图说 塔河上的管水人(一)

何自举,今可58岁,是农二师35团16连的职工,看泵珀已经6年了这个泵珀就足兵团人现在的活命水的通道.水从30公里外的新北山上通过管道直接引下来,供应34.35团地区饮用.见到他的那天,别的地方天气好好的,一走进35团的地界风开始嗷嗷叫着卷起沙子抽打过来,一条砂石路上横拦着大大小小的沙包.     

图说 塔河上的管水人(二)

来到塔河中游,河床依然是干的,大片新开的棉田靠的是井水灌溉.据我们了解,中游打井也只是近三四年才开始的.随着塔河水愈来愈紧张,井的规模和数量也急剧增加.     

塔河上的管水人（三）

西大桥引水枢纽是阿克苏河上的重要的闸门之一。一条十几米宽的河被五条宽窄不同的渠道把水引向不同的灌区．有地方的有兵团的,另有一个通向天然河道的闸门。“生产要先够了．才能下泄生态水。”水管站负责人说。     

塔河上的管水人（一）

何自举,今年58岁,是农二师35团16连的职工．看泵站已经6年了。这个泵站就是兵团人现在的“活命水”的通道。水从30公里外的新北山上通过管道直接引下来,供应34．35团地区饮用。     

塔河上的管水人（二）

来到塔河中游．河床依然是干的,大片新开的棉田靠的是井水灌溉。据我们了解,中游打井也只是近三四年才开始的。随着塔河水愈来愈紧张．井的规模和数量也急剧增加。     

问题解答(三)

问:在植物学84页的图54小麦的花中2鳞被在雄蕊下,我们在观察小麦花的构造时鳞被的所在部位与图的部位有所不同,是在单一雄蕊的两侧,希望,把小麦花的构造情况详细的给我们写来才好.答:植物学教科书84页的小麦花的构造是不正确的,再版时,一定要改换。小麦花的构造是这样的:外稃内稃各一片,套合着生长,像肥皂盒似的,外稃扣在内稃的外面。如果是有芒的花,芒长在外稃上。在这两面稃片里面,包藏着浆片[书上叫鳞被]两个;雄蕊三枚;雌蕊一枚,柱头两个,上面生有羽状分枝。这两个浆片相当花被,它们长在靠近外稃的那面。你观察的很正确,正对着外稃有一个雄蕊两个浆片生在这一个雄蕊的两侧;也就是说,有一个雄蕊是在两个浆片之间生长着的。(徐晋铭答)     

微管(上)

一、序真核细胞的进化伴随着细胞的结构体制较大的变化。和它们的原核祖先相比较,真核细胞具有更复杂的细胞膜排列,各式各样的不对称的细胞形状,许多新的分泌、运动以及细胞内运送的系统,和遗传物质分离的新方法。这些进展中有许多可能紧紧地依赖着微管的进化,微管实际上是在所有真核生物的生活周期或发育史的某个时候在其细胞里找到的一种用途异常多的蛋白质聚合体。微管是真核生物所独有的并普     

问题解答(三)

问:骨密质的骨小管怎样才能看出来? 答:骨小管(由骨腔隙辐射出来的小管)所以看不见,大概是因为包埋用的树脂太稀,树脂进人骨小管而把它变成与周围基质一样的缘故.如果不用树脂包埋而仅封固盖玻璃,或用浓厚树脂(将块状树脂加温熔化)骨小管由它里面所存在的空气可以显示出来.或用1%硝酸银将将要磨成的骨片(清洗后)泡一昼夜(放暗处),取出后再磨去两面(表面着色太深)即可(磨时须随时在显微镜观察求其适度).(张鋆答)     

问题解答(三)

问:蚜虫的生活史是怎样的?卵怎样会过冬?答:蚜虫种类很多,生活史也有些不同,现在举棉蚜为例:它在春初从卵孵化以后,就单性生殖起来,一年间可以有几十代。到秋末冬初,它在寄主植物上产卵,这些卵再度过冬季。当棉苗没有生长以前,它在几种植物上(如苦贾菜,夏至草等)上生活,五、六月间大部分飞迁到棉株上或瓜上去。等到秋冬之际,棉和瓜都渐苦萎,它又移到其他几种植物上(如苦贾菜夏至草等),然后发生有性生殖,产卵越冬。     

塔河,塔河!尾闾干涸是致命的

2009年春,我们来到塔里木河下游的尾端.这条我国最大的内陆坷在即将走完它里程的时候,完全失去了浩荡的气质,狭窄的河床蜿蜒在沙丘里,仅剩下几米宽河床里有的仅是干透了的泥沙.     

Early Childhood Music Education in Australia: A Snapshot

Policy for early childhood music education (birth to eight years of age) in Australia covers a complex and diverse range of curriculum guidelines and legislation relating to the contexts of day care, preschool, and the early years of school. Australian models and policies vary from state to state and according to setting. Furthermore, early childhood education is constantly changing and evolving, responding to new practices, altered government priorities and funding, and community needs. In this article, the author aims to provide a snapshot of the situation by reviewing and analyzing educational policies, teacher training, and providers of early childhood music programs as well as suggesting some future directions.     

A Snapshot of CNVs in the Pig Genome

Recent studies of mammalian genomes have uncovered the extent of copy number variation (CNV) that contributes to phenotypic diversity, including health and disease status. Here we report a first account of CNVs in the pig genome covering part of the chromosomes 4, 7, 14, and 17 already sequenced and assembled. A custom tiling oligonucleotide array was used with a median probe spacing of 409 bp for screening 12 unrelated Duroc boars that are founders of a large family material. After a strict CNV calling pipeline, 37 copy number variable regions (CNVRs) across all four chromosomes were identified, with five CNVRs overlapping segmental duplications, three overlapping pig unigenes and one overlapping a RefSeq pig mRNA. This CNV snapshot analysis is the first of its kind in the porcine genome and constitutes the basis for a better understanding of porcine phenotypes and genotypes with the prospect of identifying important economic traits.     

The Tenebrionidae of California: A Time Sensitive Snapshot Assessment

Due to a diversity of habitats and its geologic history, the US state of California hosts a spectacular assemblage of darkling beetle species (Coleoptera: Tenebrionidae). In addition to being part of the California Floristic Province, one of 34 global biodiversity hotspots identified by Conservation International, California also has additional areas which are parts of the Great Basin, Mojave, and Sonoran deserts. California is divided into nine floristic regions. Each region is assessed in terms of faunal composition and endemism. A “snapshot” of our present knowledge of the Tenebrionidae indicates that 447 currently recognized species, representing 108 genera, occur in California of which one hundred and ninety are endemic. California is compared to other nearby regions in diversity and endemism. An analysis of currently valid species vs a more realistic species account based on unpublished records of likely synonyms and known species yet to be described in the scientific literature is presented. The California Floristic Region, rather than other more arid parts of California, has the highest number of total and endemic species. Because of their high diversity and endemism, tenebrionids could potentially provide a valuable tool for monitoring the environment for conservation purposes.     

A comparison of the effects of linolenic (18:3 omega 3) and docosahexaenoic (22:6 omega 3) acids on phospholipid bilayers

The class of long chain polyunsaturated fatty acids known as omega-3 are believed to be involved in prevention of a number of human afflictions. The mode of action for two of the most common omega-3 fatty acids, linolenic 18:3 delta 9,12,15 and docosahexaenoic 22:6 delta 4,7,10,13,16,19 (DHA), is not known. One suggestion is that they may be incorporated into membranes and there provide some specific function. Here we compare the effects of DHA and its metabolic precursor linolenic acid on the membrane properties of fluidity, fusion and permeability. The fatty acids were investigated as both free fatty acids and mixed chain 18:0, 18:3 and 18:0, 22:6 phosphatidylcholines (PCs). Fluorescence polarization of 1,6-diphenyl-1,3,5-hexatriene (DPH) and a series of anthracene stearic acid probes indicates 20 mol% incorporation of either fatty acid into dipalmitoylphosphatidylcholine bilayers broadens and depresses the temperature of the phase transition, but has almost no effect on fluidity in the liquid crystalline state. Similar fluidity was also observed in the liquid crystalline bilayers of the mixed chain PCs using the same set of fluorescent fatty acid probes. In contrast, DHA as a free fatty acid or as part of a mixed chain PC, causes a much greater enhancement than linolenic acid of the rates of fusion and permeability as monitored by fluorescence resonance energy transfer and aqueous compartment mixing (fusion) and by lipid vesicle swelling in isotonic erythritol, (permeability). These experiments establish a clear distinction between the effects of linolenic acid and DHA in membranes.