351 research outputs found
Propulsion and airframe aerodynamic interactions of supersonic V/STOL configurations, phase 1
A wind tunnel model of a supersonic V/STOL fighter configuration has been tested to measure the aerodynamic interaction effects which can result from geometrically close-coupled propulsion system/airframe components. The approach was to configure the model to present two different test techniques. One was a coventional test technique composed of two test modes. In the Flow-Through mode, absolute configuration aerodynamics are measured, including inlet/airframe interactions. In the Jet-Effects mode, incremental nozzle/airframe interactions are measured. The other test technique is a propulsion simulator approach, where a subscale, externally powered engine is mounted in the model. This allows proper measurement of inlet/airframe and nozzle/airframe interactions simultaneously
Building Conceptual Understanding through Vocabulary Instruction
Instructional design is an integral part of a balanced approach to teaching vocabulary instruction. This article presents several instructional procedures using research-based vocabulary strategies and explains how to design and adapt those strategies in order to reach desired learning outcomes. Emphasis is placed on research-based principles that guide effective vocabulary instruction and on the importance of incorporating vocabulary instruction into all phases of the reading lesson framework--before, during, and after reading (Blair, Rupley, & Nichols 2007; Vacca, Vacca, & Mraz 2011). Vocabulary instruction should encourage students to make associations and accommodations to their experiences and provide them with varied opportunities to practice, apply, and discuss their word knowledge in meaningful contexts (Beck & McKeown, 2002; Rupley & Nichols, 2005). The ultimate goal of teaching vocabulary is for the students to expand, refine, and add to their existing conceptual knowledge and enhance their comprehension and understanding of what they read (Baumann, Font, Edwards, & Boland , 2005; Stahl & Fairbanks, 1986). This article seeks to provide educators with both a theoretical framework and practical classroom instructional suggestions for doing so
Improving Upper Extremity Motor Skills in Girls with Rett Syndrome Using Virtual Reality
Introduction: Rett Syndrome is a genetic disorder that limits a girl's ability to use her upper extremities for daily activities, such as dressing and playing. One possible intervention to improve upper extremity function in this population is virtual reality, which can be used to increase activity demands during therapy sessions.
Objectives: To determine the feasibility of using internet-based virtual reality intervention for Rett Syndrome (RTT-IVR), to decrease hand wringing/mouthing and increase hand and arm movements away from the midline by identifying attributes and limitations to the proposed intervention.
Materials and Methods: Using FAAST Software and Microsoft Kinect sensor, RTT-IVR was trialed with 6 girls with RTT. Upper extremity movements were used to play free Internet games as means of increasing repetitions and purposeful arm movements. Data regarding attributes and limitations of the RTT-IVR intervention were collected via observation and post-session parent interviews.
Results: Interviews and observation revealed successful game play when games were motivating, clearly established cause and effect, and matched level of cognitive ability of the participant. Limitations include technological glitches regarding Kinect sensor sensitivity and identifying appropriate games for each participant's interests and abilities.
Conclusion: Internet based virtual reality interventions for girls with RTT should be highly individualized to increase motivation and success of intervention
The Effects of Virtual Reality on the Upper Extremity Skills of Girls with Rett Syndrome: A Single Case Study
Introduction: Rett Syndrome (RTT) is a genetic disorder primarily seen in females that inhibits the use of a girl's hands in everyday activities. A girl with RTT spends the majority of her day engaged in stereotypical hand wringing/mouthing movements at midline of the body. The probable cause behind the neurological effects of RTT is a mutation in the gene that encodes for methyl-CpG protein 2 (MeCP2). The hand wringing/mouthing behaviors preclude a girl with RTT from using the upper extremities in purposeful tasks such as school work, play skills, and other activities of daily living.Objectives: To develop a virtual reality (VR)-based therapeutic intervention that 1) decreases upper extremity stereotypies (repetitive movements that serve no function) that interfere with purposeful arm and hand use and 2) promotes purposeful, goal-directed arm function; improve upper extremity motor skills in girls with RTT.Materials and Methods: Using FAAST Software and Microsoft Kinect sensor, one girl with RTT participated in a 12-week IVR intervention (1 hour/session, 3 sessions/week, 36 total hours). Pre- and post-assessments were administered to examine any changes in upper extremity function.Results: The VR intervention led to improvements in use of the upper extremities to complete self-care activities, an increased number of reaches completed in a 15-minute period, and decreased time engaged in stereotypical hand movements.Conclusion: Future work will add additional support to determine the effectiveness of virtual reality as an intervention for girls with RTT
Crystal Structure of Orthorhombic {bis-[(pyridin-2-yl)methyl](3,5,5,5-tetrachloropentyl)amine-κ\u3csup\u3e3\u3c/sup\u3e\u3cem\u3eN,N\u27,N\u27\u27\u3c/em\u3e}chloridocopper(II) Perchlorate
In the title compound, [CuCl(C17H19Cl4N3)]ClO4, the CuII ion adopts a distorted square-planar geometry defined by one chloride ligand and the three nitrogen atoms from the bis[(pyridin-2-yl)methyl](3,5,5,5-tetrachloropentyl)amine ligand. The perchlorate counter-ion is disordered over three sets of sites with refined occupancies 0.0634 (17), 0.221 (16) and 0.145 (7). In addition, the hetero-scorpionate arm of the bis[(pyridin-2-yl)methyl](3,5,5,5-tetrachloropentyl)amine ligand is disordered over two sets of sites with refined occupancies 0.839 (2) and 0.161 (2). In the crystal, weak Cu⋯Cl interactions between symmetry-related molecules create a dimerization with a chloride occupying the apical position of the square-pyramidal geometry typical of many copper(II) chloride hetero-scorpionate complexes
Novel insights into the cardio-protective effects of FGF21 in lean and obese rat hearts
Aims: Fibroblast growth factor 21 (FGF21) is a hepatic metabolic regulator with pleotropic actions. Its plasma concentrations are increased in obesity and diabetes; states associated with an increased incidence of cardiovascular disease. We therefore investigated the direct effect of FGF21 on cardio-protection in obese and lean hearts in response to ischemia.
Methods and Results: FGF21, FGF21-receptor 1 (FGFR1) and beta-Klotho (βKlotho) were expressed in rodent, human hearts and primary rat cardiomyocytes. Cardiac FGF21 was expressed and secreted (real time RT-PCR/western blot and ELISA) in an autocrine-paracrine manner, in response to obesity and hypoxia, involving FGFR1-βKlotho components. Cardiac-FGF21 expression and secretion were increased in response to global ischemia. In contrast βKlotho was reduced in obese hearts. In isolated adult rat cardiomyocytes, FGF21 activated PI3K/Akt (phosphatidylinositol 3-kinase/Akt), ERK1/2(extracellular signal-regulated kinase) and AMPK (AMP-activated protein kinase) pathways. In Langendorff perfused rat [adult male wild-type wistar] hearts, FGF21 administration induced significant cardio-protection and restoration of function following global ischemia. Inhibition of PI3K/Akt, AMPK, ERK1/2 and ROR-α (retinoic-acid receptor alpha) pathway led to significant decrease of FGF21 induced cardio-protection and restoration of cardiac function in response to global ischemia. More importantly, this cardio-protective response induced by FGF21 was reduced in obesity, although the cardiac expression profiles and circulating FGF21 levels were increased.
Conclusion: In an ex vivo Langendorff system, we show that FGF21 induced cardiac protection and restoration of cardiac function involving autocrine-paracrine pathways, with reduced effect in obesity. Collectively, our findings provide novel insights into FGF21-induced cardiac effects in obesity and ischemia
Heat treatment significantly increases the sharpness of silcrete stone tools
Humans were regularly heat-treating stone tool raw materials as early as 130,000 years ago. The late Middle Stone Age (MSA) and Late Stone Age (LSA) of South Africa's Western Cape region provides some of the earliest and most pervasive archaeological evidence for this behaviour. While archaeologists are beginning to understand the flaking implications of raw material heat treatment, its potential functional benefits remain unanswered. Using silcrete from the Western Cape region, we investigate the impact of heat treatment on stone tool cutting performance. We quantify the sharpness of silcrete in its natural, unheated form, before comparing it with silcrete heated in three different conditions. Results show that heat-treated silcrete can be significantly sharper than unheated alternatives, with cutting forces halving and energy requirements reducing by approximately two-thirds. The data suggest that silcrete may have been heat treated during the South African MSA and LSA to increase the sharpness and performance of stone cutting edges. This early example of material engineering has implications for understanding Stone Age populations’ technological capabilities, inventiveness and raw material choices. We predict that heat-treatment behaviours in other prehistoric and ethnographic contexts may also be linked to increases in edge sharpness and concerns about functional performance
MicroRNA-296 is enriched in cancer cells and downregulates p21WAF1 mRNA expression via interaction with its 3′ untranslated region
MicroRNAs (miRNAs) are a class of noncoding small RNAs that act as negative regulators of gene expression. To identify miRNAs that may regulate human cell immortalization and carcinogenesis, we performed comparative miRNA array profiling of human normal and SV40-T antigen immortalized cells. We found that miR-296 was upregulated in immortalized cells that also had activation of telomerase. By an independent experiment on genomic analysis of cancer cells we found that chromosome region (20q13.32), where miR-296 is located, was amplified in 28/36 cell lines, and most of these showed enriched miR-296 expression. Overexpression of miR-296 in human cancer cells, with and without telomerase activity, had no effect on their telomerase function. Instead, it suppressed p53 function that is frequently downregulated during human cell immortalization and carcinogenesis. By monitoring the activity of a luciferase reporter connected to p53 and p21WAF1 (p21) untranslated regions (UTRs), we demonstrate that miR-296 interacts with the p21-3′UTR, and the Hu binding site of p21-3′UTR was identified as a potential miR-296 target site. We demonstrate for the first time that miR-296 is frequently upregulated during immortalization of human cells and contributes to carcinogenesis by downregulation of p53-p21WAF1 pathway
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