Ecophysiological factors affecting growth,sporulation and survival of the biocontrol agent Penicillium oxalicum

The effect of temperature, pH, water potential and sources of nitrogen and carbon on the biocontrol agent Penicillium oxalicum were studied in vitro. The fungus is xerotolerant, mesophillic and has a wide pH tolerance. The parameters evaluated (germination, germ tube length, growth rate and sporulation) showed different sensitivities to the environmental factors. Peptone and free amino acids gave the highest growth rates and high levels of sporulation. Xylose, mannose and fructose gave the highest growth rates and mannose induced strong sporulation. The effect of nutrients (mannose + arginine) and water potential was also studied in vivo. The xerotolerant character of the fungus was confirmed. From this study we consider Penicillium oxalicum ecologically competent to perform effectively as a biocontrol agent in the soil environment. This revised version was published online in June 2006 with corrections to the Cover Date.     

Fluxes theory in experiments with random distributed channels on vesicles

When channels are randomly distributed in a population of vesicles, disregarding the number of channels per vesicle, these channels follow a Poisson distribution. This has been verified in many cases, determining the average of channels per vesicle. However, to determine kinetic parameters in population studies, a mathematical expression for the mean flux of solute through channels per vesicle is necessary. Hence, here, this mean flux is calculated, assuming Poisson distributed channels in a population of vesicle. Moreover, this result has been generalized to any number of different kinds of channels (i.e., channels with different permeabilities). These results, useful for in vitro experiments with mixed both channels and vesicles, can be supplemented with those from other techniques, in order to understanding how the nature of the lipid membrane affects kinetic parameters of channel.     

Upslope migration of Andean trees

Aim Climate change causes shifts in species distributions, or ‘migrations’. Despite the centrality of species distributions to biodiversity conservation, the demonstrated large migration of tropical plant species in response to climate change in the past, and the expected sensitivity of species distributions to modern climate change, no study has tested for modern species migrations in tropical plants. Here we conduct a first test of the hypothesis that increasing temperatures are causing tropical trees to migrate to cooler areas. Location Tropical Andes biodiversity hotspot, south‐eastern Peru, South America. Methods We use data from repeated (2003/04–2007/08) censuses of 14 1‐ha forest inventory plots spanning an elevational gradient from 950 to 3400 m in Manu National Park in south‐eastern Peru, to characterize changes in the elevational distributions of 38 Andean tree genera. We also analyse changes in the genus‐level composition of the inventory plots through time. Results We show that most tropical Andean tree genera shifted their mean distributions upslope over the study period and that the mean rate of migration is approximately 2.5–3.5 vertical metres upslope per year. Consistent with upward migrations we also find increasing abundances of tree genera previously distributed at lower elevations in the majority of study plots. Main conclusions These findings are in accord with the a priori hypothesis of upward shifts in species ranges due to elevated temperatures, and are potentially the first documented evidence of present‐day climate‐driven migrations in a tropical plant community. The observed mean rate of change is less than predicted from the temperature increases for the region, possibly due to the influence of changes in moisture or non‐climatic factors such as substrate, species interactions, lags in tree community response and/or dispersal limitations. Whatever the cause(s), continued slower‐than‐expected migration of tropical Andean trees would indicate a limited ability to respond to increased temperatures, which may lead to increased extinction risks with further climate change.     

Biostratigraphy or biochronology? Lessons from the Early and Middle Miocene small Mammal Events in Europe

Since the proposition in 1975 of the European Neogene Mammal (MN) scale by Pierre Mein, the amount of taxonomical, stratigraphical and chronological information around Europe has increased exponentially. In this paper, the stratigraphical schemes of three of the best studied areas for the Lower and Middle Miocene, the Aragonian type area in Spain and the Upper Freshwater Molasse from the North Alpine Foreland Basin in Switzerland and Bavaria, are compared. The correlation of their local biostratigraphies are discussed. Sixteen rodent's events are studied and ranked in the three areas according to their local biostratigraphy. This study shows, and quantifies for the first time, the significant asynchronies of the different included rodent events. The MN-system is discussed in the light of those results. In accordance, we propose that it is still useful but only in a biochronological way, as a sequence of time-ordered reference localities allowing coarse long-distance correlations. In order to obtain better temporal resolution, this system has to be combined with local biostratigraphies that are well calibrated to the time scale, implementing the information about synchrony and diachrony of mammal events in different areas.     

Myogenic Differentiation Potential of Mesenchymal Stem Cells Derived from Fetal Bovine Bone Marrow

The myogenic potential of bovine fetal MSC (bfMSC) derived from bone marrow (BM) remains unknown; despite its potential application for the study of myogenesis and its implications for livestock production. In the present study, three protocols for in vitro myogenic differentiation of bfMSC based on the use of DNA methyltransferase inhibitor 5-Aza-2′-deoxycytidine (5-Aza), myoblast-secreted factor Galectin-1 (Gal-1), and myoblast culture medium SkGM-2 BulletKit were used. Plastic-adherent bfMSC were isolated from fetal BM collected from abattoir-derived fetuses. Post-thaw viability analyses detected 85.6% bfMSC negative for propidium iodine (PI). Levels of muscle regulatory factors (MRF) MYF5, MYF6, MYOD, and DES mRNA were higher (P?MYOD mRNA (Days 7 to 21) and up-regulation of MYF6 (Day 7), MYF5, and DES mRNA (Day 21). Gal-1 and SkGM-2 BulletKit induced sequential down-regulation of early MRF (MYF5) and up-regulation of intermediate (MYOD) and late MRF (DES) mRNA. Moreover, DES and MYF5 were immunodetected in differentiated bfMSC. In conclusion, protocols evaluated in bfMSC induced progress into myogenic differentiation until certain extent evidenced by changes in MRF gene expression.     

Immune complexes and human neoplasia

Summary We have investigated the membrane-binding properties of fetal liver cells (FLC) and developed an assay to quantitate circulating immune complexes (CIC) based on complement (C) receptor binding on FLC. Both binding and blocking studies identified FLC membrane receptors for IgG-Fc, C, and antifetal antibodies (FL-Ab), but not IgG F(ab)2. Fc binding of IgG or aggregated human IgG (AHG) was relatively weak, with an association constant of 1.5×10⁷ l/mol. In contrast, there was a six- to seven-fold increase in binding of AHG by C receptors, with an association constant of 10⁸ l/mol. A simple and sensitive procedure for detecting CIC in the sera of patients with various disease states has been developed by the use of C receptors on FLC. Reference to an AHG standard curve permits quantitation of CIC in micrograms of AHG equivalent per milliliter of serum. Clinical evaluation in patients with active collagen vascular disease and in cancer patients confirmed the reliability, specificity of binding, and sensitivity of the FLC method. Although there was overall agreement with the Raji cell method for CIC detection, FLC-RIA quantiation of CIC was found to be more sensitive than the Raji cell assay. Other discrepancies could be explained by differing sensitivity to CIC size.Preliminary results were presented at the Seventieth Annual Meeting of the American Association for Cancer Research, May 1979 [40]     

Sipuncula of the southeastern Weddell Sea (Antarctica)

Sipunculans collected during the EPOS (European Polarstern Study) leg 3 cruise (13.1.89–10.3.89) to the Weddell Sea shelf area from depths ranging from 186 to 2037 m are recorded. Seven species in three genera are recognized; Nephasoma capilleforme and Phascolion convestitum have not been recorded hitherto in Antarctica. Significant morphological characters as shown by light (LM) and electron (SEM) photographs are described and illustrated. Antarctic distribution maps of the species collected and a checklist of the sipunculan species south of the Antarctic Convergence with depths and bibliographic references are included.