不同N、K用量对苹果产量与品质的影响

通过9年田间试验,对幼龄M26砧Aroma苹果树施用0、60及120公斤N(硝酸钙)/公顷和 0、120及240公斤K(氯化钾)/公顷,植株5年生,试验初期便结果.砂壤土,含有机质10.5%.在除草剂处理     

水分亏缺和钾对拉维林娜脐橙裂果的影响

拉维林娜是一种易于裂果(一种生理失调症)的脐橙。本研究以其酸橙砧的10年生树为试材,每隔8—12天从树冠顶上喷灌一次,均施等量的N、P、K为基肥。试验处理设置如下:1)1987年7月15日—8月7日和1988年7月12日—8月8日间不灌溉;     

Exophthalmos due to a wooden foreign body in a dog

An 8-year-old Golden Retriever dog was presented with a 10-month history of right-sided exophthalmos. Radiographs and CT demonstrated a linear density, suggestive of a foreign body, in the region of the ramus of the right mandible. A 7 cm stick, located medial to the right zygomatic arch, was removed during exploratory surgery. The dog recovered with the aid of antibiotics, however was left with a residual facial nerve paralysis.     

Differences between primiparous and multiparous dairy cows in the inter-relationships between metabolic traits, milk yield and body condition score in the periparturient period

During the early postpartum period dairy cows mobilize fat and muscle to support lactation. This is associated with alterations in blood metabolite and hormone profiles which in turn influence milk yield and fertility. This study developed models to determine how metabolic traits, milk yield and body condition score were inter-related at different times in the periparturient period and to compare these relationships in primiparous (PP, n=188) and multiparous (MP, n=312) cows. Data from four previous studies which included information on blood metabolic parameters, parity, milk yield, body condition score and diet were collated into a single dataset. Coefficients of polynomial equations were calculated for each trait between -1 week pre-calving and week +7 postpartum using residual maximum likelihood modelling. The completed dataset was used in a multiple correlation model to determine how the best fit curves were related to each other over time. PP cows had higher concentrations of insulin-like growth factor-I and lower beta-hydroxybutyrate concentrations throughout, higher leptin concentrations pre-partum and both the peak in non-esterified fatty acids and the nadir in urea concentration occurred earlier after calving. These differences were associated with significantly lower milk production. Leptin concentrations fell at calving and were related to body condition score. Insulin was negatively correlated with yield in MP cows only. In MP cows the relationship between insulin-like growth factor-I and yield switched from negative to positive between weeks +4 and +7. Both beta-hydroxybutyrate and urea were positively related to yield in PP cows. In contrast, in MP cows beta-hydroxybutyrate was negatively correlated with yield and urea was strongly related to body condition score but not yield. These results suggest that there are differences in the control of tissue mobilization between PP and MP cows which may promote nutrient partitioning into growth as well as milk during the first lactation.     

Pre-pubertal measurements of the somatotrophic axis as predictors of milk production in Holstein-Friesian dairy cows

This study investigated possible relationships between measurements of the somatotrophic axis in pre-pubertal dairy calves and subsequent milk yields. Endogenous growth hormone (GH) release was measured through a fed and fasted period in fifty 6-month-old Holstein-Friesian heifers and they were then challenged with growth hormone-releasing factor (GRF) to assess their GH release pattern. Insulin-like growth factor-I (IGF-I), insulin and glucose concentrations were measured in relation to time of feeding. Cows were subsequently monitored through their first three lactations to record peak and 305-day milk yields. In the first lactation, milk energy output for the first 120 days of lactation was also calculated. The mean 305-day milk yield increased from 7417 +/- 191 kg in the first lactation (n=37) to 8749 +/- 252 kg in the third (n=25). There were no significant relationships between any measures of GH secretion and peak or 305-day yield in any lactation. A highly significant positive relationship was established between the GH peak measured 10 min post-GRF challenge and 120-day milk energy values in the first lactation. This relationship was, however, only present in the sub-population of 12 cows culled after one or two lactations and was absent in the 25 animals remaining for the third lactation. There were no significant relationships between pre-pubertal IGF-I and fed or fasted insulin or glucose concentrations and any subsequent measurement of yield. The usefulness of GH secretagogue challenges in calves as a predictive test for future milk production is thus limited but may have some bearing on nutrient partitioning and longevity.     

Clinical and magnetic resonance imaging findings in 92 cats with clinical signs of spinal cord disease

Medical records of 92 cats presented with clinical signs of spinal cord disease, which had undergone magnetic resonance imaging (MRI), were reviewed. The cats were grouped into seven categories based upon the diagnosis suggested by results of MRI, cerebrospinal fluid analysis and other diagnostic procedures: neoplastic (n=25), inflammatory or infectious (n=13), traumatic (n=8), vascular (n=6), degenerative (n=5), anomalous (n=3) and those with an unremarkable MRI (n=32). There were two independent predictors of abnormal MRI findings: severity of clinical signs and presence of spinal pain. Abnormal MRI findings and speed of onset of disease were significantly associated with survival. For the 32 cats with unremarkable MRI findings, only nine died due to spinal disease and, therefore, the median survival time (MST) was not reached (lower 95% confidence interval (CI)=970 days). For the 60 cats with abnormal MRI findings, 37 died due to their disease and the MST was 138 days (95% CI: 7-807).     

Production of DAPG and HCN by Pseudomonas sp. LBUM300 contributes to the biological control of bacterial canker of tomato

Bacterial canker caused by Clavibacter michiganensis subsp. michiganensis is known to cause significant economic losses to tomato production worldwide. Biological control has been proposed as an alternative to current chemical containment methods, which are often inefficient and may leave adverse effects on the environment. However, only little headway has so far been made in developing biocontrol strategies against C. michiganensis subsp. michiganensis. To address this knowledge gap, we investigated the antagonistic capacity of PCA, produced by Pseudomonas sp. LBUM223, and DAPG and HCN, both produced by Pseudomonas sp. LBUM300, on C. michiganensis subsp. michiganensis under in vitro and in planta conditions. Nonsynthesizing isogenic mutants of the producer strains were also developed to further dissect the role of each individual metabolite on C. michiganensis subsp. michiganensis biological control. Novel specific quantitative polymerase chain reaction TaqMan assays allowed quantification of C. michiganensis subsp. michiganensis in tomato plants and rhizospheric soil. Pseudomonas spp. LBUM223 and LBUM300 significantly repressed C. michiganensis subsp. michiganensis growth in vitro, while their respective nonproducing mutants showed less or no significant antagonistic activity. In planta, only Pseudomonas sp. LBUM300 was capable of significantly reducing disease development and C. michiganensis subsp. michiganensis rhizospheric population, suggesting that the production of both DAPG and HCN was involved. In summary, simultaneous DAPG/HCN production by Pseudomonas sp. LBUM300 shows great potential for controlling bacterial canker of tomato.     

Gaseous hydrocarbons in sea water: determination

Low-molecular-weight hydrocarbons in the C(l) to C(4) range have been detected and measured in sea water. Methane shows by far the highest concentration, followed in order by the C(2), C(3), and C(4) fractions. In general, the concentration tends to decrease with depth, but there is a strong indication that a maximum may exist about 30 to 50 meters below the surface.