Physical and hydraulic properties of baked ceramic aggregates used for plant growth medium.     

Susan L Steinberg  Gerard J Kluitenberg  Scott B Jones  Nihad E Daidzic  Lakshmi N Reddi  Ming Xiao  Markus Tuller  Rebecca M Newman  Dani Or  J Iwan D Alexander 《Journal of the American Society for Horticultural Science》2005,130(5):767-774

Baked ceramic aggregates (fritted clay, arcillite) have been used for plant research both on the ground and in microgravity. Optimal control of water and air within the root zone in any gravity environment depends on physical and hydraulic properties of the aggregate, which were evaluated for 0.25-1-mm and 1-2-mm particle size distributions. The maximum bulk densities obtained by any packing technique were 0.68 and 0.64 g cm-3 for 0.25-1-mm and 1-2-mm particles, respectively. Wettable porosity obtained by infiltration with water was approximately 65%, substantially lower than total porosity of approximately 74%. Aggregate of both particle sizes exhibited a bimodal pore size distribution consisting of inter-aggregate macropores and intra-aggregate micropores, with the transition from macro- to microporosity beginning at volumetric water content of approximately 36% to 39%. For inter-aggregate water contents that support optimal plant growth there is 45% change in water content that occurs over a relatively small matric suction range of 0-20 cm H2O for 0.25-1-mm and 0 to -10 cm H2O for 1-2-mm aggregate. Hysteresis is substantial between draining and wetting aggregate, which results in as much as a approximately 10% to 20% difference in volumetric water content for a given matric potential. Hydraulic conductivity was approximately an order of magnitude higher for 1-2-mm than for 0.25-1-mm aggregate until significant drainage of the inter-aggregate pore space occurred. The large change in water content for a relatively small change in matric potential suggests that significant differences in water retention may be observed in microgravity as compared to earth.  相似文献   

Mycobacterium kansasii infection in a Chinese soft shell turtle (Pelodiscus sinensis)     

Orós J  Acosta B  Gaskin JM  Déniz S  Jensen HE 《The Veterinary record》2003,152(15):474-476

  相似文献   

Alkanes in fungal spores   总被引：1，自引：0，他引：1  

J Oró  J L Laseter  D Weber 《Science (New York, N.Y.)》1966,154(747):399-400

The chlamydospores of Ustilago maydis, U. nuda, and Sphacelotheca reiliana were analyzed by gas chromatography and mass spectrometry for their hydrocarbon contents. For the first time we observed that they contain paraffinic hydrocarbons; the average contents were 42, 58, and 146 parts per million, respectively. n-Alkanes having odd numbers of carbon atoms predom-inate, with carbon-chain lengths ranging from C(14) to C(37). The major alkanes are n-C(27) in U. maydis, n-C(27) and n-C(35) in U. nuda, and n-C(29) in S. reiliana. Each type of spore carried a distinctly characteristic population of hydrocarbons.  相似文献   

Type A-like retroviral particles in a metastatic intestinal adenocarcinoma in an emerald tree boa (Corallus caninus)     

Orós J  Lorenzo H  Andrada M  Recuero J 《Veterinary pathology》2004,41(5):515-518

  相似文献   

Computed tomographic anatomy of the head of the loggerhead sea turtle (Caretta caretta)     

Arencibia A  Rivero MA  De Miguel I  Contreras S  Cabrero A  Orós J 《Research in veterinary science》2006,81(2):165-169

The heads of three loggerhead sea turtles were disarticulated and imaged immediately to minimize postmortem changes and then frozen and sectioned. For computed tomography (CT) imaging, the heads were positioned in ventral recumbency. Transverse CT images with soft-tissue window were obtained from the olfactory sac region to the temporomandibular joint region. After CT imaging, the heads were sectioned and the gross sections were compared to CT images, to assist in the accurate identification of the anatomic structures. Different clinically relevant anatomic structures were identified and labelled in two series of photographs (CT images and anatomic cross-sections). CT images provided good differentiation between the bones and the soft tissues of the head. The information presented in this paper should serve as an initial reference to evaluate CT images of the head of the loggerhead sea turtle and to assist in the interpretation of lesions of this region.  相似文献   

Black yeast-like fungi associated with Lethargic Crab Disease (LCD) in the mangrove-land crab, Ucides cordatus (Ocypodidae)     

Vicente VA  Orélis-Ribeiro R  Najafzadeh MJ  Sun J  Guerra RS  Miesch S  Ostrensky A  Meis JF  Klaassen CH  de Hoog GS  Boeger WA 《Veterinary microbiology》2012,158(1-2):109-122

Lethargic Crab Disease (LCD) caused extensive epizootic mortality of the mangrove land crab Ucides cordatus (Brachyura: Ocypodidae) along the Brazilian coast, mainly in the Northeastern region. The disease was named after the symptoms of slow movement of infected crabs. Causative agents were suspected to be two black yeast-like fungi of the family Herpotrichiellaceae (ascomycete order Chaetothyriales), judged by infected tissue biopsies from moribund U. cordatus. The aim of the present study is to prove that two species are involved in the disease: the recently described black yeast Exophiala cancerae, but also a less virulent, hitherto undescribed fonsecaea-like species, introduced here as the novel species Fonsecaea brasiliensis. Strains were identified by ITS rDNA sequencing, and species borderlines were established by multilocus sequencing and AFLP analysis. Fonsecaea brasiliensis proved to be closely related to the pathogenic species Cladophialophora devriesii which originally was isolated from a systemic infection in a human patient. The virulence of F. brasiliensis is lower than that of E. cancerae, as established by artificial inoculation of mangrove crabs.  相似文献   

Levels of circulating plasma immune complexes after thiacetarsamide treatment in dogs naturally infected with Dirofilaria immitis.     

J M Molina  A Ruiz  O Ferrer  M C Mu?oz  J Orós  M Morales 《The Veterinary record》1999,144(18):506-507

  相似文献   

Morphologic and Cytochemical Characteristics of the Blood Cells of the Yellow‐Bellied Slider (Trachemys scripta scripta)          下载免费PDF全文

J. D. Hernández  P. Castro  P. Saavedra  P. Ramírez  J. Orós 《Anatomia, histologia, embryologia》2017,46(5):446-455

  相似文献   

Ground-level hyperspectral imagery for detecting weeds in wheat fields     

I. Herrmann  U. Shapira  S. Kinast  A. Karnieli  D. J. Bonfil 《Precision Agriculture》2013,14(6):637-659

Site-specific weed management can allow more efficient weed control from both an environmental and an economic perspective. Spectral differences between plant species may lead to the ability to separate wheat from weeds. The study used ground-level image spectroscopy data, with high spectral and spatial resolutions, for detecting annual grasses and broadleaf weeds in wheat fields. The image pixels were used to cross-validate partial least squares discriminant analysis classification models. The best model was chosen by comparing the cross-validation confusion matrices in terms of their variances and Cohen’s Kappa values. This best model used four classes: broadleaf, grass weeds, soil and wheat and resulted in Kappa of 0.79 and total accuracy of 85 %. Each of the classes contains both sunlit and shaded data. The variable importance in projection method was applied in order to locate the most important spectral regions for each of the classes. It was found that the red-edge is the most important region for the vegetation classes. Ground truth pixels were randomly selected and their confusion matrix resulted in a Kappa of 0.63 and total accuracy of 72 %. The results obtained were reasonable although the model used wheat and weeds from different growth stages, acquisition dates and fields. It was concluded that high spectral and spatial resolutions can provide separation between wheat and weeds based on their spectral data. The results show feasibility for up-scaling the spectral methods to air or spaceborne sensors as well as developing ground-level application.  相似文献   

Morbidity and mortality associated with a new mycoplasma species from captive American alligators (Alligator mississippiensis).     

T L Clippinger  R A Bennett  C M Johnson  K A Vliet  S L Deem  J Orós  E R Jacobson  I M Schumacher  D R Brown  M B Brown 《Journal of zoo and wildlife medicine》2000,31(3):303-314

Nine of 74 American alligators (Alligator mississippiensis) from a captive Florida herd of 3-4-m-long, 200-350-kg, adult males greater than 30 yr of age died within a 10-day period during 1995. Nonspecific clinical signs included anorexia, lethargy, muscle weakness, paraparesis, bilateral white ocular discharge, and various degrees of periocular, facial, cervical, and limb edema. Pneumonia, pericarditis, and arthritis were found on postmortem evaluation of the spontaneously dead and euthanatized alligators. Rapidly growing mycoplasmas were identified by culture, and mycoplasma nucleotide sequences were identified by polymerase chain reaction testing of fresh lung and synovial fluid from an affected alligator. Culture of banked frozen lung from necropsy specimens and fresh lung and fresh synovial fluid from newly affected alligators confirmed the presence of a new mycoplasma species in seven of eight individuals. Oxytetracycline was administered, but related deaths continued for 6 mo until only 14 of the initial alligators remained. An enzyme-linked immunosorbent assay to detect antibody was developed, and the organism was transmitted experimentally to naive juvenile alligators, although the source of the organism, Mycoplasma sp. (ATCC 700619), has not been identified. The alligator isolate is a novel species in the mycoplasma family because its nucleotide sequence does not match those of over 75 characterized mycoplasma species. Such factors as population density, animal age, and mycoplasmal virulence likely contributed to the course of disease.  相似文献