Título del artículo:

Evaluation of the efficiency of bio-polymers derived from desertic plants as flocculation agents

In the treatment of wastewater, flocculation is one of the most used processes, which aims to eliminate colloidal particles cannot be removed by other methods; Traditionally it has been used aluminum or iron salts and synthetic polymer, which generate little biodegradable sludge; moreover biopolymers, have coagulation and flocculation properties which can remove over 80-90% of solids contaminated; additionally, the use of natural polymers produce sludge increased biodegradability. The present work analyzes the efficiency of a biopolimer based on 6 endemic plants (Opuntia dilleni, Stenocereus griseus, Cereus forbesii, Melocactus sp. Aloe arborescens and Aloe vera) found at the desertic indian reservation \"Kululumana\".

Acerca de la revista donde se publicó este artículo:

Chemical Engineering Transactions

Título del artículo:

Improvement of biomass and dha production on a semi-continuous culture of aurantiochytrium sp NYH-2

Aurantiochytrium sp has been recognized as one of the most suitable sources of high valuable fatty acids (FA) including docosahexaenoic acid (DHA), docosapentaenoic acid, arachidonic acid, eicosapentaenoic acid (EPA), and saturated FA; however it\'s necessary to improve total biomass production and high value FA specially DHA. The aim of this research is to improve the production of biomass and DHA on the novel Aurantiochytrium sp NYH-2 strain via an optimization of culture time (2, 3 and 5 days) and removal of culture (20, 50 and 80% v/v) using a 23 experimental design. It was found that in order to improve biomass production a large amount of culture media must be replaced (>90%), however after the third cycle biomass production was reduced from 10 g/L to 9 g/L; similarly under the same conditions lipids and DHA production increased from 15% to 20% (w/w) and from 3 to 5% (w/w) respectively in the first 3 cycles and then reduced in cycle 5. Finally results suggest that in a semi-continuous process the algae is only functional 3 cycles (9 to 12 days) and in order to improve total biomass lipids and DHA production, a volume of culture media between 80-92% must be removed every 3-4 days.

Acerca de la revista donde se publicó este artículo:

Chemical Engineering Transactions

Título del artículo:

Evaluation of a two-phase extraction system of carbohydrates and proteins from chlorella vulgaris utex 1803

Microalgae are a valuable source of high-value products and biofuels, however the high-energy cost required for the extraction of their metabolites has kept questioning on possible industrial upgrading. The aim of this study was to evaluate the effect of temperature, solvent/biomass, NaOH concentration and thermal pretreatment of the biomass in a 2-cycle carbohydrate and protein extraction system. Results shown that best conditions for carbohydrates extraction are achieved at a solvent concentration of 3.67 M, 55°C and a solvent/biomass ratio of 30mL/g. On the other side, the best conditions for protein were 3 M, 85°C and 45 mL/g. The efficiencies achieved under these conditions were 95% for carbohydrates and 98% for proteins. Using the best extraction conditions for each metabolite a thermal pre-treatment was performed at 25°C, 75°C and 105°C. Results indicate that highest efficiencies were achieved with dry biomass pretreated at 105°C, with values of 95% for carbohydrates and 98% for proteins.

Acerca de la revista donde se publicó este artículo:

Chemical Engineering Transactions

Título del artículo:

Life cycle assessment to identify environmental improvements in an aerobic waste water treatment plant

Currently, reduce the environmental impacts generated by industries is vital; that is the reason why many companies are changing their processes to biotechnological processes which seem to be more sustainable alternatives. The Life Cycle Analysis (LCA) is an internationally accepted tool that allows environmental assessment of products and processes. In addition, LCA has been used to identify environmental improvement opportunities in different production systems and, that is the reason why it has been selected to be used on this research in order to diagnose the environmental performance of a Waste Water Treatment Plant (WWTP) of a cattle benefit plant. The system studied was a WWTP located in Cúcuta (Colombia), which treats 118.477 kg/day of water from cattle benefit plant. The stages of the WWTP are: screening, grit removal, primary sedimentation tank, homogenizer, grease traps, activated sludge reactor, secondary sedimentation tank, slow down flow filter and drying bed. In this paper the process diagrams and the mass and energy balances were constructed with information provided directly by the cattle benefit plant. The impact analysis was carried out using the software SIMAPRO 7.0 and the following impact categories were evaluated: climate change, eutrophication, photochemical oxidation, depletion of the ozone layer, acidification and biotic exhaustion. It was found that the environmental impacts of the WWTP of the cattle benefit plant are generated mainly due to the high electricity consumption in screening, homogenizer, and slurry reactor. Eutrophication was also observed due to the enrichment caused by the increase of the amounts of nutrients, which affected decomposition of excess of organic matter in the water so it could not be a complete mineralization of the nutrients it possesses. All the calculations were carried out using the Ecoinvent data bases. Favourable indicators were observed comparing the environmental profiles of the biological WWTP under study with the environmental indicators of a physicochemical WWTP of cattle benefit plant located in Bucaramanga (Colombia). The potential environmental impacts were lower in all the impact categories evaluated.

Acerca de la revista donde se publicó este artículo:

Chemical Engineering Transactions

Título del artículo:

Molecular characterization and evaluation of oil-degrading native bacteria isolated from automotive service station oilcontaminated soils

In this study, a hydrocarbon-degrading mixed inoculum which is able to use used oil as sole carbon source, was selected from 15 bacterial isolates obtained from automotive service station oil-contaminated soils. Degrading microorganisms were isolated using different oils as sole carbon source and identified by the amplification and sequencing of the 16s rRNA sequences. In addition, the presence of hydrocarbon-degrading genes such as catechol 2,3 dioxygenase (nahH), alkane monooxygenase (alkB), Gram-negative (GN-RHDá) and Gram-positive PAH-Ring Hydroxylating Dioxygenase alpha (GP-RHDá) was analyzed by PCR and the molecular diversity by LSSP-PCR methods. Four (4) out of fifteen (15) isolates corresponding to Stenotrophomonas maltophilia, Pseudomonas aeruginosa and Klebsiella pneumoniae showed significant differences regarding oil/grease removal in liquid culture after 72 hours. Subsequently, a degrading mixed inoculum composed of these isolates was constructed and its degrading potential tested in a two-liter bioreactor containing unsterile liquid oily wastes with 0.8 % (w/v) Total Petroleum Hydrocarbons (TPHs) concentration for 42 days. The use of the mixed inoculum led to a decrease of 98.4 % Biological Oxygen Demand (BOD), 97.5 % Chemical Oxygen Demand (COD) and 97.2 % TPHs after 40 days. Further scale-up of the process to five liters using 0.2 % (w/v) unsterile oily wastes produced similar results, with a reduction of 85 % BOD, 39 % COD and 87 % TPHs after 38 days. The degrading mixed microbial inoculum presented high potential for the treatment of impacted soils at automotive service stations and sites polluted with oily wastes due to its elevated growth at high hydrocarbon concentrations and its capacity to utilize oils as energy source.

Acerca de la revista donde se publicó este artículo:

Chemical Engineering Transactions

Título del artículo:

Effect of carbon-nitrogen ratio for the biomass production, hydrocarbons and lipids on botryoccus braunii UIS 003.

The genus Botryococcus compiles a variety of green microalgae which accumulate large quantities of hydrocarbons, this genus is classified in four types or races (A, B, L and R) based on chemical structure of hydrocarbons. Race B has been acknowledge due to its hability to accumulate triterpene hydrocarbons C30-C37 best known as botriococene and methylated squalene C31-C34 which are considerate as candidates for biofuels production; however, one of the main problems that face biofuels production using this alga as feedstock is the continuous production, both lipids and hydrocarbons; that is why it\'s mandatory to find the best carbon and nitrogen source that maximizes biomass and total lipid production. It was found that by adjusting the carbon/nitrogen ratio using sodium carbonate (Na2CO3) it was possible to substantially improve the production of biomass from 1 to 2 g/L in 15 days thus doubling the production of biomass in the same time; however, both the lipids and hydrocarbons production will not be affected positively showing a significant reduction from baseline.

Acerca de la revista donde se publicó este artículo:

Chemical Engineering Transactions

Título del artículo:

A profile of corporate social responsibility for mining companies present in the Santurban Moorland, Santander, Colombia

This work is an attempt to develop a corporate social responsibility (CSR) profile based on the practices and processes used by the mining companies present in the Santurban moorland, in the department of Santander. To achieve this, a census was applied based on 82 variables in 6 planes related to corporate social responsibility and the stakeholders. Information was collected between June of 2013 and May of 2014 using a census that was applied only to those mining companies with current registrations in the Bucaramanga Chamber of Commerce and with more than 10 employees each. The results enabled the evaluation of sectorial strengths as well as those elements that need to be improved in order to achieve an optimal level of CSR. The weaknesses found in the gold companies include: lack of clear and transparent hiring practices; lack of programs for employees who are mothers with small children; and lack of sufficient tools for identifying the needs of the closest community to the sites. They do practice diverse social investment strategies but do not track the impact of applying these in the region. It was also found that they have no clear processes for identifying, selecting, contracting and evaluating their suppliers. The greatest weakness found was with respect to the Client given that they have no client service department.The strengths found amongst the Mining Companies in the Santurban Moorland include that most of them do have a CSR policy or strategy and demonstrate a positive attitude towards implementing this kind of program. In addition, they have gender equity and anti-discrimination policies and agreements that go beyond they law.

Acerca de la revista donde se publicó este artículo:

Global Ecology and Conservation

Título del artículo:

Herding effect in economic sectors of the Latin American stock markets: A pre and post-subprime crisis vision

In recent years the behavior of the agents and what motivates them to make their investment decisions; it has been the focus of study by many researchers in the fields of economics, finance and related fields. With this in mind, this article seeks to test empirically one of these behaviors, the herd effect, using the models proposed by Christie y Huang (1995) and Chang, Cheng y Khorana (2000), in the most representative index and the sectors that compose it, of the main markets in Latin America (Brazil, Mexico, Chile, Colombia, Peru and Argentina) in the period 2002-2014, as well as in the sub periods pre and post crisis caused by the subprime mortgage. The findings of this research show that the herd effect is present in the most representative stock index in Colombia, Chile and Peru and in some of the sectors that comprise it, either in the total period and/or in sub periods pre and post crisis; in the Brazilian stock market, the effect is present in the banking sector in the total period and in the sub period of pre-crisis; Argentina stock market that effect is present in the banking sector and in the oil and gas sector, and Mexico stock market there is no evidence of this effect.

Acerca de la revista donde se publicó este artículo:

Contaduria y Administracion

Título del artículo:

Assessing global risk factors for non-fatal injuries from road traffic accidents and falls in adults aged 35–70 years in 17 countries: A cross-sectional analysis of the prospective urban rural Epidemiological (PURE) study

Objectives To assess risk factors associated with non-fatal injuries (NFIs) from road traffic accidents (RTAs) or falls. Methods Our study included 151 609 participants from the Prospective Urban Rural Epidemiological study. Participants reported whether they experienced injuries within the past 12 months that limited normal activities. Additional questions elicited data on risk factors. We employed multivariable logistic regression to analyse data. Results Overall, 5979 participants (3.9% of 151 609) reported at least one NFI. Total number of NFIs was 6300: 1428 were caused by RTAs (22.7%), 1948 by falls (30.9%) and 2924 by other causes (46.4%). Married/common law status was associated with fewer falls, but not with RTA. Age 65–70 years was associated with fewer RTAs, but more falls; age 55–64 years was associated with more falls. Male versus female was associated with more RTAs and fewer falls. In lowermiddle- income countries, rural residence was associated with more RTAs and falls; in low-income countries, rural residence was associated with fewer RTAs. Previous alcohol use was associated with more RTAs and falls; current alcohol use was associated with more falls. Education was not associated with either NFI type. Conclusions This study of persons aged 35–70 years found that some risk factors for NFI differ according to whether the injury is related to RTA or falls. Policymakers may use these differences to guide the design of prevention policies for RTA-related or fall-related NFI.

Acerca de la revista donde se publicó este artículo:

Injury Prevention

Título del artículo:

Barriers for the participation in cardiac rehabilitation programmes in patients undergoing percutaneous revascularisation due to a coronary disease

Introduction Cardiac rehabilitation programmes encourage lifestyle changes and reduce the recurrence of morbidity and mortality by 25 %. Nevertheless, attendance rate to such programmes varies between 7.5 and 29%, and around 40 to 50 % of users abandon the treatment during the early stages. Motivation To describe the barriers found in those who participated or not in cardiac rehabilitation programmes after percutaneous revascularisation. Methods Cross-sectional study of 30 patients, who were applied the barrier scale for cardiac rehabilitation, using Likert-type questions, where the highest scores indicated a bigger perception of the barrier to participate in a cardiad rehabilitation programme. Results The major barriers per item were: «I find this exercise is tiring and/or painful» with an average of 2.86, followed by «I currently exercise» and «I did not know about cardiac rehabilitation» with an average of 2.73. The lowest score was: «Many people have heart problems and do not go», with 1.73. More barriers were shown in those who did not attend a cardiac rehabilitation programme (p < 0.05) than whose who did; in addition, most barriers were found in the fields of perceived needs and comorbidities/functional state (p < 0.05). This indicates a lack of orientation and education when it comes to the benefits that users could obtain by joining and participating in a cardiac rehabilitation programme, no matter how they feels or the type of functional limitations they may have.

Acerca de la revista donde se publicó este artículo:

Revista Colombiana de Cardiologia

Título del artículo:

Microalgae immobilization using hydrogels for environmental applications: Study of transient photopolymerization

Immobilization of microalgae has emerged as a useful technique for effective environmental applications as removal of undesirable compounds from water, culture collection handling for CO2 capture, development of biosensors, and production of clean energy among others. In this work, polymerization of hydrogels is evaluated in order to generate adequate nanoporous morphology for microalgae immobilization via use of transient light intensity. Hydrogels were polymerized using a UV light intensity range between 140 and 700 mW/cm2 during 0.8 h and characterized using rheology evaluation using an angular frequency of 1 rad/s for defined monomer, initiator and solvent amounts. Results shows that transient light polymerization has a significant effect on average pore size and pore size distribution, obtaining different gel points between 1,300 and 1,700 s and modules between 4,000 and 13,000 Pa, allowing to adjust nanoporous morphology of hydrogels improving the attach viability of species of microalgae with variable sizes and shapes, and allowing to develop better hydrogels for novel microalgae immobilization-based applications.

Acerca de la revista donde se publicó este artículo:

Chemical Engineering Transactions

Título del artículo:

Passive microalgae immobilization for wastewater treatment: Study of residual glycerol consumption

The aim of the present study is to evaluate the viability of glycerol as carbon source on immobilized algae cultures coupled with a modification on nitrogen (NO3-) and phosphate (PO4) concentration for the production of high valuable compounds (carbohydrates, proteins and lipids). it was determined that the conditions who favour the deposition of carbohydrates are 3-5% (v/v) of glycerol and 0.37 (g/L) of NaNO3. On The other hand, for obtain higher amounts of lipids, a 3% (v/v) of glycerol coupled with a limitation in the nitrogen source (0.04 g/L) are needed. Finally, in order to improve deposition of total proteins, larger concentrations of glycerol (5% v/v), NaNO3 (>0.37 g/L) and phosphate are needed.

Acerca de la revista donde se publicó este artículo:

Chemical Engineering Transactions

Título del artículo:

Peripheral Blood MCEMP1 Gene Expression as a Biomarker for Stroke Prognosis

A limitation when making early decisions on stroke management is the lack of rapid diagnostic and prognostic testing. Our study sought to identify peripheral blood RNA biomarkers associated with stroke. The secondary aims were to assess the discriminative capacity of RNA biomarkers for primary stroke type and stroke prognosis at 1-month. Methods-Whole-blood gene expression profiling was conducted on the discovery cohort: 129 first-time stroke cases that had blood sampling within 5 days of symptom onset and 170 control participants with no history of stroke. Results-Through multiple regression analysis, we determined that expression of the gene MCEMP1 had the strongest association with stroke of 11 181 genes tested. MCEMP1 increased by 2.4-fold in stroke when compared with controls (95% confidence interval, 2.0-2.8; P=8.2×10-22). In addition, expression was elevated in intracerebral hemorrhage when compared with ischemic stroke cases (P=3.9×10-4). MCEMP1 was also highest soon after symptom onset and had no association with stroke risk factors. Furthermore, MCEMP1 expression independently improved discrimination of 1-month outcome. Indeed, discrimination models for disability and mortality that included MCEMP1 expression, baseline modified Rankin Scale score, and primary stroke type improved discrimination when compared with a model without MCEMP1 (disability Net Reclassification Index, 0.76; P=3.0×10-6 and mortality Net Reclassification Index, 1.3; P=1.1×10-9). Significant associations with MCEMP1 were confirmed in an independent validation cohort of 28 stroke cases and 34 controls. Conclusions-This study demonstrates that peripheral blood expression of MCEMP1 may have utility for stroke diagnosis and as a prognostic biomarker of stroke outcome at 1-month.

Acerca de la revista donde se publicó este artículo:

Stroke

Título del artículo:

Novel Approaches in Primary Cardiovascular Disease Prevention: The HOPE-3 Trial Rationale, Design, and Participants\' Baseline Characteristics

Background: Cholesterol and blood pressure (BP) can be effectively and safely lowered with statin drugs and BP-lowering drugs, reducing major cardiovascular (CV) events by 20%-30% within 5 years in high-risk individuals. However, there are limited data in lower-risk populations. The Heart Outcomes Prevention Evaluation-3 (HOPE-3) trial is evaluating whether cholesterol lowering with a statin drug, BP lowering with low doses of 2 antihypertensive agents, and their combination safely reduce major CV events in individuals at intermediate risk who have had no previous vascular events and have average cholesterol and BP levels. Methods: A total of 12,705 women 65 years or older and men 55 years or older with at least 1 CV risk factor, no known CV disease, and without any clear indication or contraindication to the study drugs were randomized to rosuvastatin 10 mg/d or placebo and to candesartan/hydrochlorothiazide 16/12.5 mg/d or placebo (2 × 2 factorial design) and will be followed for a mean of 5.8 years. The coprimary study outcomes are the composite of CV death, nonfatal myocardial infarction (MI), and nonfatal stroke and the composite of CV death, nonfatal MI, nonfatal stroke, resuscitated cardiac arrest, heart failure, and arterial revascularization. Results: Participants were recruited from 21 countries in North America, South America, Europe, Asia, and Australia. Mean age at randomization was 66 years and 46% were women. Conclusions: The HOPE-3 trial will provide new information on cholesterol and BP lowering in intermediate-risk populations with average cholesterol and BP levels and is expected to inform approaches to primary prevention worldwide (HOPE-3 ClinicalTrials.gov NCT00468923).

Acerca de la revista donde se publicó este artículo:

Canadian Journal of Cardiology

Título del artículo:

A structural study of the hydrogen absorption properties by replacing vanadium with zirconium in metal alloys

Hydrogen storage and microstructure the TiCrV0.9, TiCrV0.9Zr0.2 and TiCrV0.7Zr0.4 alloys were investigated. The alloys were melted in arc furnace, the structure was analysed by X- ray diffraction and hydrogen absorption times were analysed by Sievert\'s type apparatus. The results showed that the addition of Zr replacing the V decreases in the absorption capacity passing of 3.8%wt to 2.0%wt in contrast the speed of hydrogen absorption increases considerably.

Acerca de la revista donde se publicó este artículo:

Journal of Physics: Conference Series

Título del artículo:

Brain Circuitry Supporting Multi-Organ Autonomic Outflow in Response to Nausea

While autonomic outflow is an important co-factor of nausea physiology, central control of this outflow is poorly understood. We evaluated sympathetic (skin conductance level) and cardiovagal (high-frequency heart rate variability) modulation, collected synchronously with functional MRI (fMRI) data during nauseogenic visual stimulation aimed to induce vection in susceptible individuals. Autonomic data guided analysis of neuroimaging data, using a stimulus-based (analysis windows set by visual stimulation protocol) and percept-based (windows set by subjects\' ratings) approach. Increased sympathetic and decreased parasympathetic modulation was associated with robust and anti-correlated brain activity in response to nausea. Specifically, greater autonomic response was associated with reduced fMRI signal in brain regions such as the insula, suggesting an inhibitory relationship with premotor brainstem nuclei. Interestingly, some sympathetic/parasympathetic specificity was noted. Activity in default mode network and visual motion areas was anti-correlated with parasympathetic outflow at peak nausea. In contrast, lateral prefrontal cortical activity was anti-correlated with sympathetic outflow during recovery, soon after cessation of nauseogenic stimulation. These results suggest divergent central autonomic control for sympathetic and parasympathetic response to nausea. Autonomic outflow and the central autonomic network underlying ANS response to nausea may be an important determinant of overall nausea intensity and, ultimately, a potential therapeutic target.

Acerca de la revista donde se publicó este artículo:

Cerebral Cortex

Título del artículo:

Corrigendum to \"heart failure in low- and middle-income countries: Background, rationale, and design of the INTERnational Congestive Heart Failure Study (INTER-CHF)\" (Am Heart J. (2015) 170:4 (627-634))

Acerca de la revista donde se publicó este artículo:

American Heart Journal

Título del artículo:

Heart Failure in Africa, Asia, the Middle East and South America: The INTER-CHF study

Background There are few data on heart failure (HF) patients from Africa, Asia, the Middle East and South America. Methods INTER-CHF is a prospective study that enrolled HF patients in 108 centers in 16 countries from 2012 to 2014. Consecutive ambulatory or hospitalized adult patients with HF were enrolled. Baseline data were recorded on sociodemographics, clinical characteristics, HF etiology and treatments. Age- and sex-adjusted results are reported. Results We recruited 5813 HF patients: mean(SE) age = 59(0.2) years, 39% female, 65% outpatients, 31% from rural areas, 26% with HF with preserved ejection fraction, with 1294 from Africa, 2661 from Asia, 1000 from the Middle-East, and 858 from South America. Participants from Africa - closely followed by Asians - were younger, had lower literacy levels, and were less likely to have health or medication insurance or be on beta-blockers compared with participants from other regions, but were most likely to be in NYHA class IV. Participants from South America were older, had higher insurance and literacy levels, and, along with Middle Eastern participants, were more likely to be on beta-blockers, but had the lowest proportion in NYHA IV. Ischemic heart disease was the most common HF etiology in all regions except Africa where hypertensive heart disease was most common. Conclusions INTER-CHF describes significant regional variability in socioeconomic and clinical factors, etiologies and treatments in HF patients from Africa, Asia, the Middle East and South America. Opportunities exist for improvement in health/medication insurance rates and proportions of patients on beta blockers, particularly in Africa and Asia.

Acerca de la revista donde se publicó este artículo:

International Journal of Cardiology

Título del artículo:

Relationship between cardiac vagal activity and mood congruent memory bias in major depression

Background Previous studies suggest that autonomic reactivity during encoding of emotional information could modulate the neural processes mediating mood-congruent memory. In this study, we use a point-process model to determine dynamic autonomic tone in response to negative emotions and its influence on long-term memory of major depressed subjects. Methods Forty-eight patients with major depression and 48 healthy controls were randomly assigned to either neutral or emotionally arousing audiovisual stimuli. An adaptive point-process algorithm was applied to compute instantaneous estimates of the spectral components of heart rate variability [Low frequency (LF), 0.04-0.15 Hz; High frequency (HF), 0.15-0.4 Hz]. Three days later subjects were submitted to a recall test. Results A significant increase in HF power was observed in depressed subjects in response to the emotionally arousing stimulus (p=0.03). The results of a multivariate analysis revealed that the HF power during the emotional segment of the stimulus was independently associated with the score of the recall test in depressed subjects, after adjusting for age, gender and educational level (Coef. 0.003, 95%CI, 0.0009-0.005, p=0.008). Limitations These results could only be interpreted as responses to elicitation of specific negative emotions, the relationship between HF changes and encoding/recall of positive stimuli should be further examined. Conclusions Alterations on parasympathetic response to emotion are involved in the mood-congruent cognitive bias observed in major depression. These findings are clinically relevant because it could constitute the mechanism by which depressed patients maintain maladaptive patterns of negative information processing that trigger and sustain depressed mood.

Acerca de la revista donde se publicó este artículo:

Journal of Affective Disorders

Título del artículo:

Storage system scheduling effects on the life of lead-acid batteries

Storage systems are a key element to take advantage of renewable energy due to its ability to transfer energy consumption from one time period to another. With high charge/discharge ratios one can increase the short term revenue stream from a renewable energy system whereas with a low charge/discharge ratios one can increase the long term benefits. Hence, when compared against nominal charge or discharge operation, the storage system life can be increased/reduced with a low/high charge or discharge ratios. In order to quantify this fact for different storage management strategies, this work analyze the effect on the life of a lead-acid battery system of three scheduling strategies: linear programming, crisp logic and fuzzy logic. The three cases will be compared against a reference strategy which consist on solving a linear optimization problem with perfect forecast of load, energy price and renewable availability. A photovoltaic system is taken as the renewable source and historic values for eight months are used to study the trend in the life of the storage system. it can be concluded that higher storage capacity leads to higher overall benefits, however, this cannot be said for the maximum storage system power, even when considering only the costs benefits, which suggest that a proper strategy and parameter selection can be better than high power ratio.

Acerca de la revista donde se publicó este artículo:

2015 IEEE PES Innovative Smart Grid Technologies Latin America, ISGT LATAM 2015

Título del artículo:

Assessing the loss due to working in the informal sector in Venezuela

In Venezuela, 40% of the workers are employed in the informal sector. This sector is known for being underproductive, meaning that the income received by its workers is less than what they could earn working in formal sector jobs. This paper uses data from the Household Sample Survey (2012-2013) to estimate difference-in-differences linear and quantile regression models, controlling for some demographic characteristics, to quantify the loss associated with working in this market, as an indirect way to quantify the size of the informal sector. The parallel trend assumption is satisfied through propensity score matching, exception made for the highest quartile. The results suggest that informal sector workers lose about 34% of their potential income, loss that is larger for women and with an ambiguous behavior across levels of education. The study also indicates that the average difference in wages between the two sectors tends to narrow over time.

Acerca de la revista donde se publicó este artículo:

Lecturas de Economia

Título del artículo:

Metabolic syndrome and subclinical left ventricular dysfunction

Recent studies using both conventional and tissue Doppler echocardiography have gathered evidence of myocardial dysfunction in individuals with metabolic syndrome. Recently, two-dimensional speckle-tracking echocardiography (2D-STE) has become a robust method for the detection of subclinical left ventricular dysfunction through quantitative assessment of myocardial deformation. Some studies suggest that metabolic syndrome is associated with longitudinal deformation of the left ventricle and that global longitudinal strain measured by 2D-STE is impaired in individuals with metabolic syndrome. It may be inferred that the early identification of subclinical left ventricular dysfunction and the determination of the role of the components of metabolic syndrome in impaired myocardial contractility can help elucidate and predict the risk of cardiovascular diseases in this syndrome.

Acerca de la revista donde se publicó este artículo:

Scientia Medica

Título del artículo:

Use of molecular biomarkers in studies of aquatic environmental impact

Molecular biomarkers refer to specific genes and/or its products present in ecosystems which have been exposed to physic or chemical alterations as a result of anthropogenic activities. These molecules are useful to estimate both change and spread of the damage level. The studies of DNA specific sequences, gene expression and proteins production allow to understand the consequences of the presence of specific pollutants or its mixtures in different ecosystems, but mainly in aquatic environments. To date, different gene targets have been used to understand the consequences derived by the introduction of specific pollutants into the environment and serve as excellent tools for environmental toxicology studies. In this review, some of the most commonly reported molecular biomarkers used to monitor the environmental impact in aquatic ecosystems and the pertinent considerations when they are used in environmental risk assessment studies are described.

Acerca de la revista donde se publicó este artículo:

Journal of Industrial Pollution Control

Título del artículo:

Neck circumference as a predictor of metabolic syndrome, insulin resistance and low-grade systemic inflammation in children: The ACFIES study

Background: The current study aims to evaluate the association between neck circumference (NC) and several cardio-metabolic risk factors, to compare it with well-established anthropometric indices, and to determine the cut-off point value of NC for predicting children at increased risk of metabolic syndrome, insulin resistance and low-grade systemic inflammation. Methods: A total of 669 school children, aged 8-14, were recruited. Demographic, clinical, anthropometric and biochemical data from all patients were collected. Correlations between cardio-metabolic risk factors and NC and other anthropometric variables were evaluated using the Spearman\'s correlation coefficient. Multiple linear regression analysis was applied to further examine these associations. We then determined by receiver operating characteristic (ROC) analyses the optimal cut-off for NC for identifying children with elevated cardio-metabolic risk. Results: NC was positively associated with fasting plasma glucose and triglycerides (p = 0.001 for all), and systolic and diastolic blood pressure, C-reactive protein, insulin and HOMA-IR (p < 0.001 for all), and negatively with HDL-C (p = 0.001). Whereas, other anthropometric indices were associated with fewer risk factors. Conclusions: NC could be used as clinically relevant and easy to implement indicator of cardio-metabolic risk in children.

Acerca de la revista donde se publicó este artículo:

BMC Pediatrics

Título del artículo:

Characteristics of innovation in services at companies inside the textile sector and características de la innovación en servicios en compañías del sector textil

This article aims to describe the characteristics of innovation in services at small and medium companies (SMEs) in the textile sector at Valledupar, Colombia. The characteristic of innovation are: (1) the formalization and systematization of innovation processes related with the economics activities, (2) The difficulty of make any difference between product innovations and process innovations, (3) The preference in the organizational innovations face to the technological innovations, (4) The difficulty of protecting the innovations, (5) the incremental and flexible role of the innovation, and (6) The origin concentrated on the market. The research is the type descriptive, not experimental and cross-sectional. The population of this research is fifteen small and medium companies at the textile sector of Valledupar, Colombia. The research uses a Likert type questionnaire applied to the managers. The results indicate that the predominant characteristics are the difficult to protect innovations, the difficulty for differentiate between product and process innovation, and its incremental and flexible role. However, the companies analyzed lacks of formalization and systematization in the innovation process.

Acerca de la revista donde se publicó este artículo:

International Journal of Applied Business and Economic Research