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1.
The number of animals required to represent the collective characteristics of a group remains a concern in animal movement monitoring with GPS. Monitoring a subset of animals from a group instead of all animals can reduce costs and labor; however, incomplete data may cause information losses and inaccuracy in subsequent data analyses. In cattle studies, little work has been conducted to determine the number of cattle within a group needed to be instrumented considering subsequent analyses. Two different groups of cattle (a mixed group of 24 beef cows and heifers, and another group of 8 beef cows) were monitored with GPS collars at 4 min intervals on intensively managed pastures and corn residue fields in 2011. The effects of subset group size on cattle movement characterization and spatial occupancy analysis were evaluated by comparing the results between subset groups and the entire group for a variety of summarization parameters. As expected, more animals yield better results for all parameters. Results show the average group travel speed and daily travel distances are overestimated as subset group size decreases, while the average group radius is underestimated. Accuracy of group centroid locations and group radii are improved linearly as subset group size increases. A kernel density estimation was performed to quantify the spatial occupancy by cattle via GPS location data. Results show animals among the group had high similarity of spatial occupancy. Decisions regarding choosing an appropriate subset group size for monitoring depend on the specific use of data for subsequent analysis: a small subset group may be adequate for identifying areas visited by cattle; larger subset group size (e.g. subset group containing more than 75% of animals) is recommended to achieve better accuracy of group movement characteristics and spatial occupancy for the use of correlating cattle locations with other environmental factors.  相似文献   

2.
摘要 目的:通过动物实验,具体探讨微小RNA(miR-10a)通过含F-框WD重复域蛋白7(FBXW7)-E盒锌指结合蛋白2(ZEB2)轴调控非小细胞肺癌的肿瘤化疗耐药作用。方法:非小细胞肺癌模型小鼠(n=42)随机平分为三组-模型组、miR-10a组与环磷酰胺组,模型组给予生理盐水0.2 mL腹腔注射,环磷酰胺组给予环磷酰胺20 mg/kg腹腔注射,miR-10a组给hsa-miR-10a mimics 15 mg/kg 联合环磷酰胺20 mg/kg腹腔注射,1次/d,持续给药14 d。结果:miR-10a组与环磷酰胺组治疗第7 d与第14 d的肿瘤体积低于模型组,miR-10a组低于环磷酰胺组(P<0.05)。miR-10a组与环磷酰胺组治疗第14 d与第28 d的瘤体质量低于模型组,抑瘤率高于模型组,miR-10a组与环磷酰胺组对比差异也有统计学意义(P<0.05)。miR-10a组与环磷酰胺组治疗第14 d与第28 d的肿瘤细胞凋亡指数高于模型组,miR-10a组高于环磷酰胺组(P<0.05)。miR-10a组与环磷酰胺组治疗第14 d与第28 d的血清FBXW7、ZEB2含量低于模型组,miR-10a组低于环磷酰胺组(P<0.05)。miR-10a组与环磷酰胺组治疗第14 d与第28 d的FBXW7、ZEB2 mRNA与蛋白相对表达水平低于模型组,miR-10a组低于环磷酰胺组(P<0.05)。结论:过表达miR-10a能抑制非小细胞肺癌小鼠的FBXW7-ZEB2轴的激活,抑制血清FBXW7、ZEB2的表达,从而促进肿瘤细胞凋亡,改善肿瘤化疗耐药性,促进缩小肿瘤体积。  相似文献   

3.
I apply skew theory to the division of resources within multimember social foraging and antipredator groups. Resource division is modeled as a game between an individual controlling resources (recruiter) and a potential joiner to the group. If a recruiter benefits from the presence of a joiner, it will allocate sufficient resources to the joiner so that the joiner gains as much from group foraging as it would from foraging alone. Joiners should receive a greater proportion of resources controlled by the recruiter when benefits to grouping are low. If group success is a concave-down function of group size, this framework can be used to predict the stable group size. The stable group size is larger than the optimal group size, given equal division of resources, and smaller than the stable group size, given equal division of resources. Furthermore, both current group members and potential joiners agree on the stable group size, so long as the recruiter is able to control resource division. If the recruiter cannot control resource division, there may be conflict over group size and the opportunity for group members to contribute less to group success than they are able.  相似文献   

4.
The social unit of chimpanzees   总被引:2,自引:0,他引:2  
It has been said that there is no stable and permanent social unit in a society of chimpanzees. From observations at Filabanga in Western Tanzania and some other observed cases, we concluded that a large-sized group consisting of 30–50 animals is a social unit common to chimpanzees, and pointed out that chimpanzees freely repeat grouping and dispersion within a large-sized group, and such changeability in grouping is the most characteristic nature of chimpanzee society. The size, composition, and various other characteristics of the large-sized group are discussed and compared with the group of Japanese monkey and gorilla. A large-sized group of chimpanzees is not a group basically consisting of a one-male group like a group of gorilla, but usually contains more than five adult males and more than ten adult females as its members, and when they gather to form a larger group, young adult males rarely join it. In a largesized group there is no stable social unit lower than the group itself. It may be considered that two or three large-sized groups concentrate in an area and form a community, but this problem and inter-large-sized group relations are important subjects to be solved in the future. We related these various characteristics of the social organization of chimpanzees to the developed behavior displayed by the chimpanzees, especially those living in the savanna woodland, and discussed one important stage in the evolution of society in non-human primates.The investigation has been supported by the Scientific Research Fund of the Ministry of Education since 1961.  相似文献   

5.
目的:研究应用缺氧对体外培养的大鼠神经干细胞增殖的影响。方法:将细胞分为4小时缺氧组、12小时缺氧组、促红细胞生成素(EPO)中和抗体组、IgG组以及对照组.测定大鼠神经干细胞经缺氧培养后的各组细胞克隆形成率以及EPO的表达变化。结果:单细胞培养条件下,与对照组相比,4小时缺氧组和IgG组克隆形成率明显增高;中和抗体组无明显变化;12小时组克隆形成率降低。但无统计学意义。缺氧4小时后,EPO蛋白在预处理后即刻出现表迭,4h达高峰,8h仍有部分表达。结论:短时间缺氧可以促进神经干细胞增殖.长时间缺氧则作用相反。缺氧对NSCs增殖作用的影响可能是由EPO介导产生。  相似文献   

6.
A series of nine synthetic polyaromatic compounds were synthesized by polymerization of aromatic ring monomers with formaldehyde, which yield substantially ordered backbones with different functional anionic groups (hydroxyl and carboxyl) on the phenol ring. These compounds were tested for their heparin-mimicking activity: (1) inhibition of heparanase activity; (2) inhibition of SMC proliferation; and (3) release of bFGF from the ECM. We demonstrate that compounds that have two hydroxyl groups para and ortho to the carboxylic group and a carboxylic group at a distance of two carbons from the phenol ring inhibit heparanase activity and SMC proliferation, as well as induced an almost complete release of bFGF from ECM. Addition of a methyl group next to the carboxylic group led to a preferential inhibition of heparanase activity. Similar results were obtained with a compound that contains one hydroxyl group para to the carboxylic group and an ether group near the carboxylic group on the phenol ring. Preferential inhibition of SMC proliferation was best achieved when the position of the hydroxyl group is para and ortho to the carboxylic group and the carboxylic group is at a distance of one carbon from the phenol ring. On the other hand, for maximal release of bFGF from ECM, the position of the carboxylic group should be three carbons away from the phenol ring. These new heparin-mimicking compounds may have a potential use in inhibition of tumor metastasis, arteriosclerosis, and inflammation.  相似文献   

7.
Hung MC  Swallow WH 《Biometrics》2000,56(1):204-212
In group testing, the test unit consists of a group of individuals. If the group test is positive, then one or more individuals in the group are assumed to be positive. A group observation in binomial group testing can be, say, the test result (positive or negative) for a pool of blood samples that come from several different individuals. It has been shown that, when the proportion (p) of infected individuals is low, group testing is often preferable to individual testing for identifying infected individuals and for estimating proportions of those infected. We extend the potential applications of group testing to hypothesis-testing problems wherein one wants to test for a relationship between p and a classification or quantitative covariable. Asymptotic relative efficiencies (AREs) of tests based on group testing versus the usual individual testing are obtained. The Pitman ARE strongly favors group testing in many cases. Small-sample results from simulation studies are given and are consistent with the large-sample (asymptotic) findings. We illustrate the potential advantages of group testing in hypothesis testing using HIV-1 seroprevalence data.  相似文献   

8.
Crayfish glutamic acid decarboxylase (GAD) is inhibited by some aliphatic carboxylic acid analogs of glutamate and gamma-amino-n-butyric acid (GABA). Variations in the length of the carbon skeleton, substitution of a keto for a methylene group, replacement of the carboxyl group or attachment of a bulky basic moiety to the amino terminus of GABA all lead to a drastic reduction in its inhibitory activity. Substitution of a methyl group for the amino group of GABA is a permissible alteration which does not reduce the inhibitory potency. Some structural analogs of glutamate are inhibitory also, particularly if they possess a comparable carbon skeleton and a keto group in the alpha position or a sulfhydryl group. Most of the sulfhydryl analogs are significantly more potent as inhibitors than the corresponding compounds in which the SH group is replaced by an H atom.  相似文献   

9.
A population of siamang in lowland dipterocarp forest at Kuala Lompat, Pahang, Malaysia, was studied discontinuously between April 1969 and November 1971. Between March and May 1970 a sub-adult male in the main study group became increasingly peripheral. The frequency of aggressive interactions with the adult male increased, and the sub-adult played a greater part in group calling sessions. These changes coincided with the onset of sexual activity between the adult pair. By October 1970 the sub-adult male had left the group, established a territory in an adjacent vacant area of forest, and been joined by a young adult female. A second, older female joined the new group in April 1971, left it again in July, and returned in September. Social relations within the new group were unstable, and its activities were less coordinated than that of the old group. It is suggested that the intolerance of the adult male during a period of reproductive activity, together with the maturation of the sub-adult, were the crucial factors in the latter leaving the group, and that the sub-adult's increased participation in group calling played a part in attracting females.  相似文献   

10.
We monitored one group of muriquis, or woolly spider monkeys (Brachyteles arachnoides), over a 9-year period at Fazenda Montes Claros, Minas Gerais, Brazil. The group grew from 22 to 42 individuals due to the births of 21 surviving infants. Eight immigrations involving immature females were offset by emigrations and disappearances. The home range of the group expanded as the group size increased. The group traveled as a cohesive unit during the first 6 years of the study, but recently it has begun to show greater tendencies to fission temporarily into smaller subgroups. Six adult males from the other muriqui group at this site have simultaneously increased their associations with the main study group. These observations indicate that the group is in a state of transition which may lead, ultimately, either to its division into two smaller units or to a more fluid social structure.  相似文献   

11.
The interaction of blood group reactive substances in saliva with bacteria was investigated by testing saliva from persons with different blood groups in a bacterial aggregation assay with Streptococcus rattus HG 59, originally S. rattus BHT. For blood group A, saliva from 10 persons out of 11 aggregated S. rattus and for blood group O, saliva from 10 persons out of 16 aggregated S. rattus. For blood group B, saliva from 6 persons out of 8 aggregated S. rattus weakly and the average aggregation activity of blood group B was much lower than for blood group A or O. In addition, saliva from 3 non-secretors did not aggregate S. rattus. The role of blood group antigens in bacterial aggregation was confirmed by inhibition studies with blood group specific sugars and various other sugars. GalNAc, specific for blood group A, inhibited bacterial aggregation by saliva whereas D-galactose, specific for blood group B, and D-fucose, specific for blood group O, did not. In addition, sialic acid, a major terminal sugar residue in mucins, also inhibited the bacterial aggregation. This study shows that the blood group and secretor status of a person may influence the interaction of saliva with bacteria in the oral cavity.  相似文献   

12.
A fully carbamylated derivative of plasminogen having no free amino groups has been prepared and converted by urokinase to an active enzyme, called carbamyl plasmin A, with a single free NH2-terminal amino group (Val-561). Carbamyl plasmin A was shown to possess a catalytically essential ionizing group having pK 8.6. Carbamylation of the free NH2-terminal amino group of carbamyl plasmin A led to complete loss of catalytic activity. The results of solvent perturbation studies of normal plasmin (EC 3.4.21.7) indicate that the group with pK 8.4 is a neutral acid group. It is suggested that the catalytically essential ionizing group of plasmin having a pK of 8.4 is the alpha-ammonium group of the NH2-terminal Val-561 or the light chain of plasmin, forming an ion pair with a COO- group of an aspartate or glutamate residue.  相似文献   

13.
目的:探讨miR-34a在幼鼠海马神经元细胞增殖凋亡中的作用。方法:分离幼鼠海马神经元细胞,转染miR-34a抑制剂(miR-34a inhibitor)、抑制剂对照(inhibitor control)、miR-34a模拟物(miR-34a mimics)、模拟物对照(mimics control),RT-PCR检测细胞中miR-34a表达水平。MTT检测转染后细胞增殖情况。流式细胞仪检测细胞凋亡情况。Western blot检测细胞中Cleaved-caspase-3、Bcl-2、Bax的表达水平。结果:转染miR-34a inhibitor可以抑制miR-34a的表达,miR-34a mimics可以促进miR-34a的表达。miR-34a mimics对细胞增殖抑制率明显高于mimics control组(P0.05),miR-34a inhibitor组抑制率明显低于inhibitor control组(P0.05)。miR-34a inhibitor组神经元细胞凋亡率明显低于inhibitor control组(P0.05),miR-34a mimics组神经元细胞凋亡率明显高于mimics control组(P0.01),inhibitor control组和mimics control组神经元细胞凋亡率差异不显著(P0.05)。miR-34a inhibitor组Cleaved-caspase-3、Bax蛋白表达量低于inhibitor control组,差异显著(P0.05);miR-34a inhibitor组Bcl-2蛋白表达量高于inhibitor control组,差异显著(P0.05);miR-34a mimics组Cleaved-caspase-3、Bax蛋白表达量高于mimics control,差异显著(P0.05);miR-34a mimics组Bcl-2蛋白表达量低于mimics control,差异显著(P0.05)。结论:miR-34a抑制海马神经元细胞增殖,促进细胞凋亡,其作用机制可能与调控Cleaved-caspase-3、Bcl-2、Bax表达有关。  相似文献   

14.
The steric course of the methyl group transfer to polygalacturonic acid to form the methyl ester group in pectin was studied using S-adenosylmethionine (AdoMet) carrying a methyl group made chiral by labeling with 1H, 2H, 3H, in an asymmetric arrangement. The incubation of the two diastereomers of this substrate with a particulate enzyme preparation obtained from Phaseolus aureus (mung bean) shoots gave the corresponding pectins. These were degraded in a series of stereochemically unambiguous reactions that converted the methoxy group into the methyl group of acetate, which was then analyzed for its configuration. The results indicate that the transfer of the methyl group from the sulfur of AdoMet to the oxygen of the carboxyl group proceeds with inversion of configuration of the methyl group.  相似文献   

15.
R T Lee  Y C Lee 《Biochemistry》1986,25(22):6835-6841
On the basis of the knowledge that the D-galactose/N-acetyl-D-galactosamine-specific lectin of rabbit liver can tolerate a large group on the C-6 hydroxyl group of a galactoside [Lee, R. T. (1982) Biochemistry 21, 1045-1050], we prepared a high-affinity photolabeling reagent for this lectin from a triantennary glycopeptide fraction of asialofetuin. The C-6 hydroxyl group of a D-galactopyranoside was converted, under mild conditions, into a primary amino group. The procedure involves conversion of the hydroxyl group to an oxo group with galactose oxidase, followed by reductive amination using benzylamine and sodium cyanoborohydride. Catalytic hydrogenolysis of the benzylamino derivative yielded the desired 6-amino-6-deoxy-D-galactoside. A 4-azidobenzoyl group was attached to the newly produced amino group to yield a photoactivatable affinity-labeling reagent. The reagent labeled the Triton-solubilized, purified hepatic lectins of rabbit and rat in a photo- and affinity-dependent manner. All the polypeptide subunits of the lectins were labeled, indicating that each subunit contains at least one D-galactose-combining site. In the case of the rabbit hepatic lectin, the minor subunit (46 kDa) was labeled more efficiently than the major one (40 kDa).  相似文献   

16.
徐云亮 《人类学学报》2021,40(6):1023-1031
为探究不同球类运动对上下肢骨密度及其方向性不对称的影响,特选取研究对象共210人,均分为7组,即篮球组、排球组、足球组、羽毛球组、乒乓球组、网球组和对照组,测量其上下肢的骨密度和方向性不对称性(DA)。结果显示,篮球组、排球组、羽毛球组、乒乓球组和网球组的上肢骨密度都是右侧明显高于左侧,下肢骨密度仅足球组表现为右侧高于左侧;不同组间的上下肢骨密度和DA具有统计学差异。结果还显示,左侧上肢骨密度的组间排序为排球组>足球组>第二亚组(乒乓球组、网球组和羽毛球组)>对照组,篮球组>乒乓球组、网球组和羽毛球组>对照组;右侧上肢骨密度的排序为网球组>乒乓球组、排球组和篮球组>足球组>对照组,乒乓球组>羽毛球组>足球组>对照组;左侧下肢骨密度的排序为足球组>篮球组、排球组、羽毛球组、乒乓球组和网球组>对照组;右侧下肢骨密度的排序为足球组>排球组、篮球组、网球组、羽毛球组和乒乓球组>对照组,排球组>羽毛球组和乒乓球组>对照组;DA的排序为网球组>乒乓球组、羽毛球组、篮球组和排球组,乒乓球组&g...  相似文献   

17.
Early microsurgical reconstruction of complex trauma of the extremities   总被引:18,自引:0,他引:18  
Five hundred and thirty-two patients underwent microsurgical reconstruction following trauma to their extremities. They were divided into three groups for the purpose of review. Group 1 underwent free-flap transfer within 72 hours of the injury, group 2 between 72 hours and 3 months of the injury, and group 3 between 3 months and 12.6 years, with a mean of 3.4 years. The results were analyzed with respect to flap failure, infection, bone-healing time, length of hospital stay, and number of operative procedures. The flap failure rate was 0.75 percent in group 1, 12 percent in group 2, and 9.5 percent in group 3 (p less than 0.0005 early versus delayed; p less than 0.0025 early versus late). Postoperative infection occurred in 1.5 percent of group 1, 17.5 percent of group 2, and 6 percent of group 3. Bone-healing time was 6.8 months in group 1, 12.3 months in group 2, and 29 months in group 3. The average length of total hospital stay was 27 days for group 1, 130 days for group 2, and 256 days for group 3. The number of operations averaged 1.3 for group 1, 4.1 for group 2, and 7.8 for group 3.  相似文献   

18.
目的:研究针刺联合依达拉奉对大鼠视网膜缺血再灌注时自由基代谢的影响.方法:大鼠随机分为五组:假手术组、模型组、针刺组、依达拉奉组和联合(针刺+依达拉奉)组.建立缺血再灌注模型,于造模后1d,行视网膜电流图(ERG)检查,取视网膜组织,测定各组MDA含量及T-SOD、GSH-Px、CAT活性的变化.结果:①ERG a、b波振幅相对恢复率:联合组、针刺组及依达拉奉组与模型组相比,a、b波振幅相对恢复率升高,差异有显著性(P<0.05),与针刺组和依达拉奉组相比,联合组作用更为显著(P<0.05).②MDA含量及T-SOD、GSH-Px、CAT活性:联合组、针刺组及依达拉奉组与模型组相比,MDA显著降低,SOD、GSH-Px、CAT显著升高,差异有显著性(P<0.05),联合组作用显著优于针剌组或依达拉奉组(P<0.05).结论:针刺联合依达拉奉具有干预自由基代谢作用,明显减轻缺血再灌注引起的视网膜氧化应激损伤,对视网膜功能起保护作用.  相似文献   

19.
目的:观察Wnt5a在大鼠髓核突出模型的表达变化,探索Wnt5a在神经根病中的作用。方法:将80只成年雄性大鼠随机分为假手术组(Sham组,n=20)、髓核突出组(NP组,n=20)、髓核突出+生理盐水组(NP+Saline组,n=20)、髓核突出+益赛普组(NP+Etanercept组,n=20)。从大鼠尾椎椎间盘中取髓核,将髓核种植于L5背根神经节旁,制作髓核突出大鼠模型。采用免疫组织化学法分别检测各组大鼠背根神经节中的Wnt5a蛋白的表达,利用RT-PCR的方法分别检测各组大鼠背根神经节中Wnt5a m RNA的表达。结果:免疫组化结果显示,各组大鼠背根神经节的大中小神经元均有Wnt5a的表达,NP组较Sham组在3天、7天时Wnt5a表达量均增加(P0.01),3天和7天时NP+Etanercept组大鼠背根神经节中Wnt5a的表达量较NP+Saline组均减少(P0.01)。RT-PCR的结果与免疫组化的结果相符,表现为NP组较Sham组在3天、7天时Wnt5a mRNA的相对表达量增加(P0.01),NP+Etanercept组大鼠背根神经节中Wnt5a的相对表达量较NP+Saline组均减少(P0.01)。结论:髓核突出并压迫背根神节时,可引起背根神经节Wnt5a的表达增加,且阻断肿瘤坏死因子α(TNF-α)时,背根神经节的Wnt5a表达减少。  相似文献   

20.
为探讨载氢-纳米氧化铈微泡对小鼠辐射损伤的防护作用。本研究检测载氢-纳米氧化铈微泡的表征,并将60只BALB/c小鼠随机分为正常对照组、照射对照组、载氢-纳米氧化铈微泡组。小鼠经6Gy x射线一次性全身照射(剂量率2 Gy/min)。于照射后3 d和8 d处死小鼠,检测其外周血细胞数、脾脏和胸腺指数、骨髓和脾脏组织病理学变化。结果显示,照射后3 d和8 d,与正常对照组相比,载氢-纳米氧化铈微泡组和照射对照组的白细胞均明显下降,相比照射对照组,载氢-纳米氧化铈微泡组有改善(p<0.05或p<0.01);而载氢-纳米氧化铈微泡组和照射对照组的红细胞数和血红蛋白均略有下降,但差异无统计学意义。与正常对照组相比,微泡组的胸腺指数、脾脏指数均有下降,和照射对照组相比,载氢-纳米氧化铈微泡组的胸腺指数明显改善(p<0.05或p<0.01)。照射后3 d,与正常对照组相比,照射对照组的骨髓细胞较少,存在细胞碎片,载氢-纳米氧化铈微泡组骨髓细胞数量略有减少,存在细胞核松散现象。而照射后8 d,与正常对照组相比,照射对照组的骨髓细胞几乎找不到,载氢-纳米氧化铈微泡组骨髓细胞有一定数量,存在细胞凋亡现象。本研究表明,载氢-纳米氧化铈微泡通过保护造血组织、改善造血功能,对机体起到一定的辐射防护作用。  相似文献   

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