Science.gov

Sample records for avian avoidance behaviour

  1. Session: Avoiding, minimizing, and mitigating avian and bat impacts

    SciTech Connect

    Thelander, Carl; Kerlinger, Paul

    2004-09-01

    This session at the Wind Energy and Birds/Bats workshop consisted of two presentations followed by a discussion/question answer period. The session addressed a variety of questions related to avoiding, minimizing, and mitigating the avian and bat impacts of wind power development including: what has been learned from operating turbines and mitigating impacts where they are unavoidable, such as at Altamont Pass WRA, and should there be mitigation measures such as habitat creation or land conservation where impacts occur. Other impact minimization and mitigation approaches discussed included: location and siting evaluations; options for construction and operation of wind facilities; turbine lighting; and the physical alignment/orientation. Titles and authors of the presentations were: 'Bird Fatalities in the Altamont Pass Wind Resource Area: A Case Study, Part II' by Carl Thelander and 'Prevention and Mitigation of Avian Impacts at Wind Power Facilities' by Paul Kerlinger.

  2. Pathological Demand Avoidance: Exploring the Behavioural Profile

    ERIC Educational Resources Information Center

    O'Nions, Elizabeth; Viding, Essi; Greven, Corina U; Ronald, Angelica; Happé, Francesca

    2014-01-01

    "Pathological Demand Avoidance" is a term increasingly used by practitioners in the United Kingdom. It was coined to describe a profile of obsessive resistance to everyday demands and requests, with a tendency to resort to "socially manipulative" behaviour, including outrageous or embarrassing acts. Pathological demand…

  3. Evidence for an expectancy-based theory of avoidance behaviour.

    PubMed

    Declercq, Mieke; De Houwer, Jan; Baeyens, Frank

    2008-01-01

    In most studies on avoidance learning, participants receive an aversive unconditioned stimulus after a warning signal is presented, unless the participant performs a particular response. Lovibond (2006) recently proposed a cognitive theory of avoidance learning, according to which avoidance behaviour is a function of both Pavlovian and instrumental conditioning. In line with this theory, we found that avoidance behaviour was based on an integration of acquired knowledge about, on the one hand, the relation between stimuli and, on the other hand, the relation between behaviour and stimuli.

  4. Infection-avoidance behaviour in humans and other animals.

    PubMed

    Curtis, Valerie A

    2014-10-01

    Compared with living free, the parasitic way of life has many attractions. Parasites create problems for all animals. Potential hosts can respond by learning to live with parasites (tolerance), actively fighting them (resistance), or they can avoid becoming infected in the first place (avoidance). I propose here a new classification of avoidance behaviour according to the epidemiology of infection risk, where animals must avoid (i) conspecifics, (ii) parasites and their vectors, (iii) parasite-rich environments, and (iv) niche infestation. I further explore how the disgust adaptive system, which coordinates avoidance behaviour, may form a continuum with the immune system through the sharing of signalling pathways, sites of action, and evolutionary history.

  5. Adolescents' approach-avoidance behaviour in the context of pain.

    PubMed

    Fisher, Emma; Keogh, Edmund; Eccleston, Christopher

    2016-02-01

    Adolescents who experience pain often face competing goals and have to choose whether to approach (confront) or avoid pain. This study investigates the decisions adolescents make when their pain conflicts with a valued goal. Adolescents between the ages of 15 and 18 years (N = 170) completed questionnaires on general and pain-specific anxiety, courage, and dispositional avoidance. Adolescents were presented with 16 vignettes (8 high pain intensity, 8 low pain intensity), which described pain conflicting with a goal (eg, doing well at school, seeing friends). Adolescents rated goals for importance and reported how likely they would be to approach or avoid each pain. Adolescents were more likely to avoid and were more fearful of high pain intensity than low pain intensity vignettes. Pain anxiety predicted higher levels of avoidance for both pain intensities. General anxiety was not a significant predictor of avoidance for either pain intensity. Goal importance promoted approach of goals, but only when pain was described as intense. However, pain anxiety predicted avoidance beyond the importance of goals for high pain intensity vignettes. In addition, we compared approach-avoidance of adolescents with and without chronic pain; analyses revealed no differences in approach-avoidance behaviour. We also found that behavioural endurance was predictive of approach and dispositional avoidance predicted higher avoidance, but courage was not predictive of behaviour in this task. We adopt a motivational perspective when interpreting the findings and consider whether the fear-avoidance model should be extended to include the function of avoidance or approach in the pursuit of a desired goal.

  6. Avian Hearing and the Avoidance of Wind Turbines

    SciTech Connect

    Dooling, R.

    2002-06-01

    This report provides a complete summary of what is known about basic hearing capabilities in birds in relation to the characteristics of noise generated by wind turbines. It is a review of existing data on bird hearing with some preliminary estimates of environmental noise and wind turbine noise at Altamont Pass, California, in the summer of 1999. It is intended as a resource in future discussions of the role that hearing might play in bird avoidance of turbines.

  7. Contamination sensitivity and the development of disease-avoidant behaviour

    PubMed Central

    Siegal, Michael; Fadda, Roberta; Overton, Paul G.

    2011-01-01

    Owing to their developing cognitive abilities and their limited knowledge about the biological basis of illness, children often have less expertise at disease avoidance than adults. However, affective reactions to contaminants through the acquisition of disgust and the social and cultural transmissions of knowledge about contamination and contagion provide impetus for children to learn effective disease-avoidant behaviours early in their development. In this article, we review the ontogenetic development of knowledge about contamination and contagion with particular attention to the role of socialization and culture. Together with their emerging cognitive abilities and affective reactions to contaminants, informal and formal cultural learning shape children's knowledge about disease. Through this process, the perceptual cues of contamination are linked to threats of disease outcomes and can act as determinants of disease-avoidant behaviours. PMID:22042919

  8. Disgust as an adaptive system for disease avoidance behaviour

    PubMed Central

    Curtis, Valerie; de Barra, Mícheál; Aunger, Robert

    2011-01-01

    Disgust is an evolved psychological system for protecting organisms from infection through disease avoidant behaviour. This ‘behavioural immune system’, present in a diverse array of species, exhibits universal features that orchestrate hygienic behaviour in response to cues of risk of contact with pathogens. However, disgust is also a dynamic adaptive system. Individuals show variation in pathogen avoidance associated with psychological traits like having a neurotic personality, as well as a consequence of being in certain physiological states such as pregnancy or infancy. Three specialized learning mechanisms modify the disgust response: the Garcia effect, evaluative conditioning and the law of contagion. Hygiene behaviour is influenced at the group level through social learning heuristics such as ‘copy the frequent’. Finally, group hygiene is extended symbolically to cultural rules about purity and pollution, which create social separations and are enforced as manners. Cooperative hygiene endeavours such as sanitation also reduce pathogen prevalence. Our model allows us to integrate perspectives from psychology, ecology and cultural evolution with those of epidemiology and anthropology. Understanding the nature of disease avoidance psychology at all levels of human organization can inform the design of programmes to improve public health. PMID:21199843

  9. The influence of object identity on obstacle avoidance reaching behaviour.

    PubMed

    de Haan, A M; Van der Stigchel, S; Nijnens, C M; Dijkerman, H C

    2014-07-01

    When reaching for target objects, we hardly ever collide with other objects located in our working environment. Behavioural studies have demonstrated that the introduction of non-target objects into the workspace alters both spatial and temporal parameters of reaching trajectories. Previous studies have shown the influence of spatial object features (e.g. size and position) on obstacle avoidance movements. However, obstacle identity may also play a role in the preparation of avoidance responses as this allows prediction of possible negative consequences of collision based on recognition of the obstacle. In this study we test this hypothesis by asking participants to reach towards a target as quickly as possible, in the presence of an empty or full glass of water placed about half way between the target and the starting position, at 8 cm either left or right of the virtual midline. While the spatial features of full and empty glasses of water are the same, the consequences of collision are clearly different. Indeed, when there was a high chance of collision, reaching trajectories veered away more from filled than from empty glasses. This shows that the identity of potential obstacles, which allows for estimating the predicted consequences of collision, is taken into account during obstacle avoidance.

  10. Do malaria parasites manipulate the escape behaviour of their avian hosts? An experimental study.

    PubMed

    Garcia-Longoria, Luz; Møller, Anders P; Balbontín, Javier; de Lope, Florentino; Marzal, Alfonso

    2015-12-01

    Escape behaviour is the behaviour that birds and other animals display when already caught by a predator. An individual exhibiting higher intensity of such anti-predator behaviour could have greater probabilities of escape from predators. Parasites are known to affect different aspects of host behaviour to increase their own fitness. Vector-transmitted parasites such as malaria parasites should gain by manipulating their hosts to enhance the probability of transmission. Several studies have shown that malaria parasites can manipulate their vectors leading to increased transmission success. However, little is known about whether malaria parasites can manipulate escape behaviour of their avian hosts thereby increasing the spread of the parasite. Here we used an experimental approach to explore if Plasmodium relictum can manipulate the escape behaviour of one of its most common avian hosts, the house sparrow Passer domesticus. We experimentally tested whether malaria parasites manipulate the escape behaviour of their avian host. We showed a decrease in the intensity of biting and tonic immobility after removal of infection with anti-malaria medication compared to pre-experimental behaviour. These outcomes suggest that infected sparrows performed more intense escape behaviour, which would increase the likelihood of individuals escaping from predators, but also benefit the parasite by increasing its transmission opportunities.

  11. Air pollution, avoidance behaviour and children's respiratory health: evidence from England.

    PubMed

    Janke, Katharina

    2014-12-01

    Despite progress in air pollution control, concerns remain over the health impact of poor air quality. Governments increasingly issue air quality information to enable vulnerable groups to avoid exposure. Avoidance behaviour potentially biases estimates of the health effects of air pollutants. But avoidance behaviour imposes a cost on individuals and therefore may not be taken in all circumstances. This paper exploits panel data at the English local authority level to estimate the relationship between children's daily hospital emergency admissions for respiratory diseases and common air pollutants, while allowing for avoidance behaviour in response to air pollution warnings. A 1% increase in nitrogen dioxide or ozone concentrations increases hospital admissions by 0.1%. For the subset of asthma admissions - where avoidance is less costly - there is evidence of avoidance behaviour. Ignoring avoidance behaviour, however, does not result in statistically significant underestimation of the health effect of air pollution.

  12. Avian evolution: from Darwin's finches to a new way of thinking about avian forebrain organization and behavioural capabilities.

    PubMed

    Reiner, Anton

    2009-02-23

    The study of birds, especially the Galapagos finches, was important to Darwin in the development of the theory of evolution by natural selection. Birds have also been at the centre of a recent reformulation in understanding cerebral evolution and the substrates for higher cognition. While it was once thought that birds possess a simple cerebrum and were thus limited to instinctive behaviours, it is now clear that birds possess a well-developed cerebrum that looks very different from the mammalian cerebrum but can support a cognitive ability that for some avian species rivals that in primates.

  13. Developmental Profiles of Task-Avoidant Behaviour and Reading Skills in Grades 1 and 2

    ERIC Educational Resources Information Center

    Magi, Katrin; Torppa, Minna; Lerkkanen, Marja-Kristiina; Poikkeus, Anna-Maija; Rasku-Puttonen, Helena; Nurmi, Jari-Erik

    2013-01-01

    A latent profile analysis approach was used to examine the developmental profiles of task-avoidant behaviour and reading skills in Grades 1 and 2, as well as their antecedents in kindergarten. The participants in this study were 448 children. Four different developmental profiles of task-avoidant behaviour and reading skills were identified. Our…

  14. Nesting behaviour influences species-specific gas exchange across avian eggshells

    PubMed Central

    Portugal, Steven J.; Maurer, Golo; Thomas, Gavin H.; Hauber, Mark E.; Grim, Tomáš; Cassey, Phillip

    2014-01-01

    Carefully controlled gas exchange across the eggshell is essential for the development of the avian embryo. Water vapour conductance (GH2O) across the shell, typically measured as mass loss during incubation, has been demonstrated to optimally ensure the healthy development of the embryo while avoiding desiccation. Accordingly, eggs exposed to sub-optimal gas exchange have reduced hatching success. We tested the association between eggshell GH2O and putative life-history correlates of adult birds, ecological nest parameters and physical characteristics of the egg itself to investigate how variation in GH2O has evolved to maintain optimal water loss across a diverse set of nest environments. We measured gas exchange through eggshell fragments in 151 British breeding bird species and fitted phylogenetically controlled, general linear models to test the relationship between GH2O and potential predictor parameters of each species. Of our 17 life-history traits, only two were retained in the final model: wet-incubating parent and nest type. Eggs of species where the parent habitually returned to the nest with wet plumage had significantly higher GH2O than those of parents that returned to the nest with dry plumage. Eggs of species nesting in ground burrows, cliffs and arboreal cups had significantly higher GH2O than those of species nesting on the ground in open nests or cups, in tree cavities and in shallow arboreal nests. Phylogenetic signal (measured as Pagel's λ) was intermediate in magnitude, suggesting that differences observed in the GH2O are dependent upon a combination of shared ancestry and species-specific life history and ecological traits. Although these data are correlational by nature, they are consistent with the hypothesis that parents constrained to return to the nest with wet plumage will increase the humidity of the nest environment, and the eggs of these species have evolved a higher GH2O to overcome this constraint and still achieve optimal water

  15. Preservation of ovarian follicles reveals early evolution of avian reproductive behaviour.

    PubMed

    Zheng, Xiaoting; O'Connor, Jingmai; Huchzermeyer, Fritz; Wang, Xiaoli; Wang, Yan; Wang, Min; Zhou, Zhonghe

    2013-03-28

    The two groups of archosaurs, crocodilians and birds, form an extant phylogenetic bracket for understanding the reproductive behaviour of dinosaurs. This behaviour is inferred from preserved nests and eggs, and even gravid individuals. Data indicate that many 'avian' traits were already present in Paraves--the clade that includes birds and their close relatives--and that the early evolution of the modern avian form of reproduction was already well on its way. Like living neornithine birds, non-avian maniraptorans had daily oviposition and asymmetrical eggs with complex shell microstructure, and were known to protect their clutches. However, like crocodilians, non-avian maniraptorans had two active oviducts (one present in living birds), relatively smaller eggs, and may not have turned their eggs in the way that living birds do. Here we report on the first discovery of fossilized mature or nearly mature ovarian follicles, revealing a previously undocumented stage in dinosaur reproduction: reproductively active females near ovulation. Preserved in a specimen of the long bony-tailed Jeholornis and two enantiornithine birds from the Early Cretaceous period lacustrine Jehol Biota in northeastern China, these discoveries indicate that basal birds only had one functional ovary, but retained primitive morphologies as a result of their lower metabolic rate relative to living birds. They also indicate that basal birds reached sexual maturity before skeletal maturity, as in crocodiles and paravian dinosaurs. Differences in follicular morphology between Jeholornis and the enantiornithines are interpreted as forming an evolutionary gradient from the reproductive condition in paravian dinosaurs towards neornithine birds. Furthermore, differences between the two enantiornithines indicate that this lineage might also have evolved advanced reproductive traits in parallel to the neornithine lineage. PMID:23503663

  16. Lane formation in pedestrian counterflows driven by a potential field considering following and avoidance behaviours

    NASA Astrophysics Data System (ADS)

    Guo, Wei; Wang, Xiaolu; Zheng, Xiaoping

    2015-08-01

    Lane formation in pedestrian counterflows is an interesting self-organization phenomenon. It is believed to be caused by the following or avoidance behaviours of pedestrians. In this paper, a potential field CA model that considers the velocity and density distributions of a crowd and their subjective consciousness is proposed to study the effects of the two behaviours on lane formation in the case of a pedestrian counterflow in a corridor with a periodic boundary. An indexing system is introduced to distinguish the three different patterns observed in the counterflow, and a smoothness index is introduced to measure the smoothness of the counterflow. It is found that avoidance behaviour is more relevant to lane formation than following behaviour. Some differences between the two behaviours are also presented.

  17. Non-avoidance behaviour in enchytraeids to boric acid is related to the GABAergic mechanism.

    PubMed

    Bicho, Rita C; Gomes, Susana I L; Soares, Amadeu M V M; Amorim, Mónica J B

    2015-05-01

    Soil invertebrates, e.g. enchytraeids, are known to be able to avoid unfavourable conditions, which gives them an important ecological advantage. These organisms possess chemoreceptors that can detect stressors, which in turn activate responses such as avoidance behaviour. We studied the avoidance behaviour in response to boric acid (BA) using enchytraeids. Results showed not only no avoidance, but that increasing concentrations seemed to have an "attraction" effect. To study the underlying mechanism, a selection of genes targeting for neurotransmission pathways (acetylcholinesterase (AChE) and gamma-aminobutyric acid receptor (GABAr)) were quantified via quantitative real-time polymerase chain reaction (qPCR). Evidences were that BA is neurotoxic via the GABAergic system mechanism where it acts as a GABA-associated protein receptor (GABAAR) antagonist possibly causing anaesthetic effects. This is the first time that (non)avoidance behaviour in invertebrates was studied in relation with the GABAergic system. We strongly recommend the combination of such gene and/or functional assay studies with the avoidance behaviour test as it can bring many advantages and important interpretation lines for ecotoxicity with minor effort.

  18. Magnetically induced behaviour of ferritin corpuscles in avian ears: can cuticulosomes function as magnetosomes?

    PubMed Central

    Jandacka, Petr; Burda, Hynek; Pistora, Jaromir

    2015-01-01

    Magnetoreception is an enigmatic, poorly understood sensory ability, described mainly on the basis of behavioural studies in animals of diverse taxa. Recently, corpuscles containing superparamagnetic iron-storage protein ferritin were found in the inner ear hair cells of birds, a predominantly single ferritin corpuscle per cell. It was suggested that these corpuscles might represent magnetosomes and function as magnetosensors. Here we determine ferritin low-field paramagnetic susceptibility to estimate its magnetically induced intracellular behaviour. Physical simulations show that ferritin corpuscles cannot be deformed or rotate in weak geomagnetic fields, and thus cannot provide magnetoreception via deformation of the cuticular plate. Furthermore, we reached an alternative hypothesis that ferritin corpuscle in avian ears may function as an intracellular electromagnetic oscillator. Such an oscillator would generate additional cellular electric potential related to normal cell conditions. Though the phenomenon seems to be weak, this effect deserves further analyses. PMID:25551148

  19. Rapid loss of antipredatory behaviour in captive-bred birds is linked to current avian invasions

    PubMed Central

    Carrete, Martina; Tella, José L.

    2015-01-01

    Despite the importance of behaviour in conservation biology, there have been few studies that address behaviour in areas such as invasion ecology. There is an urgent need to identify specific traits that facilitate the establishment and spread of alien species to prevent biological invasions and their impact on biodiversity. Changes in antipredatory behaviour in captivity have been proposed to explain the higher invasiveness of wild-caught exotic species. We experimentally tested this hypothesis by assessing the response of wild-caught and captive-bred cage birds facing an approaching predator and their ability to escape from human capture, using species available in the Spanish pet market. Results showed the loss of antipredatory responses and escape abilities in captive-bred birds compared with wild-caught ones. An intraspecific comparison between wild-caught and the first generation of captive-bred birds pointed to a rapid behavioural loss in captivity (individual lifetime) rather than to differences among species (evolutionary exposure). In the context of current avian invasions, the proportion of individuals showing antipredatory responses within a species was positively related to the likelihood of the species being found escaped and breeding in the wild. These results offer a link between behaviour, fitness, and the invasion syndrome in birds. PMID:26667185

  20. Rapid loss of antipredatory behaviour in captive-bred birds is linked to current avian invasions.

    PubMed

    Carrete, Martina; Tella, José L

    2015-12-15

    Despite the importance of behaviour in conservation biology, there have been few studies that address behaviour in areas such as invasion ecology. There is an urgent need to identify specific traits that facilitate the establishment and spread of alien species to prevent biological invasions and their impact on biodiversity. Changes in antipredatory behaviour in captivity have been proposed to explain the higher invasiveness of wild-caught exotic species. We experimentally tested this hypothesis by assessing the response of wild-caught and captive-bred cage birds facing an approaching predator and their ability to escape from human capture, using species available in the Spanish pet market. Results showed the loss of antipredatory responses and escape abilities in captive-bred birds compared with wild-caught ones. An intraspecific comparison between wild-caught and the first generation of captive-bred birds pointed to a rapid behavioural loss in captivity (individual lifetime) rather than to differences among species (evolutionary exposure). In the context of current avian invasions, the proportion of individuals showing antipredatory responses within a species was positively related to the likelihood of the species being found escaped and breeding in the wild. These results offer a link between behaviour, fitness, and the invasion syndrome in birds.

  1. TRPV channel-mediated calcium transients in nociceptor neurons are dispensable for avoidance behaviour

    PubMed Central

    Lindy, Amanda S.; Parekh, Puja K.; Zhu, Richard; Kanju, Patrick; Chintapalli, Sree V.; Tsvilovskyy, Volodymyr; Patterson, Randen L.; Anishkin, Andriy; van Rossum, Damian B.; Liedtke, Wolfgang B.

    2014-01-01

    Animals need to sense and react to potentially dangerous environments. TRP ion channels participate in nociception, presumably via Ca2+ influx, in most animal species. However, the relationship between ion permeation and animals’ nocifensive behaviour is unknown. Here we use an invertebrate animal model with relevance for mammalian pain. We analyse the putative selectivity filter of OSM-9, a TRPV channel, in osmotic avoidance behaviour of Caenorhabditis elegans. Using mutagenized OSM-9 expressed in the head nociceptor neuron, ASH, we study nocifensive behaviour and Ca2+ influx. Within the selectivity filter, M601-F609, Y604G strongly reduces avoidance behaviour and eliminates Ca2+ transients. Y604F also abolishes Ca2+ transients in ASH, while sustaining avoidance behaviour, yet it disrupts behavioral plasticity. Homology modelling of the OSM-9 pore suggests that Y604 may assume a scaffolding role. Thus, aromatic residues in the OSM-9 selectivity filter are critical for pain behaviour and ion permeation. These findings have relevance for understanding evolutionary roots of mammalian nociception. PMID:25178952

  2. Hesitation behaviour of hoverflies Sphaerophoria spp. to avoid ambush by crab spiders

    NASA Astrophysics Data System (ADS)

    Yokoi, Tomoyuki; Fujisaki, Kenji

    2009-02-01

    Pollinators possess several antipredator adaptations that minimise predation risk during foraging. In addition to morphological adaptations, hoverflies might have behavioural antipredator adaptations. We conducted three field experiments to investigate whether the “hesitation behaviour” of hoverflies Sphaerophoria spp., moving backwards and forwards in front of a flower, is effective in avoiding ambush predators on flowers. First, we compared the behaviour of different flower visitors, including several bees and other hoverflies, with Sphaerophoria spp. behaviour. Only Sphaerophoria spp. exhibited the hesitation behaviour in front of flowers. The flight behaviour was observed more frequently before landing on flowers than on leaves. Second, we investigated rejection by Sphaerophoria spp. to artificially placed corpses of the crab spider Thomisus labefactus. The rejection rate of flowers with a crab spider placed on or under it was significantly higher than that of non-treated flowers. Moreover, the presence of a spider on the flower decreased the number of hesitation displays, compared with non-treated flowers. Finally, to determine whether hesitation behaviour could be a consequence of floral assessment, we investigated hoverfly rejection of previously foraged flowers. Sphaerophoria spp. did not reject flowers that had been visited by the same individual or conspecifics within 3 min. We suggest that hesitation behaviour may be adaptive, enabling assessment of predation risk and hence avoiding ambush predators on flowers.

  3. Ictal symptoms of anxiety, avoidance behaviour, and dissociation in patients with dissociative seizures

    PubMed Central

    Goldstein, L H; Mellers, J D C

    2006-01-01

    Objective To examine anxiety related seizure symptoms and avoidance behaviour in adults with dissociative (psychogenic non‐epileptic) seizures (DS) in comparison with a group suffering from partial epilepsy. Methods 25 DS and 19 epilepsy patients completed an attack symptom measure, the hospital anxiety and depression scale, the dissociative experiences scale, and the fear questionnaire. Results DS patients reported the presence of significantly greater numbers of somatic symptoms of anxiety during their attacks than the epilepsy group, despite not reporting subjectively higher levels of anxiety. The DS patients also reported higher levels of agoraphobic‐type avoidance behaviour than the epilepsy group. Measures of dissociation were higher in the DS group, who also reported greater symptoms of depression. Conclusions The findings support a model whereby DS occur as a paroxysmal, dissociative response to heightened arousal in the absence of raised general anxiety levels. The model has practical implications for clinical assessment and treatment: in clinical practice, inquiry about these symptoms may help in the diagnosis of DS; with respect to treatment, the anxiety related symptoms and avoidance behaviour prevalent in DS are a potential focus for a cognitive behavioural approach analogous to that used in the treatment of other anxiety disorders. PMID:16614021

  4. Assessment of avoidance behaviour by earthworms (Lumbricus rubellus and Octolasion cyaneum) in linear pollution gradients.

    PubMed

    Lowe, Christopher N; Butt, Kevin R; Cheynier, Kevin Yves-Marie

    2016-02-01

    Avoidance behaviour by earthworms is recognised as a valuable endpoint in soil quality assessment and has resulted in the development of a standardised test (ISO 17512-1, 2008) providing epigeic earthworms with a choice between test and control soils. This study sought to develop and evaluate an avoidance test utilising soil-dwelling earthworms in linear pollution gradients with Visible Implant Elastomer (VIE) tags used to identify individual organisms. Sequential experiments were established in laboratory-based mesocosms (0.6m×0.13m×0.1m) that determined the relative sensitivities (in terms of associated avoidance behaviour) of Octolasion cyaneum and Lumbricus rubellus at varying levels of polluted soil and also assessed the influence of introduction point on recorded movement within gradients. In an initial gradient (0%, 25%, 50%, 75%, 100% polluted soil), both species exhibited a clear avoidance response with all surviving earthworms retrieved (after 7 days) from the unpolluted soil. In a less polluted gradient (0%, 6.25%, 12.5%, 18.75%, 25%) L. rubellus were retrieved throughout the gradient while O. cyaneum were located within the 0% and 6.25% divisions, suggesting a species-specific response to polluted soil. Results also showed that the use of a linear pollution gradient system has the potential to assess earthworm avoidance behaviour and could provide a more ecologically relevant alternative to the ISO 17512: 2008 avoidance test. However, further work is required to establish the effectiveness of this procedure, specifically in initial chemical screening and assessment of single contaminant bioavailability, where uptake of pollutants by earthworms could be measured and directly related to the point of introduction and retrieval. PMID:26590693

  5. Assessment of avoidance behaviour by earthworms (Lumbricus rubellus and Octolasion cyaneum) in linear pollution gradients.

    PubMed

    Lowe, Christopher N; Butt, Kevin R; Cheynier, Kevin Yves-Marie

    2016-02-01

    Avoidance behaviour by earthworms is recognised as a valuable endpoint in soil quality assessment and has resulted in the development of a standardised test (ISO 17512-1, 2008) providing epigeic earthworms with a choice between test and control soils. This study sought to develop and evaluate an avoidance test utilising soil-dwelling earthworms in linear pollution gradients with Visible Implant Elastomer (VIE) tags used to identify individual organisms. Sequential experiments were established in laboratory-based mesocosms (0.6m×0.13m×0.1m) that determined the relative sensitivities (in terms of associated avoidance behaviour) of Octolasion cyaneum and Lumbricus rubellus at varying levels of polluted soil and also assessed the influence of introduction point on recorded movement within gradients. In an initial gradient (0%, 25%, 50%, 75%, 100% polluted soil), both species exhibited a clear avoidance response with all surviving earthworms retrieved (after 7 days) from the unpolluted soil. In a less polluted gradient (0%, 6.25%, 12.5%, 18.75%, 25%) L. rubellus were retrieved throughout the gradient while O. cyaneum were located within the 0% and 6.25% divisions, suggesting a species-specific response to polluted soil. Results also showed that the use of a linear pollution gradient system has the potential to assess earthworm avoidance behaviour and could provide a more ecologically relevant alternative to the ISO 17512: 2008 avoidance test. However, further work is required to establish the effectiveness of this procedure, specifically in initial chemical screening and assessment of single contaminant bioavailability, where uptake of pollutants by earthworms could be measured and directly related to the point of introduction and retrieval.

  6. Brain–immune interactions and the neural basis of disease-avoidant ingestive behaviour

    PubMed Central

    Pacheco-López, Gustavo; Bermúdez-Rattoni, Federico

    2011-01-01

    Neuro–immune interactions are widely manifested in animal physiology. Since immunity competes for energy with other physiological functions, it is subject to a circadian trade-off between other energy-demanding processes, such as neural activity, locomotion and thermoregulation. When immunity is challenged, this trade-off is tilted to an adaptive energy protecting and reallocation strategy that is identified as ‘sickness behaviour’. We review diverse disease-avoidant behaviours in the context of ingestion, indicating that several adaptive advantages have been acquired by animals (including humans) during phylogenetic evolution and by ontogenetic experiences: (i) preventing waste of energy by reducing appetite and consequently foraging/hunting (illness anorexia), (ii) avoiding unnecessary danger by promoting safe environments (preventing disease encounter by olfactory cues and illness potentiation neophobia), (iii) help fighting against pathogenic threats (hyperthermia/somnolence), and (iv) by associative learning evading specific foods or environments signalling danger (conditioned taste avoidance/aversion) and/or at the same time preparing the body to counteract by anticipatory immune responses (conditioning immunomodulation). The neurobiology behind disease-avoidant ingestive behaviours is reviewed with special emphasis on the body energy balance (intake versus expenditure) and an evolutionary psychology perspective. PMID:22042916

  7. Avoidance behaviour of Eisenia fetida to carbofuran, chlorpyrifos, mancozeb and metamidophos in natural soils from the highlands of Colombia.

    PubMed

    García-Santos, Glenda; Keller-Forrer, Karin

    2011-07-01

    Earthworm avoidance behaviour test is an important screening tool in soil eco-toxicology. This test has been developed and validated under North American and European conditions. However, little research has been performed on the avoidance test in the tropics. This work demonstrates the potential suitability of the avoidance behaviour test as screening method in the highlands of Colombia using Eisenia fetida as the bio-indicator species on contaminated soils with carbofuran and chlorpyrifos. Though for the two active ingredients 100% avoidance was not reached, a curve with six meaningful concentrations is provided. No significant avoidance behaviour trend was found for mancozeb and methamidophos. Tests were conducted in the field yielded similar results to the tests carried out in the laboratory for chlorpyrifos and mancozeb. However, for the case of carbofuran and methamidophos, differences of more than double in avoidance were obtained. Divergence might be explained by soil and temperature conditions.

  8. Comparing and validating models of driver steering behaviour in collision avoidance and vehicle stabilisation

    NASA Astrophysics Data System (ADS)

    Markkula, G.; Benderius, O.; Wahde, M.

    2014-12-01

    A number of driver models were fitted to a large data set of human truck driving, from a simulated near-crash, low-friction scenario, yielding two main insights: steering to avoid a collision was best described as an open-loop manoeuvre of predetermined duration, but with situation-adapted amplitude, and subsequent vehicle stabilisation could to a large extent be accounted for by a simple yaw rate nulling control law. These two phenomena, which could be hypothesised to generalise to passenger car driving, were found to determine the ability of four driver models adopted from the literature to fit the human data. Based on the obtained results, it is argued that the concept of internal vehicle models may be less valuable when modelling driver behaviour in non-routine situations such as near-crashes, where behaviour may be better described as direct responses to salient perceptual cues. Some methodological issues in comparing and validating driver models are also discussed.

  9. Avoidance behaviour response and esterase inhibition in the earthworm, Lumbricus terrestris, after exposure to chlorpyrifos.

    PubMed

    Martínez Morcillo, S; Yela, J L; Capowiez, Y; Mazzia, C; Rault, M; Sanchez-Hernandez, Juan C

    2013-05-01

    The avoidance response of earthworms to polluted soils has been standardised using a simple and low-cost test, which facilitates soil toxicity screening. In this study, the avoidance response of Lumbricus terrestris was quantified in chlorpyrifos-spiked soils, depending on the pesticide concentration and exposure duration. The inhibition of acetylcholinesterase (AChE) and carboxylesterase (CbE) activities was also determined as indirect measures of pesticide bioavailability. The effects of different chlorpyrifos concentrations were examined in a standardised test (two-chamber system) with 0.6, 3 and 15 mg/kg chlorpyrifos. A modification of the test involved a pre-exposure step (24, 48 or 72 h) in soils spiked with 15 mg/kg. In both protocols, earthworms were unable to avoid the contaminated soils. However, the esterase activities showed that all earthworms were exposed to chlorpyrifos. Acetylcholinesterase activity did not change in earthworms in the standardised behavioural test (0.58 ± 0.20 U/mg protein, mean ± SD; n = 72), whereas the CbE activity was significantly inhibited (62-87 % inhibition) in earthworms exposed to 3 and 15 mg/kg. In the modified test, earthworms had greatly inhibited AChE activity (0.088 ± 0.034 U/mg protein, n = 72), which was supported by reactivation of the inhibited enzyme activity in the presence of pralidoxime (2-PAM). Similarly, the CbE activity was significantly inhibited in earthworms with all treatments. This study suggests that the avoidance behaviour test for organophosphorus-contaminated soils could be supported by specific biomarkers to facilitate a better understanding of pesticide exposure and toxicity during this test. PMID:23435687

  10. Theropod courtship: large scale physical evidence of display arenas and avian-like scrape ceremony behaviour by Cretaceous dinosaurs.

    PubMed

    Lockley, Martin G; McCrea, Richard T; Buckley, Lisa G; Lim, Jong Deock; Matthews, Neffra A; Breithaupt, Brent H; Houck, Karen J; Gierliński, Gerard D; Surmik, Dawid; Kim, Kyung Soo; Xing, Lida; Kong, Dal Yong; Cart, Ken; Martin, Jason; Hadden, Glade

    2016-01-01

    Relationships between non-avian theropod dinosaurs and extant and fossil birds are a major focus of current paleobiological research. Despite extensive phylogenetic and morphological support, behavioural evidence is mostly ambiguous and does not usually fossilize. Thus, inferences that dinosaurs, especially theropods displayed behaviour analogous to modern birds are intriguing but speculative. Here we present extensive and geographically widespread physical evidence of substrate scraping behavior by large theropods considered as compelling evidence of "display arenas" or leks, and consistent with "nest scrape display" behaviour among many extant ground-nesting birds. Large scrapes, up to 2 m in diameter, occur abundantly at several Cretaceous sites in Colorado. They constitute a previously unknown category of large dinosaurian trace fossil, inferred to fill gaps in our understanding of early phases in the breeding cycle of theropods. The trace makers were probably lekking species that were seasonally active at large display arena sites. Such scrapes indicate stereotypical avian behaviour hitherto unknown among Cretaceous theropods, and most likely associated with terrirorial activity in the breeding season. The scrapes most probably occur near nesting colonies, as yet unknown or no longer preserved in the immediate study areas. Thus, they provide clues to paleoenvironments where such nesting sites occurred. PMID:26741567

  11. Theropod courtship: large scale physical evidence of display arenas and avian-like scrape ceremony behaviour by Cretaceous dinosaurs

    PubMed Central

    Lockley, Martin G.; McCrea, Richard T.; Buckley, Lisa G.; Deock Lim, Jong; Matthews, Neffra A.; Breithaupt, Brent H.; Houck, Karen J.; Gierliński, Gerard D.; Surmik, Dawid; Soo Kim, Kyung; Xing, Lida; Yong Kong, Dal; Cart, Ken; Martin, Jason; Hadden, Glade

    2016-01-01

    Relationships between non-avian theropod dinosaurs and extant and fossil birds are a major focus of current paleobiological research. Despite extensive phylogenetic and morphological support, behavioural evidence is mostly ambiguous and does not usually fossilize. Thus, inferences that dinosaurs, especially theropods displayed behaviour analogous to modern birds are intriguing but speculative. Here we present extensive and geographically widespread physical evidence of substrate scraping behavior by large theropods considered as compelling evidence of “display arenas” or leks, and consistent with “nest scrape display” behaviour among many extant ground-nesting birds. Large scrapes, up to 2 m in diameter, occur abundantly at several Cretaceous sites in Colorado. They constitute a previously unknown category of large dinosaurian trace fossil, inferred to fill gaps in our understanding of early phases in the breeding cycle of theropods. The trace makers were probably lekking species that were seasonally active at large display arena sites. Such scrapes indicate stereotypical avian behaviour hitherto unknown among Cretaceous theropods, and most likely associated with terrirorial activity in the breeding season. The scrapes most probably occur near nesting colonies, as yet unknown or no longer preserved in the immediate study areas. Thus, they provide clues to paleoenvironments where such nesting sites occurred. PMID:26741567

  12. Children's selective attention to pain and avoidance behaviour: the role of child and parental catastrophizing about pain.

    PubMed

    Vervoort, Tine; Trost, Zina; Van Ryckeghem, Dimitri M L

    2013-10-01

    The present study investigated selective attention to pain in children, its implications for child avoidance behaviour, and the moderating role of dimensions comprising child and parental catastrophizing about pain (ie, rumination, magnification, and helplessness). Participants were 59 children (31 boys) aged 10-16 years and one of their parents (41 mothers). Children performed a dot-probe task in which child facial pain displays of varying pain expressiveness were presented. Child avoidance behaviour was indexed by child pain tolerance during a cold-pressor task. Children and parents completed measures of child and parent pain catastrophizing, respectively. Findings indicated that both the nature of child selective attention to pain and the impact of selective attention upon child avoidance behaviour were differentially sensitive to specific dimensions of child and parental catastrophizing. Specifically, findings showed greater tendency to shift attention away from pain faces (i.e.,, attentional avoidance) among children reporting greater pain magnification. A similar pattern was observed in terms of parental characteristics, such that children increasingly shifted attention away from pain with increasing levels of parental rumination and helplessness. Furthermore, child attentional avoidance was associated with greater avoidance behaviour (i.e., lower pain tolerance) among children reporting high levels of pain magnification and those whose parents reported greater rumination about pain. The current findings corroborate catastrophizing as a multidimensional construct that may differentially impact outcomes and attest to the importance of assessing both child and parental characteristics in relation to child pain-related attention and avoidance behaviour. Further research directions are discussed.

  13. Behaviourally inhibited temperament and female sex, two vulnerability factors for anxiety disorders, facilitate conditioned avoidance (also) in humans.

    PubMed

    Sheynin, Jony; Beck, Kevin D; Pang, Kevin C H; Servatius, Richard J; Shikari, Saima; Ostovich, Jacqueline; Myers, Catherine E

    2014-03-01

    Acquisition and maintenance of avoidance behaviour is a key feature of all human anxiety disorders. Animal models have been useful in understanding how anxiety vulnerability could translate into avoidance learning. For example, behaviourally inhibited temperament and female sex, two vulnerability factors for clinical anxiety, are associated with faster acquisition of avoidance responses in rodents. However, to date, the translation of such empirical data to human populations has been limited since many features of animal avoidance paradigms are not typically captured in human research. Here, using a computer-based task that captures many features of rodent escape-avoidance learning paradigms, we investigated whether avoidance learning would be faster in humans with inhibited temperament and/or female sex and, if so, whether this facilitation would take the same form. Results showed that, as in rats, both vulnerability factors were associated with facilitated acquisition of avoidance behaviour in humans. Specifically, inhibited temperament was associated with higher rate of avoidance responding, while female sex was associated with longer avoidance duration. These findings strengthen the direct link between animal avoidance work and human anxiety vulnerability, further motivating the study of animal models while also providing a simple testbed for a direct human testing. PMID:24412263

  14. Behaviourally-inhibited temperament and female sex, two vulnerability factors for anxiety disorders, facilitate conditioned avoidance (also) in humans

    PubMed Central

    Sheynin, Jony; Beck, Kevin D.; Pang, Kevin C.H.; Servatius, Richard J.; Shikari, Saima; Ostovich, Jacqueline; Myers, Catherine E.

    2014-01-01

    Acquisition and maintenance of avoidance behaviour is a key feature of all human anxiety disorders. Animal models have been useful in understanding how anxiety vulnerability could translate into avoidance learning. For example, behaviourally-inhibited temperament and female sex, two vulnerability factors for clinical anxiety, are associated with faster acquisition of avoidance responses in rodents. However, to date, the translation of such empirical data to human populations has been limited since many features of animal avoidance paradigms are not typically captured in human research. Here, using a computer-based task that captures many features of rodent escape-avoidance learning paradigms, we investigated whether avoidance learning would be faster in humans with inhibited temperament and/or female sex and, if so, whether this facilitation would take the same form. Results showed that, as in rats, both vulnerability factors were associated with facilitated acquisition of avoidance behaviour in humans. Specifically, inhibited temperament was specifically associated with higher rate of avoidance responding, while female sex was associated with longer avoidance duration. These findings strengthen the direct link between animal avoidance work and human anxiety vulnerability, further motivating the study of animal models while also providing a simple testbed for a direct human testing. PMID:24412263

  15. Prior exposure influences the behavioural avoidance by an intertidal gastropod, Bembicium auratum, of acidified waters

    NASA Astrophysics Data System (ADS)

    Amaral, Valter; Cabral, Henrique N.; Bishop, Melanie J.

    2014-01-01

    Phenotypic plasticity may be critical to the maintenance of viable populations under future environmental change. Here we examined the role of behavioural avoidance of sub-optimal conditions in enabling the intertidal gastropod, Bembicium auratum, to persist in mangrove forests affected by the low pH runoff from acid sulphate soils (ASS). Behaviourally, the gastropod may be able to avoid periods of particularly high acidity by using pneumatophores and/or mangrove trunks to vertically migrate above the water line or by retreating into its shell. We hypothesised that (1) B. auratum would display greater and more rapid vertical migration out of acidified than reference estuarine waters, and (2) responses would be more pronounced in gastropods collected from acidified than reference sites. Gastropods from acidified sites showed significantly higher activity in and more rapid migration out of acidified waters of pH 6.2-7.0, than reference waters or waters of pH < 5.0. Gastropods from reference locations showed a significantly weaker response to acidified water than those from acidified waters, and which did not significantly differ from their response to reference water. At extremely low pHs, <5.0, a higher proportion of both acidified and reference gastropods retreated into their shell than at higher pHs. Both the migration of gastropods out of acidified waters and retraction into their shells serves to reduce exposure time to acidified waters and may reduce the impact of this stressor on their populations. The stronger response to acidification of gastropods from populations previously exposed to this stressor suggests that the response may be learned, inherited or induced over multiple exposures. Our study adds to growing evidence that estuarine organisms may exhibit considerable physiological and behaviour adaptive capacity to acidification. The potential for such adaptive capacity should be incorporated into studies seeking to forecast impacts to marine organisms

  16. Measured voluntary avoidance behaviour during the 2009 A/H1N1 epidemic

    PubMed Central

    Bayham, Jude; Kuminoff, Nicolai V.; Gunn, Quentin; Fenichel, Eli P.

    2015-01-01

    Managing infectious disease is among the foremost challenges for public health policy. Interpersonal contacts play a critical role in infectious disease transmission, and recent advances in epidemiological theory suggest a central role for adaptive human behaviour with respect to changing contact patterns. However, theoretical studies cannot answer the following question: are individual responses to disease of sufficient magnitude to shape epidemiological dynamics and infectious disease risk? We provide empirical evidence that Americans voluntarily reduced their time spent in public places during the 2009 A/H1N1 swine flu, and that these behavioural shifts were of a magnitude capable of reducing the total number of cases. We simulate 10 years of epidemics (2003–2012) based on mixing patterns derived from individual time-use data to show that the mixing patterns in 2009 yield the lowest number of total infections relative to if the epidemic had occurred in any of the other nine years. The World Health Organization and other public health bodies have emphasized an important role for ‘distancing’ or non-pharmaceutical interventions. Our empirical results suggest that neglect for voluntary avoidance behaviour in epidemic models may overestimate the public health benefits of public social distancing policies. PMID:26511046

  17. Measured voluntary avoidance behaviour during the 2009 A/H1N1 epidemic.

    PubMed

    Bayham, Jude; Kuminoff, Nicolai V; Gunn, Quentin; Fenichel, Eli P

    2015-11-01

    Managing infectious disease is among the foremost challenges for public health policy. Interpersonal contacts play a critical role in infectious disease transmission, and recent advances in epidemiological theory suggest a central role for adaptive human behaviour with respect to changing contact patterns. However, theoretical studies cannot answer the following question: are individual responses to disease of sufficient magnitude to shape epidemiological dynamics and infectious disease risk? We provide empirical evidence that Americans voluntarily reduced their time spent in public places during the 2009 A/H1N1 swine flu, and that these behavioural shifts were of a magnitude capable of reducing the total number of cases. We simulate 10 years of epidemics (2003-2012) based on mixing patterns derived from individual time-use data to show that the mixing patterns in 2009 yield the lowest number of total infections relative to if the epidemic had occurred in any of the other nine years. The World Health Organization and other public health bodies have emphasized an important role for 'distancing' or non-pharmaceutical interventions. Our empirical results suggest that neglect for voluntary avoidance behaviour in epidemic models may overestimate the public health benefits of public social distancing policies. PMID:26511046

  18. Characteristics of heart rate fluctuations and respiratory movements during orienting, passive avoidance and flight-fight behaviour in rabbits.

    PubMed

    Richter, A; Schumann, N P; Zwiener, U

    1990-11-01

    In the present study different heart rate patterns were demonstrated to accompany flight-fight behaviour, orienting behaviour and passive avoidance in rabbits. Flight-fight behaviour was characterized by markedly increased heart rate and diminished overall heart rate variability. The effect was mediated by vagal inhibition and beta-adrenergic activation in a type-specific relation. Orienting behaviour was accompanied by a smaller heart rate increase and the exaggeration of slow heart rate fluctuations. The latter effect was absent during beta-adrenergic blockade suggesting a behaviourally provoked beta-adrenergic activation. Single beta-adrenergic blockade did not change the characteristics of the heart rate fluctuations at rest. During passive avoidance a vagally mediated heart rate deceleration was followed by a slow heart rate return toward the initial heart rate level. This level was not reached during beta-adrenergic blockade. The enhanced overall heart rate variability during passive avoidance was mainly caused by strengthened respiratory-induced heart rate fluctuations and, furthermore, by exaggerated slow rhythmical heart rate fluctuations. The latter effect was not observed during beta-adrenergic blockade and is referred to as an orienting component within passive avoidance. Three individual behavioural types may be differentiated in rabbits 'Weisses Gross-Silber' by stable behavioural characteristics i.e. spontaneous motor activities, preferred postures at rest and coping behaviour. The results of the present study suggest that different neurovegetative reaction types, i.e. dominating beta-adrenergic or vagal activation are correlated with stable behavioural characteristics, especially in terms of preferring active or passive coping behaviour, respectively.

  19. Comparative osteohistology of Hesperornis with reference to pygoscelid penguins: the effects of climate and behaviour on avian bone microstructure

    PubMed Central

    Wilson, Laura E.; Chin, Karen

    2014-01-01

    The broad biogeographic distribution of Hesperornis fossils in Late Cretaceous Western Interior Seaway deposits has prompted questions about whether they endured polar winters or migrated between mid- and high latitudes. Here, we compare microstructures of hesperornithiform long bones from Kansas and the Arctic to investigate whether migration or Late Cretaceous polar climate affected bone growth. We also examine modern penguin bones to determine how migration and climate may influence bone growth in birds with known behaviours. Histological analysis of hesperornithiform samples reveals continuous bone deposition throughout the cortex, plus an outer circumferential layer in adults. No cyclic growth marks, zonation or differences in vasculature are apparent in the Hesperornis specimens. Comparatively, migratory Adélie and chinstrap penguin bones show no zonation or changes in microstructure, suggesting that migration is not necessarily recorded in avian bone microstructure. Non-migratory gentoos show evidence of rapid bone growth possibly associated with increased chick growth rates in high-latitude populations and large body size. The absence of histological evidence for migration in extinct Hesperornis and extant pygoscelid penguins may reflect that these birds reached skeletal maturity before migration or overwintering. This underscores the challenges of using bone microstructure to infer the effects of behaviour and climate on avian growth. PMID:26064560

  20. Communication and social capital in the control of avian influenza: lessons from behaviour change experiences in the Mekong Region.

    PubMed

    Waisbord, S R; Michaelides, T; Rasmuson, M

    2008-01-01

    International development agencies, national governments, and nongovernmental organizations are increasingly collaborating with local civil society groups in mounting behaviour change communication (BCC) interventions. Even in countries with weakened civil societies, the social capital of local organizations can be a fundamental communication resource. The experience of three programmes in the Mekong Region that used BCC to prevent and control outbreaks of avian influenza bore out this finding. These programmes worked with the Vietnam Women's Union to mobilize local women as conduits for education; worked with the Centre d'Etude et de Developpement Agricole Cambodgien (CEDAC), in Cambodia, to educate and train village health promoters and model farmers; and worked with the Lao Journalists Association to educate and build skills among print and broadcast journalists to enhance avian influenza coverage. Collaborating with civil society organizations can enhance communication reach, trust, and local ownership, but poses many challenges, particularly institutional capacity. Our experience, nevertheless, holds promise for a measured approach that views social capital as a set of communication resources at the community level that can be mobilized to promote complex behaviours, particularly in a rapidly changing outbreak situation.

  1. Comparative osteohistology of Hesperornis with reference to pygoscelid penguins: the effects of climate and behaviour on avian bone microstructure.

    PubMed

    Wilson, Laura E; Chin, Karen

    2014-11-01

    The broad biogeographic distribution of Hesperornis fossils in Late Cretaceous Western Interior Seaway deposits has prompted questions about whether they endured polar winters or migrated between mid- and high latitudes. Here, we compare microstructures of hesperornithiform long bones from Kansas and the Arctic to investigate whether migration or Late Cretaceous polar climate affected bone growth. We also examine modern penguin bones to determine how migration and climate may influence bone growth in birds with known behaviours. Histological analysis of hesperornithiform samples reveals continuous bone deposition throughout the cortex, plus an outer circumferential layer in adults. No cyclic growth marks, zonation or differences in vasculature are apparent in the Hesperornis specimens. Comparatively, migratory Adélie and chinstrap penguin bones show no zonation or changes in microstructure, suggesting that migration is not necessarily recorded in avian bone microstructure. Non-migratory gentoos show evidence of rapid bone growth possibly associated with increased chick growth rates in high-latitude populations and large body size. The absence of histological evidence for migration in extinct Hesperornis and extant pygoscelid penguins may reflect that these birds reached skeletal maturity before migration or overwintering. This underscores the challenges of using bone microstructure to infer the effects of behaviour and climate on avian growth.

  2. Anaemia adjusts the aerobic physiology of snapper (Pagrus auratus) and modulates hypoxia avoidance behaviour during oxygen choice presentations.

    PubMed

    Cook, Denham G; Wells, Rufus M G; Herbert, Neill A

    2011-09-01

    The effect of altered oxygen transport potential on behavioural responses to environmental hypoxia was tested experimentally in snapper, Pagrus auratus, treated with a haemolytic agent (phenylhydrazine) or a sham protocol. Standard metabolic rate was not different between anaemic and normocythaemic snapper (Hct=6.7 and 25.7 g dl(-1), respectively), whereas maximum metabolic rate, and hence aerobic scope (AS), was consistently reduced in anaemic groups at all levels of water P(O(2)) investigated (P<0.01). This reduction of AS conferred a higher critical oxygen limit (P(crit)) to anaemic fish (8.6±0.6 kPa) compared with normocythaemic fish (5.3±0.4 kPa), thus demonstrating reduced hypoxic tolerance in anaemic groups. In behavioural choice experiments, the critical avoidance P(O(2)) in anaemic fish was 6.6±2.5 kPa compared with 2.9±0.5 kPa for controls (P<0.01). Behavioural avoidance was not associated with modulation of swimming speed. Despite differences in physiological and behavioural parameters, both groups avoided low P(O(2)) just below their P(crit), indicating that avoidance was triggered consistently when AS limits were reached and anaerobic metabolism was unavoidable. This was confirmed by high levels of plasma lactate in both treatments at the point of avoidance. This is the first experimental demonstration of avoidance behaviour being modulated by internal physiological state. From an ecological perspective, fish with disturbed oxygen delivery potential arising from anaemia, pollution or stress are likely to avoid environmental hypoxia at a higher P(O(2)) than normal fish.

  3. Children's selective attention to pain and avoidance behaviour: the role of child and parental catastrophizing about pain.

    PubMed

    Vervoort, Tine; Trost, Zina; Van Ryckeghem, Dimitri M L

    2013-10-01

    The present study investigated selective attention to pain in children, its implications for child avoidance behaviour, and the moderating role of dimensions comprising child and parental catastrophizing about pain (ie, rumination, magnification, and helplessness). Participants were 59 children (31 boys) aged 10-16 years and one of their parents (41 mothers). Children performed a dot-probe task in which child facial pain displays of varying pain expressiveness were presented. Child avoidance behaviour was indexed by child pain tolerance during a cold-pressor task. Children and parents completed measures of child and parent pain catastrophizing, respectively. Findings indicated that both the nature of child selective attention to pain and the impact of selective attention upon child avoidance behaviour were differentially sensitive to specific dimensions of child and parental catastrophizing. Specifically, findings showed greater tendency to shift attention away from pain faces (i.e.,, attentional avoidance) among children reporting greater pain magnification. A similar pattern was observed in terms of parental characteristics, such that children increasingly shifted attention away from pain with increasing levels of parental rumination and helplessness. Furthermore, child attentional avoidance was associated with greater avoidance behaviour (i.e., lower pain tolerance) among children reporting high levels of pain magnification and those whose parents reported greater rumination about pain. The current findings corroborate catastrophizing as a multidimensional construct that may differentially impact outcomes and attest to the importance of assessing both child and parental characteristics in relation to child pain-related attention and avoidance behaviour. Further research directions are discussed. PMID:23792243

  4. Patterns of avoidance behaviours in the light/dark preference test in young juvenile zebrafish: a pharmacological study.

    PubMed

    Steenbergen, Peter J; Richardson, Michael K; Champagne, Danielle L

    2011-09-12

    The light/dark preference test is commonly used to assess anxiety-like phenotypes and validate the pharmacological effects of neuroactive compounds. This test has been recently adapted for adult zebrafish but has not yet been characterized and pharmacologically validated for young juvenile zebrafish. In the present study, we provide a detailed description of the pattern of exploratory behaviours encountered in juvenile zebrafish when exposed to the light/dark preference test. We report that juveniles display strong dark-avoidance behaviours in this test. Specifically, juveniles spent significantly less time, displayed high latency to enter and moved significantly less in the dark compartment relative to the white compartment of the testing apparatus. The expression of these dark-avoidance behaviours was significantly attenuated and increased by commonly used anxiolytic (diazepam, buspirone, ethanol) and anxiogenic (caffeine but not FG-7142) drugs, respectively. We also show that the expression of dark-avoidance behaviours can be significantly reduced in a manner similar to what is achieved with anxiolytic drugs, simply by decreasing the contrast between the white and dark zones, which made the dark zone less dark. Taken together, these findings provide the first pharmacological validation of the light/dark preference test for juvenile zebrafish and ascertain the nature of dark-avoidance behaviours as anxiety-like behaviours in young juvenile zebrafish. This behavioural-based assay is also versatile and can accommodate drug screening of both anxiolytic and anxiogenic compounds while eventually amenable to automation and high-throughput capacity in a near future.

  5. Performance-Approach Goals, Task-Avoidant Behaviour and Conceptual Knowledge as Predictors of First Graders' School Performance

    ERIC Educational Resources Information Center

    Magi, Katrin; Haidkind, Pille; Kikas, Eve

    2010-01-01

    The present paper aims to examine the relationship between first grade children's performance-approach goal orientation, task-avoidant behaviours, conceptual knowledge and their achievement in maths and literacy. The sample consisted of 174 first grade children and their class teachers. Children's self reports of their performance-approach goals…

  6. A New Mass Mortality of Juvenile Protoceratops and Size-Segregated Aggregation Behaviour in Juvenile Non-Avian Dinosaurs

    PubMed Central

    Hone, David W. E.; Farke, Andrew A.; Watabe, Mahito; Shigeru, Suzuki; Tsogtbaatar, Khishigjav

    2014-01-01

    Background Monodominant bonebeds are a relatively common occurrence for non-avian dinosaurs, and have been used to infer associative, and potentially genuinely social, behavior. Previously known assemblages are characterized as either mixed size-classes (juvenile and adult-sized specimens together) or single size-classes of individuals (only juveniles or only adult-sized individuals within the assemblage). In the latter case, it is generally unknown if these kinds of size-segregated aggregations characterize only a particular size stage or represent aggregations that happened at all size stages. Ceratopsians (“horned dinosaurs”) are known from both types of assemblages. Methods/Principal Findings Here we describe a new specimen of the ceratopsian dinosaur Protoceratops andrewsi, Granger and Gregory 1923 from Mongolia representing an aggregation of four mid-sized juvenile animals. In conjunction with existing specimens of groups of P. andrewsi that includes size-clustered aggregations of young juveniles and adult-sized specimens, this new material provides evidence for some degree of size-clustered aggregation behaviour in Protoceratops throughout ontogeny. This continuity of size-segregated (and presumably age-clustered) aggregation is previously undocumented in non-avian dinosaurs. Conclusions The juvenile group fills a key gap in the available information on aggregations in younger ceratopsians. Although we support the general hypothesis that many non-avian dinosaurs were gregarious and even social animals, we caution that evidence for sociality has been overstated and advocate a more conservative interpretation of some data of ‘sociality’ in dinosaurs. PMID:25426957

  7. Social approach and avoidance behaviour for negative emotions is modulated by endogenous oxytocin and paranoia in schizophrenia.

    PubMed

    Brown, Elliot C; Tas, Cumhur; Kuzu, Duygu; Esen-Danaci, Aysen; Roelofs, Karin; Brüne, Martin

    2014-11-30

    Patients with schizophrenia suffer from dysfunctional social behaviour. Social approach and avoidance (AA) has been associated with motor responses, as the affective valence and gaze direction of facial stimuli can bias push and pull motor tendencies. The aim of this study was to investigate the role of endogenous oxytocin in social AA behaviour in schizophrenia. Basal plasma oxytocin levels were collected from 28 patients who were then given a joystick-based Approach-Avoidance Task (AAT). Reaction times were recorded and AAT effect scores calculated for responses to happy and angry faces, which either had direct or averted gaze. Individual differences in basal oxytocin had a significant relationship with AAT responses, and patients with higher levels of oxytocin tended to avoid angry faces more. Furthermore, greater avoidance of angry faces was correlated with more severe psychotic (positive and general) symptoms and greater paranoia. This suggests that the endogenous effects of oxytocin may be specific to the interpretation of negative threatening emotions in schizophrenia patients, and also provides evidence that psychotic symptoms and paranoia can impact on social AA behaviour by heightening threat avoidance.

  8. From Affective Experience to Motivated Action: Tracking Reward-Seeking and Punishment-Avoidant Behaviour in Real-Life.

    PubMed

    Wichers, Marieke; Kasanova, Zuzana; Bakker, Jindra; Thiery, Evert; Derom, Catherine; Jacobs, Nele; van Os, Jim

    2015-01-01

    Many of the decisions and actions in everyday life result from implicit learning processes. Important to psychopathology are, for example, implicit reward-seeking and punishment-avoidant learning processes. It is known that when specific actions get associated with a rewarding experience, such as positive emotions, that this will increase the likelihood that an organism will engage in similar actions in the future. Similarly, when actions get associated with punishing experiences, such as negative emotions, this may reduce the likelihood that the organism will engage in similar actions in the future. This study examines whether we can observe these implicit processes prospectively in the flow of daily life. If such processes take place then we expect that current behaviour can be predicted by how similar behaviour was experienced (in terms of positive and negative affect) at previous measurement moments. This was examined in a sample of 621 female individuals that had participated in an Experience Sampling data collection. Measures of affect and behaviour were collected at 10 semi-random moments of the day for 5 consecutive days. It was examined whether affective experience that was paired with certain behaviours (physical activity and social context) at previous measurements modified the likelihood to show similar behaviours at next measurement moments. Analyses were performed both at the level of observations (a time scale with units of ± 90 min) and at day level (a time scale with units of 24 h). As expected, we found that affect indeed moderated the extent to which previous behaviour predicted similar behaviour later in time, at both beep- and day-level. This study showed that it is feasible to track reward-seeking and punishment-avoidant behaviour prospectively in humans in the flow of daily life. This opens up a new toolbox to examine processes determining goal-oriented behaviour in relation to psychopathology in humans.

  9. From Affective Experience to Motivated Action: Tracking Reward-Seeking and Punishment-Avoidant Behaviour in Real-Life.

    PubMed

    Wichers, Marieke; Kasanova, Zuzana; Bakker, Jindra; Thiery, Evert; Derom, Catherine; Jacobs, Nele; van Os, Jim

    2015-01-01

    Many of the decisions and actions in everyday life result from implicit learning processes. Important to psychopathology are, for example, implicit reward-seeking and punishment-avoidant learning processes. It is known that when specific actions get associated with a rewarding experience, such as positive emotions, that this will increase the likelihood that an organism will engage in similar actions in the future. Similarly, when actions get associated with punishing experiences, such as negative emotions, this may reduce the likelihood that the organism will engage in similar actions in the future. This study examines whether we can observe these implicit processes prospectively in the flow of daily life. If such processes take place then we expect that current behaviour can be predicted by how similar behaviour was experienced (in terms of positive and negative affect) at previous measurement moments. This was examined in a sample of 621 female individuals that had participated in an Experience Sampling data collection. Measures of affect and behaviour were collected at 10 semi-random moments of the day for 5 consecutive days. It was examined whether affective experience that was paired with certain behaviours (physical activity and social context) at previous measurements modified the likelihood to show similar behaviours at next measurement moments. Analyses were performed both at the level of observations (a time scale with units of ± 90 min) and at day level (a time scale with units of 24 h). As expected, we found that affect indeed moderated the extent to which previous behaviour predicted similar behaviour later in time, at both beep- and day-level. This study showed that it is feasible to track reward-seeking and punishment-avoidant behaviour prospectively in humans in the flow of daily life. This opens up a new toolbox to examine processes determining goal-oriented behaviour in relation to psychopathology in humans. PMID:26087323

  10. Avian responses to an extreme ice storm are determined by a combination of functional traits, behavioural adaptations and habitat modifications

    PubMed Central

    Zhang, Qiang; Hong, Yongmi; Zou, Fasheng; Zhang, Min; Lee, Tien Ming; Song, Xiangjin; Rao, Jiteng

    2016-01-01

    The extent to which species’ traits, behavior and habitat synergistically determine their response to extreme weather events (EWE) remains poorly understood. By quantifying bird and vegetation assemblages before and after the 2008 ice storm in China, combined with interspecific interactions and foraging behaviours, we disentangled whether storm influences avian reassembly directly via functional traits (i.e. behavioral adaptations), or indirectly via habitat variations. We found that overall species richness decreased, with 20 species detected exclusively before the storm, and eight species detected exclusively after. These shifts in bird relative abundance were linked to habitat preferences, dietary guild and flocking behaviours. For instance, forest specialists at higher trophic levels (e.g. understory-insectivores, woodpeckers and kingfishers) were especially vulnerable, whereas open-habitat generalists (e.g. bulbuls) were set to benefit from potential habitat homogenization. Alongside population fluctuations, we found that community reassembly can be rapidly adjusted via foraging plasticity (i.e. increased flocking propensity and reduced perching height). And changes in preferred habitat corresponded to a variation in bird assemblages and traits, as represented by intact canopy cover and high density of large trees. Accurate predictions of community responses to EWE are crucial to understanding ecosystem disturbances, thus linking species-oriented traits to a coherent analytical framework. PMID:26929387

  11. Avian responses to an extreme ice storm are determined by a combination of functional traits, behavioural adaptations and habitat modifications.

    PubMed

    Zhang, Qiang; Hong, Yongmi; Zou, Fasheng; Zhang, Min; Lee, Tien Ming; Song, Xiangjin; Rao, Jiteng

    2016-01-01

    The extent to which species' traits, behavior and habitat synergistically determine their response to extreme weather events (EWE) remains poorly understood. By quantifying bird and vegetation assemblages before and after the 2008 ice storm in China, combined with interspecific interactions and foraging behaviours, we disentangled whether storm influences avian reassembly directly via functional traits (i.e. behavioral adaptations), or indirectly via habitat variations. We found that overall species richness decreased, with 20 species detected exclusively before the storm, and eight species detected exclusively after. These shifts in bird relative abundance were linked to habitat preferences, dietary guild and flocking behaviours. For instance, forest specialists at higher trophic levels (e.g. understory-insectivores, woodpeckers and kingfishers) were especially vulnerable, whereas open-habitat generalists (e.g. bulbuls) were set to benefit from potential habitat homogenization. Alongside population fluctuations, we found that community reassembly can be rapidly adjusted via foraging plasticity (i.e. increased flocking propensity and reduced perching height). And changes in preferred habitat corresponded to a variation in bird assemblages and traits, as represented by intact canopy cover and high density of large trees. Accurate predictions of community responses to EWE are crucial to understanding ecosystem disturbances, thus linking species-oriented traits to a coherent analytical framework. PMID:26929387

  12. Avian responses to an extreme ice storm are determined by a combination of functional traits, behavioural adaptations and habitat modifications.

    PubMed

    Zhang, Qiang; Hong, Yongmi; Zou, Fasheng; Zhang, Min; Lee, Tien Ming; Song, Xiangjin; Rao, Jiteng

    2016-03-01

    The extent to which species' traits, behavior and habitat synergistically determine their response to extreme weather events (EWE) remains poorly understood. By quantifying bird and vegetation assemblages before and after the 2008 ice storm in China, combined with interspecific interactions and foraging behaviours, we disentangled whether storm influences avian reassembly directly via functional traits (i.e. behavioral adaptations), or indirectly via habitat variations. We found that overall species richness decreased, with 20 species detected exclusively before the storm, and eight species detected exclusively after. These shifts in bird relative abundance were linked to habitat preferences, dietary guild and flocking behaviours. For instance, forest specialists at higher trophic levels (e.g. understory-insectivores, woodpeckers and kingfishers) were especially vulnerable, whereas open-habitat generalists (e.g. bulbuls) were set to benefit from potential habitat homogenization. Alongside population fluctuations, we found that community reassembly can be rapidly adjusted via foraging plasticity (i.e. increased flocking propensity and reduced perching height). And changes in preferred habitat corresponded to a variation in bird assemblages and traits, as represented by intact canopy cover and high density of large trees. Accurate predictions of community responses to EWE are crucial to understanding ecosystem disturbances, thus linking species-oriented traits to a coherent analytical framework.

  13. Shorebird avoidance of nearshore feeding and roosting areas at night correlates with presence of a nocturnal avian predator

    USGS Publications Warehouse

    Piersma, Theunis; Gill, Robert E.; de Goeij, Petra; Dekinga, Anne; Shepherd, Marnie; Ruthrauff, Daniel R.; Tibbitts, T. Lee

    2006-01-01

    We here report two anecdotes about avianinteractions relevant to the interpretation of differences in shorebirdhabitat use between day and night. Several studies have reported that shorebirds avoid feeding and roosting along nearshore areasat night yet commonly use these sites during daytime. This suggests that nighttime avoidance of nearshore places is a response to increased danger of predation. When mist-netting during autumn 2005 on nearshore intertidal habitats along South Spit, Egegik Bay (Alaska Peninsula), Alaska, we discovered that shorebirds that occurred there in large numbers during daytime low tides and roosted there during daytime high tides (especially Dunlin Calidris alpina, Rock Sandpipers Calidris ptilocnemis, Black-bellied Plover Pluvialis squatarola, and Surfbirds Aphriza virgata), were absent at night. Their avoidance of the area correlated with Short-eared Owls Asio flammeus concurrently hunting over the beach and adjacent intertidal habitats. Spotlighting over nearby expansive intertidal mudflats confirmed that the same suite of species continued to forage or roost nearby at night. To bring the story full circle, the morning following one mist-netting effort we found a Short-eared Owl on the beach that had been killed earlier by a Gyrfalcon Falco rusticolus. In the owl’s stomach were remains of a freshly devoured Dunlin.

  14. Male Roman high and low avoidance rats show different patterns of copulatory behaviour: comparison with Sprague Dawley rats.

    PubMed

    Sanna, Fabrizio; Corda, Maria Giuseppa; Melis, Maria Rosaria; Piludu, Maria Antonietta; Giorgi, Osvaldo; Argiolas, Antonio

    2014-03-29

    Roman high- (RHA) and low-avoidance (RLA) rats, selectively bred for, respectively, rapid vs. extremely poor acquisition of avoidant behaviour in the shuttle-box, display different coping strategies when exposed to aversive environmental conditions: RLA rats are reactive copers and show hyperemotional behaviour characterized by hypomotility and freezing, while RHA rats show a proactive coping behaviour aimed at gaining control over the stressor. RHA rats also display a robust sensation/novelty seeking profile, high baseline levels of impulsivity, and marked preference for, and intake of, natural and drug rewards. This study shows that the Roman lines also differ in sexual behaviour, a main source of natural reward. Thus, male RHA rats engaged in copulatory activity with a receptive female showing more mounts, intromissions and ejaculations in the first copulation test as compared with their RLA counterparts and Sprague Dawley rats used as an external reference strain. Such differences decreased only partially in subsequent copulation tests, with RHA rats always showing higher levels of sexual motivation and performance than RLA rats. Accordingly, analysis of copulatory parameters of five copulation tests performed at 3-day intervals confirmed that the Roman lines display different patterns of copulatory activity that persist after stabilization of copulatory behaviour by sexual experience. Finally, the weight of the testes, epididymides and seminal vesicles increased to a similar extent in both Roman lines after sexual activity. These results are discussed in terms of the relative contribution of differences in brain neurotransmission (mainly dopamine) and neuroendocrine function to the different patterns of copulatory behaviour of the Roman lines.

  15. Repeated elicitation of the acoustic startle reflex leads to sensitisation in subsequent avoidance behaviour and induces fear conditioning

    PubMed Central

    2011-01-01

    Background Autonomous reflexes enable animals to respond quickly to potential threats, prevent injury and mediate fight or flight responses. Intense acoustic stimuli with sudden onsets elicit a startle reflex while stimuli of similar intensity but with longer rise times only cause a cardiac defence response. In laboratory settings, habituation appears to affect all of these reflexes so that the response amplitude generally decreases with repeated exposure to the stimulus. The startle reflex has become a model system for the study of the neural basis of simple learning processes and emotional processing and is often used as a diagnostic tool in medical applications. However, previous studies did not allow animals to avoid the stimulus and the evolutionary function and long-term behavioural consequences of repeated startling remain speculative. In this study we investigate the follow-up behaviour associated with the startle reflex in wild-captured animals using an experimental setup that allows individuals to exhibit avoidance behaviour. Results We present evidence that repeated elicitation of the acoustic startle reflex leads to rapid and pronounced sensitisation of sustained spatial avoidance behaviour in grey seals (Halichoerus grypus). Animals developed rapid flight responses, left the exposure pool and showed clear signs of fear conditioning. Once sensitised, seals even avoided a known food source that was close to the sound source. In contrast, animals exposed to non-startling (long rise time) stimuli of the same maximum sound pressure habituated and flight responses waned or were absent from the beginning. The startle threshold of grey seals expressed in units of sensation levels was comparable to thresholds reported for other mammals (93 dB). Conclusions Our results demonstrate that the acoustic startle reflex plays a crucial role in mediating flight responses and strongly influences the motivational state of an animal beyond a short-term muscular response by

  16. Avoidance behaviour of two eco-physiologically different earthworms (Eisenia fetida and Aporrectodea caliginosa) in natural and artificial saline soils.

    PubMed

    Owojori, O J; Reinecke, A J

    2009-04-01

    We studied the avoidance behaviour of Eisenia fetida and Aporrectodea caliginosa in OECD artificial soil spiked with NaCl and in natural saline soil (of varying ionic constitutions) collected from Robertson Experimental Farm (ROBS) in Western Cape, South Africa. For each organism, the ecotoxicological test was performed using a two-chamber test over a period of 48 h. The results showed that in the OECD soil, the avoidance EC50 (the concentration/electrical conductivity at which there is effect on 50% of the organisms) for A. caliginosa of 667 mg kg(-1) NaCl was lower than 1164 mg kg(-1) for E. fetida. Similarly in ROBS soil, the avoidance EC50 for A. caliginosa of 0.26 dS m(-1) was lower than 0.56 dS m(-1) in E. fetida. These results indicated that A. caliginosa showed better avoidance to salinity than E. fetida irrespective of soil types or ionic constitution. When compared with literature data, EC50 values in avoidance tests were either lower or comparable to those of reproduction, which was the most sensitive life-cycle parameter. The only exception was the EC50 value for avoidance of E. fetida in natural soil which was higher than for reproduction suggesting that the predictive value of the avoidance test for this species might be lower in natural soils. The variation in sensitivities of these earthworms could be as a result of differences in their eco-physiology. These findings suggest the relevance of the avoidance test as a suitable screening method showing first tendencies of saline stress on the habitat function of soils. PMID:19211128

  17. Stigmatisation, Avoidance Behaviour and Difficulties in Coping are Common Among Adult Patients with Vitiligo.

    PubMed

    Krüger, Christian; Schallreuter, Karin U

    2015-05-01

    Vitiligo is a non-contagious skin disorder with loss of pigmentation, often impairing patients' well-being. This study used Dermatology Life Quality Index (DLQI), Adjustment to Chronic Skin Disorders Questionnaire (ACS), Beck Depression Inventory (BDI) and additional questions to explore quality of life (QoL), coping, depression and stigmatisation and included 96 patients with vitiligo and 23 controls. Stigmatisation was common: 87/96 patients (90%) reported questions/approaches, 23/96 (24%) experienced nasty comments. Sixty-four out of 96 (66.7%) had avoided situations because of vitiligo or concealed their white spots. Sixty patients (62.5%) implied psychological stress as influential on disease's course. Patients scored higher in all questionnaires than controls (DLQI = 4.9/1.6, ACS-social anxiety/avoidance = 36.9/22.1, ACS-helplessness = 27.3/16.0, ACS-anxious-depressive mood = 19.4/15.6), except BDI (6.8/7.3). QoL of 65 patients (67.7%) was hardly impaired, 70 (72.9%) were not depressed. Treatment with pro-pseudocatalase PC-KUS reduced social anxiety/avoidance, anxious-depressive mood and depression. Patients without low-key stigmatisation scored highest in DLQI and social anxiety/avoidance. Avoidance and concealing behavior correlated with all questionnaires' scores. PMID:25269389

  18. Stigmatisation, Avoidance Behaviour and Difficulties in Coping are Common Among Adult Patients with Vitiligo.

    PubMed

    Krüger, Christian; Schallreuter, Karin U

    2015-05-01

    Vitiligo is a non-contagious skin disorder with loss of pigmentation, often impairing patients' well-being. This study used Dermatology Life Quality Index (DLQI), Adjustment to Chronic Skin Disorders Questionnaire (ACS), Beck Depression Inventory (BDI) and additional questions to explore quality of life (QoL), coping, depression and stigmatisation and included 96 patients with vitiligo and 23 controls. Stigmatisation was common: 87/96 patients (90%) reported questions/approaches, 23/96 (24%) experienced nasty comments. Sixty-four out of 96 (66.7%) had avoided situations because of vitiligo or concealed their white spots. Sixty patients (62.5%) implied psychological stress as influential on disease's course. Patients scored higher in all questionnaires than controls (DLQI = 4.9/1.6, ACS-social anxiety/avoidance = 36.9/22.1, ACS-helplessness = 27.3/16.0, ACS-anxious-depressive mood = 19.4/15.6), except BDI (6.8/7.3). QoL of 65 patients (67.7%) was hardly impaired, 70 (72.9%) were not depressed. Treatment with pro-pseudocatalase PC-KUS reduced social anxiety/avoidance, anxious-depressive mood and depression. Patients without low-key stigmatisation scored highest in DLQI and social anxiety/avoidance. Avoidance and concealing behavior correlated with all questionnaires' scores.

  19. Echolocation behaviour of the big brown bat (Eptesicus fuscus) in an obstacle avoidance task of increasing difficulty.

    PubMed

    Sändig, Sonja; Schnitzler, Hans-Ulrich; Denzinger, Annette

    2014-08-15

    Four big brown bats (Eptesicus fuscus) were challenged in an obstacle avoidance experiment to localize vertically stretched wires requiring progressively greater accuracy by diminishing the wire-to-wire distance from 50 to 10 cm. The performance of the bats decreased with decreasing gap size. The avoidance task became very difficult below a wire separation of 30 cm, which corresponds to the average wingspan of E. fuscus. Two of the bats were able to pass without collisions down to a gap size of 10 cm in some of the flights. The other two bats only managed to master gap sizes down to 20 and 30 cm, respectively. They also performed distinctly worse at all other gap sizes. With increasing difficulty of the task, the bats changed their flight and echolocation behaviour. Especially at gap sizes of 30 cm and below, flight paths increased in height and flight speed was reduced. In addition, the bats emitted approach signals that were arranged in groups. At all gap sizes, the largest numbers of pulses per group were observed in the last group before passing the obstacle. The more difficult the obstacle avoidance task, the more pulses there were in the groups and the shorter the within-group pulse intervals. In comparable situations, the better-performing bats always emitted groups with more pulses than the less well-performing individuals. We hypothesize that the accuracy of target localization increases with the number of pulses per group and that each group is processed as a package. PMID:24902745

  20. The costs of avian brood parasitism explain variation in egg rejection behaviour in hosts.

    PubMed

    Medina, Iliana; Langmore, Naomi E

    2015-07-01

    Many bird species can reject foreign eggs from their nests. This behaviour is thought to have evolved in response to brood parasites, birds that lay their eggs in the nest of other species. However, not all hosts of brood parasites evict parasitic eggs. In this study, we collate data from egg rejection experiments on 198 species, and perform comparative analyses to understand the conditions under which egg rejection evolves. We found evidence, we believe for the first time in a large-scale comparative analysis, that (i) non-current host species have rejection rates as high as current hosts, (ii) egg rejection is more likely to evolve when the parasite is relatively large compared with its host and (iii) egg rejection is more likely to evolve when the parasite chick evicts all the host eggs from the nest, such as in cuckoos. Our results suggest that the interactions between brood parasites and their hosts have driven the evolution of egg rejection and that variation in the costs inflicted by parasites is fundamental to explaining why only some host species evolve egg rejection.

  1. Field and laboratory simulations of storm water pulses: behavioural avoidance by marine epifauna.

    PubMed

    Roberts, David A; Johnston, Emma L; Müller, Stefanie; Poore, Alistair G B

    2008-03-01

    Epifaunal communities associated with macroalgae were exposed to storm water pulses using a custom made irrigation system. Treatments included Millipore freshwater, freshwater spiked with trace metals and seawater controls to allow for the relative importance of freshwater inundation, trace metals and increased flow to be determined. Experimental pulses created conditions similar to those that occur following real storm water events. Brief storm water pulses reduced the abundance of amphipods and gastropods. Freshwater was the causative agent as there were no additional effects of trace metals on the assemblages. Laboratory assays indicated that neither direct nor latent mortality was likely following experimental pulses and that epifauna readily avoid storm water. Indirect effects upon epifauna through salinity-induced changes to algal habitats were not found in field recolonisation experiments. Results demonstrate the importance of examining the effects of pulsed contaminants under realistic exposure conditions and the need to consider ecologically relevant endpoints.

  2. Effects of elevated CO2 on predator avoidance behaviour by reef fishes is not altered by experimental test water

    PubMed Central

    Welch, Megan J.; Allan, Bridie J.M.; Watson, Sue-Ann; McMahon, Shannon J.; McCormick, Mark I.

    2016-01-01

    Pioneering studies into the effects of elevated CO2 on the behaviour of reef fishes often tested high-CO2 reared fish using control water in the test arena. While subsequent studies using rearing treatment water (control or high CO2) in the test arena have confirmed the effects of high CO2 on a range of reef fish behaviours, a further investigation into the use of different test water in the experimental arena is warranted. Here, we used a fully factorial design to test the effect of rearing treatment water (control or high CO2) and experimental test water (control or high CO2) on antipredator responses of larval reef fishes. We tested antipredator behaviour in larval clownfish Amphiprion percula and ambon damselfish Pomacentrus amboinensis, two species that have been used in previous high CO2 experiments. Specifically, we tested if: (1) using control or high CO2 water in a two channel flume influenced the response of larval clownfish to predator odour; and (2) using control or high CO2 water in the test arena influenced the escape response of larval damselfish to a startle stimulus. Finally, (3) because the effects of high CO2 on fish behaviour appear to be caused by altered function of the GABA-A neurotransmitter we tested if antipredator behaviours were restored in clownfish treated with a GABA antagonist (gabazine) in high CO2 water. Larval clownfish reared from hatching in control water (496 µatm) strongly avoided predator cue whereas larval clownfish reared from hatching in high CO2 (1,022 µatm) were attracted to the predator cue, as has been reported in previous studies. There was no effect on fish responses of using either control or high CO2 water in the flume. Larval damselfish reared for four days in high CO2 (1,051 µatm) exhibited a slower response to a startle stimulus and slower escape speed compared with fish reared in control conditions (464 µatm). There was no effect of test water on escape responses. Treatment of high-CO2 reared clownfish with

  3. Pre-treatment of Stegomyia aegypti mosquitoes with a sublethal dose of imidacloprid impairs behavioural avoidance induced by lemon oil and DEET.

    PubMed

    Thany, S H; Tong, F; Bloomquist, J R

    2015-03-01

    The present study was conducted to determine whether imidacloprid can impair the avoidance behaviour of the mosquito Stegomyia aegypti. Laboratory investigations using a T-maze apparatus showed that St. aegypti mosquitoes present long term avoidance behaviour when they are exposed to repetitive trials with lemon oil and DEET. The present study tested the effect of a sublethal dose of imidacloprid on the avoidance behaviour of St. aegypti mosquitoes over a 48 h period. Data suggest that 0.5 ng of imidacloprid/mosquito reduces the avoidance behaviour of mosquitoes exposed to lemon oil, on the first day of exposure, after the second trial; whereas imidacloprid affected DEET repellency only the first day of exposure, after the second trial. Imidacloprid was toxic against St. aegypti mosquitoes, and at sublethal doses was able to impair the repellency induced by lemon oil and DEET. The present data were consistent with the finding that St. aegypti mosquitoes exhibit long term avoidance behaviour, and treatment of mosquitoes with a sublethal dose of imidacloprid under DEET application can affect the repellency of DEET against St. aegypti. PMID:25155403

  4. Numerical study of DNA denaturation with self-avoidance: pseudo-critical temperatures and finite size behaviour

    NASA Astrophysics Data System (ADS)

    Coluzzi, Barbara; Yeramian, Edouard

    2016-04-01

    We perform an extensive numerical study of the disordered Poland-Scheraga (PS) model for DNA denaturation in which self-avoidance is completely taken into account. To complement to our previous work, we focus here on the finite size scaling in terms of pseudo-critical temperatures. Notably, we find that the mean value and the fluctuations of the pseudo-T c scale with the same exponent, the correlation length exponent {ν\\text{r}} (for which we provide the refined evaluation {ν\\text{r}}=2.9+/- 0.4 ). This result (coherent with the typical picture that describes random ferromagnets when disorder is relevant) is at variance with the numerical results reported in the literature for the PS model with self-avoidance, leading to an alternative scenario with a pseudo-first-order transition. We moreover introduce a crossover chain length N *, which we evaluate, appropriate for characterizing the approach to the asymptotic regime in this model. Essentially, below N *, the behaviour of the model in our study could also agree with such an alternative scenario. Based on an approximate prediction of the dependence of N * on the parameters of the model, we show that following the choice of such parameters it would not be possible to reach the asymptotic regime in practice. In such a context it becomes then possible to reconcile the apparently contradictory numerical studies.

  5. Affective and cognitive attitudes, uncertainty avoidance and intention to obtain genetic testing: an extension of the Theory of Planned Behaviour.

    PubMed

    Wolff, Katharina; Nordin, Karin; Brun, Wibecke; Berglund, Gunilla; Kvale, Gerd

    2011-09-01

    To ensure successful implementation of genetic screening and counselling according to patients best interests, the attitudes and motives of the public are important to consider. The aim of this study was to apply a theoretical framework in order to investigate which individual and disease characteristics might facilitate the uptake of genetic testing. A questionnaire using an extended version of the Theory of Planned Behaviour was developed to assess the predictive value of affective and cognitive expected outcomes, subjective norms, perceived control and uncertainty avoidance on the intention to undergo genetic testing. In addition to these individual characteristics, the predictive power of two disease characteristics was investigated by systematically varying the diseases fatality and penetrance (i.e. the probability of getting ill in case one is a mutation carrier). This resulted in four versions of the questionnaire which was mailed to a random sample of 2400 Norwegians. Results showed genetic test interest to be quite high, and to vary depending on the characteristics of the disease, with participants preferring tests for highly penetrant diseases. The most important individual predictor was uncertainty avoidance.

  6. Avian Astrovirus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Avian astroviruses comprise a diverse group of viruses affecting many avian species and causing enteritis, hepatitis and nephritis. To date, six different astroviruses have been identified in avian species based on the species of origin and viral genome characteristics: two turkey-origin astroviru...

  7. Low-O₂ acclimation shifts the hypoxia avoidance behaviour of snapper (Pagrus auratus) with only subtle changes in aerobic and anaerobic function.

    PubMed

    Cook, Denham G; Iftikar, Fathima I; Baker, Daniel W; Hickey, Anthony J R; Herbert, Neill A

    2013-02-01

    It was hypothesised that chronic hypoxia acclimation (preconditioning) would alter the behavioural low-O(2) avoidance strategy of fish as a result of both aerobic and anaerobic physiological adaptations. Avoidance and physiological responses of juvenile snapper (Pagrus auratus) were therefore investigated following a 6 week period of moderate hypoxia exposure (10.2-12.1 kPa P(O(2)), 21 ± 1 °C) and compared with those of normoxic controls (P(O(2))=20-21 kPa, 21 ± 1 °C). The critical oxygen pressure (P(crit)) limit of both groups was unchanged at ~7 kPa, as were standard, routine and maximum metabolic rates. However, hypoxia-acclimated fish showed increased tolerances to hypoxia in behavioural choice chambers by avoiding lower P(O(2)) levels (3.3 ± 0.7 vs 5.3 ± 1.1 kPa) without displaying greater perturbations of lactate or glucose. This behavioural change was associated with unexpected physiological adjustments. For example, a decrease in blood O(2) carrying capacity was observed after hypoxia acclimation. Also unexpected was an increase in whole-blood P(50) following acclimation to low O(2), perhaps facilitating Hb-O(2) off-loading to tissues. In addition, cardiac mitochondria measured in situ using permeabilised fibres showed improved O(2) uptake efficiencies. The proportion of the anaerobic enzyme lactate dehydrogenase, at least relative to the aerobic marker enzyme citrate synthase, also increased in heart and skeletal red muscle, indicating enhanced anaerobic potential, or in situ lactate metabolism, in these tissues. Overall, these data suggest that a prioritization of O(2) delivery and O(2) utilisation over O(2) uptake during long-term hypoxia may convey a significant survival benefit to snapper in terms of behavioural low-O(2) tolerance.

  8. Influence of Municipal Abattoir Conditions and Animal-related Factors on Avoidance-related Behaviour, Bleeding Times at Slaughter and the Quality of Lamb Meat.

    PubMed

    Njisane, Yonela Z; Muchenje, Voster

    2013-10-01

    The objective of this study was to determine the effect of municipal abattoir conditions and animal factors on avoidance-related behaviour (AB) of sheep at slaughter, bleeding times (BT) and mutton quality. The behaviour of 66 castrates and 19 ewes of different age categories was observed at three stages of slaughter. Higher behaviour scores indicated higher levels of AB. Time intervals between the start of blood flow and the time the flow changed from a constant stream into drips were recorded as BT. Thirty two meat samples were obtained to measure quality variables. These were colour (L*, a* and b*), pH24, temperature, cooking loss (CL) and tenderness. Correlations were determined between BT and meat quality variables. Animal behaviour at slaughter differed with breed, gender and age group. Avoidance behaviour was higher in the Dorper breed than in both the Merino breed and their crosses. It was also higher in younger (<10 months) lambs than in older sheep. Castrates were more aggressive or in panic than ewes. Castrates had longer (72.6±0.53 s) BT than the ewes (63.6±2.82 s). Ewes had higher CL (39.8±1.04%) values than castrates (35.1±0.95%). Meat from castrates was tougher (32.6±1.95 N) than the meat from ewes (24.3±1.16 N). There were no significant correlations obtained between BT and meat quality variables. It can therefore be concluded that abattoir conditions, breed, age and gender had an effect on AB at slaughter. Gender had an effect on BT and mutton quality. PMID:25049733

  9. The Interplay between Expressed Parental Anxiety and Infant Behavioural Inhibition Predicts Infant Avoidance in a Social Referencing Paradigm

    ERIC Educational Resources Information Center

    Aktar, Evin; Majdandzic, Mirjana; de Vente, Wieke; Bogels, Susan M.

    2013-01-01

    Background: Anxiety aggregates in families. Environmental factors, such as modelling of anxious behaviours, are assumed to play a causal role in the development of child anxiety. We investigated the predictive value of paternal and maternal anxiety (lifetime anxiety disorders and expressed parental anxiety) on infants' fear and avoidance…

  10. Feasibility of a cognitive behavioural group intervention to reduce fear of falling and associated avoidance of activity in community-living older people: a process evaluation

    PubMed Central

    van Haastregt, Jolanda CM; Zijlstra, GA Rixt; van Rossum, Erik; van Eijk, Jacques ThM; de Witte, Luc P; Kempen, Gertrudis IJM

    2007-01-01

    Background Fear of falling and associated avoidance of activity are common among older people and may have negative consequences in terms of functional decline, quality of life and institutionalisation. We evaluated the effects of a cognitive behavioural group intervention to reduce fear of falling and associated avoidance of activity among older persons. This intervention showed favourable effects on fear of falling, avoidance of activity, daily activity, and several secondary outcomes. The aim of the present study is to assess the feasibility of this cognitive behavioural group intervention for participants and facilitators. Methods The intervention consisted of eight weekly group sessions lasting two hours each and a booster session after six months. Self-administered questionnaires, registration forms and interviews were used to collect data from participants (n = 168) and facilitators (n = 6) on the extent to which the intervention was performed according to protocol, participant attendance, participant adherence, and participants' and facilitators' opinion of the intervention. Quantitative data from the questionnaires and registration forms were analysed by means of descriptive statistics. Qualitative data were categorised based on matching contents of the answers. Results Facilitators reported no major protocol deviations. Twenty-six percent of the participants withdrew before the start of the programme. Of the persons who started the programme, 84% actually completed it. The participants reported their adherence as good, but facilitators had a less favourable opinion of this. The majority of participants still reported substantial benefits from the programme after six and twelve months of follow-up (71% and 61% respectively). Both participants and facilitators provided suggestions for improvement of the intervention. Conclusion Results of this study show that the current cognitive behavioural group intervention is feasible for both participants and

  11. The propensity for schedule-induced polydipsia is related to differences in conditioned avoidance behaviour and in defense reactions in a defeat test.

    PubMed

    Dantzer, R; Terlouw, C; Tazi, A; Koolhaas, J M; Bohus, B; Koob, G F; Le Moal, M

    1988-01-01

    In line with previous research showing that animals predisposed to develop schedule-induced polydipsia when submitted to intermittent distribution of food show differential behavioural and neurochemical characteristics, the present experiments investigated the nature of defense reactions to aversive situations in rats that do or do not develop schedule-induced polydipsia. It was found that rats that engage in excessive drinking during intermittent feeding display more rapid active avoidance learning in a 2-way shuttle-box and show less freezing when confronted with an aggressive resident male in a defeat test than those that do not develop schedule-induced polydipsia. These results are consistent with the hypothesis that individual differences in the propensity to exhibit oral consummatory activities in conditions of mild stress are related to the ability to shift behavioural programmes in response to external stimulation. PMID:3174839

  12. The dark side of competition: How competitive behaviour and striving to avoid inferiority are linked to depression, anxiety, stress and self-harm.

    PubMed

    Gilbert, Paul; McEwan, Kirsten; Bellew, Rebecca; Mills, Alison; Gale, Corinne

    2009-06-01

    This study was guided by the social rank theory of depression and aimed to explore the relationship between depression, anxiety, stress and self-harm with striving to avoid inferiority, feelings of shame and styles of attachment. Participants diagnosed with depression (n = 62) completed a series of questionnaires measuring striving to avoid inferiority, fears of missing out, being overlooked and active rejection, attachment, social rank and psychopathologies. Striving to avoid inferiority was significantly linked to social rank variables and anxious attachment. Mediator analyses revealed that the relationship between striving to avoid inferiority and depression was mediated by the social rank variable of external shame, and also anxious attachment. These findings suggest that elevated competitive behaviour can have a 'dark side'. When people feel insecure in their social environments, it can focus them on a hierarchical view of themselves and others, with a fear of rejection if they feel they have become too inferior or subordinate. This may increase vulnerability to depression, anxiety and stress.

  13. Relic behaviours, coevolution and the retention versus loss of host defences after episodes of avian brood parasitism.

    PubMed

    Rothstein, Stephen I.

    2001-01-01

    Most previous studies of brood parasitism have stressed that host defences, such as egg recognition, are lost in the absence of parasitism. Such losses could result in coevolutionary cycles in which parasites shift away from well-defended hosts only to switch back to them later at a time when these hosts have lost much or all of their defences and the parasite's current hosts have built up effective defences. However, the alternative 'single trajectory' model predicts that parasites rarely switch back to old hosts because ex-hosts retain egg recognition for long periods in the absence of parasitism. If true, egg recognition by the host may be a 'relic behaviour', because in the absence of parasitism its adaptive value is close to neutral. Using artificial nonmimetic eggs, I tested for egg recognition in two populations that are currently unparasitized but that are descended from lineages likely to have been parasitized in the past: the grey catbird, Dumetella carolinensis, on Bermuda and the loggerhead shrike, Lanius ludovicianus, in California. Both of these populations showed long-term retention, ejecting nonmimetic eggs at rates of nearly 100%. Because potential present-day selection pressures, such as conspecific parasitism, do not explain this egg recognition, Bermuda catbirds apparently retain recognition from North American conspecifics that were cowbird hosts before colonizing Bermuda and shrikes retain recognition from Old World congeners that were hosts of cuckoos. Retention is also indicated by passerines in California and the Caribbean that had high rejection rates of nonmimetic eggs before coming into contact with cowbirds. These new data suggest that both the coevolutionary cycles and single trajectory models have importance and that rejection behaviour can have insignificant costs, which is consistent with evolutionary lag explanations for the acceptance of parasitic eggs shown by some cuckoo and many cowbird hosts. Copyright 2001 The Association for

  14. Comparative avoidance behaviour of the earthworm Eisenia fetida towards chloride, nitrate and sulphate salts of Cd, Cu and Zn using filter paper and extruded water agar gels as exposure media.

    PubMed

    Demuynck, Sylvain; Lebel, Aurélie; Grumiaux, Fabien; Pernin, Céline; Leprêtre, Alain; Lemière, Sébastien

    2016-07-01

    We studied the avoidance behaviour of the earthworm Eisenia fetida towards Cd, Cu, and Zn, trace elements (TEs) tested as chloride, nitrate and sulphate salts. Sub adults were exposed individually using dual-cell chambers at 20+2°C in the dark. Recordings were realised at different dates from 2h to 32h. We used filter paper and extruded water agar gel as exposure media to evaluate the contribution of the dermal and the digestive exposure routes on the avoidance reactions. Exposures to Cu or Cd (10mgmetal ionL(-1)) resulted in highly significant avoidance reactions through the exposure duration. Worms avoided Zn poorly and reactions towards Zn salts varied along the exposure. Worm sensitivity towards TEs differed between salts and this could result from differential toxicity or accessibility of these TE salts to earthworms. The anion in itself was not the determinant of the avoidance reactions since exposures to similar concentrations of these anions using calcium salts did not result in significant avoidance worm behaviour. Avoidance responses towards TEs were higher in the case of water agar exposures than in filter paper exposures. Thus, dermal contacts with TE solutions would elicit worm avoidance but signals from receptors located inside the digestive tract could reinforce this behaviour. The use of extruded water agar gels as the substrate allows checking the real sensitivity of earthworm species towards TEs since the TE concentrations leading to significant avoidance reactions were below those reported in the literature when using TE-spiked soils.

  15. Avian Influenza

    MedlinePlus

    ... infectious viral disease of birds. Most avian influenza viruses do not infect humans; however some, such as ... often causing no apparent signs of illness. AI viruses can sometimes spread to domestic poultry and cause ...

  16. Avian Wings

    NASA Technical Reports Server (NTRS)

    Liu, Tianshu; Kuykendoll, K.; Rhew, R.; Jones, S.

    2004-01-01

    This paper describes the avian wing geometry (Seagull, Merganser, Teal and Owl) extracted from non-contact surface measurements using a three-dimensional laser scanner. The geometric quantities, including the camber line and thickness distribution of airfoil, wing planform, chord distribution, and twist distribution, are given in convenient analytical expressions. Thus, the avian wing surfaces can be generated and the wing kinematics can be simulated. The aerodynamic characteristics of avian airfoils in steady inviscid flows are briefly discussed. The avian wing kinematics is recovered from videos of three level-flying birds (Crane, Seagull and Goose) based on a two-jointed arm model. A flapping seagull wing in the 3D physical space is re-constructed from the extracted wing geometry and kinematics.

  17. Avian botulism

    USGS Publications Warehouse

    Friend, Milton; Locke, Louis N.; Kennelly, James J.

    1985-01-01

    What is avian botulism? Avian botulism, or Western duck sickness, is one of the three most important disease problems of wild migratory birds. Each year, many birds are paralyzed or die after exposure to a toxin produced by the botulinum bacterium. Two of the seven toxin types that have been identifies cause mortality in wild birds; one of these types, type C, is most often associated with dieoffs of ducks, while type E primarily affects gulls and loons.

  18. Avian Flu

    SciTech Connect

    Eckburg, Paul

    2006-11-06

    Since 2003, a severe form of H5N1 avian influenza has rapidly spread throughout Asia and Europe, infecting over 200 humans in 10 countries. The spread of H5N1 virus from person-to-person has been rare, thus preventing the emergence of a widespread pandemic. However, this ongoing epidemic continues to pose an important public health threat. Avian flu and its pandemic potential in humans will be discussed.

  19. Comparative avoidance behaviour of the earthworm Eisenia fetida towards chloride, nitrate and sulphate salts of Cd, Cu and Zn using filter paper and extruded water agar gels as exposure media.

    PubMed

    Demuynck, Sylvain; Lebel, Aurélie; Grumiaux, Fabien; Pernin, Céline; Leprêtre, Alain; Lemière, Sébastien

    2016-07-01

    We studied the avoidance behaviour of the earthworm Eisenia fetida towards Cd, Cu, and Zn, trace elements (TEs) tested as chloride, nitrate and sulphate salts. Sub adults were exposed individually using dual-cell chambers at 20+2°C in the dark. Recordings were realised at different dates from 2h to 32h. We used filter paper and extruded water agar gel as exposure media to evaluate the contribution of the dermal and the digestive exposure routes on the avoidance reactions. Exposures to Cu or Cd (10mgmetal ionL(-1)) resulted in highly significant avoidance reactions through the exposure duration. Worms avoided Zn poorly and reactions towards Zn salts varied along the exposure. Worm sensitivity towards TEs differed between salts and this could result from differential toxicity or accessibility of these TE salts to earthworms. The anion in itself was not the determinant of the avoidance reactions since exposures to similar concentrations of these anions using calcium salts did not result in significant avoidance worm behaviour. Avoidance responses towards TEs were higher in the case of water agar exposures than in filter paper exposures. Thus, dermal contacts with TE solutions would elicit worm avoidance but signals from receptors located inside the digestive tract could reinforce this behaviour. The use of extruded water agar gels as the substrate allows checking the real sensitivity of earthworm species towards TEs since the TE concentrations leading to significant avoidance reactions were below those reported in the literature when using TE-spiked soils. PMID:26995062

  20. Survival, Pb-uptake and behaviour of three species of earthworm in Pb treated soils determined using an OECD-style toxicity test and a soil avoidance test.

    PubMed

    Langdon, Caroline J; Hodson, Mark E; Arnold, Rebecca E; Black, Stuart

    2005-11-01

    Mature (clitellate) Eisenia andrei Bouché (ultra epigeic), Lumbricus rubellus Hoffmeister (epigeic), and Aporrectodea caliginosa (Savigny) (endogeic) earthworms were placed in soils treated with Pb(NO(3))(2) to have concentrations in the range 1,000 to 10,000 mg Pb kg(-1). After 28 days LC50(-95%confidence limit)(+95%confidence limit) values were E. andrei 5824(-361)(+898) mg Pb kg(-1), L. rubellus 2867(-193)(+145) mg Pb kg(-1) and A. caliginosa2747(-304)(+239) mg Pb kg(-1) and EC50s for weight change were E. andrei2841(-68)(+150) mg Pb kg(-1), L. rubellus1303(-201)(+240) mg Pb kg(-1) and A. caliginosa1208(-206)(+212) mg Pb kg(-1). At any given soil Pb concentration, Pb tissue concentrations after 28 days were the same for all three earthworm species. In a soil avoidance test there was no difference between the behaviour of the different species. The lower sensitivity to Pb exhibited by E. andrei is most likely due to physiological adaptations associated with the modes of life of the earthworms, and could have serious implications for the use of this earthworm as the species of choice in standard toxicological testing. PMID:15951078

  1. AVIAN IMMUNOTOXICOLOGY

    EPA Science Inventory

    Methods for studying the avian immune system have matured during the past two decades, with laboratory studies predominating in earlier years and field studies being conducted only in the past decade. One application has been to determine the potential for environmental contamina...

  2. Avian psychology and communication.

    PubMed

    Rowe, Candy; Skelhorn, John

    2004-07-22

    The evolution of animal communication is a complex issue and one that attracts much research and debate. 'Receiver psychology' has been highlighted as a potential selective force, and we review how avian psychological processes and biases can influence the evolution and design of signals as well as the progress that has been made in testing these ideas in behavioural studies. Interestingly, although birds are a focal group for experimental psychologists and behavioural ecologists alike, the integration of theoretical ideas from psychology into studies of communication has been relatively slow. However, recent operant experiments are starting to address how birds perceive and respond to complex natural signals in an attempt to answer evolutionary problems in communication. This review outlines how a psychological approach to understanding communication is useful, and we hope that it stimulates further research addressing the role of psychological mechanisms in signal evolution.

  3. Avian psychology and communication.

    PubMed Central

    Rowe, Candy; Skelhorn, John

    2004-01-01

    The evolution of animal communication is a complex issue and one that attracts much research and debate. 'Receiver psychology' has been highlighted as a potential selective force, and we review how avian psychological processes and biases can influence the evolution and design of signals as well as the progress that has been made in testing these ideas in behavioural studies. Interestingly, although birds are a focal group for experimental psychologists and behavioural ecologists alike, the integration of theoretical ideas from psychology into studies of communication has been relatively slow. However, recent operant experiments are starting to address how birds perceive and respond to complex natural signals in an attempt to answer evolutionary problems in communication. This review outlines how a psychological approach to understanding communication is useful, and we hope that it stimulates further research addressing the role of psychological mechanisms in signal evolution. PMID:15306314

  4. Avian Influenza.

    PubMed

    Zeitlin, Gary Adam; Maslow, Melanie Jane

    2005-05-01

    The current epidemic of H5N1 highly pathogenic avian influenza in Southeast Asia raises serious concerns that genetic reassortment will result in the next influenza pandemic. There have been 164 confirmed cases of human infection with avian influenza since 1996. In 2004, there were 45 cases of human H5N1 in Vietnam and Thailand, with a mortality rate more than 70%. In addition to the potential public health hazard, the current zoonotic epidemic has caused severe economic losses. Efforts must be concentrated on early detection of bird outbreaks with aggressive culling, quarantining, and disinfection. To prepare for and prevent an increase in human cases, it is essential to improve detection methods and stockpile effective antivirals. Novel therapeutic modalities, including short-interfering RNAs and new vaccine strategies that use plasmid-based genetic systems, offer promise should a pandemic occur. PMID:15847721

  5. Avian influenza.

    PubMed

    Zeitlin, Gary A; Maslow, Melanie J

    2006-03-01

    The current epidemic of H5N1 highly pathogenic avian influenza in Southeast Asia raises serious concerns that genetic reassortment will result in the next influenza pandemic. There have been 164 confirmed cases of human infection with avian influenza since 1996. In 2004 alone, there were 45 cases of human H5N1 in Vietnam and Thailand, with a mortality rate over 70%. In addition to the potential public health hazard, the current zoonotic epidemic has caused severe economic losses. Efforts must be concentrated on early detection of bird outbreaks with aggressive culling, quarantines, and disinfection. To prepare for and prevent increased human cases, it is essential to improve detection methods and stockpile effective antivirals. Novel therapeutic modalities, including short, interfering RNAs and new vaccine strategies that use plasmid-based genetic systems offer promise, should a pandemic occur. PMID:16566867

  6. Avian influenza virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Avian influenza virus (AIV) is type A influenza, which is adapted to an avian host. Although avian influenza has been isolated from numerous avian species, the primary natural hosts for the virus are dabbling ducks, shorebirds, and gulls. The virus can be found world-wide in these species and in o...

  7. Avoiding Ticks

    MedlinePlus

    ... Avoiding ticks On people On pets In the yard Removing a tick Symptoms of tickborne illness Geographic ... ticks on your pets Preventing ticks in the yard File Formats Help: How do I view different ...

  8. Avian Influenza (Bird Flu)

    MedlinePlus

    ... this page: About CDC.gov . Avian Influenza H5 Viruses in the United States Updates and Publications Information ... Humans Examples of Human Infections with Avian Influenza Viruses Outbreaks Health Care and Laboratorian Guidance HPAI A ...

  9. Avian respiratory system disorders

    USGS Publications Warehouse

    Olsen, G.H.

    1989-01-01

    Diagnosing and treating respiratory diseases in avian species requires a basic knowledge about the anatomy and physiology of this system in birds. Differences between mammalian and avian respiratory system function, diagnosis, and treatment are highlighted.

  10. Avian malaria in New Zealand.

    PubMed

    Schoener, E R; Banda, M; Howe, L; Castro, I C; Alley, M R

    2014-07-01

    Avian malaria parasites of the genus Plasmodium have the ability to cause morbidity and mortality in naïve hosts, and their impact on the native biodiversity is potentially serious. Over the last decade, avian malaria has aroused increasing interest as an emerging disease in New Zealand with some endemic avian species, such as the endangered mohua (Mohua ochrocephala), thought to be particularly susceptible. To date, avian malaria parasites have been found in 35 different bird species in New Zealand and have been diagnosed as causing death in threatened species such as dotterel (Charadrius obscurus), South Island saddleback (Philesturnus carunculatus carunculatus), mohua, hihi (Notiomystis cincta) and two species of kiwi (Apteryx spp.). Introduced blackbirds (Turdus merula) have been found to be carriers of at least three strains of Plasmodium spp. and because they are very commonly infected, they are likely sources of infection for many of New Zealand's endemic birds. The spread and abundance of introduced and endemic mosquitoes as the result of climate change is also likely to be an important factor in the high prevalence of infection in some regions and at certain times of the year. Although still limited, there is a growing understanding of the ecology and epidemiology of Plasmodium spp. in New Zealand. Molecular biology has played an important part in this process and has markedly improved our understanding of the taxonomy of the genus Plasmodium. This review presents our current state of knowledge, discusses the possible infection and disease outcomes, the implications for host behaviour and reproduction, methods of diagnosis of infection, and the possible vectors for transmission of the disease in New Zealand. PMID:24313228

  11. Shade Avoidance

    PubMed Central

    Casal, Jorge J.

    2012-01-01

    The presence of neighboring vegetation modifies the light environment experienced by plants, generating signals that are perceived by phytochromes and cryptochromes. These signals cause large changes in plant body form and function, including enhanced growth of the hypocotyl and petioles, a more erect position of the leaves and early flowering in Arabidopsis thaliana. Collectively, these so-called shade-avoidance responses tend to reduce the degree of current or future shade by neighbors. Shade light signals increase the abundance of PHYTOCHROME INTERACTING FACTOR 4 (PIF4) and PIF5 proteins, promote the synthesis and redirection of auxin, favor the degradation of DELLA proteins and increase the expression of auxin, gibberellins and brassinosteroid-promoted genes, among other events downstream the photoreceptors. Selectively disrupting these events by genetic or pharmacological approaches affects shade-avoidance responses with an intensity that depends on the developmental context and the environment. Shade-avoidance responses provide a model to investigate the signaling networks used by plants to take advantage of the cues provided by the environment to adjust to the challenges imposed by the environment itself. PMID:22582029

  12. Avian Retroviral Replication

    PubMed Central

    Justice, James; Beemon, Karen L.

    2013-01-01

    Avian retroviruses have undergone intense study since the beginning of the 20th century. They were originally identified as cancer-inducing filterable agents in chicken neoplasms. Since their discovery, the study of these simple retroviruses has contributed greatly to our understanding of retroviral replication and cancer. Avian retroviruses are continuing to evolve and have great economic importance in the poultry industry worldwide. The aim of this review is to provide a broad overview of the genome, pathology, and replication of avian retroviruses. Notable gaps in our current knowledge are highlighted, and areas where avian retroviruses differ from other retrovirus are also emphasized. PMID:24011707

  13. Avian Influenza in Birds

    MedlinePlus

    ... and even kill certain domesticated bird species including chickens, ducks, and turkeys. Infected birds can shed avian ... virus’ ability to cause disease and mortality in chickens in a laboratory setting [2.5 MB, 64 ...

  14. Avian Fact Sheet

    SciTech Connect

    NWCC Wildlife Work Group

    2004-12-01

    OAK-B135 After conducting four national research meetings, producing a document guiding research: Metrics and Methods for Determining or Monitoring Potential Impacts on Birds at Existing and Proposed Wind Energy Sites, 1999, and another paper, Avian Collisions with Wind Turbines: A Summary of Existing Studies and Comparisons to Other Sources of Avian Collision Mortality in the United States, 2001, the subcommittee recognized a need to summarize in a short fact sheet what is known about avian-wind interaction and what questions remain. This fact sheet attempts to summarize in lay terms the result of extensive discussion about avian-wind interaction on land. This fact sheet does not address research conducted on offshore development. This fact sheet is not intended as a conclusion on the subject; rather, it is a summary as of Fall/Winter 2002.

  15. Seasonal change in the avian hippocampus.

    PubMed

    Sherry, David F; MacDougall-Shackleton, Scott A

    2015-04-01

    The hippocampus plays an important role in cognitive processes, including memory and spatial orientation, in birds. The hippocampus undergoes seasonal change in food-storing birds and brood parasites, there are changes in the hippocampus during breeding, and further changes occur in some species in association with migration. In food-storing birds, seasonal change in the hippocampus occurs in fall and winter when the cognitively demanding behaviour of caching and retrieving food occurs. The timing of annual change in the hippocampus of food-storing birds is quite variable, however, and appears not to be under photoperiod control. A variety of factors, including cognitive performance, exercise, and stress may all influence seasonal change in the avian hippocampus. The causal processes underlying seasonal change in the avian hippocampus have not been extensively examined and the more fully described hormonal influences on the mammalian hippocampus may provide hypotheses for investigating the control of hippocampal seasonality in birds.

  16. Teachers Avoiding Learners' Avoidance: Is It Possible?

    ERIC Educational Resources Information Center

    Tadayyon, Maedeh; Zarrinabadi, Nourollah; Ketabi, Saeed

    2016-01-01

    Dealing with learners who prefer to take the back seat and avoid classroom participation can be every teacher's nightmare. This lack of participation may cause teacher frustration, and possibly the only way to reduce this lack of participation is to access the concept of avoidance strategy. Avoidance strategy is the abandonment of a classroom task…

  17. Behavioural adaptations of birds to environments where evaporation is high and water is in short supply.

    PubMed

    Davies, S J

    1982-01-01

    1. Behaviour that reduces the heat load or evaporation experienced by birds living in arid areas is reviewed. Many species have evolved hunting behaviour that enables them to remain inactive during the hottest parts of the day and thus greatly reduce the amount of metabolic heat that they need to dissipate. Flights to water are made at low ambient temperatures, either early in the morning or late in the evening. Fighting is rare in many species of desert birds, avoiding the excess generation of heat by this activity. Many arid zone birds maintain long-lasting pair bonds, avoiding the necessity for active, elaborate display before breeding and again reducing activity. 2. The observations on nomadism are discussed. No unifying principles that might control the behaviour of birds seeking widely separated areas of abundance of food have yet emerged. 3. Some species have evolved mechanisms, embodied in behavioural characteristics, that ensure that the eggs and chicks are sheltered from high temperatures and are provided with adequate moisture. 4. Birds have evolved many different kinds of behavioural adaptation to arid zones and representatives from many avian families live there, apparently successfully. PMID:6124344

  18. Grouping facilitates avoidance of parasites by fish

    PubMed Central

    2013-01-01

    Background Parasite distribution is often highly heterogeneous, and intensity of infection depends, among other things, on how well hosts can avoid areas with a high concentration of parasites. We studied the role of fish behaviour in avoiding microhabitats with a high infection risk using Oncorhynchus mykiss and cercariae of Diplostomum pseudospathaceum as a model. Spatial distribution of parasites in experimental tanks was highly heterogeneous. We hypothesized that fish in groups are better at recognizing a parasitized area and avoiding it than solitary fish. Methods Number of fish, either solitary or in groups of 5, was recorded in different compartments of a shuttle tank where fish could make a choice between areas with different risk of being infected. Intensity of infection was assessed and compared with the number of fish recorded in the compartment with parasites and level of fish motility. Results Both solitary fish and fish in groups avoided parasitized areas, but fish in groups avoided it more strongly and thus acquired significantly fewer parasites than solitary fish. Prevalence of infection among grouped and solitary fish was 66 and 92 %, respectively, with the mean abundance two times higher in the solitary fish. Between-individual variation in the number of parasites per fish was higher in the “groups” treatment (across all individuals) than in the “solitary” treatment. Avoidance behaviour was more efficient when fish were allowed to explore the experimental arena prior to parasite exposure. High motility of fish was shown to increase the acquisition of D. pseudospathaceum. Conclusion Fish in groups better avoided parasitized habitat, and acquired significantly fewer parasites than solitary fish. We suggest that fish in groups benefit from information about parasites gained from other members of a group. Grouping behaviour may be an efficient mechanism of parasite avoidance, together with individual behaviour and immune responses of fishes

  19. Cognitive ornithology: the evolution of avian intelligence

    PubMed Central

    Emery, Nathan J

    2005-01-01

    Comparative psychologists interested in the evolution of intelligence have focused their attention on social primates, whereas birds tend to be used as models of associative learning. However, corvids and parrots, which have forebrains relatively the same size as apes, live in complex social groups and have a long developmental period before becoming independent, have demonstrated ape-like intelligence. Although, ornithologists have documented thousands of hours observing birds in their natural habitat, they have focused their attention on avian behaviour and ecology, rather than intelligence. This review discusses recent studies of avian cognition contrasting two different approaches; the anthropocentric approach and the adaptive specialization approach. It is argued that the most productive method is to combine the two approaches. This is discussed with respects to recent investigations of two supposedly unique aspects of human cognition; episodic memory and theory of mind. In reviewing the evidence for avian intelligence, corvids and parrots appear to be cognitively superior to other birds and in many cases even apes. This suggests that complex cognition has evolved in species with very different brains through a process of convergent evolution rather than shared ancestry, although the notion that birds and mammals may share common neural connectivity patterns is discussed. PMID:16553307

  20. Avian influenza control strategies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Control strategies for avian influenza in poultry vary depending on whether the goal is prevention, management, or eradication. Components used in control programs include: 1) education which includes communication, public awareness, and behavioral change, 2) changes to production and marketing sys...

  1. The avian heterophil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Heterophils play an indispensable role in the immune defense of the avian host. To accomplish this defense, heterophils use sophisticated mechanisms to both detect and destroy pathogenic microbes. Detection of pathogens through toll-like receptors (TLR), FC and complement receptors, and other path...

  2. Avian dark cells

    NASA Technical Reports Server (NTRS)

    Hara, J.; Plymale, D. R.; Shepard, D. L.; Hara, H.; Garry, Robert F.; Yoshihara, T.; Zenner, Hans-Peter; Bolton, M.; Kalkeri, R.; Fermin, Cesar D.

    2002-01-01

    Dark cells (DCs) of mammalian and non-mammalian species help to maintain the homeostasis of the inner ear fluids in vivo. Although the avian cochlea is straight and the mammalian cochlea is coiled, no significant difference in the morphology and/or function of mammalian and avian DCs has been reported. The mammalian equivalent of avian DCs are marginal cells and are located in the stria vascularis along a bony sheet. Avian DCs hang free from the tegmentum vasculosum (TV) of the avian lagena between the perilymph and endolymph. Frame averaging was used to image the fluorescence emitted by several fluorochromes applied to freshly isolated dark cells (iDCs) from chickens (Gallus domesticus) inner ears. The viability of iDCs was monitored via trypan blue exclusion at each isolation step. Sodium Green, BCECF-AM, Rhodamine 123 and 9-anthroyl ouabain molecules were used to test iDC function. These fluorochromes label iDCs ionic transmembrane trafficking function, membrane electrogenic potentials and Na+/K+ ATPase pump's activity. Na+/K+ ATPase pump sites, were also evaluated by the p-nitrophenyl phosphatase reaction. These results suggest that iDCs remain viable for several hours after isolation without special culturing requirements and that the number and functional activity of Na+/K+ ATPase pumps in the iDCs were indistinguishable from in vivo DCs. Primary cultures of freshly iDCs were successfully maintained for 28 days in plastic dishes with RPMI 1640 culture medium. The preparation of iDCs overcomes the difficulty of DCs accessability in vivo and the unavoidable contamination that rupturing the inner ear microenvironments induces.

  3. Highly pathogenic avian influenza.

    PubMed

    Swayne, D E; Suarez, D L

    2000-08-01

    Highly pathogenic (HP) avian influenza (AI) (HPAI) is an extremely contagious, multi-organ systemic disease of poultry leading to high mortality, and caused by some H5 and H7 subtypes of type A influenza virus, family Orthomyxoviridae. However, most AI virus strains are mildly pathogenic (MP) and produce either subclinical infections or respiratory and/or reproductive diseases in a variety of domestic and wild bird species. Highly pathogenic avian influenza is a List A disease of the Office International des Epizooties, while MPAI is neither a List A nor List B disease. Eighteen outbreaks of HPAI have been documented since the identification of AI virus as the cause of fowl plague in 1955. Mildly pathogenic avian influenza viruses are maintained in wild aquatic bird reservoirs, occasionally crossing over to domestic poultry and causing outbreaks of mild disease. Highly pathogenic avian influenza viruses do not have a recognised wild bird reservoir, but can occasionally be isolated from wild birds during outbreaks in domestic poultry. Highly pathogenic avian influenza viruses have been documented to arise from MPAI viruses through mutations in the haemagglutinin surface protein. Prevention of exposure to the virus and eradication are the accepted methods for dealing with HPAI. Control programmes, which imply allowing a low incidence of infection, are not an acceptable method for managing HPAI, but have been used during some outbreaks of MPAI. The components of a strategy to deal with MPAI or HPAI include surveillance and diagnosis, biosecurity, education, quarantine and depopulation. Vaccination has been used in some control and eradication programmes for AI.

  4. Optimal diving behaviour and respiratory gas exchange in birds.

    PubMed

    Halsey, Lewis G; Butler, Patrick J

    2006-11-01

    This review discusses the advancements in our understanding of the physiology and behaviour of avian diving that have been underpinned by optimal foraging theory and the testing of optimal models. To maximise their foraging efficiency during foraging periods, diving birds must balance numerous factors that are directly or indirectly related to the replenishment of the oxygen stores and the removal of excess carbon dioxide. These include (1) the time spent underwater (which diminishes the oxygen supply, increases carbon dioxide levels and may even include a build up of lactate due to anaerobic metabolism), (2) the time spent at the surface recovering from the previous dive and preparing for the next (including reloading their oxygen supply, decreasing their carbon dioxide levels and possibly also metabolising lactate) and (3) the trade-off between maximising oxygen reserves for consumption underwater by taking in more air to the respiratory system, and minimising the energy costs of positive buoyancy caused by this air, to maximise the time available underwater to forage. Due to its importance in avian diving, replenishment of the oxygen stores has become integral to models of optimal diving, which predict the time budgeting of animals foraging underwater. While many of these models have been examined qualitatively, such tests of predictive trends appear fallible and only quantifiable support affords strong evidence of their predictive value. This review describes how the quantification of certain optimal diving models, using tufted ducks, indeed demonstrates some predictive success. This suggests that replenishment of the oxygen stores and removal of excess carbon dioxide have significant influences on the duration of the surface period between dives. Nevertheless, present models are too simplistic to be robust predictors of diving behaviour for individual animals and it is proposed that they require refinement through the incorporation of other variables that also

  5. An avian vocalization detector.

    PubMed

    Severns, M; Gray, L; Rubel, E W

    1985-05-01

    A simple circuit to detect avian vocalizations is described. Adjustments of five different controls (frequency, bandwidth, amplitude, duration and spacing) allow the circuit to accurately detect the vocalizations of different ages and species of birds. Analyses of over 4000 peeps and 500 inter-peep intervals from 40 chicks and 16 ducklings showed that the circuit and an experienced observer agreed closely in the timing and counting of vocalizations.

  6. Applications of avian transgenesis.

    PubMed

    Scott, Benjamin B; Velho, Tarciso A; Sim, Shuyin; Lois, Carlos

    2010-01-01

    The ability to introduce foreign DNA into the genome of an organism has proven to be one of the most powerful tools in modern biology. Methods for the manipulation of the animal genome have been developed at an impressive pace for 3 decades, but only in the past 5 years have useful tools for avian transgenesis emerged. The most efficient technique involves the use of replication-deficient lentiviral vectors to deliver foreign DNA into the avian germline. Although lentiviral-mediated transgenesis presents some constraints, progress in this area has garnered interest in both industry and academia for its potential applications in biological research, biotechnology, and agriculture. In this review we evaluate methods for the production of transgenic birds, focusing on the advantages and limitations of lentiviral-mediated transgenesis. We also provide an overview of future applications of this technology. The most exciting of these include disease-resistant transgenic poultry, genetically modified hens that produce therapeutic proteins in their eggs, and transgenic songbirds that serve as a model to study communication disorders. Finally, we discuss technological advances that will be necessary to make avian transgenesis a more versatile tool.

  7. Avoiding the Flu

    MedlinePlus

    ... of this page please turn Javascript on. Feature: Flu Avoiding the Flu Past Issues / Fall 2009 Table of Contents Children ... help avoid getting and passing on the flu. Influenza (Seasonal) The flu is a contagious respiratory illness ...

  8. Avian influenza in Mexico.

    PubMed

    Villarreal, C

    2009-04-01

    The outbreak of highly pathogenic avian influenza (HPAI) H5N2 in Mexico in 1994 led to a clear increase in biosecurity measures and improvement of intensive poultry production systems. The control and eradication measures implemented were based on active surveillance, disease detection, depopulation of infected farms and prevention of possible contacts (identified by epidemiological investigations), improvement of biosecurity measures, and restriction of the movement of live birds, poultry products, by-products and infected material. In addition, Mexico introduced a massive vaccination programme, which resulted in the eradication of HPAI in a relatively short time in two affected areas that had a high density of commercial poultry.

  9. Rapid jamming avoidance in biosonar.

    PubMed

    Gillam, Erin H; Ulanovsky, Nachum; McCracken, Gary F

    2007-03-01

    The sonar systems of bats and dolphins are in many ways superior to man-made sonar and radar systems, and considerable effort has been devoted to understanding the signal-processing strategies underlying these capabilities. A major feature determining the efficiency of sonar systems is the sensitivity to noise and jamming signals. Previous studies indicated that echolocating bats may adjust their signal structure to avoid jamming ('jamming avoidance response'; JAR). However, these studies relied on behavioural correlations and not controlled experiments. Here, we provide the first experimental evidence for JAR in bats. We presented bats (Tadarida brasiliensis) with 'playback stimuli' consisting of recorded echolocation calls at one of six frequencies. The bats exhibited a JAR by shifting their call frequency away from the presented playback frequency. When the approaching bats were challenged by an abrupt change in the playback stimulus, they responded by shifting their call frequencies upwards, away from the playback. Interestingly, even bats initially calling below the playback's frequency shifted their frequencies upwards, 'jumping' over the playback frequency. These spectral shifts in the bats' calls occurred often within less than 200 ms, in the first echolocation call emitted after the stimulus switch-suggesting that rapid jamming avoidance is important for the bat.

  10. Local poultry biosecurity risks to highly pathogenic avian influenza in Kaduna State, Nigeria.

    PubMed

    Paul, Abdu A; Assam, Assam; Ndang, Tabe-Ntui L

    2013-01-01

    The study appraised local poultry biosecurity risks to highly pathogenic avian influenza by assessing farmers' knowledge, beliefs and poultry practices using a standard questionnaire. Farmers' knowledge on transmission and prevention was high but low on disease recognition. Radio was ineffective at informing Islamic educated farmers. Extensive knowledge on transmission and protection did not result in behavioural change as farmers engaged in risky practices of selling, eating or medicating infected poultry and not reporting poultry death. Islamic educated farmers do not believe highly pathogenic avian influenza is a serious and preventable disease. Women are more likely to self medicate when experiencing influenza-like illness. Audio-visual aids would improve avian influenza recognition while involvement of community leaders would enhance disease reporting. Outbreak of highly pathogenic avian influenza in local poultry in Nigeria would follow a similar pattern in Southeast Asia if the risk perception among farmers is not urgently articulated.

  11. Avoiding Statistical Mistakes

    ERIC Educational Resources Information Center

    Strasser, Nora

    2007-01-01

    Avoiding statistical mistakes is important for educators at all levels. Basic concepts will help you to avoid making mistakes using statistics and to look at data with a critical eye. Statistical data is used at educational institutions for many purposes. It can be used to support budget requests, changes in educational philosophy, changes to…

  12. The avian haemophili.

    PubMed Central

    Blackall, P J

    1989-01-01

    There are four currently recognized taxa to accommodate the avian haemophili: Haemophilus paragallinarum, Pasteurella avium, Pasteurella volantium, and Pasteurella species A (the last three being formerly united as Haemophilus avium). A range of other taxa has also been recognized, but they have been neither named nor assigned to a genus. All of these various taxa, legitimate and otherwise, have the common characteristic of requiring V factor, but not X factor, for in vitro growth. Several recent studies have established the phenotypic properties that allow the differentiation of the recognized taxa, both named and unnamed. The serological properties of H. paragallinarum, the causative agent of infectious coryza of chickens, has received considerable recent attention. In contrast, many questions on the pathogenicity and virulence mechanisms of H. paragallinarum remain unanswered. Another area requiring further work is the identification of those antigens responsible for inducing protective immunity in vaccinated or naturally infected chickens. PMID:2670190

  13. The Avian Development Facility

    NASA Technical Reports Server (NTRS)

    2003-01-01

    The Avian Development Facility (ADF) supports 36 eggs in two carousels, one of which rotates to provide a 1-g control for comparing to eggs grown in microgravity. The ADF was designed to incubate up to 36 Japanese quail eggs, 18 in microgravity and 18 in artificial gravity. The two sets of eggs were exposed to otherwise identical conditions, the first time this is been accomplished in space. Eggs are preserved at intervals to provide snapshots of their development for later analysis. Quails incubate in just 15 days, so they are an ideal species to be studied within the duration of space shuttle missions. Further, several investigators can use the same specimens to address different questions. The ADF originated in NASA's Shuttle Student Involvement program in the 1980s and was developed under the NASA Small Business Irnovation Research program. In late 2001, the ADF made its first flight and carried eggs used in two investigations.

  14. Thromboelastography in Selected Avian Species.

    PubMed

    Strindberg, Sophie; Nielsen, Tenna W; Ribeiro, Ângela M; Wiinberg, Bo; Kristensen, Annemarie T; Bertelsen, Mads F

    2015-12-01

    Currently available assay methods and reagents are not optimized for evaluating avian hemostasis; therefore, assessing avian coagulopathies is challenging. Recently, thromboelastography (TEG), which measures the viscoelastic properties of blood, has been used clinically in mammalian species to diagnose and characterize hemostatic disorders. To evaluate TEG in healthy individuals of 6 avian species, we modified existing mammalian TEG protocols to allow analysis of citrated, avian whole-blood samples collected from scarlet ibis (Eudocimus ruber) (n = 13), American flamingos ( Phoenicopterus ruber ) (n = 13), helmeted Guinea fowl ( Numida meleagris ) (n = 12), Amazon parrots (Amazona species) (n = 9), Humboldt penguins ( Spheniscus humboldti ) (n = 6), and domestic chickens (n = 16). Activated partial thromboplastin time, prothrombin time, and fibrinogen were measured as a means of comparison. Regardless of the mode of activation, clot formation in the species studied was markedly delayed compared with mammals. Because of prolonged reaction time (14.7-52.7 minutes) with kaolin and diluted tissue factor, undiluted human tissue factor was used in all avian samples because it provided the shortest reaction time. Species differed significantly in reaction time (P = .007), clotting rate (P < .001), rate of clot formation (α angle; P < .001), and maximum amplitude (P < .001) values, indicating that species-specific reference intervals are necessary. Based on these results, TEG with specific reference intervals could prove useful in evaluating avian hemostatic disorders.

  15. Thromboelastography in Selected Avian Species.

    PubMed

    Strindberg, Sophie; Nielsen, Tenna W; Ribeiro, Ângela M; Wiinberg, Bo; Kristensen, Annemarie T; Bertelsen, Mads F

    2015-12-01

    Currently available assay methods and reagents are not optimized for evaluating avian hemostasis; therefore, assessing avian coagulopathies is challenging. Recently, thromboelastography (TEG), which measures the viscoelastic properties of blood, has been used clinically in mammalian species to diagnose and characterize hemostatic disorders. To evaluate TEG in healthy individuals of 6 avian species, we modified existing mammalian TEG protocols to allow analysis of citrated, avian whole-blood samples collected from scarlet ibis (Eudocimus ruber) (n = 13), American flamingos ( Phoenicopterus ruber ) (n = 13), helmeted Guinea fowl ( Numida meleagris ) (n = 12), Amazon parrots (Amazona species) (n = 9), Humboldt penguins ( Spheniscus humboldti ) (n = 6), and domestic chickens (n = 16). Activated partial thromboplastin time, prothrombin time, and fibrinogen were measured as a means of comparison. Regardless of the mode of activation, clot formation in the species studied was markedly delayed compared with mammals. Because of prolonged reaction time (14.7-52.7 minutes) with kaolin and diluted tissue factor, undiluted human tissue factor was used in all avian samples because it provided the shortest reaction time. Species differed significantly in reaction time (P = .007), clotting rate (P < .001), rate of clot formation (α angle; P < .001), and maximum amplitude (P < .001) values, indicating that species-specific reference intervals are necessary. Based on these results, TEG with specific reference intervals could prove useful in evaluating avian hemostatic disorders. PMID:26771317

  16. Faecal avoidance and selective foraging: do wild mice have the luxury to avoid faeces?

    PubMed

    Walsh, Patrick T; McCreless, Erin; Pedersen, Amy B

    2013-09-01

    Host-parasite interactions are a key determinant of the population dynamics of wild animals, and behaviours that reduce parasite transmission and infection may be important for improving host fitness. While antiparasite behaviours have been demonstrated in laboratory animals and domesticated ungulates, whether these behaviours operate in the wild is poorly understood. Therefore, examining antiparasite behaviours in natural populations is crucial for understanding their ecological significance. In this study, we examined whether two wild rodents (white-footed mice, Peromyscus leucopus, and deer mice, Peromyscus maniculatus), selectively foraged away from conspecific faeces or avoided faeces altogether, and whether faecal gastrointestinal parasite status affected their behaviour. We also tested whether wild mice, when nesting, avoided using material that had previously been used by healthy or parasite-infected conspecifics. Our results, in contrast to laboratory mouse studies, suggest that wild mice do not demonstrate faecal avoidance, selective foraging or selective use of nesting material; they preferred being near faeces and did not differentiate between faeces from parasitized and uninfected conspecifics. Behavioural avoidance to reduce parasite infection may still represent an important strategy; however, mice in our study population appeared to favour the opportunity to feed and nest over the risks of coming into contact with faecal-transmitted parasites. Furthermore, the presence of conspecific faeces may actually provide a positive cue of a good foraging or nesting location. Ultimately, balancing the trade-off of performing antiparasite behaviours to reduce infection with missing an important feeding or nesting opportunity may be very different for animals in the wild facing complex and stochastic environments. PMID:24027342

  17. Exploratory behaviour and novel predator recognition: behavioural correlations across contexts.

    PubMed

    Blake, C A; Gabor, C R

    2016-08-01

    It was hypothesized that the exploratory behaviour of an individual measured in a novel environment could predict its behaviour in response to a novel predator. This study examined novel predator recognition in the western mosquitofish Gambusia affinis, a species with individual differences in risk-taking, activity and exploration in novel environments. Prey responded with characteristic shoaling and avoidance in response to native predators, but did not show characteristic antipredator behaviour towards novel predators. Furthermore, G. affinis exhibited individual-level behavioural correlations across contexts but only when prey were tested with native predators. This could be the result of native predatory selection on behavioural correlations in the prey species. PMID:27220896

  18. Adaptive evolution in an avian reproductive protein: ZP3.

    PubMed

    Calkins, Jennifer D; El-Hinn, Diana; Swanson, Willie J

    2007-11-01

    Proteins involved in reproduction appear to be evolving adaptively across taxa. This rapid evolution is thought to be the result of forces involved in sexual selection. One of the most often suggested of these forces is sexual conflict involving sperm competition and polyspermy avoidance. Bird species offer a unique opportunity to test this hypothesis since the avian egg coat tolerates physiological polyspermy, or the penetration of multiple sperm during fertilization, without negative effects on later development. Despite this, and the extensive amount of data gathered on sexual selection in birds, there are limited studies on the patterns of evolution of avian reproductive proteins. Here we present an analysis of the pattern of evolution of Zona Pellucida 3 (ZP3), a protein present on the avian egg coat. We found that, across several galliform and a single anseriform species, ZP3 appears to be diverging by positive adaptive evolution. In an exploratory analysis of portions of the gene in Callipepla californica we also found evidence of a selective sweep at the putative sperm binding region of the protein. In sum, ZP3 in birds, like reproductive proteins in other species, appears to be adaptively evolving. This result suggests that polyspermy avoidance is not sufficient to explain positive Darwinian selection in reproductive proteins across taxonomic groups. Clearly, the inclusion of bird species in the study of reproductive proteins across taxa promises to add greatly to the discussion of the factors driving the widespread phenomenon of adaptive evolution in reproductive proteins. PMID:17909693

  19. Avoiding Computer Viruses.

    ERIC Educational Resources Information Center

    Rowe, Joyce; And Others

    1989-01-01

    The threat of computer sabotage is a real concern to business teachers and others responsible for academic computer facilities. Teachers can minimize the possibility. Eight suggestions for avoiding computer viruses are given. (JOW)

  20. Avoiding Construction Snafus.

    ERIC Educational Resources Information Center

    Rochefort, Mark; Gosch, Jerry

    2001-01-01

    Discusses risk management planning tips that help schools avoid project-delaying construction problems. Preconstruction planning topics explored include the type of construction method to use, contract selection, and the need for efficient project management. (GR)

  1. Avoiding the SCAMs.

    PubMed

    Kidd, Thomas; Condron, Barry

    2007-05-01

    Dendrites from the same neuron usually avoid contact with one another, a behavior known as self-avoidance. In this issue of Neuron and in the upcoming May 4, 2007 issue of Cell, a pair of studies by Soba et al. and Hughes et al. and a study by Matthews et al., respectively, identify products from the highly alternatively spliced Dscam gene as central to this behavior in Drosophila. Signaling induced by adhesion between identical isoforms triggers repulsion between sister dendrites.

  2. Avoided Crossing and Synchronization

    NASA Astrophysics Data System (ADS)

    Sekii, T.; Shibahashi, H.

    2013-12-01

    We examine avoided crossing of stellar pulsations in the nonlinear regime, where synchronization may occur, based on a simple model of weakly coupled van der Pol oscillators with close frequencies. For this simple case, avoided crossing is unaffected in the sense that there is a frequency difference between the symmetric and antisymmetric modes, but as a result of synchronization, unlike the linear oscillations case, the system can vibrate in only one of the modes.

  3. Operational Collision Avoidance

    NASA Technical Reports Server (NTRS)

    Guit, Bill

    2015-01-01

    This presentation will describe the early days of the EOS Aqua and Aura operational collision avoidance process. It will highlight EOS debris avoidance maneuvers, EOS high interest event statistic and A-Train systematic conjunctions and conclude with future challenges. This is related to earlier e-DAA (tracking number 21692) that an abstract was submitted to a different conference. Eric Moyer, ESMO Deputy Project Manager has reviewed and approved this presentation on May 6, 2015

  4. Avian Influenza A Virus Infections in Humans

    MedlinePlus

    ... Research Making a Candidate Vaccine Virus Related Links Influenza Types Seasonal Avian Swine Variant Pandemic Other Get ... Submit What's this? Submit Button Past Newsletters Avian Influenza A Virus Infections in Humans Language: English Españ ...

  5. The importance of pattern similarity between Müllerian mimics in predator avoidance learning.

    PubMed

    Rowe, Candy; Lindström, Leena; Lyytinen, Anne

    2004-02-22

    Müllerian mimicry, where unpalatable prey share common warning patterns, has long fascinated evolutionary biologists. It is commonly assumed that Müllerian mimics benefit by sharing the costs of predator education, thus reducing per capita mortality, although there has been no direct test of this assumption. Here, we specifically measure the selection pressure exerted by avian predators on unpalatable prey with different degrees of visual similarity in their warning patterns. Using wild-caught birds foraging on novel patterned prey in the laboratory, we unexpectedly found that pattern similarity did not increase the speed of avoidance learning, and even dissimilar mimics shared the education of naive predators. This was a consistent finding across two different densities of unpalatable prey, although mortalities were lower at the higher density as expected. Interestingly, the mortalities of Müllerian mimics were affected by pattern similarity in the predicted way by the end of our experiment, although the result was not quite significant. This suggests that the benefits to Müllerian mimics may emerge only later in the learning process, and that predator experience of the patterns may affect the degree to which pattern similarity is important. This highlights the need to measure the behaviour of real predators if we are to understand fully the evolution of mimicry systems.

  6. Pathogenesis and transmission of highly pathogenic avian influenza H5Nx in swine

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Introduction Influenza A viruses (IAV) periodically transmit between pigs, people, and birds. If two IAV strains infect the same host, genes can reassort to generate progeny virus with potential to be more infectious or avoid immunity. Pigs pose a risk for such reassortment. Highly pathogenic avian ...

  7. Current situation on highly pathogenic avian influenza

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Avian influenza is one of the most important diseases affecting the poultry industry worldwide. Avian influenza viruses can cause a range of clinical disease in poultry. Viruses that cause severe disease and mortality are referred to as highly pathogenic avian influenza (HPAI) viruses. The Asian ...

  8. Reactive Collision Avoidance Algorithm

    NASA Technical Reports Server (NTRS)

    Scharf, Daniel; Acikmese, Behcet; Ploen, Scott; Hadaegh, Fred

    2010-01-01

    The reactive collision avoidance (RCA) algorithm allows a spacecraft to find a fuel-optimal trajectory for avoiding an arbitrary number of colliding spacecraft in real time while accounting for acceleration limits. In addition to spacecraft, the technology can be used for vehicles that can accelerate in any direction, such as helicopters and submersibles. In contrast to existing, passive algorithms that simultaneously design trajectories for a cluster of vehicles working to achieve a common goal, RCA is implemented onboard spacecraft only when an imminent collision is detected, and then plans a collision avoidance maneuver for only that host vehicle, thus preventing a collision in an off-nominal situation for which passive algorithms cannot. An example scenario for such a situation might be when a spacecraft in the cluster is approaching another one, but enters safe mode and begins to drift. Functionally, the RCA detects colliding spacecraft, plans an evasion trajectory by solving the Evasion Trajectory Problem (ETP), and then recovers after the collision is avoided. A direct optimization approach was used to develop the algorithm so it can run in real time. In this innovation, a parameterized class of avoidance trajectories is specified, and then the optimal trajectory is found by searching over the parameters. The class of trajectories is selected as bang-off-bang as motivated by optimal control theory. That is, an avoiding spacecraft first applies full acceleration in a constant direction, then coasts, and finally applies full acceleration to stop. The parameter optimization problem can be solved offline and stored as a look-up table of values. Using a look-up table allows the algorithm to run in real time. Given a colliding spacecraft, the properties of the collision geometry serve as indices of the look-up table that gives the optimal trajectory. For multiple colliding spacecraft, the set of trajectories that avoid all spacecraft is rapidly searched on

  9. Collision Avoidance System

    NASA Technical Reports Server (NTRS)

    1991-01-01

    Ames Research Center teamed with the Federal Aviation Administration (FAA) to study human performance factors associated with the use of the Traffic Alert and Collision Avoidance system (TCAS II) in an operational environment. TCAS is designed to alert pilots of the presence of other aircraft in their vicinity, to identify and track those who could be a threat, and to recommend action to avoid a collision. Ames conducted three laboratory experiments. The first showed that pilots were able to use the TCAS II correctly in the allowable time. The second tested pilots' response to changes in the avoidance advisories, and the third examined pilots' reactions to alternative displays. After a 1989 congressional mandate, the FAA ruled that TCAS would be required on all passenger carrying aircraft (to be phased in completely by 1995).

  10. Avian influenza virus in pregnancy.

    PubMed

    Liu, Shelan; Sha, Jianping; Yu, Zhao; Hu, Yan; Chan, Ta-Chien; Wang, Xiaoxiao; Pan, Hao; Cheng, Wei; Mao, Shenghua; Zhang, Run Ju; Chen, Enfu

    2016-07-01

    The unprecedented epizootic of avian influenza viruses, such as H5N1, H5N6, H7N1 and H10N8, has continued to cause disease in humans in recent years. In 2013, another novel influenza A (H7N9) virus emerged in China, and 30% of those patients died. Pregnant women are particularly susceptible to avian influenza and are more likely to develop severe complications and to die, especially when infection occurs in the middle and late trimesters. Viremia is believed to occur infrequently, and thus vertical transmission induced by avian influenza appears to be rare. However, avian influenza increases the risk of adverse pregnancy outcomes, including spontaneous abortion, preterm birth and fatal distress. This review summarises 39 cases of pregnant women and their fetuses from different countries dating back to 1997, including 11, 15 and 13 infections with H7N9, H5N1 and the 2009 pandemic influenza (H1N1), respectively. We analysed the epidemic features, following the geographical, population and pregnancy trimester distributions; underlying diseases; exposure history; medical timelines; human-to-human transmission; pathogenicity and vertical transmission; antivirus treatments; maternal severity and mortality and pregnancy outcome. The common experiences reported in different countries and areas suggest that early identification and treatment are imperative. In the future, vigilant virologic and epidemiologic surveillance systems should be developed to monitor avian influenza viruses during pregnancy. Furthermore, extensive study on the immune mechanisms should be conducted, as this will guide safe, rational immunomodulatory treatment among this high-risk population. Most importantly, we should develop a universal avian influenza virus vaccine to prevent outbreaks of the different subtypes. Copyright © 2016 John Wiley & Sons, Ltd. PMID:27187752

  11. Avoiding the "M" Word.

    ERIC Educational Resources Information Center

    Klinger, Donna

    2001-01-01

    Provides an overview of roundtable discussions by top business officers about how higher education can capitalize on strategic alliances. Describes how, by working with one another and with corporate partners, colleges and universities can avoid closing their doors or merging with stronger institutions. (EV)

  12. Psychological Treatments to Avoid

    ERIC Educational Resources Information Center

    Thomason, Timothy C.

    2010-01-01

    Certain psychological treatments should be avoided, and a list of such treatments would provide valuable guidance for counselors, as well as potential clients. It is well established that some therapies are potentially dangerous, and some fringe therapies are highly unlikely to help clients beyond a placebo effect. This article provides an…

  13. Myelin Avoids the JAM.

    PubMed

    Follis, Rose M; Carter, Bruce D

    2016-08-17

    In this issue of Neuron, Redmond et al. (2016) identify junction adhesion molecule 2 (JAM2) as an inhibitor of somatodendritic myelination in spinal cord neurons, thereby elucidating how myelin forms on axons but avoids dendrites and cell bodies. PMID:27537479

  14. Plants to Avoid

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Knowledge of poisonous plants is extremely important for home owners, gardeners, farmers, hunters, hikers, and the rest of the general public. Among the most important plants to avoid in the Delta Region are poison ivy, bull nettle, eastern black nightshade, Queen Ann’s lace, jimsonweed, and trumpe...

  15. Avian reproductive physiology

    USGS Publications Warehouse

    Gee, G.F.; Gibbons, Edward F.; Durrant, Barbara S.; Demarest, Jack

    1995-01-01

    Knowledge of the many physiological factors associated with egg production , fertility, incubation, and brooding in nondomestic birds is limited. Science knows even less about reproduction in most of the 238 endangered or threatened birds. This discussion uses studies of nondomestic and, when necessary, domestic birds to describe physiological control of reproduction. Studies of the few nondomestic avian species show large variation in physiological control of reproduction. Aviculturists, in order to successfully propagate an endangered bird, must understand the bird's reproductive peculiarities. First, investigators can do studies with carefully chosen surrogate species, but eventually they need to confirm the results in the target endangered bird. Studies of reproduction in nondomestic birds increased in the last decade. Still, scientists need to do more comparative studies to understand the mechanisms that control reproduction in birds. New technologies are making it possible to study reproductive physiology of nondomestic species in less limiting ways. These technologies include telemetry to collect information without inducing stress on captives (Howey et al., 1987; Klugman, 1987), new tests for most of the humoral factors associated with reproduction, and the skill to collect small samples and manipulate birds without disrupting the physiological mechanisms (Bercovitz et al., 1985). Managers are using knowledge from these studies to improve propagation in zoological parks, private and public propagation facilities, and research institutions. Researchers need to study the control of ovulation, egg formation, and oviposition in the species of nondomestic birds that lay very few eggs in a season, hold eggs in the oviduct for longer intervals, or differ in other ways from the more thoroughly studied domestic birds. Other techniques that would enhance propagation for nondomestlc birds include tissue culture of cloned embryonic cells, cryopreservation of embryos

  16. Avian vocal mimicry: a unified conceptual framework.

    PubMed

    Dalziell, Anastasia H; Welbergen, Justin A; Igic, Branislav; Magrath, Robert D

    2015-05-01

    Mimicry is a classical example of adaptive signal design. Here, we review the current state of research into vocal mimicry in birds. Avian vocal mimicry is a conspicuous and often spectacular form of animal communication, occurring in many distantly related species. However, the proximate and ultimate causes of vocal mimicry are poorly understood. In the first part of this review, we argue that progress has been impeded by conceptual confusion over what constitutes vocal mimicry. We propose a modified version of Vane-Wright's (1980) widely used definition of mimicry. According to our definition, a vocalisation is mimetic if the behaviour of the receiver changes after perceiving the acoustic resemblance between the mimic and the model, and the behavioural change confers a selective advantage on the mimic. Mimicry is therefore specifically a functional concept where the resemblance between heterospecific sounds is a target of selection. It is distinct from other forms of vocal resemblance including those that are the result of chance or common ancestry, and those that have emerged as a by-product of other processes such as ecological convergence and selection for large song-type repertoires. Thus, our definition provides a general and functionally coherent framework for determining what constitutes vocal mimicry, and takes account of the diversity of vocalisations that incorporate heterospecific sounds. In the second part we assess and revise hypotheses for the evolution of avian vocal mimicry in the light of our new definition. Most of the current evidence is anecdotal, but the diverse contexts and acoustic structures of putative vocal mimicry suggest that mimicry has multiple functions across and within species. There is strong experimental evidence that vocal mimicry can be deceptive, and can facilitate parasitic interactions. There is also increasing support for the use of vocal mimicry in predator defence, although the mechanisms are unclear. Less progress has

  17. Avian influenza virus RNA extraction

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The efficient extraction and purification of viral RNA is critical for down-stream molecular applications whether it is the sensitive and specific detection of virus in clinical samples, virus gene cloning and expression, or quantification of avian influenza (AI) virus by molecular methods from expe...

  18. The history of avian influenza.

    PubMed

    Lupiani, Blanca; Reddy, Sanjay M

    2009-07-01

    The first description of avian influenza (AI) dates back to 1878 in northern Italy, when Perroncito [Perroncito E. Epizoozia tifoide nei gallinacei. Annali Accad Agri Torino 1878;21:87-126] described a contagious disease of poultry associated with high mortality. The disease, termed "fowl plague", was initially confused with the acute septicemic form of fowl cholera. However, in 1880, soon after its first description, Rivolta and Delprato [as reported by Stubs EL. Fowl pest, In: Biester HE, Devries L, editors. Diseases of poultry. 1st ed. Ames, IO: Iowa State College Press; 1943. p. 493-502] showed it to be different from fowl cholera, based on clinical and pathological properties, and called it Typhus exudatious gallinarum. In 1901, Centanni and Savunzzi [Centanni E, Savonuzzi E, La peste aviaria I & II, Communicazione fatta all'accademia delle scienze mediche e naturali de Ferrara, 1901] determined that fowl plague was caused by a filterable virus; however, it was not until 1955 that the classical fowl plague virus was shown to be a type A influenza virus based on the presence of type A influenza virus type-specific ribonucleoprotein [Schäfer W. Vergleichender sero-immunologische Untersuchungen über die Viren der Influenza und klassischen Geflügelpest. Z Naturf 1955;10b:81-91]. The term fowl plague was substituted by the more appropriate term highly pathogenic avian influenza (HPAI) at the First International Symposium on Avian Influenza [Proceedings of the First International Symposium on Avian Influenza. Beltsville, MD. 1981, Avian Dis 47 (Special Issue) 2003.] and will be used throughout this review when referring to any previously described fowl plague virus.

  19. Avian disease at the Salton Sea

    USGS Publications Warehouse

    Friend, M.

    2002-01-01

    A review of existing records and the scientific literature was conducted for occurrences of avian diseases affecting free-ranging avifauna within the Salton Sea ecosystem. The period for evaluation was 1907 through 1999. Records of the U.S. Department of Agriculture, Bureau of Biological Survey and the scientific literature were the data sources for the period of 1907a??1939. The narrative reports of the U.S. Fish and Wildlife Service's Sonny Bono National Wildlife Refuge Complex and the epizootic database of the U.S. Geological Survey's National Wildlife Health Center were the primary data sources for the remainder of the evaluation. The pattern of avian disease at the Salton Sea has changed greatly over time. Relative to past decades, there was a greater frequency of major outbreaks of avian disease at the Salton Sea during the 1990s than in previous decades, a greater variety of disease agents causing epizootics, and apparent chronic increases in the attrition of birds from disease. Avian mortality was high for about a decade beginning during the mid-1920s, diminished substantially by the 1940s and was at low to moderate levels until the 1990s when it reached the highest levels reported. Avian botulism (Clostridium botulinum type C) was the only major cause of avian disease until 1979 when the first major epizootic of avian cholera (Pasteurella multocidia) was documented. Waterfowl and shorebirds were the primary species affected by avian botulism. A broader spectrum of species have been killed by avian cholera but waterfowl have suffered the greatest losses. Avian cholera reappeared in 1983 and has joined avian botulism as a recurring cause of avian mortality. In 1989, avian salmonellosis (Salmonella typhimurium) was first diagnosed as a major cause of avian disease within the Salton Sea ecosystem and has since reappeared several times, primarily among cattle egrets (Bubulcus ibis). The largest loss from a single epizootic occurred in 1992, when an estimated

  20. Modelling inhibition of avian aromatase by azole pesticides

    PubMed Central

    Saxena, A.K.; Devillers, J.; Bhunia, S.S.; Bro, E.

    2015-01-01

    The potential effects of pesticides and their metabolites on the endocrine system are of major concern to wildlife and human health. In this context, the azole pesticides have earned special attention due to their cytochrome P450 aromatase inhibition potential. Cytochrome P450 aromatase (CYP19) catalyses the conversion of androstenedione and testosterone into oestrone and oestradiol, respectively. Thus, aromatase modulates the oestrogenic balance essential not only for females, but also for male physiology, including gonadal function. Its inhibition affects reproductive organs, fertility and sexual behaviour in humans and wildlife species. Several studies have shown that azole pesticides are able to inhibit human and fish aromatases but the information on birds is lacking. Consequently, it appeared to be of interest to estimate the aromatase inhibition of azoles in three different avian species, namely Gallus gallus, Coturnix coturnix japonica and Taeniopygia guttata. In the absence of the crystal structure of the aromatase enzyme in these bird species, homology models for the individual avian species were constructed using the crystal structure of human aromatase (hAr) (pdb: 3EQM) that showed high sequence similarity for G. gallus (82.0%), T. guttata (81.9%) and C. japonica (81.2%). A homology model with Oncorhynchus mykiss (81.9%) was also designed for comparison purpose. The homology-modelled aromatase for each avian and fish species and crystal structure of human aromatase were selected for docking 46 structurally diverse azoles and related compounds. We showed that the docking behaviour of the chemicals on the different aromatases was broadly the same. We also demonstrated that there was an acceptable level of correlation between the binding score values and the available aromatase inhibition data. This means that the homology models derived on bird and fish species can be used to approximate the potential inhibitory effects of azoles on their aromatase. PMID

  1. Landing Hazard Avoidance Display

    NASA Technical Reports Server (NTRS)

    Abernathy, Michael Franklin (Inventor); Hirsh, Robert L. (Inventor)

    2016-01-01

    Landing hazard avoidance displays can provide rapidly understood visual indications of where it is safe to land a vehicle and where it is unsafe to land a vehicle. Color coded maps can indicate zones in two dimensions relative to the vehicles position where it is safe to land. The map can be simply green (safe) and red (unsafe) areas with an indication of scale or can be a color coding of another map such as a surface map. The color coding can be determined in real time based on topological measurements and safety criteria to thereby adapt to dynamic, unknown, or partially known environments.

  2. Avoidable waste management costs

    SciTech Connect

    Hsu, K.; Burns, M.; Priebe, S.; Robinson, P.

    1995-01-01

    This report describes the activity based costing method used to acquire variable (volume dependent or avoidable) waste management cost data for routine operations at Department of Energy (DOE) facilities. Waste volumes from environmental restoration, facility stabilization activities, and legacy waste were specifically excluded from this effort. A core team consisting of Idaho National Engineering Laboratory, Los Alamos National Laboratory, Rocky Flats Environmental Technology Site, and Oak Ridge Reservation developed and piloted the methodology, which can be used to determine avoidable waste management costs. The method developed to gather information was based on activity based costing, which is a common industrial engineering technique. Sites submitted separate flow diagrams that showed the progression of work from activity to activity for each waste type or treatability group. Each activity on a flow diagram was described in a narrative, which detailed the scope of the activity. Labor and material costs based on a unit quantity of waste being processed were then summed to generate a total cost for that flow diagram. Cross-complex values were calculated by determining a weighted average for each waste type or treatability group based on the volume generated. This study will provide DOE and contractors with a better understanding of waste management processes and their associated costs. Other potential benefits include providing cost data for sites to perform consistent cost/benefit analysis of waste minimization and pollution prevention (WMIN/PP) options identified during pollution prevention opportunity assessments and providing a means for prioritizing and allocating limited resources for WMIN/PP.

  3. Radical-pair based avian magnetoreception

    NASA Astrophysics Data System (ADS)

    Procopio, Maria; Ritz, Thorsten

    2014-03-01

    Behavioural experiments suggest that migratory birds possess a magnetic compass sensor able to detect the direction of the geomagnetic. One hypothesis for the basis of this remarkable sensory ability is that the coherent quantum spin dynamics of photoinduced radical pair reactions transduces directional magnetic information from the geomagnetic field into changes of reaction yields, possibly involving the photoreceptor cryptochrome in the birds retina. The suggested radical-pair based avian magnetoreception has attracted attention in the field of quantum biology as an example of a biological sensor which might exploit quantum coherences for its biological function. Investigations on such a spin-based sensor have focussed on uncovering the design features for the design of a biomimetic magnetic field sensor. We study the effects of slow fluctuations in the nuclear spin environment on the directional signal. We quantitatively evaluate the robustness of signals under fluctuations on a timescale longer than the lifetime of a radical pair, utilizing two models of radical pairs. Our results suggest design principles for building a radical-pair based compass sensor that is both robust and highly directional sensitive.

  4. Generalisation of fear and avoidance along a semantic continuum.

    PubMed

    Boyle, Sean; Roche, Bryan; Dymond, Simon; Hermans, Dirk

    2016-01-01

    Directly conditioned fear and avoidance readily generalises to dissimilar but conceptually related stimuli. Here, for the first time, we examined the conceptual/semantic generalisation of both fear and avoidance using real words (synonyms). Participants were first exposed to a differential fear conditioning procedure in which one word (e.g., "broth"; CS+) was followed with brief electric shock [unconditioned stimulus (US)] and another was not (e.g., "assist"; CS-). Next, an instrumental conditioning phase taught avoidance in the presence the CS+ but not the CS-. During generalisation testing, synonyms of the CS+ (e.g., "soup"; GCS+) and CS- (e.g., "help"; GCS-) were presented in the absence of shock. Conditioned fear and avoidance, measured via skin conductance responses, behavioural avoidance and US expectancy ratings, generalised to the semantically related, but not to the semantically unrelated, synonyms. Findings have implications for how natural language categories and concepts mediate the expansion of fear and avoidance repertoires in clinical contexts.

  5. Conflict: run! Reduced Stroop interference with avoidance responses.

    PubMed

    Schouppe, Nathalie; De Houwer, Jan; Ridderinkhof, K Richard; Notebaert, Wim

    2012-01-01

    Conflict has been hypothesized to be aversive, triggering avoidance behaviour (Botvinick, 2007). To test this hypothesis, a standard Stroop task was modified such that avoiding was part of the response set. More precisely, participants were asked to move a manikin towards or away from Stroop stimuli, depending on the colour of the words. Results showed that the type of response (approach versus avoidance) modulated the Stroop congruency effect. Specifically, the reaction time analysis revealed that the stimulus congruency effect disappeared with avoidance responses, contrary to approach responses where a stimulus congruency effect was present. Moreover, the error data showed a reduction of the general congruency effect when avoiding. These results suggest that in the face of conflict, avoidance is the predominant response.

  6. Providing a food reward reduces inhibitory avoidance learning in zebrafish.

    PubMed

    Manuel, Remy; Zethof, Jan; Flik, Gert; van den Bos, Ruud

    2015-11-01

    As shown in male rats, prior history of subjects changes behavioural and stress-responses to challenges: a two-week history of exposure to rewards at fixed intervals led to slightly, but consistently, lower physiological stress-responses and anxiety-like behaviour. Here, we tested whether similar effects are present in zebrafish (Danio rerio). After two weeks of providing Artemia (brine shrimp; Artemia salina) as food reward or flake food (Tetramin) as control at fixed intervals, zebrafish were exposed to a fear-avoidance learning task using an inhibitory avoidance protocol. Half the number of fish received a 3V shock on day 1 and were tested and sacrificed on day 2; the other half received a second 3V shock on day 2 and were tested and sacrificed on day 3. The latter was done to assess whether effects are robust, as effects in rats have been shown to be modest. Zebrafish that were given Artemia showed less inhibitory avoidance after one shock, but not after two shocks, than zebrafish that were given flake-food. Reduced avoidance behaviour was associated with lower telencepahalic gene expression levels of cannabinoid receptor 1 (cnr1) and higher gene expression levels of corticotropin releasing factor (crf). These results suggest that providing rewards at fixed intervals alters fear avoidance behaviour, albeit modestly, in zebrafish. We discuss the data in the context of similar underlying brain structures in mammals and fish.

  7. Providing a food reward reduces inhibitory avoidance learning in zebrafish.

    PubMed

    Manuel, Remy; Zethof, Jan; Flik, Gert; van den Bos, Ruud

    2015-11-01

    As shown in male rats, prior history of subjects changes behavioural and stress-responses to challenges: a two-week history of exposure to rewards at fixed intervals led to slightly, but consistently, lower physiological stress-responses and anxiety-like behaviour. Here, we tested whether similar effects are present in zebrafish (Danio rerio). After two weeks of providing Artemia (brine shrimp; Artemia salina) as food reward or flake food (Tetramin) as control at fixed intervals, zebrafish were exposed to a fear-avoidance learning task using an inhibitory avoidance protocol. Half the number of fish received a 3V shock on day 1 and were tested and sacrificed on day 2; the other half received a second 3V shock on day 2 and were tested and sacrificed on day 3. The latter was done to assess whether effects are robust, as effects in rats have been shown to be modest. Zebrafish that were given Artemia showed less inhibitory avoidance after one shock, but not after two shocks, than zebrafish that were given flake-food. Reduced avoidance behaviour was associated with lower telencepahalic gene expression levels of cannabinoid receptor 1 (cnr1) and higher gene expression levels of corticotropin releasing factor (crf). These results suggest that providing rewards at fixed intervals alters fear avoidance behaviour, albeit modestly, in zebrafish. We discuss the data in the context of similar underlying brain structures in mammals and fish. PMID:26342856

  8. Avian influenza: an agricultural perspective.

    PubMed

    Morgan, Andrea

    2006-11-01

    Recent outbreaks of infection with highly pathogenic H5N1 strains of avian influenza virus in poultry in Asia, Africa, Europe, and the Middle East have raised concern over the potential emergence of a pandemic strain that can easily infect humans and cause serious morbidity and mortality. To prevent and control a national outbreak, the US Department of Agriculture (USDA) conducts measures based on the ecology of avian influenza viruses. To prevent an outbreak in the United States, the USDA conducts surveillance of bird populations, restrictions on bird importation, educational outreach, and regulation of agricultural practices, in collaboration with local, state, and federal organizations. To manage an outbreak, the USDA has in place a well-established emergency management system for optimizing efforts. The USDA also collaborates with international organizations for disease prevention and control in other countries.

  9. Gender determination of avian embryo

    DOEpatents

    Daum, Keith A.; Atkinson, David A.

    2002-01-01

    Disclosed is a method for gender determination of avian embryos. During the embryo incubation process, the outer hard shells of eggs are drilled and samples of allantoic fluid are removed. The allantoic fluids are directly introduced into an ion mobility spectrometer (IMS) for analysis. The resulting spectra contain the relevant marker peaks in the positive or negative mode which correlate with unique mobilities which are sex-specific. This way, the gender of the embryo can be determined.

  10. UV Impacts Avoided by the Montreal Protocol

    NASA Technical Reports Server (NTRS)

    Newman, Paul; McKenzie, Richard

    2010-01-01

    Temporal and geographical variabilities in the future "World Expected" UV environment are compared with the "World Avoided", which would have occurred without the Montreal Protocol on protection of the ozone layer and its subsequent amendments and adjustments. Based on calculations of clear-sky UV irradiances, the effects of the Montreal Protocol have been hugely beneficial to avoid the health risks, such as skin cancer, which are associated with high UV, while there is only a small increase in health risks, such as vitamin D deficiency, that are associated with low UV. However, interactions with climate change may lead to changes in cloud and albedo, and possibly behavioural changes which could also be important.

  11. UV impacts avoided by the Montreal Protocol.

    PubMed

    Newman, Paul A; McKenzie, Richard

    2011-07-01

    Temporal and geographical variabilities in the future "world expected" UV environment are compared with the "world avoided", which would have occurred without the Montreal Protocol on Substances That Deplete the Ozone Layer and its subsequent amendments and adjustments. Based on calculations of clear-sky UV irradiances, the effects of the Montreal Protocol have been hugely beneficial to avoid the health risks, such as skin cancer, which are associated with high UV, while there is only a small increase in health risks, such as vitamin D deficiency, that are associated with low UV. However, interactions with climate change may lead to changes in cloud and albedo, and possibly behavioural changes that could also be important.

  12. Unpleasant auditory illusions and related avoidance behaviour in a child.

    PubMed

    Barba, Carmen; Guerrini, Renzo

    2008-03-01

    Auditory aura is a rare symptom in focal epilepsy. It has been described in autosomal dominant partial epilepsy with auditory features, but is, in general, poorly documented. We report on a 7-year-old, right-handed boy, who suffered seizures characterized by positive auditory illusions with verbal and gestural automatisms and noticeable attempts at covering his ears. Clinical evaluation and video-recording of the seizures, confirmed that most of the ictal behavior was deliberately directed at trying to prevent the unpleasant sensations reaching his ears. [Published with video sequences]. PMID:18367430

  13. Avoiding dangerous climate change

    SciTech Connect

    Hans Joachim Schellnhuber; Wolfgang Cramer; Nebojsa Nakicenovic; Tom Wigley; Gary Yohe

    2006-02-15

    In 2005 the UK Government hosted the Avoiding Dangerous Climate Change conference to take an in-depth look at the scientific issues associated with climate change. This volume presents the most recent findings from the leading international scientists that attended the conference. The topics addressed include critical thresholds and key vulnerabilities of the climate system, impacts on human and natural systems, socioeconomic costs and benefits of emissions pathways, and technological options for meeting different stabilisation levels of greenhouse gases in the atmosphere. Contents are: Foreword from Prime Minister Tony Blair; Introduction from Rajendra Pachauri, Chairman of the IPCC; followed by 41 papers arranged in seven sections entitled: Key Vulnerabilities of the Climate System and Critical Thresholds; General Perspectives on Dangerous Impacts; Key Vulnerabilities for Ecosystems and Biodiversity; Socio-Economic Effects; Regional Perspectives; Emission Pathways; and Technological Options. Four papers have been abstracted separately for the Coal Abstracts database.

  14. Avian embryos in hypoxic environments.

    PubMed

    León-Velarde, F; Monge-C, C

    2004-08-12

    Avian embryos at high altitude do not benefit of the maternal protection against hypoxia as in mammals. Nevertheless, avian embryos are known to hatch successfully at altitudes between 4,000 and 6,500 m. This review considers some of the processes that bring about the outstanding modifications in the pressure differences between the environment and mitochondria of avian embryos in hypoxic environments. Among species, some maintain normal levels of oxygen consumption ( VO2) have a high oxygen carrying capacity, lower the air cell-arterial pressure difference ( PAO2 - PaO2 ) with a constant pH. Other species decrease VO2, increase only slightly the oxygen carrying capacity, have a higher PAO2 - PaO2 difference than sea-level embryos and lower the PCO2 and pH. High altitude embryos, and those exposed to hypoxia have an accelerated decline of erythrocyte ATP levels during development and an earlier stimulation of 2,3-BPG synthesis. A higher Bohr effect may ensure high tissue PO2 in the presence of the high-affinity hemoglobin. Independently of the strategy used, they serve together to promote suitable rates of development and successful hatching of high altitude birds in hypoxic environments.

  15. Avian utilization of subsidence wetlands

    SciTech Connect

    Nawrot, J.R.; Conley, P.S.; Smout, C.L.

    1995-09-01

    Diverse and productive wetlands have resulted from coal mining in the midwest. The trend from surface to underground mining has increased the potential for subsidence. Planned subsidence of longwall mining areas provides increased opportunities for wetland habitat establishment. Planned subsidence over a 180 meter (590 foot) deep longwall mine in southern Illinois during 1984 to 1986 produced three subsidence wetlands totaling 15 hectares (38 acres). The resulting palustrine emergent wetlands enhanced habitat diversity within the surrounding palustrine forested unsubsided area. Habitat assessments and evaluations of avian utilization of the subsidence wetlands were conducted during February 1990 through October 1991. Avian utilization was greatest within the subsided wetlands. Fifty-three bird species representing seven foraging guilds utilized the subsidence wetlands. Wading/fishing, dabbling waterfowl, and insectivorous avian guilds dominated the subsidence wetlands. The subsidence wetlands represented ideal habitat for wood ducks and great blue herons which utilized snags adjacent to and within the wetlands for nesting (19 great blue heron nests produced 25 young). Dense cover and a rich supply of macroinvertebrates provide excellent brood habitat for wood ducks, while herpetofauna and ichthyofauna provided abundant forage in shallow water zones for great blue herons and other wetland wading birds. The diversity of game and non-game avifauna utilizing the subsidence areas demonstrated the unique value of these wetlands. Preplanned subsidence wetlands can help mitigate loss of wetland habitats in the midwest.

  16. Measuring Experiential Avoidance in Adults: The Avoidance and Fusion Questionnaire

    ERIC Educational Resources Information Center

    Schmalz, Jonathan E.; Murrell, Amy R.

    2010-01-01

    To date, general levels of experiential avoidance are primarily measured by the Acceptance and Action Questionnaire-II (AAQ-II), but it includes items of questionable comprehensibility. The Avoidance and Fusion Questionnaire for Youth (AFQ-Y), previously validated as a measure of experiential avoidance with children and adolescents, was…

  17. Microhabitat choice in island lizards enhances camouflage against avian predators.

    PubMed

    Marshall, Kate L A; Philpot, Kate E; Stevens, Martin

    2016-01-01

    Camouflage can often be enhanced by genetic adaptation to different local environments. However, it is less clear how individual behaviour improves camouflage effectiveness. We investigated whether individual Aegean wall lizards (Podarcis erhardii) inhabiting different islands rest on backgrounds that improve camouflage against avian predators. In free-ranging lizards, we found that dorsal regions were better matched against chosen backgrounds than against other backgrounds on the same island. This suggests that P. erhardii make background choices that heighten individual-specific concealment. In achromatic camouflage, this effect was more evident in females and was less distinct in an island population with lower predation risk. This suggests that behavioural enhancement of camouflage may be more important in females than in sexually competing males and related to predation risk. However, in an arena experiment, lizards did not choose the background that improved camouflage, most likely due to the artificial conditions. Overall, our results provide evidence that behavioural preferences for substrates can enhance individual camouflage of lizards in natural microhabitats, and that such adaptations may be sexually dimorphic and dependent on local environments. This research emphasizes the importance of considering links between ecology, behaviour, and appearance in studies of intraspecific colour variation and local adaptation. PMID:26804463

  18. Microhabitat choice in island lizards enhances camouflage against avian predators

    PubMed Central

    Marshall, Kate L. A.; Philpot, Kate E.; Stevens, Martin

    2016-01-01

    Camouflage can often be enhanced by genetic adaptation to different local environments. However, it is less clear how individual behaviour improves camouflage effectiveness. We investigated whether individual Aegean wall lizards (Podarcis erhardii) inhabiting different islands rest on backgrounds that improve camouflage against avian predators. In free-ranging lizards, we found that dorsal regions were better matched against chosen backgrounds than against other backgrounds on the same island. This suggests that P. erhardii make background choices that heighten individual-specific concealment. In achromatic camouflage, this effect was more evident in females and was less distinct in an island population with lower predation risk. This suggests that behavioural enhancement of camouflage may be more important in females than in sexually competing males and related to predation risk. However, in an arena experiment, lizards did not choose the background that improved camouflage, most likely due to the artificial conditions. Overall, our results provide evidence that behavioural preferences for substrates can enhance individual camouflage of lizards in natural microhabitats, and that such adaptations may be sexually dimorphic and dependent on local environments. This research emphasizes the importance of considering links between ecology, behaviour, and appearance in studies of intraspecific colour variation and local adaptation. PMID:26804463

  19. Avoidance of late abortion.

    PubMed

    1979-11-24

    Induced abortion is now a common procedure in the United States and Britain. Methods for performing induced abortion are reviewed. Menstrual regulation, aspiration with a hand-held syringe and a flexible cannula within 6 weeks of the last period, is not often practiced in Britain. Several developing countries are using this simple technique to advantage. Vacuum aspiration in the 1st 12 weeks of pregnancy is the main method being used everywhere for 1st trimester procedures. Mortality rates with this method are low and, in well-organized clinics with experienced personnel, the rates can be reduced even further. It is agreed that 2nd trimester procedures are more complex, both physically and emotionally. In the last several years, dilatation and evacuation (D&E) has increased in popularity for 2nd trimester procedures. Dilation of the cervix is generally accomplished with laminaria, evacuation of the uterus with forceps, and then suction curettage applied. This procedure has replaced intraamniotic infusion, hysterotomy, and hysterectomy as the most commonly - practiced method, despite its need for special surgical skills and good clinical backup. Follow-up of abortions is difficult. Different long-term effects have been noted with different abortion procedures. Early abortion seems to have only a modest effect, if that. Whether late abortion has long-lasting effects remains open to question. Late abortion should be avoided.

  20. CAT altitude avoidance system

    NASA Technical Reports Server (NTRS)

    Gary, B. L. (Inventor)

    1982-01-01

    A method and apparatus are provided for indicating the altitude of the tropopause or of an inversion layer wherein clear air turbulence (CAT) may occur, and the likely severity of any such CAT, includes directing a passive microwave radiometer on the aircraft at different angles with respect to the horizon. The microwave radiation measured at a frequency of about 55 GHz represents the temperature of the air at an ""average'' range of about 3 kilometers, so that the sine of the angle of the radiometer times 3 kilometers equals the approximate altitude of the air whose temperature is measured. A plot of altitude (with respect to the aircraft) versus temperature of the air at that altitude, can indicate when an inversion layer is present and can indicate the altitude of the tropopause or of such an inversion layer. The plot can also indicate the severity of any CAT in an inversion layer. If CAT has been detected in the general area, then the aircraft can be flown at an altitude to avoid the tropopause or inversion layer.

  1. The global nature of avian influenza

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Avian influenza virus is a global virus which knows no geographic boundaries, has no political agenda, and can infect poultry irrespective of their agricultural or anthropocentric production systems. Avian influenza viruses or evidence of their infection have been detected in poultry and wild birds...

  2. MANAGING AVIAN FLU, CARCASS MANAGEMENT & BIOSOLIDS

    EPA Science Inventory

    The avian influenza virus is discussed with emphasis on the impact to poultry and possible movement of the highly pathogenic H5N 1 virus to humans. A review is made of the worldwide effects to date of the avian influenza viruses; methods for the viruses to enter recreational wate...

  3. DIVA vaccination strategies for avian influenza virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Vaccination for both low pathogenic and highly pathogenic avian influenza is commonly used for countries that have been endemic for avian influenza influenza virus, but stamping out policies are common for countries that are normally free of the disease. Stamping out policies of euthanizing infecte...

  4. 76 FR 24793 - Highly Pathogenic Avian Influenza

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-03

    ... (76 FR 4046-4056, Docket No. APHIS-2006-0074) an interim rule that amended the regulations governing... Inspection Service 9 CFR Parts 93, 94, and 95 RIN 0579-AC36 Highly Pathogenic Avian Influenza AGENCY: Animal... products from regions where any subtype of highly pathogenic avian influenza is considered to exist....

  5. Collision avoidance sensor skin

    NASA Technical Reports Server (NTRS)

    1991-01-01

    The objective was to totally eliminate the possibility of a robot (or any mechanism for that matter) inducing a collision in space operations. We were particularly concerned that human beings were safe under all circumstances. This was apparently accomplished, and it is shown that GSFC has a system that is ready for space qualification and flight. However, it soon became apparent that much more could be accomplished with this technology. Payloads could be made invulnerable to collision avoidance and the blind spots behind them eliminated. This could be accomplished by a simple, non-imaging set of 'Capaciflector' sensors on each payload. It also is evident that this system could be used to align and dock the system with a wide margin of safety. Throughout, lighting problems could be ignored, and unexpected events and modeling errors taken in stride. At the same time, computational requirements would be reduced. This can be done in a simple, rugged, reliable manner that will not disturb the form factor of space systems. It will be practical for space applications. The lab experiments indicate we are well on the way to accomplishing this. Still, the research trail goes deeper. It now appears that the sensors can be extended to end effectors to provide precontact information and make robot docking (or any docking connection) very smooth, with minimal loads impacted back into the mating structures. This type of ability would be a major step forward in basic control techniques in space. There are, however, baseline and restructuring issues to be tackled. The payloads must get power and signals to them from the robot or from the astronaut servicing tool. This requires a standard electromechanical interface. Any of several could be used. The GSFC prototype shown in this presentation is a good one. Sensors with their attendant electronics must be added to the payloads, end effectors, and robot arms and integrated into the system.

  6. Genetic Applications in Avian Conservation

    USGS Publications Warehouse

    Haig, Susan M.; Bronaugh, Whitcomb M.; Crowhurst, Rachel S.; D'Elia, Jesse; Eagles-Smith, Collin A.; Epps, Clinton W.; Knaus, Brian; Miller, Mark P.; Moses, Michael L.; Oyler-McCance, Sara; Robinson, W. Douglas; Sidlauskas, Brian

    2011-01-01

    A fundamental need in conserving species and their habitats is defining distinct entities that range from individuals to species to ecosystems and beyond (Table 1; Ryder 1986, Moritz 1994, Mayden and Wood 1995, Haig and Avise 1996, Hazevoet 1996, Palumbi and Cipriano 1998, Hebert et al. 2004, Mace 2004, Wheeler et al. 2004, Armstrong and Ball 2005, Baker 2008, Ellis et al. 2010, Winker and Haig 2010). Rapid progression in this interdisciplinary field continues at an exponential rate; thus, periodic updates on theory, techniques, and applications are important for informing practitioners and consumers of genetic information. Here, we outline conservation topics for which genetic information can be helpful, provide examples of where genetic techniques have been used best in avian conservation, and point to current technical bottlenecks that prevent better use of genomics to resolve conservation issues related to birds. We hope this review will provide geneticists and avian ecologists with a mutually beneficial dialogue on how this integrated field can solve current and future problems.

  7. Identification of avian wax synthases

    PubMed Central

    2012-01-01

    Background Bird species show a high degree of variation in the composition of their preen gland waxes. For instance, galliform birds like chicken contain fatty acid esters of 2,3-alkanediols, while Anseriformes like goose or Strigiformes like barn owl contain wax monoesters in their preen gland secretions. The final biosynthetic step is catalyzed by wax synthases (WS) which have been identified in pro- and eukaryotic organisms. Results Sequence similarities enabled us to identify six cDNAs encoding putative wax synthesizing proteins in chicken and two from barn owl and goose. Expression studies in yeast under in vivo and in vitro conditions showed that three proteins from chicken performed WS activity while a sequence from chicken, goose and barn owl encoded a bifunctional enzyme catalyzing both wax ester and triacylglycerol synthesis. Mono- and bifunctional WS were found to differ in their substrate specificities especially with regard to branched-chain alcohols and acyl-CoA thioesters. According to the expression patterns of their transcripts and the properties of the enzymes, avian WS proteins might not be confined to preen glands. Conclusions We provide direct evidence that avian preen glands possess both monofunctional and bifunctional WS proteins which have different expression patterns and WS activities with different substrate specificities. PMID:22305293

  8. Avian botulism and avian chlamydiosis in wild water birds, Benton Lake National Wildlife Refuge, Montana, USA.

    PubMed

    Docherty, Douglas E; Franson, J Christian; Brannian, Roger E; Long, Renee R; Radi, Craig A; Krueger, David; Johnson, Robert F

    2012-12-01

    In 1999, the U.S. Geological Survey (USGS) National Wildlife Health Center, Madison, Wisconsin, conducted a diagnostic investigation into a water bird mortality event involving intoxication with avian botulism type C and infection with avian chlamydiosis at the Benton Lake National Wildlife Refuge in Montana, USA. Of 24 carcasses necropsied, 11 had lesions consistent with avian chlamydiosis, including two that tested positive for infectious Chlamydophila psittaci, and 12 were positive for avian botulism type C. One bird tested positive for both avian botulism type C and C. psittaci. Of 61 apparently healthy water birds sampled and released, 13 had serologic evidence of C. psittaci infection and 7 were, at the time of capture, shedding infectious C. psittaci via the cloacal or oropharyngeal route. Since more routinely diagnosed disease conditions may mask avian chlamydiosis, these findings support the need for a comprehensive diagnostic investigation when determining the cause of a wildlife mortality event.

  9. Avian botulism and avian chlamydiosis in wild water birds, Benton Lake National Wildlife Refuge, Montana, USA

    USGS Publications Warehouse

    Docherty, Douglas E.; Franson, J. Christian; Brannian, Roger E.; Long, Renee R.; Radi, Craig A.; Krueger, David; Johnson, Robert F.

    2012-01-01

    In 1999, the U.S. Geological Survey (USGS) National Wildlife Health Center, Madison, Wisconsin, conducted a diagnostic investigation into a water bird mortality event involving intoxication with avian botulism type C and infection with avian chlamydiosis at the Benton Lake National Wildlife Refuge in Montana, USA. Of 24 carcasses necropsied, 11 had lesions consistent with avian chlamydiosis, including two that tested positive for infectious Chlamydophila psittaci, and 12 were positive for avian botulism type C. One bird tested positive for both avian botulism type C and C. psittaci. Of 61 apparently healthy water birds sampled and released, 13 had serologic evidence of C. psittaci infection and 7 were, at the time of capture, shedding infectious C. psittaci via the cloacal or oropharyngeal route. Since more routinely diagnosed disease conditions may mask avian chlamydiosis, these findings support the need for a comprehensive diagnostic investigation when determining the cause of a wildlife mortality event.

  10. Stimulus conflict triggers behavioral avoidance.

    PubMed

    Dignath, David; Eder, Andreas B

    2015-12-01

    According to a recent extension of the conflict-monitoring theory, conflict between two competing response tendencies is registered as an aversive event and triggers a motivation to avoid the source of conflict. In the present study, we tested this assumption. Over five experiments, we examined whether conflict is associated with an avoidance motivation and whether stimulus conflict or response conflict triggers an avoidance tendency. Participants first performed a color Stroop task. In a subsequent motivation test, participants responded to Stroop stimuli with approach- and avoidance-related lever movements. These results showed that Stroop-conflict stimuli increased the frequency of avoidance responses in a free-choice motivation test, and also increased the speed of avoidance relative to approach responses in a forced-choice test. High and low proportions of response conflict in the Stroop task had no effect on avoidance in the motivation test. Avoidance of conflict was, however, obtained even with new conflict stimuli that had not been presented before in a Stroop task, and when the Stroop task was replaced with an unrelated filler task. Taken together, these results suggest that stimulus conflict is sufficient to trigger avoidance.

  11. Healthcare avoidance: a critical review.

    PubMed

    Byrne, Sharon K

    2008-01-01

    The purpose of this study is to provide a critical review and synthesis of theoretical and research literature documenting the impact of avoidance on healthcare behaviors, identify the factors that influence healthcare avoidance and delay in the adult population, and propose a direction for future research. The Theory of Reasoned Action, Theory of Planned Behavior, Theory of Care-Seeking Behavior, the Transtheoretical Model, and the Behavioral Model of Health Services Use/Utilization are utilized to elaborate on the context within which individual intention to engage in healthcare behaviors occurs. Research literature on the concept of healthcare avoidance obtained by using computerized searches of CINAHL, MEDLINE, PSYCH INFO, and HAPI databases, from 1995 to 2007, were reviewed. Studies were organized by professional disciplines. Healthcare avoidance is a common and highly variable experience. Multiple administrative, demographic, personal, and provider factors are related to healthcare avoidance, for example, distrust of providers and/or the science community, health beliefs, insurance status, or socioeconomic/income level. Although the concept is recognized by multiple disciplines, limited research studies address its impact on healthcare decision making. More systematic research is needed to determine correlates of healthcare avoidance. Such studies will help investigators identify patients at risk for avoidant behaviors and provide the basis for health-promoting interventions. Methodological challenges include identification of characteristics of individuals and environments that hinder healthcare behaviors, as well as, the complexity of measuring healthcare avoidance. Studies need to systematically explore the influence of avoidance behaviors on specific healthcare populations at risk.

  12. Stimulus conflict triggers behavioral avoidance.

    PubMed

    Dignath, David; Eder, Andreas B

    2015-12-01

    According to a recent extension of the conflict-monitoring theory, conflict between two competing response tendencies is registered as an aversive event and triggers a motivation to avoid the source of conflict. In the present study, we tested this assumption. Over five experiments, we examined whether conflict is associated with an avoidance motivation and whether stimulus conflict or response conflict triggers an avoidance tendency. Participants first performed a color Stroop task. In a subsequent motivation test, participants responded to Stroop stimuli with approach- and avoidance-related lever movements. These results showed that Stroop-conflict stimuli increased the frequency of avoidance responses in a free-choice motivation test, and also increased the speed of avoidance relative to approach responses in a forced-choice test. High and low proportions of response conflict in the Stroop task had no effect on avoidance in the motivation test. Avoidance of conflict was, however, obtained even with new conflict stimuli that had not been presented before in a Stroop task, and when the Stroop task was replaced with an unrelated filler task. Taken together, these results suggest that stimulus conflict is sufficient to trigger avoidance. PMID:25931151

  13. Healthcare avoidance: a critical review.

    PubMed

    Byrne, Sharon K

    2008-01-01

    The purpose of this study is to provide a critical review and synthesis of theoretical and research literature documenting the impact of avoidance on healthcare behaviors, identify the factors that influence healthcare avoidance and delay in the adult population, and propose a direction for future research. The Theory of Reasoned Action, Theory of Planned Behavior, Theory of Care-Seeking Behavior, the Transtheoretical Model, and the Behavioral Model of Health Services Use/Utilization are utilized to elaborate on the context within which individual intention to engage in healthcare behaviors occurs. Research literature on the concept of healthcare avoidance obtained by using computerized searches of CINAHL, MEDLINE, PSYCH INFO, and HAPI databases, from 1995 to 2007, were reviewed. Studies were organized by professional disciplines. Healthcare avoidance is a common and highly variable experience. Multiple administrative, demographic, personal, and provider factors are related to healthcare avoidance, for example, distrust of providers and/or the science community, health beliefs, insurance status, or socioeconomic/income level. Although the concept is recognized by multiple disciplines, limited research studies address its impact on healthcare decision making. More systematic research is needed to determine correlates of healthcare avoidance. Such studies will help investigators identify patients at risk for avoidant behaviors and provide the basis for health-promoting interventions. Methodological challenges include identification of characteristics of individuals and environments that hinder healthcare behaviors, as well as, the complexity of measuring healthcare avoidance. Studies need to systematically explore the influence of avoidance behaviors on specific healthcare populations at risk. PMID:18758277

  14. Emerging and reemerging diseases of avian wildlife

    USGS Publications Warehouse

    Pello, Susan J.; Olsen, Glenn H.

    2013-01-01

    Of the many important avian wildlife diseases, aspergillosis, West Nile virus, avipoxvirus, Wellfleet Bay virus, avian influenza, and inclusion body disease of cranes are covered in this article. Wellfleet Bay virus, first identified in 2010, is considered an emerging disease. Avian influenza and West Nile virus have recently been in the public eye because of their zoonotic potential and links to wildlife. Several diseases labeled as reemerging are included because of recent outbreaks or, more importantly, recent research in areas such as genomics, which shed light on the mechanisms whereby these adaptable, persistent pathogens continue to spread and thrive.

  15. Emerging and reemerging diseases of avian wildlife.

    PubMed

    Pello, Susan J; Olsen, Glenn H

    2013-05-01

    Of the many important avian wildlife diseases, aspergillosis, West Nile virus, avipoxvirus, Wellfleet Bay virus, avian influenza, and inclusion body disease of cranes are covered in this article. Wellfleet Bay virus, first identified in 2010, is considered an emerging disease. Avian influenza and West Nile virus have recently been in the public eye because of their zoonotic potential and links to wildlife. Several diseases labeled as reemerging are included because of recent outbreaks or, more importantly, recent research in areas such as genomics, which shed light on the mechanisms whereby these adaptable, persistent pathogens continue to spread and thrive. PMID:23642867

  16. The evolution of avian wing shape and previously unrecognized trends in covert feathering

    PubMed Central

    Wang, Xia; Clarke, Julia A.

    2015-01-01

    Avian wing shape has been related to flight performance, migration, foraging behaviour and display. Historically, linear measurements of the feathered aerofoil and skeletal proportions have been used to describe this shape. While the distribution of covert feathers, layered over the anterior wing, has long been assumed to contribute to aerofoil properties, to our knowledge no previous studies of trends in avian wing shape assessed their variation. Here, these trends are explored using a geometric–morphometric approach with landmarks describing the wing outline as well as the extent of dorsal and ventral covert feathers for 105 avian species. We find that most of the observed variation is explained by phylogeny and ecology but shows only a weak relationship with previously described flight style categories, wing loading and an investigated set of aerodynamic variables. Most of the recovered variation is in greater primary covert feather extent, followed by secondary feather length and the shape of the wing tip. Although often considered a plastic character strongly linked to flight style, the estimated ancestral wing morphology is found to be generally conservative among basal parts of most major avian lineages. The radiation of birds is characterized by successive diversification into largely distinct areas of morphospace. However, aquatic taxa show convergence in feathering despite differences in flight style, and songbirds move into a region of morphospace also occupied by basal taxa but at markedly different body sizes. These results have implications for the proposed inference of flight style in extinct taxa. PMID:26446812

  17. Mixed species flock, nest height, and elevation partially explain avian haemoparasite prevalence in Colombia.

    PubMed

    González, Angie D; Matta, Nubia E; Ellis, Vincenzo A; Miller, Eliot T; Ricklefs, Robert E; Gutiérrez, H Rafael

    2014-01-01

    The high avian biodiversity present in the Neotropical region offers a great opportunity to explore the ecology of host-parasite relationships. We present a survey of avian haemoparasites in a megadiverse country and explore how parasite prevalences are related to physical and ecological host characteristics. Using light microscopy, we documented the presence of haemoparasites in over 2000 individuals belonging to 246 species of wild birds, from nine localities and several ecosystems of Colombia. We analysed the prevalence of six avian haemoparasite taxa in relation to elevation and the following host traits: nest height, nest type, foraging strata, primary diet, sociality, migratory behaviour, and participation in mixed species flocks. Our analyses indicate significant associations between both mixed species flocks and nest height and Haemoproteus and Leucocytozoon prevalence. The prevalence of Leucocytozoon increased with elevation, whereas the prevalence of Trypanosoma and microfilariae decreased. Plasmodium and Haemoproteus prevalence did not vary significantly with elevation; in fact, both parasites were found up to 3300 m above sea level. The distribution of parasite prevalence across the phylogeny of bird species included in this study showed little host phylogenetic signal indicating that infection rates in this system are evolutionarily labile. Vector distribution as well as the biology of transmission and the maintenance of populations of avian haemoparasites deserve more detailed study in this system.

  18. Mixed Species Flock, Nest Height, and Elevation Partially Explain Avian Haemoparasite Prevalence in Colombia

    PubMed Central

    González, Angie D.; Matta, Nubia E.; Ellis, Vincenzo A.; Miller, Eliot T.; Ricklefs, Robert E.; Gutiérrez, H. Rafael

    2014-01-01

    The high avian biodiversity present in the Neotropical region offers a great opportunity to explore the ecology of host-parasite relationships. We present a survey of avian haemoparasites in a megadiverse country and explore how parasite prevalences are related to physical and ecological host characteristics. Using light microscopy, we documented the presence of haemoparasites in over 2000 individuals belonging to 246 species of wild birds, from nine localities and several ecosystems of Colombia. We analysed the prevalence of six avian haemoparasite taxa in relation to elevation and the following host traits: nest height, nest type, foraging strata, primary diet, sociality, migratory behaviour, and participation in mixed species flocks. Our analyses indicate significant associations between both mixed species flocks and nest height and Haemoproteus and Leucocytozoon prevalence. The prevalence of Leucocytozoon increased with elevation, whereas the prevalence of Trypanosoma and microfilariae decreased. Plasmodium and Haemoproteus prevalence did not vary significantly with elevation; in fact, both parasites were found up to 3300m above sea level. The distribution of parasite prevalence across the phylogeny of bird species included in this study showed little host phylogenetic signal indicating that infection rates in this system are evolutionarily labile. Vector distribution as well as the biology of transmission and the maintenance of populations of avian haemoparasites deserve more detailed study in this system. PMID:24950223

  19. Chemical avoidance responses of fishes.

    PubMed

    Tierney, Keith B

    2016-05-01

    The hydrosphere is a repository for all of our waste and mistakes, be they sewage, garbage, process-affected waters, runoff, and gases. For fish living in environments receiving undesirable inputs, moving away seems an obvious way to avoid harm. While this should occur, there are numerous examples where it will not. The inability to avoid harmful environments may lead to sensory impairments that in turn limit the ability to avoid other dangers or locate benefits. For avoidance to occur, the danger must first be perceived, which may not happen if the fish is 'blinded' in some capacity. Second, the danger must be recognized for what it is, which may also not happen if the fish is cognitively confused or impaired. Third, it is possible that the fish may not be able to leave the area, or worse, learns to prefer a toxic environment. Concerning generating regulations around avoidance, there are two possibilities: that an avoidance threshold be used to set guidelines for effluent release with the intention of driving fishes away; the second is to set a contaminant concentration that would not affect the avoidance or attraction responses to other cues. With the complexities of the modern world in which we release diverse pollutants, from light to municipal effluents full of 1000s of chemicals, to the diversity present in ecosystems, it is impossible to have avoidance data on every stimulus-species combination. Nevertheless, we may be able to use existing avoidance response data to predict the likelihood of avoidance of untested stimuli. Where we cannot, this review includes a framework that can be used to direct new research. This review is intended to collate existing avoidance response data, provide a framework for making decisions in the absence of data, and suggest studies that would facilitate the prediction of risk to fish health in environments receiving intentional and unintentional human-based chemical inputs.

  20. Chemical avoidance responses of fishes.

    PubMed

    Tierney, Keith B

    2016-05-01

    The hydrosphere is a repository for all of our waste and mistakes, be they sewage, garbage, process-affected waters, runoff, and gases. For fish living in environments receiving undesirable inputs, moving away seems an obvious way to avoid harm. While this should occur, there are numerous examples where it will not. The inability to avoid harmful environments may lead to sensory impairments that in turn limit the ability to avoid other dangers or locate benefits. For avoidance to occur, the danger must first be perceived, which may not happen if the fish is 'blinded' in some capacity. Second, the danger must be recognized for what it is, which may also not happen if the fish is cognitively confused or impaired. Third, it is possible that the fish may not be able to leave the area, or worse, learns to prefer a toxic environment. Concerning generating regulations around avoidance, there are two possibilities: that an avoidance threshold be used to set guidelines for effluent release with the intention of driving fishes away; the second is to set a contaminant concentration that would not affect the avoidance or attraction responses to other cues. With the complexities of the modern world in which we release diverse pollutants, from light to municipal effluents full of 1000s of chemicals, to the diversity present in ecosystems, it is impossible to have avoidance data on every stimulus-species combination. Nevertheless, we may be able to use existing avoidance response data to predict the likelihood of avoidance of untested stimuli. Where we cannot, this review includes a framework that can be used to direct new research. This review is intended to collate existing avoidance response data, provide a framework for making decisions in the absence of data, and suggest studies that would facilitate the prediction of risk to fish health in environments receiving intentional and unintentional human-based chemical inputs. PMID:26970365

  1. Speed kills: ineffective avian escape responses to oncoming vehicles.

    PubMed

    DeVault, Travis L; Blackwell, Bradley F; Seamans, Thomas W; Lima, Steven L; Fernández-Juricic, Esteban

    2015-02-22

    Animal-vehicle collisions cause high levels of vertebrate mortality worldwide, and what goes wrong when animals fail to escape and ultimately collide with vehicles is not well understood. We investigated alert and escape behaviours of captive brown-headed cowbirds (Molothrus ater) in response to virtual vehicle approaches of different sizes and at speeds ranging from 60 to 360 km h(-1). Alert and flight initiation distances remained similar across vehicle speeds, and accordingly, alert and flight initiation times decreased at higher vehicle speeds. Thus, avoidance behaviours in cowbirds appeared to be based on distance rather than time available for escape, particularly at 60-150 km h(-1); however, at higher speeds (more than or equal to 180 km h(-1)) no trend in response behaviour was discernible. As vehicle speed increased, cowbirds did not have enough time to assess the approaching vehicle, and cowbirds generally did not initiate flight with enough time to avoid collision when vehicle speed exceeded 120 km h(-1). Although potentially effective for evading predators, the decision-making process used by cowbirds in our study appears maladaptive in the context of avoiding fast-moving vehicles. Our methodological approach and findings provide a framework to assess how novel management strategies could affect escape rules, and the sensory and cognitive abilities animals use to avoid vehicle collisions.

  2. Speed kills: ineffective avian escape responses to oncoming vehicles

    PubMed Central

    DeVault, Travis L.; Blackwell, Bradley F.; Seamans, Thomas W.; Lima, Steven L.; Fernández-Juricic, Esteban

    2015-01-01

    Animal–vehicle collisions cause high levels of vertebrate mortality worldwide, and what goes wrong when animals fail to escape and ultimately collide with vehicles is not well understood. We investigated alert and escape behaviours of captive brown-headed cowbirds (Molothrus ater) in response to virtual vehicle approaches of different sizes and at speeds ranging from 60 to 360 km h−1. Alert and flight initiation distances remained similar across vehicle speeds, and accordingly, alert and flight initiation times decreased at higher vehicle speeds. Thus, avoidance behaviours in cowbirds appeared to be based on distance rather than time available for escape, particularly at 60–150 km h−1; however, at higher speeds (more than or equal to 180 km h−1) no trend in response behaviour was discernible. As vehicle speed increased, cowbirds did not have enough time to assess the approaching vehicle, and cowbirds generally did not initiate flight with enough time to avoid collision when vehicle speed exceeded 120 km h−1. Although potentially effective for evading predators, the decision-making process used by cowbirds in our study appears maladaptive in the context of avoiding fast-moving vehicles. Our methodological approach and findings provide a framework to assess how novel management strategies could affect escape rules, and the sensory and cognitive abilities animals use to avoid vehicle collisions. PMID:25567648

  3. Cigarette tax avoidance and evasion.

    PubMed

    Stehr, Mark

    2005-03-01

    Variation in state cigarette taxes provides incentives for tax avoidance through smuggling, legal border crossing to low tax jurisdictions, or Internet purchasing. When taxes rise, tax paid sales of cigarettes will decline both because consumption will decrease and because tax avoidance will increase. The key innovation of this paper is to compare cigarette sales data to cigarette consumption data from the Behavioral Risk Factor Surveillance System (BRFSS). I show that after subtracting percent changes in consumption, residual percent changes in sales are associated with state cigarette tax changes implying the existence of tax avoidance. I estimate that the tax avoidance response to tax changes is at least twice the consumption response and that tax avoidance accounted for up to 9.6% of sales between 1985 and 2001. Because of the increase in tax avoidance, tax paid sales data understate the level of smoking and overstate the drop in smoking. I also find that the level of legal border crossing was very low relative to other forms of tax avoidance. If states have strong preferences for smoking control, they must pair high cigarette taxes with effective policies to curb smuggling and other forms of tax avoidance or employ alternative policies such as counter-advertising and smoking restrictions. PMID:15721046

  4. Urban behavioural adaptation.

    PubMed

    Garroway, Colin J; Sheldon, Ben C

    2013-07-01

    A large and growing proportion of the world is impacted directly by human activities; among the most extreme of these is the spread of urban environments. Environmental change associated with urbanization represents a potentially potent source of selection. While urban environments generally have lowered biodiversity, some clades seem to thrive in urban settings. For example, many members of the bird family Turdidae, known as the ‘truethrushes’ and the blackbird Turdus merula (Fig. 1) in particular, are familiar urban species. Indeed, the colonization of urban environments by blackbirds has become a textbook case study for our understanding of the many ways a wild species can deal with urbanization. In this issue, Mueller et al. (Molecular Ecology, 00, 2013, 00) add to that story by beginning to address the genetic nature of behavioural adaptation of blackbirds colonizing urban areas. They do this by testing for divergence between paired urban and rural samples at a suite of candidate genes with hypothesized effects on behaviours thought to be important for the colonization of urban environments.They find evidence for consistent patterns of divergence at an exonic microsatellite associated with the SERT gene. SERT has a number of hypothesized behavioural effects, including harm avoidance, which may be associated with tolerating the hustle and bustle of urban environments. This is among the first evidence that behavioural differences between urban and rural environments have a genetic basis and this work suggests that urban environments can in some cases exert homogeneous selection pressures. PMID:23967452

  5. Immunizing Canada geese against avian cholera

    USGS Publications Warehouse

    Price, J.I.

    1985-01-01

    A small flock of captive giant Canada geese were vaccinated with the experimental bac- terin in Nebraska to test its efficacy under field conditions. Only 2 of 157 vaccinates died from avian cholera during an annual spring die-off.

  6. Are wetlands the reservoir for avian cholera?

    USGS Publications Warehouse

    Samuel, M.D.; Shadduck, D.J.; Goldberg, D.R.

    2004-01-01

    Wetlands have long been suspected to be an important reservoir for Pasteurella multocida and therefore the likely source of avian cholera outbreaks. During the fall of 1995a??98 we collected sediment and water samples from 44 wetlands where avian cholera epizootics occurred the previous winter or spring. We attempted to isolate P. multocida in sediment and surface water samples from 10 locations distributed throughout each wetland. We were not able to isolate P. multocida from any of the 440 water and 440 sediment samples collected from these wetlands. In contrast, during other investigations of avian cholera we isolated P. multocida from 20 of 44 wetlands, including 7% of the water and 4.5% of the sediment samples collected during or shortly following epizootic events. Our results indicate that wetlands are an unlikely reservoir for the bacteria that causes avian cholera.

  7. Germline Modification and Engineering in Avian Species.

    PubMed

    Lee, Hong Jo; Lee, Hyung Chul; Han, Jae Yong

    2015-09-01

    Production of genome-edited animals using germline-competent cells and genetic modification tools has provided opportunities for investigation of biological mechanisms in various organisms. The recently reported programmed genome editing technology that can induce gene modification at a target locus in an efficient and precise manner facilitates establishment of animal models. In this regard, the demand for genome-edited avian species, which are some of the most suitable model animals due to their unique embryonic development, has also increased. Furthermore, germline chimera production through long-term culture of chicken primordial germ cells (PGCs) has facilitated research on production of genome-edited chickens. Thus, use of avian germline modification is promising for development of novel avian models for research of disease control and various biological mechanisms. Here, we discuss recent progress in genome modification technology in avian species and its applications and future strategies. PMID:26333275

  8. Seasonal biology: avian photoreception goes deep.

    PubMed

    Wyse, Cathy; Hazlerigg, David

    2009-08-25

    The avian hypothalamus senses light directly, allowing endocrine physiology to synchronise to seasonal day-length changes. New data implicate the photopigment VA-opsin in this deep brain photoreception. PMID:19706275

  9. Avian Models in Teratology and Developmental Toxicology

    PubMed Central

    Smith, Susan M.; Flentke, George R.; Garic, Ana

    2015-01-01

    The avian embryo is a long-standing model for developmental biology research. It also has proven utility for toxicology research both in ovo and in explant culture. Like mammals, avian embryos have an allantois and their developmental pathways are highly conserved with those of mammals, thus avian models have biomedical relevance. Fertile eggs are inexpensive and the embryo develops rapidly, allowing for high throughput. The chick genome is sequenced and significant molecular resources are available for study including the ability for genetic manipulation. The absence of a placenta permits the direct study of an agent’s embryotoxic effects. Here we present protocols for using avian embryos in toxicology research including egg husbandry and hatch, toxicant delivery, and assessment of proliferation, apoptosis, and cardiac structure and function. PMID:22669661

  10. Avian models in teratology and developmental toxicology.

    PubMed

    Smith, Susan M; Flentke, George R; Garic, Ana

    2012-01-01

    The avian embryo is a long-standing model for developmental biology research. It also has proven utility for toxicology research both in ovo and in explant culture. Like mammals, avian embryos have an allantois and their developmental pathways are highly conserved with those of mammals, thus avian models have biomedical relevance. Fertile eggs are inexpensive and the embryo develops rapidly, allowing for high-throughput. The chick genome is sequenced and significant molecular resources are available for study, including the ability for genetic manipulation. The absence of a placenta permits the direct study of an agent's embryotoxic effects. Here, we present protocols for using avian embryos in toxicology research, including egg husbandry and hatch, toxicant delivery, and assessment of proliferation, apoptosis, and cardiac structure and function.

  11. Germline Modification and Engineering in Avian Species

    PubMed Central

    Lee, Hong Jo; Lee, Hyung Chul; Han, Jae Yong

    2015-01-01

    Production of genome-edited animals using germline-competent cells and genetic modification tools has provided opportunities for investigation of biological mechanisms in various organisms. The recently reported programmed genome editing technology that can induce gene modification at a target locus in an efficient and precise manner facilitates establishment of animal models. In this regard, the demand for genome-edited avian species, which are some of the most suitable model animals due to their unique embryonic development, has also increased. Furthermore, germline chimera production through long-term culture of chicken primordial germ cells (PGCs) has facilitated research on production of genome-edited chickens. Thus, use of avian germline modification is promising for development of novel avian models for research of disease control and various biological mechanisms. Here, we discuss recent progress in genome modification technology in avian species and its applications and future strategies. PMID:26333275

  12. Overview of the U.S. Department of Energy/National Renewable Energy Laboratory avian research program

    SciTech Connect

    Sinclair, K.C.; Morrison, M.L.

    1997-06-01

    As wind energy use continues to expand, concern over the possible impacts of wind farms on birds continues to be an issue. The concern includes two primary areas: the effect of avian mortality on bird populations, and possible litigation over the killing of even one bird if it is protected by the Migratory Bird Treaty Act or the Endangered Species Act or both. In order to address these concerns, the US Department of Energy (DOE) and the National Renewable Energy Laboratory (NREL), working collaboratively with all stakeholders including utilities, environmental groups, consumer advocates, utility regulators, government officials, and the wind industry, has an active avian-wind power research program. DOE/NREL is conducting and sponsoring research with the expectation of developing solutions to educe or avoid avian mortality due to wind energy development throughout the US. This paper outlines the DOE/NREL approach and summarizes completed, current, and planned projects.

  13. A review of avian probiotics.

    PubMed

    Smith, Jeanne Marie

    2014-06-01

    Probiotics have been used in poultry for decades and have become common in the pet bird industry. Desirable characteristics of probiotic organisms are that they are nonpathogenic, have the ability to adhere to intestinal epithelial cells, have the ability to colonize and reproduce in the host, have the ability to be host-specific, survive transit through the gastrointestinal tract and exposure to stomach acid and bile, produce metabolites that inhibit or kill pathogenic bacteria, modulate gastrointestinal immune responses, and survive processing and storage. Purported benefits in birds are disease prevention and promotion of growth. Recommendations for use in avian species are for periodic use to replenish normal flora, use after antibiotic therapy to reestablish normal flora, and use during periods of stress to counter effects of immunosuppression. PMID:25115036

  14. Avian influenza: an emerging pandemic threat.

    PubMed

    Jin, Xian Wen; Mossad, Sherif B

    2005-12-01

    While we are facing the threat of an emerging pandemic from the current avian flu outbreak in Asia, we have learned important traits of the virus responsible for the 1918 Spanish influenza pandemic that made it so deadly. By using stockpiled antiviral drugs effectively and developing an effective vaccine, we can be in a better position than ever to mitigate the global impact of an avian influenza pandemic. PMID:16392727

  15. Avian study protocols and wind energy development

    SciTech Connect

    Fisher, K.

    1995-12-01

    This paper identifies the need to develop and use standardized avian study protocols to determine avian impacts at new and existing wind energy facilities. This will allow data collected from various sites to be correlated for better understanding wind energy related avian impacts. Factors contributing to an increased interest in wind energy facilities by electric utilities include: (1) Increased demand for electricity;(2) increased constraints on traditional electrical generating facilities (i.e. hydroelectric and nuclear power plants);(3) improved wind turbine technology. During the 1980`s generous tax credits spawned the development of wind energy facilities, known as wind farms, in California. Commercial scale wind farm proposals are being actively considered in states across the country - Washington, Oregon, Wyoming, Wisconsin, Texas, and Vermont to name a few. From the wind farms in California the unexpected issue of avian impacts, especially to birds-of-prey, or raptor, surfaced and continues to plague the wind industry. However, most of the avian studies did not followed a standardized protocol or methodology and, therefore, data is unavailable to analyze and compare impacts at different sites or with differing technologies and configurations. Effective mitigation can not be designed and applied until these differences are understood. The Bonneville Power Administration is using comparable avian study protocols to collect data for two environmental impact statements being prepared for two separate wind farm proposals. Similar protocol will be required for any other avian impact analysis performed by the agency on proposed or existing wind farms. The knowledge gained from these studies should contribute to a better understanding of avian interactions with wind energy facilities and the identification of effective mitigation measures.

  16. Report of the Avian Development Working Group

    NASA Technical Reports Server (NTRS)

    Fallon, J. F.

    1985-01-01

    The anteroposterior axis of the avian embryo is established before it is laid. Baer's rule states that the cephalic end of the avian embryo will be away from the observer when the pointed end of the shell is on the observer's right. There are experimental data available which indicate gravity has a role in the establishment of the anteroposterior axis while the egg is in the uterus; this results in Baer's rule. The influence of gravity on egg development is studied.

  17. Ecology and conservation biology of avian malaria.

    PubMed

    Lapointe, Dennis A; Atkinson, Carter T; Samuel, Michael D

    2012-02-01

    Avian malaria is a worldwide mosquito-borne disease caused by Plasmodium parasites. These parasites occur in many avian species but primarily affect passerine birds that have not evolved with the parasite. Host pathogenicity, fitness, and population impacts are poorly understood. In contrast to continental species, introduced avian malaria poses a substantial threat to naive birds on Hawaii, the Galapagos, and other archipelagoes. In Hawaii, transmission is maintained by susceptible native birds, competence and abundance of mosquitoes, and a disease reservoir of chronically infected native birds. Although vector habitat and avian communities determine the geographic distribution of disease, climate drives transmission patterns ranging from continuous high infection in warm lowland forests, seasonal infection in midelevation forests, and disease-free refugia in cool high-elevation forests. Global warming is expected to increase the occurrence, distribution, and intensity of avian malaria across this elevational gradient and threaten high-elevation refugia, which is the key to survival of many susceptible Hawaiian birds. Increased temperatures may have already increased global avian malaria prevalence and contributed to an emergence of disease in New Zealand. PMID:22320256

  18. Ecology and conservation biology of avian malaria.

    PubMed

    Lapointe, Dennis A; Atkinson, Carter T; Samuel, Michael D

    2012-02-01

    Avian malaria is a worldwide mosquito-borne disease caused by Plasmodium parasites. These parasites occur in many avian species but primarily affect passerine birds that have not evolved with the parasite. Host pathogenicity, fitness, and population impacts are poorly understood. In contrast to continental species, introduced avian malaria poses a substantial threat to naive birds on Hawaii, the Galapagos, and other archipelagoes. In Hawaii, transmission is maintained by susceptible native birds, competence and abundance of mosquitoes, and a disease reservoir of chronically infected native birds. Although vector habitat and avian communities determine the geographic distribution of disease, climate drives transmission patterns ranging from continuous high infection in warm lowland forests, seasonal infection in midelevation forests, and disease-free refugia in cool high-elevation forests. Global warming is expected to increase the occurrence, distribution, and intensity of avian malaria across this elevational gradient and threaten high-elevation refugia, which is the key to survival of many susceptible Hawaiian birds. Increased temperatures may have already increased global avian malaria prevalence and contributed to an emergence of disease in New Zealand.

  19. Ecology and conservation biology of avian malaria

    USGS Publications Warehouse

    LaPointe, Dennis A.; Atkinson, Carter T.; Samuel, Michael D.

    2012-01-01

    Avian malaria is a worldwide mosquito-borne disease caused by Plasmodium parasites. These parasites occur in many avian species but primarily affect passerine birds that have not evolved with the parasite. Host pathogenicity, fitness, and population impacts are poorly understood. In contrast to continental species, introduced avian malaria poses a substantial threat to naive birds on Hawaii, the Galapagos, and other archipelagoes. In Hawaii, transmission is maintained by susceptible native birds, competence and abundance of mosquitoes, and a disease reservoir of chronically infected native birds. Although vector habitat and avian communities determine the geographic distribution of disease, climate drives transmission patterns ranging from continuous high infection in warm lowland forests, seasonal infection in midelevation forests, and disease-free refugia in cool high-elevation forests. Global warming is expected to increase the occurrence, distribution, and intensity of avian malaria across this elevational gradient and threaten high-elevation refugia, which is the key to survival of many susceptible Hawaiian birds. Increased temperatures may have already increased global avian malaria prevalence and contributed to an emergence of disease in New Zealand.

  20. Postcopulatory inbreeding avoidance in guppies.

    PubMed

    Fitzpatrick, J L; Evans, J P

    2014-12-01

    In many species, the negative fitness effects of inbreeding have facilitated the evolution of a wide range of inbreeding avoidance mechanisms. Although avoidance mechanisms operating prior to mating are well documented, evidence for postcopulatory mechanisms of inbreeding avoidance remain scarce. Here, we examine the potential for paternity biases to favour unrelated males when their sperm compete for fertilizations though postcopulatory inbreeding avoidance mechanisms in the guppy, Poecilia reticulata. To test this possibility, we used a series of artificial inseminations to deliver an equal number of sperm from a related (either full sibling or half sibling) and unrelated male to a female while statistically controlling for differences in sperm quality between rival ejaculates. In this way, we were able to focus exclusively on postcopulatory mechanisms of inbreeding avoidance and account for differences in sperm competitiveness between rival males. Under these carefully controlled conditions, we report a significant bias in paternity towards unrelated males, although this effect was only apparent when the related male was a full sibling. We also show that sperm competition generally favours males with highly viable sperm and thus that some variance in sperm competitiveness can be attributed to difference in sperm quality. Our findings for postcopulatory inbreeding avoidance are consistent with prior work on guppies, revealing that sperm competition success declines linearly with the level of relatedness, but also that such effects are only apparent at relatedness levels of full siblings or higher. These findings reveal that postcopulatory processes alone can facilitate inbreeding avoidance.

  1. Postcopulatory inbreeding avoidance in guppies.

    PubMed

    Fitzpatrick, J L; Evans, J P

    2014-12-01

    In many species, the negative fitness effects of inbreeding have facilitated the evolution of a wide range of inbreeding avoidance mechanisms. Although avoidance mechanisms operating prior to mating are well documented, evidence for postcopulatory mechanisms of inbreeding avoidance remain scarce. Here, we examine the potential for paternity biases to favour unrelated males when their sperm compete for fertilizations though postcopulatory inbreeding avoidance mechanisms in the guppy, Poecilia reticulata. To test this possibility, we used a series of artificial inseminations to deliver an equal number of sperm from a related (either full sibling or half sibling) and unrelated male to a female while statistically controlling for differences in sperm quality between rival ejaculates. In this way, we were able to focus exclusively on postcopulatory mechanisms of inbreeding avoidance and account for differences in sperm competitiveness between rival males. Under these carefully controlled conditions, we report a significant bias in paternity towards unrelated males, although this effect was only apparent when the related male was a full sibling. We also show that sperm competition generally favours males with highly viable sperm and thus that some variance in sperm competitiveness can be attributed to difference in sperm quality. Our findings for postcopulatory inbreeding avoidance are consistent with prior work on guppies, revealing that sperm competition success declines linearly with the level of relatedness, but also that such effects are only apparent at relatedness levels of full siblings or higher. These findings reveal that postcopulatory processes alone can facilitate inbreeding avoidance. PMID:25387854

  2. Safe from harm: learned, instructed, and symbolic generalization pathways of human threat-avoidance.

    PubMed

    Dymond, Simon; Schlund, Michael W; Roche, Bryan; De Houwer, Jan; Freegard, Gary P

    2012-01-01

    Avoidance of threatening or unpleasant events is usually an adaptive behavioural strategy. Sometimes, however, avoidance can become chronic and lead to impaired daily functioning. Excessive threat-avoidance is a central diagnostic feature of anxiety disorders, yet little is known about whether avoidance acquired in the absence of a direct history of conditioning with a fearful event differs from directly learned avoidance. In the present study, we tested whether avoidance acquired indirectly via verbal instructions and symbolic generalization result in similar levels of avoidance behaviour and threat-beliefs to avoidance acquired after direct learning. Following fear conditioning in which one conditioned stimulus was paired with shock (CS+) and another was not (CS-), participants either learned or were instructed to make a response that cancelled impending shock. Three groups were then tested with a learned CS+ and CS- (learned group), instructed CS+ (instructed group), and generalized CS+ (derived group) presentations. Results showed similar levels of avoidance behaviour and threat-belief ratings about the likelihood of shock across each of the three pathways despite the different mechanisms by which they were acquired. Findings have implications for understanding the aetiology of clinical avoidance in anxiety. PMID:23077631

  3. Vertical jumping and signaled avoidance

    PubMed Central

    Cándido, Antonio; Maldonado, Antonio; Vila, Jaime

    1988-01-01

    This paper reports an experiment intended to demonstrate that the vertical jumping response can be learned using a signaled-avoidance technique. A photoelectric cell system was used to record the response. Twenty female rats, divided equally into two groups, were exposed to intertrial intervals of either 15 or 40 s. Subjects had to achieve three successive criteria of acquisition: 3, 5, and 10 consecutive avoidance responses. Results showed that both groups learned the avoidance response, requiring increasingly larger numbers of trials as the acquisition criteria increased. No significant effect of intertrial interval was observed. PMID:16812559

  4. Avian mothers create different phenotypes by hormone deposition in their eggs

    PubMed Central

    Eising, Corine M; Müller, Wendt; Groothuis, Ton G.G

    2005-01-01

    An increasing number of studies in a variety of taxa demonstrate the role of maternal sex steroids on offspring development. In avian species, mothers deposit substantial amounts of androgens in their eggs, and experimental evidence indicates that these maternal androgens influence the chick's early development. Despite the well-known organizing role of sex steroids on brain and behaviour, studies on avian maternal egg hormones almost exclusively focus on the chick phase. Here, we show experimentally that in Black-headed gulls maternal androgens in the egg enhance the development of the nuptial plumage and the frequency of aggressive and sexual displays almost 1 year after hatching. We conclude that maternal sex steroids may be a key factor for the determination of subtle but important individual differences within the same sex and species, which may have important consequences for Darwinian fitness and evolutionary processes. PMID:17148315

  5. Food avoidance in athletes: FODMAP foods on the list.

    PubMed

    Lis, Dana; Ahuja, Kiran D K; Stellingwerff, Trent; Kitic, Cecilia M; Fell, James

    2016-09-01

    We surveyed 910 athletes to assess behaviours towards self-selected food/ingredient avoidance to minimize gastrointestinal distress. Fifty-five percent eliminated at least 1 high fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAP) food/category, with up to 82.6% reporting symptom improvement. In athletes indicating that high FODMAP foods trigger gastrointestinal symptoms, lactose (86.5%) was most frequently eliminated, followed by galactooligosaccharides (23.9%), fructose (23.0%), fructans (6.2%), and polyols (5.4%). Athletes avoid predominantly lactose and to a lesser extent other high FODMAP foods to reduce gastrointestinal distress. PMID:27507006

  6. Vision-based obstacle avoidance

    DOEpatents

    Galbraith, John

    2006-07-18

    A method for allowing a robot to avoid objects along a programmed path: first, a field of view for an electronic imager of the robot is established along a path where the electronic imager obtains the object location information within the field of view; second, a population coded control signal is then derived from the object location information and is transmitted to the robot; finally, the robot then responds to the control signal and avoids the detected object.

  7. Using avian radar to examine relationships among avian activity, bird strikes, and meteorological factors

    USGS Publications Warehouse

    Coates, Peter S.; Casazza, Michael L.; Halstead, Brian J.; Fleskes, Joseph P.; Laughlin, James A.

    2011-01-01

    Radar systems designed to detect avian activity at airfields are useful in understanding factors that influence the risk of bird and aircraft collisions (bird strikes). We used an avian radar system to measure avian activity at Beale Air Force Base, California, USA, during 2008 and 2009. We conducted a 2-part analysis to examine relationships among avian activity, bird strikes, and meteorological and time-dependent factors. We found that avian activity around the airfield was greater at times when bird strikes occurred than on average using a permutation resampling technique. Second, we developed generalized linear mixed models of an avian activity index (AAI). Variation in AAI was first explained by seasons that were based on average migration dates of birds at the study area. We then modeled AAI by those seasons to further explain variation by meteorological factors and daily light levels within a 24-hour period. In general, avian activity increased with decreased temperature, wind, visibility, precipitation, and increased humidity and cloud cover. These effects differed by season. For example, during the spring bird migration period, most avian activity occurred before sunrise at twilight hours on clear days with low winds, whereas during fall migration, substantial activity occurred after sunrise, and birds generally were more active at lower temperatures. We report parameter estimates (i.e., constants and coefficients) averaged across models and a relatively simple calculation for safety officers and wildlife managers to predict AAI and the relative risk of bird strike based on time, date, and meteorological values. We validated model predictability and assessed model fit. These analyses will be useful for general inference of avian activity and risk assessment efforts. Further investigation and ongoing data collection will refine these inference models and improve our understanding of factors that influence avian activity, which is necessary to inform

  8. Predator Avoidance in Extremophile Fish

    PubMed Central

    Bierbach, David; Schulte, Matthias; Herrmann, Nina; Zimmer, Claudia; Arias-Rodriguez, Lenin; Indy, Jeane Rimber; Riesch, Rüdiger; Plath, Martin

    2013-01-01

    Extreme habitats are often characterized by reduced predation pressures, thus representing refuges for the inhabiting species. The present study was designed to investigate predator avoidance of extremophile populations of Poecilia mexicana and P. sulphuraria that either live in hydrogen sulfide-rich (sulfidic) springs or cave habitats, both of which are known to have impoverished piscine predator regimes. Focal fishes that inhabited sulfidic springs showed slightly weaker avoidance reactions when presented with several naturally occurring predatory cichlids, but strongest differences to populations from non-sulfidic habitats were found in a decreased shoaling tendency with non-predatory swordtail (Xiphophorus hellerii) females. When comparing avoidance reactions between P. mexicana from a sulfidic cave (Cueva del Azufre) and the adjacent sulfidic surface creek (El Azufre), we found only slight differences in predator avoidance, but surface fish reacted much more strongly to the non-predatory cichlid Vieja bifasciata. Our third experiment was designed to disentangle learned from innate effects of predator recognition. We compared laboratory-reared (i.e., predator-naïve) and wild-caught (i.e., predator-experienced) individuals of P. mexicana from a non-sulfidic river and found no differences in their reaction towards the presented predators. Overall, our results indicate (1) that predator avoidance is still functional in extremophile Poecilia spp. and (2) that predator recognition and avoidance reactions have a strong genetic basis. PMID:25371337

  9. Predator avoidance in extremophile fish.

    PubMed

    Bierbach, David; Schulte, Matthias; Herrmann, Nina; Zimmer, Claudia; Arias-Rodriguez, Lenin; Indy, Jeane Rimber; Riesch, Rüdiger; Plath, Martin

    2013-01-01

    Extreme habitats are often characterized by reduced predation pressures, thus representing refuges for the inhabiting species. The present study was designed to investigate predator avoidance of extremophile populations of Poecilia mexicana and P. sulphuraria that either live in hydrogen sulfide-rich (sulfidic) springs or cave habitats, both of which are known to have impoverished piscine predator regimes. Focal fishes that inhabited sulfidic springs showed slightly weaker avoidance reactions when presented with several naturally occurring predatory cichlids, but strongest differences to populations from non-sulfidic habitats were found in a decreased shoaling tendency with non-predatory swordtail (Xiphophorus hellerii) females. When comparing avoidance reactions between P. mexicana from a sulfidic cave (Cueva del Azufre) and the adjacent sulfidic surface creek (El Azufre), we found only slight differences in predator avoidance, but surface fish reacted much more strongly to the non-predatory cichlid Vieja bifasciata. Our third experiment was designed to disentangle learned from innate effects of predator recognition. We compared laboratory-reared (i.e., predator-naïve) and wild-caught (i.e., predator-experienced) individuals of P. mexicana from a non-sulfidic river and found no differences in their reaction towards the presented predators. Overall, our results indicate (1) that predator avoidance is still functional in extremophile Poecilia spp. and (2) that predator recognition and avoidance reactions have a strong genetic basis.

  10. Avian cholera in Nebraska's Rainwater Basin

    USGS Publications Warehouse

    Windingstad, R.M.; Hurt, J.J.; Trout, A.K.; Cary, J.

    1984-01-01

    The first report of avian cholera in North America occurred in northwestern Texas in winter 1944 (Quortrup et al. 1946). In 1975, mortality from avian cholera occurred for the first time in waterfowl in the Rainwater Basin of Nebraska when an estimated 25,000 birds died (Zinkl et al. 1977). Avian cholera has continued to cause mortality in wild birds in specific areas of the Basin each spring since. Losses of waterfowl from avian cholera continue to be much greater in some of the wetlands in the western part of the Basin than in the east. Several wetlands in the west have consistently higher mortality and are most often the wetlands where initial mortality is noticed each spring (Figure 1). The establishment of this disease in Nebraska is of considerable concern because of the importance of the Rainwater Basin as a spring staging area for waterfowl migrating to their breeding grounds. The wetlands in this area are on a major migration route used by an estimated 5 to 9 million ducks and several hundred thousand geese. A large portion of the western mid-continental greater white-fronted goose (Anser albifrons) population stage in the Basin each spring. Occasionally, whooping cranes (Grus americana) use these wetlands during migration, and lesser sandhill cranes (Grus canadensis) staging on the nearby Platte River sometimes use wetlands where avian cholera occurs (Anonymous 1981). Our objectives were to determine whether certain water quality variables in the Rainwater Basin differed between areas of high and low avian cholera incidence. These results would then be used for laboratory studies involving the survivability of Pasteurella multocida, the causative bacterium of avian cholera. Those studies will be reported elsewhere.

  11. Songbirds and the revised avian brain nomenclature.

    PubMed

    Reiner, Anton; Perkel, David J; Mello, Claudio V; Jarvis, Erich D

    2004-06-01

    It has become increasingly clear that the standard nomenclature for many telencephalic and related brainstem structures of the avian brain is based on flawed once-held assumptions of homology to mammalian brain structures, greatly hindering functional comparisons between avian and mammalian brains. This has become especially problematic for those researchers studying the neurobiology of birdsong, the largest single group within the avian neuroscience community. To deal with the many communication problems this has caused among researchers specializing in different vertebrate classes, the Avian Brain Nomenclature Forum, held at Duke University from July 18-20, 2002, set out to develop a new terminology for the avian telencephalon and some allied brainstem cell groups. In one major step, the erroneous conception that the avian telencephalon consists mainly of a hypertrophied basal ganglia has been purged from the telencephalic terminology, and the actual parts of the basal ganglia and its brainstem afferent cell groups have been given new names to reflect their now-evident homologies. The telencephalic regions that were incorrectly named to reflect presumed homology to mammalian basal ganglia have been renamed as parts of the pallium. The prefixes used for the new names for the pallial subdivisions have retained most established abbreviations, in an effort to maintain continuity with the pre-existing nomenclature. Here we present a brief synopsis of the inaccuracies in the old nomenclature, a summary of the nomenclature changes, and details of changes for specific songbird vocal and auditory nuclei. We believe this new terminology will promote more accurate understanding of the broader neurobiological implications of song control mechanisms and facilitate the productive exchange of information between researchers studying avian and mammalian systems. PMID:15313771

  12. Avian Influenza A (H7N9) Virus

    MedlinePlus

    ... this page: About CDC.gov . Avian Influenza H5 Viruses in the United States Updates and Publications Information ... Humans Examples of Human Infections with Avian Influenza Viruses Outbreaks Health Care and Laboratorian Guidance HPAI A ...

  13. Prevention and Treatment of Avian Influenza A Viruses in People

    MedlinePlus

    ... Research Making a Candidate Vaccine Virus Related Links Influenza Types Seasonal Avian Swine Variant Pandemic Other Get ... Button Past Newsletters Prevention and Treatment of Avian Influenza A Viruses in People Language: English Español ...

  14. Are mature female voles more susceptible than immature ones to avian predation?

    NASA Astrophysics Data System (ADS)

    Koivunen, Vesa; Korpimäki, Erkki; Hakkarainen, Harri

    1998-08-01

    It is well known that a number of activities related to reproduction can increase the predation risk for individuals. Both in the aviary and in the field, we studied whether maturity of female field voles ( Microtus agrestis) affected their behaviour and consequently their risk of predation by Tengmalm's owls ( Aegolius funereus). In an aviary, we recorded the behaviour of mature and immature voles in control (owl absent) and predator (owl present) treatments, but did not find obvious differences in behaviour or vulnerability between mature and immature female voles. In the field, we compared maturity status of female field voles snap-trapped in owl territories with those caught by breeding owls in 1992 and 1994. In accordance with the results from an aviary experiment, there were no obvious differences in vulnerability to Tengmalm's owls between mature and immature individuals. This suggests that mature and immature female field voles are equally exposed to avian predation.

  15. Automatic Collision Avoidance Technology (ACAT)

    NASA Technical Reports Server (NTRS)

    Swihart, Donald E.; Skoog, Mark A.

    2007-01-01

    This document represents two views of the Automatic Collision Avoidance Technology (ACAT). One viewgraph presentation reviews the development and system design of Automatic Collision Avoidance Technology (ACAT). Two types of ACAT exist: Automatic Ground Collision Avoidance (AGCAS) and Automatic Air Collision Avoidance (AACAS). The AGCAS Uses Digital Terrain Elevation Data (DTED) for mapping functions, and uses Navigation data to place aircraft on map. It then scans DTED in front of and around aircraft and uses future aircraft trajectory (5g) to provide automatic flyup maneuver when required. The AACAS uses data link to determine position and closing rate. It contains several canned maneuvers to avoid collision. Automatic maneuvers can occur at last instant and both aircraft maneuver when using data link. The system can use sensor in place of data link. The second viewgraph presentation reviews the development of a flight test and an evaluation of the test. A review of the operation and comparison of the AGCAS and a pilot's performance are given. The same review is given for the AACAS is given.

  16. Approach/avoidance in dreams.

    PubMed

    Malcolm-Smith, Susan; Koopowitz, Sheri; Pantelis, Eleni; Solms, Mark

    2012-03-01

    The influential threat simulation theory (TST) asserts that dreaming yields adaptive advantage by providing a virtual environment in which threat-avoidance may be safely rehearsed. We have previously found the incidence of biologically threatening dreams to be around 20%, with successful threat avoidance occurring in approximately one-fifth of such dreams. TST asserts that threat avoidance is over-represented relative to other possible dream contents. To begin assessing this issue, we contrasted the incidence of 'avoidance' dreams with that of their opposite: 'approach' dreams. Because TST states that the threat-avoidance function is only fully activated in ecologically valid (biologically threatening) contexts, we also performed this contrast for populations living in both high- and low-threat environments. We find that 'approach' dreams are significantly more prevalent across both contexts. We suggest these results are more consistent with the view that dreaming is generated by reward-seeking systems than by fear-conditioning systems, although reward-seeking is clearly not the only factor determining the content of dreams.

  17. DIVA vaccination strategies for avian influenza virus.

    PubMed

    Suarez, David L

    2012-12-01

    Vaccination for both low pathogenicity avian influenza and highly pathogenic avian influenza is commonly used by countries that have become endemic for avian influenza virus, but stamping-out policies are still common for countries with recently introduced disease. Stamping-out policies of euthanatizing infected and at-risk flocks has been an effective control tool, but it comes at a high social and economic cost. Efforts to identify alternative ways to respond to outbreaks without widespread stamping out has become a goal for organizations like the World Organisation for Animal Health. A major issue with vaccination for avian influenza is trade considerations because countries that vaccinate are often considered to be endemic for the disease and they typically lose their export markets. Primarily as a tool to promote trade, the concept of DIVA (differentiate infected from vaccinated animals) has been considered for avian influenza, but the goal for trade is to differentiate vaccinated and not-infected from vaccinated and infected animals because trading partners are unwilling to accept infected birds. Several different strategies have been investigated for a DIVA strategy, but each has advantages and disadvantages. A review of current knowledge on the research and implementation of the DIVA strategy will be discussed with possible ways to implement this strategy in the field. The increased desire for a workable DIVA strategy may lead to one of these ideas moving from the experimental to the practical.

  18. Proceedings of National Avian-Wind Power Planning Meeting IV

    SciTech Connect

    NWCC Avian Subcommittee

    2001-05-01

    OAK-B135 The purpose of the fourth meeting was to (1) share research and update research conducted on avian wind interactions (2) identify questions and issues related to the research results, (3) develop conclusions about some avian/wind power issues, and (4) identify questions and issues for future avian research.

  19. Avian Metapneumovirus Subgroup C Infection in Chickens, China

    PubMed Central

    Wei, Li; Zhu, Shanshan; Yan, Xv; Wang, Jing; Zhang, Chunyan; She, Ruiping; Hu, Fengjiao; Quan, Rong

    2013-01-01

    Avian metapneumovirus causes acute respiratory tract infection and reductions in egg production in various avian species. We isolated and characterized an increasingly prevalent avian metapneumovirus subgroup C strain from meat-type commercial chickens with severe respiratory signs in China. Culling of infected flocks could lead to economic consequences. PMID:23763901

  20. 9 CFR 113.208 - Avian Encephalomyelitis Vaccine, Killed Virus.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 1 2012-01-01 2012-01-01 false Avian Encephalomyelitis Vaccine... STANDARD REQUIREMENTS Killed Virus Vaccines § 113.208 Avian Encephalomyelitis Vaccine, Killed Virus. Avian Encephalomyelitis Vaccine (Killed Virus) shall be prepared from virus-bearing tissues or fluids obtained...

  1. 9 CFR 113.208 - Avian Encephalomyelitis Vaccine, Killed Virus.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 9 Animals and Animal Products 1 2013-01-01 2013-01-01 false Avian Encephalomyelitis Vaccine... STANDARD REQUIREMENTS Killed Virus Vaccines § 113.208 Avian Encephalomyelitis Vaccine, Killed Virus. Avian Encephalomyelitis Vaccine (Killed Virus) shall be prepared from virus-bearing tissues or fluids obtained...

  2. 9 CFR 113.208 - Avian Encephalomyelitis Vaccine, Killed Virus.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 1 2014-01-01 2014-01-01 false Avian Encephalomyelitis Vaccine... STANDARD REQUIREMENTS Killed Virus Vaccines § 113.208 Avian Encephalomyelitis Vaccine, Killed Virus. Avian Encephalomyelitis Vaccine (Killed Virus) shall be prepared from virus-bearing tissues or fluids obtained...

  3. Deforestation and avian infectious diseases

    PubMed Central

    Sehgal, R. N. M.

    2010-01-01

    In this time of unprecedented global change, infectious diseases will impact humans and wildlife in novel and unknown ways. Climate change, the introduction of invasive species, urbanization, agricultural practices and the loss of biodiversity have all been implicated in increasing the spread of infectious pathogens. In many regards, deforestation supersedes these other global events in terms of its immediate potential global effects in both tropical and temperate regions. The effects of deforestation on the spread of pathogens in birds are largely unknown. Birds harbor many of the same types of pathogens as humans and in addition can spread infectious agents to humans and other wildlife. It is thought that avifauna have gone extinct due to infectious diseases and many are presently threatened, especially endemic island birds. It is clear that habitat degradation can pose a direct threat to many bird species but it is uncertain how these alterations will affect disease transmission and susceptibility to disease. The migration and dispersal of birds can also change with habitat degradation, and thus expose populations to novel pathogens. Some recent work has shown that the results of landscape transformation can have confounding effects on avian malaria, other haemosporidian parasites and viruses. Now with advances in many technologies, including mathematical and computer modeling, genomics and satellite tracking, scientists have tools to further research the disease ecology of deforestation. This research will be imperative to help predict and prevent outbreaks that could affect avifauna, humans and other wildlife worldwide. PMID:20190120

  4. Deforestation and avian infectious diseases.

    PubMed

    Sehgal, R N M

    2010-03-15

    In this time of unprecedented global change, infectious diseases will impact humans and wildlife in novel and unknown ways. Climate change, the introduction of invasive species, urbanization, agricultural practices and the loss of biodiversity have all been implicated in increasing the spread of infectious pathogens. In many regards, deforestation supersedes these other global events in terms of its immediate potential global effects in both tropical and temperate regions. The effects of deforestation on the spread of pathogens in birds are largely unknown. Birds harbor many of the same types of pathogens as humans and in addition can spread infectious agents to humans and other wildlife. It is thought that avifauna have gone extinct due to infectious diseases and many are presently threatened, especially endemic island birds. It is clear that habitat degradation can pose a direct threat to many bird species but it is uncertain how these alterations will affect disease transmission and susceptibility to disease. The migration and dispersal of birds can also change with habitat degradation, and thus expose populations to novel pathogens. Some recent work has shown that the results of landscape transformation can have confounding effects on avian malaria, other haemosporidian parasites and viruses. Now with advances in many technologies, including mathematical and computer modeling, genomics and satellite tracking, scientists have tools to further research the disease ecology of deforestation. This research will be imperative to help predict and prevent outbreaks that could affect avifauna, humans and other wildlife worldwide.

  5. Avian biology, the human influence on global avian influenza transmission, and performing surveillance in wild birds.

    PubMed

    Gibbs, Samantha E J

    2010-06-01

    This paper takes a closer look at three interrelated areas of study: avian host biology, the role of human activities in virus transmission, and the surveillance activities centered on avian influenza in wild birds. There are few ecosystems in which birds are not found. Correspondingly, avian influenza viruses are equally global in distribution, relying on competent avian hosts. The immune systems, annual cycles, feeding behaviors, and migration patterns of these hosts influence the ecology of the disease. Decreased biodiversity has also been linked to heightened disease transmission in several disease systems, and it is evident that active destruction and modification of wetland environments for human use is impacting avian populations drastically. Legal and illegal trade in wild birds present a significant risk for introduction and maintenance of exotic diseases. After the emergence of HPAI H5N1 in Hong Kong in 1996 and the ensuing geographic spread of outbreaks after 2003, both infected countries and those at risk of introduction began intensifying avian influenza surveillance efforts. Several techniques for sampling wild birds for influenza viruses have been applied. Benefits, problems, and biases exist for each method. The wild bird avian influenza surveillance programs taking place across the continents are now scaling back due to the rise of other spending priorities; hopefully the lessons learned from this work will be preserved and will inform future research and disease outbreak response priorities.

  6. Predator avoidance and immune defence: costs and trade-offs in snails.

    PubMed

    Rigby, M C; Jokela, J

    2000-01-22

    Organisms are often confronted by both predators and pathogens. Defending against such widely divergent enemies requires more than one type of defence. Multiple defences, however, raise the possibility of trade-offs among defences. We tested for such trade-offs by manipulating the level of predator-avoidance behaviour and immune function in the freshwater snail Lymnaea stagnalis (Gastropoda: Pulmonata). Our results show that predator avoidance and immune function had clear costs in terms of reproduction and survival. Further, we show that increased levels of predator-avoidance behaviour reduced the snails' ability to defend against potential pathogens. Predator-avoidance behaviour may thus have the additional indirect cost of reduced immunocompetence and increased susceptibility to pathogens. Our results suggest that ecological factors (e.g. predator density) may considerably modify the expression and costs of immune defences.

  7. Motive to Avoid Success, Locus of Control, and Reinforcement Avoidance.

    ERIC Educational Resources Information Center

    Katovsky, Walter

    Subjects were four groups of 12 college women, high or low in motive to avoid success (MAS) and locus of control (LC), were reinforced for response A on a fixed partial reinforcement schedule on three concept learning tasks, one task consisting of combined reward and punishment, another of reward only, and one of punishment only. Response B was…

  8. Food Avoidance Diets for Dermatitis.

    PubMed

    Scott, Jeffrey F; Hammond, Margaret I; Nedorost, Susan T

    2015-10-01

    Food allergy is relatively common in both children and adults, and its prevalence is increasing. Early exposure of food allergens onto skin with an impaired epidermal barrier predisposes to sensitization and prevents the development of oral tolerance. While immediate-type food allergies are well described, less is known about delayed-type food allergies manifesting as dermatitis. This is due, in part, to limitations with current diagnostic testing for delayed-type food allergy, including atopy patch testing. We conducted a systematic review of food avoidance diets in delayed-type food allergies manifesting as dermatitis. While beneficial in some clinical circumstances, avoidance diets should be used with caution in infants and children, as growth impairment and developmental delay may result. Ultimately, dermatitis is highly multifactorial and avoidance diets may not improve symptoms of delayed-type food allergy until combined with other targeted therapies, including restoring balance in the skin microbiome and re-establishing proper skin barrier function.

  9. A problem of collision avoidance

    NASA Technical Reports Server (NTRS)

    Vincent, T. L.; Cliff, E. M.; Grantham, W. J.; Peng, W. Y.

    1972-01-01

    Collision avoidance between two vehicles of constant speed with limited turning radii, moving in a horizontal plane is investigated. Collision avoidance is viewed as a game by assuming that the operator of one vehicle has perfect knowledge of the state of the other, whereas the operator of the second vehicle is unaware of any impending danger. The situation envisioned is that of an encounter between a commercial aircraft and a small light aircraft. This worse case situation is examined to determine the conditions under which the commercial aircraft should execute a collision avoidance maneuver. Three different zones of vulnerability are defined and the boundaries, or barriers, between these zones are determined for a typical aircraft encounter. A discussion of the methods used to obtain the results as well as some of the salient features associated with the resultant barriers is included.

  10. A quantitative method to analyze the quality of EIA information in wind energy development and avian/bat assessments

    SciTech Connect

    Chang, Tony; Nielsen, Erik; Auberle, William; Solop, Frederic I.

    2013-01-15

    The environmental impact assessment (EIA) has been a tool for decision makers since the enactment of the National Environmental Policy Act (NEPA). Since that time, few analyses have been performed to verify the quality of information and content within EIAs. High quality information within assessments is vital in order for decision makers, stake holders, and the public to understand the potential impact of proposed actions on the ecosystem and wildlife species. Low quality information has been a major cause for litigation and economic loss. Since 1999, wind energy development has seen an exponential growth with unknown levels of impact on wildlife species, in particular bird and bat species. The purpose of this article is to: (1) develop, validate, and apply a quantitative index to review avian/bat assessment quality for wind energy EIAs; and (2) assess the trends and status of avian/bat assessment quality in a sample of wind energy EIAs. This research presents the development and testing of the Avian and Bat Assessment Quality Index (ABAQI), a new approach to quantify information quality of ecological assessments within wind energy development EIAs in relation to avian and bat species based on review areas and factors derived from 23 state wind/wildlife siting guidance documents. The ABAQI was tested through a review of 49 publicly available EIA documents and validated by identifying high variation in avian and bat assessments quality for wind energy developments. Of all the reviewed EIAs, 66% failed to provide high levels of preconstruction avian and bat survey information, compared to recommended factors from state guidelines. This suggests the need for greater consistency from recommended guidelines by state, and mandatory compliance by EIA preparers to avoid possible habitat and species loss, wind energy development shut down, and future lawsuits. - Highlights: Black-Right-Pointing-Pointer We developed, validated, and applied a quantitative index to review

  11. Generation of Avian Induced Pluripotent Stem Cells.

    PubMed

    Lu, Yangqing; West, Franklin D; Jordan, Brian J; Beckstead, Robert B; Jordan, Erin T; Stice, Steven L

    2015-01-01

    Avian species are among the most diverse vertebrates on our planet and significantly contribute to the balance of the ecology. They are also important food source and serve as a central animal model to decipher developmental biology and disease principles. Derivation of induced pluripotent stem cells (iPSCs) from avian species would enable conservation of genetic diversity as well as offer a valuable cell source that facilitates the use of avian models in many areas of basic and applied research. In this chapter, we describe methods used to successfully reprogram quail fibroblasts into iPSCs by using human transcription factors and the techniques critical to the characterization of their pluripotency. PMID:26621592

  12. Avian influenza surveillance of wild birds

    USGS Publications Warehouse

    Slota, Paul

    2007-01-01

    The President's National Strategy for Pandemic Influenza directs federal agencies to expand the surveillance of United States domestic livestock and wildlife to ensure early warning of hightly pathogenic avian influenza (HPAI) in the U.S. The immediate concern is a potential introduction of HPAI H5N1 virus into the U.S. The presidential directive resulted in the U.S. Interagency Strategic Plan for Early Detection of H5N1 Highly Pathogenic Avian Influenza in Wild Migratory Birds (referred to as the Wild Bird Surveillance Plan or the Plan).

  13. A brief introduction to avian influenza virus.

    PubMed

    Spackman, Erica

    2014-01-01

    Avian influenza virus (AIV) causes a disease of high economic importance for poultry production worldwide. The earliest recorded cases of probable high-pathogenicity AIV in poultry were reported in Italy in the 1870s, and avian influenza has been recognized in domestic poultry through the modern era of poultry production. Approaches to control vary widely, but elimination of the disease in poultry is a common goal. The basics of AIV biology, clinical disease, molecular aspects, and AIV detection are briefly reviewed. PMID:24899420

  14. Biochar aging reduces earthworm avoidance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Biochar, a black carbon substance produced by the pyrolysis of organic feedstocks, has been used in many soil improvement strategies ranging from nutrient addition to sequestration of C. Simple toxicity studies and laboratory preference/avoidance assays are recommended but results rarely reported. ...

  15. Avoided cost pricing: who wins

    SciTech Connect

    Einhorn, M.A.

    1985-05-30

    This article calls for a reevaluation of current Federal Energy Regulatory Commission regulations on the calculation of avoided cost rates for sales of power to utilities by small producers in the light of market conditions not contemplated at the time of the regulations' adoption. 8 references.

  16. Avoiding plagiarism in academic writing.

    PubMed

    Anderson, Irene

    Plagiarism means taking the work of another and presenting it as one's own, resulting in potential upset for the original author and disrepute for the professions involved. This article aims to explore the issue of plagiarism and some mechanisms for detection and avoidance.

  17. Thermal emissivity of avian eggshells.

    PubMed

    Björn, Lars Olof; Bengtson, Sven-Axel; Li, Shaoshan; Hecker, Christoph; Ullah, Saleem; Roos, Arne; Nilsson, Annica M

    2016-04-01

    The hypothesis has been tested that evolution has resulted in lower thermal emissivity of eggs of birds breeding openly in cold climates than of eggs of birds that nest under protective covering or in warmer climates. Directional thermal emissivity has been estimated from directional-hemispherical reflectance spectra. Due to several methodological difficulties the absolute emissivity is not accurately determined, but differences between species are obvious. Most notably, small waders of the genus Calidris, breeding in cold climates on the tundra, and in most cases with uniparental nest attendance, have low directional emissivity of their eggshells, about 0.92 when integration is carried out for wavelengths up to 16μm. Species belonging to Galloanserinae have the highest directional emissivity, about 0.96, of their eggs. No differences due to climate or breeding conditions were found within this group. Eggs of most other birds tested possess intermediate emissivity, but the values for Pica pica and Corvus corone cornix are as low as for Calidris. Large species-dependent differences in spectral reflectance were found at specific wavelengths. For instance, at 4.259μm the directional-hemispherical reflectance for galliforms range from 0.05 to 0.09, while for Fratercula arctica and Fulmarus glacialis it is about 0.3. The reflection peaks at 6.5 and 11.3μm due to calcite are differentially attenuated in different species. In conclusion, the hypothesis that evolution has resulted in lower thermal emissivity of bird eggs being exposed in cold climates is not supported by our results. The emissivity is not clearly related to nesting habits or climate, and it is unlikely that the small differences observed are ecologically important. The spectral differences between eggs that nevertheless exist should be taken into account when using infrared thermometers for estimating the surface temperature of avian eggs.

  18. Thermal emissivity of avian eggshells.

    PubMed

    Björn, Lars Olof; Bengtson, Sven-Axel; Li, Shaoshan; Hecker, Christoph; Ullah, Saleem; Roos, Arne; Nilsson, Annica M

    2016-04-01

    The hypothesis has been tested that evolution has resulted in lower thermal emissivity of eggs of birds breeding openly in cold climates than of eggs of birds that nest under protective covering or in warmer climates. Directional thermal emissivity has been estimated from directional-hemispherical reflectance spectra. Due to several methodological difficulties the absolute emissivity is not accurately determined, but differences between species are obvious. Most notably, small waders of the genus Calidris, breeding in cold climates on the tundra, and in most cases with uniparental nest attendance, have low directional emissivity of their eggshells, about 0.92 when integration is carried out for wavelengths up to 16μm. Species belonging to Galloanserinae have the highest directional emissivity, about 0.96, of their eggs. No differences due to climate or breeding conditions were found within this group. Eggs of most other birds tested possess intermediate emissivity, but the values for Pica pica and Corvus corone cornix are as low as for Calidris. Large species-dependent differences in spectral reflectance were found at specific wavelengths. For instance, at 4.259μm the directional-hemispherical reflectance for galliforms range from 0.05 to 0.09, while for Fratercula arctica and Fulmarus glacialis it is about 0.3. The reflection peaks at 6.5 and 11.3μm due to calcite are differentially attenuated in different species. In conclusion, the hypothesis that evolution has resulted in lower thermal emissivity of bird eggs being exposed in cold climates is not supported by our results. The emissivity is not clearly related to nesting habits or climate, and it is unlikely that the small differences observed are ecologically important. The spectral differences between eggs that nevertheless exist should be taken into account when using infrared thermometers for estimating the surface temperature of avian eggs. PMID:27033033

  19. Prey choice and cannibalistic behaviour in the theropod Coelophysis.

    PubMed

    Nesbitt, Sterling J; Turner, Alan H; Erickson, Gregory M; Norell, Mark A

    2006-12-22

    Direct evidence of prey choice in carnivorous dinosaurs is rare in the fossil record. The most celebrated example pertains to purported stomach contents in the carnivorous dinosaur Coelophysis bauri, which besides revealing prey choice, also points to cannibalistic behaviour as being commonplace (Colbert 1989, 1995). Here, we test this hypothesis by conducting the first comprehensive anatomical and histological examination of the famed Coelophysis 'cannibals'. The results unequivocally show that the gut contents derive from early crocodylomorphs rather than juveniles of Coelophysis. These findings suggest that this taxon is not cannibalistic and bring into question the commonality of this behaviour among non-avian dinosaurs. PMID:17148302

  20. Host Tissue and Glycan Binding Specificities of Avian Viral Attachment Proteins Using Novel Avian Tissue Microarrays

    PubMed Central

    Ambepitiya Wickramasinghe, Iresha N.; de Vries, Robert P.; Eggert, Amber M.; Wandee, Nantaporn; de Haan, Cornelis A. M.; Gröne, Andrea; Verheije, Monique H.

    2015-01-01

    The initial interaction between viral attachment proteins and the host cell is a critical determinant for the susceptibility of a host for a particular virus. To increase our understanding of avian pathogens and the susceptibility of poultry species, we developed novel avian tissue microarrays (TMAs). Tissue binding profiles of avian viral attachment proteins were studied by performing histochemistry on multi-species TMA, comprising of selected tissues from ten avian species, and single-species TMAs, grouping organ systems of each species together. The attachment pattern of the hemagglutinin protein was in line with the reported tropism of influenza virus H5N1, confirming the validity of TMAs in profiling the initial virus-host interaction. The previously believed chicken-specific coronavirus (CoV) M41 spike (S1) protein displayed a broad attachment pattern to respiratory tissues of various avian species, albeit with lower affinity than hemagglutinin, suggesting that other avian species might be susceptible for chicken CoV. When comparing tissue-specific binding patterns of various avian coronaviral S1 proteins on the single-species TMAs, chicken and partridge CoV S1 had predominant affinity for the trachea, while pigeon CoV S1 showed marked preference for lung of their respective hosts. Binding of all coronaviral S1 proteins was dependent on sialic acids; however, while chicken CoV S1 preferred sialic acids type I lactosamine (Gal(1-3)GlcNAc) over type II (Gal(1-4)GlcNAc), the fine glycan specificities of pigeon and partridge CoVs were different, as chicken CoV S1-specific sialylglycopolymers could not block their binding to tissues. Taken together, TMAs provide a novel platform in the field of infectious diseases to allow identification of binding specificities of viral attachment proteins and are helpful to gain insight into the susceptibility of host and organ for avian pathogens. PMID:26035584

  1. Comparative Pharmacokinetics and Allometric Scaling of Carboplatin in Different Avian Species

    PubMed Central

    De Baere, Siegrid; Hellebuyck, Tom; Van de Maele, Isabel; Rouffaer, Lieze; Stemkens, Hendrickus J. J.; De Backer, Patrick; Martel, An; Croubels, Siska

    2015-01-01

    The use of chemotherapeutics as a possible treatment strategy in avian oncology is steadily increasing over the last years. Despite this, literature reports regarding dosing strategies and pharmacokinetic behaviour of chemotherapeutics in avian species are lacking. The aim of the present study was to investigate the pharmacokinetics of carboplatin in a representative species of the order of Galliformes, Anseriformes, Columbiformes and Psittaciformes. Eight chickens, ducks and pigeons and twenty-eight parakeets were administered carboplatin intravenously (5 mg/kg body weight). A specific and sensitive liquid chromatography-tandem mass spectrometry method was developed and validated for quantification of the free carboplatin in plasma of the four birds species (limit of quantification: 20 ng/mL for chicken and duck, 50 ng/mL for pigeon and 100 ng/mL for parakeets). Non-compartmental pharmacokinetic analysis and allometric scaling demonstrated a significant correlation (R² = 0.9769) between body weight (BW) and elimination half-life (T1/2el). T1/2el ranged from 0.41 h in parakeets (BW: 61 ± 8 g) to 1.16 h chickens (BW: 1909 ± 619 g). T1/2el is a good parameter for dose optimization of carboplatin in other avian species, since also the previously reported T1/2el in cockatoos (average BW: 769 ± 68 g) of 1.00 h corresponds to the results obtained in the present study. PMID:26222777

  2. Comparative Pharmacokinetics and Allometric Scaling of Carboplatin in Different Avian Species.

    PubMed

    Antonissen, Gunther; Devreese, Mathias; De Baere, Siegrid; Hellebuyck, Tom; Van de Maele, Isabel; Rouffaer, Lieze; Stemkens, Hendrickus J J; De Backer, Patrick; Martel, An; Croubels, Siska

    2015-01-01

    The use of chemotherapeutics as a possible treatment strategy in avian oncology is steadily increasing over the last years. Despite this, literature reports regarding dosing strategies and pharmacokinetic behaviour of chemotherapeutics in avian species are lacking. The aim of the present study was to investigate the pharmacokinetics of carboplatin in a representative species of the order of Galliformes, Anseriformes, Columbiformes and Psittaciformes. Eight chickens, ducks and pigeons and twenty-eight parakeets were administered carboplatin intravenously (5 mg/kg body weight). A specific and sensitive liquid chromatography-tandem mass spectrometry method was developed and validated for quantification of the free carboplatin in plasma of the four birds species (limit of quantification: 20 ng/mL for chicken and duck, 50 ng/mL for pigeon and 100 ng/mL for parakeets). Non-compartmental pharmacokinetic analysis and allometric scaling demonstrated a significant correlation (R² = 0.9769) between body weight (BW) and elimination half-life (T1/2el). T1/2el ranged from 0.41 h in parakeets (BW: 61 ± 8 g) to 1.16 h chickens (BW: 1909 ± 619 g). T1/2el is a good parameter for dose optimization of carboplatin in other avian species, since also the previously reported T1/2el in cockatoos (average BW: 769 ± 68 g) of 1.00 h corresponds to the results obtained in the present study.

  3. The relationship between the maladaptive self-beliefs characteristic of social anxiety and avoidance.

    PubMed

    Wong, Quincy J J; Moulds, Michelle L

    2011-06-01

    The Clark and Wells (1995) model of social phobia proposes that there are three types of maladaptive self-beliefs responsible for persistent social anxiety (high standard, conditional, and unconditional beliefs). Another prominent feature of social phobia is the avoidance of social-evaluative situations. To our knowledge, there have been no studies that have examined the relationship between these specific maladaptive self-belief types and avoidance. We hypothesised that while accounting for potential confounding variables (i.e., fear of negative evaluation and general symptomology), each of the three maladaptive self-belief types would be significantly and positively associated with cognitive and behavioural avoidance in the social domain, but not these forms of avoidance in the non-social domain. In a sample of undergraduates (N = 361), we found only partial support for our hypotheses. In the social domain, stronger high standard beliefs predicted less behavioural avoidance, stronger unconditional beliefs predicted more behavioural avoidance, and stronger conditional beliefs predicted more cognitive avoidance. In the non-social domain, stronger unconditional beliefs predicted more cognitive avoidance. These relationships were obtained at all levels of social anxiety. Additionally, the unconditional beliefs partially mediated the relationship between social anxiety and behavioural avoidance in the social domain, and the conditional beliefs fully mediated the relationship between social anxiety and cognitive avoidance in the social domain. These results emphasise the distinct nature of each of the maladaptive self-belief types and the need to elucidate their relationship with other components in theoretical models of social phobia. PMID:21315878

  4. Procrastination and counterfactual thinking: avoiding what might have been.

    PubMed

    Sirois, Fuschia M

    2004-06-01

    The possible negative consequences of counterfactuals were explored in the current study by examining the relationship between counterfactual direction and trait procrastination, a self-defeating behavioural style. Eighty participants generated counterfactuals in response to two experimental anxiety inductions. Trait procrastination was overall related to avoiding thoughts about how things could have been better (making more downward and relatively fewer upward counterfactuals) in response to the two anxiety-provoking scenarios, suggesting the involvement of a self-enhancement motive (mood repair). Evidence for the involvement of this self-motive in procrastinating behaviour also emerged, as procrastination was more related to making more downward counterfactuals for a delay-specific anxiety scenario than for a general anxiety scenario. The pattern of results supports the proposal that downward counterfactuals may be associated with negative behavioural styles such as procrastination and implicates self-enhancement motives in this relationship. The behavioural and motivational consequences of downward counterfactuals are discussed and possible connections between downward counterfactuals and other self-defeating behaviours are presented.

  5. Transcriptional analysis of the innate immune response using the avian innate immunity microarray

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The avian innate immunity microarray (AIIM) is a genomics tool designed to study the transcriptional activity of the avian immune response (Cytogenet. Genome Res. 117:139-145, 2007). It is an avian cDNA microarray representing 4,959 avian genes spotted in triplicate. The AIIM contains 25 avian int...

  6. Mechanosensory interactions drive collective behaviour in Drosophila.

    PubMed

    Ramdya, Pavan; Lichocki, Pawel; Cruchet, Steeve; Frisch, Lukas; Tse, Winnie; Floreano, Dario; Benton, Richard

    2015-03-12

    Collective behaviour enhances environmental sensing and decision-making in groups of animals. Experimental and theoretical investigations of schooling fish, flocking birds and human crowds have demonstrated that simple interactions between individuals can explain emergent group dynamics. These findings indicate the existence of neural circuits that support distributed behaviours, but the molecular and cellular identities of relevant sensory pathways are unknown. Here we show that Drosophila melanogaster exhibits collective responses to an aversive odour: individual flies weakly avoid the stimulus, but groups show enhanced escape reactions. Using high-resolution behavioural tracking, computational simulations, genetic perturbations, neural silencing and optogenetic activation we demonstrate that this collective odour avoidance arises from cascades of appendage touch interactions between pairs of flies. Inter-fly touch sensing and collective behaviour require the activity of distal leg mechanosensory sensilla neurons and the mechanosensory channel NOMPC. Remarkably, through these inter-fly encounters, wild-type flies can elicit avoidance behaviour in mutant animals that cannot sense the odour--a basic form of communication. Our data highlight the unexpected importance of social context in the sensory responses of a solitary species and open the door to a neural-circuit-level understanding of collective behaviour in animal groups. PMID:25533959

  7. Avian Schistosomes and Outbreaks of Cercarial Dermatitis

    PubMed Central

    Mikeš, Libor; Lichtenbergová, Lucie; Skála, Vladimír; Soldánová, Miroslava; Brant, Sara Vanessa

    2015-01-01

    SUMMARY Cercarial dermatitis (swimmer's itch) is a condition caused by infective larvae (cercariae) of a species-rich group of mammalian and avian schistosomes. Over the last decade, it has been reported in areas that previously had few or no cases of dermatitis and is thus considered an emerging disease. It is obvious that avian schistosomes are responsible for the majority of reported dermatitis outbreaks around the world, and thus they are the primary focus of this review. Although they infect humans, they do not mature and usually die in the skin. Experimental infections of avian schistosomes in mice show that in previously exposed hosts, there is a strong skin immune reaction that kills the schistosome. However, penetration of larvae into naive mice can result in temporary migration from the skin. This is of particular interest because the worms are able to migrate to different organs, for example, the lungs in the case of visceral schistosomes and the central nervous system in the case of nasal schistosomes. The risk of such migration and accompanying disorders needs to be clarified for humans and animals of interest (e.g., dogs). Herein we compiled the most comprehensive review of the diversity, immunology, and epidemiology of avian schistosomes causing cercarial dermatitis. PMID:25567226

  8. Are we ready for the avian flu?

    PubMed

    Huff, Charlotte

    2006-01-01

    It may be tempting to dismiss headlines about a potential avian flu pandemic as "the sky is falling" sensationalism, but experts continue to warn that the disease is likely to show up here in the not-too-distant future. What must hospitals do to prepare for a sudden influx of patients and other huge demands such a crisis would create? PMID:16485802

  9. Avian influenza virus and Newcastle disease virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Avian influenza virus (AIV) and Newcastle disease virus (NDV) severely impact poultry egg production. Decreased egg yield and hatchability, as well as misshapen eggs, are often observed during infection with AIV and NDV, even with low-virulence strains or in vaccinated flocks. Data suggest that in...

  10. The global nature of avian influenza

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Avian influenza (AI) virus (AIV) is a global virus which knows no geographic boundaries, has no political agenda, and can infect poultry irrespective of their occupying ecosystem, agricultural production system, or other anthropocentric niches. AIVs or evidence of their infection have been detected...

  11. Avian Disease & Oncology Lab (ADOL) Research Update

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Employing Genomics, Epigenetics, and Immunogenetics to Control Diseases Induced by Avian Tumor Viruses - Gene expression is a major factor accounting for phenotypic variation. Taking advantage of allele-specific expression (ASE) screens, we found the use of genetic markers was superior to traditiona...

  12. 77 FR 34783 - Highly Pathogenic Avian Influenza

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-12

    ... avian influenza (HPAI). On January 24, 2011, we published in the Federal Register (76 FR 4046-4056... Register on May 3, 2011 (76 FR 24793, Docket No. APHIS-2006-0074), we reopened the comment period for an... publication of the interim rule establishing that pigeons (and other Columbiform species such as doves) have...

  13. Pathobiology of avian influenza in domestic ducks

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Domestic ducks are an important source of food and income in many parts of the world. The susceptibility of domestic ducks to avian influenza (AI) viruses varies depending on many factors, including the species and the age of the ducks, the virus strain, and management practices. Although wild wat...

  14. Avoiding congestion in recommender systems

    NASA Astrophysics Data System (ADS)

    Ren, Xiaolong; Lü, Linyuan; Liu, Runran; Zhang, Jianlin

    2014-06-01

    Recommender systems use the historical activities and personal profiles of users to uncover their preferences and recommend objects. Most of the previous methods are based on objects’ (and/or users’) similarity rather than on their difference. Such approaches are subject to a high risk of increasingly exposing users to a narrowing band of popular objects. As a result, a few objects may be recommended to an enormous number of users, resulting in the problem of recommendation congestion, which is to be avoided, especially when the recommended objects are limited resources. In order to quantitatively measure a recommendation algorithm's ability to avoid congestion, we proposed a new metric inspired by the Gini index, which is used to measure the inequality of the individual wealth distribution in an economy. Besides this, a new recommendation method called directed weighted conduction (DWC) was developed by considering the heat conduction process on a user-object bipartite network with different thermal conductivities. Experimental results obtained for three benchmark data sets showed that the DWC algorithm can effectively avoid system congestion, and greatly improve the novelty and diversity, while retaining relatively high accuracy, in comparison with the state-of-the-art methods.

  15. Remote Sensing and Avian Biodiversity Patterns in the United States

    NASA Astrophysics Data System (ADS)

    Culbert, Patrick Davis

    Avian biodiversity is threatened, and in order to prioritize limited conservation resources and conduct effective conservation planning, a better understanding of avian species richness patterns is needed. In general, habitat structure, climatic stability, and sensed data to characterize these three drivers at a national scale, determine the influence and relative importance of these drivers of avian biodiversity, and produce nationwide, predictive maps of avian species richness for all birds, forest birds, grassland birds, shrubland birds, Neotropical migrants, short-distance migrants, and permanent residents. The quantification of habitat structure from remotely sensed data was a primary objective, including the evaluation of remotely sensed image texture and both horizontal and vertical vegetation structure, such as landscape composition and forest canopy height. These measures explained up to 70 percent of variability in avian species richness across the United States, and vertical and horizontal structure measures were complementary. I then developed models of avian species richness as a function of all three drivers of biodiversity. When modeling avian species richness at the scale of a North American Breeding Bird Survey route, all three factors had some explanatory power, but measures of habitat structure dominated, followed by productivity, then climatic stability. Models for specific avian guilds explained between 21 and 67 percent of the variability in avian species richness. Lastly, in order to generate a product useful to planners and resource managers, I produced a nationwide, 30-m spatial resolution map of predicted avian species richness for each of the seven avian guilds. My dissertation makes several technical, theoretical, and applied contributions to biodiversity conservation. The main technical contribution is the use of remotely sensed image texture over a nationwide extent. Theoretical contributions include the evaluation of the relative

  16. Detection of oocyte perivitelline membrane-bound sperm: a tool for avian collection management

    PubMed Central

    Croyle, Kaitlin E.; Durrant, Barbara S.; Jensen, Thomas

    2015-01-01

    The success and sustainability of an avian breeding programme depend on managing productive and unproductive pairs. Given that each breeding season can be of immeasurable importance, it is critical to resolve pair fertility issues quickly. Such problems are traditionally diagnosed through behavioural observations, egg lay history and hatch rates, with a decision to re-pair generally taking one or more breeding seasons. In pairs producing incubated eggs that show little or no signs of embryonic development, determining fertility is difficult. Incorporating a technique to assess sperm presence on the oocyte could, in conjunction with behaviour and other data, facilitate a more timely re-pair decision. Detection of perivitelline membrane-bound (PVM-bound) sperm verifies successful copulation, sperm production and sperm functionality. Alternatively, a lack of detectable sperm, at least in freshly laid eggs, suggests no mating, lack of sperm production/function or sperm–oviduct incompatibility. This study demonstrated PVM-bound sperm detection by Hoechst staining in fresh to 24-day-incubated exotic eggs from 39 species representing 13 orders. However, a rapid and significant time-dependent loss of detectable PVM-bound sperm was observed following incubation of chicken eggs. The PCR detection of sperm in seven species, including two bacterially infected eggs, demonstrated that this method was not as reliable as visual detection using Hoechst staining. The absence of amplicons in visually positive PVMs was presumably due to large PVM size and low sperm count, resulting in DNA concentrations too low for standard PCR detection. In summary, this study demonstrated the feasibility and limitations of using PVM-bound sperm detection as a management tool for exotic avian species. We verified that sperm presence or absence on fluorescence microscopy can aid in the differentiation of fertile from infertile eggs to assist breeding managers in making prompt decisions for pair

  17. ["Constanze": a trinational project on avian influenza in wild birds at Lake Constance].

    PubMed

    Brunhart, I; Baumer, A; Reist, M; Stärk, K; Griot, C

    2010-11-01

    When highly pathogenic avian influenza H5N1 (HPAI H5N1) arrived at Lake Constance in February 2006, little was known about its ecology and epidemiology in wild birds. In order to prevent virus transmission from wild birds to poultry, the adjacent countries initiated the tri-national, interdisciplinary research program «Constanze» to investigate avian influenza infections in water birds at Lake Constance. In collaboration with government agencies scientists examined the prevalence of AI virus in the region of Lake Constance for a period of 33 months, compared the effectiveness of different surveillance methods and analysed the migration behaviour of water birds. Although virus introduction from regions as far as the Ural Mountains seemed possible based on the migration behaviour of certain species, no influenza A viruses of the highly pathogenic subtype H5N1 (HPAIV) was found. However, influenza A viruses of different low pathogenic subtypes were isolated in 2.2 % of the sampled birds (swabs). Of the different surveillance methods utilised in the program the sampling of so called sentinel birds was particularly efficient.

  18. ["Constanze": a trinational project on avian influenza in wild birds at Lake Constance].

    PubMed

    Brunhart, I; Baumer, A; Reist, M; Stärk, K; Griot, C

    2010-11-01

    When highly pathogenic avian influenza H5N1 (HPAI H5N1) arrived at Lake Constance in February 2006, little was known about its ecology and epidemiology in wild birds. In order to prevent virus transmission from wild birds to poultry, the adjacent countries initiated the tri-national, interdisciplinary research program «Constanze» to investigate avian influenza infections in water birds at Lake Constance. In collaboration with government agencies scientists examined the prevalence of AI virus in the region of Lake Constance for a period of 33 months, compared the effectiveness of different surveillance methods and analysed the migration behaviour of water birds. Although virus introduction from regions as far as the Ural Mountains seemed possible based on the migration behaviour of certain species, no influenza A viruses of the highly pathogenic subtype H5N1 (HPAIV) was found. However, influenza A viruses of different low pathogenic subtypes were isolated in 2.2 % of the sampled birds (swabs). Of the different surveillance methods utilised in the program the sampling of so called sentinel birds was particularly efficient. PMID:21043024

  19. On avian influenza epidemic models with time delay.

    PubMed

    Liu, Sanhong; Ruan, Shigui; Zhang, Xinan

    2015-12-01

    After the outbreak of the first avian influenza A virus (H5N1) in Hong Kong in 1997, another avian influenza A virus (H7N9) crossed the species barrier in mainland China in 2013 and 2014 and caused more than 400 human cases with a death rate of nearly 40%. In this paper, we take account of the incubation periods of avian influenza A virus and construct a bird-to-human transmission model with different time delays in the avian and human populations combining the survival probability of the infective avian and human populations at the latent time. By analyzing the dynamical behavior of the model, we obtain a threshold value for the prevalence of avian influenza and investigate local and global asymptotical stability of equilibria of the system.

  20. [Avian diversity and bird strike risk at Fuyang Airport].

    PubMed

    Li, Yong-min; Jiang, Shuang-lin; Nie, Chuan-peng; Zhou, Hou-long; Li, Yan-yan; Chen, Nai-tang; Zhao, Zhi-hua

    2011-07-01

    From June 2008 to January 2010, a survey of avian communities was conducted in five habitats (grassland, farmland, town, wetland, and woodland) at Fuyang Airport and its surrounding areas, with the diversity indices in different seasons and different habitats analyzed. A total of 122 avian species belonging to 15 orders and 40 families were recorded. At Fuyang Airport, the avian species number was significantly higher in summer and autumn than in winter and spring, the avian density was the highest in autumn, and the Shannon diversity index and Pielou evenness index were the highest in summer. Among the five habitats at the Airport and its surrounding areas, woodland had the greatest avian species number and density, and the woodland, wetland, and farmland had higher Shannon diversity index than grassland and town. The most dangerous avian species to the airplanes at Fuyang Airport were Passer montanus, Pycnonotus sinensis, Hirundo rustica, Columba livia f. domestica, Pica pica, Streptopelia chinensis, and Sturnus cineraceu.

  1. Blue light regulated shade avoidance.

    PubMed

    Keuskamp, Diederik H; Keller, Mercedes M; Ballaré, Carlos L; Pierik, Ronald

    2012-04-01

    Most plants grow in dense vegetation with the risk of being out-competed by neighboring plants. These neighbors can be detected not only through the depletion in light quantity that they cause, but also through the change in light quality, which plants perceive using specific photoreceptors. Both the reduction of the red:far-red ratio and the depletion of blue light are signals that induce a set of phenotypic traits, such as shoot elongation and leaf hyponasty, which increase the likelihood of light capture in dense plant stands. This set of phenotypic responses are part of the so called shade avoidance syndrome (SAS). This addendum discusses recent findings on the regulation of the SAS of Arabidopsis thaliana upon blue light depletion. Keller et al. and Keuskamp et al. show that the low blue light attenuation induced shade avoidance response of seedling and rosette-stage A. thaliana plants differ in their hormonal regulation. These studies also show there is a regulatory overlap with the R:FR-regulated SAS.

  2. Obstacle-avoiding navigation system

    DOEpatents

    Borenstein, Johann; Koren, Yoram; Levine, Simon P.

    1991-01-01

    A system for guiding an autonomous or semi-autonomous vehicle through a field of operation having obstacles thereon to be avoided employs a memory for containing data which defines an array of grid cells which correspond to respective subfields in the field of operation of the vehicle. Each grid cell in the memory contains a value which is indicative of the likelihood, or probability, that an obstacle is present in the respectively associated subfield. The values in the grid cells are incremented individually in response to each scan of the subfields, and precomputation and use of a look-up table avoids complex trigonometric functions. A further array of grid cells is fixed with respect to the vehicle form a conceptual active window which overlies the incremented grid cells. Thus, when the cells in the active window overly grid cell having values which are indicative of the presence of obstacles, the value therein is used as a multiplier of the precomputed vectorial values. The resulting plurality of vectorial values are summed vectorially in one embodiment of the invention to produce a virtual composite repulsive vector which is then summed vectorially with a target-directed vector for producing a resultant vector for guiding the vehicle. In an alternative embodiment, a plurality of vectors surrounding the vehicle are computed, each having a value corresponding to obstacle density. In such an embodiment, target location information is used to select between alternative directions of travel having low associated obstacle densities.

  3. Social Modeling Influences on Pain Experience and Behaviour.

    ERIC Educational Resources Information Center

    Craig, Kenneth D.

    The impact of exposure to social models displaying variably tolerant pain behaviour on observers' expressions of pain is examined. Findings indicate substantial effects on verbal reports of pain, avoidance behaviour, psychophysiological indices, power function parameters, and sensory decision theory indices. Discussion centers on how social models…

  4. Avian influenza virus and free-ranging wild birds

    USGS Publications Warehouse

    Dierauf, Leslie A.; Karesh, W.B.; Ip, Hon S.; Gilardi, K.V.; Fischer, John R.

    2006-01-01

    Recent media and news reports and other information implicate wild birds in the spread of highly pathogenic avian influenza in Asia and Eastern Europe. Although there is little information concerning highly pathogenic avian influenza viruses in wild birds, scientists have amassed a large amount of data on low-pathogenicity avian influenza viruses during decades of research with wild birds. This knowledge can provide sound guidance to veterinarians, public health professionals, the general public, government agencies, and other entities with concerns about avian influenza.

  5. Avian use of Norris Hill Wind Resource Area, Montana

    SciTech Connect

    Harmata, A.; Podruzny, K.; Zelenak, J.

    1998-07-01

    This document presents results of a study of avian use and mortality in and near a proposed wind resource area in southwestern Montana. Data collected in autumn 1995 through summer 1996 represented preconstruction condition; it was compiled, analyzed, and presented in a format such that comparison with post-construction data would be possible. The primary emphasis of the study was recording avian migration in and near the wind resource area using state-of-the-art marine surveillance radar. Avian use and mortality were investigated during the breeding season by employing traditional avian sampling methods, radiotelemetry, radar, and direct visual observation. 61 figs., 34 tabs.

  6. Avian circadian organization: a chorus of clocks.

    PubMed

    Cassone, Vincent M

    2014-01-01

    In birds, biological clock function pervades all aspects of biology, controlling daily changes in sleep: wake, visual function, song, migratory patterns and orientation, as well as seasonal patterns of reproduction, song and migration. The molecular bases for circadian clocks are highly conserved, and it is likely the avian molecular mechanisms are similar to those expressed in mammals, including humans. The central pacemakers in the avian pineal gland, retinae and SCN dynamically interact to maintain stable phase relationships and then influence downstream rhythms through entrainment of peripheral oscillators in the brain controlling behavior and peripheral tissues. Birds represent an excellent model for the role played by biological clocks in human neurobiology; unlike most rodent models, they are diurnal, they exhibit cognitively complex social interactions, and their circadian clocks are more sensitive to the hormone melatonin than are those of nocturnal rodents. PMID:24157655

  7. Avian Circadian Organization: A Chorus of Clocks

    PubMed Central

    Cassone, Vincent M

    2013-01-01

    In birds, biological clock function pervades all aspects of biology, controlling daily changes in sleep: wake, visual function, song, migratory patterns and orientation, as well as seasonal patterns of reproduction, song and migration. The molecular bases for circadian clocks are highly conserved, and it is likely the avian molecular mechanisms are similar to those expressed in mammals, including humans. The central pacemakers in the avian pineal gland, retinae and SCN dynamically interact to maintain stable phase relationships and then influence downstream rhythms through entrainment of peripheral oscillators in the brain controlling behavior and peripheral tissues. Birds represent an excellent model for the role played by biological clocks in human neurobiology; unlike most rodent models, they are diurnal, they exhibit cognitively complex social interactions, and their circadian clocks are more sensitive to the hormone melatonin than are those of nocturnal rodents. PMID:24157655

  8. Sound improves visual discrimination learning in avian predators.

    PubMed

    Rowe, Candy

    2002-07-01

    Aposematic insects use warning colours to deter predators, but many also produce odours or sounds when attacked by a predator. One possible role for these additional components is that they promote the association between the warning colour and the non-profitability it signals, thus reducing the chance of future attacks from visually hunting predators. This experiment explicitly tests this idea by looking at the effects of sound on a visual discrimination task. Young domestic chicks were trained to look for food rewards under coloured paper cones scattered in an experimental arena. In a subsequent visual discrimination task, they learned to discriminate between rewarded and non-rewarded hats on the basis of colour. Half the chicks performed this task in silence, whilst the other half had a tone played when they attacked non-rewarded hats. The presence of the tone improved the speed of colour discrimination learning. This demonstrates that there could be a selective advantage for aposematic coloured insects to emit sounds when attacked, since avian predators will learn to avoid their coloration more quickly. The role of psychological interactions between signal components in receivers is discussed in relation to the evolution of multimodal displays.

  9. Expornitic of avian pox in a zoo.

    PubMed

    Ensley, P K; Anderson, M P; Costello, M L; Powell, H C; Cooper, R

    1978-11-01

    During a 6-week period at the San Diego Zoo, avian pox occurred in 9 pheasants representing 5 species. Lesions were limited to facial skin and consisted of epithelial cell hyperplasia, secondary inflammatory changes, and intracytoplasmic eosinophilic inclusion bodies which, by electron microscopy, were shown to contain pox virus. The disease was self-limiting in 7 pheasants, but 2 pheasants died. Free-ranging Indian red junglefowl were implicated as the source of the infection. PMID:216657

  10. Common Avian Infection Plagued the Tyrant Dinosaurs

    PubMed Central

    Wolff, Ewan D. S.; Salisbury, Steven W.; Horner, John R.; Varricchio, David J.

    2009-01-01

    Background Tyrannosaurus rex and other tyrannosaurid fossils often display multiple, smooth-edged full-thickness erosive lesions on the mandible, either unilaterally or bilaterally. The cause of these lesions in the Tyrannosaurus rex specimen FMNH PR2081 (known informally by the name ‘Sue’) has previously been attributed to actinomycosis, a bacterial bone infection, or bite wounds from other tyrannosaurids. Methodology/Principal Findings We conducted an extensive survey of tyrannosaurid specimens and identified ten individuals with full-thickness erosive lesions. These lesions were described, measured and photographed for comparison with one another. We also conducted an extensive survey of related archosaurs for similar lesions. We show here that these lesions are consistent with those caused by an avian parasitic infection called trichomonosis, which causes similar abnormalities on the mandible of modern birds, in particular raptors. Conclusions/Significance This finding represents the first evidence for the ancient evolutionary origin of an avian transmissible disease in non-avian theropod dinosaurs. It also provides a valuable insight into the palaeobiology of these now extinct animals. Based on the frequency with which these lesions occur, we hypothesize that tyrannosaurids were commonly infected by a Trichomonas gallinae-like protozoan. For tyrannosaurid populations, the only non-avian dinosaur group that show trichomonosis-type lesions, it is likely that the disease became endemic and spread as a result of antagonistic intraspecific behavior, consumption of prey infected by a Trichomonas gallinae-like protozoan and possibly even cannibalism. The severity of trichomonosis-related lesions in specimens such as Tyrannosaurus rex FMNH PR2081 and Tyrannosaurus rex MOR 980, strongly suggests that these animals died as a direct result of this disease, mostly likely through starvation. PMID:19789646

  11. The avian egg and the retina

    PubMed Central

    MALCOLM, J. E.

    1973-01-01

    A mathematical model for study of blood flow has been derived from the avian egg, utilizing the theories of crystallography and photosynthesis. The model is employed to explain the form of the eye and the function of the cells of the human retina, with special reference to colour vision and the pathology of migraine. ImagesFig. 1Fig. 4Fig. 5Fig. 7Fig. 8Fig. 9Fig. 10Fig. 11 PMID:4736600

  12. Osteonecrosis: avoiding total hip arthroplasty.

    PubMed

    Hungerford, David S

    2002-06-01

    Osteonecrosis of the femoral head afflicts approximately 20,000 new patients per year, at an average age of 38. Of the patients seen in our institution, 25% are <25 years old. Without treatment, most of these patients can be expected to need a total hip arthroplasty. Joint-preserving procedures have a significant failure rate, and some have significant morbidity. It is desirable to avoid or delay total hip arthroplasty because most patients with osteonecrosis outlive the current state-of-the-art prostheses. Four issues need to be weighed to arrive at a reasonable algorithm for the preservative treatment of osteonecrosis: i) patient risk factors, ii) morbidity of the proposed procedure, iii) size of the lesion, and iv) stage of the lesion. All of the issues must be considered to make sense out of a complex clinical situation.

  13. Autonomous hazard detection and avoidance

    NASA Technical Reports Server (NTRS)

    Pien, Homer

    1992-01-01

    During GFY 91, Draper Laboratory was awarded a task by NASA-JSC under contract number NAS9-18426 to study and evaluate the potential for achieving safe autonomous landings on Mars using an on-board autonomous hazard detection and avoidance (AHDA) system. This report describes the results of that study. The AHDA task had four objectives: to demonstrate, via a closed-loop simulation, the ability to autonomously select safe landing sites and the ability to maneuver to the selected site; to identify key issues in the development of AHDA systems; to produce strawman designs for AHDA sensors and algorithms; and to perform initial trade studies leading to better understanding of the effect of sensor/terrain/viewing parameters on AHDA algorithm performance. This report summarizes the progress made during the first year, with primary emphasis on describing the tools developed for simulating a closed-loop AHDA landing. Some cursory performance evaluation results are also presented.

  14. Survival of the Stillest: Predator Avoidance in Shark Embryos

    PubMed Central

    Kempster, Ryan M.; Hart, Nathan S.; Collin, Shaun P.

    2013-01-01

    Sharks use highly sensitive electroreceptors to detect the electric fields emitted by potential prey. However, it is not known whether prey animals are able to modulate their own bioelectrical signals to reduce predation risk. Here, we show that some shark (Chiloscyllium punctatum) embryos can detect predator-mimicking electric fields and respond by ceasing their respiratory gill movements. Despite being confined to the small space within the egg case, where they are vulnerable to predators, embryonic sharks are able to recognise dangerous stimuli and react with an innate avoidance response. Knowledge of such behaviours, may inform the development of effective shark repellents. PMID:23326342

  15. Conservation planning and monitoring avian habitat

    USGS Publications Warehouse

    Twedt, D.J.; Loesch, C.R.; Bonney, Rick; Pashley, David N.; Cooper, Robert; Niles, Larry

    2000-01-01

    Migratory bird conservation plans should not only develop population goals, they also should establish attainable objectives for optimizing avian habitats. Meeting population goals is of paramount importance, but progress toward established habitat objectives can generally be monitored more easily than can progress toward population goals. Additionally, local or regional habitat objectives can be attained regardless of perturbations to avian populations that occur outside the geographic area covered by conservation plans. Assessments of current avian habitats, obtained from remotely sensed data, and the historical distribution of habitats should be used in establishing habitat objectives. Habitat planning and monitoring are best conducted using a geographic information system. Habitat objectives are assigned to three categories: maintaining existing habitat, restoring habitat, and creating new or alternative habitat. Progress toward meeting habitat objectives can be monitored through geographic information systems by incorporating georeferenced information on public lands, private lands under conservation easements, corporate lands under prescribed management, habitat restoration areas, and private lands under alternative management to enhance wildlife values. We recommend that the area and distribution of habitats within the area covered by conservation plans be reassessed from remotely sensed imagery at intervals appropriate to detect predicted habitat changes.

  16. Global phylogeographic limits of Hawaii's avian malaria

    USGS Publications Warehouse

    Beadell, J.S.; Ishtiaq, F.; Covas, R.; Melo, M.; Warren, B.H.; Atkinson, C.T.; Bensch, S.; Graves, G.R.; Jhala, Y.V.; Peirce, M.A.; Rahmani, A.R.; Fonseca, D.M.; Fleischer, R.C.

    2006-01-01

    The introduction of avian malaria (Plasmodium relictum) to Hawaii has provided a model system for studying the influence of exotic disease on naive host populations. Little is known, however, about the origin or the genetic variation of Hawaii's malaria and traditional classification methods have confounded attempts to place the parasite within a global ecological and evolutionary context. Using fragments of the parasite mitochondrial gene cytochrome b and the nuclear gene dihydrofolate reductase-thymidylate synthase obtained from a global survey of greater than 13 000 avian samples, we show that Hawaii's avian malaria, which can cause high mortality and is a major limiting factor for many species of native passerines, represents just one of the numerous lineages composing the morphological parasite species. The single parasite lineage detected in Hawaii exhibits a broad host distribution worldwide and is dominant on several other remote oceanic islands, including Bermuda and Moorea, French Polynesia. The rarity of this lineage in the continental New World and the restriction of closely related lineages to the Old World suggest limitations to the transmission of reproductively isolated parasite groups within the morphological species. ?? 2006 The Royal Society.

  17. Sensorimotor Model of Obstacle Avoidance in Echolocating Bats.

    PubMed

    Vanderelst, Dieter; Holderied, Marc W; Peremans, Herbert

    2015-10-01

    Bat echolocation is an ability consisting of many subtasks such as navigation, prey detection and object recognition. Understanding the echolocation capabilities of bats comes down to isolating the minimal set of acoustic cues needed to complete each task. For some tasks, the minimal cues have already been identified. However, while a number of possible cues have been suggested, little is known about the minimal cues supporting obstacle avoidance in echolocating bats. In this paper, we propose that the Interaural Intensity Difference (IID) and travel time of the first millisecond of the echo train are sufficient cues for obstacle avoidance. We describe a simple control algorithm based on the use of these cues in combination with alternating ear positions modeled after the constant frequency bat Rhinolophus rouxii. Using spatial simulations (2D and 3D), we show that simple phonotaxis can steer a bat clear from obstacles without performing a reconstruction of the 3D layout of the scene. As such, this paper presents the first computationally explicit explanation for obstacle avoidance validated in complex simulated environments. Based on additional simulations modelling the FM bat Phyllostomus discolor, we conjecture that the proposed cues can be exploited by constant frequency (CF) bats and frequency modulated (FM) bats alike. We hypothesize that using a low level yet robust cue for obstacle avoidance allows bats to comply with the hard real-time constraints of this basic behaviour.

  18. Sensorimotor Model of Obstacle Avoidance in Echolocating Bats.

    PubMed

    Vanderelst, Dieter; Holderied, Marc W; Peremans, Herbert

    2015-10-01

    Bat echolocation is an ability consisting of many subtasks such as navigation, prey detection and object recognition. Understanding the echolocation capabilities of bats comes down to isolating the minimal set of acoustic cues needed to complete each task. For some tasks, the minimal cues have already been identified. However, while a number of possible cues have been suggested, little is known about the minimal cues supporting obstacle avoidance in echolocating bats. In this paper, we propose that the Interaural Intensity Difference (IID) and travel time of the first millisecond of the echo train are sufficient cues for obstacle avoidance. We describe a simple control algorithm based on the use of these cues in combination with alternating ear positions modeled after the constant frequency bat Rhinolophus rouxii. Using spatial simulations (2D and 3D), we show that simple phonotaxis can steer a bat clear from obstacles without performing a reconstruction of the 3D layout of the scene. As such, this paper presents the first computationally explicit explanation for obstacle avoidance validated in complex simulated environments. Based on additional simulations modelling the FM bat Phyllostomus discolor, we conjecture that the proposed cues can be exploited by constant frequency (CF) bats and frequency modulated (FM) bats alike. We hypothesize that using a low level yet robust cue for obstacle avoidance allows bats to comply with the hard real-time constraints of this basic behaviour. PMID:26502063

  19. Thermal avoidance during flight in the locust Locusta migratoria

    PubMed

    Robertson; Kuhnert; Dawson

    1996-01-01

    In this paper, thermal avoidance in tethered flying locusts is described for the first time. Changes in body posture examined using high-speed cinematography revealed that the animals responded to a laterally positioned heat source with contralaterally directed abdomen and hindleg ruddering, behavioural patterns resembling manoeuvres observed in collision avoidance and in response to auditory signals. The analysis also showed that, during stimulation, left and right forewing depression became asymmetrical during the downstroke but remained symmetrical during the upstroke. Hindwing depression and elevation remained symmetrical during stimulus presentations. Electromyographic recordings from the left and right first basalar muscles (M97; forewing depressors) showed that contralateral depressor muscle activity was advanced by 10­12 ms relative to that on the stimulated side. There was also an increase in burst duration on the contralaterally stimulated side and an increase in wingbeat frequency of approximately 3 Hz. Ablation experiments showed that removal of the antennal flagella, which are the site of previously described thermoreceptors, did not abolish thermal avoidance manoeuvres. We conclude that thermal avoidance is triggered by an infrared sensitivity that is not mediated by the compound eyes, the ocelli or the antennal flagella. PMID:9319276

  20. Sensorimotor Model of Obstacle Avoidance in Echolocating Bats

    PubMed Central

    Vanderelst, Dieter; Holderied, Marc W.; Peremans, Herbert

    2015-01-01

    Bat echolocation is an ability consisting of many subtasks such as navigation, prey detection and object recognition. Understanding the echolocation capabilities of bats comes down to isolating the minimal set of acoustic cues needed to complete each task. For some tasks, the minimal cues have already been identified. However, while a number of possible cues have been suggested, little is known about the minimal cues supporting obstacle avoidance in echolocating bats. In this paper, we propose that the Interaural Intensity Difference (IID) and travel time of the first millisecond of the echo train are sufficient cues for obstacle avoidance. We describe a simple control algorithm based on the use of these cues in combination with alternating ear positions modeled after the constant frequency bat Rhinolophus rouxii. Using spatial simulations (2D and 3D), we show that simple phonotaxis can steer a bat clear from obstacles without performing a reconstruction of the 3D layout of the scene. As such, this paper presents the first computationally explicit explanation for obstacle avoidance validated in complex simulated environments. Based on additional simulations modelling the FM bat Phyllostomus discolor, we conjecture that the proposed cues can be exploited by constant frequency (CF) bats and frequency modulated (FM) bats alike. We hypothesize that using a low level yet robust cue for obstacle avoidance allows bats to comply with the hard real-time constraints of this basic behaviour. PMID:26502063

  1. The effects of verbal information and approach-avoidance training on children's fear-related responses

    PubMed Central

    Lester, Kathryn J.; Lisk, Stephen C.; Mikita, Nina; Mitchell, Sophie; Huijding, Jorg; Rinck, Mike; Field, Andy P.

    2015-01-01

    Background and objectives This study examined the effects of verbal information and approach-avoidance training on fear-related cognitive and behavioural responses about novel animals. Methods One hundred and sixty children (7–11 years) were randomly allocated to receive: a) positive verbal information about one novel animal and threat information about a second novel animal (verbal information condition); b) approach-avoidance training in which they repeatedly pushed away (avoid) or pulled closer (approach) pictures of the animals (approach-avoidance training), c) a combined condition in which verbal information was given prior to approach-avoidance training (verbal information + approach-avoidance training) and d) a combined condition in which approach-avoidance training was given prior to verbal information (approach-avoidance training + verbal information). Results Threat and positive information significantly increased and decreased fear beliefs and avoidance behaviour respectively. Approach-avoidance training was successful in training the desired behavioural responses but had limited effects on fear-related responses. Verbal information and both combined conditions resulted in significantly larger effects than approach-avoidance training. We found no evidence for an additive effect of these pathways. Limitations This study used a non-clinical sample and focused on novel animals rather than animals about which children already had experience or established fears. The study also compared positive information/approach with threat information/avoid training, limiting specific conclusions regarding the independent effects of these conditions. Conclusions The present study finds little evidence in support of a possible causal role for behavioural response training in the aetiology of childhood fear. However, the provision of verbal information appears to be an important pathway involved in the aetiology of childhood fear. PMID:25698069

  2. ACAT Ground Collision Avoidance Flight Tests Over

    NASA Video Gallery

    NASA's Dryden Flight Research Center has concluded flight tests of an Automatic Ground Collision Avoidance System (Auto GCAS) under the joint U.S. Air Force/NASA F-16D Automatic Collision Avoidance...

  3. Avoidant/Restrictive Food Intake Disorder

    MedlinePlus

    ... Professional Version Eating Disorders Definition of Eating Disorders Anorexia Nervosa Avoidant/Restrictive Food Intake Disorder Binge Eating ... they eat. Eating Disorders Definition of Eating Disorders Anorexia Nervosa Avoidant/Restrictive Food Intake Disorder Binge Eating ...

  4. Math Avoidance and Pursuit of Fantasy Careers.

    ERIC Educational Resources Information Center

    Benton, Barbara L.

    Math avoidance has been hypothesized as related to career choice restrictions. Few attempts have been made, however, to assess the relative importance of the various components of math avoidance to career choice. Furthermore, it has been implied that persons fearful of math not only avoid specific careers but also reject careers that are otherwise…

  5. Termites eavesdrop to avoid competitors.

    PubMed

    Evans, Theodore A; Inta, Ra; Lai, Joseph C S; Prueger, Stefan; Foo, Nyuk Wei; Fu, Eugene Wei'en; Lenz, Michael

    2009-11-22

    Competition exclusion, when a single species dominates resources due to superior competitiveness, is seldom observed in nature. Termites compete for resources with deadly consequences, yet more than one species can be found feeding in the same wooden resource. This is especially surprising when drywood species, with colonies of a few hundred, are found cohabiting with subterranean species, with colonies of millions. Termites communicate vibro-acoustically and, as these signals can travel over long distances, they are vulnerable to eavesdropping. We investigated whether drywood termites could eavesdrop on vibration cues from subterranean species. We show, using choice experiments and recordings, that the drywood termite Cryptotermes secundus can distinguish its own species from the dominant competitor in the environment, the subterranean termite Coptotermes acinaciformis. The drywood termite was attracted to its own vibration cues, but was repelled by those of the subterranean species. This response increased with decreasing wood size, corresponding with both increased risk and strength of the cue. The drywood termites appear to avoid confrontation by eavesdropping on the subterranean termites; these results provide further evidence that vibro-acoustic cues are important for termite sensory perception and communication.

  6. Young People with Down Syndrome: A Preliminary Investigation of Health Knowledge and Associated Behaviours

    ERIC Educational Resources Information Center

    Jobling, Anne; Cuskelly, Monica

    2006-01-01

    Background: Adults with intellectual disability have a range of significant health problems. If they are to live independently, they need to engage in behaviours that are health promoting, as well as avoiding behaviours that might directly lead to ill health. There is very little research about health-related knowledge and behaviour in this group.…

  7. Practical aspects of vaccination of poultry against avian influenza virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Although little has changed in vaccine technology for avian influenza virus (AIV) in the past 20 years, the approach to vaccination of poultry (chickens, turkeys and ducks) for avian influenza has evolved as highly pathogenic (HP) AIV has become endemic in several regions of the world. Vaccination f...

  8. Avian cholera and organochlorine residues in an American oystercatcher

    USGS Publications Warehouse

    Blus, L.J.; Locke, L.N.; Cromartie, E.

    1978-01-01

    Pasteurella multocida, the causative bacterium of avian cholera, was isolated from cultures of the liver and heart blood of a female, adult American oystercatcher (Haematopus palliatus) found dead on the Cape Romain National Wildlife Refuge, South Carolina, in May 1973. This is apparently the first record of avian cholera in the oystercatcher. Low levels of DDE were identified in tissues of the oystercatcher.

  9. Decay of Influenza a Viruses of Human and Avian Origin

    PubMed Central

    Mitchell, Chas. A.; Guerin, L. F.; Robillard, John

    1968-01-01

    The decay rate of six strains of Influenza virus Type A of human origin and eight strains of avian origin were examined in aerosol form under fixed conditions of temperature and humidity. Strains of avian origin were demonstrated to have greater resistance to decay of viability. PMID:4234786

  10. Experimental vaccinations for avian influenza virus including DIVA approaches

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Avian influenza (AI) is a viral disease of poultry that remains an economic threat to commercial poultry throughout the world by negatively impacting animal health and trade. Strategies to control avian influenza (AI) virus are developed to prevent, manage or eradicate the virus from the country, re...

  11. A simple vitrification method for cryobanking avian testicular tissue

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cryopreservation of testicular tissue is a promising method of preserving male reproductive potential for avian species. This study was conducted to assess whether a vitrification method can be used to preserve avian testicular tissue, using the Japanese quail (Coturnix japonica) as a model. A sim...

  12. Susceptibility of avian species to north american H13 low pathogenic avian influenza viruses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Gulls are widely recognized reservoirs for low pathogenic avian influenza (LPAI) viruses; however, the subtypes maintained in these populations and/or the transmission mechanisms involved are poorly understood. Although, a wide diversity of influenza viruses have been isolated from gulls, two hemag...

  13. Comparative susceptibility of avian species to low pathogenic avian influenza viruses of the H13 subtype

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Gulls are widely recognized reservoirs for low pathogenic avian influenza (LPAI) viruses; however, the subtypes maintained in these populations and/or the transmission mechanisms involved are poorly understood. Although, a wide diversity of influenza viruses have been isolated from gulls, two hemag...

  14. Avian influenza in shorebirds: experimental infection of ruddy turnstones (Arenaria interpres) with avian influenza virus

    USGS Publications Warehouse

    Hall, Jeffrey S.; Krauss, Scott; Franson, J. Christian; TeSlaa, Joshua L.; Nashold, Sean W.; Stallknecht, David E.; Webby, Richard J.; Webster, Robert G.

    2013-01-01

    Background: Low pathogenic avian influenza viruses (LPAIV) have been reported in shorebirds, especially at Delaware Bay, USA, during spring migration. However, data on patterns of virus excretion, minimal infectious doses, and clinical outcome are lacking. The ruddy turnstone (Arenaria interpres) is the shorebird species with the highest prevalence of influenza virus at Delaware Bay. Objectives: The primary objective of this study was to experimentally assess the patterns of influenza virus excretion, minimal infectious doses, and clinical outcome in ruddy turnstones. Methods: We experimentally challenged ruddy turnstones using a common LPAIV shorebird isolate, an LPAIV waterfowl isolate, or a highly pathogenic H5N1 avian influenza virus. Cloacal and oral swabs and sera were analyzed from each bird. Results: Most ruddy turnstones had pre-existing antibodies to avian influenza virus, and many were infected at the time of capture. The infectious doses for each challenge virus were similar (103·6–104·16 EID50), regardless of exposure history. All infected birds excreted similar amounts of virus and showed no clinical signs of disease or mortality. Influenza A-specific antibodies remained detectable for at least 2 months after inoculation. Conclusions: These results provide a reference for interpretation of surveillance data, modeling, and predicting the risks of avian influenza transmission and movement in these important hosts.

  15. Multiple value signals in dopaminergic midbrain and their role in avoidance contexts.

    PubMed

    Rigoli, Francesco; Chew, Benjamin; Dayan, Peter; Dolan, Raymond J

    2016-07-15

    The role of dopaminergic brain regions in avoidance behaviour is unclear. Active avoidance requires motivation, and the latter is linked to increased activity in dopaminergic regions. However, avoidance is also often tethered to the prospect of punishment, a state typically characterized by below baseline levels of dopaminergic function. Avoidance has been considered from the perspective of two-factor theories where the prospect of safety is considered to act as a surrogate for reward, leading to dopamine release and enhanced motivational drive. Using fMRI we investigated predictions from two-factor theory by separating the neural representation of a conventional net expected value, which is negative in the case of avoidance, from an adjusted expected value which factors in a possibility of punishment and is larger for both big rewards and big (predictably avoidable) punishments. We show that neural responses in ventral striatum and ventral tegmental area/substantial nigra (VTA/SN) covaried with net expected value. Activity in VTA/SN also covaried with an adjusted expected value, as did activity in anterior insula. Consistent with two-factor theory models, the findings indicate that VTA/SN and insula process an adjusted expected value during avoidance behaviour.

  16. Multiple value signals in dopaminergic midbrain and their role in avoidance contexts.

    PubMed

    Rigoli, Francesco; Chew, Benjamin; Dayan, Peter; Dolan, Raymond J

    2016-07-15

    The role of dopaminergic brain regions in avoidance behaviour is unclear. Active avoidance requires motivation, and the latter is linked to increased activity in dopaminergic regions. However, avoidance is also often tethered to the prospect of punishment, a state typically characterized by below baseline levels of dopaminergic function. Avoidance has been considered from the perspective of two-factor theories where the prospect of safety is considered to act as a surrogate for reward, leading to dopamine release and enhanced motivational drive. Using fMRI we investigated predictions from two-factor theory by separating the neural representation of a conventional net expected value, which is negative in the case of avoidance, from an adjusted expected value which factors in a possibility of punishment and is larger for both big rewards and big (predictably avoidable) punishments. We show that neural responses in ventral striatum and ventral tegmental area/substantial nigra (VTA/SN) covaried with net expected value. Activity in VTA/SN also covaried with an adjusted expected value, as did activity in anterior insula. Consistent with two-factor theory models, the findings indicate that VTA/SN and insula process an adjusted expected value during avoidance behaviour. PMID:27132047

  17. Avoidance of aluminum by rainbow trout

    SciTech Connect

    Exley, C.

    2000-04-01

    Aluminum is the principal toxicant in fish in acid waters. The ability to avoid Al, particularly at low concentrations, would confer a considerable ecological advantage, but previous research into avoidance of Al has produced mixed results. The author used a cylindrical perspex tank, 150 cm in length, to study avoidance of Al by rainbow trout fry. The fish avoided Al, and their response was dependent on pH. Avoidance that was demonstrated at pHs of 5.00, 5.50, 5.50, and 5.75 was abolished at a pH of 6.00. Fry avoided very low Al concentrations being sensitive to [Al] > 1.00 {micro}mol L{sup {minus}1} at a pH of 5.00. This unequivocal demonstration of avoidance by rainbow trout fry of Al may have important implications for the ecology of indigenous fish populations in surface waters impacted by acidic deposition.

  18. "Thou Shalt Not Plagiarise": From Self-Reported Views to Recognition and Avoidance of Plagiarism

    ERIC Educational Resources Information Center

    Risquez, Angelica; O'Dwyer, Michele; Ledwith, Ann

    2013-01-01

    Throughout much of the literature on plagiarism in higher education, there is an implicit assumption that students who understand plagiarism, who have high ethical views and declare not to engage in plagiaristic behaviour are able to recognise it and avoid it in practice. Challenging this supposition, this paper contrasts students' self-reported…

  19. New USDA licensed avian influenza vaccine (rHVT-AI) for protection against H5 avian influenza and usage discussion

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Recently, a new avian influenza vaccine was licensed by USDA for use in the United States for protection of commercial poultry. The vaccine is a recombinant herpes virus of turkeys expressing the hemagglutinin gene of an H5 subtype avian influenza virus belonging to the 2.2 clade of the H5N1 highly ...

  20. Knowledge, attitudes and practices related to avian influenza among poultry workers in Nepal: a cross sectional study

    PubMed Central

    2012-01-01

    Background Avian influenza is a considerable threat to global public health. Prevention and control depend on awareness and protective behaviours of the general population as well as high risk-groups. This study aims to explore the knowledge, attitudes and practices related to avian influenza among poultry workers in Nepal. Methods The study was based on a cross-sectional study design, using a structured questionnaire administered in face-to-face interviews with 96 poultry workers age 15 and above from the Rupandehi district in Nepal. Results The majority of respondents were male (80%), mean age was 35 (SD = 11.6). Nearly everybody was aware that AI cases had been detected in Nepal and that poultry workers were at risk for infection. The major sources of AI information were radio, TV and newspapers. Knowledge about preventive measures was high with regard to some behaviours (hand washing), but medium to low with regard to others (using cleaning and disinfecting procedures or protective clothing). Poultry workers who got their information from TV and newspapers and those who were more afraid of contracting AI had higher knowledge than those who did not. Being employed as compared to being an owner of a poultry farm as well as having a high level of knowledge was associated with practising more preventive behaviours. While on one hand many specific government control measures found a high degree of acceptance, a majority of study participants also thought that government control and compensation measures as a whole were insufficient. Conclusions The study provides information about knowledge and practices regarding avian influenza among poultry workers in Nepal. It highlights the importance of targeting lack of knowledge as well as structural-material barriers to successfully build preparedness for a major outbreak situation. PMID:22458535

  1. Consequences of the size structure of fish populations for their effects on a generalist avian predator.

    PubMed

    Kloskowski, Janusz

    2011-06-01

    Size-structured interspecific interactions can shift between predation and competition, depending on ontogenetic changes in size relationships. I examined the effects of common carp (Cyprinus carpio), an omnivorous fish, on the reproductive success of the red-necked grebe (Podiceps grisegena), an avian gape-limited predator, along a fish size gradient created by stocking distinct age-cohorts in seminatural ponds. Young-of-the-year (0+) carp were an essential food source for young grebes. Only adult birds were able to consume 1-year-old (1+) fish, while 2-year-old (2+) fish attained a size refuge from grebes. Amphibian larvae were the principal alternative prey to fish, followed by macroinvertebrates, but the abundance of both dramatically decreased along the carp size gradient. Fledging success was 2.8 times greater in ponds with 0+ versus 1+ carp; in ponds with 1+ carp, chicks received on average 2.6-3 times less prey biomass from their parents, and over 1/3 of broods suffered total failure. Breeding birds avoided settling on 2+ ponds. These results show that changes in prey fish size structure can account for shifts from positive trophic effects on the avian predator to a negative impact on the predator's alternative resources. However, competition did not fully explain the decrease in grebe food resources in the presence of large fish, as carp and grebes overlapped little in diet. In experimental cages, 1+ carp totally eliminated young larvae of amphibians palatable to fish. In field conditions, breeding adults of palatable taxa avoided ponds with 1+ and older carp. Non-trophic interactions such as habitat selection by amphibians or macroinvertebrates to avoid large fish may provide an indirect mechanism strengthening the adverse bottom-up effects of fish on birds.

  2. Cigarette tax avoidance and evasion: findings from the International Tobacco Control Policy Evaluation Project

    PubMed Central

    Guindon, G. Emmanuel; Driezen, Pete; Chaloupka, Frank J.; Fong, Geoffrey T.

    2014-01-01

    Background Decades of research have produced overwhelming evidence that tobacco taxes reduce tobacco use and increase government tax revenue. The magnitude and effectiveness of taxes at reducing tobacco use provide an incentive for tobacco users, manufacturers and others, most notably criminal networks, to devise ways to avoid or evade tobacco taxes. Consequently, tobacco tax avoidance and tax evasion can reduce the public health and fiscal benefit of tobacco taxes. Objectives First, this study aims to document, using data from the International Tobacco Control Policy Evaluation Project (ITC), levels and trends in cigarette users’ tax avoidance and tax evasion behaviour in a sample of sixteen low-, middle- and high-income countries. Second, this study explores factors associated with cigarette tax avoidance and evasion. Methods We use data from ITC surveys conducted in 16 countries to estimate the extent and the type of cigarette tax avoidance/evasion between countries and across time. We use self-reported information about the source of a smoker’s last purchase of cigarettes or self-reported packaging information, or similar information gathered by the interviewers during face-to-face interviews to measure tax avoidance/evasion behaviours. We use generalized estimating equations (GEE) to explore individual-level factors that may affect the likelihood of cigarette tax avoidance or evasion in Canada, United States, United Kingdom and France. Findings We find prevalence estimates of cigarette tax avoidance/evasion vary substantially between countries and across time. In Canada, France and the United Kingdom, more than 10% of smokers report last purchasing cigarettes from low or untaxed sources while in Malaysia, some prevalence estimates suggest substantial cigarette tax avoidance/evasion. We also find important associations between household income and education and the likelihood to engage in tax avoidance/evasion. These associations, however, vary both in

  3. A model linking sources of stress to approach and avoidance coping styles of Turkish basketball referees.

    PubMed

    Anshel, Mark Howard; Sutarso, Toto; Ekmekci, Ridvan; Saraswati, Intan W

    2014-01-01

    Purpose of this study was to externally validate and test a conceptual transient model involving six paths that linked sources of acute stress to avoidance and approach coping styles among Turkish basketball referees. The sample consisted of 125 Turkish basketball referees ranging in age from 18 to 36 years (mean = 25.58. σ = 3.69). The path analysis tested the relationships simultaneously from stressors, in consecutive order, distractions, subpar performance and verbal abuse, to coping styles, first both avoidance-cognitive and approach-cognitive, and then approach-behaviour. Results indicated that the model achieved a good fit and that all paths tested simultaneously were significant. The distractions stressor was positively related to subpar performance, which, in turn, was positively related to verbal abuse. Verbal abuse was negatively associated with an avoidance-cognitive coping style and positively related to the approach-cognitive coping style. The results also supported a crossover effect of both avoidance-cognitive and approach-cognitive on approach-behaviour. One implication of this study is that coping should be studied in naturally occurring stages, a process-oriented approach. Another implication is that approach and avoidance coping styles, each sub-divided into cognitive and behavioural categories, provide a meaningful framework which provides sports officials a coherent structure for learning and improving ways to cope with acute stress experienced during the contest.

  4. Infection control: avoiding the inevitable.

    PubMed

    Mollitt, Daniel L

    2002-04-01

    Infection, while a major cause of morbidity, should not be considered an inevitable consequence of injury. Good aseptic technique, compulsive attention to detail, and thorough understanding of the points addressed in the following list of critical points are the best guarantee that infection will not add avoidable morbidity to misfortune. Critical points regarding infectious problems in care of the injured child: 1. Polymicrobial infection is the rule with 50% of isolates being mixed aerobic and anaerobic bacteria. 2. It is a misnomer to consider antibiotic use in a pediatric trauma victim as prophylactic. Antimicrobials used in this setting are best considered adjunctive. 3. The major indication for anti-infective therapy in pediatric trauma is an injury with a high probability of infection. 4. Antibiotics do not sterilize the wound or body cavity; they limit bacterial proliferation, thereby supplementing effective immune control. 5. Available studies suggest that 24 hours is as efficacious as a longer treatment duration in a purely adjunctive mode. 6. In bites inflicted by dogs and cats, Pasturella species are frequent. 7. Human bites may result in infection by Eikenella corrodens. 8. Based on this bacteriology, adjunctive intravenous ampicillin sulbactam or oral amoxicillin clavulanate are recommended for human and animal bites. 9. Tetanus prophylaxis is indicated in all significant soft tissue injuries. 10. Risk of osteomyelitis correlates directly with the extent of the associated soft tissue injury and vascular compromise. 11. The majority of infectious complications in the injured child are not a consequence of the injury itself, but rather in the treatment thereof. 12. In the injured child the most common nosocomial infection is lower respiratory followed by primary blood stream and the urinary tract. 13. The management of nosocomial pneumonia in the injured child is based on the time of diagnoses. Early evidence of pulmonary infection requires treatment

  5. Avian pox in birds from Trinidad.

    PubMed

    Tikasingh, E S; Worth, C B; Spence, L; Aitken, T H

    1982-04-01

    Over a 7-year period in Trinidad, 9,514 birds were examined for avian pox and four species were found infected: the golden-headed manakin, Pipra erythrocephala (7% infected), the white-bearded manakin, Manacus manacus (5%), the violaceous euphonia Euphonia violacea (1%), and the bare-eyed thrush, Turdus nudigenis (less than 1%). The elaborate courtship displays of manakins may have a bearing on a "common source" type of infection. The apparently abrupt appearance of the disease at three localities in Trinidad in 1964 perhaps indicates introduction of the virus by migratory birds. PMID:6285009

  6. Avian genetics: A field and ecological approach

    SciTech Connect

    Cooke, F.; Buckley, P.A.

    1987-01-01

    The authors wanted to present the ecological/population approach they used in their own research, and a compendium of carefully referred chapters written by invited experts was essential. The book follows the historical evolution of work in avian genetics, proceeding from a discussion of Mendelian (i.e. classical) genes through quantitative genetics, chromosomal genetics, biochemical genetics, to extensive treatment of population genetics, and concluding with some examples of long-term studies. In this book concentration has been more on intra- than on inter-specific variation; in that sense the approach has been more genetic than evolutionary or taxonomic.

  7. Current genomic editing approaches in avian transgenesis.

    PubMed

    Park, Tae Sub; Kang, Kyung Soo; Han, Jae Yong

    2013-09-01

    The chicken was domesticated from Red Jungle Fowl over 8000years ago and became one of the major food sources worldwide. At present, the poultry industry is one of the largest industrial animal stocks in the world, and its economic scale is expanding significantly with increasing consumption. Additionally, since Aristotle used chicken eggs as a model to provide remarkable insights into how life begins, chickens have been used as invaluable and powerful experimental materials for studying embryo development, immune systems, biomedical processes, and hormonal regulation. Combined with advancements in efficient transgenic technology, avian models have become even more important than would have been expected.

  8. USGS highly pathogenic avian influenza research strategy

    USGS Publications Warehouse

    Harris, M. Camille; Miles, A. Keith; Pearce, John M.; Prosser, Diann J.; Sleeman, Jonathan M.; Whalen, Mary E.

    2015-09-09

    Avian influenza viruses are naturally occurring in wild birds such as ducks, geese, swans, and gulls. These viruses generally do not cause illness in wild birds, however, when spread to poultry they can be highly pathogenic and cause illness and death in backyard and commercial farms. Outbreaks may cause devastating agricultural economic losses and some viral strains have the potential to infect people directly. Furthermore, the combination of avian influenza viruses with mammalian viruses can result in strains with the ability to transmit from person to person, possibly leading to viruses with pandemic potential. All known pandemic influenza viruses have had some genetic material of avian origin. Since 1996, a strain of highly pathogenic avian influenza (HPAI) virus, H5N1, has caused infection in wild birds, losses to poultry farms in Eurasia and North Africa, and led to the deaths of several hundred people. Spread of the H5N1 virus and other influenza strains from China was likely facilitated by migratory birds. In December 2014, HPAI was detected in poultry in Canada and migratory birds in the United States. Since then, HPAI viruses have spread to large parts of the United States and will likely continue to spread through migratory bird flyways and other mechanisms throughout North America. In the United States, HPAI viruses have severely affected the poultry industry with millions of domestic birds dead or culled. These strains of HPAI are not known to cause disease in humans; however, the Centers for Disease Control and Prevention (CDC) advise caution when in close contact with infected birds. Experts agree that HPAI strains currently circulating in wild birds of North America will likely persist for the next few years. This unprecedented situation presents risks to the poultry industry, natural resource management, and potentially human health. Scientific knowledge and decision support tools are urgently needed to understand factors affecting the persistence

  9. USGS highly pathogenic avian influenza research strategy

    USGS Publications Warehouse

    Harris, M. Camille; Miles, A. Keith; Pearce, John M.; Prosser, Diann J.; Sleeman, Jonathan M.; Whalen, Mary E.

    2015-01-01

    Avian influenza viruses are naturally occurring in wild birds such as ducks, geese, swans, and gulls. These viruses generally do not cause illness in wild birds, however, when spread to poultry they can be highly pathogenic and cause illness and death in backyard and commercial farms. Outbreaks may cause devastating agricultural economic losses and some viral strains have the potential to infect people directly. Furthermore, the combination of avian influenza viruses with mammalian viruses can result in strains with the ability to transmit from person to person, possibly leading to viruses with pandemic potential. All known pandemic influenza viruses have had some genetic material of avian origin. Since 1996, a strain of highly pathogenic avian influenza (HPAI) virus, H5N1, has caused infection in wild birds, losses to poultry farms in Eurasia and North Africa, and led to the deaths of several hundred people. Spread of the H5N1 virus and other influenza strains from China was likely facilitated by migratory birds. In December 2014, HPAI was detected in poultry in Canada and migratory birds in the United States. Since then, HPAI viruses have spread to large parts of the United States and will likely continue to spread through migratory bird flyways and other mechanisms throughout North America. In the United States, HPAI viruses have severely affected the poultry industry with millions of domestic birds dead or culled. These strains of HPAI are not known to cause disease in humans; however, the Centers for Disease Control and Prevention (CDC) advise caution when in close contact with infected birds. Experts agree that HPAI strains currently circulating in wild birds of North America will likely persist for the next few years. This unprecedented situation presents risks to the poultry industry, natural resource management, and potentially human health. Scientific knowledge and decision support tools are urgently needed to understand factors affecting the persistence

  10. Avian artificial insemination and semen preservation

    USGS Publications Warehouse

    Gee, G.F.; Risser, Arthur C.; Todd, Frank S.

    1983-01-01

    Summary: Artificial insemination is a practical propagation tool that has been successful with a variety of birds. Cooperative, massage, and electroejaculation and modifications of these three basic methods of semen collection are described for a variety of birds. Semen color and consistency and sperm number, moti!ity, and morphology, as discussed, are useful indicators of semen quality, but the most reliable test of semen quality is the production of fertile eggs. Successful cryogenic preservation of avian semen with DMSO or glycerol as the cryoprotectant has been possible. Although the methods for preservation require special equipment, use of frozen semen requires only simple insemination supplies

  11. Observations from a live bird market in Indonesia following a contained outbreak of avian influenza A (H5N1).

    PubMed

    Naysmith, Scott

    2014-01-01

    Live bird markets are considered high-risk environments facilitating viral transfer and replication of influenza A H5N1. In Indonesia, these markets have been the source for multiple human infections of H5N1 resulting in death, and thus have been the focus of government-led interventions. This paper examines the aftermath of an intervention in one market in Bali, Indonesia. It highlights the social and economic factors influencing the adoption of risk prevention behaviour and concludes by arguing for further qualitative research to understand why at-risk individuals fail to adopt biosecurity measures, even after recently experiencing an outbreak of avian influenza.

  12. Generalization of socially transmitted and instructed avoidance.

    PubMed

    Cameron, Gemma; Schlund, Michael W; Dymond, Simon

    2015-01-01

    Excessive avoidance behavior, in which an instrumental action prevents an upcoming aversive event, is a defining feature of anxiety disorders. Left unchecked, both fear and avoidance of potentially threatening stimuli may generalize to perceptually related stimuli and situations. The behavioral consequences of generalization mean that aversive learning experiences with specific threats may lead to the inference that classes of related stimuli are threatening, potentially dangerous, and need to be avoided, despite differences in physical form. Little is known however about avoidance generalization in humans and the learning pathways by which it may be transmitted. In the present study, we compared two pathways to avoidance-instructions and social observation-on subsequent generalization of avoidance behavior, fear expectancy and physiological arousal. Participants first learned that one cue was a danger cue (conditioned stimulus, CS+) and another was a safety cue (CS-). Groups were then either instructed that a simple avoidance response in the presence of the CS+ cancelled upcoming shock (instructed-learning group) or observed a short movie showing a demonstrator performing the avoidance response to prevent shock (observational-learning group). During generalization testing, danger and safety cues were presented along with generalization stimuli that parametrically varied in perceptual similarity to the CS+. Reinstatement of fear and avoidance was also tested. Findings demonstrate, for the first time, generalization of socially transmitted and instructed avoidance: both groups showed comparable generalization gradients in fear expectancy, avoidance behavior and arousal. Return of fear was evident, suggesting that generalized avoidance remains persistent following extinction testing. The utility of the present paradigm for research on avoidance generalization is discussed. PMID:26150773

  13. Avfail in color avoidance learning by starlings (Sturnus vulgaris) and red-winged blackbirds (Agelaius phoeniceus).

    PubMed

    Mason, J R; Arzt, A H; Reidinger, R F

    1985-12-01

    Certain unconditioned stimuli (UCS) in flavor avoidance learning sometimes become ineffective after pairings with relatively stronger UCS. This failure of avoidance learning (avfail) has been demonstrated only with rodents. The present investigations were conducted to determine whether avfail might also occur with avian species, the food selection of which is guided primarily by visual cues. In Experiment 1, starlings were given pairings of methiocarb (a relatively weak UCS) and LiCl (a relatively strong UCS). In Experiment 2, red-winged blackbirds were given pairings of two concentrations of methiocarb (relatively weak and relatively strong UCS, respectively). Pairings were followed by a conditioning trial (UCS gavage in the presence of a color cue) and two-choice tests. Conditioned avoidance was always observed except when methiocarb preceded LiCl and when the low preceded the high methiocarb dose in preconditioning pairings. Experiment 3 demonstrated that UCS habituation could not account for the results of Experiments 1 and 2. The data reflect avfail in the visual modality, and a biological implication of the results is that birds may not learn strong avoidance of aposematic prey containing varied levels of toxicant.

  14. Obstacle avoidance in social groups: new insights from asynchronous models.

    PubMed

    Croft, Simon; Budgey, Richard; Pitchford, Jonathan W; Wood, A Jamie

    2015-05-01

    For moving animals, the successful avoidance of hazardous obstacles is an important capability. Despite this, few models of collective motion have addressed the relationship between behavioural and social features and obstacle avoidance. We develop an asynchronous individual-based model for social movement which allows social structure within groups to be included. We assess the dynamics of group navigation and resulting collision risk in the context of information transfer through the system. In agreement with previous work, we find that group size has a nonlinear effect on collision risk. We implement examples of possible network structures to explore the impact social preferences have on collision risk. We show that any social heterogeneity induces greater obstacle avoidance with further improvements corresponding to groups containing fewer influential individuals. The model provides a platform for both further theoretical investigation and practical application. In particular, we argue that the role of social structures within bird flocks may have an important role to play in assessing the risk of collisions with wind turbines, but that new methods of data analysis are needed to identify these social structures.

  15. Obstacle avoidance in social groups: new insights from asynchronous models

    PubMed Central

    Croft, Simon; Budgey, Richard; Pitchford, Jonathan W.; Wood, A. Jamie

    2015-01-01

    For moving animals, the successful avoidance of hazardous obstacles is an important capability. Despite this, few models of collective motion have addressed the relationship between behavioural and social features and obstacle avoidance. We develop an asynchronous individual-based model for social movement which allows social structure within groups to be included. We assess the dynamics of group navigation and resulting collision risk in the context of information transfer through the system. In agreement with previous work, we find that group size has a nonlinear effect on collision risk. We implement examples of possible network structures to explore the impact social preferences have on collision risk. We show that any social heterogeneity induces greater obstacle avoidance with further improvements corresponding to groups containing fewer influential individuals. The model provides a platform for both further theoretical investigation and practical application. In particular, we argue that the role of social structures within bird flocks may have an important role to play in assessing the risk of collisions with wind turbines, but that new methods of data analysis are needed to identify these social structures. PMID:25833245

  16. Obstacle avoidance in social groups: new insights from asynchronous models.

    PubMed

    Croft, Simon; Budgey, Richard; Pitchford, Jonathan W; Wood, A Jamie

    2015-05-01

    For moving animals, the successful avoidance of hazardous obstacles is an important capability. Despite this, few models of collective motion have addressed the relationship between behavioural and social features and obstacle avoidance. We develop an asynchronous individual-based model for social movement which allows social structure within groups to be included. We assess the dynamics of group navigation and resulting collision risk in the context of information transfer through the system. In agreement with previous work, we find that group size has a nonlinear effect on collision risk. We implement examples of possible network structures to explore the impact social preferences have on collision risk. We show that any social heterogeneity induces greater obstacle avoidance with further improvements corresponding to groups containing fewer influential individuals. The model provides a platform for both further theoretical investigation and practical application. In particular, we argue that the role of social structures within bird flocks may have an important role to play in assessing the risk of collisions with wind turbines, but that new methods of data analysis are needed to identify these social structures. PMID:25833245

  17. Behavioral avoidance of contagion in childhood.

    PubMed

    Blacker, Katy-Ann; LoBue, Vanessa

    2016-03-01

    Although there is a large literature on children's reasoning about contagion, there has been no empirical research on children's avoidance of contagious individuals. This study is the first to investigate whether children avoid sick individuals. Participants (4- to 7-year-old children) were invited to play with two confederates-one of whom was "sick." Afterward, their knowledge of contagion was assessed. Overall, children avoided proximity to and contact with the sick confederate and her toys, but only 6- and 7-year-olds performed above chance. The best predictor of avoidance behavior was not age but rather children's ability to make predictions about illness outcomes. This provides the first evidence of behavioral avoidance of contagious illness in childhood and suggests that causal knowledge underlies avoidance behavior. PMID:26615972

  18. Avian-like breathing mechanics in maniraptoran dinosaurs.

    PubMed

    Codd, Jonathan R; Manning, Phillip L; Norell, Mark A; Perry, Steven F

    2008-01-22

    In 1868 Thomas Huxley first proposed that dinosaurs were the direct ancestors of birds and subsequent analyses have identified a suite of 'avian' characteristics in theropod dinosaurs. Ossified uncinate processes are found in most species of extant birds and also occur in extinct non-avian maniraptoran dinosaurs. Their presence in these dinosaurs represents another morphological character linking them to Aves, and further supports the presence of an avian-like air-sac respiratory system in theropod dinosaurs, prior to the evolution of flight. Here we report a phylogenetic analysis of the presence of uncinate processes in Aves and non-avian maniraptoran dinosaurs indicating that these were homologous structures. Furthermore, recent work on Canada geese has demonstrated that uncinate processes are integral to the mechanics of avian ventilation, facilitating both inspiration and expiration. In extant birds, uncinate processes function to increase the mechanical advantage for movements of the ribs and sternum during respiration. Our study presents a mechanism whereby uncinate processes, in conjunction with lateral and ventral movements of the sternum and gastral basket, affected avian-like breathing mechanics in extinct non-avian maniraptoran dinosaurs.

  19. A new avian brain nomenclature: why, how and what.

    PubMed

    Reiner, A

    2005-09-15

    Many of the assumptions of homology on which the standard nomenclature for the cell groups and fiber tracts of the avian brain have been based are in error, and consequently that terminology promotes misunderstanding of the functional organization of avian brain and its evolutionary relationship to mammalian brain. Recognizing this problem, a number of avian brain researchers began an effort to revise the terminology, which culminated in the Avian Brain Nomenclature Forum, held at Duke University from 18 to 20 July 2002. In the new terminology approved at this Forum, the flawed conception that the telencephalon of birds consists nearly entirely of a hypertrophied basal ganglia has been purged, and the actual parts of the basal ganglia and its brainstem afferent cell groups given names reflecting their now-evident mammalian homologues. The pallial telencephalic regions that were erroneously named to reflect presumed homology to mammalian basal ganglia were renamed as parts of pallium, using prefixes in most cases that retained established abbreviations (for continuity with the replaced nomenclature). The new nomenclature should lead to better communication among neuroscientists, especially between avian brain specialists and those not specialized in avian neurobiology. More information is available at the Avian Brain Nomenclature Exchange website (). PMID:16144608

  20. Pandemic Threat Posed by Avian Influenza A Viruses

    PubMed Central

    Horimoto, Taisuke; Kawaoka, Yoshihiro

    2001-01-01

    Influenza pandemics, defined as global outbreaks of the disease due to viruses with new antigenic subtypes, have exacted high death tolls from human populations. The last two pandemics were caused by hybrid viruses, or reassortants, that harbored a combination of avian and human viral genes. Avian influenza viruses are therefore key contributors to the emergence of human influenza pandemics. In 1997, an H5N1 influenza virus was directly transmitted from birds in live poultry markets in Hong Kong to humans. Eighteen people were infected in this outbreak, six of whom died. This avian virus exhibited high virulence in both avian and mammalian species, causing systemic infection in both chickens and mice. Subsequently, another avian virus with the H9N2 subtype was directly transmitted from birds to humans in Hong Kong. Interestingly, the genes encoding the internal proteins of the H9N2 virus are genetically highly related to those of the H5N1 virus, suggesting a unique property of these gene products. The identification of avian viruses in humans underscores the potential of these and similar strains to produce devastating influenza outbreaks in major population centers. Although highly pathogenic avian influenza viruses had been identified before the 1997 outbreak in Hong Kong, their devastating effects had been confined to poultry. With the Hong Kong outbreak, it became clear that the virulence potential of these viruses extended to humans. PMID:11148006

  1. Generalization of socially transmitted and instructed avoidance

    PubMed Central

    Cameron, Gemma; Schlund, Michael W.; Dymond, Simon

    2015-01-01

    Excessive avoidance behavior, in which an instrumental action prevents an upcoming aversive event, is a defining feature of anxiety disorders. Left unchecked, both fear and avoidance of potentially threatening stimuli may generalize to perceptually related stimuli and situations. The behavioral consequences of generalization mean that aversive learning experiences with specific threats may lead to the inference that classes of related stimuli are threatening, potentially dangerous, and need to be avoided, despite differences in physical form. Little is known however about avoidance generalization in humans and the learning pathways by which it may be transmitted. In the present study, we compared two pathways to avoidance—instructions and social observation—on subsequent generalization of avoidance behavior, fear expectancy and physiological arousal. Participants first learned that one cue was a danger cue (conditioned stimulus, CS+) and another was a safety cue (CS−). Groups were then either instructed that a simple avoidance response in the presence of the CS+ cancelled upcoming shock (instructed-learning group) or observed a short movie showing a demonstrator performing the avoidance response to prevent shock (observational-learning group). During generalization testing, danger and safety cues were presented along with generalization stimuli that parametrically varied in perceptual similarity to the CS+. Reinstatement of fear and avoidance was also tested. Findings demonstrate, for the first time, generalization of socially transmitted and instructed avoidance: both groups showed comparable generalization gradients in fear expectancy, avoidance behavior and arousal. Return of fear was evident, suggesting that generalized avoidance remains persistent following extinction testing. The utility of the present paradigm for research on avoidance generalization is discussed. PMID:26150773

  2. Studying avian encephalization with geometric morphometrics.

    PubMed

    Marugán-Lobón, Jesús; Watanabe, Akinobu; Kawabe, Soichiro

    2016-08-01

    Encephalization is a core concept in comparative neurobiology, aiming to quantify the neurological capacity of organisms. For measuring encephalization, many studies have employed relative brain sizes corrected for expected allometric scaling to body size. Here we highlight the utility of a multivariate geometric morphometric (GM) approach for visualizing and analyzing neuroanatomical shape variation associated with encephalization. GM readily allows the statistical evaluation of covariates, such as size, and many software tools exist for visualizing their effects on shape. Thus far, however, studies using GM have not attempted to translate the meaning of encephalization to shape data. As such, we tested the statistical relationship between size and encephalization quotients (EQs) to brain shape utilizing a broad interspecific sample of avian endocranial data. Although statistically significant, the analyses indicate that allometry accounts for <10% of total neuroanatomical shape variation. Notably, we find that EQs, despite being corrected for allometric scaling based on size, contain size-related neuroanatomical shape changes. In addition, much of what is traditionally considered encephalization comprises clade-specific trends in relative forebrain expansion, particularly driven by landbirds. EQs, therefore, fail to capture 90% of the total neuroanatomical variation after correcting for allometry and shared phylogenetic history. Moving forward, GM techniques provide crucial tools for investigating key drivers of this vast, largely unexplored aspect of avian brain morphology. PMID:27112986

  3. Collapsing avian community on a Hawaiian island

    USGS Publications Warehouse

    Paxton, Eben; Camp, Richard J.; Gorresen, P. Marcos; Crampton, Lisa H.; Leonard, David L.; VanderWerf, Eric

    2016-01-01

    The viability of many species has been jeopardized by numerous negative factors over the centuries, but climate change is predicted to accelerate and increase the pressure of many of these threats, leading to extinctions. The Hawaiian honeycreepers, famous for their spectacular adaptive radiation, are predicted to experience negative responses to climate change, given their susceptibility to introduced disease, the strong linkage of disease distribution to climatic conditions, and their current distribution. We document the rapid collapse of the native avifauna on the island of Kaua‘i that corresponds to changes in climate and disease prevalence. Although multiple factors may be pressuring the community, we suggest that a tipping point has been crossed in which temperatures in forest habitats at high elevations have reached a threshold that facilitates the development of avian malaria and its vector throughout these species’ ranges. Continued incursion of invasive weeds and non-native avian competitors may be facilitated by climate change and could also contribute to declines. If current rates of decline continue, we predict multiple extinctions in the coming decades. Kaua‘i represents an early warning for the forest bird communities on the Maui and Hawai‘i islands, as well as other species around the world that are trapped within a climatic space that is rapidly disappearing.

  4. Avian colibacillosis: still many black holes.

    PubMed

    Guabiraba, Rodrigo; Schouler, Catherine

    2015-08-01

    Avian pathogenic Escherichia coli (APEC) strains cause severe respiratory and systemic diseases, threatening food security and avian welfare worldwide. Intensification of poultry production and the quick expansion of free-range production systems will increase the incidence of colibacillosis through greater exposure of birds to pathogens and stress. Therapy is mainly based on antibiotherapy and current vaccines have poor efficacy. Serotyping remains the most frequently used diagnostic method, only allowing the identification of a limited number of APEC strains. Several studies have demonstrated that the most common virulence factors studied in APEC are all rarely present in the same isolate, showing that APEC strains constitute a heterogeneous group. Different isolates may harbor different associations of virulence factors, each one able to induce colibacillosis. Despite its economical relevance, pathogenesis of colibacillosis is poorly understood. Our knowledge on the host response to APEC is based on very descriptive studies, mostly restricted to bacteriological and histopathological analysis of infected organs such as lungs. Furthermore, only a small number of APEC isolates have been used in experimental studies. In the present review, we discuss current knowledge on APEC diversity and virulence, including host response to infection and the associated inflammatory response with a focus on pulmonary colibacillosis.

  5. Avian cytokines - the natural approach to therapeutics.

    PubMed

    Lowenthal, J W; Lambrecht, B; van den Berg, T P; Andrew, M E; Strom, A D; Bean, A G

    2000-01-01

    While the effective use of antibiotics for the control of human disease has saved countless lives and has increased life expectancy over the past few decades, there are concerns arising from their usage in livestock. The use of antibiotic feed additives in food production animals has been linked to the emergence in the food chain of multiple drug-resistant bacteria that appear impervious to even the most powerful antimicrobial agents. Furthermore, the use of chemical antimicrobials has led to concerns involving environmental contamination and unwanted residues in food products. The imminent banning of antibiotic usage in livestock feed has intensified the search for environmentally-friendly alternative methods to control disease. Cytokines, as natural mediators and regulators of the immune response, offer exciting new alternatives to conventional chemical-based therapeutics. The utilisation of cytokines is becoming more feasible, particularly in poultry, with the recent cloning of a number of avian cytokine genes. Chickens offer an attractive small animal model system with which to study the effectiveness of cytokine therapy in the control of disease in intensive livestock. In this report we will review the status of avian cytokines and focus on our recent studies involving the therapeutic potential of chicken interferon gamma (ChIFN-gamma) as a vaccine adjuvant and a growth promoter. PMID:10717298

  6. Avian colibacillosis: still many black holes.

    PubMed

    Guabiraba, Rodrigo; Schouler, Catherine

    2015-08-01

    Avian pathogenic Escherichia coli (APEC) strains cause severe respiratory and systemic diseases, threatening food security and avian welfare worldwide. Intensification of poultry production and the quick expansion of free-range production systems will increase the incidence of colibacillosis through greater exposure of birds to pathogens and stress. Therapy is mainly based on antibiotherapy and current vaccines have poor efficacy. Serotyping remains the most frequently used diagnostic method, only allowing the identification of a limited number of APEC strains. Several studies have demonstrated that the most common virulence factors studied in APEC are all rarely present in the same isolate, showing that APEC strains constitute a heterogeneous group. Different isolates may harbor different associations of virulence factors, each one able to induce colibacillosis. Despite its economical relevance, pathogenesis of colibacillosis is poorly understood. Our knowledge on the host response to APEC is based on very descriptive studies, mostly restricted to bacteriological and histopathological analysis of infected organs such as lungs. Furthermore, only a small number of APEC isolates have been used in experimental studies. In the present review, we discuss current knowledge on APEC diversity and virulence, including host response to infection and the associated inflammatory response with a focus on pulmonary colibacillosis. PMID:26204893

  7. Avian Bornaviruses in North American Gulls.

    PubMed

    Guo, Jianhua; Tizard, Ian; Baroch, John; Shivaprasad, H L; Payne, Susan L

    2015-07-01

    Avian bornaviruses, recently described members of the family Bornaviridae, have been isolated from captive parrots and passerines as well as wild waterfowl in which they may cause lethal neurologic disease. We report detection of avian bornavirus RNA in the brains of apparently healthy gulls. We tested 439 gull brain samples from 18 states, primarily in the northeastern US, using a reverse-transcriptase PCR assay with primers designed to detect a conserved region of the bornavirus M gene. Nine birds yielded a PCR product of appropriate size. Sequencing of PCR products indicated that the virus was closely related to aquatic bird bornavirus 1 (ABBV-1). Viral RNA was detected in Herring Gulls (Larus argentatus), Ring-billed Gulls (Larus delawarensis), and Laughing Gulls (Leucophaeus atricilla). Eight of the nine positive birds came from the New York/New Jersey area. One positive Herring Gull came from New Hampshire. Histopathologic examination of one well-preserved brain from a Herring Gull from Union County New Jersey, showed a lymphocytic encephalitis similar to that observed in bornavirus-infected parrots and geese. Bornavirus N protein was confirmed in two Herring Gull brains by immunohistochemistry. Thus ABBV-1 can infect gulls and cause encephalitic brain lesions similar to those observed in other birds.

  8. Avian influenza: genetic evolution under vaccination pressure

    PubMed Central

    Escorcia, Magdalena; Vázquez, Lourdes; Méndez, Sara T; Rodríguez-Ropón, Andrea; Lucio, Eduardo; Nava, Gerardo M

    2008-01-01

    Antigenic drift of avian influenza viruses (AIVs) has been observed in chickens after extended vaccination program, similar to those observed with human influenza viruses. To evaluate the evolutionary properties of endemic AIV under high vaccination pressure (around 2 billion doses used in the last 12 years), we performed a pilot phylogenic analysis of the hemagglutinin (HA) gene of AIVs isolated from 1994 to 2006. This study demonstrates that Mexican low pathogenicity (LP) H5N2-AIVs are constantly undergoing genetic drifts. Recent AIV isolates (2002–2006) show significant molecular drifts when compared with the H5N2 vaccine-strain or other field isolates (1994–2000). This study also demonstrates that molecular drifts in the HA gene lineages follow a yearly trend, suggesting gradually cumulative sequence mutations. These findings might explain the increasing incidence of LP H5N2 AIV isolated from commercial avian farms. These findings support recent concerns about the challenge of AIV antigenic drift and influenza epidemics. PMID:18218105

  9. Collapsing avian community on a Hawaiian island

    PubMed Central

    Paxton, Eben H.; Camp, Richard J.; Gorresen, P. Marcos; Crampton, Lisa H.; Leonard, David L.; VanderWerf, Eric A.

    2016-01-01

    The viability of many species has been jeopardized by numerous negative factors over the centuries, but climate change is predicted to accelerate and increase the pressure of many of these threats, leading to extinctions. The Hawaiian honeycreepers, famous for their spectacular adaptive radiation, are predicted to experience negative responses to climate change, given their susceptibility to introduced disease, the strong linkage of disease distribution to climatic conditions, and their current distribution. We document the rapid collapse of the native avifauna on the island of Kaua‘i that corresponds to changes in climate and disease prevalence. Although multiple factors may be pressuring the community, we suggest that a tipping point has been crossed in which temperatures in forest habitats at high elevations have reached a threshold that facilitates the development of avian malaria and its vector throughout these species’ ranges. Continued incursion of invasive weeds and non-native avian competitors may be facilitated by climate change and could also contribute to declines. If current rates of decline continue, we predict multiple extinctions in the coming decades. Kaua‘i represents an early warning for the forest bird communities on the Maui and Hawai‘i islands, as well as other species around the world that are trapped within a climatic space that is rapidly disappearing. PMID:27617287

  10. Collapsing avian community on a Hawaiian island.

    PubMed

    Paxton, Eben H; Camp, Richard J; Gorresen, P Marcos; Crampton, Lisa H; Leonard, David L; VanderWerf, Eric A

    2016-09-01

    The viability of many species has been jeopardized by numerous negative factors over the centuries, but climate change is predicted to accelerate and increase the pressure of many of these threats, leading to extinctions. The Hawaiian honeycreepers, famous for their spectacular adaptive radiation, are predicted to experience negative responses to climate change, given their susceptibility to introduced disease, the strong linkage of disease distribution to climatic conditions, and their current distribution. We document the rapid collapse of the native avifauna on the island of Kaua'i that corresponds to changes in climate and disease prevalence. Although multiple factors may be pressuring the community, we suggest that a tipping point has been crossed in which temperatures in forest habitats at high elevations have reached a threshold that facilitates the development of avian malaria and its vector throughout these species' ranges. Continued incursion of invasive weeds and non-native avian competitors may be facilitated by climate change and could also contribute to declines. If current rates of decline continue, we predict multiple extinctions in the coming decades. Kaua'i represents an early warning for the forest bird communities on the Maui and Hawai'i islands, as well as other species around the world that are trapped within a climatic space that is rapidly disappearing. PMID:27617287

  11. Diffusive resistance of avian eggshell pores.

    PubMed

    Tøien, O; Paganelli, C V; Rahn, H; Johnson, R R

    1988-12-01

    Resistance to gas diffusion through the avian eggshell resides in the microscopic pores which penetrate the shell. We calculated the resistance to water vapor diffusion of individual pores in the shells of 23 species of avian eggs, based on measurements of pore dimensions taken from drawings of 321 pore casts published by Tyler (1962, 1964, 1965) and Tyler and Simkiss (1959). Diffusive resistances were calculated from Fick's first law, using a 100-segment model of each pore. In addition, we added 2 series resistances, calculated from Stefan's law, to account for boundary layer resistances at the inner and outer pore apertures. Convective resistances for the same 100-segment model were computed from Poiseuille's law. A special, symmetrically branching model is presented for the diffusive resistance of the branched pores of ostrich eggshells, based on the drawings of Tyler and Simkiss (1959). The total aperture resistance was less than 6.2% of total pore resistance, while the outside aperture effect was on average only 1.5%. The calculated average pore conductance for all species was 5.4 micrograms (day Torr)-1, about three times higher than the average value of 1.6 micrograms (day Torr)-1 obtained by dividing measured shell conductance by the number of pores (Ar and Rahn, 1985). A possible explanation for this discrepancy is advanced. However, it is to be noted that in spite of the discrepancy, both calculated and functional values of pore conductance appear to be independent of egg mass.

  12. Coevolution is linked with phenotypic diversification but not speciation in avian brood parasites.

    PubMed

    Medina, Iliana; Langmore, Naomi E

    2015-12-22

    Coevolution is often invoked as an engine of biological diversity. Avian brood parasites and their hosts provide one of the best-known examples of coevolution. Brood parasites lay their eggs in the nests of other species, selecting for host defences and reciprocal counteradaptations in parasites. In theory, this arms race should promote increased rates of speciation and phenotypic evolution. Here, we use recently developed methods to test whether the three largest avian brood parasitic lineages show changes in rates of phenotypic diversity and speciation relative to non-parasitic lineages. Our results challenge the accepted paradigm, and show that there is little consistent evidence that lineages of brood parasites have higher speciation or extinction rates than non-parasitic species. However, we provide the first evidence that the evolution of brood parasitic behaviour may affect rates of evolution in morphological traits associated with parasitism. Specifically, egg size and the colour and pattern of plumage have evolved up to nine times faster in parasitic than in non-parasitic cuckoos. Moreover, cuckoo clades of parasitic species that are sympatric (and share similar host genera) exhibit higher rates of phenotypic evolution. This supports the idea that competition for hosts may be linked to the high phenotypic diversity found in parasitic cuckoos. PMID:26702044

  13. Model to Track Wild Birds for Avian Influenza by Means of Population Dynamics and Surveillance Information

    PubMed Central

    Alba, Anna; Bicout, Dominique J.; Vidal, Francesc; Curcó, Antoni; Allepuz, Alberto; Napp, Sebastián; García-Bocanegra, Ignacio; Costa, Taiana; Casal, Jordi

    2012-01-01

    Design, sampling and data interpretation constitute an important challenge for wildlife surveillance of avian influenza viruses (AIV). The aim of this study was to construct a model to improve and enhance identification in both different periods and locations of avian species likely at high risk of contact with AIV in a specific wetland. This study presents an individual-based stochastic model for the Ebre Delta as an example of this appliance. Based on the Monte-Carlo method, the model simulates the dynamics of the spread of AIV among wild birds in a natural park following introduction of an infected bird. Data on wild bird species population, apparent AIV prevalence recorded in wild birds during the period of study, and ecological information on factors such as behaviour, contact rates or patterns of movements of waterfowl were incorporated as inputs of the model. From these inputs, the model predicted those species that would introduce most of AIV in different periods and those species and areas that would be at high risk as a consequence of the spread of these AIV incursions. This method can serve as a complementary tool to previous studies to optimize the allocation of the limited AI surveillance resources in a local complex ecosystem. However, this study indicates that in order to predict the evolution of the spread of AIV at the local scale, there is a need for further research on the identification of host factors involved in the interspecies transmission of AIV. PMID:22952962

  14. Mechanical analysis of avian feet: multiarticular muscles in grasping and perching

    PubMed Central

    Backus, Spencer B.; Sustaita, Diego; Odhner, Lael U.; Dollar, Aaron M.

    2015-01-01

    The grasping capability of birds' feet is a hallmark of their evolution, but the mechanics of avian foot function are not well understood. Two evolutionary trends that contribute to the mechanical complexity of the avian foot are the variation in the relative lengths of the phalanges and the subdivision and variation of the digital flexor musculature observed among taxa. We modelled the grasping behaviour of a simplified bird foot in response to the downward and upward forces imparted by carrying and perching tasks, respectively. Specifically, we compared the performance of various foot geometries performing these tasks when actuated by distally inserted flexors only, versus by both distally inserted and proximally inserted flexors. Our analysis demonstrates that most species possess relative phalanx lengths that are conducive to grasps actuated only by a single distally inserted tendon per digit. Furthermore, proximally inserted flexors are often required during perching, but the distally inserted flexors are sufficient when grasping and carrying objects. These results are reflected in differences in the relative development of proximally and distally inserted digital flexor musculature among ‘perching’ and ‘grasping’ taxa. Thus, our results shed light on the relative roles of variation in phalanx length and digit flexor muscle distribution in an integrative, mechanical context. PMID:26064598

  15. Ecophysiology of avian migration in the face of current global hazards.

    PubMed

    Klaassen, Marcel; Hoye, Bethany J; Nolet, Bart A; Buttemer, William A

    2012-06-19

    Long-distance migratory birds are often considered extreme athletes, possessing a range of traits that approach the physiological limits of vertebrate design. In addition, their movements must be carefully timed to ensure that they obtain resources of sufficient quantity and quality to satisfy their high-energy needs. Migratory birds may therefore be particularly vulnerable to global change processes that are projected to alter the quality and quantity of resource availability. Because long-distance flight requires high and sustained aerobic capacity, even minor decreases in vitality can have large negative consequences for migrants. In the light of this, we assess how current global change processes may affect the ability of birds to meet the physiological demands of migration, and suggest areas where avian physiologists may help to identify potential hazards. Predicting the consequences of global change scenarios on migrant species requires (i) reconciliation of empirical and theoretical studies of avian flight physiology; (ii) an understanding of the effects of food quality, toxicants and disease on migrant performance; and (iii) mechanistic models that integrate abiotic and biotic factors to predict migratory behaviour. Critically, a multi-dimensional concept of vitality would greatly facilitate evaluation of the impact of various global change processes on the population dynamics of migratory birds.

  16. Bottlenecks and multiple introductions: Population genetics of the vector of avian malaria in Hawaii

    USGS Publications Warehouse

    Fonseca, Dina M.; LaPointe, Dennis A.; Fleischer, Robert C.

    2000-01-01

    Avian malaria has had a profound impact on the demographics and behaviour of Hawaiian forest birds since its vector, Culex quinquefasciatusthe southern house mosquito, was first introduced to Hawaii around 1830. In order to understand the dynamics of the disease in Hawaii and gain insights into the evolution of vector-mediated parasite–host interactions in general we studied the population genetics of Cx. quinquefasciatus in the Hawaiian Islands. We used both microsatellite and mitochondrial loci. Not surprisingly we found that mosquitoes in Midway, a small island in the Western group, are quite distinct from the populations in the main Hawaiian Islands. However, we also found that in general mosquito populations are relatively isolated even among the main islands, in particular between Hawaii (the Big Island) and the remaining Hawaiian Islands. We found evidence of bottlenecks among populations within the Big Island and an excess of alleles in Maui, the site of the original introduction. The mitochondrial diversity was typically low but higher than expected. The current distribution of mitochondrial haplotypes combined with the microsatellite information lead us to conclude that there have been several introductions and to speculate on some processes that may be responsible for the current population genetics of vectors of avian malaria in Hawaii.

  17. Ecophysiology of avian migration in the face of current global hazards

    PubMed Central

    Klaassen, Marcel; Hoye, Bethany J.; Nolet, Bart A.; Buttemer, William A.

    2012-01-01

    Long-distance migratory birds are often considered extreme athletes, possessing a range of traits that approach the physiological limits of vertebrate design. In addition, their movements must be carefully timed to ensure that they obtain resources of sufficient quantity and quality to satisfy their high-energy needs. Migratory birds may therefore be particularly vulnerable to global change processes that are projected to alter the quality and quantity of resource availability. Because long-distance flight requires high and sustained aerobic capacity, even minor decreases in vitality can have large negative consequences for migrants. In the light of this, we assess how current global change processes may affect the ability of birds to meet the physiological demands of migration, and suggest areas where avian physiologists may help to identify potential hazards. Predicting the consequences of global change scenarios on migrant species requires (i) reconciliation of empirical and theoretical studies of avian flight physiology; (ii) an understanding of the effects of food quality, toxicants and disease on migrant performance; and (iii) mechanistic models that integrate abiotic and biotic factors to predict migratory behaviour. Critically, a multi-dimensional concept of vitality would greatly facilitate evaluation of the impact of various global change processes on the population dynamics of migratory birds. PMID:22566678

  18. Flight Tests Validate Collision-Avoidance System

    NASA Video Gallery

    Flights tests of a smartphone-assisted automatic ground collision avoidance system at NASA's Dryden Flight Research Center consistently commanded evasive maneuvers when it sensed that the unmanned ...

  19. Integration of Weather Avoidance and Traffic Separation

    NASA Technical Reports Server (NTRS)

    Consiglio, Maria C.; Chamberlain, James P.; Wilson, Sara R.

    2011-01-01

    This paper describes a dynamic convective weather avoidance concept that compensates for weather motion uncertainties; the integration of this weather avoidance concept into a prototype 4-D trajectory-based Airborne Separation Assurance System (ASAS) application; and test results from a batch (non-piloted) simulation of the integrated application with high traffic densities and a dynamic convective weather model. The weather model can simulate a number of pseudo-random hazardous weather patterns, such as slow- or fast-moving cells and opening or closing weather gaps, and also allows for modeling of onboard weather radar limitations in range and azimuth. The weather avoidance concept employs nested "core" and "avoid" polygons around convective weather cells, and the simulations assess the effectiveness of various avoid polygon sizes in the presence of different weather patterns, using traffic scenarios representing approximately two times the current traffic density in en-route airspace. Results from the simulation experiment show that the weather avoidance concept is effective over a wide range of weather patterns and cell speeds. Avoid polygons that are only 2-3 miles larger than their core polygons are sufficient to account for weather uncertainties in almost all cases, and traffic separation performance does not appear to degrade with the addition of weather polygon avoidance. Additional "lessons learned" from the batch simulation study are discussed in the paper, along with insights for improving the weather avoidance concept. Introduction

  20. Local avian density influences risk of mortality from window strikes.

    PubMed

    Sabo, Ann M; Hagemeyer, Natasha D G; Lahey, Ally S; Walters, Eric L

    2016-01-01

    Up to a billion birds die per year in North America as a result of striking windows. Both transparent and reflective glass panes are a cause for concern, misleading birds by either acting as invisible, impenetrable barriers to desired resources, or reflecting those resources over a large surface area. A high number of window strikes occur during migration, but little is known about the factors of susceptibility, or whether particular avian taxa are more vulnerable than others. We report on a study of window strikes and mist-netting data at the Virginia Zoological Park (Norfolk, Virginia, USA), conducted in the autumn of 2013 and 2014. We focused on three factors likely to contribute to an individual's predisposition to collide with windows: (i) taxonomic classification, (ii) age, and (iii) migrant vs. resident status. Thrushes, dominated by the partial migrant American Robin (Turdus migratorius), were significantly less likely to strike glass than be sampled in mist nets (χ(2) = 9.21, p = 0.002), while wood-warblers (Parulidae) were more likely to strike than expected (χ(2) = 13.55, p < 0.001). The proportion of juveniles striking windows (45.4%) was not significantly different (χ(2) = 0.05, p = 0.827) than the population of juvenile birds naturally occurring at the zoo (48.8%). Migrants, however, were significantly more susceptible to window strikes than residents (χ(2) = 6.35, p = 0.012). Our results suggest that resident birds are able to learn to avoid and thus reduce their likelihood of striking windows; this intrinsic risk factor may help explain the apparent susceptibility of certain taxa to window strikes. PMID:27366656

  1. Local avian density influences risk of mortality from window strikes.

    PubMed

    Sabo, Ann M; Hagemeyer, Natasha D G; Lahey, Ally S; Walters, Eric L

    2016-01-01

    Up to a billion birds die per year in North America as a result of striking windows. Both transparent and reflective glass panes are a cause for concern, misleading birds by either acting as invisible, impenetrable barriers to desired resources, or reflecting those resources over a large surface area. A high number of window strikes occur during migration, but little is known about the factors of susceptibility, or whether particular avian taxa are more vulnerable than others. We report on a study of window strikes and mist-netting data at the Virginia Zoological Park (Norfolk, Virginia, USA), conducted in the autumn of 2013 and 2014. We focused on three factors likely to contribute to an individual's predisposition to collide with windows: (i) taxonomic classification, (ii) age, and (iii) migrant vs. resident status. Thrushes, dominated by the partial migrant American Robin (Turdus migratorius), were significantly less likely to strike glass than be sampled in mist nets (χ(2) = 9.21, p = 0.002), while wood-warblers (Parulidae) were more likely to strike than expected (χ(2) = 13.55, p < 0.001). The proportion of juveniles striking windows (45.4%) was not significantly different (χ(2) = 0.05, p = 0.827) than the population of juvenile birds naturally occurring at the zoo (48.8%). Migrants, however, were significantly more susceptible to window strikes than residents (χ(2) = 6.35, p = 0.012). Our results suggest that resident birds are able to learn to avoid and thus reduce their likelihood of striking windows; this intrinsic risk factor may help explain the apparent susceptibility of certain taxa to window strikes.

  2. Local avian density influences risk of mortality from window strikes

    PubMed Central

    Sabo, Ann M.; Hagemeyer, Natasha D.G.; Lahey, Ally S.

    2016-01-01

    Up to a billion birds die per year in North America as a result of striking windows. Both transparent and reflective glass panes are a cause for concern, misleading birds by either acting as invisible, impenetrable barriers to desired resources, or reflecting those resources over a large surface area. A high number of window strikes occur during migration, but little is known about the factors of susceptibility, or whether particular avian taxa are more vulnerable than others. We report on a study of window strikes and mist-netting data at the Virginia Zoological Park (Norfolk, Virginia, USA), conducted in the autumn of 2013 and 2014. We focused on three factors likely to contribute to an individual’s predisposition to collide with windows: (i) taxonomic classification, (ii) age, and (iii) migrant vs. resident status. Thrushes, dominated by the partial migrant American Robin (Turdus migratorius), were significantly less likely to strike glass than be sampled in mist nets (χ2 = 9.21, p = 0.002), while wood-warblers (Parulidae) were more likely to strike than expected (χ2 = 13.55, p < 0.001). The proportion of juveniles striking windows (45.4%) was not significantly different (χ2 = 0.05, p = 0.827) than the population of juvenile birds naturally occurring at the zoo (48.8%). Migrants, however, were significantly more susceptible to window strikes than residents (χ2 = 6.35, p = 0.012). Our results suggest that resident birds are able to learn to avoid and thus reduce their likelihood of striking windows; this intrinsic risk factor may help explain the apparent susceptibility of certain taxa to window strikes. PMID:27366656

  3. Daytime avoidance of chemosensory alarm cues by adult sea lamprey (Petromyzon marinus)

    USGS Publications Warehouse

    Di Rocco, Richard; Belanger, Cowan; Imre, István; Brown, Grant; Johnson, Nicholas S.

    2014-01-01

    Sea lamprey (Petromyzon marinus) avoid damage-released and predator chemosensory cues at night, but their response to these cues during the day is unknown. Here, we explored (i) whether sea lamprey avoid these cues during the day and (ii) the effect of water temperature on the avoidance of chemosensory alarm cues in two diurnal laboratory experiments. We hypothesized that daytime activity would be temperature-dependent and that only sea lamprey vulnerable to predation (i.e., not hiding) would behaviourally respond to chemosensory alarm cues. Ten groups of ten sea lamprey were exposed to one of a variety of potential chemosensory cues. The experiments were conducted over a range of temperatures to quantify the effect of temperature on avoidance behaviour. Consistent with our hypothesis, a higher proportion of animals were active during daytime as water temperature increased. Moving sea lamprey showed an avoidance response to 2-phenylethylamine (a compound found in mammalian urine) and human saliva once water temperatures had risen to mean (±SD) = 13.7 (±1.4) °C. Resting and hiding sea lamprey did not show an avoidance response to any of the experimental stimuli.

  4. Avoidance of a generalist entomopathogenic fungus by the ladybird, Coccinella septempunctata.

    PubMed

    Ormond, Emma L; Thomas, Alison P M; Pell, Judith K; Freeman, Stephen N; Roy, Helen E

    2011-08-01

    Fungal entomopathogens are ubiquitous within the environment and susceptible insects are predicted to be under strong selection pressure to detect and avoid virulent isolates. Beauveria bassiana is an entomopathogenic fungus with a wide host range including coccinellids. Seven-spot ladybirds, Coccinella septempunctata, overwinter predominantly in leaf litter and B. bassiana is one of their major mortality factors during winter in temperate regions. Behavioural assays were conducted to assess the ability of adult C. septempunctata to avoid lethal densities of B. bassiana conidia in soil or on leaves. Further assays considered avoidance by C. septempunctata of mycosed (B. bassiana) C. septempunctata cadavers compared with uninfected C. septempunctata cadavers or in vitro B. bassiana. Treatments in any bioassays entirely avoided by C. septempunctata were regarded as censored data, to overcome the difficulties associated with zeros in log-ratio analyses. Male and female C. septempunctata avoided contact with leaf surfaces and soil inoculated with B. bassiana and mycosed cadavers. The ability of C. septempunctata to detect and avoid B. bassiana conidia is an adaptation that undoubtedly increases survival and ultimately fitness. We predict that such behavioural responses are widespread and driven by the high cost of fungal infection to a host.

  5. The In Vitro Synthesis of Avian Myeloblastosis Viral RNA Sequences

    PubMed Central

    Jacquet, Michel; Groner, Yoram; Monroy, Gladys; Hurwitz, Jerard

    1974-01-01

    Isolated nuclei, prepared from myeloblasts of chicks infected with avian myeloblastosis virus, synthesize RNA sequences present in avian myeloblastosis viral RNA. These sequences are also formed during transcription of chromatin, isolated from myeloblasts, by DNA-dependent RNA polymerases purified from Escherichia coli or calfthymus. In the latter case, transcription is α-amanitin sensitive. Formation of hybrids between RNA and avian myeloblastosis virus DNA probes has been monitored by the combined use of ribonucleases A, T1, and H, and ribonucleases specific for single strands. PMID:4370472

  6. Avians as a Model System of Vascular Development

    PubMed Central

    Bressan, Michael; Mikawa, Takashi

    2015-01-01

    Summary For more then 2000 years philosophers and scientists have turned to the avian embryo with questions of how life begins (Aristotle; Needham, 1959). Then, as now, the unique accessibility of the embryo both in terms of acquisition of eggs from domesticated fowl, and ease at which the embryo can be visualized by simply opening the shell, have made avians an appealing and powerful model system for the study of development. Thus, as the field of embryology has evolved through observational, comparative, and experimental embryology, into its current iteration as the cellular and molecular biology of development, avians have remained a useful and practical system of study. PMID:25468608

  7. Implications of an avian-style respiratory system for gigantism in sauropod dinosaurs.

    PubMed

    Perry, Steven F; Christian, Andreas; Breuer, Thomas; Pajor, Nadine; Codd, Jonathan R

    2009-10-01

    In light of evidence for avian-like lungs in saurischian dinosaurs, the physiological implications of cross-current gas exchange and voluminous, highly heterogeneous lungs for sauropod gigantism are critically examined. At 12 ton the predicted body temperature and metabolic rate of a growing sauropod would be similar to that of a bird scaled to the same body weight, but would increase exponentially as body mass increases. Although avian-like lung structure would be consistent with either a tachymetabolic-endothermic or a bradymetabolic-gigantothermic model, increasing body temperature requires adjustments to avoid overheating. We suggest that a unique sauropod structure/function unit facilitated the evolution of gigantism. This unit consisted of (1) a reduction in metabolic rate below that predicted by the body temperature, akin to thermal adaptation as seen in extant squamates, (2) presence of air-filled diverticula in the long neck and in the visceral cavity, and (3) low activity of respiratory muscles coupled with the high efficiency of cross-current gas exchange.

  8. Latitudinal variation in avian incubation attentiveness and a test of the food limitation hypothesis

    USGS Publications Warehouse

    Chalfoun, A.D.; Martin, T.E.

    2007-01-01

    Avian incubation attentiveness has important fitness consequences through its influence on the number and quality of hatched young and energetic costs imposed on parents. Nest attentiveness is highly variable across species and geographical regions. We reviewed the literature and found a worldwide pattern that nest attentiveness of passerines is generally lower in south temperate and tropical regions than in north temperate regions. We also conducted a food manipulation experiment to assess the extent to which nest attentiveness may reflect proximate responses versus an evolved behaviour. We used the karoo prinia, Prinia maculosa, in South Africa, which has very low nest attentiveness (???49%) compared with that of many passerine birds. We provided supplemental food during early incubation to experimental females and compared nest attentiveness and on- and off-bout lengths of experimental and paired control females.??Nest attentiveness of females at food-provisioned nests was significantly higher than that of control females (57% versus 49%). Food-supplemented females also spent significantly less time off the nest than did control females, whereas mean on-bout lengths did not differ. However, mean nest attentiveness of food-provisioned females was still substantially below that of other similar bird species worldwide. Food can be an important proximate influence on parental care behaviour, but proximate influences of food do not explain broad latitudinal patterns of attentiveness. ?? 2007 The Association for the Study of Animal Behaviour.

  9. Resonance effects indicate a radical-pair mechanism for avian magnetic compass.

    PubMed

    Ritz, Thorsten; Thalau, Peter; Phillips, John B; Wiltschko, Roswitha; Wiltschko, Wolfgang

    2004-05-13

    Migratory birds are known to use the geomagnetic field as a source of compass information. There are two competing hypotheses for the primary process underlying the avian magnetic compass, one involving magnetite, the other a magnetically sensitive chemical reaction. Here we show that oscillating magnetic fields disrupt the magnetic orientation behaviour of migratory birds. Robins were disoriented when exposed to a vertically aligned broadband (0.1-10 MHz) or a single-frequency (7-MHz) field in addition to the geomagnetic field. Moreover, in the 7-MHz oscillating field, this effect depended on the angle between the oscillating and the geomagnetic fields. The birds exhibited seasonally appropriate migratory orientation when the oscillating field was parallel to the geomagnetic field, but were disoriented when it was presented at a 24 degrees or 48 degrees angle. These results are consistent with a resonance effect on singlet-triplet transitions and suggest a magnetic compass based on a radical-pair mechanism.

  10. Agoraphobia, compulsive behaviours and behaviour completion mechanisms.

    PubMed

    McConaghy, N

    1983-06-01

    Anxiety is identified with a state of high arousal. Agoraphobia is differentiated from specific phobias which are inherent responses to situations which threatened primitive man. In agoraphobia, attacks of high arousal are produced by situations which delay ongoing activity. It is hypothesised that such delays produce arousal by activating behaviour completion mechanisms. Evidence is reviewed which indicates desensitization has a lasting effect in agoraphobia but not in specific phobias. It is suggested that desensitization reduces the arousal produced by behaviour completion mechanisms. Aversive therapy in homosexuality reduces the subjects' drive to carry out compulsive sexual behaviours but does not alter sexual orientation. It is suggested that compulsive sexual behaviours are not activated by primary sexual drives but by behaviour completion mechanisms which are also responsible for other compulsive behaviours. Aversive therapy acts by reducing the arousal produced by the behaviour completion mechanisms. As both aversive therapy and desensitization reduce such arousal, desensitization should be able to replace aversive therapy in the treatment of compulsive behaviours.

  11. How Do Speakers Avoid Ambiguous Linguistic Expressions?

    ERIC Educational Resources Information Center

    Ferreira, V.S.; Slevc, L.R.; Rogers, E.S.

    2005-01-01

    Three experiments assessed how speakers avoid linguistically and nonlinguistically ambiguous expressions. Speakers described target objects (a flying mammal, bat) in contexts including foil objects that caused linguistic (a baseball bat) and nonlinguistic (a larger flying mammal) ambiguity. Speakers sometimes avoided linguistic-ambiguity, and they…

  12. Recommendations for Sense and Avoid Policy Compliance

    NASA Technical Reports Server (NTRS)

    2005-01-01

    Since unmanned aircraft do not have a human on board, they need to have a sense and avoid capability that provides an "equivalent level of safety" (ELOS) to manned aircraft. The question then becomes - is sense and avoid ELOS for unmanned aircraft adequate to satisfy the requirements of 14 CFR 91.113? Access 5 has proposed a definition of sense and avoid, but the question remains as to whether any sense and avoid system can comply with 14 CFR 91.113 as currently written. The Access 5 definition of sense and avoid ELOS allows for the development of a sense and avoid system for unmanned aircraft that would comply with 14 CFR 91.113. Compliance is based on sensing and avoiding other traffic at an equivalent level of safety for collision avoidance, as manned aircraft. No changes to Part 91 are necessary, with the possible exception of changing "see" to "sense," or obtaining an interpretation from the FAA General Counsel that "sense" is equivalent to "see."

  13. 47 CFR 74.604 - Interference avoidance.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Interference avoidance. 74.604 Section 74.604 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) BROADCAST RADIO SERVICES EXPERIMENTAL RADIO... Stations § 74.604 Interference avoidance. (a) (b) Where two or more licensees are assigned a common...

  14. Human Hippocampus Arbitrates Approach-Avoidance Conflict

    PubMed Central

    Bach, Dominik R.; Guitart-Masip, Marc; Packard, Pau A.; Miró, Júlia; Falip, Mercè; Fuentemilla, Lluís; Dolan, Raymond J.

    2014-01-01

    Summary Animal models of human anxiety often invoke a conflict between approach and avoidance [1, 2]. In these, a key behavioral assay comprises passive avoidance of potential threat and inhibition, both thought to be controlled by ventral hippocampus [2–6]. Efforts to translate these approaches to clinical contexts [7, 8] are hampered by the fact that it is not known whether humans manifest analogous approach-avoidance dispositions and, if so, whether they share a homologous neurobiological substrate [9]. Here, we developed a paradigm to investigate the role of human hippocampus in arbitrating an approach-avoidance conflict under varying levels of potential threat. Across four experiments, subjects showed analogous behavior by adapting both passive avoidance behavior and behavioral inhibition to threat level. Using functional magnetic resonance imaging (fMRI), we observe that threat level engages the anterior hippocampus, the human homolog of rodent ventral hippocampus [10]. Testing patients with selective hippocampal lesions, we demonstrate a causal role for the hippocampus with patients showing reduced passive avoidance behavior and inhibition across all threat levels. Our data provide the first human assay for approach-avoidance conflict akin to that of animal anxiety models. The findings bridge rodent and human research on passive avoidance and behavioral inhibition and furnish a framework for addressing the neuronal underpinnings of human anxiety disorders, where our data indicate a major role for the hippocampus. PMID:24560572

  15. The avian fossil record in Insular Southeast Asia and its implications for avian biogeography and palaeoecology.

    PubMed

    Meijer, Hanneke J M

    2014-01-01

    Excavations and studies of existing collections during the last decades have significantly increased the abundance as well as the diversity of the avian fossil record for Insular Southeast Asia. The avian fossil record covers the Eocene through the Holocene, with the majority of bird fossils Pleistocene in age. Fossil bird skeletal remains represent at least 63 species in 54 genera and 27 families, and two ichnospecies are represented by fossil footprints. Birds of prey, owls and swiftlets are common elements. Extinctions seem to have been few, suggesting continuity of avian lineages since at least the Late Pleistocene, although some shifts in species ranges have occurred in response to climatic change. Similarities between the Late Pleistocene avifaunas of Flores and Java suggest a dispersal route across southern Sundaland. Late Pleistocene assemblages of Niah Cave (Borneo) and Liang Bua (Flores) support the rainforest refugium hypothesis in Southeast Asia as they indicate the persistence of forest cover, at least locally, throughout the Late Pleistocene and Holocene. PMID:24688871

  16. The avian fossil record in Insular Southeast Asia and its implications for avian biogeography and palaeoecology

    PubMed Central

    2014-01-01

    Excavations and studies of existing collections during the last decades have significantly increased the abundance as well as the diversity of the avian fossil record for Insular Southeast Asia. The avian fossil record covers the Eocene through the Holocene, with the majority of bird fossils Pleistocene in age. Fossil bird skeletal remains represent at least 63 species in 54 genera and 27 families, and two ichnospecies are represented by fossil footprints. Birds of prey, owls and swiftlets are common elements. Extinctions seem to have been few, suggesting continuity of avian lineages since at least the Late Pleistocene, although some shifts in species ranges have occurred in response to climatic change. Similarities between the Late Pleistocene avifaunas of Flores and Java suggest a dispersal route across southern Sundaland. Late Pleistocene assemblages of Niah Cave (Borneo) and Liang Bua (Flores) support the rainforest refugium hypothesis in Southeast Asia as they indicate the persistence of forest cover, at least locally, throughout the Late Pleistocene and Holocene. PMID:24688871

  17. Population properties affect inbreeding avoidance in moose.

    PubMed

    Herfindal, Ivar; Haanes, Hallvard; Røed, Knut H; Solberg, Erling J; Markussen, Stine S; Heim, Morten; Sæther, Bernt-Erik

    2014-12-01

    Mechanisms reducing inbreeding are thought to have evolved owing to fitness costs of breeding with close relatives. In small and isolated populations, or populations with skewed age- or sex distributions, mate choice becomes limited, and inbreeding avoidance mechanisms ineffective. We used a unique individual-based dataset on moose from a small island in Norway to assess whether inbreeding avoidance was related to population structure and size, expecting inbreeding avoidance to be greater in years with larger populations and even adult sex ratios. The probability that a potential mating event was realized was negatively related to the inbreeding coefficient of the potential offspring, with a stronger relationship in years with a higher proportion or number of males in the population. Thus, adult sex ratio and population size affect the degree of inbreeding avoidance. Consequently, conservation managers should aim for sex ratios that facilitate inbreeding avoidance, especially in small and isolated populations.

  18. Living with food allergy: allergen avoidance.

    PubMed

    Kim, Jennifer S; Sicherer, Scott H

    2011-04-01

    The primary treatment of food allergy is to avoid the culprit foods. This is a complex undertaking that requires education about reading the labels of manufactured products, understanding how to avoid cross-contact with allergens during food preparation, and communicating effectively with persons who are providing allergen-safe meals including relatives and restaurant personnel. Successful avoidance also requires a knowledge of nuances such as appropriate cleaning practices, an understanding of the risks of ingestion compared to skin contact or inhalation, that exposure could occur through unanticipated means such as through sharing utensils or passionate kissing, and that food may be a component of substances that are not ingested such as cosmetics, bath products, vaccines and medications. The authors review the necessary tools of avoidance that physicians and medical practitioners can use to guide their patients through the complexities of food avoidance.

  19. How do speakers avoid ambiguous linguistic expressions?

    PubMed

    Ferreira, Victor S; Slevc, L Robert; Rogers, Erin S

    2005-07-01

    Three experiments assessed how speakers avoid linguistically and nonlinguistically ambiguous expressions. Speakers described target objects (a flying mammal, bat) in contexts including foil objects that caused linguistic (a baseball bat) and nonlinguistic (a larger flying mammal) ambiguity. Speakers sometimes avoided linguistic-ambiguity, and they did so equally regardless of whether they also were about to describe foils. This suggests that comprehension processes can sometimes detect linguistic-ambiguity before producing it. However, once produced, speakers consistently avoided using the same linguistically ambiguous expression again for a different meaning. This suggests that production processes can successfully detect linguistic-ambiguity after-the-fact. Speakers almost always avoided nonlinguistic-ambiguity. Thus, production processes are especially sensitive to nonlinguistic- but not linguistic-ambiguity, with the latter avoided consistently only once it is already articulated.

  20. Shared epitopes of avian immunoglobulin light chains.

    PubMed

    Benčina, Mateja; Cizelj, Ivanka; Berčič, Rebeka Lucijana; Narat, Mojca; Benčina, Dušan; Dovč, Peter

    2014-04-15

    Like all jawed vertebrates, birds (Aves) also produce antibodies i.e. immunoglobulins (Igs) as a defence mechanism against pathogens. Their Igs are composed of two identical heavy (H) and light (L) chains which are of lambda isotype. The L chain consists of variable (VL), joining (JL) and constant (CL) region. Using enzyme immunoassays (EIA) and two monoclonal antibodies (mAbs) (3C10 and CH31) to chicken L chain, we analysed their cross-reactivity with sera from 33 avian species belonging to nine different orders. Among Galliformes tested, mAbs 3C10 and CH31 reacted with L chains of chicken, turkey, four genera of pheasants, tragopan and peafowl, but not with sera of grey partridge, quail and Japanese quail. Immunoglobulins of guinea-fowl reacted only with mAb 3C10. Both mAbs reacted also with the L chain of Eurasian griffon (order Falconiformes) and domestic sparrow (order Passeriformes). Sera from six other orders of Aves did not react with either of the two mAbs. EIA using mAbs 3C10 and CH31 enabled detection of antibodies to major avian pathogens in sera of chickens, turkeys, pheasants, peafowl, Eurasian griffon and guinea-fowl (only with mAb 3C10). The N-terminal amino acid sequence of pheasant L chain (19 residues) was identical to that of chicken. Sequences of genes encoding the L chain constant regions of pheasants, turkey and partridge were determined and deposited in the public database (GenBank accession numbers: FJ 649651, FJ 649652 and FJ 649653, respectively). Among them, amino acid sequence of pheasants is the most similar to that of chicken (97% similarity), whereas those of turkey and partridge have greater similarity to each other (89%) than to any other avian L chain sequence. The characteristic deletion of two amino acids which is present in the L chain constant region in Galliformes has been most likely introduced to their L chain after their divergence from Anseriformes.

  1. Shared epitopes of avian immunoglobulin light chains.

    PubMed

    Benčina, Mateja; Cizelj, Ivanka; Berčič, Rebeka Lucijana; Narat, Mojca; Benčina, Dušan; Dovč, Peter

    2014-04-15

    Like all jawed vertebrates, birds (Aves) also produce antibodies i.e. immunoglobulins (Igs) as a defence mechanism against pathogens. Their Igs are composed of two identical heavy (H) and light (L) chains which are of lambda isotype. The L chain consists of variable (VL), joining (JL) and constant (CL) region. Using enzyme immunoassays (EIA) and two monoclonal antibodies (mAbs) (3C10 and CH31) to chicken L chain, we analysed their cross-reactivity with sera from 33 avian species belonging to nine different orders. Among Galliformes tested, mAbs 3C10 and CH31 reacted with L chains of chicken, turkey, four genera of pheasants, tragopan and peafowl, but not with sera of grey partridge, quail and Japanese quail. Immunoglobulins of guinea-fowl reacted only with mAb 3C10. Both mAbs reacted also with the L chain of Eurasian griffon (order Falconiformes) and domestic sparrow (order Passeriformes). Sera from six other orders of Aves did not react with either of the two mAbs. EIA using mAbs 3C10 and CH31 enabled detection of antibodies to major avian pathogens in sera of chickens, turkeys, pheasants, peafowl, Eurasian griffon and guinea-fowl (only with mAb 3C10). The N-terminal amino acid sequence of pheasant L chain (19 residues) was identical to that of chicken. Sequences of genes encoding the L chain constant regions of pheasants, turkey and partridge were determined and deposited in the public database (GenBank accession numbers: FJ 649651, FJ 649652 and FJ 649653, respectively). Among them, amino acid sequence of pheasants is the most similar to that of chicken (97% similarity), whereas those of turkey and partridge have greater similarity to each other (89%) than to any other avian L chain sequence. The characteristic deletion of two amino acids which is present in the L chain constant region in Galliformes has been most likely introduced to their L chain after their divergence from Anseriformes. PMID:24603015

  2. Children, avian influenza H5N1 and preparing for the next pandemic.

    PubMed

    Nicoll, A

    2008-05-01

    The emergence of avian influenza A/H5N1 viruses has driven pandemic preparations to become government priorities across Europe. To date these viruses have remained poorly adapted to humans and the risk of a pandemic based on H5N1 is unquantifiable. However, the risk of a future pandemic is 100%. Preparations are essential and without these many avoidable deaths will occur. Children will be affected at least as much as adults and may play an important role in amplifying transmission. Pharmacological and public health interventions focused on children will save lives through suggested community measures such as pre-emptive closures of schools, and need to be considered carefully, balancing benefits against negative consequences. Child health services will be hugely stressed by any pandemic but also have the potential to save many lives. The challenge will be to deliver core services in the face of major staff illnesses. Detailed local business continuity planning will be essential.

  3. Chemical ions affect survival of avian cholera organisms in pondwater

    USGS Publications Warehouse

    Price, J.I.; Yandell, B.S.; Porter, W.P.

    1992-01-01

    Avian cholera (Pasteurella multocida) is a major disease of wild waterfowl, but its epizootiology remains little understood. Consequently, we examined whether chemical ions affected survival of avian cholera organisms in water collected from the Nebraska Rainwater Basin where avian cholera is enzootic. We tested the response of P. multocida to ammonium (NH4), calcium (Ca), magnesium (Mg), nitrate (NO3), and ortho-phosphate (PO4) ions individually and in combination using a fractional factorial design divided into 4 blocks. High concentrations of Ca and Mg, singly or in combination, increased survival of P. multocida organisms (P < 0.001). We developed a survival index to predict whether or not specific ponds could be "problem" or "nonproblem" avian cholera sites based on concentrations of these ions in the water.

  4. The avian tectorial membrane: Why is it tapered?

    NASA Astrophysics Data System (ADS)

    Iwasa, Kuni H.; Ricci, Anthony J.

    2015-12-01

    While the mammalian- and the avian inner ears have well defined tonotopic organizations as well as hair cells specialized for motile and sensing roles, the structural organization of the avian ear is different from its mammalian cochlear counterpart. Presumably this difference stems from the difference in the way motile hair cells function. Short hair cells, whose role is considered analogous to mammalian outer hair cells, presumably depends on their hair bundles, and not motility of their cell body, in providing the motile elements of the cochlear amplifier. This report focuses on the role of the avian tectorial membrane, specifically by addressing the question, "Why is the avian tectorial membrane tapered from the neural to the abneural direction?"

  5. Comparative genomics reveals insights into avian genome evolution and adaptation.

    PubMed

    Zhang, Guojie; Li, Cai; Li, Qiye; Li, Bo; Larkin, Denis M; Lee, Chul; Storz, Jay F; Antunes, Agostinho; Greenwold, Matthew J; Meredith, Robert W; Ödeen, Anders; Cui, Jie; Zhou, Qi; Xu, Luohao; Pan, Hailin; Wang, Zongji; Jin, Lijun; Zhang, Pei; Hu, Haofu; Yang, Wei; Hu, Jiang; Xiao, Jin; Yang, Zhikai; Liu, Yang; Xie, Qiaolin; Yu, Hao; Lian, Jinmin; Wen, Ping; Zhang, Fang; Li, Hui; Zeng, Yongli; Xiong, Zijun; Liu, Shiping; Zhou, Long; Huang, Zhiyong; An, Na; Wang, Jie; Zheng, Qiumei; Xiong, Yingqi; Wang, Guangbiao; Wang, Bo; Wang, Jingjing; Fan, Yu; da Fonseca, Rute R; Alfaro-Núñez, Alonzo; Schubert, Mikkel; Orlando, Ludovic; Mourier, Tobias; Howard, Jason T; Ganapathy, Ganeshkumar; Pfenning, Andreas; Whitney, Osceola; Rivas, Miriam V; Hara, Erina; Smith, Julia; Farré, Marta; Narayan, Jitendra; Slavov, Gancho; Romanov, Michael N; Borges, Rui; Machado, João Paulo; Khan, Imran; Springer, Mark S; Gatesy, John; Hoffmann, Federico G; Opazo, Juan C; Håstad, Olle; Sawyer, Roger H; Kim, Heebal; Kim, Kyu-Won; Kim, Hyeon Jeong; Cho, Seoae; Li, Ning; Huang, Yinhua; Bruford, Michael W; Zhan, Xiangjiang; Dixon, Andrew; Bertelsen, Mads F; Derryberry, Elizabeth; Warren, Wesley; Wilson, Richard K; Li, Shengbin; Ray, David A; Green, Richard E; O'Brien, Stephen J; Griffin, Darren; Johnson, Warren E; Haussler, David; Ryder, Oliver A; Willerslev, Eske; Graves, Gary R; Alström, Per; Fjeldså, Jon; Mindell, David P; Edwards, Scott V; Braun, Edward L; Rahbek, Carsten; Burt, David W; Houde, Peter; Zhang, Yong; Yang, Huanming; Wang, Jian; Jarvis, Erich D; Gilbert, M Thomas P; Wang, Jun

    2014-12-12

    Birds are the most species-rich class of tetrapod vertebrates and have wide relevance across many research fields. We explored bird macroevolution using full genomes from 48 avian species representing all major extant clades. The avian genome is principally characterized by its constrained size, which predominantly arose because of lineage-specific erosion of repetitive elements, large segmental deletions, and gene loss. Avian genomes furthermore show a remarkably high degree of evolutionary stasis at the levels of nucleotide sequence, gene synteny, and chromosomal structure. Despite this pattern of conservation, we detected many non-neutral evolutionary changes in protein-coding genes and noncoding regions. These analyses reveal that pan-avian genomic diversity covaries with adaptations to different lifestyles and convergent evolution of traits. PMID:25504712

  6. Development of reference antisera to enteric-origin avian viruses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Recent molecular surveys have revealed geographically distinct lineages of avian reovirus, rotavirus and astrovirus circulating in commercial poultry. To improve our understanding of enteric virus pathogenesis, specific immunological reagents are needed to detect viruses in histological samples. To ...

  7. Comparative genomics reveals insights into avian genome evolution and adaptation.

    PubMed

    Zhang, Guojie; Li, Cai; Li, Qiye; Li, Bo; Larkin, Denis M; Lee, Chul; Storz, Jay F; Antunes, Agostinho; Greenwold, Matthew J; Meredith, Robert W; Ödeen, Anders; Cui, Jie; Zhou, Qi; Xu, Luohao; Pan, Hailin; Wang, Zongji; Jin, Lijun; Zhang, Pei; Hu, Haofu; Yang, Wei; Hu, Jiang; Xiao, Jin; Yang, Zhikai; Liu, Yang; Xie, Qiaolin; Yu, Hao; Lian, Jinmin; Wen, Ping; Zhang, Fang; Li, Hui; Zeng, Yongli; Xiong, Zijun; Liu, Shiping; Zhou, Long; Huang, Zhiyong; An, Na; Wang, Jie; Zheng, Qiumei; Xiong, Yingqi; Wang, Guangbiao; Wang, Bo; Wang, Jingjing; Fan, Yu; da Fonseca, Rute R; Alfaro-Núñez, Alonzo; Schubert, Mikkel; Orlando, Ludovic; Mourier, Tobias; Howard, Jason T; Ganapathy, Ganeshkumar; Pfenning, Andreas; Whitney, Osceola; Rivas, Miriam V; Hara, Erina; Smith, Julia; Farré, Marta; Narayan, Jitendra; Slavov, Gancho; Romanov, Michael N; Borges, Rui; Machado, João Paulo; Khan, Imran; Springer, Mark S; Gatesy, John; Hoffmann, Federico G; Opazo, Juan C; Håstad, Olle; Sawyer, Roger H; Kim, Heebal; Kim, Kyu-Won; Kim, Hyeon Jeong; Cho, Seoae; Li, Ning; Huang, Yinhua; Bruford, Michael W; Zhan, Xiangjiang; Dixon, Andrew; Bertelsen, Mads F; Derryberry, Elizabeth; Warren, Wesley; Wilson, Richard K; Li, Shengbin; Ray, David A; Green, Richard E; O'Brien, Stephen J; Griffin, Darren; Johnson, Warren E; Haussler, David; Ryder, Oliver A; Willerslev, Eske; Graves, Gary R; Alström, Per; Fjeldså, Jon; Mindell, David P; Edwards, Scott V; Braun, Edward L; Rahbek, Carsten; Burt, David W; Houde, Peter; Zhang, Yong; Yang, Huanming; Wang, Jian; Jarvis, Erich D; Gilbert, M Thomas P; Wang, Jun

    2014-12-12

    Birds are the most species-rich class of tetrapod vertebrates and have wide relevance across many research fields. We explored bird macroevolution using full genomes from 48 avian species representing all major extant clades. The avian genome is principally characterized by its constrained size, which predominantly arose because of lineage-specific erosion of repetitive elements, large segmental deletions, and gene loss. Avian genomes furthermore show a remarkably high degree of evolutionary stasis at the levels of nucleotide sequence, gene synteny, and chromosomal structure. Despite this pattern of conservation, we detected many non-neutral evolutionary changes in protein-coding genes and noncoding regions. These analyses reveal that pan-avian genomic diversity covaries with adaptations to different lifestyles and convergent evolution of traits.

  8. Comparative genomics reveals insights into avian genome evolution and adaptation

    PubMed Central

    Zhang, Guojie; Li, Cai; Li, Qiye; Li, Bo; Larkin, Denis M.; Lee, Chul; Storz, Jay F.; Antunes, Agostinho; Greenwold, Matthew J.; Meredith, Robert W.; Ödeen, Anders; Cui, Jie; Zhou, Qi; Xu, Luohao; Pan, Hailin; Wang, Zongji; Jin, Lijun; Zhang, Pei; Hu, Haofu; Yang, Wei; Hu, Jiang; Xiao, Jin; Yang, Zhikai; Liu, Yang; Xie, Qiaolin; Yu, Hao; Lian, Jinmin; Wen, Ping; Zhang, Fang; Li, Hui; Zeng, Yongli; Xiong, Zijun; Liu, Shiping; Zhou, Long; Huang, Zhiyong; An, Na; Wang, Jie; Zheng, Qiumei; Xiong, Yingqi; Wang, Guangbiao; Wang, Bo; Wang, Jingjing; Fan, Yu; da Fonseca, Rute R.; Alfaro-Núñez, Alonzo; Schubert, Mikkel; Orlando, Ludovic; Mourier, Tobias; Howard, Jason T.; Ganapathy, Ganeshkumar; Pfenning, Andreas; Whitney, Osceola; Rivas, Miriam V.; Hara, Erina; Smith, Julia; Farré, Marta; Narayan, Jitendra; Slavov, Gancho; Romanov, Michael N; Borges, Rui; Machado, João Paulo; Khan, Imran; Springer, Mark S.; Gatesy, John; Hoffmann, Federico G.; Opazo, Juan C.; Håstad, Olle; Sawyer, Roger H.; Kim, Heebal; Kim, Kyu-Won; Kim, Hyeon Jeong; Cho, Seoae; Li, Ning; Huang, Yinhua; Bruford, Michael W.; Zhan, Xiangjiang; Dixon, Andrew; Bertelsen, Mads F.; Derryberry, Elizabeth; Warren, Wesley; Wilson, Richard K; Li, Shengbin; Ray, David A.; Green, Richard E.; O’Brien, Stephen J.; Griffin, Darren; Johnson, Warren E.; Haussler, David; Ryder, Oliver A.; Willerslev, Eske; Graves, Gary R.; Alström, Per; Fjeldså, Jon; Mindell, David P.; Edwards, Scott V.; Braun, Edward L.; Rahbek, Carsten; Burt, David W.; Houde, Peter; Zhang, Yong; Yang, Huanming; Wang, Jian; Jarvis, Erich D.; Gilbert, M. Thomas P.; Wang, Jun

    2015-01-01

    Birds are the most species-rich class of tetrapod vertebrates and have wide relevance across many research fields. We explored bird macroevolution using full genomes from 48 avian species representing all major extant clades. The avian genome is principally characterized by its constrained size, which predominantly arose because of lineage-specific erosion of repetitive elements, large segmental deletions, and gene loss. Avian genomes furthermore show a remarkably high degree of evolutionary stasis at the levels of nucleotide sequence, gene synteny, and chromosomal structure. Despite this pattern of conservation, we detected many non-neutral evolutionary changes in protein-coding genes and noncoding regions. These analyses reveal that pan-avian genomic diversity covaries with adaptations to different lifestyles and convergent evolution of traits. PMID:25504712

  9. Approach, avoidance and weight-related testing: An investigation of frontal EEG asymmetry.

    PubMed

    Faries, Mark D; Kephart, Wesley; Jones, Eric J

    2015-01-01

    Two motivational systems underlie behaviour and affective responses - an inhibition/avoidance system and an activation/approach system. The purpose of the present study was to explore if individual differences in these motivational systems would occur in response to common weight and body composition testing within a sample of young, adult women. Electroencephalogram was used to distinguish approach or avoidance orientations via frontal asymmetry before and after testing sessions. Clear distinctions in motivational response were found, with 65% of the sample responding with an approach motivation, while 35% responded with an avoidance motivation. Even though all participants, on average, experienced a negative affective response, only the avoidance group self-reported a subsequent increase in "comfort food" consumption of desserts and snacks the week following the testing session. As shown with other stressors, clear individual differences exist in motivational responses to common weight and body composition testing. Such testing produces a general negative affective response; however, the individual differences in motivational responses might produce different behavioural choices. Future research and interventions in health communication should be considerate to this variation in motivational responses to help explain changes in both healthy and unhealthy behaviours following interactions involving one's body weight and/or body composition. PMID:25220609

  10. Brachyspira pilosicoli-induced avian intestinal spirochaetosis.

    PubMed

    Le Roy, Caroline I; Mappley, Luke J; La Ragione, Roberto M; Woodward, Martin J; Claus, Sandrine P

    2015-01-01

    Avian intestinal spirochaetosis (AIS) is a common disease occurring in poultry that can be caused by Brachyspira pilosicoli, a Gram-negative bacterium of the order Spirochaetes. During AIS, this opportunistic pathogen colonises the lower gastrointestinal (GI) tract of poultry (principally, the ileum, caeca, and colon), which can cause symptoms such as diarrhoea, reduced growth rate, and reduced egg production and quality. Due to the large increase of bacterial resistance to antibiotic treatment, the European Union banned in 2006 the prophylactic use of antibiotics as growth promoters in livestock. Consequently, the number of outbreaks of AIS has dramatically increased in the UK resulting in significant economic losses. This review summarises the current knowledge about AIS infection caused by B. pilosicoli and discusses various treatments and prevention strategies to control AIS. PMID:26679774

  11. Degradation of some pesticides in avian embryos.

    PubMed

    Várnagy, L

    1999-01-01

    On day 9 or 12 of the hatching period different pesticides (parathion, methyl-parathion, carbendazim, 2,4-D-amine Na, phosmethylane) were applied in ecotoxicological trials. The formulations were either injected into the air space of pheasant, quail or hen eggs or hen eggs were treated by the immersion technique. The residues of pesticides were measured in samples on days 13, 14 and 16 of incubation of chicken and pheasant embryos, while the Japanese quail embryos were analysed on days 10-14 of incubation. Analytical chemistry data showed a varying degradation rate of the compounds in avian embryos of the same species. The residues directly affect the embryos, disturbing their normal development and causing pathophysiological and morphological changes.

  12. Efficient statistical mapping of avian count data

    USGS Publications Warehouse

    Royle, J. Andrew; Wikle, C.K.

    2005-01-01

    We develop a spatial modeling framework for count data that is efficient to implement in high-dimensional prediction problems. We consider spectral parameterizations for the spatially varying mean of a Poisson model. The spectral parameterization of the spatial process is very computationally efficient, enabling effective estimation and prediction in large problems using Markov chain Monte Carlo techniques. We apply this model to creating avian relative abundance maps from North American Breeding Bird Survey (BBS) data. Variation in the ability of observers to count birds is modeled as spatially independent noise, resulting in over-dispersion relative to the Poisson assumption. This approach represents an improvement over existing approaches used for spatial modeling of BBS data which are either inefficient for continental scale modeling and prediction or fail to accommodate important distributional features of count data thus leading to inaccurate accounting of prediction uncertainty.

  13. Brachyspira pilosicoli-induced avian intestinal spirochaetosis

    PubMed Central

    Le Roy, Caroline I.; Mappley, Luke J.; La Ragione, Roberto M.; Woodward, Martin J.; Claus, Sandrine P.

    2015-01-01

    Avian intestinal spirochaetosis (AIS) is a common disease occurring in poultry that can be caused by Brachyspira pilosicoli, a Gram-negative bacterium of the order Spirochaetes. During AIS, this opportunistic pathogen colonises the lower gastrointestinal (GI) tract of poultry (principally, the ileum, caeca, and colon), which can cause symptoms such as diarrhoea, reduced growth rate, and reduced egg production and quality. Due to the large increase of bacterial resistance to antibiotic treatment, the European Union banned in 2006 the prophylactic use of antibiotics as growth promoters in livestock. Consequently, the number of outbreaks of AIS has dramatically increased in the UK resulting in significant economic losses. This review summarises the current knowledge about AIS infection caused by B. pilosicoli and discusses various treatments and prevention strategies to control AIS. PMID:26679774

  14. Artist conception of the Avian Development Facility

    NASA Technical Reports Server (NTRS)

    2003-01-01

    The Avian Development Facility (ADF) supports 36 eggs in two carousels, one of which rotates to provide a 1-g control for comparing to eggs grown in microgravity. The ADF was designed to incubate up to 36 Japanese quail eggs, 18 in microgravity and 18 in artificial gravity. The two sets of eggs were exposed to otherwise identical conditions, the first time this is been accomplished in space. Eggs are preserved at intervals to provide snapshots of their development for later analysis. Quails incubate in just 15 days, so they are an ideal species to be studied within the duration of space shuttle missions. Further, several investigators can use the same specimens to address different questions. The ADF originated in NASA's Shuttle Student Involvement program in the 1980s and was developed under the NASA Small Business Irnovation Research program. In late 2001, the ADF made its first flight and carried eggs used in two investigations.

  15. Avian Influenza spread and transmission dynamics

    USGS Publications Warehouse

    Bourouiba, Lydia; Gourley, Stephen A.; Liu, Rongsong; Takekawa, John Y.; Wu, Jianhong; Chen, Dongmei; Moulin, Bernard; Wu, Jianhong

    2015-01-01

    The spread of highly pathogenic avian influenza (HPAI) viruses of type A of subtype H5N1 has been a serious threat to global public health. Understanding the roles of various (migratory, wild, poultry) bird species in the transmission of these viruses is critical for designing and implementing effective control and intervention measures. Developing appropriate models and mathematical techniques to understand these roles and to evaluate the effectiveness of mitigation strategies have been a challenge. Recent development of the global health surveillance (especially satellite tracking and GIS techniques) and the mathematical theory of dynamical systems combined have gradually shown the promise of some cutting-edge methodologies and techniques in mathematical biology to meet this challenge.

  16. Seroprevalence of avian pneumovirus in Minnesota turkeys.

    PubMed

    Goyal, Sagar M; Lauer, Dale; Friendshuh, Keith; Halvorson, David A

    2003-01-01

    Avian pneumovirus (APV) causes respiratory tract infection in turkeys and was first seen in the United States in Colorado in late 1996. In early 1997, the disease was recognized in Minnesota and caused estimated losses of up to 15 million dollars per year. This virus has not been reported in the other turkey producing states. We here report the seroprevalence of APV in Minnesota from August 1998 to July 2002. The average rate of seroprevalence has been 36.3% (range = 14.2%-64.8%). A seasonal bias was observed, with peak incidences in the fall and spring. A higher rate of seropositivity was observed in counties with the highest concentration of turkeys.

  17. A glossary for avian conservation biology

    USGS Publications Warehouse

    Koford, Rolf R.; Dunning, J.B.; Ribic, C.A.; Finch, D.M.

    1994-01-01

    This glossary provides standard definitions for many of the terms used in avian conservation biology. We compiled these definitions to assist communication among researchers, managers, and others involved in the Neotropical Migratory Bird Conservation Program, also known as Partners in Flight. We used existing glossaries and recent literature to prepare this glossary. The cited sources were not necessarily the first ones to use the terms. Many definitions were taken verbatim from the cited source material. Others were modified slightly to clarify the meaning. Definitions that were modified to a greater extent are indicated as being adapted from the originals. Terms that have been used in more than one way by different authors are listed with numbered alternative definitions if the definitions differ substantially.

  18. Infrasound and the avian navigational map

    USGS Publications Warehouse

    Hagstrum, J.T.

    2001-01-01

    Birds can accurately navigate over hundreds to thousands of kilometres, and use celestial and magnetic compass senses to orient their flight. How birds determine their location in order to select the correct homeward bearing (map sense) remains controversial, and has been attributed to their olfactory or magnetic senses. Pigeons can hear infrasound down to 0??05 Hz, and an acoustic avian map is proposed consisting of infrasonic cues radiated from steep-sided topographic features. The source of these infrasonic signals is microseisms continuously generated by interfering oceanic waves. Atmospheric processes affecting the infrasonic map cues can explain perplexing experimental results from pigeon releases. Moreover, four recent disrupted pigeon races in Europe and the north-eastern USA intersected infrasonic shock waves from the Concorde supersonic transport. Having an acoustic map might also allow clock-shifted birds to test their homeward progress and select between their magnetic and solar compasses.

  19. Identifying avian sources of faecal contamination using sterol analysis.

    PubMed

    Devane, Megan L; Wood, David; Chappell, Andrew; Robson, Beth; Webster-Brown, Jenny; Gilpin, Brent J

    2015-10-01

    Discrimination of the source of faecal pollution in water bodies is an important step in the assessment and mitigation of public health risk. One tool for faecal source tracking is the analysis of faecal sterols which are present in faeces of animals in a range of distinctive ratios. Published ratios are able to discriminate between human and herbivore mammal faecal inputs but are of less value for identifying pollution from wildfowl, which can be a common cause of elevated bacterial indicators in rivers and streams. In this study, the sterol profiles of 50 avian-derived faecal specimens (seagulls, ducks and chickens) were examined alongside those of 57 ruminant faeces and previously published sterol profiles of human wastewater, chicken effluent and animal meatwork effluent. Two novel sterol ratios were identified as specific to avian faecal scats, which, when incorporated into a decision tree with human and herbivore mammal indicative ratios, were able to identify sterols from avian-polluted waterways. For samples where the sterol profile was not consistent with herbivore mammal or human pollution, avian pollution is indicated when the ratio of 24-ethylcholestanol/(24-ethylcholestanol + 24-ethylcoprostanol + 24-ethylepicoprostanol) is ≥0.4 (avian ratio 1) and the ratio of cholestanol/(cholestanol + coprostanol + epicoprostanol) is ≥0.5 (avian ratio 2). When avian pollution is indicated, further confirmation by targeted PCR specific markers can be employed if greater confidence in the pollution source is required. A 66% concordance between sterol ratios and current avian PCR markers was achieved when 56 water samples from polluted waterways were analysed. PMID:26370196

  20. Identifying avian sources of faecal contamination using sterol analysis.

    PubMed

    Devane, Megan L; Wood, David; Chappell, Andrew; Robson, Beth; Webster-Brown, Jenny; Gilpin, Brent J

    2015-10-01

    Discrimination of the source of faecal pollution in water bodies is an important step in the assessment and mitigation of public health risk. One tool for faecal source tracking is the analysis of faecal sterols which are present in faeces of animals in a range of distinctive ratios. Published ratios are able to discriminate between human and herbivore mammal faecal inputs but are of less value for identifying pollution from wildfowl, which can be a common cause of elevated bacterial indicators in rivers and streams. In this study, the sterol profiles of 50 avian-derived faecal specimens (seagulls, ducks and chickens) were examined alongside those of 57 ruminant faeces and previously published sterol profiles of human wastewater, chicken effluent and animal meatwork effluent. Two novel sterol ratios were identified as specific to avian faecal scats, which, when incorporated into a decision tree with human and herbivore mammal indicative ratios, were able to identify sterols from avian-polluted waterways. For samples where the sterol profile was not consistent with herbivore mammal or human pollution, avian pollution is indicated when the ratio of 24-ethylcholestanol/(24-ethylcholestanol + 24-ethylcoprostanol + 24-ethylepicoprostanol) is ≥0.4 (avian ratio 1) and the ratio of cholestanol/(cholestanol + coprostanol + epicoprostanol) is ≥0.5 (avian ratio 2). When avian pollution is indicated, further confirmation by targeted PCR specific markers can be employed if greater confidence in the pollution source is required. A 66% concordance between sterol ratios and current avian PCR markers was achieved when 56 water samples from polluted waterways were analysed.

  1. Intranasal Immunization with Pressure Inactivated Avian Influenza Elicits Cellular and Humoral Responses in Mice

    PubMed Central

    Barroso, Shana P. C.; Nico, Dirlei; Nascimento, Danielle; Santos, Ana Clara V.; Couceiro, José Nelson S. S.; Bozza, Fernando A.; Ferreira, Ana M. A.; Ferreira, Davis F.; Palatnik-de-Sousa, Clarisa B.; Souza, Thiago Moreno L.; Gomes, Andre M. O.; Silva, Jerson L.; Oliveira, Andréa C.

    2015-01-01

    Influenza viruses pose a serious global health threat, particularly in light of newly emerging strains, such as the avian influenza H5N1 and H7N9 viruses. Vaccination remains the primary method for preventing acquiring influenza or for avoiding developing serious complications related to the disease. Vaccinations based on inactivated split virus vaccines or on chemically inactivated whole virus have some important drawbacks, including changes in the immunogenic properties of the virus. To induce a greater mucosal immune response, intranasally administered vaccines are highly desired as they not only prevent disease but can also block the infection at its primary site. To avoid these drawbacks, hydrostatic pressure has been used as a potential method for viral inactivation and vaccine production. In this study, we show that hydrostatic pressure inactivates the avian influenza A H3N8 virus, while still maintaining hemagglutinin and neuraminidase functionalities. Challenged vaccinated animals showed no disease signs (ruffled fur, lethargy, weight loss, and huddling). Similarly, these animals showed less Evans Blue dye leakage and lower cell counts in their bronchoalveolar lavage fluid compared with the challenged non-vaccinated group. We found that the whole inactivated particles were capable of generating a neutralizing antibody response in serum, and IgA was also found in nasal mucosa and feces. After the vaccination and challenge we observed Th1/Th2 cytokine secretion with a prevalence of IFN-γ. Our data indicate that the animals present a satisfactory immune response after vaccination and are protected against infection. Our results may pave the way for the development of a novel pressure-based vaccine against influenza virus. PMID:26056825

  2. Estimating avian population size using Bowden's estimator

    USGS Publications Warehouse

    Diefenbach, D.R.

    2009-01-01

    Avian researchers often uniquely mark birds, and multiple estimators could be used to estimate population size using individually identified birds. However, most estimators of population size require that all sightings of marked birds be uniquely identified, and many assume homogeneous detection probabilities. Bowden's estimator can incorporate sightings of marked birds that are not uniquely identified and relax assumptions required of other estimators. I used computer simulation to evaluate the performance of Bowden's estimator for situations likely to be encountered in bird studies. When the assumptions of the estimator were met, abundance and variance estimates and confidence-interval coverage were accurate. However, precision was poor for small population sizes (N ??? 50) unless a large percentage of the population was marked (>75%) and multiple (???8) sighting surveys were conducted. If additional birds are marked after sighting surveys begin, it is important to initially mark a large proportion of the population (pm ??? 0.5 if N ??? 100 or pm > 0.1 if N ??? 250) and minimize sightings in which birds are not uniquely identified; otherwise, most population estimates will be overestimated by >10%. Bowden's estimator can be useful for avian studies because birds can be resighted multiple times during a single survey, not all sightings of marked birds have to uniquely identify individuals, detection probabilities among birds can vary, and the complete study area does not have to be surveyed. I provide computer code for use with pilot data to design mark-resight surveys to meet desired precision for abundance estimates. ?? 2009 by The American Ornithologists' Union. All rights reserved.

  3. Impacts of climate change on avian populations.

    PubMed

    Jenouvrier, Stephanie

    2013-07-01

    This review focuses on the impacts of climate change on population dynamics. I introduce the MUP (Measuring, Understanding, and Predicting) approach, which provides a general framework where an enhanced understanding of climate-population processes, along with improved long-term data, are merged into coherent projections of future population responses to climate change. This approach can be applied to any species, but this review illustrates its benefit using birds as examples. Birds are one of the best-studied groups and a large number of studies have detected climate impacts on vital rates (i.e., life history traits, such as survival, maturation, or breeding, affecting changes in population size and composition) and population abundance. These studies reveal multifaceted effects of climate with direct, indirect, time-lagged, and nonlinear effects. However, few studies integrate these effects into a climate-dependent population model to understand the respective role of climate variables and their components (mean state, variability, extreme) on population dynamics. To quantify how populations cope with climate change impacts, I introduce a new universal variable: the 'population robustness to climate change.' The comparison of such robustness, along with prospective and retrospective analysis may help to identify the major climate threats and characteristics of threatened avian species. Finally, studies projecting avian population responses to future climate change predicted by IPCC-class climate models are rare. Population projections hinge on selecting a multiclimate model ensemble at the appropriate temporal and spatial scales and integrating both radiative forcing and internal variability in climate with fully specified uncertainties in both demographic and climate processes.

  4. Avian rotavirus enteritis - an updated review.

    PubMed

    Dhama, Kuldeep; Saminathan, Mani; Karthik, Kumaragurubaran; Tiwari, Ruchi; Shabbir, Muhammad Zubair; Kumar, Naveen; Malik, Yashpal Singh; Singh, Raj Kumar

    2015-01-01

    Rotaviruses (RVs) are among the leading causes of enteritis and diarrhea in a number of mammalian and avian species, and impose colossal loss to livestock and poultry industry globally. Subsequent to detection of rotavirus in mammalian hosts in 1973, avian rotavirus (AvRV) was first reported in turkey poults in USA during 1977 and since then RVs of group A (RVA), D (RVD), F (RVF) and G (RVG) have been identified around the globe. Besides RVA, other AvRV groups (RVD, RVF and RVG) may also contribute to disease. However, their significance has yet to be unraveled. Under field conditions, co-infection of AvRVs occurs with other infectious agents such as astroviruses, enteroviruses, reoviruses, paramyxovirus, adenovirus, Salmonella, Escherichia coli, cryptosporidium and Eimeria species prospering severity of disease outcome. Birds surviving to RV disease predominantly succumb to secondary bacterial infections, mostly E. coli and Salmonella spp. Recent developments in molecular tools including state-of-the-art diagnostics and vaccine development have led to advances in our understanding towards AvRVs. Development of new generation vaccines using immunogenic antigens of AvRV has to be explored and given due importance. Till now, no effective vaccines are available. Although specific as well as sensitive approaches are available to identify and characterize AvRVs, there is still need to have point-of-care detection assays to review disease burden, contemplate new directions for adopting vaccination and follow improvements in public health measures. This review discusses AvRVs, their epidemiology, pathology and pathogenesis, immunity, recent trends in diagnostics, vaccines, therapeutics as well as appropriate prevention and control strategies.

  5. Avian rotavirus enteritis - an updated review.

    PubMed

    Dhama, Kuldeep; Saminathan, Mani; Karthik, Kumaragurubaran; Tiwari, Ruchi; Shabbir, Muhammad Zubair; Kumar, Naveen; Malik, Yashpal Singh; Singh, Raj Kumar

    2015-01-01

    Rotaviruses (RVs) are among the leading causes of enteritis and diarrhea in a number of mammalian and avian species, and impose colossal loss to livestock and poultry industry globally. Subsequent to detection of rotavirus in mammalian hosts in 1973, avian rotavirus (AvRV) was first reported in turkey poults in USA during 1977 and since then RVs of group A (RVA), D (RVD), F (RVF) and G (RVG) have been identified around the globe. Besides RVA, other AvRV groups (RVD, RVF and RVG) may also contribute to disease. However, their significance has yet to be unraveled. Under field conditions, co-infection of AvRVs occurs with other infectious agents such as astroviruses, enteroviruses, reoviruses, paramyxovirus, adenovirus, Salmonella, Escherichia coli, cryptosporidium and Eimeria species prospering severity of disease outcome. Birds surviving to RV disease predominantly succumb to secondary bacterial infections, mostly E. coli and Salmonella spp. Recent developments in molecular tools including state-of-the-art diagnostics and vaccine development have led to advances in our understanding towards AvRVs. Development of new generation vaccines using immunogenic antigens of AvRV has to be explored and given due importance. Till now, no effective vaccines are available. Although specific as well as sensitive approaches are available to identify and characterize AvRVs, there is still need to have point-of-care detection assays to review disease burden, contemplate new directions for adopting vaccination and follow improvements in public health measures. This review discusses AvRVs, their epidemiology, pathology and pathogenesis, immunity, recent trends in diagnostics, vaccines, therapeutics as well as appropriate prevention and control strategies. PMID:25917772

  6. Individual differences in women's rape avoidance behaviors.

    PubMed

    McKibbin, William F; Shackelford, Todd K; Miner, Emily J; Bates, Vincent M; Liddle, James R

    2011-04-01

    Rape can exact severe psychological, physical, and reproductive costs on women, and likely was a recurrent adaptive problem over human evolutionary history. Therefore, women may have evolved psychological mechanisms that motivate rape avoidance behaviors. Guided heuristically by an evolutionary perspective, we tested the hypothesis that women's rape avoidance behaviors would vary with several individual difference variables. Specifically, we predicted that rape avoidance behaviors would covary positively with (1) women's attractiveness, (2) women's involvement in a committed romantic relationship, and (3) the number of family members living nearby. We also predicted that women's rape avoidance behaviors would covary negatively with age. We administered the Rape Avoidance Inventory (McKibbin et al., Pers Indiv Differ 39:336-340, 2009) and a demographic survey to a sample of women (n = 144). The results of correlational and regression analyses were consistent with the predictions, with the exception that women's rape avoidance behaviors did not covary with women's age. Discussion highlighted limitations of the current research and directions for future research on women's rape avoidance psychology and behaviors.

  7. Moving Obstacle Avoidance for Unmanned Aerial Vehicles

    NASA Astrophysics Data System (ADS)

    Lin, Yucong

    There has been a vast increase in applications of Unmanned Aerial Vehicles (UAVs) in civilian domains. To operate in the civilian airspace, a UAV must be able to sense and avoid both static and moving obstacles for flight safety. While indoor and low-altitude environments are mainly occupied by static obstacles, risks in space of higher altitude primarily come from moving obstacles such as other aircraft or flying vehicles in the airspace. Therefore, the ability to avoid moving obstacles becomes a necessity for Unmanned Aerial Vehicles. Towards enabling a UAV to autonomously sense and avoid moving obstacles, this thesis makes the following contributions. Initially, an image-based reactive motion planner is developed for a quadrotor to avoid a fast approaching obstacle. Furthermore, A Dubin's curve based geometry method is developed as a global path planner for a fixed-wing UAV to avoid collisions with aircraft. The image-based method is unable to produce an optimal path and the geometry method uses a simplified UAV model. To compensate these two disadvantages, a series of algorithms built upon the Closed-Loop Rapid Exploratory Random Tree are developed as global path planners to generate collision avoidance paths in real time. The algorithms are validated in Software-In-the-Loop (SITL) and Hardware-In-the-Loop (HIL) simulations using a fixed-wing UAV model and in real flight experiments using quadrotors. It is observed that the algorithm enables a UAV to avoid moving obstacles approaching to it with different directions and speeds.

  8. Neuroscience and approach/avoidance personality traits: a two stage (valuation-motivation) approach.

    PubMed

    Corr, Philip J; McNaughton, Neil

    2012-11-01

    Many personality theories link specific traits to the sensitivities of the neural systems that control approach and avoidance. But there is no consensus on the nature of these systems. Here we combine recent advances in economics and neuroscience to provide a more solid foundation for a neuroscience of approach/avoidance personality. We propose a two-stage integration of valuation (loss/gain) sensitivities with motivational (approach/avoidance/conflict) sensitivities. Our key conclusions are: (1) that valuation of appetitive and aversive events (e.g. gain and loss as studied by behavioural economists) is an independent perceptual input stage--with the economic phenomenon of loss aversion resulting from greater negative valuation sensitivity compared to positive valuation sensitivity; (2) that valuation of an appetitive stimulus then interacts with a contingency of presentation or omission to generate a motivational 'attractor' or 'repulsor', respectively (vice versa for an aversive stimulus); (3) the resultant behavioural tendencies to approach or avoid have distinct sensitivities to those of the valuation systems; (4) while attractors and repulsors can reinforce new responses they also, more usually, elicit innate or previously conditioned responses and so the perception/valuation-motivation/action complex is best characterised as acting as a 'reinforcer' not a 'reinforcement'; and (5) approach-avoidance conflict must be viewed as activating a third motivation system that is distinct from the basic approach and avoidance systems. We provide examples of methods of assessing each of the constructs within approach-avoidance theories and of linking these constructs to personality measures. We sketch a preliminary five-element reinforcer sensitivity theory (RST-5) as a first step in the integration of existing specific approach-avoidance theories into a coherent neuroscience of personality. PMID:23041073

  9. Neuroscience and approach/avoidance personality traits: a two stage (valuation-motivation) approach.

    PubMed

    Corr, Philip J; McNaughton, Neil

    2012-11-01

    Many personality theories link specific traits to the sensitivities of the neural systems that control approach and avoidance. But there is no consensus on the nature of these systems. Here we combine recent advances in economics and neuroscience to provide a more solid foundation for a neuroscience of approach/avoidance personality. We propose a two-stage integration of valuation (loss/gain) sensitivities with motivational (approach/avoidance/conflict) sensitivities. Our key conclusions are: (1) that valuation of appetitive and aversive events (e.g. gain and loss as studied by behavioural economists) is an independent perceptual input stage--with the economic phenomenon of loss aversion resulting from greater negative valuation sensitivity compared to positive valuation sensitivity; (2) that valuation of an appetitive stimulus then interacts with a contingency of presentation or omission to generate a motivational 'attractor' or 'repulsor', respectively (vice versa for an aversive stimulus); (3) the resultant behavioural tendencies to approach or avoid have distinct sensitivities to those of the valuation systems; (4) while attractors and repulsors can reinforce new responses they also, more usually, elicit innate or previously conditioned responses and so the perception/valuation-motivation/action complex is best characterised as acting as a 'reinforcer' not a 'reinforcement'; and (5) approach-avoidance conflict must be viewed as activating a third motivation system that is distinct from the basic approach and avoidance systems. We provide examples of methods of assessing each of the constructs within approach-avoidance theories and of linking these constructs to personality measures. We sketch a preliminary five-element reinforcer sensitivity theory (RST-5) as a first step in the integration of existing specific approach-avoidance theories into a coherent neuroscience of personality.

  10. How cooperatively breeding birds identify relatives and avoid incest: New insights into dispersal and kin recognition.

    PubMed

    Riehl, Christina; Stern, Caitlin A

    2015-12-01

    Cooperative breeding in birds typically occurs when offspring - usually males - delay dispersal from their natal group, remaining with the family to help rear younger kin. Sex-biased dispersal is thought to have evolved in order to reduce the risk of inbreeding, resulting in low relatedness between mates and the loss of indirect fitness benefits for the dispersing sex. In this review, we discuss several recent studies showing that dispersal patterns are more variable than previously thought, often leading to complex genetic structure within cooperative avian societies. These empirical findings accord with recent theoretical models suggesting that sex- biased dispersal is neither necessary, nor always sufficient, to prevent inbreeding. The ability to recognize relatives, primarily by learning individual or group-specific vocalizations, may play a more important role in incest avoidance than currently appreciated.

  11. How cooperatively breeding birds identify relatives and avoid incest: New insights into dispersal and kin recognition.

    PubMed

    Riehl, Christina; Stern, Caitlin A

    2015-12-01

    Cooperative breeding in birds typically occurs when offspring - usually males - delay dispersal from their natal group, remaining with the family to help rear younger kin. Sex-biased dispersal is thought to have evolved in order to reduce the risk of inbreeding, resulting in low relatedness between mates and the loss of indirect fitness benefits for the dispersing sex. In this review, we discuss several recent studies showing that dispersal patterns are more variable than previously thought, often leading to complex genetic structure within cooperative avian societies. These empirical findings accord with recent theoretical models suggesting that sex- biased dispersal is neither necessary, nor always sufficient, to prevent inbreeding. The ability to recognize relatives, primarily by learning individual or group-specific vocalizations, may play a more important role in incest avoidance than currently appreciated. PMID:26577076

  12. Global dynamics of avian influenza epidemic models with psychological effect.

    PubMed

    Liu, Sanhong; Pang, Liuyong; Ruan, Shigui; Zhang, Xinan

    2015-01-01

    Cross-sectional surveys conducted in Thailand and China after the outbreaks of the avian influenza A H5N1 and H7N9 viruses show a high degree of awareness of human avian influenza in both urban and rural populations, a higher level of proper hygienic practice among urban residents, and in particular a dramatically reduced number of visits to live markets in urban population after the influenza A H7N9 outbreak in China in 2013. In this paper, taking into account the psychological effect toward avian influenza in the human population, a bird-to-human transmission model in which the avian population exhibits saturation effect is constructed. The dynamical behavior of the model is studied by using the basic reproduction number. The results demonstrate that the saturation effect within avian population and the psychological effect in human population cannot change the stability of equilibria but can affect the number of infected humans if the disease is prevalent. Numerical simulations are given to support the theoretical results and sensitivity analyses of the basic reproduction number in terms of model parameters that are performed to seek for effective control measures for avian influenza.

  13. Avian Antimicrobial Host Defense Peptides: From Biology to Therapeutic Applications

    PubMed Central

    Zhang, Guolong; Sunkara, Lakshmi T.

    2014-01-01

    Host defense peptides (HDPs) are an important first line of defense with antimicrobial and immunomoduatory properties. Because they act on the microbial membranes or host immune cells, HDPs pose a low risk of triggering microbial resistance and therefore, are being actively investigated as a novel class of antimicrobials and vaccine adjuvants. Cathelicidins and β-defensins are two major families of HDPs in avian species. More than a dozen HDPs exist in birds, with the genes in each HDP family clustered in a single chromosomal segment, apparently as a result of gene duplication and diversification. In contrast to their mammalian counterparts that adopt various spatial conformations, mature avian cathelicidins are mostly α-helical. Avian β-defensins, on the other hand, adopt triple-stranded β-sheet structures similar to their mammalian relatives. Besides classical β-defensins, a group of avian-specific β-defensin-related peptides, namely ovodefensins, exist with a different six-cysteine motif. Like their mammalian counterparts, avian cathelicidins and defensins are derived from either myeloid or epithelial origin expressed in a majority of tissues with broad-spectrum antibacterial and immune regulatory activities. Structure-function relationship studies with several avian HDPs have led to identification of the peptide analogs with potential for use as antimicrobials and vaccine adjuvants. Dietary modulation of endogenous HDP synthesis has also emerged as a promising alternative approach to disease control and prevention in chickens. PMID:24583933

  14. Fusariotoxins in Avian Species: Toxicokinetics, Metabolism and Persistence in Tissues.

    PubMed

    Guerre, Philippe

    2015-06-23

    Fusariotoxins are mycotoxins produced by different species of the genus Fusarium whose occurrence and toxicity vary considerably. Despite the fact avian species are highly exposed to fusariotoxins, the avian species are considered as resistant to their toxic effects, partly because of low absorption and rapid elimination, thereby reducing the risk of persistence of residues in tissues destined for human consumption. This review focuses on the main fusariotoxins deoxynivalenol, T-2 and HT-2 toxins, zearalenone and fumonisin B1 and B2. The key parameters used in the toxicokinetic studies are presented along with the factors responsible for their variations. Then, each toxin is analyzed separately. Results of studies conducted with radiolabelled toxins are compared with the more recent data obtained with HPLC/MS-MS detection. The metabolic pathways of deoxynivalenol, T-2 toxin, and zearalenone are described, with attention paid to the differences among the avian species. Although no metabolite of fumonisins has been reported in avian species, some differences in toxicokinetics have been observed. All the data reviewed suggest that the toxicokinetics of fusariotoxins in avian species differs from those in mammals, and that variations among the avian species themselves should be assessed.

  15. Avian-like breathing mechanics in maniraptoran dinosaurs

    PubMed Central

    Codd, Jonathan R; Manning, Phillip L; Norell, Mark A; Perry, Steven F

    2007-01-01

    In 1868 Thomas Huxley first proposed that dinosaurs were the direct ancestors of birds and subsequent analyses have identified a suite of ‘avian’ characteristics in theropod dinosaurs. Ossified uncinate processes are found in most species of extant birds and also occur in extinct non-avian maniraptoran dinosaurs. Their presence in these dinosaurs represents another morphological character linking them to Aves, and further supports the presence of an avian-like air-sac respiratory system in theropod dinosaurs, prior to the evolution of flight. Here we report a phylogenetic analysis of the presence of uncinate processes in Aves and non-avian maniraptoran dinosaurs indicating that these were homologous structures. Furthermore, recent work on Canada geese has demonstrated that uncinate processes are integral to the mechanics of avian ventilation, facilitating both inspiration and expiration. In extant birds, uncinate processes function to increase the mechanical advantage for movements of the ribs and sternum during respiration. Our study presents a mechanism whereby uncinate processes, in conjunction with lateral and ventral movements of the sternum and gastral basket, affected avian-like breathing mechanics in extinct non-avian maniraptoran dinosaurs. PMID:17986432

  16. Molecular cloning and comparison of avian preproghrelin genes.

    PubMed

    Yuan, Jing; Zhou, Jianjun; Hu, Xiaoxiang; Li, Ning

    2007-04-01

    We report cDNA sequences for the preproghrelin gene from goose, duck, and emu. This gene is involved in stimulating the release of growth hormone in mammals and may play a similar role in avian species. The complete coding sequence of avian preproghrelin encodes a 116 amino acid (aa) protein, which is organized into three parts: the N-terminal hydrophobic signal peptide, a 26 aa peptide for mature ghrelin, and a long C-terminal polypeptide. Domain/motif structures of preproghrelin protein are highly conserved among avian species. Although the avian and mammalian homologs are not highly similar for the whole 116 aa sequence, the identity of the highly conserved "active core" sequence and the n-octanoyl modification of the serine 3 residue avian ghrelin protein with its mammalian homologs implies conserved function of ghrelin protein during evolution. Information provided in this study will be useful in further studies to determine the role the preproghrelin gene plays in the regulation of growth hormone release and body weight gain in avian species. PMID:17347866

  17. When Is Topic Avoidance Unsatisfying? Examining Moderators of the Association between Avoidance and Dissatisfaction

    ERIC Educational Resources Information Center

    Caughlin, John P.; Afifi, Tamara D.

    2004-01-01

    Despite theoretical arguments that avoiding certain topics can be functional, there is consistent evidence that avoiding topics tends to be associated with dissatisfying relationships. This disparity between theory and empirical findings suggests a need to understand better the connection between topic avoidance and relational dissatisfaction. The…

  18. Divorce in cooperatively breeding long-tailed tits: a consequence of inbreeding avoidance?

    PubMed

    Hatchwell, B J; Russell, A F; Ross, D J; Fowlie, M K

    2000-04-22

    The decision of whether to divorce a breeding partner between reproductive attempts can significantly affect individual fitness. In this paper, we report that 63% of surviving pairs of long-tailed tits Aegithalos caudatus divorced between years. We examine three likely explanations for the high divorce rate in this cooperative breeder. The 'better option' hypothesis predicts that divorce and re-pairing increases an individual's reproductive success. However, divorcees did not secure better partners or more helpers and there was no improvement in their reproductive success following divorce. The 'inbreeding avoidance' hypothesis predicts that females should disperse from their family group to avoid breeding with philopatric sons. The observed pattern of divorce was consistent with this hypothesis because, in contrast to the usual avian pattern, divorce was typical for successful pairs (81%) and less frequent in unsuccessful pairs (36-43%). The 'forced divorce' hypothesis predicts that divorce increases as the number of competitors increases. The pattern of divorce among failed breeders was consistent with this hypothesis, but it fails to explain the overall occurrence of divorce because divorcees rarely re-paired with their partners' closest competitors. We discuss long-tailed tits' unique association between divorce and reproductive success in the context of dispersal strategies for inbreeding avoidance. PMID:10819152

  19. Neural architecture of choice behaviour in a concurrent interval schedule.

    PubMed

    Kalenscher, Tobias; Diekamp, Bettina; Güntürkün, Onur

    2003-11-01

    Concurrent interval schedules are classic experimental paradigms that are traditionally employed in psychological research on choice behaviour. To analyse the neural basis of choice in a concurrent fixed interval schedule, pigeons were trained to peck on two response keys. Responses were differentially rewarded in key specific short or long time intervals (SI vs. LI). Using tetrodotoxin, we reversibly blocked the neostriatum caudolaterale (NCL, the avian functional equivalent of the prefrontal cortex), avian caudate-putamen and nucleus accumbens to examine their contribution. A detailed analysis of baseline choice behaviour revealed that response distribution and key affinity were determined by cued or time-related expectancy for rewards on the SI key. The pigeons' response frequency increased on the SI key and decreased on the LI key with increasing temporal proximity to the SI reward and pigeons switched to the LI key after reward delivery. Pecking bursts on the LI key were negatively correlated with bursts on the SI key. Neostriatum caudolaterale inactivation did not affect pecking activity per se but interfered with reward-related temporal modulation of pecking frequency, switching pattern and coupling of LI to SI pecks. Blockade of caudate-putamen resulted in a complete behavioural halt, while inactivation of nucleus accumbens diminished operant behaviour without affecting consummatory responses. These data suggest that the NCL is tuned via indirect striato-pallial projections to integrate cued or time-related reward expectancy into a response selection process in order to set, maintain or shift goals. The NCL possibly feeds forward the resulting motor commands to the caudate-putamen for execution.

  20. Imitation as behaviour parsing.

    PubMed Central

    Byrne, R W

    2003-01-01

    Non-human great apes appear to be able to acquire elaborate skills partly by imitation, raising the possibility of the transfer of skill by imitation in animals that have only rudimentary mentalizing capacities: in contrast to the frequent assumption that imitation depends on prior understanding of others' intentions. Attempts to understand the apes' behaviour have led to the development of a purely mechanistic model of imitation, the 'behaviour parsing' model, in which the statistical regularities that are inevitable in planned behaviour are used to decipher the organization of another agent's behaviour, and thence to imitate parts of it. Behaviour can thereby be understood statistically in terms of its correlations (circumstances of use, effects on the environment) without understanding of intentions or the everyday physics of cause-and-effect. Thus, imitation of complex, novel behaviour may not require mentalizing, but conversely behaviour parsing may be a necessary preliminary to attributing intention and cause. PMID:12689378

  1. No discrimination shock avoidance with sequential presentation of stimuli but shore crabs still reduce shock exposure

    PubMed Central

    Magee, Barry; Elwood, Robert W.

    2016-01-01

    ABSTRACT Insights into the potential for pain may be obtained from examination of behavioural responses to noxious stimuli. In particular, prolonged responses coupled with long-term motivational change and avoidance learning cannot be explained by nociceptive reflex but are consistent with the idea of pain. Here, we placed shore crabs alternately in two halves of a test area divided by an opaque partition. Each area had a dark shelter and in one repeated small electric shocks were delivered in an experimental but not in a control group. Crabs showed no specific avoidance of the shock shelter either during these trials or in a subsequent test in which both were offered simultaneously; however they often emerged from the shock shelter during a trial and thus avoided further shock. More crabs emerged in later trials and took less time to emerge than in early trials. Thus, despite the lack of discrimination learning between the two shelters they used other tactics to markedly reduce the amount of shock received. We note that a previous experiment using simultaneous presentation of two shelters demonstrated rapid discrimination and avoidance learning but the paradigm of sequential presentation appears to prevent this. Nevertheless, the data show clearly that the shock is aversive and tactics, other than discrimination learning, are used to avoid it. Thus, the behaviour is only partially consistent with the idea of pain. PMID:27305928

  2. Prey aggregation is an effective olfactory predator avoidance strategy

    PubMed Central

    Dunn, Alison M.; Morrell, Lesley J.

    2014-01-01

    Predator–prey interactions have a major effect on species abundance and diversity, and aggregation is a well-known anti-predator behaviour. For immobile prey, the effectiveness of aggregation depends on two conditions: (a) the inability of the predator to consume all prey in a group and (b) detection of a single large group not being proportionally easier than that of several small groups. How prey aggregation influences predation rates when visual cues are restricted, such as in turbid water, has not been thoroughly investigated. We carried out foraging (predation) experiments using a fish predator and (dead) chironomid larvae as prey in both laboratory and field settings. In the laboratory, a reduction in visual cue availability (in turbid water) led to a delay in the location of aggregated prey compared to when visual cues were available. Aggregated prey suffered high mortality once discovered, leading to better survival of dispersed prey in the longer term. We attribute this to the inability of the dead prey to take evasive action. In the field (where prey were placed in feeding stations that allowed transmission of olfactory but not visual cues), aggregated (large groups) and semi-dispersed prey survived for longer than dispersed prey—including long term survival. Together, our results indicate that similar to systems where predators hunt using vision, aggregation is an effective anti-predator behaviour for prey avoiding olfactory predators. PMID:24918032

  3. Prey aggregation is an effective olfactory predator avoidance strategy.

    PubMed

    Johannesen, Asa; Dunn, Alison M; Morrell, Lesley J

    2014-01-01

    Predator-prey interactions have a major effect on species abundance and diversity, and aggregation is a well-known anti-predator behaviour. For immobile prey, the effectiveness of aggregation depends on two conditions: (a) the inability of the predator to consume all prey in a group and (b) detection of a single large group not being proportionally easier than that of several small groups. How prey aggregation influences predation rates when visual cues are restricted, such as in turbid water, has not been thoroughly investigated. We carried out foraging (predation) experiments using a fish predator and (dead) chironomid larvae as prey in both laboratory and field settings. In the laboratory, a reduction in visual cue availability (in turbid water) led to a delay in the location of aggregated prey compared to when visual cues were available. Aggregated prey suffered high mortality once discovered, leading to better survival of dispersed prey in the longer term. We attribute this to the inability of the dead prey to take evasive action. In the field (where prey were placed in feeding stations that allowed transmission of olfactory but not visual cues), aggregated (large groups) and semi-dispersed prey survived for longer than dispersed prey-including long term survival. Together, our results indicate that similar to systems where predators hunt using vision, aggregation is an effective anti-predator behaviour for prey avoiding olfactory predators.

  4. Differential effects of safety behaviour subtypes in social anxiety disorder.

    PubMed

    Plasencia, M Leili; Alden, Lynn E; Taylor, Charles T

    2011-10-01

    Clinical observations indicate that individuals with Social Anxiety Disorder (SAD) use a variety of safety behaviours; however, virtually no research has examined the functional effect of different safety-seeking strategies. Accordingly, we conducted two studies to address this issue. Study 1 measured global patterns of safety behaviour use in a large analogue sample. Factor analysis revealed two primary safety behaviour categories, avoidance and impression management. Study 2 assessed situational use of safety behaviours during a controlled social interaction in a clinical sample of 93 patients with Generalised SAD. Factor analysis again revealed support for avoidance and impression-management subtypes. Notably, the two types of safety behaviours were associated with different social outcomes. Avoidance safety behaviours were associated with higher state anxiety during the interaction and negative reactions from participants' interaction partners. Impression-management strategies appeared to impede corrections in negative predictions about subsequent interactions. These findings suggest that it may be beneficial to consider the unique effects of different safety-seeking strategies when assessing and treating SAD. PMID:21831356

  5. Frequency-dependent taste-rejection by avian predation may select for defence chemical polymorphisms in aposematic prey.

    PubMed

    Skelhorn, John; Rowe, Candy

    2005-12-22

    Chemically defended insects advertise their unpalatability to avian predators using conspicuous aposematic coloration that predators learn to avoid. Insects utilize a wide variety of different compounds in their defences, and intraspecific variation in defence chemistry is common. We propose that polymorphisms in insect defence chemicals may be beneficial to insects by increasing survival from avian predators. Birds learn to avoid a colour signal faster when individual prey possesses one of two unpalatable chemicals rather than all prey having the same defence chemical. However, for chemical polymorphisms to evolve within a species, there must be benefits that allow rare chemical morphs to increase in frequency. Using domestic chicks as predators and coloured crumbs for prey, we provide evidence that birds taste and reject proportionally more of the individuals with rare defence chemicals than those with common defence chemicals. This indicates that the way in which birds attack and reject prey could enhance the survival of rare chemical morphs and select for chemical polymorphism in aposematic species. This is the first experiment to demonstrate that predators can directly influence the form taken by prey's chemical defences.

  6. Family Key to Helping Teens Avoid Obesity

    MedlinePlus

    ... 159681.html Family Key to Helping Teens Avoid Obesity Good relationship with parents, especially between fathers and ... develop healthy habits that may protect them against obesity, a new study suggests. The researchers also found ...

  7. Avoiding Anemia: Boost Your Red Blood Cells

    MedlinePlus

    ... link, please review our exit disclaimer . Subscribe Avoiding Anemia Boost Your Red Blood Cells If you’re ... and sluggish, you might have a condition called anemia. Anemia is a common blood disorder that many ...

  8. The challenges for scientists in avoiding plagiarism.

    PubMed

    Fisher, E R; Partin, K M

    2014-01-01

    Although it might seem to be a simple task for scientists to avoid plagiarism and thereby an allegation of research misconduct, assessment of trainees in the Responsible Conduct of Research and recent findings from the National Science Foundation Office of Inspector General regarding plagiarism suggests otherwise. Our experiences at a land-grant academic institution in assisting researchers in avoiding plagiarism are described. We provide evidence from a university-wide multi-disciplinary course that understanding how to avoid plagiarism in scientific writing is more difficult than it might appear, and that a failure to learn the rules of appropriate citation may cause dire consequences. We suggest that new strategies to provide training in avoiding plagiarism are required.

  9. When Should a Mother Avoid Breastfeeding?

    MedlinePlus

    ... Address What's this? Submit What's this? Submit Button Breastfeeding Information for Families Breastfeeding Hotline The HHS Office ... Tweet Share Compartir When should a mother avoid breastfeeding? Health professionals agree that human milk provides the ...

  10. Avoid the Consequences of High Blood Pressure

    MedlinePlus

    ... Tools & Resources Stroke More Avoid the Consequences of High Blood Pressure Infographic Updated:Jun 19,2014 View a downloadable version of this infographic High Blood Pressure • Home • About High Blood Pressure (HBP) • Why HBP ...

  11. Active Collision Avoidance for Planetary Landers

    NASA Technical Reports Server (NTRS)

    Rickman, Doug; Hannan, Mike; Srinivasan, Karthik

    2014-01-01

    Present day robotic missions to other planets require precise, a priori knowledge of the terrain to pre-determine a landing spot that is safe. Landing sites can be miles from the mission objective, or, mission objectives may be tailored to suit landing sites. Future robotic exploration missions should be capable of autonomously identifying a safe landing target within a specified target area selected by mission requirements. Such autonomous landing sites must (1) 'see' the surface, (2) identify a target, and (3) land the vehicle. Recent advances in radar technology have resulted in small, lightweight, low power radars that are used for collision avoidance and cruise control systems in automobiles. Such radar systems can be adapted for use as active hazard avoidance systems for planetary landers. The focus of this CIF proposal is to leverage earlier work on collision avoidance systems for MSFC's Mighty Eagle lander and evaluate the use of automotive radar systems for collision avoidance in planetary landers.

  12. Predator-prey coevolution: Australian native bees avoid their spider predators.

    PubMed Central

    Heiling, A M; Herberstein, M E

    2004-01-01

    Australian crab spiders Thomisus spectabilis manipulate visual flower signals to lure introduced Apis mellifera. We gave Australian native bees, Austroplebia australis, the choice between two white daisies, Chrysanthemum frutescens, one of them occupied by a crab spider. The colour contrast between flowers and spiders affected the behaviour of native bees. Native bees approached spider-occupied flowers more frequently. However, native bees avoided flowers occupied by spiders and landed on vacant flowers more frequently. In contrast to honeybees that did not coevolve with T. spectabilis, Australian native bees show an anti-predatory response to avoid flowers occupied by this predator. PMID:15252982

  13. Predator-prey coevolution: Australian native bees avoid their spider predators.

    PubMed

    Heiling, A M; Herberstein, M E

    2004-05-01

    Australian crab spiders Thomisus spectabilis manipulate visual flower signals to lure introduced Apis mellifera. We gave Australian native bees, Austroplebia australis, the choice between two white daisies, Chrysanthemum frutescens, one of them occupied by a crab spider. The colour contrast between flowers and spiders affected the behaviour of native bees. Native bees approached spider-occupied flowers more frequently. However, native bees avoided flowers occupied by spiders and landed on vacant flowers more frequently. In contrast to honeybees that did not coevolve with T. spectabilis, Australian native bees show an anti-predatory response to avoid flowers occupied by this predator. PMID:15252982

  14. Measuring situational avoidance in older drivers: An application of Rasch analysis.

    PubMed

    Davis, Jessica; Conlon, Elizabeth; Ownsworth, Tamara; Morrissey, Shirley

    2016-02-01

    Situational avoidance is a form of driving self-regulation at the strategic level of driving behaviour. It has typically been defined as the purposeful avoidance of driving situations perceived as challenging or potentially hazardous. To date, assessment of the psychometric properties of existing scales that measure situational avoidance has been sparse. This study examined the contribution of Rasch analysis to the situational avoidance construct. Three hundred and ninety-nine Australian drivers (M=66.75, SD=10.14, range: 48-91 years) completed the Situational Avoidance Questionnaire (SAQ). Following removal of the item Parallel Parking, the scale conformed to a Rasch model, showing good person separation, sufficient reliability, little disordering of thresholds, and no evidence of differential item functioning by age or gender. The residuals were independent supporting the assumption of unidimensionality and in conforming to a Rasch model, SAQ items were found to be hierarchical or cumulative. Increased avoidance was associated with factors known to be related to driving self-regulation more broadly, including older age, female gender, reduced driving space and frequency, reporting a change in driving in the past five years and poorer indices of health (i.e., self-rated mood, vision and cognitive function). Overall, these results support the use of the SAQ as a psychometrically sound measure of situational avoidance. Application of Rasch analysis to this area of research advances understanding of the driving self-regulation construct and its practice by drivers in baby boomer and older adult generations.

  15. Rats learn to eat more to avoid hunger.

    PubMed

    Jarvandi, Soghra; Thibault, Louise; Booth, David A

    2009-04-01

    Several recent experiments have provided evidence that the ingestion of a distinctive food by rats can be a learnt instrumental act as well as an associatively conditioned reaction. In the previous work, maintenance food was withheld for shorter and longer durations on different days following access to the training food. Extra eating before the longer fast was interpreted as avoidance of hunger. This interpretation was based on the evidence showing that extra eating as a result of classical conditioning comes from pairing food stimuli with the presence of little or no hunger because of repletion with energy nutrients. The theory that the extra eating arose from a response-depletion contingency was tested in the present experiment by training rats on only a long fast or only a short fast. Greater increase in intake was seen before the longer fast. The results also replicated previously seen cycles of increase, decrease, and renewed increase in putative deficit-avoidant eating over about three trials, indicating that the extra eating reduces the response-reinforcing hunger and that the consequent part-extinction restores reinforcement. The shape of the learning curve was consistent with these cycles occurring from the start of training, further supporting the view that the increase in food intake before a long delay in refeeding is hunger-reinforced instrumental behaviour.

  16. Rats learn to eat more to avoid hunger.

    PubMed

    Jarvandi, Soghra; Thibault, Louise; Booth, David A

    2009-04-01

    Several recent experiments have provided evidence that the ingestion of a distinctive food by rats can be a learnt instrumental act as well as an associatively conditioned reaction. In the previous work, maintenance food was withheld for shorter and longer durations on different days following access to the training food. Extra eating before the longer fast was interpreted as avoidance of hunger. This interpretation was based on the evidence showing that extra eating as a result of classical conditioning comes from pairing food stimuli with the presence of little or no hunger because of repletion with energy nutrients. The theory that the extra eating arose from a response-depletion contingency was tested in the present experiment by training rats on only a long fast or only a short fast. Greater increase in intake was seen before the longer fast. The results also replicated previously seen cycles of increase, decrease, and renewed increase in putative deficit-avoidant eating over about three trials, indicating that the extra eating reduces the response-reinforcing hunger and that the consequent part-extinction restores reinforcement. The shape of the learning curve was consistent with these cycles occurring from the start of training, further supporting the view that the increase in food intake before a long delay in refeeding is hunger-reinforced instrumental behaviour. PMID:19048448

  17. Singularity avoidance and time in quantum gravity

    SciTech Connect

    Kreienbuehl, Andreas

    2009-06-15

    We consider the quantization of a Friedmann-Robertson-Walker universe. We derive a reduced square root Hamiltonian by choosing the scale factor as time variable and quantize the theory using Pauli matrices a la Dirac. From the resulting spinor equation we show that there is no semiclassical wave packet that avoids the big bang singularity. Our work raises the question concerning the relationship between the choice of time and singularity avoidance.

  18. Do approach-avoidance actions create attitudes?

    PubMed

    Centerbar, David B; Clore, Gerald L

    2006-01-01

    Do approach-avoidance actions create attitudes? Prior influential studies suggested that rudimentary attitudes could be established by simply pairing novel stimuli (Chinese ideographs) with arm flexion (approach) or arm extension (avoidance). In three experiments, we found that approach-avoidance actions alone were insufficient to account for such effects. Instead, we found that these affective influences resulted from the interaction of these actions with a priori differences in stimulus valence. Thus, with negative stimuli, the effect of extension on attitude was more positive than the effect of flexion. Experiment 2 demonstrated that the affect from motivationally compatible or incompatible action can also influence task evaluations. A final experiment, using Chinese ideographs from the original studies, confirmed these findings. Both approach and avoidance actions led to more positive evaluations of the ideographs when the actions were motivationally compatible with the prior valence of the ideographs. The attitudinal impact of approach-avoidance action thus reflects its situated meaning, which depends on the valence of stimuli being approached or avoided.

  19. Osmotic stress mimics effects of vasopressin on learned behaviour.

    PubMed

    Koob, G F; Dantzer, R; Rodriguez, F; Bloom, F E; Le Moal, M

    It has been suggested that arginine vasopressin (AVP) is involved in the retention of learned responses, in addition to its classical physiological functions of water retention and modulation of blood pressure. AVP administered subcutaneously (s.c.), intraventricularly or intracerebrally can prolong extinction of active avoidance behaviour and can enhance retention in inhibitory (passive) avoidance. These effects have been interpreted as a direct action of AVP on the central nervous system to facilitate memory consolidation. AVP also has facilitatory effects on cognitive function in humans, and marked deficits in AVP function have been associated with certain types of psychopathology. Alternative hypotheses for the behavioural actions of AVP have involved motivational constructs such as arousal, and our recent work has focused on the role of arousal resulting from the activation of peripheral visceral signals in the behavioural effects of peripherally administered AVP. The development of a specific antagonist for AVP, 1-deaminopenicillamine-2-O-methyl tyrosine arginine vasopressin (dPTyr(Me)AVP), which can reverse the behavioural effects of exogenously administered AVP, has provided a powerful tool for examining the role of AVP in the behavioural responses produced by physiological challenges known to release vasopressin. However, the relationship between the behavioural effects of exogenously administered AVP and the behavioural function of endogenously released AVP has not been evaluated. We report here that a potent peripheral osmotic stimulus, the intraperitoneal (i.p.) injection of hypertonic saline, at doses known to release AVP both centrally and peripherally, will produce behavioural effects similar to those of exogenously administered AVP. Furthermore, the prolongation of active avoidance induced by this osmotic stimulus is reversed by pretreatment with dPTyr(Me)AVP, suggesting that endogenously released AVP may also produce behavioural effects.

  20. Beyond negligence: avoidability and medical injury compensation.

    PubMed

    Kachalia, Allen B; Mello, Michelle M; Brennan, Troyen A; Studdert, David M

    2008-01-01

    Disenchantment with the tort system and negligence standard in the United States is fueling interest in alternate compensation systems for medical injury. One possibility is experimentation with administrative "health courts," through which specialized adjudicators would utilize neutral experts to render compensability determinations. Compensation would be based not on negligence, but rather on a broader avoidable medical injury (avoidability) standard. Although considerable interest in health courts exists, stakeholders frequently express uncertainty about the meaning and operation of an avoidability standard. Three nations-Sweden, Denmark, and New Zealand-have long operated administrative schemes. We conducted interviews with administrators and stakeholders in these systems. Our goal was to garner lessons on how to operate a health court, and specifically, how to develop and apply alternate compensation criteria such as avoidability. This article reports our findings on the origins and operations of the systems, the evolution of their compensation criteria, and how these criteria are actually applied. We found that all three systems had their primary genesis in ensuring compensation for the injured, as opposed to sanctioning providers. All have abandoned the negligence standard. The Nordic systems use an avoidability standard, principally defined as injury that would not occur in the hands of the best practitioner. Their experience demonstrates that this definition is feasible to apply. New Zealand's recent move to a no-fault system sheds light on the benefits and drawbacks of a variety of compensation standards. Key lessons for successfully applying an alternate standard, such as avoidability, include a strict adherence to national precedent, the use of neutral and experienced experts, and a block on routine transfer of information from compensation investigations to disciplinary authorities. Importantly, all three nations are harnessing their systems' power to

  1. Beyond negligence: avoidability and medical injury compensation.

    PubMed

    Kachalia, Allen B; Mello, Michelle M; Brennan, Troyen A; Studdert, David M

    2008-01-01

    Disenchantment with the tort system and negligence standard in the United States is fueling interest in alternate compensation systems for medical injury. One possibility is experimentation with administrative "health courts," through which specialized adjudicators would utilize neutral experts to render compensability determinations. Compensation would be based not on negligence, but rather on a broader avoidable medical injury (avoidability) standard. Although considerable interest in health courts exists, stakeholders frequently express uncertainty about the meaning and operation of an avoidability standard. Three nations-Sweden, Denmark, and New Zealand-have long operated administrative schemes. We conducted interviews with administrators and stakeholders in these systems. Our goal was to garner lessons on how to operate a health court, and specifically, how to develop and apply alternate compensation criteria such as avoidability. This article reports our findings on the origins and operations of the systems, the evolution of their compensation criteria, and how these criteria are actually applied. We found that all three systems had their primary genesis in ensuring compensation for the injured, as opposed to sanctioning providers. All have abandoned the negligence standard. The Nordic systems use an avoidability standard, principally defined as injury that would not occur in the hands of the best practitioner. Their experience demonstrates that this definition is feasible to apply. New Zealand's recent move to a no-fault system sheds light on the benefits and drawbacks of a variety of compensation standards. Key lessons for successfully applying an alternate standard, such as avoidability, include a strict adherence to national precedent, the use of neutral and experienced experts, and a block on routine transfer of information from compensation investigations to disciplinary authorities. Importantly, all three nations are harnessing their systems' power to

  2. A Complete Molecular Diagnostic Procedure for Applications in Surveillance and Subtyping of Avian Influenza Virus

    PubMed Central

    Tseng, Chun-Hsien; Tsai, Hsiang-Jung; Chang, Chung-Ming

    2014-01-01

    Introduction. The following complete molecular diagnostic procedure we developed, based on real-time quantitative PCR and traditional PCR, is effective for avian influenza surveillance, virus subtyping, and viral genome sequencing. Method. This study provides a specific and sensitive step-by-step procedure for efficient avian influenza identification of 16 hemagglutinin and 9 neuraminidase avian influenza subtypes. Result and Conclusion. This diagnostic procedure may prove exceedingly useful for virological and ecological advancements in global avian influenza research. PMID:25057497

  3. Trade-offs between predator avoidance and electric shock avoidance in hermit crabs demonstrate a non-reflexive response to noxious stimuli consistent with prediction of pain.

    PubMed

    Magee, Barry; Elwood, Robert W

    2016-09-01

    Arthropods have long been thought to respond to noxious stimuli by reflex reaction. One way of testing if this is true is to provide the animal with a way to avoid the stimulus but to vary the potential cost of avoidance. If avoidance varies with potential cost then a decision making process is evident and the behaviour is not a mere reflex. Here we examine the responses of hermit crabs to electric shock within their shell when also exposed to predator or non-predator odours or to no odour. The electric shocks start with low voltage but increase in voltage with each repetition to determine how odour affects the voltage at which the shell is abandoned. There was no treatment effect on the voltage at which hermit crabs left their shells, however, those exposed to predator odours were less likely to evacuate their shells compared with no odour or low concentrations of non-predator odour. However, highly concentrated non-predator also inhibited evacuation. The data show that these crabs trade-off avoidance of electric shock with predator avoidance. They are thus not responding purely by reflex and the data are thus consistent with predictions of pain but do not prove pain.

  4. Key conclusions from AVOID Work Stream One

    NASA Astrophysics Data System (ADS)

    Warren, Rachel

    2010-05-01

    AVOID work stream (WS1)one has produced emission scenarios that simulate potential future global emission pathways for greenhouse gases during the 21st century. The study explored the influence of three key features of such pathways: (1) the year in which emissions peak globally, (2) the rate of emission reduction, and (3) the minimum level to which emissions are eventually reduced. It examined the resultant climate change, climate change impacts and economic implications using computer simulations. Avoided impacts, carbon taxes and GDP change increase throughout the 21st century in the models. AVOID-WS1 showed that in the absence of climate policy it is very likely that global mean temperatures would exceed 3 degrees and there are evens chances that the temperature would rise by 4 degrees relative to pre-industrial times. Scenarios that peak emissions in 2016 were more effective at constraining temperatures to below 3 degrees than those that peaked in 2030: one ‘2016' scenario achieved a probability of 45% of avoiding breaching of a 2 degree threshold. Scenarios peaking in 2030 were inconsistent with constraining temperatures to below 2 degrees. Correspondingly, scenarios that peak in 2030 are more effective at avoiding climate impacts than scenarios that peak in 2016, for all sectors that we studied. Hence the date at which emissions peak is more important than the rate of subsequent emissions reduction in determining the avoided impacts. Avoided impacts increase with time, being negligible in the 2030s, significant by the 2050s and large by the 2080s. Finally, the choice of GCM influences the magnitude of the avoided impacts strongly, so that the uncertainties in our estimates of avoided impacts for each scenario are larger than the difference between the scenarios. Our economic analysis is based on models which differ greatly in the assumptions that they make, but generally show that the date at which emissions peak is a stronger driver of induced GDP changes

  5. Unintentional behaviour change.

    PubMed

    Aunger, Robert; Curtis, Valerie

    2014-08-01

    We argue that the authors ignore a broad range of possible means of changing behaviour: unintentional change. Most of the behaviours that people seek to change - either in themselves or that are the subject of public health campaigns-are habitual, and hence not necessarily responsive to intentions. An evolutionary approach should take into account all kinds of evolved behavioural responses. PMID:25162861

  6. Rape avoidance behavior among Slovak women.

    PubMed

    Prokop, Pavol

    2013-05-28

    Rape has been a recurrent adaptive problem for many species, including humans. Rape is costly to women in terms of disease transmission, partner abandonment, and unwanted pregnancy (among other costs). Therefore, behavioral strategies which allow women to avoid coercive men may have been favored by selection. In line with this evolutionary reasoning, the current research documented that physically stronger women and those in a committed romantic relationship reported more rape avoidance behavior. In addition, virgin women tended to perform more rape avoidance behavior compared with their non-virgin counterparts. Women with high conception risk perceived themselves as physically stronger, which may protect them against a potential rapist. Fear of unwanted pregnancy from rape decreased as age increased, reflecting higher fertility among younger participants. However, older women reported more rape avoidance behavior, which contradicts evolutionary predictions. The results provide some support for evolutionary hypotheses of rape avoidance behavior which suggest that woman's perception of rape is influenced by parental investment and perceived physical condition.

  7. Avoidance of Phycomyces in a controlled environment.

    PubMed Central

    Meyer, P W; Matus, I J; Berg, H C

    1987-01-01

    The sporangiophore of the fungus Phycomyces bends away from nearby objects without ever touching them. It has been thought that these objects act as aerodynamic obstacles that damp random winds, thereby generating asymmetric distributions of a growth-promoting gas emitted by the growth zone. In the interest of testing this hypothesis, we studied avoidance in an environmental chamber in which convection was suppressed by a shallow thermal gradient. We also controlled pressure, temperature, and relative humidity of the air, electrostatic charge, and ambient light. A protocol was established that yielded avoidance rates constant from sporangiophore to sporangiophore to within +/- 10%. We found that avoidance occurred at normal rates in the complete absence of random winds. The rates were smaller at 100% than at lower values of relative humidity, but not by much. Remarkably, at a distance as great as 0.5 mm, avoidance from a 30-micron diam glass fiber (aligned parallel to the sporangiophore) was about the same as that from a planar glass sheet. However, the rate for the fiber fell more rapidly with distance. The rate for the sheet remained nearly constant out to approximately 4 mm. We conclude that avoidance depends either on adsorption by the barrier of a growth-inhibiting substance or emission by the barrier of a growth-promoting substance; it cannot occur by passive reflection. Models that can explain these effects are analyzed in the Appendix. PMID:3567313

  8. Persistence of Pasteurella multocida in wetlands following avian cholera outbreaks

    USGS Publications Warehouse

    Blanchong, Julie A.; Samuel, M.D.; Goldberg, D.R.; Shadduck, D.J.; Lehr, M.A.

    2006-01-01

    Avian cholera, caused by Pasteurella multocida, affects waterbirds across North America and occurs worldwide among various avian species. Once an epizootic begins, contamination of the wetland environment likely facilitates the transmission of P. multocida to susceptible birds. To evaluate the ability of P. multocida serotype-1, the most common serotype associated with avian cholera in waterfowl in western and central North America, to persist in wetlands and to identify environmental factors associated with its persistence, we collected water and sediment samples from 23 wetlands during winters and springs of 1996a??99. These samples were collected during avian cholera outbreaks and for up to 13 wk following initial sampling. We recovered P. multocida from six wetlands that were sampled following the initial outbreaks, but no P. multocida was isolated later than 7 wk after the initial outbreak sampling. We found no significant relationship between the probability of recovery of P. multocida during resampling and the abundance of the bacterium recovered during initial sampling, the substrate from which isolates were collected, isolate virulence, or water quality conditions previously suggested to be related to the abundance or survival of P. multocida. Our results indicate that wetlands are unlikely to serve as a long-term reservoir for P. multocida because the bacterium does not persist in wetlands for long time periods following avian cholera outbreaks.

  9. Community response to avian flu in Central Java, Indonesia.

    PubMed

    Padmawati, Siwi; Nichter, Mark

    2008-04-01

    This pilot study suggests that it is more appropriate to think of avian flu as a bio-social and bio-political challenge for Indonesia than merely an epidemiological challenge involving a disease of zoonotic origin. Our examination of popular perceptions of avian flu in Central Java reveals important differences of opinion about which types of fowl are responsible for avian flu transmission and the degree of risk H5N1 poses to humans. The opinions of backyard farmers and commercial poultry farmers are motivated by different forms of practical logic and are differentially influenced by media accounts, government education programmes, foreign aid and rumours about who stands to profit from the disease. Rumours reflect collective anxieties about globalization, the agenda of big business and the trustworthiness of the national government. We also illustrate how a commodity chain analysis can assist in the identification of different stake-holders in the informal and formal poultry industries. The position of each stake-holder needs to be considered in any comprehensive investigation of avian flu. An economic analysis of the capital investment of stake-holders provides insight into how each responds to government directives about the reporting of dead chickens, vaccinating birds etc. Finally, we call for research on avian flu preparedness attentive to Indonesia's de-centralized form of political rule and the social organization of communities so that clear lines of communication and command can be established and mutual assistance mobilized.

  10. Planning and executing a vaccination campaign against avian influenza.

    PubMed

    Marangon, S; Cristalli, A; Busani, L

    2007-01-01

    Vaccination against avian influenza infection caused by H5 or H7 virus subtypes has been used on several occasions in recent years to control and in some cases eradicate the disease. In order to contain avian influenza infection effectively, immunization should be combined with a coordinated set of control and monitoring measures. The outcome of an immunization campaign depends on the territorial strategy; whereas the capacity of the veterinary services in developed countries permits enforcement of strategies aimed at eradicating avian influenza, many countries currently affected by highly pathogenic avian influenza (HPAI) H5N1 viruses have a limited veterinary infrastructure and a limited capacity to respond to such epidemics. In these countries, resources are still insufficient to conduct adequate surveillance for identification and reaction to avian influenza outbreaks when they occur. When properly applied in this scenario, immunization can reduce mortality and production losses. In the long term, immunization might also decrease the prevalence of infection to levels at which stamping-out and surveillance can be applied. Countries should adapt their immunization programmes to local conditions in order to guarantee their efficacy and sustainability. In the initial emergency phase, human resources can be mobilized, with reliance on personal responsibility and motivation, thus compensating for potential shortcomings in organization. A more appropriate allocation of resources must be pursued in the long term, remembering that biosecurity is the main component of an exit strategy and must always be improved.

  11. Next generation sequencing technologies: tool to study avian virus diversity.

    PubMed

    Kapgate, S S; Barbuddhe, S B; Kumanan, K

    2015-03-01

    Increased globalisation, climatic changes and wildlife-livestock interface led to emergence of novel viral pathogens or zoonoses that have become serious concern to avian, animal and human health. High biodiversity and bird migration facilitate spread of the pathogen and provide reservoirs for emerging infectious diseases. Current classical diagnostic methods designed to be virus-specific or aim to be limited to group of viral agents, hinder identifying of novel viruses or viral variants. Recently developed approaches of next-generation sequencing (NGS) provide culture-independent methods that are useful for understanding viral diversity and discovery of novel virus, thereby enabling a better diagnosis and disease control. This review discusses the different possible steps of a NGS study utilizing sequence-independent amplification, high-throughput sequencing and bioinformatics approaches to identify novel avian viruses and their diversity. NGS lead to the identification of a wide range of new viruses such as picobirnavirus, picornavirus, orthoreovirus and avian gamma coronavirus associated with fulminating disease in guinea fowl and is also used in describing viral diversity among avian species. The review also briefly discusses areas of viral-host interaction and disease associated causalities with newly identified avian viruses. PMID:25790045

  12. Next generation sequencing technologies: tool to study avian virus diversity.

    PubMed

    Kapgate, S S; Barbuddhe, S B; Kumanan, K

    2015-03-01

    Increased globalisation, climatic changes and wildlife-livestock interface led to emergence of novel viral pathogens or zoonoses that have become serious concern to avian, animal and human health. High biodiversity and bird migration facilitate spread of the pathogen and provide reservoirs for emerging infectious diseases. Current classical diagnostic methods designed to be virus-specific or aim to be limited to group of viral agents, hinder identifying of novel viruses or viral variants. Recently developed approaches of next-generation sequencing (NGS) provide culture-independent methods that are useful for understanding viral diversity and discovery of novel virus, thereby enabling a better diagnosis and disease control. This review discusses the different possible steps of a NGS study utilizing sequence-independent amplification, high-throughput sequencing and bioinformatics approaches to identify novel avian viruses and their diversity. NGS lead to the identification of a wide range of new viruses such as picobirnavirus, picornavirus, orthoreovirus and avian gamma coronavirus associated with fulminating disease in guinea fowl and is also used in describing viral diversity among avian species. The review also briefly discusses areas of viral-host interaction and disease associated causalities with newly identified avian viruses.

  13. [Avian diversity in Wuhu City in summer and winter].

    PubMed

    Li, Yongmin; Wu, Xiaobing

    2006-02-01

    From May 2004 to February 2005, an investigation was made on the avian communities in four typical habitats, i.e., village and farmland, urban woodlot, floodplain, and riverine wetland in Wuhu City, with the related diversity indices analyzed. A total of 117 species belonging to 15 orders and 31 families was recorded. The avian species and G-F index in village and farmland, urban woodlot, and floodplain were higher in summer than in winter, while the species number, Shannon-Wiener index and Pielou index in riverine wetland were significantly higher in winter than in summer. The avian species and G-F index in urban woodlot were the highest, and the Shannon-Wiener index and Pielou index in floodplain were higher than those in other three habitats. The highest density was observed in village and farmland in summer and in urban woodlot in winter, being 31.1140 and 42.9160 ind x hm(-2), respectively. The avian species, density, Shannon-Wiener index and G-F index in riverine wetland were the lowest. Avian diversity could be enhanced by increasing spatial heterogeneity and reducing human disturbance.

  14. Epizootiology and effect of avian pox on Hawaiian forest birds

    USGS Publications Warehouse

    van Riper, Charles; van Riper, S. G.; Hansen, Wallace R.

    2002-01-01

    We determined prevalence and altitudinal distribution of forest birds infected with avian pox at 16 locations on Hawaii, from sea level to tree line in mesic and xeric habitats, during 1977a??1980. Isolates from lesions were cultured in the laboratory for positive identification of Poxvirus avium. Infected birds from the wild were brought into the laboratory to assess differences in the course of infection in native versus introduced species. We also documented distributions and activity cycles of potential avian pox vectors.>Native forest birds were (1) more susceptible to avian pox infection than were introduced species, (2) most likely to be infected during the wet season, and (3) found to have a higher prevalence in mesic when compared to xeric forests. Avian pox occurred in forest birds at all elevations, but highest levels were in the mid-elevational ranges (1,200 m) where vectors and native birds had the greatest overlap. Temporal and elevational differences in prevalence were apparent throughout the annual cycle. Avian pox probably did not reach epizootic proportions on Hawaii until after introduction of the mosquito and domestic birds in the early 1800s, and since then has had a negative effect on the population dynamics of native forest birds. Today, this introduced disease is an important factor that should be considered in future conservation efforts that are directed at the recovery of native forest birds in Hawaii.

  15. Exploring the avian gut microbiota: current trends and future directions

    PubMed Central

    Waite, David W.; Taylor, Michael W.

    2015-01-01

    Birds represent a diverse and evolutionarily successful lineage, occupying a wide range of niches throughout the world. Like all vertebrates, avians harbor diverse communities of microorganisms within their guts, which collectively fulfill crucial roles in providing the host with nutrition and protection from pathogens. Across the field of avian microbiology knowledge is extremely uneven, with several species accounting for an overwhelming majority of all microbiological investigations. These include agriculturally important birds, such as chickens and turkeys, as well as birds of evolutionary or conservation interest. In our previous study we attempted the first meta-analysis of the avian gut microbiota, using 16S rRNA gene sequences obtained from a range of publicly available data sets. We have now extended our analysis to explore the microbiology of several key species in detail, to consider the avian microbiota within the context of what is known about other vertebrates, and to identify key areas of interest in avian microbiology for future study. PMID:26191057

  16. H5N1 Avian Flu (H5N1 Bird Flu)

    MedlinePlus

    ... H5N1 - Avian/Bird Flu H5N1 Avian Flu - H5N1 Bird Flu H5N1 is a highly pathogenic avian (bird) flu virus that has caused serious outbreaks in ... been no reported infections with these viruses in birds, poultry, or people in the United States. You ...

  17. 9 CFR 145.15 - Diagnostic surveillance program for low pathogenic avian influenza.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... low pathogenic avian influenza. 145.15 Section 145.15 Animals and Animal Products ANIMAL AND PLANT... pathogenic avian influenza. (a) The Official State Agency must develop a diagnostic surveillance program for H5/H7 low pathogenic avian influenza for all poultry in the State. The exact provisions of...

  18. 9 CFR 145.15 - Diagnostic surveillance program for low pathogenic avian influenza.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... low pathogenic avian influenza. 145.15 Section 145.15 Animals and Animal Products ANIMAL AND PLANT... pathogenic avian influenza. (a) The Official State Agency must develop a diagnostic surveillance program for H5/H7 low pathogenic avian influenza for all poultry in the State. The exact provisions of...

  19. 9 CFR 145.15 - Diagnostic surveillance program for low pathogenic avian influenza.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... low pathogenic avian influenza. 145.15 Section 145.15 Animals and Animal Products ANIMAL AND PLANT... pathogenic avian influenza. (a) The Official State Agency must develop a diagnostic surveillance program for H5/H7 low pathogenic avian influenza for all poultry in the State. The exact provisions of...

  20. Tracking avian flu on the Web.

    PubMed

    Gruwell, Cindy A

    2007-01-01

    To some the term avian flu or H5N1 has become synonymous with the pandemic flu of 1918. Like the former pandemic, this current threat has the potential to cause up to 7.4 million deaths worldwide. Yet as of mid-2006, the viability of this threat is still unclear. There is no doubt that birds, especially poultry, have been the primary target of this particular strain of influenza. Human illnesses and deaths have resulted from direct contact with birds; farmers and food handlers are most at risk. Fortunately there has not been a shift to human-to-human transmission. However, it is imperative for public heath officers, health professionals, and other appropriate officials to keep current on the progress of this virus within the bird population, and its spread around the world. Preventative measures including worst case scenarios have been widely discussed and even resulted in a made-for-TV movie. The need for up-to-date information is essential in order to track the extent of transmission, location of current outbreaks, and most importantly steps for preparedness that could be vital for prevention and containment. This article explores and identifies major Web sites along with basic Internet search techniques to find informative and credible Webbased resources. doi:10.1300/J115v26n01_06.

  1. Fossil avian eggshell preserves ancient DNA

    PubMed Central

    Oskam, Charlotte L.; Haile, James; McLay, Emma; Rigby, Paul; Allentoft, Morten E.; Olsen, Maia E.; Bengtsson, Camilla; Miller, Gifford H.; Schwenninger, Jean-Luc; Jacomb, Chris; Walter, Richard; Baynes, Alexander; Dortch, Joe; Parker-Pearson, Michael; Gilbert, M. Thomas P.; Holdaway, Richard N.; Willerslev, Eske; Bunce, Michael

    2010-01-01

    Owing to exceptional biomolecule preservation, fossil avian eggshell has been used extensively in geochronology and palaeodietary studies. Here, we show, to our knowledge, for the first time that fossil eggshell is a previously unrecognized source of ancient DNA (aDNA). We describe the successful isolation and amplification of DNA from fossil eggshell up to 19 ka old. aDNA was successfully characterized from eggshell obtained from New Zealand (extinct moa and ducks), Madagascar (extinct elephant birds) and Australia (emu and owl). Our data demonstrate excellent preservation of the nucleic acids, evidenced by retrieval of both mitochondrial and nuclear DNA from many of the samples. Using confocal microscopy and quantitative PCR, this study critically evaluates approaches to maximize DNA recovery from powdered eggshell. Our quantitative PCR experiments also demonstrate that moa eggshell has approximately 125 times lower bacterial load than bone, making it a highly suitable substrate for high-throughput sequencing approaches. Importantly, the preservation of DNA in Pleistocene eggshell from Australia and Holocene deposits from Madagascar indicates that eggshell is an excellent substrate for the long-term preservation of DNA in warmer climates. The successful recovery of DNA from this substrate has implications in a number of scientific disciplines; most notably archaeology and palaeontology, where genotypes and/or DNA-based species identifications can add significantly to our understanding of diets, environments, past biodiversity and evolutionary processes. PMID:20219731

  2. Tracking avian flu on the Web.

    PubMed

    Gruwell, Cindy A

    2007-01-01

    To some the term avian flu or H5N1 has become synonymous with the pandemic flu of 1918. Like the former pandemic, this current threat has the potential to cause up to 7.4 million deaths worldwide. Yet as of mid-2006, the viability of this threat is still unclear. There is no doubt that birds, especially poultry, have been the primary target of this particular strain of influenza. Human illnesses and deaths have resulted from direct contact with birds; farmers and food handlers are most at risk. Fortunately there has not been a shift to human-to-human transmission. However, it is imperative for public heath officers, health professionals, and other appropriate officials to keep current on the progress of this virus within the bird population, and its spread around the world. Preventative measures including worst case scenarios have been widely discussed and even resulted in a made-for-TV movie. The need for up-to-date information is essential in order to track the extent of transmission, location of current outbreaks, and most importantly steps for preparedness that could be vital for prevention and containment. This article explores and identifies major Web sites along with basic Internet search techniques to find informative and credible Webbased resources. doi:10.1300/J115v26n01_06. PMID:17210550

  3. What's missing from avian global diversification analyses?

    PubMed

    Reddy, Sushma

    2014-08-01

    The accumulation of vast numbers of molecular phylogenetic studies has contributed to huge knowledge gains in the evolutionary history of birds. This permits subsequent analyses of avian diversity, such as how and why diversification varies across the globe and among taxonomic groups. However, available genetic data for these meta-analyses are unevenly distributed across different geographic regions and taxonomic groups. To comprehend the impact of this variation on the interpretation of global diversity patterns, I examined the availability of genetic data for possible biases in geographic and taxonomic sampling of birds. I identified three main disparities of sampling that are geographically associated with latitude (temperate, tropical), hemispheres (East, West), and range size. Tropical regions, which host the vast majority of species, are substantially less studied. Moreover, Eastern regions, such as the Old World Tropics and Australasia, stand out as being disproportionately undersampled, with up to half of communities not being represented in recent studies. In terms of taxonomic discrepancies, a majority of genetically undersampled clades are exclusively found in tropical regions. My analysis identifies several disparities in the key regions of interest of global diversity analyses. Differential sampling can have considerable impacts on these global comparisons and call into question recent interpretations of latitudinal or hemispheric differences of diversification rates. Moreover, this review pinpoints understudied regions whose biota are in critical need of modern systematic analyses.

  4. Worldwide phylogenetic relationship of avian poxviruses

    USGS Publications Warehouse

    Gyuranecz, Miklós; Foster, Jeffrey T.; Dán, Ádám; Ip, Hon S.; Egstad, Kristina F.; Parker, Patricia G.; Higashiguchi, Jenni M.; Skinner, Michael A.; Höfle, Ursula; Kreizinger, Zsuzsa; Dorrestein, Gerry M.; Solt, Szabolcs; Sós, Endre; Kim, Young Jun; Uhart, Marcela; Pereda, Ariel; González-Hein, Gisela; Hidalgo, Hector; Blanco, Juan-Manuel; Erdélyi, Károly

    2013-01-01

    Poxvirus infections have been found in 230 species of wild and domestic birds worldwide in both terrestrial and marine environments. This ubiquity raises the question of how infection has been transmitted and globally dispersed. We present a comprehensive global phylogeny of 111 novel poxvirus isolates in addition to all available sequences from GenBank. Phylogenetic analysis of Avipoxvirus genus has traditionally relied on one gene region (4b core protein). In this study we have expanded the analyses to include a second locus (DNA polymerase gene), allowing for a more robust phylogenetic framework, finer genetic resolution within specific groups and the detection of potential recombination. Our phylogenetic results reveal several major features of avipoxvirus evolution and ecology and propose an updated avipoxvirus taxonomy, including three novel subclades. The characterization of poxviruses from 57 species of birds in this study extends the current knowledge of their host range and provides the first evidence of the phylogenetic effect of genetic recombination of avipoxviruses. The repeated occurrence of avian family or order-specific grouping within certain clades (e.g. starling poxvirus, falcon poxvirus, raptor poxvirus, etc.) indicates a marked role of host adaptation, while the sharing of poxvirus species within prey-predator systems emphasizes the capacity for cross-species infection and limited host adaptation. Our study provides a broad and comprehensive phylogenetic analysis of the Avipoxvirus genus, an ecologically and environmentally important viral group, to formulate a genome sequencing strategy that will clarify avipoxvirus taxonomy.

  5. Avian Blood-Vessel Formation in Space

    NASA Technical Reports Server (NTRS)

    Lelkes, Peter I.

    1999-01-01

    Based on previous studies, we hypothesized that the developmental anomalies observed in the past might be related to or caused by delayed or improper vascular development. The objective of our research is to test the hypothesis that exposure to microgravity during space flight cause delayed or improper vascular development during embryogenesis. The effects of microgravity on the time course and extent of avian blood-vessel formation are assessed using two models, one for angiogenesis and one for vasculogenesis. The methodological approach is dictated by the constraints of the tissue preservation method used in space. Thus, both in the chorioallantoic membrane (CAM) and in the adrenal, we will evaluate microscopically the vascular architecture and immunostain endothelial cells with specific antibodies (anti- vWF and QH1). The extent of ECM protein deposition will be assessed by immunohistochemistry and correlated with the degree of vascularization, using computer-based image analysis. Also, the cellular source for ECM proteins will be assessed by in situ hybridization.

  6. Avian leucocyte counting using the hemocytometer

    USGS Publications Warehouse

    Dein, F.J.; Wilson, A.; Fischer, D.; Langenberg, P.

    1994-01-01

    Automated methods for counting leucocytes in avian blood are not available because of the presence of nucleated erythrocytes and thrombocytes. Therefore, total white blood cell counts are performed by hand using a hemocytometer. The Natt and Herrick and the Unopette methods are the most common stain and diluent preparations for this procedure. Replicate hemocytometer counts using these two methods were performed on blood from four birds of different species. Cells present in each square of the hemocytometer were counted. Counting cells in the corner, side, or center hemocytometer squares produced statistically equivalent results; counting four squares per chamber provided a result similar to that obtained by counting nine squares; and the Unopette method was more precise for hemocytometer counting than was the Natt and Herrick method. The Unopette method is easier to learn and perform but is an indirect process, utilizing the differential count from a stained smear. The Natt and Herrick method is a direct total count, but cell identification is more difficult.

  7. Worldwide Phylogenetic Relationship of Avian Poxviruses

    PubMed Central

    Foster, Jeffrey T.; Dán, Ádám; Ip, Hon S.; Egstad, Kristina F.; Parker, Patricia G.; Higashiguchi, Jenni M.; Skinner, Michael A.; Höfle, Ursula; Kreizinger, Zsuzsa; Dorrestein, Gerry M.; Solt, Szabolcs; Sós, Endre; Kim, Young Jun; Uhart, Marcela; Pereda, Ariel; González-Hein, Gisela; Hidalgo, Hector; Blanco, Juan-Manuel; Erdélyi, Károly

    2013-01-01

    Poxvirus infections have been found in 230 species of wild and domestic birds worldwide in both terrestrial and marine environments. This ubiquity raises the question of how infection has been transmitted and globally dispersed. We present a comprehensive global phylogeny of 111 novel poxvirus isolates in addition to all available sequences from GenBank. Phylogenetic analysis of the Avipoxvirus genus has traditionally relied on one gene region (4b core protein). In this study we expanded the analyses to include a second locus (DNA polymerase gene), allowing for a more robust phylogenetic framework, finer genetic resolution within specific groups, and the detection of potential recombination. Our phylogenetic results reveal several major features of avipoxvirus evolution and ecology and propose an updated avipoxvirus taxonomy, including three novel subclades. The characterization of poxviruses from 57 species of birds in this study extends the current knowledge of their host range and provides the first evidence of the phylogenetic effect of genetic recombination of avipoxviruses. The repeated occurrence of avian family or order-specific grouping within certain clades (e.g., starling poxvirus, falcon poxvirus, raptor poxvirus, etc.) indicates a marked role of host adaptation, while the sharing of poxvirus species within prey-predator systems emphasizes the capacity for cross-species infection and limited host adaptation. Our study provides a broad and comprehensive phylogenetic analysis of the Avipoxvirus genus, an ecologically and environmentally important viral group, to formulate a genome sequencing strategy that will clarify avipoxvirus taxonomy. PMID:23408635

  8. Avian endocrine responses to environmental pollutants

    USGS Publications Warehouse

    Rattner, B.A.; Eroschenko, V.P.; Fox, G.A.; Fry, D.M.; Gorsline, J.

    1984-01-01

    Many environmental contaminants are hazardous to populations of wild birds. Chlorinated hydrocarbon pesticides and industrial pollutants are thought to be responsible for population declines of several species of predatory birds through eggshell thinning. Studies have demonstrated that these contaminants have estrogenic potency and may affect the functioning of the gonadal and thyroidal endocrine subsystems. Petroleum crude oil exerts toxicity externally, by oiling of plumage, and internally, by way of ingestion of oil while feeding or preening. Extensive ultrastructural damage to the inner zone of the adrenal, diminished adrenal responsiveness to adrenocorticotrophic hormone, and reduced corticosterone secretion rate suggest that low levels of plasma corticosterone reflect a direct effect of petroleum on the adrenal gland. Suppressive effects of oil on the ovary and decreases in circulating prolactin have been associated with impaired reproductive function. Large-scale field studies of free-living seabirds have confirmed some of the inhibitory effects of oil on reproduction that have been observed in laboratory studies. Organophosphorus insecticides, representing the most widely used class of pesticides in North America, have been shown to impair reproductive function, possibly by altering secretion of luteinizing hormone and progesterone. Relevant areas of future research on the effects of contaminants on avian endocrine function are discussed.

  9. Relationships between perceived teachers' controlling behaviour, psychological need thwarting, anger and bullying behaviour in high-school students.

    PubMed

    Hein, Vello; Koka, Andre; Hagger, Martin S

    2015-07-01

    We tested a model of the associations between students' perceptions of their physical education teacher's controlling behaviour, perceptions of basic psychological need thwarting, anger and bullying behaviour. School students (N = 602; M age = 12.88, SD = 1.37) from 10 schools completed measures of perceived teachers' controlling behaviour and perceived thwarting of the psychological needs for autonomy, competence, and relatedness in physical education context and self-reported bullying and anger. A well-fitting structural equation model demonstrated that students' perceptions of the negative conditional regard and intimidation exhibited by the teacher had significant indirect effect on students' feelings of anger and bullying behaviour through the perceived psychological need thwarting in physical education. Findings suggest that physical education teachers who avoid the use of negative conditional regard and intimidation in their classes have students who perceive less need thwarting and report less bullying behaviour.

  10. Relationships between perceived teachers' controlling behaviour, psychological need thwarting, anger and bullying behaviour in high-school students.

    PubMed

    Hein, Vello; Koka, Andre; Hagger, Martin S

    2015-07-01

    We tested a model of the associations between students' perceptions of their physical education teacher's controlling behaviour, perceptions of basic psychological need thwarting, anger and bullying behaviour. School students (N = 602; M age = 12.88, SD = 1.37) from 10 schools completed measures of perceived teachers' controlling behaviour and perceived thwarting of the psychological needs for autonomy, competence, and relatedness in physical education context and self-reported bullying and anger. A well-fitting structural equation model demonstrated that students' perceptions of the negative conditional regard and intimidation exhibited by the teacher had significant indirect effect on students' feelings of anger and bullying behaviour through the perceived psychological need thwarting in physical education. Findings suggest that physical education teachers who avoid the use of negative conditional regard and intimidation in their classes have students who perceive less need thwarting and report less bullying behaviour. PMID:25968108

  11. Serological survey of avian influenza virus infection in non-avian wildlife in Xinjiang, China.

    PubMed

    Wei, Yu-Rong; Yang, Xue-Yun; Li, Yuan-Guo; Wei, Jie; Ma, Wen-Ge; Ren, Zhi-Guang; Guo, Hui-Ling; Wang, Tie-Cheng; Mi, Xiao-Yun; Adili, Gulizhati; Miao, Shu-Kui; Shaha, Ayiqiaolifan; Gao, Yu-Wei; Huang, Jiong; Xia, Xian-Zhu

    2016-04-01

    We conducted a serological survey to detect antibodies against avian influenza virus (AIV) in Gazella subgutturosa, Canis lupus, Capreolus pygargus, Sus scrofa, Cervus elaphus, Capra ibex, Ovis ammon, Bos grunniens and Pseudois nayaur in Xinjiang, China. Two hundred forty-six sera collected from 2009 to 2013 were assayed for antibodies against H5, H7 and H9 AIVs using hemagglutination inhibition (HI) tests and a pan-influenza competitive ELISA. Across all tested wildlife species, 4.47 % harbored anti-AIV antibodies that were detected by the HI assay. The seroprevalence for each AIV subtype across all species evaluated was 0 % for H5 AIV, 0.81 % for H7 AIV, and 3.66 % for H9 AIV. H7-reactive antibodies were found in Canis lupus (9.09 %) and Ovis ammon (4.55 %). H9-reactive antibodies were found in Gazella subgutturosa (4.55 %), Canis lupus (27.27 %), Pseudois nayaur (23.08 %), and Ovis ammon (4.55 %). The pan-influenza competitive ELISA results closely corresponded to the cumulative prevalence of AIV exposure as measured by subtype-specific HI assays, suggesting that H7 and H9 AIV subtypes predominate in the wildlife species evaluated. These data provide evidence of prior infection with H7 and H9 AIVs in non-avian wildlife in Xinjiang, China.

  12. Serological survey of avian influenza virus infection in non-avian wildlife in Xinjiang, China.

    PubMed

    Wei, Yu-Rong; Yang, Xue-Yun; Li, Yuan-Guo; Wei, Jie; Ma, Wen-Ge; Ren, Zhi-Guang; Guo, Hui-Ling; Wang, Tie-Cheng; Mi, Xiao-Yun; Adili, Gulizhati; Miao, Shu-Kui; Shaha, Ayiqiaolifan; Gao, Yu-Wei; Huang, Jiong; Xia, Xian-Zhu

    2016-04-01

    We conducted a serological survey to detect antibodies against avian influenza virus (AIV) in Gazella subgutturosa, Canis lupus, Capreolus pygargus, Sus scrofa, Cervus elaphus, Capra ibex, Ovis ammon, Bos grunniens and Pseudois nayaur in Xinjiang, China. Two hundred forty-six sera collected from 2009 to 2013 were assayed for antibodies against H5, H7 and H9 AIVs using hemagglutination inhibition (HI) tests and a pan-influenza competitive ELISA. Across all tested wildlife species, 4.47 % harbored anti-AIV antibodies that were detected by the HI assay. The seroprevalence for each AIV subtype across all species evaluated was 0 % for H5 AIV, 0.81 % for H7 AIV, and 3.66 % for H9 AIV. H7-reactive antibodies were found in Canis lupus (9.09 %) and Ovis ammon (4.55 %). H9-reactive antibodies were found in Gazella subgutturosa (4.55 %), Canis lupus (27.27 %), Pseudois nayaur (23.08 %), and Ovis ammon (4.55 %). The pan-influenza competitive ELISA results closely corresponded to the cumulative prevalence of AIV exposure as measured by subtype-specific HI assays, suggesting that H7 and H9 AIV subtypes predominate in the wildlife species evaluated. These data provide evidence of prior infection with H7 and H9 AIVs in non-avian wildlife in Xinjiang, China. PMID:26733295

  13. The avian and mammalian host range of highly pathogenic avian H5N1 influenza

    PubMed Central

    Kaplan, Bryan S.; Webby, Richard J.

    2013-01-01

    Highly pathogenic H5N1 influenza viruses have been isolated from a number of avian and mammalian species. Despite intensive control measures the number of human and animal cases continues to increase. A more complete understanding of susceptible species and of contributing environmental and molecular factors is crucial if we are to slow the rate of new cases. H5N1 is currently endemic in domestic poultry in only a handful of countries with sporadic and unpredictable spread to other countries. Close contact of terrestrial bird or mammalian species with infected poultry/waterfowl or their biological products is the major route for interspecies transmission. Intra-species transmission of H5N1 in mammals, including humans, has taken place on a limited scale though it remains to be seen if this will change; recent laboratory studies suggest that it is indeed possible. Here we review the avian and mammalian species that are naturally susceptible to H5N1 infection and the molecular factors associated with its expanded host range. PMID:24025480

  14. A relationship between avian carcasses and living invertebrates in the epizootiology of avian botulism

    USGS Publications Warehouse

    Duncan, R.M.; Jensen, Wayne I.

    1976-01-01

    A survey of the sources of Clostridium botulinum type C toxin possibly utilized as food by aquatic birds in an epizootic area of avian botulism in northern Utah showed that living aquatic and terrestrial invertebrates normally found in close association with dead, decomposing birds commonly carried the toxin. Of 461 samples associated with 21 species of avian carcasses, 198 were toxin-positive. Invertebrate species not normally scavengers of vertebrate tissues were less commonly and less highly toxic, particularly when captured 30 cm or more from a carcass; six of 237 samples of such aquatic invertebrates low-level toxin. Of the species tested, blow fly larvae (Calliphoridae) were the most consistently and highly toxic, although others, particularly adult and larval stages of several species of beetles (Coleoptera), contained toxin at levels probably significant in the epizootiology of the disease. An estimated 0.05 to 0.25 g of the most toxic fly larvae or 15 g of the most toxic beetles tested carried a mediam lethal dose for an adult mallard duck. Examination of stomach contents of aquatic birds dead of botulism showed that some had consumed invertebrates.

  15. Enemy avoidance task: a novel behavioral paradigm for assessing spatial avoidance of a moving subject.

    PubMed

    Telensky, Petr; Svoboda, Jan; Pastalkova, Eva; Blahna, Karel; Bures, Jan; Stuchlik, Ales

    2009-05-30

    Navigation with respect to moving goals represents a useful ability in the everyday life of animals. We have developed a novel behavioral paradigm, "enemy avoidance task", in which a laboratory rat (subject) was trained to avoid another rat (enemy), while searching for small pasta pellets dispensed onto an experimental arena. Whenever the distance between the two animals was smaller than 25 cm, the subject was given a mild electric footshock. The results have shown that rats are capable of avoiding another rat while exploring an environment. Therefore, the enemy avoidance task can be used in electrophysiological, lesion or neuropharmacological studies exploring neuronal substrate coding for egocentric and allocentric positions of an observed animal.

  16. Is Avoiding an Aversive Outcome Rewarding? Neural Substrates of Avoidance Learning in the Human Brain

    PubMed Central

    Kim, Hackjin; Shimojo, Shinsuke

    2006-01-01

    Avoidance learning poses a challenge for reinforcement-based theories of instrumental conditioning, because once an aversive outcome is successfully avoided an individual may no longer experience extrinsic reinforcement for their behavior. One possible account for this is to propose that avoiding an aversive outcome is in itself a reward, and thus avoidance behavior is positively reinforced on each trial when the aversive outcome is successfully avoided. In the present study we aimed to test this possibility by determining whether avoidance of an aversive outcome recruits the same neural circuitry as that elicited by a reward itself. We scanned 16 human participants with functional MRI while they performed an instrumental choice task, in which on each trial they chose from one of two actions in order to either win money or else avoid losing money. Neural activity in a region previously implicated in encoding stimulus reward value, the medial orbitofrontal cortex, was found to increase, not only following receipt of reward, but also following successful avoidance of an aversive outcome. This neural signal may itself act as an intrinsic reward, thereby serving to reinforce actions during instrumental avoidance. PMID:16802856

  17. A collision avoidance system for workpiece protection

    SciTech Connect

    Schmitt, D.J.; Weber, T.M.; Novak, J.L.; Maslakowski, J.E.

    1995-04-01

    This paper describes an application of Sandia`s non-contact capacitive sensing technology for collision avoidance during the manufacturing of rocket engine thrust chambers. The collision avoidance system consists of an octagon shaped collar with a capacitive proximity sensor mounted on each face. The sensors produced electric fields which extend several inches from the face of the collar and detect potential collisions between the robot and the workpiece. A signal conditioning system processes the sensor output and provides varying voltage signals to the robot controller for stopping the robot.

  18. Autonomous Landing and Hazard Avoidance Technology (ALHAT)

    NASA Technical Reports Server (NTRS)

    Epp, Chirold

    2007-01-01

    This viewgraph presentation reviews the work towards technology that will result in an autonomous landing on the lunar surface, that will avoid the hazards of lunar landing. In October 2005, the Exploration Systems Mission Directorate at NASA Headquarters assigned the development of new technologies to support the return to the moon. One of these was Autonomous Precision Landing and Hazard Detection and Avoidance Technology now known as ALHAT ALHAT is a lunar descent and landing GNC technology development project led by Johnson Space Center (JSC) with team members from Langley Research Center (LaRC), Jet Propulsion Laboratory (JPL), Draper Laboratories (CSDL) and the Applied Physics Laboratory (APL)

  19. Telerobotics with whole arm collision avoidance

    SciTech Connect

    Wilhelmsen, K.; Strenn, S.

    1993-09-01

    The complexity of teleorbotic operations in a cluttered environment is exacerbated by the need to present collision information to the operator in an understandable fashion. In addition to preventing movements which will cause collisions, a system providing some form of virtual force reflection (VFR) is desirable. With this goal in mind, Lawrence Livermore National Laboratory (LLNL) has installed a kinematically master/slave system and developed a whole arm collision avoidance system which interacts directly with the telerobotic controller. LLNL has also provided a structure to allow for automated upgrades of workcell models and provide collision avoidance even in a dynamically changing workcell.

  20. Integrated Collision Avoidance System for Air Vehicle

    NASA Technical Reports Server (NTRS)

    Lin, Ching-Fang (Inventor)

    2013-01-01

    Collision with ground/water/terrain and midair obstacles is one of the common causes of severe aircraft accidents. The various data from the coremicro AHRS/INS/GPS Integration Unit, terrain data base, and object detection sensors are processed to produce collision warning audio/visual messages and collision detection and avoidance of terrain and obstacles through generation of guidance commands in a closed-loop system. The vision sensors provide more information for the Integrated System, such as, terrain recognition and ranging of terrain and obstacles, which plays an important role to the improvement of the Integrated Collision Avoidance System.

  1. Collision avoidance for CTV: Requirements and capabilities

    NASA Astrophysics Data System (ADS)

    Nosek, Thomas; Rourke, Kenneth

    Collision avoidance must be ensured during Cargo Transfer Vehicle (CTV) operations near the space station. The design of the Collision Avoidance Maneuver (CAM) will involve analysis of CTV failure modes during rendezvous and proximity operations as well as analysis of possible problems external to the CTV, but that would require CTV to execute a CAM. In considering the requirements and design of the CAM for the CTV, the CAM design for the Orbital Maneuvering Vehicle (OMV) is a useful reference point from which some lessons can be learned and many CTV design options can be set forth.

  2. Collision avoidance for CTV: Requirements and capabilities

    NASA Technical Reports Server (NTRS)

    Nosek, Thomas; Rourke, Kenneth

    1991-01-01

    Collision avoidance must be ensured during Cargo Transfer Vehicle (CTV) operations near the space station. The design of the Collision Avoidance Maneuver (CAM) will involve analysis of CTV failure modes during rendezvous and proximity operations as well as analysis of possible problems external to the CTV, but that would require CTV to execute a CAM. In considering the requirements and design of the CAM for the CTV, the CAM design for the Orbital Maneuvering Vehicle (OMV) is a useful reference point from which some lessons can be learned and many CTV design options can be set forth.

  3. Protective and Compensatory Factors Mitigating the Influence of Deviant Friends on Delinquent Behaviours during Early Adolescence

    ERIC Educational Resources Information Center

    Fergusson, David M.; Vitaro, Frank; Wanner, Brigitte; Brendgen, Mara

    2007-01-01

    This study examined factors that could moderate or compensate the link between exposure to deviant friends and delinquent behaviours in a sample of 265 early adolescents. The putative moderating or compensatory factors referred to the behavioural domain (i.e. novelty seeking, harm avoidance), the biological domain (i.e. physical maturation), the…

  4. Structural basis for preferential avian receptor binding by the human-infecting H10N8 avian influenza virus.

    PubMed

    Wang, Min; Zhang, Wei; Qi, Jianxun; Wang, Fei; Zhou, Jianfang; Bi, Yuhai; Wu, Ying; Sun, Honglei; Liu, Jinhua; Huang, Chaobin; Li, Xiangdong; Yan, Jinghua; Shu, Yuelong; Shi, Yi; Gao, George F

    2015-01-01

    Since December 2013, at least three cases of human infections with H10N8 avian influenza virus have been reported in China, two of them being fatal. To investigate the epidemic potential of H10N8 viruses, we examined the receptor binding property of the first human isolate, A/Jiangxi-Donghu/346/2013 (JD-H10N8), and determined the structures of its haemagglutinin (HA) in complex with both avian and human receptor analogues. Our results suggest that JD-H10N8 preferentially binds the avian receptor and that residue R137-localized within the receptor-binding site of HA-plays a key role in this preferential binding. Compared with the H7N9 avian influenza viruses, JD-H10N8 did not exhibit the enhanced binding to human receptors observed with the prevalent H7N9 virus isolate Anhui-1, but resembled the receptor binding activity of the early-outbreak H7N9 isolate (Shanghai-1). We conclude that the H10N8 virus is a typical avian influenza virus.

  5. The Cross-Lagged Relations between Children's Academic Skill Development, Task-Avoidance, and Parental Beliefs about Success

    ERIC Educational Resources Information Center

    Magi, Katrin; Lerkkanen, Marja-Kristiina; Poikkeus, Anna-Maija; Rasku-Puttonen, Helena; Nurmi, Jari-Erik

    2011-01-01

    This longitudinal study investigated the cross-lagged associations between children's academic skill development, task-avoidant behaviour in the context of homework, and parental beliefs about their child's success from kindergarten to Grade 2. The participants were 1267 children. The children's pre-skills were assessed at the end of the…

  6. Toxicity of the ionophore antibiotic lasalocid to soil-dwelling invertebrates: avoidance tests in comparison to classic sublethal tests.

    PubMed

    Žižek, Suzana; Zidar, Primož

    2013-07-01

    Lasalocid is a veterinary ionophore antibiotic used for prevention and treatment of coccidiosis in poultry. It enters the environment with the use of contaminated manure on agricultural land. Despite its extensive use, the effects of lasalocid on non-target soil organisms are poorly explored. We used classical subleathal ecotoxicity tests to assess the effects of lasalocid on earthworms (Eisenia andrei) and isopods (Porcellio scaber) and compared the results with tests using avoidance behaviour as the endpoint. The results showed that avoidance is a much more sensitive endpoint. For earthworms, EC50 for avoidance (12.3 mg kg(-1) dry soil) was more than five times lower than EC50 for reproduction (69.6 mg kg(-1) dry soil). In isopods the sensitivity of the behavioural response test was even higher. While the highest lasalocid concentration 202 mg kg(-1) had no significant effects on isopod growth or survival, already the lowest used concentration in the behavioural assay (4.51 mg kg(-1)) caused significant impact on isopod behaviour. Using the avoidance test results for calculating the predicted no-effect concentration (PNEC) of lasalocid to soil invertebrates, the value is close to the predicted environmental concentration (PEC). This indicates that the use of lasalocid-contaminated manure could potentially impair the habitat function of agricultural soils.

  7. Avians as a model system of vascular development.

    PubMed

    Bressan, Michael; Mikawa, Takashi

    2015-01-01

    For more than 2,000 years, philosophers and scientists have turned to the avian embryo with questions of how life begins (Aristotle and Peck Generations of Animals. Loeb Classics, vol. XIII. Harvard University Press, Cambridge, 1943; Needham, A history of embryology. Abelard-Schuman, New York, 1959). Then, as now, the unique accessibility of the embryo both in terms of acquisition of eggs from domesticated fowl and ease at which the embryo can be visualized by simply opening the shell has made avians an appealing and powerful model system for the study of development. Thus, as the field of embryology has evolved through observational, comparative, and experimental embryology into its current iteration as the cellular and molecular biology of development, avians have remained a useful and practical system of study.

  8. When not to copy: female fruit flies use sophisticated public information to avoid mated males

    NASA Astrophysics Data System (ADS)

    Loyau, Adeline; Blanchet, Simon; van Laere, Pauline; Clobert, Jean; Danchin, Etienne

    2012-10-01

    Semen limitation (lack of semen to fertilize all of a female's eggs) imposes high fitness costs to female partners. Females should therefore avoid mating with semen-limited males. This can be achieved by using public information extracted from watching individual males' previous copulating activities. This adaptive preference should be flexible given that semen limitation is temporary. We first demonstrate that the number of offspring produced by males Drosophila melanogaster gradually decreases over successive copulations. We then show that females avoid mating with males they just watched copulating and that visual public cues are sufficient to elicit this response. Finally, after males were given the time to replenish their sperm reserves, females did not avoid the males they previously saw copulating anymore. These results suggest that female fruit flies may have evolved sophisticated behavioural processes of resistance to semen-limited males, and demonstrate unsuspected adaptive context-dependent mate choice in an invertebrate.

  9. When not to copy: female fruit flies use sophisticated public information to avoid mated males

    PubMed Central

    Loyau, Adeline; Blanchet, Simon; Van Laere, Pauline; Clobert, Jean; Danchin, Etienne

    2012-01-01

    Semen limitation (lack of semen to fertilize all of a female's eggs) imposes high fitness costs to female partners. Females should therefore avoid mating with semen-limited males. This can be achieved by using public information extracted from watching individual males' previous copulating activities. This adaptive preference should be flexible given that semen limitation is temporary. We first demonstrate that the number of offspring produced by males Drosophila melanogaster gradually decreases over successive copulations. We then show that females avoid mating with males they just watched copulating and that visual public cues are sufficient to elicit this response. Finally, after males were given the time to replenish their sperm reserves, females did not avoid the males they previously saw copulating anymore. These results suggest that female fruit flies may have evolved sophisticated behavioural processes of resistance to semen-limited males, and demonstrate unsuspected adaptive context-dependent mate choice in an invertebrate. PMID:23105967

  10. Participation of metanauplii and juvenile individuals of Artemia parthenogenetica (Branchiopoda) in the circulation of avian cestodes.

    PubMed

    Redón, Stella; Amat, Francisco; Hontoria, Francisco; Vasileva, Gergana P; Nikolov, Pavel N; Georgiev, Boyko B

    2011-04-01

    Adult crustaceans of the genus Artemia (brine shrimps) are intermediate hosts in the life cycle of cestode species parasitic in aquatic birds as their definitive hosts. However, there are no data on the role of larval and juvenile brine shrimps in the transmission of avian helminth parasites. In order to examine the possible role of early developmental stages (nauplii, metanauplii and juveniles) of Artemia for the circulation of avian cestodes, the natural cestode infection in the population of Artemia parthenogenetica from La Mata Lagoon, Mediterranean coast of Spain, was studied. Metacestodes (cysticercoids) of four cestode species were recorded in adult brine shrimps: Flamingolepis liguloides and Flamingolepis flamingo (hymenolepidids parasitic in flamingos), Confluaria podicipina (a hymenolepidid species parasitic in grebes) and Eurycestus avoceti (a dilepidid species parasitic in avocets, stilts, plovers and, to a lesser extent, in flamingos). No cysticercoids were found in nauplii. Two species, F. liguloides and F. flamingo, were found in metanauplii and juvenile brine shrimps. Only 36.3% of the cysticercoids of F. liguloides occurred in adult brine shrimps; the remaining 63.7% were parasitic in metanauplii (39.6%) and juveniles (24.1%). Similarly, the metacestodes of F. flamingo were also distributed among various age groups: in adults (44.4% of cysticercoids), juveniles (27.8%) and metanauplii (27.8%). These results indicate that the early developmental stages of Artemia have an important role for the circulation of certain parasite species. No cysticercoids of C. podicipina and E. avoceti were recorded in larval and juvenile brine shrimps. The selective infestation of larval brine shrimps with flamingo parasites is probably associated with the feeding behaviour of definitive hosts, which are filtering predators; in contrast, grebes and waders pick brine shrimps individually one by one. The possible underlying mechanism for selective infestation of

  11. Participation of metanauplii and juvenile individuals of Artemia parthenogenetica (Branchiopoda) in the circulation of avian cestodes.

    PubMed

    Redón, Stella; Amat, Francisco; Hontoria, Francisco; Vasileva, Gergana P; Nikolov, Pavel N; Georgiev, Boyko B

    2011-04-01

    Adult crustaceans of the genus Artemia (brine shrimps) are intermediate hosts in the life cycle of cestode species parasitic in aquatic birds as their definitive hosts. However, there are no data on the role of larval and juvenile brine shrimps in the transmission of avian helminth parasites. In order to examine the possible role of early developmental stages (nauplii, metanauplii and juveniles) of Artemia for the circulation of avian cestodes, the natural cestode infection in the population of Artemia parthenogenetica from La Mata Lagoon, Mediterranean coast of Spain, was studied. Metacestodes (cysticercoids) of four cestode species were recorded in adult brine shrimps: Flamingolepis liguloides and Flamingolepis flamingo (hymenolepidids parasitic in flamingos), Confluaria podicipina (a hymenolepidid species parasitic in grebes) and Eurycestus avoceti (a dilepidid species parasitic in avocets, stilts, plovers and, to a lesser extent, in flamingos). No cysticercoids were found in nauplii. Two species, F. liguloides and F. flamingo, were found in metanauplii and juvenile brine shrimps. Only 36.3% of the cysticercoids of F. liguloides occurred in adult brine shrimps; the remaining 63.7% were parasitic in metanauplii (39.6%) and juveniles (24.1%). Similarly, the metacestodes of F. flamingo were also distributed among various age groups: in adults (44.4% of cysticercoids), juveniles (27.8%) and metanauplii (27.8%). These results indicate that the early developmental stages of Artemia have an important role for the circulation of certain parasite species. No cysticercoids of C. podicipina and E. avoceti were recorded in larval and juvenile brine shrimps. The selective infestation of larval brine shrimps with flamingo parasites is probably associated with the feeding behaviour of definitive hosts, which are filtering predators; in contrast, grebes and waders pick brine shrimps individually one by one. The possible underlying mechanism for selective infestation of

  12. Predictive model of avian electrocution risk on overhead power lines.

    PubMed

    Dwyer, J F; Harness, R E; Donohue, K

    2014-02-01

    Electrocution on overhead power structures negatively affects avian populations in diverse ecosystems worldwide, contributes to the endangerment of raptor populations in Europe and Africa, and is a major driver of legal action against electric utilities in North America. We investigated factors associated with avian electrocutions so poles that are likely to electrocute a bird can be identified and retrofitted prior to causing avian mortality. We used historical data from southern California to identify patterns of avian electrocution by voltage, month, and year to identify species most often killed by electrocution in our study area and to develop a predictive model that compared poles where an avian electrocution was known to have occurred (electrocution poles) with poles where no known electrocution occurred (comparison poles). We chose variables that could be quantified by personnel with little training in ornithology or electric systems. Electrocutions were more common at distribution voltages (≤ 33 kV) and during breeding seasons and were more commonly reported after a retrofitting program began. Red-tailed Hawks (Buteo jamaicensis) (n = 265) and American Crows (Corvus brachyrhynchos) (n = 258) were the most commonly electrocuted species. In the predictive model, 4 of 14 candidate variables were required to distinguish electrocution poles from comparison poles: number of jumpers (short wires connecting energized equipment), number of primary conductors, presence of grounding, and presence of unforested unpaved areas as the dominant nearby land cover. When tested against a sample of poles not used to build the model, our model distributed poles relatively normally across electrocution-risk values and identified the average risk as higher for electrocution poles relative to comparison poles. Our model can be used to reduce avian electrocutions through proactive identification and targeting of high-risk poles for retrofitting. PMID:24033371

  13. Avian oncogenic virus differential diagnosis in chickens using oligonucleotide microarray.

    PubMed

    Wang, Lih-Chiann; Huang, Dean; Pu, Chang-En; Wang, Ching-Ho

    2014-12-15

    Avian oncogenic viruses include the avian leukosis virus (ALV), reticuloendotheliosis virus (REV) and Marek's disease virus (MDV). Multiple oncogenic viral infections are frequently seen, with even Marek's disease vaccines reported to be contaminated with ALV and REV. The gross lesions caused by avian oncogenic viruses often overlap, making differentiation diagnosis based on histopathology difficult. The objective of this study is to develop a rapid approach to simultaneously differentiate, subgroup and pathotype the avian oncogenic viruses. The oligonucleotide microarray was employed in this study. Particular DNA sequences were recognized using specific hybridization between the DNA target and probe on the microarray, followed with colorimetric development through enzyme reaction. With 10 designed probes, ALV-A, ALV-E, ALV-J, REV, MDV pathogenic and vaccine strains were clearly discriminated on the microarray with the naked eyes. The detection limit was 27 copy numbers, which was 10-100 times lower than multiplex PCR. Of 102 field samples screened using the oligonucleotide microarray, 32 samples were positive for ALV-E, 17 samples were positive for ALV-J, 6 samples were positive for REV, 4 samples were positive for MDV, 7 samples were positive for both ALV-A and ALV-E, 5 samples were positive for ALV-A, ALV-E and ALV-J, one sample was positive for both ALV-J and MDV, and 3 samples were positive for both REV and MDV. The oligonucleotide microarray, an easy-to-use, high-specificity, high-sensitivity and extendable assay, presents a potent technique for rapid differential diagnosis of avian oncogenic viruses and the detection of multiple avian oncogenic viral infections under field conditions.

  14. Predictive model of avian electrocution risk on overhead power lines.

    PubMed

    Dwyer, J F; Harness, R E; Donohue, K

    2014-02-01

    Electrocution on overhead power structures negatively affects avian populations in diverse ecosystems worldwide, contributes to the endangerment of raptor populations in Europe and Africa, and is a major driver of legal action against electric utilities in North America. We investigated factors associated with avian electrocutions so poles that are likely to electrocute a bird can be identified and retrofitted prior to causing avian mortality. We used historical data from southern California to identify patterns of avian electrocution by voltage, month, and year to identify species most often killed by electrocution in our study area and to develop a predictive model that compared poles where an avian electrocution was known to have occurred (electrocution poles) with poles where no known electrocution occurred (comparison poles). We chose variables that could be quantified by personnel with little training in ornithology or electric systems. Electrocutions were more common at distribution voltages (≤ 33 kV) and during breeding seasons and were more commonly reported after a retrofitting program began. Red-tailed Hawks (Buteo jamaicensis) (n = 265) and American Crows (Corvus brachyrhynchos) (n = 258) were the most commonly electrocuted species. In the predictive model, 4 of 14 candidate variables were required to distinguish electrocution poles from comparison poles: number of jumpers (short wires connecting energized equipment), number of primary conductors, presence of grounding, and presence of unforested unpaved areas as the dominant nearby land cover. When tested against a sample of poles not used to build the model, our model distributed poles relatively normally across electrocution-risk values and identified the average risk as higher for electrocution poles relative to comparison poles. Our model can be used to reduce avian electrocutions through proactive identification and targeting of high-risk poles for retrofitting.

  15. Antigenic properties of avian hepatitis E virus capsid protein.

    PubMed

    Zhao, Qin; Syed, Shahid Faraz; Zhou, En-Min

    2015-10-22

    Avian hepatitis E virus (HEV) is the main causative agent of big liver and spleen disease and hepatitis-splenomegaly syndrome in chickens, and is genetically and antigenically related to mammalian HEVs. HEV capsid protein contains immunodominant epitopes and induces a protective humoral immune response. A better understanding of the antigenic composition of this protein is critically important for the development of effective vaccine and sensitive and specific serological assays. To date, six linear antigenic domains (I-VI) have been characterized in avian HEV capsid protein and analyzed for their applications in the serological diagnosis and vaccine design. Domains I and V induce strong immune response in chickens and are common to avian, human, and swine HEVs, indicating that the shared epitopes hampering differential diagnosis of avian HEV infection. Domains III and IV are not immunodominant and elicit a weak immune response. Domain VI, located in the N-terminal region of the capsid protein, can also trigger an intense immune response, but the anti-domain VI antibodies are transient. The protection analysis showed that the truncated capsid protein containing the C-terminal 268 amino acid residues expressed by the bacterial system can provide protective immunity against avian HEV infection in chickens. However, the synthetic peptides incorporating the different linear antigenic domains (I-VI) and epitopes are non-protective. The antigenic composition of avian HEV capsid protein is altogether complex. To develop an effective vaccine and accurate serological diagnostic methods, more conformational antigenic domains or epitopes are to be characterized in detail. PMID:26340899

  16. Genetics of impulsive behaviour

    PubMed Central

    Bevilacqua, Laura; Goldman, David

    2013-01-01

    Impulsivity, defined as the tendency to act without foresight, comprises a multitude of constructs and is associated with a variety of psychiatric disorders. Dissecting different aspects of impulsive behaviour and relating these to specific neurobiological circuits would improve our understanding of the etiology of complex behaviours for which impulsivity is key, and advance genetic studies in this behavioural domain. In this review, we will discuss the heritability of some impulsivity constructs and their possible use as endophenotypes (heritable, disease-associated intermediate phenotypes). Several functional genetic variants associated with impulsive behaviour have been identified by the candidate gene approach and re-sequencing, and whole genome strategies can be implemented for discovery of novel rare and common alleles influencing impulsivity. Via deep sequencing an uncommon HTR2B stop codon, common in one population, was discovered, with implications for understanding impulsive behaviour in both humans and rodents and for future gene discovery. PMID:23440466

  17. Behavioural aspects of terrorism.

    PubMed

    Leistedt, Samuel J

    2013-05-10

    Behavioural and social sciences are useful in collecting and analysing intelligence data, understanding terrorism, and developing strategies to combat terrorism. This article aims to examine the psychopathological concepts of terrorism and discusses the developing roles for behavioural scientists. A systematic review was conducted of studies investigating behavioural aspects of terrorism. These studies were identified by a systematic search of databases, textbooks, and a supplementary manual search of references. Several fundamental concepts were identified that continue to influence the motives and the majority of the behaviours of those who support or engage in this kind of specific violence. Regardless of the psychological aspects and new roles for psychiatrists, the behavioural sciences will continue to be called upon to assist in developing better methods to gather and analyse intelligence, to understand terrorism, and perhaps to stem the radicalisation process.

  18. Women Coping with a Partner's Sexual Avoidance.

    ERIC Educational Resources Information Center

    Renshaw, Domeena C.

    2001-01-01

    Discusses the complexities of sexual avoidance, or Hypoactive Sexual Desire (HSD), a previously neglected aspect of a couple's relationship. Suggests that learning from a therapist to accept and enjoy other forms of sexual exchange can open up new horizons of physical and emotional intimacy. (Contains 17 references.) (GCP)

  19. Doppler micro sense and avoid radar

    NASA Astrophysics Data System (ADS)

    Gorwara, Ashok; Molchanov, Pavlo; Asmolova, Olga

    2015-10-01

    There is a need for small Sense and Avoid (SAA) systems for small and micro Unmanned Aerial Systems (UAS) to avoid collisions with obstacles and other aircraft. The proposed SAA systems will give drones the ability to "see" close up and give them the agility to maneuver through tight areas. Doppler radar is proposed for use in this sense and avoid system because in contrast to optical or infrared (IR) systems Doppler can work in more harsh conditions such as at dusk, and in rain and snow. And in contrast to ultrasound based systems, Doppler can better sense small sized obstacles such as wires and it can provide a sensing range from a few inches to several miles. An SAA systems comprised of Doppler radar modules and an array of directional antennas that are distributed around the perimeter of the drone can cover the entire sky. These modules are designed so that they can provide the direction to the obstacle and simultaneously generate an alarm signal if the obstacle enters within the SAA system's adjustable "Protection Border". The alarm signal alerts the drone's autopilot to automatically initiate an avoidance maneuver. A series of Doppler radar modules with different ranges, angles of view and transmitting power have been designed for drones of different sizes and applications. The proposed Doppler radar micro SAA system has simple circuitry, works from a 5 volt source and has low power consumption. It is light weight, inexpensive and it can be used for a variety of small unmanned aircraft.

  20. An Examination of Avoided Costs in Utah

    SciTech Connect

    Bolinger, Mark; Wiser, Ryan

    2005-01-07

    The Utah Wind Working Group (UWWG) believes there are currently opportunities to encourage wind power development in the state by seeking changes to the avoided cost tariff paid to qualifying facilities (QFs). These opportunities have arisen as a result of a recent renegotiation of Pacificorp's Schedule 37 tariff for wind QFs under 3 MW, as well as an ongoing examination of Pacificorp's Schedule 38 tariff for wind QFs larger than 3 MW. It is expected that decisions made regarding Schedule 38 will also impact Schedule 37. Through the Laboratory Technical Assistance Program (Lab TAP), the UWWG has requested (through the Utah Energy Office) that LBNL provide technical assistance in determining whether an alternative method of calculating avoided costs that has been officially adopted in Idaho would lead to higher QF payments in Utah, and to discuss the pros and cons of this method relative to the methodology recently adopted under Schedule 37 in Utah. To accomplish this scope of work, I begin by summarizing the current method of calculating avoided costs in Utah (per Schedule 37) and Idaho (the ''surrogate avoided resource'' or SAR method). I then compare the two methods both qualitatively and quantitatively. Next I present Pacificorp's four main objections to the use of the SAR method, and discuss the reasonableness of each objection. Finally, I conclude with a few other potential considerations that might add value to wind QFs in Utah.

  1. Social Work Education and Avoidable Ignorance

    ERIC Educational Resources Information Center

    Gambrill, Eileen

    2014-01-01

    The quality of professional education affects the quality of services offered to clients. Examples of avoidable ignorance that dilute the quality of education social workers receive are suggested, indicating that we have not been honest and energetic brokers of knowledge and ignorance. Related reasons are suggested, including a reluctance to take…

  2. Learn to Avoid or Overcome Leadership Obstacles

    ERIC Educational Resources Information Center

    D'Auria, John

    2015-01-01

    Leadership is increasingly recognized as an important factor in moving schools forward, yet we have been relatively random in how we prepare and support them. Four obstacles often block or diminish their effectiveness. Avoiding or overcoming each of these requires an underlying set of skills and knowledge that we believe can be learned and…

  3. Perspectives in avoidance-preference bioassays

    SciTech Connect

    Steele, C.W.; Taylor, D.H.; Strickler-Shaw, S.

    1996-12-31

    Although behavioral endpoints are used in hazard assessment, establishment of water quality criteria and assessment of a contaminant`s hazard to aquatic life rely primarily on standard acute and chronic toxicity tests. Sublethal effects of pollutants should, however, be of major concern because more organisms experience sublethal rather than acutely or chronically lethal exposures of contaminants. The avoidance-preference approach to behavioral bioassays is very useful in screening pollutants for which the mechanisms of perception or response are largely unknown. The underlying philosophy of these studies is that an animal which perceives a chemical can be attracted or repulsed by it. No response is frequently assumed to indicate lack of perception. All three responses have broad ecological implications. The authors discuss the conditions required for performing avoidance-preference bioassays, as well as their sensitivities, advantages, and limitations. In this regard, a comparative approach is used in examining the results of avoidance-preference bioassays with zebrafish in two different apparatuses. Finally, they compare the results of avoidance-preference studies with other measures of the behavioral toxicity of lead to tadpoles.

  4. Digital-Difference Processing For Collision Avoidance.

    NASA Technical Reports Server (NTRS)

    Shores, Paul; Lichtenberg, Chris; Kobayashi, Herbert S.; Cunningham, Allen R.

    1988-01-01

    Digital system for automotive crash avoidance measures and displays difference in frequency between two sinusoidal input signals of slightly different frequencies. Designed for use with Doppler radars. Characterized as digital mixer coupled to frequency counter measuring difference frequency in mixer output. Technique determines target path mathematically. Used for tracking cars, missiles, bullets, baseballs, and other fast-moving objects.

  5. Organising European technical documentation to avoid duplication.

    PubMed

    Donawa, Maria

    2006-04-01

    The development of comprehensive accurate and well-organised technical documentation that demonstrates compliance with regulatory requirements is a resource-intensive, but critically important activity for medical device manufacturers. This article discusses guidance documents and method of organising technical documentation that may help avoid costly and time-consuming duplication.

  6. The employment interview. Avoiding discriminatory questioning.

    PubMed

    Poteet, G W

    1984-04-01

    The potential for legal action against health care institutions for unlawful preemployment interviews has never been greater. This article shows how to avoid discriminatory questions when interviewing job applicants in the health care setting. The author presents guidelines for helping nursing administrators obtain necessary information without violating the basic rights of the potential employee.

  7. Disgust as a Disease-Avoidance Mechanism

    ERIC Educational Resources Information Center

    Oaten, Megan; Stevenson, Richard J.; Case, Trevor I.

    2009-01-01

    Many researchers have claimed that the emotion of disgust functions to protect us from disease. Although there have been several discussions of this hypothesis, none have yet reviewed the evidence in its entirety. The authors derive 14 hypotheses from a disease-avoidance account and evaluate the evidence for each, drawing upon research on pathogen…

  8. Organising European technical documentation to avoid duplication.

    PubMed

    Donawa, Maria

    2006-04-01

    The development of comprehensive accurate and well-organised technical documentation that demonstrates compliance with regulatory requirements is a resource-intensive, but critically important activity for medical device manufacturers. This article discusses guidance documents and method of organising technical documentation that may help avoid costly and time-consuming duplication. PMID:16736662

  9. Pathogen evolution under host avoidance plasticity.

    PubMed

    McLeod, David V; Day, Troy

    2015-09-01

    Host resistance consists of defences that limit pathogen burden, and can be classified as either adaptations targeting recovery from infection or those focused upon infection avoidance. Conventional theory treats avoidance as a fixed strategy which does not vary from one interaction to the next. However, there is increasing empirical evidence that many avoidance strategies are triggered by external stimuli, and thus should be treated as phenotypically plastic responses. Here, we consider the implications of avoidance plasticity for host-pathogen coevolution. We uncover a number of predictions challenging current theory. First, in the absence of pathogen trade-offs, plasticity can restrain pathogen evolution; moreover, the pathogen exploits conditions in which the host would otherwise invest less in resistance, causing resistance escalation. Second, when transmission trades off with pathogen-induced mortality, plasticity encourages avirulence, resulting in a superior fitness outcome for both host and pathogen. Third, plasticity ensures the sterilizing effect of pathogens has consequences for pathogen evolution. When pathogens castrate hosts, selection forces them to minimize mortality virulence; moreover, when transmission trades off with sterility alone, resistance plasticity is sufficient to prevent pathogens from evolving to fully castrate. PMID:26336170

  10. Freeze tolerance and avoidance in plants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cold acclimation is a multigenic, quantitative trait that involves biochemical and structural changes that effect the physiology of a plant. Mechanisms associated with freeze tolerance or freeze avoidance develop and are lost on an annual cycle. When conducting studies to characterize and determin...

  11. Pathogen evolution under host avoidance plasticity.

    PubMed

    McLeod, David V; Day, Troy

    2015-09-01

    Host resistance consists of defences that limit pathogen burden, and can be classified as either adaptations targeting recovery from infection or those focused upon infection avoidance. Conventional theory treats avoidance as a fixed strategy which does not vary from one interaction to the next. However, there is increasing empirical evidence that many avoidance strategies are triggered by external stimuli, and thus should be treated as phenotypically plastic responses. Here, we consider the implications of avoidance plasticity for host-pathogen coevolution. We uncover a number of predictions challenging current theory. First, in the absence of pathogen trade-offs, plasticity can restrain pathogen evolution; moreover, the pathogen exploits conditions in which the host would otherwise invest less in resistance, causing resistance escalation. Second, when transmission trades off with pathogen-induced mortality, plasticity encourages avirulence, resulting in a superior fitness outcome for both host and pathogen. Third, plasticity ensures the sterilizing effect of pathogens has consequences for pathogen evolution. When pathogens castrate hosts, selection forces them to minimize mortality virulence; moreover, when transmission trades off with sterility alone, resistance plasticity is sufficient to prevent pathogens from evolving to fully castrate.

  12. Teaching Preschool Children to Avoid Poison Hazards

    ERIC Educational Resources Information Center

    Dancho, Kelly A.; Thompson, Rachel H.; Rhoades, Melissa M.

    2008-01-01

    We evaluated the effectiveness of group safety training and in situ feedback and response interruption to teach preschool children to avoid consuming potentially hazardous substances. Three children ingested ambiguous substances during a baited baseline assessment condition and continued to ingest these substances following group safety training.…

  13. Pathogen evolution under host avoidance plasticity

    PubMed Central

    McLeod, David V.; Day, Troy

    2015-01-01

    Host resistance consists of defences that limit pathogen burden, and can be classified as either adaptations targeting recovery from infection or those focused upon infection avoidance. Conventional theory treats avoidance as a fixed strategy which does not vary from one interaction to the next. However, there is increasing empirical evidence that many avoidance strategies are triggered by external stimuli, and thus should be treated as phenotypically plastic responses. Here, we consider the implications of avoidance plasticity for host–pathogen coevolution. We uncover a number of predictions challenging current theory. First, in the absence of pathogen trade-offs, plasticity can restrain pathogen evolution; moreover, the pathogen exploits conditions in which the host would otherwise invest less in resistance, causing resistance escalation. Second, when transmission trades off with pathogen-induced mortality, plasticity encourages avirulence, resulting in a superior fitness outcome for both host and pathogen. Third, plasticity ensures the sterilizing effect of pathogens has consequences for pathogen evolution. When pathogens castrate hosts, selection forces them to minimize mortality virulence; moreover, when transmission trades off with sterility alone, resistance plasticity is sufficient to prevent pathogens from evolving to fully castrate. PMID:26336170

  14. The Role of Risk Avoidance in Anxiety

    ERIC Educational Resources Information Center

    Maner, Jon K.; Schmidt, Norman B.

    2006-01-01

    Various forms of disinhibitory psychopathology (e.g., substance use disorder) are characterized by a tendency to make overly risky decisions. The current paper reports on data suggesting that, in contrast, anxiety is associated with an exaggerated tendency to engage in risk-avoidant decision making. In a nonclinical sample of university students,…

  15. Tobacco Road Finland - how did an accepted pleasure turn into an avoidable risk behaviour?

    PubMed

    Hakkarainen, Pekka

    2013-12-01

    Smoking was once defined as an appropriate recreational substance or life comfort, but is now understood as a serious health risk and a public health problem important enough to be controlled by society. In this article the changed social position and development of tobacco regulations in Finland are studied from a perspective of social constructionism. The emergence of recent tobacco controls can be seen as a process whereby tobacco came to be defined as a social problem. I will argue that there were three primary definitions which played a decisive role in this process. Put in historical order, these three definitions contained (1) claims about harms to smokers, (2) claims about harms to others, and (3) claims about tobacco as a highly addictive drug. These conceptions together drove a complementary and mutually reinforcing re-conception of tobacco harms. Consequently, the emergence of these definitions led to the founding of new institutions, practices, and treatments. The leading value in the claim-making process was public health, which transferred the state's interest away from fiscal revenues towards lowering the costs caused by tobacco diseases. Correspondingly, medical science and medical doctors gained a position as the leading authority in the defining the tobacco issue. The latest conceptual innovation is the idea of a tobacco-free Finland by 2040, representing a strategy of 'de-normalising' tobacco use. The reversal in the social and cultural position of tobacco, which in Finland went from one extreme to another, was not based on pressure created by any wider social movements or organised tobacco-specific citizens groups, as in some other countries, but rather by a state health administration supported by a relatively small network of tobacco control advocates. PMID:24331906

  16. Tobacco Road Finland - how did an accepted pleasure turn into an avoidable risk behaviour?

    PubMed

    Hakkarainen, Pekka

    2013-12-01

    Smoking was once defined as an appropriate recreational substance or life comfort, but is now understood as a serious health risk and a public health problem important enough to be controlled by society. In this article the changed social position and development of tobacco regulations in Finland are studied from a perspective of social constructionism. The emergence of recent tobacco controls can be seen as a process whereby tobacco came to be defined as a social problem. I will argue that there were three primary definitions which played a decisive role in this process. Put in historical order, these three definitions contained (1) claims about harms to smokers, (2) claims about harms to others, and (3) claims about tobacco as a highly addictive drug. These conceptions together drove a complementary and mutually reinforcing re-conception of tobacco harms. Consequently, the emergence of these definitions led to the founding of new institutions, practices, and treatments. The leading value in the claim-making process was public health, which transferred the state's interest away from fiscal revenues towards lowering the costs caused by tobacco diseases. Correspondingly, medical science and medical doctors gained a position as the leading authority in the defining the tobacco issue. The latest conceptual innovation is the idea of a tobacco-free Finland by 2040, representing a strategy of 'de-normalising' tobacco use. The reversal in the social and cultural position of tobacco, which in Finland went from one extreme to another, was not based on pressure created by any wider social movements or organised tobacco-specific citizens groups, as in some other countries, but rather by a state health administration supported by a relatively small network of tobacco control advocates.

  17. Engager and Avoider Behaviour in Types of Activities Performed by Out-of-Class Learning Groups

    ERIC Educational Resources Information Center

    Yan, Louisa; Kember, David

    2004-01-01

    This study examines the out-of-class learning activities undertaken, at the students' volition, by groups of students. Data were gathered through 57 individual and 15 focus group interviews with university students in Hong Kong. Group activities reported included: copying, sharing material, consulting peers, consulting teachers, studying and…

  18. Does facilitating pollinator learning impede deceptive orchid attractiveness? A multi-approach test of avoidance learning.

    PubMed

    Juillet, N; Salzmann, C C; Scopece, G

    2011-07-01

    It has often been proposed that nectarless deceptive orchid species exploit naïve pollinators in search of food before they learn to avoid their flowers, and that intraspecific floral trait polymorphism, often noted in this plant group, could prolong the time needed for learning, thus increasing orchid reproductive success. We tested the importance of avoidance learning in a European deceptive orchid, Anacamptis morio, which has been reported to have a highly variable fragrance bouquet among individuals. We used an indirect approach, i.e. we facilitated pollinators' ability to learn to avoid A. morio by adding anisaldehyde to selected inflorescences, a scent compound that is easily perceived by the natural pollinators and produced in large quantities by the closely related, nectar producing Anacamptis coriophora, a species that shares pollinator species with A. morio. In a series of three experiments (in artificial arrays, in natural populations and in bumblebee behavioural observations), we consistently found no difference either of reproductive success of or visitation rates to scent-added versus control inflorescences. We also found that the decrease of reproductive success over time in artificial populations of this deceptive species was not as important as expected. Together, these data suggest that pollinators do not fully learn to avoid deceptive inflorescences, and that pollinator avoidance behaviour alone may explain the lower reproductive success usually found in deceptive orchids. We discuss the possible explanations for this pattern in deceptive orchids, particularly in relation to pollinator cognition and learning abilities. Lastly, in light of our results, the potential for higher average reproductive success in deceptive orchids with high phenotypic variability driven by avoidance learning thus appears to be challenged.

  19. Sensitivity and entanglement in the avian chemical compass.

    PubMed

    Zhang, Yiteng; Berman, Gennady P; Kais, Sabre

    2014-10-01

    The radical pair mechanism can help to explain avian orientation and navigation. Some evidence indicates that the intensity of external magnetic fields plays an important role in avian navigation. In this paper, using a two-stage model, we demonstrate that birds could reasonably detect the directions of geomagnetic fields and gradients of these fields using a yield-based chemical compass that is sensitive enough for navigation. Also, we find that the lifetime of entanglement in this proposed compass is angle dependent and long enough to allow adequate electron transfer between molecules.

  20. Sensitivity and entanglement in the avian chemical compass

    NASA Astrophysics Data System (ADS)

    Zhang, Yiteng; Berman, Gennady P.; Kais, Sabre

    2014-10-01

    The radical pair mechanism can help to explain avian orientation and navigation. Some evidence indicates that the intensity of external magnetic fields plays an important role in avian navigation. In this paper, using a two-stage model, we demonstrate that birds could reasonably detect the directions of geomagnetic fields and gradients of these fields using a yield-based chemical compass that is sensitive enough for navigation. Also, we find that the lifetime of entanglement in this proposed compass is angle dependent and long enough to allow adequate electron transfer between molecules.