La modelación matemática- M: una nueva alternativa pedagógica didáctica, para la enseñanza y el aprendizaje de las matemáticas

Esta ponencia, es el resultado del trabajo desarrollado en el Discurso Matemático Escolar (DME) para el tema de Sistemas de Ecuaciones Lineales (SEL), en la asignatura de álgebra lineal para la carrera de Ingeniería Industrial, en los Institutos Tecnológicos de Pinotepa, Oax. y Tlalnepantla, Edo. de Mex. Casi siempre, la enseñanza y el aprendizaje de las matemáticas, genera muchos problemas de corte matemático, pedagógico y didáctico; razón por la cual, existe un abundante trabajo de investigación educativa en esta dirección, sin embargo, parece que nada de todas estas aportaciones han funcionado de manera general, pues el problema pedagógico y didáctico persiste; pues los altos índices de reprobación en esta área, cada vez son más grandes. El propósito es determinar si con el uso de la Teoría de la Modelación Matemática (MM), el que aprende alcanza un aprendizaje significativo en lo refiere a la conceptualización matemática de prerrequisito y de los nuevos temas de la asignatura que nos ocupe. Mientras que el objetivo, está focalizado para que todos los aprendedores se apropien con un nivel de aceptación del cien por ciento, la teoría del Cálculo vectorial y Varias variables

Relation between energy metabolism, glycolysis, noradrenaline release and duration of ischemia

We studied the effect of 12-36 min of global ischemia followed by 36 min of reperfusion in Langendorff perfused rabbit hearts (n = 26). Metabolism was determined in terms of peak and total release of purines (adenosine, inosine, hypoxanthine), lactate and noradrenaline during reperfusion; and myocardial content of nucleotides (ATP, ADP, AMP), glycogen and noradrenaline at the end of reperfusion. An inverse relationship (r = -0.79) existed between duration of ischemia and developed pressure post-ischemia. Early during reperfusion, after 12 min of ischemia, the purine concentration (peak release) increased 100x (p < 0.01), that of lactate and noradrenaline 10x (p < 0.05). Total purine release rose with progression of the ischemic period (30x after 36 min of ischemia; p < 0.01), concomitant with a reduction in nucleotide content. Lactate release was independent from the duration of ischemia, although glycogen had declined by 30\% (p < 0.01) after 36 min of ischemia. The acid insoluble glycogen fraction, which presumably contains proglycogen, increased substantially during short-term ischemia. Peak noradrenaline increased 100x, and 200x, (p < 0.05) after 24 and 36 min of ischemia, respectively. Total noradrenaline release due to various periods of ischemia mirrored its peak release. Function recovery was inversely related to total purine and noradrenaline efflux (both r = -0.81); it correlated with tissue nucleotide content (r = 0.84). In conclusion, larger amounts of noradrenaline are released only after a substantial drop in myocardial ATP. During severe ischemia ATP consumption more than limited ATP production by anaerobic glycolysis, is a key factor affecting recovery on subsequent reperfusion. In contrast to lactate efflux, purine and noradrenaline release are useful markers of ischemic and reperfusion damage

Sustained low-efficiency dialysis with regional citrate anticoagulation in critically ill patients with COVID-19 associated AKI: A pilot study

Acute Kidney Injury (AKI) is a frequent complication in critically ill patients with Coronavirus disease 2019 (COVID-19), and it has been associated with worse clinical outcomes, especially when Kidney Replacement Therapy (KRT) is required. A condition of hypercoagulability has been frequently reported in COVID-19 patients, and this very fact may complicate KRT management. Sustained Low Efficiency Dialysis (SLED) is a hybrid dialysis modality increasingly used in critically ill patients since it allows to maintain acceptable hemodynamic stability and to overcome the increased clotting risk of the extracorporeal circuit, especially when Regional Citrate Anticoagulation (RCA) protocols are applied. Notably, given the mainly diffusive mechanism of solute transport, SLED is associated with lower stress on both hemofilter and blood cells as compared to convective KRT modalities. Finally, RCA, as compared with heparin-based protocols, does not further increase the already high hemorrhagic risk of patients with AKI. Based on these premises, we performed a pilot study on the clinical management of critically ill patients with COVID-19 associated AKI who underwent SLED with a simplified RCA protocol. Low circuit clotting rates were observed, as well as adequate KRT duration was achieved in most cases, without any relevant metabolic complication nor worsening of hemodynamic status

"Textural analysis of multiparametric MRI detects transition zone prostate cancer"

OBJECTIVES: To evaluate multiparametric-MRI (mpMRI) derived histogram textural-analysis parameters for detection of transition zone (TZ) prostatic tumour. METHODS: Sixty-seven consecutive men with suspected prostate cancer underwent 1.5T mpMRI prior to template-mapping-biopsy (TPM). Twenty-six men had 'significant' TZ tumour. Two radiologists in consensus matched TPM to the single axial slice best depicting tumour, or largest TZ diameter for those with benign histology, to define single-slice whole TZ-regions-of-interest (ROIs). Textural-parameter differences between single-slice whole TZ-ROI containing significant tumour versus benign/insignificant tumour were analysed using Mann Whitney U test. Diagnostic accuracy was assessed by receiver operating characteristic area under curve (ROC-AUC) analysis cross-validated with leave-one-out (LOO) analysis. RESULTS: ADC kurtosis was significantly lower (p < 0.001) in TZ containing significant tumour with ROC-AUC 0.80 (LOO-AUC 0.78); the difference became non-significant following exclusion of significant tumour from single-slice whole TZ-ROI (p = 0.23). T1-entropy was significantly lower (p = 0.004) in TZ containing significant tumour with ROC-AUC 0.70 (LOO-AUC 0.66) and was unaffected by excluding significant tumour from TZ-ROI (p = 0.004). Combining these parameters yielded ROC-AUC 0.86 (LOO-AUC 0.83). CONCLUSION: Textural features of the whole prostate TZ can discriminate significant prostatic cancer through reduced kurtosis of the ADC-histogram where significant tumour is included in TZ-ROI and reduced T1 entropy independent of tumour inclusion. KEY POINTS: MR textural features of prostate transition zone may discriminate significant prostatic cancer; Transition zone (TZ) containing significant tumour demonstrates a less peaked ADC histogram; TZ containing significant tumour reveals higher post-contrast T1-weighted homogeneity; The utility of MR texture analysis in prostate cancer merits further investigation

Loop-Mediated Isothermal Amplification (LAMP) and SYBR Green qPCR for Fast and Reliable Detection of Geosmithia morbida (Kola&#345;ik) in Infected Walnut

Walnut species (Juglans spp.) are multipurpose trees, widely employed in plantation forestry for high-quality timber and nut production, as well as in urban greening as ornamental plants. These species are currently threatened by the thousand cankers disease (TCD) complex, an insect–fungus association which involves the ascomycete Geosmithia morbida (GM) and its vector, the bark beetle Pityophthorus juglandis. While TCD has been studied extensively where it originated in North America, little research has been carried out in Europe, where it was more recently introduced. A key step in research to cope with this new phytosanitary emergency is the development of effective molecular detection tools. In this work, we report two accurate molecular methods for the diagnosis of GM, based on LAMP (real-time and visual) and SYBR Green qPCR, which are complimentary to and integrated with similar recently developed assays. Our protocols detected GM DNA from pure mycelium and from infected woody tissue with high accuracy, sensitivity, and specificity, without cross-reactivity to a large panel of taxonomically related species. The precision and robustness of our tests guarantee high diagnostic standards and could be used to support field diagnostic end-users in TCD monitoring and surveillance campaigns

Uso de anti-helmínticos e bioestimulantes no desempenho de bovinos de corte suplementados a pasto no estado do Pará.

O experimento avaliou o efeito da vermifugação e da utilização de bioestimulantes no ganho de peso e no escore de condição corporal (ECC) de bovinos de corte, criados em sistema de pastejo rotacionado com suplementação a pasto, no Estado do Pará, durante 160 dias. Foram utilizados 132 bovinos machos não castrados, com idade média de 24 meses, da raça Nelore (Bos taurus indicus). Os grupos experimentais compreenderam o grupo G1 (controle; n=33), G2 (moxidectina 1%; n=33), G3 (moxidectina 10%; n=33) e G4 (ivermectina 3,15%; n=33). Em todos os grupos foram estabelecidas três subparcelas, a fim de serem testados dois bioestimulantes de crescimento animal (bioestimulante 1 e bioestimulante 2). Não houve diferença estatística significativa no ganho de peso médio, no ECC e nas contagens de OPG entre animais do G1, G2, G3 e G4, independentemente dos anti-helmínticos e/ou bioestimulantes usados. Contudo, o tratamento baseado na associação de moxidectina 1% e o bioestimulante 2 apresentou maior receita líquida e incrementou a lucratividade da terminação em 1,24%. Os resultados sugerem que não há necessidade de um controle contra nematódeos durante a terminação, desde que os animais apresentem uma baixa carga parasitária, porém o uso de fármacos pode, sob certas condições, apresentar resultado econômico favorável

Diferencias en la implicación en los deberes escolares en función del rendimiento académico en estudiantes de primaria

The present study aims to find out whether there are differences in homework involvement (in terms of amount of homework completed, time spent on doing homework and homework time management) among students with various levels of achievement. Gender and school level have been controlled as they may impact on the relation intended to be studied and this way they have been included in the covariate performed in the design. The sample consisted of 535 students from the three last years of Elementary School. Findings suggest that the more students achieve higher the more they improve their level of involvement relating to the amount of homework completed and the quality of homework time management. On the other hand, although no statistic significant differences have been found concerning the relation between achievement and time spent on homework, students who achieve lower tend to spend more time completing homework compared to those achieving higher who prove to spend less time completing the assignments. Furthermore, as students go from fourth to sixth forms their time spent on homework increases however, the quality of their homework time management deteriorates.El objetivo de este trabajo fue comprobar si hay diferencias en la implicación en los deberes escolares (en términos de cantidad de deberes escolares realizados, tiempo dedicado a los deberes y aprovechamiento del tiempo) en función de los distintos niveles de rendimiento académico de los estudiantes. Debido al posible efecto que pueden tener en esta asociación el género y curso, se controló sus efectos incorporándolas como covariables en el diseño. La muestra está integrada por 535 estudiantes de los tres últimos cursos de Educación Primaria. Los resultados indican que a medida que los niveles de rendimiento académico de los estudiantes son más altos, hay un aumento progresivo en la cantidad de deberes realizados y en el aprovechamiento del tiempo dedicado a los deberes. Por otra parte, aunque no parece haber diferencias estadísticamente significativas en el tiempo dedicado a los deberes en función de los distintos niveles de rendimiento, la tendencia que se observa es que cuando el rendimiento es bajo, el tiempo dedicado a los deberes es mayor, mientras que cuando el rendimiento es alto, el tiempo que dedican los estudiantes a los deberes es menor. Además, otro resultado destacado es que según van avanzando los estudiantes de 4º a 6º curso de Primaria se produce un aumento progresivo del tiempo que dedican a hacer los deberes escolares y, sin embargo, el aprovechamiento que hacen de ese tiempo va siendo cada vez menor.

Experimentos como estratégia de aprendizagem de processos de oxidação-redução: uma análise da linguagem química

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Percepção dos alunos do curso Médio Integrado sobre a disciplina de Química: um estudo de caso no IFAL - Campus Murici

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