221 research outputs found

    Perceptions of Efficacy in Connecticut Social Studies Certification: An Analysis of the #026 Social Studies Certification as It Relates to Sufficiency in Content Knowledge According to the Perceptions of Department Chairpersons

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    Content knowledge is important to the success of any teacher. A lack of content knowledge possessed by a teacher results in challenges for both teaching and learning. The purpose of this study was to analyze the perceptions of social studies department chairpersons throughout the state of Connecticut in regards to the #026 History/Social Studies 7-12 certification. The topics explored in the literature review of this paper comprise the importance of content knowledge, the sufficiency of social studies teacher preparation programs, and the benefits of content-based online professional development. The research questions asked included whether or not the #026 certification encompasses too many content categories for social studies teachers and whether this results in a lack of content knowledge in social studies departments throughout the state. This study also analyzed how such a numerous amount of content categories may potentially lead to scheduling and staffing conflicts faced by department chairpersons. It also explores which content categories social studies teachers come into teaching with the least and the most amounts of content knowledge in and how teachers gain content knowledge required to effectively teach. This study gathered data from social studies department chairpersons throughout the state of Connecticut

    Ultrastructural analysis of periapical granulomas

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    A large portion of periapical granulomas is composed by cells of the mononuclear-phagocyte and lymphoid system. The ultrastructural features of the monocytes/macrophages differ in relationship to the state of activity of the cells (phagocytosis or secretion). A close correlation between cells of these two systems can be surmised by their tight contacts. An important role in the bone resorption is probably played by cytokines like IL-1 and TNF.Une grande partie des granulomes pĂ©riapicaux est constituĂ©e de cellules du systĂšme mononuclĂ©aire phagocytaire et lymphoĂŻde. Les caractĂ©ristiques ultrastructurales des monocytes/macrophages diffĂšrent selon le type d’activitĂ© des cellules (phagocytose ou sĂ©crĂ©tion). Une corrĂ©lation intime entre les cellules de ces deux systĂšmes peut ĂȘtre supposĂ©e Ă©tant donnĂ© leurs contacts serrĂ©s. Un rĂŽle important dans la rĂ©sorption osseuse est exercĂ©, probablement par l’intermĂ©diaire de cytokines comme IL-1 beta et TNF

    Monitoring of Land Subsidence in Ravenna Municipality Using Integrated SAR - GPS Techniques: Description and First Results

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    The Emilia Romagna Region (N-E Italy) and in particular the Adriatic Sea coastline of Ravenna, is affected by a noticeable subsidence that started in the 1950s, when the exploitation of on and off-shore methane reservoirs began, along with the pumping of groundwater for industrial uses. In such area the current subsidence rate, even if lower than in the past, reaches the -2 cm/y. Over the years, local Authorities have monitored this phenomenon with different techniques: spirit levelling, GPS surveys and, more recently, Differential Interferometric Synthetic Aperture Radar (DInSAR) techniques, confirming the critical situation of land subsidence risk. In this work, we present the comparison between the results obtained with DInSAR and GPS techniques applied to the study of the land subsidence in the Ravenna territory. With regard to the DInSAR, the Small Baseline Subset (SBAS) and the Coherent Pixel Technique (CPT) techniques have been used. Different SAR datasets have been exploited: ERS-1/2, ENVISAT, TerraSAR-X and Sentinel-1. Some GPS campaigns have been also carried out in a subsidence prone area. 3D vertices have been selected very close to existing persistent scatterers in order to link the GPS measurement results to the SAR ones. GPS data were processed into the International reference system and the comparisons between the coordinates, for the first 6 months of the monitoring, provided results with the same trend of the DInSAR data, even if inside the precision of the method

    The association of food ingredients in breakfast cereal products and fumonisins production: risks identification and predictions

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    Breakfast processed products are remarkably at risk of fungal contamination. This research surveyed the fumonisins concentration in different breakfast products, and carried out in-vitro experiments measuring fumonisins content in different substrates inoculated with Fusarium verticillioides. The pipeline started with the identification of combinations of ingredients for 58 breakfast products. Twenty-three core ingredients, seven nutritional components and production types were analyzed using a Pearson correlation, k-means clustering and principal component analysis to show that no single factor is responsible for high fumonisins detection in processed cereals products. Consequently, decision tree regression was used as a means of determining and visualizing complex logical interactions between the same factors. We clustered the association of ingredients in low, medium, and high risk of fumonisin detection. The analysis showed that high fumonisins concentration is associated with those products that have high maize concentrations coupled especially with high sodium or rice. In a in-vitro experiment, different media were prepared by mixing the ingredients in the proportion found in the first survey and by measuring fumonisins production by Fusarium verticillioides. Results showed that: 1) fumonisins production by F. verticillioides is boosted by the synergistic effect of maize and highly ready carbohydrate content such as white flour; 2) a combination of maize >26%(w/w), rice >2.5%(w/w), NaCl >2.2%(w/w) led to high fumonisins production, while mono-ingredient products were more protective against fumonisins production. The observations in the in-vitro experiments appeared to align with the decision tree model that an increase in ingredient complexity can lead to fumonisins production by Fusarium. However, more research is urgently needed to develop the area of predictive mycology based on the association of processing, ingredients, fungal development, and mycotoxins production

    Computational analysis of Human Immunodeficiency Virus (HIV) Type-1 reverse transcriptase crystallographic models based on significant conserved residues found in Highly Active Antiretroviral Therapy (HAART)-treated patients.

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    Reverse transcription of the viral single-stranded (+) RNA genome into double-stranded DNA is an essential step in the human immunodeficiency virus' (HIV) life-cycle. Although several viral proteins are involved in the regulation and/or efficiency of reverse transcription, the process of retroviral DNA synthesis is entirely dependent on the enzymatic activities of the retroviral reverse transcriptase enzyme (RT). Due to its crucial role in the HIV life-cycle, RT is a primary target for anti-HIV drug development. Nonetheless, drug resistance is the major problem affecting the clinical efficacy of antiretroviral agents. Incomplete pharmacological pressure represents the logical cause and not the consequence of different mutation pathways in RT associated with approved inhibitors resistance. In this review we have analyzed RT Protein Data Bank (PDB) models using our innovative computational approach “GRID Based Pharmacophore Model” (GBPM). This method was applied to clinically relevant RT conserved residues found in a large cohort of HAART treated patients. The PDB entries have been selected among the unbound and the complexed models with DNA and/or inhibitors. Such an approach has revealed itself useful to highlight the mutation effects in the drug-RT recognition as well as in the heterodimer stabilization of the enzyme. Most of the clinical and biochemical evidences already reported in the literature have been rationalized at molecular level via the GBPM computational approach. A definite future application of this method will be the identification of conserved regions of critical macromolecules, such as the HIV-1 RT, to be targeted for the development of innovative therapeutic agents

    Structure-based virtual screening of novel natural alkaloid derivatives as potential binders of h-telo and c-myc DNA G-quadruplex conformations

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    Several ligands can bind to the non-canonical G-quadruplex DNA structures thereby stabilizing them. These molecules can act as effective anticancer agents by stabilizing the telomeric regions of DNA or by regulating oncogene expression. In order to better interact with the quartets of G-quadruplex structures, G-binders are generally characterized by a large aromatic core involved in pi-pi stacking. Some natural flexible cyclic molecules from Traditional Chinese Medicine have shown high binding affinity with G-quadruplex, such as berbamine and many other alkaloids. Using the structural information available on G-quadruplex structures, we performed a high throughput in silico screening of commercially available alkaloid derivative databases by means of a structure-based approach based on docking and molecular dynamics simulations against the human telomeric sequence d[AG(3)(T(2)AG(3))(3)] and the c-myc promoter structure. We identified 69 best hits reporting an improved theoretical binding affinity with respect to the active set. Among them, a berberine derivative, already known to remarkably inhibit telomerase activity, was related to a better theoretical affinity versus c-myc

    Multi-Targeting Bioactive Compounds Extracted from Essential Oils as Kinase Inhibitors

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    Essential oils (EOs) are popular in aromatherapy, a branch of alternative medicine that claims their curative effects. Moreover, several studies reported EOs as potential anti-cancer agents by inducing apoptosis in different cancer cell models. In this study, we have considered EOs as a potential resource of new kinase inhibitors with a polypharmacological profile. On the other hand, computational methods offer the possibility to predict the theoretical activity profile of ligands, discovering dangerous off-targets and/or synergistic effects due to the potential multi-target action. With this aim, we performed a Structure-Based Virtual Screening (SBVS) against X-ray models of several protein kinases selected from the Protein Data Bank (PDB) by using a chemoinformatics database of EOs. By evaluating theoretical binding affinity, 13 molecules were detected among EOs as new potential kinase inhibitors with a multi-target profile. The two compounds with higher percentages in the EOs were studied more in depth by means Induced Fit Docking (IFD) protocol, in order to better predict their binding modes taking into account also structural changes in the receptor. Finally, given its good binding affinity towards five different kinases, cinnamyl cinnamate was biologically tested on different cell lines with the aim to verify the antiproliferative activity. Thus, this work represents a starting point for the optimization of the most promising EOs structure as kinase inhibitors with multi-target feature

    Effect of the human immunodeficiency virus type 1 reverse transcriptase polymorphism Leu-214 on replication capacity and drug susceptibility

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    A negative association between polymorphism Leu-214 and type-1 thymidine analogue mutations (TAM1) and a positive association with a clinically favorable virological response to thymidine analogue-based combination antiretroviral therapy have been described. In this study, the impact of Leu-214 on replication capacity and resistance to zidovudine (ZDV) of viruses containing TAM1 or TAM2 was determined. Leu-214 decreased the growth rate of viruses bearing Tyr-215, as well as their resistance to ZDV. This observation was confirmed by structural and molecular modeling data, suggesting a regulatory role for Leu-214 in the emergence and phenotypic resistance of TAM1
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