684 research outputs found
Stereotypes and prejudices in the Italian L2 class : a conversation analysis of their emergence in teachers’ talk
The paper explores teachers’ interactional uses of stereotypes and prejudices in the Italian L2 classroom. Drawing from video-ethnographic research in a voluntary association, this study adopts a discursive approach to stereotypes and prejudices, analyzing their pragmatic uses during classroom activities. Even though previous literature has mostly argued against these social devices, the analysis illustrates that teachers make use of stereotypes and prejudices to pursue their local aims in the classroom. Specifically, teachers mobilize stereotyped talk to achieve specific social and didactic aims (e.g., to explain a lexical items or to prompt laughter). In the discussion, we critically consider the risks and opportunities of this kind of practice and advance few implications for teachers’ professional practice, arguing for the relevance of video-based teacher training
Efek Daun Sirih Merah (Piper Crocatum) Terhadap Kadar Gula Darah Dan Gambaran Morfologi Endokrin Pankreas Tikus Wistar (Rattus Norvegicus)
: Leaves of 'sirih merah‘ (Piper Crocatum) contain compounds such as flavonoid, alkaloid and tannin, wich are capable of lowering blood sugar levels. This study aimed to investigate the effects of the administration of ‘sirih merah' broth on blood sugar levels and histopathological features of pancreatic endocrine. This was a laboratory experimental study which was conducted for five month using 12 wistar rats as objects. The rats were divided into four groups: Group A (negative control), which received no treatment; group B, which were given the broth of ‘sirih merah' at 2,4 ml; Group C, which were given sugar solution at 2,4 ml; and Group D, which were given the broth (1,2 ml) and sugar solution (1,2 ml). The results revealed that the levels of blood sugar decreased in rats in Groups B and D but increased in Group C. When compared with rats in Group A, the size and the number of Langerhans islets increased in Group C (more than twice). On the contrary, the number of Langerhans islets in Group D was relatively similar with that of Group A. Conclusion: The administration of the broth of ‘sirih merah' leaves is able to lower blood sugar levels and to cause hyperplasia of pancreatic Langerhans islets
Can stigmatizing attitudes be prevented in psychology students?
Background: Stigmatizing attitudes have been found among psychology students in many studies, and they are becoming more common with time. Aims: This study examines whether participation in clinical psychology lessons reduces levels of stigmatization in a population of psychology students and whether it leads to any change in stigmatization. Methods: The study is a pre/post evaluation of the effectiveness of clinical psychology lessons (63 hours of lectures) as a tool to fight stigma. The presence of stigmatizing attitudes was detected using the Italian version of the Attribution Questionnaire-27 (AQ-27-I). Stigmatization was described before and after the lessons with structured equation modeling (SEM). Results: Of a total of 387 students contacted, 302 (78.04%) agreed to be involved in the study, but only 266 (68.73%) completed the questionnaires at both t0 and t1. A statistically significant reduction was seen in all six scales and the total score on the AQ-27-I. The models defined by the SEM (pre- and post-intervention) showed excellent model fit indices and described different dynamics of the phenomenon of stigma. Conclusions: A cycle of clinical psychology lessons can be a useful tool for reducing stigmatizing attitudes in a population of students seeking a psychology degree
Influence of hydrogen on the structural stability of annealed ultrathin Si/Ge amorphous layers
Semiconductor structures based on Si and Ge are generally submitted to hydrogenation because H passivates the dangling bonds of Si and Ge. By this way the devices prepared from those semiconductors, e.g., solar cells, have much better electrical properties. However, H stability is still a critical issue. In fact, there is wide evidence that H is very unstable against illumination as well as heat treatment. It has been seen that H out effuses from the samples under such treatments. As this causes unsaturation of the dangling bonds the electrical properties worsen significantly. In this work we will show that in the case of ultrathin Si/Ge amorphous layers the H thermal instability also affects the structural stability even up to the micrometric scale depending on the H content. Such type of structure can also be used to prepare SiGe alloys by mixing the layers with heat treatments. The samples were amorphous multilayers (MLs) of alternating ultrathin (3 nm) layers of Si and Ge deposited by sputtering on (100) oriented Si substrate. The total thickness of the MLs was 300 nm. The samples were hydrogenated by introducing H in the sputter chamber with flow rates varying from 0.8 to 6 ml/min. The MLs underwent different heat treatments, from the one at 350 ?C for 1 h up to the one at 250 ?C for 0.5 h + 450 ?C for 5 h. The samples were analysed by AFM, TEM, energy filtering TEM and Small-Angle X-Ray Diffraction (SAXRD). AFM showed that upon annealing the structure of the samples degrades with formation of surface bumps whose size increases by increasing the annealing temperature and/or time, for the same H content, or by increasing the H content for the same annealing conditions. For high H content and/or annealing conditions AFM showed that the bumps have blown up giving rise to craters. This suggests that H was released from its dangling bonds to Si and Ge and formed H bubbles in the MLs because of the energy supplied by the annealing. Additional energy for the break of the Si-H and Ge-H bonds could be the one supplied by the recombination of thermally generated carriers associated with the band gap fluctuations caused by the not uniform distribution of H in the MLs. The first sites of H accumulation are very likely nanocavities certainly present in the amorphous MLs. By TEM it has been seen that layer intermixing occurred which could be the first step of H bubbles formation. SAXRD measurements as well as TEM energy filtering maps for Si and Ge showed that Si and Ge interdiffusion took place in an asymmetric way as Si was seen to diffuse to the Ge layers whereas Ge did not diffuse to the Si layers. This might be due to the higher density of free dangling bonds in the Ge layers created by annealing because the binding energy of the Ge-H bond is smaller than the one of the Si-H bond
InAs/InP/InSb Nanowires as Low Capacitance n-n Heterojunction Diodes
Nanowire diodes have been realized by employing an axial heterojunction between InAs and InSb semiconductor materials. The broken-gap band alignment (type III) leads to a strong rectification effect when the current-voltage (I-V) characteristic is inspected at room temperature. The additional insertion of a narrow InP barrier reduces the thermionic contribution, which results in a net decrease of leakage current in the reverse bias with a corresponding enhanced rectification in terms of asymmetry in the I-V characteristics. The investigated diodes compare favorably with the ones realized with p-n heterostructured nanowires, making InAs/InP/InSb devices appealing candidates to be used as building blocks for nanowire-based ultrafast electronics and for the realization of photodetectors in the THz spectral range
Guidance for better governance towards a sustainable, participatory and inclusive wild meat sector.
Agenda item 4 at the twenty-first meeting of the Subsidiary Body on Scientific, Technical and Technological Advice (SBSTTA) established under Article 25 of the Convention will be held in Montreal, Canada, at the Palais des Congrès, from 11 to 14 December 2017
Critical Strain Region Evaluation of Self-Assembled Semiconductor Quantum Dots
A novel peak finding method to map the strain from high resolution transmission electron micrographs, known as the Peak Pairs method, has been applied to In(Ga) As/AlGaAs quantum dot (QD) samples, which present stacking faults emerging from the QD edges. Moreover, strain distribution has been simulated by the finite element method applying the elastic theory on a 3D QD model. The agreement existing between determined and simulated strain values reveals that these techniques are consistent enough to qualitatively characterize the strain distribution of nanostructured materials. The correct application of both methods allows the localization of critical strain zones in semiconductor QDs, predicting the nucleation of defects, and being a very useful tool for the design of semiconductor device
Tuning morphology and magnetism in epitaxial L10-FePt films
In this work, well-ordered epitaxial FePt thin ¿lms have been grown by RF sputtering on two different substrates (MgO (100) and SrTiO3 (100)) and the effect of different lattice parameters between the substrate and FePt ¿lm on morphology and magnetic behavior has been considered. Growth conditions have been optimized to obtain different morphologies and magnetic behaviors
Synthesis and anticancer activity of CDDO and CDDO-me, two derivatives of natural triterpenoids
Triterpenoids are natural compounds synthesized by plants through cyclization of squalene, known for their weak anti-inflammatory activity. 2-cyano-3,12-dioxooleana-1,9(11)-dien-28-oic acid (CDDO), and its C28 modified derivative, methyl-ester (CDDO-Me, also known as bardoxolone methyl), are two synthetic derivatives of oleanolic acid, synthesized more than 20 years ago, in an attempt to enhance the anti-inflammatory behavior of the natural compound. These molecules have been extensively investigated for their strong ability to exert antiproliferative, antiangiogenic, and antimetastatic activities, and to induce apoptosis and differentiation in cancer cells. Here, we discuss the chemical properties of natural triterpenoids, the pathways of synthesis and the biological effects of CDDO and its derivative CDDO-Me. At nanomolar doses, CDDO and CDDO-Me have been shown to protect cells and tissues from oxidative stress by increasing the transcriptional activity of the nuclear factor (erythroid-derived 2)-like 2 (Nrf2). At doses higher than 100 nM, CDDO and CDDO-Me are able to modulate the differentiation of a variety of cell types, both tumor cell lines or primary culture cell, while at micromolar doses these compounds exert an anticancer effect in multiple manners; by inducing extrinsic or intrinsic apoptotic pathways, or autophagic cell death, by inhibiting telomerase activity, by disrupting mitochondrial functions through Lon protease inhibition, and by blocking the deubiquitylating enzyme USP7. CDDO-Me demonstrated its efficacy as anticancer drugs in different mouse models, and versus several types of cancer. Several clinical trials have been started in humans for evaluating CDDO-Me efficacy as anticancer and anti-inflammatory drug; despite promising results, significant increase in heart failure events represented an obstacle for the clinical use of CDDO-Me
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