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511.
As neurological diseases in horses share many overlapping clinical signs, the veterinarian is required to know how to perform a focused evaluation of this system as well as how to carry out complementary examinations to establish an aetiological diagnosis. This is a case report of an ataxic horse presenting with an extradural haematoma in the region of the 7th cervical vertebra. The 7‐year‐old Criollo mare presented with clinical signs of ataxia grade 3 (scale 1–5) in all limbs and a proprioceptive deficit. Radiological evaluation did not show bone changes or narrowing of the cervical canal. Samples of blood, serum and cerebrospinal fluid were collected and tested negative for antibodies to equine herpes virus type 1–4, Trypanosoma evansi and Sarcocystis neurona. The disease evolution was followed over a 4‐week period, after which the animal showed worsening overall clinical signs, and thus euthanasia was performed. A necropsy did not reveal macroscopic changes in any organs, except for an extradural haematoma in the region of the 7th cervical vertebra causing spinal cord compression. Histological examinations showed that the nodular lesion consisted of fibrovascular tissue, granulation tissue at different stages of maturation, red blood cells, cellular debris, fibrin and macrophages. The white matter of the ventral horn of the spinal cord contained degenerative lesions. In addition, the brain tested negative for rabies virus encephalitis. Based on the history, the laboratory test results, anamnesis and the lesion observed at necropsy, it was concluded that the ataxia was due to spinal cord compression, which was caused by an extradural haematoma in the region of the 7th cervical vertebra. Evaluation of the equine neurological system is highly important in localising the area of lesions, and complementary examinations are useful in differentiating between diseases affecting this system. Spinal cord compression injuries, such as extradural haematomas, are rarely reported in the literature, and their pathophysiology is difficult to understand. Nevertheless, they should be included in the differential diagnosis of ataxia in horses.  相似文献   
512.
  1. Extreme climate changes during the Cenozoic Era strengthened different biogeographical barriers that decreased the connectivity among populations, triggering lineage diversification of different species worldwide.
  2. The mitochondrial DNA control region was employed to explore the phylogeography of Sphyrna zygaena, a globally distributed species threatened by unsustainable, illegal, unreported and unregulated fisheries triggered by the international shark fin trade. It is listed as ‘Vulnerable’ by the IUCN Red List and its trade is regulated by CITES Appendix II.
  3. Only 13 haplotypes were found with low genetic diversity levels (hd = 0.686 ± 0.014; π = 0.00206 ± 0.00004) compared with other species of the Sphyrnidae family. The species has a very strong phylogeographic population structure among the Atlantic, Indian and Pacific Oceans (ΦST = 0.79132). Worldwide, there are six distinct populations with some haplotype sharing.
  4. These populations are probably connected by a stepping-stone dispersal of a small number of migrants per generation from the Indo-Pacific towards the Atlantic. Modelling suggests that S. zygaena diverged into two lineages around 6.96 million years ago which have been isolated in glacial refuges in the Atlantic and Indo-Pacific oceans; and after deglaciation, a population expansion probably permitted secondary contact.
  5. Conservation plans to establish differentiated management units should be adopted in each of the identified populations. Among these, the Eastern Central Atlantic and West Indo-Pacific are the most important areas for the species considering the historical migration routes that act as a bridge connecting the Atlantic and Indo-Pacific Oceans while the Gulf of Guinea connects the Atlantic populations. Still, further studies are required to know if these populations are also linked with nursery areas for the species.
  6. The results herein can help to delimit the main evolutionarily significant units to implement effective policies to establish differentiated management units as starting points to genetic monitoring programmes for Sphyrna zygaena.
  相似文献   
513.
Heritabilities and Minimum Gene Number Estimates of Carrot Carotenoids   总被引:1,自引:0,他引:1  
Summary Broad sense heritabilities and gene numbers were estimated for the production of total carotenoids and the major component carotenoids of carrot storage roots: phytoene, ζ-carotene, β-carotene, α-carotene, and lycopene. Two crosses with different backgrounds were evaluated: orange B493 × white QAL and orange Brasilia × dark orange HCM. The HCM (high carotene mass selection), Brasilia and B493 parents had both α-carotene and β-carotene, but HCM had proportionally more α-carotene. Carotene content in F 2 populations ranged from 522 ppm to 1714 ppm in Brasilia × HCM and from 0 to 695 ppm in B493 × QAL progeny. F 2 plants segregating for absence of α-carotene were identified in B493 × QAL. Broad-sense heritabilities ranged from 28% to 48% for all carotenes except lycopene and phytoene where estimates were 44% to 89% in the Brasilia × HCM cross, All heritability values exceeded 88% for the B493 × QAL cross, except one estimate for lycopene. The estimated number of genes was 4 conditioning α-carotene, 2 to 3 each for β-carotene and total carotenes and one each for ζ-carotene, lycopene and phytoene in the orange × dark orange cross. In the orange × white cross, the estimates were 4 genes for α-carotene, 1 to 2 each for lycopene and total carotenes and 1 for each of the other carotenes. These results are in general agreement with QTL studies and they provided evidence for continuous inheritance of α-carotene, β-carotene and total carotenoids in the orange × dark orange cross and discrete inheritance for β-carotene and total carotenoids in the orange × white cross.Part of thesis “Biometrical studies and quantitative trait loci associated with major products of the carotenoids pathway of carrot (Daucus carota L.)” presented by the first author as partial fulfillment of the requirement of the PhD degree in Plant Breeding and Plant Genetics, UW-Madison, USA, 2001.  相似文献   
514.

Understanding of the mechanisms involved in the restoration of degraded soils is necessary in order to assess the sustainability of a cropping system. For this purpose, an 8-year experiment was set up to test the efficiency of four cropping systems involving applications of fertilizer and/or manure and incorporation of crop residues and/or fallows on the regeneration of a Haplic Acrisol degraded by about 90 years of traditional cropping (groundnut-millet rotation without any input). The supply of nitrogen by the soil and particle size and chemical distribution were measured and used to characterize the soil organic matter (SOM) after 2 and 8 years of treatments, and then related to nutrients uptake. Two of the four cropping systems tested that were expected to regenerate soil fertility (Q1 and Q2: 4-year rotations including a plowed-in fallow, incorporation of crop residues, and mineral fertilization) both had a depressive effect on SOM content, although the losses of total C and N observed during the experiment (e.g .,-23% N and -20% N for Q1 and Q2, respectively) were less than that for the control (traditional cropping B, -33% N). Only the multiyear fallow did not result in further degradation of SOM, without, however, enriching the soil. On the other hand, an annual application of 10 Mg dry matter of manure ha -1 , combined with fertilizer, markedly increased the SOM (total N increased by factor 2 after only 2 years), an effect that seemed, however, stabilized at the end of the 8 years. Only a strong (10 Mg dry matter ha -1 ) and annual supply of manure, associated with mineral fertilization, had a positive effect on SOM, but its durability is not established.  相似文献   
515.
Condensation reactions of procyanidin dimer B4 with two representative oak wood cinnamic aldehydes (coniferaldehyde and sinapaldehyde) were conducted in winelike model solutions. Coniferaldehyde led to the formation of guaiacylcatechin-pyrylium-catechin (GCP-catechin, 737 m/z), whereas sinapaldehyde led to the formation of syringylcatechin-pyrylium-catechin (SCP-catechin, 767 m/z). The former was also structurally characterized by 1D and 2D NMR, allowing an elucidation of the formation mechanism of these oaklin-catechin adducts and demonstrating the importance of procyanidins in the formation of colored compounds through the reaction with cinnamic aldehydes extracted from oaks during storage.  相似文献   
516.
Espresso spent coffee grounds were chemically characterized to predict their potential, as a source of bioactive compounds, by comparison with the ones from the soluble coffee industry. Sampling included a total of 50 samples from 14 trademarks, collected in several coffee shops and prepared with distinct coffee machines. A high compositional variability was verified, particularly with regard to such water-soluble components as caffeine, total chlorogenic acids (CGA), and minerals, supported by strong positive correlations with total soluble solids retained. This is a direct consequence of the reduced extraction efficiency during espresso coffee preparation, leaving a significant pool of bioactivity retained in the extracted grounds. Besides the lipid (12.5%) and nitrogen (2.3%) contents, similar to those of industrial coffee residues, the CGA content (478.9 mg/100 g), for its antioxidant capacity, and its caffeine content (452.6 mg/100 g), due to its extensive use in the food and pharmaceutical industries, justify the selective assembly of this residue for subsequent use.  相似文献   
517.
The Mormon cricket (MC),Anabrus simplex (Orthoptera:Tettigoniidae),has a long and negative history with agriculture in the western states of the USA where MC often migrates in large groups and causes significant damage to forage plants and cultivated crops.In this review, virulence to MC of isolates of the insect-pathogenic fungus Metarhizium anisopliae varieties acridum and anisopliae were compared in an effort to identify isolates with promise for use as MC biological control agents.All of the isolates tested induced 100% or nearly 100% mortality by six days post application of the fungal conidia.Searches for new Metarhizium isolates with high heat and UV-B tolerance included isolation fungi from field-caught MC and grasshopper after they died in the laboratory and culturing fungi from soil samples collected from numerous western USA sites.The survey was preceded by development of a dodine based selective medium that,at 0.002% active ingredient,permitted growth of M.anisopliae var.acridum,but inhibited most contaminating fungi.The M.anisopliae var.acridum isolates examined to date have much higher tolerance to heat and UV-B irradiation than M.anisopliae var.anisopliae isolates,and this may be critical to successful field applications.The variety acridum has not yet been found in the USA,so our search for such isolates continues.Several new M.anisopliae var.anisopliae and Beauveria spp.were found,and the Metarhizium isolates are being characterized as to stress tolerance and virulence to insects.Characterization includes comparisons of new and pre-existing Metarhizium isolates by amplified fragment-length polymorphism (AFLP) analysis.Finally, experiments on MC developmental biology were conducted to gather data needed to develop a degree day model and to establish laboratory colonies of MC.  相似文献   
518.
Neotropical rivers support a diverse array of endemic taxa, including electric fishes of the order Gymnotiformes. A comprehensive survey of the main channels of the Amazon River and its major tributaries (>2000-kilometer transect) yielded 43 electric fish species. Biogeographical analyses suggest that local mainstem electric fish diversity is enhanced by tributaries. Mainstem species richness tends to increase downstream of tributary confluences, and species composition is most similar between tributaries and adjacent downstream mainstem locations. These findings support a "nodal" or heterogeneous model of riverine community organization across a particularly extensive and diverse geographical region.  相似文献   
519.
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