Effects of carbohydrate source and polyethylene glycol on maturation and germination of somatic embryos in walnut (<Emphasis Type="Italic">Juglans regia</Emphasis> L.)     

Maryam Aflaki Jalali  Hassan Bahrami Sirmandi  Abdullah Hatamzadeh 《Journal of Crop Science and Biotechnology》2017,20(1):29-35

Low efficiency of somatic embryo maturation, germination, and conversion to plantlets is a major problem in many species including J. regia L. Germination efficiency of somatic embryos is very low in walnut. In this study, effects of two carbohydrate sources, sucrose and maltose (each at 3% and 6%), and two kinds of PEG (4000 and 6000) (each at four levels of 1.5%, 3%, 5% and 7.5%) on maturation and germination of walnut embryos were tested. The number of somatic embryos increased conspicuously on medium containing PEG. Furthermore, higher levels of PEG-4000 (7.5%) could remarkably enhance the morphogenesis of somatic embryos and the number of embryos produced. PEG-4000 stimulated somatic embryo maturation of walnut. This stimulatory effect was dependent on the carbohydrate source used. Sucrose in combination with PEG-4000 produced 50% of cotyledonary and normal somatic embryos. Different concentrations of PEG were effective on the number of embryos with a shoot meristem. PEG-4000 7.5% and sucrose 3.0% produced the highest rate (50.0%) of normal shooting embryos. However, PEG (4000, 6000) and maltose caused an unfavorable effect and increased the frequency of abnormal shaped somatic embryos.  相似文献   

Effect of a Probiotic on Prevention of Diarrhea and Clostridium difficile and Clostridium perfringens Shedding in Foals          下载免费PDF全文

A. Schoster  H.R. Staempfli  M. Abrahams  M. Jalali  J.S. Weese  L. Guardabassi 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2015,29(3):925-931

Background

Up to 60% of foals develop diarrhea within 6 months after birth. Preventive measures are limited but potentially probiotics could be used.

Objective

To evaluate the effect of a newly designed probiotic on the incidence of foal diarrhea in a randomized field trial.

Animals

Seventy‐two healthy neonatal foals.

Methods

Randomized, placebo‐controlled field trial. Foals were administered a placebo or probiotic for 3 weeks and monitored for an additional week. A total of 3 fecal samples were taken from each foal at biweekly intervals. Statistical modeling was applied for comparison of incidence and duration of diarrhea and fecal shedding of Clostridium perfringens and Clostridium difficile between treatment and age groups.

Results

The overall incidence of diarrhea was 41 of 72 (59%) and did not differ (P = 0.37) between treatment groups. Foals treated with probiotics were more likely to develop diarrhea requiring veterinary intervention (P = 0.007). Age had a significant effect on incidence of diarrhea (P < 0.001); foals 8–15 days old having the highest probability of developing diarrhea. Duration of diarrhea and soft feces were not significantly different between groups. The prevalence of C. perfringens shedding was 55% with no difference between treatment groups (P = 0.23). The prevalence of C. difficile shedding was 11%.

Conclusion and Clinical Importance

There was no benefit of administering a 3‐week course of probiotics, but potential adverse effects were noted. Whether the probiotics lacked a clinical effect, or the choice of strains or dose was inadequate, is unknown. Clostridial shedding was not influenced by probiotics despite in vitro activity of probiotics.  相似文献   

Cryopreservation of Ram Semen in Extenders Containing Soybean Lecithin as Cryoprotectant and Hyaluronic Acid as Antioxidant     

A Najafi  MH Najafi  Z Zanganeh  M Sharafi  F Martinez‐Pastor  H Adeldust 《Reproduction in domestic animals》2014,49(6):934-940

A soybean lecithin‐based extender supplemented with hyaluronic acid (HA) was assayed for effectiveness to improve the quality of frozen–thawed ram semen. HA has not been tested yet in an extender containing soybean lecithin for freezing ram semen. Thus, the aim of this study was to analyse the effects of soybean lecithin at 1% or 1.5% along with HA at 0, 0.5 and 1 mg ml^‐1 in a Tris‐based extender on the motion characteristics, membrane integrity (HOST), viability, GSH peroxidase (GSH‐PX) activity, lipid peroxidation and acrosomal status after freezing–thawing. Semen was collected from four Mehraban rams during the breeding season and frozen in the six lecithin×HA extenders. The extender containing 1.5% lecithin supplemented with no HA yielded higher total motility (52.5%±1.6), viability (55.8%±1.6) and membrane integrity (44.5%±1.7), but the effects of the lecithin concentration did not reach signification. Linearity‐related parameters, ALH, BCF, lipid peroxidation, GSH‐PX activity, morphology and acrosomal status were not affected by the extender composition. In general, adding HA significantly decreased sperm velocity (1 mg ml^‐1 HA), total motility (only with 1.5% lecithin), viability (1 mg ml^‐1 HA for 1% lecithin; both concentrations for 1.5% lecithin) and membrane integrity. In conclusion, adding HA to the freezing extender supplemented with soybean lecithin failed to improve quality‐related variables in ram semen. Increasing the lecithin content could have a positive effect, but further studies are needed.  相似文献   

Determination of Feeder Cell‐Based Cellular Niches Supporting the Colonization and Maintenance of Spermatogonial Stem Cells from Prepubertal Domestic Cat Testes     

JI Yun  HJ Park  MH Park  MS Kim  JH Choi  E Lee  SP Gong  JM Lim  ST Lee 《Reproduction in domestic animals》2014,49(5):705-710

Recently, isolation and in vitro culture of putative spermatogonial stem cells (SSCs) in the domestic cat have been conducted. However, the cellular niche conditions that facilitate the establishment and long‐term maintenance of feline SSCs (FSSCs) have not been described. Therefore, we investigated the type of feeder cells used to stimulate colony formation and growth of FSSCs among the various factors in the FSSC niche. Spermatogonial stem cells isolated from feline testes were cultured on mitotically inactivated testicular stromal cells (TSCs) derived from cats, dogs and mice, and mouse embryonic fibroblasts (MEFs). The formation and growth of colonies derived from SSCs cultured on each type of feeder cell were identified at passage 0, and the morphology, alkaline phosphatase (AP) activity and expression of SSC‐specific genes in surviving colonies were investigated at passage 4. Among these diverse feeder cells, TSCs from cat showed the greatest colony formation, growth and maintenance of FSSCs, and SSC colonies cultured by passage 4 showed a typical dome‐shaped morphology, AP activity and expression of SSC‐specific genes (NANOG, OCT4, SOX2 and CD9). Accordingly, these results demonstrate that feline TSCs could be used as feeder cells to support the establishment and maintenance of SSCs from domestic cats.  相似文献   

Comparative mapping and discovery of segregation distortion and linkage disequilibrium across the known fragrance chromosomal regions in a rice F2 population     

Farahnaz Sadat Golestan Hashemi  Mohd Y. Rafii  Mohd Razi Ismail  Mahmud Tengku Muda Mohamed  Harun A. Rahim  Mohamad Abd Latif  Farzad Aslani 《Euphytica》2015,204(3):557-569

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Superradiance in a torus magnetosphere around a black hole     

van Putten MH 《Science (New York, N.Y.)》1999,284(5411):115-118

The coalescence of a neutron star and a black hole in a binary system is believed to form a torus around a Kerr black hole. A similarly shaped magnetosphere then results from the remnant magnetic field of the neutron star. In the strong-field case, it contains a cavity for plasma waves located between the barrier of the gravitational potential and the surrounding torus. This cavity may be unstable to superradiance of electromagnetic waves. Superradiant amplification of such waves, initially excited by turbulence in the torus, should inflate into a bubble in a time as short as approximately 0.75 (1 percent/&cjs3539;epsilon&cjs3539;2)(M/7M middle dot in circle) seconds approximately 0.15 to 1.5 seconds, assuming an efficiency &cjs3539;epsilon&cjs3539;2 = 0.5 to 5 percent and a mass M = 7M middle dot in circle. These bubbles may burst and repeat, of possible relevance to intermittency in cosmological gamma-ray bursts. The model predicts gamma-ray bursts to be anticorrelated with their gravitational wave emissions.  相似文献   

Human chromosome 7: DNA sequence and biology     

Scherer SW  Cheung J  MacDonald JR  Osborne LR  Nakabayashi K  Herbrick JA  Carson AR  Parker-Katiraee L  Skaug J  Khaja R  Zhang J  Hudek AK  Li M  Haddad M  Duggan GE  Fernandez BA  Kanematsu E  Gentles S  Christopoulos CC  Choufani S  Kwasnicka D  Zheng XH  Lai Z  Nusskern D  Zhang Q  Gu Z  Lu F  Zeesman S  Nowaczyk MJ  Teshima I  Chitayat D  Shuman C  Weksberg R  Zackai EH  Grebe TA  Cox SR  Kirkpatrick SJ  Rahman N  Friedman JM  Heng HH  Pelicci PG  Lo-Coco F  Belloni E  Shaffer LG  Pober B  Morton CC  Gusella JF  Bruns GA  Korf BR 《Science (New York, N.Y.)》2003,300(5620):767-772

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Serum Profiles of Luteinizing Hormone,Oestradiol and Cholesterol and Ovarian Functions in Layer Poultry Birds (Gallus domesticus) Fed Diets Containing Furazolidone     

Khan LA  Jalali S  Andrabi SM  Mirza MA 《Veterinary research communications》2004,28(3):247-259

This study was carried out to assess the serum profiles of luteinizing hormone (LH), oestradiol, cholesterol and ovarian functions in layer poultry birds (Rhode Island Red: Gallus domesticus) fed a diet containing various concentrations of furazolidone (FZ). A total of 40 birds were randomly assigned to receive FZ 0, 200, 400 or 800 mg/kg feed (ppm) daily during the pre-laying age, i.e. 13-18 weeks (for 5 weeks). Blood samples were collected at weekly intervals. Concentrations of LH and oestradiol in serum were estimated at alternate weeks using radioimmunoassays. Serum cholesterol levels were analysed by an enzymatic calorimetric method. Furazolidone administration was terminated at the 18th week of age. The birds were sacrificed at 22nd week of age and ovarian tissues were processed for morphometric studies. Serum LH, oestradiol and cholesterol levels were affected by age (p < 0.001) and FZ dose (p < 0.001). Serum LH and oestradiol levels were lower (p < 0.05) in birds receiving FZ 800 mg/kg feed daily compared with the controls, whereas serum cholesterol profiles were lower (p < 0.05) in all FZ-administered groups than in the control group. The mean weight of ovaries having no yolky follicles observed in the group receiving FZ 400 or 800 mg/kg feed per day was reduced (p < 0.05) compared with the control group. Dosing FZ at 800 mg/kg feed per day reduced (p < 0.05) the mean volume of ovaries having no yolky follicles compared with the control group. In birds receiving FZ 800 mg/kg feed per day, the mean length of the oviduct was reduced (p < 0.05) as compared with the control group. Morphometric studies revealed that the mean number of oocytes with diameter in the range 401-800 microm decreased (p < 0.05) in birds fed FZ 400 or 800 mg/kg feed per day. Initial egg production was affected by age (p < 0.001) and dose (p < 0.001) of FZ. The mean number of eggs laid by different groups revealed that egg production was reduced (p < 0.05) in birds receiving FZ 800 mg/kg feed per day as compared with the controls. The present data suggest that FZ causes suppression in serum profiles of LH, oestradiol, cholesterol and ovarian functions in Rhode Island Red layer poultry birds. Therefore, great care must be taken with use of FZ in layer poultry birds (Gallius domesticus) with regard to dosage and duration of administration.  相似文献   

Detection of specific hydatid antigens and antibodies in serum and urine of experimentally infected sheep     

Ghorbanpoor M  Razi Jalali MH  Hoghooghi Rad N  Nabavi L  Esmail Zadeh S  Rafiei A  Haji Hajikolaei MR 《Veterinary parasitology》2006,142(1-2):91-94

Immunodiagnostic confirmation of cystic human hydatidosis is frequently required before surgical intervention or of chemotherapy. However, it remains inadequate to detect specific antibodies or antigens in some confirmed cases of echinococcosis. This study was carried out to investigate the accuracy of three different immunodiagnostic tests for detection of specific circulating antigens or antibodies in the serum and urine of 13 experimentally infected sheep. For this purpose, Echinococcus granulosus were collected from small intestine of experimentally infected dogs, and 2000 taenid eggs were orally administered to each of the 13 sheep. There were six other sheep, which were kept as the control group. Biweekly serum and urine samples were collected from all the sheep for 4 months after infection. The sera were subjected to indirect hemagglutination test and the concentrated urine samples were subjected to coagglutination and counter immunoelectrophoresis tests. The results revealed that the sensitivity of these tests in detecting the hydatid antigens in the urine or antihydatid antibodies in the serum of the infected sheep reached their maximum in 12th and 13th week after infection; then it decreased in the following weeks. Examination of the non-infected sheep samples throughout the experiment showed that the aforesaid findings were specific only to the infected sheep. It seems that the appearance of specific hydatid antigen in urine and its antibodies in the serum were simultaneous. Although these tests are highly specific, false negative outcomes were encountered in their detection of cystic echinococcosis. In general, it seems rational to establish some series of diagnostic procedures in order to reveal antibodies and antigen of metacestode in serum and urine of the patients.  相似文献   

Ability of sorption–desorption experiments to predict potassium leaching from calcareous soils     

Mohsen Jalali  Zahra Kolahchi 《植物养料与土壤学杂志》2008,171(5):785-794

When potassium (K⁺) fertilizers are applied to the soil, K⁺ is subject to displacement through the soil profile. Leaching can play an important role in agricultural K⁺ losses that can decrease groundwater quality. To avoid overfertilization, estimation of K⁺ leaching from soil is important. The ability of the soils to retain K⁺ against leaching varies according to the adsorption coefficient of the soils. The aim of this study was to relate the K⁺ leaching from a wide range of calcareous soils to the values obtained from a sorption–desorption experiment. The soil columns were leached with 10 mM CaCl₂ solution and the leachate was analyzed for K⁺. The breakthrough curves for K⁺ were different, and the amounts of K⁺ leached varied considerably between different soils. In these calcareous soils where crops are irrigated with water containing significant concentrations of Ca²⁺ and other cations, large amounts of K⁺ will be leached. Cumulative K⁺ leached after five pore volumes leaching with 10 mM CaCl₂ was significantly (r = 0.776, p < 0.01) related to the equilibrium K⁺ concentration. The results of this study enabled us in many cases to estimate the K⁺ leaching from soil without conducting column experiments, minimizing the laborotary work.  相似文献