A Sib-Pair analysis of impulsivity in bipolar disorder type I

OBJECTIVE: The aim of this study was to compare impulsivity among patients with bipolar disorder, their siblings, and healthy controls in order to examine whether impulsivity in bipolar disorder is related to genetic liability for the illness. METHODS: Using the Barratt Impulsiveness Scale, we assessed 204 subjects: 67 euthymic outpatients with bipolar disorder type I, 67 siblings without bipolar disorder, and 70 healthy controls. RESULTS: Impulsivity scores were higher among patients with bipolar disorder than among healthy controls. Siblings showed higher motor impulsivity scores than did healthy controls. CONCLUSIONS: Our results suggest that motor impulsivity may be a vulnerability marker for bipolar disorder. Our data may contribute to further improve preventive strategies in subjects at high risk for bipolar disorder.

Genome-Wide Analysis in Brazilian Xavante Indians Reveals Low Degree of Admixture

Characterization of population genetic variation and structure can be used as tools for research in human genetics and population isolates are of great interest. The aim of the present study was to characterize the genetic structure of Xavante Indians and compare it with other populations. The Xavante, an indigenous population living in Brazilian Central Plateau, is one of the largest native groups in Brazil. A subset of 53 unrelated subjects was selected from the initial sample of 300 Xavante Indians. Using 86,197 markers, Xavante were compared with all populations of HapMap Phase III and HGDP-CEPH projects and with a Southeast Brazilian population sample to establish its population structure. Principal Components Analysis showed that the Xavante Indians are concentrated in the Amerindian axis near other populations of known Amerindian ancestry such as Karitiana, Pima, Surui and Maya and a low degree of genetic admixture was observed. This is consistent with the historical records of bottlenecks experience and cultural isolation. By calculating pair-wise F-st statistics we characterized the genetic differentiation between Xavante Indians and representative populations of the HapMap and from HGDP-CEPH project. We found that the genetic differentiation between Xavante Indians and populations of Ameridian, Asian, European, and African ancestry increased progressively. Our results indicate that the Xavante is a population that remained genetically isolated over the past decades and can offer advantages for genome-wide mapping studies of inherited disorders.

Present bounds on new neutral vector resonances from electroweak gauge boson pair production at the LHC

Several extensions of the standard model predict the existence of new neutral spin-1 resonances associated with the electroweak symmetry breaking sector. Using the data from ATLAS (with integrated luminosity of L = 1.02 fb(-1)) and CMS (with integrated luminosity of L = 1.55 fb(-1)) on the production of W+W- pairs through the process pp --> l(+)l(-)' is not an element of(T), we place model independent bounds on these new vector resonances masses, couplings, and widths. Our analyses show that the present data exclude new neutral vector resonances with masses up to 1-2.3 TeV depending on their couplings and widths. We also demonstrate how to extend our analysis framework to different models with a specific example.

Ultra-low friction coefficient in alumina-silicon nitride pair lubricated with water

In a ball-on-disc wear test, an alumina ceramic body sliding against a silicon nitride ceramic body in water achieved an ultra-low friction coefficient (ULFC) of 0.004. The profilometer and EDX measurements indicated that the ULFC regime in this unmated Al2O3-Si3N4 pair was achieved because of the formation of a flat and smooth interface of nanometric roughness, which favored the hydrodynamic lubrication. The triboreactions formed silicon and aluminum hydroxides which contributed to decrease roughness and shear stress at the contact interface. This behavior enables the development of low energy loss water-based tribological systems using oxide ceramics. 13 2012 Elsevier B.V. All rights reserved.

cDNA-AFLP analysis of Psidium guajava L. cultivars under water stress and mechanical injury: methodological implications

Studies involving amplified fragment length polymorphism (cDNA-AFLP) have often used polyacrylamide gels with radiolabeled primers in order to establish best primer combinations, to analyze, and to recover transcript-derived fragments. Use of automatic sequencer to establish best primer combinations is convenient, because it saves time, reduces costs and risks of contamination with radioactive material and acrylamide, and allows objective band-matching and more precise evaluation of transcript-derived fragments intensities. This study aimed at examining the gene expression of commercial cultivars of P. guajava subjected to water and mechanical injury stresses, combining analyses by automatic sequencer and fluorescent kits for polyacrylamide gel electrophoresis. Firstly, 64 combinations of EcoRI and MseI primers were tested. Ten combinations with higher number of polymorphic fragments were then selected for transcript-derived fragments recovering and cluster analysis, involving 45 saplings of P. guajava. Two groups were obtained, one composed by the control samplings, and another formed by samplings undergoing stress, with no clear distinction between stress treatments. The results revealed the convenience of using a combination of automatic sequencer and fluorescent kits for polyacrylamide gel electrophoreses to examine gene expression profiles. The Unweighted Pair Group Method with Arithmetic Mean analysis using Euclidean distances points out a similar induced response mechanism of P. guajava undergoing water stress and mechanical injury.

Pair approximation for a model of vertical and horizontal transmission of parasites.

We apply Stochastic Dynamics method for a differential equations model, proposed by Marc Lipsitch and collaborators (Proc. R. Soc. Lond. B 260, 321, 1995), for which the transmission dynamics of parasites occurs from a parent to its offspring (vertical transmission), and by contact with infected host (horizontal transmission). Herpes, Hepatitis and AIDS are examples of diseases for which both horizontal and vertical transmission occur simultaneously during the virus spreading. Understanding the role of each type of transmission in the infection prevalence on a susceptible host population may provide some information about the factors that contribute for the eradication and/or control of those diseases. We present a pair mean-field approximation obtained from the master equation of the model. The pair approximation is formed by the differential equations of the susceptible and infected population densities and the differential equations of pairs that contribute to the former ones. In terms of the model parameters, we obtain the conditions that lead to the disease eradication, and set up the phase diagram based on the local stability analysis of fixed points. We also perform Monte Carlo simulations of the model on complete graphs and Erdös-Rényi graphs in order to investigate the influence of population size and neighborhood on the previous mean-field results; by this way, we also expect to evaluate the contribution of vertical and horizontal transmission on the elimination of parasite. Pair Approximation for a Model of Vertical and Horizontal Transmission of Parasites.

Dynamics of cell and tissue genesis in the male reproductive system of ticks (Acari: Ixodidae) Amblyomma cajennense (Fabricius, 1787) and Amblyomma aureolatum (Pallas, 1772): a comparative analysis

Ticks are classified into three families: Argasidae, Ixodidae, and Nutalliellidae. The taxonomy and phylogeny within Ixodidae are still discussed by the specialists, thus requiring further studies. Amblyomma cajennese and Amblyomma aureolatum (Brazil) belong to two species complexes known as “cajennese” and “ovale”, respectively, and are directly related to the transmission of the Brazilian spotted fever. This confirms the medical and veterinary significance of these species, as well as the need for further morphological studies that will bring a better understanding of their taxonomy, phylogeny, and control. In this context, the present study aimed to characterize the morphology of the male reproductive system of A. cajennese and A. aureolatum when unfed and after 4 days of feeding, thereby seeking to: (a) distinguish the two species or “complexes”, and (b) study an internal system which has the potential to be targeted by acaricides. Therefore, males from both species (unfed and after 4 days of feeding) were cold-anesthetized, dissected, and had their reproductive systems removed for histological analysis. The results showed that the morphology of the male reproductive system is generally similar between both species, like in other Ixodidae ticks, exhibiting a multilobed accessory gland complex related to seminal fluid secretion, a pair of vasa deferentia and a pair of testes housing germ cells (spermatocytes) in different stages. The main differences were found in the development of the accessory gland complex cells and germ cells, showing that the maturation of the male reproductive system starts later in A. aureolatum, when compared to A. cajennese. However, during the blood meal, A. aureolatum development is increased, thus making germ cell maturation and gland complex activity higher than in A. cajennese. This study shows the differences in the development of the male reproductive systems of both species, while providing information that can assist in the establishment of new control methods.