Recovery of canine retina and optic nerve function after acute elevation of intraocular pressure: implications for canine glaucoma treatment     

Sinisa D. Grozdanic  Milan Matic  Daniel M. Betts  Donald S. Sakaguchi†  Randy H. Kardon‡ 《Veterinary ophthalmology》2007,10(S1):101-107

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Response of vegetation and fire to Little Ice Age climate change: regional continuity and landscape heterogeneity   总被引：1，自引：0，他引：1  

Hotchkiss  Sara C.  Calcote  Randy  Lynch  Elizabeth A. 《Landscape Ecology》2007,22(1):25-41

Late-Holocene climatic conditions in the upper Great Lakes region have changed sufficiently to produce significant changes in vegetation and fire regimes. The objective of this study was to determine how the vegetation mosaic and fire regimes on an oak (Quercus spp.)- and pine (Pinus spp.)-dominated sand plain in northwestern Wisconsin responded to climatic changes of the past 1,200 years. We used pollen and charcoal records from a network of sites to investigate the range of natural variability of vegetation on a 1,500-km² landscape on the southern part of the sand plain. A major vegetation shift from jack pine (Pinus banksiana) and red pine (P. resinosa) to increased abundance of white pine (P. strobus) occurred between 700 and 600 calendar years before present (cal yr BP), apparently corresponding to more mesic conditions regionally. A decrease in charcoal accumulation rate also occurred at most sites but was not synchronous with the vegetation change. At some sites there were further changes in vegetation and fire regimes occurring ～500–300 cal yr BP, but these changes were not as strong or unidirectional as those that occurred 700–600 cal yr BP. Our results suggest that both the composition and the distribution of vegetation of the southern part of the sand plain have been sensitive to relatively small climatic changes, and that the vegetation at the time of European settlement was a transitory phenomenon, rather than a long-term stable condition.  相似文献   

Response of four winter wheat cultivars to triallate     

Peter N. Mascia  W. Randy Deaton  Thomas L. Beil  Dale F. Loussaert 《Euphytica》1988,37(2):111-116

Summary Genetic variation among four winter wheat cultivars for response to treatment with triallate was examined. The cultivars showed differential tolerance based on stand count, however, differential tolerance was not seen for any of the other traits examined including visual score, and the mature plant traits, tiller count and yield. Significant effects due to increasing the rate of chemical were observed. An increase in yield was seen at the 0.5 and 1.0 kg/ha rates of triallate. This yield increase was paralleled by trends toward increasing seed number/head and tiller number/unit area. The results indicate that the effect of triallate on wheat has two components. The first component, toxicity, is seen on all cultivars, but the extent of damage varies significantly among cultivars. The second component is positive and leads to an increase in yield without interacting significantly with genotype.  相似文献   

Hippo pathway inhibits Wnt signaling to restrain cardiomyocyte proliferation and heart size     

Heallen T  Zhang M  Wang J  Bonilla-Claudio M  Klysik E  Johnson RL  Martin JF 《Science (New York, N.Y.)》2011,332(6028):458-461

Genetic regulation of mammalian heart size is poorly understood. Hippo signaling represents an organ-size control pathway in Drosophila, where it also inhibits cell proliferation and promotes apoptosis in imaginal discs. To determine whether Hippo signaling controls mammalian heart size, we inactivated Hippo pathway components in the developing mouse heart. Hippo-deficient embryos had overgrown hearts with elevated cardiomyocyte proliferation. Gene expression profiling and chromatin immunoprecipitation revealed that Hippo signaling negatively regulates a subset of Wnt target genes. Genetic interaction studies indicated that β-catenin heterozygosity suppressed the Hippo cardiomyocyte overgrowth phenotype. Furthermore, the Hippo effector Yap interacts with β-catenin on Sox2 and Snai2 genes. These data uncover a nuclear interaction between Hippo and Wnt signaling that restricts cardiomyocyte proliferation and controls heart size.  相似文献   

Retrospective: George E. Palade (1912-2008)     

Schekman RW 《Science (New York, N.Y.)》2008,322(5902):695

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Addendum     

Kenneth A. Rykbost  Randy L. Dovel  Neil W. Christensen 《American Journal of Potato Research》1991,68(11):798-799

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Evaluation of an avirulent strain ofPseudomonas solanacearum for biological control of bacterial wilt of potato     

Randy J. McLaughlin  Luis Sequeira 《American Journal of Potato Research》1988,65(5):255-268

An avirulent strain ofPseudomonas solanacearum, B82, was tested for its ability to protect the potato cultivar, Ontario, from bacterial wilt caused by virulent strains of this bacterium. Strain B82 was not antagonistic to 124 virulent strains ofP. solanacearum and was not bacteriocinogenic. When potato seedpieces were soaked for 5 hr in suspensions of B82 (10⁸ to 10⁹ cfu/ml), reduction in disease severity (up to 50%) was noted in some experiments. The treated plants, grown in the greenhouse or growth room for 4–5 wk, were challenged by stem inoculation, soil drenching, or root-to-root infection with virulent strains (276 or Br5) of the bacterium. Protection was not obtained consistently, however, and much of the variability could be attributed to differences in ambient temperature and light conditions in the greenhouse between experiments. In general, high ambient temperatures and/or reduced sunlight resulted in no protection. Protection appeared to depend on the ability of strain B82 to multiply in the vascular system in the crown region and to colonize the rhizosphere of treated plants. Soil temperatures above 24 C affected the ability of strain B82 to survive in the rhizosphere. The close dependence of protection on environmental conditions suggests that this method of control may not be practical under field conditions.  相似文献   

Cohabitation of pregnant white-tailed deer and cattle persistently infected with Bovine viral diarrhea virus results in persistently infected fawns     

Passler T  Walz PH  Ditchkoff SS  Brock KV  Deyoung RW  Foley AM  Daniel Givens M 《Veterinary microbiology》2009,134(3-4):362-367

Economic losses due to infection with Bovine viral diarrhea virus (BVDV) have prompted introduction of organized control programs. These programs primarily focus on the removal of persistently infected (PI) animals, the main source of BVDV transmission. Recently, persistent BVDV infection was demonstrated experimentally in white-tailed deer, the most abundant wild ruminant in North America. Contact of cattle and white-tailed deer may result in interspecific BVDV transmission and birth of persistently infected offspring that could be a threat to control programs. The objective of this study was to assess the potential for interspecific BVDV transmission from persistently infected cattle cohabitated with pregnant white-tailed deer. Seven female and one male white-tailed deer were captured and bred in captivity. At approximately 50 days of gestation, two cattle persistently infected with BVDV 1 were cohabitated with the deer. In a pen of approximately 0.8 ha, both species shared food and water sources for a period of 60 days. Transmission of BVDV as indicated by seroconversion was demonstrated in all exposed adult deer. Of the seven pregnancies, four resulted in offspring that were infected with BVDV. Persistent infection was demonstrated in three singlet fawns by immunohistochemistry and ELISA on skin samples, PCR, and virus isolation procedures. Furthermore, two stillborn fetuses were apparently persistently infected. This is the first report of BVDV transmission from cattle to white-tailed deer using a model of natural challenge. Under appropriate circumstances, BVDV may efficiently cross the species barrier to cause transplacental infection and persistently infected offspring in a wildlife species.  相似文献   

Application of Exogenous Esterified Hyaluronan to Equine Distal Limb Wounds     

Stefan H. Witte  Abayomi K. Olaifa  Andrew J. Lewis  Randy B. Eggleston  Jaroslava Halper  Manfred Kietzmann  Wolfgang Baeumer  P.O. Eric Mueller 《Journal of Equine Veterinary Science》2009

The objective of this study was to evaluate the efficacy of topical application of a hyaluronan (HA) derivative in wound healing with respect to the rate of epithelialization, fibroplasia, angiogenesis and contraction, magnitude of the local inflammatory response, local expression of transforming growth factor-β 1 and 3 (TGF-β 1 and 3), tumor necrosis factor-α (TNF-α), and collagen type III deposition. In six healthy adult horses, six full-thickness skin wounds were created on the dorsal aspect of both metacarpi using a sterile template. Sites were sampled at 0, 1, 2, 5, 14, 21, and 35 days following wounding. Wounds on one limb were dressed with commercially available esterified HA fleece under a nonadherent dressing. The opposite limb was covered with the nonadherent dressing alone (control). Images of the most proximal wounds were used to determine the area of total healing and the relative contributions of epithelialization and contraction to healing. At each sample time, a control and treatment biopsy were taken for histological evaluation and special stains. All samples were evaluated for degree of inflammation, fibroplasia and angiogenesis; in situ hybridization for type III collagen, TGFβ1 and 3, and immunohistochemistry for TNF-α. Mean percentages of total wound healing, epithelialization, and wound contraction were not significantly different between control and treatment groups. In treated horses, initial wound expansion was significantly decreased during the first 2 weeks. Mononuclear cell numbers, counted in the granulation tissue, increased in both control and treated limbs over the entire course of the study. However at day 35 the macrophage numbers counted in the treated horses were significantly increased compared with the control limbs (P < .05). Although not statistically significant, relative staining for type III collagen in the treated wounds was less than that of control wounds. Results of the present study do not support a benefit of an exogenous HA-derivative in the healing of distal limb wounds in horses. The shortcomings of the study design are discussed.  相似文献   

Method for determining frying oil degradation by near-infrared spectroscopy     

Ng CL  Wehling RL  Cuppett SL 《Journal of agricultural and food chemistry》2007,55(3):593-597

A rapid near-infrared (NIR) spectroscopic method for measuring degradation products in frying oils, including total polar materials (TPMs) and free fatty acids (FFAs), has been developed. Calibration models were developed using both forward stepwise multiple linear regression (FSMLR) and partial least-squares (PLS) regression techniques and then tested with two independent sets of validation samples. Derivative treatments had limited usefulness, especially in the longer (1100-2500 nm) wavelength region. When using a wavelength region of 700-1100 nm, PLS models gave improved results compared to FSMLR models. The best correlations (r) between the NIR and wet chemical methods for TPM and FFA were 0.983 and 0.943, respectively. In the longer wavelength region (1100-2500 nm), FSMLR models were as good or better than PLS models. The best correlations for TPM and FFA obtained in this region were 0.999 and 0.983, respectively.  相似文献