Comparative study on the use of specific and heterologous microsatellite primers in the stingless bees Melipona rufiventris and M. mondury (Hymenoptera, Apidae)

Due to their high degree of polymorphism, microsatellites are considered useful tools for studying population genetics. Nevertheless, studies of genetic diversity in stingless bees by means of these primers have revealed a low level of polymorphism, possibly the consequence of the heterologous primers used, since in most cases these were not specifically designed for the species under consideration. Herein we compared the number of polymorphic loci and alleles per locus, as well as observed heterozygosity in Melipona rufiventris and M. mondury populations, using specific and heterologous primers. The use of specific primers placed in evidence the greater frequency of polymorphic loci and alleles per locus, besides an expressive increase in observed heterozygosity in M. rufiventris and M. mondury, thereby reinforcing the idea that populational studies should be undertaken by preferably using species-specific microsatellite primers

Karyotypic description of the stingless bee Oxytrigona cf. flaveola (Hymenoptera, Apidae, Meliponina) of a colony from Tangará da Serra, Mato Grosso State, Brazil

The aim was to broaden knowledge on the cytogenetics of the subtribe Meliponina, by furnishing cytogenetic data as a contribution to the characterization of bees from the genus Oxytrigona. Individuals of the species Oxytrigona cf. flaveola, members of a colony from Tangará da Serra, Mato Grosso State, Brazil, were studied. The chromosome number was 2n = 34, distributed among four chromosomal morphologies, with the karyotype formula 8m+8sm+16st+2t. Size heteromorphism in the first metacentric pair, subsequently confirmed by sequential staining with fluorochrome (DA/DAPI/CMA3 ), was apparent in all the examined individuals The nucleolar organizing regions (NORs) are possibly located in this metacentric chromosome pair. These data will contribute towards a better understanding of the genus Oxytrigona. Given that species in this group are threatened, the importance of their preservation and conservation can be shown in a sensible, concise fashion through studies such as this

Detection of diploid males in a natural colony of the cleptobiotic bee Lestrimelitta sp (Hymenoptera, Apidae)

When working at quantifying the genome size of stingless bees, it was observed that males of Lestrimelitta sp possessed the same amount of nuclear DNA as the females. Thus, we used flow cytometry (FCM) and cytogenetic analysis to confirm the ploidy of these individuals. The males analyzed proved to be diploid, since, through cytometric analysis, it was demonstrated that the mean genome size of both males and females was the same (C = 0.463 pg), and, furthermore, cytogenetic analysis demonstrated that both had 2n = 28 chromosomes

Variation and genetic structure of Melipona quadrifasciata Lepeletier (Hymenoptera, Apidae) populations based on ISSR pattern

For a study of diversity and genetic structuring in Melipona quadrifasciata, 61 colonies were collected in eight locations in the state of Minas Gerais, Brazil. By means of PCR analysis, 119 ISSR bands were obtained, 80 (68%) being polymorphic. He and H B were 0.20 and 0.16, respectively. Two large groups were obtained by the UPGMA method, one formed by individuals from Januária, Urucuia, Rio Vermelho and Caeté and the other by individuals from São João Del Rei, Barbacena, Ressaquinha and Cristiano Otoni. The Φst and θB values were 0.65 and 0.58, respectively, thereby indicating high population structuring. UPGMA grouping did not reveal genetic structuring of M. quadrifasciata in function of the tergite stripe pattern. The significant correlation between dissimilarity values and geographic distances (r = 0.3998; p < 0.05) implies possible geographic isolation. The genetic differentiation in population grouping was probably the result of an interruption in gene flow, brought about by geographic barriers between mutually close geographical locations. Our results also demonstrate the potential of ISSR markers in the study of Melipona quadrifasciata population structuring, possibly applicable to the studies of other bee species

Cytogenetic characterization of Partamona cupira (Hymenoptera, Apidae) by fluorochromes

Four colonies of the stingless bee Partamona cupira (Hymenoptera: Apidae) were cytogenetically analyzed using conventional staining and the fluorochromes CMA3 e DAPI. The females have 2n = 34 chromosomes (2K = 32 M¯+2 A¯). Some females, however, presented an additional large B acrocentric chromosome, to a total of 2n = 35. Chromosome B and the chromosomal pairs 2, 9 and 10 showed CMA 3+ bands, indicating an excess of CG base-pairs. A clear association was verified between the P. helleri B chromosome SCAR marker and the presence of a B chromosome in P. cupira. The data obtained suggests that B chromosomes in P. helleri and P. cupira share a common origin

A versatile synthesis method of dendrites-free segmented nanowires with a precise size control

We report an innovative strategy to obtain cylindrical nanowires combining well established and low-cost bottom-up methods such as template-assisted nanowires synthesis and electrodeposition process. This approach allows the growth of single-layer or multi-segmented nanowires with precise control over their length (from few nanometers to several micrometers). The employed techniques give rise to branched pores at the bottom of the templates and consequently dendrites at the end of the nanowires. With our method, these undesired features are easily removed from the nanowires by a selective chemical etching. This is crucial for magnetic characterizations where such non-homogeneous branches may introduce undesired features into the final magnetic response. The obtained structures show extremely narrow distributions in diameter and length, improved robustness and high-yield, making this versatile approach strongly compatible with large scale production at an industrial level. Finally, we show the possibility to tune accurately the size of the nanostructures and consequently provide an easy control over the magnetic properties of these nanostructures

The role of cognitive dysfunction in the symptoms and remission from depression.

The disability and burden associated with major depression comes only in part from its affective symptoms; cognitive dysfunctions associated with depression also play a crucial role. Furthermore, these cognitive impairments during depression are manifold and multilevel affecting elementary and more complex cognitive processes equally. Several models from different directions tried to evaluate, conceptualize and understand the depth and magnitude of cognitive dysfunctions in depression and their bidirectional interactions with other types of depressive symptomatology including mood symptoms. In the current review, we briefly overview different types of cognitive symptoms and deficits related to major depression including hot and cold as well as trait- and state-like cognitive alterations and we also describe current knowledge related to the impact of cognitive impairments on the course and outcomes of depression including remission, residual symptoms, function, and response to treatment. We also emphasize shortcomings of currently available treatments for depression in sufficiently improving cognitive dysfunctions and point out the need for newer pharmacological approaches especially in cooperation with psychotherapeutic interventions

A systematic experimental neuropsychological investigation of the functional integrity of working memory circuits in major depression

Verbal and visuospatial working memory (WM) impairment is a well-documented finding in psychiatric patients suffering from major psychoses such as schizophrenia or bipolar affective disorder. However, in major depression (MDD) the literature on the presence and the extent of WM deficits is inconsistent. The use of a multitude of different WM tasks most of which lack process-specificity may have contributed to these inconsistencies. Eighteen MDD patients and 18 healthy controls matched with regard to age, gender and education were tested using process- and circuit-specific WM tasks for which clear brain-behaviour relationships had been established in prior functional neuroimaging studies. Patients suffering from acute MDD showed a selective impairment in articulatory rehearsal of verbal information in working memory. By contrast, visuospatial WM was unimpaired in this sample. There were no significant correlations between symptom severity and WM performance. These data indicate a dysfunction of a specific verbal WM system in acutely ill patients with MDD. As the observed functional deficit did not correlate with different symptom scores, further, longitudinal studies are required to clarify whether and how this deficit is related to illness acuity and clinical state of MDD patients

Measurement of the cross-section of high transverse momentum vector bosons reconstructed as single jets and studies of jet substructure in pp collisions at √s = 7 TeV with the ATLAS detector

This paper presents a measurement of the cross-section for high transverse momentum W and Z bosons produced in pp collisions and decaying to all-hadronic final states. The data used in the analysis were recorded by the ATLAS detector at the CERN Large Hadron Collider at a centre-of-mass energy of √s = 7 TeV;{\rm Te}{\rm V}$and correspond to an integrated luminosity of$4.6\;{\rm f}{{{\rm b}}^{-1}}$. The measurement is performed by reconstructing the boosted W or Z bosons in single jets. The reconstructed jet mass is used to identify the W and Z bosons, and a jet substructure method based on energy cluster information in the jet centre-of-mass frame is used to suppress the large multi-jet background. The cross-section for events with a hadronically decaying W or Z boson, with transverse momentum${{p}_{{\rm T}}}\gt 320\;{\rm Ge}{\rm V}$and pseudorapidity$|\eta |\lt 1.9$, is measured to be${{\sigma }_{W+Z}}=8.5\pm 1.7$ pb and is compared to next-to-leading-order calculations. The selected events are further used to study jet grooming techniques