黔北地区主要竹种竹材气干密度与力学性质的关系研究     

王健  司徒春南  杜文军  谢双喜 《广东农业科学》2011,38(5):194-196

对黔北地区几种主要竹种的气干密度与力学性质的关系研究表明:各竹种的气千密度与力学性质除部分竹种外均存在一定的曲线或直线关系,其中在气干密度与抗剪强度关系中,除慈竹、花吊丝、毛脚龙竹、金佛山方竹等竹种外,其他竹种均可利用回归方程T12=ap12b,T12=ap12+b进行估测.在气干密度与顺纹抗拉强度关系中除硬头黄、花吊...  相似文献   

Glucocorticoid‐deficient hypoadrenocorticism secondary to intravascular lymphoma in the adrenal glands of a dog          下载免费PDF全文

ME Buckley  PS Chapman  A Walsh 《Australian veterinary journal》2017,95(3):64-67

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Comparative analysis of the early transcriptome of Brucella abortus--infected monocyte-derived macrophages from cattle naturally resistant or susceptible to brucellosis     

Rossetti CA  Galindo CL  Everts RE  Lewin HA  Garner HR  Adams LG 《Research in veterinary science》2011,91(1):40-51

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High intakes of l⁺ and d⁻ lactic acid are efficiently metabolized by pigs and rats     

II. Everts  N. Salden  A. G. Lemmens  J. Wijers  A. C. Beynen 《Journal of animal physiology and animal nutrition》2000,83(4-5):224-230

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Diagnosing feline immunodeficiency virus (FIV) and feline leukaemia virus (FeLV) infection: an update for clinicians     

ME Westman  R Malik  JM Norris 《Australian veterinary journal》2019,97(3):47-55

With the commercial release in Australia in 2004 of a vaccine against feline immunodeficiency virus (FIV; Fel‐O‐Vax FIV®), the landscape for FIV diagnostics shifted substantially. Point‐of‐care (PoC) antibody detection kits, which had been the mainstay for diagnosing FIV infection since the early 1990s, were no longer considered accurate to use in FIV‐vaccinated cats, because of the production of vaccine‐induced antibodies that were considered indistinguishable from those produced in natural FIV infections. Consequently, attention shifted to alternative diagnostic methods such as nucleic acid detection. However, over the past 5 years we have published a series of studies emphasising that FIV PoC test kits vary in their methodology, resulting in differing accuracy in FIV‐vaccinated cats. Importantly, we demonstrated that two commercially available FIV antibody test kits (Witness? and Anigen Rapid?) were able to accurately distinguish between FIV‐vaccinated and FIV‐infected cats, concluding that testing with either kit offers an alternative to PCR testing. This review summarises pertinent findings from our work published in a variety of peer‐reviewed research journals to inform veterinarians (particularly veterinarians in Australia, New Zealand and Japan, where the FIV vaccine is currently commercially available) about how the approach to the diagnosis of FIV infection has shifted. Included in this review is our work investigating the performance of three commercially available FIV PoC test kits in FIV‐vaccinated cats and our recommendations for the diagnosis of FIV infection; the effect of primary FIV vaccination (three FIV vaccines, 4 weeks apart) on PoC test kit performance; our recommendations regarding annual testing of FIV‐vaccinated cats to detect ‘vaccine breakthroughs’; and the potential off‐label use of saliva for the diagnosis of FIV infection using some FIV PoC test kits. We also investigated the accuracy of the same three brands of test kits for feline leukaemia virus (FeLV) diagnosis, using both blood and saliva as diagnostic specimens. Based on these results, we discuss our recommendations for confirmatory testing when veterinarians are presented with a positive FeLV PoC test kit result. Finally, we conclude with our results from the largest and most recent FIV and FeLV seroprevalence study conducted in Australia to date.  相似文献   

Interrelated effects of temperature, light and oxygen on Amaranthus caudatus L. seed germination     

Y. GUTTERMAN  F. CORBINEAU  D. CÔME 《Weed Research》1992,32(2):111-117

The aim of this study was to investigate the effects of temperature, light and oxygen on the germination of Amaranthus caudatus (var. viridis) seeds. At the highest temperature studied (35°C), seed germination was found to be most rapid and highest in both the dark and the light. Germination was inhibited by continuous white light. The lower the temperature, the greater the inhibitory effect of light. The far-red and blue spectral regions were the most effective in light inhibition. The light effect was also dependent on the percentage of oxygen in the atmosphere around the seeds; it was less marked in O₂-enriched atmospheres. Light/ oxygen dependency resulted from the action of the seed coat and endosperm. Scarified seeds were much less sensitive to light and hypoxia than non-scarified seeds. Effets combinés de la température, de la lumière et de I'oxygène sur la germination des graines d'Amaranthus caudatus L. Le but de ce travail était d'étudier les effets de la température, de la lumiere et de I'oxygène sur la germination des graines d'Amaranthus caudatus (var. viridis). A la temperature la plus élevée utilisée (35°C), la germination était la plus rapide et la plus complète tant à la lumière qu'à 1'obscuritè. La germination était inhibée par la lumière blanche continue. Plus la temperature était basse, plus 1'effet inhibiteur de la lumière était important. Les radiations rouge sombre et bleues du spectre étaient les plus in-hibitrices. L'effet de la lumière dépendait aussi de la teneur de 1'atmosphère en oxygène; il était moins marqué dans des atmosphères enrichies en oxygène. L'interaction lumière/oxygène provenait du tégument et de 1'albumen. Les graines scarifiées étaient beaucoup moins sensibles à la lumière et a 1'hypoxie que les graines non scarifiées. Wechselwirkungen von Temperatur, Licht und Sauerstoff auf die Keimung der Samen von Amaranthus caudatus L. Sowohl im Dunkeln als auch im Licht keimten die Samen von Amaranthus caudatus (var. viridis) bei 35°C, der höchsten Temperatur der Versuche, am schnellsten und meisten. Durch weiβes Dauerlicht wurde die Keimung gehemmt. Je niedriger die Temperatur, desto hölier die Hemmung durch Licht. Im entfernt roten und blauen Spektralbereich war die Lichthemmung am stärksten. Die Wirkung des Lichts hing auch vom Sauerstoffgehalt der die Samen umgebenden Luft ab: Bei O₂₅-Anreiche-rung war sie weniger deutlich. Die Licht/ Sauerstoff-Wechselwirkung wurde von der Samenschale und dem Endosperm beeinfluβt: Geritzte Samen waren gegenüber Licht und O₂-Mangel viel weniger empfindlich als ganze.  相似文献   

Dormancy of Bromus rubens L. seeds in relation to temperature, light and oxygen effects     

F. CORBINEAU  D. BELAID  D. CÔME 《Weed Research》1992,32(4):303-310

Freshly harvested mature Bromus rubens L. seeds are dormant. This dormancy corresponds to the inability of seeds to germinate in the dark at temperatures above 15°C, but is practically not apparent at temperatures between 5 and 15°C. Continuous white light markedly inhibits germination of dormant seeds, even at low irradiances, and reinforces their sensitivity to oxygen deprivation. However, prolonged illumination with white light does not alter subsequent germination in the dark. Breaking of dormancy during dry storage at 20°C results in a widening of the temperature range within which a high rate of germination occurs, and in almost complete disappearance of sensitivity of seeds to light. The structures surrounding the embryo (glumellae, caryopsis envelopes and possibly endosperm) are mainly responsible for dormancy and photosensitivity of whole seeds, probably because they limit the oxygen supply to the embryo. However, the embryo itself appears to play a role in dormancy. The results obtained are discussed in relation to dormancy of cereal seeds, and in relation to field establishment of B. rubens as a weed. La dormance des semences de Bromus rubens L. en relation avec les effets de la température, de la lumière et de l'oxygène Les semences mûres de Bromus rubens L. fraîchement récoltées sont dormantes. Leur dormance correspond à une inaptitude à germer à l'obscuritéà des températures supérieures à 15°C, mais elle ne se manifeste pratiquement pas entre 5 et 15°C. La lumière blanche continue inhibe nettement la germination des semences dormantes, même à de faibles énergies, et renforce leur sensibilitéà la privation d'oxygène. Cependant, un éclairement prolongé n'a aucune conséquence sur la germination ultérieure à l'obscurité. L'élimination de la dormance pendant la conservation au sec, à 20°C, se traduit par un élargissement de la gamme thermique qui assure une bonne germination et par la disparition presque complète de la sensibilité des semences à la lumière. Les structures qui entourent l'embryon (glumelles, enveloppes du caryopse et peut-être albumen) sont, en grande partie, responsables de la dormance et de la photosensibilité des semences entières, sans doute parce qu'elles limitent l'apport d'oxygène à l'embryon. Toutefois, l'embryon lui-même semble participer à la dormance. Les résultats obtenus sont discutés par comparaison avec la dormance des semences des céréales et en relation avec l'implantation, dans les cultures, de B. rubens en tant que mauvaise herbe. Dormanz der Samen von Bromus rubens L. in Bezug auf Temperatur, Licht und Sauerstoffversorgung Frisch geerntete Samen von Bromus rubens L. sind im Dunkeln bei Temperaturen über 15°C dormant, während diese Dormanz bei Temperaturen zwischen 5 und 15°C praktisch nicht vorliegt. Ständiges weißes Licht hemmt die Keimung dormanter Samen deutlich, sogar bei niedriger Intensität, und verstärkt ihre Empfindlichkeit gegenüber Sauerstoffmangel. Ständige Beleuchtung mit weißem Licht verändert jedoch nicht die folgende Dunkelkeimung. Das Brechen der Dormanz während der trockenen Lagerung bei 20 °C führt zu einem vergrößerten Temperaturbereich, in dem die Samen gut keimen, und läßt ihre Lichtempfindlichkeit fast vollständig verschwinden. Die Strukturen um den Embryo (Spelzen, Schale der Caryopse und möglicherweise Endosperm) sind hauptsächlich für die Dormanz und die Lichtempfindlichkeit des ganzen Samens verantwortlich, vermutlich deshalb, weil sie die Sauerstoffversorgung des Embryos einschränken. Aber auch der Embryo selbst scheint bei der Dormanz eine Rolle zu spielen. Die Untersuchungsergebnisse werden im Vergleich zur Dormanz von Getreidesamen und hinsichtlich des Vorkommens von Bromus rubens als Unkraut diskutiert.  相似文献   

Expression of the μ Opioid Receptor and Effects of the Opioid Antagonist Naloxone on In Vitro Maturation of Oocytes Recovered from Anoestrous Bitches     

AI Iorga  L Valentini  T De Santis  B Ambruosi  M Albrizio  AC Guaricci  M Caira  ME Dell'Aquila 《Reproduction in domestic animals》2009,44(S2):263-268

The μ-opioid receptor (MOR) is expressed in bovine, human, equine and canine oocytes, and in seasonal breeders, it is expressed with higher intensity during the anoestrous phase. Supplementation of in vitro maturation (IVM) medium with opioid agents, agonists or antagonists, was shown to affect oocyte maturation in several species such as rat, bovine and equine. This study reports the effects of supplementing IVM medium with naloxone (Nx), an opioid antagonist, on nuclear and cytoplasmic maturation rate of oocytes recovered from anoestrous bitches. Cytoplasmic maturation was examined in terms of mitochondrial (mt) distribution. In order to confirm the receptor-mediated action of Nx, in oocytes of anoestrous bitches, MOR expression was analyzed by Western blot. Cumulus–oocyte complexes, recovered from the ovaries of bitches in anoestrous, were cultured in vitro and Nx was added at the concentrations of 1 × 10⁻⁶, 1 × 10⁻⁸ and 1 × 10⁻¹⁰  m . The rate of oocytes resuming meiosis after culture in presence of 1 × 10⁻⁶  m Nx (29%) was significantly higher than that of oocytes of control group (12%; p < 0.05). However, treatment with Nx did not affect mt distribution pattern. In denuded oocytes and in corresponding cumulus cells, a doublet of 65 and 50 kDa was observed. We conclude that, in oocytes of anoestrous bitches, MOR is expressed and Nx significantly improves nuclear maturation rate. Further studies should be performed to elucidate the expression of other opioid receptors, such as δ and κ, and possible interactive effects of their antagonists on canine oocyte maturation.  相似文献   

Extension plant pathology: strengthening resources to continue serving the public interest     

Everts KL  Osborne L  Gevens AJ  Vasquez SJ  Gugino BK  Ivors K  Harmon C 《Phytopathology》2012,102(7):652-655

Extension plant pathologists deliver science-based information that protects the economic value of agricultural and horticultural crops in the United States by educating growers and the general public about plant diseases. Extension plant pathologists diagnose plant diseases and disorders, provide advice, and conduct applied research on local and regional plant disease problems. During the last century, extension plant pathology programs have adjusted to demographic shifts in the U.S. population and to changes in program funding. Extension programs are now more collaborative and more specialized in response to a highly educated clientele. Changes in federal and state budgets and policies have also reduced funding and shifted the source of funding of extension plant pathologists from formula funds towards specialized competitive grants. These competitive grants often favor national over local and regional plant disease issues and typically require a long lead time to secure funding. These changes coupled with a reduction in personnel pose a threat to extension plant pathology programs. Increasing demand for high-quality, unbiased information and the continued reduction in local, state, and federal funds is unsustainable and, if not abated, will lead to a delay in response to emerging diseases, reduce crop yields, increase economic losses, and place U.S. agriculture at a global competitive disadvantage. In this letter, we outline four recommendations to strengthen the role and resources of extension plant pathologists as they guide our nation's food, feed, fuel, fiber, and ornamental producers into an era of increasing technological complexity and global competitiveness.  相似文献   

Retrospective study of the survival of cats with acquired chronic renal insufficiency offered different commercial diets     

Plantinga EA  Everts H  Kastelein AM  Beynen AC 《The Veterinary record》2005,157(7):185-187

A retrospective study was carried out on the efficacy of seven commercial diets designed to be fed to cats with chronic renal failure. The median survival time of 175 cats that received conventional diets was seven months, whereas the median survival time of 146 cats given one of the seven diets was 16 months. The cats on the most effective of the diets had a median survival time of 23 months and those on the least effective diet had a median survival time of 12 months. The composition of the seven diets was comparable, except that the most effective diet had a particularly high content of eicosapentaenoic acid.  相似文献