Antibiotic residue release at the beginning of lactation following dry cow therapy

In response to farmer complaints about unfair penalties, for the presence of inhibitory substances in early lactation following the use of dry-cow antibiotic therapy, a two-part study was carried out to try and establish why these unexplained grades occur. A survey of instructions supplied with each of 13 registered dry-cow products suggested that the directions for drug use were in some cases inappropriate for long-acting antibiotics. A residue release study was conducted at the beginning of lactation following antibiotic therapy at various times during the dry period. The results showed, for the-three dry-cow preparations studied, that treatment during the dry period, especially within six weeks of calving, could lead to detectable residues in milk from treated quarters.     

Carbon isotopic composition, gas exchange, and growth of three populations of ponderosa pine differing in drought tolerance

Effects of water supply on gas exchange, carbon isotopic composition, and relative growth rate were compared among seedlings from three populations of ponderosa pine (Pinus ponderosa Dougl. ex Laws.) grown in a controlled environment chamber. The three populations were chosen to represent high, moderate and low drought tolerance. There was no indication that drought tolerance was related to high water-use efficiency. Populations differed (P < 0.05) in relative growth rate (RGR), but did not differ (P > 0.10) in gas exchange variables or carbon isotope ratio (delta(13)C). Well-watered seedlings had significantly higher RGR, xylem pressure potential (Psi(xpp)), net photosynthesis (A), stomatal conductance to water vapor (g), and lower delta(13)C and instantaneous water-use efficiency than water-stressed seedlings. With decreasing Psi(xpp), A decreased linearly, whereas g decreased exponentially. Seedlings of the highly drought-tolerant population were more sensitive to water availability than seedlings from the other populations; they used water quickly when water was available, but closed their stomata in response to water stress. We conclude that, in ponderosa pine, the drought avoidance mechanism is more important for survival and growth in arid and semiarid environments than the efficient use of water.     

基于多层卷积滤波与HSV颜色提取的茶轮斑病识别研究

利用卷积滤波对原始图像进行显示轮廓以及锐化处理,引入了HSV模型进行颜色提取,通过二值化再次滤波完成了茶轮斑病斑区的提取,实现茶叶的茶轮斑病的快速诊断。结果表明,采用卷积滤波与HSV模型等图像处理技术能够较好地识别茶轮斑病的病斑区,对于图像清晰、面积大的病斑区识别比较精确。利用Python语言的嵌入性,为进一步实现茶叶茶轮斑病的精准喷雾系统打下了基础。     

A unified description of linear and nonlinear polarization in organic polymethine dyes

An internal or external electric field F can drive the chemical structure, bond order alternation, and electronic structure of linear polymethine dyes from a neutral, bond-alternated, polyene-like structure, through a cyanine-like structure, and ultimately to a zwitterionic (charge-separated) bond-alternated structure. As the structure evolves under the influence of F, the linear polarizability alpha, the first hyperpolarizability beta, and the second hyperpolarizability gamma are seen to be derivatives, with respect to F, of their next lower order polarization (for alpha) or polarizability (for beta and gamma). These derivative relations provide a unified picture of the dependence of the polarizability and hyperpolarizabilities on the structure in linear polymethine dyes. In addition, they allow for predictions of structure-property relations of higher order hyperpolarizabilities.     

Rotational and continuous grazing of sheep in the Inner Mongolian steppe of China

The aim of this study was to compare the effects of rotational and continuous grazing on herbage mass (HM), organic matter digestibility (dOM) and intake (OMI) and live weight gain (LWG) of sheep grazing on the inner Mongolian steppe, China at a stocking rate of 4.5 sheep/ha during the growing season. In the years 2005 and 2006, four 2-ha plots were used of which two were divided into four 0.5 ha paddocks each for rotational grazing, where sheep were moved each 10 days to the next paddock. The dOM was estimated from faecal crude protein concentration and OMI by oral administration of titanium dioxide. Herbage mass was similar in both grazing systems and dOM and OMI were higher (p < 0.05) at continuous grazing than at rotational grazing, but LWG did not differ probably because of extra energy expenditure for grazing and walking in a larger area. The dOM and OMI decreased (p < 0.05) with progress of the growing season and differed between years. Since precipitation during the growing season in both years was lower than the 30 years average which was probably the reason that positive effects of non-grazing periods on herbage regrowth and quality at rotational grazing could not occur, further studies are required in years with average precipitations before a final evaluation of these grazing systems can be made. Moreover, it seems necessary to quantify energy expenditure for physical activity of animals in grazing studies.     

Impact of ovariohysterectomy and food intake on body composition, physical activity, and adipose gene expression in cats

The mechanisms contributing to BW gain following ovariohysterectomy in domestic cats are poorly understood. Moreover, the effects of food restriction to maintain BW following spaying have been poorly studied. Thus, our primary objective was to determine the effects of spaying and food restriction to maintain BW on adipose and skeletal muscle mRNA abundance and activity levels in cats. After a 4-wk baseline period (wk 0), 8 adult (approximately 1.5 yr old) domestic shorthair cats were spayed and fed to maintain BW for 12 wk. After 12 wk, cats were fed ad libitum for an additional 12 wk. Body composition was determined, activity levels were measured, and adipose and muscle biopsies were collected at wk 0, 12, and 24. Fasting blood samples were collected at wk 0, 6, 12, 18, and 24. To maintain BW post-spay, food intake was decreased (P < 0.05) by 30%. During this phase, mRNA abundance of adipose tissue lipoprotein lipase and leptin was decreased (P < 0.05), representing only 52 and 23% of baseline expression, respectively. Interleukin-6 mRNA, however, was increased (P < 0.05) 2-fold. Physical activity was decreased (P < 0.05) by wk 12, most dramatically during the dark period (approximately 20% of baseline activity). During ad libitum feeding (wk 12 to 24), food intake, BW, body fat percentage, and total fat mass were greatly increased (P < 0.05). Compared with wk 0, circulating leptin concentrations tended to increase (P < 0.10) by wk 18 and 24 (4.45 vs. 10.02 and 9.14 ng/mL, respectively), whereas glucose (91 vs. 162 mg/dL) and triacylglyceride (30 vs. 48 mg/dL) concentrations were increased (P < 0.05) by wk 24. Adipose tissue lipoprotein lipase, hormone sensitive lipase, and adiponectin mRNA were decreased (P < 0.05) at wk 24. Adipose interleukin-6 mRNA was increased (P < 0.05) at 24 wk. Physical activity was further decreased (P < 0.05) by wk 24, during the light (60% of baseline) and dark (33% of baseline) periods. In summary, spaying and food restriction affect physical activity levels and several genes associated with lipid metabolism (decreased lipoprotein lipase), food intake (decreased leptin expression), and insulin insensitivity (increased interleukin-6). By identifying these changes, targets for nutritional intervention or lifestyle management have been identified that may curb the risk of obesity and related disorders in spayed cats.     

Free radical scavenging activity of three Equisetum species from Fruska gora mountain

The scavenger activities of Equisetum arvense, Equisetum ramosissimum and Equisetum telmateia aboveground parts phosphate buffer (pH 7) extracts were evaluated using three different methods: DPPH assay, ESR and NO radical inhibition assay. Total reducing power was determined by FRAP assay. The E. telmateia extract demonstrated the most relevant scavenger and antioxidant properties. ESR signal of DMPO-OH radical adducts in the presence of E. telmateia phosphate buffer (pH 7) extract was reduced to 98.9% which indicated that E. telmateia could be a useful source of antioxidants with huge scavenger ability.     

Development of a monoclonal antibody-based enzyme-linked immunosorbent assay for the herbicide chlorimuron-ethyl

Hybridomas secreting a monoclonal antibody (mAb) against the herbicide chlorimuron-ethyl (CE) were produced by fusing the mouse myeloma cell line (SP2/0) with splenocytes from a mouse immunized against the conjugate of the sulfonamide moiety of CE and bovine serum albumin (BSA). The mAb, designated 1F5C5A10, had very weak affinity with metsulfuron, ethametsulfuron, pyrazosulfuron, bensulfuron, and chlorsulfuron. Two mAb-based indirect competitive enzyme-linked immunosorbent assays (icELISA) were developed. A conventional icELISA (icELISA-I) showed a concentration of half-maximum inhibition (IC(50)) of 11.6 ng/mL with a dynamic range of 1.6-84 ng/mL. A simplified icELISA (icELISA-II) had an IC(50) of 28.7 ng/mL and a dynamic range of 2.2-372 ng/mL. The two assays were tested on spiked water and soil samples. CE (1-500 ng/mL) fortified in water samples could be analyzed directly without any sample preparation by both immunoassays with an average recovery between 74 and 114%. icELISA-II, but not icELISA-I, was able to accurately analyze the herbicide residues in the crude soil extracts with recoveries between 99 and 129% without obvious matrix effects due to its lesser amount of sample used. In contrast to icELISA-I, icELISA-II is more convenient, whereas it consumes more reagents of coating antigen and goat anti-mouse IgG-peroxidase.     

Canine cardiac mesothelioma with granular cell morphology

Cardiac mesothelioma with granular cell features was diagnosed in a 10-year-old Golden Retriever presenting with pericardial and abdominal effusions. The diagnosis was based on gross, morphologic, and immunohistochemical features. The immunohistochemical profile of the neoplasm was pancytokeratin positive, vimentin positive, and S-100 negative; most gross and morphologic features were consistent with both mesothelioma and granular cell tumor. To the authors' knowledge, the prognosis for either primary cardiac mesothelioma or granular cell tumor in the dog is unknown. At 4 months after thoracotomy, pericardectomy, and mass excision, this dog was alive and without clinical evidence of pericardial or abdominal effusions. We describe a granular morphologic variant of cardiac mesothelioma in a dog.