黔北地区主要竹种竹材气干密度与力学性质的关系研究

对黔北地区几种主要竹种的气干密度与力学性质的关系研究表明:各竹种的气千密度与力学性质除部分竹种外均存在一定的曲线或直线关系,其中在气干密度与抗剪强度关系中,除慈竹、花吊丝、毛脚龙竹、金佛山方竹等竹种外,其他竹种均可利用回归方程T12=ap12b,T12=ap12+b进行估测.在气干密度与顺纹抗拉强度关系中除硬头黄、花吊...     

成都平原不同耕作模式的农田效应研究—— II.土壤综合质量评价

 【目的】研究成都平原不同耕作模式对土壤质量性状的影响,探索建立适合当地生产条件的土壤质量评价体系,筛选出适宜该地的耕作模式,为提高当地土壤生产力水平、改善土壤质量提供借鉴。【方法】通过长期定位试验获取不同耕作模式对土壤性状及作物生产指标的影响效应,采用主成分分析的方法筛选评价指标,运用因子分析法对土壤质量进行综合评价。【结果】筛选出的评价土壤综合质量的指标在不同土壤层次存在明显差别：0—10 cm土层的主要影响因子为毛管孔隙度、土壤比重、土壤饱和渗水速率、土壤紧实度、土壤有机质;10—20 cm土层的主要影响因子为总孔隙度、非毛管孔隙度、饱和渗水速率、土壤吸湿水、土壤紧实度;0—20 cm土层的主要影响因子为非毛管孔隙度、土壤比重、土壤饱和渗水速率、土壤紧实度。其中,不同土层的共同影响因子——土壤饱和渗水速率和土壤紧实度是目前当地土壤质量的限制因子。土壤质量综合评价结果表明0—10 cm土层以麦稻双免耕作模式最好,10—20 cm土层麦免+稻旋最好,0—20 cm土层麦免+稻旋最好。【结论】在本研究的试验条件和当地实际情况下,对成都平原土壤质量具有良好效益的耕作模式为麦免+稻旋模式。     

Clinical Use of Deslorelin for the Control of Reproduction in the Bitch

This study was conducted to evaluate clinical efficacy of deslorelin for inhibiting reproduction in the bitch. Ten adult healthy bitches or bitches with mammary neoplasia for which owners were requesting suppression of cyclicity without performing gonadectomy were administered a 4.7- or a 9.4-mg deslorelin implant subcutaneously. The first implant of deslorelin was administered in anoestrus (n = 5) or in dioestrus (n = 5). Treatment was repeated every 5 months for as long as necessary based on the clinical situation of the dog and owner's desires. Some of the bitches implanted in anoestrus came in heat within 4–15 days after treatment, while none of the bitches implanted in dioestrus showed heat during treatment. Suppression of reproductive cyclicity was successfully achieved in 6/10 bitches for 1–4 years. No behavioural and local/general side-effects were observed in any of the treated bitches. The 4.7-mg deslorelin implant may work well for suppression of cyclicity provided that it is administered in dioestrus and at intervals of 4.5 months. A 9.4-mg implant may be more suitable for this use although its efficacy may also be shorter than 12 months. Owner compliance is an important limiting factor.     

CAN SONOGRAPHIC FINDINGS PREDICT THE RESULTS OF LIVER ASPIRATES IN DOGS WITH SUSPECTED LIVER DISEASE?

While abdominal ultrasound and ultrasound-guided fine-needle aspiration cytology are often combined to help determine the type of liver disease in dogs, little is known about the relationship that may exist between the results of these tests. We hypothesized that specific sonographic findings, or combinations of findings, may predict results of liver ultrasound-guided fine-needle aspiration cytology. Hepatic and extrahepatic sonographic findings were recorded prospectively using a standardized form in 70 dogs with clinically suspected liver disease and in which liver ultrasound-guided fine-needle aspiration cytology was performed. The predictive value of sonographic findings in regard to the category of cytology results was assessed with stepwise logistic regression analysis. Sonographic detection of a hepatic mass (≥3 cm; risk ratio [RR] 3.83, 95% Wald confidence intervals [95% CI] 2.42–3.93, P =0.0036), ascites (RR 3.82, 95% CI 1.94–4.28, P =0.0044), abnormal hepatic lymph node(s) (RR 3.01, 95% CI 1.22–4.88, P =0.0262), and abnormal spleen (RR 3.26, 95% CI 1.20–3.85, P =0.0274) were the most predictive of liver neoplasia on cytology. Conversely, sonographic detection of hepatic nodules (<3 cm; RR 1.97, 95% CI 0.95–2.96, P =0.0666) was most predictive of vacuolar hepatopathy on cytology. In dogs with suspected liver disease, several sonographic findings, alone or combined, are thus predictive of liver ultrasound-guided fine-needle aspiration cytology results. In the light of the fact that ultrasound-guided fine-needle aspiration cytology of the liver has limitations, these predictabilities could influence the selection of diagnostic tests to reach a reliable diagnosis.     

Haematological and biochemical investigations of diseased koalas (Phascolarctos cinereus)

Haematological and biochemical investigations were performed on 14 koalas with uncomplicated cystitis, 8 with complicated cystitis, 8 with conjunctivitis, 8 with lymphosarcoma, and 14 with miscellaneous diseases. Changes were limited and inconsistent in individual koalas with uncomplicated cystitis and conjunctivitis. In contrast, individual koalas with complicated cystitis were more likely to have anaemia, leukocytosis due to neutrophilia, hypoproteinaemia due to hypoalbuminaemia, and azotaemia due to elevated urea concentration. Although these changes were non-specific they did allow assessment of prognosis for survival and response to treatment. Koalas with lymphosarcoma were invariably anaemic, leukaemic, azotaemic and hypoalbuminaemic. Elevated enzymes (aspartate transaminase [AST]. lactate dehydrogenase [LD] and gamma glutamyl transferase [GGT]) were more common in koalas with lymphosarcoma. Koalas affected by miscellaneous conditions showed variable changes but once again anaemia, leukocytosis, azotaemia, elevated AST and LD, and hypoalbuminaemia were not uncommon. On the basis of these findings a minimal profile is suggested for the investigation of sick koalas and would include haematocrit, total and differential leukocyte counts, urea, total protein and albumin concentrations and AST, GGT and LD activities.     

Simulation study of the competitive ability of erect, semi-erect and prostrate cowpea (Vigna unguiculata) genotypes

Ecophysiological simulation models provide a quantitative method to predict the effects of management practices, plant characteristics and environmental factors on crop and weed growth and competition. The INTERCOM interplant competition model was parameterised, calibrated by monoculture data for three cowpea (Vigna unguiculata) genotypes that differed in growth habit, common sunflower (Helianthus annuus) and common purslane (Portulaca oleracea), and used to simulate competition of cowpea cover crops with sunflower or purslane. The simulation results were compared with observations from field competition experiments in 2003 and 2004. INTERCOM more accurately simulated actual field data for the competition of cowpea genotypes and sunflower than companion field experiments for the competition of cowpea and purslane. The validated simulation model of cowpea and sunflower at two densities was used to study the effects of cowpea growth habit on final biomass production of cowpea and sunflower. The model suggested that erect growth habit was more competitive than semi‐erect and prostrate growth habit, when cowpea genotypes were grown with sunflower. Cowpea leaf area distribution was important to higher cowpea biomass production, while cowpea height growth was important to reduce sunflower biomass. Our simulation approach is suggested as a method for crop breeders to gauge the likely success of selection for competitive crops before undertaking expensive long‐term breeding experiments.     

Effect of short‐term exposure of cumulus–oocyte complex to 3‐morpholinosydnonimine on in vitro embryo development and gene expression in cattle

Short‐term exposure of gametes to different types of stress might induce stress tolerance in mammalian embryos. The aim of this study was to evaluate the effect of short‐term exposure of bovine mature cumulus–oocyte complex (COC) to 3‐morpholinosydnonimine (SIN‐1) on subsequent in vitro embryo development, embryo quality and relative gene expression. Matured COCs were incubated with SIN‐1 (0, 0.1, 1, 10 and 100 μM SIN‐1) for 1 hr before in vitro fertilization and zygotes were cultured until Day 7. The cleavage rate at 72 hr did not show any differences among groups. However, the blastocyst rate on Day 7 decreased with all treatments evaluated, with the embryos generated with 10 μM SIN‐1 showing the lowest embryo production rate. Embryo quality analysis did not show any differences in total cell number (TCN) or inner cell mass (ICM) among groups. Relative gene expression analysis showed a downregulation of eNOS expression and an upregulation of nNOS expression in all treatments evaluated compared to the control group. Also, a downregulation was observed in some treatments: SOD2 at 0.1 μM; SOD1 at 0.1 and 100 μM; PRDX5 at 0.1, 10 and 100 μM; and NANOG at 10 and 100 μM; and an upregulation of CDX2 expression was observed at 100 μM. The other genes (OCT4, HIF1A, HSPA1A, BCL2A and iNOS) did not show any differences in the relative gene expression. These results suggest that the short‐term exposure of mature bovine COCs to SIN‐1 does not induce stress tolerance and has no beneficial effect on bovine in vitro embryo production.