普通朱雀标准代谢率的初步研究

以普通朱雀的耗氧量为指标 ,探讨了普通朱雀的能量代谢特征。普通朱雀的热中性区为 2 6.7～3 7.5℃ ,最低标准代谢率为 4 .2 1mlO2 g·h ,最低热传导为 0 .2 4mlO2 g·h·℃。环境温度 (Ta)在 5～ 2 5℃范围内 ,其代谢率与Ta呈负相关 ,回归方程为SMR =8.74 -0 .1 7Ta ,体温稍有降低。Ta超过 3 7.5℃ ,SMR升高。     

我国东南部地区夏季两种雀形目鸟类的代谢产热特征及其体温调节

采用封闭式流体压力呼吸计,分别在5-35℃和5-40℃的环境温度范围内测定了白头鹎(Pycnonotussinensis)和丝光椋鸟(Sturnussericeus)的代谢率、热传导和体温等指标,探讨其代谢产热特征。结果显示:在环境温度(Ta)为5-35℃时,白头鹎的体温基本维持恒定,平均温度为40.3±0.1℃,热中性区为26.6-32.8℃,基础代谢率为73.10±4.11mlO2/h,是体重预期值的79%;Ta在5-26℃范围内,代谢率(MR)与Ta呈负相关,回归方程为:MR[mlO2/h]=265.37-7.24Ta(℃);Ta在5-30℃范围内,热传导值最低且基本保持恒定,平均为0.24±0.01mlO2/g·h·℃,是体重预期值的126%。丝光椋鸟的热中性区为27.6-34.5℃,平均体温为40.5±0.1℃(5-40℃),基础代谢率为160.64±9.20mlO2/h,是体重预期值的90%;最低热传导为0.16±0.05mlO2/g·h·℃,是体重预期值的129%。在5-25℃范围内,MR与Ta的回归方程为:MR[mlO2/h]=377.96-7.88Ta(℃)。白头鹎和丝光椋鸟的基本生物学特征为:较高的体温,热传导和上临界温度,较宽的热中性区和较低的代谢率,符合南方小型鸟类的代谢特征.     

北朱雀、燕雀和白腰朱顶雀的能量代谢特征和体温调节

本实验采用封闭式流体压力呼吸计 ,测定了环境温度在 5 - 34℃范围内北朱雀 (Carpodacusroseus)、燕雀 (Fringillamontifringilla)和白腰朱顶雀 (Acanthisflammea)的耗氧量、热传导、体温等指标 ,探讨了其代谢产热特征。结果表明 :在环境温度 (Ta)为 5 - 30℃的范围内 ,北朱雀的体温基本维持恒定 ,平均体温为4 0 4 6± 0 1 0℃ ,热中性区为 2 2 5 - 2 7 5℃ ,基础代谢率为 4 30± 0 0 8mlO2 /(g·h) ;环境温度在 5 - 2 0℃范围内 ,代谢率 (MR)与Ta 呈负相关 ,回归方程为MR [mlO2 /(g·h) ]=9 34- 0 2 1Ta (℃ ) ;在此范围内 ,北朱雀的热传导率最低且基本保持恒定 ,平均为 0 2 4± 0 0 0mlO2 /(g·h·℃ )。在环境温度为 5 - 34℃的范围内 ,燕雀的体温基本保持稳定 ,为 4 0 4 0± 0 1 1℃ ,热中性区为 2 5 - 30℃ ,基础代谢率为 4 1 9± 0 0 5mlO2 /(g·h) ;环境温度在 5 - 2 5℃范围内 ,MR与Ta 的回归方程为 :MR [mlO2 / (g·h) ]=1 1 6 4 - 0 2 9Ta (℃ ) ;在 5- 30℃内 ,燕雀的热传导最低 ,平均为 0 2 9± 0 0 1mlO2 / (g·h·℃ )。白腰朱顶雀的热中性区为 2 5 - 2 8℃ ,平均体温为 4 0 4 8± 0 1 1℃ (5 - 34℃ ) ,最低代谢率为 4 4 5± 0 1 4mlO2 / (g·h) ,最低热传导为 0 3     

太平鸟和灰头鹀的代谢产热特征及体温调节

采用封闭式流体压力呼吸仪,测定了在环境温度5、10、15、16、18、20、22、25、26、28和30℃时,捕自黑龙江省齐齐哈尔市的太平鸟(Bombycillagarrulus,1♀、7♂)和灰头(Emberizaspodocephala,8♂)的代谢率(MR),计算每个温度点的热传导(C)、MR和C的体重预期值。结果显示:在环境温度(Ta)为5~30℃时,太平鸟的体温(Tb)基本维持恒定,平均Tb为(38·20±0·05)℃;热中性区(TNZ)为18~27℃,基础代谢率(BMR)为(2·33±0·47)mLO2/(g·h);Ta在5~18℃,MR与Ta呈负相关,回归方程为:MR=5·46(±0·19)-0·17(±0·01)Ta;Ta在5~22℃,C最低且基本保持恒定,平均为(0·13±0·00)mLO2/(g·h·℃)。5~30℃时,灰头Tb也基本维持恒定,平均Tb为(38·25±0·05)℃;TNZ为20~26℃,BMR为(4·75±0·18)mLO2/(g·h),最低C为(0·26±0·00)mLO2/(g·h·℃);在5~20℃时,MR与Ta的回归方程为:MR=9·54(±0·52)-0·23(±0·03)Ta。两种鸟具有BMR和Tb较高、下临界温度较低和TNZ较宽、热传导稍高的北方地区小型鸟类的代谢特点,通过自身的物理和化学调节(代谢产热)以更好地适应其生存环境。     

太平鸟和灰头wu的代谢产热特征及体温调节

采用封闭式流体压力呼吸仪,测定了在环境温度5、10、15、16、18、20、22、25、26、28和30 ℃时,捕自黑龙江省齐齐哈尔市的太平鸟(Bombycilla garrulus,1♀、7♂)和灰头wu(Emberiza spodocephala,8♂)的代谢率(MR),计算每个温度点的热传导?、MR和C的体重预期值。结果显示：在环境温度(Ta)为5～30 ℃时,太平鸟的体温(Tb)基本维持恒定,平均Tb为(38.20±0.05) ℃;热中性区(TNZ)为18～27 ℃,基础代谢率(BMR)为(2.33±0.47)mL O.2/(g·h);Ta在5～18 ℃,MR与Ta呈负相关,回归方程为：MR=5.46(±0.19)-0.17(±0.01)Ta;Ta在5～22 ℃,C最低且基本保持恒定,平均为(0.13±0.00)mL O.2／(g·h·℃)。5～30 ℃时,灰头wu Tb也基本维持恒定,平均Tb为(38.25±0.05) ℃; TNZ为20～26 ℃,BMR为(4.75±0.18)mL O.2／(g·h),最低C为(0.26±0.00)mL O.2／(g·h· ℃);在5～20 ℃时,MR与Ta的回归方程为：MR=9.54(±0.52)-0.23(±0.03)Ta。两种鸟具有BMR和Tb较高、下临界温度较低和TNZ较宽、热传导稍高的北方地区小型鸟类的代谢特点,通过自身的物理和化学调节(代谢产热)以更好地适应其生存环境。     

珠颈斑鸠的代谢产热特征

采用封闭式氧气流体压力呼吸仪和数字式温度计,测定在环境温度(Ta)为0℃、6.5℃、10.5℃、16.5℃、20℃、22.5℃、25℃、27.5℃和30℃时珠颈斑鸠(Streptopelia chinesis)的代谢率(MR)和体温(Tb),由此计算出每个温度点的热传导(C)以及MR和C的体质量预期值等指标,探讨其代谢产热特征。结果表明:在Ta为0℃～30℃时,珠颈斑鸠的体温基本维持恒定,平均体温为(40.7±0.1)℃,热中性区(TNZ)为22.5～27.5℃,基础代谢率为(160.48±6.05)mlO2.h-1,是体质量预期值的65%;Ta在0℃～25℃范围内,热传导值最低且基本保持恒定,平均为(0.07±0.01)mlO2.g-1.h-1.℃-1,是体质量预期值的122%。珠颈斑鸠具有较低的MR,较高的C和Tb,能较好地适应南方较热的气候环境。     

黑腹绒鼠的代谢产热特征及其体温调节

为探讨东洋界华中区黑腹绒鼠的代谢产热特征及体温调节,本文采用封闭式流体压力呼吸仪对其代谢率、热传导和体温等热生物学指标进行了测定.结果显示:在环境温度为5～25℃的范围内,黑腹绒鼠的体温基本维持恒定,平均体温为36.5±0.1℃;热中性区为25～30℃;基础代谢率为2.99±0.09 ml O2/(g·h);环境温度(Ta)在5～25℃范围内,代谢率(MR)与Ta呈负相关,回归方程为:MR[ ml O2/(g·h)]= 6.56-0.16 Ta(℃),在此范围内,黑腹绒鼠的热传导率C最低,平均为0.26±0.01 ml O2/(g·h·℃).黑腹绒鼠的基本热生物学特征为:较高的BMR、热传导率和体温以及较宽的热中性区.     

华北农田大仓鼠的能量代谢特征及其体温调节

利用封闭式流体压力呼吸计 ,测定了华北农田主要害鼠大仓鼠 (CricetulustritondeWinton)在 5～36℃范围内的能量代谢特征。结果表明 :在 5～ 31℃范围内 ,大仓鼠的体温基本维持恒定 ,平均体温为 (36 7±0 1)℃ ;热中性区为 2 9～ 34℃ ;基础代谢率 (BMR)为 (1 2 3± 0 0 2 )mLO2 /(g·h)。在 5～ 15℃范围内 ,热传导率维持恒定 ,平均为 (0 12± 0 0 0 )mLO2 /(g·h·℃ )。大仓鼠的能量代谢特征是 :在总兽类中 ,高于期望值 ;在啮齿动物中 ,低于期望值 ;在仓鼠亚科动物中 ,稍高于期望值 ;从食性上看 ,高于食种子类的期望值 ,而与食草类的期望值相似 ;体温稍低 ;热传导较高 ;这些特征与该物种夜行性、主要以作物的种子为食、独居和穴居等生活习性密切相关。结合大仓鼠在我国主要分布于长江以北 ,但在极端干旱和高寒地区则没有分布的特点 ,提出了生理生态特征可能是限制大仓鼠地理分布的重要因素的观点。     

棕眉山岩鹨的代谢产热特征的初步研究

实验采用封闭式流体压力呼吸计和数字式温度计 ,分别测定了环境温度 (Ta)在 5～ 35℃范围内棕眉山岩鹨 (Prunellamontanella)的耗氧量和体温 (Tb) ,由此计算出代谢率 (MR)、热传导率 (C)和代谢预期比与热传导预期比 (F)等值 ,以探讨该种的代谢产热特征。结果表明 :棕眉山岩鹨在Ta 为 5～ 35℃时 ,Tb 基本维持恒定 (为 4 1 2 5± 0 12℃ ) ,MR的最低值为 4 2 7± 0 0 7mLO2 /(g·h) ;Ta 在 5～ 2 4℃时 ,MR与之负相关 :MR [mLO2 /(g·h) ]=10 39- 0 2 4Ta℃ ;Ta 在 5～ 2 6 5℃时 ,C最低且基本保持恒定 ,平均为 0 2 6±0 0 0mLO2 /(g·h·℃ ) ;Ta 在 2 4～ 30℃时 ,F值为 1 0 5 ,表明该种具有较好的体温调节能力。与热带地区鸟类比较 ,棕眉山岩鹨具较高的MR和Tb,稍高的C ,符合北方小型鸟类的代谢特点 ,能较好的适应冬寒冷、夏炎热的环境。     

八哥的代谢产热特征及体温调节

采用封闭式流体压力呼吸计和数字式温度计,在环境温度(Ta)5.0～37.5℃范围内,测定了成体八哥(Acridotheres cristatellus)的代谢率(MR)和体温(Tb),并计算出每个温度点的热传导(C),以及MR和C的体重预期值等指标,探讨其代谢产热特征。在Ta为5.0～37.5℃时,八哥的体温基本维持恒定,平均为(41.4±0.1)℃,热中性区(TNZ)为25.0～32.5℃,基础代谢率(BMR)为(125.33±2.08)ml O2/h,是体重预期值的60%;Ta在5.0～25.0℃范围内,MR[ml O2/h]与Ta(℃)呈负相关,回归方程为:MR=365.30-10.07Ta;Ta在10.0～25.0℃时,C最低且基本恒定,平均为(0.06±0.00)ml O2/(g.h.℃),是体重预期值的100%。八哥具有较低的基础代谢率,相对较高的热传导和体温,符合南方小型鸟类的代谢特征。     

Land,livestock, and livelihoods: Changing dynamics of gender,caste, and ethnicity in a Nepalese Village

Over the past 10 years, Ghusel VDC, Lalitpur District has moved from primarily subsistence agriculture into the wider cash economy aided by the Small Farmers' Development Program (SFDP), which provides credit to farmers mainly for the purchase of buffalo for milk production, and by the National Dairy Corporation, which supports local dairy cooperatives. Analysis reveals that buffalo-keeping and milk sales are increasing the well-being of many households, while at the same time creating new inequalities in gender roles and responsibilities, greater inequities between Brahmin and Tamang residents in Ghusel, and placing pressures on the ecosystem for increased supplies of fodder and fuelwood. Evidence suggests that there is critical, need for attention to the social, and particularly gender-based, implications of maintaining livestock for milk sales and to the ecological underpinnings of this livelihood system.     

Tuning of electronic properties of one-dimensional cyano-bridged Cu-Ni, Cu-Pd, and Cu-Pt bimetallic assemblies by stereochemistry of ligands

Preparations, XPS and electronic spectroscopy, and magnetism of seven new one-dimensional cyano-bridged coordination polymers, chiral [Cu(RR-chxn)₂][Pd(CN)₄] · 2H₂O (1), [Cu(trans-chxn)₂][M(CN)₄] · 2H₂O (2, 4, and 6 for M = Pd, Ni, and Pt), and [Cu(cis-chxn)₂][M(CN)₄] · 2H₂O (3, 5, and 7 for M = Pd, Ni, and Pt) (RR-chxn = cyclohexane-(1R,2R)-diamine, trans-chxn = racemic trans-cyclohexane-(1,2)-diamine, and cis-chxn = racemic cis-cyclohexane-(1,2)-diamine) have been reported in view of tuning of their electronic properties by stereochemistry of chxn ligands and metal-substitution. Comparison of Cu 2p_1/2 and 2p_3/2 peaks of XPS and broad d-d bands around 18 000 cm⁻¹ of electronic spectra are described systematically for 1-7. Variable-temperature magnetic measurement shows that complexes 1-7 indicate weak antiferromagnetic interactions via cyano-bridges. Because of semi-coordination coupled with pseudo Jahn-Teller elongation and electrostatic interaction for 1, the axial Cu-N coordination bond distances of 2.330(7) and 3.092(8) Å are considerably longer than those of equatorial ones in the range from 2.016(6) to 2.030(6) Å. The former bond distances of 1 are intermediate values among the related Ni (2.324(6) and 3.120(8) Å) and Pt (2.34(1) and 3.09(1) Å) complexes.     

Structure and function of S-adenosylhomocysteine hydrolase

In mammals, S-adenosylhomocysteine hydrolase (AdoHcyase) is the only known enzyme to catalyze the breakdown of S-adenosylhomocysteine (AdoHcy) to homocysteine and adenosine. AdoHcy is the product of all adenosylmethionine (AdoMet)-dependent biological transmethylations. These reactions have a wide range of products, and are common in all facets of biometabolism. As a product inhibitor, elevated levels of AdoHcy suppress AdoMet-dependent transmethylations. Thus, AdoHcyase is a regulator of biological transmethylation in general. The three-dimensional structure of AdoHcyase complexed with reduced nicotinamide adenine dinucleotide phosphate (NADH) and the inhibitor (1′R, 2′S, 3′R)-9-(2′,3′-dihyroxycyclopenten-1-yl)adenine (DHCeA) was solved by a combination of the crystallographic direct methods program, SnB, to determine the selenium atom substructure and by treating the multiwavelength anomalous diffraction data as a special case of multiple isomorphous replacement. The enzyme architecture resembles that observed for NAD-dependent dehydrogenases, with the catalytic domain and the cofactor binding domain each containing a modified Rossmann fold. The two domains form a deep active site cleft containing the cofactor and bound inhibitor molecule. A comparison of the inhibitor complex of the human enzyme and the structure of the rat enzyme, solved without inhibitor, suggests that a 17° rigid body movement of the catalytic domain occurs upon inhibitor/substrate binding.     

Chiral Separation of G‐type Chemical Warfare Nerve Agents via Analytical Supercritical Fluid Chromatography

Chemical warfare nerve agents (CWNAs) are extremely toxic organophosphorus compounds that contain a chiral phosphorus center. Undirected synthesis of G‐type CWNAs produces stereoisomers of tabun, sarin, soman, and cyclosarin (GA, GB, GD, and GF, respectively). Analytical‐scale methods were developed using a supercritical fluid chromatography (SFC) system in tandem with a mass spectrometer for the separation, quantitation, and isolation of individual stereoisomers of GA, GB, GD, and GF. Screening various chiral stationary phases (CSPs) for the capacity to provide full baseline separation of the CWNAs revealed that a Regis WhelkO1 (SS) column was capable of separating the enantiomers of GA, GB, and GF, with elution of the P(+) enantiomer preceding elution of the corresponding P(–) enantiomer; two WhelkO1 (SS) columns had to be connected in series to achieve complete baseline resolution. The four diastereomers of GD were also resolved using two tandem WhelkO1 (SS) columns, with complete baseline separation of the two P(+) epimers. A single WhelkO1 (RR) column with inverse stereochemistry resulted in baseline separation of the GD P(–) epimers. The analytical methods described can be scaled to allow isolation of individual stereoisomers to assist in screening and development of countermeasures to organophosphorus nerve agents. Chirality 26:817–824, 2014. © 2014 The Authors. Chirality published by John Wiley Periodicals, Inc.     

Influence of Fluoride on Rat Kidney Antioxidant System: Effects of Methionine and Vitamin E

The aim of the study has been to determine and compare the influence upon the kidney antioxidative system, exercised by administration of vitamin E, and vitamin E in combination with methionine, under conditions of oxidative stress induced by sodium fluoride. The experiment was carried out on Wistar FL rats (adult males) that, for 35 days, were administered water, NaF, NaF with vitamin E, or vitamin E with methionine (doses: 10 mg NaF/kg of body mass/24 h, 3 mg vitamin E per 10 μl per rat for 24 h, 2 mg methionine per rat for 24 h). The influence of administered sodium fluoride and antioxidants upon the antioxidative system in kidney was examined by analyzing the concentration of malondialdehyde (MDA) and the activity of the most important antioxidative enzymes (SOD, total and both its isoenzymes, GPX, GST, GR, and CAT). The studies carried out confirmed the disadvantageous effect of the administered dose of NaF upon the antixodiative system in rats (increase in the concentration MDA, decrease activity of all antioxidative enzymes). The administration of vitamin E increased the activity of studied enzymes with the exception of glutathione reductase GR; it also reduced the procesess of lipid peroxidation. It has been found that combined doses of vitamin E and methionine were most effective in inhibiting lipid peroxidation processes. The results confirmed the antioxidative properties of methionine.     

Reorientation of Microfibrils and Microtubules at the Outer Epidermal Wall of Maize Coleoptiles During Auxin-Mediated Growth

Auxin-mediated elongation growth of isolated subapical coleoptile segments of maize (Zea mays L.) is controlled by the extensibility of the outer cell wall of the outer epidermis (Kutschera et al., 1987). Here we investigate the hypothesis that auxin controls the extensibility of this wall by changing the orientation of newly deposited microfibrils through a corresponding change in the orientation of cortical microtubules. On the basis of electron micrographs it is shown that cessation of growth after removal of the endogenous source of auxin is correlated with a relative increase of longitudinally orientated microfibrils and microtubules at the inner wall surface. Conversely, reinduction of growth by exogenous auxin is correlated with a relative increase of transversely orientated microfibrils and microtubules at the inner wall surface. These changes can be detected 30–60 min after the removal and addition of auxin, respectively. The functional significance of directional changes of newly desposited wall microfibrils for the control of elongation growth is discussed.     

Gamma-glutamylcysteine protects ergothioneine-deficient Mycobacterium tuberculosis mutants against oxidative and nitrosative stress

Mycobacterium tuberculosis (M.tb.), the causative agent of tuberculosis (TB), cannot synthesize GSH, but synthesizes two major low molecular weight thiols namely mycothiol (MSH) and ergothioneine (ERG). Gamma-glutamylcysteine (GGC), an intermediate in GSH synthesis, has been implicated in the protection of lactic acid bacteria from oxidative stress in the absence of GSH. In mycobacteria, GGC is an intermediate in ERG biosynthesis, and its formation is catalysed by EgtA (GshA). GGC is subsequently used by EgtB in the formation of hercynine-sulphoxide-GGC. In this study, M.tb. mutants harbouring unmarked, in-frame deletions in each of the fives genes involved in ERG biosynthesis (egtA, egtB, egtC, egtD and egtE) or a marked deletion of the mshA gene (required for MSH biosynthesis) were generated. Liquid chromatography tandem mass spectrometry analyses (LC-MS) revealed that the production of GGC was elevated in the MSH-deficient and the ERG-deficient mutants. The ERG-deficient ΔegtB mutant which accumulated GGC was more resistant to oxidative and nitrosative stress than the ERG-deficient, GGC-deficient ΔegtA mutant. This implicates GGC in the detoxification of reactive oxygen and nitrogen species in M.tb.     

In vitro studies of the rabbit immune system. IV. Differential mitogen responses of isolated T and B cells.

The mitogenic responses of separated rabbit lymphocyte populations functionally analogous to mouse T and B cells have been tested in vitro. Purified T cells were prepared by passage over nylon wool (NW) and purified B cells prepared by treatment with antithymocyte serum and complement (ATS + C). ATS + C kills 70% of peripheral blood lymphocytes (PBL's) and 50% of the spleen cells while passage over NW yields 40% of the applied PBL's and 5–23% of the applied spleen cells. NW-purified T cells from the spleen or PBL's respond fully to concanavalin A (Con A) but have a reduced response to phytohemaglutinin (PHA) and little or no response to goat anti-rabbit immunoglobulin (anti-Ig). PBL's that survive ATS + C (B cells) are stimulated by anti-Ig but not by Con A or PHA. B cells purified from spleen do not respond to Con A or PHA but will respond to anti-Ig under appropriate conditions. A full spleen B-cell response to anti-Ig required removal of Ig produced by the cultures that blocked anti-Ig stimulation. It is concluded that, for rabbit lymphocytes, Con A and PHA are primarily T-cell mitogens and that anti-Ig is primarily a B-cell mitogen. However, the mitogen response of unfractionated PBL or spleen cell populations indicates an overlap in reactivity. This could be due to cells sharing T and B properties, alteration of cell populations by the fractionation procedures used, or recruitment of one population in the presence of a mitogenic response of the other population.     

八种脑-肠肽侧脑室内注射对大鼠基础胃酸分泌的影响

用乌拉坦麻醉大鼠作急性实验,采用连续灌流胃并收集流出液的方法,观察向侧脑室内注射微量脑-肠肽对大鼠基础胃酸分泌的影响。实验结果如下:(1)雨蛙肽、八肽胆囊收缩素、促甲状腺素释放激素及四肽胃泌素均使总酸排出量增加;(2)生长抑素、胰多肽、P 物质、胰高血糖素则使总酸排出量减少;(3)上述肽类用侧脑室注射的剂量作肌肉注射,除四肽胃泌素也产生明显的刺激胃酸分泌作用外,对胃酸分泌均无明显影响。以上结果提示,脑内的一些肽类可能以神经递质或调制物的方式,参与中枢对胃酸分泌的调节。     

A chromium-tolerant plant growing in Cr-contaminated land

In this paper, a kind of Typhaceae plant species, Typha angustifolia L, with a high tolerance to Cr is described. Experiments were carried out to examine its ability to tolerant Cr and its physiological response. The results showed that there was no difference in growth, plant height, and biomass response to external Cr (VI) between the plants exposed to 100 microM Cr (VI) and control (0 microM), while increasing Cr levels to 200-800 microM induced a significant decrease in plant height and biomass, but no significant injury was detected, even for the plants exposed to 800 microM Cr. Chromium induced significant increases in superoxide dismutase (SOD) and peroxidase (POD) activities. Meanwhile, a significantly positive correlation was found between Cr and Mn or Cu in leaves and roots, respectively. The Cr tolerance of the plant appeared to be associated with the enhancement of SOD and POD activities and the improvement in uptake and translocation of the essential microelements.