663 research outputs found

    Development of a Solar House Design Methodology and its Implementation into a Design Tool

    Get PDF
    Buildings consume on the order of 40% of energy in Canada and the developed world. It has been demonstrated that buildings can supplement a large fraction (or all) of their energy use by collecting solar energy. In order to design such buildings, an integrated design process should be used, in which they are designed as a system rather than as discrete subsystems. Otherwise, opportunities for cost-savings are missed. Energy-conserving and energy-collecting upgrades should be considered early in the design process when costs can be minimized and disruptions to construction avoided. The optimal solution to solar buildings typically balances energy efficiency measures and energy generation, since they both have diminishing returns. Houses that offset their energy use with solar energy generation cannot justify the formality of the use of multiple designers because of the associated costs and potential cost savings. Therefore there is a need for a design methodology for solar houses and a corresponding design tool that can be used to support the process. It should enable the energy modeling of all relevant subsystems and provide guidance towards the near-optimal design space. The tool โ€“ called Ecos - will focus on early stage design and should enable the design of a near-optimal house within about an hour. This thesis covers both a solar house design tool and the prerequisite work. There are four major interconnected parts of the work, including; a detailed energy model of a solar house; innovative ways of graphically representing performance data, a detailed design methodology, and finally the design tool itself. Ecos provides two main types of graphical feedback: 1) visualization of the design space and 2) visualization of key performance metrics during solar design days. One of the methods to support efficient design is to provide quasi real-time feedback to the user. In order to provide real-time feedback to support an efficient design process, a combination of shortened simulation periods and regression models are used. The final part of this thesis discusses recently built solar house and applies the current model in a re-design study to examine potential further reductions in energy use

    The role of polycyclic frameworks in modulating P2X<inf>7</inf> receptor function

    Full text link
    Herein we describe our recent attempts to target the P2X7 receptor for potential treatment of neurological disorders. This work focusses on different polycycles including carborane, adamantane or cubane, joined by either a cyanoguanidine or an amide linker to phenyl or isoquinoline moieties. We have demonstrated the superiority of the adamantyl moiety over other polycycles in terms of synthetic accessibility and biological (cellular) activity. We have also shown that an amide or cyanoguanidine linker can greatly alter the biological activity of compounds. This SAR study provides important insights into the types of functionality required to target the P2X7 receptor

    All Optical Implementation of Multi-Spin Entanglement in a Semiconductor Quantum Well

    Full text link
    We use ultrafast optical pulses and coherent techniques to create spin entangled states of non-interacting electrons bound to donors (at least three) and at least two Mn2+ ions in a CdTe quantum well. Our method, relying on the exchange interaction between localized excitons and paramagnetic impurities, can in principle be applied to entangle a large number of spins.Comment: 17 pages, 3 figure

    Mycobacterial infections in a large Virginia hospital, 2001-2009

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>In areas where both tuberculosis (TB) and nontuberculous mycobacteria (NTM) are prevalent, descriptive studies of the clinical features of individual mycobacteria are needed to inform clinical triage.</p> <p>Methods</p> <p>We queried the University of Virginia Clinical Data Repository for all mycobacterial infections from 2001-2009.</p> <p>Results</p> <p>Of 494 mycobacterial infections in 467 patients there were 22 species. Patients with pulmonary Tb were more likely to be reported as immigrants (p < 0.001) and less likely to have a predisposing risk factor for NTM (pre-existing lung disease or host predisposition; p = 0.002). Review of chest CT scans revealed that TB infection was more likely to exhibit cavities and pleural effusion than NTM infection (p < 0.05). Among NTM infections <it>M. kansasii</it>, <it>M. xenopi</it>, and <it>M. fortuitum </it>were more likely than MAC to have cavities. There were at least 83 patients that met criteria for NTM lung disease and these were caused by 9 species. <it>M. abscessus </it>infection was associated with cystic fibrosis and <it>M. xenopi </it>infection was associated with male gender.</p> <p>Conclusions</p> <p>In our center mycobacterial infections were common and of diverse species. Immigrant status, cavities, and effusion were associated with TB vs. NTM.</p

    Managing childhood fever and pain โ€“ the comfort loop

    Get PDF
    Parents can transmit their anxiety to their child, and just as children can pick up on parental anxiety, they can also respond to a parent's ability to stay calm in stressful situations. Therefore, when treating children, it is important to address parental anxiety and to improve their understanding of their child's ailment. Parental understanding and management of both pain and fever โ€“ common occurrences in childhood โ€“ is of utmost importance, not just in terms of children's health and welfare, but also in terms of reducing the economic burden of unnecessary visits to paediatric emergency departments. Allaying parental anxiety reduces the child's anxiety and creates a positive feedback loop, which ultimately affects both the child and parent

    Adjuvant radiation therapy in metastatic lymph nodes from melanoma

    Get PDF
    <p>Abstract</p> <p>Purpose</p> <p>To analyze the outcome after adjuvant radiation therapy with standard fractionation regimen in metastatic lymph nodes (LN) from cutaneous melanoma.</p> <p>Patients and methods</p> <p>86 successive patients (57 men) were treated for locally advanced melanoma in our institution. 60 patients (69%) underwent LN dissection followed by radiation therapy (RT), while 26 patients (31%) had no radiotherapy.</p> <p>Results</p> <p>The median number of resected LN was 12 (1 to 36) with 2 metastases (1 to 28). Median survival after the first relapse was 31.8 months. Extracapsular extension was a significant prognostic factor for regional control (p = 0.019). Median total dose was 50 Gy (30 to 70 Gy). A standard fractionation regimen was used (2 Gy/fraction). Median number of fractions was 25 (10 to 44 fractions). Patients were treated with five fractions/week. Patients with extracapsular extension treated with surgery followed by RT (total dose โ‰ฅ50 Gy) had a better regional control than patients treated by surgery followed by RT with a total dose <50 Gy (80% vs. 35% at 5-year follow-up; p = 0.004).</p> <p>Conclusion</p> <p>Adjuvant radiotherapy was able to increase regional control in targeted sub-population (LN with extracapsular extension).</p

    Medical students' and facilitators' experiences of an Early Professional Contact course: Active and motivated students, strained facilitators

    Get PDF
    Background: Today, medical students are introduced to patient contact, communication skills, and clinical examination in the preclinical years of the curriculum with the purpose of gaining clinical experience. These courses are often evaluated from the student perspective. Reports with an additional emphasis on the facilitator perspective are scarce. According to constructive alignment, an influential concept from research in higher education, the learning climate between students and teachers is also of great importance. In this paper, we approach the learning climate by studying both students' and facilitators' course experiences.\ud \ud In 2001, a new "Early Professional Contact" longitudinal strand through term 1โ€“4, was introduced at the Sahlgrenska Academy, University of Gothenburg, Sweden. General practitioners and hospital specialists were facilitators.\ud \ud The aim of this study was to assess and analyse students' and clinical facilitators' experiences of the Early Professional Contact course and to illuminate facilitators' working conditions.\ud \ud Methods: Inspired by a Swedish adaptation of the Course Experience Questionnaire, an Early Professional Contact Questionnaire was constructed. In 2003, on the completion of the first longitudinal strand, a student and facilitator version was distributed to 86 students and 21 facilitators. In the analysis, both Chi-square and the Mann-Whitney tests were used.\ud \ud Results: Sixty students (70%) and 15 facilitators (71%) completed the questionnaire. Both students and facilitators were satisfied with the course. Students reported gaining [inspiration] for their future work as doctors along with increased confidence in meeting patients. They also reported increased motivation for biomedical studies. Differences in attitudes between facilitators and students were found. Facilitators experienced a greater workload, less reasonable demands and less support, than students.\ud \ud Conclusion: In this project, a new Early Professional Contact course was analysed from both student and facilitator perspectives. The students experienced the course as providing them with a valuable introduction to the physician's professional role in clinical practice. In contrast, course facilitators often experienced a heavy workload and lack of support, despite thorough preparatory education. A possible conflict between the clinical facilitator's task as educator and member of the workplace is suggested. More research is needed on how doctors combine their professional tasks with work as facilitators

    Expression of RHOGTPase regulators in human myometrium

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>RHOGTPases play a significant role in modulating myometrial contractility in uterine smooth muscle. They are regulated by at least three families of proteins, RHO guanine nucleotide exchange factors (RHOGEFs), RHOGTPase-activating proteins (RHOGAPs) and RHO guanine nucleotide inhibitors (RHOGDIs). RHOGEFs activate RHOGTPases from the inactive GDP-bound to the active GTP-bound form. RHOGAPs deactivate RHOGTPases by accelerating the intrinsic GTPase activity of the RHOGTPases, converting them from the active to the inactive form. RHOGDIs bind to GDP-bound RHOGTPases and sequester them in the cytosol, thereby inhibiting their activity. Ezrin-Radixin-Moesin (ERM) proteins regulate the cortical actin cytoskeleton, and an ERM protein, moesin (MSN), is activated by and can also activate RHOGTPases.</p> <p>Methods</p> <p>We therefore investigated the expression of various RHOGEFs, RHOGAPs, a RHOGDI and MSN in human myometrium, by semi-quantitative reverse transcription PCR, real-time fluorescence RT-PCR, western blotting and immunofluorescence microscopy. Expression of these molecules was also examined in myometrial smooth muscle cells.</p> <p>Results</p> <p>ARHGEF1, ARHGEF11, ARHGEF12, ARHGAP5, ARHGAP24, ARHGDIA and MSN mRNA and protein expression was confirmed in human myometrium at term pregnancy, at labour and in the non-pregnant state. Furthermore, their expression was detected in myometrial smooth muscle cells. It was determined that ARHGAP24 mRNA expression significantly increased at labour in comparison to the non-labour state.</p> <p>Conclusion</p> <p>This study demonstrated for the first time the expression of the RHOGTPase regulators ARHGEF1, ARHGEF11, ARHGEF12, ARHGAP5, ARHGAP24, ARHGDIA and MSN in human myometrium, at term pregnancy, at labour, in the non-pregnant state and also in myometrial smooth muscle cells. ARHGAP24 mRNA expression significantly increased at labour in comparison to the non-labouring state. Further investigation of these molecules may enable us to further our knowledge of RHOGTPase regulation in human myometrium during pregnancy and labour.</p

    Rgnef (p190RhoGEF) Knockout Inhibits RhoA Activity, Focal Adhesion Establishment, and Cell Motility Downstream of Integrins

    Get PDF
    Cell migration is a highly regulated process that involves the formation and turnover of cell-matrix contact sites termed focal adhesions. Rho-family GTPases are molecular switches that regulate actin and focal adhesion dynamics in cells. Guanine nucleotide exchange factors (GEFs) activate Rho-family GTPases. Rgnef (p190RhoGEF) is a ubiquitous 190 kDa GEF implicated in the control of colon carcinoma and fibroblast cell motility.Rgnef exon 24 floxed mice (Rgnef(flox)) were created and crossed with cytomegalovirus (CMV)-driven Cre recombinase transgenic mice to inactivate Rgnef expression in all tissues during early development. Heterozygous Rgnef(WT/flox) (Cre+) crosses yielded normal Mendelian ratios at embryonic day 13.5, but Rgnef(flox/flox) (Cre+) mice numbers at 3 weeks of age were significantly less than expected. Rgnef(flox/flox) (Cre+) (Rgnef-/-) embryos and primary mouse embryo fibroblasts (MEFs) were isolated and verified to lack Rgnef protein expression. When compared to wildtype (WT) littermate MEFs, loss of Rgnef significantly inhibited haptotaxis migration, wound closure motility, focal adhesion number, and RhoA GTPase activation after fibronectin-integrin stimulation. In WT MEFs, Rgnef activation occurs within 60 minutes upon fibronectin plating of cells associated with RhoA activation. Rgnef-/- MEF phenotypes were rescued by epitope-tagged Rgnef re-expression.Rgnef-/- MEF phenotypes were due to Rgnef loss and support an essential role for Rgnef in RhoA regulation downstream of integrins in control of cell migration

    A transcription factor contributes to pathogenesis and virulence in streptococcus pneumoniae

    Get PDF
    To date, the role of transcription factors (TFs) in the progression of disease for many pathogens is yet to be studied in detail. This is probably due to transient, and generally low expression levels of TFs, which are the central components controlling the expression of many genes during the course of infection. However, a small change in the expression or specificity of a TF can radically alter gene expression. In this study, we combined a number of quality-based selection strategies including structural prediction of modulated genes, gene ontology and network analysis, to predict the regulatory mechanisms underlying pathogenesis of Streptococcus pneumoniae (the pneumococcus). We have identified two TFs (SP_0676 and SP_0927 [SmrC]) that might control tissue-specific gene expression during pneumococcal translocation from the nasopharynx to lungs, to blood and then to brain of mice. Targeted mutagenesis and mouse models of infection confirmed the role of SP_0927 in pathogenesis and virulence, and suggests that SP_0676 might be essential to pneumococcal viability. These findings provide fundamental new insights into virulence gene expression and regulation during pathogenesis.Layla K. Mahdi, Esmaeil Ebrahimie, David L. Adelson, James C. Paton, Abiodun D. Ogunniy
    • โ€ฆ
    corecore