NIH guidelines. Researchers get green light for work on stem cells

The National Institutes of Health (NIH) issued final guidelines last week allowing NIH-funded researchers to derive human pluripotent stem cells from fetal tissue, but not from embryos. Scientists may also work with embryonic stem cells, but may obtain them only from private sources and must ensure that derivation meets certain ethical conditions. The NIH spent nearly a year finalizing the guidelines, which researchers hope will allow work leading to the improved treatment of diabetes, Parkinson's, and other diseases.     

Light and stomatal function: blue light stimulates swelling of guard cell protoplasts

Onion guard cell protoplasts swell when illuminated with blue light. The response is a 35 to 60 percent increase in volume and is dependent on potassium ion. Epidermal cell protoplasts do not swell under the same conditions. It is postulated that a membrane-bound blue photoreceptor mediates a direct response of guard cells to light.     

Stem cell research. Reports give green light in Australia, Israel

BERLIN AND MELBOURNE--After 2 years of deliberation, an Australian government committee has endorsed legislation that would allow both human embryonic stem cell research and the derivation of ES cells from unwanted embryos created during fertility treatments. And in Israel, another country at the forefront of work on ES cells, a national bioethics committee has approved both the derivation of ES cells and research into therapeutic cloning.     

鲟鱼剥制标本的制作

鱼类标本的制作方法较多,依个体大小及用途的不同,有浸渍标本、剥制标本、骨骼标本等.剥制标本是剥取动物的外皮,内面涂以防腐剂或将整张皮用防腐固定液浸泡,再用钢棍、铅丝、木架和填充物支撑制成的标本,它的制作是动物学技术的主要内容之一.剥制标本主要供教学、研究、博物馆陈列观摩和家庭等场所的陈设.现将鲟鱼（Acipenser）剥制标本制作过程介绍如下.     

酸凝乳的制作工艺

酸凝乳是以新鲜全脂牛奶为原料,经乳酸菌发酵制成的凝固型乳制品,长期饮用对人体有很多好处:第一,营养作用.酸牛奶中蛋白质、脂肪、糖类、矿物质及各种维生素含量丰富;第二,保健作用.酸牛奶中的钙在乳酸的作用下生成乳酸钙,便于人体吸收,有治疗乳糖分解酶缺乏症,减轻抗菌素药物的副作用,降低体内胆固醇等功能;第三,增强肌体免疫力.酸凝乳中含有的乳酸可以使胃肠道内中性和碱性环境变成酸性,增强胃肠消化能力,抑制有害细菌的生长繁殖,促进肝脏功能活力,减少疾病的发生.