•Microbiologically influenced corrosion (MIC) is studied in vials and glass cells.•Biogenic H2S is not the primary corrosive agent in MIC by Desulfovibrio vulgaris.•A larger headspace allows more H2S ...to escape and this increases liquid-phase pH.•A larger headspace leads to a lower dissolved H2S concentration in the liquid phase.•A larger headspace results in more weight loss and more severe pitting corrosion.
The role of biogenic H2S in the microbiologically influenced corrosion (MIC) of carbon steel was investigated. Desulfovibrio vulgaris (ATCC 7757), a sulfate reducing bacterium, was tested against C1018 carbon steel in anaerobic vials with three different sizes, each filled with 40mL of ATCC 1249 culture medium, providing headspace volumes of 10mL, 85mL and 160mL, respectively for H2S to escape. Results showed that a larger headspace led to a lower H2S concentration in the culture medium, and this increased the sessile cell count and made the iron sulfide film thinner, resulting in increased MIC.
SUMMARY
Are high audit fees a signal that the auditor exerted more effort or a signal that the auditor may be losing her independence? Prior literature offers conflicting evidence. In this paper, we ...reexamine the issue on a sample of clients who have both the incentive and the ability to use discretionary accruals to meet or beat the consensus earnings forecast. We find a negative relationship between the level of abnormal audit fees paid by the client and the likelihood of using discretionary accruals to meet or beat the consensus analyst forecast. The evidence is consistent with the notion that abnormal audit fees are indicative of greater effort on the engagement. In other words, the results suggest a positive relationship between abnormal audit fees and audit quality. We show that the conflicting evidence in prior research was caused by research designs that did not consider the incentives of the manager.
JEL Classifications: M42; M41.
Data Availability: All data are available from public sources quoted in the text.
COVID-19 has disproportionately affected racial and ethnic minority groups, and race and ethnicity have been associated with disease severity. However, the association of socioeconomic determinants ...with racial disparities in COVID-19 outcomes remains unclear.
To evaluate the association of race and ethnicity with COVID-19 outcomes and to examine the association between race, ethnicity, COVID-19 outcomes, and socioeconomic determinants.
A systematic search of PubMed, medRxiv, bioRxiv, Embase, and the World Health Organization COVID-19 databases was performed for studies published from January 1, 2020, to January 6, 2021.
Studies that reported data on associations between race and ethnicity and COVID-19 positivity, disease severity, and socioeconomic status were included and screened by 2 independent reviewers. Studies that did not have a satisfactory quality score were excluded. Overall, less than 1% (0.47%) of initially identified studies met selection criteria.
Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed. Associations were assessed using adjusted and unadjusted risk ratios (RRs) and odds ratios (ORs), combined prevalence, and metaregression. Data were pooled using a random-effects model.
The main measures were RRs, ORs, and combined prevalence values.
A total of 4 318 929 patients from 68 studies were included in this meta-analysis. Overall, 370 933 patients (8.6%) were African American, 9082 (0.2%) were American Indian or Alaska Native, 101 793 (2.4%) were Asian American, 851 392 identified as Hispanic/Latino (19.7%), 7417 (0.2%) were Pacific Islander, 1 037 996 (24.0%) were White, and 269 040 (6.2%) identified as multiracial and another race or ethnicity. In age- and sex-adjusted analyses, African American individuals (RR, 3.54; 95% CI, 1.38-9.07; P = .008) and Hispanic individuals (RR, 4.68; 95% CI, 1.28-17.20; P = .02) were the most likely to test positive for COVID-19. Asian American individuals had the highest risk of intensive care unit admission (RR, 1.93; 95% CI, 1.60-2.34, P < .001). The area deprivation index was positively correlated with mortality rates in Asian American and Hispanic individuals (P < .001). Decreased access to clinical care was positively correlated with COVID-19 positivity in Hispanic individuals (P < .001) and African American individuals (P < .001).
In this study, members of racial and ethnic minority groups had higher risks of COVID-19 positivity and disease severity. Furthermore, socioeconomic determinants were strongly associated with COVID-19 outcomes in racial and ethnic minority populations.
Stratospheric water vapor concentrations decreased by about 10% after the year 2000. Here we show that this acted to slow the rate of increase in global surface temperature over 2000-2009 by about ...25% compared to that which would have occurred due only to carbon dioxide and other greenhouse gases. More limited data suggest that stratospheric water vapor probably increased between 1980 and 2000, which would have enhanced the decadal rate of surface warming during the 1990s by about 30% as compared to estimates neglecting this change. These findings show that stratospheric water vapor is an important driver of decadal global surface climate change.
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•Moving boundary simulation takes into account zinc electrode consumption by time.•Oxygen concentration variation in the scratch region plays a critical role in protection ...mechanism.•Sacrificial protection in the middle and barrier protection at the corners of the scratch.•Sacrificial protection period was predicted, and galvanic corrosion rate was quantified.•Current density is a better criterion than potential for sacrificial protection systems with a large Zn to Fe area ratio.
The mechanism of corrosion protection of steel substrate by a 96 wt% zinc primer that was damaged by scratch was simulated. The primer was approximated to pure zinc layer due to high percentage of zinc. Results show that while the middle of scratch is protected by sacrificial protection, at the corners of scratch a local cathodic inhibition results in barrier protection due to variations in the dissolved oxygen concentration. Moving boundary simulation allowed to predict the changes to the geometry of the corroding electrodes. Finally, taking into account zinc electrodes consumption, the period of sacrificial protection was predicted by simulations.
Anthropogenic increases in atmospheric greenhouse gas
concentrations are the main driver of current and future climate change. The
integrated assessment community has quantified anthropogenic ...emissions for
the shared socio-economic pathway (SSP) scenarios, each of which represents
a different future socio-economic projection and political environment.
Here, we provide the greenhouse gas concentrations for these SSP scenarios
– using the reduced-complexity climate–carbon-cycle model MAGICC7.0. We
extend historical, observationally based concentration data with SSP
concentration projections from 2015 to 2500 for 43 greenhouse gases with monthly and latitudinal resolution. CO2 concentrations by 2100 range
from 393 to 1135 ppm for the lowest (SSP1-1.9) and highest (SSP5-8.5)
emission scenarios, respectively. We also provide the concentration
extensions beyond 2100 based on assumptions regarding the trajectories of fossil
fuels and land use change emissions, net negative emissions, and the
fraction of non-CO2 emissions. By 2150, CO2 concentrations in the
lowest emission scenario are approximately 350 ppm and approximately plateau
at that level until 2500, whereas the highest fossil-fuel-driven scenario
projects CO2 concentrations of 1737 ppm and reaches concentrations
beyond 2000 ppm by 2250. We estimate that the share of CO2 in the total
radiative forcing contribution of all considered 43 long-lived greenhouse
gases increases from 66 % for the present day to roughly 68 % to 85 % by
the time of maximum forcing in the 21st century. For this estimation,
we updated simple radiative forcing parameterizations that reflect the Oslo
Line-By-Line model results. In comparison to the representative concentration pathways (RCPs), the five main SSPs
(SSP1-1.9, SSP1-2.6, SSP2-4.5, SSP3-7.0, and SSP5-8.5) are more evenly spaced
and extend to lower 2100 radiative forcing and temperatures. Performing two
pairs of six-member historical ensembles with CESM1.2.2, we estimate the
effect on surface air temperatures of applying latitudinally and seasonally
resolved GHG concentrations. We find that the ensemble differences in the
March–April–May (MAM) season provide a regional warming in higher northern
latitudes of up to 0.4 K over the historical period, latitudinally averaged
of about 0.1 K, which we estimate to be comparable to the upper bound
(∼5 % level) of natural variability. In comparison to the
comparatively straight line of the last 2000 years, the greenhouse gas
concentrations since the onset of the industrial period and this studies'
projections over the next 100 to 500 years unequivocally depict a
“hockey-stick” upwards shape. The SSP concentration time series derived in
this study provide a harmonized set of input assumptions for long-term
climate science analysis; they also provide an indication of the wide set of
futures that societal developments and policy implementations can lead to –
ranging from multiple degrees of future warming on the one side to
approximately 1.5 ∘C warming on the other.
Although the technological relevance of mesoporous ceramic polymer hybrid materials is well accepted, missing functionalization concepts enabling 3D nanoscale local control of polymer placement into ...mesoporous materials, including thin films, and ideally using controlled polymerization techniques limit the application potential. Here, nanolocal functionalization of mesoporous separation layers using controlled, visible light iniferter initiated polymerization allowing responsive polymer functionalization locally limited to the irradiated spot is introduced. Thereby, two visible light sensitive iniferters, s‐p‐trimethoxysilylbenzyl‐S´‐dodecyltrithiocarbonate and 4‐cyano‐4‐((dodecylsulfanylthiocarbonyl)sulfanyl)pentanoic acid, are developed for polymer functionalization of mesoporous films in a grafting from and a grafting through approach. 3D nanolocal polymer placement close to the proximity of the plasmonic field source is demonstrated by combining these visible light iniferter initiated polymerizations with optical near field modes, such as localized surface plasmon resonance (LSPR). As the location of the LSPR in mesoporous films can be controlled by placing metal alloy nanoparticles into these films and film thicknesses can be adjusted, this strategy is applied for precise positioning of polymers into mesoporous films with nanolocal control in three dimensions and thus reduces the gap in precision of functional group positioning between technological and biological nanopores.
Polymer functionalization of mesoporous separation layers with 3D nanolocal control is demonstrated by applying visible light and near field induced iniferter initiated polymerization. Two visible light sensitive iniferters are investigated in grafting through as well as grafting from approaches. Nanolocal polymer functionalization is achieved by applying gold‐silver alloy nanoparticles as the nanoscopic light source located inside the mesoporous separation layers.
Gestational diabetes mellitus (GDM) is one of the most common medical complications during pregnancy. eHealth technologies are proving to be successful in supporting the self-management of medical ...conditions. Digital technologies have the potential to improve GDM self-management. The primary objective of this systematic literature review was to identify the views of health professionals (HPs) and women with GDM regarding the use of eHealth for GDM self-management. The secondary objective was to investigate the usability and user satisfaction levels when using these technologies. Following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) approach, the search included primary papers in English on the evaluation of technology to support self-management of GDM from January 2008 to September 2021 using MEDLINE, CINAHL, Embase, ACM, and IEEE databases. The lists of references from previous systematic literature reviews, which were related to technology and GDM, were also examined for primary studies. Papers with qualitative, quantitative, and mixed methodologies were included and evaluated. The selected papers were assessed for quality using the Cochrane Collaboration tool, National Institute for Health and Care Excellence clinical guidelines, Critical Appraisal Skills Programme Qualitative Checklist, and McGill University Mixed Methods Appraisal Tool. NVivo (QSR International) was used to extract qualitative data, which were subjected to thematic analysis. Narrative synthesis was used to analyze the quantitative data. A total of 26 papers were included in the review. Of these, 19% (5/26) of studies used quantitative research methodologies, 19% (5/26) used qualitative methods, and 62% (16/26) used mixed methods. In all, 4 themes were identified from the qualitative data: the benefits of using technology, engagement with people via technology, the usability of technology, and discouragement factors for the use of technology. The thematic analysis revealed a vast scope of challenges and facilitators in the use of GDM self-management systems. The challenges included usability aspects of the system, technical problems, data privacy, lack of emotional support, the accuracy of reported data, and adoption of the system by HPs. Convenience, improved GDM self-management, peer support, increased motivation, increased independence, and consistent monitoring were facilitators to use these technologies. Quantitative data showed that there is potential for improving the usability of the GDM self-management systems. It also showed that convenience, usefulness, increasing motivation for GDM self-management, helping with GDM self-management, and being monitored by HPs were facilitators to use the GDM self-management systems. This novel systematic literature review shows that HPs and women with GDM encountered some challenges in using GDM self-management systems. The usability of GDM systems was the primary challenge derived from qualitative and quantitative results, with convenience, consistent monitoring, and optimization of GDM self-management emerging as important facilitators.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
The past years have seen the rise of genomic biobanks and mega-scale meta-analysis of genomic data, which promises to reveal the genetic underpinnings of health and disease. However, the ...over-representation of Europeans in genomic studies not only limits the global understanding of disease risk but also inhibits viable research into the genomic differences between carriers and patients. Whilst the community has agreed that more diverse samples are required, it is not enough to blindly increase diversity; the diversity must be quantified, compared and annotated to lead to insight. Genetic annotations from separate biobanks need to be comparable and computable and to operate without access to raw data due to privacy concerns. Comparability is key both for regular research and to allow international comparison in response to pandemics. Here, we evaluate the appropriateness of the most common genomic tools used to depict population structure in a standardized and comparable manner. The end goal is to reduce the effects of confounding and learn from genuine variation in genetic effects on phenotypes across populations, which will improve the value of biobanks (locally and internationally), increase the accuracy of association analyses and inform developmental efforts.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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