Cardiovascular disease versus periodontal disease: chronic systemic infection as a link

Objective : Analysis of the alleged connection between the periodontal and cardiovascular disease, with reference to periodontal pathogens as a risk factor for heart disease. Researching method : A research was carried out at Medline/Pubmed. Included criteria and researching strategy. The articles selection has been made taking into account key-terms appearing either in the title or in the summary. Experimental studies in animals, clinical prospective studies performed with a minimum sample size (>30) and studies written in English have been included. The rejected criteria were the following: clinical retrospective studies and/or studies carried out with a low sample size (n<30). Results : Within systemic diseases related to periodontal ones, the alleged link between periodontal and heart and circulatory disease has been one of the most investigated in recent times. Different authors consider the existence of a link between the diseases as such, inappropriate and implausible since both the diseases have risk factors in common (age, gender, smoking, diet, oral hygiene and diabetes). However, speculations about the origin of the diseases were raised when it was demonstrated that some bacteria species, bacteria proteins and lipopolysaccharide are present at the plaques of atherosclerosis that obstruct the coronary arteries. The mechanisms of this connection have been analyzed following an actualized review. Conclusion : Most of the experimental and clinical studies ensure that a positive association between periodontal disease and heart disease has been found, once the con-founder factors have been eliminate

X-Ray Fluorescence Analysis of Ground Coffee

Coffee is becoming one of the most popular beverages in Mexico. In the present work, X-ray Fluorescence (XRF) was used to determine the contents of several elements (with atomic numbers between 11 and 38) in 11 samples of commercial ground coffee, comparing with another one of soluble coffee and two of used ground coffee. Samples were dried at room temperature and pelletized. XRF analyses were carried out using a spectrometer based on an Rh X-ray tube, registering the characteristic x-rays with a Silicon Drift Detector. The system detection calibration and accuracy check was performed through the analysis of NIST certified reference materials 1547 (peach leaves), 1570a (spinach leaves), 1573a (tomato leaves), and 1571 (orchid leaves). As a general rule, the elemental concentrations measured are similar in all samples of coffee, in values not exceeding toxic levels. However, the differences among the elemental concentrations are shown

Discrete-time heavy-tailed chains, and their properties in modelling network traffic

The particular statistical properties found in network measurements, namely self-similarity and long-range dependence, cannot be ignored in modelling network and Internet traffic. Thus, despite their mathematical tractability, traditional Markov models are not appropriate for this purpose, since their memoryless nature contradicts the burstiness of transmitted packets. However, it is desirable to find a similarly tractable model which is, at the same time, rigorous at capturing the features of network traffic. This work presents the discrete-time heavy-tailed chains, a tractable approach to characterise network traffic as a superposition of discrete-time “on/off” sources. This is a particular case of the generic “on/off” heavy-tailed model, thus showing the same statistical features as the former; particularly, self-similarity and long-range dependence, when the number of aggregated sources approaches infinity. The model is then applicable to characterise a number of discrete-time communication systems, for instance ATM and Optical Packet Switching, and further derive meaningful performance met- rics, such as the average burst duration and the number of active sources in a random instant

Horizontal collaboration in freight transport: concepts, benefits and environmental challenges

[EN] Since its appearance in the 1990s, horizontal collaboration (HC) practices have revealed themselves as catalyzers for optimizing the distribution of goods in freight transport logistics. After introducing the main concepts related to HC, this paper offers a literature review on the topic and provides a classification of best practices in HC. Then, the paper analyses the main benefits and optimization challenges associated with the use of HC at the strategic, tactical, and operational levels. Emerging trends such as the concept of ` green' or environmentally- friendly HC in freight transport logistics are also introduced. Finally, the paper discusses the need of using hybrid optimization methods, such as simheuristics and learnheuristics, in solving some of the previously identified challenges in real- life scenarios dominated by uncertainty and dynamic conditions.This work has been partially supported by the Spanish Ministry of Economy and Competitiveness & FEDER (TRA2013-48180-C3-P, TRA2015-71883-REDT), The Erasmus+ program (2016-1-ES01-KA108-023465), the Ibero American Program of Science and Technology for Development (CYTED2014-515RT-0489), the CAN Foundation (CAN2014-3758, CAN2015-70473), and the Spanish Ministry of Education (FPU-14/00024).Serrano-Hernandez, A.; Juan, AA.; Faulin, J.; Perez-Bernabeu, E. (2017). Horizontal collaboration in freight transport: concepts, benefits and environmental challenges. SORT. Statistics and Operations Research Transactions. 41(2):393-414. https://doi.org/10.2436/20.8080.02.65S39341441

Software Radio para antenas inteligentes en comunicaciones personales multistandard

Peer ReviewedPostprint (published version

Board 399: The Freshman Year Innovator Experience (FYIE): Bridging the URM Gap in STEM

The project focuses on increasing “effective STEM education and broadening participation” in underrepresented minority STEM students at the University of Texas Rio Grande Valley (UTRGV) to successfully face academic and professional challenges, recently exacerbated by the COVID-19 pandemic. The Freshman Year Innovator Experience proposes the development of self-transformation skills in freshman mechanical engineering students to successfully face academic and professional challenges exacerbated by the COVID-19 pandemic while working on two parallel projects of technical design innovation and academic career pathways. The authors will present the work in progress and preliminary results from a pilot implementation of the Freshman Year Innovator Experience. This project is funded by NSF award 2225247

Longitudinal variability of size-fractionated N-2 fixation and DON release rates along 24.5 degrees N in the subtropical North Atlantic

Dinitrogen (N-2) fixation and dissolved organic nitrogen (DON) release rates were measured on fractionated samples (\u3e10 mu m and m) along 24.5 degrees N in the subtropical North Atlantic. Net N-2 fixation rates (N-2 assimilation into biomass) ranged from 0.01 to 0.4 nmol N L-1 h(-1), and DON release rates ranged from 0.001 to 0.09 nmol N L-1 h(-1). DON release represented approximate to 14% and approximate to 23% of \u3e10 mu m and (assimilation into biomass plus DON release), respectively. This implies that by overlooking DON release, N-2 fixation rates are underestimated. Net N-2 fixation rates were higher in the east and decreased significantly toward the west (r(s)=-0.487, p=0.002, and r(s)=-0.496, p=0.001, for the \u3e10 mu m and fractions, respectively). The sum of both fractions correlated with aerosol optical depth at 550 nm (AOD 550 nm) (r(s)=0.382, p=0.017) and phosphate (PO43-) concentrations (r(s)=0.453, p=0.018), suggesting an enhancement of diazotrophy as a response to aerosol inputs and phosphorus availability. In contrast, DON release was constant among size fractions and did not correlate with any of these variables. We also compared N-2 fixation rates obtained using the N-15(2) dissolved and bubble methods. The first gave average rates 50% (49% 39) higher than the latter, which supports the finding that previously published N-2 fixation rates are likely underestimated. We suggest that by combining N-2 fixation and DON release measurements using dissolved N-15(2), global N-2 fixation rates could increase enough to balance oceanic fixed nitrogen budget disequilibria