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51.
Extract Ectoparasites known to cause skin lesions in alpacas (Vicugna pacos) include the mites Sarcoptes scabiei, Chorioptes bovis and Psoroptes spp., and the lice Microthoracius mazzai and Bovicola breviceps (Cicchino et al. 1998; Foster et al. 2007). Occasionally, Demodex spp. infestations have been reported or mentioned as incidental fi ndings in llamas (Lama glama) (Atlee et al. 1997) and alpacas (Foster et al. 2007). So far, only Sarcoptes scabiei (McKenna et al. 2005), Chorioptes bovis (Arthur 1997, non-peer reviewed) and Bovicola breviceps (Palma et al. 2006) have been recorded on lamoids in New Zealand. Here, we report the first record of Demodex spp. infestation of an alpaca in New Zealand. 相似文献
52.
The effect of three commonly used anthelmintics, levamisole hydrochloride, ivermectin and closantel, on the development of the sheep blowfly, Lucilia cuprina, was determined. Sheep were treated with each anthelmintic using the manufacturers' recommended dose for helminth control. Both ivermectin and closantel significantly (p < 0.05) reduced the growth rate of larvae of L cuprina cultured in vitro on serum from these sheep. Levamisole hydrochloride had no effect. Ivermectin was effective for less than 6 days after treatment, whereas closantel significantly reduced larval growth 21 days after treatment. Dose-response experiments showed that lower concentrations of both ivermectin and closantel were not as effective in reducing larval growth. 相似文献
53.
A cellular microRNA mediates antiviral defense in human cells 总被引:4,自引:0,他引:4
Lecellier CH Dunoyer P Arar K Lehmann-Che J Eyquem S Himber C Saïb A Voinnet O 《Science (New York, N.Y.)》2005,308(5721):557-560
In eukaryotes, 21- to 24-nucleotide-long RNAs engage in sequence-specific interactions that inhibit gene expression by RNA silencing. This process has regulatory roles involving microRNAs and, in plants and insects, it also forms the basis of a defense mechanism directed by small interfering RNAs that derive from replicative or integrated viral genomes. We show that a cellular microRNA effectively restricts the accumulation of the retrovirus primate foamy virus type 1 (PFV-1) in human cells. PFV-1 also encodes a protein, Tas, that suppresses microRNA-directed functions in mammalian cells and displays cross-kingdom antisilencing activities. Therefore, through fortuitous recognition of foreign nucleic acids, cellular microRNAs have direct antiviral effects in addition to their regulatory functions. 相似文献
54.
用透射电镜观察了短尾鮠精子细胞和精子的形态以及细胞核、拟染色体和线粒体等的结构变化规律。结果表明,随着精子细胞的发育,核质凝聚程度逐渐增强。精子细胞时期细胞器较丰富,到精子细胞后期,细胞器的形态和数量发生了较大变化。短尾鮠的精子具有椭圆的头部和复杂的中片;近侧中心粒和远侧中心粒靠近核的中央;鞭毛呈9+2轴丝结构,并具有由外膜折迭形成的波浪形的鳍状结构。 相似文献
55.
Fibrin–alginate hydrogel supports steroidogenesis,in vitro maturation of oocytes and parthenotes production from caprine preantral follicles cultured in group 下载免费PDF全文
IR Brito GM Silva AD Sales CH Lobo GQ Rodrigues RF Sousa AAA Moura CEM Calderón M Bertolini CC Campello J Smitz JR Figueiredo 《Reproduction in domestic animals》2016,51(6):997-1009
This study aimed to establish a culture system that improves the in vitro development of caprine preantral follicles. In a first experiment, follicles were encapsulated as a single unit per bead and cultured singly or in groups or with five follicles in the same alginate (ALG) bead for 18 days. In a subsequent experiment, the “five follicles per bead” design was chosen to culture in ALG, fibrin–alginate (FA) or hyaluronate (HA) for 18 days. In a third experiment, we chose the five follicles per bead in FA to culture for 30 days. The culture set‐up of five follicles per ALG bead increased antrum formation and follicle diameter compared to the other culture designs (p < .05). Moreover, under this condition, 44.44% of the oocytes from in vitro cultured preantral follicles reached meiotic resumption. A significant increase of follicle diameter occurred in attachment system and FA (p < .05), but the ALG condition reached the highest among all groups on day 18 (p < .05). Follicles encapsulated in matrix produced more estradiol and progesterone than attachment system (p < .05). The expression of MMP‐9 mRNA was higher in FA than in other groups (p < .05) and similar to antral follicles from in vivo control (p > .05). Only FA group resulted in oocytes matured. After 30 days, oocytes from preantral follicles in vitro grown in FA developed to eight‐cell parthenotes. In conclusion, a culture system using FA supported the development of caprine preantral follicles cultured in group and included in the same bead of hydrogel, improving the oocyte maturation and producing parthenotes. 相似文献
56.
LG Bermúdez-Humarán P Chávez-Zamarripa A Guzmán-Velasco CH Leal-Garza R Montes de Oca-Luna 《Reproduction in domestic animals》2002,37(6):321-323
Molecular sexing is a rapid and safe procedure for bird sex determination. Two universal methods based on the amplification of a chromo‐helicase‐DNA‐Binding 1 (CHD) gene region, located in both sexual chromosomes (Z and W), have been established. We found that molecular sexing of Oreophasis derbianus failed by using these two procedures. One of them is based on a restriction site located in CHD1W gene but absent in CHD1Z. The DdeI restriction site, used successfully to determine gender in several bird species, was found to be lost because of nucleotide change in O. derbianus. This change created a new restriction site, NlaIII, that was successfully applied for sexing this endangered bird. 相似文献
57.
CH NEWTON LR NELSON SJ DEWALT EA MIKHAILOVA CJ POST MA SCHLAUTMAN SK COX WC BRIDGES KC HALL 《Weed Research》2008,48(5):394-397
The effects of translucent polyethylene sheeting as a thermal covering to eradicate Pueraria montana (kudzu) were investigated at Clemson, South Carolina on a clay loam. In 2005, the highest reduction of live root crowns was observed where P. montana was covered for the entire growing season (May–October) with a reduction of 42% of live root crowns compared with the control plots. Where P. montana was covered for alternate weeks throughout the growing season live root crowns were reduced by 35%. Covering P. montana for one week and then uncovering for four weeks repeatedly through the season killed 24% of root crowns. In 2006, the second year of treatment to the same plots, the three solarization treatments had similar efficacy of about 97%. The use of polyethylene sheeting appears not to be cost‐effective for general control of large P. montana infestations, but may be useful for small patches. 相似文献
58.
59.
The commercial available diatomaceous earth Fossil Shield® and the neem product Neem Azal-T/S® are tested as single treatments and in combination as controls for the stored product pests Sitophilus oryzae (L.) and Tribolium castaneum (Herbst). The diatomaceous earth, applied in concentrations of 0.5 g, 1 g and 2 g kg-1 rice, reduced numbers of surviving beetles significantly (over a period of 3 weeks). A single treatment with the neem product, in concentrations of 0.01 g, 0.1 g, 0.2 g and 1 g azadirachtin kg-1 rice, increased the mortality rate for both species significantly. The combination of neem and diatomaceous earth (1 g diatomaceous earth with 0.2 g or 1 g azadirachtin kg-1 rice) was more effective than the single treatment in reducing numbers of surviving beetles. 相似文献
60.
CH. Iben 《Journal of animal physiology and animal nutrition》1999,82(2-3):66-79
Introduction Carnitine (trimethyl-γ-amino-β-hydroxybutyrate; molecular weight 161 g) is not only essential for the transport and utilization of long-chain fatty acids, it also occurs as a medium and short-chain ester and serves as an acetyl and acyl pool. Short-term muscle exercise causes an increase of acetyl-carnitine levels in the serum and in the liver. It prevents the accumulation of acyl-coenzyme A (CoA) and provides the organism with CoA by producing acetyl-carnitine from acetyl-CoA. Human muscle tissue contains approximately 10 μmol CoA/kg, whereas carnitine levels range between 2000 and 5000 μmol/kg. 相似文献