Rediscovery of Bothynus cribrarius (Fairmaire) (Coleoptera, Melolonthidae, Dynastinae, Pentodontini): description of the male and precise location data

AbstractBothynus cribrarius (Fairmaire) was rediscovered after studying the MNRJ and FIOC collections. The male is described and illustrated for the first time. Accurate location data is presented after 130 years since its species description

Effect of biotin antagonists and related substances upon the growth of the coagulase-negative staphylococci

The biotin activity, or anti-biotin properties of a number of substances, wastested on a group of biotin-requiring, coagulase-negative Staphylococcus strains. Of the 18 cultures tested desthiobiotin served as a source of biotin for 17 strains. This substance appeared to be 40 per cent as active as biotin in supporting growth for two of the cultures tested. This substance possessed antibiotin properties for one strain (S19). Homobiotin, one of the chemical homologs of biotin, served as a biotin source for 17 of the 18 strains. Its activity appeared to be less than 0.1 percent of that of biotin among the 8 strains tested. Although it replaced biotin in high concentrations, small quantities appeared to possess anti-biotin properties for one of the Staphylococcus strains. Homobiotin acted as an ariti-biotin substance for strain S36 in all concentrations tested. In contrast 'to studies reported on other biotin-requiring microorganisms, there appeared to be no stoichiometric relationship between biotin and avidin in the nutrition of Staphylococcus, strain H17C. Upon adding increasing increments of egg white to a medium containing a limited amount of biotion, growth was unaffected until a critical concentration of avidin was reached. At this level little or no growth of the microorganism occurred. At higher levels growth again occurred, the amount depending directly upon the level of egg white added. All Staphylococcus cultures tested (18 strains) were able to utilize biocytin in place of biotin. On a molar basis this substance appeared to have an activity equal to that of biotin. Strain S36 failed to grow in a biotin deficient medium to which 0.1 percent Tween 80 was added. All other strains tested were able to grow under these conditions. In comparison with other strains culture H10A appeared to require approximately 100 times as much biotin for growth. This high requirement could be demonstrated in spite of the fact that the culture was able to grow to a limited degree in the absence of added biotin. This culture also demonstrated similar high requirements for biocytin, homobiotion, and desthiobiotin in a biotin free medium.O artigo não apresenta resumo

Spin-phonon coupling in Gd(Co1/2Mn1/2)O3 perovskite

We have investigated the temperature-dependent Raman-active phonons and the magnetic properties of Gd(Co1/2Mn1/2)O3 perovskite ceramics in the temperature range from 40 K to 300 K. The samples crystallized in an orthorhombic distorted simple perovskite, whose symmetry belongs to the Pnma space group. The data reveals spin-phonon coupling near the ferromagnetic transition occurring at around 120 K. The correlation of the Raman and magnetization data suggests that the structural order influences the magnitude of the spin-phonon coupling.Comment: 3 Figures, suplementary materia

Prediction of potential novel microRNAs in soybean when in symbiosis.

MicroRNAs (miRNAs) are small molecules, noncoding proteins that are involved in many biological processes, especially in plants; among these processes is nodulation in the legume. Biological nitrogen fixation is a key process, with critical importance to the soybean crop. This study aimed to identify the potential of novel miRNAs to act during the root nodulation process. We utilized a set of transcripts that were differentially expressed in soybean roots 10 days after inoculation with Bradyrhizobium japonicum, which were obtained in a previous study, and performed a set of computational analyses that led us to select new miRNAs potentially involved in nodulation. Among these analyses, the set of transcripts were submitted to an in silico annotation of noncoding RNAs, including a search of similarity against miRNA public databases, ab initio tools for miRNA identification, structural search against miRNA families, prediction of the secondary structure of miRNA precursors, and prediction of the sequences of mature miRNAs. Subsequently, we applied filter procedures based on miRNA selections described in the literature (e.g., free energy value). In the next step, a manual curation inspection of the annotation was performed and the top candidates were selected and used for prediction of potential target genes, which were later checked manually in the database of the soybean genome. This prediction led us to the identification of 9 potential new miRNAs; among these, 4 were conserved in other plants. Moreover, we predicted their target genes might play important roles in the regulation of nodulation

Spin-phonon coupling in the incommensurate magnetic ordered phase of orthorhombic TmMnO₃

International audienceThe search for materials with strong magnetoelectric coupling has been intense since interesting properties were discovered in the perovskite TbMnO 3. Among the manganese-based perovskite family (RMnO 3), magnetic and electric orders coexist in the orthorhombic phase of the distorted perovskite TmMnO 3. The antiferromagnetic phase induces ferroelectricity, leading to type-II multiferroic behavior. Although the temperature-dependent behavior of the Raman-active phonons of other members of the orthorhombic RMnO 3 family was already reported, little information about orthorhombic TmMnO 3 has been published. In this paper, bulk samples of orthorhombic TmMnO 3 were obtained through HPHT treatment. Structural and magnetic properties of the synthesized samples were analyzed for phase con rmation. Temperature-dependent Raman spectra of bulk orthorhombic TmMnO 3 revealed weak spin-phonon coupling in the incommensurate antiferromagnetic ordered phase around 44 K. Raman spectra are also sensitive to the magnetic transition from the incommensurate to Etype antiferromagnetic phase, where the frequency renormalization due to the spin-phonon coupling vanishes. This feature shows the existence of an orbital-spin-phonon coupling based on the magnetic ordering of the lowtemperature phase