the conceptual cornerstone of this ambitious program be that of correlation. To illustrate this idea we address the case of collective behavior in bird flocks. Two key threads emerge, as two sides of one single story: the presence of scale-free correlations and the dynamical mechanism of information transfer. We discuss first static correlations in starling flocks, in particular the experimental finding of their scale-free nature, the formulation of models that account for this fact using maximum entropy, and the relation of scale-free correlations to information transfer. This is followed by a dynamic treatment of information propagation (propagation of turns across a flock), starting with a discussion of experimental results and following with possible theoretical explanations of those, which require the addition of behavioral

Validating a Model of Motivational Factors Influencing Involvement for Parents of Transition-Age Youth with Disabilities

Science.gov (United States)

Hirano, Kara A.; Shanley, Lina; Garbacz, S. Andrew; Rowe, Dawn A.; Lindstrom, Lauren; Leve, Leslie D.

2018-01-01

Parent involvement is a predictor of postsecondary education and employment outcomes, but rigorous measures of parent involvement for youth with disabilities are lacking. Hirano, Garbacz, Shanley, and Rowe adapted scales based on Hoover-Dempsey and Sandler model of parent involvement for use with parents of youth with disabilities aged 14 to 23.…

A multigenerational effect of parental age on offspring size but not fitness in common duckweed (Lemna minor).

Science.gov (United States)

Barks, P M; Laird, R A

2016-04-01

Classic theories on the evolution of senescence make the simplifying assumption that all offspring are of equal quality, so that demographic senescence only manifests through declining rates of survival or fecundity. However, there is now evidence that, in addition to declining rates of survival and fecundity, many organisms are subject to age-related declines in the quality of offspring produced (i.e. parental age effects). Recent modelling approaches allow for the incorporation of parental age effects into classic demographic analyses, assuming that such effects are limited to a single generation. Does this 'single-generation' assumption hold? To find out, we conducted a laboratory study with the aquatic plant Lemna minor, a species for which parental age effects have been demonstrated previously. We compared the size and fitness of 423 laboratory-cultured plants (asexually derived ramets) representing various birth orders, and ancestral 'birth-order genealogies'. We found that offspring size and fitness both declined with increasing 'immediate' birth order (i.e. birth order with respect to the immediate parent), but only offspring size was affected by ancestral birth order. Thus, the assumption that parental age effects on offspring fitness are limited to a single generation does in fact hold for L. minor. This result will guide theorists aiming to refine and generalize modelling approaches that incorporate parental age effects into evolutionary theory on senescence. © 2016 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2016 European Society For Evolutionary Biology.

Parental Predictors of Children’s Shame and Guilt at Age 6 in a Multi-Method, Longitudinal Study

Science.gov (United States)

Parisette-Sparks, Alyssa; Bufferd, Sara J.; Klein, Daniel N.

2015-01-01

Objective Shame and guilt are self-conscious emotions that begin to develop early in life and are associated with various forms of psychopathology. However, little is known about the factors that contribute to these emotions in young children. Specifically, no longitudinal studies to date have examined a range of parent factors that shape the expression of children’s shame and guilt. The current multi-method, longitudinal study sought to determine whether parenting style, parental psychopathology, and parents’ marital satisfaction assessed when children were age 3 predict expressions of shame and guilt in children at age 6. Method A large community sample of families (N = 446; 87.4% Caucasian) with three-year-old children (45.7% female) was recruited through commercial mailing lists. Parent variables were assessed when children were age 3 with mother- and father-report questionnaires and a diagnostic interview. Children’s expressions of shame and guilt were observed in the laboratory at age 6. Results Fathers’, but not mothers’, history of depression and permissive parenting assessed when children were age 3 predicted children’s expressions of shame and guilt when children were age 6; parents’ marital dissatisfaction also predicted children’s shame and guilt. Conclusions These findings suggest that parents, and fathers in particular, contribute to expressions of self-conscious emotions in children. These data on emotional development may be useful for better characterizing the risk and developmental pathways of psychopathology. PMID:26538055

Self-Determination among Transition-Age Youth with Autism or Intellectual Disability: Parent Perspectives

Science.gov (United States)

Carter, Erik W.; Lane, Kathleen Lynne; Cooney, Molly; Weir, Katherine; Moss, Colleen K.; Machalicek, Wendy

2013-01-01

This study examined 68 parents' views of the self-determination skills and capacities of their young adult children with autism spectrum disorders and intellectual disability (ages 19-21 years). Results indicated parents placed a high value on the importance of all seven component skills (i.e., choice-making skills, decision-making skills,…

Cohesive motion in one-dimensional flocking

International Nuclear Information System (INIS)

Dossetti, V

2012-01-01

A one-dimensional rule-based model for flocking, which combines velocity alignment and long-range centering interactions, is presented and studied. The induced cohesion in the collective motion of the self-propelled agents leads to unique group behavior that contrasts with previous studies. Our results show that the largest cluster of particles, in the condensed states, develops a mean velocity slower than the preferred one in the absence of noise. For strong noise, the system also develops a non-vanishing mean velocity, alternating its direction of motion stochastically. This allows us to address the directional switching phenomenon. The effects of different sources of stochasticity on the system are also discussed. (paper)

PARENT NURTURE MODEL IN SHAPING BEHAVIOR OF ADOLESCENCE 12-15 AGES

Directory of Open Access Journals (Sweden)

Dimas Hadi Prayoga

2017-02-01

Full Text Available Introduction: The deviation problem of smoking activity an adolescent is come to anxious level for parents, teachers, and society. The correlation between parents nurture model and smoking activity of adolescent needs to be examined further. The purpose of this study was to analyze the correlation between parents nurture model with smoking activity of adolescent (12-15 years old. Method: This was correlational research with cross sectional approach. The sample were 84 adolescent (12-15 years old at MTs Mojosari Nganjuk. The independent variables was parents nurture model and the dependent variable was adolescent smoking activity. Data were collected by using questionnare, then examined by using chi square with the level of significant α=0,05. Result: Statistical analysis had showed the low correlation between permissive parents nurture model with smoking activity of adolescent (12-15 years old at MTs Mojosari Nganjuk (p=0,049; r = 0,210 and no correlation between democratic nurture model (p=0,554 and authoritative nurture model (p=0,418 with smoking activity of adolescent (12-15 years old at MTs Mojosari Nganjuk, but only permissive model which correlate with smoking activity. The permissive parents with no control and demand caused adolescent to be feeling unimpeded to do smoking activity since there is no warning and punishment from the parents. Discussion: So that, School nurses should provide health promotion to parents in making appropriate parenting in adolescence. Parents should have the right parenting provided in accordance with the age and development of adolescents because appropriate parenting will have a positive impact on adolescent behavior. Further research on parenting questionnaires must be checked for cross-compatibility between questionnaire answers given adolescent and parents to know the truth in filling out the questionnaire. The differences in this study compared to previous studies is the researcher doing research in

A Distributed Flocking Approach for Information Stream Clustering Analysis

Energy Technology Data Exchange (ETDEWEB)

Cui, Xiaohui [ORNL; Potok, Thomas E [ORNL

2006-01-01

Intelligence analysts are currently overwhelmed with the amount of information streams generated everyday. There is a lack of comprehensive tool that can real-time analyze the information streams. Document clustering analysis plays an important role in improving the accuracy of information retrieval. However, most clustering technologies can only be applied for analyzing the static document collection because they normally require a large amount of computation resource and long time to get accurate result. It is very difficult to cluster a dynamic changed text information streams on an individual computer. Our early research has resulted in a dynamic reactive flock clustering algorithm which can continually refine the clustering result and quickly react to the change of document contents. This character makes the algorithm suitable for cluster analyzing dynamic changed document information, such as text information stream. Because of the decentralized character of this algorithm, a distributed approach is a very natural way to increase the clustering speed of the algorithm. In this paper, we present a distributed multi-agent flocking approach for the text information stream clustering and discuss the decentralized architectures and communication schemes for load balance and status information synchronization in this approach.

Assortative flocking in crossbills and implications for ecological speciation.

Science.gov (United States)

Smith, Julie W; Sjoberg, Stephanie M; Mueller, Matthew C; Benkman, Craig W

2012-10-22

How reproductive isolation is related to divergent natural selection is a central question in speciation. Here, we focus on several ecologically specialized taxa or 'call types' of red crossbills (Loxia curvirostra complex), one of the few groups of birds providing much evidence for ecological speciation. Call types differ in bill sizes and feeding capabilities, and also differ in vocalizations, such that contact calls provide information on crossbill phenotype. We found that two call types of red crossbills were more likely to approach playbacks of their own call type than those of heterotypics, and that their propensity to approach heterotypics decreased with increasing divergence in bill size. Although call similarity also decreased with increasing divergence in bill size, comparisons of responses to familiar versus unfamiliar call types indicate that the decrease in the propensity to approach heterotypics with increasing divergence in bill size was a learned response, and not a by-product of calls diverging pleiotropically as bill size diverged. Because crossbills choose mates while in flocks, assortative flocking could lead indirectly to assortative mating as a by-product. These patterns of association therefore provide a mechanism by which increasing divergent selection can lead to increasing reproductive isolation.

9 CFR 145.83 - Terminology and classification; flocks and products.

Science.gov (United States)

2010-01-01

... manufacturing process; (B) Mash feed may contain animal protein if the finished feed is treated with a salmonella control product approved by the U.S. Food and Drug Administration. (C) All feed is stored and transported in such a manner as to prevent possible contamination. (iii) The flock is maintained in compliance...

9 CFR 145.23 - Terminology and classification; flocks and products.

Science.gov (United States)

2010-01-01

... house, between 15-20 days prior to the flock being moved to laying quarters. (5) Started poultry shall... being moved to laying quarters. (5) Started poultry shall be delivered to and from the farm premises in... qualification is being sought and (a) infected wild birds, (b) contaminated feed or waste, or (c) birds...

Maintaining genetic stability in a control flock of South African ...

African Journals Online (AJOL)

means of whole progeny and replacement groups for the measured characters ... The whole problem of the estimation of genetic change was ... that a genetic control flock is a segregating population in which ... 5,5 years, were divided into five equal groups by stratified ..... A note on tests of significance and optimal ex-.

Parental media mediation styles for children aged 2 to 11 years.

Science.gov (United States)

Barkin, Shari; Ip, Edward; Richardson, Irma; Klinepeter, Sara; Finch, Stacia; Krcmar, Marina

2006-04-01

Studies indicate that children use media (television, video, and computer) more than the recommended limit of 2 h/d, but little is known about parents' role in mediating their children's media use. Office-based survey. Data were collected on demographics, reported media behaviors, parental awareness about media effects, television in the bedroom, and parental concern. We developed logistic regression models to examine factors associated with the following 3 mediation approaches: restrictive, instructive, and unlimited. Pediatric Research in Office Settings practices. Parents with children aged 2 to 11 years (n = 1831) presenting for a well-child visit. Almost half of parents reported a single mediation approach, including restrictive for 23%, instructive for 11%, and unlimited for 7%, with 59% reporting the use of multiple strategies. Restrictive (odds ratio [OR], 1.16; Peffects, whereas a decreased awareness existed for those who used an unlimited approach (OR, 0.87; Pparental concern (OR, 1.77; Pchildren (OR, 1.41; Pparents permitted a television in the child's bedroom (OR, 2.13; Pparental practices and reinforce active media mediation strategies.

Novel Textile Scaffolds Generated by Flock Technology for Tissue Engineering of Bone and Cartilage

Science.gov (United States)

Walther, Anja; Hoyer, Birgit; Springer, Armin; Mrozik, Birgit; Hanke, Thomas; Cherif, Chokri; Pompe, Wolfgang; Gelinsky, Michael

2012-01-01

Textile scaffolds can be found in a variety of application areas in regenerative medicine and tissue engineering. In the present study we used electrostatic flocking—a well-known textile technology—to produce scaffolds for tissue engineering of bone. Flock scaffolds stand out due to their unique structure: parallel arranged fibers that are aligned perpendicularly to a substrate, resulting in mechanically stable structures with a high porosity. In compression tests we demonstrated good mechanical properties of such scaffolds and in cell culture experiments we showed that flock scaffolds allow attachment and proliferation of human mesenchymal stem cells and support their osteogenic differentiation. These matrices represent promising scaffolds for tissue engineering. PMID:28817062

Prevalence of gastrointestinal nematode infections in goat flocks on semi-arid rangelands of northeastern Mexico.

Science.gov (United States)

Olivas-Salazar, Raquel; Estrada-Angulo, Alfredo; Mellado, Miguel; Aguilar-Caballero, Armando Jacinto; Castro-Pérez, Beatriz Isabel; Gutiérrez-Blanco, Eduardo; Ruiz-Zárate, Fernando

2018-04-01

The objective of this study was to determine the prevalence of gastrointestinal nematode (GIN) infection in goat flocks on semi-arid rangelands of northeastern Mexico (25° N, 350-400 mm annual precipitation). The study included 668 pluriparous goats from 18 herds in five municipalities of Coahuila and Nuevo Leon, Mexico. Five genetic groups were considered (predominance of Boer, Nubian, Alpine, Saanen, and Toggenburg). Fecal samples were taken from the rectum of each animal to determine the number of eggs per gram (EPG) of GIN. The prevalence of flocks with GIN infections was 88.9%. Similar results were observed for the number of goats infected in the flocks. The Alpine breed presented the highest prevalence and highest EPG loads of GIN, whereas Boer and Nubian were the genetic groups with the lowest (P arid zones of Mexico was found a high prevalence of infections with gastrointestinal nematodes. The municipality and the breed of the animals were factors that showed influence on this prevalence and the level of infection of the goats.

Spatially balanced topological interaction grants optimal cohesion in flocking models.

Science.gov (United States)

Camperi, Marcelo; Cavagna, Andrea; Giardina, Irene; Parisi, Giorgio; Silvestri, Edmondo

2012-12-06

Models of self-propelled particles (SPPs) are an indispensable tool to investigate collective animal behaviour. Originally, SPP models were proposed with metric interactions, where each individual coordinates with neighbours within a fixed metric radius. However, recent experiments on bird flocks indicate that interactions are topological: each individual interacts with a fixed number of neighbours, irrespective of their distance. It has been argued that topological interactions are more robust than metric ones against external perturbations, a significant evolutionary advantage for systems under constant predatory pressure. Here, we test this hypothesis by comparing the stability of metric versus topological SPP models in three dimensions. We show that topological models are more stable than metric ones. We also show that a significantly better stability is achieved when neighbours are selected according to a spatially balanced topological rule, namely when interacting neighbours are evenly distributed in angle around the focal individual. Finally, we find that the minimal number of interacting neighbours needed to achieve fully stable cohesion in a spatially balanced model is compatible with the value observed in field experiments on starling flocks.

Sensitivity of Direct Culture, Enrichment and PCR for Detection of Campylobacter jejuni and C. coli in Broiler Flocks at Slaughter.

Science.gov (United States)

Rodgers, J D; Simpkin, E; Lee, R; Clifton-Hadley, F A; Vidal, A B

2017-06-01

Broiler chicken flocks are a significant source of Campylobacter jejuni and Campylobacter coli that result in the major public health problem of campylobacteriosis. Accurate estimates of the prevalence of both C. coli and C. jejuni in flocks would enhance epidemiological understanding, risk assessment and control options. This study combined results from a panel of 10 detection tests (direct culture, enrichment and PCR) on caecal samples from flocks at slaughter. A parallel interpretation approach was used to determine the presence of Campylobacter spp. and for C. jejuni and C. coli individually. The sample was considered positive if at least one method detected the target and this interpretation was taken to represent a 'proxy gold standard' for detection in the absence of a gold standard reference test. The sensitivity of each individual method to detect Campylobacter spp., C. jejuni and C. coli was then estimated relative to the proxy gold standard. Enrichment in adapted Exeter broth (deficient in polymyxin B) with a resuscitation step was 100% sensitive, whilst direct culture on modified charcoal cefoperazone deoxycholate agar (mCCDA) was highly sensitive (97.9%). Enrichment methods using Preston broth and Bolton broth were significantly less sensitive. Enrichment in Exeter broth promoted the recovery of C. jejuni, whilst enrichment in Bolton broth favoured C. coli. A RT-PCR detection test could identify 80% of flocks that were co-colonised with both species. This study found that 76.3% (n = 127) of flocks were colonised with Campylobacter spp. The majority (95.9%) of Campylobacter-positive flocks were colonised with C. jejuni; however, approximately one-third of positive flocks were simultaneously colonised with both C. jejuni and C. coli. The findings highlight the impact of different detection methodologies on the accuracy of the estimated incidence of both C. jejuni and C. coli entering the abattoir within broiler flocks and the associated

Stable Flocking of Multiple Agents Based on Molecular Potential Field and Distributed Receding Horizon Control

International Nuclear Information System (INIS)

Zhang Yun-Peng; Duan Hai-Bin; Zhang Xiang-Yin

2011-01-01

A novel distributed control scheme to generate stable flocking motion for a group of agents is proposed. In this control scheme, a molecular potential field model is applied as the potential field function because of its smoothness and unique shape. The approach of distributed receding horizon control is adopted to drive each agent to find its optimal control input to lower its potential at every step. Experimental results show that this proposed control scheme can ensure that all agents eventually converge to a stable flocking formation with a common velocity and the collisions can also be avoided at the same time. (general)

Uncertainty Quantification in Control Problems for Flocking Models

Directory of Open Access Journals (Sweden)

Giacomo Albi

2015-01-01

Full Text Available The optimal control of flocking models with random inputs is investigated from a numerical point of view. The effect of uncertainty in the interaction parameters is studied for a Cucker-Smale type model using a generalized polynomial chaos (gPC approach. Numerical evidence of threshold effects in the alignment dynamic due to the random parameters is given. The use of a selective model predictive control permits steering of the system towards the desired state even in unstable regimes.

A positive role of multiplicative noise on the emergence of flocking in a stochastic Cucker-Smale system

Energy Technology Data Exchange (ETDEWEB)

Sun, Yongzheng, E-mail: yzsung@gmail.com [School of Science, China University of Mining and Technology, Xuzhou 221008 (China); Lin, Wei, E-mail: wlin@fudan.edu.cn [School of Mathematical Sciences, LMNS, and Shanghai Key Laboratory of Data Science, Fudan University, Shanghai 200433 (China)

2015-08-15

In this article, we investigate the flocking of a stochastic Cucker-Smale system with multiplicative measurement noise. We show that there is a noise strength, below which the flocking occurs and the convergence time is a decreasing function of noise strength. Specifically, we find a power-law relationship between the convergence time and the density of group. We also investigate the influence of control parameter and an optimal value is found that minimizes the convergence time.

A positive role of multiplicative noise on the emergence of flocking in a stochastic Cucker-Smale system

International Nuclear Information System (INIS)

Sun, Yongzheng; Lin, Wei

2015-01-01

In this article, we investigate the flocking of a stochastic Cucker-Smale system with multiplicative measurement noise. We show that there is a noise strength, below which the flocking occurs and the convergence time is a decreasing function of noise strength. Specifically, we find a power-law relationship between the convergence time and the density of group. We also investigate the influence of control parameter and an optimal value is found that minimizes the convergence time

A positive role of multiplicative noise on the emergence of flocking in a stochastic Cucker-Smale system.

Science.gov (United States)

Sun, Yongzheng; Lin, Wei

2015-08-01

In this article, we investigate the flocking of a stochastic Cucker-Smale system with multiplicative measurement noise. We show that there is a noise strength, below which the flocking occurs and the convergence time is a decreasing function of noise strength. Specifically, we find a power-law relationship between the convergence time and the density of group. We also investigate the influence of control parameter and an optimal value is found that minimizes the convergence time.

Factors affecting the reproductive performance of Awassi sheep flocks in north-east of Jordan: an epidemiological study.

Science.gov (United States)

Lafi, S Q; Talafha, A Q; Giadinis, N; Kalaitzakis, E; Pourliotis, K; Panousis, N

2009-12-01

A prospective cohort study was conducted using 32 randomly selected Awassi sheep flocks to identify factors hypothesized to be associated with the occurrence of pregnancy, twinning and fetal loss between August 2005 and May 2006 in the region of Al-Safawi (northeast of Jordan). Vitamins A and E and selenium concentrations were determined on 448 blood samples. Using the forward selection procedure of the logistic regression module, models with statistically significant risk factors (P loss. Serum vitamin A concentration levels were associated with pregnancy (OR = 2.26, 2.48), twinning (OR = 6.49, 17.74) and fetal loss (OR = 0.13, 0.19). Primiparous ewes were 48% less likely to become pregnant than fourth or higher parity ewes. The likelihood of twinning increased significantly in ewes up to the third parity. Ewes that were fed 700-900 g barley, 250-300 g wheat-bran per head per day and grazed on vegetables residues were 4.15 times more likely to have twins than ewes that were fed 600 g barley and 200 g wheat-bran per head per day. Fetal loss in first and second parity ewes was about 3 times more likely than that in third or higher-parity ewes. Ewes pregnant with twins were about 14 times more likely to have fetal loss than ewes carrying single fetus. Pregnant ewes of the stationary flocks were 37% less likely to have fetal loss than ewes of the semi-nomadic flocks. These results demonstrate that stationary Awassi sheep flocks had higher pregnancy and twinning rates and less pregnancy loss. Supplementation of vitamin A, providing sufficient quantity of dry feed and increasing ram: ewe ratio for primiparous ewes of semi-nomadic flocks is essential to improve Awassi sheep reproductive performance.

Flock Size and System of Turkey Management by Farmers in Zuru ...

African Journals Online (AJOL)

The study examined flock size and system of management by Turkey producers in Zuru Emirate of Kebbi State, Nigeria. Proportionate random sampling technique was used to select one hundred and eighty seven (187) Turkey producers from four Local Government Areas of the Emirate. Primary data were collected using ...

Generational shift in parental perceptions of overweight among school-aged children.

Science.gov (United States)

Hansen, Andrew R; Duncan, Dustin T; Tarasenko, Yelena N; Yan, Fei; Zhang, Jian

2014-09-01

Parental perceptions of child's weight status may influence family readiness to foster healthy behaviors. This study investigated the generational shifting of parental perceptions about children's weight. Data were collected in the NHANES 1988-1994 (n = 2871) and 2005-2010 (n = 3202). Parents, mainly mothers, were asked whether they considered their child, ages 6 to 11 years, to be overweight, underweight, or just about the right weight. The Centers for Disease Control and Prevention 2000 growth chart was used for reference. We ran Poisson regression to estimate the probability ratio between the 2 surveys for parents perceiving their child as overweight after controlling for actual weight. The 10th percentile of BMI z scores for children who were parentally perceived as overweight shifted with statistical significance from 84th percentile of reference population in the early survey to 91st percentile of reference population in the recent survey (P children parentally perceived as overweight also increased between surveys with the largest increase among children from poor families (from 1.60 [SE: 0.20] to 1.98 [0.08], P overweight/obese children being correctly perceived as overweight by the parents declined by 24% between surveys (probability ratio = 0.76 [95% confidence interval: 0.67-0.87]). Overweight/obese children were less likely to be perceived as overweight in the recent survey compared with peers of similar weight but surveyed 10+ years earlier. The declining tendency among parents to perceive overweight children appropriately may indicate a generational shift in social norms related to body weight. Copyright © 2014 by the American Academy of Pediatrics.

Measurement Properties and Classification Accuracy of Two Spanish Parent Surveys of Language Development for Preschool-Age Children

Science.gov (United States)

Guiberson, Mark; Rodriguez, Barbara L.

2010-01-01

Purpose: To describe the concurrent validity and classification accuracy of 2 Spanish parent surveys of language development, the Spanish Ages and Stages Questionnaire (ASQ; Squires, Potter, & Bricker, 1999) and the Pilot Inventario-III (Pilot INV-III; Guiberson, 2008a). Method: Forty-eight Spanish-speaking parents of preschool-age children…

Entangled time in flocking: Multi-time-scale interaction reveals emergence of inherent noise.

Science.gov (United States)

Niizato, Takayuki; Murakami, Hisashi

2018-01-01

Collective behaviors that seem highly ordered and result in collective alignment, such as schooling by fish and flocking by birds, arise from seamless shuffling (such as super-diffusion) and bustling inside groups (such as Lévy walks). However, such noisy behavior inside groups appears to preclude the collective behavior: intuitively, we expect that noisy behavior would lead to the group being destabilized and broken into small sub groups, and high alignment seems to preclude shuffling of neighbors. Although statistical modeling approaches with extrinsic noise, such as the maximum entropy approach, have provided some reasonable descriptions, they ignore the cognitive perspective of the individuals. In this paper, we try to explain how the group tendency, that is, high alignment, and highly noisy individual behavior can coexist in a single framework. The key aspect of our approach is multi-time-scale interaction emerging from the existence of an interaction radius that reflects short-term and long-term predictions. This multi-time-scale interaction is a natural extension of the attraction and alignment concept in many flocking models. When we apply this method in a two-dimensional model, various flocking behaviors, such as swarming, milling, and schooling, emerge. The approach also explains the appearance of super-diffusion, the Lévy walk in groups, and local equilibria. At the end of this paper, we discuss future developments, including extending our model to three dimensions.

Novel Textile Scaffolds Generated by Flock Technology for Tissue Engineering of Bone and Cartilage

Directory of Open Access Journals (Sweden)

Thomas Hanke

2012-03-01

Full Text Available Textile scaffolds can be found in a variety of application areas in regenerative medicine and tissue engineering. In the present study we used electrostatic flocking—a well-known textile technology—to produce scaffolds for tissue engineering of bone. Flock scaffolds stand out due to their unique structure: parallel arranged fibers that are aligned perpendicularly to a substrate, resulting in mechanically stable structures with a high porosity. In compression tests we demonstrated good mechanical properties of such scaffolds and in cell culture experiments we showed that flock scaffolds allow attachment and proliferation of human mesenchymal stem cells and support their osteogenic differentiation. These matrices represent promising scaffolds for tissue engineering.

An economic evaluation of preclinical testing strategies compared to the compulsory scrapie flock scheme in the control of classical scrapie.

Directory of Open Access Journals (Sweden)

Lisa Boden

Full Text Available Cost-benefit is rarely combined with nonlinear dynamic models when evaluating control options for infectious diseases. The current strategy for scrapie in Great Britain requires that all genetically susceptible livestock in affected flocks be culled (Compulsory Scrapie Flock Scheme or CSFS. However, this results in the removal of many healthy sheep, and a recently developed pre-clinical test for scrapie now offers a strategy based on disease detection. We explore the flock level cost-effectiveness of scrapie control using a deterministic transmission model and industry estimates of costs associated with genotype testing, pre-clinical tests and the value of a sheep culled. Benefit was measured in terms of the reduction in the number of infected sheep sold on, compared to a baseline strategy of doing nothing, using Incremental Cost Effectiveness analysis to compare across strategies. As market data was not available for pre-clinical testing, a threshold analysis was used to set a unit-cost giving equal costs for CSFS and multiple pre-clinical testing (MT, one test each year for three consecutive years. Assuming a 40% within-flock proportion of susceptible genotypes and a test sensitivity of 90%, a single test (ST was cheaper but less effective than either the CSFS or MT strategies (30 infected-sales-averted over the lifetime of the average epidemic. The MT strategy was slightly less effective than the CSFS and would be a dominated strategy unless preclinical testing was cheaper than the threshold price of £6.28, but may be appropriate for flocks with particularly valuable livestock. Though the ST is not currently recommended, the proportion of susceptible genotypes in the national flock is likely to continue to decrease; this may eventually make it a cost-effective alternative to the MT or CSFS.

Understanding the experience of adult daughters caring for an ageing parent, a qualitative study.

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Lopez Hartmann, Maja; Anthierens, Sibyl; Van Assche, Elisa; Welvaert, Joanna; Verhoeven, Véronique; Wens, Johan; Remmen, Roy

2016-06-01

The objective of this study is to describe how adult daughters experience caring for a frail older parent at home. In the near future the ageing of the population will have a major impact on the demand for formal and informal long-term care. Relatives, especially spouses and adult children are the main providers of informal care. Qualitative research methodology was used to study the experience of adult daughters caring for their frail older parents. A phenomenological research perspective was used to better understand the daily experiences of caring for an ageing parent. Data were collected using open-ended interviews. Interviews were audio recorded and transcribed verbatim. Data were subject to thematic analysis. Eleven women between 40-70 years of age participated in this study. Inductive coding of the interview data led to four main themes: being a caregiver as a natural process in life, the perception and consequences of caregiving activities, sharing care and finding a good balance between caring for an ageing parent and other responsibilities. Caregiving activities could be divided into visible and invisible activities and generated different feelings. The visible activities were more easily shared with other family members and professionals than the invisible ones. The women who struggled the most and tended to have a higher level of burden were those who experienced less support from their family. This study provided more insight into the experiences women have when caring for a parent. Supporting family networks that help in both visible and invisible activities may prevent overburden. Consumer-led care and the active participation of the informal caregiver in the decision-making process for building the care plan need to become more prominent. © 2016 John Wiley & Sons Ltd.

Detecting Pedestrian Flocks by Fusion of Multi-Modal Sensors in Mobile Phones

DEFF Research Database (Denmark)

Kjærgaard, Mikkel Baun; Wirz, Martin; Roggen, Daniel

2012-01-01

derived from multiple sensor modalities of modern smartphones. Automatic detection of flocks has several important applications, including evacuation management and socially aware computing. The novelty of this paper is, firstly, to use data fusion techniques to combine several sensor modalities (WiFi...

Coping and Psychological Health of Aging Parents of Adult Children with Developmental Disabilities

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Piazza, Vivian E.; Floyd, Frank J.; Mailick, Marsha R.; Greenberg, Jan S.

2014-01-01

Among aging parents (mean age = 65, "N" = 139) of adults with developmental disabilities, we examined the effectiveness of multiple forms of coping with caregiver burden. As expected, accommodative strategies of adapting to stress (secondary engagement), used frequently in later life, buffered the impact of caregiver burden, whereas…

ASSOCIATION BETWEEN SINGLE-PARENT FAMILY STRUCTURE AND AGE OF SEXUAL DEBUT AMONG YOUNG PERSONS IN JAMAICA.

Science.gov (United States)

Oshi, Daniel C; Mckenzie, Jordan; Baxter, Martin; Robinson, Royelle; Neil, Stephan; Greene, Tayla; Wright, Wayne; Lodge, Jeorghino

2018-02-26

There is a high and increasing proportion of single-parent families in Jamaica. This has raised concerns about the potential impact of single-parent families on the social, cognitive and behavioural development of children, including their sexual relationships. The aim of this study was to investigate the association between being raised in a single-parent family and age of sexual debut among young people in Jamaica. The study was cross-sectional in design, and based on a multi-stage sampling procedure. The study was conducted in July/September 2016. The study sample comprised 233 respondents (110 males and 123 females) aged from 18 to 35 years (mean 26.37 years; SD 5.46). Respondents completed a self-administered questionnaire with questions on socio-demographic characteristics, family structure, sexual debut and current sexual behaviour. Ninety-seven (41.7%) respondents grew up in single-parent families. A total of 201 (86.3%) had had sex (102 males and 99 females). Their mean age of sexual debut was 15.51 years (SD 3.41). Sixty-five (32.3%) had early sexual debut (single-parent families were more likely to have had early sexual debut (56.9%; n=37) compared with those from two-parent families (43.1%, n=28; p=0.004). Only 44.6% (n=29) of those who experienced early sexual debut used a condom during their first sexual encounter compared with 73% (n=100) of those who had a later sexual debut (≥16 years; p=single-father family structure was a significant predictor of early sexual debut (AOR 5.5; 95%CI: 1.1-25.8). The study found a significant association between single-parent family structure and age of sexual debut.

Winter body mass and over-ocean flocking as components of danger management by Pacific dunlins.

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Ydenberg, Ronald C; Dekker, Dick; Kaiser, Gary; Shepherd, Philippa C F; Ogden, Lesley Evans; Rickards, Karen; Lank, David B

2010-01-21

We compared records of the body mass and roosting behavior of Pacific dunlins (Calidris alpina pacifica) wintering on the Fraser River estuary in southwest British Columbia between the 1970s and the 1990s. 'Over-ocean flocking' is a relatively safe but energetically-expensive alternative to roosting during the high tide period. Fat stores offer protection against starvation, but are a liability in escape performance, and increase flight costs. Peregrine falcons (Falco peregrinus) were scarce on the Fraser River estuary in the 1970s, but their numbers have since recovered, and they prey heavily on dunlins. The increase has altered the balance between predation and starvation risks for dunlins, and thus how dunlins regulate roosting behavior and body mass to manage the danger. We therefore predicted an increase in the frequency of over-ocean flocking as well as a decrease in the amount of fat carried by dunlins over these decades. Historical observations indicate that over-ocean flocking of dunlins was rare prior to the mid-1990s and became common thereafter. Residual body masses of dunlins were higher in the 1970s, with the greatest difference between the decades coinciding with peak peregrine abundance in October, and shrinking over the course of winter as falcon seasonal abundance declines. Whole-body fat content of dunlins was lower in the 1990s, and accounted for most of the change in body mass. Pacific dunlins appear to manage danger in a complex manner that involves adjustments both in fat reserves and roosting behavior. We discuss reasons why over-ocean flocking has apparently become more common on the Fraser estuary than at other dunlin wintering sites.

Similarity of avian paramyxovirus serotype 1 isolates of low virulence for chickens obtained from contaminated poultry vaccines and from poultry flocks

DEFF Research Database (Denmark)

Jørgensen, Poul Henrik; Handberg, K. J.; Ahrens, Peter

2000-01-01

flocks. one of which had been vaccinated with two of the contaminated vaccines. The flocks belonged to the same hatchery organisation. A comparison of viral F0 gene sequences and typing of virus isolates with a panel of monoclonal antibodies showed that the vaccine and field isolates were identical....

Evaluation of sampling methods for the detection of Salmonella in broiler flocks

DEFF Research Database (Denmark)

Skov, Marianne N.; Carstensen, B.; Tornoe, N.

1999-01-01

The present study compares four different sampling methods potentially applicable to detection of Salmonella in broiler flocks, based on collection of faecal samples (i) by hand, 300 fresh faecal samples (ii) absorbed on five sheets of paper (iii) absorbed on five pairs of socks (elastic cotton...... horizontal or vertical) were found in the investigation. The results showed that the sock method (five pairs of socks) had a sensitivity comparable with the hand collection method (60 pools of five faecal samples); the paper collection method was inferior, as was the use of only one pair of socks, Estimation...... tubes pulled over the boots and termed 'socks') and (iv) by using only one pair of socks. Twenty-three broiler flocks were included in the investigation and 18 of these were found to be positive by at least one method. Seven serotypes of Salmonella with different patterns of transmission (mainly...

Mothers' Parenting Behaviors in Families of School-Aged Children with Autism Spectrum Disorder: An Observational and Questionnaire Study

Science.gov (United States)

Boonen, Hannah; van Esch, Lotte; Lambrechts, Greet; Maljaars, Jarymke; Zink, Inge; Van Leeuwen, Karla; Noens, Ilse

2015-01-01

Although parents of children with ASD face specific challenges in parenting, only a few studies have empirically investigated parenting behaviors among these parents. The current study examined differences in parenting behaviors between mothers of school-aged children with ASD (n = 30) and mothers of typically developing children (n = 39), using…

Microbial ecology of Campylobacter jejuni in a United Kingdom chicken supply chain: intermittent common source, vertical transmission, and amplification by flock propagation.

Science.gov (United States)

Pearson, A D; Greenwood, M H; Feltham, R K; Healing, T D; Donaldson, J; Jones, D M; Colwell, R R

1996-12-01

A study of Campylobacter jejuni on a broiler chicken farm between 1989 and 1994 gave an estimated isolation rate of 27% (3,304 of 12,233) from a 0.9% sample of 1.44 million broiler chickens from six to eight sheds over 32 consecutive rearing flocks comprising 251 broiler shed flocks. During the study, C. jejuni was found in 35.5% of the 251 shed flocks but only 9.2% (23 of 251) had Campylobacter isolates in successive flocks, with 9 of those 23 sheds having the same serotype between consecutive flocks, indicating a low level of transmission between flocks. Analysis of a systematic sample of 484 of 3,304 (14.6%) C. jejuni isolates showed that 85% were of 10 serotype complexes but 58% were of 3 serotype complexes, indicating a high degree of strain similarity throughout the entire study. The three commonest types were detected in 8 of 32 flocks during the 5-year study period, suggesting an intermittent common external Campylobacter source. This hypothesis was tested by a retrospective cohort analysis of C. jejuni rates and types by reference to hatchery supplier of the 1-day-old chicks. Isolation rates of C. jejuni and frequency distribution of types were determined in 6-week-old broiler chickens identified by the hatchery supplying the original chicks. The isolation rate of C. jejuni in broilers, supplied by hatchery A, was 17.6%, compared to 42.9% (P hatchery B. In two instances, when both hatcheries were used to stock the same farm flock, Campylobacter isolates were found only in those sheds with chicks supplied by hatchery B. Thus, the frequency distribution of Campylobacter types for chickens supplied by the two hatcheries over the 5-year period showed marked dissimilarity. These findings suggest that the isolation rate and type of Campylobacter isolates in broiler chickens was associated with the hatchery supplying chicks. The lack of diversity of types and the intermittent high positivity of sheds is evidence for a common source of C. jejuni introduced by

Flocking dynamics and mean-field limit in the Cucker-Smale-type model with topological interactions

KAUST Repository

Haskovec, Jan

2013-10-01

We introduce a Cucker-Smale-type model for flocking, where the strength of interaction between two agents depends on their relative separation (called "topological distance" in previous works), which is the number of intermediate individuals separating them. This makes the model scale-free and is motivated by recent extensive observations of starling flocks, suggesting that the interaction ruling animal collective behavior depends on topological rather than the metric distance. We study the conditions leading to asymptotic flocking in the topological model, defined as the convergence of the agents\\' velocities to a common vector. The shift from metric to topological interactions requires development of new analytical methods, taking into account the graph-theoretical nature of the problem. Moreover, we provide a rigorous derivation of the mean-field limit of large populations, recovering kinetic and hydrodynamic descriptions. In particular, we introduce the novel concept of relative separation in continuum descriptions, which is applicable to a broad variety of models of collective behavior. As an example, we shortly discuss a topological modification of the attraction-repulsion model and illustrate with numerical simulations that the modified model produces interesting new pattern dynamics. © 2013 Elsevier B.V. All rights reserved.

Thermophilic Campylobacter spp. in Danish broiler production: a cross-sectional survey and a retrospective analysis of risk factors for occurrence in broiler flocks

DEFF Research Database (Denmark)

Hald, Birthe; Wedderkopp, A.; Madsen, Mogens

2000-01-01

In order to elucidate the rate of thermophilic Campylobacter spp, carriage in Danish broiler production and to identify risk factors for occurrence of campylobacter in broiler flocks, a total of 88 randomly selected broiler flocks were tested for campylobacter infection, and a subsequent study...... of processing, 24% of the flocks were positive. The species distribution was 87% Campylobacter jejuni, 8% Campylobacter coli and 5% Campylobacter lari, The following parameters were identified as significant risk factors: lack of a hygiene barrier (odds ratio (OR) = 3.1, 1.1

Fever Management in Parents who Have Children Aged 0-5 Year

Directory of Open Access Journals (Sweden)

S. Reshadat

2012-07-01

Full Text Available Introduction & Objective: Fever is very common in children and is usually due to self-limiting viral infections. Management of fever is based on culture, community and religion of people all over the world. Parental concerns arise in part because of the belief that fever is a disease rather than a symptom or sign of illness. Misconceptions about childhood fevers heighten parents' concerns leading to inappropriate use of antipyretic drugs or overdosing may cause drug toxicity and frequent use of health care services. This study aimed to identify parental views of fever management in their children aged 0-5 yr.Materials & Methods: In this cross sectional study, 350 parents with children less than 5 years referred to various units of clinics covered by community oriented center of Kermanshah, completed the research questionnaire. Validity and reliability of the questionnaire were determined and the data was analyzed by SPSS Software.Results: Findings showed that the first medical care was sponging (53.1%. Sponging with saltwater was common (47.7% and Over - the - counter medications were (30%. Acetaminophen was the first drug in 90% of the cases. However, many parents express high levels of anxiety so that they seek for self-medication with antibiotic 34% of the cases. Our study showed that correlation between over concern about fever management and parents who had a positive past medical history in their children with P=0.02, parents education (P=0.018 and in employed mothers (P=0.005 was statistically significant.Conclusion: Considerable efforts will be required to educate parents about fever and its management.(Sci J Hamadan Univ Med Sci 2012;19(2:28-33

Swedish parents' activities together with their children and children's health: a study of children aged 2-17 years.

Science.gov (United States)

Berntsson, Leeni T; Ringsberg, Karin C

2014-11-01

Nordic children's health has declined. Studies show that parents' engagement in children's leisure-time activities might provide beneficial health outcomes for children. The aim of the present study was to examine the association between Swedish parents' activities together with their children, the parents' experiences of time pressure and their children's health. Data of 1461 Swedish children aged 2-17 years old that were collected in the NordChild study of 2011 were used. We analyzed physical health, diseases and disabilities, psychosomatic health and well-being, and the parents' experiences of time pressure; and we calculated the associations between parental activity together with the child and health indicators. Activities that were significantly and positively associated with children's health at ages 2-17 years of age were: playing and playing games; going to the cinema, theatre, and sporting events; reading books; playing musical instruments/singing; sports activities; watching TV/video/DVD. Playing video games or computer games, driving child to activities and going for walks were significantly and positively associated at age groups 7-12 years and 13-17 years. Activities that were negatively associated with health were: surfing/blogging on the Internet, going shopping and doing homework. Parents who were not experiencing time pressures had a higher level of activity together with their children. The parental experience of time pressure was associated with work time, with less homework activity and more symptoms in children. The family and home are important settings for the development of children's health we found eight parental activities together with their children that promoted the children's health parents' working time and their time pressure experiences affected their activities with their children there is a need for an increased focus on parental activities that are positively associated with children's health. © 2014 the Nordic Societies of

Comparison of automated processing of flocked swabs with manual processing of fiber swabs for detection of nasal carriage of Staphylococcus aureus.

Science.gov (United States)

Jones, Gillian; Matthews, Roger; Cunningham, Richard; Jenks, Peter

2011-07-01

The sensitivity of automated culture of Staphylococcus aureus from flocked swabs versus that of manual culture of fiber swabs was prospectively compared using nasal swabs from 867 patients. Automated culture from flocked swabs significantly increased the detection rate, by 13.1% for direct culture and 10.2% for enrichment culture.

Risk factors for Campylobacter colonization in Danish broiler flocks, 2010 to 2011

DEFF Research Database (Denmark)

Sandberg, M; Sørensen, L L; Steenberg, B

2015-01-01

in the Danish Broiler Production ( KIK: ) database. House- and flock-specific data collected in the surveys were supplemented with information obtained from the KIK database. Data obtained from the two studies were analyzed separately by logistic regression analysis. In both models, the dependent variable...

Evaluating the control of HPAIV H5N1 in Vietnam: virus transmission within infected flocks reported before and after vaccination

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Pfeiffer Dirk U

2010-06-01

Full Text Available Abstract Background Currently, the highly pathogenic avian influenza virus (HPAIV of the subtype H5N1 is believed to have reached an endemic cycle in Vietnam. We used routine surveillance data on HPAIV H5N1 poultry outbreaks in Vietnam to estimate and compare the within-flock reproductive number of infection (R0 for periods before (second epidemic wave, 2004-5; depopulation-based disease control and during (fourth epidemic wave, beginning 2007; vaccination-based disease control vaccination. Results Our results show that infected premises (IPs in the initial (exponential phases of outbreak periods have the highest R0 estimates. The IPs reported during the outbreak period when depopulation-based disease control was implemented had higher R0 estimates than IPs reported during the outbreak period when vaccination-based disease control was used. In the latter period, in some flocks of a defined size and species composition, within-flock transmission estimates were not significantly below the threshold for transmission (R0 Conclusions Our results indicate that the current control policy based on depopulation plus vaccination has protected the majority of poultry flocks against infection. However, in some flocks the determinants associated with suboptimal protection need to be further investigated as these may explain the current pattern of infection in animal and human populations.

Evaluation of ELISA and haemagglutination inhibition as screening tests in serosurveillance for H5/H7 avian influenza in commercial chicken flocks

DEFF Research Database (Denmark)

Arnold, M E; Slomka, M J; Breed, A C

2018-01-01

with an ELISA, which detects antibodies to all subtypes. Sera (n = 1055) from 74 commercial chicken flocks were tested by both methods. A Bayesian approach served to estimate diagnostic test sensitivities and specificities, without assuming any 'gold standard'. Sensitivity and specificity of the ELISA was 97......% and 99.8%, and for H5/H7 HI 43% and 99.8%, respectively, although H5/H7 HI sensitivity varied considerably between infected flocks. ELISA therefore provides superior sensitivity for the screening of chicken flocks as part of an algorithm, which subsequently utilises H5/H7 HI to identify infection...

Parental depressive history, parenting styles, and child psychopathology over 6 years: The contribution of each parent's depressive history to the other's parenting styles.

Science.gov (United States)

Kopala-Sibley, Daniel C; Jelinek, Caitlin; Kessel, Ellen M; Frost, Allison; Allmann, Anna E S; Klein, Daniel N

2017-10-01

The link between parental depressive history and parenting styles is well established, as is the association of parenting with child psychopathology. However, little research has examined whether a depressive history in one parent predicts the parenting style of the other parent. As well, relatively little research has tested transactional models of the parenting-child psychopathology relationship in the context of parents' depressive histories. In this study, mothers and fathers of 392 children were assessed for a lifetime history of major depression when their children were 3 years old. They then completed measures of permissiveness and authoritarianism and their child's internalizing and externalizing symptoms when children were 3, 6, and 9 years old. The results showed that a depressive history in one parent predicted the other parent's permissiveness. Analyses then showed that child externalizing symptoms at age 3 predicted maternal permissiveness and authoritarianism and paternal permissiveness at age 6. Maternal permissiveness at age 6 predicted child externalizing symptoms at age 9. No relationships in either direction were found between parenting styles and child internalizing symptoms. The results highlight the importance of considering both parents' depressive histories when understanding parenting styles, and support transactional models of parenting styles and child externalizing symptoms.

Effects of stocking density, flock size and management on the welfare of laying hens in single-tier aviaries.

Science.gov (United States)

Nicol, C J; Brown, S N; Glen, E; Pope, S J; Short, F J; Warriss, P D; Zimmerman, P H; Wilkins, L J

2006-04-01

Management practices, stocking rate and flock size may affect laying hen welfare but there have been few replicated studies in commercial non-cage systems that investigate this. This study used a broad range of physical and physiological indicators to assess the welfare of hens in 36 commercial flocks. Six laying period treatments were examined with each treatment replicated 6 times. It was not possible to randomly allocate treatments to houses, so treatment and house were largely confounded. Three stocking rates were compared: 7 birds/m(2) (n = 2450), 9 birds/m(2) (n = 3150) and 12 birds/m(2) in either small (n = 2450) or large (n = 4200) flocks. In addition, at 12 birds/m(2), in both small and large flocks, birds were subjected to either standard (SM) or modified (MM) management. MM flocks had nipple drinkers and no nest-box lights. Bone strength, fracture incidence, heterophil:lymphocyte (H:L) ratio, live weight, organ weights, serum creatine, serum osmolality, muscle pH and faecal corticosterone were measured on samples of birds at the end of the rearing period and at the end of lay. During the laying period, mortality, production and integument condition were recorded at regular intervals. Birds housed at 9 birds/m(2) had higher mortality than birds housed at 12 birds/m(2) by the end of lay, but not higher than birds housed at 7 birds/m(2). Birds housed at 7 and 9 birds/m(2) had lower percent liver weight, and worse plumage condition than most of the 12 bird/m(2) treatments. Modified management tended to improve plumage condition. There were no clear effects of flock size on the welfare indicators recorded. At the end of the rearing period fracture incidence was almost negligible and H:L ratio was within a normal range. By the end of lay fracture incidence was 60% and H:L ratio was high, with no treatment effect for either measure. This, together with information on faecal corticosterone, feather loss and mortality, suggests that the welfare of birds in all

Parent-reported Mental Health Problems and Mental Health Services Use in South Australian School-aged Children

Directory of Open Access Journals (Sweden)

Jing Wu

2016-09-01

Full Text Available Background:Monitoring and reporting childhood mental health problems and mental health services utilization over time provide important information to identify mental health related issues and to guide early intervention. This paper aims to describe the recent prevalence of parent-reported mental health problems among South Australian (SA children; to identify mental health problems associated characteristics; and to describe mental health services utilization and its related characteristics among this population. Methods:Parent-reported mental health problems were assessed against the first item of the Strength and Difficulties Questionnaire. School-aged children were randomly sampled monthly and data were collected using a surveillance system between 2005 and 2015. Associations between mental health problems and various factors were analysed using univariable analysis and multivariable logistic regression modelling. Results:Prevalence of parent-reported mental health problems among children was 9.1% and 9.3% for children aged 5 to 11 years and children aged 12 to 15 years, respectively. No change in prevalence was observed during the past decade. Mental health problems were associated with male sex, long-term illness or pain, negative school experiences, not living with biological parents, and living in a rental dwelling. Less than half (48.7% of the children with mental health problems received professional help. An increasing trend was found in mental health services utilisation among children aged 5 to 15 years. Utilization of mental health services was associated with male sex, older age, long-term illness or pain, and feeling unhappy at school. Conclusion:This study reports the prevalence of parent-reported mental and mental health services utilisation among SA school-aged children. Identified characteristics associated with mental health problems and mental health services utilisation provide useful information for the planning of

Influence of girth strap placement and panel flocking material on the saddle pressure pattern during riding of horses.

Science.gov (United States)

Byström, A; Stalfelt, A; Egenvall, A; Von Peinen, K; Morgan, K; Roepstorff, L

2010-11-01

Saddle fit is well recognised as an important factor for the health and performance of riding horses. However, only few studies have addressed general effects of different saddle construction details within a group of horses. To assess the influence of girth strap placement, traditional vs. v-system, and panel flocking material, wool vs. synthetic foam, on the saddle pressure pattern during riding. Six horses were ridden by 3 riders in sitting and rising trot and sitting canter. Saddle pressure was measured with 3 different saddle variants: 1) wool flocked panels and traditional girthing (baseline); 2) wool flocked panels and v-system girthing; and 3) foam filled panels and traditional girthing. From the pressure data, a number of descriptive variables were extracted. These were analysed using ANCOVA models with horse, rider, saddle, seat (sitting/rising, trot only) and speed as independent variables. With foam filled panels stride maximum pressures under the hind part of the saddle increased by 7-12% and the area under the saddle with a stride mean pressure >11 kPa increased by 114 cm(2) in trot and 127 cm(2) in canter. With v-system girthing, the latter variable also increased, but only by 53 and 38 cm(2) in trot and canter, respectively. In addition, stride maximum pressures under the front part of the saddle tended to increase (≤ 9%). Both flocking material and girthing have a significant influence on the saddle pressure and should thus be considered in saddle fitting. Wool seems a better flocking material than foam of the type used in the current study. For girthing, traditional placement seems equally good if not better than the v-system. However, further studies are needed to show if these results are valid for a larger population of riding horses. © 2010 EVJ Ltd.

Parent Perceptions of Parent Involvement with Elementary-Aged Students with Learning Disabilities

Science.gov (United States)

Rice, Holly

2017-01-01

The purpose of this research was to explore parent perceptions concerning their involvement in their children's special education. The goal of this study was to better understand why some parents become involved while others do not. Survey methodology was utilized to determine parent perceptions of (a) levels of parent and children's participation…

Attitudes to HPV Vaccination among Parents of Children Aged 10 to 13 Years.

Science.gov (United States)

Seven, Memnun; Güvenç, Gülten; Şahin, Eda; Akyüz, Aygül

2015-10-01

This study aimed to determine the willingness of parents to allow their sons and/or daughters aged 10-13 years to be vaccinated for human papillomavirus (HPV). This was a descriptive study conducted in an elementary school to recruit students' parents into the study. The sample consisted of 368 (69.1%) parents of children aged 10-13 years who were willing to participate in the study as a couple. Questionnaire-based data were collected from the couples. Prior information regarding HPV and vaccination and the opinions of parents of children aged 10-13 about HPV vaccination for their daughter or son. Only 26.9% of mothers and 25.0% of fathers claimed to be aware of HPV, and only 24.5% of mothers and 21.2% of fathers claimed to be aware of its vaccine. If the vaccine were available in Turkey, 21.6% of mothers and 22.4% of fathers would be willing to vaccinate their sons; although the vaccine for girls is available in Turkey, only 14.4% of mothers and 15.5% of fathers were willing to vaccinate their daughters. Few participants reported knowing about the HPV vaccine, while far fewer intended to vaccinate their daughters and sons against the infection. Both males and females should be informed about HPV and its vaccine, and initiatives to increase both awareness and the information of health care professionals should be encouraged. Copyright © 2015 North American Society for Pediatric and Adolescent Gynecology. Published by Elsevier Inc. All rights reserved.

The Study of Cooperative Obstacle Avoidance Method for MWSN Based on Flocking Control

Directory of Open Access Journals (Sweden)

Zuo Chen

2014-01-01

Full Text Available Compared with the space fixed feature of traditional wireless sensor network (WSN, mobile WSN has better robustness and adaptability in unknown environment, so that it is always applied in the research of target tracking. In order to reach the target, the nodes group should find a self-adaptive method to avoid the obstacles together in their moving directions. Previous methods, which were based on flocking control model, realized the strategy of obstacle avoidance by means of potential field. However, these may sometimes lead the nodes group to fall into a restricted area like a trap and never get out of it. Based on traditional flocking control model, this paper introduced a new cooperative obstacle avoidance model combined with improved SA obstacle avoidance algorithm. It defined the tangent line of the intersection of node’s velocity line and the edge of obstacle as the steering direction. Furthermore, the cooperative obstacle avoidance model was also improved in avoiding complex obstacles. When nodes group encounters mobile obstacles, nodes will predict movement path based on the spatial location and velocity of obstacle. And when nodes group enters concave obstacles, nodes will temporarily ignore the gravity of the target and search path along the edge of the concave obstacles. Simulation results showed that cooperative obstacle avoidance model has significant improvement on average speed and time efficiency in avoiding obstacle compared with the traditional flocking control model. It is more suitable for obstacle avoidance in complex environment.

The study of cooperative obstacle avoidance method for MWSN based on flocking control.

Science.gov (United States)

Chen, Zuo; Ding, Lei; Chen, Kai; Li, Renfa

2014-01-01

Compared with the space fixed feature of traditional wireless sensor network (WSN), mobile WSN has better robustness and adaptability in unknown environment, so that it is always applied in the research of target tracking. In order to reach the target, the nodes group should find a self-adaptive method to avoid the obstacles together in their moving directions. Previous methods, which were based on flocking control model, realized the strategy of obstacle avoidance by means of potential field. However, these may sometimes lead the nodes group to fall into a restricted area like a trap and never get out of it. Based on traditional flocking control model, this paper introduced a new cooperative obstacle avoidance model combined with improved SA obstacle avoidance algorithm. It defined the tangent line of the intersection of node's velocity line and the edge of obstacle as the steering direction. Furthermore, the cooperative obstacle avoidance model was also improved in avoiding complex obstacles. When nodes group encounters mobile obstacles, nodes will predict movement path based on the spatial location and velocity of obstacle. And when nodes group enters concave obstacles, nodes will temporarily ignore the gravity of the target and search path along the edge of the concave obstacles. Simulation results showed that cooperative obstacle avoidance model has significant improvement on average speed and time efficiency in avoiding obstacle compared with the traditional flocking control model. It is more suitable for obstacle avoidance in complex environment.

Smothering in UK free-range flocks. Part 1: incidence, location, timing and management.

Science.gov (United States)

Barrett, J; Rayner, A C; Gill, R; Willings, T H; Bright, A

2014-07-05

Smothering in poultry is an economic and welfare-related concern. This study presents the first results from a questionnaire addressing the incidence, location, timing and management of smothering of free-range farm managers from two commercial egg companies (representing 35 per cent of the UK free-range egg supply). Overall, nearly 60 per cent of farm mangers experienced smothering in their last flock, with an average of 25.5 birds lost per incidence, although per cent mortality due to smothering was low (x̄=1.6 per cent). The majority of farm managers also reported that over 50 per cent of all their flocks placed had been affected by smothering. The location and timing of smothering (excluding smothering in nest boxes) tended to be unpredictable and varied between farms. Blocking off corners/nest boxes and walking birds more frequently were identified as popular smothering reduction measures, although there was a wide variety of reduction measures reported overall. The motivation to implement reduction measures was related to a farm manager's previous experience of smothering. To our knowledge, this is the first study to provide a representative industry estimate on the incidence, location, timing and management of smothering. The results suggest that smothering is a common problem, unpredictable between flocks with no clear, effective reduction strategies. A follow-up study will investigate the correlations among smothering, disease and other welfare problems and may shed further light on management solutions. British Veterinary Association.

[Prevention groups for school-age children of mentally ill parents ("Auryn Groups")].

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Dierks, H

2001-09-01

Children of psychiatrically ill parents have a high risk themselves to develop a psychiatric illness in adulthood. Prevention aims at strengthening the resilience of these children and reducing psychosocial risk factors. This article found and describes a theoretical concept of prevention groups for children in schoolage (7-16 years) whose parents are psychiatrically ill. First practical experiences are depicted. The Hamburgian model of prevention works with closed and temporary limited groups of children as well as with the parents. It is based on supporting the children's existing coping strategies and the children are encouraged to exchange their individual experiences of the relationships within their families. One conclusion was, that the main thematic emphasis varied considerably depending on the age of the children.

Flocking particles in a non-Newtonian shear thickening fluid

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Mucha, Piotr B.; Peszek, Jan; Pokorný, Milan

2018-06-01

We prove the existence of strong solutions to the Cucker–Smale flocking model coupled with an incompressible viscous non-Newtonian fluid with the stress tensor of a power–law structure for . The fluid part of the system admits strong solutions while the solutions to the CS part are weak. The coupling is performed through a drag force on a periodic spatial domain . Additionally, we construct a Lyapunov functional determining the large time behavior of solutions to the system.

Parental Monitoring, Parent-Adolescent Communication, and Adolescents' Trust in Their Parents in China.

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Liuhua Ying

Full Text Available Trust is an important aspect of interpersonal relationships, but little is known about adolescents' interpersonal trust. The aim of the present study was to examine the associations among parental monitoring, parent-adolescent communication, and adolescents' trust in their parents in China.Data in this study were collected as part of the cross-sectional study of children in China. 3349 adolescents (female 48.6%, age range of 12-15 years were randomly selected from 35 secondary schools in April, 2009 and administered to the Adolescent Interpersonal Trust Scale, the Parental Monitoring Scale, and the Parent-Adolescent Communication Scale.Adolescents' trust in their parents was positively related to parental monitoring and parent-adolescent communication. Furthermore, parent-adolescent communication mediated the association between parental monitoring and adolescents' trust in their parents. The mediation model fit data of both genders and three age groups equally well.Parental monitoring and parent-adolescent communication play an importance role in fostering adolescents' trust in their parents.

Filicide-suicide ideation among Taiwanese parents with school-aged children: prevalence and associated factors.

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Wei, Hsi-Sheng; Chen, Ji-Kang

2014-03-01

This study explored the prevalence of filicide-suicide ideation among Taiwanese parents with school-aged children. Multiple risk factors associated with filicide-suicide ideation were assessed, and the potential effect of traditional family values was evaluated. A random sample of 1,564 parents was recruited from 21 elementary schools in a rural area of Taiwan. Potential risk factors, including demographics, family finance, psychological maladjustment, family interaction, and cultural beliefs, were further examined using a hierarchical logistic regression. Overall, 14.6% of the respondents reported having filicide-suicide ideation during the past year. The hierarchical logistic regression analysis showed that demographic factors including age, gender, and ethnicity had no significant effect. Family finances, depression, and conflict with the respondent's spouse were positively associated with filicide-suicide ideation. Finally, the parents' beliefs in traditional family values had a positive effect on filicide-suicide ideation. In other words, filicide-suicide thoughts were more common among those who upheld a strong parental responsibility for care giving and family solidarity. This study revealed a substantial prevalence of filicide-suicide ideation among local parents and identified a number of risk factors associated with those thoughts, namely family financial status, parental depression, and conflict with one's spouse. More importantly, the results highlighted the effect of traditional family values in the process. The potential intention of filicide-suicide as mercy killing and its cultural relevance were discussed. Copyright © 2013 Elsevier Ltd. All rights reserved.

RELATIONSHIP BETWEEN ALEXITHYMIA, PARENTING STYLE, AND PARENTAL CONTROL.

Science.gov (United States)

Cuzzocrea, Francesca; Barberis, Nadia; Costa, Sebastiano; Larcan, Rosalba

2015-10-01

Research on the relationship between parental alexithymia and parenting is relatively scarce. The purpose of this study was to investigate the relationships between parental alexithymia and three styles of parenting (authoritarian, authoritative, and permissive) and the relationships between parental alexithymia and two domains of psychological control (dependency and achievement). The participants were 946 parents ages 29-60 years (mothers: n = 473, M age = 44.6 yr., SD = 4.7; fathers: n = 473, M age = 48.1 yr., SD = 5.1) of children ages 11-18 years. All participants completed a sociodemographic questionnaire, the Toronto Alexithymia Scale-20 (TAS-20), the Parental Authority Questionnaire-Revised (PAQ-R), and the Dependency-Oriented and Achievement-Oriented Psychological Control Scale (DAPCS). Structural Equation Modeling (SEM) was used to examine whether alexithymia could predict the three parenting styles (authoritarian, authoritative, and permissive) and the two domains of psychological control (dependency and achievement). The first model showed that alexithymia was a positive predictor of authoritative and permissive parenting and a negative predictor of authoritarian parenting in both paternal and maternal data. The second model showed that, in both paternal and maternal data, alexithymia was a positive predictor of both dependency-oriented psychological control (DPC) and achievement-oriented psychological control (APC).

A Randomized Controlled Trial of a Parent Training and Emotion Socialization Program for Families of Hyperactive Preschool-Aged Children

Science.gov (United States)

Herbert, Sharonne D.; Harvey, Elizabeth A.; Roberts, Jasmin L.; Wichowski, Kayla; Lugo-Candelas, Claudia I.

2013-01-01

The present study evaluated the effectiveness of a parent training and emotion socialization program designed specifically for hyperactive preschoolers. Participants were 31 preschool-aged children whose parents were randomly assigned to a parent training (PT) or waitlist (WL) control group. PT parents took part in a 14-week parenting program that…

Winter body mass and over-ocean flocking as components of danger management by Pacific dunlins

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Ogden Lesley

2010-01-01

Full Text Available Abstract Background We compared records of the body mass and roosting behavior of Pacific dunlins (Calidris alpina pacifica wintering on the Fraser River estuary in southwest British Columbia between the 1970s and the 1990s. 'Over-ocean flocking' is a relatively safe but energetically-expensive alternative to roosting during the high tide period. Fat stores offer protection against starvation, but are a liability in escape performance, and increase flight costs. Peregrine falcons (Falco peregrinus were scarce on the Fraser River estuary in the 1970s, but their numbers have since recovered, and they prey heavily on dunlins. The increase has altered the balance between predation and starvation risks for dunlins, and thus how dunlins regulate roosting behavior and body mass to manage the danger. We therefore predicted an increase in the frequency of over-ocean flocking as well as a decrease in the amount of fat carried by dunlins over these decades. Results Historical observations indicate that over-ocean flocking of dunlins was rare prior to the mid-1990s and became common thereafter. Residual body masses of dunlins were higher in the 1970s, with the greatest difference between the decades coinciding with peak peregrine abundance in October, and shrinking over the course of winter as falcon seasonal abundance declines. Whole-body fat content of dunlins was lower in the 1990s, and accounted for most of the change in body mass. Conclusions Pacific dunlins appear to manage danger in a complex manner that involves adjustments both in fat reserves and roosting behavior. We discuss reasons why over-ocean flocking has apparently become more common on the Fraser estuary than at other dunlin wintering sites.

Why is parental lifespan linked to children's chances of reaching a high age? A transgenerational hypothesis.

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Vågerö, Denny; Aronsson, Vanda; Modin, Bitte

2018-04-01

Transgenerational determinants of longevity are poorly understood. We used data from four linked generations (G0, G1, G2 and G3) of the Uppsala Birth Cohort Multigeneration Study to address this issue. Mortality in G1 (N = 9565) was followed from 1961-2015 and analysed in relation to tertiles of their parents' (G0) age-at-death using Cox regression. Parental social class and marital status were adjusted for in the analyses, as was G1's birth order and adult social class. For an almost entirely deceased segment of G1 (n = 1149), born 1915-1917, we compared exact age-at-death with G0 parents' age-at-death. Finally, we explored 'resilience' as a potentially important mechanism for intergenerational transmission of longevity, using conscript information from psychological interviews of G2 and G3 men. G0 men's and women's ages-at-death were independently associated with G1 midlife and old age mortality. This association was robust and minimally reduced when G0 and G1 social class were adjusted for. We observed an increased lifespan in all social groups. Median difference in age-at-death for sons compared to fathers was + 3.9 years, and + 6.9 years for daughters compared to mothers.Parents' and maternal grandmother's longevity were associated with resilience in subsequent generations. Resilience scores of G2 men were also associated with those of their G3 sons and with their own mortality in midlife. The chance of reaching a high age is transmitted from parents to children in a modest, but robust way. Longevity inheritance is paralleled by the inheritance of individual resilience. Individual resilience, we propose, develops in the first part of life as a response to adversity and early experience in general. This gives rise to a transgenerational pathway, distinct from social class trajectories. A theory of longevity inheritance should bring together previous thinking around general susceptibility, frailty and resilience with new insights from epigenetics and social

'Mixed blessings': parental religiousness, parenting, and child adjustment in global perspective.

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Bornstein, Marc H; Putnick, Diane L; Lansford, Jennifer E; Al-Hassan, Suha M; Bacchini, Dario; Bombi, Anna Silvia; Chang, Lei; Deater-Deckard, Kirby; Di Giunta, Laura; Dodge, Kenneth A; Malone, Patrick S; Oburu, Paul; Pastorelli, Concetta; Skinner, Ann T; Sorbring, Emma; Steinberg, Laurence; Tapanya, Sombat; Tirado, Liliana Maria Uribe; Zelli, Arnaldo; Alampay, Liane Peña

2017-08-01

Most studies of the effects of parental religiousness on parenting and child development focus on a particular religion or cultural group, which limits generalizations that can be made about the effects of parental religiousness on family life. We assessed the associations among parental religiousness, parenting, and children's adjustment in a 3-year longitudinal investigation of 1,198 families from nine countries. We included four religions (Catholicism, Protestantism, Buddhism, and Islam) plus unaffiliated parents, two positive (efficacy and warmth) and two negative (control and rejection) parenting practices, and two positive (social competence and school performance) and two negative (internalizing and externalizing) child outcomes. Parents and children were informants. Greater parent religiousness had both positive and negative associations with parenting and child adjustment. Greater parent religiousness when children were age 8 was associated with higher parental efficacy at age 9 and, in turn, children's better social competence and school performance and fewer child internalizing and externalizing problems at age 10. However, greater parent religiousness at age 8 was also associated with more parental control at age 9, which in turn was associated with more child internalizing and externalizing problems at age 10. Parental warmth and rejection had inconsistent relations with parental religiousness and child outcomes depending on the informant. With a few exceptions, similar patterns of results held for all four religions and the unaffiliated, nine sites, mothers and fathers, girls and boys, and controlling for demographic covariates. Parents and children agree that parental religiousness is associated with more controlling parenting and, in turn, increased child problem behaviors. However, children see religiousness as related to parental rejection, whereas parents see religiousness as related to parental efficacy and warmth, which have different

Risk factors associated with the introduction of acute clinical infectious bursal disease among Danish broiler chickens in 1998

DEFF Research Database (Denmark)

Flensburg, Mimi Folden; Ersbøll, Annette Kjær; Jørgensen, Poul Henrik

2002-01-01

The objective of the present study was to investigate risk factors associated with the introduction of acute clinical infectious bursal disease (IBD) among Danish broiler chickens in 1998. Data on 218 flocks were collected from hatcheries, abattoirs, farmers and veterinarians; 49 of the flocks had...... from each unaffected farm. The resulting numbers of cases and controls used for statistical analyses were 16 and 61, respectively. Statistically significant associations were seen between the initial 16 Danish cases of acute clinical IBD in 1998 and certain hatcheries, age of parent birds and a certain...

Circulation of Coxiella burnetii in a Naturally Infected Flock of Dairy Sheep: Shedding Dynamics, Environmental Contamination, and Genotype Diversity

OpenAIRE

Joulié, A.; Laroucau, K.; Bailly, X.; Prigent, M.; Gasqui, P.; Lepetitcolin, E.; Blanchard, B.; Rousset, E.; Sidi-Boumedine, K.; Jourdain, E.

2015-01-01

Q fever is a worldwide zoonosis caused by Coxiella burnetii. Domestic ruminants are considered to be the main reservoir. Sheep, in particular, may frequently cause outbreaks in humans. Because within-flock circulation data are essential to implementing optimal management strategies, we performed a follow-up study of a naturally infected flock of dairy sheep. We aimed to (i) describe C. burnetii shedding dynamics by sampling vaginal mucus, feces, and milk, (ii) assess circulating strain divers...

Knowledge and behaviour of parents in relation to the oral and dental health of children aged 4-6 years.

Science.gov (United States)

ElKarmi, R; Shore, E; O'Connell, A

2015-04-01

To evaluate baseline knowledge and behaviour of parents with regard to the oral and dental health of their young children. Following ethical approval, six urban and rural schools were identified. Questionnaires were distributed to the parents of pupils (children aged 4-6 years). The questionnaire included several questions evaluating parental knowledge and behaviour of oral and dental health issues in their children. Each question was assigned a score of either 0 or 1 being inconsistent or consistent with current paediatric guidelines giving a maximum score of 6 for knowledge and 7 for behaviour. Chi-square analysis was used to analyse associations among variables. Parental knowledge varied widely among parents and across questions; however, 70.2 % of parents had scores greater than 3 (range 0-6). The majority of parents (65.8 %) also had scores greater than 3 (range 0-7) for behaviour. Deficiencies were noted in oral hygiene practices; very few parents brushed their child's teeth and were not aware of the recommended age of the first dental visit at 1 year (Age 1 visit). Parents without free medical care demonstrated high levels of knowledge (P parents thought that the information available to them on the oral health of their young children was insufficient. Parents appeared to have limited knowledge regarding the dental and oral health of their young children. This study indicates a need for improved education for parents, particularly in toothbrushing behaviour and use of toothpaste. Education strategies tailored to the Irish population should be explored.

Identifying disordered eating behaviours in adolescents: how do parent and adolescent reports differ by sex and age?

Science.gov (United States)

Bartholdy, Savani; Allen, Karina; Hodsoll, John; O'Daly, Owen G; Campbell, Iain C; Banaschewski, Tobias; Bokde, Arun L W; Bromberg, Uli; Büchel, Christian; Quinlan, Erin Burke; Conrod, Patricia J; Desrivières, Sylvane; Flor, Herta; Frouin, Vincent; Gallinat, Jürgen; Garavan, Hugh; Heinz, Andreas; Ittermann, Bernd; Martinot, Jean-Luc; Artiges, Eric; Nees, Frauke; Orfanos, Dimitri Papadopoulos; Paus, Tomáš; Poustka, Luise; Smolka, Michael N; Mennigen, Eva; Walter, Henrik; Whelan, Robert; Schumann, Gunter; Schmidt, Ulrike

2017-06-01

This study investigated the prevalence of disordered eating cognitions and behaviours across mid-adolescence in a large European sample, and explored the extent to which prevalence ratings were affected by informant (parent/adolescent), or the sex or age of the adolescent. The Development and Well-Being Assessment was completed by parent-adolescent dyads at age 14 (n = 2225) and again at age 16 (n = 1607) to explore the prevalence of 7 eating disorder symptoms (binge eating, purging, fear of weight gain, distress over shape/weight, avoidance of fattening foods, food restriction, and exercise for weight loss). Informant agreement was assessed using kappa coefficients. Generalised estimating equations were performed to explore the impact of age, sex and informant on symptom prevalence. Slight to fair agreement was observed between parent and adolescent reports (kappa estimates between 0.045 and 0.318); however, this was largely driven by agreement on the absence of behaviours. Disordered eating behaviours were more consistently endorsed amongst girls compared to boys (odds ratios: 2.96-5.90) and by adolescents compared to their parents (odds ratios: 2.71-9.05). Our data are consistent with previous findings in epidemiological studies. The findings suggest that sex-related differences in the prevalence of disordered eating behaviour are established by mid-adolescence. The greater prevalence rates obtained from adolescent compared to parent reports may be due to the secretive nature of the behaviours and/or lack of awareness by parents. If adolescent reports are overlooked, the disordered behaviour may have a greater opportunity to become more entrenched.

Daily interactions with aging parents and adult children: Associations with negative affect and diurnal cortisol.

Science.gov (United States)

Birditt, Kira S; Manalel, Jasmine A; Kim, Kyungmin; Zarit, Steven H; Fingerman, Karen L

2017-09-01

Midlife adults report greater investment in their children than in their parents, and these ties have important implications for well-being. To date, little research has addressed daily experiences in these ties. The present study examines daily experiences (negative and positive) with aging parents and adult children and their associations with daily negative affect and diurnal cortisol rhythms. Participants were middle-aged adults (N = 156; 56% women) from Wave 2 of the Family Exchanges Study, conducted in 2013, who completed a 7-day daily diary study, which included assessments of daily negative and positive social encounters and negative affect, and 4 days of saliva collection, which was collected 3 times a day (upon waking, 30 min after waking, and at bedtime) and assayed for cortisol. Multilevel models revealed that individuals were more likely to have contact with adult children than with parents but more likely to have negative experiences (negative interactions, avoidance, negative thoughts) with parents than with adult children. Nevertheless, contact and negative experiences with adult children were more consistently associated with negative affect and daily cortisol patterns than were interactions with parents. Findings are consistent with the intergenerational stake hypothesis, which suggests that individuals have a greater stake in their children than in their parents. Indeed, negative experiences with adult children may be more salient because tensions with adult children occur less frequently than do tensions with parents. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

A controlled clinical evaluation of the Parents Plus Children's Programme for parents of children aged 6-12 with mild intellectual disability in a school setting.

Science.gov (United States)

Hand, Ailish; Raghallaigh, Ciara Ní; Cuppage, Jennifer; Coyle, Sadhbh; Sharry, John

2013-10-01

The aim of this study was to evaluate the effectiveness of the parent training, Parents Plus Children's Programme (PPCP) as an intervention for parents of children with mild intellectual disabilities. Participants were parents of children, aged six to 12, attending a special school for children with mild general learning disability (n = 29). Minor programme adaptations were made. Pre and post-assessment included the Strengths and Difficulties Questionnaire, the Parenting Stress Index, the Kansas Parent Satisfaction Scale and parent identified personal and child-related goals. A significant reduction in clinical range scores for treatment group participants (n = 16) was observed. Conversely, clinical range scores for control group participants (n = 13) increased, or remained elevated. These preliminary results suggest that PPCP may be successfully delivered as a routine community-based intervention and aid to prevent and reduce behavioural problems, reduce parent stress and increase parent confidence and satisfaction. Further investigation of programme effectiveness for parents of children with developmental disability is warranted.

Death of a child and parental wellbeing in old age: Evidence from Taiwan

Science.gov (United States)

Lee, Chioun; Glei, Dana A.; Weinstein, Maxine; Goldman, Noreen

2014-01-01

The death of a child is one of the most traumatic events that a parent can experience. The psychological and physical consequences of bereavement are well established, and the consequences are more severe for mothers than fathers. However, little is known about how the death of an adult child affects parental wellbeing in old age or how the deceased child’s sex may moderate the association. We use data from the Taiwanese Longitudinal Study of Aging (TLSA) to investigate how the death of a son or a daughter differentially affects the wellbeing of older parents, measured by depressive symptoms and self-rated health. We find that for mothers, a son’s death is associated with an increase in depressive symptoms and a decline in self-rated health, but fathers’ health is not adversely affected by a son’s death. There is little evidence that a daughter’s death has a negative effect on either maternal or paternal wellbeing. We situate these findings within their social and cultural contexts and discuss social policies that would reduce gender and health inequality. PMID:24054310

Death of a child and parental wellbeing in old age: evidence from Taiwan.

Science.gov (United States)

Lee, Chioun; Glei, Dana A; Weinstein, Maxine; Goldman, Noreen

2014-01-01

The death of a child is one of the most traumatic events that a parent can experience. The psychological and physical consequences of bereavement are well established, and the consequences are more severe for mothers than fathers. However, little is known about how the death of an adult child affects parental wellbeing in old age or how the deceased child's sex may moderate the association. We use data from the Taiwanese Longitudinal Study of Aging (TLSA) to investigate how the death of a son or a daughter differentially affects the wellbeing of older parents, measured by depressive symptoms and self-rated health. We find that for mothers, a son's death is associated with an increase in depressive symptoms and a decline in self-rated health, but fathers' health is not adversely affected by a son's death. There is little evidence that a daughter's death has a negative effect on either maternal or paternal wellbeing. We situate these findings within their social and cultural contexts and discuss social policies that would reduce gender and health inequality. Copyright © 2013 Elsevier Ltd. All rights reserved.

Support for comprehensive sexuality education: perspectives from parents of school-age youth.

Science.gov (United States)

Eisenberg, Marla E; Bernat, Debra H; Bearinger, Linda H; Resnick, Michael D

2008-04-01

Controversy about school-based sexuality education in public schools has continued over the past decade, despite mounting evidence that comprehensive sexuality education effectively promotes sexual health and that parents support these programs in public schools. The present study replicates and expands upon previous findings regarding public views on school-based sexuality education. One thousand six hundred five parents of school-age children in Minnesota responded to telephone surveys in 2006-2007 (63% participation rate), including items regarding general sexuality education, 12 specific topics, the grade level at which each should be taught, and attitudes toward sexuality education. The large majority of parents supported teaching about both abstinence and contraception (comprehensive sexuality education [CSE]; 89.3%), and support was high across all demographic categories of parents. All specific sexuality education topics received majority support (63.4%-98.6%), even those often viewed as controversial. Parents believed most topics should first be taught during the middle school years. Parents held slightly more favorable views on the effectiveness of CSE compared to abstinence-only education, and these views were strongly associated with support for CSE (odds ratio [OR](CSE) = 14.3; OR(abstinence) = 0.11). This study highlights a mismatch between parents' expressed opinions and preferences, and actual sexuality education content as currently taught in the majority of public schools. In light of broad parental support for education that emphasizes multiple strategies for prevention of pregnancy and sexually transmitted infections (including abstinence), parents should be encouraged to express their opinions on sexuality education to teachers, administrators, and school boards regarding the importance of including a variety of topics and beginning instruction during middle school years or earlier.

The Transmission of Values to School-Age and Young Adult Offspring: Race and Gender Differences in Parenting

Science.gov (United States)

Pagano, Maria E.; Hirsch, Barton J.; Deutsch, Nancy L.; McAdams, Dan P.

2003-01-01

The current study explores parental socialization practices and the values transmitted to school-aged and young adult off-spring, focusing on race and gender issues involved in parental teachings. A community sample of 187 black and white mothers and fathers were interviewed with regards to their parenting practices using both quantitative and…

Social-cognitive predictors of low-income parents' restriction of screen time among preschool-aged children.

Science.gov (United States)

Lampard, Amy M; Jurkowski, Janine M; Davison, Kirsten K

2013-10-01

Parents' rules regarding child television, DVD, video game, and computer use (screen time) have been associated with lower screen use in children. This study aimed to identify modifiable correlates of this behavior by examining social-cognitive predictors of parents' restriction of child screen time. Low-income parents (N = 147) of preschool-aged children (2-6 years) completed self-administered questionnaires examining parent and child screen time, parent restriction of screen time, self-efficacy to restrict screen time, and beliefs about screen time. Structural equation modeling results indicated that greater self-efficacy to restrict screen time (β = .29, p = .016) and greater perceived importance of restricting child screen use (β = .55, p < .001) were associated with greater restriction of child screen use, after controlling for parent screen time. Family-based interventions that consider broader attitudinal factors around child screen time may be necessary to engage parents in restricting screen use.

Birds of a Feather Don't Always Flock Together : User Problems in ...

African Journals Online (AJOL)

Birds of a Feather Don't Always Flock Together : User Problems in Identifying ... for Advanced Learners and Oxford Advanced Learner's Dictionary) revealed a lack ... This paper is based on 14 of these phrasemes, which appear in one or more of ... Five strategies are presented to help learners with their dictionary searches.

Comparison of Automated Processing of Flocked Swabs with Manual Processing of Fiber Swabs for Detection of Nasal Carriage of Staphylococcus aureus▿‡

Science.gov (United States)

Jones, Gillian; Matthews, Roger; Cunningham, Richard; Jenks, Peter

2011-01-01

The sensitivity of automated culture of Staphylococcus aureus from flocked swabs versus that of manual culture of fiber swabs was prospectively compared using nasal swabs from 867 patients. Automated culture from flocked swabs significantly increased the detection rate, by 13.1% for direct culture and 10.2% for enrichment culture. PMID:21525218

The unified mechanism of aging effects in both martensite and parent phase for shape-memory alloys: atomic-level simulations

Science.gov (United States)

Deng, J.; Ding, X.; Suzuki, T.; Otsuka, K.; Lookman, T.; Saxena, A.; Sun, J.; Ren, X.

2011-03-01

Most shape-memory alloys (SMAs) subject to the aging effects not only in the martensite phase but also in the parent phase. These aging effects have been attracted much attention as they strongly affect the practical applications of SMAs. So far, the intrinsic mechanism of them has remained controversial due to the difficulty in visualization of what happens in atomic scale. In the present study, by using a combination of molecular dynamics method and Monte-Carlo method [1], we investigate the aging effects in both martensite and parent phase. We successfully reproduced the thermal behaviors of aging effects for SMAs, i.e., the Af temperature increase with aging time in martensite and the Ms temperature decrease with aging time in parent phase, which keep good agreement with the experimental observations [2]. In addition, quantitative analysis of the atomic configurations during aging reveals that the aging effects are not associated with a change in the average structure.

The Autism Parent Screen for Infants: Predicting risk of autism spectrum disorder based on parent-reported behavior observed at 6-24 months of age.

Science.gov (United States)

Sacrey, Lori-Ann R; Bryson, Susan; Zwaigenbaum, Lonnie; Brian, Jessica; Smith, Isabel M; Roberts, Wendy; Szatmari, Peter; Vaillancourt, Tracy; Roncadin, Caroline; Garon, Nancy

2018-04-01

This study examined whether a novel parent-report questionnaire, the Autism Parent Screen for Infants, could differentiate infants subsequently diagnosed with autism spectrum disorder from a high-risk cohort (siblings of children diagnosed with autism spectrum disorder (n = 66)) from high-risk and low-risk comparison infants (no family history of autism spectrum disorder) who did not develop autism spectrum disorder (n = 138 and 79, respectively). Participants were assessed prospectively at 6, 9, 12, 15, 18, and 24 months of age. At 36 months, a blind independent diagnostic assessment for autism spectrum disorder was completed. Parent report on the Autism Parent Screen for Infants was examined in relation to diagnostic outcome and risk status (i.e. high-risk sibling with autism spectrum disorder, high-risk sibling without autism spectrum disorder, and low-risk control). The results indicated that from 6 months of age, total score on the Autism Parent Screen for Infants differentiated between the siblings with autism spectrum disorder and the other two groups. The sensitivity, specificity, and positive and negative predictive validity of the Autism Parent Screen for Infants highlight its potential for the early screening of autism spectrum disorder in high-risk cohorts.

Association of parental history of type 2 diabetes with age, lifestyle, anthropometric factors, and clinical severity at type 2 diabetes diagnosis

DEFF Research Database (Denmark)

Svensson, Elisabeth; Berencsi, Klara; Sander, Simone

2016-01-01

in Type 2 Diabetes cohort. We examined the prevalence ratios (PR) of demographic, lifestyle, anthropometric, and clinical factors according to parental history, using Poisson regression adjusting for age and gender. RESULTS: Of 2825 T2D patients, 34% (n = 964) had a parental history of T2D. Parental......BACKGROUND: We investigated whether parental history of type 2 diabetes mellitus (T2D) is associated with age, lifestyle, anthropometric factors, and clinical severity at the time of T2D diagnosis. METHODS: We conducted a cross-sectional study based on the Danish Centre for Strategic Research...... history was associated with younger age at diagnosis [adjusted (a)PR 1.66, 95% confidence interval: 1.19, 2.31) for age

Evidence that certain clones of Campylobacter jejuni persist during successive broiler flock rotations

DEFF Research Database (Denmark)

Petersen, L.; Wedderkopp, A.

2001-01-01

selected. Twelve broiler houses located on 10 farms were included in the study. The C,jejuni isolates collected from the selected houses during the surveillance were typed using fla typing and macrorestriction profiling (MRP), and a subset of the isolates, representing each of the identified clones...... (7 of 13) had fla type 1/1, but MRPs distinguished between isolates from different houses, and fla type 1/1 clones belonged to different serotypes, Seven houses carried persistent clones that covered an interval of at least four broiler flock rotations, or at least one half year. The dominant fla...... with recurrent Campylobacter problems. The MRPs of clones belonging to fla type 1/1 serotype O:2 isolated from persistently infected flocks shared a high percentage of bands compared to the remaining isolates, indicating that some clones that have the ability to cause persistent infections in broiler farms...

Flocking transitions in confluent tissues.

Science.gov (United States)

Giavazzi, Fabio; Paoluzzi, Matteo; Macchi, Marta; Bi, Dapeng; Scita, Giorgio; Manning, M Lisa; Cerbino, Roberto; Marchetti, M Cristina

2018-04-25

Collective cell migration in dense tissues underlies important biological processes, such as embryonic development, wound healing and cancer invasion. While many aspects of single cell movements are now well established, the mechanisms leading to displacements of cohesive cell groups are still poorly understood. To elucidate the emergence of collective migration in mechanosensitive cells, we examine a self-propelled Voronoi (SPV) model of confluent tissues with an orientational feedback that aligns a cell's polarization with its local migration velocity. While shape and motility are known to regulate a density-independent liquid-solid transition in tissues, we find that aligning interactions facilitate collective motion and promote solidification, with transitions that can be predicted by extending statistical physics tools such as effective temperature to this far-from-equilibrium system. In addition to accounting for recent experimental observations obtained with epithelial monolayers, our model predicts structural and dynamical signatures of flocking, which may serve as gateway to a more quantitative characterization of collective motility.

Collective motion with anticipation: flocking, spinning, and swarming.

Science.gov (United States)

Morin, Alexandre; Caussin, Jean-Baptiste; Eloy, Christophe; Bartolo, Denis

2015-01-01

We investigate the collective dynamics of self-propelled particles able to probe and anticipate the orientation of their neighbors. We show that a simple anticipation strategy hinders the emergence of homogeneous flocking patterns. Yet anticipation promotes two other forms of self-organization: collective spinning and swarming. In the spinning phase, all particles follow synchronous circular orbits, while in the swarming phase, the population condensates into a single compact swarm that cruises coherently without requiring any cohesive interactions. We quantitatively characterize and rationalize these phases of polar active matter and discuss potential applications to the design of swarming robots.

Cosmic-ray exposure ages of the ordinary chondrites and their significance for parent body stratigraphy

Science.gov (United States)

Crabb, J.; Schultz, L.

1981-01-01

Improved exposure ages are derived for 201 H, 203 L, and 38 LL chondrites in an effort to understand the characteristics of the chondrite parent body. The Ne-21 exposure ages were calculated from literature values taking into account shielding differences, a trapped component and radiogenic He. The exposure age distributions show clear peaks at 4.5 and 20 million years for the H chondrites, while the Ls and LLs appear more as a continuous series of intermediate peaks which may be modeled by at least six peaks between 1 and 35 million years in the case of L chondrites. The observations that every petrological type occurs in each large peak and contain solar wind gases suggest that the parent bodies have been fragmented and reassembled into a megabreccia. The H meteorites are proposed to represent the surface layer of a body with a substantial, active regolith as indicated by the relatively high abundances of solar gases. The L chondrites, on the other hand, are attributed to a parent body that was fragmented by collision about 500 million years ago.

Dynamical Modeling of Collective Behavior from Pigeon Flight Data: Flock Cohesion and Dispersion

Science.gov (United States)

Xu, Xiao-Ke; Small, Michael

2012-01-01

Several models of flocking have been promoted based on simulations with qualitatively naturalistic behavior. In this paper we provide the first direct application of computational modeling methods to infer flocking behavior from experimental field data. We show that this approach is able to infer general rules for interaction, or lack of interaction, among members of a flock or, more generally, any community. Using experimental field measurements of homing pigeons in flight we demonstrate the existence of a basic distance dependent attraction/repulsion relationship and show that this rule is sufficient to explain collective behavior observed in nature. Positional data of individuals over time are used as input data to a computational algorithm capable of building complex nonlinear functions that can represent the system behavior. Topological nearest neighbor interactions are considered to characterize the components within this model. The efficacy of this method is demonstrated with simulated noisy data generated from the classical (two dimensional) Vicsek model. When applied to experimental data from homing pigeon flights we show that the more complex three dimensional models are capable of simulating trajectories, as well as exhibiting realistic collective dynamics. The simulations of the reconstructed models are used to extract properties of the collective behavior in pigeons, and how it is affected by changing the initial conditions of the system. Our results demonstrate that this approach may be applied to construct models capable of simulating trajectories and collective dynamics using experimental field measurements of herd movement. From these models, the behavior of the individual agents (animals) may be inferred. PMID:22479176

Dynamical modeling of collective behavior from pigeon flight data: flock cohesion and dispersion.

Directory of Open Access Journals (Sweden)

Graciano Dieck Kattas

Full Text Available Several models of flocking have been promoted based on simulations with qualitatively naturalistic behavior. In this paper we provide the first direct application of computational modeling methods to infer flocking behavior from experimental field data. We show that this approach is able to infer general rules for interaction, or lack of interaction, among members of a flock or, more generally, any community. Using experimental field measurements of homing pigeons in flight we demonstrate the existence of a basic distance dependent attraction/repulsion relationship and show that this rule is sufficient to explain collective behavior observed in nature. Positional data of individuals over time are used as input data to a computational algorithm capable of building complex nonlinear functions that can represent the system behavior. Topological nearest neighbor interactions are considered to characterize the components within this model. The efficacy of this method is demonstrated with simulated noisy data generated from the classical (two dimensional Vicsek model. When applied to experimental data from homing pigeon flights we show that the more complex three dimensional models are capable of simulating trajectories, as well as exhibiting realistic collective dynamics. The simulations of the reconstructed models are used to extract properties of the collective behavior in pigeons, and how it is affected by changing the initial conditions of the system. Our results demonstrate that this approach may be applied to construct models capable of simulating trajectories and collective dynamics using experimental field measurements of herd movement. From these models, the behavior of the individual agents (animals may be inferred.

‘Inconvenient biology:’ advantages and disadvantages of first-time parenting after age 40 using in vitro fertilization

Science.gov (United States)

Mac Dougall, K.; Beyene, Y.; Nachtigall, R.D.

2012-01-01

BACKGROUND As ages at first birth have steadily risen in the industrial west over the last several decades, the phenomenon of ‘delayed childbearing’ has come under research scrutiny by demographers, medical specialists and social scientists. In this study, we specifically explore the perceived advantages and disadvantages of postponed conception as well as participants’ retrospective opinions on the ‘optimal age’ for parenting. METHODS To this end, we examined a cohort purposely chosen to epitomize delayed childbearing, i.e. men and women who used IVF to conceive at the very end of their reproductive capability. In-depth qualitative interviews were conducted between 2009 and 2011 with 46 couples and 15 individual self-selected US women and men who had used IVF to conceive their first child when the woman was aged 40 or older at the time of delivery. Although the demographics of this cohort were consistent with others who use IVF in the USA, their median income was 3–4 times higher than that of the average US family, which may bias their largely positive parenting experiences. RESULTS Most women and men believed that childbearing later in life resulted in advantages for themselves and their families. These included having established careers with financial security and career-time flexibility, enhanced emotional preparedness, committed co-parenting relationships and a positive overall family experience. The main disadvantage was the unexpected difficulty in conceiving that culminated in the use of IVF and resulted in a smaller family than desired, although many expressed feeling ‘lucky’ to have children at all. Other disadvantages were lack of energy for parenting, less available lifetime to spend with children and anticipated stigma as older parents. CONCLUSIONS These disadvantages appear to have influenced conception and parenting experiences so that in hindsight the majority of participants identified the optimal age for first-time parenting as 5�

Parental questionnaire as a screening instrument for motor function at age five

DEFF Research Database (Denmark)

Nordbye-Nielsen, Kirsten; Kesmodel, Ulrik Schiøler

2014-01-01

, Pearson’s χ2-test, logistic regression analyses and sensitivity and specificity were used to assess the correlation between the questionnaire and the M-ABC test. Results: The best screening tool was six questions in combination: sensitivity 39.8%, specificity 87.1%. Asking if a health professional ever......Introduction: No standardised method is used to determine motor function in children in general practice in Denmark. Our aim was to evaluate the correlation between a parental questionnaire assessing motor function at the age of five years and the clinical test Movement Assessment Battery...... for Children (M-ABC), and to assess whether one or more questions could be used to screen for motor problems at the age of five years. Methods: This study was based on a parental questionnaire containing ten questions. The M-ABC was used as the gold standard. n = 755 children. The Mann-Whitney rank sum test...

Caring from Afar: Asian H1B Migrant Workers and Aging Parents.

Science.gov (United States)

Lee, Yeon-Shim; Chaudhuri, Anoshua; Yoo, Grace J

2015-09-01

With the growth in engineering/technology industries, the United States has seen an increase in the arrival of highly skilled temporary migrant workers on H1B visas from various Asian countries. Limited research exists on how these groups maintain family ties from afar including caring for aging parents. This study explores the experiences and challenges that Asian H1B workers face when providing care from a distance. A total of 21 Chinese/Taiwanese, Korean, and Indian H1B workers participated in in-depth qualitative interviews. Key findings indicate that despite distance, caring relationships still continue through regular communications, financial remittances, and return visits, at the same time creating emotional, psychological, and financial challenges for the workers. Findings highlight the need for further research in understanding how the decline of aging parent's health impacts the migrants' adjustment and health in the United States.

Vancomycin-resistant enterococci (VRE) in broiler flocks 5 years after the avoparcin ban

DEFF Research Database (Denmark)

Heuer, Ole Eske; Pedersen, Karl; Andersen, J.S.

2002-01-01

The glycopeptide growth promoter avoparcin was banned from animal production in Denmark in 1995. In this study, we investigated the occurrence of vancomycin-resistant enterococci (VRE) in broiler flocks in the absence of the selective pressure exerted by the use of avoparcin. One hundred sixty...

Impacts of Oreochromis mossambicus (Perciformes: Cichlidae upon habitat segregation among cyprinodontids (Cyprinodontiformes of a species flock in Mexico

Directory of Open Access Journals (Sweden)

Linda Fuselier

2001-06-01

Full Text Available Five species of Cyprinodon in Laguna Chichancanab, Yucatan, Mexico comprise a young species flock whose ecology and evolution has not been thoroughly studied, but whose existence is threatened with extinction. Species flocks evolve in isolated areas where predators and competitors are absent. Since the description of the Chichancanab flock, Oreochromis mossambicus, a species introduced into the lake for which I examined habitat in the 1980’s, has become common throughout the basin. I assessed relative abundance of flock species in the lake. examined habitat use and segregation among the three most common flock species and examined the affects of O. mossambicus upon flock species habitat use. Cyprinodon beltrani was the most abundant flock species in 1997, followed by C. maya and C. labiosus; C. verecundus and C. simus were rare. Cyprinodon beltrani was found in shallow water, nearshore, over thick beds of submerged Chara, and little emergent vegetation Cyprinodon beltrani exhibited diurnal variation in nearshore habitat use. In the field, the habitat use of C. beltrani and O. mossambicus broadly overlapped. In aquarium experiments, three flock species exhibited habitat use segregation and C. beltrani and C. labiosus showed agonistic behaviors that strengthened segregation. Cyprinodon maya differed from C. beltrani and C. labiosus by its greater dispersion of individuals and use of areas higher in the water column. The presence of O. mossambicus caused a shift in habitat use by C. maya and C. labiosus that put these species into habitat occupied by C. beltrani. The presence of introduced species has caused a significant perturbation of the conditions that fomented speciation of the Chichancanab flock 8000 years ago.Cinco especies de Cyprinodon en la Laguna Chichancanab, Yucatán, México comprenden un cardumen jóven de especies cuya ecología y evolución no ha sido estudiada a fondo, pero cuya existencia está siendo amenazada con la extinci

Managing the screen-viewing behaviours of children aged 5-6 years: a qualitative analysis of parental strategies.

Science.gov (United States)

Jago, R; Zahra, J; Edwards, M J; Kesten, J M; Solomon-Moore, E; Thompson, J L; Sebire, S J

2016-03-01

The present study used qualitative methods to: (1) examine the strategies that were used by parents of children aged 5-6 years to manage screen viewing; (2) identify key factors that affect the implementation of the strategies and (3) develop suggestions for future intervention content. Telephone interviews were conducted with parents of children aged 5-6 years participating in a larger study. Interviews were transcribed verbatim and analysed using an inductive and deductive content analysis. Coding and theme generation was iterative and refined throughout. Parents were recruited through 57 primary schools located in the greater Bristol area (UK). 53 parents of children aged 5-6 years. Parents reported that for many children, screen viewing was a highly desirable behaviour that was difficult to manage, and that parents used the provision of screen viewing as a tool for reward and/or punishment. Parents managed screen viewing by setting limits in relation to daily events such as meals, before and after school, and bedtime. Screen-viewing rules were often altered depending on parental preferences and tasks. Inconsistent messaging within and between parents represented a source of conflict at times. Potential strategies to facilitate reducing screen viewing were identified, including setting screen-viewing limits in relation to specific events, collaborative rule setting, monitoring that involves mothers, fathers and the child, developing a family-specific set of alternative activities to screen viewing and developing a child's ability to self-monitor their own screen viewing. Managing screen viewing is a challenge for many parents and can often cause tension in the home. The data presented in this paper provide key suggestions of new approaches that could be incorporated into behaviour change programmes to reduce child screen viewing. 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/

Management-Related Traffic as a Stressor Eliciting Parental Care in a Roadside-Nesting Bird: The European Bee-Eater Merops apiaster.

Science.gov (United States)

Blas, Julio; Abaurrea, Teresa; D'Amico, Marcello; Barcellona, Francesca; Revilla, Eloy; Román, Jacinto; Carrete, Martina

2016-01-01

Traffic is often acknowledged as a threat to biodiversity, but its effects have been mostly studied on roads subjected to high traffic intensity. The impact of lower traffic intensity such as those affecting protected areas is generally neglected, but conservation-oriented activities entailing motorized traffic could paradoxically transform suitable habitats into ecological traps. Here we questioned whether roadside-nesting bee-eaters Merops apiaster perceived low traffic intensity as a stressor eliciting risk-avoidance behaviors (alarm calls and flock flushes) and reducing parental care. Comparisons were established within Doñana National Park (Spain), between birds exposed to either negligible traffic (ca. 0-10 vehicles per day) or low traffic intensity (ca. 10-90 vehicles per day) associated to management and research activities. The frequencies of alarm calls and flock flushes were greater in areas of higher traffic intensity, which resulted in direct mortality at moderate vehicle speeds (≤ 40 km/h). Parental feeding rates paralleled changes in traffic intensity, but contrary to our predictions. Indeed, feeding rates were highest in traffic-exposed nests, during working days and traffic rush-hours. Traffic-avoidance responses were systematic and likely involved costs (energy expenditure and mortality), but vehicle transit positively influenced the reproductive performance of bee-eaters through an increase of nestling feeding rates. Because the expected outcome of traffic on individual performance can be opposed when responses are monitored during mating (i.e. negative effect by increase of alarm calls and flock flushes) or nestling-feeding period (i.e. at least short-term positive effect by increase of nestling feeding rates), caution should be taken before inferring fitness consequences only from isolated behaviors or specific life history stages.

Parenting behavior at 2 years predicts school-age performance at 7 years in very preterm children.

Science.gov (United States)

Treyvaud, Karli; Doyle, Lex W; Lee, Katherine J; Ure, Alexandra; Inder, Terrie E; Hunt, Rod W; Anderson, Peter J

2016-07-01

Parenting influences child development, but it is unclear whether early parenting behavior can influence school-age outcomes in very preterm (VPT) children, and/or if certain groups of VPT children may be more affected by early parenting behavior. These research questions were examined. Participants were 147 children born parent-child interaction was assessed, and at 7 years CA, general intelligence (IQ), language, executive function, academic skills, and social-emotional functioning were assessed. Higher levels of parent-child synchrony, and parent facilitation, sensitivity and positive affect at 2 years were associated with better child outcomes at 7 years, while higher levels of intrusiveness and negative affect were associated with poorer outcomes. Many of these relationships remained after controlling for early child cognitive development. Interactions between child medical risk (higher/lower) and parenting were limited to child reading, math, and executive functioning outcomes, with stronger relationships for lower medical risk children. The contribution of early parenting to VPT children's school-age performance is significant, with stronger effects for lower medical risk children in some outcomes. These findings support the premise that parenting strategies should be included in the NICU and early interventions programs for VPT infants. © 2015 Association for Child and Adolescent Mental Health.

Diseases of whooping cranes seen during annual migration of the Rocky Mountain flock

Science.gov (United States)

Snyder, S. Bret; Richard, Michael J.; Drewien, Roderick C.; Thomas, Nancy J.; Thilsted, John P.; Junge, Randall E.

1991-01-01

Diagnosis and treatment of ill whooping cranes of the Rocky Mountain flock was provided by a zoological facility. Cases of avian cholera, lead poisoning and avian tuberculosis were encountered. The zoo efforts were an adjunct to the U.S. Fish and Wildlife Service, Whooping Crane Recovery Plan.

Brief Report : Influence of gender and age on parent reported subjective well-being in children with and without autism

NARCIS (Netherlands)

Begeer, Sander; Ma, Yujie; Koot, Hans M.; Wierda, Marlies; van Beijsterveldt, C.E.M.; Boomsma, Dorret I.; Bartels, Meike

2017-01-01

Autism spectrum disorders (ASD) are associated with reduced Subjective well-being (SWB). To examine the influence of gender and age on well-being we collected parent reported SWB in children with or without ASD (total n = 1030), aged 8–14 years. Parents reported lower SWB for children with ASD

Association between parents' attitudes and behaviors toward children's visual care and myopia risk in school-aged children.

Science.gov (United States)

Zhou, Shuang; Yang, Lihua; Lu, Benlin; Wang, Hexin; Xu, Ting; Du, Dandan; Wu, Shiqing; Li, Xiuxiu; Lu, Meixia

2017-12-01

The purpose of this survey was to determine the association of parents' attitudes and behaviors toward children's visual care with myopia risk in school-aged children.A total of 894 parents of school-aged children were investigated in primary and middle schools in the central and noncentral urban area in Wuhan through stratified cluster random sampling on July, 2015. We analyzed the association by the generalized linear mixed model.The results indicated that children with parents' high expectations of 1.5 or higher on their vision exhibited a decreased risk of myopia compared with 1.0 and 0.5 or lower (OR = 0.49, 95%CI = 0.36-0.67). Children whose parents only paid attention to their vision in junior and senior school and in primary school had an increased myopia risk than that in preschool (OR = 2.12, 95%CI = 1.01-4.45, and OR = 3.11, 95%CI = 1.28-7.58, respectively). Children whose parents ensured for their sufficient sleep had a decreased myopia risk (OR = 0.45, 95%CI = 0.24-0.85). Compared with children whose parents who never adjusted electronic devices' parameters, the odds ratio of sometimes was 0.49 (95%CI = 0.31-0.79), often 0.53 (95%CI = 0.33-0.85), and always 0.44 (95%CI = 0.26-0.75), respectively.Parents' attitudes and behaviors toward children's visual care are significantly associated with the myopia risk in school-aged children. Consequently, efforts should be made to educate parents on how they protect children's vision and reduce their risk of myopia. Copyright © 2017 The Authors. Published by Wolters Kluwer Health, Inc. All rights reserved.

Comparing Mental Health of School-Age Children of Parents With/Without Bipolar Disorders: A Case Control Study

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Shamsaei

2015-05-01

Full Text Available Background Children of parents with bipolar disorder appear to have an increased risk of early-onset Bipolar Disorder (BP, mood disorders and other psychiatric disorders. Objectives The aim of this study was to compare the mental health of school-age children of parents, with/without bipolar disorder. Materials and Methods This case-control study included one hundred children aged six to twelve years, who had parents with bipolar disorder and 200 children of 163 demographically-matched control parents. Parents with bipolar disorder were recruited from Farshchian Psychiatric Hospital of Hamadan, Iran, during year 2014. The parent version of the Child Symptom Inventory-4 questionnaire was used to measure mental health. Mean comparisons were performed using Student’s t test while effect sizes were estimated by Cohen’s d coefficient. The Chi-square test was used to assess significant differences between frequency distribution of demographic variables in both groups. The significance level was considered less than 0.05. Results There were statistically significant differences between children of parents with and those without bipolar disorder regarding attention deficit hyperactivity disorder, oppositional defiant disorder, conduct, generalized anxiety disorder, schizophrenia, major depression, separation anxiety (P< 0.001 and social phobia (P < 0.05. Children of parents with BP are at high risk for psychiatric disorders. Conclusions These findings support that the careful evaluation and prospective following of the psychopathology of children of parents with bipolar disorder are critical for early identification and treatment.

9 CFR 54.8 - Requirements for flock plans and post-exposure management and monitoring plans.

Science.gov (United States)

2010-01-01

... HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE COOPERATIVE CONTROL AND ERADICATION OF LIVESTOCK OR... identification the owner of the flock may choose to maintain; (2) Sex, year of birth, breed, and when possible to...

Aerobic and strength exercises for youngsters aged 12 to 15: what do parents think?

OpenAIRE

ten Hoor, Gill A.; Sleddens, Ester F. C.; Kremers, Stef P. J.; Schols, Annemie M. W. J.; Kok, Gerjo; Plasqui, Guy

2015-01-01

Background Although strength exercises evidently have both physiological and psychological health benefits across all ages, they are erroneously considered to adversely affect health status in youngsters. The aim of this study was to examine parental attitudes towards their child’s physical activity in general, as well as aerobic and strength exercises in particular. Methods In total, 314 parents from an online panel representative of the Dutch population completed an online survey about thei...

Parental Stress and Related Factors in Parents of Children with Cerebral Palsy

Directory of Open Access Journals (Sweden)

Hui-Yi Wang

2004-07-01

Full Text Available Children with cerebral palsy display prominent motor dysfunction associated with other developmental disorders. Parenting a child with cerebral palsy presents a number of challenges and stresses. The first purpose of this study was to compare parental stress in parents of children with cerebral palsy to that in parents of children with typical development. The second purpose was to analyze the correlations between parental stress and parents' characteristics, the child's characteristics, the child's earliest age when rehabilitation was first commenced, and weekly frequency of rehabilitation for the child. A convenience sample of 63 parents of children with cerebral palsy (mean age of children, 4.3 ± 1.8 years was recruited. Forty parents of children with typical development were recruited as a comparison group. All parents filled out the Chinese version of the Parenting Stress Index (PSI, which consists of child domain and parent domain scales. The scores reported by parents of children with cerebral palsy in the child domain, parent domain, and PSI total scale were significantly higher than those for parents in the comparison group. The child domain score was significantly correlated to the child's age and severity of motor disability. A significant correlation was also found between the parent domain score and the child's earliest age of commencing rehabilitation. The PSI total scale score was significantly associated with both the child's severity of motor disability and age of commencing rehabilitation. Clinical professionals should be concerned about parental stress in parents of children with cerebral palsy and provide resources to support such parents. We suggest some strategies to reduce parental stress by strengthening parents' child-care skills.

Distributed leader-follower flocking control for multi-agent dynamical systems with time-varying velocities

NARCIS (Netherlands)

Yu, Wenwu; Chen, Guanrong; Cao, Ming

Using tools from algebraic graph theory and nonsmooth analysis in combination with ideas of collective potential functions, velocity consensus and navigation feedback, a distributed leader-follower flocking algorithm for multi-agent dynamical systems with time-varying velocities is developed where

Parenting Behavior at 2 Years Predicts School-age Performance at 7 Years in Very Preterm Children

Science.gov (United States)

Treyvaud, Karli; Doyle, Lex W.; Lee, Katherine J.; Ure, Alexandra; Inder, Terrie E.; Hunt, Rod W.; Anderson, Peter J.

2016-01-01

Parenting influences child development, but it is unclear whether early parenting behavior can influence school-age outcomes in very preterm (VPT) children, and/or if certain groups of VPT children may be more affected by early parenting behavior. These research questions were examined. Participants were 147 children born <30 weeks' gestation…

Obese parents--obese children? Psychological-psychiatric risk factors of parental behavior and experience for the development of obesity in children aged 0-3: study protocol.

Science.gov (United States)

Grube, Matthias; Bergmann, Sarah; Keitel, Anja; Herfurth-Majstorovic, Katharina; Wendt, Verena; von Klitzing, Kai; Klein, Annette M

2013-12-17

The incidences of childhood overweight and obesity have increased substantially and with them the prevalence of associated somatic and psychiatric health problems. Therefore, it is important to identify modifiable risk factors for early childhood overweight in order to develop effective prevention or intervention programs. Besides biological factors, familial interactions and parental behavioral patterns may influence children's weight development. Longitudinal investigation of children at overweight risk could help to detect significant risk and protective factors. We aim to describe infants' weight development over time and identify risk and protective factors for the incidence of childhood obesity. Based on our findings we will draw up a risk model that will lay the foundation for an intervention/prevention program. We present the protocol of a prospective longitudinal study in which we investigate families with children aged from 6 months to 47 months. In half of the families at least one parent is obese (risk group), in the other half both parents are normal weight (control group). Based on developmental and health-psychological models, we consider measurements at three levels: the child, the parents and parent-child-relationship. Three assessment points are approximately one year apart. At each assessment point we evaluate the psychological, social, and behavioral situation of the parents as well as the physical and psychosocial development of the child. Parents are interviewed, fill in questionnaires, and take part in standardized interaction tasks with their child in a feeding and in a playing context in our research laboratory. The quality of these video-taped parent-child interactions is assessed by analyzing them with standardized, validated instruments according to scientific standards. Strengths of the presented study are the prospective longitudinal design, the multi-informant approach, including the fathers, and the observation of parent

Parenting Intervention for Prevention of Behavioral Problems in Elementary School-Age Filipino-American Children: A Pilot Study in Churches.

Science.gov (United States)

Javier, Joyce R; Coffey, Dean M; Schrager, Sheree M; Palinkas, Lawrence A; Miranda, Jeanne

This study aims to test an evidence-based parenting program offered in churches among Filipino-American parents and estimate effect size for a fully powered trial. Twenty-two parents of children aged 6 to 12 years were randomly assigned to either an intervention or a waiting-list control group. Parents' perceptions of child behavior, parenting practices, and parenting stress were obtained at baseline. Parents in the experimental group attended The Incredible Years School Age Program, which consisted of 12 weekly 2-hour sessions. A follow-up assessment was performed after the intervention and 12 weeks later. The intervention was subsequently repeated with the control group. Satisfaction was assessed with a 40-item measure. Analysis of covariance was used to compare the intervention group postintervention versus the control group. Paired t-tests compared mean parenting practices, parenting stress, and child behavior outcomes. Satisfaction was assessed descriptively. Twenty-two parents completed all assessments and the intervention. Analysis of variance comparing intervention and control groups with repeated measures (pre- and post-test measures) revealed that the program has a positive impact on parenting stress, parenting practices (physical punishment, positive verbal discipline), and parent's perception of their child's behavior (internalizing symptoms, externalizing symptoms, and number of problematic behaviors). Analyses of all participants comparing pre- and post intervention revealed improvements in parenting stress, positive verbal discipline, and child externalizing and total problem behaviors. Families reported high satisfaction with the content and format of the intervention. Results support the feasibility of providing an evidence-based parenting program to Filipino parents in churches to prevent future behavioral health problems.

Shared reality of the abusive and the vulnerable: the experience of aging for parents living with abusive adult children coping with mental disorder.

Science.gov (United States)

Band-Winterstein, Tova; Smeloy, Yael; Avieli, Hila

2014-11-01

Increasing numbers of aging parents are finding themselves in the role of caregiver for their mentally ill adult child due to global deinstitutionalization policy. The aim of this paper is to describe the daily aging experience of parents abused by an adult child with mental disorder and the challenges confronting them in this shared reality. Data collection was performed through in-depth semi-structured interviews with 16 parents, followed by content analysis. Three major themes emerged: (a) old age as a platform for parent's vulnerability facing ongoing abuse; (b) "whose needs come first?" in a shared reality of abusive and vulnerable protagonists; (c) changes in relationship dynamics. Old age becomes an arena for redefined relationships combining increased vulnerability, needs of both sides, and its impact on the well-being of the aging parents. This calls for better insights and deeper understanding in regard to intervention with such families.

Support for Families: Working with Parents and Caregivers to Support Children from Birth to Three Years of Age.

Science.gov (United States)

Hanssen, Elizabeth, Ed.; Zimanyi, Louise, Ed.

2000-01-01

This theme issue of Coordinators' Notebook focuses on how early childhood care and development (ECCD) programs world-wide can work with parents and caregivers to support children from birth to 3 years of age. Section 1 of the journal describes the needs of parents and families and the development of parent programs around the world. Section 2…

Parenting and Children's Internalizing Symptoms: How Important are Parents?

Science.gov (United States)

van der Sluis, Cathy M; van Steensel, Francisca J A; Bögels, Susan M

Parenting behaviors are associated with children's internalizing symptoms, however, it is not often examined which factors could possibly influence this relationship. The goals of this study were twofold. One goal was to examine whether the association between parenting and children's internalizing symptoms would increase if parenting behaviors were assessed behaviorally and in a context where the child displayed specific anxious behaviors. Another goal was to examine whether this relationship was influenced by the age and gender of the child, and by possible parenting differences between mothers and fathers. These questions were examined in a sample of 211 children aged 4-12 years; 140 community children and 71 clinically referred anxious children. Parents completed questionnaires regarding children's internalizing symptoms and parenting behaviors (positive reinforcement, punishment, force, reinforcement of dependency, and modeling/reassurance). In line with expectations, more punishment and less modeling/reassurance by parents were related to more internalizing symptoms in children. Child gender, child age, parent gender and clinical anxiety status were not found to influence the relationship between parenting and children's internalizing symptoms. Our results suggest that paternal parenting is as important as maternal parenting with respect to children's internalizing symptoms, and therefore, fathers could be included in child treatment as well.

Styles of parent-child interactions in families with preschool-age children.

Directory of Open Access Journals (Sweden)

Shvedovskaya A.A.

2015-06-01

Full Text Available With regard to cultural-historical and activity approaches, collaborative activity with an adult, including communication as a type of meta-activity, is considered to be the necessary mechanism of child development. A child is considered to be an active partner, possessing his/her own motives, and is guided by mental representations of the parent and interactions with him/her. Russian psychologists have developed a range of parenting style classifications; however, these styles primarily emphasize a parent’s position, contrary to methodological perspectives, with inadequate consideration of a child’s own agency. The aims of the current research were to investigate actual goal-oriented interactions between preschoolers and their parents and to outline certain patterns (types of interactions, considering both partners and analyzing interac- tions according to the activity model. A total of 75 parent-child dyads (children aged from 4.6 years to 6.11 years participated in “collaborative activity trials” in which the observational method was based on the activity approach. Cluster analysis (k-means clusterization revealed five different groups of parent-child dyads: conflictual, harmonious, distant and two-fold dominant (with dominant parent or dominant child. Between-group comparisons (Mann-Whitney U test showed significant differences in a range of parameters of activity and emotional components of interactions. The harmonious type of interactions is not prevalent, although subgroups with different types of domination are the most common, which may be attributed to cultural peculiarities. Domination-subordination misbalance does not seem to seriously distort the normal developmental trajectory; however, in cases of conflictual and distant dyads, interactional issues might hinder the course of goal-oriented activity, which might serve as a predictor for potential difficulties in further learning.

Early cumulative risk predicts externalizing behavior at age 10: The mediating role of adverse parenting.

Science.gov (United States)

Gach, Emily J; Ip, Ka I; Sameroff, Arnold J; Olson, Sheryl L

2018-02-01

Multiple environmental risk factors in early childhood predict a broad range of adverse developmental outcomes. However, most prior longitudinal research has not illuminated explanatory mechanisms. Our main goals were to examine predictive associations between cumulative ecological risk factors in early childhood and children's later externalizing problems and to determine whether these associations were explained by variations in parenting quality. Participants were 241 children (118 girls) at risk for school-age conduct problems and their parents and teachers. Children were approximately 3 years old at Time 1 (T1) and 10 years old at Time 2 (T2). Reports of contextual risk at T1 were used to develop a cumulative risk index consisting of 6 singular risk variables from 3 ecological levels: social resources (low income; social isolation), family resources (marital aggression; poor total family functioning), and maternal resources (single parent status; poor maternal mental health). At T1, parenting variables were measured (corporal punishment, warm responsiveness, maternal efficacy, and negative perceptions of child behavior). At T2, mothers, fathers, and teachers reported child externalizing problems. Johnson's relative weight analysis revealed that the cumulative risk index was a more powerful predictor of age 10 years externalizing behavior than any of the singular contextual risk variables. Adverse parenting mediated the effects of cumulative risk on later child externalizing problems. Our findings have significant implications for understanding long-term effects of multiple contextual risk factors present in early childhood and for the implementation of positive parenting interventions early on. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Flocking dynamics and mean-field limit in the Cucker-Smale-type model with topological interactions

KAUST Repository

Haskovec, Jan

2013-01-01

separating them. This makes the model scale-free and is motivated by recent extensive observations of starling flocks, suggesting that the interaction ruling animal collective behavior depends on topological rather than the metric distance. We study

Preliminary Report: Analysis of the baseline study on the prevalence of Salmonella in laying hen flocks of Gallus gallus

DEFF Research Database (Denmark)

Hald, Tine

This is a preliminary report on the analysis of the Community-wide baseline study to estimate the prevalence of Salmonella in laying hen flocks. It is being published pending the full analysis of the entire dataset from the baseline study. The report contains the elements necessary for the establ......This is a preliminary report on the analysis of the Community-wide baseline study to estimate the prevalence of Salmonella in laying hen flocks. It is being published pending the full analysis of the entire dataset from the baseline study. The report contains the elements necessary...