Sector integration and the benefits on global diversification

One of the main reasons that financial analysts recommend international investments is that foreign stocks are not highly correlated with U.S. stocks. As world economies become increasingly interrelated, it may become more difficult for investors to achieve effective diversification. This research investigates international stock market correlation, and assesses whether global diversification on a sector basis is beneficial to U.S. investors. This analysis includes 38 developed and emerging stock markets from 1981-2000. In addition to demonstrating a potential loss of diversification benefits, this paper utilizes an optimal global asset allocation model to illustrate the effects of sector diversification on portfolio performance over time. The results indicate that although the correlation between most foreign sectors and U.S. sectors is increasing over time, there are still substantial international diversification benefits. Further, the inclusion of emerging market sectors significantly enhances the return-to-risk performance of international portfolios.Indisponível

The effect of financial liberalization on cross-autocorrelation in the brazilian equit market

This study examines the effect of financial liberalization on crossautocorrelation in the Brazilian equity market. The sample consists of daily data from January 1986 through December 1999. Prior studies have found conflicting evidence of crossautocorrelation in U.S. data. Differences in size-based portfolios are tested through correlation, cross-autocorrelation, Grangercausality, asymmetric responses, and trading volume. The results confirm that large stock portfolio returns lead small stock portfolio returns, but the lagged response of small stock portfolio returns diminish following financial liberalization.Indisponível

Reducing risk of type 2 diabetes after gestational diabetes: a qualitative study to explore the potential of technology in primary care

BACKGROUND: Despite the seven-fold increased risk of type 2 diabetes mellitus (T2DM) among females previously diagnosed with gestational diabetes (GD), annual rates of follow-up in primary care are low. There is a need to consider how to reduce the incidence of progression to T2DM among this high-risk group. AIM: To examine the views of females diagnosed with GD to ascertain how to improve primary care support postnatally, and the potential role of technology in reducing the risk of progression to T2DM. DESIGN AND SETTING: A qualitative study of a purposive sample of 27 postnatal females leaving secondary care with a recent diagnosis of GD. METHOD: Semi-structured interviews were conducted with 27 females, who had been previously diagnosed with GD, at around 6-12 weeks postnatally. Interviews were audiotaped, transcribed, and analysed thematically. RESULTS: Facilitators and barriers to engaging in a healthy postnatal lifestyle were identified, the most dominant being competing demands on time. Although females were generally satisfied with the secondary care they received antenatally, they felt abandoned postnatally and were uncertain what to expect from their GP in terms of follow-up and support. Females felt postnatal care could be improved by greater clarity regarding this, and enhanced by peer support, multidisciplinary input, and subsidised facilities. Technology was seen as a potential adjunct by providing information, enabling flexible and personalised self-management, and facilitating social support. CONCLUSION: A more tailored approach for females previously diagnosed with GD may help reduce the risk of progression to T2DM. A need for future research to test the efficacy of using technology as an adjunct to current care was identified

Temporal Variability of Human Vaginal Bacteria and Relationship with Bacterial Vaginosis

Little is known about short-term bacterial fluctuations in the human vagina. This study used PCR to assess the variability in concentrations of key vaginal bacteria in healthy women and the immediate response to antibiotic treatment in women with bacterial vaginosis (BV).Twenty-two women assessed for BV using Amsel's criteria were evaluated daily for 7 or 14 days, then at 2, 3 and 4 weeks, using a panel of 11 bacterium-specific quantitative PCR assays. Participants with BV were treated with 5 days of intravaginal metronidazole. Participants without BV had vaginal biotas dominated by lactobacilli, whose levels fluctuated with menses. With onset of menstruation, quantities of Lactobacillus jensenii and Lactobacillus crispatus decreased and were found to be inversely related to Gardnerella vaginalis concentrations (p<0.001). Women with BV had a variety of fastidious bacteria whose concentrations dropped below detection thresholds 1-5 days after starting metronidazole. Recurrent BV was characterized by initial profound decreases of BV-associated bacteria after treatment followed by subsequent increases at relapse.The microbiota of the human vagina can be highly dynamic. Healthy women are colonized with Lactobacillus species, but levels can change dramatically over a month. Marked increases in G. vaginalis were observed during menses. Participants with BV have diverse communities of fastidious bacteria that are depleted by vaginal metronidazole therapy. Women with recurrent BV initially respond to antibiotic treatment with steep declines in bacterial concentrations, but these bacteria later reemerge, suggesting that antibiotic resistance in these bacteria is not an important factor mediating BV recurrence

Plasma surface modification of chitosan membranes: characterization and preliminary cell response studies

Surface modification of biomaterials is a way to tailor cell responses whilst retaining the bulk properties. In this work, chitosan membranes were prepared by solvent casting and treated with nitrogen or argon plasma at 20Wfor 10–40 min. AFM indicated an increase in the surface roughness as a result of the ongoing etching process. XPS and contact angle measurements showed different surface elemental compositions and higher surface free energy. The MTS test and direct contact assays with an L929 fibroblast cell line indicated that the plasma treatment improved the cell adhesion and proliferation. Overall, the results demonstrated that such plasma treatments could significantly improve the biocompatibility of chitosan membranes and thus improve their potential in wound dressings and tissue engineering applications

Pneumolysin Activates Macrophage Lysosomal Membrane Permeabilization and Executes Apoptosis by Distinct Mechanisms without Membrane Pore Formation

Intracellular killing of Streptococcus pneumoniae is complemented by induction of macrophage apoptosis. Here, we show that the toxin pneumolysin (PLY) contributes both to lysosomal/phagolysosomal membrane permeabilization (LMP), an upstream event programing susceptibility to apoptosis, and to apoptosis execution via a mitochondrial pathway, through distinct mechanisms. PLY is necessary but not sufficient for the maximal induction of LMP and apoptosis. PLY’s ability to induce both LMP and apoptosis is independent of its ability to form cytolytic pores and requires only the first three domains of PLY. LMP involves TLR (Toll-like receptor) but not NLRP3/ASC (nucleotide-binding oligomerization domain [Nod]-like receptor family, pyrin domain-containing protein 3/apoptosis-associated speck-like protein containing a caspase recruitment domain) signaling and is part of a PLY-dependent but phagocytosis-independent host response that includes the production of cytokines, including interleukin-1 beta (IL-1β). LMP involves progressive and selective permeability to 40-kDa but not to 250-kDa fluorescein isothiocyanate (FITC)-labeled dextran, as PLY accumulates in the cytoplasm. In contrast, the PLY-dependent execution of apoptosis requires phagocytosis and is part of a host response to intracellular bacteria that also includes NO generation. In cells challenged with PLY-deficient bacteria, reconstitution of LMP using the lysomotrophic detergent LeuLeuOMe favored cell necrosis whereas PLY reconstituted apoptosis. The results suggest that PLY contributes to macrophage activation and cytokine production but also engages LMP. Following bacterial phagocytosis, PLY triggers apoptosis and prevents macrophage necrosis as a component of a broad-based antimicrobial strategy. This illustrates how a key virulence factor can become the focus of a multilayered and coordinated innate response by macrophages, optimizing pathogen clearance and limiting inflammation

Modulating cell adhesion to polybutylene succinate biotextile constructs for tissue engineering applications

Textile-based technologies are powerful routes for the production of three-dimensional porous architectures for tissue engineer- ing applications because of their feasibility and possibility for scaling-up. Herein, the use of knitting technology to produce polybutylene succinate fibre-based porous architectures is described. Furthermore, different treatments have been applied to functionalize the surface of the scaffolds developed: sodium hydroxide etching, ultraviolet radiation exposure in an ozone atmosphere and grafting (acrylic acid, vinyl phosphonic acid and vinyl sulphonic acid) after oxygen plasma activation as a way to tailor cell adhesion. A possible effect of the applied treatments on the bulk properties of the textile scaffolds has been considered and thus tensile tests in dry and hydrated states were also carried out. The microscopy results indicated that the surface morphol- ogy and roughness were affected by the applied treatments. The X-ray photoelectron spectroscopy and contact angle measure- ments showed the incorporation of oxygen-containing groups and higher surface free energy as result of the surface treatments applied. The DNA quantification and scanning electron microscopy analysis revealed that these modifications enhanced cell adhesion and altered cell morphology. Generally, sodium hydroxide treatment altered most significantly the surface properties, which in turn resulted in a high number of cells adherent to these surfaces. Based on the results obtained, the proposed surface treatments are appropriate to modify polybutylene succinate knitting scaffolds, influencing cell adhesion and its potential for use in tissue engineering applications. Portuguese Foundation for Science and Technology (FCT) under POCTI and/or FEDERprogrammes under the scope of the project TISSUE2TISSUE (PTDC/CTM/105703/ 2008). The FCT distinction attributed to ALO under the Investigator FCT programme (IF/00411/2013

Pathogen Sensing Pathways in Human Embryonic Stem Cell Derived-Endothelial Cells: Role of NOD1 Receptors.

Human embryonic stem cell-derived endothelial cells (hESC-EC), as well as other stem cell derived endothelial cells, have a range of applications in cardiovascular research and disease treatment. Endothelial cells sense Gram-negative bacteria via the pattern recognition receptors (PRR) Toll-like receptor (TLR)-4 and nucleotide-binding oligomerisation domain-containing protein (NOD)-1. These pathways are important in terms of sensing infection, but TLR4 is also associated with vascular inflammation and atherosclerosis. Here, we have compared TLR4 and NOD1 responses in hESC-EC with those of endothelial cells derived from other stem cells and with human umbilical vein endothelial cells (HUVEC). HUVEC, endothelial cells derived from blood progenitors (blood outgrowth endothelial cells; BOEC), and from induced pluripotent stem cells all displayed both a TLR4 and NOD1 response. However, hESC-EC had no TLR4 function, but did have functional NOD1 receptors. In vivo conditioning in nude rats did not confer TLR4 expression in hESC-EC. Despite having no TLR4 function, hESC-EC sensed Gram-negative bacteria, a response that was found to be mediated by NOD1 and the associated RIP2 signalling pathways. Thus, hESC-EC are TLR4 deficient but respond to bacteria via NOD1. This data suggests that hESC-EC may be protected from unwanted TLR4-mediated vascular inflammation, thus offering a potential therapeutic advantage