165 research outputs found

    An Assessment of Stream Health Through Use of Macroinvertebrates as Bio-­‐Indicators

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    The Stoney Creek Off--‐Channel Habitat Improvement Project aimed to restore a stream section in Burnaby, BC. The species assemblages of macroinvertebrate bioindicators were analyzed with reference to stream health of the restored ecosystem. Using a region specific B-IBI, species assemblages were characterized according to their tolerance to pollution. Samples where collected from a previously restored upstream site and recently restored downstream site and individually from riffle and pool zones within each site. Frequency distributions and relative abundances were used to measure actual and relative representation of categories. Overall, pollution tolerant species showed the highest representation over both sites when compared to pollution intolerant and somewhat tolerant species. Riffles exhibited a higher presence of pollution intolerant species then pools. These results indicate relatively low stream quality. Results of the WQI did not support the stream quality data provided by macroinvertebrates. Further study needs to be undertaken to involve baseline data and address additional determinants for species assemblages

    Instability of Glucocorticoid Metabolites in Coyote Scats: Implications for Field Sampling

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    Studying physiologic stress responses can assist in understanding the welfare of animals. One method of measuring the physiologic stress response is evaluating concentrations of glucocorticoid metabolites in feces. Previously, using an adrenocorticotropic hormone challenge, we found fecal glucocorticoid metabolite levels were a reliable indicator of physiologic stress response in coyotes (Canis latrans). We determine whether glucocorticoid metabolite concentrations remain stable when collecting feces over a 2-week period, a timeframe commonly used in scat surveys for wild canids. We collected feces from 6 captive coyotes maintained at the U.S. Department of Agriculture, Wildlife Services, National Wildlife Research Center, Predator Research Facility near Millville, Utah, USA, and exposed them to the environment for 13 days during summer (August 26 to September 8, 2011) and winter (January 11–24, 2012). Every 2 days, we collected a sub-sample from each individual scat and then quantified the concentration of fecal glucocorticoid metabolites. We found changes in fecal glucocorticoid metabolite concentrations over the 13-day period, with values increasing 45–79% from day 1 to day 3 of sampling. There was also high variation in fecal glucocorticoid metabolites among individuals over time. We provide evidence that fecal samples collected in the field even 3 days after defecation will not provide reliable measures of fecal glucocorticoid metabolites and thus recommend using only fresh fecal samples. We also recommend that, due to high individual variability in fecal glucocorticoid metabolites, a large number of individuals be sampled when a population-wide assessment is desired

    Changes in Fecal Glucocorticoid Metabolites in Captive Coyotes (\u3ci\u3eCanis latrans\u3c/i\u3e): Influence of Gender, Time, and Reproductive Status

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    Reproduction is considered an energetically and physiologically demanding time in the life of an animal. Changes in physiological stress are partly reflected in changes in glucocorticoid metabolites and can be measured from fecal samples. We examined levels of fecal glucocorticoid metabolites (fGCMs) in 24 captive coyotes (Canis latrans) to investigate responses to the demands of reproduction. Using 12 pairs of coyotes (five pairs produced pups, seven pairs did not), we analyzed 633 fecal samples covering 11 biological periods (e.g., breeding, gestation, and lactation). Levels of fGCMs showed high individual variability, with females having higher fGCM levels than males. The production of pups showed no statistical effect on fGCM levels among females or males. Among females, fGCM levels were highest during 4–6 weeks of gestation compared to other periods but were not significantly different between pregnant and nonpregnant females. Among males, the highest fGCM levels were during 1–3 weeks of gestation compared to other periods, but were not significantly different between males with a pregnant mate versus nonpregnant mate. Of females producing pups, litter size did not influence fGCM levels. Given that they were fed ample food throughout the year, we found that the demands of producing pups did not appear to statistically influence measures of fGCM concentrations in captive coyotes

    Spinal plasticity in robot-mediated therapy for the lower limbs

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    Robot-mediated therapy can help improve walking ability in patients following injuries to the central nervous system. However, the efficacy of this treatment varies between patients, and evidence for the mechanisms underlying functional improvements in humans is poor, particularly in terms of neural changes in the spinal cord. Here, we review the recent literature on spinal plasticity induced by robotic-based training in humans and propose recommendations for the measurement of spinal plasticity using robotic devices. Evidence for spinal plasticity in humans following robotic training is limited to the lower limbs. Body weight-supported (BWS) robotic-assisted step training of patients with spinal cord injury (SCI) or stroke patients has been shown to lead to changes in the amplitude and phase modulation of spinal reflex pathways elicited by electrical stimulation or joint rotations. Of particular importance is the finding that, among other changes to the spinal reflex circuitries, BWS robotic-assisted step training in SCI patients resulted in the re-emergence of a physiological phase modulation of the soleus H-reflex during walking. Stretch reflexes elicited by joint rotations constitute a tool of interest to probe spinal circuitry since the technology necessary to produce these perturbations could be integrated as a natural part of robotic devices. Presently, ad-hoc devices with an actuator capable of producing perturbations powerful enough to elicit the reflex are available but are not part of robotic devices used for training purposes. A further development of robotic devices that include the technology to elicit stretch reflexes would allow for the spinal circuitry to be routinely tested as a part of the training and evaluation protocols

    A ciliopathy complex builds distal appendages to initiate ciliogenesis

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    Cells inherit two centrioles, the older of which is uniquely capable of generating a cilium. Using proteomics and superresolved imaging, we identify a module that we term DISCO (distal centriole complex). The DISCO components CEP90, MNR, and OFD1 underlie human ciliopathies. This complex localizes to both distal centrioles and centriolar satellites, proteinaceous granules surrounding centrioles. Cells and mice lacking CEP90 or MNR do not generate cilia, fail to assemble distal appendages, and do not transduce Hedgehog signals. Disrupting the satellite pools does not affect distal appendage assembly, indicating that it is the centriolar populations of MNR and CEP90 that are critical for ciliogenesis. CEP90 recruits the most proximal known distal appendage component, CEP83, to root distal appendage formation, an early step in ciliogenesis. In addition, MNR, but not CEP90, restricts centriolar length by recruiting OFD1. We conclude that DISCO acts at the distal centriole to support ciliogenesis by restraining centriole length and assembling distal appendages, defects in which cause human ciliopathies

    Survival of Spray-Dried Rhodotorula mucilaginosa Isolated from Natural Microbiota of Murta Berries and Antagonistic Effect on Botrytis cinerea

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    Svrha je ovoga rada bila ispitati preživljavanje i antagonističku aktivnost kvasca Rhodotorula mucilaginosa, izoliranog iz prirodne mikrobiote bobica čileanske guave, na plijesan Botrytis cinerea, uzročnika sive plijesni na voću i povrću, nakon sušenja raspršivanjem pri različitim uvjetima kao što su: ulazna temperatura, udjel inkapsulirajućeg sredstva (maltodekstrin) i pritok supstrata. Stopostotno preživljavanje kvasca postignuto je nakon sušenja raspršivanjem s 18 % maltodekstrina pri ulaznoj temperaturi od 130 °C i pritoku supstrata od 9,25 mL/min. Suhi kvasac dobiven pri tim uvjetima imao je najveće antagonističko djelovanje in vitro i in vivo na jabukama, čime je potvrđeno da je sušenje raspršivanjem prikladna metoda proizvodnje aktivnih suhih stanica kvasca R. mucilaginosa koje se mogu primijeniti za biokontrolu kvarenja sivom plijesni. Također je potvrđeno da maltodekstrin kao inkapsulirajuće sredstvo poboljšava in vitro antagonističku aktivnost kvasca R. mucilaginosa.The aim of this study is to evaluate the survival rate and effective antagonistic activity against Botrytis cinerea, responsible for grey mould on harvested fruits and vegetables, of yeast Rhodotorula mucilaginosa, isolated and identified from the natural microbiota of murta (Chilean guava) berries, after spray drying at different inlet air temperatures, mass per volume ratio of encapsulating agent (maltodextrin) and feed flow rates. The 100 % survival of the yeast was obtained after spray drying with 18 % maltodextrin at 130 °C inlet temperature and a feed flow rate of 9.25 mL/min. The dried yeast obtained under such conditions had the highest antagonistic activity in vitro and in vivo on apples, which showed that spray drying is a valid method to produce active dried cells of R. mucilaginosa that can be used for biocontrol of grey mould spoilage. It was also found that the encapsulating agent maltodextrin improved the in vitro antagonistic activity of R. mucilaginosa

    Physical and immunological aspects of exercise in chronic diseases.

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    Physical inactivity and sedentary lifestyles are believed to be independent risk factors for the occurrence of numerous diseases, including, obesity, Type 2 diabetes, metabolic syndrome, cardiovascular disease, cancer and mental health, all leading to substantial morbidity and/or premature death. It has been found that regular exercise, is associated with better quality of life and health outcomes, and reduces the risk of cardiovascular disease and cancer. Here, we review the effects regular exercise has on mental health and well-being, on the immune system and in cancer, cardiovascular disease, autoimmunity and metabolic syndrome. Is exercise the new immunotherapy to treat diseases

    Association between subjective rating and behaviour coding and the role of experience in making video assessments on the personality of the domestic dog (Canis familiaris)

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    In this paper our first aim was to investigate the association between behaviour coding based on a test battery called the FIDO Personality test for dogs (Canis familiaris) and a subjective rating given by dog owners. For the latter we asked dog owners to fin in the Dog Personality Questionnaire (DPQ) which established four personality traits for dogs: Stranger-directed Sociability, Activity, Aggressiveness and Trainability. The FIDO Personality test consists of a series of subtests in which we utilised an ethogram and measured different aspects of dog behaviour. Prior to this study we established a set of possible associations between the behavioural and the questionnaire variables. With regard to Trainability no correlation could be detected between any of the questionnaire variables and the hypothetically corresponding test battery variables. In the case of Stranger-directed Sociability, we revealed correlation between owners' reports and the dogs' behaviour during the test situation. Those dogs which were reported 'initiative' and 'not mistrustful with unfamiliar humans' approached the experimenter with shorter latency (r = -0.25, p < 0.01; r = 0.24, p < 0.01) and played more with her than those who were scored lower on these questionnaire items (r = -0.27, p < 0.01). For the factor Activity, no correlation was found between the owners' report and the behaviour of dogs displayed in the Spontaneous activity phase of the test battery. Association was revealed between the owners' report regarding the dogs' preference for ball games and playing and their behaviour in the corresponding subtest. Those dogs which were reported to like ball games and like playing with the owner played with the ball as well as with a tug more in the test situation than those which were scored lower on the questionnaire variable 'likes fetching balls' (r = 0.47, p < 0.001; r = 0.25, p < 0.01). As regards the factor Aggressiveness, the questionnaire variable 'shows a tendency to bark' correlated with the dogs' aggressive reactions (growl, bite, attack) (r = 0.25, p < 0.01) in the Bone take-away subtest and with the 'latency of getting the DNA sample' (r = 0.30, p < 0.001) in the Getting DNA sample subtest. The results show that despite of the investigated associations there is a need for more effort to refine both questionnaire-based and behaviour-based assessment of dog personality. The second aim of our experiments was to reveal whether owner ratings on the above personality factors converged with the ratings of independent groups of observers based on the video recordings of the FIDO Personality test. First, in the case of each factor, we compared the degrees of ratings given by the owners and by the three rater groups with different levels of hands-on experience with dogs. We found no difference in the case of Stranger-directed Sociability, Activity and Trainability (F(3, 128) = 1.17, p = 0.17; F(3, 128) = 0.99, p = 0.4; F(3, 128) = 1.6,p = 0.18 respectively) but there was a significant variability in judging Aggressiveness (F(3, 128)= 2.86, p = 0.04). In the case of Stranger-directed Sociability, Activity and Aggressiveness the owner's report correlated with the assessments of all the three rater groups and the assessments of the rater groups correlated with each other as well. As regards Trainability, the owners' report did not correlate with the assessments of any of the rating groups, but the assessments of all the rating groups correlated with each other. Our investigations provide a contribution to the field of research on comparing behaviour coding based on test batteries and subjective rating based on questionnaire studies as methods for establishing the personality factors of individual animals

    Investigation of Host Candidate Malaria-Associated Risk/Protective SNPs in a Brazilian Amazonian Population

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    The Brazilian Amazon is a hypo-endemic malaria region with nearly 300,000 cases each year. A variety of genetic polymorphisms, particularly in erythrocyte receptors and immune response related genes, have been described to be associated with susceptibility and resistance to malaria. In order to identify polymorphisms that might be associated with malaria clinical outcomes in a Brazilian Amazonian population, sixty-four human single nucleotide polymorphisms in 37 genes were analyzed using a Sequenom massARRAY iPLEX platform. A total of 648 individuals from two malaria endemic areas were studied, including 535 malaria cases (113 individuals with clinical mild malaria, 122 individuals with asymptomatic infection and 300 individuals with history of previous mild malaria) and 113 health controls with no history of malaria. The data revealed significant associations (p<0.003) between one SNP in the IL10 gene (rs1800896) and one SNP in the TLR4 gene (rs4986790) with reduced risk for clinical malaria, one SNP in the IRF1 gene (rs2706384) with increased risk for clinical malaria, one SNP in the LTA gene (rs909253) with protection from clinical malaria and one SNP in the TNF gene (RS1800750) associated with susceptibility to clinical malaria. Also, a new association was found between a SNP in the CTL4 gene (rs2242665), located at the major histocompatibility complex III region, and reduced risk for clinical malaria. This study represents the first association study from an Amazonian population involving a large number of host genetic polymorphisms with susceptibility or resistance to Plasmodium infection and malaria outcomes. Further studies should include a larger number of individuals, refined parameters and a fine-scale map obtained through DNA sequencing to increase the knowledge of the Amazonian population genetic diversity
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