22 results on '"Nicole Riem"'
Search Results
2. Microphysical properties of atmospheric soot and organic particles: measurements, modeling, and impacts
- Author
-
Weijun Li, Nicole Riemer, Liang Xu, Yuanyuan Wang, Kouji Adachi, Zongbo Shi, Daizhou Zhang, Zhonghua Zheng, and Alexander Laskin
- Subjects
Environmental sciences ,GE1-350 ,Meteorology. Climatology ,QC851-999 - Abstract
Abstract Atmospheric soot and organic particles from fossil fuel combustion and biomass burning modify Earth’s climate through their interactions with solar radiation and through modifications of cloud properties by acting as cloud condensation nuclei and ice nucleating particles. Recent advancements in understanding their individual properties and microscopic composition have led to heightened interest in their microphysical properties. This review article provides an overview of current advanced microscopic measurements and offers insights into future avenues for studying microphysical properties of these particles. To quantify soot morphology and ageing, fractal dimension (D f ) is a commonly employed quantitative metric which allows to characterize morphologies of soot aggregates and their modifications in relation to ageing factors like internal mixing state, core-shell structures, phase, and composition heterogeneity. Models have been developed to incorporate D f and mixing diversity metrics of aged soot particles, enabling quantitative assessment of their optical absorption and radiative forcing effects. The microphysical properties of soot and organic particles are complex and they are influenced by particle sources, ageing process, and meteorological conditions. Furthermore, soluble organic particles exhibit diverse forms and can engage in liquid–liquid phase separation with sulfate and nitrate components. Primary carbonaceous particles such as tar balls and soot warrant further attention due to their strong light absorbing properties, presence of toxic organic constituents, and small size, which can impact human health. Future research needs include both atmospheric measurements and modeling approaches, focusing on changes in the mixing structures of soot and organic particle ensembles, their effects on climate dynamics and human health.
- Published
- 2024
- Full Text
- View/download PDF
3. PyPartMC: A Pythonic interface to a particle-resolved, Monte Carlo aerosol simulation framework
- Author
-
Zachary D’Aquino, Sylwester Arabas, Jeffrey H. Curtis, Akshunna Vaishnav, Nicole Riemer, and Matthew West
- Subjects
Python-to-Fortran interface ,Particle-resolved aerosol simulation ,Atmospheric modeling ,Computer software ,QA76.75-76.765 - Abstract
PyPartMC is a Pythonic interface to PartMC, a stochastic, particle-resolved aerosol model implemented in Fortran. Both PyPartMC and PartMC are free, libre, and open-source. PyPartMC reduces the number of steps and mitigates the effort necessary to install and utilize the resources of PartMC. Without PyPartMC, setting up PartMC requires: working with UNIX shell, providing Fortran and C libraries, and performing standard Fortran and C source code configuration, compilation and linking. This can be challenging for those less experienced with computational research or those intending to use PartMC in environments where provision of UNIX tools is less straightforward (e.g., on Windows). PyPartMC offers a single-step installation/upgrade process of PartMC and all dependencies through the pip Python package manager on Linux, macOS, and Windows. This allows streamlined access to the unmodified and versioned Fortran internals of the PartMC codebase from both Python and other interoperable environments (e.g., Julia through PyCall). In particular, PyPartMC can be set up to handle the time-stepping loop for PartMC simulations making it possible to couple PartMC with other Python-interoperable packages, for either online diagnostics or additional simulation logic. Altogether, users of PyPartMC can setup, run, process and visualize output of PartMC simulations using a single general-purpose programming language.
- Published
- 2024
- Full Text
- View/download PDF
4. Improving BC Mixing State and CCN Activity Representation With Machine Learning in the Community Atmosphere Model Version 6 (CAM6)
- Author
-
Wenxiang Shen, Minghuai Wang, Nicole Riemer, Zhonghua Zheng, Yawen Liu, and Xinyi Dong
- Subjects
mixing state representation ,machine learning ,black carbon aerosol ,aerosol CCN activation ,climate model improvement ,Physical geography ,GB3-5030 ,Oceanography ,GC1-1581 - Abstract
Abstract Representing mixing state of black carbon (BC) is challenging for global climate models (GCMs). The Community Atmosphere Model version 6 (CAM6) with the four‐mode version of the Modal Aerosol Module (MAM4) represents aerosols as fully internal mixtures with uniform composition within each aerosol mode, resulting in high degree of internal mixing of BC with non‐BC species and large mass ratio of coating to BC (RBC, the mass ratio of non‐BC species to BC in BC‐containing particles). To improve BC mixing state representation, we coupled a machine learning (ML) model of BC mixing state index trained on particle‐resolved simulations to the CAM6 with MAM4 (MAM4‐ML). In MAM4‐ML, we use RBC to partition accumulation mode particles into two new modes, BC‐free particles and BC‐containing particles. We adjust RBC to make the modeled BC mixing state index (χmode) match the one predicted by the ML model (χML). On a global average, the mass fraction of BC‐containing particles in accumulation mode decreases from 100% (MAM4‐default) to 48% (MAM4‐ML). The globally averaged χmode decreases from 78% (MAM4‐default) to 63% (MAM4‐ML, 19% reduction) and agrees well with χML (66%). The RBC decreases by 52% for accumulation mode and better agrees with observations. The hygroscopicity drops by 9% for BC‐containing particles in accumulation mode, leading to a 20% reduction in the BC activation fraction. The surface BC concentration increases most (6.9%) in the Arctic, and the BC burden increases by 4%, globally. Our study highlights the application of the ML model for improving key aerosol processes in GCMs.
- Published
- 2024
- Full Text
- View/download PDF
5. A 1D Model for Nucleation of Ice From Aerosol Particles: An Application to a Mixed‐Phase Arctic Stratus Cloud Layer
- Author
-
Daniel A. Knopf, Israel Silber, Nicole Riemer, Ann M. Fridlind, and Andrew S. Ackerman
- Subjects
aerosol ,mixed‐phase cloud ,ice‐nucleating particle ,immersion freezing ,ice crystal ,Physical geography ,GB3-5030 ,Oceanography ,GC1-1581 - Abstract
Abstract Mixed‐phase clouds (MPCs) have been identified as significant contributors to uncertainties in climate projections, attributable to model representation of processes controlling the formation and loss of supercooled water droplets and ice particles from the atmosphere. Arctic MPCs are commonly widespread and long‐lived, with sustained ice crystal formation processes that challenge current understanding. This study examines the ice‐nucleating particle (INP) reservoir dynamics governing immersion‐mode heterogeneous freezing in an observed case of Arctic MPCs using a simplified 1D aerosol‐cloud model. The model setup includes prescribed dynamical forcings and thermodynamic profiles, and represents INPs as multicomponent and polydisperse particle size distributions. Diagnostic and prognostic approaches to immersion freezing parameterization are compared, including time‐independent (singular) number‐ and surface area‐based descriptions and a time‐dependent description following classical nucleation theory (CNT). The choice of freezing parameterization defines the size of the INP reservoir. The CNT‐based description yields an orders of magnitude larger INP reservoir than the singular parameterizations, which is the dominant factor for sustained ice crystal formation. The efficiency of the freezing process and cloud cooling are of secondary importance. A diagnostic treatment neglecting INP loss is only accurate when the INP reservoir size is large and INP depletion weak. Since a larger INP reservoir sustains ice crystal formation substantially longer, and ice water path scales with ice crystal concentrations for the conditions considered, resolving the source of differences in INP reservoir dynamics due to model implementation is a high priority for advancing climate model physics.
- Published
- 2023
- Full Text
- View/download PDF
6. Obstructive sleep apnea: are we going overboard?
- Author
-
Nicole Riem
- Subjects
medicine.medical_specialty ,Sleep Apnea, Obstructive ,business.industry ,MEDLINE ,Sleep apnea ,030208 emergency & critical care medicine ,medicine.disease ,Obstructive sleep apnea ,03 medical and health sciences ,0302 clinical medicine ,Anesthesiology and Pain Medicine ,030202 anesthesiology ,Risk Factors ,Emergency medicine ,medicine ,Humans ,business - Published
- 2017
7. Does warm-up using mental practice improve crisis resource management performance? A simulation study
- Author
-
Nicole Riem, Megan A. Hayter, Sylvain Boet, Michelle Chiu, M. Afsari, and M. D. Bould
- Subjects
Adult ,Male ,medicine.medical_specialty ,Epinephrine ,Endpoint Determination ,medicine.medical_treatment ,Electric Countershock ,Intervention group ,Shock, Hemorrhagic ,Manikins ,Crisis resource management ,law.invention ,Mental practice ,Randomized controlled trial ,Anesthesiology ,law ,Monitoring, Intraoperative ,Intervention (counseling) ,Humans ,Vasoconstrictor Agents ,Medicine ,Blood Transfusion ,Computer Simulation ,Cardiopulmonary resuscitation ,business.industry ,Significant difference ,Internship and Residency ,Cardiopulmonary Resuscitation ,Heart Arrest ,Crisis Intervention ,Anesthesiology and Pain Medicine ,Practice, Psychological ,Sample Size ,Emergency medicine ,Physical therapy ,Female ,business ,Case Management ,Crisis intervention - Abstract
Background Mental practice (MP) is defined as the ‘symbolic rehearsal of a physical activity in the absence of any gross-muscular movements' and has been used in sport and music to enhance performance. In healthcare, MP has been demonstrated to improve technical skill performance of surgical residents. However, its effect on crisis resource management (CRM) skills has yet to be determined. We aimed to investigate the effect of warm-up with MP on CRM skill performance during a simulated crisis scenario. Methods Following ethics board approval, 40 anaesthesia residents were randomized. The intervention group performed 20 min of MP of a script based on CRM principles. The control group received a 20 min didactic teaching session on an unrelated topic. Each subject then managed a simulated cardiac arrest. Two CRM experts rated the video recordings of each performance using the previously validated Ottawa GRS. The time to start chest compressions, administer epinephrine, and give blood was recorded. Results There was no significant difference between the intervention and control groups: total Ottawa GRS score was 24.50 (18.63–28.88 [6.50–34.50]) (median (inter-quartile range [range]) vs 20.50 (13.00–29.13 [6.50–34.50]) (P=0.53); the time to start chest compressions 146.0 s (138.0–231.0 [115.0–323.0]) vs 162.5 s (138.0–231.0 [100.0–460.0]) (P=0.27), the time to epinephrine administration 163.0 s (151.0–187.0 [111.0–337.0]) vs 187.0 s (164.0–244.0 [115.0–310.0]) (P=0.09), and the time to blood administration 220.5 s (130.8–309.0 [92.0–485.0]) vs 252.5 (174.5–398.8 [65.0–527.0]) (P=0.48). Conclusion Unlike technical skills, warm-up with MP does not seem to improve CRM skills in simulated crisis scenarios.
- Published
- 2013
- Full Text
- View/download PDF
8. HISTORY AND EDUCATION
- Author
-
Eugène Zoumenou, Michael McGaughlin, Garrido Gomez Ignacio, Diego Garcia Picasso, Deryk Chen, Melissa Duan, Akihito Kakinuma, Yoshinori Nakata, Din Z. Kagalwala, Antonio Bedin, Nicole Riem, Ignacio Marques, Feng Qian, Jeffery S. Vender, Mark Levine, Frank Costello, W. Bosseau Murray, Joseph W. Szokol, Ana I. Whizar-Figueroa, George Bause, Cao Avellaneda Enrique, Susan Vassallo, Renee Ford, Correa Chacon Olga Cecilia, Farhad Safari, Roger Webster, Phongthara Vichitvejpaisal, Michael J. Avram, Patricia Szulman, Katherine Beaudry, Veiga Ruiz Gloria, M. Ramez Salem, Enrique Hernández-Cortez, Preetam Cholli, Susan DeSousa, Manisha Shah, Richard Bugembe, Robert Truog, Carol Ann Diachun, Manu-Priya Sharma, Benito Cortes-Blanco, Sylvain Boet, Julio Rotondo, Chi Davies, Maurice Lamy, Glenn Murphy, Leonard Pott, George J. Crystal, Hirokazu Nagatani, David Weisel, Walter Tavares, Stephen Ttendo, Bernard Lepopaindewaroux, Tippawan Panjamawat, Norma Sandrock, Martin Chobli, Diana Finkel, Lopez Lozano Esther, Sanjib Das Adhikary, Ronnie Strauch, Anita Pramod, Paula Carmona, Steven Greenberg, Anthony Kovac, H. Stoeckel, Luc Barvais, Siavosh Saatee, Tatsuya Yoshimura, Lourdes Navarro, Kamran mottaghi, Jordan Tarshis, Yuhji Saitoh, Robert Pascucci, Edward Kosik, Pinda Varasunun, Cecilia Sucari, Arjang Khorasani, Juan Jose Peña, Hanuman S Murthy, J. Carlos Flores-Carrillo, Agustina Rocco, Anita Sarmah, Gundappa Parameswara, Marta Londoño, Dylan Bould, Gerald Dubowitz, Agnes Ryzynski, Seetharaman Hariharan, Kirtida Mukherjee, Venkatesh Kumar, and Víctor M. Whizar-Lugo
- Subjects
Medical education ,Anesthesiology and Pain Medicine ,business.industry ,Primary education ,Social history ,Medicine ,business ,Schools of history - Published
- 2012
- Full Text
- View/download PDF
9. Setting standards for simulation in anesthesia: the role of safety criteria in accreditation standards
- Author
-
Deven B. Chandra, Nicole Riem, and Sylvain Boet
- Subjects
Safety Management ,medicine.medical_specialty ,Hot Temperature ,Manikins ,Accreditation ,Simulation training ,Anesthesiology ,Health care ,Safety criteria ,Accidents, Occupational ,Humans ,Sodium Hydroxide ,Medicine ,Anesthesia ,Critical event ,business.industry ,Medical simulation ,Oxides ,General Medicine ,Calcium Compounds ,Carbon Dioxide ,Variety (cybernetics) ,Equipment failure ,Anesthesiology and Pain Medicine ,Equipment Failure ,business ,Software - Abstract
In this article, we describe a critical event which occurred in a simulation centre, and we also review possible safety issues for participants and staff involved in medical simulation training. The authors report an incident with the potential of harming trainees and staff which occurred during a full-scale simulation. The episode raised the question of training safety in simulation centres. In this instance, the computer program controlling the mannequin enabled a continuous and non-regulated outflow of carbon dioxide which led to an intense reaction in the soda lime canister. The absorbent canister became too hot to be touched (a temperature probe, later placed in the centre of the front canister, measured 53°C). All activities involving the mannequin and anesthesia machine were stopped immediately. Simulation in healthcare is a valuable educational tool to train for a variety of clinical encounters in a safe environment without harming a patient. Due to technological progress and the use of authentic equipment recreating near real environments, simulation training has become exceedingly realistic. The Society for Simulation in Healthcare (SSH) has published revised accreditation standards for simulation centres which incorporate training safety sub-criteria to address and manage. By highlighting recommendations of other high-risk industries on this issue, SSH proposes a possible approach to enhance safety in medical simulation.
- Published
- 2011
- Full Text
- View/download PDF
10. National representation in the anaesthesia literature: a bibliometric analysis of highly cited anaesthesia journals*
- Author
-
Heinz R. Bruppacher, A. Sossou, Sylvain Boet, Nicole Riem, C. Kasanda, and M.D. Bould
- Subjects
Anesthesiology and Pain Medicine ,business.industry ,Measures of national income and output ,MEDLINE ,Medicine ,Subject (documents) ,Bibliometrics ,Social science ,business ,China ,Citation ,Country of origin ,Representation (politics) - Abstract
While previous studies have investigated the country of origin of anaesthetic publications, they have generally used a medline computer search to identify original articles and have often excluded non-English language articles. We undertook a hand-search of journals in the Journal Citation Reports using the subject category of Anesthesiology. We quantified the number of original articles, editorials, review articles, case reports and correspondence attributed to each country. We also calculated the proportion of articles of each type from countries of each national income category. We analysed 9684 articles published in 2007 and 2008. The United States published more original articles than any other country. High-income countries published 89.2% of original articles, middle-income countries 10.5%, and low-income countries just 0.3%. There were more articles published by middle-income countries during the study period than a decade earlier, notably from Turkey, China and India. We discuss barriers to publications from low-income countries.
- Published
- 2010
- Full Text
- View/download PDF
11. Cricothyrotomy training increases adherence to the ASA difficult airway algorithm in a simulated crisis: a randomized controlled trial
- Author
-
Kong Eric You-Ten, Devin Sydor, M. Dylan Bould, Sylvain Boet, Zeev Friedman, and Nicole Riem
- Subjects
Male ,medicine.medical_specialty ,medicine.medical_treatment ,Fibreoptic intubation ,law.invention ,Cricoid Cartilage ,Randomized controlled trial ,Laryngeal mask airway ,law ,Anesthesiology ,medicine ,Intubation, Intratracheal ,Intubation ,Humans ,Cricothyrotomy ,Airway Management ,Difficult airway ,Societies, Medical ,business.industry ,General Medicine ,United States ,Anesthesiology and Pain Medicine ,Thyroid Cartilage ,Practice Guidelines as Topic ,Female ,Clinical Competence ,Guideline Adherence ,Airway ,business ,Algorithm ,Algorithms - Abstract
Non-adherence to airway guidelines in a ‘cannot intubate–cannot oxygenate’ (CICO) crisis situation is associated with adverse patient outcomes. This study investigated the effects of hands-on training in cricothyrotomy on adherence to the American Society of Anesthesiologists difficult airway algorithm (ASA-DAA) during a simulated CICO scenario. A total of 21 postgraduate second-year anesthesia residents completed a pre-test teaching session during which they reviewed the ASA-DAA, became familiarized with the Melker cricothyrotomy kit, and watched a video on cricothyrotomy. Participants were randomized to either the intervention ‘Trained’ group (n = 10) (taught and practiced cricothyrotomy) or the control ‘Non-Trained’ group (n = 11) (no extra training). After two to three weeks, performances of the groups were assessed in a simulated CICO scenario. The primary outcome measure was major deviation from the ASA-DAA. Secondary outcome measures were (1) performance of the four categories of non-technical behaviours using the validated Anaesthetists’ Non-Technical Skills scale (ANTS) and (2) time to perform specific tasks. Significantly more non-trained than trained participants (6/11 vs 0/10, P = 0.012) committed at least one major ASA-DAA deviation, including failure to insert an oral airway, failure to call for help, bypassing the laryngeal mask airway, and attempting fibreoptic intubation. ANTS scores for all four categories of behaviours, however, were similar between the groups. Trained participants called for help faster [26 (2) vs 63 (48) sec, P = 0.012] but delayed opening of the cricothyrotomy kit [130 (50) vs 74 (36) sec, P = 0.014]. Hands-on training in cricothyrotomy resulted in fewer major ASA-DAA deviations in a simulated CICO scenario. Training in cricothyrotomy may play an important role in complying with the ASA-DAA in a CICO situation but does not appear to affect non-technical behaviours such as decision-making.
- Published
- 2014
12. Do technical skills correlate with non-technical skills in crisis resource management: a simulation study
- Author
-
Sylvain Boet, M. D. Bould, Nicole Riem, Walter Tavares, and Viren N. Naik
- Subjects
Male ,medicine.medical_specialty ,Future studies ,medicine.medical_treatment ,MEDLINE ,Crisis management ,cardiopulmonary resuscitation ,Crisis resource management ,Skills management ,Resource Allocation ,Clinical Practice ,Patient safety ,Anesthesiology ,Acute care ,medicine ,Humans ,Cardiopulmonary resuscitation ,Technical skills ,Intraoperative Complications ,Retrospective Studies ,Observer Variation ,business.industry ,Retrospective cohort study ,Arrhythmias, Cardiac ,respiratory system ,medicine.disease ,Checklist ,patient simulation ,Heart Arrest ,Anesthesiology and Pain Medicine ,nervous system ,Models, Organizational ,Female ,Medical emergency ,Clinical Competence ,Patient Safety ,Emergencies ,business ,medical education - Abstract
Background Both technical skills (TS) and non-technical skills (NTS) are key to ensuring patient safety in acute care practice and effective crisis management. These skills are often taught and assessed separately. We hypothesized that TS and NTS are not independent of each other, and we aimed to evaluate the relationship between TS and NTS during a simulated intraoperative crisis scenario. Methods This study was a retrospective analysis of performances from a previously published work. After institutional ethics approval, 50 anaesthesiology residents managed a simulated crisis scenario of an intraoperative cardiac arrest secondary to a malignant arrhythmia. We used a modified Delphi approach to design a TS checklist, specific for the management of a malignant arrhythmia requiring defibrillation. All scenarios were recorded. Each performance was analysed by four independent experts. For each performance, two experts independently rated the technical performance using the TS checklist, and two other experts independently rated NTS using the Anaesthetists' Non-Technical Skills score. Results TS and NTS were significantly correlated to each other (r=0.45, P Conclusions During a simulated 5 min resuscitation requiring crisis resource management, our results indicate that TS and NTS are related to one another. This research provides the basis for future studies evaluating the nature of this relationship, the influence of NTS training on the performance of TS, and to determine whether NTS are generic and transferrable between crises that require different TS.
- Published
- 2012
13. Complex procedural skills are retained for a minimum of 1 yr after a single high-fidelity simulation training session
- Author
-
Hwan S. Joo, Lyndon W. Siu, Sylvain Boet, Deven B. Chandra, Nicole Riem, Bruno C. R. Borges, M.D. Bould, and Viren N. Naik
- Subjects
medicine.medical_specialty ,Emergency Medical Services ,Time Factors ,medicine.medical_treatment ,Retention interval ,Manikins ,law.invention ,Cricoid Cartilage ,Random order ,Procedural skill ,Randomized controlled trial ,High Fidelity Simulation Training ,law ,Anesthesiology ,medicine ,Humans ,Learning ,Cricothyrotomy ,Anesthesia ,Single-Blind Method ,Session (computer science) ,Airway Management ,Intraoperative Complications ,Observer Variation ,business.industry ,Debriefing ,Checklist ,Surgery ,Anesthesiology and Pain Medicine ,Sample size determination ,Sample Size ,Physical therapy ,Thyroidectomy ,Airway management ,Clinical Competence ,business - Abstract
Background Simulation has been shown to be effective in teaching complex emergency procedural skills. However, the retention of these skills for a period of up to 1 yr has not been studied. We aimed to investigate the 6 month and 1 yr retention of the complex procedural skill of cricothyroidotomy in attending anaesthetists using a high-fidelity-simulated cannot intubate, cannot ventilate (CICV) scenario. Methods Thirty-eight attending anaesthetists participated individually in a high-fidelity-simulated CICV scenario (pretest) that required a cricothyroidotomy for definitive airway management. Immediately after a debriefing and structured teaching session on cricothyroidotomy insertion, subjects managed a second identical CICV scenario (post-test). Each anaesthetist was randomized to either a ‘6 month retention' or a ‘12 month retention' group. No further teaching occurred. At their respective retention times, each anaesthetist managed a third identical CICV scenario (retention post-test). Two blinded experts independently rated videos of all performances in a random order, using a specific checklist (CL) score, a global-rating scale (GRS) score, and procedural time (PT). Results Subjects from both groups improved on their cricothyroidotomy skill performances from pretest to immediate post-test and from pretest to retention post-test, irrespective of the retention interval; CL mean (sd) 8.00 (2.39) vs 8.88 (1.53), P =0.49; GRS 28.00 (7.80) vs 31.25 (5.31), P =0.25; PT 102.83 (63.81) s vs 106.88 (36.68) s, P =0.73. Conclusions After a single simulation training session, improvements in cricothyroidotomy skills are retained for at least 1 yr. These findings suggest that high-fidelity simulation training, along with practice and feedback, can be used to maintain complex procedural skills for at least 1 yr.
- Published
- 2011
14. High-fidelity simulation demonstrates the influence of anesthesiologists' age and years from residency on emergency cricothyroidotomy skills
- Author
-
Bruno C. R. Borges, Viren N. Naik, Heinz R. Bruppacher, Lyndon W. Siu, Sylvain Boet, Vicki R. LeBlanc, Nicole Riem, Deven B. Chandra, and Hwan S. Joo
- Subjects
Adult ,Male ,medicine.medical_specialty ,medicine.medical_treatment ,Population ,Manikins ,Continuing medical education ,Anesthesiology ,Physicians ,medicine ,Humans ,Single-Blind Method ,Prospective Studies ,education ,Aged ,education.field_of_study ,business.industry ,Age Factors ,Internship and Residency ,Mean age ,Cognition ,Middle Aged ,Respiration, Artificial ,Checklist ,Global Rating ,Anesthesiology and Pain Medicine ,High fidelity simulation ,Physical therapy ,Emergency Medicine ,Airway management ,Education, Medical, Continuing ,Female ,Clinical Competence ,Laryngeal Muscles ,business - Abstract
BACKGROUND: Age-related deterioration in both cognitive function and the capacity to control fine motor movements has been demonstrated in numerous studies. However, this decline has not been described with respect to complex clinical anesthesia skills. Cricothyroidotomy is an example of a complex, lifesaving procedure that requires competency in the domains of both cognitive processing and fine motor control. Proficiency in this skill is vital to minimize time to reestablish oxygenation during a "cannot intubate, cannot ventilate" scenario. In this prospective, controlled, single-blinded study, we tested the hypothesis that age affects the leaming and performance of emergency percutaneous cricothyroidotomy in a high-fidelity simulated cannot intubate/cannot ventilate scenario. METHODS: Thirty-six staff anesthesiologists (19 aged younger than 45 years and 17 older than 45 years) managed a high-fidelity cannot intubate/cannot ventilate scenario in a high-fidelity simulator before and after a 1-hour standardized training session. The group division cutoff age of 45 years was based on the median age of our sample subject population before enrollment. The scenarios required the insertion of an emergency percutaneous cricothyroidotomy. We compared cricothyroidotomy skills in the older group with those in the younger group using procedural time, 5-point task-specific checklist score, and global rating scale score. Correlation based on age, years from residency, weekly clinical hours worked, previous continuing medical education in airway management, and previous simulation experience was also performed. RESULTS: In both prestandardization and poststandardization, age and years from residency correlated with procedural time, checklist scores, and global rating scores. Baseline, prestandardization variables were all better for the younger group, with a mean age of 37 years, compared with the older group, with a mean age of 58 years. Procedural time was 100 (72-128) seconds versus 152 (120-261) seconds. Checklist scores were 7.0 (6.1-8.0) versus 6.0 (4.8-8.0). Global rating scale scores were 22.0 (17.8―29.8) versus 17.5 (10.4-20.6). After the 1-hour standardized training session, the younger group continued to perform better than the older group with procedural time of 75 (66-91) seconds versus 87 (78-123) seconds, checklist scores of 10.0 (9.1―10.0) versus 9.0 (8.0-10.0), and global rating scale scores of 35.0 (32.1―35.0) versus 32.0 (29.0-33.8). Regression analysis was performed on the poststandardization data. Both age and years from residency independently affected procedural time, checklist scores, and global rating scale scores (all P < 0.05). CONCLUSIONS: Baseline proficiency with simulated emergency cricothyroidotomy is associated with age and years from residency. Despite standardized training, operator age and years from residency were associated with decreased proficiency. Further research should explore the potential of using age and years from residency as factors for implementing periodic continuing medical education.
- Published
- 2010
15. Incomplete adherence to the ASA difficult airway algorithm is unchanged after a high-fidelity simulation session
- Author
-
Viren N. Naik, Nicole Riem, Sylvain Boet, Bruno C. R. Borges, Heinz R. Bruppacher, Lyndon W. Siu, and Hwan S. Joo
- Subjects
Adult ,Male ,medicine.medical_specialty ,medicine.medical_treatment ,Fracture Fixation, Internal ,Laryngeal mask airway ,Informed consent ,Anesthesiology ,Mandibular Fractures ,Fracture fixation ,medicine ,Intubation, Intratracheal ,Intubation ,Humans ,business.industry ,Debriefing ,General Medicine ,Middle Aged ,Patient Simulation ,Anesthesiology and Pain Medicine ,Anesthesia ,Sample Size ,Airway management ,Education, Medical, Continuing ,Female ,Clinical Competence ,Guideline Adherence ,Airway ,business ,Algorithm ,Algorithms - Abstract
Although guidelines for difficult airway management have been published, the extent to which consultant anesthesiologists follow these guidelines has not been determined. The purpose of this study is to observe how consultant anesthesiologists manage a "cannot intubate, cannot ventilate" (CICV) scenario in a high-fidelity simulator and to evaluate whether a simulation teaching session improves their adherence to the American Society of Anesthesiologists (ASA) difficult airway algorithm.With Ethics Board approval and informed consent, all staff anesthesiologists in a single tertiary care institution were invited to enrol in this study where they managed a simulated unanticipated CICV scenario in a high-fidelity simulator. The scenario involved a patient with a difficult airway whose trachea could not be intubated and where it was impossible to ventilate the patient's lungs. Airway management options, including laryngeal mask airway, a fibreoptic bronchoscope, and a Glidescope were available for use but scripted to fail. A percutaneous cricothyroidotomy was required to re-establish adequate ventilation. Following the scenario, there was a personalized one-hour video-assisted expert debriefing focusing on the ASA difficult airway guidelines and "hands-on" cricothyroidotomy teaching. The second scenario followed immediately with an identical CICV scenario. The content to either scenario was not revealed beforehand. Outcome measures included: 1) major deviations from the ASA difficult airway guidelines; 2) time to start cricothyroidotomy; and 3) time to achieve ventilation.Thirty-eight anesthesiologists agreed to participate. The number of major deviations from the ASA algorithm was similar in the first and second sessions. These deviations included: multiple laryngoscopies (0 vs 2 pre-post; P = 0.49), use of fibreoptic bronchoscope (8 vs 7 pre-post; P = 1.0), bypass of laryngeal mask airway attempt (7 vs 13 pre-post; P = 0.19), and failure to call for anesthetic help (12 vs 8 pre-post; P = 0.43). However, more participants failed to call for surgical help in the second session (7 vs 16; P = 0.04). The times to start cricothyroidotomy and the times to achieve ventilation were significantly shorter in the second session (205.5 +/- 61.3 sec vs 179.7 +/- 65.1 sec; P = 0.01 and 356.9 +/- 117.2 sec vs 269.4 +/- 77.43 sec; P = 0.0002, respectively).No substantial changes in airway management in a CICV scenario were observed after an intense one-hour personalized video-assisted airway-focused simulation debriefing session with an expert. It appears that multiple factors other than airway algorithms come into play in emergency airway decision-making processes, including one's personal clinical experience with the many available airway devices.
- Published
- 2010
16. Estimating Submicron Aerosol Mixing State at the Global Scale With Machine Learning and Earth System Modeling
- Author
-
Zhonghua Zheng, Jeffrey H. Curtis, Yu Yao, Jessica T. Gasparik, Valentine G. Anantharaj, Lei Zhao, Matthew West, and Nicole Riemer
- Subjects
Astronomy ,QB1-991 ,Geology ,QE1-996.5 - Abstract
Abstract This study integrates machine learning and particle‐resolved aerosol simulations to develop emulators that predict submicron aerosol mixing state indices from the Earth system model (ESM) simulations. The emulators predict aerosol mixing state using only quantities that are predicted by the ESM, including bulk aerosol species concentrations, which do not by themselves carry mixing state information. We used PartMC‐MOSAIC as the particle‐resolved model and NCAR's CESM as the ESM. We trained emulators for three different mixing state indices for submicron aerosol in terms of chemical species abundance (χa), the mixing of optically absorbing and nonabsorbing species (χo), and the mixing of hygroscopic and nonhygroscopic species (χh). Our global mixing state maps show considerable spatial and seasonal variability unique to each mixing state index. Seasonal averages varied spatially between 13% and 94% for χa, between 38% and 94% for χo, and between 20% and 87% for χh with global annual averages of 67%, 68%, and 56%, respectively. High values in one index can be consistent with low values in another index depending on the grouping of species and their relative abundance, meaning that each mixing state index captures different aspects of the population mixing state. Although a direct validation with observational data has not been possible yet, our results are consistent with mixing state index values derived from ambient observations. This work is a prototypical example of using machine learning emulators to add information to ESM simulations.
- Published
- 2021
- Full Text
- View/download PDF
17. Black carbon absorption at the global scale is affected by particle-scale diversity in composition
- Author
-
Laura Fierce, Tami C. Bond, Susanne E. Bauer, Francisco Mena, and Nicole Riemer
- Subjects
Science - Abstract
Model and laboratory experiments disagree with observations regarding the absorption properties of black carbon particles. Here, using a particle-resolved aerosol model, the authors show that when composition diversity is considered, absorption enhancement is consistent with ambient observations.
- Published
- 2016
- Full Text
- View/download PDF
18. Role of the convergence zone over West Africa in controlling Saharan mineral dust load and transport in the boreal summer
- Author
-
Owen M. Doherty, Nicole Riemer, and Sultan Hameed
- Subjects
Saharan mineral dust ,ITCZ ,West Africa ,interannual variability ,climate ,Centres of Action ,Meteorology. Climatology ,QC851-999 - Abstract
During summer, large amounts of mineral dust are emitted and transported from North Africa over the tropical North Atlantic towards the Caribbean with the exact quantity varying greatly from year to year. Much effort has been made to explain the variability of summer season mineral dust load, for example, by relating dust variability to teleconnection indices such as ENSO and the NAO. However, only weak relationships between such climate indices and the abundance of mineral dust have been found. In this work, we demonstrate the role of the near-surface convergence zone over West Africa in controlling dust load and transport of mineral dust. We apply the ‘Center of Action’ approach to obtain indices that quantify the movement and strength of the convergence zone using NCEP/NCAR Reanalysis data. The latitudinal position of the convergence zone is significantly correlated with the quantity of mineral dust at Barbados over the period 1965–2003 (r=−0.47). A southward displacement of the convergence zone is associated with both increased near-surface flow and decreased precipitation over the dust source regions of the southern Saharan desert, Sahel and Lake Chad. This in turn reduces soil moisture and vegetation, furthering the potential for dust emission. In contrast, the intensity of the convergence zone is not correlated with dust concentration at Barbados. We conclude that the coupling of changes in near-surface winds with changes in precipitation in source regions driven by a southward movement of the convergence zone most directly influence dust load at Barbados and over the tropical North Atlantic during summer.
- Published
- 2014
- Full Text
- View/download PDF
19. Machine Learning to Predict the Global Distribution of Aerosol Mixing State Metrics
- Author
-
Michael Hughes, John K. Kodros, Jeffrey R. Pierce, Matthew West, and Nicole Riemer
- Subjects
aerosol modeling ,mixing state ,machine learning ,Meteorology. Climatology ,QC851-999 - Abstract
Atmospheric aerosols are evolving mixtures of chemical species. In global climate models (GCMs), this “aerosol mixing state” is represented in a highly simplified manner. This can introduce errors in the estimates of climate-relevant aerosol properties, such as the concentration of cloud condensation nuclei. The goal for this study is to determine a global spatial distribution of aerosol mixing state with respect to hygroscopicity, as quantified by the mixing state metric χ . In this way, areas can be identified where the external or internal mixture assumption is more appropriate. We used the output of a large ensemble of particle-resolved box model simulations in conjunction with machine learning techniques to train a model of the mixing state metric χ . This lower-order model for χ uses as inputs only variables known to GCMs, enabling us to create a global map of χ based on GCM data. We found that χ varied between 20% and nearly 100%, and we quantified how this depended on particle diameter, location, and time of the year. This framework demonstrates how machine learning can be applied to bridge the gap between detailed process modeling and a large-scale climate model.
- Published
- 2018
- Full Text
- View/download PDF
20. Quantifying Impacts of Aerosol Mixing State on Nucleation-Scavenging of Black Carbon Aerosol Particles
- Author
-
Joseph Ching, Matthew West, and Nicole Riemer
- Subjects
black carbon ,nucleation-scavenging ,aerosol mixing state ,cloud microphysics ,particle- resolved model ,Meteorology. Climatology ,QC851-999 - Abstract
Recent observational studies suggest that nucleation-scavenging is the principal path to removing black carbon-containing aerosol from the atmosphere, thus affecting black carbon’s lifetime and radiative forcing. Modeling the process of nucleation-scavenging is challenging, since black carbon (BC) forms complex internal mixtures with other aerosol species. Here, we examined the impacts of black carbon mixing state on nucleation scavenging using the particle-resolved aerosol model PartMC-MOSAIC. This modeling approach has the unique advantage that complex aerosol mixing states can be represented on a per-particle level. For a scenario library that comprised hundreds of diverse aerosol populations, we quantified nucleation-scavenged BC mass fractions. Consistent with measurements, these vary widely, depending on the amount of BC, the amount of coating and coating material, as well as the environmental supersaturation. We quantified the error in the nucleation-scavenged black carbon mass fraction introduced when assuming an internally mixed distribution, and determined its bounds depending on environmental supersaturation and on the aerosol mixing state index χ . For a given χ value, the error decreased at higher supersaturations. For more externally mixed populations ( χ < 20 %), the nucleation-scavenged BC mass fraction could be overestimated by more than 1000% at supersaturations of 0.1%, while for more internally mixed populations ( χ > 75 %), the error was below 100% for the range of supersaturations (from 0.02% to 1%) investigated here. Accounting for black carbon mixing state and knowledge of the supersaturation of the environment are crucial when determining the amount of black carbon that can be incorporated into clouds.
- Published
- 2018
- Full Text
- View/download PDF
21. LMA with positive pressure ventilation is safe!
- Author
-
Laurent Tritsch, Sylvain Boet, Dylan Bould, and Nicole Riem
- Subjects
business.industry ,Library science ,government.political_district ,Creative commons ,St. Michael ,lcsh:RD78.3-87.3 ,Anesthesiology and Pain Medicine ,lcsh:Anesthesiology ,government ,Medicine ,Positive pressure ventilation ,business ,License ,Letter to the Editor - Abstract
Corresponding author: Nicole Riem, M.D., Department of Anesthesia, St Michael’s Hospital, University of Toronto, 30 Bond Street, Toronto, Ontario, M5B 1W8, Canada. Tel: 1-416-864-5071, Fax: 1-416-864-6014, E-mail: nriem@aol.com This is an open-access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http:// creativecommons.org/licenses/by-nc/3.0/), which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. CC Implication statement
22. Relationship of Sahel Precipitation and Atmospheric Centers of Action
- Author
-
Sultan Hameed and Nicole Riemer
- Subjects
Meteorology. Climatology ,QC851-999 - Abstract
The dynamics associated with drought in the Sahel have attracted considerable attention in the recent literature. This paper evaluates Sahel precipitation using the paradigm of the atmospheric centers of action, that is, the extended semipermanent highs and lows that dominate regional circulations and are evident in sea level pressure patterns. We find that Sahel precipitation is significantly influenced by changes in the Azores High and the South Asia Low. Specifically, about 50 percent of the variance of July to September rainfall over the Sahel is explained by changes in the Azores High Longitude position and South Asia Low pressure. In contrast, the contribution of the Southern Oscillation to Sahel precipitation is smaller in comparison. Results presented in this paper suggest that a key test for a climate model in simulating variability of Sahel rainfall is the accuracy with which the model simulates the dynamics of South Asia Low and the Azores High.
- Published
- 2012
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.