scholarly journals The diversity of the circumgalactic medium around z = 0 Milky Way-mass galaxies from the Auriga simulations

2019 ◽  
Vol 488 (1) ◽  
pp. 135-152 ◽  
Author(s):  
Maan H Hani ◽  
Sara L Ellison ◽  
Martin Sparre ◽  
Robert J J Grand ◽  
Rüediger Pakmor ◽  
...  
Keyword(s):  
Star Formation ◽  
Environmental Factors ◽  
Active Galactic Nucleus ◽  
Observational Studies ◽  
Milky Way ◽  
Narrow Range ◽  
Gas Reservoirs ◽  
Circumgalactic Medium ◽  
The Impact

ABSTRACT Galaxies are surrounded by massive gas reservoirs (i.e. the circumgalactic medium; CGM) which play a key role in their evolution. The properties of the CGM, which are dependent on a variety of internal and environmental factors, are often inferred from absorption line surveys which rely on a limited number of single lines-of-sight. In this work we present an analysis of 28 galaxy haloes selected from the Auriga project, a cosmological magneto-hydrodynamical zoom-in simulation suite of isolated Milky Way-mass galaxies, to understand the impact of CGM diversity on observational studies. Although the Auriga haloes are selected to populate a narrow range in halo mass, our work demonstrates that the CGM of L⋆ galaxies is extremely diverse: column densities of commonly observed species span ∼3 − 4 dex and their covering fractions range from ${\sim } 5$ to $90{{\ \rm per\ cent}}$. Despite this diversity, we identify the following correlations: 1) the covering fractions (CF) of hydrogen and metals of the Auriga haloes positively correlate with stellar mass, 2) the CF of H i, C iv, and Si ii anticorrelate with active galactic nucleus luminosity due to ionization effects, and 3) the CF of H i, C iv, and Si ii positively correlate with galaxy disc fraction due to outflows populating the CGM with cool and dense gas. The Auriga sample demonstrates striking diversity within the CGM of L⋆ galaxies, which poses a challenge for observations reconstructing CGM characteristics from limited samples, and also indicates that long-term merger assembly history and recent star formation are not the dominant sculptors of the CGM.

scholarly journals On the safety and effectiveness of COVID-19 vaccines, certainties and uncertainties

2021 ◽  
Vol 9 (4) ◽  
pp. 16-24
Author(s):  
Ana Cecilia Amado Xavier de Oliveira ◽  
◽  
Isabella Fernandes Delgado ◽  
Francisco José Roma Paumgartten ◽  
◽  
...  
Keyword(s):  
Observational Studies ◽  
Clinical Trial Data ◽  
Vaccine Safety ◽  
Efficacy And Safety ◽  
Phase 3 ◽  
Degree Of Protection ◽  
Overwhelming Evidence ◽  
The Impact ◽  
Site Pain

Introduction: The COVID-19 vaccines in use (inactivaded virus, encapsulated m-RNA, non-replicating adenovirus-vectored DNA) were clinically tested in randomized placebocontrolled phase-3 studies. Objective: To address certainties and uncertainties about safety and effectiveness of COVID-19 vaccines that were approved for use in various countries. Method: The evidence provided by clinical studies on the efficacy and safety of COVID-19 vaccines was critically appraised. Results: COVID-19 vaccines proved to be efficacious and safe in clinical trials. Adverse events were mostly those of minor severity commonly noted with other vaccines such as injection site pain, mild flu-like symptoms, headache and asthenia. Although being very rare, anaphylaxis-like reactions were noted with mRNA vaccines. Uncertainties regarding vaccine effectiveness refer mainly to the (long-term) duration of immunity provided by vaccination, the degree of protection conferred to elderly people, and how effective vaccines are against emerging SARS-CoV-2 variants. There are few uncertainties about vaccine safety including the absence of clinical trial data in pregnant women (and the impact on the unborn child), children and adolescents. Conclusions: Notwithstanding the knowledge gaps about effectiveness and safety of COVID-19 vaccines (to be further addressed by observational studies), there is overwhelming evidence that public health benefits of vaccination by far outweigh any foreseeable risk.

Immunological footprint: the development of a child's immune system in environments rich in microorganisms and parasites

Parasitology ◽  
2011 ◽  
Vol 138 (12) ◽  
pp. 1508-1518 ◽  
Author(s):  
YENNY DJUARDI ◽  
LINDA J. WAMMES ◽  
TANIAWATI SUPALI ◽  
ERLIYANI SARTONO ◽  
MARIA YAZDANBAKHSH
Keyword(s):  
Immune System ◽  
Environmental Factors ◽  
Later Life ◽  
Third Party ◽  
Middle Income ◽  
Middle Income Countries ◽  
Geographical Regions ◽  
Micro Organisms ◽  
The Impact

SUMMARYThe shaping of a child's immune system starts in utero, with possible long-term consequences in later life. This review highlights the studies conducted on the development of the immune system in early childhood up to school-age, discussing the impact that environmental factors may have. Emphasis has been put on studies conducted in geographical regions where exposure to micro-organisms and parasites are particularly high, and the effect that maternal exposures to these may have on an infant's immune responses to third-party antigens. In this respect we discuss the effect on responses to vaccines, co-infections and on the development of allergic disorders. In addition, studies of the impact that such environmental factors may have on slightly older (school) children are highlighted emphasizing the need for large studies in low to middle income countries, that are sufficiently powered and have longitudinal follow-up components to understand the immunological footprint of a child and the consequences throughout life.

scholarly journals Physical properties and scaling relations of molecular clouds: the impact of star formation

2020 ◽  
Vol 500 (3) ◽  
pp. 3552-3568
Author(s):  
Kearn Grisdale
Keyword(s):  
Star Formation ◽  
Molecular Clouds ◽  
Milky Way ◽  
Free Fall ◽  
Scaling Relations ◽  
Formation Method ◽  
Hydrodynamical Simulations ◽  
Formation Efficiency ◽  
The Impact ◽  
Very High

ABSTRACT Using hydrodynamical simulations of a Milky Way-like galaxy, reaching 4.6 pc resolution, we study how the choice of star formation criteria impacts both galactic and giant molecular cloud (GMC) scales. We find that using a turbulent, self-gravitating star formation criteria leads to an increase in the fraction of gas with densities between 10 and $10^{4}{\, \rm {cm^{-3}}}$ when compared with a simulation using a molecular star formation method, despite both having nearly identical gaseous and stellar morphologies. Furthermore, we find that the site of star formation is effected with the the former tending to only produce stars in regions of very high density (${\gt}10^{4}{\, \rm {cm^{-3}}}$) gas, while the latter forms stars along the entire length of its spiral arms. The properties of GMCs are impacted by the choice of star formation criteria with the former method producing larger clouds. Despite the differences, we find that the relationships between clouds properties, such as the Larson relations, remain unaffected. Finally, the scatter in the measured star formation efficiency per free-fall time of GMCs remains present with both methods and is thus set by other factors.

Strategic Culture and Environmental Dimensions as Determinants of Anomie in Publicly-Traded and Privately-Held Firms

2011 ◽  
Vol 21 (3) ◽  
pp. 473-502 ◽  
Author(s):  
Jean L. Johnson ◽  
Kelly D. Martin ◽  
Amit Saini
Keyword(s):  
Environmental Factors ◽  
Organizational Factors ◽  
Strategic Flexibility ◽  
Publicly Traded ◽  
Technological Turbulence ◽  
Ethics Research ◽  
Strategic Aggressiveness ◽  
The Impact ◽  
Privately Held

ABSTRACT:Anomie is a condition in which normative guidelines for governing conduct are absent. Using survey data from a sample of U.S. manufacturing firms, we explore the impact of internal (cultural) and external (environmental) determinants of organizational anomie. We suggest that four internal organizational factors can generate or suppress organizational anomie, including strategic aggressiveness, long-term orientation, competitor orientation, and strategic flexibility. Similarly, we argue that external contextual factors, including competitive intensity and technological turbulence, can influence organizational anomie. We extend anomie and ethics research by considering the impact of these firm cultural and environmental factors according to whether firms are publicly-traded or privately-held. Findings demonstrate that a number of firm cultural and environmental factors can generate or reduce anomie in firms. Moreover, strategic aggressiveness, long-term orientation, and strategic flexibility influence organizational anomie differently depending on whether the firm is publicly-traded or privately-held. Theoretical and practical implications of our findings are discussed.

scholarly journals Evaluating the impacts of environmental factors on soil moisture temporal dynamics at different time scales

2020 ◽  
Author(s):  
Qi Chai ◽  
Tiejun Wang ◽  
Chongli Di
Keyword(s):  
Soil Moisture ◽  
Environmental Factors ◽  
Time Scales ◽  
Temporal Dynamics ◽  
Soil Moisture Dynamics ◽  
Temporal Variance ◽  
The Impact ◽  
Moisture Dynamics ◽  
Different Time Scales

Abstract Soil moisture displays complex spatiotemporal patterns across scales, making it important to disentangle the impacts of environmental factors on soil moisture temporal dynamics at different time scales. This study evaluated the factors affecting soil moisture dynamics at different time scales using long-term soil moisture data obtained from Nebraska and Utah. The empirical mode decomposition method was employed to decompose soil moisture time series into different temporal components with several intrinsic mode functions (IMFs) and one residual component. Results showed that the percent variance contribution (PVC) of IMFs to the total soil moisture temporal variance tended to increase for the IMFs with longer time periods. It indicated that the long-term soil moisture variations in study regions were mainly determined by low-temporal frequency signals related to seasonal climate and vegetation variations. Besides, the PVCs at short- and medium-temporal ranges were positively correlated with climate dryness, while negatively at longer temporal ranges. Moreover, the results suggested that the impact of climate on soil moisture dynamics at different time scales might vary across different climate zones, while soil effect was comparatively less in both regions. It provides additional insights into understanding soil moisture temporal dynamics in regions with contrasting climatic conditions.

Long-Term Quality of Life After Extracorporeal Membrane Oxygenation in ARDS Survivors: Systematic Review and Meta-Analysis

2017 ◽  
Vol 35 (3) ◽  
pp. 233-243 ◽  
Author(s):  
M. Elizabeth Wilcox ◽  
Valente Jaramillo-Rocha ◽  
Carol Hodgson ◽  
Michael S. Taglione ◽  
Niall D. Ferguson ◽  
...  
Keyword(s):  
Quality Of Life ◽  
Extracorporeal Membrane Oxygenation ◽  
Critically Ill ◽  
Observational Studies ◽  
Membrane Oxygenation ◽  
Critically Ill Adults ◽  
The Impact ◽  
Ill Adults

Purpose: Extracorporeal membrane oxygenation (ECMO) is an increasingly prevalent treatment for acute respiratory failure (ARF). To evaluate the impact of ECMO support on long-term outcomes for critically ill adults with ARF. Methods: We searched electronic databases 1948 through to November 30 2016; selected controlled trials or observational studies of critically ill adults with acute respiratory distress syndrome, examining long-term morbidity specifically health-related quality of life (HRQL); 2 authors independently selected studies, extracted data, and assessed methodological quality. Analysis: Of the 633 citations, 1 randomized controlled trial and 5 observational studies met the selection criteria. Overall quality of observational studies was moderate to high (mean score on Newcastle-Ottawa scale, 7.2/9; range, 6-8). In 3 studies (n = 245), greater decrements in HRQL were seen for survivors of ECMO when compared to survivors of conventional mechanical ventilation (CMV) as measured by the Short Form 36 (SF-36) scores ([ECMO-CMV]: 5.40 [95% confidence interval, CI, 4.11 to 6.68]). As compared to CMV survivors, those who received ECMO experienced significantly less psychological morbidity (2 studies; n = 217 [ECMO-CMV]: mean weighted difference [MWD], −1.31 [95% CI, −1.98 to −0.64] for depression and MWD, −1.60 [95% CI, −1.80 to −1.39] for anxiety). Conclusions: Further studies are required to confirm findings and determine prognostic factors associated with more favorable outcomes in survivors of ECMO.

scholarly journals The impact of star formation feedback on the circumgalactic medium

2016 ◽  
Vol 466 (4) ◽  
pp. 3810-3826 ◽  
Author(s):  
Drummond Fielding ◽  
Eliot Quataert ◽  
Michael McCourt ◽  
Todd A. Thompson
Keyword(s):  
Star Formation ◽  
Circumgalactic Medium ◽  
The Impact

scholarly journals Cosmological simulations of the same spiral galaxy: the impact of baryonic physics

2020 ◽  
Vol 501 (1) ◽  
pp. 62-77
Author(s):  
A Nuñez-Castiñeyra ◽  
E Nezri ◽  
J Devriendt ◽  
R Teyssier
Keyword(s):  
Star Formation ◽  
Galaxy Evolution ◽  
Galaxy Formation ◽  
Spiral Galaxy ◽  
Milky Way ◽  
Spiral Galaxies ◽  
Cosmological Simulations ◽  
Star Forming ◽  
Small Scales ◽  
The Impact

ABSTRACT The interplay of star formation (SF) and supernova (SN) feedback in galaxy formation is a key element for understanding galaxy evolution. Since these processes occur at small scales, it is necessary to have sub-grid models that recover their evolution and environmental effects at the scales reached by cosmological simulations. In this work, we present the results of the Mochima simulation, where we simulate the same spiral galaxy inhabiting a Milky Way (MW) size halo in a cosmological environment changing the sub-grid models for SN feedback and SF. We test combinations of the Schmidt law and a multifreefall based SF with delayed cooling feedback or mechanical feedback. We reach a resolution of 35 pc in a zoom-in box of 36 Mpc. For this, we use the code $\rm{\small RAMSES}$ with the implementation of gas turbulence in time and trace the local hydrodynamical features of the star-forming gas. Finally, we compare the galaxies at redshift 0 with global and interstellar medium observations in the MW and local spiral galaxies. The simulations show successful comparisons with observations. Nevertheless, diverse galactic morphologies are obtained from different numerical implementations. We highlight the importance of detailed modelling of the SF and feedback processes, especially for simulations with a resolution that start to reach scales relevant for molecular cloud physics. Future improvements could alleviate the degeneracies exhibited in our simulated galaxies under different sub-grid models.

scholarly journals The analysis of the impact of environmental factors on turbine performance, develpoment of the models relating the periods between maintenances with selected maintenance factors

2021 ◽  
pp. 1-10
Author(s):  
Magdalena THIELMANN
Keyword(s):  
Environmental Factors ◽  
Gas Turbines ◽  
Time Model ◽  
Reliability Models ◽  
Average Value ◽  
Turbine Performance ◽  
Maintenance Factors ◽  
Maintenance And Inspection ◽  
The Impact

There are currently around 18,000 commissioned Gas Turbines in use worldwide, with almost 7,500 long-term service agreements[1]. At the same time, orders for new units increase year by year, and after a decrease in production in 2020 from 353 to 328 new units, from 2022 onwards, the level is planned to rise to the previous level of growth. Gas turbines operate worldwide and are exposed to variations in environmental conditions, such as changes in humidity, temperature, and salinity, which can significantly affect the efficiency and faster degradation of individual components. Based on the unit's maintenance report, there are more than 1,940 event alerts annually. A need exists to create a more dynamic analytical and numerical model that determines the impact of environmental variables on gas turbine stability. It is necessary to analyze and improve existing reliability models, which vary due to configurations and the impact of working conditions. The first step should be an analysis of the impact of environmental factors on turbine performance. This paper describes how the maintenance and inspection model developed from an average value over time model to a model tracking the actual degradation of gas turbines. It includes a comparison ofthree models used in the research, considering the developed methodology for selecting input parameters, their correlation, and their appropriateness for use in further analyses.

scholarly journals Estimation of the Medico-Ecological Component of Life Quality at the Level of Risk of Morbidity with Mass Non-Infectious Diseases

2019 ◽  
Vol 4 (2) ◽  
pp. 44-50
Author(s):  
A. V. Prusakova ◽  
V. M. Prusakov
Keyword(s):  
Environmental Factors ◽  
Objective Assessment ◽  
Anthropogenic Load ◽  
Noncommunicable Diseases ◽  
Time Interval ◽  
Environmental Pressures ◽  
Atmospheric Air ◽  
Industrial Cities ◽  
The Impact

For an objective assessment of the quality of life (QOL) in areas with different environmental pressures and the development of recommendations for improving medical care, population studies of children are used. The purpose of this study is to assess the risk of a general incidence of mass noncommunicable diseases (МND) of the child population of industrial cities with various environmental pressures as an indicator of QOL. To assess the anthropogenic load in industrial cities, atmospheric air pollution with harmful substances was analyzed. The assessment of the influence of local factors of cities was determined by relative and attributable risks of morbidity using synchronous annual and corresponding to the studied time interval values of background and estimated morbidity, and the influence of common background factors by the value of initial background morbidity at the beginning of the long-term observation period. To assess and rank changes in QOL in areas with different environmental loads, we used the results of the analysis of the long-term risk dynamics of the minority disease of children’s population with long-term exposure to a complex of general and local environmental factors of industrial cities of the Irkutsk region. To do this, we used the criteria developed by the authors for assessing the degree of tension of the medico-ecological situation and the strength of the impact of environmental factors on them by the relative risk levels of the minimum level and the corresponding QOL levels for the specified component.QOL in terms of the minimum number of children’s diseases in the period under review decreases as a whole due to the increasing influence of general background (regional) factors throughout the region, and in the studied cities in addition from the influence of local adverse factors, including anthropogenic pollution of atmospheric air.A significant decrease in the local anthropogenic load is accompanied by a decrease in the associated additional МND and the severity of the additional to the background decrease in QOL in the industrial cities of the region, especially in Angarsk.

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