222 research outputs found
Risk of asthmatic episodes in children exposed to sulfur dioxide stack emissions from a refinery point source in Montreal, Canada.
BACKGROUND: Little is known about the respiratory effects of short-term exposures to petroleum refinery emissions in young children. This study is an extension of an ecologic study that found an increased rate of hospitalizations for respiratory conditions among children living near petroleum refineries in Montreal (Canada). METHODS: We used a time-stratified case-crossover design to assess the risk of asthma episodes in relation to short-term variations in sulfur dioxide levels among children 2-4 years of age living within 0.5-7.5 km of the refinery stacks. Health data used to measure asthma episodes included emergency department (ED) visits and hospital admissions from 1996 to 2004. We estimated daily levels of SO2 at the residence of children using a) two fixed-site SO2 monitors located near the refineries and b) the AERMOD (American Meteorological Society/Environmental Protection Agency Regulatory Model) atmospheric dispersion model. We used conditional logistic regression to estimate odds ratios associated with an increase in the interquartile range of daily SO2 mean and peak exposures (31.2 ppb for AERMOD peaks). We adjusted for temperature, relative humidity, and regional/urban background air pollutant levels. RESULTS: The risks of asthma ED visits and hospitalizations were more pronounced for same-day (lag 0) SO2 peak levels than for mean levels on the same day, or for other lags: the adjusted odds ratios estimated for same-day SO2 peak levels from AERMOD were 1.10 [95% confidence interval (CI), 1.00-1.22] and 1.42 (95% CI, 1.10-1.82), over the interquartile range, for ED visits and hospital admissions, respectively. CONCLUSIONS: Short-term episodes of increased SO2 exposures from refinery stack emissions were associated with a higher number of asthma episodes in nearby children
The deep distributions of helium isotopes, radiocarbon, and noble gases along the U.S. GEOTRACES East Pacific Zonal Transect (GP16)
Author Posting. © The Author(s), 2017. This is the author's version of the work. It is posted here under a nonexclusive, irrevocable, paid-up, worldwide license granted to WHOI. It is made available for personal use, not for redistribution. The definitive version was published in Marine Chemistry 201 (2018): 167-182, doi:10.1016/j.marchem.2017.03.009.We report the deep distributions of noble gases, helium isotopes, and radiocarbon measured during the U.S. GEOTRACES GP16 East Pacific Zonal Transect between 152 and 77°W at 12- 15°S in the South Pacific. The dominant feature is an intense tongue of hydrothermal effluent that extends more than 4,000 km westward from the East Pacific Rise (EPR) at ~2500m depth. The patterns reveal significant “downstream” variations in water mass structure, advection, and mixing that belie the simple perception of a continuous plume extending westward from the EPR. For example, one feature observed at 120°W, 14°S has tracer signatures that are consistent with a water mass originating from an area as much as 2,000 km south of this section, suggesting a quasi-permanent northward flow on the western flank of the EPR. Helium isotope variations in the plume show a uniquely high 3He/4He source in the tongue compared with typical mid-ocean ridge basalts (MORB), consistent with the anomalously high ratios observed in MORB glasses from the EPR segment just south of this transect. The water column data also reveal that the background 3He/4He east of the EPR is significantly lower than values characteristic of MORB, suggesting an additional, more geographically distributed radiogenic 4He flux of order 107 mol/y into the deep Pacific.
In the western end of the section, incoming bottom waters have relatively less hydrothermal hydrothermal helium, more radiocarbon, and more oxygen, as well as negative saturation anomalies for the heavy noble gases (Ar, Kr, and Xe). During the basin-scale upwelling of this water, diapycnal mixing serves to erase these negative anomalies. The relative magnitudes of the increases for the heavy noble gases (Ar, Kr, and Xe) are quantitatively consistent with this process. This leads us to estimate the relatively smaller effects on He and Ne saturations, which range from near zero to 0.2% and 0.3% respectively. With this information, we are able to refine our estimates of the magnitude of 3He and 4He excesses and the absolute 3He/4He ratio of non-atmospheric helium introduced into deep Pacific waters.The work was funded under National Science Foundation grant number OCE-1232991 for WJJ and OCE-1130870 for CRG
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Status of ParaDyn: DYNA3D for parallel computing
The evolution of DYNA3D from a vector supercomputer code into a parallel code is reviewed. Current status and target applications, especially those of interest to the Department of Defense
Finite Element Modeling of Ultrasonic Inspection of Weldments
High performance weldments for critical service applications require 100% inspection. Balanced against the adaptability of the ultrasonic method for automated inspection are the difficulties encountered with nonhomogeneous and anisotropic materials. This research utilizes crystals and bicrystals of nickel to model austenitic weld metal, where the anisotropy produces scattering and mode conversion, making detection and measurement of actual defects difficult.
Well characterized samples of Ni are produced in a levitation zone melting facility. Crystals in excess of 25 mm diameter and length are large enough to permit ultrasonic measurements of attenuation, wave speed, and spectral content. At the same time, the experiments are duplicated as finite element models for comparison purposes.
Finite element models permit easy description of boundary conditions, geometry, and loading. Direct integration of the wave equation is done with the Newmark-Beta and Wilson-Theta Methods. The usual problem with the large number of degress of freedom can be alleviated with the use of Guyan reduction.
Two-dimensional comparisons showing mode conversion and a plate with a flaw are made. The continued development of this computational tool should increase understanding of quantitative ultrasonic inspection
Risk of Asthmatic Episodes in Children Exposed to Sulfur Dioxide Stack Emissions from a Refinery Point Source in Montreal, Canada
BACKGROUND: Little is known about the respiratory effects of short-term exposures to petroleum refinery emissions in young children. This study is an extension of an ecologic study that found an increased rate of hospitalizations for respiratory conditions among children living near petroleum refineries in Montreal (Canada). METHODS: We used a time-stratified case-crossover design to assess the risk of asthma episodes in relation to short-term variations in sulfur dioxide levels among children 2-4 years of age living within 0.5-7.5 km of the refinery stacks. Health data used to measure asthma episodes included emergency department (ED) visits and hospital admissions from 1996 to 2004. We estimated daily levels of SO2 at the residence of children using a) two fixed-site SO2 monitors located near the refineries and b) the AERMOD (American Meteorological Society/Environmental Protection Agency Regulatory Model) atmospheric dispersion model. We used conditional logistic regression to estimate odds ratios associated with an increase in the interquartile range of daily SO2 mean and peak exposures (31.2 ppb for AERMOD peaks). We adjusted for temperature, relative humidity, and regional/urban background air pollutant levels. RESULTS: The risks of asthma ED visits and hospitalizations were more pronounced for same-day (lag 0) SO2 peak levels than for mean levels on the same day, or for other lags: the adjusted odds ratios estimated for same-day SO2 peak levels from AERMOD were 1.10 [95% confidence interval (CI), 1.00-1.22] and 1.42 (95% CI, 1.10-1.82), over the interquartile range, for ED visits and hospital admissions, respectively. CONCLUSIONS: Short-term episodes of increased SO2 exposures from refinery stack emissions were associated with a higher number of asthma episodes in nearby children
Behavioral health emergencies encountered by community paramedics: lessons from the field and opportunities for skills advancement
INTRODUCTION: When an individual calls 911 because of a behavioral health emergency, paramedics may be the first health care professional on scene to address that crisis. Traditionally, the paramedic profession has been educated to respond to life-threatening medical emergencies.1 Paramedics are increasingly expected to respond to behavioral health crises but may not be adequately prepared to do so. 1 There has been limited research regarding paramedics’ experiences, attitudes, and perceptions about responding to behavioral health crises, with a particular dearth of literature on this subject from the USA. 1,2,3,4,5 As the first point of contact, paramedics may influence the quality of care individuals experiencing behavioral health emergencies receive, rendering this gap in knowledge concerning. 1,4 Paramedics encounter a range of behavioral health crises, from individuals who have self-harmed, substance use, to older adults experiencing social isolation. 6,7 This study aimed to answer the following questions: Do paramedics feel well prepared to respond to behavioral health crises? How do paramedics describe the challenges and facilitators involved in responding to these situations? What are the skills they use to respond to these situations? The present study examined paramedics’ experiences and perceptions regarding behavioral health emergencies, aiming to address a significant gap in the literature on paramedics’ ability to respond to the needs of individuals experiencing behavioral health crises.
BACKGROUND: Limited research based in the UK, Europe, and Australia has examined the extent to which paramedics feel equipped by their training to respond to situations of a behavioral health nature, with a marked lack of USA-based research in this area. In a survey of members of the College of Paramedics (UK), 98% of the 623 respondents endorsed the need for increased mental health education and training. 2 Paramedic training curriculums in the UK have evolved to incorporate more of an emphasis on behavioral health, yet whether or not this behavioral health training is effective has not yet been investigated. 1 Several Australian studies investigated paramedic perceptions of their mental health training and decision-making during mental health emergencies.5,8. Paramedic participants reported inadequate mental health training and indicated a need for increased education on mental illness, particularly regarding possible treatment options that are feasible as part of prehospital care.8. Paramedics described relying more on intuition than education when faced with challenging cases.5 In a mixed methods study, Australian paramedics reported the need for more education on how to adequately respond to older adults experiencing complex mental health crises including depression, social isolation, and food insecurity.7
Limited research has explored paramedic perceptions, attitudes, and experiences responding to behavioral health emergencies, but the existing research indicates that many emergency healthcare providers consider physical health emergencies more valuable or important than behavioral health emergencies.8,9,10 Studies indicate that paramedic students do not consider training in mental health issues as relevant to the profession,1 with an Australian study of paramedic undergraduate students indicating a lower level of regard for those with intellectual disabilities, substance abuse disorders, or acute mental illness compared to students studying in other health professions.11
A multi-site, qualitative study based in Paris, France and New York, New York examined how social and professional values influenced prehospital emergency workers’ responses.9 The authors found that patients deemed to have lower social value were lower priority to emergency providers, with cases involving substance use or calls from lower socioeconomic areas, for instance, regarded as less legitimate uses of emergency services.9 Notably, situations that required more complex or heroic medical or surgical actions were also attributed higher value by emergency healthcare workers.9 Greater importance was attributed to medical (versus behavioral health) emergencies across additional studies, with paramedic participants implying that behavioral health calls were not valid emergencies,5 and with paramedic participants indicating that their role is mainly to transport—not to treat—individuals experiencing behavioral health crises.8 Additionally, paramedic participants perceived their services as often used inappropriately for behavioral health emergencies due to the limited availability of more appropriate behavioral health services.8
Related research regarding the perceptions of emergency department physicians and nurses in the USA also revealed a greater value placed on physical versus behavioral health emergencies, as well as perceptions that certain crises (such as self-harm) were less valid, or less worthy of emergency treatment.10 This is particularly concerning given that emergency department healthcare providers interact with a substantial number of persons seeking behavioral health emergency care: in 2015, approximately 4.1% of visits to an emergency department were related to diagnosed mental health disorders (approximately 5,666,000 visits).12 The number of emergency department visits related to opioid overdose increased by 29.7% in the USA between July 2016 and September 2017.13 Emergency healthcare workers are treating a significant number of behavioral health emergencies, rendering improved understanding of healthcare providers’ perceptions and attitudes towards this population crucial.
Existing research into the perceptions of experienced paramedic practitioners regarding behavioral health emergencies is limited.1,3,4 With the exception of a multi-site study based in New York, New York and Paris, France,9 a thorough review of the extant literature failed to unearth research on the perceptions and experiences of paramedics responding to behavioral health crises in the USA. This is a particularly significant gap, as differences in paramedic education, relevant behavioral health legislation, and culture may exist across countries. The present study used qualitative analyses of in-depth interviews of practicing paramedics to address this gap by examining paramedics’ perceptions and experiences responding to behavioral health crises in the USA.
METHODS: This study was part of a Patient-Centered Outcomes Research Institute (PCORI) contract funding an examination of the Acute Community Care Program (ACCP) at Commonwealth Care Alliance (CCA). The Acute Community Care Program is a state-funded community paramedicine intervention for the patients of CCA, in conjunction with EasCare Ambulance Company.
INTERVIEW GUIDE AND RECRUITMENT: The research team, which included experienced paramedics at EasCare Ambulance Company, worked together to create an open-ended guide to interview paramedics. The interview protocol consisted of six sections: (1) history of career as paramedic, (2) current skills and job experiences, (3) views of paramedic experience, (4) career goals, (5) final questions and wrap up, and (6) demographics. The research team revised the original guide after several pilot interviews and based on feedback from key informants, namely seasoned paramedic supervisors from the research team. Interviews with paramedics lasted approximately 1 h and were conducted over the phone by either the PI or Co-PI, who are experienced in qualitative research.
The research team intended to interview 25 paramedics who would be identified through two large ambulance companies in the Greater Boston area of Massachusetts. The director at these ambulance companies asked their paramedics on staff if they would be willing to be interviewed and, if they agreed, the director gave us their contact information. Six paramedics who had initially agreed could not be reached, and arrangements were made with one paramedic who did not follow through with the interview. In total, the researchers conducted telephone interviews with 23 paramedics, after receiving verbal informed consent to perform and record the interview. Participants were mailed a $50 gift card to thank them for their time. Professional transcription service transcribed digital recordings verbatim, and the project manager reviewed all transcripts against the digital recording, making small corrections as needed.
DATA ANALYSIS: Audiotapes of the sessions were analyzed by three research team members. A thematic analysis approach was utilized, starting with familiarization with the data, generating initial codes, searching for themes, reviewing themes, defining and naming themes, and producing a final analysis.14 The researchers worked both separately and collaboratively, working individually at each stage of the process and then coming together to compare results in order to ensure the validity of identified themes. Early readings of the transcript data allowed the researchers to develop preliminary ideas regarding potential themes. Each researcher then thoroughly analyzed the individual transcripts, generating initial codes and beginning to search for themes both within and across documents. During this stage, the researchers met frequently to compare and contrast the results of each individual’s analysis, reviewing emerging themes and collaborating to refine themes into a coherent set. To asses inter-rater reliability, two un-read transcripts were reviewed by all team members and coded independently, followed by meetings as a research team to compare coding decisions on each transcript and reconcile any discrepancies. This rigorous process helped to ensure strong inter-rater reliability as we were able to gain consensus in our coding process for all other transcripts. Researchers individually arranged transcript data verbatim into groups of initial themes, and a master document was then created collaboratively, which outlined each finalized theme and included transcript excerpts embodying each theme.
Memo-writing was employed throughout the analytic process to document coding decisions.15 As a final check for validity, the two experienced paramedic supervisors from the research team reviewed the themes and subthemes and provided feedback about the findings. The paramedic supervisors confirmed that these themes were what they might have expected the data to reveal, further validating the findings.
RESULTS: Table 1 shows demographic characteristics of the 23 participants. Results for this paper will focus on three themes identified in the data analysis. Namely, paramedics (1) report frequently working with patients who are having a behavioral health crisis, (2) report having inadequate behavioral health training, and (3) have many difficulties managing these patients, relying primarily on their professional experiences and/or strong interpersonal skills rather than explicit training to address patients’ needs (see Table 2).Accepted manuscrip
Finite Element Studies of Transient Wave Propagation
The National Bureau of Standards (NBS) has been working to develop a nondestructive test method for heterogenous solids using transient stress waves [1-5]. The method is referred to as the impact-echo method. The technique involves introducing a transient stress pulse into a test object by mechanical impact at a point and measuring the surface displacement caused by the arrival of reflections of the pulse from internal defects and external boundaries. Successful signal interpretation requires an understanding of the nature of transient stress wave propagation in solids containing defects. A primary focus of the NBS program is on using the finite element method to gain this understanding.</p
Peptide Array X-Linking (PAX): A New Peptide-Protein Identification Approach
Many protein interaction domains bind short peptides based on canonical sequence consensus motifs. Here we report the development of a peptide array-based proteomics tool to identify proteins directly interacting with ligand peptides from cell lysates. Array-formatted bait peptides containing an amino acid-derived cross-linker are photo-induced to crosslink with interacting proteins from lysates of interest. Indirect associations are removed by high stringency washes under denaturing conditions. Covalently trapped proteins are subsequently identified by LC-MS/MS and screened by cluster analysis and domain scanning. We apply this methodology to peptides with different proline-containing consensus sequences and show successful identifications from brain lysates of known and novel proteins containing polyproline motif-binding domains such as EH, EVH1, SH3, WW domains. These results suggest the capacity of arrayed peptide ligands to capture and subsequently identify proteins by mass spectrometry is relatively broad and robust. Additionally, the approach is rapid and applicable to cell or tissue fractions from any source, making the approach a flexible tool for initial protein-protein interaction discovery.National Institutes of Health (U.S.) (Grant R21-CA-140030-01
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Predicting breast cancer response to neoadjuvant treatment using multi-feature MRI: results from the I-SPY 2 TRIAL.
Dynamic contrast-enhanced (DCE) MRI provides both morphological and functional information regarding breast tumor response to neoadjuvant chemotherapy (NAC). The purpose of this retrospective study is to test if prediction models combining multiple MRI features outperform models with single features. Four features were quantitatively calculated in each MRI exam: functional tumor volume, longest diameter, sphericity, and contralateral background parenchymal enhancement. Logistic regression analysis was used to study the relationship between MRI variables and pathologic complete response (pCR). Predictive performance was estimated using the area under the receiver operating characteristic curve (AUC). The full cohort was stratified by hormone receptor (HR) and human epidermal growth factor receptor 2 (HER2) status (positive or negative). A total of 384 patients (median age: 49 y/o) were included. Results showed analysis with combined features achieved higher AUCs than analysis with any feature alone. AUCs estimated for the combined versus highest AUCs among single features were 0.81 (95% confidence interval [CI]: 0.76, 0.86) versus 0.79 (95% CI: 0.73, 0.85) in the full cohort, 0.83 (95% CI: 0.77, 0.92) versus 0.73 (95% CI: 0.61, 0.84) in HR-positive/HER2-negative, 0.88 (95% CI: 0.79, 0.97) versus 0.78 (95% CI: 0.63, 0.89) in HR-positive/HER2-positive, 0.83 (95% CI not available) versus 0.75 (95% CI: 0.46, 0.81) in HR-negative/HER2-positive, and 0.82 (95% CI: 0.74, 0.91) versus 0.75 (95% CI: 0.64, 0.83) in triple negatives. Multi-feature MRI analysis improved pCR prediction over analysis of any individual feature that we examined. Additionally, the improvements in prediction were more notable when analysis was conducted according to cancer subtype
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