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31.
Seminal plasma (SP) is known to play an important role in mammalian fertilization. However, the variability found in its composition among species, males and even fractions of the same ejaculate has made difficult to completely understand its effect in sperm function. Proteins are one of the major SP components that modulate sperm functionality. During the last years, intensive work has been performed to characterize the role of these proteins. They have been found to influence sperm capacitation, formation of the oviductal sperm reservoir and sperm-oocyte interaction. Sperm biotechnologies, such as sperm cryopreservation and flow cytometric sex-sorting, that involve a substantial dilution of the SP are detrimental to sperm quality. Attempts to improve the outcome of these biotechnologies include the restoration of SP, which has produced contradictory results. To overcome this variability, different research groups have proposed the application of isolated SP proteins. Herein, we will review the current knowledge in the role of the major SP proteins as modulators of sperm functionality. Furthermore, we will discuss the possible applications of the SP proteins in sperm cryopreservation and flow cytometric sex-sorting.  相似文献   
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This work describes the first isolation of Streptococcus iniae in red porgy, Pagrus pagrus (L.), and the first European isolation of this pathogen in gilthead seabream, Sparus aurata (L.). In both farmed fish species, infection resulted in lethargy, anorexia, abnormal swimming, exophthalmia and sudden death, with mortality rates of over 25% in red porgy and 10% in gilthead seabream. Beta-haemolytic Gram-positive cocci, catalase negative and oxidase negative, were isolated in pure culture from internal organs. Conventional and rapid identification systems, and 16S rRNA gene partial sequencing were used to identify the causative agent of the natural disease. LD50 trials were carried out to show the virulence of this isolated strain in these species, with values of 1.7 × 104 CFU per fish in red porgy and 1.32 × 105 CFU per fish in gilthead seabream. The most prominent lesions were meningoencephalitis and multifocal infiltration of macrophage cells in the kidney and spleen.  相似文献   
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The reclamation and monitoring methodologies implemented at the mining waste dump at the As Pontes Lignite Mine in Galicia (NW Spain) are briefly described. In addition the factors affecting achievement of reclamation objectives and an evaluation of the factors limiting plant growth on the constructed soils are outlined. The most serious limitations were found in the oldest mine soils constructed from sulphide-bearing spoils; high acidity, toxicity, nutrient deficiency, seasonal waterlogging due to their impermeability, and compaction. The youngest soils were constructed using sulphide-free spoils as topsoil substitutes and had fewer limitations for plant development. The results show that proper handling of spoils, and paying special attention to selective placement of sulphide bearing materials, are the most important factors in providing a suitable medium for plant growth. © 1998 John Wiley & Sons, Ltd.  相似文献   
34.
Eocene El Niño: evidence for robust tropical dynamics in the "hothouse"   总被引:2,自引:0,他引:2  
Much uncertainty surrounds the interactions between the El Ni?o-Southern Oscillation (ENSO) and long-term global change. Past periods of extreme global warmth, exemplified by the Eocene (55 to 35 million years ago), provide a good testing ground for theories for this interaction. Here, we compare Eocene coupled climate model simulations with annually resolved variability records preserved in lake sediments. The simulations show Pacific deep-ocean and high-latitude surface warming of approximately 10 degrees C but little change in the tropical thermocline structure, atmosphere-ocean dynamics, and ENSO, in agreement with proxies. This result contrasts with theories linking past and future "hothouse" climates with a shift toward a permanent El Ni?o-like state.  相似文献   
35.
ABSTRACT Pseudomonas savastanoi pv. savastanoi causes olive knot disease, which is present in most countries where olive trees are grown. Although the use of cultivars with low susceptibility may be one of the most appropriate methods of disease control, little information is available from inoculation assays, and cultivar susceptibility assessments have been limited to few cultivars. We have evaluated the effects of pathogen virulence, plant age, the dose/response relationship, and the induction of secondary tumors in olive inoculation assays. Most P. savastanoi pv. savastanoi strains evaluated were highly virulent to olive plants, but interactions between cultivars and strains were found. The severity of the disease in a given cultivar was strongly dependent of the pathogen dose applied at the wound sites. Secondary tumors developed in noninoculated wounds following inoculation at another position on the stem, suggesting the migration of the pathogen within olive plants. Proportion and weight of primary knots and the presence of secondary knots were evaluated in 29 olive cultivars inoculated with two pathogen strains at two inoculum doses, allowing us to rate most of the cultivars as having either high, medium, or low susceptibility to olive knot disease. None of the cultivars were immune to the disease.  相似文献   
36.
Summary Amaranth (Amaranthus spp.) is an important food resource for indigenous peoples of México. Grain-producing species are mostly cultivated plants, while the species used as vegetables are commonly encouraged in maize plots. Notable biological differences exist between these two types of amaranths. This study analyzes the morphophysiological variation in some Mexican species of Amaranthus and its relationship to the use and management of this taxa. A sample of individuals grown from 14 field collections representing 3 species and putative hybrid derivatives were grown in experimental plots and 18 morphological and physiological characters were measured. A statistical multivariate analysis was performed on these data. The results show that the grain-producing plants tend to allocate a high proportion of energy to the production of inflorescences while the plants used as vegetables allocate a higher proportion of biomass to the foliage. This suggests thatdomestication of Mexican species of Amaranthus have taken two different evolutionary paths depending upon the form of use and management by humans.  相似文献   
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Diagnosis of canine aspergillosis is difficult using currently available methods. It often passes unnoticed or is diagnosed in the later phases of the disease. We developed an ELISA technique to detect anti‐Aspergillus antibodies in canine serum using an Aspergillus antigenic mycelial extract, which could then be used for the diagnosis of canine aspergillosis. We used a cut‐off of X + 3SD obtained from 20 control sera. The test was performed on 46 dogs with lesions indicating possible aspergillosis and gave nine positive results: one systemic mycosis, two discospondylitis, one uveitis, two bronchopulmonary processes and three rhinitis. We compared this methodology with the PLATELIA technique in the follow‐up of the affected dogs, obtaining the same limitations as in the diagnosis of human aspergillosis. We consider our ELISA technique using sera samples a speedy, safe and reliable method which enables us to follow up the evolution of the disease and the efficacy of the therapy chosen. A definitive diagnosis must still take into account the results of other tests such as clinical examination, radiographic studies, endoscopy and biopsy.  相似文献   
39.
Large tracts of European rural land, mostly in the less favored areas (LFA), are devoted to low-inputs and large scale grazing systems (LSGS) with potential environmental and social functions. Although these LSGS may provide harbor for a good part of European nature values, their continuity is facing contrasting threats of intensification and abandonment. These areas, however, may be characterized by particular grazing structures and social dynamics of change that should be unveiled prior to attempts to devise rural development strategies or to adapt policy frameworks in general. To wit, stakeholder interactions and legal and institutional processes are described and analyzed for the cereal-sheep system of Castile-La Mancha (CLM) in the central Iberian plain. Farmers and pastoralists still share the use of the land, but their roles and interests have changed over time, and particularly in the last 50 years. Arable farming, mainly cereal cropping, has followed an intensification path, partially tempered by the environmental constraints of the Castilian plain. Extensive pastoralism is still a secondary option of land use; in the main, sheep farmers depend on, and look to, the management practices of arable farmers. A mixed cereal and sheep operation may deliver environmental and economic benefits, but successful implementation of this strategy is only possible when the system serves the needs of both types of stakeholders. Paradoxically, the main drivers of change in the countryside overall are arrayed against this sensible and traditional agricultural system. We argue that the recent legal and institutional frameworks do not favor social cohesion and that policy-support schemes of the European Union (EU) have been, and continue to be, devised without taking into account the particular structures and social dynamic of the farming system.
Rafael CaballeroEmail:

Rafael Caballero   is PhD in Agronomy with the Agroecology Department, Environmental Science Center, CSIC, Madrid, Spain. His main interests are centered on extensive systems of grassland management and analytical methods that can address the interplay of natural and social sciences. His main area of work is the cereal-sheep system, represented in most of the Mediterranean basin, the Middle East and Central Asia. Dr. Caballero has been co-coordinator of Spanish teams in three successive EU-funded research projects in the last 15 years, dealing with extensive systems of grassland management. He is main author or co-author of more than 40 research papers (on journals included in the JCR).  相似文献   
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