3D Seismic Velocity Structure Around Plate Boundaries and Active Fault Zones

Active continental margins, including most of those bordering continents facing the Pacific Ocean, have many earthquakes. These continental margins mark major plate boundaries and are usually flanked by high mountains and deep trenches, departing from the main elevations of continents and ocean basins, and they also contain active volcanoes and, sometimes, active fault zones. Thus, most earthquakes occur predominantly at deep‐sea trenches, mid‐ocean spreading ridges, and active mountain belts on continents. These earthquakes generate seismic waves; strong vibrations that propagate away from the earthquake focus at different speeds, due to the release of stored stress. Along their travel path from earthquake hypocenters to the recording stations, the seismic waves can image the internal Earth structure through the application of seismic tomography techniques. In the last few decades, there have been many advances in the theory and application of the seismic tomography methods to image the 3D structure of the Earth\u27s internal layers, especially along major plate boundaries. Applications of these new techniques to arrival time data enabled the detailed imaging of active fault zones, location of magma chambers beneath active volcanoes, and the forecasting of future major earthquakes in seismotectonically active regions all over the world

Perceptions and Expectations of Medical Students towards the Quality of Educational Services offered at A Sudanese University: How Far is the Gap?

Background: Students are the primary customers of high education service, and are becoming more aware of their consumer rights and of gaps between their expectations of service delivery and the reality of services.Objective: of this study was to investigate medical students’ perceptions and expectations of educational services quality at X University in Sudan.Methods: One hundred ninety six registered medical students in the academic year 2013- 2014, were enrolled; sample was collected through convenience sample technique. The study was conducted by the use of Modified SERVQUAL questionnaire. SPSS version 20 was used for data analysis.Results: There was a negative mean score for quality gap in all dimensions of service quality. Students perceived tangibles as quality indicators of the service quality at university, and expect universities to have modern-looking equipment, so that staff can provide efficient service to them. There was a strong student concern about teaching staff promises regarding timetables and exam schedules to be fulfilled on time, which indicated the area of most concern amongst the respondents (gap score – 1.94). A clear communication problem regarding service delivery was inferred, as students perception towards solving their problems was very low (gap score -1.91).Conclusion: students’ perceptions of services delivered by X University falls below their expectations; that indicates student’s dissatisfaction. This large gap constitutes a great challenge to the administrators and educational policy makers, who are recommended to consider students feedback as a quality indicator in the quality assurance process.Keywords: medical student, quality education, Sudan

Phytochemical composition and antimicrobial properties of Markhamia platycalyx (Baker) Sprague leaf

Purpose: To isolate new antimicrobial agents from the leaves of Markhamia platycalyx (Baker) Sprague and assess their phytochemical characteristics and antimicrobial activity. Methods: Different chromatographic and spectroscopic techniques (NMR and ESI-MS) were applied for the identification of antimicrobial compounds. Agar-well diffusion technique was used for determination of antimicrobial activity. Anti-HCV effects were investigated using VITROS Anti-HCV assay. Results: Eighteen compounds were isolated for the first time from this genus. These were phytol, noctacosanoic acid (OCTA), tormentic acid and β-sitosterol-3-O-(6'-O-heptadecanoyl)-β-Dglucopyranoside. The other compounds were β-sitosterol, ursolic acid (URSA), oleanolic acids, pomolic acid (POMA), 2-epi-tormentic and β-sitosterol-3-O-β-D-glucopyranoside. However, stigmasterol and acteoside, which were seen in previous studies, were also present. Total ethanol extract (TEE) was the most effective against Escherichia coli, with the lowest minimum inhibitory concentration (MIC) of 1.0 µg/mL. Acteoside, URSA and 2-epi-tormentic acid showed the highest antibacterial effect on Pseudomonas aeruginosa while 2-epi-tormentic acid and acteoside produced the least MIC on Candida glabrata. These effects were superior to those produced by standard antibiotics. However, 2-epitormentic acid and β-sitosterol-3-O-β-D-glucopyranoside had no anti-HCV effects. Conclusion: Due to the good antimicrobial properties of Markhamia platycalyx, it is a potential source of new antimicrobial drugs

Improving the Antimicrobial Activity of Bagasse Packaging Paper using Organophosphorus Dimers

The antimicrobial properties of bagasse paper sheets coated with natural polymers (chitosan, different ratios of (gelatin/glycerol) + chitosan, hemicellulose, hemicellulose + glycerol, hemicellulose+chitosan) or synthetic organophosphorus dimer compounds were evaluated in this work. Hemicelluloses showed moderate activity against Bacillus subtilis and Candida albicans, while chitosan showed weak activity against B. subtilis. The condition that offered the highest inhibitory activity of bagasse paper was the one coated with 1,3-diaryl-2,2,2,4,4,4-hexachlorocyclodiphosph(V)azane (where aryl is p-chloroaniline or p-anisidine). The developed bagasse papers were evaluated against Gram-positive bacteria, Gram-negative bacteria, yeasts, and fungi. The highest inhibitory activity was obtained at a concentration of 200 mg/mL for p-chloroaniline with an inhibition zone that varied for different microbes from 6.9 mm to 26 mm. The highest inhibitory activity was obtained at 300–250 mg/mL for p-anisidine against most of the pathogenic microorganisms with an inhibition zone that varied for different microbes from 8 mm to 14.75 mm. The observed antimicrobial and antifungal activity properties for bagasse paper coated with 1,3-diaryl 2,2,2,4,4,4-hexachlorocyclodiphosph(V)azane could be attributed to the presence of Cl, P atoms, and the lone pair of electrons on N atoms in the structure of the dimers

Diatomite alleviates the adverse effects of salinity stress on growth and yield of Stevia rebaudiana

ABSTRACT The present study was planned to investigate the role of diatomitein salt tolerance of Stevia rebaudiana using pot experimental. Diatomite increased the growth characters of plants, hence resulted in higher yields. In contrast, the seawater treatments alone significantly decreased these parameters in both seasons. While, treating Stevia rebaudianaplants with diatomite prior to salinity stress decreased the detrimental effectof salt stress on growth and yield.The Esterase isoenzymesprofiles has indicated that salinity, diatomite and their combinations has caused biochemical changes in Steviar. plants. On the other hand, saline water irrigation decreased Rebaudioside A concentration at the second harvest as estimated by HPLC analysis in both seasons .The effect of the interaction between salinity and diatomite was the mosteffective treatments for Rebaudioside A when Stevia rebaudianaplants treated by salt concentration 4000 ppm and 2.5 g/kgsoil diatomite

Predictors of Bicuspid Aortic Valve-Associated Aortopathy in Childhood: A Report From the MIBAVA Consortium

BACKGROUND: Bicuspid aortic valve (BAV) is the most prevalent congenital heart defect affecting 1% to 2% of the population. It is associated with ascending aorta dilatation. Valve morphology, aortic stenosis (AS), and aortic insufficiency (AI) have been proposed as potential risk factors; however, evaluating their role is difficult, as these factors are inherently related. The aim of this study was to determine whether BAV morphology and dysfunction are independent determinants for ascending aorta dilatation in pediatric patients. METHODS: A multicenter, retrospective, cross-sectional study of pediatric BAV patients followed since 2004 was performed. Imaging data were assessed for BAV morphology, severity of AS and AI, history of coarctation, and aortic dimensions. Associations were determined using multivariable regression analysis. A subset of patients undergoing aortic interventions (balloon dilation or Ross) were assessed longitudinally. RESULTS: Data were obtained from 2122 patients (68% male; median age 10.2 years). Fifty percent of patients had ascending aorta dilatation. Right and noncoronary cusp fusion, increasing AS and AI, and older age were independently associated with ascending aorta dilatation. A history of coarctation was associated with less ascending aorta dilatation. In patients with neither AS nor AI, 37% had ascending aorta dilatation (4% severe). No complications related to aortic dilatation occurred in this cohort. Aortic CONCLUSIONS: In this large pediatric cohort of patients with BAV, valve morphology, AS, and AI are independently associated with ascending aorta dilatation, suggesting that hemodynamic factors influence aortopathy. However, even in BAVs with no AS or AI, there is significant ascending aorta dilatation independent of valve morphology. Interventions that led to changes in degree of AI and AS did not seem to influence change in aortic dimensions. The current BAV cohort can be used as a reference group for expected changes in aortic dimensions during childhood

Biopiracy <i>versus </i>one-world medicine – from colonial relicts to global collaborative concepts

Background: Practices of biopiracy to use genetic resources and indigenous knowledge by Western companies without benefit-sharing of those, who generated the traditional knowledge, can be understood as form of neocolonialism.Hypothesis: : The One-World Medicine concept attempts to merge the best of traditional medicine from developing countries and conventional Western medicine for the sake of patients around the globe.Study design: Based on literature searches in several databases, a concept paper has been written. Legislative initiatives of the United Nations culminated in the Nagoya protocol aim to protect traditional knowledge and regulate benefit-sharing with indigenous communities. The European community adopted the Nagoya protocol, and the corresponding regulations will be implemented into national legislation among the member states. Despite pleasing progress, infrastructural problems of the health care systems in developing countries still remain. Current approaches to secure primary health care offer only fragmentary solutions at best. Conventional medicine from industrialized countries cannot be afforded by the impoverished population in the Third World. Confronted with exploding costs, even health systems in Western countries are endangered to burst. Complementary and alternative medicine (CAM) is popular among the general public in industrialized countries, although the efficacy is not sufficiently proven according to the standards of evidence-based medicine. CAM is often available without prescription as over-the-counter products with non-calculated risks concerning erroneous self-medication and safety/toxicity issues. The concept of integrative medicine attempts to combine holistic CAM approaches with evidence-based principles of conventional medicine.Conclusion: To realize the concept of One-World Medicine, a number of standards have to be set to assure safety, efficacy and applicability of traditional medicine, e.g. sustainable production and quality control of herbal products, performance of placebo-controlled, double-blind, randomized clinical trials, phytovigilance, as well as education of health professionals and patients

Anti-PD-1 immunotherapy leads to tuberculosis reactivation via dysregulation of TNF-alpha

Previously, we developed a 3-dimensional cell culture model of human tuberculosis (TB) and demonstrated its potential to interrogate the host-pathogen interaction (Tezera et al., 2017a). Here, we use the model to investigate mechanisms whereby immune checkpoint therapy for cancer paradoxically activates TB infection. In patients, PD-1 is expressed in Mycobacterium tuberculosis (Mtb)-infected lung tissue but is absent in areas of immunopathology. In the microsphere model, PD-1 ligands are up-regulated by infection, and the PD-1/PD-L1 axis is further induced by hypoxia. Inhibition of PD-1 signalling increases Mtb growth, and augments cytokine secretion. TNF-a is responsible for accelerated Mtb growth, and TNF-a neutralisation reverses augmented Mtb growth caused by anti-PD-1 treatment. In human TB, pulmonary TNF-a immunoreactivity is increased and circulating PD-1 expression negatively correlates with sputum TNF-a concentrations. Together, our findings demonstrate that PD-1 regulates the immune response in TB, and inhibition of PD-1 accelerates Mtb growth via excessive TNF-a secretion.</p

The ENIGMA Stroke Recovery Working Group: Big data neuroimaging to study brain–behavior relationships after stroke

The goal of the Enhancing Neuroimaging Genetics through Meta‐Analysis (ENIGMA) Stroke Recovery working group is to understand brain and behavior relationships using well‐powered meta‐ and mega‐analytic approaches. ENIGMA Stroke Recovery has data from over 2,100 stroke patients collected across 39 research studies and 10 countries around the world, comprising the largest multisite retrospective stroke data collaboration to date. This article outlines the efforts taken by the ENIGMA Stroke Recovery working group to develop neuroinformatics protocols and methods to manage multisite stroke brain magnetic resonance imaging, behavioral and demographics data. Specifically, the processes for scalable data intake and preprocessing, multisite data harmonization, and large‐scale stroke lesion analysis are described, and challenges unique to this type of big data collaboration in stroke research are discussed. Finally, future directions and limitations, as well as recommendations for improved data harmonization through prospective data collection and data management, are provided