Marine biodiversity hotspots and conservation priorities for tropical reefs   总被引：1，自引：0，他引：1  

Roberts CM  McClean CJ  Veron JE  Hawkins JP  Allen GR  McAllister DE  Mittermeier CG  Schueler FW  Spalding M  Wells F  Vynne C  Werner TB 《Science (New York, N.Y.)》2002,295(5558):1280-1284

Coral reefs are the most biologically diverse of shallow water marine ecosystems but are being degraded worldwide by human activities and climate warming. Analyses of the geographic ranges of 3235 species of reef fish, corals, snails, and lobsters revealed that between 7.2% and 53.6% of each taxon have highly restricted ranges, rendering them vulnerable to extinction. Restricted-range species are clustered into centers of endemism, like those described for terrestrial taxa. The 10 richest centers of endemism cover 15.8% of the world's coral reefs (0.012% of the oceans) but include between 44.8 and 54.2% of the restricted-range species. Many occur in regions where reefs are being severely affected by people, potentially leading to numerous extinctions. Threatened centers of endemism are major biodiversity hotspots, and conservation efforts targeted toward them could help avert the loss of tropical reef biodiversity.  相似文献   

Mars-like soils in the Atacama Desert, Chile, and the dry limit of microbial life     

Navarro-González R  Rainey FA  Molina P  Bagaley DR  Hollen BJ  de la Rosa J  Small AM  Quinn RC  Grunthaner FJ  Cáceres L  Gomez-Silva B  McKay CP 《Science (New York, N.Y.)》2003,302(5647):1018-1021

The Viking missions showed the martian soil to be lifeless and depleted in organic material and indicated the presence of one or more reactive oxidants. Here we report the presence of Mars-like soils in the extreme arid region of the Atacama Desert. Samples from this region had organic species only at trace levels and extremely low levels of culturable bacteria. Two samples from the extreme arid region were tested for DNA and none was recovered. Incubation experiments, patterned after the Viking labeled-release experiment but with separate biological and nonbiological isomers, show active decomposition of organic species in these soils by nonbiological processes.  相似文献   

Looking at a renegade's predecessors     

Burton F 《Science (New York, N.Y.)》2002,296(5571):1237

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Membership Secretary’s report July 1983–June 1984     

Fred J. Cole 《American Journal of Potato Research》1984,61(10):627-628

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Health effects of wheat lectins: A review     

Vincent J. van Buul  Fred J.P.H. Brouns 《Journal of Cereal Science》2014

Lectins are carbohydrate-binding proteins present in most plants. They play a role in protecting plants against external pathogens, like fungi, and other organisms. Some common dietary staples, such as cereal grains and legumes, have relatively high concentrations of a variety of lectins. A part of the proteins present in wheat germ is characterized as wheat germ agglutinin (WGA), in this respect. Authors of popular nutritional plans propose adverse health effects of this wheat lectin. With the use of different arguments, the consumption of foods high in lectins is discouraged. In this context, we discuss the effects of lectins from wheat on human health. Up-to-date research findings on mechanisms that wheat lectins have effects on health factors, such as obesity, autoimmune disease, and celiac disease, are critically reviewed. We conclude that there are many unsubstantiated assumptions made. Current data about health effects of dietary lectins, as consumed in cooked, baked, or extruded foods do not support negative health effects in humans. In contrast, consumption of WGA containing foods, such as cereals and whole grain products, has been shown to be associated with significantly reduced risks of type 2 diabetes, cardiovascular disease, some types of cancer, as well as a more favourable long-term weight management. Research is recommended to define actual active lectin contents in wheat-based foods after heat preparation for human consumption.  相似文献   

Erodibility of a soil drainage sequence in the loess uplands of Mississippi     

Fred E. Rhoton  Sjoerd W. Duiker 《CATENA》2008

The susceptibility of loess soils in the lower Mississippi to runoff and erosion losses varies as a function of landscape position and mapping units. This study was conducted to determine the effects of soil drainage on physical and chemical properties that influence erodibility through their control of aggregate stability. Soil samples were collected from the A- and B-horizons of the five representative pedons in the Memphis catena whose drainage class varied from well-drained to poorly-drained. The fine earth fraction (< 2 mm) of each soil was characterized for a range of basic soil physical and chemical properties. Additional sub-samples (< 8 mm) were placed in a rainfall simulator pan (0.6 m × 0.6 m test area) and subjected to simulated rainfall at an intensity of 64 mm h^− 1. Soil erodibility was assessed by the use of an aggregation index (AI) computed from water dispersible clay (WDC) relative to total clay contents. The data show that as soil drainage classes became wetter, the percentage of sediment < 53 µm increased with a decrease in soil AI resulting from a loss of Fe, Al, and Si oxide cementing agents. These results suggest that cementing agents responsible for soil aggregate stabilization are mobilized under conditions of relatively low redox potentials which increase soil erodibility.  相似文献   

Geophysics. A new class of earthquake observations     

Pollitz FF 《Science (New York, N.Y.)》2006,313(5787):619-620

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p53 regulates mitochondrial respiration   总被引：4，自引：0，他引：4  

Matoba S  Kang JG  Patino WD  Wragg A  Boehm M  Gavrilova O  Hurley PJ  Bunz F  Hwang PM 《Science (New York, N.Y.)》2006,312(5780):1650-1653

The energy that sustains cancer cells is derived preferentially from glycolysis. This metabolic change, the Warburg effect, was one of the first alterations in cancer cells recognized as conferring a survival advantage. Here, we show that p53, one of the most frequently mutated genes in cancers, modulates the balance between the utilization of respiratory and glycolytic pathways. We identify Synthesis of Cytochrome c Oxidase 2 (SCO2) as the downstream mediator of this effect in mice and human cancer cell lines. SCO2 is critical for regulating the cytochrome c oxidase (COX) complex, the major site of oxygen utilization in the eukaryotic cell. Disruption of the SCO2 gene in human cancer cells with wild-type p53 recapitulated the metabolic switch toward glycolysis that is exhibited by p53-deficient cells. That SCO2 couples p53 to mitochondrial respiration provides a possible explanation for the Warburg effect and offers new clues as to how p53 might affect aging and metabolism.  相似文献   

Priorities and funding. "Knowledge innovation" and the Chinese Academy of Sciences     

Suttmeier RP  Cao C  Simon DF 《Science (New York, N.Y.)》2006,312(5770):58-59

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An assessment of radiative heating as a thermal treatment for invasive snakes in cargo     

Fred Kraus  Randal Stahl  William Pitt 《国际虫害防治杂志》2018,64(1):27-38

The brown tree snake (Boiga irregularis) is invasive in Guam and presents a continuous threat of accidental export to new islands in outbound cargo. Current attempts to avoid that scenario rely primarily on canine teams to inspect outbound cargo and vehicles. In prior work, we showed that thermal fumigation could effectively elicit snake exit of cargo under conditions when free flow of air streams is feasible, but this method cannot work with tightly packed cargo. Here we show radiative heating can effectively induce snake exit from cargo refuges at temperatures of 44–48 °C; however, we find passive solar heating of cargo to be unreliable in attaining sufficiently high temperatures for cargo sterilization. Although passive solar radiant heating proved unreliable, an active radiant-heating system has promise as a reliable means of treating tightly packed cargo. Times needed for treatment in a closed, controlled setting are sufficiently short that routine application of the method should provide no serious interruption of normal cargo-handling procedures.  相似文献