The Effect of Mandatory Fitness Requirements on Cardiovascular Events: A State-by-State Analysis Using a National Database.

BACKGROUND: Cardiovascular events are known to be the leading cause of death among on-duty firefighters. Implementing fitness standards may help reduce the incidence of cardiovascular deaths; however, standards vary between firefighter type and states. We aimed to investigate the rate of cardiovascular events among firefighters across states. METHODS: Using publicly available data from the United States Fire Administration, we explored the rates of cardiovascular deaths between firefighter type (e.g., career, volunteer, and wildland) and state. Specifically, we examined rates of cardiovascular deaths between California and Tennessee, which have fitness standards for all firefighters, and New York, which does not have fitness standards for volunteer firefighters. We used descriptive statistics and trend analysis to examine the data. FINDINGS: Most cardiovascular events occur among volunteer firefighters (60.6%, n = 877). Volunteer firefighters had 7.5 (95% CI = [4.8, 11.7], p < .001) greater odds of cardiovascular events compared to wildland firefighters, who had the lowest incidence of cardiovascular events (1.7%, n = 24). New York reported the most cardiovascular events (n = 161), primarily among volunteer firefighters (73.9%, n = 119). After the passage of legislation mandating fitness standards in California, a downtrend in the number of volunteer firefighter fatalities is observed. However, a null effect was observed in Tennessee after the passage of similar fitness standards as in California. CONCLUSIONS/APPLICATIONS TO PRACTICE: Volunteer firefighters are significantly more likely to die of a cardiovascular event than career and wildland firefighters, both of which have stricter fitness standards. However, the effect of legislation mandating stricter fitness standards among volunteers did not produce a clear benefit for preventing fatalities. Nurses need to promote cardiovascular health among volunteer firefighters.

Point Mean Beam Length, a New Concept to Enhance the Computational Efficiency of Multi-Dimensional, Non-Gray Radiative Heat Transfer.

A new concept of point mean beam length (PMBL) is introduced. For enclosures with simple geometry, this concept provides a fundamental self-consistent interpretation on the various different definition of the conventional mean beam length. The concept is further demonstrated to be effective in enhancing the computational efficiency for multi-dimensional radiative heat transfer in non-gray media. In the evaluation of radiative exchange between two perpendicular areas with a common edge, the use of PMBL leads to a factor of 100 to 400 reduction in computational effort compared to the direct integration approach. For practical applications, PMBL is combined with RADNNET (a neural network correlation for a one-dimensional CO2/H2O/soot combustion mixture) to generate two highly efficient and accurate solvers for the evaluation of exchange factors between two parallel or perpendicular rectangular areas of arbitrary dimensions with an intervening combustion mixture.

Prevention of Cooktop Ignition Using Detection and Multi-Step Machine Learning Algorithms.

This paper presents a study to examine the potential use of machine learning models to build a real-time detection algorithm for prevention of kitchen cooktop fires. Sixteen sets of time-dependent sensor signals were obtained from 60 normal/ignition cooking experiments. A total of 200 000 data instances are documented and analyzed. The raw data are preprocessed. Selected features are generated for time series data focusing on real-time detection applications. Utilizing the leave-one-out cross validation method, three machine learning models are built and tested. Parametric studies are carried out to understand the diversity, volume, and tendency of the data. Given the current dataset, the detection algorithm based on Support Vector Machine (SVM) provides the most reliable prediction (with an overall accuracy of 96.9 %) on pre-ignition conditions. Analyses indicate that using a multi-step approach can further improve overall prediction accuracy. The development of an accurate detection algorithm can provide reliable feedback to intercept ignition of unattended cooking and help reduce fire losses.

P-Flash - A Machine Learning-based Model for Flashover Prediction using Recovered Temperature Data.

Research was conducted to examine the use of Support Vector Regression (SVR) to build a model to forecast the potential occurrence of flashover in a single-floor, multi-room compartment fire. Synthetic temperature data for heat detectors in different rooms were generated, 1000 simulation cases are considered, and a total of 8 million data points are utilized for model development. An operating temperature limitation is placed on heat detectors where they fail at a fixed exposure temperature of 150 °C and no longer provide data to more closely follow actual performance. The forecast model P-Flash (Prediction model for Flashover occurrence) is developed to use an array of heat detector temperature data, including in adjacent spaces, to recover temperature data from the room of fire origin and predict potential for flashover. Two special treatments, sequence segmentation and learning from fitting, are proposed to overcome the temperature limitation of heat detectors in real-life fire scenarios and to enhance prediction capabilities to determine if the flashover condition is met even with situations where there is no temperature data from all detectors. Experimental evaluation shows that P-Flash offers reliable prediction. The model performance is approximately 83 % and 81 %, respectively, for current and future flashover occurrence, considering heat detector failure at 150 °C. Results demonstrate that P-Flash, a new data-driven model, has potential to provide fire fighters real-time, trustworthy, and actionable information to enhance situational awareness, operational effectiveness, and safety for firefighting.

The Evolving Temperature Field in a 1 m Methanol Pool Fire.

Thin filament pyrometry is used to measure the time-varying temperature field in a 1 m methanol pool fire. A digital camera with optical filters and zoom lens recorded the emission intensity of an array of 12 µm Silicon-Carbide filaments oriented horizontally at various heights across the steadily burning pool fire. A 50 µm diameter thermocouple measured the temperature at locations corresponding to the filament positions. A correlation was developed between the local probability density functions of the thermocouple time series measurements corrected for radiation and thermal inertia effects and the camera grayscale pixel intensity of the filaments. A regression analysis yields the local mean temperature and its variance. The time series of the temperature field is transformed into average values during consecutive phases of the fire's puffing cycle, providing quantitative insight into the complex and dynamic structure of a turbulent fire.

Generating Synthetic Sensor Data to Facilitate Machine Learning Paradigm for Prediction of Building Fire Hazard.

Using the zone fire model CFAST as the simulation engine, time series data for building sensors, such as heat detectors, smoke detectors, and other targets at any arbitrary locations in multi-room compartments with different geometric configurations, can be obtained. An automated process for creating inputs files and summarizing model results, CData, is being developed as a companion to CFAST. An example case is presented to demonstrate the use of CData where synthetic data is generated for a wide range of fire scenarios. Three machine learning algorithms: support vector machine (SVM), decision tree (DT), and random forest (RF), are used to develop classification models that can predict the location of a fire based on temperature data within a compartment. Results show that DT and RF have excellent performance on the prediction of fire location and achieve model accuracy in between 93 % and 96 %. For SVM, model performance is sensitive to the size of training data. Additional study shows that results obtained from DT and RT can be used to examine the importance of each input feature. This paper contributes a learning-by-synthesis approach to facilitate the utilization of a machine learning paradigm to enhance situational awareness for fire fighting in buildings.

Experimental study of the effect of internal pressure on oscillating behavior of pool fires.

A series of experiments have been conducted to study the flame behavior of ethanol pool fires in a closed chamber. The effect of internal pressure and the size of the pool burner is considered. Tests include pressure conditions ranging from 50 kPa to 350 kPa and 5 circular pool burners with different diameters (2 cm, 4 cm, 6 cm, 8 cm, and 10 cm). Measurements such as gas temperature, internal pressure, oxygen concentration, and video record for all tests are obtained. Steady-state burning period is identified to facilitate a quantitative analysis of flame behavior. Image processing is carried out to obtain time average appearance of pool fires. The concept of oscillation intensity is introduced. Oscillation behaviors of pool fires in a closed system as a function of internal pressure and pan diameter are correlated with oscillation intensity. Four flame structures are observed: laminar, tip flicking, sinuous meandering, and turbulent flame. Relationships between oscillation intensity to flame structure and Grashof number to flame structure are established. Effect of internal pressure and gravitational force to oscillation frequency is also accessed. Simple theoretical model is developed. An empirical expression using the relationship of Strouhal number and Grashof number is established. Two distinct behaviors on oscillation frequency as a function of pressure are observed. Results obtained from this work will facilitate the understanding of oscillation behavior of ethanol pool fires in different sizes with various internal pressure conditions in a closed chamber.

Estimation of the critical external heat leading to the failure of lithium-ion batteries.

A detailed experimental investigation on the critical external heat leading to the failure of lithium-ion (Li-ion) batteries was conducted using an Accelerating Rate Calorimeter (ARC) at the National Institute for Occupational Safety and Health (NIOSH). Several types of commercial Li-ion batteries were selected for the study, including an iron phosphate Li-ion battery (LFP), a lithium-titanate battery (LTO), and a lithium-nickel-manganese-cobalt-oxide battery (NMC). Each battery was placed in a specially designed sealed steel canister and heated in the ARC. Battery voltage throughout the test was monitored and used to indicate the time to a battery failure. Three thermocouples, one attached to the battery surface, one measuring air temperature inside the canister, and one attached to the canister's internal surface, were used to record temperature changes during the heating tests. Different thermal behaviors were observed for the various battery types. An analytical model was developed to estimate the total external heat received by the battery using the measured temperatures. Experimental data ranked the batteries tested in terms of the heat to failure as: LFP 26650 (11 kJ) > LFP 18650 (4.3 kJ) > NMC 18650 MH1 (3.6 kJ) ≈ LTO 18650 (3.6 kJ) > NMC 18650 HG2 (3 kJ). Total heat normalized to the battery nominal energy capacity was also calculated and ranked as: LTO 18650 ≈ LFP 26650 ≈ LFP 18650 > NMC 18650 MH1 ≈ NMC 18650 HG2. The test and analysis method developed can be extended to other types of batteries with a cylindrical shape. Results from this work provide insights to the thermal safety of Li-ion batteries and can help enhance battery thermal design and management.

Effect of pressure on the heat transfer of pool fire in a closed chamber.

A combined experimental and analytical study was performed to determine the effect of pressure on the heat transfer of pool fire in a closed chamber. A series of ethanol pool fires with nominal diameters from 4 cm to 10 cm were conducted for a wide range of pressure conditions in between ~ 60 kPa to 250 kPa. Considering the effect of pressure, a theoretical formulation was proposed to estimate the radiation flux received by the pool surface from the chamber wall and hot gases. The relationship between the modified mass burning flux of pool fire and pressure was obtained. It was found that external radiation heat transfer received by pool surface depends significantly on gas temperature and its radiative properties and wall temperature. Results showed that these parameters are highly coupled in determining the effect of pressure to the external radiation. Furthermore, the average mass burning flux modified by the obtained external radiation was fitted with pressure by a power function and the fitted exponent value was consistent with theoretical analysis.

Thin Filament Pyrometry Field Measurements in a Medium-Scale Pool Fire.

This paper presents the development of a thin filament pyrometry method to characterize the time-varying temperature field in a medium-scale pool fire burning in a quiescent environment. A digital camera with optical filters and zoom lens was used to record the high temperature emission intensity of 14 µm diameter, Silicon-Carbide filaments oriented horizontally at various heights above the center of a steadily burning 0.30 m diameter methyl alcohol (methanol; CH3OH) pool fire. Experiments collected 30 Hz video of the planar filament array. In a separate experiment, a 50 µm diameter thermocouple was used to acquire independent temperature measurements in the high temperature zone of the fire. A correlation was developed between the probability density functions of the radiation-corrected thermocouple measurements and the camera grayscale pixel intensity of the filaments. This arrangement enables measurement of the time-varying temperature field over a temperature range from about 1150 K to 1900 K with a spatial resolution of 160 µm, a temporal resolution of 0.033 s, and an expanded uncertainty of about 150 K (at a mean temperature of 1300 K). Measurements of the grayscale pixel intensities of the filaments were obtained. False color maps of the temperature field were produced to characterize the high temperature field as a function of time. Using statistical analysis, the local time-averaged temperatures and their variance for each location on the filaments were determined. Time-averaged temperatures were compared favorably to previously reported measurements. The dominant frequency of the puffing fire was determined. The temperature field time series was transformed to consider its character during consecutive phases of the fire's puffing cycle. The analysis emphasizes the cyclic nature of a pool fire, providing insight on its complex dynamic structure.

A pilot study on the Chinese Minnesota Multiphasic Personality Inventory-2 in detecting feigned mental disorders: Simulators classified by using the Structured Interview of Reported Symptoms.

The Minnesota Multiphasic Personality Inventory-2 (MMPI-2) is often used in forensic psychological/psychiatric assessment. This was a pilot study on the utility of the Chinese MMPI-2 in detecting feigned mental disorders. The sample consisted of 194 university students who were either simulators (informed or uninformed) or controls. All the participants were administered the Chinese MMPI-2 and the Structured Interview of Reported Symptoms-2 (SIRS-2). The results of the SIRS-2 were utilized to classify the participants into the feigning or control groups. The effectiveness of eight detection indices was investigated by using item analysis, multivariate analysis of covariance (MANCOVA), and receiver operating characteristic (ROC) analysis. Results indicated that informed-simulating participants with prior knowledge of mental disorders did not perform better in avoiding feigning detection than uninformed-simulating participants. In addition, the eight detection indices of the Chinese MMPI-2 were effective in discriminating participants in the feigning and control groups, and the best cut-off scores of three of the indices were higher than those obtained from the studies using the English MMPI-2. Thus, in this sample of university students, the utility of the Chinese MMPI-2 in detecting feigned mental disorders was tentatively supported, and the Chinese Infrequency Scale (ICH), a scale developed specifically for the Chinese MMPI-2, was also supported as a valid scale for validity checking.

Religion and Subjective Well-Being: Western and Eastern Religious Groups Achieved Subjective Well-Being in Different Ways.

Culture can moderate which variables most influence subjective well-being (SWB). Because religion can be conceptualized as culture, religious differences can be considered cultural differences. However, there have been few studies comparing how different religious groups evaluate SWB at any given time. This study is among the first to investigate this issue. The present study compared Buddhists, Taoists, Christians, and atheists. In addition to demographic items, 451 Chinese adults completed Chinese version of the Socially Oriented Cultural Conception of SWB Scale. Religious belief was distributed as follows: 10 % Christian, 20 % Buddhist, 25 % Taoist, and 43 % atheists. As predicted, the socially oriented cultural conception of SWB was found to be highest among Buddhists, followed in order by Taoists, atheists, and Christians. It was concluded that the various religious groups achieved SWB in different ways.

Cultural and linguistic adaptability of the Rorschach Performance Assessment System as a measure of psychotic characteristics and severity of mental disturbance in Taiwan.

This study investigated the cultural and linguistic adaptability of the Rorschach Performance Assessment System (R-PAS), a new Rorschach administration, scoring, and interpretation system that minimizes psychometric weaknesses of the Comprehensive System (CS). This investigation addressed the validity of R-PAS measures of psychotic characteristics and psychopathology severity in Taiwan, including the incremental validity of the R-PAS relative to the CS variables measuring the same constructs. Ninety Taiwanese individuals (75 psychiatric patients and 15 nonpatients) were tested with standard R-PAS administration and scoring. Two non-Rorschach severity of disturbance measures and 2 psychosis measures served as independent criterion measures. The R-PAS measures were found to be valid in Taiwan in assessing psychotic symptoms and psychopathology severity, thus demonstrating cultural and linguistic adaptability. Moreover, hierarchical regression analyses demonstrated incremental validity for the R-PAS variables over their CS counterparts, providing support that the R-PAS revisions enhance the test psychometrically. These research findings also demonstrate the viability of the R-PAS as a Rorschach system that can be effectively employed outside the U.S. in a different language and culture.

Religion and health: anxiety, religiosity, meaning of life and mental health.

We examined the association among anxiety, religiosity, meaning of life and mental health in a nonclinical sample from a Chinese society. Four hundred fifty-one Taiwanese adults (150 males and 300 females) ranging in age from 17 to 73 years (M = 28.9, SD = 11.53) completed measures of Beck Anxiety Inventory, Medical Outcomes Study Health Survey, Perceived Stress Scale, Social Support Scale, and Personal Religiosity Scale (measuring religiosity and meaning of life). Meaning of life has a significant negative correlation with anxiety and a significant positive correlation with mental health and religiosity; however, religiosity does not correlate significantly anxiety and mental health after controlling for demographic measures, social support and physical health. Anxiety explains unique variance in mental health above meaning of life. Meaning of life was found to partially mediate the relationship between anxiety and mental health. These findings suggest that benefits of meaning of life for mental health can be at least partially accounted for by the effects of underlying anxiety.

Detection of malingering: psychometric evaluation of the Chinese version of the structured interview of reported symptoms-2.

BACKGROUND: Malingering detection has emerged as an important issue in clinical and forensic settings. The Structured Interview of Reported Symptoms-2 (SIRS-2) was designed to assess the feigned symptoms in both clinical and non-clinical subjects. The aim of the study was to examine the reliability and validity of the Chinese version of this scale. METHODS: Two studies were conducted to evaluate the reliability and validity of the Chinese Version of SIRS-2. In Study one, with a simulation design, the subjects included a. 40 students asked to simulate symptoms of mental illness; b. 40 general psychiatric inpatients and c. 40 students asked to reply to questions honestly. Scales scores for feigning symptoms among three groups were carried out for discriminant validity of the Chinese Version of SIRS-2. Minnesota Multiphasic Personality Inventory-2(MMPI-2) was administered in 80 undergraduate students. In Study two, with a known-groups comparison design, scales scores for feigning symptoms were compared between 20 suspected malingerers and 80 psychiatric outpatients from two forensic centers using the Chinese Version of SIRS-2. RESULTS: The Chinese Version of SIRS-2 demonstrated satisfactory internal consistency in both study one and two. In study one, criterion validity of this scale was supported by its significantly positive correlation with the MMPI-2 (r = 0.282 ~ 0.481 for Infrequency), and by its significantly negative correlation with the MMPI-2 (r = -0.255 ~ -0.519 for Lie and -0.205 ~ 0.391 for Correction). Scores of 10 out of 13 subscales of the Chinese Version of SIRS-2 for simulators were significantly higher than scores of honest students and general psychiatric patients. In study two, the mean scores of the Chinese Version of 13 subscales for suspected malingerers were significantly higher than those of psychiatric outpatients. For discriminant validity, it yielded a large effect size (d = 1.80) for the comparison of the participant groups in study one and two. Moreover, the sensitivity (proportion of malingerers accurately identified by the measure) and specificity (proportion of people accurately classified as responding honestly) of the Chinese version of SIRS-2 in the detection of malingering in these two studies are acceptable. CONCLUSIONS: The Chinese version of the SIRS-2 has good psychometric properties and is a valid and reliable tool for detection of malingering in Chinese populations.

Recognition of tactile relief by children and adults.

This study was designed to compare tactile sensitivity of children and adults on printed target stimuli covering a wide range of elevations and requiring different resolutions. A recognition-relief task using 9 digits at 6 levels of elevation from a surface (0.5, 0.4, 0.3, 0.2, 0.1, and 0.05 mm) was presented to 24 young adults and 24 children. As predicted, relief elevations as low as 0.05 mm were recognized above chance. As predicted, children performed significantly more poorly than the adults on recognition at all elevations, although the difference increased as elevation increased. Adults performed significantly better than children on high-resolution digit 8, but there was no reliable age difference on low-resolution digit 1. Recognition difference between the high- and low-resolution digits decreased nonlinearly as elevation increased, irrespective of age. Overall, the findings support previous research indicating greater tactile sensitivity in adults than in children, but the superiority was moderated by the elevation and resolution requirements of the stimuli.

Paranormal beliefs and religiosity: Chinese version of the Revised Paranormal Belief Scale.

This paper reports an initial study investigating the relations of paranormal beliefs with religiosity in a Chinese sample, as well as the development of a Chinese version of the Revised Paranormal Belief Scale and a test of its psychometric properties with 310 college students (5.5% Christians, 21.3% Buddhists, 61% believers in traditional Chinese religions, and 12% atheists). The reliability and validity of the Chinese version were satisfactory. In general, traditional Chinese religious believers had higher scores on paranormal belief than did Christians and atheists, and the mean total score of the Chinese participants was higher than previously reported in a Western sample. It was concluded that the greater involvement of practitioners of traditional Chinese religions in activities emphasizing paranormal experiences might contribute to their greater paranormal belief, especially as compared to the minority Christian group. The results are consistent with the idea that Christianity may offer the least support for paranormal belief.

Replication of factor structure of Wechsler Adult Intelligence Scale-III Chinese version in Chinese mainland non-clinical and schizophrenia samples.

The aim of the present study was to evaluate the construct validity of the special four-factor structure of the Wechsler Adult Intelligence Scale (WAIS)-III Chinese version in a clinical sample of inpatients with schizophrenia as well as a sample of healthy adults. A sample of 114 inpatients with schizophrenia and a sample of 114 close-matched non-clinical adults on the Chinese mainland were studied with the measures of the WAIS-III Chinese version. Four competing hypothetical models of factors were tested for model fit and parsimony in both research samples, using maximum likelihood confirmatory factor analysis. Confirmatory factor analysis indicated that a four-factor model of Verbal Comprehension, Perceptual Organization, Working Memory, and Processing Speed best fit the data from both the schizophrenia sample and the healthy adult sample, and also fitted the data from both samples better than alternative models, which is similar to that reported by the developers and revisers of this scale. These empiric analyses and results support the construct validity of the WAIS-III Chinese version in patients with schizophrenia and healthy adults on the Chinese mainland.

Positive and negative symptom profile schizophrenia and abnormalities in the P300 component of the event-related potential: a longitudinal controlled study.

The relationship between symptoms of schizophrenia and abnormalities in the P300 component of the event-related potential (ERP) was investigated in 22 and 27 patients diagnosed with positive and negative profile schizophrenia, respectively. The Positive and Negative Syndrome Scale (PANSS) was used to characterize clinical symptoms. A group of 30 normal controls were also studied. Results showed that patients with schizophrenia exhibited reduced P300 amplitudes compared with controls and that those with negative profile schizophrenia had amplitude decrements and longer latencies. These findings suggest that there are neurobiological differences between positive and negative profile schizophrenia.

Comparison of neurocognition between drug-free patients with schizophrenia and bipolar disorder.

It is often difficult to make a differential diagnosis between schizophrenia and bipolar disorder because of the overlapping symptoms. The patients of both disorders have been shown to have neurocognitive deficits. In this study, a computerized battery of neurocognitive tasks, COGLAB, was administered to four participant groups: 30 patients with positive schizophrenia, 22 patients with negative schizophrenia, 27 patients with bipolar disorder, and 28 normal controls. All the patients were drug-free for at least 1 month. The tasks included Mueller-Lyer illusion, reaction time, size estimation, a variant of the Wisconsin Card Sorting Test, backward masking, and Asarnow continuous performance. Discriminant analyses were used to investigate the differences among the four groups. Results indicated that COGLAB correctly classified 73.5% of the cases of negative schizophrenia and bipolar disorder. The best discriminative tasks were card sort, Asarnow continuous performance, and backward masking. The results of this study were also compared with results of a previous study with medicated patients. Neurocognitive tasks had better discriminative power for medicated patients with schizophrenia and bipolar disorder than for drug-free patients. Moreover, medication effects did not seem to significantly change the pattern of the neurocognitive task responses of patients with schizophrenia.