Large-scale habitat use of some declining British birds

1. Large-scale habitat use of eight species of breeding birds was considered using data collected across Britain. The species were skylark Alauda arvensis (L.), dunnock Prunella modularis (L.), blackbird Turdus merula (L.), song thrush Turdus philomelos (L.), starling Sturnus vulgaris (L.), linnet Carduelis cannabina (L.), bullfinch Pyrrhula pyrrhula (L.) and reed bunting Emberiza schoeniclus (L.). All are linked by roughly synchronous population declines over the last 25 years in southern Britain (and mostly in farmland landscapes). Discussion is limited to the conservation status of these species.
2. Breeding densities were estimated for broad habitat types and these were used to estimate population sizes within habitat types. Confidence limits on the estimates were derived using a bootstrap procedure.
3. For most species considered, farmland holds a high proportion of their population (in excess of 50% for four species), reflecting the predominance of this land use across Britain. This suggests that sympathetic changes in farming practices are likely to provide the best mechanism for improving the status of these species.
4. Substantial proportions of particular species occur outside farmland, but different species occur in different habitats. A considerable proportion of skylarks occur on upland moor, bullfinches in wooded habitats, and reed buntings in riparian habitats. Conservation of this group of species thus requires appropriate management of the wider countryside, including their main habitats.
5. Habitats associated with human habitation hold > 20% of the British populations of blackbird, song thrush and starling, and considerable numbers of other species. The management of parks, gardens and other 'green space' may have an important impact on their populations and should not be neglected by conservationists.     

组织型纤溶酶原激活剂(t-PA)突变体工程细胞株生物学特性分析

t-PA突变体工程细胞株FSGGI48形态与其亲代细胞CHO-dhfr相似呈多角形,类似上皮细胞。在MTX加压至5×10~(-6)mol/L时,少数细胞形态略变瘦长,但仍呈多角形,因此该工程细胞株形态正常。抗体中和抑制试验及纤维蛋白板80℃加热试验显示,FSGGI48细胞表达产物与st-PA的活性均能被抗t-PA抗体所抑制,而胰酶的活性则不被抑制,且二者在80℃加热的纤维蛋白板上均不产生溶解圈,胰酶则产生溶解圈,由此可知,该细胞株表达产物为特异的rt-PA产品。细胞无血清培养上清经FA-PA检测,亚克隆株表达水平为4000IU/10~6细胞/24h。分别测定冻存3个月后复苏和体外传代3个月以上细胞的表达水平,结果显示部分亚克隆细胞株表达水平下降,多数仍为3000-4000IU/10~6细胞/24h,说明细胞株稳定性好。裸鼠试验表明,该工程株活细胞、细胞DNA、纯化的细胞表达产物均无致瘤性。支原体检查结果为阴性。染色体分析显示,FSGGI48细胞与其亲代细胞(CHO-dhfr细胞)染色体数目相同均为20条,但均有不同程度不同类型的畸变。CHO-dhfr细胞畸变率为6%。该工程细胞的畸变率为15%-18%,在允许范围内。结果证明,t-PA突变体细胞株FSGGI48为性能优良的工程细胞株。     

“龙麦15”2＋12与5＋10亚基近等基因系面粉品质差异的研究

通过对小麦栽培品种龙麦１５中的同形小种进行ＳＤＳ－ＰＡＧＥ和Ａ－ＰＡＧＥ的分析,在国内首次获得了一对Ｇｌｕ－Ｄ１位点高分子量麦谷蛋白亚基分别为２＋１２和５＋１０的近等基因系。对该近等基因系面粉品质的分析表明,带有５＋１０亚基的龙麦１５比事有２＋１２亚基的龙麦１５的Ｚｅｌｅｎｙ沉淀值高１２％,沉淀值／湿面筋的比值由１．０３提高到１．３２。该实验结果证明,５＋１０亚基对面粉品质贡献确实优于２＋１２亚基     

Variation of wheatgrass chromosomes in wheat-wheatgrass alien addition line "TAI-27"revealed by fluorescence in situ hybridization (FISH)

The Karyotyp of the primary wheat-whastgrass alien addition line TAI-27 was 2n = 44 in which all d the chromosomes were metacentric and subrmetacentric. However, in the progeny of TAI-27 a pair of chromosomes had become small chromosomea in the two morphologically different plants. Fluorescence in situ hybridizstionm (FISH) technique was used to analyze the two different plants. The observations indicate that a pair of small chromosomes in one varietion line are from wheatgrass. In another variation line, a pair of small chromosomes are also from whest-grass, while another pair of wheatgrass chromosomes have substituted the wheat chromosomes. TAI-27 and its variant lines showed a high level of resistance to barley yellow dwarf virus (BYDV). The pessible explanation for such a variation and the potential use of the variant lines were discussed briefly.     

N-乙酰氨基葡萄糖基转移酶Ⅲ,Ⅳ及Ⅴ在7721人肝癌细胞周期中的变化

为了研究N-乙酰氨基葡萄糖基转移酶(GlcNAc-T)Ⅲ,Ⅳ和Ⅴ在细胞周期中的变化,采用血清饥饿法对7721人肝癌细胞进行同步化培养,用流式细胞仪(FCM)测定处于不同生长期的细胞比例,同时测定P34~(cdc2)激酶活性验证细胞周期。GlcNAc-TⅢ的活性在G_0/G_1期细胞的高峰时相较高,与该期的细胞百分比存在着明显的相关性(r=0.760,P<0.05),而GlcNAc-T Ⅴ活性的升高出现在G_2/M期细胞最多的时相,且与该期的细胞百分比间亦存有明显的相关性(r=0.868,P<0.001)。GlcNAc-T Ⅳ的活性改变与细胞周期关系不大。GlcNAc-T Ⅲ和GlcNAc-T Ⅴ在细胞周期中的变化呈现出相反的趋势(r=-0.951,P<0.001),提示GlcNAc-T Ⅲ可能与细胞分裂的静止有关,或者说是抗增殖的,而GlcNAc-T Ⅴ则可能与细胞的增殖有关。用免疫组化法发现GlcNAc-TⅤ的蛋白含量在整个细胞周期中无明显改变,与酶活性之间无相关性存在,故此酶在细胞周期中活性变化不是由酶蛋白合成改变而引起的。GlcNAc-T Ⅴ其活性在细胞周期中的变化与p34~(cdc2)激酶活性改变相一致(r=0.752,P<0.05),推测该酶的活性变化可能受到p34~(cdc2)激酶的调控。     

The lateral line canal sensory organs of the Epaulette Shark (Hemiscyllium ocellatum)

Examination of the lateral line canals in the Epaulette Shark reveals a much more differentiated sensory system than previously reported from any elasmobranch. Two main types of lateral line canals are found. In one type rounded patches of sensory epithelia are separated by elevations of the canal floor. The other type is a straight canal without restrictions and with an almost continuous sensory epithelium. In addition, we found epithelia (type A) with very long apical microvilli on the supporting cells. These microvilli reach beyond the stereovilli of the hair cells. Another type (B) of sensory epithelium has short microvilli on the supporting cells. In this latter type of epithelium the stereovilli of the hair cells are comparatively tall and reach out beyond the supporting cell microvilli.
  New hair cells are found widely in both types of sensory epithelia. These always occur as single cells, unlike those described in teleost lateral line canal sensory epithelia where new hair cells seem to form in pairs. Dying hair cells are also widespread, indicating a continuous turnover of hair cells.     

X连锁隐性遗传性Marinesco-Sjgren综合征一家系五代11例报告

报告一个Marinesco -Sj gren综合征 (MSS)的大家系。通过家系调查和查体发现MSS患者 11例 ,均为男性 ,已死亡 7例 ,死亡年龄为 15～ 2 0岁。患者均具有先天性白内障 ,智能发育迟滞、小脑性共济失调及骨骼畸形等征候。存活 4例还伴有FSH水平增高 ,LH及T水平降低。结论认为该MSS家系为X连锁隐性遗传。     

Latitudinal response of subarctic tree lines to recent climate change in eastern Canada

Aim The predictions from biogeographical models of poleward expansion of biomes under a warmer 2 × CO2 scenario might not be warranted, given the non‐climatic influences on vegetation dynamics. Milder climatic conditions have occurred in northern Québec, Canada, in the 20th century. The purpose of this study was to document the early signs of a northward expansion of the boreal forest into the subarctic forest‐tundra, a vast heterogeneous ecotone. Colonization of upland tundra sites by black spruce (Picea mariana (Mill.) BSP.) forming local subarctic tree lines was quantified at the biome scale. Because it was previously shown that the regenerative potential of spruce is reduced with increasing latitude, we predicted that tree line advances and recent establishment of seedlings above tree lines will also decrease northwards. Location Black spruce regeneration patterns were surveyed across a > 300‐km latitudinal transect spanning the forest‐tundra of northern Québec, Canada (55°29′–58°27′ N). Methods Elevational transects were positioned at forest–tundra interfaces in two regions from the southern forest‐tundra and two regions from the northern forest‐tundra, including the arctic tree line. The surroundings of stunted black spruce, forming the species limit in the shrub tundra, were also examined. Position, total height and origin (seed or layer) of all black spruce stems established in the elevational transects were determined. Dendrochronological and topographical data allowed recent subarctic tree line advances to be estimated. Age structures of spruce recently established from seed (< 2.5 m high) were constructed and compared between forest‐tundra regions. Five to 20‐year heat sum (growing degree‐days, > 5 °C) and precipitation fluctuations were computed from regional climatic data, and compared with seedling recruitment patterns. Results During the 20th century, all tree lines from the southern forest‐tundra rose slightly through establishment of seed‐origin spruce, while some tree lines in the northern forest‐tundra rose through height growth of stunted spruce already established on the tundra hilltops. However, the rate of rise in tree lines did not slow down with latitude. The density of < 2.5‐m spruce established by seed declined exponentially with latitude. While the majority of < 2.5‐m spruce has established since the late 1970s on the southernmost tundra hilltops, the regeneration pool was mainly composed of old, suppressed individuals in the northern forest‐tundra. Spruce age generally decreased with increasing elevation in the southern forest‐tundra stands, therefore indicating current colonization of tundra hilltops. Although spruce reproductive success has improved over the twentieth century in the southern forest‐tundra, there was hardly any evidence that recruitment of seed‐origin spruce was controlled by 5‐ to 20‐year regional climatic fluctuations, except for winter precipitation. Main conclusions Besides the milder 20th century climate, local topographic factors appear to have influenced the rise in tree lines and recent establishment by seed. The effect of black spruce's semi‐serotinous cones in trapping seeds and the difficulty of establishment on exposed, drought‐prone tundra vegetation are some factors likely to explain the scarcity of significant correlations between tree establishment and climatic variables in the short term. The age data suggest impending reforestation of the southernmost tundra sites, although the development of spruce seedlings into forest might be slowed down by the harsh wind‐exposure conditions.     

On-line estimation of the metabolic burden resulting from the synthesis of plasmid-encoded and heat-shock proteins by monitoring respiratory energy generation.

Human basic fibroblast growth factor (hFGF-2) was produced in high-cell density cultures of recombinant Escherichia coli using a temperature-inducible expression system. The synthesis rates of proteins were followed by two-dimensional gel electrophoresis of the (35)S-methionine-labeled proteom. After temperature induction of hFGF-2 synthesis, the rate of total protein synthesis per biomass increased by a factor of three, mainly as a result of the additional synthesis of hFGF-2 and heat-shock proteins. The synthesis rates of heat-shock proteins and constitutive plasmid-encoded proteins increased after the temperature upshift also in the control strain without hFGF-2 gene but followed time profiles different from the producing strain. The energy demand for the extra synthesis of plasmid-encoded and heat-shock proteins resulted in an elevated respiratory activity and, consequently, in a reduction of the growth rate and the biomass yield. A procedure was developed to relate the energy demand for the additional synthesis of these proteins to the generation of energy in the respiratory pathway. Specific energy production was estimated based on on-line measurable rates of oxygen consumption, or carbondioxide evolution and growth, respectively. In this way, the metabolic burden resulting from the synthesis of plasmid-encoded and heat-shock proteins was quantified from on-line accessible data.     

Development and characterization of SV40 immortalized rat parotid acinar cell lines

Summary Rat parotid salivary gland acinar cells were transfected by CaPO₄ precipitation using a plasmid containing a replication-defective simian virus (SV40) genome. Out of 30 clonal cell lines, 2 were shown to have moderate to high levels of cytodifferentiation and salivary gland acinar cell function. Functional studies with the two cell lines indicated that the β-adrenergic agonist (isoproterenol), vasoactive intestinal peptide prostaglandin E₁, and forskolin were effective activators of intracellular cyclic adenosine 3′:5′-cyclic monophosphate production. Phenylephrine, carbamylcholine, and UTP were effective in increasing inositol phosphate production and intracellular free calcium levels, whereas substance P was without affect. Utilizing indirect immunofluorescence analysis, both cell lines were shown to express the SV40 large T antigen. Electron microscopic evaluation documented moderate to high levels of cytodifferentiation with the maintenance of tripartite junctional complexes, cellular polarization, and presence of moderate amounts of secretory granules and rough endoplasmic reticulum. The two cell lines had doubling times of 22 and 36 h, respectively.