313 research outputs found

    Scaling Laws for Transition from Varicose to Whipping Instabilities in Electrohydrodynamic Jetting

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    China Scholarship Council (CSC)European Union’s Horizon 2020 research and innovation program Grant No. 646296Engineering and Physical Sciences Research Council (UK) under Grant No. EP/N509917/

    Breakup length of electrified liquid jets: Scaling laws and applications

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    The growth rate of infinitesimal perturbations in electrified jets at the viscid and inviscid limits exhibit different behavior. Using Saville’s approach to estimate the growth rate for perturbations in the long wavelength limit and by neglecting the effects of gravity, we derived two scaling laws for the jet breakup length in two regimes of the Taylor cone mode. Our experimental measurements show clear dependency of the jet length on the flow rate; however changing the applied voltage has appeared to affect only the cone angle, but not to the jet itself. The experimental data has an excellent collapse with our theoretical model in both cases. The transition between viscid and inviscid limits appears to occur at an electric Reynolds number, based upon jet diameter of Re≃5. Finally, we showed how to enhance the quality and the resolution in Electrostatic Inkjet Printing applications by setting the printing distance lower than the jet length and predicting the line width as a function of the operational parameters.This work was supported by the Engineering and Physical Sciences Research Council (United Kingdom) under Grant No. EP/N509917/1 and the European Union’s Horizon 2020 research and innovation program under Grant No. 646296

    Influence of simulation in Malaysian healthcare education and research (ISIM-HERE): a two-decade experience

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    The use of simulation as a teaching methodology in medical institutions has been in Malaysia for over two decades. This study aimed to evaluate the current scenarios of simulation impact and utilization in Malaysian academic healthcare institutions (AHIs). We conducted a population-based survey on all AHIs in Malaysia including public and private. We performed an online survey followed by a face-to-face interview evaluating the number of institutions that used simulation, duration of experience, purpose, funding, users’ category and healthcare domain, research activities, dedicated-trained staff and the challenges faced. Out of 75 healthcare institutions approached, 38 agreed to participate in this study. Twenty-two (57.9%) were public hospitals while 16 (42.1%) were private institutions. Thirty-five (92.1%) out of 38 institutions used simulation as a teaching method. The majority (15, 42.9%) had less than five years’ experience, and about a third (11, 31.4%) used simulation for teaching, training and performance assessment. Nurses (30, 26.1%) were the main users followed by physicians and paramedic (19, 16.5% each respectively). In-hospital and procedural group were the top two domains of utilizers. Almost three quarters (25, 71.4%) have dedicated support staff to manage the centre. Funding was mainly from internal institutional support mechanisms. Seven different categories of challenges were identified, the biggest being financial support. In summary, even though healthcare simulation has been in Malaysia for the past two decades but the most substantial impact happened over the last five years. Utilization was mainly for teaching, training, and performance assessment with minimal use in research

    Dichotomous factor analysis of symptoms reported by UK and US veterans of the 1991 Gulf War

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    BACKGROUND: Factor analysis is one of the most used statistical techniques to analyze the inter-relationships among symptoms reported by Gulf War veterans. The objective of this study was to apply factor analyses to binary symptom data from the UK study of Gulf War illness and the US Air Force study of Gulf War veterans, and to compare the symptom domains derived from the distinct samples. METHODS: UK veterans of the 1991 Gulf War (n = 3,454), individuals deployed to Bosnia on U.N. peacekeeping operations (n = 1,979) and Gulf War-era servicemen (n = 2,577) who were not deployed to the Gulf were surveyed in 1997–1998, and US 1991 Gulf War veterans from four Air Force units (n = 1,163) were surveyed in 1995 to collect health characteristics including symptoms. Each sample was randomly split in half for exploratory and confirmatory dichotomous factor analyses with promax oblique rotation. RESULTS: Four correlated factors were identified in each of the samples. Three factors (Respiratory, Mood-Cognition, Peripheral Nervous) overlapped considerably across the UK cohorts. The Gastrointestinal/Urogenital factor in the UK Gulf cohort was noticeably different from the Gastrointestinal factor identified from the Bosnia and Era cohorts. Symptoms from Gulf War UK and U.S cohorts yielded similar Gastrointestinal, Respiratory and Mood-Cognition factors, despite differences in symptom inventories between the two surveys. A Musculoskeletal factor was only elicited from the US Gulf sample. CONCLUSION: Findings of this report are consistent with those from other factor analysis studies that identified similar symptom dimensions between Gulf and non-Gulf War veterans, except that the Gastrointestinal factor in Gulf veterans included other symptom types. Correlations among factors raise the question as to whether there is a general illness, even if not unique to Gulf veterans, representing the common pathway underlying the identified factors. Hierarchical factor analysis models may be useful to address this issue

    Alleviating poverty through Islamic microfinance: factors and measures of financial performance, and roles of Islamic values and financial policies

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    Indonesia has a strong presence of microfinance sector with the number of Islamic Microfinance Institutions (IMFIs) estimated to be around 5,000 currently. Microfinance is an effective tool in alleviating poverty in Indonesia due to the limited access to financial services by the poor who accounted for approximately 96 million Indonesians (or 37% of the total population), living on less than USD 1.90 a day. In the absence of collateral and steady income, the poor are considered too risky to be given credit facilities by the formal financial services providers and living in remote areas has also limited their access to formal financial services. This study aims to examine the poverty alleviation efforts from the perspective of the IMFIs in view of their direct involvement in the process and having rich information about financial issues facing the borrowers. The managers also understand about financial inclusion agenda as well as financial guidelines and regulations issued by the relevant authorities. A total of 34 managers of Baitulmaal Wa Tamwil (BMTs), which registered under the Sharia Cooperative Centre (INKOPSYAH) are taken as respondents from the Jakarta, Bogor, Depok, Tangerang and Bekasi (JABODETABEK) areas. The first instrument was a survey questionnaire, and the second one was an in-depth interview to outline data related to the model design. The findings of this research are expected to contribute to better decision-making for the BMTs to further enhance its role in alleviating poverty. The findings also elaborate several dimensions to improving financial inclusion among the poor including providing financial services, implementing Islamic principles, significant policies, community-based framework concept and training financial education. This research highlights the need for a variety of strategies to warrant success of poverty alleviation efforts by BMT

    Mapping of Mycobacterium tuberculosis Complex Genetic Diversity Profiles in Tanzania and Other African Countries

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    The aim of this study was to assess and characterize Mycobacterium tuberculosis complex (MTBC) genotypic diversity in Tanzania, as well as in neighbouring East and other several African countries. We used spoligotyping to identify a total of 293 M. tuberculosis clinical isolates (one isolate per patient) collected in the Bunda, Dar es Salaam, Ngorongoro and Serengeti areas in Tanzania. The results were compared with results in the SITVIT2 international database of the Pasteur Institute of Guadeloupe. Genotyping and phylogeographical analyses highlighted the predominance of the CAS, T, EAI, and LAM MTBC lineages in Tanzania. The three most frequent Spoligotype International Types (SITs) were: SIT21/CAS1-Kili (n = 76; 25.94%), SIT59/LAM11-ZWE (n = 22; 7.51%), and SIT126/EAI5 tentatively reclassified as EAI3-TZA (n = 18; 6.14%). Furthermore, three SITs were newly created in this study (SIT4056/EAI5 n = 2, SIT4057/T1 n = 1, and SIT4058/EAI5 n = 1). We noted that the East-African-Indian (EAI) lineage was more predominant in Bunda, the Manu lineage was more common among strains isolated in Ngorongoro, and the Central-Asian (CAS) lineage was more predominant in Dar es Salaam (p-value<0.0001). No statistically significant differences were noted when comparing HIV status of patients vs. major lineages (p-value = 0.103). However, when grouping lineages as Principal Genetic Groups (PGG), we noticed that PGG2/3 group (Haarlem, LAM, S, T, and X) was more associated with HIV-positive patients as compared to PGG1 group (Beijing, CAS, EAI, and Manu) (p-value = 0.03). This study provided mapping of MTBC genetic diversity in Tanzania (containing information on isolates from different cities) and neighbouring East African and other several African countries highlighting differences as regards to MTBC genotypic distribution between Tanzania and other African countries. This work also allowed underlining of spoligotyping patterns tentatively grouped within the newly designated EAI3-TZA lineage (remarkable by absence of spacers 2 and 3, and represented by SIT126) which seems to be specific to Tanzania. However, further genotyping information would be needed to confirm this specificity

    Microsatellite alteration and immunohistochemical expression profile of chromosome 9p21 in patients with sporadic renal cell carcinoma following surgical resection.

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    BACKGROUND: Long-term prognostic significance of loss of heterozygosity on chromosome 9p21 for localized renal cell carcinoma following surgery remains unreported. The study assessed the frequency of deletions of different loci of chromosome 9p along with immunohistochemical profile of proteins in surgically resected renal cancer tissue and correlated this with long-term outcomes. METHODS: DNA was extracted from renal tumours and corresponding normal kidney tissues in prospectively collected samples of 108 patients who underwent surgical resection for clinically localized disease between January 2001 and December 2005, providing a minimum of 9 years follow-up for each participant. After checking quality of DNA, amplified by PCR, loss of heterozygosity (LOH) on chromosome 9p was assessed using 6 microsatellite markers in 77 clear cell carcinoma. Only 5 of the markers showed LOH (D9S1814, D9S916, D9S974, D9S942, and D9S171). Protein expression of p15(INK4b), p16(INK4a), p14(ARF), CAIX, and adipose related protein (ADFP) were demonstrated by immunostaining in normal and cancer tissues. Loss of heterozygosity for microsatellite analysis was correlated with tumour characteristics, recurrence free, cancer specific, and overall survival, including significance of immunohistochemical profile of protein expressions. RESULTS: The main deletion was found at loci telomeric to CDKN2A region at D9S916. There was a significant correlation between frequency of LOH stage (p = 0.005) and metastases (p = 0.006) suggesting a higher LOH for advanced and aggressive renal cell carcinoma. Most commonly observed LOH in the 3 markers: D9S916, D9S974, and D9S942 were associated with poor survival, and were statistically significant on multivariate analysis. Immunohistochemical expression of p14, p15, and p16 proteins were either low or absent in cancer tissue compared to normal. CONCLUSIONS: Loss of heterozygosity of p921 chromosome is associated with aggressive tumours, and predicts cancer specific or recurrence free survival on long-term follow-up. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12885-016-2514-8) contains supplementary material, which is available to authorized users

    Relationship between blood lead concentration and nutritional status among Malay primary school children in Kuala Lumpur, Malaysia.

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    A cross-sectional study was conducted to identify the relationship between blood lead concentration and nutritional status among primary school children in Kuala Lumpur. A total of 225 Malay students, 113 male and 112 female, aged 6.3 to 9.8 were selected through a stratified random sampling method. The random blood samples were collected and blood lead concentration was measured by a Graphite Furnace Atomic Absorption Spectrophotometer. The nutrient intake was determined by the 24-hour Dietary Recall method and Food Frequency Questionnaire. An anthropometric assessment was reported according to growth indices (z-scores of weight-for-age, height-for-age, and weight-for-height). The mean blood lead concentration was low (3.4 ± 1.91 ug/dL) and was significantly different between gender. Only 14.7% of the respondents fulfilled the daily energy requirement. The protein and iron intakes were adequate for a majority of the children. However, 34.7% of the total children showed inadequate intake of calcium. The energy, protein, fat and carbohydrate intakes were significantly different by gender, that is, males had better intake than females. Majority of respondents had normal mean z-score of growth indices. Ten percent of the respondents were underweight, 2.8% wasted and 5.4% stunted. Multiple linear regression showed inverse significant relationships between blood lead concentration with children's age (β= -0.647, p<0.001) and per capita income (β=-0.001, p=0.018). There were inverse significant relationships between blood lead concentration with children's age (β=-0.877, p=0.001) and calcium intake (β= -0.011,p=0.014) and positive significant relationship with weight-for-height (β=0.326, p=0.041) among those with inadequate calcium intake. Among children with inadequate energy intake, children's age (β= -0.621, p< 0.001), per capita income (β= -0.001,p=0.025) and protein intake (β= -0.019, p=0.027) were inversely and significantly related with blood lead concentration. In conclusion, nutritional status might affect the children's absorption of lead and further investigation is required for confirmation

    Clinical risk factor assessment had better discriminative ability than bone mineral density in identifying subjects with vertebral fracture

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    Summary: This study evaluated the characteristics of patients with vertebral fractures and examined the discriminative ability of clinical risk factors. The findings provide further insights into possible development of a simple, cost-effective scheme for fracture risk assessment using clinical risk factors to identify high-risk patients for further evaluation. Introduction: Vertebral fractures are the most common complication of osteoporosis. The aim of this study was to evaluate the characteristics of patients with vertebral fractures and to determine the discriminative ability of bone mineral density (BMD) and other clinical risk factors. Methods: Postmenopausal Southern Chinese women (2,178) enrolled in the Hong Kong Osteoporosis Study since 1995 were prospectively followed up for fracture outcome. Subjects (1,372) with lateral spine radiographs were included in this study. Baseline demographic, BMD, and clinical risk factor information were obtained from a structured questionnaire. Results: Subjects (299; 22%) had prevalent vertebral fractures. The prevalence of vertebral fractures increased with increasing age, number of clinical risk factors, and decreasing BMD. The odds of having a prevalent vertebral fracture per SD reduction in BMD after adjustment for age in Hong Kong Southern Chinese postmenopausal women was 1.5 for the lumbar spine and femoral neck. Analysis of the receiver operating characteristic curve revealed that bone mineral apparent density did not enhance fracture risk prediction. Subjects with ≥4 clinical risk factors had 2.3-fold higher odds of having a prevalent vertebral fracture while subjects with ≥4 clinical risk factors plus a low BMD (i.e., femoral neck T-score <-2.5) had 2.6-fold. Addition of BMD to clinical risk factors did not enhance the discriminative ability to identify subjects with vertebral fracture. Conclusions: Based on these findings, we recommend that screening efforts should focus on older postmenopausal women with multiple risk factors to identify women who are likely to have a prevalent vertebral fracture. © 2010 The Author(s).published_or_final_versionSpringer Open Choice, 21 Feb 201

    Salt Stress Induced Variation in DNA Methylation Pattern and Its Influence on Gene Expression in Contrasting Rice Genotypes

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    BACKGROUND: Salinity is a major environmental factor limiting productivity of crop plants including rice in which wide range of natural variability exists. Although recent evidences implicate epigenetic mechanisms for modulating the gene expression in plants under environmental stresses, epigenetic changes and their functional consequences under salinity stress in rice are underexplored. DNA methylation is one of the epigenetic mechanisms regulating gene expression in plant's responses to environmental stresses. Better understanding of epigenetic regulation of plant growth and response to environmental stresses may create novel heritable variation for crop improvement. METHODOLOGY/PRINCIPAL FINDINGS: Methylation sensitive amplification polymorphism (MSAP) technique was used to assess the effect of salt stress on extent and patterns of DNA methylation in four genotypes of rice differing in the degree of salinity tolerance. Overall, the amount of DNA methylation was more in shoot compared to root and the contribution of fully methylated loci was always more than hemi-methylated loci. Sequencing of ten randomly selected MSAP fragments indicated gene-body specific DNA methylation of retrotransposons, stress responsive genes, and chromatin modification genes, distributed on different rice chromosomes. Bisulphite sequencing and quantitative RT-PCR analysis of selected MSAP loci showed that cytosine methylation changes under salinity as well as gene expression varied with genotypes and tissue types irrespective of the level of salinity tolerance of rice genotypes. CONCLUSIONS/SIGNIFICANCE: The gene body methylation may have an important role in regulating gene expression in organ and genotype specific manner under salinity stress. Association between salt tolerance and methylation changes observed in some cases suggested that many methylation changes are not "directed". The natural genetic variation for salt tolerance observed in rice germplasm may be independent of the extent and pattern of DNA methylation which may have been induced by abiotic stress followed by accumulation through the natural selection process
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