This report describes a previously uncharacterized occupational health hazard: work crew exposures to respirable crystalline silica during hydraulic fracturing. Hydraulic fracturing involves high ...pressure injection of large volumes of water and sand, and smaller quantities of well treatment chemicals, into a gas or oil well to fracture shale or other rock formations, allowing more efficient recovery of hydrocarbons from a petroleum-bearing reservoir. Crystalline silica ("frac sand") is commonly used as a proppant to hold open cracks and fissures created by hydraulic pressure. Each stage of the process requires hundreds of thousands of pounds of quartz-containing sand; millions of pounds may be needed for all zones of a well. Mechanical handling of frac sand creates respirable crystalline silica dust, a potential exposure hazard for workers. Researchers at the National Institute for Occupational Safety and Health collected 111 personal breathing zone samples at 11 sites in five states to evaluate worker exposures to respirable crystalline silica during hydraulic fracturing. At each of the 11 sites, full-shift samples exceeded occupational health criteria (e.g., the Occupational Safety and Health Administration calculated permissible exposure limit, the NIOSH recommended exposure limit, or the ACGIH threshold limit value), in some cases, by 10 or more times the occupational health criteria. Based on these evaluations, an occupational health hazard was determined to exist for workplace exposures to crystalline silica. Seven points of dust generation were identified, including sand handling machinery and dust generated from the work site itself. Recommendations to control exposures include product substitution (when feasible), engineering controls or modifications to sand handling machinery, administrative controls, and use of personal protective equipment. To our knowledge, this represents the first systematic study of work crew exposures to crystalline silica during hydraulic fracturing. Companies that conduct hydraulic fracturing using silica sand should evaluate their operations to determine the potential for worker exposure to respirable crystalline silica and implement controls as necessary to protect workers.
Supplementary materials are available for this article. Go to the publisher's online edition of Journal of Occupational and Environmental Hygiene for the following free supplemental resource: a file containing controls and recommendations to limit worker exposures to respirable crystalline silica at hydraulic fracturing work sites.
Heme is a cofactor with myriad roles and essential to almost all living organisms. Beyond classical gas transport and catalytic functions, heme is increasingly appreciated as a tightly controlled ...signalling molecule regulating protein expression. However, heme acquisition, biosynthesis and regulation is poorly understood beyond a few model organisms, and the heme‐binding proteome has not been fully characterised in bacteria. Yet as heme homeostasis is critical for bacterial survival, heme‐binding proteins are promising drug targets. Herein we report a chemical proteomics method for global profiling of heme‐binding proteins in live cells for the first time. Employing a panel of heme‐based clickable and photoaffinity probes enabled the profiling of 32–54 % of the known heme‐binding proteomes in Gram‐positive and Gram‐negative bacteria. This simple‐to‐implement profiling strategy could be interchangeably applied to different cell types and systems and fuel future research into heme biology.
Heme homeostasis is critical for bacterial survival, but the heme interactome is not yet fully characterised. Herein we report a chemical proteomics method for global profiling of heme‐binding proteins in live cells. Applying 6 heme probes and optimised labelling conditions, we accessed 32–54 % of the known heme‐binding proteomes in major pathogenic Gram‐positive and Gram‐negative bacteria.
This study examines whether corporate tax information from non-financial disclosure is material for investors. This is important because, recently, the Global Reporting Initiative (GRI) enacted, and ...the European Union (EU) passed, new non-financial tax disclosure requirements. By conducting a factorial survey experiment, we are the first to show that non-professional investors are more likely to invest in companies providing detailed public country-by-country-reporting (CbCR) than in those that do not. We conclude that a public CbCR – as required by the GRI and the EU – is material for (non-professional) investors. Additional analyses show that the effect of the public CbCR is stronger (i) for socially responsible investors and (ii) for investors with high tax morale. In contrast to providing public CbCR, we find no evidence that reporting the corporate tax strategy (CTS) – as solely required by the GRI – affects investment decisions. Our findings provide novel insights into whether and how different types of investors integrate different kinds of non-financial tax disclosure in their decision-making processes. For this reason, our study at the intersection of corporate taxation, reporting, and sustainability provides implications for scholars, corporate decision-makers, policy-makers, and standard setters.
The most profound consequences of the presence of Ca–Mg carbonates
(CaCO3–MgCO3) in the Earth's upper mantle may be to lower the
melting temperatures of the mantle and control the melt composition.
...Low-degree partial melting of a carbonate-bearing mantle produces
CO2-rich, silica-poor melts compositionally imposed by the
melting relations of carbonates. Thus, understanding the melting relations
in the CaCO3–MgCO3 system facilitates the interpretation of
natural carbonate-bearing silicate systems. We report the melting relations of the CaCO3–MgCO3 system and
the partition coefficient of trace elements between carbonates and carbonate
melt from experiments at high pressure (6 and 9 GPa) and temperature
(1300–1800 ∘C) using a rocking multi-anvil press. In the
absence of water, Ca–Mg carbonates are stable along geothermal
gradients typical of subducting slabs. Ca–Mg carbonates
(∼ Mg0.1–0.9Ca0.9–0.1CO3) partially melt
beneath mid-ocean ridges and in plume settings. Ca–Mg carbonates
melt incongruently, forming periclase crystals and carbonate melt between 4
and 9 GPa. Furthermore, we show that the rare earth element (REE) signature
of Group-I kimberlites, namely strong REE fractionation and depletion of
heavy REE relative to the primitive mantle, is resembled by carbonate
melt in equilibrium with Ca-bearing magnesite and periclase at 6 and
9 GPa. This suggests that the dolomite–magnesite join of the
CaCO3–MgCO3 system might be useful to approximate the REE
signature of carbonate-rich melts parental to kimberlites.
Swimming and diving are popular recreational activities, representing an effective option in maintaining and improving cardiovascular fitness in healthy people. To date, only little is known about ...the cardiovascular adaption to submersion in children. This study was conducted to improve an understanding thereof. We used a stepwise apnea protocol with apnea at rest, apnea with facial immersion, and at last apnea during whole body submersion. Continuous measurement of heart rate, oxygen saturation, and peripheral resistance index was done. Physiologic data and analysis of influencing factors on heart rate, oxygen saturation, and peripheral vascular tone response are reported. The current study presents the first data of physiologic diving response in children. Data showed that facial or whole body submersion leads to a major drop in heart rate, and increase of peripheral resistance, while the oxygen saturation seems to be unaffected by static apnea in most children, with apnea times of up to 75 s without change in oxygen saturation.
An Ir-catalyzed enantioselective hydrogenation of 2-alkyl-pyridines has been developed using ligand MeO-BoQPhos. High levels of enantioselectivities up to 93:7 er were obtained. The resulting ...enantioenriched piperidines can be readily converted into biologically interesting molecules such as the fused tricyclic structures 5, 6, and 7 in 99:1 er, providing a novel, concise synthetic route to this family of chiral piperidine-containing compounds.
Objective
In the field of cochlear implantation, the current trend toward patient-specific electrode selection and the achievement of optimal audiologic outcomes has resulted in implant manufacturers ...developing a large portfolio of electrodes. The aim of this study was to bridge the gap between the known variability of cochlea length and this electrode portfolio.
Design
Retrospective analysis on cochlear length and shape in micro–computed tomography and cone beam computed tomography data.
Setting
Tertiary care medical center.
Subjects and Methods
A simple 2-step approach was developed to accurately estimate the individual cochlear length as well as the projected length of an electrode array inside the cochlea. The method is capable of predicting the length of the cochlea and the inserted electrode length at any specific angle. Validation of the approach was performed with 20 scans of human temporal bones (micro–computed tomography) and 47 pre- and postoperative clinical scans (cone beam computed tomography).
Results
Mean ± SD absolute errors in cochlear length estimations were 0.12 ± 0.10 mm, 0.38 ± 0.26 mm, and 0.71 ± 0.43 mm for 1, 1.5, and 2 cochlea turns, respectively. Predicted insertion angles based on clinical cone beam computed tomography data showed absolute deviations of 27° ± 18° to the corresponding postoperative measurements.
Conclusion
With accuracy improvements of 80% to 90% in comparison with previously proposed approaches, the method is well suited for the use in individualized cochlear implantation.
Purpose
An overview of the current use of handwritten text recognition (HTR) on archival manuscript material, as provided by the EU H2020 funded
Transkribus
platform. It explains HTR, demonstrates
...Transkribus
, gives examples of use cases, highlights the affect HTR may have on scholarship, and evidences this turning point of the advanced use of digitised heritage content. The paper aims to discuss these issues.
Design/methodology/approach
This paper adopts a case study approach, using the development and delivery of the one openly available HTR platform for manuscript material.
Findings
Transkribus
has demonstrated that HTR is now a useable technology that can be employed in conjunction with mass digitisation to generate accurate transcripts of archival material. Use cases are demonstrated, and a cooperative model is suggested as a way to ensure sustainability and scaling of the platform. However, funding and resourcing issues are identified.
Research limitations/implications
The paper presents results from projects: further user studies could be undertaken involving interviews, surveys, etc.
Practical implications
Only HTR provided via
Transkribus
is covered: however, this is the only publicly available platform for HTR on individual collections of historical documents at time of writing and it represents the current state-of-the-art in this field.
Social implications
The increased access to information contained within historical texts has the potential to be transformational for both institutions and individuals.
Originality/value
This is the first published overview of how HTR is used by a wide archival studies community, reporting and showcasing current application of handwriting technology in the cultural heritage sector.
OBJECTIVE:The objective of this study was to evaluate if a preoperative wellness bundle significantly decreases the risk of hospital acquired infections (HAI).
BACKGROUND:HAI threaten patient ...outcomes and are a significant burden to the healthcare system. Preoperative wellness efforts may significantly decrease the risk of infections.
METHODS:A group of 12,396 surgical patients received a wellness bundle in a roller bag during preoperative screening at an urban academic medical center. The wellness bundle consisted of a chlorhexidine bath solution, immuno-nutrition supplements, incentive spirometer, topical mupirocin for the nostrils, and smoking cessation information. Study staff performed structured patient interviews, observations, and standardized surveys at key intervals throughout the perioperative period. Statistics compare HAI outcomes of patients in the wellness program to a nonintervention group using the Fisherʼs exact test, logistic regression, and Poisson regression.
RESULTS:Patients in the nonintervention and intervention groups were similar in demographics, comorbidity, and type of operations. Compliance with each element was high (80% mupirocin, 72% immuno-nutrition, 71% chlorhexidine bath, 67% spirometer). The intervention group had statistically significant reductions in surgical site infections, Clostridium difficile, catheter associated urinary tract infections, and patient safety indicator 90.
CONCLUSIONS:A novel, preoperative, patient-centered wellness program dramatically reduced HAI in surgical patients at an urban academic medical center.
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