Slight differences among individuals and the unified neutral theory of biodiversity

The unified neutral theory of biodiversity provides a very simple and counterintuitive explanation of species diversity patterns. By specifying speciation, community size and dispersal, and completely ignoring differences among individual organisms and species, it generates biodiversity patterns that remarkably resemble natural ones. Here I show that adding even slight differences among organisms generates very different patterns and predictions. In large communities with widespread dispersal, heritable differences in viability among individual organisms lead to biodiversity patterns characterised by the overdominance of a single species comprising organisms with relatively high fitness. In communities with local dispersal, the same differences produce rapid community extinction. I conclude that the unified neutral theory is not robust to slight deviations from its most controversial assumption.     

Systematic reviews and meta-analyses on treatment of asthma: critical evaluation

ObjectiveTo evaluate the clinical, methodological, and reporting aspects of systematic reviews and meta-analyses on the treatment of asthma and to compare those published by the Cochrane Collaboration with those published in paper based journals.DesignAnalysis of studies identified from Medline, CINAHL, HealthSTAR, EMBASE, Cochrane Library, personal collections, and reference lists.StudiesArticles describing a systematic review or a meta-analysis of the treatment of asthma that were published as a full report, in any language or format, in a peer reviewed journal or the Cochrane Library.Results50 systematic reviews and meta-analyses were included. More than half were published in the past two years. Twelve reviews were published in the Cochrane Library and 38 were published in 22 peer reviewed journals. Forced expiratory volume in one second was the most frequently used outcome, but few reviews evaluated the effect of treatment on costs or patient preferences. Forty reviews were judged to have serious or extensive flaws. All six reviews associated with industry were in this group. Seven of the 10 most rigorous reviews were published in the Cochrane Library.ConclusionsMost reviews published in peer reviewed journals or funded by industry have serious methodological flaws that limit their value to guide decisions. Cochrane reviews are more rigorous and better reported than those published in peer reviewed journals.     

Synthesis of glycosyl(thio)ureido sugars via carbodiimides and their conformational behaviour in water

The preparation of sugar ureas and thioureas by nucleophilic addition of water or hydrogen sulfide, respectively, to sugar-derived carbodiimides has been examined. Acetic acid efficiently catalysed the formation of ureas, whereas silica gel was found to be a more convenient catalyst in the case of the thioxo analogues. The procedures have been exploited in the development of an amine- and isocyanate-free synthesis of urea- and thiourea-tethered pseudooligosaccharides via the corresponding glycosylcarbodiimido sugars. The fully unprotected compounds adopted, preferentially, the (Z,Z) configuration at the pseudoamide bonds in water solution.     

The Ideal Therapy Must Be Def ined in Each Geographical Area: Experience with a Quadruple Therapy in Spain

Background. Multiple therapeutic combinations have been tested to determine the optimal regimen(s) for Helicobacter pylori eradication, leading to very different results depending on the geographical area. Our goal was to evaluate the efficacy of a "quadruple" therapy with omeprazole, tetracycline, bismuth and metronidazole in our area.
Materials and Methods. We investigate 106 consecutive patients with active peptic ulcer disease (duodenal, gastric or both) and Helicobacter pylori infection. One-week therapy with omeprazole 20 mg b.i.d., tetracycline hydrochloride 500 mg q.i.d., colloidal bismuth subcitrate 120 mg q.i.d., and metronidazole 250 mg t.i.d was prescribed. Between the days 30 and 40 after treatment ended follow-up endoscopy was performed. Eradication was defined as both negative urease test and histology. Between days 90 and 360 a ¹³C urea breath test was performed in 100 patients.
Results. Of the 106 patients in the study, 91 had duodenal ulcer, 12 had gastric ulcer, and 3 had both. Side effects were observed in 25% of the cases. Eradication was achieved in 87.7% (93/106; CI 79.9–93.3). Healing was obtained in 95.2% (100/105; CI 89.2–98.4); 97.8% (CI 92.4–99.7) in those eradicated and 75% (CI 42.8–94.5) in non-eradicated ( p < .01).
Conclusions. Quadruple therapy with omeprazole, tetracycline, bismuth subcitrate and metronidazole achieves healing rates up to 95–100%. The 87.7% eradication rate obtained suggests that the regimen we used is a reasonable therapeutic alternative in our area.     

Pines and oaks in the restoration of Mediterranean landscapes of Spain: New perspectives for an old practice — a review

Pines have been extensively used for land restoration in the Mediterranean basin and in other parts of the world, since the late 19^th century. The theoretical basis supporting pine utilisation was its stress-tolerant and pioneer features, and their attributed role of facilitating the development of late-successional hardwoods in the long-term. In the present work, the use of pines and hardwoods in forest restoration is discussed in the frame of the current disturbance regime and social demands for Mediterranean forests. Large pine plantations have recently disappeared because of their sensitivity to fire (e.g., Pinus nigra) or because of the short fire-intervals (e.g., Pinus halepensis). Combined pine and oak plantations are proposed for degraded land restoration on the basis of the complementary features of both groups of species. Seeding and containerised seedling plantation, soil amendments and plantation techniques to reduce transplant shock are evaluated for reforestation under water-stressing conditions, on the basis of several experiments performed in eastern Spain. Both P. halepensis and Quercus ilex are tested.     

Comparative population genetics of <Emphasis Type="Italic">Basilichthys microlepidotus</Emphasis> (Atheriniformes: Atherinopsidae) and <Emphasis Type="Italic">Trichomycterus areolatus</Emphasis> (Siluriformes: Trichomycteridae) in north central Chile

To describe comparative population genetic structure of the Chilean silverside Basilichthys microlepidotus and the catfish Trichomycterus areolatus, four rivers and three sites within each river were investigated by the analysis of haplotype polymorphisms of the mitochondrial Control Region. For both species, analyses revealed significant differentiation among rivers and low differences within rivers. However, the species differ in haplotype composition; individuals of B. microlepidotus shared some haplotypes in all four rivers, while individuals of T. areolatus showed a different haplotype composition in most rivers. This difference may be explained by the different ecological features of the species. Assuming that both silversides and catfish were present before the separation of the rivers, B. microlepidotus migrated after river isolation, probably using coastal water, while T. areolatus has probably never migrated between these rivers. The long times that the studied rivers have been separated should be taken into account in future conservation plans for the freshwater fish of Chile.     

Temperature effect on oxidative stress and egg quality-related genes on post-ovulatory eggs and ovary of red cusk-eel (Genypterus chilensis)

Red cusk-eel (Genypterus chilensis) is a native species with potential for Chilean aquaculture diversification. However, no information exists on the effects of temperature on oxidative stress and eggs quality markers in post-ovulatory eggs and ovary of this species. We determine that high and low temperature generate oxidative damage on post-ovulatory eggs, with no effect on ovary. Temperature induces thermal stress markers expression on post-ovulatory eggs, and modulates antioxidant and eggs quality markers on post-ovulatory eggs and ovary, information to consider for quality evaluation in the red cusk-eel management.     

Normal and aberrant Mesocestoides tetrathyridia from Crocidura spp. (Soricimorpha) in Corsica and Spain

Tetrathyridia of Mesocestoides sp. were collected from the body cavities of the shrews (Insectivora), Crocidura russula, in Valencia, Spain and Crocidura suaveolens on the Mediterranean island of Corsica, France. Specimens were processed by routine microscopic and histological techniques, including examination with brightfield, phase-contrast, and differential-interference-contrast optics. Most tetrathyridia were clustered together inside host-derived fibrotic capsules, but some occurred free in the body cavity. All specimens examined from both locations had solid hindbodies, i.e., lacking a primary lacuna, thus conforming to the plerocercoid metacestode type; all possessed a single normal tetra-acetabulate scolex. All metacestodes from C. russula in Valencia were normal tetrathyridia. Those from C. suaveolens in Corsica were either normal tetrathyridia or had aberrant deep convolutions of an unusually elongated hindbody. No tetrathyridium from either location or host showed tegumental or excretory duct anomalies such as those reported by several authors from aberrant tetrathyridia and spargana in some other locations. No definitive evidence of asexual proliferation was visible in any of the tetrathyridia, but those with abnormally convoluted hindbodies from a single C. suaveolens in Corsica suggest the potential for asexuality by fission of the hindbody. These results add to our understanding of morphological and developmental variation among metacestodes in this widespread and variable genus.