Germination of <Emphasis Type="Italic">Plasmodiophora brassicae</Emphasis> resting spores stimulated by a non-host plant     

Hanna?FribergEmail author  Jan?Lagerl?f  Birgitta?R?mert 《European journal of plant pathology / European Foundation for Plant Pathology》2005,113(3):275-281

Plant-induced germination of Plasmodiophora brassicae resting spores was studied in a laboratory experiment. Spore reaction was analysed in nutrient solution with exudates from growing roots of different plant species – one host plant (Brassica rapa var. pekinensis) and four non-host plants (Lolium perenne, Allium porrum, Secale cereale and Trifolium pratense) – and in controls with distilled water and nutrient solution. It was found that root exudates from L. perenne stimulated spore germination more than exudates from the other plants, including those from the host plant. The effect could not be explained by differences in the nutritional composition of the solutions due to differential uptake of the plant species, or by differences in root activity, measured as exudation of soluble sugars. This is the first time such a separation of factors has been done in analysing the influence of plants on P. brassicae germination. Although stimulation of P. brassicae resting spore germination is not restricted to the presence of host plants, it seems to vary depending on the plant species.  相似文献   

Transmission of tuberculosis from experimentally infected cattle to in-contact calves   总被引：5，自引：0，他引：5  

S D Neill  J Hanna  J J O'Brien  R M McCracken 《The Veterinary record》1989,124(11):269-271

Five of a group of six calves were inoculated with Mycobacterium bovis. Two more uninoculated calves were introduced to the group 84 days later. All the inoculated calves were subsequently shown to be excreting M bovis in nasal mucus. The uninoculated calf in the initial group of six became infected and subsequently excreted M bovis. The two uninoculated calves which were introduced later did not become infected. It was concluded that contact with nasal mucus from the infected cattle resulted in infection of the uninoculated calf and that the density of accommodation of animals excreting M bovis was an important factor in transmission of the disease.  相似文献   

From individual dispersal to species ranges: perspectives for a changing world     

Kokko H  López-Sepulcre A 《Science (New York, N.Y.)》2006,313(5788):789-791

Dispersal is often risky to the individual, yet the long-term survival of populations depends on having a sufficient number of individuals that move, find each other, and locate suitable breeding habitats. This tension has consequences that rarely meet our conservation or management goals. This is particularly true in changing environments, which makes the study of dispersal urgently topical in a world plagued with habitat loss, climate change, and species introductions. Despite the difficulty of tracking mobile individuals over potentially vast ranges, recent research has revealed a multitude of ways in which dispersal evolution can either constrain, or accelerate, species' responses to environmental changes.  相似文献   

Mapping of the <Emphasis Type="Italic">ms8</Emphasis> male sterility gene in sweet pepper (<Emphasis Type="Italic">Capsicum annuum</Emphasis> L.) on the chromosome P4 using PCR-based markers useful for breeding programmes     

Grzegorz Bartoszewski  Cezary Waszczak  Piotr Gawroński  Iwona Stępień  Hanna Bolibok-Brągoszewska  Alain Palloix  Véronique Lefebvre  Aleksandra Korzeniewska  Katarzyna Niemirowicz-Szczytt 《Euphytica》2012,186(2):453-461

The nuclear male sterility gene ms8 is expected to facilitate the production of sweet pepper (Capsicum annuum L.) hybrids as it provides means for hybridization without the labor-intensive hand emasculation of female inbred lines. The development of molecular markers linked to ms8 locus will help the breeding practice for the selection of hybrid parental lines. In this study, F₂ population resulting from a cross between the sweet pepper male sterile line 320 and the male fertile variety Elf was used to identify DNA markers linked to the ms8 locus. With the use of RAPD–BSA technique, seven markers linked to the ms8 locus were found. Four of them were converted into SCAR markers. In addition, two COSII/CAPS markers linked to the ms8 locus were identified. Comparative mapping with reference pepper maps indicated that the ms8 locus is located on the lower arm of the pepper chromosome P4. Identified markers are useful for molecular breeding, however, at present markers tightly linked to ms8 locus are still lacking. Identification of molecular markers linked to the ms8 locus and determination of its chromosomal localization are useful for fine mapping and also provide the perspective for ms8 gene cloning.  相似文献   

Designing responsive buckled surfaces by halftone gel lithography   总被引：1，自引：0，他引：1  

Kim J  Hanna JA  Byun M  Santangelo CD  Hayward RC 《Science (New York, N.Y.)》2012,335(6073):1201-1205

Self-actuating materials capable of transforming between three-dimensional shapes have applications in areas as diverse as biomedicine, robotics, and tunable micro-optics. We introduce a method of photopatterning polymer films that yields temperature-responsive gel sheets that can transform between a flat state and a prescribed three-dimensional shape. Our approach is based on poly(N-isopropylacrylamide) copolymers containing pendent benzophenone units that allow cross-linking to be tuned by irradiation dose. We describe a simple method of halftone gel lithography using only two photomasks, wherein highly cross-linked dots embedded in a lightly cross-linked matrix provide access to nearly continuous, and fully two-dimensional, patterns of swelling. This method is used to fabricate surfaces with constant Gaussian curvature (spherical caps, saddles, and cones) or zero mean curvature (Enneper's surfaces), as well as more complex and nearly closed shapes.  相似文献   

Fasciola hepatica: a light and electron microscope study of sustentacular tissue and heterophagy in the testis     

Hanna RE  Moffett D  Brennan GP  Fairweather I 《Veterinary parasitology》2012,187(1-2):168-182

In order to investigate cytolytic activity in the testis of Fasciola hepatica, flukes belonging to several different triclabendazole (TCBZ)-sensitive and TCBZ-resistant isolates, and wild-type flukes from field infections, were studied by light and electron microscopy with a view to identifying sites of heterophagy and macromolecular hydrolysis. At the periphery of the testis tubules in all the flukes examined, large euchromatic nuclei, each bearing a prominent nucleolus, were seen. These were invested with a thin cytoplasmic layer, extensions of which partially enveloped and probably supported the neighbouring spermatogonia. No lateral cell boundaries were identified in this tissue, possibly indicating syncytial organisation. The tissue, considered to be analogous to Sertoli cells in vertebrate testis, was identified as sustentacular tissue. It displayed cytoplasmic features consistent with protein/glycoprotein synthesis (through a granular endoplasmic reticulum-Golgi mediated mechanism) and intracellular digestion/heterophagy (through a lysosomal system). The intracytoplasmic hydrolytic activity of the sustentacular tissue probably serves to scavenge effete cells and cytoplasmic debris, to recycle useful molecules, to promote spermatozoon maturation and possibly to aid osmoregulation within the tubules. Certain protein-containing macromolecules synthesised in the sustentacular tissue may contribute to the seminiferous fluid, or have pheromonal activity. The presence of numerous mitochondria and abundant smooth endoplasmic reticulum is consistent with facilitation of inward and outward movement of micromolecular nutrients, metabolites including excretory products and water. In the sustentacular tissue of certain flukes with dysfunctional spermiogenesis, there was increased heterophagic and cytolytic scavenging activity. The cytoplasmic residual vacuoles remaining after the release of spermatids were also identified as possible sites for lysosome-mediated intracellular digestion and osmoregulation in the testis tubules of F. hepatica.  相似文献   

Competition Horses Housed in Single Stalls (I): Behavior and Activity Patterns during Free Exercise According to Its Configuration     

Hanna Werhahn  Engel F. HesselHerman F.A. Van den Weghe  Prof Dr Ir 《Journal of Equine Veterinary Science》2012,32(1):45-52

Although welfare of animals has become more important, housing horses in systems that limit natural behavior patterns is still widespread. Single stalls are the predominant housing system in Germany, especially for competition horses. Free exercise on fields or paddocks helps to improve welfare for the animals, but allowing it is not taken for granted by many horse keepers. In the present study, three common management practices were investigated with regard to their effect on the behavior of six competition horses housed in single stalls: 2-hour turnout after training in groups of two horses (group turnout [GT]), solitary turnout (ST) after training for 2 hours, and no turnout (NT) in addition to training. The aim of the study was to determine the differences in the horses’ behavior during turnout, training, and in the stable caused by the treatments. This article focuses on the behavior and activity patterns during turnout. The horses’ behavior was observed directly by the scan sampling method (5-minute interval), and the distance covered during turnout was measured by global positioning system devices. During turnout, the horses spent most of the time eating. After 1 hour of being turned out, eating decreased, and occupation, locomotion, and social interaction increased. When turnout was allowed in groups (GT), the horses spent more time in social interactions and less time walking and trotting than in ST. Therefore, they also covered a greater distance in ST than in GT. The distance covered in ST also showed a greater deviation both within and between days compared with GT.  相似文献   

Postoperative Septic Arthritis After Elective Equine Arthroscopy Without Antimicrobial Prophylaxis     

Hanna Borg DVM 《Veterinary surgery : VS》2013,42(3):262-266

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Efficacy of eight commercial disinfectants against Microsporum canis and Trichophyton spp. infective spores on an experimentally contaminated textile surface     

Hanna Hondzo 《Veterinary dermatology》2013,24(6):621-e152

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Extraction of green labeled pectins and pectic oligosaccharides from plant byproducts     

Zykwinska A  Boiffard MH  Kontkanen H  Buchert J  Thibault JF  Bonnin E 《Journal of agricultural and food chemistry》2008,56(19):8926-8935

Green labeled pectins were extracted by an environmentally friendly way using proteases and cellulases being able to act on proteins and cellulose present in cell walls. Pectins were isolated from different plant byproducts, i.e., chicory roots, citrus peel, cauliflower florets and leaves, endive, and sugar beet pulps. Enzymatic extraction was performed at 50 degrees C for 4 h, in order to fulfill the conditions required for microbiological safety of extracted products. High methoxy (HM) pectins of high molar mass were extracted with three different enzyme mixtures. These pectins were subsequently demethylated with two pectin methyl esterases (PMEs), either the fungal PME from Aspergillus aculeatus or the orange PME. It was further demonstrated that high molar mass low methoxy (LM) pectins could also be extracted directly from cell walls by adding the fungal PME to the mixture of protease and cellulase. Moreover, health benefit pectic oligosaccharides, the so-called modified hairy regions, were obtained after enzymatic treatment of the residue recovered after pectin extraction. The enzymatic method demonstrates that it is possible to convert vegetable byproducts into high-added value compounds, such as pectins and pectic oligosaccharides, and thus considerably reduce the amount of these residues generated by food industries.  相似文献