Genetic tracking of the brown bear in northern Pakistan and implications for conservation     

Eva Bellemain  Muhammad Ali Nawaz  Alice Valentini  Jon E. Swenson  Pierre Taberlet 《Biological conservation》2007,134(4):537-547

Asian bears face major threats due to the impact of human activities as well as a critical lack of knowledge about their status, distribution and needs for survival. Once abundant in northern Pakistan, the Himalayan brown bear (Ursus arctos isabellinus) has been exterminated in most of its former distribution range. It presently occurs sparsely, in small populations, the Deosai National Park supporting the largest isolate. This decline might imply a reduction in genetic diversity, compromising the survival of the population. Using a combination of fecal DNA analysis and field data, our study aimed at assessing the size and genetic status of the Deosai population and give guidelines for its conservation and management. Using fecal genetic analysis, we estimated the population to be 40-50 bears, which compares well with the field census of 38 bears. The northern Pakistani brown bear population may have undergone an approximate 200-300-fold decrease during the last thousand years, probably due to glaciations and the influence of growing human population. However, in spite of the presence of a bottleneck genetic signature, the Deosai population has a moderate level of genetic diversity and is not at immediate risk of inbreeding depression. Gene flow might exist with adjacent populations. We recommend careful monitoring of this population in the future both with field observations and genetic analyses, including sampling of adjacent populations to assess incoming gene flow. The connectivity with adjacent populations in Pakistan and India will be of prime importance for the long-term survival of Deosai bears.  相似文献   

10％乙霉威·腐霉利微粉剂在设施黄瓜上的沉积分布及残留消解动态     

谢学文  揣红运  李磊  柴阿丽  石延霞  李宝聚 《农药学学报》2020,22(2):378-387

为探究10%乙霉威·腐霉利微粉剂(有效成分质量分数:5%乙霉威,5%腐霉利)在设施黄瓜上施用后的沉积分布特性及残留消解动态,采用PC-3A(S)型激光粉尘仪及粉尘取样片,分别研究了不同设施类型、不同温湿度及不同施药角度下,10%乙霉威·腐霉利微粉剂在设施黄瓜上的沉积分布情况;并于2017年和2018年,分别在北京市进行了该药剂在设施黄瓜叶片和果实中的残留及消解动态试验。结果表明:不同设施类型、不同温度条件下,10%乙霉威·腐霉利微粉剂的沉积分布特性无明显差异,且其有效成分分解率不受温度影响;不同湿度条件下,该微粉剂在黄瓜叶片上的沉积量不同,湿度越大沉积量越多。乙霉威和腐霉利在黄瓜叶片和果实中的消解动态均符合准一级动力学或一级动力学方程,2种药剂在叶片中的半衰期分别为3.2 d和3.0~3.2 d,在果实中的半衰期分别为4.0~4.3 d和3.1~3.8 d。采用10%乙霉威·腐霉利微粉剂,分别按100 g/hm2和150 g/hm2(1.5倍)剂量于黄瓜幼果期施药,最多施药3次,施药间隔期为7 d,距最后一次施药间隔7、10和14 d分别采样,乙霉威在黄瓜果实中的最大残留量为0.88 mg/kg,低于中国国家标准规定的其最大残留限量(MRL)值(5 mg/kg),腐霉利在黄瓜果实中的最大残留量为0.49 mg/kg,也低于其MRL值(2 mg/kg)。该研究结果可为10%乙霉威·腐霉利微粉剂在设施黄瓜上的安全使用提供数据支持。  相似文献   

Effect of transferring lignocellulose-degrading bacteria from termite to rumen fluid of sheep on in vitro gas production,fermentation parameters,microbial populations and enzyme activity          下载免费PDF全文

Ayoub AZIZI  Afrooz SHARIFI  Hasan FAZAELI  Arash AZARFAR  Arjan JONKER  Ali KIANI 《农业科学学报》2020,19(5):1323-1331

The digestive tract of termite(Microcerotermes diversus) contains a variety of lignocellulose-degrading bacteria with exocellulases enzyme activity, not found in the rumen, which could potentially improve fiber degradation in the rumen. The objectives of the current study were to determine the effect of inoculation of rumen fluid(RF) with three species of bacteria isolated from termite digestive tract, Bacillus licheniformis, Ochrobactrum intermedium, and Microbacterium paludicola, on in vitro gas production(IVGP), fermentation parameters, nutrient disappearance, microbial populations, and hydrolytic enzyme activities with fibrous wheat straw(WS) and date leaf(DL) as incubation substrate. Inoculation of RF with either of three termite bacteria increased(P0.05) ammonia-N concentration compared with the control group(free of termite gut bacteria). Termite bacteria inoculation had no effect(P0.05) on gas production characteristics, dry matter, organic matter and neutral detergent fiber disappearance, pH, and concentration and composition of volatile fatty acids. Population of proteolytic bacteria and protozoa, but not cellulolytic bacteria, were increased(P0.05) when RF was inoculated with termite bacteria with both WS and DL substrates. Inoculation of RF with termite bacteria increased protease activity, while activities of carboxymethyl-cellulase, microcrystalline-cellulase, α-amylase and filter paper degrading activity remained unchanged(P0.05). Overall, the results of this study indicated that transferring lignocellulose-degrading bacteria, isolated from digestive tract of termite, to rumen liquid increased protozoa and proteolytic bacteria population and consequently increased protease activity and ammonia-N concentration in vitro, however, no effect on fermentation and fiber degradation parameters were detected. These results suggest that the termite bacteria might be rapidly lysed by the rumen microbes before beneficial effects on the rumen fermentation process could occur.  相似文献   

Marine-Derived Chitosan Nanoparticles Improved the Intestinal Histo-Morphometrical Features in Association with the Health and Immune Response of Grey Mullet (Liza ramada)     

Mahmoud A.O. Dawood  Mahmoud S. Gewaily  Ali A. Soliman  Mustafa Shukry  Asem A. Amer  Elsayed M. Younis  Abdel-Wahab A. Abdel-Warith  Hien Van Doan  Adel H. Saad  Mohamed Aboubakr  Hany M.R. Abdel-Latif  Sabreen E. Fadl 《Marine drugs》2020,18(12)

Marine-derived substances are known for their beneficial influences on aquatic animals’ performances and are recommended to improve intestinal health, immunity, and anti-oxidative status. The present study investigates the role of chitosan nanoparticles on the intestinal histo-morphometrical features in association with the health and immune response of Grey Mullet (Liza ramada). Chitosan nanoparticles are included in the diets at 0, 0.5, 1, and 2 g/kg and introduced to fish in a successive feeding trial for eight weeks. The final body weight (FBW), weight gain (WG), and specific growth rate (SGR) parameters are significantly increased while feed conversion ratio (FCR) decreases by chitosan nanoparticles compared to the control (p < 0.05). The morphometric analysis of the intestines reveals a significant improvement in villus height, villus width, and the number of goblet cells in chitosan-treated groups in a dose-dependent manner. Additionally, there is a positive correlation between the thickness of the enterocyte brush border and the chitosan dose, referring to an increasing absorptive activity. Histologically, the intestinal wall of Grey Mullet consists of four layers; mucosa, sub-mucosa, tunica muscularis (muscular layers), and serosa. The histological examination of the L. ramada intestine shows a normal histo-morphology. The epithelial layer of intestinal mucosa is thrown into elongated finger-like projections, the intestinal villi. The values of hemoglobin, hematocrit, red blood cells (RBCs), total protein (TP), albumin, and globulin are significantly increased in fish fed 1, and 2 g/kg of chitosan nanoparticles compared to fish fed 0 and 0.5 g/kg (p < 0.05). The highest levels of TP and albumin are observed in fish fed 1 g/kg diet (p < 0.05). The lysozyme activity and phagocytic index are significantly enhanced by feeding chitosan nanoparticles at 0.5, 1, and 2 g/kg, whereas the phagocytic activity is improved in fish fed 1 and 2 g/kg (p < 0.05). The highest lysozyme activity and phagocytic index are observed in fish fed 1 g/kg. SOD is significantly activated by feeding chitosan nanoparticles at 1 g/kg. Simultaneously, glutathione peroxidase (GPx) and catalase (CAT) activities also are enhanced by feeding chitosan at 1 and 2 g/kg, compared to fish fed 0 and 0.5 g/kg (p < 0.05). The highest GPx and CAT activities are observed in fish fed 1 g/kg (p < 0.05). Conversely, the malondialdehyde (MDA) levels are decreased by feeding chitosan at 1 and 2 g/kg, with the lowest being in fish fed 1 g/kg (p < 0.05). To summarize, the results elucidate that L. ramada fed dietary chitosan nanoparticles have a marked growth rate, immune response, and anti-oxidative response. These improvements are attributed to the potential role of chitosan nanoparticles in enhancing intestinal histo-morphometry and intestinal health. These results soundly support the possibility of using chitosan nanoparticles at 1–2 g/kg as a feasible functional supplement for aquatic animals.  相似文献   

Ecological and Industrial Implications of Dynamic Seaweed-Associated Microbiota Interactions     

Farid Menaa  P. A. U. I. Wijesinghe  Gobika Thiripuranathar  Bushra Uzair  Haroon Iqbal  Barkat Ali Khan  Bouzid Menaa 《Marine drugs》2020,18(12)

Seaweeds are broadly distributed and represent an important source of secondary metabolites (e.g., halogenated compounds, polyphenols) eliciting various pharmacological activities and playing a relevant ecological role in the anti-epibiosis. Importantly, host (as known as basibiont such as algae)–microbe (as known as epibiont such as bacteria) interaction (as known as halobiont) is a driving force for coevolution in the marine environment. Nevertheless, halobionts may be fundamental (harmless) or detrimental (harmful) to the functioning of the host. In addition to biotic factors, abiotic factors (e.g., pH, salinity, temperature, nutrients) regulate halobionts. Spatiotemporal and functional exploration of such dynamic interactions appear crucial. Indeed, environmental stress in a constantly changing ocean may disturb complex mutualistic relations, through mechanisms involving host chemical defense strategies (e.g., secretion of secondary metabolites and antifouling chemicals by quorum sensing). It is worth mentioning that many of bioactive compounds, such as terpenoids, previously attributed to macroalgae are in fact produced or metabolized by their associated microorganisms (e.g., bacteria, fungi, viruses, parasites). Eventually, recent metagenomics analyses suggest that microbes may have acquired seaweed associated genes because of increased seaweed in diets. This article retrospectively reviews pertinent studies on the spatiotemporal and functional seaweed-associated microbiota interactions which can lead to the production of bioactive compounds with high antifouling, theranostic, and biotechnological potential.  相似文献   

盐胁迫对扁桃砧木营养器官离子吸收的影响     

克热木·伊力  买合木提·卡热  侯江涛 《新疆农业大学学报》2007,30(4):46-51

温室条件下,用NaCl和Na2SO4处理石头扁桃、桃扁桃和毛桃,处理浓度为0,75,150,300和350 mmol/L,处理10,20 d分别取叶、根和茎,测定各器官中离子吸收与分布变化规律。研究结果表明,盐胁迫下,3种砧木根、茎、叶中Na ,Cl-,SO42-含量及Na /K 比均随盐浓度的增加和处理时间的延长而增加,K 含量变化规律不稳定,但桃扁桃根、茎和叶片中K 略高于其他两个品种;石头扁桃根、茎、叶片中Na /K 比值高于其它两个品种,桃扁桃中Na /K 比值最低。桃扁桃根部Na ,Cl-和SO42-含量高于石头扁桃和毛桃,而叶片和茎中Na ,Cl-和SO42-含量却低于石头扁桃和毛桃。桃扁桃根部能够积累较多的Na ,阻止和减少了Na 向地上部的运输,从而减轻了Na2SO4对它的伤害,进而表明了桃扁桃耐盐能力较强。  相似文献   

Influence of NaCl salinity on some physiological aspect of strawberry cv. Camarosa     

Asghar Rahimi  Ali Biglarifard  Majid Firozabadi 《Russian Agricultural Sciences》2011,37(5):378-384

One of the most important elements affecting the growth and development of a plant is salinity. Therefore, to evaluate the effect of salinity on some physiological aspect of Strawberry (Fragaria x ananassa Duch.) plants cv. Camarosa, a greenhouse experiment was conducted at Vali-e-Asr University of Rafsanjan in 2009. This study was carried out as Factorial experiment based on RCD design with 4 replications to determine the influence of salinities (0, 30, 60 and 9 mMol.L-1) on proline, soluble sugars content, chlorophyll a (CHLa), chlorophyll b (CHLb), total chlorophyll (TC), Spad and chlorophyll florescence. Results indicated that fresh leaves tissue were used to measure proline, soluble protein and soluble sugars content, CHLa, CHLb, TC. Salinity treatment significantly increased proline content, soluble sugars while chlorophyll a (CHLa), chlorophyll b (CHLb), Spad and chlorophyll florescence significantly decreased. Nine day after NaCl exposure, Fv/Fm and Spad in 60 and 90 mM NaCl were significantly lower than control. It was concluded that this cultivar of strawberry may uses osmoregulation by increasing proline and soluble sugars level in order to tolerate salinity conditions.  相似文献   

The effects of fascioliasis on the activities of some drug-metabolizing enzymes in desert sheep liver.   总被引：1，自引：0，他引：1  

H A Elsheikh  B H Ali  A M Homeida  A A Lutfi  H J Hapke 《The British veterinary journal》1992,148(3):249-257

Desert sheep experimentally or naturally infected with Fasciola gigantica were used to study the influence of infection on the activities of some drug-metabolizing enzymes found in the liver. The enzymes investigated were aminopyrine N-demethylase, aniline 4-hydroxylase and UDP-glucuronyltransferase. The experimental infection was confirmed histologically by detection of Fasciola eggs in faeces and by measuring the activities of sorbitol dehydrogenase (SD), glutamate dehydrogenase (GD) and aspartate aminotransferase (AST) in plasma during the course of the disease. Liver specimens from naturally infected sheep were obtained from the slaughter house. The activities of aminopyrine N-demethylase and aniline 4-hydroxylase were significantly decreased in sheep either naturally infected or during the acute stage of experimental fascioliasis (killed 5 weeks post-infection). The activity of UDP-glucuronyltransferase was decreased in naturally infected sheep and those killed 9 or 13 weeks post-experimental infection.  相似文献   

Protective Effects of Interleukin-4 on Tissue Destruction and Morphological Changes of Bovine Nasal Chondrocytes in vitro     

Maryam Yadegari  Mahmoud Orazizadeh  Mahmoud Hashemitabar  Ali Khodadadi 《Iranian Biomedical Journal》2013,17(4):187-193

Background: Previous studies have shown that some cytokines have protective effects on cartilage in joint diseases. In the current study, effects of IL-4 against morphological changes and tissue degradation induced by IL-1α on bovine nasal cartilage (BNC) explants were investigated. Methods: Fresh BNC samples were prepared from a slaughterhouse under sterile conditions. BNC explants culture was treated with both IL-lα (10 ng/ml) and IL-4 (50 ng/ml) at the same time for 28 days. The morphological characteristics of explants were assessed by using histology techniques and invert microscopy. Matrix metalloproteinase-1 (MMP-1) production was assessed within different days by using Western blotting. Results: IL-lα induced prominent cartilage morphology degradation. The pro and active form of MMP-1 band substantially increased at day 21 of culture. In the presence of both IL-lα and IL-4, chondrocytes preserved their ordinary normal phenotype with intact extracellular matrix. In addition, a significant reduction in pro-MMP-1and inhibition of active MMP-1 was seen. Conclusion: In conclusion, IL-4 could be regarded as a potential candidate in cartilage protecting against the degradation changes of IL-lα. It seems that the preservation effect of IL-4 is associated with significant reduction of MMP-1. Key Words: Chondrocyte, Interleukin-1α, Interleukin-4, Matrix metalloproteinase-1, Bovine nasal cartilage  相似文献   

Cryopreservation of Persian sturgeon (Acipenser persicus) sperm: effects of cryoprotectants,antioxidant, membrane stabilizer,equilibration time and dilution ratio on sperm motility and fertility          下载免费PDF全文

Fardin Shaluei  Ali Sadeghi  Vahid Zadmajid 《Aquaculture Research》2017,48(3):1031-1040

Three experiments were performed to develop protocols for cryopreservation of Persian sturgeon Acipenser persicus, sperm. In the first experiment, sperm from six males was individually split in three subsamples and cryopreserved using Modified Tsvetkova's extender (mT) supplemented with dimethyl sulfoxide (DMSO), methanol (MeOH), glycerol (Gly) and ethylene glycol (EG) at concentration of 5%, 10%, 15% and 20%. In the second set of experiments, the effects of six equilibration times (0, 5, 10, 20, 40 and 60 min) and dilution ratios (volume sperm: volume extender 1:0.5, 1:1, 1:2, 1:3, 1:5 and 1:10) and the additive advantage of bovine serum albumin (BSA; 0, 2.5, 5 and 10 mg mL^?1) and ascorbic acid (0, 2.5, 5 and 10 U mL^?1), on the post‐thaw survival of sperm (triplicate set of six fish) were evaluated. Then, sperm was diluted in 1:1 mT extender with 10 mg mL^?1 BSA with selected cryoprotectants (15% MeOH and 10% DMSO) for 5 min. After a month of storage in liquid nitrogen, post‐thawed sperm motility; fertilization and hatching rate and viability of derived larvae were measured (Exp.3). Evaluation of cryoprotectants efficiency showed that MeOH 15% and DMSO 10% were suitable for cryopreservation of Persian sturgeon sperm. Gly and EG resulted in very low post‐thaw motility rates even at lowest concentration. No significant difference was observed among the four different equilibration times (0, 5, 10, 20 min) (P > 0.05) although higher equilibration times than 20 min resulted low post‐thaw motility (P < 0.05). The motility of frozen–thawed sperm did not significantly change when dilution ratio was increased from 1:0.5 to 1:3 (P > 0.05). However, higher dilution ratios (1:5 and 1:10) reduced the percentage of motile sperm. Supplementation of the cryoprotectant solution with 10 mg mL^?1 BSA significantly improved post‐thaw motility (P < 0.05), but ascorbic acid did not improve post‐thaw motility (P > 0.05). The results of experiment 3 showed that the highest fertilization (30.2 ± 5.75) and hatching rates (28.2 ± 5.25) were observed when samples were frozen with 15% MeOH (P > 0.05). Our study indicates that the use of mT extender consisting of 10 mg mL^?1 BSA in 15% MeOH diluted with sperm at 1:1 ratio for 5 min can be recommended cryopreservation method for Persian sturgeon sperm.  相似文献