Trace metals especially Fe+++ as dietary factors for leafhoppers

Summary Some trace metals are required for development and reproduction, and therefore for continuous rearing of the aster leafhopper,Macrosteles fascifrons, on a holidic diet. Requirement for Fe⁺⁺⁺ becomes apparent immediately in the 1st generation; for Cu⁺⁺ and Zn⁺⁺, in the 3rd. The leafhopper has grown normally and continuously for 3 generations in the absence of manganese.We acknowledge the Minnesota Agricultural Experiment Station and the National Institute of Allergy and Infectious Diseases, USA, for financial supports.     

A 1000-year chironomid-based salinity reconstruction from varved sediments of Sugan Lake, Qaidam Basin, arid Northwest China, and its palaeoclimatic significance

A 1000-year high-resolution （-10 years） chironomid record from varved sediments of Sugan Lake, Qaidam Basin on the northern Tibetan Plateau, is presented. The chironomid assemblages are mainly composed of the relatively high-saline-water taxa Psectrocladius barbimanus-type and Orthocladius/ Cricotopus, and the relatively low-saline-water taxa Procladius and Psectrocladius sordidellus-type. Variations in the chironomid fauna and inferred salinities suggest that over the last millennium, the Sugan Lake catchment has alternated between contrasting climatic conditions, having a dry climate during the period 990-1550 AD, a relatively humid climate during the Little Ice Age （LIA） （1550-1840 AD）, and a dry climate again from 1840 AD onwards. At the decadal to centennial scale, a wet event around 1200-1230 AD, interrupting the generally arid period （990-1550 AD）, and a dry event around 1590-1700 AD, punctuating the generally humid period （1550-1840 AD）, are clearly documented. Trends in the chironomid-based salinity time series indicate a highly unstable climate during the LIA when salinity fluctuations were of greater magnitude and higher frequency. The effective moisture evolution in the Sugan Lake catchment during the last millennium reconstructed by chironomid analysis is in broad agreement with previous palaeo-moisture data derived from other sites in arid Northwest China （ANC）. The LIA, characterized by generally humid conditions over the westerly-dominated ANC was distinctly different from that in monsoonal China, implying an ＂out-of-phase＂ relationship between moisture evolution in these two regions during the past 1000 years.     

The genome sequence of Schizosaccharomyces pombe

We have sequenced and annotated the genome of fission yeast (Schizosaccharomyces pombe), which contains the smallest number of protein-coding genes yet recorded for a eukaryote: 4,824. The centromeres are between 35 and 110 kilobases (kb) and contain related repeats including a highly conserved 1.8-kb element. Regions upstream of genes are longer than in budding yeast (Saccharomyces cerevisiae), possibly reflecting more-extended control regions. Some 43% of the genes contain introns, of which there are 4,730. Fifty genes have significant similarity with human disease genes; half of these are cancer related. We identify highly conserved genes important for eukaryotic cell organization including those required for the cytoskeleton, compartmentation, cell-cycle control, proteolysis, protein phosphorylation and RNA splicing. These genes may have originated with the appearance of eukaryotic life. Few similarly conserved genes that are important for multicellular organization were identified, suggesting that the transition from prokaryotes to eukaryotes required more new genes than did the transition from unicellular to multicellular organization.     

Effectiveness of the global protected area network in representing species diversity

The Fifth World Parks Congress in Durban, South Africa, announced in September 2003 that the global network of protected areas now covers 11.5% of the planet's land surface. This surpasses the 10% target proposed a decade earlier, at the Caracas Congress, for 9 out of 14 major terrestrial biomes. Such uniform targets based on percentage of area have become deeply embedded into national and international conservation planning. Although politically expedient, the scientific basis and conservation value of these targets have been questioned. In practice, however, little is known of how to set appropriate targets, or of the extent to which the current global protected area network fulfils its goal of protecting biodiversity. Here, we combine five global data sets on the distribution of species and protected areas to provide the first global gap analysis assessing the effectiveness of protected areas in representing species diversity. We show that the global network is far from complete, and demonstrate the inadequacy of uniform--that is, 'one size fits all'--conservation targets.     

Chromatographic evidence for murein from the bacteroid symbiotes ofPeriplaneta americana (L)

Zusammenfassung Papierchromatographisch wurde Murein in symbiontischen Bakteroiden derPeriplaneta americana nachgewiesen. Die Murein-Komponente Glukosamin und der Murein-Anzeiger Muramic-Säure wurden mittels Bakteroid-Hydrolysaten identifiziert. Das Vorhandensein von --Diaminopimelic-Säure jedoch konnte nicht einwandfrei festgestellt werden.

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This is paper No. 6175, Scientific Journal Series, Minnesota Agricultural Experiment Station, St. Paul (Minnesota, USA). The work was supported by U.S. Public Health Service Research Grant No. AI 00961, from the National Institute of Allergy and Infectious Diseases of the National Institutes of Health.