469 research outputs found

    Global visualization and quantification of compressible vortex loops

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    The physics of compressible vortex loops generated due to the rolling up of the shear layer upon the diffraction of a shock wave from a shock tube is far from being understood, especially when shock-vortex interactions are involved. This is mainly due to the lack of global quantitative data available which characterizes the flow. The present study involves the usage of the PIV technique to characterize the velocity and vorticity of compressible vortex loops formed at incident shock Mach numbers ofM=1.54 and1.66. Another perk of the PIV technique over purely qualitative methods, which has been demonstrated in the current study, is that at the same time the results also provide a clear image of the various flow features. Techniques such as schlieren and shadowgraph rely on density gradients present in the flow and fail to capture regions of the flow influenced by the primary flow structure which would have relatively lower pressure and density. Various vortex loops, namely, square, elliptic and circular, were generated using different shape adaptors fitted to the end of the shock tube. The formation of a coaxial vortex loop with opposite circulation along with the generation of a third stronger vortex loop ahead of the primary with same circulation direction are of the interesting findings of the current study

    Development of chip passivated monolithic complementary MISFET circuits with beam leads

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    Fabrication method is described for alumina passivated silicon MISFET arrays. Technique involves total passivation beam-lead approach and provides completely sealed chip with double level interconnect capability. Refractory metal alloy is used to form interconnect system and obtain metal contacts that withstand temperatures of 873 K for short periods of time

    It’s the Combination: Scientific Data Review of the First Corn Silage to Bring Together Fiber and Starch Digestibility

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    This information was presented at the 2017 Cornell Nutrition Conference for Feed Manufacturers, organized by the Department of Animal Science In the College of Agriculture and Life Sciences at Cornell University. Softcover copies of the entire conference proceedings may be purchased at http://ansci.cals.cornell.edu/extension-outreach/adult-extension/dairy-management/order-proceedings-resources.A recent study compared a newly developed brown midrib 3 corn silage with floury endosperm to a conventional corn silage and a brown midrib 3 corn silage for high-producing Holstein cows. The combination of greater rumen fiber and starch fermentability of the new hybrid resulted in greater efficiency of solids-corrected milk production and milk nitrogen efficiency compared with the brown midrib and conventional hybrids

    Polymeric Branched Flocculant Effect on the Flocculation Process of Pulp Suspensions in the Papermaking Industry

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    This paper presents the effect of the structure of cationic polyacrylamides (CPAMs) on flocculation of pulp suspensions and floc properties. A focused beam reflectance measurement (FBRM) probe was used to monitor flocculation, deflocculation, and reflocculation processes in real time. To carry out the study, 1% elemental chlorine free (ECF) eucalyptus kraft pulp containing 20% ground calcium carbonate (GCC) was used. Results show that the effect of the CPAM structure depends on charge density and polymer dose. Floc size does not always decrease with branching degree, whereas floc stability and reflocculation ability increased when highly charged and branched CPAM was used. These findings indicate that the use of highly branched CPAMs with very high molecular weight is very promising as a retention aid method to improve the papermaking process

    Survey of rehabilitation support for children 0-15 years in a rural part of Kenya

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    Abstract Purpose: Information regarding the nature, availability and distribution of rehabilitation services for children with disabilities across developing countries is scarce, and data that do exist are of variable quality. If planning and development are to progress, information about service provision is vital. The aim was to establish the scope and nature of rehabilitation support available to children with disabilities (0-15 years) and their families in rural Kenya. Method: A comprehensive sample comprising service provision in the health and special education sectors was established. Non-governmental and community-based organisations were also included. A survey of rehabilitation services was conducted through examination of service-related documentation and key informant interviews with the heads of services. Results: Rehabilitation comprised hospital-based occupational therapy, physiotherapy and orthopaedic technology; and seven special education establishments plus an education assessment resource centre. There was one non-government organisation and one community-based organisation relevant to children with disabilities. Activities focused on assessment, diagnosis and raising community awareness. Provision was challenged by inadequate staffing, resources and transport. Government funding was supplemented variously by donations and self-sufficiency initiatives. Rehabilitation approaches appeared to be informed by professional background of practitioner, rather than the needs of child. Service documentation revealed use of inconsistent recording methods. Conclusions: The data highlight the challenges of rehabilitation, demanding greater investment in personnel and their training, more material resources, improved access to the community and better recording mechanisms. Implications for Rehabilitation There needs to be greater investment in rehabilitation provision in developing countries. Consideration of community-based initiatives is required to support better access for all. In order to argue the case for improved resources, better skills and mechanisms for recording, monitoring and evaluating practice are needed

    A Gene Optimization Strategy that Enhances Production of Fully Functional P-Glycoprotein in Pichia pastoris

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    Structural and biochemical studies of mammalian membrane proteins remain hampered by inefficient production of pure protein. We explored codon optimization based on highly expressed Pichia pastoris genes to enhance co-translational folding and production of P-glycoprotein (Pgp), an ATP-dependent drug efflux pump involved in multidrug resistance of cancers.Codon-optimized "Opti-Pgp" and wild-type Pgp, identical in primary protein sequence, were rigorously analyzed for differences in function or solution structure. Yeast expression levels and yield of purified protein from P. pastoris (∼130 mg per kg cells) were about three-fold higher for Opti-Pgp than for wild-type protein. Opti-Pgp conveyed full in vivo drug resistance against multiple anticancer and fungicidal drugs. ATP hydrolysis by purified Opti-Pgp was strongly stimulated ∼15-fold by verapamil and inhibited by cyclosporine A with binding constants of 4.2±2.2 µM and 1.1±0.26 µM, indistinguishable from wild-type Pgp. Maximum turnover number was 2.1±0.28 µmol/min/mg and was enhanced by 1.2-fold over wild-type Pgp, likely due to higher purity of Opti-Pgp preparations. Analysis of purified wild-type and Opti-Pgp by CD, DSC and limited proteolysis suggested similar secondary and ternary structure. Addition of lipid increased the thermal stability from T(m) ∼40 °C to 49 °C, and the total unfolding enthalpy. The increase in folded state may account for the increase in drug-stimulated ATPase activity seen in presence of lipids.The significantly higher yields of protein in the native folded state, higher purity and improved function establish the value of our gene optimization approach, and provide a basis to improve production of other membrane proteins

    Changing indications and socio-demographic determinants of (adeno)tonsillectomy among children in England--are they linked? A retrospective analysis of hospital data.

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    OBJECTIVE: To assess whether increased awareness and diagnosis of obstructive sleep apnoea syndrome (OSAS) and national guidance on tonsillectomy for recurrent tonsillitis have influenced the socio-demographic profile of children who underwent tonsillectomy over the last decade. METHOD: Retrospective time-trends study of Hospital Episodes Statistics data. We examined the age, sex and deprivation level, alongside OSAS diagnoses, among children aged <16 years who underwent (adeno)tonsillectomy in England between 2001/2 and 2011/12. RESULTS: Among children aged <16 years, there were 29,697 and 27,732 (adeno)tonsillectomies performed in 2001/2 and 2011/12, respectively. The median age at (adeno)tonsillectomy decreased from 7 (IQR: 5-11) to 5 (IQR: 4-9) years over the decade. (Adeno)tonsillectomy rates among children aged 4-15 years decreased by 14% from 350 (95%CI: 346-354) in 2001/2 to 300 (95%CI: 296-303) per 100,000 children in 2011/12. However, (adeno)tonsillectomy rates among children aged <4 years increased by 58% from 135 (95%CI: 131-140) to 213 (95%CI 208-219) per 100,000 children in 2001/2 and 2011/2, respectively. OSAS diagnoses among children aged <4 years who underwent surgery increased from 18% to 39% between these study years and the proportion of children aged <4 years with OSAS from the most deprived areas increased from 5% to 12%, respectively. CONCLUSIONS: (Adeno)tonsillectomy rates declined among children aged 4-15 years, which reflects national guidelines recommending the restriction of the operation to children with more severe recurrent throat infections. However, (adeno)tonsillectomy rates among pre-school children substantially increased over the past decade and one in five children undergoing the operation was aged <4 years in 2011/12.The increase in surgery rates in younger children is likely to have been driven by increased awareness and detection of OSAS, particularly among children from the most deprived areas

    Effect of a 12-Week Mixed Training on Body Quality in People Living with HIV: Does Age and HIV Duration Matter?

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    peer reviewed[en] BACKGROUND: The impact of HIV duration on exercise adaptations has not yet been studied. Moreover, the age at which subjects living with HIV are the most responsive to exercise is not clear. AIMS: Investigate the effect of a mixed exercise training program on physical performance changes in individuals living with HIV and explore if age or HIV duration influence these adaptations in men. METHODS: In this feasibility study, participants followed a 12-week mixed exercise training program, three times/week, 45 min/session. Physical performance including functional capacities (normal 4-m walking test, 6min walking test), grip strength (hand dynamometer), muscle power, body composition (android and gynoid fat masses, appendicular lean mass) were evaluated pre- and post-intervention. Subgroup analysis according to the median age of the participants (age<50yrs vs. age≥50yrs) and median HIV duration (HIV<20yrs vs. HIV≥20yrs) were performed in men. RESULTS: A total of 27 participants (age: 54.5±6.8yrs, men: 85%; HIV duration: 19.3±7.6yrs) were included. At the end of the intervention, significant increases compared to baseline were seen in grip strength (p=0.017), leg power (p20yrs than those with a shorter infection duration, with change (%) on total (p<0.001), android (p=0.02), and gynoid (p=0.05) fat masses as well as appendicular lean mass index (p=0.03). CONCLUSION: Mixed exercise training seems to be an effective intervention to improve physical performance in individuals living with HIV. In addition, this study suggests that neither age nor HIV duration has influence on the effect of mixed training in this population
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