1,502 research outputs found

    Effect of Non Gaussian Noises on the Stochastic Resonance-Like Phenomenon in Gated Traps

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    We exploit a simple one-dimensional trapping model introduced before, prompted by the problem of ion current across a biological membrane. The voltage-sensitive channels are open or closed depending on the value taken by an external potential that has two contributions: a deterministic periodic and a stochastic one. Here we assume that the noise source is colored and non Gaussian, with a qq-dependent probability distribution (where qq is a parameter indicating the departure from Gaussianity). We analyze the behavior of the oscillation amplitude as a function of both qq and the noise correlation time. The main result is that in addition to the resonant-like maximum as a function of the noise intensity, there is a new resonant maximum as a function of the parameter qq.Comment: Communication to LAWNP01, Proceedings to be published in Physica D, RevTex, 8 pgs, 5 figure

    Validació i control de la plausibilitat dels resultats

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    Effect of zinc intake on growth in infants: A meta-analysis

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    A systematic review and meta-analysis of available randomized controlled trials (RCTs) was conducted to evaluate the effect of zinc (Zn) intake on growth in infants. Out of 5500 studies identified through electronic searches and reference lists, 19 RCTs were selected after applying the exclusion/inclusion criteria. The influence of Zn intake on growth was considered in the overall meta-analysis. Other variables were also taken into account as possible effect modifiers: doses of Zn intake, intervention duration, nutritional status, and risk of bias. From each select growth study, final measures of weight, length, mid upper arm circumference (MUAC), head circumference, weight for age z-score (WAZ), length for age z-score (LAZ), and weight for length z-score (WLZ) were assessed. Pooled β and 95% confidence interval (CI) were calculated. Additionally, we carried out a sensitivity analysis. Zn intake was not associated with weight, length, MUAC, head circumference, and LAZ in the pooled analyses. However, Zn intake had a positive and statistically effect on WAZ (β = 0.06; 95%CI 0.02 to 0.10) and WLZ (β = 0.05; 95%CI 0.01 to 0.08). The dose–response relationship between Zn intake and these parameters indicated that a doubling of Zn intake increased WAZ and WLZ by approximately 4%. Substantial heterogeneity was present only in length analyses (I2 = 45%; p = 0.03). Zn intake was positively associated with length values at short time (four to 20 weeks) (β = 0.01; CI 95% 0 to 0.02) and at medium doses of Zn (4.1 to 8 mg/day) (β = 0.003; CI 95% 0 to 0.01). Nevertheless, the effect magnitude was small. Our results indicate that Zn intake increases growth parameters of infants. Nonetheless, interpretation of these results should be carefully considered

    The role of gender in the association between self-rated health and mortality among older adults in Santiago, Chile: A cohort study.

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    BACKGROUND: Previous studies on the role of gender in the association between self-rated health and mortality have shown contrasting results. This study was aimed to determine the importance of gender in the association between self-rated health and mortality among older people in Santiago, Chile. METHODS: A 10 year follow-up of 1066 people aged 60 or more, from the Chilean cohort of the Study of Health, Ageing and Well-Being. Self-rated health was assessed in face to face interviews through a single general question, along with socio-demographic and health status information. Cox proportional hazards and flexible parametric models for survival analyses were employed. RESULTS: By the end of follow-up, 30.7% of women and 39.4% of men died. Adjusted hazard ratio of poor self-rated health, compared to good self-rated health, was 1.92(95% CI 1.29-2.86). In models stratified by gender, an increased risk of mortality was observed among women who rated their health as poor (HR = 2.21, 95% CI 1.43-3.40), but not among men (HR = 1.04, 95% CI 0.58-1.86). Age was associated with mortality in both groups; for men, functional limitation and underweight were also risk factors and obesity was a protective factor. CONCLUSIONS: Compared to older women who rated their health as good, older women who rated their health as poor had a 2 fold increased risk of mortality over the subsequent 10 years. These findings stress the importance of considering a gender perspective into health programmes, including those focused on older people, in order to address the different elements that increase, on the long run, the risk of dying among older women and men

    Ghrelin-O-Acyltransferase (GOAT) Enzyme as a Novel Potential Biomarker in Gastroenteropancreatic Neuroendocrine Tumors

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    Objectives: The association between the presence and alterations of the components of the ghrelin system and the development and progression of neuroendocrine tumors (NETs) is still controversial and remains unclear. Methods: Here, we systematically evaluated the expression levels (by quantitative-PCR) of key ghrelin system components of in gastroenteropancreatic (GEP)-NETs, as compared to non-tumor adjacent (NTA; n = 42) and normal tissues (NT; n = 14). Then, we analyzed their putative associations with clinical-histological characteristics. Results: The results indicate that ghrelin and its receptor GHSR1a are present in a high proportion of normal tissues, while the enzyme ghrelin-O-acyltransferase (GOAT) and the splicing variants In1-ghrelin and GHSR1b were present in a lower proportion of normal tissues. In contrast, all ghrelin system components were present in a high proportion of tumor and NTA tissues. GOAT was significantly overexpressed (by quantitative-PCR (qPCR)) in tumor samples compared to NTA, while a trend was found for ghrelin, In1-ghrelin and GHSR1a. In addition, expression of these components displayed significant correlations with key clinical parameters. The marked overexpression of GOAT in tumor samples compared to NTA regions was confirmed by IHC, revealing that this enzyme is particularly overexpressed in gastrointestinal NETs, where it is directly correlated with tumor diameter. Conclusions: These results provide novel information on the presence and potential pathophysiological implications of the ghrelin system components in GEP-NETs, wherein GOAT might represent a novel diagnostic biomarker

    Control del barrenador de las semillas, bephratelloides cubensis ashmead (hymenoptera: eurytomidae) en guanábana, annona muricata l. (annonales: annonaceae)

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    The insecticides dimethoate, malathion, ethyl-chlorpyriphos, cipermetrine, endosulphan and azadirachtine were evaluated for controlling the seed borer B. cubensis on soursop under field conditions. Dosage of 40, 150, 48, 40, 94.5 and 30 g of active ingredient in 100 L of water, respectively, were used. Likewise, pocketing of fruits with organdi mesh and perforated, transparent plastic bags to avoid humidity accumulation were evaluated. The experiment was repeated twice. The evaluated variable was percentage of infested seeds. Pocketing of fruits with organdi mesh was the best treatment (0.0 and 1.6 % of infestation). The fruits covered with plastic bags showed zero percent of infestation, but these displayed burn spots and a decrease in growth. Dimethoate was the best insecticide treatment (0.75 and 5.9 % of damage), followed by cipermetrine (0.8 and 17.83 % of damage). En condiciones de campo se evaluaron los insecticidas dimetoato, malatión, clorpirifos-etil, cipermetrina, endosulfán y azadiractina para el control del barrenador de las semillas B. cubensis en guanábana. Las dosis aplicadas fueron: 40, 150, 48, 40, 94. 5 y 30 g de i.a. en 100 L de agua, respectivamente; asimismo, se evaluó el embolsado de frutos con tela de organza y bolsas de plástico transparentes y perforadas para evitar la acumulación de humedad. El experimento se repitió en dos ocasiones. La variable evaluada fue el porcentaje de semillas infestadas. El embolsado de frutos con tela de organza fue el mejor tratamiento (0.0 y 1.6% de infestación), en los frutos cubiertos con bolsas de plástico se observó cero porciento de infestación, pero éstos presentaron quemaduras y una disminución en el crecimiento. De los insecticidas evaluados el dimetoato fue el mejor tratamiento (0.75 y 5.9% de infestación) seguido de la cipermetrina (0.8 y 17.83% de infestación)

    Role of atrial tissue remodeling on rotor dynamics an in vitro study

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    The objective of this article is to present an in vitro model of atrial cardiac tissue that could serve to study the mechanisms of remodeling related to atrial fibrillation (AF). We analyze the modification on gene expression and modifications on rotor dynamics following tissue remodeling. Atrial murine cells (HL-1 myocytes) were maintained in culture after the spontaneous initiation of AF and analyzed at two time points: 3.1 +/- 1.3 and 9.7 +/- 0.5 days after AF initiation. The degree of electrophysiological remodeling (i.e., relative gene expression of key ion channels) and structural inhomogeneity was compared between early and late cell culture times both in nonfibrillating and fibrillating cell cultures. In addition, the electrophysiological characteristics of in vitro fibrillation [e.g., density of phase singularities (PS/cm2), dominant frequency, and rotor meandering] analyzed by means of optical mapping were compared with the degree of electrophysiological remodeling. Fibrillating cell cultures showed a differential ion channel gene expression associated with atrial tissue remodeling (i.e., decreased SCN5A, CACN1C, KCND3, and GJA1 and increased KCNJ2) not present in nonfibrillating cell cultures. Also, fibrillatory complexity was increased in late- vs. early stage cultures (1.12 +/- 0.14 vs. 0.43 +/- 0.19 PS/cm(2), P < 0.01), which was associated with changes in the electrical reentrant patterns (i.e., decrease in rotor tip meandering and increase in wavefront curvature). HL-1 cells can reproduce AF features such as electrophysiological remodeling and an increased complexity of the electrophysiological behavior associated with the fibrillation time that resembles those occurring in patients with chronic AF.This work was supported in part by grants from the Spanish Ministry of Science and Innovation (PLE2009-0152), the Instituto de Salud Carlos III (Ministry of Economy and Competitiveness, Spain: PI13-01882, PI13-00903, and TEC2013-50391-EXP), and the Red de Investigacion Cardiovacular (RIC) from Instituto de Salud Carlos III (Ministry of Economy and Competitiveness, Spain).Climent, A.; Guillem Sánchez, MS.; Fuentes, L.; Lee, P.; Bollensdorff, C.; Fernandez-Santos, M.; Suarez-Sancho, S.... (2015). Role of atrial tissue remodeling on rotor dynamics an in vitro study. AJP - Heart and Circulatory Physiology. 309(11):H1964-H1973. doi:10.1152/ajpheart.00055.2015SH1964H197330911Allessie, M. (2002). 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Comparison of Radiofrequency Catheter Ablation of Drivers and Circumferential Pulmonary Vein Isolation in Atrial Fibrillation. Journal of the American College of Cardiology, 64(23), 2455-2467. doi:10.1016/j.jacc.2014.09.053Bikou, O., Thomas, D., Trappe, K., Lugenbiel, P., Kelemen, K., Koch, M., … Bauer, A. (2011). Connexin 43 gene therapy prevents persistent atrial fibrillation in a porcine model. Cardiovascular Research, 92(2), 218-225. doi:10.1093/cvr/cvr209Bollmann, A., Sonne, K., Esperer, H.-D., Toepffer, I., & Klein, H. U. (2002). Patients with Persistent Atrial Fibrillation Taking Oral Verapamil Exhibit a Lower Atrial Frequency on the ECG. Annals of Noninvasive Electrocardiology, 7(2), 92-97. doi:10.1111/j.1542-474x.2002.tb00148.xBRUNDEL, B. (2004). Calpain inhibition prevents pacing-induced cellular remodeling in a HL-1 myocyte model for atrial fibrillation. Cardiovascular Research, 62(3), 521-528. doi:10.1016/j.cardiores.2004.02.007Calkins, H., Kuck, K. 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Circulation: Arrhythmia and Electrophysiology, 5(6), 1160-1167. doi:10.1161/circep.111.969519Haïssaguerre, M., Jaïs, P., Shah, D. C., Takahashi, A., Hocini, M., Quiniou, G., … Clémenty, J. (1998). Spontaneous Initiation of Atrial Fibrillation by Ectopic Beats Originating in the Pulmonary Veins. New England Journal of Medicine, 339(10), 659-666. doi:10.1056/nejm199809033391003Haralick, R. M., Shanmugam, K., & Dinstein, I. (1973). Textural Features for Image Classification. IEEE Transactions on Systems, Man, and Cybernetics, SMC-3(6), 610-621. doi:10.1109/tsmc.1973.4309314Jalife, J. (2010). Deja vu in the theories of atrial fibrillation dynamics. Cardiovascular Research, 89(4), 766-775. doi:10.1093/cvr/cvq364Koivumäki, J. T., Seemann, G., Maleckar, M. M., & Tavi, P. (2014). In Silico Screening of the Key Cellular Remodeling Targets in Chronic Atrial Fibrillation. 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Left-to-Right Gradient of Atrial Frequencies During Acute Atrial Fibrillation in the Isolated Sheep Heart. Circulation, 103(21), 2631-2636. doi:10.1161/01.cir.103.21.2631Martins, R. P., Kaur, K., Hwang, E., Ramirez, R. J., Willis, B. C., Filgueiras-Rama, D., … Jalife, J. (2014). Dominant Frequency Increase Rate Predicts Transition from Paroxysmal to Long-Term Persistent Atrial Fibrillation. Circulation, 129(14), 1472-1482. doi:10.1161/circulationaha.113.004742McDowell, K. S., Vadakkumpadan, F., Blake, R., Blauer, J., Plank, G., MacLeod, R. S., & Trayanova, N. A. (2013). Mechanistic Inquiry into the Role of Tissue Remodeling in Fibrotic Lesions in Human Atrial Fibrillation. Biophysical Journal, 104(12), 2764-2773. doi:10.1016/j.bpj.2013.05.025Narayan, S. M., Krummen, D. E., Shivkumar, K., Clopton, P., Rappel, W.-J., & Miller, J. M. (2012). Treatment of Atrial Fibrillation by the Ablation of Localized Sources. 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    The Relationship between Depressive Symptoms, Quality of Life and miRNAs 8 Years after Bariatric Surgery

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    Altres ajuts: Universidad de Málaga, UMA20-FEDERJA-144; Junta de Andalucia, PI-0194-2017, C-0028-2018, RC-005-2020, DOC_00288 and DOC_01095Background: There are conflicting results on whether weight loss after bariatric surgery (BS) might be associated with quality of life (QoL)/depressive symptomatology. We aim to determine whether BS outcomes are associated with QoL/depressive symptomatology in studied patients at the 8-year follow-up after BS, as well as their relationship with different serum proteins and miRNAs. Methods: A total of 53 patients with class III obesity who underwent BS, and then classified into "good responders" and "non-responders" depending on the percentage of excess weight lost (%EWL) 8 years after BS (%EWL ≥ 50% and %EWL < 50%, respectively), were included. Basal serum miRNAs and different proteins were analysed, and patients completed tests to evaluate QoL/depressive symptomatology at 8 years after BS. Results: The good responders group showed higher scores on SF-36 scales of physical functioning, role functioning-physical, role functioning-emotional, body pain and global general health compared with the non-responders. The expression of hsa-miR-101-3p, hsa-miR-15a-5p, hsa-miR-29c-3p, hsa-miR-144-3p and hsa-miR-19b-3p were lower in non-responders. Hsa-miR-19b-3p was the variable associated with the response to BS in a logistic regression model. Conclusions: The mental health of patients after BS is limited by the success of the intervention. In addition, the expression of basal serum miRNAs related to depression/anxiety could predict the success of BS
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