Contrasting patterns in elevational diversity between microorganisms and macroorganisms

Aim Data and analyses of elevational gradients in diversity have been central to the development and evaluation of a range of general theories of biodiversity. Elevational diversity patterns have, however, been severely understudied for microbes, which often represent decomposer subsystems. Consequently, generalities in the patterns of elevational diversity across different trophic levels remain poorly understood. Our aim was to examine elevational gradients in the diversity of macroinvertebrates, diatoms and bacteria along a stony stream that covered a large elevational gradient. Location Laojun Mountain, Yunnan province, China. Methods The sampling scheme included 26 sites spaced at elevational intervals of 89 m from 1820 to 4050 m elevation along a stony stream. Macroinvertebrate and diatom richness were determined based on the morphology of the specimens. Taxonomic richness for bacteria was quantified using a molecular fingerprinting method. Over 50 environmental variables were measured at each site to quantify environmental variables that could correlate with the patterns of diversity. We used eigenvector‐based spatial filters with multiple regressions to account for spatial autocorrelation. Results The bacterial richness followed an unexpected monotonic increase with elevation. Diatoms decreased monotonically, and macroinvertebrate richness showed a clear unimodal pattern with elevation. The unimodal richness pattern for macroinvertebrates was best explained by the mid‐domain effect (r² = 0.72). The diatom richness was best explained by the variation in nutrient supply, and the increase in bacterial richness with elevation may be related to an increased carbon supply. Main conclusions We found contrasting patterns in elevational diversity among the three studied multi‐trophic groups comprising unicellular and multicellular aquatic taxa. We also found that there may be fundamental differences in the mechanisms underlying these species diversity patterns.     

Dependence on blood acetate concentration of the metabolic effects of ethanol in perfused rat liver

Unprotected oligonucleotides and oligodeoxynucleotides terminated with an unhindered 5'-phosphate group react with nucleoside 5'- phosphorimidazolides in aqueous solution to give 'capped' pyrophosphates in at least 70% yield. If adenosine 5'- phosphorimidazolide is used as a substrate in the reaction, ligase intermediates are obtained as products.     

Fatty acid composition and content of individual lipid fractions in adipose and muscle tissue of albino rats with alloxan diabetes

A study was made of the fatty acid composition and the content of triglycerides, phospholipids and nonesterified fatty acids (NFA) in adipose and muscle tissues of rats with alloxan diabetes. The concentration of NFA in alloxan diabetes was found to be considerably reduced in both adipose and muscle tissues. Meanwhile the content of NFA and phospholipids did not experience any substantial changes. The fatty acid composition of triglycerides of the tissues under study was characterized by considerable alterations under diabetes.     

A copper-containing protein that inhibits nitrite reductase from Pseudomonas aeruginosa

A non-blue copper-containing glycoprotein was isolated from Pseudomonas aeruginosa. The protein has a molecular mass of 10 kDa and contains 1 atom of EPR-detectable type II copper. The protein inhibits oxidation of both azurin and cytochrome c-551 catalyzed by nitrite reductase from Ps. aeruginosa. Thus, it may be considered as an endogenous inhibitor of nitrite reductase.     

Molecular cloning of cis-acting regulatory alleles of the Bacillus subtilis amyR region by using gene conversion transformation.

Three cis-acting alleles (gra-10, gra-5, and amyR2) of the Bacillus subtilis amyR promoter locus each cause catabolite repression-resistance of amyE-encoded alpha-amylase synthesis. The gra-10, gra-5, and amyR2 alleles were transferred from the chromosomes of their respective hosts to a plasmid carrying the amyR1-amyE+ gene by the process of gene conversion which is carried out during transformation of competent B. subtilis by plasmid clones carrying homologous DNA. The cloned amyR promoter regions containing the gra-10 and gra-5 mutations were shown to confer catabolite repression-resistance in cis to the synthesis of chloramphenicol acetyltransferase encoded by the cat-86 indicator gene when subcloned into the promoter-probe plasmid pPL603B. Implications concerning both the regulation of amyR utilization and the process of gene conversion in B. subtilis are discussed.     

Colour-blind drivers' perception of traffic signals.

There is a dangerous and widespread assumption that colour-blind drivers drive as safely as drivers with normal vision. Colour-blind drivers have difficulties recognizing traffic and vehicle signals. However, simple and practical solutions such as changes to the design, colour and shape of signals will aid these drivers.     

Widespread cutaneous candidiasis and tinea infection masking mycosis fungoides

A 71-year-old female with a widespread double mycotic infection caused byC. Albicans andT. rubrum was discovered to be suffering from mycosis fungoides. Clinically she was found to have large, polycyclic erythematous plaques with scaly, slightly infiltrated borders, covering almost all areas of the glabrous skin, and also involving the scalp (with no hair penetration), the soles and palms, toe-webs, finger and toe nails; there was also perleche and oral thrush. Cultures yieldedC. albicans from most of the skin lesions, from the scalp, mouth, finger nails and urine and stool specimens, andT. rubrum from intermingled skin specimens, from the palms and soles and toe-nails. Blood culture was negative as were intracutaneous tests with fungal antigens and tuberculin. Histological examination confirmed the fungal invasion of the horny layer and at the same time revealed an underlying pathologic picture of mycosis fungoides, the lesions having been masked by the mycotic eruption. Intensive cytostatic and antifungal therapy led to a transient improvement but shortly thereafter there was a relapse of the fungal and lymphoproliferative manifestations and the patient died in septic shock.

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Résumé Une femme, agée 71 ans, ayant une double infection mycosique due àC. albicans et auT. rubrum, a été décélée qu'elle souffrait aussi d'un mycosis fungoïde. Au point de vue clinique elle avait de larges plaques érythémato-squameuses, polycicliques, aux bords légèrement infiltrés, répandues sur une grande partie de la peau glabre, paumes et plantes inclus, et affectant aussi le cuir chevelu (sans pénétration des poils), les ongles des doigts et des orteils. Les cultures ont permis d'isoler leC. albicans à partir de la majorité des lésions de la peau et du cuir chevelu, des ongles des doigts, ainsi que de la bouche, de l'urine et des selles. On a trouvé aussiT. rubrum dans des lésions cutanées entremêlées aux precedentes, dans la région palmaire et plantaire et dans les ongles des orteils. Les testes intradermiques aux antigens fongiques et à tuberculine ont été négatifs, ainsi que les hémocultures. L'examen histologique a montré l'invasion de la couche cornée par les champignons et en même temps a découvert un tableau pathologique sous-jacent d'un mycosis fungoïde, ayant été masqué par l'éruption fongique. Un traitement intensif par des produits cytostatiques et antifongiques a mené à une amélioration temporaire, mais brièvement après on a assisté à une réchute rapide des manifestations lymphoprolifératives et fongiques et la malade a décédé à la suite d'un état septique.