Synchronization of Ovulation and Fixed Time Intrauterine Insemination in Ewes

A novel method for oestrus-ovulation synchronization in sheep followed by fixed time insemination is presented herewith. Mature dry ewes (n = 28) of Karagouniko breed being at an unknown stage of the oestrous cycle, were used during the middle of breeding season. The treatment protocol consisted of an initial administration of a GnRH analogue followed 5 days later by a prostaglandin F2alpha injection. Thirty-six hours later a second GnRH injection was administered to synchronize ovulation, and laparoscopic intrauterine insemination was performed 12-14 h later. Three days after insemination, fertile rams were introduced into the flock twice daily and oestrus-mating detection was carried out. For progesterone (P(4)) determination, blood samples were collected on alternate days, starting 2 days before the first GnRH injection and continuing for 17 days after insemination. An additional sample was taken on the day of insemination. Pregnancy diagnosis was carried out by trans-abdominal ultrasonography. Fourteen ewes (50%) conceived at insemination and maintained pregnancy; from the remainder 14 ewes 10 became pregnant at natural service, while four, although they mated at least two to three times, failed to conceive. In response to the first GnRH, P(4) concentration increased at higher levels in ewes that conceived at AI compared with those that failed to conceive (47.54 and 22.44%, respectively; p < 0.05). Significant differences (p < 0.05) in mean P(4) concentration between pregnant and non-pregnant animals were detected 1 day before AI (0.17 +/- 0.06 and 0.26 +/- 0.14 ng/ml, respectively) on the day of AI (0.15 +/- 0.04 and 0.24 +/- 0.08 ng/ml, respectively) as well as 9 and 11 days thereafter (0.48 +/- 0.12 and 0.38 +/- 0.12 ng/ml; 0.68 +/- 0.14 and 0.50 +/- 0.18 ng/ml, respectively). These results indicate that using the proposed protocol, an acceptable conception rate can be achieved which could be further improved by modifying the time intervals between interventions.     

Ovum Pick-up in Sheep: a Comparison between Different Aspiration Devices for Optimal Oocyte Retrieval

In vivo ovum pick-up (OPU) in sheep may be improved with a proper choice of aspiration elements (needle and tubing) and aspiration vacuum pressure. In the present study, two experiments were carried out. In Expt 1, visible follicles in ovaries of slaughtered ewes (treated separately according to their diameters: small<3 mm, medium 3-5 mm and large>5 mm) were aspirated using different combinations of the three studied factors such as aspiration flow rate (10, 20, 30, 40 and 50 ml water/min), needle gauge (18 and 20 G) and tubing inner diameter (1, 2 or 3 mm internal diameter). In Expt 2, a study with two 18 G needles of different lengths (18 G: 82 mm; 18 GL: 600 mm) was carried out, using ovaries obtained post-mortem, and performing in vivo laparoscopic follicular aspiration on ewes. We considered good quality oocytes as those with both complete compact cumulus and a homogeneous cytoplasm. Recovery rate, proportion of good quality oocytes (good quality oocytes/100 oocytes recovered) and overall efficiency (good quality oocytes/100 follicles aspirated) were noted. In Expt 1, aspiration flow rate affect remarkable proportion of good quality oocytes (69.5%, 50.5%, 44.8%, 36.5% and 28.3% for flows from 10 to 50 ml/min respectively, p<0.05). Needle gauge did not affect aspiration device efficiency. Thin and intermediate tubings were more effective (overall efficiency rates: 34.9%, 32.3% and 28.1% for 1, 2 and 3 mm respectively, p<0.05). Follicle size did not affect recovery rate, but proportion of good quality oocytes was higher for large (77.9%) and medium (64.4%) follicles (p<0.05). Finally, some combinations of the aspiration device showed greater effectiveness. In Expt 2, needle length did not influence recovery rate, but good quality oocytes rate was significantly modified both post-mortem and in vivo (good quality rate for 18 G vs 18 GL needles: 69.5% vs 47.7% and 58.1% vs 25.4%, post-mortem and in vivo respectively, p<0.05). We conclude that low-aspiration flow rates (10 and 20 ml/min) with thin or intermediate tubings (1 and 2 mm), and any short needle (18 G or 20 G) are the most adequate aspiration factors for OPU in sheep.     

Pressure-induced amorphization and negative thermal expansion in ZrW2O8

It has recently been shown that zirconium tungstate (ZrW2O8) exhibits isotropic negative thermal expansion over its entire temperature range of stability. This rather unusual behavior makes this compound particularly suitable for testing model predictions of a connection between negative thermal expansion and pressure-induced amorphization. High-pressure x-ray diffraction and Raman scattering experiments showed that ZrW2O8 becomes progressively amorphous from 1.5 to 3.5 gigapascals. The amorphous phase was retained after pressure release, but the original crystalline phase returned after annealing at 923 kelvin. The results indicate a general trend between negative thermal expansion and pressure-induced amorphization in highly flexible framework structures.     

Elevation change of the southern greenland ice sheet

Seasat and Geosat satellite altimeter measurements for the Greenland ice sheet (south of 72 degreesN latitude) show that surface elevations above 2000 meters increased at an average rate of only 1. 5 +/- 0.5 centimeters per year from 1978 to 1988. In contrast, elevation changes varied regionally from -15 to +18 centimeters per year, seasonally by +/-15 centimeters, and interannually by +/-8 centimeters. The average growth rate is too small to determine if the Greenland ice sheet is undergoing a long-term change due to a warmer polar climate.     

Neofusicoccum eucalyptorum, a Eucalyptus pathogen, on native Myrtaceae in Uruguay

Neofusicoccum eucalyptorum is a canker-associated fungus apparently highly specialized on Eucalyptus . However, in surveys of the microbial population inhabiting native Myrtaceae in Uruguay, fungal cultures resembling N. eucalyptorum were isolated. The possible occurrence of N. eucalyptorum on hosts other than Eucalyptus prompted further investigation. Several surveys were conducted throughout Uruguay to obtain samples from native forests, focusing primarily on species in the Myrtaceae. Fungal identification was based on morphology and confirmed using comparison sequences for the internal transcribed spacer (ITS) of the rDNA operon. Pathogenicity was evaluated by inoculating plants of a Eucalyptus grandis clone. Morphological and molecular identification confirmed the occurrence of N. eucalyptorum on Blepharocalyx salicifolius, Myrceugenia glaucescens and Myrrhinium atropurpureum var. octandrum . This is the first report of N. eucalyptorum occurring in hosts other than Eucalyptus . Pathogenicity tests confirmed the ability of this species to produce cankers on E. grandis . This study provides information that will assist breeding programmes in attempts to obtain disease-resistant Eucalyptus plantations and it also suggests that a Eucalyptus pathogen could have moved to native trees in Uruguay.     

Histopathology of primary needles and mortality associated with white pine blister rust in resistant and susceptible Pinus strobus

White pine blister rust caused by Cronartium ribicola is a damaging non‐native disease of five‐needled pines in North America. Efforts to control the disease and mitigate damage to date have been only somewhat effective. Recent efforts to improve the health of eastern white pine and reestablish the tree as a dominant species in the North Central United States have focused on identification and propagation of disease‐free eastern white pine (Pinus strobus) growing in areas with a high incidence of blister rust. Many of these selections have been shown to resist infection following artificial inoculation with C. ribicola. In this study, 13 eastern white pine families derived from controlled pollination of selections previously determined to possess putative resistance as well as susceptible selections were inoculated with C. ribicola. Mortality data from inoculation studies show superior survivability in three families with over 60% of seedlings able to survive the 52 week post‐inoculation monitoring period compared to 0–10% survival of the most susceptible families. Primary needles were collected for histological analysis from all inoculated families 4 weeks after inoculation and from selected families 6.5 weeks and 38 weeks after inoculation. Histological observations of infection sites show distinct resistance reactions in the families more likely to survive infection based on mortality data. Analysis of the reactions in susceptible families revealed extensive hyphal colonization of the vascular bundle and adjacent mesophyll cells that appear uninhibited by tree responses. In resistant families, collapsed cells adjacent to infection sites, heavy deposition of phenolic compounds and abnormal cell growth were documented more frequently and appear to play an integral role in the ability of these eastern white pine families to impede growth of C. ribicola in primary needle tissue.     

Low glyphosate rates do not affect Citrus limonia (L.) Osbeck seedlings

BACKGROUND: Glyphosate is used to control weeds in citrus orchards, and accidental spraying or wind drift onto the seedlings may cause growth arrest owing to metabolism disturbance. Two experiments were carried out to investigate the effect of non‐lethal rates (0, 180, 360 and 720 g AI ha^?1) of glyphosate on four‐month‐old ‘Cravo’ lime, Citrus limonia (L.) Osbeck, seedlings. Photosynthesis and the concentrations of shikimic acid, total free amino acids and phenolic acids were evaluated. RESULTS: Only transitory effects were observed in the contents of shikimate and total free amino acids. No visual effects were observed. CONCLUSION: The present study showed that glyphosate at non‐lethal rates, which is very usual when accidental spraying or wind drift occurs in citrus orchard, did not cause severe metabolic damage in ‘Cravo’ lime seedlings. Copyright © 2009 Society of Chemical Industry     

家蚕新品种春华×秋实的实验室和农村鉴定

家蚕新品种春华×秋实,经省级实验室联合鉴定,春期万蚕产茧量、万蚕茧层量、解舒丝长、解舒率比对照种菁松×皓月高7.6%、3.3%、11.6%、13.7%,净度高2.75分,出丝率略低,其余经济性状相仿.秋期饲养万蚕茧层量、解舒丝长、解舒率、出丝率比对照种秋丰×白玉提高6.9%、6.4%、16.3%、9.7%、4.1%,其他经济性状与对照相仿.两年农村生产鉴定结果,盒种产茧量比对照种高5.3%,产值高4.7%,50 kg桑产值高3.5%,茧丝长、解舒丝长、解舒率、干毛茧出丝率分别比对照种提高8.1%、13.0%、3.8%、2.9%.     

克氏原螯虾原肌球蛋白的纯化及过敏原性分析

以13份甲壳类动物过敏患者血清的Western—blotting分析,确定克氏原螯虾主要过敏原为36ku蛋白质．通过盐析、等电点沉淀及热处理等方法纯化该蛋白质,以兔抗拟穴青蟹原肌球蛋白（Tropo-myosin,TM）多克隆抗体的Western—blotting分析,确定该蛋白质为TM．同源性分析表明,克氏原螯虾TM与南美白对虾TM、拟穴青蟹的氨基酸序列相似性较高（〉90％）．酶切位点预测显示,它分别有49个胰蛋白酶和6个胰凝乳蛋白酶的酶切位点．模拟胃肠液消化实验结果显示,纯化TM不易被胃蛋白酶降解,易于被胰蛋白酶和胰凝乳蛋白酶降解,进一步的Western—blotting和抑制性ELISA分析结果显示,其消化产物仍具有一定的免疫活性．采用蒸煮处理可降低TM的消化稳定性及免疫活性,且蒸煮处理时间越长,效果越显著．说明。TM为克氏原螯虾主要过敏原．与其他甲壳娄动物TM的序列相似件较高．     

Effects of Storing Pig Ovaries at 4 or 20°C for Different Periods of Time on the Morphology and Viability of Pre-Antral Follicles

The purpose of this study was to evaluate the effect of cooling ovarian tissue on pig pre-antral follicles. Ovaries were maintained in saline solution (0.9%) at 4 or 20 degrees C for 6, 12 or 18 h. After storage, pre-antral follicles were morphologically evaluated. While primordial follicles were not affected by the storage, the percentage of morphologically normal growing follicles was significantly reduced in ovarian tissue stored at 20 degrees C for 12 or 18 h. To test the viability of stored follicles, growing follicles isolated from ovaries stored at 4 degrees C for 18 h and at 20 degrees C for 6 h were cultured for 3 days. Follicles stored in either condition presented the same growth pattern in vitro as fresh follicles. We conclude that storage of pig ovaries at 4 degrees C for up to 18 h or at 20 degrees C for up to 6 h does not affect the morphology of growing follicles or their ability to grow in vitro.