Avances en la calidad de las respuestas a preguntas de probabilidad después de una actividad de aprendizaje con tecnología

En la presente comunicación, se describen y comparan las respuestas de estudiantes de secundaria (13-14 años) a tres preguntas de un cuestionario de probabilidad antes y después de haber tenido actividades de aprendizaje con apoyo de tecnología. Las preguntas analizadas se relacionan con las nociones de variable aleatoria, espacio muestral, frecuencias y distribución en sus formas más elementales. Se asume la hipótesis de que los recursos que proporciona la tecnología permiten que los estudiantes perciban que las unidades de análisis de la probabilidad son clases de experiencias y no experiencias aisladas. Con esta hipótesis se pueden explicar algunos de los avances que los estudiantes alcanzaron en las respuestas al post-test en relación con las dadas en el pre-test. Las actividades realizadas pueden proporcionar a los estudiantes referentes para los conceptos abstractos de probabilidad que estudiarán más adelante

Methane activation and exchange by titanium-carbon multiple bonds

We demonstrate that a titanium-carbon multiple bond, specifically an alkylidyne ligand in the transient complex, (PNP)Ti≡C^(t)Bu (A) (PNP^− = N[2-P(CHMe_2)_(2)-4-methylphenyl]_2), can cleanly activate methane at room temperature with moderately elevated pressures to form (PNP)Ti=CHtBu(CH_3). Isotopic labeling and theoretical studies suggest that the alkylidene and methyl hydrogens exchange, either via tautomerization invoking a methylidene complex, (PNP)Ti=CH_(2)(CH_(2)^(t)Bu), or by forming the methane adduct (PNP)Ti≡C^(t)Bu(CH_4). The thermal, fluxional and chemical behavior of (PNP)Ti=CH^(t)Bu(CH_3) is also presented in this study

Mecanismos de implantación de la hipertrofia y de la apoptosis en el cardiomiocito; progresión hacia la remodelación

Los cambios morfológicos observados en el tejido muscular en enfermedades cardíacas, son resultado del efecto de prendido - apagado de una serie de vías reguladoras. Este mecanismo se encuentra controlado tanto por agentes físicos como tróficos cuya función la ejercen al estimular la maquinaria bioquímica del cardiomiocito ya sea directa o indirectamente. Estos agentes van a ser causantes de la implantación y desarrollo de la hipertrofia, apoptosis y/o necrosis celular y, por medio de estos fenómenos, van a permitir que se establezca un estado de remodelación tisular comprometiendo la función de bomba del corazón. En estadíos iniciales, la hipertrofia de los miocitos puede permitir una compensación parcial de la disminución de la contractibilidad pero, si se mantiene el estímulo agresor el daño progresará y finalmente sobrevendrá la insuficiencia cardíaca a medida que el remodelamiento progrese por la pérdida de miocitos

In vivo extracellular matrix protein expression by human periodontal ligament after stimulation with orthodontic force

It is well known that the orthodontic force applied to teeth generates a series of events that remodel the periodontal ligament (PDL). Extracellular matrix proteins (ECM) are described as molecular regulators of these events. However, the exact contribution of these proteins in human PDL modeling by orthodontic force application in vivo is not known. The aim of this present study was to evaluate the protein expression of fibronectin, laminin and vitronectin by human PDL from teeth on which orthodontic force was applied. Twenty healthy individuals were included in the study. PDL was obtained from teeth after a 3-week treatment with orthodontic force. PDL-protein samples were separated on 7.5% SDS-PAGE Western blot analysis with specific monoclonal antibodies for fibronectin, laminin and vitronectin. Bands were visualized with an enhanced chemiluminescence detection system and densitometric. Scanning of bands was carried out to compare differences in protein expression. A significant increment in fibronectin (13.9%), laminin (16.5%) and vitronectin (14.2%) expression was found in PDL from teeth treated with orthodontic force for 3 weeks in comparison with teeth in the control group. Our results support the concept that molecular changes take place by application of orthodontic forces to the PDL. Over expression of these proteins suggests that extracellular matrix (ECM) remodeling could be generated in response to mechanical stress.Keywords: Extracellular matrix proteins, periodontal ligament, orthodontic forceAfrican Journal of Biotechnology Vol. 9(34), pp. 5599-5604, 23 August, 201

Dynamic semantic ontology generation: a proposal for social robots

[Abstract] During a human-robot interaction by dialogue/voice, the robot cannot extract semantic meaning from the words used, limiting the intervention itself. Semantic knowledge could be a solution by structuring information according to its meaning and its semantic associations. Applied to social robotics, it could lead to a natural and fluid human-robot interaction. Ontologies are useful representations of semantic knowledge, as they capture the relationships between objects and entities. This paper presents new ideas for ontology generation using already generated ontologies as feedback in an iterative way to do it dynamically. This paper also collects and describes the concepts applied in the proposed methodology and discusses the challenges to be overcome.Ministerio de Ciencia, Innovación y Universidades; RTI2018-096338-B-I0

Neogene Bony Fishes from the Bahía Inglesa Formation, Northern Chile

Despite being one of the richest Neogene deposits of marine fossil vertebrates along the Pacific coast of South America, no detailed study of bony fishes from the Bahía Inglesa Formation has been carried out. Through the revision of historical collections of the Caldera Paleontological Museum, we describe 27 fossil remains of bony fishes. Fossils described here are distributed in 13 taxa. Among these, Sardinops sp. cf. S. sagax (Clupeidae) represents the first fossil record of the genus for Chile, Labrodon sp. (Labridae) and Stelliferinae (Sciaenidae) are the first respective records for the southeast Pacific Ocean, Sarda sp. (Scombridae) represents the first fossil record for South America, Semicossyphus sp. (Labridae) and Anisotremus sp. (Haemulidae) are the first respective records for the Southern Hemisphere. Gymnosarda sp. (Scombridae) is described for the first time for the Neogene. We performed a paleobathymetric analysis of fossil fishes, including elasmobranchs, to understand the paleoenvironment followed by a similarity analysis that compares the faunal composition of the Bahía Inglesa Fm. with other fossil assemblages for the Pacific of South America. Our results show that the fish fauna from the Bahía Inglesa Fm. likely represents a depth range of 98 to 382 m with a mean depth range of 252 m in an uppermost bathyal environment. The assemblage from the Bahía Inglesa Fm. shows low taxonomic similarity levels with other Neogene geological units from the southeast Pacific Ocean. The study represents the first paleoecological and paleobiogeographic analysis of the fossil fish fauna from the Southeast Pacific. Key words. Atacama region. Clupeiformes. Eastern Pacific. Paleoenviroments. Perciformes. Ophidiiformes

Rapid assessment of the performance of malaria control strategies implemented by countries in the Amazon subregion using adequacy criteria: case study

<p>Abstract</p> <p>Background</p> <p>The objective of this study was to implement a rapid assessment of the performance of four malaria control strategies (indoor spraying, insecticide-treated bed nets, timely diagnosis, and artemisinin-based combination therapy) using adequacy criteria. The assessment was carried out in five countries of the Amazon subregion (Bolivia, Colombia, Ecuador, Guyana, and Peru).</p> <p>Methods</p> <p>A list of criteria in three areas was created for each of the four strategies: preliminary research that supports the design and adaptation of the control strategies, coverage of the control strategies and quality of the implementation of the strategies. The criteria were selected by the research team and based on the technical guidelines established by the World Health Organization. Each criterion included in the four lists was graded relative to whether evidence exists that the criterion is satisfied (value 1), not satisfied (value 0) or partially satisfied (value 0.5). The values obtained were added and reported according to a scale of three implementation categories: adequate, intermediate and deficient.</p> <p>Results</p> <p>Implementation of residual indoor spraying and timely diagnosis was adequate in one country and intermediate or deficient in the rest. Insecticide-treated bed nets ranged between deficient and intermediate in all the countries, while implementation of artemisinin-based combination therapy (ACT) was adequate in three countries and intermediate in the other two countries evaluated.</p> <p>Conclusions</p> <p>Although ACT is the strategy with the better implementation in all countries, major gaps exist in implementation of the other three malaria control strategies in terms of technical criteria, coverage and quality desiredThe countries must implement action plans to close the gaps in the various criteria and thereby improve the performance of the interventions. The assessment tools developed, based on adequacy criteria, are considered useful for a rapid assessment by malaria control authorities in the different countries.</p

Unmet Diagnostic and Therapeutic Opportunities for COPD in Low- and Middle-Income Countries

RATIONALE: Chronic obstructive pulmonary disease (COPD) is a prevalent and burdensome condition in low- and middle-income countries (LMICs). Challenges to better care include more effective diagnosis, and access to affordable interventions. There are no previous reports describing therapeutic needs in LMIC populations with COPD identified through screening. OBJECTIVE: To describe unmet therapeutic need in screening-detected COPD in LMIC settings. METHODS: We compared interventions recommended by the international 'GOLD' COPD strategy document, with that received, in 1000 people with COPD identified by population screening at three LMIC sites in Nepal, Peru and Uganda. We calculated costs using data on the availability and affordability of medicines. MEASUREMENT AND MAIN RESULTS: The greatest unmet need for non-pharmacological interventions was for education and vaccinations (applicable to all), pulmonary rehabilitation (49%), smoking cessation (30%) and advice on biomass smoke exposure (26%). 95% of cases were previously undiagnosed and few were receiving therapy (4.5% had short-acting beta-agonists). Only three of 47 people (6%) with a previous COPD diagnosis had access to drugs consistent with recommendations. None of those with more severe COPD were accessing appropriate maintenance inhalers. Even when available, maintenance treatments were unaffordable with 30 days of treatment more than a low-skilled workers' daily average wage. CONCLUSION: We found significant missed opportunity to reduce the burden of COPD in LMIC settings, with most cases undiagnosed. Whilst there is unmet need in developing novel therapies, in LMICs where the burden is greatest, better diagnosis together with access to affordable interventions could translate to immediate benefit. This article is open access and distributed under the terms of the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/)

APRIL: a double-blind, placebo-controlled, randomized, Phase Ib/IIa clinical study of ApTOLL for the treatment of acute ischemic stroke

In the reperfusion era, a new paradigm of treating patients with endovascular treatment (EVT) and neuroprotective drugs is emerging as a promising therapeutic option for patients with acute ischemic stroke (AIS). In this context, ApTOLL, a Toll-like receptor 4 (TLR4) antagonist with proven neuroprotective effect in preclinical models of stroke and a very good pharmacokinetic and safety profile in healthy volunteers, is a promising first-in-class aptamer with the potential to address this huge unmet need. This protocol establishes the clinical trial procedures to conduct a Phase Ib/IIa clinical study (APRIL) to assess ApTOLL tolerability, safety, pharmacokinetics, and biological effect in patients with AIS who are eligible for EVT. This will be a multicenter, double-blind, randomized, placebo-controlled, Phase Ib/IIa clinical study to evaluate the administration of ApTOLL together with EVT in patients with AIS. The study population will be composed of men and non-pregnant women with confirmed AIS with a <6h window from symptoms onset to ApTOLL/placebo administration. The trial is currently being conducted and is divided into two parts: Phase Ib and Phase IIa. In Phase Ib, 32 patients will be allocated to four dose ascending levels to select, based on safety criteria, the best two doses to be administered in the following Phase IIa in which 119 patients will be randomized to three arms of treatment (dose A, dose B, and placebo).Peer ReviewedPostprint (published version

Opioids: Pharmacology and Epidemiology

Los opioides desde hace muchos años son los analgésicos más utilizados y efectivos para el tratamiento del dolor. Este trabajo da a conocer la clasificación farmacológica, usos terapéuticos, riesgos a la salud y reacciones adversas de los opioides como fármacos, planteando el paradigma del usar este tipo de fármacos para el control del dolor, sin embargo se han convertido en un problema de salud en distintos países ya que en ciertas circunstancias tienen un alto potencial de causar adicción. Además de su uso contra el dolor, los opioides son utilizados como antidiarreicos, antitusivos y para el tratamiento de diversas sintomatologías. A pesar de los efectos adversos, el mal uso y abuso de los opioides; se consideran imprescindibles en la terapia contra el dolor. Actualmente las investigaciones farmacéuticas trabajan en la búsqueda constante de nuevos fármacos con efectos menos severos y con potencia analgésicaOpioids have been used for many years as the most effective analgesics for pain management. This work discloses the pharmacological classification, therapeutic uses, health risks and adverse reactions of opioids as medicines, setting out the paradigm of using this type of drug to control pain. However, they have become a health problem in distinct countries, as they have a high addictive potential under certain circumstances. In addition to their use against pain, opioids are also employed as antidiarrheal, antitussive and for the treatment of diverse symptomatology. Despite the adverse effects, misuse and abuse of opioids, they are still considered as indispensable in pain therapy. Currently pharmaceutical research is working on the constant development for new drugs with less severe effects and a high analgesic potency