88 research outputs found
Manganese pigmented anodized copper as solar selective absorber
The study concerns the optical and structural properties of layers obtained by a new efficient surface treatment totally free of chromium species. The process is made up of an anodic oxidation of copper in an alkaline solution followed by an alkaline potassium permanganate dipping post-treatment. Coatings, obtained at the lab and pilot scales, are stable up to 220 °C in air and vacuum, present low emissivity (0.14 at 70 °C) and high solar absorptivity (0.96), i.e. a suitable thermal efficiency (0.84 at 70 °C)
Electrophysiological ON and OFF responses in autosomal dominant optic atrophy
Purpose To assess the effect of ADOA on the ON and OFF components of the photopic negative response (PhNR). Methods Twelve participants from 6 families with OPA1 ADOA and 16 age matched controls were recruited. Electrophysiological assessment involved long flash focal (20o) and full field ERGs using red flash (664 nm, 250 msec, 55 cd/m2, 2 Hz) on a rod saturating blue background (454 nm, 100 scot cd/m2); and brief xenon flash ERGs using red filter (Lee Filter “Terry Red”, max 300 µs flash duration, 1.69 cd.s.m-2, 4 Hz) over a continuous rod saturating blue background (Schott Glass Filter BG28, 206 scot cd/m2). Amplitudes (from peak and baseline to fixed time point) and implicit times of the ERG components were analysed. Results Mean amplitude (peak to fixed time) of the focal PhNR-ON were significantly (p < 0.05) reduced by 40% while the focal PhNR-OFF was completely eliminated. In the long duration full field ERG, the PhNR-ON and –OFF were reduced by 21% and 57% respectively. Subtraction of the grand averaged ERG of ADOA participants from that of the controls produced a difference plot with a nearly symmetrical loss in the PhNR-ON and OFF components of the focal ERG. ROC curve analysis showed focal PhNR-ON and OFF amplitudes performed better than their full field counterparts. Conclusions We show that OFF components of the photopic ERG were more severely affected in ADOA than ON components. Additionally, the focal PhNR-ON and –OFF components were more effective in assessing ADOA than their full field components
Moisture Dependent Diffusion and Shrinkage in Yam during Drying
Crank's analytical approximations for Fick's diffusion equation were used to investigate the effect of moisture dependent sample thickness and diffusivity on the behavior of yam (Dioscoreaceae rotundata) cubicles during drying processes. Drying and shrinkage experiments were separately conducted at temperatures of 30, 40 and 50 °C in a cabinet drier. The comparative study of moisture dependent shrinkage and moisture dependent diffusivity justifies the interdependence of diffusivity and shrinkage due to water loss during drying. The behavior for yam is best explained by a combination of fractal moisture dependent shrinkage and moisture dependent diffusion, describing both the drying and rate curves better with good prediction of the high moisture regions. This assertion was reached as a result of low mean square error, standard error, percentage relative deviation, Akaike's Information Criterion and high coefficient of determination. The results may indicate a varying mobility of water in food matrix of different moisture content in the multilayer and monolayer regimes.</p
Systems integration to promote the mental health of Aboriginal and Torres Strait Islander children : protocol for a community-driven continuous quality improvement approach
Background: Systems integration to promote the mental health of Aboriginal and Torres Strait Islander children works towards developing a spectrum of effective, community-based services and supports. These services and supports are organised into a coordinated network, build meaningful partnerships with families and address their cultural and linguistic needs, to help children to function better at home, in school, in the community, and throughout life. This study is conducted in partnership with primary healthcare (PHC) and other services in three diverse Indigenous Australian communities. It entails conceptualising, co-designing, implementing, and evaluating the effectiveness of systems integration to promote the mental health and wellbeing of Indigenous school-aged children (4–17 years). This paper outlines a protocol for implementing such complex community-driven research. Methods/design: Using continuous quality improvement processes, community co-designed strategies for improved systems integration will be informed by narratives from yarning circles with Indigenous children and service providers, and quantitative data from surveys of service providers and audits of PHC client records and intersectoral systems. Agreed strategies to improve the integration of community-based services and supports will be modelled using microsimulation software, with a preferred model implemented in each community. The evaluation will investigate changes in the: 1) availability of services that are community-driven, youth-informed and culturally competent; 2) extent of collaborative service networks; 3) identification by PHC services of children’s social and emotional wellbeing concerns; and 4) ratio of children receiving services to identified need. Costs and benefits of improvements to systems integration will also be calculated. Discussion: The study will provide evidence-informed, community-driven, and tested models that can be used for implementing systems integration to promote the mental health and wellbeing of Indigenous children. It will identify the situational enablers and barriers that impact systems integration and determine the extent to which systems integration improves service availability, systems and child outcomes. Evidence for the cost effectiveness of systems-level integration will contribute to national mental health policy reform
Hypochondroplasia gain-of-function mutation in FGFR3 causes defective bone mineralization in mice
Hypochondroplasia (HCH) is a mild dwarfism caused by missense mutations in fibroblast growth factor receptor 3 (FGFR3), with the majority of cases resulting from a heterozygous p.Asn540Lys gain-of-function mutation. Here, we report the generation and characterization of the first mouse model (Fgfr3Asn534Lys/+) of HCH to our knowledge. Fgfr3Asn534Lys/+ mice exhibited progressive dwarfism and impairment of the synchondroses of the cranial base, resulting in defective formation of the foramen magnum. The appendicular and axial skeletons were both severely affected and we demonstrated an important role of FGFR3 in regulation of cortical and trabecular bone structure. Trabecular bone mineral density (BMD) of long bones and vertebral bodies was decreased, but cortical BMD increased with age in both tibiae and femurs. These results demonstrate that bones in Fgfr3Asn534Lys/+ mice, due to FGFR3 activation, exhibit some characteristics of osteoporosis. The present findings emphasize the detrimental effect of gain-of-function mutations in the Fgfr3 gene on long bone modeling during both developmental and aging processes, with potential implications for the management of elderly patients with hypochondroplasia and osteoporosis
Accelerating functional gene discovery in osteoarthritis.
Osteoarthritis causes debilitating pain and disability, resulting in a considerable socioeconomic burden, yet no drugs are available that prevent disease onset or progression. Here, we develop, validate and use rapid-throughput imaging techniques to identify abnormal joint phenotypes in randomly selected mutant mice generated by the International Knockout Mouse Consortium. We identify 14 genes with functional involvement in osteoarthritis pathogenesis, including the homeobox gene Pitx1, and functionally characterize 6 candidate human osteoarthritis genes in mouse models. We demonstrate sensitivity of the methods by identifying age-related degenerative joint damage in wild-type mice. Finally, we phenotype previously generated mutant mice with an osteoarthritis-associated polymorphism in the Dio2 gene by CRISPR/Cas9 genome editing and demonstrate a protective role in disease onset with public health implications. We hope this expanding resource of mutant mice will accelerate functional gene discovery in osteoarthritis and offer drug discovery opportunities for this common, incapacitating chronic disease
Accelerating functional gene discovery in osteoarthritis.
Osteoarthritis causes debilitating pain and disability, resulting in a considerable socioeconomic burden, yet no drugs are available that prevent disease onset or progression. Here, we develop, validate and use rapid-throughput imaging techniques to identify abnormal joint phenotypes in randomly selected mutant mice generated by the International Knockout Mouse Consortium. We identify 14 genes with functional involvement in osteoarthritis pathogenesis, including the homeobox gene Pitx1, and functionally characterize 6 candidate human osteoarthritis genes in mouse models. We demonstrate sensitivity of the methods by identifying age-related degenerative joint damage in wild-type mice. Finally, we phenotype previously generated mutant mice with an osteoarthritis-associated polymorphism in the Dio2 gene by CRISPR/Cas9 genome editing and demonstrate a protective role in disease onset with public health implications. We hope this expanding resource of mutant mice will accelerate functional gene discovery in osteoarthritis and offer drug discovery opportunities for this common, incapacitating chronic disease
Osteocyte transcriptome mapping identifies a molecular landscape controlling skeletal homeostasis and susceptibility to skeletal disease.
Osteocytes are master regulators of the skeleton. We mapped the transcriptome of osteocytes from different skeletal sites, across age and sexes in mice to reveal genes and molecular programs that control this complex cellular-network. We define an osteocyte transcriptome signature of 1239 genes that distinguishes osteocytes from other cells. 77% have no previously known role in the skeleton and are enriched for genes regulating neuronal network formation, suggesting this programme is important in osteocyte communication. We evaluated 19 skeletal parameters in 733 knockout mouse lines and reveal 26 osteocyte transcriptome signature genes that control bone structure and function. We showed osteocyte transcriptome signature genes are enriched for human orthologs that cause monogenic skeletal disorders (P = 2.4 × 10-22) and are associated with the polygenic diseases osteoporosis (P = 1.8 × 10-13) and osteoarthritis (P = 1.6 × 10-7). Thus, we reveal the molecular landscape that regulates osteocyte network formation and function and establish the importance of osteocytes in human skeletal disease
The impact of a community-based risky drinking intervention (Beat da Binge) on Indigenous young people
Highly Pathogenic Avian Influenza Virus Subtype H5N1 in Africa: A Comprehensive Phylogenetic Analysis and Molecular Characterization of Isolates
Highly pathogenic avian influenza virus A/H5N1 was first officially reported in Africa in early 2006. Since the first outbreak in Nigeria, this virus spread rapidly to other African countries. From its emergence to early 2008, 11 African countries experienced A/H5N1 outbreaks in poultry and human cases were also reported in three of these countries. At present, little is known of the epidemiology and molecular evolution of A/H5N1 viruses in Africa. We have generated 494 full gene sequences from 67 African isolates and applied molecular analysis tools to a total of 1,152 A/H5N1 sequences obtained from viruses isolated in Africa, Europe and the Middle East between 2006 and early 2008. Detailed phylogenetic analyses of the 8 gene viral segments confirmed that 3 distinct sublineages were introduced, which have persisted and spread across the continent over this 2-year period. Additionally, our molecular epidemiological studies highlighted the association between genetic clustering and area of origin in a majority of cases. Molecular signatures unique to strains isolated in selected areas also gave us a clearer picture of the spread of A/H5N1 viruses across the continent. Mutations described as typical of human influenza viruses in the genes coding for internal proteins or associated with host adaptation and increased resistance to antiviral drugs have also been detected in the genes coding for transmembrane proteins. These findings raise concern for the possible human health risk presented by viruses with these genetic properties and highlight the need for increased efforts to monitor the evolution of A/H5N1 viruses across the African continent. They further stress how imperative it is to implement sustainable control strategies to improve animal and public health at a global level
- …