269 research outputs found

    Transformative education: culture-based pedagogies in urban, predominately Black American elementary schools

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    Problems facing Black American students in underfunded urban schools continue to threaten the viability of public education for this and other nontraditional student populations. These problems, along with the growing diversity of American children, prompt a reexamination of extant data on the practices associated with the effective teaching of Black American students. This meta-ethnography illuminates the findings of four case studies and then explores their implications for teaching. By looking through the lens of critical race theory, this study explores how effective teachers use culture-based instruction to better engage Black American students in the process of learning. Findings identify core teacher behaviors and instructional practices that support the successful teaching of urban Black American primary school children

    Stem Of The Arts: Incorporating Art Into Stem Fields

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    Sherri MartinieThroughout this research project, we explored how arts can be intertwined into the STEM field. Collectively, we planned, created and facilitated three activities that centered around different styles of art-specifically the areas of art, music and dance. Our goal was to express to students how art and STEM can be used together and prove STEM is needed in areas of art. We conducted this research at Woodrow Wilson Elementary and various STEAM nights throughout the USD 383 school district. At the beginning of each activity, students were given a survey asking, “What is STEM?” and “Could art be a part of Stem?” Students recorded their responses before beginning the activities. The first activity we facilitated focused on incorporating art into STEM. Fourth-grade students were given the opportunity to let their imaginations run wild by using static electricity to make their creations come to life. Students were given a variety of materials (cardboard, tissue paper, markers and glue) to construct a “movable” project. After they finished, they were given balloons to explore how static electricity could make their art alive. The second activity we implemented centered around integrating music into STEM. Fifth-grade students used iPads to explore the Tynker App and create choreographed dances. Students activated their prior knowledge of coding to design a character and code it to create a dance. The third activity we conducted focused on incorporating music into STEM. Sixth-grade students were given a Makey Makey and asked to create a song utilizing their understanding of circuits. Using alligator clips, students were able to connect to a conductive material (bananas) and control their circuit boards. They were able to investigate how closed circuits worked in order to appropriately make the Makey Makey work. After each activity, we gave the students another short survey with the following two questions, “Could art be a part of STEM?” and “If so, how?” Before the activities, 80% of students stated that they could see art being a part of STEM. After facilitating each activity 90% of the students said they thought art was a part of STEM

    A new model for the pathophysiology of Alzheimer's disease: Aluminium toxicity is exacerbated by hydrogen peroxide and attenuated by an amyloid protein fragment and melatonin

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    Objectives. Although Alzheimer's disease (AD) is the leading cause of dementia in developed countries, there is an as yet unexplained lower prevalence of the disease in parts of Africa. AD is characterised by a catastrophic loss of neurons; free radicals (oxidative toxins) have been implicated in the destruction of the cells through the process of lipid peroxidative damage of cell membranes. Previously aluminium (Al) and a fragment of beta amyloid (Aβ 25 - 35) were shown to exacerbate tree-radical damage, while melatonin reduced this effect. The aim of the present study was: (i) to investigate the conditions detennining the toxicity of Al and Aβ 25 - 35; and (ii) to assess whether melatonin could attenuate the damage done by both aluminium and the amyloid fragment, thus suggesting a pathway for the aetiology of AD.Design. An in vitro model system was used in which free radicals were generated, causing lipid peroxidation of platelet membranes, thus simulating the disease process found in the brain.Results. 1. Al and Aβ 25 - 35 caused lipid peroxidation in the presence of the iron (II) ion (Fe2+, Al being more toxic than Aβ 25 - 35. 2. Aβ 25 - 35 attenuated the lipid peroxidation promoted by Al. 3. Hydrogen peroxide (H2O2 greatly exacerbated the toxicity of Al and Aβ 25 - 35. 4. Melatonin prevented lipid peroxidation by Al and Aβ 25 - 35 in the absence of H2O2, but only reduced the process when H2O2 was present.Conclusions. In the light of the results obtained from the present study, the following hypotheses are formulated. 1. In AD, excessive quantities of Al are taken up into the  brain, where the Al exacerbates iron-induced lipid peroxidatian in the Iysosomes. 2. In response, the normal synthetic pathway of amyloid protein is altered to produce Aβ fragments which attenuate the toxicity of Al. In the process of sequestering the Al and iron, immature plaques are formed in the brain. 3. Microglia are activated, in an attempt to destroy the plaques by secreting reactive oxygen species such as H2O2. At this point in the disease process, lipid peroxidation causes a catastrophic loss of brain cells. 4. Melatonin, together with other free radical scavengers in the brain, reduces the free-radical damage caused by Al and Aβ, except in the latter stages of the disease process. Since melatonin is produced by the pineal gland only in the dark, the excess of electric light in developed countries may help explain why AD is more prevalent in these countries than in rural Africa

    Highly Conserved Homotrimer Cavity Formed by the SARS-CoV-2 Spike Glycoprotein: A Novel Binding Site

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    An important stage in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) life cycle is the binding of the spike (S) protein to the angiotensin converting enzyme-2 (ACE2) host cell receptor. Therefore, to explore conserved features in spike protein dynamics and to identify potentially novel regions for drugging, we measured spike protein variability derived from 791 viral genomes and studied its properties by molecular dynamics (MD) simulation. The findings indicated that S2 subunit (heptad-repeat 1 (HR1), central helix (CH), and connector domain (CD) domains) showed low variability, low fluctuations in MD, and displayed a trimer cavity. By contrast, the receptor binding domain (RBD) domain, which is typically targeted in drug discovery programs, exhibits more sequence variability and flexibility. Interpretations from MD simulations suggest that the monomer form of spike protein is in constant motion showing transitions between an “up” and “down” state. In addition, the trimer cavity may function as a “bouncing spring” that may facilitate the homotrimer spike protein interactions with the ACE2 receptor. The feasibility of the trimer cavity as a potential drug target was examined by structure based virtual screening. Several hits were identified that have already been validated or suggested to inhibit the SARS-CoV-2 virus in published cell models. In particular, the data suggest an action mechanism for molecules including Chitosan and macrolides such as the mTOR (mammalian target of Rapamycin) pathway inhibitor Rapamycin. These findings identify a novel small molecule binding-site formed by the spike protein oligomer, that might assist in future drug discovery programs aimed at targeting the coronavirus (CoV) family of viruses

    Functional and gene network analyses of transcriptional signatures characterizing pre-weaned bovine mammary parenchyma or fat pad uncovered novel inter-tissue signaling networks during development

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    <p>Abstract</p> <p>Background</p> <p>The neonatal bovine mammary fat pad (<b>MFP</b>) surrounding the mammary parenchyma (<b>PAR</b>) is thought to exert proliferative effects on the PAR through secretion of local modulators of growth induced by systemic hormones. We used bioinformatics to characterize transcriptomics differences between PAR and MFP from ~65 d old Holstein heifers. Data were mined to uncover potential crosstalk through the analyses of signaling molecules preferentially expressed in one tissue relative to the other.</p> <p>Results</p> <p>Over 9,000 differentially expressed genes (<b>DEG</b>; False discovery rate ≤ 0.05) were found of which 1,478 had a ≥1.5-fold difference between PAR and MFP. Within the DEG highly-expressed in PAR vs. MFP (n = 736) we noted significant enrichment of functions related to cell cycle, structural organization, signaling, and DNA/RNA metabolism. Only actin cytoskeletal signaling was significant among canonical pathways. DEG more highly-expressed in MFP vs. PAR (n = 742) belong to lipid metabolism, signaling, cell movement, and immune-related functions. Canonical pathways associated with metabolism and signaling, particularly immune- and metabolism-related were significantly-enriched. Network analysis uncovered a central role of <it>MYC</it>, <it>TP53</it>, and <it>CTNNB1 </it>in controlling expression of DEG highly-expressed in PAR vs. MFP. Similar analysis suggested a central role for <it>PPARG</it>, <it>KLF2</it>, <it>EGR2</it>, and <it>EPAS1 </it>in regulating expression of more highly-expressed DEG in MFP vs. PAR. Gene network analyses revealed putative inter-tissue crosstalk between cytokines and growth factors preferentially expressed in one tissue (e.g., <it>ANGPTL1</it>, <it>SPP1</it>, <it>IL1B </it>in PAR vs. MFP; <it>ADIPOQ</it>, <it>IL13</it>, <it>FGF2</it>, <it>LEP </it>in MFP vs. PAR) with DEG preferentially expressed in the other tissue, particularly transcription factors or pathways (e.g., <it>MYC</it>, <it>TP53</it>, and actin cytoskeletal signaling in PAR vs. MFP; <it>PPARG </it>and LXR/RXR Signaling in MFP vs. PAR).</p> <p>Conclusions</p> <p>Functional analyses underscored a reciprocal influence in determining the biological features of MFP and PAR during neonatal development. This was exemplified by the potential effect that the signaling molecules (cytokines, growth factors) released preferentially (i.e., more highly-expressed) by PAR or MFP could have on molecular functions or signaling pathways enriched in the MFP or PAR. These bidirectional interactions might be required to coordinate mammary tissue development under normal circumstances or in response to nutrition.</p

    Changing epidemiology of meticillin-resistant Staphylococcus aureus in 42 hospitals in the Dutch-German border region, 2012 to 2016:results of the search-and-follow-policy

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    Introduction: Meticillin-resistant Staphylococcus aureus (MRSA) is a major cause of healthcare-associated infections. Aim: We describe MRSA colonisation/infection and bacteraemia rate trends in Dutch-German border region hospitals (NL-DE-BRH) in 2012-16. Methods: All 42 NL-DE BRH (8 NL-BRH, 34 DE-BRH) within the cross-border network EurSafety Health-net provided surveillance data (on average ca 620,000 annual hospital admissions, of these 68.0% in Germany). Guidelines defining risk for MRSA colonisation/infection were reviewed. MRSA-related parameters and healthcare utilisation indicators were derived. Medians over the study period were compared between NL- and DE-BRH. Results: Measures for MRSA cases were similar in both countries, however defining patients at risk for MRSA differed. The rate of nasopharyngeal MRSA screening swabs was 14 times higher in DE-BRH than in NL-BRH (42.3 vs 3.0/100 inpatients; p <0.0001). The MRSA incidence was over seven times higher in DE-BRH than in NL-BRH (1.04 vs 0.14/100 inpatients; p <0.0001). The nosocomial MRSA incidence-density was higher in DE-BRH than in NL-BRH (0.09 vs 0.03/1,000 patient days; p = 0.0002) and decreased significantly in DE-BRH (p = 0.0184) during the study. The rate of MRSA isolates from blood per 100,000 patient days was almost six times higher in DE-BRH than in NL-BRH (1.55 vs 0.26; p = 0.0041). The patients had longer hospital stays in DE-BRH than in NL-BRH (6.8 vs 4.9; p <0.0001). DE-BRH catchment area inhabitants appeared to be more frequently hospitalised than their Dutch counterparts. Conclusions: Ongoing IPC efforts allowed MRSA reduction in DE-BRH. Besides IPC, other local factors, including healthcare systems, could influence MRSA epidemiology

    Исследования гидравлических сопротивлений при движении в трубах золошлаковых тампонажно- закладочных суспензий

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    Експериментально досліджено залежність гідравлічного опору від швидкості руху та концентрації золошлакових суспензій при течії по трубах. Встановлена критична швидкість руху концентрованих гідросумішей.Dependence of hydraulic resistance is experimentally set from the rate of movement of ash-slag suspensions at a flow on pipes. The critical speed of motion of the concentrated slurries is set

    The Effect of Calcium Ions on Mechanosensation and Neuronal Activity in Proprioceptive Neurons

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    Proprioception of all animals is important in being able to have coordinated locomotion. Stretch activated ion channels (SACs) transduce the mechanical force into electrical signals in the proprioceptive sensory endings. The types of SACs vary among sensory neurons in animals as defined by pharmacological, physiological and molecular identification. The chordotonal organs within insects and crustaceans offer a unique ability to investigate proprioceptive function. The effects of the extracellular environment on neuronal activity, as well as the function of associated SACs are easily accessible and viable in minimal saline for ease in experimentation. The effect of extracellular [Ca2+] on membrane properties which affect voltage-sensitivity of ion channels, threshold of action potentials and SACs can be readily addressed in the chordotonal organ in crab limbs. It is of interest to understand how low extracellular [Ca2+] enhances neural activity considering the SACs in the sensory endings could possibly be Ca2+ channels and that all neural activity is blocked with Mn2+. It is suggested that axonal excitability might be affected independent from the SAC activity due to potential presence of calcium activated potassium channels (K(Ca)) and the ability of Ca2+ to block voltage gated Na+ channels in the axons. Separating the role of Ca2+ on the function of the SACs and the excitability of the axons in the nerves associated with chordotonal organs is addressed. These experiments may aid in understanding the mechanisms of neuronal hyperexcitability during hypocalcemia within mammals
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