Proof validation and modification by example generation: A classroom-based intervention in secondary school geometry

ArticleProceedings of the 13th International Congress on Mathematical Education (ICME-13). Hamburg, Germany, 2016-7-24/31, ICME. (2016)journal articl

N,N’-Bis(2-chloroethyl)-N-nitrosourea (BCNU)-induced Apoptosis of Neural Progenitor Cells in the Developing Fetal Rat Brain

N,N’-bis(2-chloroethyl)-N-nitrosourea (BCNU) is one of the major drugs used in chemotherapy against malignant gliomas due to its effects, such as induction of bifunctional alkylation of DNA and formation of interstrand DNA cross-linkages, and induces cortical malformations in the fetal and neonatal rat brain. In this study, pregnant rats were treated with 7.5 mg/kg of BCNU on gestational day 13 (GD 13), and their fetuses were collected from 12 to 72 hours after BCNU treatment in order to examine the timecourses of morphological and immunohistochemical changes in neural progenitor cells in the developing brain. The number of pyknotic cells in the telencephalon peaked at 24 h and then gradually decreased until 72 h. The majority of these pyknotic cells were positive for cleaved caspase-3, a key executioner of apoptosis. The pyknotic cells showed the ultrastructural characteristics of apoptosis. The number of p53-positive cells began to increase prior to the appearance of apoptotic cells and p21-positive cells. The number of phosphorylated-histone H3-positive cells (mitotic cells) decreased from 24 to 36 h. The number of Iba1-positive cells (microglial cells) in the telencephalon increased from 12 to 48 h. These results suggest that BCNU induces p53-dependent apoptosis and reduces proliferative activity, resulting in reduction of the weight of the telencephalon and the thickness of the telencephalic wall in the fetal brain. This study will help to clarify the mechanisms of BCNU-induced fetal brain toxicity

Increased intrapharyngeal pressure with combined use of high-flow nasal cannula and a surgical face mask: a preliminary study

OBJECTIVES: Nasal high-flow (NHF) therapy provides continuous positive airway pressure (CPAP), flushes the anatomical dead space, and improves mucociliary clearance. CPAP is usually applied at a flow rate at or above an established threshold value with the mouth closed because it is hard to maintain it with an open mouth. We conducted a prospective study to validate our hypothesis that CPAP can be applied with the mouth open through a surgical face mask. METHODS: We inserted 12-Fr nasogastric tubes through the noses of 18 healthy individuals and fixed each tube within the pharynx to monitor the intrapharyngeal pressure. We monitored the pressure during the following two conditions: NHF oxygen with the mouth open (condition O) and NHF oxygen with the mouth open and wearing a surgical face mask (condition OM). We set the NHF rate at 40 L/min and the oxygen concentration at 21%, under all conditions. We measured the intrapharyngeal pressure five times during each inspiration and expiration, and calculated mean values. RESULTS: The mean expiratory intrapharyngeal pressure (median [interquartile range]) increased significantly from the baseline during conditions O (2.08 [1.58–4.02] cm H(2)O) and OM (3.35 [2.72–3.79] cm H(2)O). In addition, there was a significant difference in pressure between conditions O and OM (p=0.0263, Wilcoxon signed-rank test). CONCLUSIONS: In our healthy volunteers, the intrapharyngeal pressures increased during expiration with an open mouth while wearing a surgical face mask

Early Spectroscopy of the 2010 Outburst of U Scorpii

We present early spectroscopy of the recurrent nova U~Sco during the outburst in 2010. We successfully obtained time-series spectra at $t_{\rm d}=$0.37--0.44~d, where $t_{\rm d}$ denotes the time from the discovery of the present outburst. This is the first time-resolved spectroscopy on the first night of U Sco outbursts. At $t_{\rm d}\sim 0.4$~d the H$\alpha$ line consists of a blue-shifted ($-5000$ km s$^{-1}$) narrow absorption component and a wide emission component having triple peaks, a blue ($\sim -3000$ km s$^{-1}$), a central ($\sim 0$ km s$^{-1}$) and a red ($\sim +3000$ km s$^{-1}$) ones. The blue and red peaks developed more rapidly than the central one during the first night. This rapid variation would be caused by the growth of aspherical wind produced during the earliest stage of the outburst. At $t_{\rm d}=1.4$~d the H$\alpha$ line has a nearly flat-topped profile with weak blue and red peaks at $\sim \pm 3000$ km s$^{-1}$. This profile can be attributed to a nearly spherical shell, while the asphericity growing on the first night still remains. The wind asphericity is less significant after $t_{\rm d}=9$ d.Comment: 5 pages, 3 figures, Accepted for publication of PASJ Letter

Diseño de sistema de alcantarillado sanitario y ampliación del sistema de agua potable del Barrio Villa Vallarta en la Ciudad de Managua

El presente estudio monográfico denominado "DISEÑO DEL SISTEMA DE ALCANTARILLADO SANITARIO Y AMPLIACIÓN DEL SISTEMA DE AGUA POTABLE EN EL BARRIO VILLA VALLARTA'', tiene como propósito mejorar las condiciones higiénico-sanitarias de la población, djsminuir el índice de mortalidad infantil y promover cambios de comportamientos en los miembros de las familias beneficiadas, para que mejoren su nivel de vida. EI Barrio Villa Vallarta se encuentra ubicado en la parie Nor-Este de la ciudad de Managua, localizándose en la zona alta del Acueducto de Managua; específicamente está ubicado en el Distrito No. Vl de la municipalidad de Managua. Se caracteriza por ser una zona de alta densidad debido que en dicho Barrio se encuentran construcciones sencillas y lotes con dimensiones y áreas homogéneas, de aproximadamente | 05 m2. Esta conformado por 393 viviendas,13 manzanas, 9 calles y 3 avenidas, alcanzando un área total de aproximadamente 67, 327.81 m2, incluyendo calles, avenidas y un área comunal de 1,575.45 m2 La calles miden aproximadamente 750.45 m2 Para formular el estudio monográfico, primeramente se realizó un diagnóstico situacional a través de ntrevistas y encuesta dirigidas. a funcionarios, líderes comunales y familias del Barrio. Posteriormente se efectuará el estudio topográfico y el estudio de suelo para conocer las características del terreno y la clasificación o tipo de suelo que predomina en el Barrio. Además se realizó la valoración del Sistema de Alcantarillado Sanitario y Sistema de Agua Potable existente

Long-term eradication of extranodal natural killer/T-cell lymphoma, nasal type, by induced pluripotent stem cell-derived Epstein-Barr virus-specific rejuvenated T cells in vivo

Functionally rejuvenated induced pluripotent stem cell (iPSC)-derived antigen-specific cytotoxic T lymphocytes (CTL) are expected to be a potent immunotherapy for tumors. When L-asparaginase-containing standard chemotherapy fails in extranodal natural killer/T-cell lymphoma, nasal type (ENKL), no effective salvage therapy exists. The clinical course then is miserable. We demonstrate prolonged and robust eradication of ENKL in vivo by Epstein-Barr virus-specific iPSC-derived antigen-specific CTL, with iPSC-derived antigen-specific CTL persisting as central memory T cells in the mouse spleen for at least six months. The anti-tumor response is so strong that any concomitant effect of the programmed cell death 1 (PD-1) blockade is unclear. These results suggest that long-term persistent Epstein-Barr virus-specific iPSC-derived antigen-specific CTL contribute to a continuous anti-tumor effect and offer an effective salvage therapy for relapsed and refractory ENKL