Turning Show’n’Tell into Democratic Dialogue

In this paper, I summarize an intense two-week study that I participated in at a Summer Institute on Education and Democracy at the University of Manitoba, Canada, beginning with brief descriptions of the innovation, Nos histoires, the purpose of the study, and the research method. I share the action research process and my reflections using Brown’s (2004) meaning-making model of action research, the learning circle, as an organizing framework. The four stages of this model, Wholeness, Awareness, Meaning, and Commitment, are used as headings to report stages of the study. This framework helped me align a series of actions with an overall purpose, and integrate objective knowledge from several lines of research with my own classroom experience and beliefs. The learning circle also helped me gain reflective skills for framing other educational problems and designing creative solutions. A careful description of the way my work was guided by this framework may help other teachers adapt the process for themselves

Mechanism of the Intermediary Phase Formation in Ti-20 wt. % Al Mixture during Pressureless Reactive Sintering

This work aims to describe the mechanism of intermediary phases formation in TiAl20 (wt. %) alloy composition during reactive sintering. The reaction between titanium and aluminum powders was studied by in situ diffraction and the results were confirmed by annealing at various temperatures. It was found that the Ti2Al5 phase formed preferentially and its formation was detected at 400 degrees C. So far, this phase has never been found in this alloy composition during reactive sintering processes. Subsequently, the Ti2Al5 phase reacted with the titanium, and the formation of the major phase, Ti3Al, was accompanied by the minor phase, TiAl. Equations of the proposed reactions are presented in this paper and their thermodynamic and kinetic feasibility are supported by Gibbs energies of reaction and reaction enthalpies

Polydisperse methyl β-cyclodextrin–epichlorohydrin polymers: variable contact time 13C CP-MAS solid-state NMR characterization

The polymerization of partially methylated β-cyclodextrin (CRYSMEB) with epichlorohydrin was carried out in the presence of a known amount of toluene as imprinting agent. Three different preparations (D1, D2 and D3) of imprinted polymers were obtained and characterized by solid-state 13C NMR spectroscopy under cross-polarization magic angle spinning (CP-MAS) conditions. The polymers were prepared by using the same synthetic conditions but with different molar ratios of imprinting agent/monomer, leading to morphologically equivalent materials but with different absorption properties. The main purpose of the work was to find a suitable spectroscopic descriptor accounting for the different imprinting process in three homogeneous polymeric networks. The polymers were characterized by studying the kinetics of the cross-polarization process. This approach is based on variable contact time CP-MAS spectra, referred to as VCP-MAS. The analysis of the VCP-MAS spectra provided two relaxation parameters: TCH (the CP time constant) and T1ρ (the proton spin-lattice relaxation time in the rotating frame). The results and the analysis presented in the paper pointed out that TCH is sensitive to the imprinting process, showing variations related to the toluene/cyclodextrin molar ratio used for the preparation of the materials. Conversely, the observed values of T1ρ did not show dramatic variations with the imprinting protocol, but rather confirmed that the three polymers are morphologically similar. Thus the combined use of TCH and T1ρ can be helpful for the characterization and fine tuning of imprinted polymeric matrices

Kinetic and thermodynamic description of intermediary phases formation in Ti-Al system during reactive sintering

Reactive sintering is currently considered as a promising production route for titanium aluminides in many research works. However, the published descriptions of the reaction mechanism are contradictory or lacking, especially at the temperatures below the melting point of aluminium. This work aims to fill this gap, providing the description of the reactive sintering process at the temperatures between 400 and 900 degrees C. The phases' formation sequence and reaction kinetics were studied and explained using experimental model (Ti/Al diffusion couple) and real reactively sintered samples of equiatomic Ti-Al compressed powder blend. Moreover, phase formation was thermodynamically assessed. It was revealed that Ti2Al5 phase formed preferentially. This phase has not been reported previously as a starting phase in reactive sintering. According to results obtained by experimental model, its formation is controlled by diffusion at 700 degrees C. This phase reacted with aluminium forming pure TiAl3 phase or with titanium, resulting in TiAl phase. Subsequently, TiAl phase reacted with titanium, leading to the Ti3Al phase, or with already present Ti2Al5 phase yielding TiAl2 intermetallic compound. Titanium-rich Ti3Al phase could form only at the temperature of 600 degrees C or above

J-Band Infrared Spectroscopy of a Sample of Brown Dwarfs Using Nirspec on Keck II

Near-infrared spectroscopic observations of a sample of very cool, low-mass objects are presented with higher spectral resolution than in any previous studies. Six of the objects are L-dwarfs, ranging in spectral class from L2 to L8/9, and the seventh is a methane or T-dwarf. These new observations were obtained during commissioning of NIRSPEC, the first high-resolution near-infrared cryogenic spectrograph for the Keck II 10-meter telescope on Mauna Kea, Hawaii. Spectra with a resolving power of R=2500 from 1.135 to 1.360 microns (approximately J-band) are presented for each source. At this resolution, a rich spectral structure is revealed, much of which is due to blending of unresolved molecular transitions. Strong lines due to neutral potassium (K I), and bands due to iron hydride (FeH) and steam (H2O) change significantly throughout the L sequence. Iron hydride disappears between L5 and L8, the steam bands deepen and the K I lines gradually become weaker but wider due to pressure broadening. An unidentified feature occurs at 1.22 microns which has a temperature dependence like FeH but has no counterpart in the available FeH opacity data. Because these objects are 3-6 magnitudes brighter in the near-infrared compared to the I-band, spectral classification is efficient. One of the objects studied (2MASSW J1523+3014) is the coolest L-dwarf discovered so far by the 2-Micron All-Sky Survey (2MASS), but its spectrum is still significantly different from the methane-dominated objects such as Gl229B or SDSS 1624+0029.Comment: New paper, Latex format, 2 figures, accepted to ApJ Letter

A simple remote sensing based information system for monitoring sites of conservation importance

Monitoring is essential for conservation of sites, but capacity to undertake it in the field is often limited. Data collected by remote sensing has been identified as a partial solution to this problem, and is becoming a feasible option, since increasing quantities of satellite data in particular are becoming available to conservationists. When suitably classified, satellite imagery can be used to delineate land cover types such as forest, and to identify any changes over time. However, the conservation community lacks (a) a simple tool appropriate to the needs for monitoring change in all types of land cover (e.g. not just forest), and (b) an easily accessible information system which allows for simple land cover change analysis and data sharing to reduce duplication of effort. To meet these needs, we developed a web-based information system which allows users to assess land cover dynamics in and around protected areas (or other sites of conservation importance) from multi-temporal medium resolution satellite imagery. The system is based around an open access toolbox that pre-processes and classifies Landsat-type imagery, and then allows users to interactively verify the classification. These data are then open for others to utilize through the online information system. We first explain imagery processing and data accessibility features, and then demonstrate the toolbox and the value of user verification using a case study on Nakuru National Park, Kenya. Monitoring and detection of disturbances can support implementation of effective protection, assist the work of park managers and conservation scientists, and thus contribute to conservation planning, priority assessment and potentially to meeting monitoring needs for Aichi target 11

How Do the Properties of Amphiphilic Polymer Membranes Influence the Functional Insertion of Peptide Pores?

Pore-forming peptides are of high biological relevance particularly as cytotoxic agents, but their properties are also applicable for the permeabilization of lipid membranes for biotechnological applications, which can then be translated to the more stable and versatile polymeric membranes. However, their interactions with synthetic membranes leading to pore formation are still poorly understood, hampering the development of peptide-based nanotechnological applications, such as biosensors or catalytic compartments. To elucidate these interactions, we chose the model peptide melittin, the main component of bee venom. Here, we present our systematic investigation on how melittin interacts with and inserts into synthetic membranes, based on amphiphilic block copolymers, to induce pore formation in three different setups (planar membranes and micrometric and nanometric vesicles). By varying selected molecular properties of block copolymers and resulting membranes (e.g., hydrophilic to hydrophobic block ratio, membrane thickness, surface roughness, and membrane curvature) and the stage of melittin addition to the synthetic membranes, we gained a deeper understanding of melittin insertion requirements. In the case of solid-supported planar membranes, melittin interaction was favored by membrane roughness and thickness, but its insertion and pore formation were hindered when the membrane was excessively thick. The additional property provided by micrometric vesicles, curvature, increased the functional insertion of melittin, which was evidenced by the even more curved nanometric vesicles. Using nanometric vesicles allowed us to estimate the pore size and density, and by changing the stage of melittin addition, we overcame the limitations of peptideâEuro"polymer membrane interaction. Mirroring the functionality assay of planar membranes, we produced glucose-sensing vesicles. The design of synthetic membranes permeabilized with melittin opens a new path toward the development of biosensors and catalytic compartments based on pore-forming peptides functionally inserted in synthetic planar or three-dimensional membranes

Automedicación en estudiantes de medicina de la Universidad de Ciencias Aplicadas y Ambientales U.D.C.A en el segundo semestre de 2017

The present investigation is of the descriptive type – Cross-sectional, about the phenomenon of self-medication in medical students at Universidad de Ciencias Aplicadas y Ambientales (UDCA), from I to V semester, it sets out to know the causes and behaviors by which the students decide to turn to such practice, considering that self-medication is one of the biggest problems that Colombia’s public healthcare system is facing. And that it’s also risen concern within the health authorities because of the side effects that a certain group of medication might cause. Similar studies to this investigation have demonstrated that self-medication is a phenomenon that spreads day by day amongst the population, and that students are a demographic exposed to this practice. On the study conducted by Universidad de Ciencias Aplicadas y Ambientales on medical students, it was discovered that 73% of the population self-medicates and, although 79% of students claim that they are aware of the risks of self-medicating, 45% turn to it because the symptoms don’t seem too serious and 37% say that they had managed those symptoms before.La presente investigación de tipo descriptivo –transversal sobre el fenómeno de automedicación en estudiantes de Medicina en la Universidad de Ciencias Aplicadas y Ambientales (U.D.C.A.), de primero a quinto semestres, plantea conocer los motivos y comportamientos por los cuales los estudiantes acceden a dicha práctica, ya que la automedicación es uno de los problemas más importantes de salud pública que afronta Colombia y existe gran preocupación por parte de las autoridades de salud por los efectos adversos que cierto grupo de medicamentos puedan generar. Estudios similares a la presente investigación han evidenciado que la automedicación es un fenómeno que día a día asciende en la población y que los estudiantes están expuestos a esta práctica. En el estudio realizado en la U.D.C.A., en estudiantes de medicina se encontró que el 73% de la población se automedica, a pesar de que el 79% de los estudiantes refiere que conoce con claridad los riesgos de la automedicación, el 45% lo hace porque los síntomas no le parecen graves y el 37% refiere que ya había manejado los síntomas con anterioridad.PregradoMédico(a) Cirujan

The Difference of Grammatical Error in Writing Recount Text Between Natural Science and Social Science Students

This study concerned on the difference of grammatical error in writing recount text between natural science and social science students. The objective of this study was to find out the difference of grammatical error in writing recount text between natural science and social science students. This research was conducted by using causal- comparative research. The subject of the study was the students of XI-IPA1 and XI- IPS1 of SMA Swasta Methodist Berastagi. The number of the samples was twenty eight. The techniques for data analysis were quantitative data. The t-result was 2,60 (bigger than t table 1,706). The conclusion is that there is a significant difference of grammatical error in writing recount text between natural science and social science students

Análise da secagem de café em secador solar passivo direto / Analysis of coffee drying in direct passive solar dryer

 O café é um dos principais produtos agrícolas do Brasil e seu preço está diretamente ligado à qualidade da bebida, sendo esta influenciada fortemente pelos processos pós-colheita do grão, especialmente o processo de secagem. Usualmente a secagem é realizada em terreiros a céu aberto onde o produto está sujeito a intempéries e às variações do clima, além de demandar longos períodos de tempo, entre 15 a 20 dias. É necessário, então, buscar alternativas que tornem o processo mais eficiente, atentando para a qualidade e a consequente competitividade do grão no mercado. O presente trabalho busca analisar a eficiência e aplicabilidade de um secador solar passivo direto no processo de secagem do café.  Para tal, foram dispostas amostras de grãos de café em dois secadores solares passivos e também ao ar livre a fim de comparar os dois processos e, ainda, levantar as curvas características de secagem por meio de secadores solares.  Nos secadores, a temperatura alcançou valores médios na faixa de 50 °C, com aumento de 19,6 °C em relação à temperatura ambiente média, de 30,4 °C. A radiação solar média nos quatro dias de experimento foi de 598 W/m2. A umidade inicial média dos grãos era de 67,6% e a umidade final recomendada, de 12%, foi atingida após 965 min nos secadores solares. Considerando esse mesmo período de tempo, na secagem natural, a umidade atingida foi de 38%. Na análise qualitativa dos grãos, feitos pela Cooperativa Agropecuária de Boa Esperança, situada em Cristais-MG, o café tratado no secador apresentou defeitos nos grãos, sendo que alguns chegaram a fermentar. Porém, a análise de bebida do mesmo foi classificada como do tipo dura, uma boa análise, indicando que apesar dos problemas apresentados, os secadores solares podem vir a ser uma alternativa ao atual método de secagem natural convencional do café.