255 research outputs found

    A Comparison of Parametric and Sampling Approaches to Portfolio Investment Selection using FTSE100 Stocks

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    In this paper we assess the effectiveness of two approaches to portfolio selection: the more customary parametric approach and a sampling approach using a sample of two years of daily data for the top 100 UK stocks for a period from the beginning of 2006 to the end of 2007. The portfolios are selected on a variance, VaR and CVaR basis: with the latter approach dominating. The sampling approach; involving repeated random one-month return sampling from the data set, un-encumbered by distributional assumptions, applying CVaR is optimal; possibly because it considers only one tail of a potentially non-symmetric PDF.Portfolio selection, Variance, VaR, CVaR, Random sampling

    The Effects of Synbiotic Supplementation on Metabolic Status in Women With Polycystic Ovary Syndrome: a Randomized Double-Blind Clinical Trial

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    Abstract Data on the effects of synbiotic supplementation on glycemic control, lipid profiles, and atherogenic index of plasma (AIP) of women with polycystic ovary syndrome (PCOS) are limited. The purpose of this study was to assess the effects of synbiotic supplementation on glycemic control and lipid profiles in women with PCOS. A prospective, randomized, double-blind, placebo-controlled trial was done at the Naghavi Hospital affiliated to Kashan University of Medical Sciences, Kashan, Iran, between April 2017 and June 2017. Sixty women with PCOS were randomized to intake synbiotic capsule containing Lactobacillus acidophilus strain T16 (IBRC-M10785), Lactobacillus casei strain T2 (IBRC-M10783), and Bifidobacterium bifidum strain T1 (IBRC-M10771) (2 × 109 CFU/g each) plus 800 mg inulin (n = 30) or placebo (n = 30) for 12 weeks. Fasting blood samples were taken at baseline and after the 12-week intervention to determine related variables. Compared with the placebo, synbiotic supplementation resulted in a significant reduction in serum insulin concentrations (− 2.8 ± 4.1 vs. + 1.8 ± 6.4 μIU/mL, P = 0.002) and homeostasis model of assessment-insulin resistance (− 0.7 ± 1.0 vs. + 0.4 ± 1.5, P = 0.002), and a significant elevation in the quantitative insulin sensitivity check index (+ 0.01 ± 0.01 vs. − 0.01 ± 0.03, P < 0.001). In addition, significant decreases in serum triglycerides (− 16.2 ± 31.4 vs. + 5.8 ± 23.1 mg/dL, P = 0.003), VLDL-cholesterol concentrations (− 3.3 ± 6.3 vs. + 1.1 ± 4.6 mg/dL, P = 0.003), and AIP (− 0.05 ± 0.08 vs. − 0.003 ± 0.10 mg/dL, P = 0.03) were seen following the supplementation of synbiotic compared with the placebo. Overall, we found that synbiotic supplementation to women with PCOS for 12 weeks had beneficial effects on markers of insulin resistance, triglycerides, VLDL-cholesterol concentrations, and AIP, but did not influence other lipid profiles. Keywords Synbiotic supplementation Probiotic bacteria Polycystic ovary syndrome Glycemic control Lipid profile

    The effects of Vitamin D and omega-3 fatty acids co-supplementation on biomarkers of inflammation, oxidative stress and pregnancy outcomes in patients with gestational diabetes

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    Background: This study was carried out to determine the effects of vitamin D and omega-3 fatty acids co- supplementation on biomarkers of inflammation, oxidative stress and pregnancy outcomes in gestational diabetes (GDM) patients. Methods: This randomized, double-blind, placebo-controlled trial was conducted among 120 GDM women. Participants were randomly divided into four groups to receive: 1) 1000 mg omega-3 fatty acids containing 180 mg eicosapentaenoic acid (EPA) and 120 mg docosahexaenoic acid (DHA) twice a day + vitamin D placebo (n = 30); 2) 50,000 IU vitamin D every 2 weeks + omega-3 fatty acids placebo (n = 30); 3) 50,000 IU vitamin D every 2 weeks + 1000 mg omega-3 fatty acids twice a day (n = 30) and 4) vitamin D placebo + omega-3 fatty acids placebo (n = 30) for 6 weeks. Results: Subjects who received vitamin D plus omega-3 fatty acids supplements compared with vitamin D, omega-3 fatty acids and placebo had significantly decreased high-sensitivity C-reactive protein (-2.0 ± 3.3 vs. -0.8 ± 4.4, -1.3 ± 2.4 and +0.9 ± 2.7 mg/L, respectively, P = 0.008), malondialdehyde (-0.5 ± 0.5 vs. -0.2 ± 0.5, -0.3 ± 0.9 and +0.5 ± 1.4 μmol/L, respectively, P < 0.001), and increased total antioxidant capacity (+92.1 ± 70.1 vs. +55.1 ± 123.6, +88.4 ± 95.2 and +1.0 ± 90.8 mmol/L, respectively, P = 0.001) and glutathione (+95.7 ± 86.7 vs. +23.0 ± 62.3, +30.0 ± 66.5 and -7.8 ± 126.5 μmol/L, respectively, P = 0.001). In addition, vitamin D and omega-3 fatty acids co-supplementation, compared with vitamin D, omega-3 fatty acids and placebo, resulted in lower incidences of newborns' hyperbilirubinemiain (P = 0.037) and newborns' hospitalization (P = 0.037). Conclusion: Overall, vitamin D and omega-3 fatty acids co-supplementation for 6 weeks among GDM women had beneficial effects on some biomarkers of inflammation, oxidative stress and pregnancy outcomes. © 2017 The Author(s)

    Softening Shape Memory Polymer Substrates for Bioelectronic Devices With Improved Hydrolytic Stability

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    Candidate materials for next generation neural recording electrodes include shape memory polymers (SMPs). These materials have the capability to undergo softening after insertion in the body, and therefore reduce the mismatch in modulus that usually exists between the device and the tissue. Current SMP formulations, which have shown promise for neural implants, contain ester groups within the main chain of the polymer and are therefore prone to hydrolytic decomposition under physiological conditions over periods of 11–13 months in vivo, thus limiting the utility for chronic applications. Ester free polymers are stable in harsh condition (PBS at 75°C or NaOH at 37°C) and accelerated aging results suggest that ester free SMPs are projected to be stable under physiological condition for at least 7 years. In addition, the ester free SMP is compatible with microfabrication processes needed for device fabrication. Furthermore, they demonstrate in vitro biocompatibility as demonstrated by high levels of cell viability from ISO 10993 testing

    The effects of Vitamin D and omega-3 fatty acids co-supplementation on biomarkers of inflammation, oxidative stress and pregnancy outcomes in patients with gestational diabetes

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    Background: This study was carried out to determine the effects of vitamin D and omega-3 fatty acids co- supplementation on biomarkers of inflammation, oxidative stress and pregnancy outcomes in gestational diabetes (GDM) patients. Methods: This randomized, double-blind, placebo-controlled trial was conducted among 120 GDM women. Participants were randomly divided into four groups to receive: 1) 1000 mg omega-3 fatty acids containing 180 mg eicosapentaenoic acid (EPA) and 120 mg docosahexaenoic acid (DHA) twice a day + vitamin D placebo (n = 30); 2) 50,000 IU vitamin D every 2 weeks + omega-3 fatty acids placebo (n = 30); 3) 50,000 IU vitamin D every 2 weeks + 1000 mg omega-3 fatty acids twice a day (n = 30) and 4) vitamin D placebo + omega-3 fatty acids placebo (n = 30) for 6 weeks. Results: Subjects who received vitamin D plus omega-3 fatty acids supplements compared with vitamin D, omega-3 fatty acids and placebo had significantly decreased high-sensitivity C-reactive protein (-2.0 ± 3.3 vs. -0.8 ± 4.4, -1.3 ± 2.4 and +0.9 ± 2.7 mg/L, respectively, P = 0.008), malondialdehyde (-0.5 ± 0.5 vs. -0.2 ± 0.5, -0.3 ± 0.9 and +0.5 ± 1.4 μmol/L, respectively, P < 0.001), and increased total antioxidant capacity (+92.1 ± 70.1 vs. +55.1 ± 123.6, +88.4 ± 95.2 and +1.0 ± 90.8 mmol/L, respectively, P = 0.001) and glutathione (+95.7 ± 86.7 vs. +23.0 ± 62.3, +30.0 ± 66.5 and -7.8 ± 126.5 μmol/L, respectively, P = 0.001). In addition, vitamin D and omega-3 fatty acids co-supplementation, compared with vitamin D, omega-3 fatty acids and placebo, resulted in lower incidences of newborns' hyperbilirubinemiain (P = 0.037) and newborns' hospitalization (P = 0.037). Conclusion: Overall, vitamin D and omega-3 fatty acids co-supplementation for 6 weeks among GDM women had beneficial effects on some biomarkers of inflammation, oxidative stress and pregnancy outcomes. © 2017 The Author(s)

    Adjusted prognostic association of post-myocardial infarction depression withmortality and cardiovascular events: an individual patient data meta-analysis

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    Background: The association between depression after myocardial infarction (post-MI) and increased risk of mortality and cardiac morbidity may be due to cardiac disease severity. Aims: To combine original data from studies on the association between post-MI depression and prognosis into one database. To investigate to what extent post-MI depression predicts prognosis independently of disease severity. Method: Individual patient data meta-analysis of studies, using multilevel, multivariable Cox regression analyses. Results:Sixteen studies participated, creating a database of 10,175 post-MI patients. HRs for post-MI depression were 1.32 (95%CI 1.26-1.38, p Conclusions: The association between post-MI depression and prognosis is attenuated after adjustment for cardiac disease severity. Still, depression remains independently associated with prognosis, with a 22% increased risk of all-cause mortality and a 13% increased risk of cardiovascular events per standard deviation in depression z-score. Declaration of interest: None

    Evaluation of silk fibroin-based urinary conduits in a porcine model of urinary diversion

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    Background: The primary strategy for urinary diversion in radical cystectomy patients involves incorporation of autologous gastrointestinal conduits into the urinary tract which leads to deleterious consequences including chronic infections and metabolic abnormalities. This report investigates the efficacy of an acellular, tubular bi-layer silk fibroin (BLSF) graft to function as an alternative urinary conduit in a porcine model of urinary diversion.Materials and methods: Unilateral urinary diversion with stented BLSF conduits was executed in five adult female, Yucatan mini-swine over a 3 month period. Longitudinal imaging analyses including ultrasonography, retrograde ureteropyelography and video-endoscopy were carried out monthly. Histological, immunohistochemical (IHC), and histomorphometric assessments were performed on neoconduits at harvest.Results: All animals survived until scheduled euthanasia and displayed moderate hydronephrosis (Grades 1–3) in reconstructed collecting systems over the course of the study period. Stented BLSF constructs supported formation of vascularized, retroperitoneal tubes capable of facilitating external urinary drainage. By 3 months post-operative, neoconduits contained α-smooth muscle actin+ and SM22α+ smooth muscle as well as uroplakin 3A+ and pan-cytokeratin + urothelium. However, the degree of tissue regeneration in neotissues was significantly lower in comparison to ureteral controls as determined by histomorphometry. In addition, neoconduit stenting was necessary to prevent stomal occlusion.Conclusion: BLSF biomaterials represent emerging platforms for urinary conduit construction and may offer a functional replacement for conventional urinary diversion techniques following further optimization of mechanical properties and regenerative responses

    Experimental Verification of a Predicted Intronic MicroRNA in Human NGFR Gene with a Potential Pro-Apoptotic Function

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    Neurotrophins (NTs) are a family of secreted growth factor proteins primarily involved in the regulation of survival and appropriate development of neural cells, functioning by binding to their specific (TrkA, TtkB, and TrkC) and/or common NGFR receptor. NGFR is the common receptor of NTs, binding with low-affinity to all members of the family. Among different functions assigned to NGFR, it is also involved in apoptosis induction and tumorigenesis processes. Interestingly, some of the functions of NGFR appear to be ligand-independent, suggesting a probable involvement of non-coding RNA residing within the sequence of the gene. Here, we are reporting the existence of a conserved putative microRNA, named Hsa-mir-6165 [EBI accession#: FR873488]. Transfection of a DNA segment corresponding to the pre-mir-6165 sequence in Hela cell line caused the generation of mature exogenous mir-6165 (a ∼200,000 fold overexpression). Furthermore, using specific primers, we succeeded to detect the endogenous expression of mir-6165 in several glioma cell lines and glioma primary tumors known to express NGFR. Similar to the pro-apoptotic role of NGFR in some cell types, overexpression of pre-mir-6165 in U87 cell line resulted in an elevated rate of apoptosis. Moreover, coordinated with the increased level of mir-6165 in the transfected U87 cell line, two of its predicted target genes (Pkd1 and DAGLA) were significantly down-regulated. The latter findings suggest that some of the previously attributed functions of NGFR could be explained indirectly by co-transcription of mir-6165 in the cells
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