Flow Visualization and Dynamics of Heat Exchanger Tube Arrays in Water Cross-Flow

A flow visualization technique has been developed to investigate the flow developments in tube arrays over a wide range of Reynolds numbers. The techniques is non-obtrusive and permits observations deep inside a tube bundle where the flow is unaffected by free surface or boundary effects. The technique has been used to examine flow behaviour in a rigidly and flexibly mounted square in-line and rotated square arrays in a water cross-flow. The important case of a single flexible tube in an otherwise rigid bundle, which received considerable attention in the literature, has also been examined. Results pertinent to vortex shedding, turbulence and fluidelastic instability are given which include response curves and frequency spectra together with flow visualization films and photographs. The results indicate that discrete alternate and symmetric vortex shedding can occur within the confinement of a tube bundle. Increased turbulence, as more rows are traversed by the flow, has a detrimental effect on the discrete vortex structures. Vorticity shedding and turbulence coexist as separate phenomena however, vorticity shedding is identified as the mechanism responsible for the observed resonance peaks in the response curves. Vortex shedding and the associated flow induced response in the square array is different from that in the staggered rotated square array. Fluidelastic instability is associated with marked increase in the transverse response amplitude and significant flow redistribution although it appears random in a full flexible bundle. Finally, a single flexible tube in an otherwise rigid bundle will become unstable at essentially the same flow velocity as that when the surrounding tubes are free to move. The response is predominantly in a transverse direction with significant flow redistribution. The motion of the redistributed flow lags behind the tube motion.Doctor of Philosophy (PhD

Delineating functional principles of the bow tie structure of a kinase-phosphatase network in the budding yeast

BACKGROUND: Kinases and phosphatases (KP) form complex self-regulating networks essential for cellular signal processing. In spite of having a wealth of data about interactions among KPs and their substrates, we have very limited models of the structures of the directed networks they form and consequently our ability to formulate hypotheses about how their structure determines the flow of information in these networks is restricted. RESULTS: We assembled and studied the largest bona fide kinase-phosphatase network (KP-Net) known to date for the yeast Saccharomyces cerevisiae. Application of the vertex sort (VS) algorithm on the KP-Net allowed us to elucidate its hierarchical structure in which nodes are sorted into top, core and bottom layers, forming a bow tie structure with a strongly connected core layer. Surprisingly, phosphatases tend to sort into the top layer, implying they are less regulated by phosphorylation than kinases. Superposition of the widest range of KP biological properties over the KP-Net hierarchy shows that core layer KPs: (i), receive the largest number of inputs; (ii), form bottlenecks implicated in multiple pathways and in decision-making; (iii), and are among the most regulated KPs both temporally and spatially. Moreover, top layer KPs are more abundant and less noisy than those in the bottom layer. Finally, we showed that the VS algorithm depends on node degrees without biasing the biological results of the sorted network. The VS algorithm is available as an R package (https://cran.r-project.org/web/packages/VertexSort/index.html). CONCLUSIONS: The KP-Net model we propose possesses a bow tie hierarchical structure in which the top layer appears to ensure highest fidelity and the core layer appears to mediate signal integration and cell state-dependent signal interpretation. Our model of the yeast KP-Net provides both functional insight into its organization as we understand today and a framework for future investigation of information processing in yeast and eukaryotes in general. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12918-017-0418-0) contains supplementary material, which is available to authorized users

ANTIBACTERIAL ACTIVITY OF TRIBULUS TERRESTRIS L. AGAINST ESCHERICHIA COLI AND STAPHYLOCOCCUS AUREUS

أجريت الدراسة على القطبة (الحسك) Tribulus terrestris L. من العائلة الرطراطية Zygophyllaceae الذي جمع من محافظة الضالع في منطقة خوبر خلال شهر مارس 2022، وتم عمل الاستخلاص المائي والميثانولي في مختبر قسم العقاقير لكلية الصيدلة – جامعة عدن، و من ثم أجريت الدراسة على نوعين من البكتيريا أحداهما موجبة الجرام Staphylococcus aurous والأخرى سالبة الجرام Escherichia coli. أجريت التجربة الميكروبية في مختبر الأحياء الدقيقة – جامعة العلوم والتكنولوجيا حيث أجريت تجربة عاملية ذات ثلاثة عوامل (نوع المذيب، التركيز والوقت)، وكررت كل معاملة ثلاث مرات، وكانت النتائج المتحصل عليها كالتالي: أظهر المستخلص لكلا المذيبين أكبر منطقة تثبيط ضد كلا النوعين من البكتيريا و ذلك عند التراكيز العالية 400، 600 و 800 مغ/مل و كانت أفضل النتائج بعد 72 ساعة لكلا النوعين من البكتيريا، إذ أعطت طريقة الأقراص فعالية ضد بكتيريا Staphylococcus aureus، بينما كانت طريقة الحفر هي الفعالة ضد بكتيريا Escherichia coli. التداخل بين العاملين (التراكيز المستخدمة و نوع المذيب) أظهر أفضل النتائج عند المتخلص الميثانولي باستخدام طريقة الأقراص ضد بكتيريا Escherichia coli عند تركيز 200 مغ/مل و 800 مغ/مل ضد بكتيريا Staphylococcus aureus . التداخل بين العاملين (الوقت و نوع المذيب) أظهر أفضل النتائج بعد 72 ساعة في المستخلص المائي باستخدام طريقة الحفر ضد بكتيريا Escherichia coli، بينما كانت أفضل نتائج ضد بكتيريا Staphylococcus aureus بعد 72 ساعة في المستخلص الميثانولي باستخدام طريقة الأقراص. التداخل بين العاملين (التراكيز والوقت) أظهر أفضل النتائج بعد 72 ساعة عند تركيز 800 مغ/مل باستخدام طريقة الحفر ضد بكتيريا Escherichia coli، بينما أظهر أفضل النتائج ضد بكتيريا Staphylococcus aureus بعد 72 ساعة عند تركيز 400 مغ/مل باستخدام طريقة الأقراص. تشير النتائج المتحصل عليها من التداخل بين الثلاث العوامل (نوع المذيب، التراكيز والوقت) أن المستخلص الميثانولي عند تركيز 200 مغ/مل بعد 72 ساعة باستخدام طريقة الأقراص أعلى قدرة تثبيطية ضد النوع Escherichia coli، بينما المستخلص المائي عند تركيز 600 مغ/مل بعد 72 ساعة أظهر أكبر فعالية ضد النوع Staphylococcus aureus.The experiment was performed on the plant Tribulus terrestris L. which was collected from Khobar region in Al Dhale’ Governorate, Republic of Yemen on March. The extracts used (aqueous and methanol) were prepared in Lab of Pharmacognosy, Faculty of Pharmacy – Aden University. The experiment was done on two types of bacteria, one Gram negative (Escherichia coli) and one Gram positive (Staphylococcus aureus). The antimicrobial part of the experiment was carried out in the Microbiology Lab - University of Science and Technology, Aden, Yemen. The experiment was performed in triplicates, and using three factors (Type of solvent, Time and Concentrations). The results obtained were the following: The best solvent for extracting antibacterial substances was methanol in both bacteria (E. coli and S. aureus). The concentrations that produced the highest inhibition zones in E. coli were 600 and 800 mg/ml using well method, while in S. aureus the best concentrations were 400 and 600 mg /ml. The best result was obtained after 72 h using disk method on S. aureus, and using well method on E. coli. Interaction between concentrations and type of solvent showed that the best result was obtained by methanol extract using disk method at 200 mg/ml against E. coli, while the best result against S. aureus was obtained by methanol extract using disk method at 800 mg/ml. Interaction between different times and type of solvent indicated that the best result against E. coli was observed after 72h by aqueous extract using well method, while the best result against S. aureus was observed after 72h by methanol extract using disk method. Interaction between concentrations and different times showed that the best result was obtained after 72h at concentration 800mg/ml using well method against E. coli, while the best result against S. aureus was after 72h at concentration 400mg/ml using disk method. Interaction between type of solvent, concentrations and different times indicated that the best result in E. coli was observed after 72h by methanol extract at 200mg/ml using disk method, while the best result in S. aureus was observed after 72h by aqueous extract at 600mg/ml using disk method

Quality of Primary Health Care Services Within The Framework of The National Accreditation Program

Abstract: Accreditation program (AP) has the objective of supporting the quality of primary health care (PHC) services, within the Health Sector Reform/family medicine (FM) domain. Accreditation program is implemented in Family Health Units that represent a shift from fragmented vertical PHC services, into comprehensive, integrated and continuous services. In 2000, AP has been initiated in Egypt in selected primary health care facilities. The study aims at identification of strengths and challenges regarding the quality standards of resources and process as well as efficiency (output) of the accredited versus non-accredited rural facilities. The study is an operations research quasiexperimental/ time series analysis-test and control group design. A convenient sample of three accredited family health units (AFHUs) and a control group of three non-accredited rural health units (NRHUs) located in a purposively selected health district in 6 th October governorate. Observation quality checklist (2007 & 2008) and spread sheet to report service statistics data 2005-2008 had been used. Quality standards as well as PHC services output indicators had been calculated. Findings showed that AFHUs achieved 81% of the standard quality score versus 79% for the NRHUs. Output indicators delineated non-observed differences in service efficiency regarding immunization, maternal care services and family planning. There are remaining challenges in both types of facilities related to antenatal and postnatal care. It is concluded that both the AFHUs and NRHUs are working according to vertical program momentum, with limited response to the quality dimension related to the continuity of care

Integrative pathway enrichment analysis of multivariate omics data

Multi-omics datasets represent distinct aspects of the central dogma of molecular biology. Such high-dimensional molecular profiles pose challenges to data interpretation and hypothesis generation. ActivePathways is an integrative method that discovers significantly enriched pathways across multiple datasets using statistical data fusion, rationalizes contributing evidence and highlights associated genes. As part of the ICGC/TCGA Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium, which aggregated whole genome sequencing data from 2658 cancers across 38 tumor types, we integrated genes with coding and non-coding mutations and revealed frequently mutated pathways and additional cancer genes with infrequent mutations. We also analyzed prognostic molecular pathways by integrating genomic and transcriptomic features of 1780 breast cancers and highlighted associations with immune response and anti-apoptotic signaling. Integration of ChIP-seq and RNA-seq data for master regulators of the Hippo pathway across normal human tissues identified processes of tissue regeneration and stem cell regulation. ActivePathways is a versatile method that improves systems-level understanding of cellular organization in health and disease through integration of multiple molecular datasets and pathway annotations