Science

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Now showing 1 - 6 of 6
  • (2009) Gao, Steven; Lees, Justin; Wong, Jennifer; Croll, Tristan; George, Peter; Cooper-White, Justin; Tuch, Bernard
    Journal Article
    Human embryonic stem cells (hESCs) have previously been cultured on three dimensional (3D) biodegradable polymer scaffolds. Although complex structures were formed from the hESCs, very little is known about the mechanism of adhesion of these cells to the surfaces of the scaffolds. In this study, we achieved the efficient adhesion of pluripotent hESCs to 3D poly(lactic-co-glycolic acid) (PLGA) scaffolds based on our data from a novel two dimensional (2D) model that imitates the surface properties of the scaffolds. In the 2D model, single cell preparations of pluripotent hESCs adhered efficiently and predominantly to PLGA surfaces coated with laminin in comparison to collagen I, collagen IV, or fibronectin-coated surfaces. Flow cytometry analysis revealed that almost all of the pluripotent single cells expressed the integrin 6, with a small percentage also expressing 3ß1, which facilitates adhesion to laminin. This data was then translated into the 3D environment, with the efficient binding of single pluripotent hESCs to PLGA scaffolds coated with laminin. The utility of this system was shown by the directed differentiation of single hESCs seeded within laminin-coated scaffolds toward the endoderm lineage.

  • (2009) Grulich, Andrew; Templeton, David; Jin, Feng Yi; Prestage, Garrett; Donovan, Basil; Imrie, John; Kippax, Susan; Cunningham, Philip; Kaldor, John; Mindel, Adrian; Cunningham, Anthony
    Journal Article
    BACKGROUND: Circumcision status was examined as an independent risk factor for sexually transmissible infections (STIs) in the Health in Men cohort of homosexual men in Sydney. METHODS: From 2001 through 2004, 1427 initially human immunodeficiency virus (HIV)-negative men were enrolled and followed up until mid-2007. All participants were offered annual STI testing. The history of STIs was collected at baseline, and information on sexual risk behaviors was collected every 6 months. At annual face-to-face visits, participants reported STI diagnoses received during the previous year. RESULTS: Circumcision was not associated with prevalent or incident herpes simplex virus 1, herpes simplex virus 2, or self-reported genital warts. There was also no independent association of circumcision with incident urethral gonorrhea or chlamydia. Being circumcised was associated with a significantly reduced risk of incident (hazard ratio, 0.35 [95% confidence interval, 0.15-0.84]) but not prevalent (odds ratio, 0.71 [95% confidence interval, 0.35-1.44]) syphilis. The association was somewhat stronger among men who reported predominantly insertive unprotected anal intercourse (hazard ratio, 0.10 [95% confidence interval, 0.01-0.82]). CONCLUSIONS: These are the first prospective data obtained from homosexual men to assess circumcision status as a risk factor for STIs. Circumcised men were at reduced risk of incident syphilis but no other prevalent or incident STIs. Circumcision is unlikely to have a substantial public health impact in reducing acquisition of most STIs in homosexual men.

  • (2009) Fiatarone-Singh, Maria; Singh, N; Hansen, R; Finnegan, T; Allen, Barry; Diamond, Terrence; Diwan, Ashish; Lloyd, Bradley; Williamson, Dawn; Smith, Elizabeth; Grady, J; Stavrinos, T; Thompson, M
    Journal Article
    Background. Age-related hip fractures are associated with poor functional outcomes, resulting in substantial personal and societal burden. There is a need to better identify reversible etiologic predictors of suboptimal functional recovery in this group. Methods. The Sarcopenia and Hip Fracture (SHIP) study was a 5-year prospective cohort study following community-dwelling older persons admitted to three Sydney hospitals for hip fracture. Information was collected at baseline, and 4 and 12 months, including health status, quality of life, nutritional status, body composition, muscle strength, range of motion, gait velocity, balance, walking endurance, disability, cognition, depression, fear of falling, self-efficacy, social support, physical activity level, vision, and fall-related data, with residential status, disability, and mortality reassessed at 5 years. Results. 193 participants enrolled (81 ± 8 years, 72% women). High levels of activities of daily living, disability and sedentariness were present prior to fracture. At admission, the cohort had high levels of chronic disease; 38% were depressed, 38% were cognitively impaired, and 26% had heart disease. Seventy-one percent of participants were sarcopenic, 58% undernourished, and 55% vitamin D deficient. Mobility, strength, and vision were severely impaired. There was little evidence that these comorbidities were either recognized or treated during hospitalization. Disability, sedentariness, malnutrition, and walking endurance predicted acute hospitalization length of stay. Conclusions. The complex comorbidity, pre-existing functional impairment, and sedentary behavior in patients with hip fracture suggest the need for thorough screening and targeting of potentially reversible impairments. Rehabilitation outcomes are likely to be highly dependent on amelioration of these highly prevalent accompaniments to hip fracture.

  • (2009) LeBard, Rebecca; Thompson, Rachel; Micolich, Adam; Quinnell, Rosanne
    Conference Paper
    Biglan (1973) divides academic disciplines into hard and soft, with subcategories of pure and applied, and life and non-life. We have conducted a study spanning these sub-categories in the ‘hard’ discipline of science, focused on looking for common factors that impede student learning. A survey of second year undergraduate courses in Thermal Physics, Quality of Medical Practice and Molecular Biology was conducted. A common theme identified was the students’ struggle with numeracy skills. Our survey results suggest this has less to do with a real weakness in mathematics, the students in these courses generally have strong mathematical backgrounds, and is more related to two factors – lack of relevance, which reduces their willingness to engage with the challenging aspects of the mathematics, and difficulties in transforming their ‘pure’ mathematical training into a form that allows them to use it effectively in their chosen courses.

  • (2009) Quinnell, Rosanne; Russell, Carol; Thompson, Rachel; Nancy, Marshall; Cowley, Jill
    Conference Paper
    A raft of models and definitions of SoTL exist and the best appear to transcend disciplinary contexts, and are sufficiently robust for academics to measure scholarly practices. Critical engagement with the scholarly literature is necessary for academics to gain a realistic view of where their work practices are situated within the scholarly domain. Because academic staff are disciplinary experts they are best placed to comment on whether the models of scholarship describe the scholarship of learning and teaching within the context of their own disciplines as well as within the confines of the Australian higher education sector. This paper pushes the existing debates on reconciling what evidence of scholarship in the disciplines actually is and what is considered valid, and in doing so uncovers why the process of reconciliation, between current practice and supporting evidence, remains elusive. Higher education academics need to identify and reconcile tacit disciplinary knowledge with their SoTL approach in order to unpack the complexity and value of their practices. Enabling academic staff to annotate their activities, roles and accomplishments and then map these items onto the various models of scholarship will enrich the status of scholarship of teaching and learning within the higher education sector.

  • (2009) Quinnell, Rosanne; Thompson, Rachel; Land, R; Meyer, JHF; Baillie, C
    Book Chapter
    This is chapter 17 of the book: Threshold Concepts and Transformational Learning