152 research outputs found
Learning from Post-Observation Conferences: Emerging Measures of and Mechanisms to Improve Principals’ Feedback to Teachers
As principals seek to strengthen their impact on teaching and learning, it is critical to understand how principals provide feedback to teachers about their instruction and the focus of those conversations. This study examined the content and quality of principals’ (N = 4) verbal feedback to teachers (N = 11) during post-observation conferences (N = 11) and teachers’ perceptions of that feedback. In post-observation conferences, principals emphasized students’ opportunities to learn and supportive classroom environment, but rarely provided feedback on curriculum sequencing, the balance of procedural and conceptual knowledge, and teachers’ review and feedback to students. The quality of post-observations conferences was rated relatively high by the research team and teachers, with 100% of teachers indicating they were likely or very likely to change their practice based on the feedback they received. Concrete examples from teachers of effective and ineffective feedback are provided. Implications of study findings are discussed
Effect Of Polymerization Cycles On Gloss, Roughness, Hardness And Impact Strength Of Acrylic Resins
The aim of this study was to evaluate the conventional and boiled polymerization cycles on gloss, roughness, hardness and impact strength of acrylic resins. Samples were made for each Classico and QC-20 materials (n=10) in dental stone molds obtained from rectangular metallic matrices embedded in metallic flasks. The powder-liquid ratio and manipulation of the acrylic resins' were accomplished according to manufacturers' instructions and the resins were conventionally packed in metallic flasks. After polymerization by (1) conventional: 74 °C for 9 h (Classico) and (2) boiled: 20 min (QC-20) cycles, the samples were deflasked after cooling at room temperature and conventionally finished and polished. The properties were evaluated after storage in water at 37 °C for 24 h. Gloss was verified with Multi Gloss 268 meter (Konica Minolta), surface roughness was measured with Surfcorder SE 1700 rugosimeter (Kosaka), Knoop hardness number was obtained with HMV-200 microdurometer, and impact strength was measured in an Otto Wolpert-Werke device by Charpy system (40 kpcm). Data were subjected to Student's t-test (at α=0.05). The results were: Gloss: 67.7 and 62.2 for Classico and QC-20 resins, respectively; Surface roughness: 0.874 and 1.469 Ra-µm for Classico and QC-20, respectively; Knoop hardness: 27.4 and 26.9 for Classico and QC-20, respectively; and Impact strength: 37.6 and 33.6 kgf/cm2 for Classico and QC-20, respectively. No statistically significant difference (p>0.05)were found between the resins for the evaluated properties. In conclusion, conventional and boiled polymerization cycles had similar effects on gloss, roughness, hardness and impact strength of both Classico and QC-20 resins.27217618
Nonlinear dynamics of asymmetric bistable energy harvesters
The paper investigates asymmetries effects over a nonlinear vibration energy
harvester dynamics. The asymmetric system performance is compared with
symmetric ones. Different asymmetry levels on restoring force and gravity
action are investigated from a system-sloping angle variation. Bifurcation
diagrams and basins of attraction are used to examine the local and global
characteristics underlying dynamical systems under different excitation energy.
The results show the adverse effects of asymmetries on system dynamics. They
also reveal ways to overcome them by canceling asymmetric influence from
optimal sloping angle values and improving asymmetric system performance over
symmetrical ones. This comprehensive numerical study provides novel valuable
insights into asymmetrical energy harvester dynamics, a wide and still less
explored topic
Effect of polymerization cycles on gloss, roughness, hardness and impact strength of acrylic resins
The aim of this study was to evaluate the conventional and boiled polymerization cycles on gloss, roughness, hardness and impact strength of acrylic resins. Samples were made for each Classico and QC-20 materials (n=10) in dental stone molds obtained from rectangular metallic matrices embedded in metallic flasks. The powder-liquid ratio and manipulation of the acrylic resins' were accomplished according to manufacturers' instructions and the resins were conventionally packed in metallic flasks. After polymerization by (1) conventional: 74 °C for 9 h (Classico) and (2) boiled: 20 min (QC-20) cycles, the samples were deflasked after cooling at room temperature and conventionally finished and polished. The properties were evaluated after storage in water at 37 °C for 24 h. Gloss was verified with Multi Gloss 268 meter (Konica Minolta), surface roughness was measured with Surfcorder SE 1700 rugosimeter (Kosaka), Knoop hardness number was obtained with HMV-200 microdurometer, and impact strength was measured in an Otto Wolpert-Werke device by Charpy system (40 kpcm). Data were subjected to Student's t-test (at α=0.05). The results were: Gloss: 67.7 and 62.2 for Classico and QC-20 resins, respectively; Surface roughness: 0.874 and 1.469 Ra-µm for Classico and QC-20, respectively; Knoop hardness: 27.4 and 26.9 for Classico and QC-20, respectively; and Impact strength: 37.6 and 33.6 kgf/cm2 for Classico and QC-20, respectively. No statistically significant difference (p>0.05)were found between the resins for the evaluated properties. In conclusion, conventional and boiled polymerization cycles had similar effects on gloss, roughness, hardness and impact strength of both Classico and QC-20 resins272176180CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQSem informaçãoO propósito neste estudo foi avaliar os ciclos de polimerização convencional e por fervura sobre o brilho, rugosidade, dureza e resistência ao impacto de resinas acrílicas. Amostras foram confeccionadas para cada resina Clássico ou QC-20 (n=20) em moldes de gesso obtidos de matrizes metálicas retangulares incluídas em muflas metálicas. A proporção monômero/polímero das resinas e manipulação foram de acordo com as recomendações dos fabricantes e a massa convencionalmente incluída em muflas metálicas. Após polimerização nos ciclos (1) convencional: 74 °C por 9 horas (Clássico) e (2) fervura: 20 min (QC-20), as amostras foram demufladas após esfriadas em temperatura ambiente e convencionalmente acabadas e polidas. As propriedades foram avaliadas após armazenagem das amostras em água a 37 °C por 24 h. O brilho foi verificado com medidor Multi Gloss 268 (Konica Minolta), a rugosidade avaliada com rugosímetro Surfcorder SE 1700 (Kosaka), a dureza Knoop foi obtida com microdurômetro HMV-200 (Shimadzu) e a resistência ao impacto determinada pelo sistema Charpy (Otto Wolpert Werke). Os dados submetidos ao teste t de Student (α=0.05) mostraram que Os resultados foram: brilho: 67,7 e 62,2 para Clássico e QC-20, respectivamente; rugosidade: 0,874 e 1,469 Ra-µm para Clássico e QC-20, respectivamente; dureza: 27,4 e 26,9 para Clássico e QC-20, respectivamente; e resistência ao impacto: 37,6 e 33,6 kgf/cm2 para Clássico e QC-20, respectivamente. Não houve diference estatisticamente significante entre as resinas para as propriedades avaliadas. Conclui-se que os ciclos de polimerização convencional e por fervura promoveram similares efeitos sobre o brilho, rugosidade, dureza e resistência ao impacto para ambas as resinas Clássico e QC-2
Refractory Angina Cell Therapy (ReACT) Involving Autologous Bone Marrow Cells in Patients Without Left Ventricular Dysfunction: A Possible Role for Monocytes
Autologous bone marrow mononuclear cell (BMMC) transplantation has emerged as a potential therapeutic option for refractory angina patients. Previous studies have shown conflicting myocardium reperfusion results. the present study evaluated safety and efficacy of CellPraxis Refractory Angina Cell Therapy Protocol (ReACT). in which a specific BMMC formulation was administered as the sole therapy for these patients. the phase I/IIa noncontrolled, open label. clinical trial, involved eight patients with refractory angina and viable ischemic myocardium, without left ventricular dysfunction and who were not suitable for conventional myocardial revascularization. ReACT is a surgical procedure involving a single series of multiple injections (40-90 injections, 0.2 ml each) into ischemic areas of the left ventricle. Primary endpoints were Canadian Cardiovascular Society Angina Classification (CCSAC) improvement at 18 months follow-up and myocardium ischemic area reduction (assessed by scintigraphic analysis) at 12 months follow-up, in correlation with a specific BMMC formulation. Almost all patients presented progressive improvement in angina classification beginning 3 months (p = 0.008) postprocedure which was sustained at 18 months follow-up (p = 0.004), as well as objective myocardium ischemic area reduction at 12 months (decrease of 84.4%, p < 0.004). A positive correlation was found between monocyte concentration and CCSAC improvement (r = -0.759, p < 0.05). Improvement in CCSAC, followed by correlated reduction in scintigraphic myocardium ischemic area, strongly suggests neoangiogenesis as the main stem cell action mechanism. the significant correlation between number of monocytes and improvement strongly supports a cell-related effect of ReACT. ReACT appeared safe and effective.Cryopraxis Crobiologia Ltda.Cellpraxis BiogenhariaUniversidade Federal de São Paulo, Paulista Sch Med, Dept Surg, Div Cardiovasc Surg, São Paulo, BrazilCryopraxis Criobiol Ltda, Rio de Janeiro, BrazilCellpraxis Bioengn, Rio de Janeiro, BrazilUniversidade Federal de São Paulo, Paulista Sch Med, Div Hematol, São Paulo, BrazilUniv São Paulo, Coll Med, Inst Heart, São Paulo, BrazilUniv S Florida, Coll Med, Dept Neurosurg & Brain Repair, Ctr Excellence Aging & Brain Repair, Tampa, FL USAUniv S Florida, Off Res & Innovat, Tampa, FL USAUniversidade Federal de São Paulo, Paulista Sch Med, Dept Surg, Div Cardiovasc Surg, São Paulo, BrazilUniversidade Federal de São Paulo, Paulista Sch Med, Div Hematol, São Paulo, BrazilWeb of Scienc
EEG-Based Epileptic Seizure Prediction Using Temporal Multi-Channel Transformers
Epilepsy is one of the most common neurological diseases, characterized by
transient and unprovoked events called epileptic seizures. Electroencephalogram
(EEG) is an auxiliary method used to perform both the diagnosis and the
monitoring of epilepsy. Given the unexpected nature of an epileptic seizure,
its prediction would improve patient care, optimizing the quality of life and
the treatment of epilepsy. Predicting an epileptic seizure implies the
identification of two distinct states of EEG in a patient with epilepsy: the
preictal and the interictal. In this paper, we developed two deep learning
models called Temporal Multi-Channel Transformer (TMC-T) and Vision Transformer
(TMC-ViT), adaptations of Transformer-based architectures for multi-channel
temporal signals. Moreover, we accessed the impact of choosing different
preictal duration, since its length is not a consensus among experts, and also
evaluated how the sample size benefits each model. Our models are compared with
fully connected, convolutional, and recurrent networks. The algorithms were
patient-specific trained and evaluated on raw EEG signals from the CHB-MIT
database. Experimental results and statistical validation demonstrated that our
TMC-ViT model surpassed the CNN architecture, state-of-the-art in seizure
prediction.Comment: 15 pages, 10 figure
Parallel evolution of vgsc mutations at domains IS6, IIS6 and IIIS6 in pyrethroid resistant Aedes aegypti from Mexico
Aedes aegypti is the primary urban mosquito vector of viruses causing dengue, Zika and chikungunya fevers –for which vaccines and efective pharmaceuticals are still lacking. Current strategies to suppress arbovirus outbreaks include removal of larval-breeding sites and insecticide treatment of larval and adult populations. Insecticidal control of Ae. aegypti is challenging, due to a recent rapid global increase in knockdown-resistance (kdr) to pyrethroid insecticides. Widespread, heavy use of pyrethroid spacesprays has created an immense selection pressure for kdr, which is primarily under the control of the voltage-gated sodium channel gene (vgsc). To date, eleven replacements in vgsc have been discovered, published and shown to be associated with pyrethroid resistance to varying degrees. In Mexico, F1,534C and V1,016I have co-evolved in the last 16 years across Ae. aegypti populations. Recently, a novel replacement V410L was identifed in Brazil and its efect on vgsc was confrmed by electrophysiology. Herein, we screened V410L in 25 Ae. aegypti historical collections from Mexico, the frst heterozygote appeared in 2002 and frequencies have increased in the last 16 years alongside V1,016I and F1,534C. Knowledge of the specifc vgsc replacements and their interaction to confer resistance is essential to predict and to develop strategies for resistance management
The potential therapeutic use of cord blood in autologous transplants or in special patients: a review and update
Umbilical Cord Blood is a rich source of hematopoietic stem cells widely used as a substitute of bone marrow (BM) in transplants. Cells from umbilical cord blood present advantages over BM cells, mainly as they are younger and a have higher proliferative rate. Besides hematopoietic stem cells, umbilical cord blood contains endothelial and mesenchymal progenitor cells, suggesting their possible application in cell therapy protocols for different tissues. In this paper, we discuss the importance of autologous umbilical cord blood storage and the research on stem cell transplantation for degenerative diseases.O sangue de cordão umbilical e placentário (SCUP) é uma rica fonte de células-tronco (CT) hematopoéticas e é amplamente utilizado como substituto da medula óssea em casos de transplante. As células do SCUP possuem vantagens sobre as células da medula óssea (MO), principalmente por serem mais jovens e apresentarem maior taxa proliferativa. Além dos progenitores hematopoéticos, o sangue de cordão umbilical contém progenitores endoteliais e mesenquimais, sugerindo sua possível aplicação nos novos protocolos de terapia celular para diferentes tecidos. Na presente revisão, discutimos a importância do armazenamento do sangue de cordão umbilical autólogo e as pesquisas desenvolvidas para a sua aplicação em doenças degenerativas.Cryopraxis Criobiologia LtdaUniversidade Federal de São Paulo (UNIFESP), Escola Paulista de Medicina (EPM)Instituto de Traumato-ortopediaSanta Casa de São PauloHospital Samaritano de São PauloUFRJ HUCFFHospital Central do ExércitoUFRJ IPPMGUFRJCollege of Medicine Department of Neurosurgery Center of Excellence for Aging & Brain RepairUNIFESP, EPMSciEL
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