287 research outputs found
A lattice study of the exclusive decay amplitude, using the Clover action at
We present the results of a numerical calculation of the
form factors. The results have been obtained by studying the relevant
correlation functions at , on an lattice, using the
-improved fermion action, in the quenched approximation. From the
study of the matrix element we have
obtained the form factor which controls the exclusive decay rate. The
results are compared with the recent results from CLEO. We also discuss the
compatibility between the scaling laws predicted by the Heavy Quark Effective
Theory (HQET) and pole dominance, by studying the mass- and -dependence of
the form factors. From our analysis, it appears that the form factors follow a
mass behaviour compatible with the predictions of the HQET and that the
-dependence of is weaker than would be predicted by pole dominance.Comment: 17 pages, LaTeX + epsf.sty. Uuencoded, compressed, tar archive
including the text and one postscript figur
Boron isotopes in foraminifera : systematics, biomineralisation, and CO2 reconstruction
Funding: Fellowship from University of St Andrews, $100 (pending) from Richard Zeebe, UK NERC grants NE/N003861/1 and NE/N011716/1.The boron isotope composition of foraminifera provides a powerful tracer for CO2 change over geological time. This proxy is based on the equilibrium of boron and its isotopes in seawater, which is a function of pH. However while the chemical principles underlying this proxy are well understood, its reliability has previously been questioned, due to the difficulty of boron isotope (δ11B) analysis on foraminferal samples and questions regarding calibrations between δ11B and pH. This chapter reviews the current state of the δ11B-pH proxy in foraminfera, including the pioneering studies that established this proxy’s potential, and the recent work that has improved understanding of boron isotope systematics in foraminifera and applied this tracer to the geological record. The theoretical background of the δ11B-pH proxy is introduced, including an accurate formulation of the boron isotope mass balance equations. Sample preparation and analysis procedures are then reviewed, with discussion of sample cleaning, the potential influence of diagenesis, and the strengths and weaknesses of boron purification by column chromatography versus microsublimation, and analysis by NTIMS versus MC-ICPMS. The systematics of boron isotopes in foraminifera are discussed in detail, including results from benthic and planktic taxa, and models of boron incorporation, fractionation, and biomineralisation. Benthic taxa from the deep ocean have δ11B within error of borate ion at seawater pH. This is most easily explained by simple incorporation of borate ion at the pH of seawater. Planktic foraminifera have δ11B close to borate ion, but with minor offsets. These may be driven by physiological influences on the foraminiferal microenvironment; a novel explanation is also suggested for the reduced δ11B-pH sensitivities observed in culture, based on variable calcification rates. Biomineralisation influences on boron isotopes are then explored, addressing the apparently contradictory observations that foraminifera manipulate pH during chamber formation yet their δ11B appears to record the pH of ambient seawater. Potential solutions include the influences of magnesium-removal and carbon concentration, and the possibility that pH elevation is most pronounced during initial chamber formation under favourable environmental conditions. The steps required to reconstruct pH and pCO2 from δ11B are then reviewed, including the influence of seawater chemistry on boron equilibrium, the evolution of seawater δ11B, and the influence of second carbonate system parameters on δ11B-based reconstructions of pCO2. Applications of foraminiferal δ11B to the geological record are highlighted, including studies that trace CO2 storage and release during recent ice ages, and reconstructions of pCO2 over the Cenozoic. Relevant computer codes and data associated with this article are made available online.Publisher PDFPeer reviewe
Trends in HIV/AIDS morbidity and mortality in Eastern Mediterranean countries, 1990–2015: findings from the Global Burden of Disease 2015 study
OBJECTIVES: We used the results of the Global Burden of Disease 2015 study to estimate trends of HIV/AIDS burden in Eastern Mediterranean Region (EMR) countries between 1990 and 2015. METHODS: Tailored estimation methods were used to produce final estimates of mortality. Years of life lost (YLLs) were calculated by multiplying the mortality rate by population by age-specific life expectancy. Years lived with disability (YLDs) were computed as the prevalence of a sequela multiplied by its disability weight. RESULTS: In 2015, the rate of HIV/AIDS deaths in the EMR was 1.8 (1.4–2.5) per 100,000 population, a 43% increase from 1990 (0.3; 0.2–0.8). Consequently, the rate of YLLs due to HIV/AIDS increased from 15.3 (7.6–36.2) per 100,000 in 1990 to 81.9 (65.3–114.4) in 2015. The rate of YLDs increased from 1.3 (0.6–3.1) in 1990 to 4.4 (2.7–6.6) in 2015. CONCLUSIONS: HIV/AIDS morbidity and mortality increased in the EMR since 1990. To reverse this trend and achieve epidemic control, EMR countries should strengthen HIV surveillance, and scale up HIV antiretroviral therapy and comprehensive prevention services
Laparoscopy in management of appendicitis in high-, middle-, and low-income countries: a multicenter, prospective, cohort study.
BACKGROUND: Appendicitis is the most common abdominal surgical emergency worldwide. Differences between high- and low-income settings in the availability of laparoscopic appendectomy, alternative management choices, and outcomes are poorly described. The aim was to identify variation in surgical management and outcomes of appendicitis within low-, middle-, and high-Human Development Index (HDI) countries worldwide. METHODS: This is a multicenter, international prospective cohort study. Consecutive sampling of patients undergoing emergency appendectomy over 6 months was conducted. Follow-up lasted 30 days. RESULTS: 4546 patients from 52 countries underwent appendectomy (2499 high-, 1540 middle-, and 507 low-HDI groups). Surgical site infection (SSI) rates were higher in low-HDI (OR 2.57, 95% CI 1.33-4.99, p = 0.005) but not middle-HDI countries (OR 1.38, 95% CI 0.76-2.52, p = 0.291), compared with high-HDI countries after adjustment. A laparoscopic approach was common in high-HDI countries (1693/2499, 67.7%), but infrequent in low-HDI (41/507, 8.1%) and middle-HDI (132/1540, 8.6%) groups. After accounting for case-mix, laparoscopy was still associated with fewer overall complications (OR 0.55, 95% CI 0.42-0.71, p < 0.001) and SSIs (OR 0.22, 95% CI 0.14-0.33, p < 0.001). In propensity-score matched groups within low-/middle-HDI countries, laparoscopy was still associated with fewer overall complications (OR 0.23 95% CI 0.11-0.44) and SSI (OR 0.21 95% CI 0.09-0.45). CONCLUSION: A laparoscopic approach is associated with better outcomes and availability appears to differ by country HDI. Despite the profound clinical, operational, and financial barriers to its widespread introduction, laparoscopy could significantly improve outcomes for patients in low-resource environments. TRIAL REGISTRATION: NCT02179112
Pre-Sleep Arousal Scale (PSAS): Translation and Evaluation of Its Psychometric Properties in an Arabic Version
Aseel AlSaleh,1 Waqar Husain,2 Khaled Trabelsi,3,4 Hadeel Ghazzawi,5 Achraf Ammar,6,7 Zahra Saif,8 Seithikurippu R Pandi-Perumal,9,10 Maha M AlRasheed,11 Ahmed S BaHammam,12,13 Haitham Jahrami8,14 1Department of Family and Community Medicine, College of Medicine and Health Sciences, Arabian Gulf University, Manama, Bahrain; 2Department of Humanities, COMSATS University Islamabad, Islamabad Campus, Islamabad, Pakistan; 3High Institute of Sport and Physical Education of Sfax, University of Sfax, Sfax, 3000, Tunisia; 4Research Laboratory: Education, Motricity, Sport and Health, EM2S, LR19JS01, University of Sfax, Sfax, 3000, Tunisia; 5Nutrition and Food Technology Department, Agriculture School, The University of Jordan, Amman, Jordan; 6Department of Training and Movement Science, Institute of Sport Science, Johannes Gutenberg-University Mainz, Mainz, 55099, Germany; 7Research Laboratory, Molecular Bases of Human Pathology, LR19ES13, Faculty of Medicine of Sfax, University of Sfax, Sfax, 3000, Tunisia; 8Department of Psychiatry, Government Hospitals, Manama, Bahrain; 9Centre for Research and Development, Chandigarh University, Mohali, Punjab, 140413, India; 10Division of Research and Development, Lovely Professional University, Phagwara, Punjab, 144411, India; 11Department of Clinical Pharmacy, College of Pharmacy, King Saud University, Riyadh, 11451, Saudi Arabia; 12The University Sleep Disorders Center, Department of Medicine, College of Medicine, King Saud University, King Saud University, Riyadh, Saudi Arabia; 13King Saud University Medical City, King Saud University, Riyadh, Saudi Arabia; 14Department of Psychiatry, College of Medicine and Health Sciences, Arabian Gulf University, Manama, BahrainCorrespondence: Haitham Jahrami, Department of Psychiatry, College of Medicine and Health Sciences, Arabian Gulf University, Manama, Bahrain, Email [email protected]: The Pre-Sleep Arousal Scale (PSAS) is a well-recognized instrument utilized for measuring cognitive and somatic arousal before sleep. Although the PSAS is useful, an Arabic version of the scale has not yet been developed and validated. The current study aimed to translate the PSAS into Arabic language and evaluate its psychometric properties, such as reliability and validity, in an Arabic-speaking population.Patients and Methods: A cross-sectional survey was conducted with 438 participants who completed the Arabic version of the PSAS, along with other validated measures of insomnia, anxiety, and sleep effort.Results: The results indicated that the Arabic version of the PSAS maintained the original scale’s two-factor structure. The factor loadings for PSAS-Cognitive ranged from 0.57 to 0.75, and for PSAS-Somatic, from 0.45 to 0.70, with all loadings being statistically significant (p < 0.001). The Arabic version of the PSAS exhibited high internal consistency (McDonald’s ω = 0.86; Cronbach’s α = 0.86; Guttman’s λ 2 = 0.86; Greatest Lower Bound = 0.90) and test–retest reliability (ICC = 0.88) over two weeks. The PSAS demonstrated good concurrent and convergent validity. We documented significant large differences between individuals with “no insomnia” and those with “insomnia” symptoms across cognitive, somatic, and total pre-sleep arousal (all p < 0.001). The insomnia group consistently scored higher scores for PSAP and its subscales.Conclusion: These findings suggest that the Arabic version of the PSAS is a reliable and valid tool for assessing pre-sleep arousal in Arabic-speaking individuals.Keywords: Arabic version, insomnia, pre-sleep arousal, PSAS, psychometric properties, reliability, validit
Characterization of the Oral Fungal Microbiome (Mycobiome) in Healthy Individuals
The oral microbiome–organisms residing in the oral cavity and their collective genome–are critical components of health and disease. The fungal component of the oral microbiota has not been characterized. In this study, we used a novel multitag pyrosequencing approach to characterize fungi present in the oral cavity of 20 healthy individuals, using the pan-fungal internal transcribed spacer (ITS) primers. Our results revealed the “basal” oral mycobiome profile of the enrolled individuals, and showed that across all the samples studied, the oral cavity contained 74 culturable and 11 non-culturable fungal genera. Among these genera, 39 were present in only one person, 16 genera were present in two participants, and 5 genera were present in three people, while 15 genera (including non-culturable organisms) were present in ≥4 (20%) participants. Candida species were the most frequent (isolated from 75% of participants), followed by Cladosporium (65%), Aureobasidium, Saccharomycetales (50% for both), Aspergillus (35%), Fusarium (30%), and Cryptococcus (20%). Four of these predominant genera are known to be pathogenic in humans. The low-abundance genera may represent environmental fungi present in the oral cavity and could simply be spores inhaled from the air or material ingested with food. Among the culturable genera, 61 were represented by one species each, while 13 genera comprised between 2 and 6 different species; the total number of species identified were 101. The number of species in the oral cavity of each individual ranged between 9 and 23. Principal component (PCO) analysis of the obtained data set followed by sample clustering and UniFrac analysis revealed that White males and Asian males clustered differently from each other, whereas both Asian and White females clustered together. This is the first study that identified the “basal mycobiome” of healthy individuals, and provides the basis for a detailed characterization of the oral mycobiome in health and disease
Amphotericin B-loaded nanoparticles for local treatment of cutaneous leishmaniasis
Cutaneous leishmaniasis (CL) is an infectious, parasitic disease caused by the protozoan Leishmania. Amphotericin B (AMB) is
a macrolide polyene antibiotic presenting potent antifungal and antileishmanial activity, but due to poor water solubility at
physiological pH, side effects, and toxicity, its therapeutic efficiency is limited. In the present study, poly(lactic-co-glycolic acid)
(PLGA) nanoparticles (NPs) loaded with AMB were generated to reduce drug toxicity and facilitate localized delivery over a
prolonged time. AMB NPs were characterized for particle size, zeta potential, polydispersity index, and degree of aggregation.
In vitro assessments demonstrated its sustained activity against Leishmania major promastigotes and parasite-infected macrophages.
A single intralesional administration to infected BALB/c mice revealed that AMB NPs were more effective than AMB
deoxycholate in terms of reducing lesion area. Taken together, these findings suggest thatAMB NPs improve AMB delivery and
can be used for local treatment of CL.This research was funded by the GIP program of the
Deutsche Forschungsgemeinschaft (DFG) German Research Foundation.
EZ wish to acknowledge the financial support of the RBNI-The Russell
Berrie Nanotechnology Institute at the Technion. CLJ holds the Michael
and Penny Feiwel Chair of Dermatology
Unprocessed Viral DNA Could Be the Primary Target of the HIV-1 Integrase Inhibitor Raltegravir
Integration of HIV DNA into host chromosome requires a 3′-processing (3′-P) and a strand transfer (ST) reactions catalyzed by virus integrase (IN). Raltegravir (RAL), commonly used in AIDS therapy, belongs to the family of IN ST inhibitors (INSTIs) acting on IN-viral DNA complexes (intasomes). However, studies show that RAL fails to bind IN alone, but nothing has been reported on the behaviour of RAL toward free viral DNA. Here, we assessed whether free viral DNA could be a primary target for RAL, assuming that the DNA molecule is a receptor for a huge number of pharmacological agents. Optical spectroscopy, molecular dynamics and free energy calculations, showed that RAL is a tight binder of both processed and unprocessed LTR (long terminal repeat) ends. Complex formation involved mainly van der Waals forces and was enthalpy driven. Dissociation constants (Kds) revealed that RAL affinity for unbound LTRs was stronger than for bound LTRs. Moreover, Kd value for binding of RAL to LTRs and IC50 value (half concentration for inhibition) were in same range, suggesting that RAL binding to DNA and ST inhibition are correlated events. Accommodation of RAL into terminal base-pairs of unprocessed LTR is facilitated by an extensive end fraying that lowers the RAL binding energy barrier. The RAL binding entails a weak damping of fraying and correlatively of 3′-P inhibition. Noteworthy, present calculated RAL structures bound to free viral DNA resemble those found in RAL-intasome crystals, especially concerning the contacts between the fluorobenzyl group and the conserved 5′C4pA33′ step. We propose that RAL inhibits IN, in binding first unprocessed DNA. Similarly to anticancer drug poisons acting on topoisomerases, its interaction with DNA does not alter the cut, but blocks the subsequent joining reaction. We also speculate that INSTIs having viral DNA rather IN as main target could induce less resistance
Future and potential spending on health 2015-40: development assistance for health, and government, prepaid private, and out-of-pocket health spending in 184 countries
Background The amount of resources, particularly prepaid resources, available for health can affect access to health care and health outcomes. Although health spending tends to increase with economic development, tremendous variation exists among health financing systems. Estimates of future spending can be beneficial for policy makers and planners, and can identify financing gaps. In this study, we estimate future gross domestic product (GDP), all-sector government spending, and health spending disaggregated by source, and we compare expected future spending to potential future spending. Methods We extracted GDP, government spending in 184 countries from 1980–2015, and health spend data from 1995–2014. We used a series of ensemble models to estimate future GDP, all-sector government spending, development assistance for health, and government, out-of-pocket, and prepaid private health spending through 2040. We used frontier analyses to identify patterns exhibited by the countries that dedicate the most funding to health, and used these frontiers to estimate potential health spending for each low-income or middle-income country. All estimates are inflation and purchasing power adjusted. Findings We estimated that global spending on health will increase from US24·24 trillion (uncertainty interval [UI] 20·47–29·72) in 2040. We expect per capita health spending to increase fastest in upper-middle-income countries, at 5·3% (UI 4·1–6·8) per year. This growth is driven by continued growth in GDP, government spending, and government health spending. Lower-middle income countries are expected to grow at 4·2% (3·8–4·9). High-income countries are expected to grow at 2·1% (UI 1·8–2·4) and low-income countries are expected to grow at 1·8% (1·0–2·8). Despite this growth, health spending per capita in low-income countries is expected to remain low, at 195 (157–258) per capita in 2040. Increases in national health spending to reach the level of the countries who spend the most on health, relative to their level of economic development, would mean $321 (157–258) per capita was available for health in 2040 in low-income countries. Interpretation Health spending is associated with economic development but past trends and relationships suggest that spending will remain variable, and low in some low-resource settings. Policy change could lead to increased health spending, although for the poorest countries external support might remain essential
Global, regional, and national age-sex-specific mortality and life expectancy, 1950-2017: A systematic analysis for the Global Burden of Disease Study 2017
© 2018 The Author(s). Background: Assessments of age-specifc mortality and life expectancy have been done by the UN Population Division, Department of Economics and Social Afairs (UNPOP), the United States Census Bureau, WHO, and as part of previous iterations of the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD). Previous iterations of the GBD used population estimates from UNPOP, which were not derived in a way that was internally consistent with the estimates of the numbers of deaths in the GBD. The present iteration of the GBD, GBD 2017, improves on previous assessments and provides timely estimates of the mortality experience of populations globally. Methods: The GBD uses all available data to produce estimates of mortality rates between 1950 and 2017 for 23 age groups, both sexes, and 918 locations, including 195 countries and territories and subnational locations for 16 countries. Data used include vital registration systems, sample registration systems, household surveys (complete birth histories, summary birth histories, sibling histories), censuses (summary birth histories, household deaths), and Demographic Surveillance Sites. In total, this analysis used 8259 data sources. Estimates of the probability of death between birth and the age of 5 years and between ages 15 and 60 years are generated and then input into a model life table system to produce complete life tables for all locations and years. Fatal discontinuities and mortality due to HIV/AIDS are analysed separately and then incorporated into the estimation. We analyse the relationship between age-specifc mortality and development status using the Socio-demographic Index, a composite measure based on fertility under the age of 25 years, education, and income. There are four main methodological improvements in GBD 2017 compared with GBD 2016: 622 additional data sources have been incorporated; new estimates of population, generated by the GBD study, are used; statistical methods used in diferent components of the analysis have been further standardised and improved; and the analysis has been extended backwards in time by two decades to start in 1950. Findings: Globally, 18·7% (95% uncertainty interval 18·4-19·0) of deaths were registered in 1950 and that proportion has been steadily increasing since, with 58·8% (58·2-59·3) of all deaths being registered in 2015. At the global level, between 1950 and 2017, life expectancy increased from 48·1 years (46·5-49·6) to 70·5 years (70·1-70·8) for men and from 52·9 years (51·7-54·0) to 75·6 years (75·3-75·9) for women. Despite this overall progress, there remains substantial variation in life expectancy at birth in 2017, which ranges from 49·1 years (46·5-51·7) for men in the Central African Republic to 87·6 years (86·9-88·1) among women in Singapore. The greatest progress across age groups was for children younger than 5 years; under-5 mortality dropped from 216·0 deaths (196·3-238·1) per 1000 livebirths in 1950 to 38·9 deaths (35·6-42·83) per 1000 livebirths in 2017, with huge reductions across countries. Nevertheless, there were still 5·4 million (5·2-5·6) deaths among children younger than 5 years in the world in 2017. Progress has been less pronounced and more variable for adults, especially for adult males, who had stagnant or increasing mortality rates in several countries. The gap between male and female life expectancy between 1950 and 2017, while relatively stable at the global level, shows distinctive patterns across super-regions and has consistently been the largest in central Europe, eastern Europe, and central Asia, and smallest in south Asia. Performance was also variable across countries and time in observed mortality rates compared with those expected on the basis of development. Interpretation: This analysis of age-sex-specifc mortality shows that there are remarkably complex patterns in population mortality across countries. The fndings of this study highlight global successes, such as the large decline in under-5 mortality, which refects signifcant local, national, and global commitment and investment over several decades. However, they also bring attention to mortality patterns that are a cause for concern, particularly among adult men and, to a lesser extent, women, whose mortality rates have stagnated in many countries over the time period of this study, and in some cases are increasing
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