Sucres insaturés fluorés

Treatment of 1,2:5,6-di-O-isopropylidene-α-d-ribo- and xylo-hexofuranos-3-uloses with (difluoromethylene)triphenylphosphorane and (chlorofluoromethylene)-triphenylphosphorane gave unsaturated, ramified halogeno sugars in good yield. Treatment of the chlorofluoromethylene derivatives with lithium aluminum hydride gave stereospecifically the corresponding fluoromethylene derivatives with inversion of configuration at the double bond. The configuration was determined by ¹h- and ¹⁹F-n.m.r. spectrometry.     

1980s与2020s青藏高原南部土壤质量变化

青藏高原地区气候变暖、冻土融化造成水土流失及土壤质量下降，明确青藏高原土壤质量年代际变化状况，是科学认识该地区土壤资源的基础，是植被恢复和生态重建的关键。本研究选取1980s和2020s青藏高原南部土壤有机质、全氮、全磷等8项指标，通过计算土壤质量指数(SQI)对山地针叶林地带(西藏自然地理分区Ⅱ区)和山地灌丛草原地带(Ⅳ区)土壤质量进行了评价，采用变差分解(VPA)明确造成土壤质量时空分布异质性的原因。结果表明：近40年各自然带土壤质量均呈下降趋势，Ⅱ区SQI从0.505下降至0.484,Ⅳ区SQI从0.458下降至0.425。土壤养分和质量在空间分布上具有异质性，在不同时期，Ⅱ区土壤养分状况及质量均优于Ⅳ区。VPA结果表明，气候变化、土地退化和植被差异的相互作用是造成土壤质量时间变化的主要原因。气候和植被的不同可以较好地解释SQI的空间变化。     

我国1950s～1990s推广的玉米品种叶片

自1950s以来,我国玉米（Zea maysL.）产量以年递增幅度为126kg.hm-2.a-1的速率迅速提高。在高肥力自然光照条件下,通过对我国1950s、1970s、1990s等3个年代玉米主要推广品种的光合特性研究表明：当代品种叶片光合速率高且高值持续期长,光合色素叶绿素a、叶绿素b、类胡萝卜素等的含量高且持续时间长,与光合有关的蒸腾速率（E）、细胞间隙CO2浓度（Ci）、气孔导度（gs）等也有较大改良,中下部叶片尤其明显;在生育后期,当代品种具有更高的光合优势。在品种更替过程中光合色素的组成比率没有显著变化,随品种更替生育后期当代品种细胞间隙CO2浓度低的原因不是气孔限制,而是叶片同化CO2能力增强的结果。我国玉米产量的大幅度提高在很大程度上应归功于叶片光合性能的改良。     

Eye-tracking women’s preferences for men’s somatotypes

Judging physical attractiveness involves sight, touch, sound and smells. Where visual judgments are concerned, attentional processes may have evolved to prioritize sex-typical traits that reflect cues signaling direct or indirect (i.e. genetic) benefits. Behavioral techniques that measure response times or eye movements provide a powerful test of this assumption by directly assessing how attractiveness influences the deployment of attention. We used eye-tracking to characterize women’s visual attention to men’s back-posed bodies, which varied in overall fat and muscle distribution, while they judged the potential of each model for a short- or long-term relationship. We hypothesized that when judging male bodily attractiveness women would focus more on the upper body musculature of all somatotypes, as it is a signal of metabolic health, immunocompetence and underlying endocrine function. Results showed that mesomorphs (muscular men) received the highest attractiveness ratings, followed by ectomorphs (lean men) and endomorphs (heavily-set men). For eye movements, attention was evenly distributed to the upper and lower back of both ectomorphs and mesomorphs. In contrast, for endomorphs the lower back, including the waist, captured more attention over the viewing period. These patterns in visual attention were evident in the first second of viewing, suggesting that body composition is identified early in viewing and guides attention to body regions that provide salient biological information during judgments of men’s bodily attractiveness.     

Dérivés Monotritylés du D-xylose

Monotritylation of O-acetyl derivatives of D-xylopyranose and D-xylofuranose with trityl chloride in acetonitrile-pyridine gave the tri-O-acetyl derivatives of 1-,2-, 3-, and 5-O-trityl-D-xylofuranose and of 1-, 2-, 3-, and 4-O-trityl-D-xylopyranose which were required for the identification of the various monotrityl derivatives obtained in the tritylation at 50° of D-xylose with trityl chloride in pyridine or hexamethylphosphoric triamide-silver acetate.     

Angiogenesis, Kaposi＇s Sarcoma and Kaposi＇s Sarcomaassociated Herpesvirus

Tumor angiogenesis is the uncontrolled growth of blood vessels in tumors,serving to supply nutrients and oxygen,and remove metabolic wastes.Kaposi's sarcoma (KS),a multifocal angioproliferative disorder characterized by spindle cell proliferation,neo-angiogenesis,inflammation,and edema,is associated with infection by Kaposi's sarcoma-associated herpesvirus (KSHV).Recent studies indicate that KSHV infection directly promotes angiogenesis and inflammation through an autocrine and paracrine mechanism by inducing pro-angiogenic and pro-inflammatory cytokines.Many of these cytokines are also expressed in KS lesions,implicating a direct role of KSI-IV in the pathogenesis of this malignancy.Several KSHV genes are involved in KSHV-induced angiogenesis.These studies have provided insights into the pathogenesis of KS,and identified potential therapeutic targets for this malignancy.     

Molecular pharming’s foot in the FDA’s door: Protalix’s trailblazing story

Objectives

This short commentary examines the factors that led to Food and Drug Administration’s approval of the first plant-derived biologic.

Results

In 2012, the first plant-derived protein pharmaceutical (biologic) was approved for commercial use in humans. The product, a recombinant form of human β-glucocerebrosidase marketed as ELELYSO, was developed by Protalix Biotherapeutics (Carmiel, Israel). The foresight to select this particular therapeutic product for development, flawless production pipeline, and serendipity seem to provide the key in explaining how ELELYSO became the first plant-derived biologic to achieve approval by Food and Drug Administration.

Conclusions

While the circumstances that enabled Protalix and its scientists to become the first to arrive at this historic milestone are perhaps unique, it is anticipated that more biologics will follow suit in winning regulatory endorsement.

     

Africa’s highest mountain harbours Africa’s tallest trees

While world records of tree heights were set by American, Australian and Asian tree species, Africa seemed to play no role here. In our study we show that Entandrophragma excelsum (Meliaceae) found in a remote valley at Kilimanjaro has to be included in the list of the world’s superlative trees. Estimating tree age from growth rates monitored by high resolution dendrometry indicates that tall individuals may reach more than 470 years of age. A unique combination of anatomical peculiarities and favorable site conditions might explain their enormous size. The late date of this discovery of Africa’s tallest trees may be due to the comparably low study efforts at Kilimanjaro compared with other biodiversity hotspots. Since only a few square kilometers of this habitat of Entandrophragma are left, Kilimanjaro (and Africa) is about to lose not only a unique biogeographical archive with highly diverse vegetation, but also its tallest trees. The inclusion of these valleys into the immediately neighboring Kilimanjaro National Park would be an excellent and urgent possibility of protection.     

激光辐照的林肯链霉菌（S.lincolnensis）研究

本文首次报导铜蒸气激光辐照林肯链霉菌（Ｓ．ｌｉｎｃｏｌｎｅｎｓｉｓ）的研究结果,曾获得高产株,最高发酵单位比对照未辐照者提高１５．８％。     

THE BREEDING SEASON IN S.W. ECUADOR

The breeding season on the Santa Elena peninsula in S.W. Ecuador is described on the basis of 1761 nests found in the four years 1955 to 1958. The environment and climate are outlined—a cool, dry season from about May to November and a warm, variable wet season from December to April, when alone rain may fall. It is shown that each year the general breeding season is closely correlated with the rainfall. The peak of breeding varies from year to year by at least a month and its length from about six weeks to three and a half months.
Although all species for which there are enough data, are stimulated to breed after important falls of rain, most of those species of small land-birds which are completely resident, attempt to nest before the rain and often continue for some time afterwards. Some specific differences, between seed- and insect-eating finches, seem to be adaptations to food supply and the availability of nest sites and building material. Such evidence as there is suggests that raptors, waders and waterfowl also nest in the wet season (often late), rather than in the dry season. (Unfortunately herons and sea-birds do not nest in the area.)
Annual differences in the amount of breeding by the same species are thought not to be entirely due to differences in weather between years.
It is suggested that the late (August-September) breeding in the Galápagos Islands described by Lack (1950) and the apparent dry-season nesting of raptors, waders and waterfowl there might be found to be linked with variable or abnormally wet weather, if records of rainfall from the islands were available.     

蝇髓部细胞的运动敏感性

用细胞外记录方法研究了蝇髓部细胞的运动敏感性.实验证明,在蝇髓部有运动敏感型细胞,它们的主要特点是对运动敏感,但不具有方向选择性.其主要性质如下:1.有些细胞对闪光刺激给出超极化反应,有些则为去极化反应;2.对运动反应,但不具有方向性;3.有些对大视场的运动敏感,有些则对小视场的运动敏感;4.反应幅度与图形运动速度有关;5.感受野为简单型,并且不很大.对于可能对应的算法进行了讨论.