Anal fibropapillomas containing bovine papillomavirus type 2 DNA in two groups of heifers     

JS Munday  AA Cullum  NA Thomson  M Bestbier  T McCormack  AF Julian 《New Zealand veterinary journal》2018,66(5):267-271

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Sarcocystosis in a Stillborn Lamb     

JS Agerholm  JP Dubey 《Reproduction in domestic animals》2014,49(6):e60-e63

Confirmed congenital sarcocystosis has been reported extremely rarely in domestic ruminants. Sarcocystosis was diagnosed in a stillborn lamb with microscopic lesions predominantly in the central nervous system and placenta. Encephalitis was characterized by multiple foci of glial nodules some with central necrosis, perivascular cuffing and vascular occlusion, while placental lesions consisted of multifocal necroses, inflammation and mild calcification. Immature and mature schizonts were found in vascular endothelium of several organs. It is suggested that the protozoa were Sarcocystis tenella based on their morphology, location and as this is the most pathogenic Sarcocystis sp. parasitizing sheep.  相似文献   

Shape changes of supported Rh nanoparticles during oxidation and reduction cycles     

Nolte P  Stierle A  Jin-Phillipp NY  Kasper N  Schulli TU  Dosch H 《Science (New York, N.Y.)》2008,321(5896):1654-1658

The microscopic insight into how and why catalytically active nanoparticles change their shape during oxidation and reduction reactions is a pivotal challenge in the fundamental understanding of heterogeneous catalysis. We report an oxygen-induced shape transformation of rhodium nanoparticles on magnesium oxide (001) substrates that is lifted upon carbon monoxide exposure at 600 kelvin. A Wulff analysis of high-resolution in situ x-ray diffraction, combined with transmission electron microscopy, shows that this phenomenon is driven by the formation of a oxygen-rhodium-oxygen surface oxide at the rhodium nanofacets. This experimental access into the behavior of such nanoparticles during a catalytic cycle is useful for the development of improved heterogeneous catalysts.  相似文献   

Anatomical variations in cervical vertebrae in two species of neotropical canids: What is the meaning?     

Felipe Pratalli Martins  Erick Candiota Souza  Fernanda Coelho Simas Bernardes  Marcelo Abidu-Figueiredo  Carlos Benhur Kasper  Paulo de Souza-Junior 《Anatomia, histologia, embryologia》2021,50(1):212-217

Anatomical variation in wild canids is rarely described. Altered shapes, uni- or bilaterally situated, were observed in ventral laminae of C6 and/or in C7 vertebral body of two fox species: Lycalopex gymnocercus and Cerdocyon thous. The specimens were young adults, collected dead on highways in southern Brazil. Deformities were considered anatomical variations because apparently there was no interference in function. The occurrence of such variations in two related species from the same area can suggest an environmental common cause rather than genetic issues. Future studies may deepen the understanding between cause and effect of these vertebral deformities in wild canids.  相似文献   

Correlations between ground and excited state spectra of a quantum Dot     

DR Stewart  D Sprinzak  CM Marcus  CI Duruoz  JS Harris 《Science (New York, N.Y.)》1997,278(5344):1784-1788

The ground and excited state spectra of a semiconductor quantum dot with successive electron occupancy were studied with linear and nonlinear magnetoconductance measurements. A direct correlation was observed between the mth excited state of the N-electron system and the ground state of the (N + m)-electron system for m up to 4. The results are consistent with a single-particle picture in which a fixed spectrum of energy levels is successively filled, except for a notable absence of spin degeneracy. Further departures from the single-particle picture due to electron-electron interaction were also observed. Magnetoconductance fluctuations of ground states show anticrossings where wave function characteristics are exchanged between adjacent levels.  相似文献   

Brightening depression     

Wirz-Justice A  Terman M  Oren DA  Goodwin FK  Kripke DF  Whybrow PC  Wisner KL  Wu JC  Lam RW  Berger M  Danilenko KV  Kasper S  Smeraldi E  Takahashi K  Thompson C  van den Hoofdakker RH 《Science (New York, N.Y.)》2004,303(5657):467-469

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Phenotyping a diversity panel of quinoa using UAV-retrieved leaf area index,SPAD-based chlorophyll and a random forest approach     

Jiang  Jiale  Johansen  Kasper  Stanschewski  Clara S.  Wellman  Gordon  Mousa  Magdi A. A.  Fiene  Gabriele M.  Asiry  Khalid A.  Tester  Mark  McCabe  Matthew F. 《Precision Agriculture》2022,23(3):961-983

Given its high nutritional value and capacity to grow in harsh environments, quinoa has significant potential to address a range of food security concerns. Monitoring the development of phenotypic traits during field trials can provide insights into the varieties best suited to specific environmental conditions and management strategies. Unmanned aerial vehicles (UAVs) provide a promising means for phenotyping and offer the potential for new insights into relative plant performance. During a field trial exploring 141 quinoa accessions, a UAV-based multispectral camera was deployed to retrieve leaf area index (LAI) and SPAD-based chlorophyll across 378 control and 378 saline-irrigated plots using a random forest regression approach based on both individual spectral bands and 25 different vegetation indices (VIs) derived from the multispectral imagery. Results show that most VIs had stronger correlation with the LAI and SPAD-based chlorophyll measurements than individual bands. VIs including the red-edge band had high importance in SPAD-based chlorophyll predictions, while VIs including the near infrared band (but not the red-edge band) improved LAI prediction models. When applied to individual treatments (i.e. control or saline), the models trained using all data (i.e. both control and saline data) achieved high mapping accuracies for LAI (R²?=?0.977–0.980, RMSE?=?0.119–0.167) and SPAD-based chlorophyll (R²?=?0.983–0.986, RMSE?=?2.535–2.861). Overall, the study demonstrated that UAV-based remote sensing is not only useful for retrieving important phenotypic traits of quinoa, but that machine learning models trained on all available measurements can provide robust predictions for abiotic stress experiments.

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Transitions between blocked and zonal flows in a rotating annulus with topography     

ER Weeks  Y Tian  JS Urbach  K Ide  HL Swinney  M Ghil 《Science (New York, N.Y.)》1997,278(5343):1598-1601

The mid-latitude atmosphere is dominated by westerly, nearly zonal flow. Occasionally, this flow is deflected poleward by blocking anticyclones that persist for 10 days or longer. Experiments in a rotating annulus used radial pumping to generate a zonal jet under the action of the Coriolis force. In the presence of two symmetric ridges at the bottom of the annulus, the resulting flows were nearly zonal at high forcing or blocked at low forcing. Intermittent switching between blocked and zonal patterns occurs because of the jet's interaction with the topography. These results shed further light on previous atmospheric observations and numerical simulations.  相似文献