The prevalence of feline A/B blood types in the Sydney region

Objective To determine the distribution of A/B blood types in pedigree and crossbred cats in the Sydney region, and to estimate the associated risk of administering incompatible blood in an unmatched random transfusion. Design A prospective/retrospective study of blood specimens collected from both sick and healthy cats. Materials and methods Blood was collected from 355 cats from the Sydney region over a 12-year period from 1992 to 2003. Specimens were obtained from 187 domestic crossbred cats (short and long-haired) and 168 pedigree cats. The blood type of each cat was determined by one of three different laboratories using standard methods that varied over the duration of the survey. Results The distributions of blood types obtained by the three laboratories were not significantly different. The prevalence of type-A, type-B and type-AB blood types in crossbred cats was 62% 36% and 1.6% respectively. This is the highest percentage of type-B cats so far reported for an outbred population of domestic cats, and is significantly higher than the 26% reported previously for cats in the Brisbane region. The calculated frequency for the type-B allele assuming Hardy-Weinberg equilibrium for this feline population is 0.60; the corresponding frequency of the type-A allele is thus approximately 0.40. The calculated proportion of random transfusions from this population giving rise to an incompatible blood transfusion is 46%, with half of these being life-threatening events. The calculated proportion of random matings from this population at risk for developing neonatal isoerythrolysis is 23%. The distribution of A and B blood types for pedigree cats was in general agreement with data reported previously for cats in North America and Europe, suggesting that the distribution of blood types in these purebred populations is relatively consistent throughout the world. Conclusions The prevalence of type B cats in the owned domestic and pedigree cat population is so high that blood typing or cross matching prior to transfusion should be mandatory, except in Siamese/Oriental cats

Mechanisms of Soil Aggregates Stability in Purple Paddy Soil under Conservation Tillage of Sichuan Basin, China

Part 1: Decision Support Systems, Intelligent Systems and Artificial Intelligence ApplicationsInternational audienceRidge culture is a special conservation tillage method, but the long-term influence of this tillage system on soil aggregate-size stability in paddy fields is largely unknown in southwest of china. The objectives of this paper are to evaluate soil aggregates stability and to determine the relationship between SOC and soil aggregate stability. Soil samples at 0-20 cm layer were adopted from a long-term (16 yr) field experiment including conventional tillage: plain culture, summer rice crop and winter upland crop under drained conditions (PUR-r), and conservation tillage: ridge culture without tillage, summer rice and winter fallow with floodwater layer annually (NTR-f), and winter upland crop under drained conditions (NTR-r), and wide ridge culture without tillage, summer rice crop and winter upland crop under conditions (NTRw-r), respectively. The determination of aggregate-size stability distribution involves the assumptions that soil aggregates can be categorized in terms of their size and water stability (slaking resistance). Experimentally this procedure involves the slaked and capillary-wetted pretreatments; and a subsequent slaking treatment of aggregates >0.250 mm in size. WSMA and NMWD were applied to simulate the breakdown mechanisms of aggregates for studying soil stability based on aggregate resistance to slaking in paddy soil. The results showed that the amount of aggregates-size was greatly observed in the fraction of 2~6.72 mm under ridge culture in paddy soil (more than 50%) under slaking and capillary-wetting pretreatment. The proportion of soil macro-aggregates (>0.25 mm) in conservation tillage was greatly higher than that in conventional tillage under subsequent slaking treatment. Minimal differences of aggregate stability between slaking and wetting were observed, while significant differences were found between ridge culture and plain culture. The aggregates stability under slaking treatment ranked in the order of NTR-r>NTRw-r>NTR-f>PUR-r, while under wetting was NTRw-r>NTR-r>NTR-f>PUR-r, respectively. There was a positive correlation between the aggregates stability and SOC concentrations under wetting, and low correlation was observed under slaking pretreatment. Soil exposure with tillage and lack of rice/rape-seed stubble inputs caused declines in aggregation and organic carbon, both of which make soil susceptible to water erosion. Adoption of ridge culture with no-tillage integrated with crop rotation and stubble mulch significantly alter soil organic concentration, suggesting it was a valuable conservation practice for soil aggregation and soil organic carbon sequestration on paddy soil

Resistência ao cisalhamento de um latossolo sob diferentes uso e manejo Shear strength of a latosol under different use and management

A resistência do solo ao cisalhamento é uma importante propriedade dinâmica do solo, a qual vem sendo desconsiderada na maioria das pesquisas que investigam a influência do uso e manejo, assim como os estados de consistência , sobre o comportamento da estrutura dos solos agrícolas. Isto tem contribuído para a adoção de estratégias quase sempre equivocadas, tendo, como conseqüência, o depauperamento das propriedades físicas e mecânicas do solo. Este trabalho teve como objetivo estudar a resistência ao cisalhamento de um Latossolo Vermelho distrófico submetido ao preparo convencional e semeadura direta, tendo, como tratamento-testemunha, o cerradão, considerando diferentes conteúdos de água: 0,05; 0,16; 0,18 e 0,38 kg kg-1. Com base nos resultados encontrados, verificou-se que a resistência ao cisalhamento do solo, avaliada na profundidade de 0-0,05 m do Latossolo Vermelho distrófico, foi influenciada pelo aumento da umidade, tipo de uso e manejo. De maneira geral, as equações ajustadas conforme o modelo de Coulomb constataram maior resistência do solo ao cisalhamento no cerradão, seguido do preparo convencional e semeadura direta. A menor resistência ao cisalhamento do solo estudado, corroborada pelo menor atrito interno (tg f) e maior coesão aparente (c), especificamente nos teores de água 0,16 e 0,27 kg kg-1 (contemplando, portanto, a faixa friável do solo), confere à semeadura direta a condição de maior possibilidade de preservação da sustentabilidade da estrutura do Latossolo Vermelho distrófico. A predição da tensão de cisalhamento apresentou-se sensível aos efeitos da variação do teor de água no solo, ao tipo de uso, podendo contribuir, particularmente, em estudos da sustentabilidade da estrutura dos solos agrícolas, a qual normalmente é comprometida em áreas cujo tráfego e preparo do solo são realizados inadequadamente.<br>Shear soil strength is an important dynamic property of the soil, as well as the state of soil consistence concerning the structure behavior of agricultural soils, which are mostly being ignored in research into the influence of use and management. This fact has been contributing to the perennial problem of fallacious strategies, causing degradation of the physical and mechanical soil properties. This study aimed at an evaluation of the shear soil strength of a dystrophic Red Latosol submitted to conventional tillage, direct seeding, and Cerrado as control treatment, with different water contents: 0.05; 0.16; 0.18, and 0.38 kg kg-1. Results allowed the conclusion that the shear strength of the soil, appraised at a depth of 0-0.05 m of a dystrophic Red Latosol, was affected by water content increases, use and management type. In general, the adjusted equations according to the Coulomb model evidenced greater shear strength in the Cerrado, followed by conventional tillage, and direct seeding. The lowest shear strength of the studied soil, corroborated by the smallest internal friction angle (tg f) and larger apparent cohesion (c), specifically for the water content 0.16 and 0.27 kg kg-1 (contemplating, therefore, the friable range of the soil), pointed to direct seeding as the management with the greatest possibilities of preserving the structural sustainability of the soil studied. The prediction of shear tension proved to be sensitive to the effects of soil water variations and the use type. This enables significant contributions, particularly to studies on the structural sustainability of agricultural soils, which are usually impaired by inadequate traffic and tillage operations