Título del artículo:

Physical activity in adults: recommendations, determinants and measurement

Introduction: Several studies have shown the potential benefits of the practice of Physical Activity (PA) over the years; however, some modulators known as determinants that modify its practice have also been identified. Objective: To gather and summarize available information on the importance of physical activity, its definition, determinants and evaluation methods in adults, as well as to establish the development of recommendations over time. Material and Methods: A search was made in different databases using search terms of physical activity, recommendations, and determinants in both English and Spanish during the period between 1996 and 2019. Articles related to adults were included and those about children and adolescents were excluded. Development: The recommendations have evolved from 1978 when the American College of Sports Medicine (ACSM) established very general specifications such as PA practices from 3 to 5 days per week at an intensity between 60% and 90% Heart Rate Reserve (HRR) until the most recent recommendations made by the Center for Disease Control and Prevention (CDC) in 2018. Objective and subjective criteria are among the evaluation methods. Conclusions: Regular PA practice is an efficient strategy to reduce the risk factors associated with Non-Communicable Diseases (NCDs). Likewise, subjective and objective criteria are identified for its evaluation. The recommendations have evolved from 1978 to 2018 establishing that adults should be involved in PA from 150 to 300 minutes per week.

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Revista Habanera de Ciencias Medicas

Título del artículo:

Toxoplasma gondii in small ruminants in northeastern areas of Colombia: Seroprevalence and risk factors

Sheep and goats are susceptible to infections with Toxoplasma gondii and could play an important role in the transmission of the zoonotic parasite to human. We conducted a cross sectional study to estimate the seroprevalence and to assess the risk factors for T. gondii seropositivity in small ruminants under traditional husbandry systems. This study was carried out from November 2015 to April 2016 in randomly selected small ruminants (n = 1038) from 48 farms located in Colombia, in the departments of northern Cesar in the north and La Guajira in the south. An indirect ELISA was used to detect IgG antibodies to T. gondii in the animals. A standardized questionnaire was used to obtain information on putative risk factors. We conducted the association analyses by using univariable and multivariate logistic regression and report odds ratios (OR) with 95% confidence interval (C.I). The overall seroprevalence in small ruminants was 23.5% (C.I: 21–26.2%). Sheep showed a higher seroprevalence (25.1% C.I: 22.4–28.6%) than goats (18.4% C.I: 22.4–28.6%). The association analysis recognized as risk factors for T. gondii seropositivity farming pigs in addition to small ruminants (OR = 1.96 C.I: 1.414–2.743), the inexistence of manure heap (OR = 2.254 C.I: 1.480–3.433) and drinking water from locally aqueducts (OR = 1.489 C.I: 1.006–2.204). The results of the study confirmed that exposure to T. gondii is common in sheep and goats in dry Caribbean regions of Colombia.

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Parasite Epidemiology and Control

Título del artículo:

Emerging approaches since design for theorization and creation of transmedia experiences: Approximation to meta-analysis of scientific publications

The main objective of this document is to identify the existence of predominant and emerging approaches in the design of transmedia experiences, in order to contribute from different perspectives to the transmedia concept from the modes of involvement of audiences. The bibliometric analysis is done of a total of 559 articles consolidated from the literature search carried out in WoS on the ISI Web of Knowledge platform (Thomson Reuters) and SCImago Research Group (Scopus). For the observation window 2008-2019, the indicators are analyzed: diachronic productivity, author productivity, citations and content. In the results, an exponential growth of the publications is observed until its peak in 2016, as well as its subsequent stability; similarly, the creation of author networks for collaborative production and the achievement of common goals is evident; and a tendency to cite the conventional literature existing outside the sample documents is also identified. The conclusions establish the interest of the academic community for the design of transmedia experiences and the participation of audiences as content that is transversal to the sample and not as a central theme of study.

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Arte, Individuo y Sociedad

Título del artículo:

Methodological proposal for the construction and selection of digital high-precision elevation models

Digital Elevation Models improve accuracy in terrain analysis. This work compared different interpolation methods using statistical criteria in a topographic survey of 339 points raised with a total station in the “San Juan de Lagunillas” area (Venezuela). The existence of a significant trend process with spatial autocorrelation modeled by an isotropic Gaussian semivariogram was documented. The kriging allowed to obtain residuals less than a minimum tolerable error equal to 0.1 m. The residual kriging was the best evaluated in cross validation with exclusion (absolute mean error of 0.71 m). The disjunctive kriging showed a lower error average but a wider error range and the highest mean absolute error (12.8 m). The other kriging showed mean error variance greater than 1.3 m and absolute minimum errors greater than 0.85 m. Due to the high dependence on the model specification form, graphics are recommended for a better fit.

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Colombia Forestal

Título del artículo:

COVID-19 is a new disease caused by the beta coronavirus SARS-CoV-2.

The first registers of atypical pneumonia were reported in China by the end of December 2019. The disease was rapidly disseminated in the entire world. The spectrum of the clinical manifestations is large going from individuals without any symptoms to those who develop multisystem disease and death. It has been demonstrated that hypertension and diabetes are more frequent in people with COVID-19 and the presence of diabetes is associated with an increased risk of more severe disease and higher mortality. In the present article, we review the possible mechanism why the diabetes patients have an increased risk of mortality by COVID-19 and recommend preventive actions that must be implemented in the general population and particularly in individuals with diabetes.

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Gaceta Medica de Caracas

Título del artículo:

Frequency-Dependent Effects of Exhalatory-Gated Transcutaneous Vagus Nerve Stimulation on Cardiac Autonomic Regulation in Hypertension

The objective of this study was to determine potential effects of respiratory-gated auricular vagal afferent nerve stimulation (RAVANS) on cardiovagal activity in hypertensive patients. Twenty hypertensive subjects (54.55\\pm 6.23 years; 12 females) underwent five randomized sessions of RAVANS at frequencies of 0, 2, 10, 25, and 100 Hz. Continuous electrocardiogram (ECG) and pulse rate signals were collected during 10-minute baseline, 30-minute stimulation, and 10-minute recovery periods using a Grass LP511 AC amplifier and piezo device. LabChart was used to acquire ECG and pulse signals and to process heart rate variability (HRV) indices. A significant increase in high frequency (HF) power (%) was observed during the RAVANS-100 Hz session from baseline to recovery l{n}=0.039) when compared to sham, adjusting for sex and baseline values. HRV evaluation for other frequencies did not yield significant results. These results suggest that RAVANS has a frequency-dependent effect on the modulation of cardiovagal activity (HF-HRV) in hypertension.

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2020 11th Conference of the European Study Group on Cardiovascular Oscillations: Computation and Modelling in Physiology: New Challenges and Opportunities, ESGCO 2020

Título del artículo:

Effect of the genetic group of cows of the Gyr and Holstein breeds on the in vitro production technique of bovine embryos

The aim of this study was to evaluate the genetic group effect of oocyte donors of the Gyr and Holstein breeds on the performance of the in vitro embryo production technique. Twelve multiparous cows were used, non-lactating, six of the Gyr breed (Bos indicus), and six of the Holstein (Bos taurus) breed. Prior to the implementation of the follicular aspiration technique, the animals were subjected to estrus synchronization through the administration of 3 mg estradiol benzoate (RIC-BE, Tecnopec Ltda., Brazil) plus the insertion of an ear implant with norgestomet (Crestar, Intervet, Brazil). Aspiration was performed seven days after the start of the synchronization protocol. The results showed that the cows of the Gyr breed had a higher number of visualized follicles and recovered oocytes, as well as a higher cleavage and blastocyst rate on day 7. These results allow considering that, the application of the in vitro embryo production technique in the Gyr breed offers a better performance in specific parameters in comparison to the Holstein breed.

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Ciencia Tecnologia Agropecuaria

Título del artículo:

Complex ecological interactions across a focus of cutaneous leishmaniasis in Eastern Colombia: novel description of Leishmania species, hosts and phlebotomine fauna

This study aimed to analyse the patterns of diversity, blood sources and Leishmania species of phlebotomines in a focus of cutaneous leishmaniasis in Arboledas, Eastern Colombia. In total, 1729 phlebotomines were captured in two localities (62.3% Siravita and 37.7% Cinera) and five environments of Norte de Santander. We identified 18 species of phlebotomines: Pintomyia ovallesi (29.8%), Psychodopygus davisi (20.3%), Pi. spinicrassa (18.5%) and Lutzomyia gomezi (15.8%) showed the highest abundance. Species diversities were compared between Cinera (15.00) and Siravita (20.00) and among five microenvironments: forest remnants (19.49), coffee plantations (12.5), grassland (12.99), cane plantations (11.66) and citrus plantations (12.22). Leishmania DNA was detected in 5.8% (80/1380) of females, corresponding mainly to Pi. ovallesi (22/80; 27.2%), Lu. gomezi (17/80; 21.3%) and Pi. spinicrassa (11/80; 13.8%). Leishmania species were 63.1% L. braziliensis, 18.5% L. panamensis, 13.2% L. infantum and 6.1% L. amazonensis. The most frequent feeding sources were Homo sapiens (50%), Bos taurus (13.8%) and Canis lupus familiaris (10.3%). This focus of cutaneous leishmaniasis has a high diversity of Leishmania-carrying phlebotomines that feed on domestic animals. The transmission of leishmaniasis to human hosts was mainly associated with Lu. gomezi, Pi. ovallesi and L. braziliensis.

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Royal Society Open Science

Título del artículo:

An innovative low-cost equipment for electro-concentration of microalgal biomass

Microalgal harvesting is one of the most challenging processes in the development of algal research and development. Several methods, such as centrifugation, flocculation and filtration, are available at the laboratory scale. However, the requirement for expensive pieces of equipment and the possibility of biomass contamination are recurring gaps that hinder the development of microalgae R and D (research and development) in different parts of the world. Recently, electroflotation has been proved to be a suitable method for the harvesting of different species of microalgae and cyanobacteria. To this day, there are no companies that sell laboratory-scale electroflotation equipment; this is mainly due to the gap in the knowledge of which factors (time, mixing rate, number of electrodes and others) will affect the efficiency of concentration without reducing the biomass quality. This paper aims to build an innovative, low-cost electroflotation system for under 300 USD (United States dollar) with cheap and resistant materials. To achieve our goal, we tested the interaction of three variables (time, mixing rate and amount of electrodes). Results showed that an efficiency closer to 100% could be achieved in under 20 min using > 10 electrodes and 150 rpm (round per minute). We hope this innovative approach can be used by different researchers to improve our knowledge of the concentration and harvesting of algae and cyanobacteria.

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Applied Sciences (Switzerland)

Título del artículo:

Association of nut intake with risk factors, cardiovascular disease, and mortality in 16 countries from 5 continents: Analysis from the Prospective Urban and Rural Epidemiology (PURE) study

Background: The association of nuts with cardiovascular disease and deaths has been investigated mostly in Europe, the USA, and East Asia, with few data available from other regions of the world or from low- and middle-income countries. Objective: To assess the association of nuts with mortality and cardiovascular disease (CVD). Methods: The Prospective Urban Rural Epidemiology study is a large multinational prospective cohort study of adults aged 35-70 y from 16 low-, middle-, and high-income countries on 5 continents. Nut intake (tree nuts and ground nuts) was measured at the baseline visit, using country-specific validated FFQs. The primary outcome was a composite of mortality or major cardiovascular event [nonfatal myocardial infarction (MI), stroke, or heart failure]. Results: We followed 124,329 participants (age = 50.7 y, SD = 10.2; 41.5% male) for a median of 9.5 y. We recorded 10,928 composite events [deaths (n = 8,662) or major cardiovascular events (n = 5,979)]. Higher nut intake (>120 g per wk compared with <30 g per mo) was associated with a lower risk of the primary composite outcome of mortality or major cardiovascular event [multivariate HR (mvHR): 0.88; 95% CI: 0.80, 0.96; P-trend = 0.0048]. Significant reductions in total (mvHR: 0.77; 95% CI: 0.69, 0.87; P-trend <0.0001), cardiovascular (mvHR: 0.72; 95% CI: 0.56, 0.92; P-trend = 0.048), and noncardiovascular mortality (mvHR: 0.82; 95% CI: 0.70, 0.96; P-trend = 0.0046) with a trend to reduced cancer mortality (mvHR: 0.81; 95% CI: 0.65, 1.00; P-trend = 0.081) were observed. No significant associations of nuts were seen with major CVD (mvHR: 0.91; 95% CI: 0.81, 1.02; P-trend = 0.14), stroke (mvHR: 0.98; 95% CI: 0.84, 1.14; P-trend = 0.76), or MI (mvHR: 0.86; 95% CI: 0.72, 1.04; P-trend = 0.29). Conclusions: Higher nut intake was associated with lower mortality risk from both cardiovascular and noncardiovascular causes in low-, middle-, and high-income countries.

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American Journal of Clinical Nutrition

Título del artículo:

The Effects of Maintenance Cardiac Rehabilitation: A SYSTEMATIC REVIEW

Purpose: Maintenance cardiac rehabilitation (M-CR) programs aim to preserve the health benefits achieved during phase II cardiac rehabilitation (CR). The aim of this study was to establish the effects of M-CR on functional capacity, quality of life, risk factors, costs, mortality, and morbidity, among other outcomes. Methods: Scopus, ISI Web of Science, PubMed, Embase & Embase classic OVID, and Lilacs were searched. Randomized controlled trials, published between 2000 and 2016, on the effects of M-CR in patients with cardiovascular disease, who had graduated from CR, having a control or comparison arm were included. Citations were processed by two authors, independently. Methodological quality was assessed using PEDro, and level of evidence graded with the Scottish scale. Outcomes were qualitatively synthesized. Results: The searches retrieved 1901 studies with 26 articles meeting inclusion criteria (3752 participants). Some trials tested M-CR in nonclinical settings, and others used resistance or high-intensity interval training. The methodological quality of 11 articles was good, with a level of evidence (1+) and a grade B recommendation. Results showed M-CR resulted in increased or maintained functional capacity, quality of life, and physical activity levels, when compared with the control. No adverse events were reported. Few studies assessed rehospitalizations and mortality. Conclusion: Quality of included trials was low because it is not possible to double-blind in M-CR trials and also due to the heterogeneity of M-CR interventions. Understanding, availability, and use of M-CR programs should be increased.

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Journal of Cardiopulmonary Rehabilitation and Prevention

Título del artículo:

Effect of dulaglutide on cognitive impairment in type 2 diabetes: an exploratory analysis of the REWIND trial

Background: Diabetes is an independent risk factor for cognitive impairment. We aimed to investigate the association between the glucagon-like peptide-1 (GLP-1) receptor agonist dulaglutide and cognitive impairment as an exploratory analysis within the Researching Cardiovascular Events With a Weekly Incretin in Diabetes (REWIND) trial. Methods: REWIND is a randomised, double-blind placebo-controlled trial at 371 sites in 24 countries. We included men and women (aged ≥50 years) with either established or newly diagnosed type 2 diabetes and additional cardiovascular risk factors, glycated haemoglobin of up to 9·5% (80 mmol/mol) on a maximum of two oral glucose-lowering drugs with or without basal insulin, and a body-mass index of at least 23 kg/m2. Participants were randomly assigned (1:1) subcutaneous injections once a week of either dulaglutide (1·5 mg) or an equal volume of matching placebo. Randomisation was done using a computer-generated code with stratification by site. Participants and all study personnel were masked to treatment allocation until the database was locked. Participants were followed up at least every 6 months for the composite primary outcome of stroke, myocardial infarction, or death from cardiovascular or unknown causes. Cognitive function was assessed at baseline and during follow-up using the Montreal Cognitive Assessment (MoCA) and Digit Symbol Substitution Test (DSST). We present here the exploratory primary cognitive outcome, which was the first occurrence of a follow-up score on MoCA or DSST that was 1·5 SDs or more below the baseline mean score in the participant\'s country. All analyses were done using an intention-to-treat approach. The REWIND trial is registered with ClinicalTrials.gov, NCT01394952. Findings: Between Aug 18, 2011, and Aug 14, 2013, 9901 participants were randomly assigned to either dulaglutide (n=4949) or placebo (n=4952). During median follow-up of 5·4 (IQR 5·1–5·9) years, 8828 participants provided a baseline and one or more follow-up MoCA or DSST scores, of whom 4456 were assigned dulaglutide and 4372 were assigned placebo. The cognitive outcome occurred in 4·05 per 100 patient-years in participants assigned dulaglutide and 4·35 per 100 patient-years in people assigned placebo (hazard ratio [HR] 0·93, 95% CI 0·85–1·02; p=0·11). After post-hoc adjustment for individual standardised baseline scores, the hazard of substantive cognitive impairment was reduced by 14% in those assigned dulaglutide (HR 0·86, 95% CI 0·79–0·95; p=0·0018). Interpretation: Long-term treatment with dulaglutide might reduce cognitive impairment in people with type 2 diabetes. Further studies of this drug focused on brain health and cognitive function are clearly indicated. Funding: Eli Lilly and Company.

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The Lancet Neurology

Título del artículo:

Stimulus frequency modulates brainstem response to respiratory-gated transcutaneous auricular vagus nerve stimulation

Background: The therapeutic potential of transcutaneous auricular VNS (taVNS) is currently being explored for numerous clinical applications. However, optimized response for different clinical indications may depend on specific neuromodulation parameters, and systematic assessments of their influence are still needed to optimize this promising approach. Hypothesis: We proposed that stimulation frequency would have a significant effect on nucleus tractus solitarii (NTS) functional MRI (fMRI) response to respiratory-gated taVNS (RAVANS). Methods: Brainstem fMRI response to auricular RAVANS (cymba conchae) was assessed for four different stimulation frequencies (2, 10, 25, 100 Hz). Sham (no current) stimulation was used to control for respiration effects on fMRI signal. Results: Our findings demonstrated that RAVANS delivered at 100 Hz evoked the strongest brainstem response, localized to a cluster in the left (ipsilateral) medulla and consistent with purported NTS. A co-localized, although weaker, response was found for 2 Hz RAVANS. Furthermore, RAVANS delivered at 100 Hz also evoked stronger fMRI responses for important monoamine neurotransmitter source nuclei (LC, noradrenergic; MR, DR, serotonergic) and pain/homeostatic regulation nuclei (i.e. PAG). Conclusion: Our fMRI results support previous localization of taVNS afference to pontomedullary aspect of NTS in the human brainstem, and demonstrate the significant influence of the stimulation frequency on brainstem fMRI response.

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Brain Stimulation

Título del artículo:

Endometrial and decidual stromal precursors show a different decidualization capacity

Endometrial stromal cells (EnSCs) and decidual stromal cells (DSCs) originate from fibroblastic precursors located around the vessels of the human nonpregnant endometrium and the pregnant endometrium (decidua), respectively. Under the effect of ovarian or pregnancy hormones, these precursors differentiate (decidualize), changing their morphology and secreting factors that appear to be essential for the normal development of pregnancy. However, the different physiological context - that is, non-pregnancy vs pregnancy - of those precursors (preEnSCs, preDSCs) might affect their phenotype and functions. In the present study, we established preEnSC and preDSC lines and compared the antigen phenotype and responses to decidualization factors in these two types of stromal cell line. Analyses with flow cytometry showed that preEnSCs and preDSCs exhibited a similar antigen phenotype compatible with that of bone marrow mesenchymal stem/stromal cells. The response to decidualization in cultures with progesterone and cAMP was evaluated by analyzing changes in cell morphology by microscopy, prolactin and IL-15 secretion by enzyme immunoassay and the induction of apoptosis by flow cytometry. In all four analyses, preDSCs showed a significantly higher response than preEnSCs. The expression of progesterone receptor (PR), protein kinase A (PKA) and FOXO1 was studied with Western blotting. Both types of cells showed similar levels of PR and PKA, but the increase in PKA RI subunit expression in response to decidualization was again significantly greater in preDSCs. We conclude that preEnSCs and preDSCs are equivalent cells but differ in their ability to decidualize. Functional differences between them probably derive from factors in their different milieus.

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Reproduction

Título del artículo:

Long-term exposure to outdoor and household air pollution and blood pressure in the Prospective Urban and Rural Epidemiological (PURE) study

Exposure to air pollution has been linked to elevated blood pressure (BP) and hypertension, but most research has focused on short-term (hours, days, or months) exposures at relatively low concentrations. We examined the associations between long-term (3-year average) concentrations of outdoor PM2.5 and household air pollution (HAP) from cooking with solid fuels with BP and hypertension in the Prospective Urban and Rural Epidemiology (PURE) study. Outdoor PM2.5 exposures were estimated at year of enrollment for 137,809 adults aged 35–70 years from 640 urban and rural communities in 21 countries using satellite and ground-based methods. Primary use of solid fuel for cooking was used as an indicator of HAP exposure, with analyses restricted to rural participants (n = 43,313) in 27 study centers in 10 countries. BP was measured following a standardized procedure and associations with air pollution examined with mixed-effect regression models, after adjustment for a comprehensive set of potential confounding factors. Baseline outdoor PM2.5 exposure ranged from 3 to 97 μg/m3 across study communities and was associated with an increased odds ratio (OR) of 1.04 (95% CI: 1.01, 1.07) for hypertension, per 10 μg/m3 increase in concentration. This association demonstrated non-linearity and was strongest for the fourth (PM2.5 > 62 μg/m3) compared to the first (PM2.5 < 14 μg/m3) quartiles (OR = 1.36, 95% CI: 1.10, 1.69). Similar non-linear patterns were observed for systolic BP (β = 2.15 mmHg, 95% CI: −0.59, 4.89) and diastolic BP (β = 1.35, 95% CI: −0.20, 2.89), while there was no overall increase in ORs across the full exposure distribution. Individuals who used solid fuels for cooking had lower BP measures compared to clean fuel users (e.g. 34% of solid fuels users compared to 42% of clean fuel users had hypertension), and even in fully adjusted models had slightly decreased odds of hypertension (OR = 0.93; 95% CI: 0.88, 0.99) and reductions in systolic (−0.51 mmHg; 95% CI: −0.99, −0.03) and diastolic (−0.46 mmHg; 95% CI: −0.75, −0.18) BP. In this large international multi-center study, chronic exposures to outdoor PM2.5 was associated with increased BP and hypertension while there were small inverse associations with HAP.

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Environmental Pollution

Título del artículo:

Evolution of the porous structure of cocoa beans during microwave drying

In this work, it was evaluated the morphological changes of the porous structure of the cocoa bean samples subjected to microwave drying. The use of microwaves (MWs) applied by ON-OFF on cocoa bean samples allowed to avoid both the burning and the roasting of the beans. During the MWs drying process, phenomena of breakage of cellular structure, coalescence and, pore plugging altered the average pore diameter, the pore volume, surface area, and Pore Size Distribution (PSD). When the results of sun-dried beans were compared with those of beans dried by MWs, it was concluded that the average pore diameter, the pore volume, the surface area and, PSD were also affected by the solar drying; however, the breakage of cellular structure did not occur.

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Drying Technology

Título del artículo:

Neurocognitive disorder due to neurosyphilis: a case report

Introduction: Neurosyphilis is a chronic infectious disease caused by Treponema pallidum that can cause a great variety of neuropsychiatric signs and symptoms, which complicates its diagnosis. Case description: This case occurred in a 40-year-old man who consulted the Emergency Department because of a convulsion (de novo) which was related to a chronic condition of cognitive impairment and psychosis. The appropriate studies were performed for the diagnosis of neurosyphilis and the recommended treatment was initiated. The patient presented clinical improvement and was discharged. Discussion: Positive VDRL serology results and imaging findings of marked cortical atrophy conducted to consider a late-stage parenchymatous neurosyphilis with serious cognitive impairment and associated psychosis. Treatment with crystalline penicillin was formulated, which reduced the intensity of the patient\'s symptoms; however, the patient\'s lack of interest to attend the check-ups significantly reduces his chances of an adequate recovery. Conclusions: Neurosyphilis must be suspected in patients with clinically evident neurological or psychiatric symptoms. Analysis of VDRL serology and neuroimaging studies are important as an initial evaluation of the patient and must be complemented with cognitive tests or mental examination to determine the state of cognitive impairment.

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Revista Colombiana de Psiquiatria

Título del artículo:

A proposal for updating the Response Spectrum of San Jose de Cucuta, Colombia

An analysis of seismic signals captured in three stations of the network of accelerographs of the Colombian Geological Service (SGC, by its acronym in Spanish) was developed for the city of San Jose de Cucuta, Colombia. Earthquake Equivalent, Response Analysis (EERA) and DEGTRA4 software were used for analysis, processing and calculation of signal response spectra during the characterization and propagation modelling of the signal by profiles. For the accelerograms family, a normalization factor computed with respect to the Peak Ground Acceleration (PGA) was obtained by superposition against the typical design spectrum of the Colombian earthquake resistant code (NSR10). It was found that there is a band of frequencies above the maximum acceleration zone of the design spectrum of the current standard. This suggests a revision of the seismic threat of the city of Cucuta and the urgent need to develop the seismic microzoning, which would allow a substantial reduction of the seismic risk.

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IOP Conference Series: Materials Science and Engineering

Título del artículo:

Learning styles for algebra concepts: The case of engineering students at the Universidad de Santander (Valledupar, Colombia)

The objective of this research was to evaluate the learning styles for algebra concepts of the students of the industrial engineering program of the University of Santander, Valledupar, Cesar, Colombia. A descriptive study was developed, consisting of 40 algebra students and 6 mathematics teachers, the questionnaire is self-administered elaborated with a dichotomous scale for the student and for interpretation of the means, a scale was designed based on a scale between zero and five that reveals the score obtained in said test, the styles studied were active, reflective, theoretical and pragmatic. Concluding that the predominant style is the pragmatic and theoretical, which allowed to select and apply strategies aimed at generating interactivity between students and teachers around the knowledge of algebra.

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IOP Conference Series: Materials Science and Engineering

Título del artículo:

Scientific reasoning skills and patterns of use of Information and Communication Technologies. the case of the students of the Universidad de Santander (Valledupar, Colombia)

This research establishes the relationship that has had the development of the skills of scientific reasoning and the patterns of use of tools and resources of information and communication technology (ICT). For that, it is necessary to use Lawson Test and to have into account ICT National Standards for students that USA International Society for Technology in Education (ISTE) suggest. Also, this paper is tackled from a non-experimental design featuring a correlational - transectional range. The population consists of 2035 students from a higher education institution of the Colombian Caribbean coast. Besides, stratified random sampling is used defining, defining strata and a representative sample for academic programs. Personal survey was used to collect information. The existence of relationship between scientific reasoning skills and patterns of use of information and communication technology was confirmed.

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IOP Conference Series: Materials Science and Engineering

Título del artículo:

Obtaining a sugar syrup from the use of the extract of the guácimo fruit (Guazuma ulmifolia lam)

The main objective of this work was to elaborate a sugary syrup from the use of Guácimo fruit extract (Guazuma Ulmifolia Lam) using the leaching method (solid - liquid), which can be used as a partial or total substitute for sugar. The experimental design that was applied for the extraction process was a factorial design 23; the data obtained were evaluated with the software Statgraphics. Once the extracts were obtained, physico-chemical tests were carried out and reductive sugars and dextrose equivalent were determined in each one. To obtain the syrup, the four extracts having the highest% ED were concentrated at constant temperature and time (50 ° C and 4 hours); The determination of the presence of reducing sugars was done using the techniques of colorimetric analysis (miller\'s method) and chromatography (HPLC). The products that were obtained during the process were extreme conversion syrups with a range of dextrose equivalents of 90.13% - 98.27%. The syrup that obtained the highest percentage of equivalent dextrose (J3) was subjected to a sensory hedonic test, which consisted of 3 samples of sweetened coffee at different concentrations of sweet sugar syrup and sugar (sucrose), where M1 contained 80% sugar syrup of guácimo and 20% of table sugar. M2 contained 50% guácimo sugar syrup and 50% table sugar. M3 contained 100% sugar guacimo syrup and 0% table sugar. The results showed that the mixture that obtained the highest organoleptic acceptance was M2, followed by M3, which states that the syrup can substitute partially the common sugar. The above data allow the guácimo fruit to be taken into account as an alternative raw material for the production of sugar syrups and other products aimed at human consumption.

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IOP Conference Series: Materials Science and Engineering

Título del artículo:

Bactericidal Effect of Entomopathogenic Bacterium Pseudomonas entomophila Against Xanthomonas citri Reduces Citrus Canker Disease Severity

The bacterium Pseudomonas entomophila has been recognized as an exceptional species within the Pseudomonas genus, capable of naturally infecting and killing insects from at least three different orders. P. entomophila ingestion leads to irreversible gut damage resulting from a global blockage of translation, which impairs both immune and tissue repair systems in the insect intestine. In this study we isolated a P. entomophila bacterial strain from soil samples which displayed a strong activity against Xanthomonas citri subsp, citri (Xcc), the etiological agent of citrus canker disease. The antagonism potential of isolated bacteria against Xcc and its ability to reduce citrus canker severity was assessed both ex planta and in planta. Our findings show that pathogenicity assays in Citrus x limonia by pressure infiltration and spray with a mixture of P. entomophila and Xcc leaded to a significant reduction in the number of canker lesions in high susceptible citrus leaves, at 21 days post-infection. To the best of our knowledge this is the first report of antibacterial activity of P. entomophila against a phytopathogenic bacterium. Collective action of P. entomophila factors such as diketopiperazine production and the type 6 secretion system (T6SS) may be involved in this type of biological control of citrus canker. The results suggest that the P. entomophila strain could be a promising biocontrol agent acting directly against Xcc.

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Frontiers in Microbiology

Título del artículo:

Follicular dynamics and estradiol quantification during the estrous cycle of creole cows of the Blanco Orejinegro breed

El estudio tuvo como objetivo caracterizar la dinámica folicular y cuantificar los niveles de estradiol durante un ciclo estral en vacas de la raza criolla Blanco Orejinegro. Se seleccionaron 10 vacas que se encontraban ciclando y fueron sometidas a un protocolo de sincronización del estro con la aplicación inicial de un dispositivo intravaginal progesterona (CIDR®) más 2 mg de benzoato de estradiol (día 0 - D0). En el día D8 se retiró el dispositivo y se aplicó 150 µg de cloprostenol (Ciclase DL®). En D9 se administró 1 mg de benzoato de estradiol. Luego de la ovulación se realizaron ecografías cada 24 horas, registrando la dinámica folicular y colectando sangre para la cuantificación del estradiol. La duración del ciclo estral fue de 21.0 ± 0.4 días, los diámetros del folículo ovulatorio fue de 14.3 ± 0.5 mm y del mayor folículo subordinado de 6.0 ± 0.5 mm, la tasa de crecimiento del folículo dominante durante las 96 horas previas a la ovulación fue de 1.05 ± 0.4 mm/día. En conclusión, la dinámica folicular y hormonal de vacas criollas de la raza Blanco Orejinegro presentan patrones similares a los observados en razas Bos taurus y Bos indicus.

Acerca de la revista donde se publicó este artículo:

Revista de Investigaciones Veterinarias del Peru

Título del artículo:

Immobilization of Ib-M2 peptide on core@shell nanostructures based on SPION nanoparticles and their antibacterial activity against Escherichia coli O157:H7

Antimicrobial peptides arise as a very promising alternative for the treatment of infections generated by pathogenic microorganisms. The Ib-M2 antimicrobial peptide turns out to be a very promising candidate for these types of applications. However, it is required to evaluate immobilization systems that give peptides greater stability and activity in order to be used in biological systems. Given the above, this paper reports the preparation of superparamagnetic iron oxide nanoparticles (SPIONs) coated with chitosan in order to immobilize the Ib-M2 antimicrobial peptide. Structural properties of SPIONs were studied by DLS, SEM, XRD, FT-IR, XPS and the magnetic properties were evaluated by vibrating-sample magnetometer technique. The antimicrobial activity of the Ib-M2/SPIONs@Chi bioconjugate obtained was evaluated against Escherichia coli O157:H7 by determining the minimum inhibitory concentration (MIC). Results show that the SPIONs obtained have particle size between 10 and 15 nm with a magnetite-type structure which was confirmed by FT-IR and XPS. Characterization of magnetic properties evidences a superparamagnetic behavior of nanoparticles obtained. MIC results showed that Ib-M2/SPIONs@Chi bioconjugate exhibit a comparable or higher activity against E. coli in comparison with the free Ib-M2 peptide. These results show that the bioconjugate obtained can be considered for use in biomedical applications.

Acerca de la revista donde se publicó este artículo:

Applied Surface Science

Título del artículo:

Histopathological alterations caused by puccinia nakanishikii rust (pucciniales: Pucciniaceae) in cymbopogon citratus (poaceae) plants

Introduction: Histopathological and histochemical aspects linked to the attack of fungal rusts to plants, as well as its relation with the different spore stages are topics rather scarce in the scientific literature. Objective: To describe and analyze the histopathological and histochemical aspects of Cymbopogon citratus and its relation with the different stages of the spores from the rust fungi Puccinia nakanishikii. Methods: During the months April and August 2013, leaves healthy and infected by Puccinia nakanishikii were collected in the Northwestern scarp of the Bucaramanga-Colombia plateau. The samples with injuries on diverse developmental stages were fixated and processed according to the standard protocols for embedding and sectioning in paraffin and resin. Sections obtained from paraffin (5-7 µm) were stained with Safranin-Alcian blue and Alcian blue-Hematoxylin. On the other hand, sections obtained from resin (0.5 µm) were stained with Toluidine blue. Further, freehand sections were obtained for an autofluorescence analysis. The observations and photographic record were done via photonic microscope and epifluorescence microscope. For the observations via scanning electron microscopy (SEM), the samples were fixated in Glutaraldehyde, dehydrated with 2,2 dimethoxypropane, then desiccated to critical point and finally coated with gold. Results: The leaves are generally hypostomatic, with long and short epidermic cell forming parallel rows and showing unicellular prickle trichomes and micro-trichomes. The abaxial surface is covered by epicuticular wax forming a dense layer. The adaxial epidermis is formed by groupings of bulliform cells and epidermal cells with rectangular or squared contour. In the mesophyll, there is no differentiation between palisade and spongy parenchyma, its anatomy reflects the C4 metabolism. The formation of uredosori and teliosori both hypophyllous was observed. Urediniospores are the reinfecting agents phase, they have 4-5 equatorial germ pores and echinulate wall. Teliospores have smooth wall and a persistent pedicel. The urediniospores form a germ tube, generally on the abaxial leaf surface, these tubes develop towards the stomata reaching the mesophyll interior. No appressorium were observed. The epidermis limiting the uredosorus detaches due the development and pressure that exert both the urediniospores and capitate paraphyses. As the infection progresses, autofluorescense of the chlorophyll is lost and the cells undergo necrotic processes. Afterwards, the phloem collapses and the xylem becomes slightly disorganized. At this moment, the infection is extended along the whole leaf blade, resulting in the leaf death and the plant defoliation. On advanced stages of the infection, the uredosori showed pycnidia, probably belonging to the hyperparasite Sphaerellopsis, these structures were closely associated to the rust infected tissues. Conclusions: Puccinia nakanishikii develops on the leaves of Cymbopogon citratus producing uredosori and teliosori. Urediniospores are the reinfective stage, teliospores were only observed at late stages of the infection. The epidermis and photosynthetic tissue are severely affected by cell necrosis. The vascular tissues are deeply affected on the advances stages of the infection.

Acerca de la revista donde se publicó este artículo:

Revista de Biologia Tropical