284 research outputs found

    Neuronal Agrin Promotes Proliferation of Primary Human Myoblasts in an Age-Dependent Manner

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    Neuronal agrin, a heparan sulphate proteoglycan secreted by the -motor neurons, promotes the formation and maintenance of the neuromuscular junction by binding to Lrp4 and activating muscle-specific kinase (MuSK). Neuronal agrin also promotes myogenesis by enhancing differentiation and maturation of myotubes, but its effect on proliferating human myoblasts, which are often considered to be unresponsive to agrin, remains unclear. Using primary human myoblasts, we determined that neuronal agrin induced transient dephosphorylation of ERK1/2, while c-Abl, STAT3, and focal adhesion kinase were unresponsive. Gene silencing of Lrp4 and MuSK markedly reduced the BrdU incorporation, suggesting the functional importance of the Lrp4/MuSK complex for myoblast proliferation. Acute and chronic treatments with neuronal agrin increased the proliferation of human myoblasts in old donors, but they did not affect the proliferation of myoblasts in young donors. The C-terminal fragment of agrin which lacks the Lrp4-binding site and cannot activate MuSK had a similar age-dependent effect, indicating that the age-dependent signalling pathways activated by neuronal agrin involve the Lrp4/MuSK receptor complex as well as an Lrp4/MuSK-independent pathway which remained unknown. Collectively, our results highlight an age-dependent role for neuronal agrin in promoting the proliferation of human myoblasts

    Climbing Robot for Steel Bridge Inspection: Design Challenges

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    Inspection of bridges often requires high risk operations such as working at heights, in confined spaces, in hazardous environments; or sites inaccessible by humans. There is significant motivation for robotic solutions which can carry out these inspection tasks. When inspection robots are deployed in real world inspection scenarios, it is inevitable that unforeseen challenges will be encountered. Since 2011, the New South Wales Roads & Maritime Services and the Centre of Excellence for Autonomous Systems at the University of Technology, Sydney, have been working together to develop an innovative climbing robot to inspect high risk locations on the Sydney Harbour Bridge. Many engineering challenges have been faced throughout the development of several prototype climbing robots, and through field trials in the archways of the Sydney Harbour Bridge. This paper will highlight some of the key challenges faced in designing a climbing robot for inspection, and then present an inchworm inspired robot which addresses many of these challenges

    Quantifying the contribution of material and junction resistances in nano-networks

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    Networks of nanowires and nanosheets are important for many applications in printed electronics. However, the network conductivity and mobility are usually limited by the inter-particle junction resistance, a property that is challenging to minimise because it is difficult to measure. Here, we develop a simple model for conduction in networks of 1D or 2D nanomaterials, which allows us to extract junction and nanoparticle resistances from particle-size-dependent D.C. resistivity data of conducting and semiconducting materials. We find junction resistances in porous networks to scale with nanoparticle resistivity and vary from 5 Ohm for silver nanosheets to 25 GOhm for WS2 nanosheets. Moreover, our model allows junction and nanoparticle resistances to be extracted from A.C. impedance spectra of semiconducting networks. Impedance data links the high mobility (~7 cm2/Vs) of aligned networks of electrochemically exfoliated MoS2 nanosheets to low junction resistances of ~670 kOhm. Temperature-dependent impedance measurements allow us to quantitatively differentiate intra-nanosheet phonon-limited band-like transport from inter-nanosheet hopping for the first time.Comment: 5 figure

    Fertility trends in Serbia during the 1990s

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    The 1990s represent an exceptionally complex period for the population of Serbia. In addition to the impact of long-term factors, various tumultuous events affected its demographic development, such as breaking apart of former Yugoslavia, armed conflicts in the neighboring countries, sanctions imposed by the international community, social changes (transition transformation or regression), deep economic crisis, collapse of social stratification political problems, institutional crisis, and NATO military intervention. Maladjustment to the changed system of values and norms, lower level of personal attainment, feeling of insecurity, and living under permanent stress are the main features of life at an individual psychological level. Deprivation or living at the subsistence level are the main elements of the economic cost sustained by the majority of the population. How have these changes affected an individual's decision to have children? The analysis of futility indicators points to an obvious decline in the number of births across low fertility regions of Serbia. Also, the analysis has raised the question why the decline in population fertility in the low fertility regions was not even higher, bearing in mind the experiences undergone by the countries with economy in transition as well as the depth of the crisis in society. In that sense several factors come to mind. The most important are the universality of marriage socio-psychological investigations confirmed domination of the traditional character or mentality in Serbia during the 1990s, and the government’s approach to the issue of fertility improved during this time. Besides demographic needs were carefully taken into account in all amendments to the old and formulation of the new measures in the area of social policy. Mention should be made of measures ensuring employment rights of women and their entitlement to maternity leave, maternity pay, and provision of institutionalized care for the children. On the other hand under-reporting of live births, lack of knowledge on the size and characteristics of emigration flows limited the analysis of population fertility in Kosovo and Metohia. But, registered data as well as survey results show to the perseverance of the fertility model of transitional type displaying obvious traditional elements

    Sugar-added beverages consumption among kindergarten children of Crete: effects on nutritional status and risk of obesity

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    <p>Abstract</p> <p>Objective</p> <p>To assess the intake of sugar-added beverages such as soft drinks and commercially available fruit juices in kindergarten children, and to examine its association with obesity indices, physical activity levels and dietary habits.</p> <p>Methods</p> <p>A total of 856 children aged 4–7 years living in Crete, Greece in 2004–5 were included in this cross-sectional study. Nutrient and food intake was assessed with the use of 3-day weighed food records. Body measurements were used in order to assess BMI and waist circumference, and moderate-to-vigorous physical activity was calculated with the use of a questionnaire.</p> <p>Results</p> <p>Approximately 59.8% of all children consumed sugar-added beverages on a daily basis. High intake of sugar-added beverages (> 250 g/day) was associated with low intakes of calcium (p < 0.001), vitamin A and E (p < 0.010), fruits and vegetables (p = 0.007), and milk and yogurt (p = 0.048). Compared to non or low consumers, high consumers of sugar-added beverages (> 250 g/day) had higher BMI levels and two times greater risk of being overweight and/or obese (OR:2.35, p = 0.023).</p> <p>Conclusion</p> <p>High intake of sugar-added beverages in kindergarten children is associated with poor eating habits and inadequate nutrient intake, as well as increased risk for developing childhood obesity.</p

    Evaluation of effectiveness of class-based nutrition intervention on changes in soft drink and milk consumption among young adults

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    <p>Abstract</p> <p>Background</p> <p>During last few decades, soft drink consumption has steadily increased while milk intake has decreased. Excess consumption of soft drinks and low milk intake may pose risks of several diseases such as dental caries, obesity, and osteoporosis. Although beverage consumption habits form during young adulthood, which has a strong impact on beverage choices in later life, nutrition education programs on beverages are scarce in this population. The purpose of this investigation was 1) to assess soft drink and milk consumption and 2) to evaluate the effectiveness of 15-week class-based nutrition intervention in changing beverage choices among college students.</p> <p>Methods</p> <p>A total of 80 college students aged 18 to 24 years who were enrolled in basic nutrition class participated in the study. Three-day dietary records were collected, verified, and analyzed before and after the intervention. Class lectures focused on healthful dietary choices related to prevention of chronic diseases and were combined with interactive hands on activities and dietary feedback.</p> <p>Results</p> <p>Class-based nutrition intervention combining traditional lecture and interactive activities was successful in decreasing soft drink consumption. Total milk consumption, specifically fat free milk, increased in females and male students changed milk choice favoring skim milk over low fat milk. (1% and 2%).</p> <p>Conclusion</p> <p>Class-based nutrition education focusing on prevention of chronic diseases can be an effective strategy in improving both male and female college students' beverage choices. Using this type of intervention in a general nutrition course may be an effective approach to motivate changes in eating behaviors in a college setting.</p

    Regulation of Inflammatory Gene Expression in PBMCs by Immunostimulatory Botanicals

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    Many hundreds of botanicals are used in complementary and alternative medicine for therapeutic use as antimicrobials and immune stimulators. While there exists many centuries of anecdotal evidence and few clinical studies on the activity and efficacy of these botanicals, limited scientific evidence exists on the ability of these botanicals to modulate the immune and inflammatory responses. Using botanogenomics (or herbogenomics), this study provides novel insight into inflammatory genes which are induced in peripheral blood mononuclear cells following treatment with immunomodulatory botanical extracts. These results may suggest putative genes involved in the physiological responses thought to occur following administration of these botanical extracts. Using extracts from immunostimulatory herbs (Astragalus membranaceus, Sambucus cerulea, Andrographis paniculata) and an immunosuppressive herb (Urtica dioica), the data presented supports previous cytokine studies on these herbs as well as identifying additional genes which may be involved in immune cell activation and migration and various inflammatory responses, including wound healing, angiogenesis, and blood pressure modulation. Additionally, we report the presence of lipopolysaccharide in medicinally prepared extracts of these herbs which is theorized to be a natural and active component of the immunostimulatory herbal extracts. The data presented provides a more extensive picture on how these herbs may be mediating their biological effects on the immune and inflammatory responses
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