418 research outputs found
Modified GR and Helium Nucleosynthesis
We show that a previously proposed cosmological model based on general
relativity with non vanishing divergence for the energy-momentum tensor is
consistent with the observed values for the nucleosynthesis of helium for some
values of the arbitrary parameter presented in this model. Further
more values of can be accommodated if we adopt the Randall-Sundrum
single brane model.Comment: 5 page
Observational constraints on late-time Lambda(t) cosmology
The cosmological constant, i.e., the energy density stored in the true vacuum
state of all existing fields in the Universe, is the simplest and the most
natural possibility to describe the current cosmic acceleration. However,
despite its observational successes, such a possibility exacerbates the well
known cosmological constant problem, requiring a natural explanation for its
small, but nonzero, value. In this paper we study cosmological consequences of
a scenario driven by a varying cosmological term, in which the vacuum energy
density decays linearly with the Hubble parameter. We test the viability of
this scenario and study a possible way to distinguish it from the current
standard cosmological model by using recent observations of type Ia supernova
(Supernova Legacy Survey Collaboration), measurements of the baryonic acoustic
oscillation from the Sloan Digital Sky Survey and the position of the first
peak of the cosmic microwave background angular spectrum from the three-year
Wilkinson Microwave Anisotropy Probe.Comment: Some important revisions. To appear in Physical Review
Cosmic Acceleration With A Positive Cosmological Constant
We have considered a cosmological model with a phenomenological model for the
cosmological constant of the form \Lambda=\bt\fr{\ddot R}{R}, \bt is a
constant. For age parameter consistent with observational data the Universe
must be accelerating in the presence of a positive cosmological constant. The
minimum age of the Universe is , where is the present Hubble
constant. The cosmological constant is found to decrease as . Allowing
the gravitational constant to change with time leads to an ever increasing
gravitational constant at the present epoch. In the presence of a viscous fluid
this decay law for is equivalent to the one with () provided \alpha=\fr{\bt}{3(\bt-2)}. The
inflationary solution obtained from this model is that of the de-Sitter type.Comment: a more revised versio
Limits on the integration constant of the dark radiation term in Brane Cosmology
We consider the constraints from primordial Helium abundances on the constant
of integration of the dark radiation term of the brane-world generalized
Friedmann equation derived from the Randall-Sundrum Single brane model. We
found that -- using simple, approximate and semianalytical Method -- that the
constant of integration is limited to be between -8.9 and 2.2 which limits the
possible contribution from dark radiation term to be approximately between -27%
to 7% of the background photon energy density.Comment: 8 page
The burden of disease in Greece, health loss, risk factors, and health nancing, 2000â16: an analysis of the Global Burden of Disease Study 2016
Background Following the economic crisis in Greece in 2010, the country's ongoing austerity measures include a substantial contraction of health-care expenditure, with reports of subsequent negative health consequences. A comprehensive evaluation of mortality and morbidity is required to understand the current challenges of public health in Greece. Methods We used the results of the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2016 to describe the patterns of death and disability among those living in Greece from 2000 to 2010 (pre-austerity) and 2010 to 2016 (post-austerity), and compared trends in health outcomes and health expenditure to those in Cyprus and western Europe. We estimated all-cause mortality from vital registration data, and we calculated cause-specific deaths and years of life lost. Age-standardised mortality rates were compared using the annualised rate of change (ARC). Mortality risk factors were assessed using a comparative risk assessment framework for 84 risk factors and clusters to calculative summary exposure values and population attributable fraction statistics. We assessed the association between trends in total, government, out-of-pocket, and prepaid public health expenditure and all-cause mortality with a segmented correlation analysis. Findings All-age mortality in Greece increased from 944·5 (95% uncertainty interval [UI] 923·1â964·5) deaths per 100â000 in 2000 to 997·8 (975·4â1018) in 2010 and 1174·9 (1107·4â1243·2) in 2016, with a higher ARC after 2010 and the introduction of austerity (2·72% [1·65 to 3·74] for 2010â16) than before (0·55% [0·24 to 0·85] for 2000â10) or in western Europe during the same period (0·86% [0·54 to 1·17]). Age-standardised reduction in ARC approximately halved from 2000â10 (â1·61 [95% UI â1·91 to â1·30]) to 2010â16 (â0·87% [â2·03 to 0·20]), with post-2010 ARC similar to that in Cyprus (â0·86% [â1·4 to â0·36]) and lower than in western Europe (â1·14% [â1·48 to â0·81]). Mortality changes in Greece coincided with a rapid decrease in government health expenditure, but also with aggregate population ageing from 2010 to 2016 that was faster than observed in Cyprus. Causes of death that increased were largely those that are responsive to health care. Comparable temporal and age patterns were noted for non-fatal health outcomes, with a somewhat faster rise in years lived with disability since 2010 in Greece compared with Cyprus and western Europe. Risk factor exposures, especially high body-mass index, smoking, and alcohol use, explained much of the mortality increase in Greek adults aged 15â49 years, but only explained a minority of that in adults older than 70 years. Interpretation The findings of increases in total deaths and accelerated population ageing call for specific focus from health policy makers to ensure the health-care system is equipped to meet the needs of the people in Greece
Health promotion, disease prevention and periodic health checks: perceptions and practice among family physicians in eastern Mediterranean region
Introduction: The aim of this study was to identify the current practices and perceptions of family physicians regarding health promotion, disease prevention including periodic screening and health checks in Eastern Mediterranean Region. Methods: A multi-country cross-sectional study was conducted in six countries of EMR, from September 2014 to March 2015. Family Physicians who were currently practicing in different countries of EMR were invited to participate in the study through email. A pre-tested structured questionnaire was used for data collection. Data was entered and analyzed on SPSS 19 and logistic regression analysis was performed. Results: A total of 100 physicians data was included in the final analysis. The majority were female physicians (76%): 63% were 25 to 35 years of age. Approximately 53% of Family physicians always recommend periodic screening and health checks to their patients. The common screening question asked to patients in medical history was related to their blood pressure (86%). Almost all (99%) of the Family physicians believe they should conduct periodic health checks. Those who had postgraduate training in Family Medicine (OR: 0.5; 95% CI: 0.39-1.67) and attended CME sessions regularly (OR: 0.11; 95% CI: 0.01-0.93), are more likely to recommend periodic screening and health checks to their patients. Conclusion: Periodic screening and health check is an important strategy to prevent disease and maintain health. It is an underutilized practice and a great need exists for its implementation in family practice
Infantile hypertrophic pyloric stenosis: a single institutionâs experience
Background/purpose Infantile hypertrophic pyloric stenosis (IHPS) is said to be relatively common in the western world, but its incidence in the Kingdom of Saudi Arabia is unknown. We set out to study the incidence of IHPS in children presenting at our hospital and review the clinical presentation and treatment outcomes of such patients.Patients and methods A retrospective chart review of all cases with IHPS admitted to a tertiary hospital, Riyadh Military Hospital, over 18 years (1990â2008) was conducted. Diagnosis was confirmed by ultrasonography according to the length of the pyloric channel and thickness of the pyloric muscles. An analysis of demographic data, clinical presentation, diagnostic modality, and associated congenital anomalies was carried out. Operative technique, postoperative course, and complication rates were identified.Results The review of the medical records showed 22 patients with a diagnosis of IHPS. The incidence rate of IHPS was 1.4/10 000 live births. Demographically, most cases presented in the first month of life. It is more common in boys. In all, 55% of infants were first borns. Clinically, nonbilious projectile vomiting was the main symptom. Mild dehydration was found in half of the cases with alkalotic changes. Ultrasonography was the main diagnostic modality in 82% of cases. Others were diagnosed by contrast study. Open Ramstedt pyloromyotomy was the surgical approach in 20 (91%) cases and the laparoscopic approach in 2 cases (9%). Fourteen (14%) patients had an associated congenital inguinal hernia. The mean length of hospital stay was 5.5 days. The most common postoperative complication was wound infection in 4.5% of patients. Incidence of IHPS had obvious seasonal association.Conclusion Incidence of IHPS at our hospital (the biggest hospital in the Kingdom of Saudi Arabia with an annual birth record of 14 000) is far less common than international incidences reported in North America and Europe. More reports from Saudi Arabia, the Middle East, and Asia are recommended to support the rarity of IHPS in this region of the world. Seasonal variation suggests a possible etiological role for environmental factors. It is of practical use for both epidemiologists and clinicians for future comparability.Keywords: incidence, infantile pyloric stenosis, risk factor
Alarming update on incidence of Crimean-Congo hemorrhagic fever in Iraq in 2023
Objectives: In 2021, large outbreak of Crimean-Congo hemorrhagic fever (CCHF) was reported in Iraq and cases have increased without any significant control measures. To raise awareness about the increasing cases in different regions of Iraq, hence remind the necessity to tackle contributing factors and potential outbreak interventions. Methods: The study included 511 polymerase chain reaction-confirmed CCHF infection cases out of 1827 suspected cases from 18 Provinces from January to August 2023. Approval from the Ministry of Health for data analyzed. Results: Out of 1827 suspected cases, 511 were confirmed positive by polymerase chain reaction. The total case fatality rate (CFR) was 12.7 with varying severity levels among provinces. Erbil had the highest CFR, 38.5, while Sulaimaniya and Anbar report no deaths. Independent t-test showed a significant difference in CFR between provinces west and south of Baghdad compared to north (P <0.05). Trend showed significant surges after Iftar and Adha holidays. Conclusion: Differences in CFR among provinces around the religious ceremonies, highlight the need for one public health intervention strategy. Increased temperatures affected vector behavior. Uncontrolled animal movement with neighboring countries is an important factor. Virus or host determinants can shape the clinical case outcomes, which need clinical and extensive laboratory studies to unravel the reasons leading to death
Supernova constraints on decaying vacuum cosmology
There is mounting observational evidence that the expansion of our Universe
is undergoing a late-time acceleration. Among many proposals to describe this
phenomenon, the cosmological constant seems to be the simplest and the most
natural explanation. However, despite its observational successes, such a
possibility exacerbates the well known cosmological constant problem, requiring
a natural explanation for its small, but nonzero, value. In this paper we
consider a cosmological scenario driven by a varying cosmological term, in
which the vacuum energy density decays linearly with the Hubble parameter. We
show that this model is indistinguishable from the standard one in that the
early radiation phase is followed by a long dust-dominated era, and only
recently the varying cosmological term becomes dominant, accelerating the
cosmic expansion. In order to test the viability of this scenario we have used
the most recent type Ia supernova data, i.e., the High-Z SN Search (HZS) Team
and the Supernova Legacy Survey (SNLS) Collaboration data. In particular, for
the SNLS sample we have found the present matter density and Hubble parameters
in the intervals [0.27, 0.37] and [0.68, 0.72], respectively (at 95% c.l.),
which is in good agreement with the currently accepted estimates for these
parameters.Comment: Version accepted for publication in Physical Review
New leadership model for family physicians in the Eastern Mediterranean region: a pilot study across selected countries
Background: Family Medicine is growing rapidly across the Eastern Mediterranean Region. However, it needs support in terms of overall health system development. This will require strong leadership in family medicine to implement the change required to improve current conditions.
Objective: To collect data that will support the development of a leadership program for the future family physicians in the region.
Methods: A cross-sectional study was conducted from July 2016 to September 2016 in eight countries of the Eastern Mediterranean Region, (Bahrain, Egypt, Iraq, Jordan, Kuwait, Qatar, Pakistan, and Saudi Arabia). These countries were selected to obtain perceptions of Family Physicians (FPs) regarding the current leadership model and to explore the need for a new future innovative model in Family Medicine (FM) across the region.
Results: The information of 68 family physicians was included in the final analysis. The majority of the FPs was females as compared to males (71% vs. 29%). Forty-four percent of the FPs had 10 to 19 years of experience. Almost all of the FPs (96%) had completed some training in family medicine after graduation. About three fifths of the FPs had completed postgraduate qualifications and out of those, 64% had passed Board or Membership Examinations. Twenty-one percent of them are currently in a leadership role and 45% who were not in any leadership role responded that the current situation of FM in their country is poor. All of the leaders believed that it is important to develop strong leadership in FM to take the specialty forward. Almost similar proportions (67% and 64%) of leaders and non-leaders thought that establishing regional associations would enhance the FM practice model. Approximately two thirds of leaders (67%) responded that the current role of decision makers in the Ministry of Health (MOH) regarding capacity building in FM is not effective. The majority of the FPs (54% and 38%) considers that the existing postgraduate curriculum does not address leadership skill development in FM. Eighty-eight percent of the FPs both from leadership and non-leadership groups agreed that academic institutions and practicing FPs can play an effective leadership role in taking FM forward.
Conclusion: The Family Medicine specialty will have to develop leadership capabilities in line with todayâs fast-moving changes in healthcare for it to obtain the due recognition in the healthcare delivery system
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