392 research outputs found
3D Slope Stability Analyses of a Complex Formation with a Block-in-Matrix Fabric
Heterogeneous rock bodies composed of strong rock blocks surrounded by a weaker finer-grained matrix are often referred to as “BIMrocks” (Block-In-Matrix rocks). These complex formations present a high spatial, dimensional and lithological variability, which makes their characterization an extremely challenging task. As a consequence, geopracticioners have often planned engineering works in bimrocks ignoring the presence of the stronger rock inclusions. However, it is essential that blocks be considered in the analyses in order to obtain reliable results. In fact, rock inclusions strongly affects the strength, deformability and failure surfaces of these geomaterials.
In this paper 3D stability analyses are performed with the FLAC 3D code on slope models with variable Volumetric Block Proportions (VBP) to investigate the influence of the rock inclusions on their stability. In order to take the inherent variability of bimrocks into account, a Matlab code was implemented to generate spherical blocks of variable dimensions and locate them randomly within the slope models. Moreover, the stability of a matrix-only slope model is also analyzed by way of comparison. Finally, the paper compares and comments on the results of 2D numerical simulations previously carried out by the author for the same complex block-in-matrix formation
Influence of Maternal Dysmetabolic Conditions During Pregnancy on Cardiovascular Disease
Pathogenic factors associated with maternal hypercholesterolemia, obesity, and diabetic conditions during pregnancy influence fetal development and predispose offspring to cardiovascular disease. Animal models have established cause–effect relationships consistent with epidemiological findings in humans and have demonstrated, in principle, that interventions before or during pregnancy can reduce or prevent pathogenic in utero programming. However, little is known about the mechanisms by which maternal dysmetabolic conditions enhance disease susceptibility in offspring. Identification of these mechanisms is rendered more difficult by the fact that programming effects in offspring may be latent and may require conventional risk factors and inherited genetic co-factors to become clinically manifest. Given the increasing prevalence of maternal risk factors, which is expected to lead to a wave of cardiovascular disease in the coming decades, and the length of prospective studies on developmental programming in humans, greater-than-usual emphasis on experimental models and translational studies is necessary
Prevention of healthcare-associated infections: knowledge among dental students in seven Italian universities
Background: Lack of knowledge is the major reason for non-compliance with correct healthcare-associated infections (HAI) prevention procedures. The aim of this study was to evaluate knowledge of the Dental School (DSS) and Dental Hygiene (DHS) students with regard to the prevention of HAI, as basic knowledge for improving and harmonizing the educational content in the different Italian Universities. Methods: A cross-sectional study was carried out using an anonymous questionnaire that was completed by DSS (I, II, III, IV, and V year) in seven Universities and DHS (I, II, and III year) in three Universities. The questions dealt with three specific areas: healthcare-associated infections, standard recautions and hand hygiene. Factors associated with an unacceptable level of knowledge (score <17.5) were analyzed using a logistic regression model. A p value <0.05 was considered to be significant. Results: Five hundred and four questionnaires were collected: 81.5% for DSS and 18.5% for DHS. Mean overall score (\ub1DS) achieved by the total number of students was 18.2\ub12.93 on an overall perfect score of 25; 18.2\ub13.04 for DSS and 17.8\ub12.31 for DHS. Stratifying by area, the average score 2.7\ub11.07 (53%) for
HAI, 10.3\ub11.61 (85.9%) for standard precautions, and 5.2\ub11.44 (64.8%) for hand hygiene was observed. A significantly different level of knowledge (p<0.001) between DSS and DHS was observed only for HAI (2.8\ub11.07 for DSS vs 2.1\ub10.96 for DHS). Significant differences among the academic years were found only for DSS concerning HAI and standard precautions. The logistic regression model showed that an age <23 years was a risk factor for lack of knowledge on HAI, but a protective factor for lack of knowledge
about standard precautions and hand hygiene; attending DH degree course was associated with lack of knowledge on HAI
Body piercing and tattoos: a survey on young adults' knowledge of the risks and practices in body art
<p>Abstract</p> <p>Background</p> <p>The practice of tattooing and piercing has expanded in western society. In order to verify young adults' knowledge of the risk and practices related to body art, an investigation was conducted among freshmen of the University of Bari in the region of Apulia, Italy.</p> <p>Methods</p> <p>The study was carried out in the Academic Year 2009-2010 through an anonymous self-administered written questionnaire distributed to 1.656 freshmen enrolled in 17 Degree Courses.</p> <p>Results</p> <p>Of the 1.598 students included in the analysis, 78.3% believe it is risky to undergo piercing/tattoo practices. AIDS was indicated as a possible infection by 60.3% of freshmen, hepatitis C by 38.2%, tetanus by 34.3% and hepatitis B by 33.7% of the sample. 28.1% of freshmen were not aware that there are also non-infectious complications. 29% of the sample had at least one piercing or tattoo (this percentage does not include earlobe piercing in women). Of those with body art, the decision to undergo body art was made autonomously in 57.9% of the participants. 56.3% of freshmen undergoing body art had taken less than a month to decide. With regard to the reasons that led the sample to undergo body art, 28.4% were unable to explain it, 23.8% answered to improve their aesthetic aspect, 18.4% to distinguish themselves from others, 12.3% for fashion; 17.1% for other reasons. 25.4% of the sample declared that they had a piercing (79.8% female vs 20.2% male; ratio M/F 1:4.0). The average age for a first piercing was 15.3 years (range 10-27; SD ± 2.9). 9.6% of the sample declared that they have a tattoo (69.9% female vs 30.1% male; ratio M/F 1:2.3). The average age for a first tattoo was 17.5 years (range 10-26, SD ± 2.4).</p> <p>Conclusions</p> <p>Most of the freshmen knew about AIDS-related risks but not other potential risks. Body art is fairly common among young adults (especially women). The decision is often not shared with the family and is undertaken mostly without a specific reason or for the improvement of aesthetic aspect. Information about freshmen's knowledge, attitudes and practices could help in effective planning of health promotion strategies.</p
Identification of Giardia lamblia DHHC Proteins and the Role of Protein S-palmitoylation in the Encystation Process
Protein S-palmitoylation, a hydrophobic post-translational modification, is performed by protein acyltransferases that have a common DHHC Cys-rich domain (DHHC proteins), and provides a regulatory switch for protein membrane association. In this work, we analyzed the presence of DHHC proteins in the protozoa parasite Giardia lamblia and the function of the reversible S-palmitoylation of proteins during parasite differentiation into cyst. Two specific events were observed: encysting cells displayed a larger amount of palmitoylated proteins, and parasites treated with palmitoylation inhibitors produced a reduced number of mature cysts. With bioinformatics tools, we found nine DHHC proteins, potential protein acyltransferases, in the Giardia proteome. These proteins displayed a conserved structure when compared to different organisms and are distributed in different monophyletic clades. Although all Giardia DHHC proteins were found to be present in trophozoites and encysting cells, these proteins showed a different intracellular localization in trophozoites and seemed to be differently involved in the encystation process when they were overexpressed. dhhc transgenic parasites showed a different pattern of cyst wall protein expression and yielded different amounts of mature cysts when they were induced to encyst. Our findings disclosed some important issues regarding the role of DHHC proteins and palmitoylation during Giardia encystation.Fil: Merino, Maria Cecilia. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - CĂłrdoba. Instituto de InvestigaciĂłn MĂ©dica Mercedes y MartĂn Ferreyra. Universidad Nacional de CĂłrdoba. Instituto de InvestigaciĂłn MĂ©dica Mercedes y MartĂn Ferreyra; ArgentinaFil: Zamponi, Nahuel. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - CĂłrdoba. Instituto de InvestigaciĂłn MĂ©dica Mercedes y MartĂn Ferreyra. Universidad Nacional de CĂłrdoba. Instituto de InvestigaciĂłn MĂ©dica Mercedes y MartĂn Ferreyra; ArgentinaFil: Vranych, Cecilia VerĂłnica. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - CĂłrdoba. Instituto de InvestigaciĂłn MĂ©dica Mercedes y MartĂn Ferreyra. Universidad Nacional de CĂłrdoba. Instituto de InvestigaciĂłn MĂ©dica Mercedes y MartĂn Ferreyra; ArgentinaFil: Touz, Maria Carolina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - CĂłrdoba. Instituto de InvestigaciĂłn MĂ©dica Mercedes y MartĂn Ferreyra. Universidad Nacional de CĂłrdoba. Instituto de InvestigaciĂłn MĂ©dica Mercedes y MartĂn Ferreyra; ArgentinaFil: Ropolo, Andrea Silvana. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - CĂłrdoba. Instituto de InvestigaciĂłn MĂ©dica Mercedes y MartĂn Ferreyra. Universidad Nacional de CĂłrdoba. Instituto de InvestigaciĂłn MĂ©dica Mercedes y MartĂn Ferreyra; Argentin
Ontology-guided data preparation for discovering genotype-phenotype relationships
International audienceComplexity of post-genomic data and multiplicity of mining strategies are two limits to Knowledge Discovery in Databases (KDD) in life sciences. Because they provide a semantic frame to data and because they benefit from the progress of semantic web technologies, bio-ontologies should be considered for playing a key role in the KDD process. In the frame of a case study relative to the search of genotype-phenotype relationships, we demonstrate the capability of bio-ontologies to guide data selection during the preparation step of the KDD process. We propose three scenarios to illustrate how domain knowledge can be taken into account in order to select or aggregate data to mine, and consequently how it can facilitate result interpretation at the end of the process
Vitamin D and breast cancer: interpreting current evidence
Preclinical investigations and selected clinical observational studies support an association between higher vitamin D intake and 25-hydroxyvitamin D levels with lower breast cancer risk. However, the recently updated report from the Institute of Medicine concluded that, for cancer and vitamin D, the evidence was 'inconsistent and insufficient to inform nutritional requirements'. Against this background, reports examining vitamin D intake, 25-hydroxyvitamin D levels and breast cancer incidence and outcome were reviewed. Current evidence supports the pursuit of several research questions but not routine 25-hydroxyvitamin D monitoring and vitamin D supplementation to reduce breast cancer incidence or improve breast cancer outcome
Follow-up of atheroma burden with sequential whole body contrast enhanced MR angiography:a feasibility study
Assess the feasibility of whole body magnetic resonance angiography (WB-MRA) for monitoring global atheroma burden in a population with peripheral arterial disease (PAD). 50 consecutive patients with symptomatic PAD referred for clinically indicated MRA were recruited. Whole body MRA (WB-MRA) was performed at baseline, 6 months and 3 years. The vasculature was split into 31 anatomical arterial segments. Each segment was scored according to degree of luminal narrowing: 0 = normal, 1 = <50 %, 2 = 50–70 %, 3 = 71–99 %, 4 = vessel occlusion. The score from all assessable segments was summed, and then normalised to the number of assessable vessels. This normalised score was divided by four (the maximum vessel score) and multiplied by 100 to give a final standardised atheroma score (SAS) with a score of 0–100. Progression was assessed with repeat measure ANOVA. 36 patients were scanned at 0 and 6 months, with 26 patients scanned at the 3 years follow up. Only those who completed all three visits were included in the final analysis. Baseline atherosclerotic burden was high with a mean SAS of 15.7 ± 10.3. No significant progression was present at 6 months (mean SAS 16.4 ± 10.5, p = 0.67), however there was significant disease progression at 3 years (mean SAS 17.7 ± 11.5, p = 0.01). Those with atheroma progression at follow-up were less likely to be on statin therapy (79 vs 100 %, p = 0.04), and had significantly higher baseline SAS (17.6 ± 11.2 vs 10.7 ± 5.1, p = 0.043). Follow up of atheroma burden is possible with WB-MRA, which can successfully quantify and monitor atherosclerosis progression at 3 years follow-up
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