La objetivación del número racional

Esta comunicación da cuenta de la investigación en proceso, donde se pretende analizar la objetivación del número racional desde los procesos de medición que generan la razón. Los lineamientos curriculares de matemáticas de Colombia proponen un enfoque que busca el desarrollo de competencias que permitan a los alumnos afrontar los problemas matemáticos de la vida y del trabajo, empleando los mejores medios posibles, para ello, las instituciones educativas están facultadas para proponer procesos de aprendizaje que armonicen el desarrollo del pensamiento matemático con actividades matemáticas

β-Lactoglobulin als Nanotransporter für bioaktive Verbindungen aus Knoblauch (Allium sativum L.)

The suitability of the whey protein β-lactoglobulin as nanotransporter for bioactive organosulfur compounds of garlic, i.e. allicin and diallyl disulfide, was investigated. Since allicin is relatively unstable and causes an intensive smell and pungency, a delivery system is necessary to enable its enrichment in a functional food. The interactions of allicin and diallyl disulfide with β-lactoglobulin were comprehensively analyzed, the physico-chemical and organoleptic properties of β-lactoglobulin modified with allicin were evaluated and the bioavailability of the bioactive compound transported by the protein was assessed. The binding reaction was analyzed by fluorescence quenching, high performance liquid chromatography and the spectrophotometric detection of free amino and thiol groups. Allicin and diallyl disulfide were covalently bound to the free thiol group of β-lactoglobulin under alkaline conditions. The binding resulted in moderate conformational changes of the protein structure, primarily on tertiary level. According to mass spectrometric analysis of the intact and hydrolyzed protein, the binding reaction with allicin and diallyl disulfide resulted in the formation of S-allylmercaptocysteine, a stable, non-volatile, bioactive compound. Through the binding of allicin by β-lactoglobulin, the typical smell and taste of garlic was significantly reduced. The food grade production of β-lactoglobulin modified with allicin resulted in a consumable beverage that delivered physiologically relevant amounts of bioactive organosulfur compounds without significant garlic like sensory properties. A double-blind, randomized, diet-controlled cross-over study with nine healthy volunteers showed that the bioavailability of S-allylmercaptocysteine was not impaired by the incorporation in the protein chain. Conclusively, the covalent binding of allicin to β-lactoglobulin provides an innovative approach for the delivery of bioactive compounds.In der vorliegenden Arbeit wurde die Eignung des Molkenproteins β-Lactoglobulin als Nanotransporter für die bioaktiven Schwefelverbindungen Allicin und Diallyldisulfid aus Knoblauch untersucht. Allicin ist eine relativ unstabile Verbindung, die bedeutend zu dem typischen Geruch und der Schärfe von Knoblauch beiträgt. Für die Anreicherung von Allicin in einem funktionellen Lebensmittel ist daher ein Transportsystem notwendig. Die Interaktionen zwischen Allicin bzw. Diallyldisulfid und β-Lactoglobulin wurden umfangreich analysiert. Des Weiteren wurden die physiko-chemischen und organoleptischen Eigenschaften des mit Allicin modifizierten Proteins untersucht. Abschließend wurde die Bioverfügbarkeit der transportierten bioaktiven Verbindung ermittelt. Allicin und Diallyldisulfid wurden kovalent durch die freie Thiolgruppe von β-Lactoglobulin gezielt unter alkalischen Bedingungen gebunden. Die massenspektrometrische Analyse des intakten und des hydrolysierten modifizierten Proteins zeigte, dass durch die Bindung von Allicin bzw. Diallyldisulfid eine S-Allyl-Gruppe auf die freie Thiolgruppe der Cysteinseitenkette übertragen wurde, wodurch das stabile, nicht-flüchtige, bioaktive S-Allymercaptocystein entstand. Durch die Bindung von Allicin an β-Lactoglobulin wurde der Knoblauch-typische Geruch und Geschmack signifikant reduziert. Ein mit Allicin modifiziertem β-Lactoglobulin angereichertes Getränk enthielt physiologisch relevante Mengen bioaktiver Schwefelverbindungen ohne ein deutlich wahrnehmbares Knoblaucharoma aufzuweisen. Durch eine doppelt-blinde, randomisierte, Diät-kontrollierte Cross-Over-Studie mit neun gesunden Probanden wurde gezeigt, dass die Bioverfügbarkeit von S-Allylmercaptocystein durch die Integration in die Polypeptidkette von β-Lactoglobulin nicht beeinträchtigt wurde. Schlussfolgernd erwies sich die kovalente Bindung von Allicin an β-Lactoglobulin als ein innovativer Ansatz zum Transport bioaktiver Verbindungen

The Development of the Numeracy Apprehension Scale for Children Aged 4-7 Years: Qualitative Exploration of Associated Factors and Quantitative Testing

Previous psychological literature has shown mathematics anxiety in older populations to have an association with many factors, including an adverse effect on task performance. However, the origins of mathematics anxiety have, until recently, received limited attention. It is now accepted that this anxiety is rooted within the early educational years, but research has not explored the associated factors in the first formal years of schooling. Based on previous focus groups with children aged 4-7 years, ‘numeracy apprehension’ is suggested in this body of work, as the foundation phase of negative emotions and experiences, in which mathematics anxiety can develop. Building on this research, the first piece of research utilized 2 interviews and 5 focus groups to obtain insight from parents (n=7), teachers (n=9) and mathematics experts (n=2), to explore how children experience numeracy and their observations of children’s attitudes and responses. Thematic and content analysis uncovered a range of factors that characterised children’s numeracy experiences. These included: stigma and peer comparisons; the difficulty of numeracy and persistent failure; a low sense of ability; feelings of inadequacy; peer evaluation; transference of teacher anxieties; the right or wrong nature of numeracy; parental influences; dependence on peers; avoidance and children being aware of a hierarchy based on numeracy performance. Key themes reflected the focus group findings of children aged 4-7 years. This contributed to an item pool for study 2, to produce a first iteration of the Numeracy Apprehension Scale (NAS) that described day-to-day numeracy lesson situations. This 44-item measure was implemented with 307 children aged 4-7 years, across 4 schools in the U.K. Exploratory factor analysis led to a 26-item iteration of the NAS, with a 2-factor structure of Prospective Numeracy Task Apprehension and On-line Number Apprehension, which related to, for example, observation and evaluation anxiety, worry and teacher anxiety. The results suggested that mathematics anxiety may stem from the initial development of numeracy apprehension and is based on consistent negative experiences throughout an educational career. The 26-item iteration of the NAS was further validated in study 3 with 163 children aged 4-7 years, across 2 schools in the U.K. The construct validity of the scale was tested by comparing scale scores against numeracy performance on a numeracy task to determine whether a relationship between scale and numeracy task scores was evident. Exploratory factor analysis was again conducted and resulted in the current 19-item iteration of the NAS that related to a single factor of On-line Number Apprehension. This related to the experience of an entire numeracy lesson, from first walking in to completing a task and was associated with, for example, explaining an answer to the teacher, making mistakes and getting work wrong. A significant negative correlation was observed between the NAS and numeracy performance scores, suggesting that apprehensive children demonstrate a performance deficit early in education and that the NAS has the potential to be a reliable assessment of children’s numeracy apprehension. This empirical reinforces that the early years of education are the origins of mathematics anxiety, in the form of numeracy apprehension

Non-chemically modified waxy rice starch stabilised wow emulsions for salt reduction

Water-in-oil-in-water emulsions containing an internalised salt solution were stabilised with non-chemically modified waxy rice starch (WRS), and octinyl succinic anhydride (OSA) as reference, to release salt during oral processing due to amylase-induced destabilisation. Salt levels were 1.5 g salt and 0.47 g salt per 100 g external and internal aqueous phases, respectively. Variables were the starch content (2, 3, 4 g per 100 g emulsion; 20 g oil per 100 g emulsion), level of polyglycerol polyricinoleate (PGPR) as a lipophilic emulsifier (0.29, 0.57 g per 100 g emulsion) and ambient-pressure processing temperature for WRS gelatinisation, the non-chemical modification process, (75 ± 3, 88 ± 5 °C). OSA starch was used under previously applied conditions (2, 3, 4 g starch, 0.57 g PGPR per 100 g emulsion, 25 ± 5 °C). Emulsions were stable for three months, except OSA and lower level PGPR low temperature processed WRS emulsions lost salt into the external emulsion phase. One day after processing, encapsulation efficiency (EE) was as predicted from the composition for OSA emulsions, while at the same PGPR content an external aqueous phase was incorporated into the oil droplets of the WRS emulsion increasing EE. Salt release was assessed in vitro and through sensory evaluation using paired comparison testing. The results revealed that the efficacy of this salt reduction approach was enhanced for gelatinised WRS compared to OSA starch stabilised emulsions. Consumer tests on a tomato soup, to validate this salt reduction approach for a real food, revealed a possible 25% salt reduction, compared to current UK products

Deficits in Analogical Reasoning in Adolescents with Traumatic Brain Injury

Individuals with traumatic brain injury (TBI) exhibit deficits in executive control, which may impact their reasoning abilities. Analogical reasoning requires working memory and inhibitory abilities. In this study, we tested adolescents with moderate to severe TBI and typically developing (TD) controls on a set of picture analogy problems. Three factors were varied: complexity (number of relations in the problems), distraction (distractor item present or absent), and animacy (living or non-living items in the problems). We found that TD adolescents performed significantly better overall than TBI adolescents. There was also an age effect present in the TBI group where older participants performed better than younger ones. This age effect was not observed in the TD group. Performance was affected by complexity and distraction. Further, TBI participants exhibited lower performance with distractors present than TD participants. The reasoning deficits exhibited by the TBI participants were correlated with measures of executive function that required working memory updating, attention, and attentional screening. Using MRI-derived measures of cortical thickness, correlations were carried out between task accuracy and cortical thickness. The TD adolescents showed negative correlations between thickness and task accuracy in frontal and temporal regions consistent with cortical maturation in these regions. This study demonstrates that adolescent TBI results in impairments in analogical reasoning ability. Further, TBI youth have difficulty effectively screening out distraction, which may lead to failures in comprehension of the relations among items in visual scenes. Lastly, TBI youth fail to show robust cortical–behavior correlations as observed in TD individuals

The N Terminus of Adhesion G Protein–Coupled Receptor GPR126/ ADGRG6 as Allosteric Force Integrator

The adhesion G protein–coupled receptor (aGPCR) GPR126/ADGRG6 plays an important role in several physiological functions, such as myelination or peripheral nerve repair. This renders the receptor an attractive pharmacological target. GPR126 is a mechano-sensor that translates the binding of extracellular matrix (ECM) molecules to its N terminus into a metabotropic intracellular signal. To date, the structural requirements and the character of the forces needed for this ECM-mediated receptor activation are largely unknown. In this study, we provide this information by combining classic second-messenger detection with single-cell atomic force microscopy. We established a monoclonal antibody targeting the N terminus to stimulate GPR126 and compared it to the activation through its known ECM ligands, collagen IV and laminin 211. As each ligand uses a distinct mode of action, the N terminus can be regarded as an allosteric module that can fine-tune receptor activation in a context-specific manner

Recommendations for the use of common outcome measures in pediatric traumatic brain injury research

This article addresses the need for age-relevant outcome measures for traumatic brain injury (TBI) research and summarizes the recommendations by the inter-agency Pediatric TBI Outcomes Workgroup. The Pediatric Workgroup\u27s recommendations address primary clinical research objectives including characterizing course of recovery from TBI, prediction of later outcome, measurement of treatment effects, and comparison of outcomes across studies. Consistent with other Common Data Elements (CDE) Workgroups, the Pediatric TBI Outcomes Workgroup adopted the standard three-tier system in its selection of measures. In the first tier, core measures included valid, robust, and widely applicable outcome measures with proven utility in pediatric TBI from each identified domain including academics, adaptive and daily living skills, family and environment, global outcome, health-related quality of life, infant and toddler measures, language and communication, neuropsychological impairment, physical functioning, psychiatric and psychological functioning, recovery of consciousness, social role participation and social competence, social cognition, and TBI-related symptoms. In the second tier, supplemental measures were recommended for consideration in TBI research focusing on specific topics or populations. In the third tier, emerging measures included important instruments currently under development, in the process of validation, or nearing the point of published findings that have significant potential to be superior to measures in the core and supplemental lists and may eventually replace them as evidence for their utility emerges

Feasibility of a mobile and web-based intervention to support self-management in outpatients with cancer pain

Purpose: Cancer pain is a prevalent and distressing symptom. To enhance self-management in outpatients, a multi-component intervention was developed, integrating patient self-management and professional care through healthcare technology. This article describes feasibility of the intervention in everyday practice. Method: Patients with moderate to severe cancer pain (n = 11) and registered nurses specialized in pain and palliative care (n = 3) participated in a four-week study. The intervention involved daily monitoring, graphical feedback, education, and advice by means of a mobile application for patients and a web application for nurses. Learnability, usability and desirability were measured in patients with a 20-item questionnaire (1–5 scale), higher scores indicating better feasibility. Patients' adherence was based on completion rates from server logs. Single semi-structured interviews with patients and a focus group interview with nurses provided insight into experiences. Results: Questionnaire findings confirmed learnability (4.8), usability (4.8) and desirability (4.6) of the application for patients. Average completion rates were 76.8% for pain monitoring, 50.4% for medication monitoring and 100% for education sessions. Interviews revealed that patients were pleased with the simplicity of the mobile application and appreciated different components. Nurses agreed upon the added value and were mostly positive about the possibilities of the web application. Patients and nurses provided ideas for improvements relating to the content and technical performance of the intervention. Conclusions: Study results demonstrate feasibility of the intervention in everyday practice. Provided that content-related and technical adjustments are made, the intervention enables patients with cancer pain to practice self-management and nurses to remotely support these patients

MYH7 p.(Arg1712Gln) is pathogenic founder variant causing hypertrophic cardiomyopathy with overall relatively delayed onset

Introduction: The MYH7 c.5135G &gt; A p.(Arg1712Gln) variant has been identified in several patients worldwide and is classified as pathogenic in the ClinVar database. We aimed to delineate its associated phenotype and evaluate a potential founder effect.Methods: We retrospectively collected clinical and genetic data of 22 probands and 74 family members from an international cohort.Results: In total, 53 individuals carried the MYH7 p.(Arg1712Gln) variant, of whom 38 (72%) were diagnosed with hypertrophic cardiomyopathy (HCM). Mean age at HCM diagnosis was 48.8 years (standard deviation: 18.1; range: 8–74). The clinical presentation ranged from asymptomatic HCM to arrhythmias (atrial fibrillation and malignant ventricular arrhythmias). Aborted sudden cardiac death (SCD) leading to the diagnosis of HCM occurred in one proband at the age of 68 years, and a family history of SCD was reported by 39% (5/13) probands. Neither heart failure deaths nor heart transplants were reported. Women had a generally later-onset disease, with 14% of female carriers diagnosed with HCM at age 50 years compared with 54% of male carriers. In both sexes, the disease was fully penetrant by age 75 years. Haplotypes were reconstructed for 35 patients and showed a founder effect in a subset of patients.Conclusion: MYH7 p.(Arg1712Gln) is a pathogenic founder variant with a consistent HCM phenotype that may present with delayed penetrance. This suggested that clinical follow-up should be pursued after the seventh decade in healthy carriers and that longer intervals between screening may be justified in healthy women &lt; 30 years.</p