Ascorbic acid-induced modulation of rectal temperature fluctuations in pigs during the harmattan season

The experiment was carried out with the aim of investigating the effect of ascorbic acid (AA) on fluctuations in rectal temperature (RT) of pigs during the harmattan season. Sixteen pigs administered with AA at the dose of 250 mg/kg orally and individually served as experimental animals, and 13 others administered orally with sterile water were used as control animals. The RT was measured from all the pigs at 06:00, 13:00 and 18:00 h twice in a week for three consecutive weeks. The lowest overall mean RT value of 37.52±0.90 °C was obtained at 06:00 h in the experimental pigs, while the corresponding value in control pigs was 37.63±0.90 °C (P>0.05). The maximum RT values of 38.75±0.18 °C and 39.27±0.11 °C were recorded at 13:00 h in experimental and control pigs, respectively (P<0.05). The results indicate that AA modulates the body temperature by decreasing the maximum RT value in pigs exposed to harmattan stress, and may alleviate the risk of adverse effects of the stress on health and productivity of pigs during the cold-dry season.     

Effects influencing boar semen

The aim of this study was to analyze the main influences on the quality and quantity of boar semen. A total of 230,705 records of semen collections were utilised to estimate statistics of semen traits of 2712 boars belonging to the following breeds: Czech Meat Pig, Duroc, Hampshire, Landrace, Large White, Czech Large White and Pietrain, and various crosses of these breeds. The evaluation was based on semen volume (VO), concentration of spermatozoa (CO), progressive motion of spermatozoa (MO), abnormal spermatozoa (AB), total number of spermatozoa (NO_T) and corrected number of spermatozoa (NO_C). The breeds differed significantly for all examined traits. The maximal differences between the breeds were 95 ml for VO, 109 × 10³ mm⁻³ for CO, 9% for MO, 1.6% for AB, 24 × 10⁹ for NO_T and 19 × 10⁹ for NO_C. The maximal heterosis effect reached 12% for VO, 17% for CO, 4% for MO, −14% for AB, and 8% for NO_T and NO_C. The results demonstrate that the year-season effect has a clear effect on semen quality. The lowest values of semen traits were observed in summer while the highest values were found in autumn and winter. Age of boar was found to have a strong impact on sperm output. Sperm output tended to increase up to a boars’ age of 3.5 years. An acceptable level of semen volume occurred after a sexual pause of 3 days and the pool of spermatozoa was restoring after 5–7 days and fully after 10–11 days.     

手掌参γ-硫素的原核表达及纯化

目的：在原核系统中高效表达手掌参γ-硫素,并对其进行纯化。方法：通过筛选手掌参cDNA文库获得γ-硫素基因（gcthionin）,分别对其全长及信号肽编码序列缺失的cDNA片段进行PCR扩增,克隆入原核表达载体pET-32（a）,构建重组质粒pET-32（a）/gcthionin和pET-32（a）/Δgcthionin;测序鉴定后,转化大肠杆菌BL21（DE3）,经IPTG诱导表达融合蛋白;SDS-PAGE分析后,采用Ni-NTA亲和层析柱及凝胶柱对可溶性蛋白进行纯化,Western blotting鉴定。结果：gcthionin基因开放式阅读框全长225nt,编码一个由74个氨基酸残基组成的蛋白;带有信号肽的重组质粒在大肠杆菌BL21（DE3）中以包涵体形式表达;信号肽缺失可以极大地提高外源蛋白的可溶性,该可溶性产物经Ni-NTA柱及凝胶过滤后可获得纯度较高的蛋白,经Western blotting分析,相对分子质量约21.9×10^3处有明显的蛋白条带,与预期蛋白分子大小一致。结论：信号肽编码序列缺失的Δgcthionin可在大肠杆菌中可溶、高效表达。     

亚热带森林林分更新对地表径流4种盐基离子浓度的影响

地表径流不仅是水循环的重要组成部分,也是森林物质迁移的重要途径,其动态过程可能受林分更新的调控,目前仍缺乏必要的关注.通过对福建省三明市米槠(Castanpsis carlesii)次生林、杉木(Cunning-hamia lanceolata)人工林、杉木人工幼林和米槠人工幼林近5年的定位观测,探讨林分更新对地表径流...     

Taxonomic revision of the genus Cryptogramma R.Br.from China

Cryptogramma R.Br.from China is taxonomically revised.Two species and one variety are recognized,namely C.stelleri（Gm l.）Prantl,C.brunoniana Wall.ex Hook.&Grev.,and C.brunoniana var.sinensis（Christ）G.M.Zhang.C.emeiensis Ching&K.H.Shing is reduced to synon     

羊草种群生物量和能量生殖分配的研究

从构件入手,研究了生长季羊草种群根茎、营养枝和生殖枝及其构件的生物量和能量分配及季节动态,结果表明种群营养枝和生殖枝的生物量和能量分配没有显著的颉抗关系,但营养枝和根茎生物量和能量分配比例间呈显著的颉抗关系。研究结果还表明种群根茎、营养枝和生殖枝及构件的生物量和能量分配比例间的差异基本不显著,而且季节动态趋势一致,即生物量分配和能量分配是等价的。     

大仓鼠在繁殖期的行为关系及交配行为

在Ｙ型迷宫中进行气味选择测定时,被试大仓鼠偏好异性的气味,证明身体气味有性吸引和性识别作用。在Ｙ型迷宫进行性别选择测定时,在雌雄靶鼠个体之间,被试大仓鼠不表现出性别偏好,这是攻击行为和交配行为共同影响的结果;与空白相比较,被试鼠都选择靶鼠,说明独居大仓鼠之间存在频繁的探究行为。通过观察箱内对两鼠间的行为关系的观察发现,异性之间主要有攻击行为和交配行为;同性之间主要发生攻击行为,同时胜鼠或优势鼠的胁腺标记行为显著多于从属鼠,说明胁腺标记可以表明优势地位;雄鼠与非性接受状态的雌鼠相遇时,攻击行为很少,但无友好行为,只有简单的雄鼠爬跨雌鼠的行为;任何陌生的雄鼠与性接受状态的雌鼠相遇发生交配行为,交配结束又相互攻击;交配行为表现为多次爬跨多次射精;雄鼠有库利奇（Ｃｏｏｌｉｄｇｅ）效应,雌鼠可以连续接受几只雄鼠的交配,表明大仓鼠为多配制的婚配制度。从行为关系和交配行为看大仓鼠在繁殖期独居,无固定的配偶     

Proportional dry-mass content as an underlying trait for the variation in relative growth rate among 22 Eurasian populations of Dactylis glomerata s.l.

1. Relative growth rate (RGR), proportional dry-mass content of leaf and stem tissues, and biomass-allocation pattern were assessed under controlled conditions for 22 populations of Dactylis glomerata s.l. from contrasting latitudes and altitudes in Europe, Israel and Kazakstan. Furthermore, width and thickness of leaves were measured in garden-grown mature plants.
2. All these parameters varied significantly among the populations. RGR correlated negatively with dry-mass content of leaves and stems, but not with biomass-allocation parameters, leaf thickness or leaf width. We argue that the close association of RGR with variation in dry-mass content among species and genetically distinct populations is a result of the larger volume of tissue, and correspondingly larger leaf area and longer root system, that a plant with a low tissue density can build per unit dry mass.
3. Leaf tissue dry-mass content decreased and RGR increased with increasing latitude and elevation of the originating site, indicating that a high growth rate may be an advantage in habitats with a short growing season. This contrasts with earlier findings of a negative correlation between inherent RGR and altitude.     

酵母3-脱氧葡糖醛酮代谢酶的分离纯化及部分性质

3-脱氧葡糖醛酮 ( 3- deoxyglucosone)是美拉德反应的主要中间产物 ,对生物体具有毒性作用 .用硫酸铵分部沉淀、DEAE- cellulose52、Hydroxyapatite、DEAE- Sepharose CL- 6B柱层析从酿酒酵母 YBr-M( S.cerevisiae YBr-M)抽提液中分离纯化了 3-脱氧葡糖醛酮代谢酶 (以 NADPH为辅酶 ) .该酶是单一的分子 ,分子量为 44k D,反应最适 p H为 7.0 ,p H6.0～ 8.0之间酶活性相对稳定 ,以 3-脱氧葡糖醛酮为底物的米氏常数 Km 为 2 .2 5mmol/ L.在 35℃以下保温 30 min酶活不变 ,50℃保温 30 min后酶活损失 50 % .该酶对二羰基化合物的活性较高 ,对单羰基化合物则较低 ,其催化作用受碘乙酸、N-乙基顺丁烯二酰亚胺的抑制 ,而被β-巯基乙醇、二硫苏糖醇激活 ,催化作用必须以 NADPH为专一辅酶 ,当用 NADH代替 NADPH时 ,活力只有 5.3% .