100 research outputs found
Monitoring training response in young Friesian dressage horses using two different standardised exercise tests (SETs)
Most Friesian horses reach their anaerobic threshold during a standardized exercise test (SET) which requires lower intensity exercise than daily routine training.to study strengths and weaknesses of an alternative SET-protocol. Two different SETs (SETA and SETB) were applied during a 2 month training period of 9 young Friesian dressage horses. SETB alternated short episodes of canter with trot and walk, lacking long episodes of cantering, as applied in SETA. Following parameters were monitored: blood lactic acid (BLA) after cantering, average heart rate (HR) in trot and maximum HR in canter. HR and BLA of SETA and SETB were analyzed using a paired two-sided T-test and Spearman Correlation-coefficient (p* < 0.05).BLA after cantering was significantly higher in SETA compared to SETB and maximum HR in canter was significantly higher in SETA compared to SETB. The majority of horses showed a significant training response based upon longitudinal follow-up of BLA. Horses with the lowest fitness at start, displayed the largest training response. BLA was significantly lower in week 8 compared to week 0, in both SETA and SETB. A significantly decreased BLA level after cantering was noticeable in week 6 in SETA, whereas in SETB only as of week 8. In SETA a very strong correlation for BLA and average HR at trot was found throughout the entire training period, not for canter.Young Friesian horses do reach their anaerobic threshold during a SET which requires lower intensity than daily routine training. Therefore close monitoring throughout training is warranted. Longitudinal follow up of BLA and not of HR is suitable to assess training response. In the current study, horses that started with the lowest fitness level, showed the largest training response. During training monitoring HR in trot rather than in canter is advised. SETB is best suited as a template for daily training in the aerobic window.Cornelis Marinus de Bruijn, Willem Houterman, Margreet Ploeg, Bart Ducro, Berit Boshuizen, Klaartje Goethals, Elisabeth-Lidwien Verdegaal and Catherine Delesall
Anti-inflammatory phytotherapeutics: a valuable alternative to NSAID treatment in horses?
ABSTRACT In equine practice, phytotherapy is meeting the increasing demand of horse owners for "natural", safe treatment methods. Long-term use of NSAIDs can cause severe adverse effects, hence the growing popularity of anti-inflammatory phytotherapeutics. At the current time, several different herbal mixes are being commercialized, which makes it difficult for horse owners and veterinarians alike to make a well-founded choice. Harpagophytum procumbens (devil's claw), Salix spp. (willow) and Ribes nigrum (blackcurrant), three plants that are often used in these mixes, have been evaluated both in vitro and in vivo. Based on published studies and the evaluation of these studies, for example by the Cochrane Collaboration, there seems to be some evidence for Harpagophytum procumbens and Salix spp. having a stronger analgesic and anti-inflammatory effect than placebos in humans. In horses, however, only one limited clinical study on Harpagophytum has been performed up until now, while no studies were found on the use of Salix in horses. More research is needed before any claims concerning efficacy or safety can be made regarding the use of these plants in treating horses. It has also been claimed that Ribes nigrum leaves have an anti-inflammatory effect, though this has not yet been clinically proven either in humans or in horses. Although veterinary phytotherapy is as old as animal husbandry itself, little scientific proof can be found regarding its uses. More research is needed before phytotherapy can be advertised as a valuable and safe alternative to the more conventional treatment protocols. SAMENVATTING In de paardengeneeskunde is fytotherapie een antwoord op de toenemende vraag van eigenaren naar "natuurlijke", veilige behandelmethoden. Het langdurig gebruik van NSAID's kan ernstige bijwerkingen geven, vandaar de groeiende populariteit van ontstekingsremmende fytotherapeutica. Momenteel zijn er meerdere kruidenpreparaten commercieel beschikbaar maar het is moeilijk voor de paardeneigenaar en de dierenarts om hier een verantwoorde keuze uit te maken. Harpagophytum procumbens (duivelsklauw), Salix spp. (wilg) en Ribes nigrum (zwarte bes of cassisbes), drie planten die veel gebruikt worden in de commerciële preparaten, werden zowel in vitro als in vivo geëvalueerd. Op basis van gepubliceerde studies en de beoordeling van deze studies door onder andere de Cochrane Collaboration zijn er aanwijzingen dat Harpagophytum procumbens en Salix spp. bij de mens een groter analgetisch en ontstekingsremmend effect hebben dan een placebo. Bij paarden is er echter slechts één beperkte klinische studie met Harpagophytum uitgevoerd, en het effect van Salix werd nog nooit onderzocht. Om de werkzaamheid en veiligheid van deze planten bij het paard te kunnen beoordelen, dient er meer onderzoek verricht te worden. De bladeren van Ribes nigrum zouden ook een ontstekingsremmende werking hebben, maar dit is momenteel noch bij de mens, noch bij het paard klinisch aangetoond. Hoewel de veterinaire fytotherapie al even lang bestaat als de dierhouderij, is er weinig wetenschappelijk bewijs omtrent een efficiënte werking ervan. Vooraleer men de fytotherapie kan aanraden als een waardevol en veilig alternatief voor de conventionele behandelmethoden, is er duidelijk nog meer onderzoek nodig
Can hibernators sense and evade fires? Olfactory acuity and locomotor performance during deep torpor.
Increased habitat fragmentation, global warming and other human activities have caused a rise in the frequency of wildfires worldwide. To reduce the risks of uncontrollable fires, prescribed burns are generally conducted during the colder months of the year, a time when in many mammals torpor is expressed regularly. Torpor is crucial for energy conservation, but the low body temperatures (T b) are associated with a decreased responsiveness and torpid animals might therefore face an increased mortality risk during fires. We tested whether hibernators in deep torpor (a) can respond to the smell of smoke and (b) can climb to avoid fires at T bs below normothermic levels. Our data show that torpid eastern pygmy-possums (Cercartetus nanus) are able to detect smoke and also can climb. All males aroused from torpor when the smoke stimulus was presented at an ambient temperature (T a) of 15 °C (T b ∼18 °C), whereas females only raised their heads. The responses were less pronounced at T a 10 °C. The first coordinated movement of possums along a branch was observed at a mean T b of 15.6 °C, and animals were even able to climb their prehensile tail when they reached a mean T b of 24.4 °C. Our study shows that hibernators can sense smoke and move at low T b. However, our data also illustrate that at T b ≤13 °C, C. nanus show decreased responsiveness and locomotor performance and highlight that prescribed burns during winter should be avoided on very cold days to allow torpid animals enough time to respond
Microgeographical, inter-individual, and intra-individual variation in the flower characters of Iberian pear Pyrus bourgaeana (Rosaceae)
Flower characteristics have been traditionally considered relatively constant within species. However, there are an increasing number of examples of variation in flower characteristics. In this study, we examined the variation in attracting and rewarding flower characters at several ecological levels in a metapopulation of Pyrus bourgaeana in the Doñana area (SW Spain). We answered the following questions: what are the variances of morphological and nectar characters of flowers? How important are intra-individual and inter-individual variance in flower characters? Are there microgeographical differences in flower characters? And if so, are they consistent between years? In 2008 and 2009, we sampled flowers of 72 trees from five localities. For six flower morphological and two nectar characteristics, we calculated coefficients of variation (CV). The partitioning of total variation among-localities, among-individuals, and within-individuals was estimated. To analyze differences among localities and their consistency between years, we conducted generalized linear mixed models. The CVs of nectar characters were always higher than those of morphological characters. As expected, inter-individual variation was the main source of variation of flower morphology, but nectar characters had significant variation at both intra- and inter-individual levels. For most floral traits, there were no differences among localities. Our study documents that variation is a scale-dependent phenomenon and that it is essential to consider intra- and inter-individual variance when investigating the causes and consequences of variation. It also shows that single year studies of floral characters should be viewed with caution
Depleted dissolved organic carbon and distinct bacterial communities in the water column of a rapid-flushing coral reef ecosystem
Author Posting. © The Author(s), 2011. This is the author's version of the work. It is posted here by permission of Nature Publishing Group for personal use, not for redistribution. The definitive version was published in The ISME Journal 5 (2011): 1374–1387, doi:10.1038/ismej.2011.12.Coral reefs are highly productive ecosystems bathed in unproductive, low-nutrient oceanic waters, where microbially-dominated food webs are supported largely by bacterioplankton recycling of dissolved compounds. Despite evidence that benthic reef organisms efficiently scavenge particulate organic matter and inorganic nutrients from advected oceanic waters, our understanding of the role of bacterioplankton and dissolved organic matter in the interaction between reefs and the surrounding ocean remains limited. Here we present the results of a four-year study conducted in a well-characterized coral reef ecosystem (Paopao Bay, Moorea, French Polynesia) where changes in bacterioplankton abundance and dissolved organic carbon (DOC) concentrations were quantified and bacterial community structure variation was examined along spatial gradients of the reef:ocean interface. Our results illustrate that the reef is consistently depleted in concentrations of both DOC and bacterioplankton relative to offshore waters (averaging 79 µmol L-1 DOC and 5.5 X 108 cells L-1 offshore and 68 µmol L-1 DOC and 3.1 X 108 cells L-1 over the reef, respectively) across a four year time period. In addition, using a suite of culture-independent measures of bacterial community structure, we found consistent differentiation of reef bacterioplankton communities from those offshore or in a nearby embayment across all taxonomic levels. Reef habitats were enriched in Gamma-, Delta-, and Beta-proteobacteria, Bacteriodetes, Actinobacteria and Firmicutes. Specific bacterial phylotypes, including members of the SAR11, SAR116, Flavobacteria, and Synechococcus clades, exhibited clear gradients in relative abundance among nearshore habitats. Our observations indicate that this reef system removes oceanic DOC and exerts selective pressures on bacterioplankton community structure on timescales approximating reef water residence times, observations which are notable both because fringing reefs do not exhibit long residence times (unlike those characteristic of atoll lagoons) and because oceanic DOC is generally recalcitrant to degradation by ambient microbial assemblages. Our findings thus have interesting implications for the role of oceanic DOM and bacterioplankton in the ecology and metabolism of reef ecosystems.This project was supported by the US National Science Foundation Moorea Coral Reef Long Term Ecological Research project (NSF OCE-0417412) through minigrants to CAC and NSF OCE-0927411 to CAC as well as the MIRADA-LTERs program (NSF DEB-0717390 to LAZ)
«La relation de limitation et d’exception dans le français d’aujourd’hui : excepté, sauf et hormis comme pivots d’une relation algébrique »
L’analyse des emplois prépositionnels et des emplois conjonctifs d’ “excepté”, de “sauf” et d’ “hormis” permet d’envisager les trois prépositions/conjonctions comme le pivot d’un binôme, comme la plaque tournante d’une structure bipolaire. Placées au milieu du binôme, ces prépositions sont forcées par leur sémantisme originaire dûment métaphorisé de jouer le rôle de marqueurs d’inconséquence systématique entre l’élément se trouvant à leur gauche et celui qui se trouve à leur droite. L’opposition qui surgit entre les deux éléments n’est donc pas une incompatibilité naturelle, intrinsèque, mais extrinsèque, induite. Dans la plupart des cas (emplois limitatifs), cette opposition prend la forme d’un rapport entre une « classe » et le « membre (soustrait) de la classe », ou bien entre un « tout » et une « partie » ; dans d’autres (emplois exceptifs), cette opposition se manifeste au contraire comme une attaque de front portée par un « tout » à un autre « tout ». De plus, l’inconséquence induite mise en place par la préposition/conjonction paraît, en principe, tout à fait insurmontable. Dans l’assertion « les écureuils vivent partout, sauf en Australie » (que l’on peut expliciter par « Les écureuils vivent partout, sauf [qu’ils ne vivent pas] en Australie »), la préposition semble en effet capable d’impliquer le prédicat principal avec signe inverti, et de bâtir sur une telle implication une sorte de sous énoncé qui, à la rigueur, est totalement inconséquent avec celui qui le précède (si « les écureuils ne vivent pas en Australie », le fait qu’ils « vivent partout » est faux). Néanmoins, l’analyse montre qu’alors que certaines de ces oppositions peuvent enfin être dépassées, d’autres ne le peuvent pas. C’est, respectivement, le cas des relations limitatives et des relations exceptives. La relation limitative, impliquant le rapport « tout » - « partie », permet de résoudre le conflit dans les termes d’une somme algébrique entre deux sous énoncés pourvus de différent poids informatif et de signe contraire. Les valeurs numériques des termes de la somme étant déséquilibrées, le résultat est toujours autre que zéro. La relation exceptive, au contraire, qui n’implique pas le rapport « tout » - « partie », n’est pas capable de résoudre le conflit entre deux sous énoncés pourvus du même poids informatif et en même temps de signe contraire : les valeurs numériques des termes de la somme étant symétriques et égales, le résultat sera toujours équivalent à zéro
Uncovering the Importance of Selenium in Muscle Disease
A connection between selenium bioavailability and development of muscular
disorders both in humans and livestock has been established for a long time.
With the development of genomics, the function of several selenoproteins was
shown to be involved in muscle activity, including SELENON, which was linked to
an inherited form of myopathy. Development of animal models has helped to dissect
the physiological dysfunction due to mutation in the SELENON gene; however the
molecular activity remains elusive and only recent analysis using both in vivo and
in vitro experiment provided hints toward its function in oxidative stress defence
and calcium transport control. This review sets out to summarise most recent findings
for the importance of selenium in muscle function and the contribution of this
information to the design of strategies to cure the diseases
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