533 research outputs found

    Anisotropic Inflation from Charged Scalar Fields

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    We consider models of inflation with U(1) gauge fields and charged scalar fields including symmetry breaking potential, chaotic inflation and hybrid inflation. We show that there exist attractor solutions where the anisotropies produced during inflation becomes comparable to the slow-roll parameters. In the models where the inflaton field is a charged scalar field the gauge field becomes highly oscillatory at the end of inflation ending inflation quickly. Furthermore, in charged hybrid inflation the onset of waterfall phase transition at the end of inflation is affected significantly by the evolution of the background gauge field. Rapid oscillations of the gauge field and its coupling to inflaton can have interesting effects on preheating and non-Gaussianities.Comment: minor changes, references added, figures are modified, conforms JCAP published versio

    Neuropsychological function in relation to dysmenorrhea in adolescents

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    Objective: Hormonal variations during the menstrual cycle may affect emotional regulation. We aimed to investigate the association between dysmenorrhea (the severe abdominal pain and cramps associated with menstruation) and cognitive abilities, emotional function and sleep patterns in adolescent girls. Moreover, we evaluated the frequency of premenstrual syndrome (PMS) in our population and then divided them into 4 groups: subjects with only PMS; subjects with only dysmenorrhea; individuals with both PMS and dysmenorrhea and normal subjects. Study design: In this cross sectional study, 897 adolescent girls who had entered menarche were recruited. Of these, 35.9% had only dysmenorrhea, 14.9% had only PMS, 32.7% had both PMS and dysmenorrhea while 16.5% had no PMS and/or dysmenorrhea (Normal). We assessed the tests for cognitive, emotional function and sleep patterns were compared for these groups. Results: Individuals in the dysmenorrhea group had significantly higher depression, aggression, insomnia, daytime sleepiness and sleep apnea scores compared to normal controls and the PMS group, but did not have significantly different cognitive ability (P value < 0.05). These differences were strongly correlated to pain intensity (P < 0.001). However, there were no significant differences between those with only PMS and control subjects with regard to cognitive ability, emotional function and sleep pattern tests. Conclusions: Dysmenorrhea is highly prevalent among adolescents and appears to be associated with depressive mood, a tendency to aggressive behavior and sleep disorders among adolescent girls. (C) 2017 Elsevier B.V. All rights reserved

    Dynamics of laser-bumped electron–hole semiconductor plasma

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    Electron–hole pairs in semiconductors can be stimulated by a laser beam with energy larger than the energy gap of the semiconductor. The interaction between an electron–hole plasma with a laser beam can be a source of instability. The dependence of the instability on the electron and hole temperatures and the unperturbed potential of the incident laser are examined. Using Maxwell’s equations along with electron–hole fluid equations, an evolution equation describing the system is obtained. The latter is reduced to an energy equation that characterizes localized pulse propagation

    Conversion of fused knee following distal femur tumor surgery to total knee arthroplasty

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    Conversion of knee arthrodesis to total knee arthroplasty is a difficult procedure accompanied by many complications due to soft tissue and extensor mechanism contracture and bone defects. We report two cases of distal femur osteosarcoma that had been undergone wide resection arthrodesis initially. Arthrodesis was converted to total knee arthroplasty with hinged prosthesis after many years. We describe patients' history and outline their surgical therapy and prognosis. To the best of the authors' knowledge, few cases have been previously reported in the literature. © 2013, Iranian Red Crescent Medical Journal

    Global, regional, and national comparative risk assessment of 84 behavioural, environmental and occupational, and metabolic risks or clusters of risks for 195 countries and territories, 1990–2017 : a systematic analysis for the Global Burden of Disease Study 2017

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    Background: The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2017 comparative risk assessment (CRA) is a comprehensive approach to risk factor quantification that offers a useful tool for synthesising evidence on risks and risk outcome associations. With each annual GBD study, we update the GBD CRA to incorporate improved methods, new risks and risk outcome pairs, and new data on risk exposure levels and risk outcome associations. Methods: We used the CRA framework developed for previous iterations of GBD to estimate levels and trends in exposure, attributable deaths, and attributable disability-adjusted life-years (DALYs), by age group, sex, year, and location for 84 behavioural, environmental and occupational, and metabolic risks or groups of risks from 1990 to 2017. This study included 476 risk outcome pairs that met the GBD study criteria for convincing or probable evidence of causation. We extracted relative risk and exposure estimates from 46 749 randomised controlled trials, cohort studies, household surveys, census data, satellite data, and other sources. We used statistical models to pool data, adjust for bias, and incorporate covariates. Using the counterfactual scenario of theoretical minimum risk exposure level (TMREL), we estimated the portion of deaths and DALYs that could be attributed to a given risk. We explored the relationship between development and risk exposure by modelling the relationship between the Socio-demographic Index (SDI) and risk-weighted exposure prevalence and estimated expected levels of exposure and risk-attributable burden by SDI. Finally, we explored temporal changes in risk-attributable DALYs by decomposing those changes into six main component drivers of change as follows: (1) population growth; (2) changes in population age structures; (3) changes in exposure to environmental and occupational risks; (4) changes in exposure to behavioural risks; (5) changes in exposure to metabolic risks; and (6) changes due to all other factors, approximated as the risk-deleted death and DALY rates, where the risk-deleted rate is the rate that would be observed had we reduced the exposure levels to the TMREL for all risk factors included in GBD 2017. Findings: In 2017,34.1 million (95% uncertainty interval [UI] 33.3-35.0) deaths and 121 billion (144-1.28) DALYs were attributable to GBD risk factors. Globally, 61.0% (59.6-62.4) of deaths and 48.3% (46.3-50.2) of DALYs were attributed to the GBD 2017 risk factors. When ranked by risk-attributable DALYs, high systolic blood pressure (SBP) was the leading risk factor, accounting for 10.4 million (9.39-11.5) deaths and 218 million (198-237) DALYs, followed by smoking (7.10 million [6.83-7.37] deaths and 182 million [173-193] DALYs), high fasting plasma glucose (6.53 million [5.23-8.23] deaths and 171 million [144-201] DALYs), high body-mass index (BMI; 4.72 million [2.99-6.70] deaths and 148 million [98.6-202] DALYs), and short gestation for birthweight (1.43 million [1.36-1.51] deaths and 139 million [131-147] DALYs). In total, risk-attributable DALYs declined by 4.9% (3.3-6.5) between 2007 and 2017. In the absence of demographic changes (ie, population growth and ageing), changes in risk exposure and risk-deleted DALYs would have led to a 23.5% decline in DALYs during that period. Conversely, in the absence of changes in risk exposure and risk-deleted DALYs, demographic changes would have led to an 18.6% increase in DALYs during that period. The ratios of observed risk exposure levels to exposure levels expected based on SDI (O/E ratios) increased globally for unsafe drinking water and household air pollution between 1990 and 2017. This result suggests that development is occurring more rapidly than are changes in the underlying risk structure in a population. Conversely, nearly universal declines in O/E ratios for smoking and alcohol use indicate that, for a given SDI, exposure to these risks is declining. In 2017, the leading Level 4 risk factor for age-standardised DALY rates was high SBP in four super-regions: central Europe, eastern Europe, and central Asia; north Africa and Middle East; south Asia; and southeast Asia, east Asia, and Oceania. The leading risk factor in the high-income super-region was smoking, in Latin America and Caribbean was high BMI, and in sub-Saharan Africa was unsafe sex. O/E ratios for unsafe sex in sub-Saharan Africa were notably high, and those for alcohol use in north Africa and the Middle East were notably low. Interpretation: By quantifying levels and trends in exposures to risk factors and the resulting disease burden, this assessment offers insight into where past policy and programme efforts might have been successful and highlights current priorities for public health action. Decreases in behavioural, environmental, and occupational risks have largely offset the effects of population growth and ageing, in relation to trends in absolute burden. Conversely, the combination of increasing metabolic risks and population ageing will probably continue to drive the increasing trends in non-communicable diseases at the global level, which presents both a public health challenge and opportunity. We see considerable spatiotemporal heterogeneity in levels of risk exposure and risk-attributable burden. Although levels of development underlie some of this heterogeneity, O/E ratios show risks for which countries are overperforming or underperforming relative to their level of development. As such, these ratios provide a benchmarking tool to help to focus local decision making. Our findings reinforce the importance of both risk exposure monitoring and epidemiological research to assess causal connections between risks and health outcomes, and they highlight the usefulness of the GBD study in synthesising data to draw comprehensive and robust conclusions that help to inform good policy and strategic health planning

    Mapping 123 million neonatal, infant and child deaths between 2000 and 2017

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    Since 2000, many countries have achieved considerable success in improving child survival, but localized progress remains unclear. To inform efforts towards United Nations Sustainable Development Goal 3.2—to end preventable child deaths by 2030—we need consistently estimated data at the subnational level regarding child mortality rates and trends. Here we quantified, for the period 2000–2017, the subnational variation in mortality rates and number of deaths of neonates, infants and children under 5 years of age within 99 low- and middle-income countries using a geostatistical survival model. We estimated that 32% of children under 5 in these countries lived in districts that had attained rates of 25 or fewer child deaths per 1,000 live births by 2017, and that 58% of child deaths between 2000 and 2017 in these countries could have been averted in the absence of geographical inequality. This study enables the identification of high-mortality clusters, patterns of progress and geographical inequalities to inform appropriate investments and implementations that will help to improve the health of all populations

    From competency mapping to Digital Twin integration: developing a Next-Gen Digital Project Manager model for Smart construction

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    The digital transformation of the construction industry has outpaced the evolution of traditional project management competency frameworks, leaving many Project Managers (PMs) underprepared to meet the demands of emerging technologies such as Digital Twins (DTs). This study develops and validates a Next-Gen Digital PM Competency List tailored to the Smart Built Environment (SBE) through a structured two-stage methodology. Stage 1 applied a three-phase process comprising (1) a Systematic Literature Review (SLR), (2) NVivo-based thematic analysis, and (3) Large Language Model (LLM)-driven synthesis. These phases identified, categorised, and defined 55 digital PM competencies, systematically organised into Skills, Knowledge, and Core Personality Traits. Stage 2 evaluates the practical relevance of these competencies by mapping them against six thematic functional requirements of DTs, including interoperability and integration, real-time data management, simulation and predictive modelling, cybersecurity and data governance, stakeholder collaboration, and scalability and lifecycle continuity. DTs were selected as an exemplar because they integrate multiple digital technologies, Building Information Modelling (BIM), Internet of Things (IoT), Artificial Intelligence (AI), and cloud computing, making them a representative test case for evaluating competency alignment in digital transformation. The mapping confirmed strong alignment in digital integration and collaboration while exposing gaps in cybersecurity readiness and lifecycle resilience. The resulting framework provides a validated reference for competency benchmarking, targeted training, and digital leadership development. By equipping PMs with the competencies to lead, manage, and support digitally enabled projects, this research contributes directly to advancing smart and sustainable construction practices in the digital built environment

    Two kinds of rogue waves of the general nonlinear Schr\"odinger equation with derivative

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    In this letter,the designable integrability(DI) of the variable coefficient derivative nonlinear Schr\"odinger equation (VCDNLSE) is shown by construction of an explicit transformation which maps VCDNLSE to the usual derivative nonlinear Schr\"odinger equation(DNLSE). One novel feature of VCDNLSE with DI is that its coefficients can be designed artificially and analytically by using transformation. What is more, from the rogue wave and rational traveling solution of the DNLSE, we get two kinds of rogue waves of the VCDNLSE by this transformation. One kind of rogue wave has vanishing boundary condition, and the other non-vanishing boundary condition. The DI of the VCDNLSE also provides a possible way to control the profile of the rogue wave in physical experiments.Comment: 8 pages, 5 figure
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