西藏札达及米林发现噪鹃

正在开展西藏第二次陆生野生动物资源调查工作过程中,于2015年6月18日在西藏自治区札达县底雅乡底雅村(31°46′55.5″N,78°52′5.1″E,海拔2 977 m)观察并拍摄到1只雄性噪鹃(Eudynamys scolopaceus)。另一组调查人员曾于2015年5月1日在西藏自治区林芝市米林县羌纳乡岗嘎村遮磨岗(29°18′28.15″N,94°21′44.23″E,3 000 m)听到过噪鹃的叫声。     

西藏雅鲁藏布江中游发现黄斑褶[鱼兆]

正2016年4月,在西藏雅鲁藏布江中游干流下段的派镇段(29°31′9″N,94°52′12″E,海拔2 897 m),6月在米林段(29°12′1″N,94°5′16″E,海拔2 947 m),2017年7月在里龙段(29°8′32″N,93°54′34″E,海拔2 960 m),使用定置刺网共捕获到15尾疑似黄斑褶(Pseudecheneis sulcatus)的鱼类标本(图1a,b)。2017年4月在雅鲁藏布江下游墨脱段(29°18′10″N,95°16′52″E,海拔682 m)采集到一批黄斑褶标本(图1c,d),并与中游的黄斑褶进行了形态学比较鉴定。     

西藏墨脱发现黑胸楔嘴鹩鹛（Sphenocichla humei）

2014年11月10日在西藏自治区林芝地区墨脱县于墨脱公路海拔1 437 m处(29°35′45″N,95°28′25″E)路边灌丛中发现1群约7只黑胸楔嘴鹩鹛(Sphenocichla humei),经查阅文献,确认这是该物种在中国于印控藏南地区之外的首次记录。     

上海市发现钝尾两头蛇

正2017年9月8日,在上海市大金山岛的南坡中段(30°41′30″N,121°25′04″E,海拔40 m)距山脚约30 m和40 m处,采集到2号蛇类尸体标本。经查阅文献(浙江动物志委员会1990,赵尔宓1999,2006)和鉴定,确认为游蛇科(Colubridae)两头蛇属(Calamaria)的钝尾两头蛇(C.septentrionalis),系上海市首次发现。标本现保存于上海自然博物馆的两栖爬行类标本库房。     

西藏林芝发现宝兴歌鸫

正2012年9月8日上午,在西藏东南部林芝市林芝县色季拉山东坡(29°39′03.39″N,94°42′52.47″E,海拔3 894 m)的急尖长苞冷杉(Abies georgei var.)林中的西南花楸(Sorbus rehderiana)上,发现并拍摄到1只鸫。该鸟体长约25 cm,上体褐色,下体皮黄而具明显黑点,耳羽后侧具月牙状黑色斑块,2条白色的点状翼斑明显(图1)。     

西藏林芝发现宝兴歌鸫北大核心CSCD

2012年9月8日上午,在西藏东南部林芝市林芝县色季拉山东坡(29°39′03.39″N,94°42′52.47″E,海拔3 894 m)的急尖长苞冷杉(Abies georgei var.)林中的西南花楸(Sorbus rehderiana)上,发现并拍摄到1只鸫。该鸟体长约25 cm,上体褐色,下体皮黄而具明显黑点,耳羽后侧具月牙状黑色斑块,2条白色的点状翼斑明显(图1)。     

粗毛肉果草青藏高原新分布

报道了青藏高原通泉草科(Mazaceae)肉果草属(Lancea)粗毛肉果草(Lancea hirsuta Bonati)新分布。该种分布于西藏八宿县(30°12′3.8″N,97°16′48″E)、西藏林周县(30°4′58.8″N,91°16′48″E)、西藏当雄县(30°32′24″N,91°20′24″E)和青海杂多县(33°4′48″N,95°9′36″E),该次发现将中国该种自然分布区扩大到西藏、青海等地,海拔分布也增加至4 300m。凭证标本现存于中国科学院青藏高原生物标本馆(HNWP)。     

西藏墨脱发现棕腹隼雕

正2019年4月15日在西藏林芝市墨脱县墨崩公路段(95°13′23″E,29°16′02″N,海拔800 m)、4月18日在波墨公路80k附近(95°29′28″E,29°39′33″N,海拔2 097 m)分别发现1只棕腹隼雕(Lophotriorchis kienerii)亚成体,并拍摄到其中1只的照片(图1)。该鸟具有白色的眉纹,深色的过眼纹向后延伸至后颈,脸颊、颈侧和喉部白色,翅形宽大,初级飞羽基部腹面有较明显的深色条带,尾黑褐色具黑色     

陕西镇坪发现灰背燕尾

正2015年12月30日,在镇坪县境内陕西化龙山国家级自然保护区浪河口(32°04′38″N,109°29′35″E,海拔813 m)发现并拍摄到2只灰背燕尾(Enicurus schistaceus,图1)正在河道乱石滩上觅食。经查阅《陕西化龙山国家级自然保护区脊椎动物资源及保护》(于晓平等2013)、《中国陕西鸟类图志》(孙承骞2007)、《中国鸟类分类与分布名录》(郑光美2011)和相关文献资料(巩会生等     

Investigation of the mechanism of temperature sensitivity of the electroreceptors of ampullae of lorenzini

In experiments on Black Sea skates (Raja clavata), the potential of the receptor epithelium of the ampullae of Lorenzini and spike activity of single nerve fibers connected to them were investigated during electrical and temperature stimulation. Usually the potential within the canal was between 0 and –2 mV, and the input resistance of the ampulla 250–400 k. Heating of the region of the receptor epithelium was accompanied by a negative wave of potential, an increase in input resistance, and inhibition of spike activity. With worsening of the animal's condition the transepithelial potential became positive (up to +10 mV) but the input resistance of the ampulla during stimulation with a positive current was nonlinear in some cases: a regenerative spike of positive polarity appeared in the channel. During heating, the spike response was sometimes reversed in sign. It is suggested that fluctuations of the transepithelial potential and spike responses to temperature stimulation reflect changes in the potential difference on the basal membrane of the receptor cells, which is described by a relationship of the Nernst's or Goldman's equation type.I. P. Pavlov Institute of Physiology, Academy of Sciences of the USSR, Leningrad. I. M. Sechenov, Institute of Evolutionary Physiology and Biochemistry, Academy of Sciences of the USSR, Leningrad. Pacific Institute of Oceanology, Far Eastern Scientific Center, Academy of Sciences of the USSR, Vladivostok. Translated from Neirofiziologiya, Vol. 12, No. 1, pp. 67–74, January–February, 1980.     

Shapes of curves of pH-dependence of reactions

A simple case is considered in which the rate of a two-step reaction depends on pH because the intermediate formed in the first step has to gain (or lose) a proton before it can react in the second step, and in which the rate-determining step therefore changes with pH. The curves of reaction rate against pH are shown to be symmetrical, and the sharpest peak possible has a width at half its height of 1.53pH units, i.e. of 2log(3+2 radical2). Any particular curve for this situation proves to be identical with a curve that could be generated for the pH-dependence of a single-step reaction in which the rate is proportional to the concentration of a particular ionic form of a reactant. Curves for the latter situation, however, can have forms impossible for the former case in which the rate-determining step changes, but only if the protonations that activate and deactivate the reactant are co-operative. The peak can then become even sharper, and its width at half its height can fall to 1.14pH units, i.e. to 2log(2+ radical3).     

Overview of mechanisms of action of lycopene

Dietary intakes of tomatoes and tomato products containing lycopene have been shown to be associated with decreased risk of chronic diseases such as cancer and cardiovascular diseases in numerous studies. Serum and tissue lycopene levels have also been inversely related to the risk of lung and prostate cancers. Lycopene functions as a very potent antioxidant, and this is clearly a major important mechanism of lycopene action. In this regard, lycopene can trap singlet oxygen and reduce mutagenesis in the Ames test. However, evidence is accumulating for other mechanisms as well. Lycopene at physiological concentrations can inhibit human cancer cell growth by interfering with growth factor receptor signaling and cell cycle progression specifically in prostate cancer cells without evidence of toxic effects or apoptosis of cells. Studies using human and animal cells have identified a gene, connexin 43, whose expression is upregulated by lycopene and which allows direct intercellular gap junctional communication (GJC). GJC is deficient in many human tumors and its restoration or upregulation is associated with decreased proliferation. The combination of low concentrations of lycopene with 1,25-dihydroxyvitamin D3 exhibits a synergistic effect on cell proliferation and differentiation and an additive effect on cell cycle progression in the HL-60 promyelocytic leukemia cell line, suggesting some interaction at a nuclear or subcellular level. The combination of lycopene and lutein synergistically interact as antioxidants, and this may relate to specific positioning of different carotenoids in membranes. This review will focus on the growing body of evidence that carotenoids have unexpected biologic effects in experimental systems, some of which may contribute to their cancer preventive properties in models of carcinogenesis. Consideration of solubility in vitro, comparison with doses achieved in humans by dietary means, interactions with other phytochemicals, and other potential mechanisms such as stimulation of xenobiotic metabolism, inhibition of cholesterogenesis, modulation of cyclooxygenase pathways, and inhibition of inflammation will be considered. This review will point out areas for future research where more evidence is needed on the effects of lycopene on the etiology of chronic disease.