Synergistic interaction between long shifts and short rest periods on depression in shift workers: A cross-sectional study from Korea.

BACKGROUND: Long shifts and short rest periods (SRP) between shifts are important factors that greatly affect shift workers' health. However, reports on the psychological effects of shift work, such as depression, have been inconsistent. Therefore, this study aimed to investigate the combined effect of long shifts and SRP on depression in shift workers. METHODS: This cross-sectional study included 3295 shift workers in the sixth Korean Working Conditions Survey. The relative excess risk due to interaction (RERI) was computed to estimate the combined effect of long shifts and SRP on depression. RESULTS: Depression in shift workers was not significantly associated with long shifts or SRP after adjustment, but the risk was significantly increased when exposed to both factors simultaneously (odds ratio 1.36, 95% confidence interval 1.03-1.79). The RERI between the two factors was statistically significant (p = 0.020), indicating a synergistic interaction with depression. Sensitivity analysis by occupation showed a significant interaction in the combined group of office and service workers (p = 0.034). CONCLUSIONS: Simultaneous exposure to SRP and long shifts should be avoided when planning shift work schedules or devising health policies for shift workers. Special consideration is needed for healthcare and service workers, who may be particularly vulnerable to negative health impacts due to shift work.

The relationship between exposure to environmental noise and risk of atopic dermatitis, asthma, and allergic rhinitis.

BACKGROUND: Noise is defined as unwanted sound. It may induce negative emotions and mental health problems and may even lead to increased suicide risk. However, the impact of noise exposure on environmental diseases and disease severity is not well understood. This study aimed to elucidate the association between night-time noise exposure and the prevalence of environmental diseases in South Korea. METHODS: We conducted an analysis of the Environmental Disease Database provide by the National Health Insurance Service (NHIS) from 2013 to 2017. After spatially interpolating the noise data provided by the National Noise Information System (NNIS), night-time noise values in the district level were obtained by calculating the mean noise values at the administrative district level. The linear regression analyses were performed to test the association between the age-standardized prevalence ratio (SPR) and the night-time noise exposure in the district level. RESULTS: In areas with high night-time noise exposure (≥55 dB), the SPR for atopic dermatitis and allergic rhinitis were 1.0515 (95 % confidence interval [CI]:1.0508-1.0521) and 1.0202 (95 % CI:1.0201-1.0204), respectively, which were higher than those in the general population. The SPR for environmental diseases, including atopic dermatitis, asthma, and allergic rhinitis, was 1.0104 (95 % CI:1.0103-1.0105). Additionally, a significant linear association was observed between the level of nocturnal noise exposure and the total hospitalization period for atopic dermatitis (ß = 399.3, p < 0.01). CONCLUSION: We provide evidence of a significant association between night-time environmental noise and environmental diseases, particularly atopic dermatitis and allergic rhinitis. Furthermore, we observed a significant linear association between night-time noise exposure and the severity of atopic dermatitis.

SMAX1 Integrates Karrikin and Light Signals into GA-Mediated Hypocotyl Growth during Seedling Establishment.

Morphogenic adaptation of young seedlings to light environments is a critical developmental process that ensures plant survival and propagation, as they emerge from the soil. Photomorphogenic responses are facilitated by a network of light and growth hormonal signals, such as auxin and gibberellic acid (GA). Karrikins (KARs), a group of butenolide compounds produced from burning plant materials in wildfires, are known to stimulate seed germination in fire-prone plant species. Notably, recent studies support that they also regulate seedling growth, while underlying molecular mechanisms have been unexplored yet. Here, we demonstrate that SUPPRESSOR OF MAX2 1 (SMAX1), a negative regulator of KAR signaling, integrates light and KAR signals into GA-DELLA pathways that regulate hypocotyl growth during seedling establishment. We found that SMAX1 facilitates degradation of DELLA proteins in the hypocotyls. Interestingly, light induces the accumulation of SMAX1 proteins, and SMAX1-mediated degradation of DELLA is elevated in seedling establishment during the dark-to-light transition. Our observations indicate that SMAX1-mediated integration of light and KAR signals into GA pathways elaborately modulates seedling establishment.

Phytochrome B Conveys Low Ambient Temperature Cues to the Ethylene-Mediated Leaf Senescence in Arabidopsis.

Leaf senescence is an active developmental process that is tightly regulated through extensive transcriptional and metabolic reprogramming events, which underlie controlled degradation and relocation of nutrients from aged or metabolically inactive leaves to young organs. The onset of leaf senescence is coordinately modulated by intrinsic aging programs and environmental conditions, such as prolonged darkness and temperature extremes. Seedlings growing under light deprivation, as often experienced in severe shading or night darkening, exhibit an accelerated senescing process, which is mediated by a complex signaling network that includes sugar starvation responses and light signaling events via the phytochrome B (phyB)-PHYTOCHROME-INTERACTING FACTOR (PIF) signaling routes. Notably, recent studies indicate that nonstressful ambient temperatures profoundly influence the onset and progression of leaf senescence in darkness, presumably mediated by the phyB-PIF4 signaling pathways. However, it is not fully understood how temperature signals regulate leaf senescence at the molecular level. Here, we demonstrated that low ambient temperatures repress the nuclear export of phyB and the nuclear phyB suppresses the transcriptional activation activity of ethylene signaling mediator ETHYLENE INSENSITIVE3 (EIN3), thus delaying leaf senescence. Accordingly, leaf senescence was insensitive to low ambient temperatures in transgenic plants overexpressing a constitutively nuclear phyB form, as observed in ein3 eil1 mutants. In contrast, leaf senescence was significantly promoted in phyB-deficient mutants under identical temperature conditions. Our data indicate that phyB coordinately integrates light and temperature cues into the EIN3-mediated ethylene signaling pathway that regulates leaf senescence under light deprivation, which would enhance plant fitness under fluctuating natural environments.

Associations of occupational and leisure-time physical activity with self-rated health in Korea.

Recent findings have suggested that not all physical activity (PA) types improve health and that the health effects of occupational PA (OPA) and leisure-time PA (LTPA) can be different. However, few studies have been reported the association of OPA and LTPA with self-rated health (SRH). Therefore, we aimed to examine the association between different PA domains and general health and the impact of LTPA on the relationship between health and OPA. In total, 33440 adults from the Korea National Health and Nutrition Examination Survey 2014-2019 were analyzed in September 2021. SRH was dichotomized into "poor" and "good." Sedentary behavior (SB) was evaluated by measuring the daily sitting time. Multiple logistic regression was used to investigate the relationship of SRH with OPA, LTPA, and SB, stratified by LTPA to identify its impact on the relationship. In the fully adjusted model, OPA was found to increase the risk of poor SRH, while LTPA was found to lower the risk. In those who did not engage in LTPA, OPA and poor SRH were significantly associated. Poor SRH was not significantly associated with OPA in those who engaged in LTPA. SB was also associated with poor SRH, independent of LTPA. To improve health, it is important to promote LTPA and reduce OPA and SB. In particular, for workers with a higher level of OPA, additional LTPA should be introduced to prevent SRH from worsening.

EIN3-Mediated Ethylene Signaling Attenuates Auxin Response during Hypocotyl Thermomorphogenesis.

The gaseous phytohormone ethylene plays vital roles in diverse developmental and environmental adaptation processes, such as fruit ripening, seedling establishment, mechanical stress tolerance and submergence escape. It is also known that in the light, ethylene promotes hypocotyl growth by stimulating the expression of PHYTOCHROME INTERACTING FACTOR3 (PIF3) transcription factor, which triggers microtubule reorganization during hypocotyl cell elongation. In particular, ethylene has been implicated in plant responses to warm temperatures in recent years. However, it is currently unclear how ethylene signals are functionally associated with hypocotyl thermomorphogenesis at the molecular level. Here, we show that ETHYLENE-INSENSITIVE3 (EIN3)-mediated ethylene signals attenuate hypocotyl thermomorphogenesis by suppressing auxin response. At warm temperatures, when the activity of the PIF4 thermomorphogenesis promoter is prominently high, the ethylene-activated EIN3 transcription factor directly induces the transcription of ARABIDOPSIS PP2C CLADE D7 (APD7) gene encoding a protein phosphatase that inactivates the plasma membrane (PM) H+-ATPase proton pumps. In conjunction with the promotive role of the PM H+-ATPases in hypocotyl cell elongation, our observations strongly support that the EIN3-directed induction of APD7 gene is linked with the suppression of auxin-induced cell expansion, leading to the reduction in thermomorphogenic hypocotyl growth. Our data demonstrate that APD7 acts as a molecular hub that integrates ethylene and auxin signals into hypocotyl thermomorphogenesis. We propose that the ethylene-auxin signaling crosstalks via the EIN3-APD7 module facilitate the fine-tuning of hypocotyl thermomorphogenesis under natural environments, which often fluctuate in a complex manner.

Safeguarding genome integrity under heat stress in plants.

Heat stress adversely affects an array of molecular and cellular events in plant cells, such as denaturation of protein and lipid molecules and malformation of cellular membranes and cytoskeleton networks. Genome organization and DNA integrity are also disturbed under heat stress, and accordingly, plants have evolved sophisticated adaptive mechanisms that either protect their genomes from deleterious heat-induced damages or stimulate genome restoration responses. In particular, it is emerging that DNA damage responses are a critical defense process that underlies the acquirement of thermotolerance in plants, during which molecular players constituting the DNA repair machinery are rapidly activated. In recent years, thermotolerance genes that mediate the maintenance of genome integrity or trigger DNA repair responses have been functionally characterized in various plant species. Furthermore, accumulating evidence supports that genome integrity is safeguarded through multiple layers of thermoinduced protection routes in plant cells, including transcriptome adjustment, orchestration of RNA metabolism, protein homeostasis, and chromatin reorganization. In this review, we summarize topical progresses and research trends in understanding how plants cope with heat stress to secure genome intactness. We focus on molecular regulatory mechanisms by which plant genomes are secured against the DNA-damaging effects of heat stress and DNA damages are effectively repaired. We will also explore the practical interface between heat stress response and securing genome integrity in view of developing biotechnological ways of improving thermotolerance in crop species under global climate changes, a worldwide ecological concern in agriculture.

Developmental Programming of Thermonastic Leaf Movement.

Plants exhibit diverse polar behaviors in response to directional and nondirectional environmental signals, termed tropic and nastic movements, respectively. The ways in which plants incorporate directional information into tropic behaviors is well understood, but it is less well understood how nondirectional stimuli, such as ambient temperatures, specify the polarity of nastic behaviors. Here, we demonstrate that a developmentally programmed polarity of auxin flow underlies thermo-induced leaf hyponasty in Arabidopsis (Arabidopsis thaliana). In warm environments, PHYTOCHROME-INTERACTING FACTOR4 (PIF4) stimulates auxin production in the leaf. This results in the accumulation of auxin in leaf petioles, where PIF4 directly activates a gene encoding the PINOID (PID) protein kinase. PID is involved in polarization of the auxin transporter PIN-FORMED3 to the outer membranes of petiole cells. Notably, the leaf polarity-determining ASYMMETRIC LEAVES1 (AS1) directs the induction of PID to occur predominantly in the abaxial petiole region. These observations indicate that the integration of PIF4-mediated auxin biosynthesis and polar transport, and the AS1-mediated developmental shaping of polar auxin flow, coordinate leaf thermonasty, which facilitates leaf cooling in warm environments. We believe that leaf thermonasty is a suitable model system for studying the developmental programming of environmental adaptation in plants.

Correction to: Spontaneous and repeat spontaneous abortion risk in relation to occupational characteristics among working Korean women: a cross-sectional analysis of nationally representative data from Korea.

It was highlighted that the original article [1] contained a mismatch between the result section of the abstract and Table 2. This Correction article shows the incorrect and correct result section of this article's Abstract.

Spontaneous and repeat spontaneous abortion risk in relation to occupational characteristics among working Korean women: a cross-sectional analysis of nationally representative data from Korea.

BACKGROUND: The association between spontaneous abortion (SA) and occupational characteristics among working women is not well-studied. This study aimed to assess the risk of SA and occupational factors such as occupational classification, working hours, and work schedules among working Korean women aged > 19 years. METHODS: In this cross-sectional study, 4078 working women were identified from among 25,534 workers in the Korea National Health and Nutrition Examination Surveys V (2010-2012) database, to obtain data on SA history and the number of SAs. Odds ratios (ORs) and 95% confidence intervals (CIs) for SA were calculated using multiple logistic regression models after adjusting for age, education, household income, cigarette smoking, alcohol consumption, and obesity status. The weighted prevalence for the number of SAs was calculated according to occupational characteristics to demonstrate the SA status among working Korean women. RESULTS: SA occurrence was reported in 5.7% of the study participants. The ORs (95% CIs) for SA were significantly higher in pink-, green-, and blue-collared workers than in white-collared workers. Regarding weekly working hours, compared with ≤50 h spent working, the ORs (95% CIs) for 51-60, 61-70, and > 70 h per week were 1.26 (0.87-1.84), 1.63 (1.04-2.56), and 1.73 (1.10-2.70), respectively. A significantly higher weighted prevalence of repeat SAs was observed in pink- and green-collared workers and in those who worked long hours. CONCLUSION: We found a significant association between SA, repeat SA, and occupational characteristics among working Korean women.

A 12-Gb/s Stacked Dual-Channel Interface for CMOS Image Sensor Systems.

We propose a dual-channel interface architecture that allocates high and low transition-density bit streams to two separate channels. The transmitter utilizes the stacked drivers with charge-recycling to reduce the power consumption. The direct current (DC)-coupled receiver front-end circuits manage the common-mode level variations and compensate for the channel loss. The tracked oversampling clock and data recovery (CDR), which realizes fast lock acquisition below 1 baud period and low logic latency, is shared by the two channels. Fabricated in a 65-nm low-power complementary metal-oxide semiconductor (CMOS) technology, the dual-channel transceiver achieves 12-Gb/s data rate while the transmitter consumes 20.43 mW from a 1.2-V power supply.

The association between low blood lead levels and the prevalence of prehypertension among nonhypertensive adults in Korea.

OBJECTIVES: Low-level lead exposure has been associated with increases in blood pressure (BP) and impairment of the cardiovascular system. Prehypertension is not categorized as a disease currently; however, individuals with untreated prehypertension are known to be at increased risk of progression to hypertension and mortality caused by cardiovascular disease. We investigated the association between blood lead levels below the threshold for the harmful effects of lead and the prevalence of prehypertension in Korean adults. METHODS: A total of 8,493 participants (3,945 men and 4,548 women) were included in the current analysis, using data from the fourth, fifth, and sixth Korean National Health and Nutrition Examination Survey (KNHANES) in 2007-2013. Blood analysis, self-report questionnaires, and physical examinations were used to assess blood lead levels, BP, and medical history. Odds ratios (OR) and 95% confidence intervals (95% CI) for prehypertension were calculated using multiple logistic regression models. RESULTS: Compared to the first quartile (Q1) blood lead level (0.206-1.539 µg/dl), the ORs (95% CI) were 1.24 (1.04-1.48) in Q2, (1.540-2.056 µg/dl), 1.27 (1.06-1.52) in Q3, (2.057-2.716 µg/dl), and 1.30 (1.07-1.60) in Q4 (2.717-24.532 µg/dl) for the prevalence of prehypertension after adjusting for age, sex, morbidity status, socioeconomic status, and health behavioral variables. CONCLUSIONS: Our large, cross-sectional, nationwide study revealed that blood lead levels below the threshold for the harmful effects of lead were significantly associated with prehypertension. Am. J. Hum. Biol. 28:729-735, 2016. © 2016 Wiley Periodicals, Inc.

Metabolic outcomes of workers according to the International Standard Classification of Occupations in Korea.

BACKGROUND: Occupation influences the risk for developing chronic metabolic diseases. METHODS: We compared the prevalence of MetS by International Standard Classification of Occupations using the nationally representative data in Korea (KNHANES). We enrolled 16,763 workers (9,175 males; 7,588 females) who had measurements for the National Cholesterol Education Program criteria III and other variables. OR and 95%CIs for MetS and its components were estimated according to occupation using the multiple logistic regression models. RESULTS: The occupational groups with the highest age-standardized prevalence of MetS were lower skilled white-collar men (31.1 ± 2.4%) and green-collar women (24.2 ± 2.9%). Compared with the unskilled male blue-collar group, which had the lowest prevalence of MetS, the OR (95%CIs) of MetS in men were 1.77 (1.45-2.15) in higher skilled white-collar, 1.82 (1.47-2.26) in lower-skilled white-collar, 1.63 (1.32-2.01) in pink-collar and 1.37 (1.13-1.66) in skilled blue-collar workers in final logistic regression model. CONCLUSIONS: MetS and its components vary by occupational category and gender in ways that may guide health interventions. Am. J. Ind. Med. 59:685-694, 2016. © 2016 Wiley Periodicals, Inc.

Concealing Emotions at Work Is Associated with Allergic Rhinitis in Korea.

Concealing emotions at work can cause considerable psychological stress. While there is extensive research on the adverse health effects of concealing emotions and the association between allergic diseases and stress, research has not yet investigated whether concealing emotions at work is associated with allergic rhinitis. Allergic rhinitis is a common disease in many industrialized countries, and its prevalence is increasing. Thus, our aim was to determine the strength of this association using data from three years (2007-2009) of the 4th Korean National Health and Nutrition Examination Survey. Participants (aged 20-64) were 8,345 individuals who were economically active and who had completed the questionnaire items on concealing emotions at work. Odds ratio (OR) and 95% confidence intervals (95% CIs) were calculated for allergic rhinitis using logistic regression models. Among all participants, 3,140 subjects (37.6%) reported concealing their emotions at work: 1,661 men and 1,479 women. The OR (95% CIs) for allergic rhinitis among those who concealed emotions at work versus those who did not was 1.318 (1.148-1.512). Stratified by sex, the OR (95% CIs) was 1.307 (1.078-1.585) among men and 1.346 (1.105-1.639) among women. Thus, individuals who concealed their emotions at work were significantly more likely to have a diagnosis of AR in comparison to those who did not. Because concealing emotions at work has adverse health effects, labor policies that aim to reduce this practice are needed.

The Perceived Socioeconomic Status Is an Important Factor of Health Recovery for Victims of Occupational Accidents in Korea.

We aimed to examine whether there is a correlation between the health recovery of industrial accident victims and their perceived socioeconomic status. Data were obtained from the first Panel Study of Worker's Compensation Insurance, which included 2,000 participants. We performed multivariate regression analysis and determined the odds ratios for participants with a subjectively lower socioeconomic status and for those with a subjectively lower middle socioeconomic status using 95% confidence intervals. An additional multivariate regression analysis yielded the odds ratios for participants with a subjectively lower socioeconomic status and those with a subjectively upper middle socioeconomic class using 95% confidence intervals. Of all participants, 299 reported a full recovery, whereas 1,701 did not. We examined the odds ratio (95% confidence intervals) for participants' health recovery according to their subjective socioeconomic status while controlling for sex, age, education, tobacco use, alcohol use, subjective state of health prior to the accident, chronic disease, employment duration, recovery period, accident type, disability status, disability rating, and economic participation. The odds of recovery in participants with a subjectively lower middle socioeconomic status were 1.707 times greater (1.264-2.305) than that of those with a subjectively lower socioeconomic status. Similarly, the odds of recovery in participants with a subjectively upper middle socioeconomic status were 3.124 times greater (1.795-5.438) than that of those with a subjectively lower socioeconomic status. Our findings indicate that participants' perceived socioeconomic disparities extend to disparities in their health status. The reinforcement of welfare measures is greatly needed to temper these disparities.

Patient-reported assessment of self-management strategies of health in cancer patients: development and validation of the Smart Management Strategy for Health Assessment Tool (SAT).

OBJECTIVE: The objective of this study was to evaluate the psychometric properties of the Smart Management Strategy for Health Assessment Tool (SAT), which we developed to enable cancer patients to assess their self-management (SM) strategies of health by themselves. PATIENTS AND METHODS: The development of the questionnaire included four phases: item generation, construction, pilot testing, and field testing. To assess the instrument's sensitivity and validity, we recruited 300 cancer patients from three Korean hospitals who were 18 or more years old and accustomed to using the Internet or email. Using the appropriate and priority criteria for pilot and field testing, we tightened the content and constructed the first version of the SAT. RESULTS: We developed the core strategies with 28 items, preparation strategies with 30 items, and implementation strategies with 33 items. Factor analysis of data from 300 patients resulted in core strategies with four factors, preparation strategies with five factors, and implementation strategies with six factors. All the SAT subscales demonstrated a high reliability with good internal consistency. The total scores of the three SAT sets differentiated participant groups well according to their stage of goal implementation and proportions of action of the 10 Rules for Highly Effective Health Behavior. Each factor of the three SAT sets correlated positively with the scores for additional assessment tool. CONCLUSION: The SAT is a three-set, 16-factor, 91-item tool that assesses the SM strategies of health that patients use to overcome a crisis. Patients can use the SAT to assess their SM strategies of health and obtain feedback from clinicians in the practice setting.

Relationship between symptoms of dry eye syndrome and occupational characteristics: the Korean National Health and Nutrition Examination Survey 2010-2012.

BACKGROUND: Dry Eye Syndrome (DES) is a broad spectrum of uncomfortable ocular conditions that are caused by reduced production of tears or an increased tear evaporation rate. This study evaluated the relationship between symptoms of DES and occupational characteristics to identify the occupation-dependent differences in the prevalence of symptoms of DES using the Korean National Health and Nutrition Examination Survey V (2010-2012) data. METHODS: A total of 6023 participants were included (3203 men and 2820 women). Questionnaires and physical examinations were used to record clinical characteristics, occupational characteristics and medical history. Odds ratios (ORs) and 95 % confidence intervals (95 % CIs) for symptoms of DES were calculated according to the occupational characteristics. RESULTS: Among the participants, 963 persons (16.0 %) had symptoms of DES. An increased risk (relative to the green-collar group) was observed for the ordinary white-collar (OR, 1.73; 95 % CI, 1.73-1.41), executive white-collar (OR, 1.40; 95 % CI, 1.02-1.92) and skilled blue-collar (OR, 1.44; 95 % CI, 1.04-2.00) groups. Furthermore, paid workers had a significantly higher risk of dry eye symptoms (OR, 1.21; 95 % CI, 1.02-1.45), compared to self-employed workers. CONCLUSION: Our study is the first research to reveal that white-collar workers have a higher risk of symptoms of DES than blue-collar workers, that skilled blue-collar workers have a higher risk than unskilled blue-collar workers, and that paid workers have a higher risk than self-employed workers.

Workplace Violence Experienced by Substitute (Daeri) Drivers and Its Relationship to Depression in Korea.

Workplace violence is related to various health effects including mental illness such as anxiety or depression. In this study, the relationship between the experience of workplace violence and depression in substitute drivers in Korea, namely, daeri drivers, was investigated. To assess workplace violence, questions regarding types and frequency of the experience of violence over the past year were asked to the daeri drivers. In order to assess the risk of depression, the Center for Epidemiological Studies Depression Scale was used. Odds ratios with 95% confidence intervals of depression were estimated using multiple logistic regression analysis. All of the daeri drivers had experienced instance of verbal violence while driving and 66 of the drivers (34.1%) had been in such a situation more than once in the past quarter of a year. Sixty-eight daeri drivers (42.2%) had experienced certain type of physical violence over the past year. Compared to daeri drivers who had experienced workplace verbal violence less than 4 times and who had not experienced workplace physical violence over the past year, higher odds ratio was observed in daeri drivers who had experienced workplace verbal violence or physical violence, more than 4 times and more than one time respectively, after adjustment. Experience of verbal or physical type of workplace violence over the past year increased the risk of depression in the daeri drivers. Because violence against drivers can compromise the safety of the driver, the customer, and all the passengers, it is imperative that the safety and health of daeri drivers be highlighted.

Carious typodont teeth's effectiveness in pre-doctoral SIM lab to reinforce operative learning.

INTRODUCTION: The concept of ideal preparations in dental schools are highly emphasized during the first two years of students' learning. However, students do not have as much opportunity to practice skills that would prepare them for real-life stituations such as non-ideal preparations and caries removal. OBJECTIVE: This study aimed to determine the benefits of utilizing carious typodont teeth in the Operative curriculum for first- and second-year UCSF dental students METHODS: This study was completed by hosting a workshop in which the students performed a Class II preparation on #19 carious typodont tooth. The students filled out pre- and post-surveys with questions about their confidence with performing a preparation and their opinions on the current curriculum. RESULTS: The pre-survey responses showed that the majority of the first- and second-year students did not believe that the traditional non-carious typodont teeth were a good representation of prepping on real, carious teeth. The pre-survey responses also showed that most of the first- and second-year students thought that the addition of carious typodont teeth would improve their learning experience. The post-survey results displayed that the majority of the students thought that prepping carious typodont teeth helped to better reinforce concepts such as preparation design, taught them the difference between ideal and non-ideal preparations, and allowed them to better understand tooth anatomy with the addition of the dentin layer. CONCLUSION: The use of the carious typodont teeth in pre-clinical operative lab was found to be beneficial to first- and second-year UCSF student's learning based on the pre- and post-survey results.

Who Hurt You at Work? Results From a Nationwide Survey of Association Between Absenteeism and Workplace Violence, Stratified by Perpetrator.

OBJECTIVE: This study aimed to determine the association between workplace violence and sickness absenteeism. METHODS: We analyzed the data from the fifth and sixth waves of the Korean Working Conditions Surveys. Individuals younger than 18 years and self-employed or unpaid family workers were excluded. Descriptive statistics, χ 2 tests, and multiple logistic regression analysis were conducted. RESULTS: After adjusting for sociodemographic, occupational, and job-related characteristics, we found that the workers who had experienced workplace violence had higher rates of sickness absenteeism, especially when the perpetrator of violence was a coworker. CONCLUSIONS: Daily contact with the perpetrator at the workplace can cause distress and recollection of painful memories; thus, the aftermath of being harassed inside the workplace can be even more devastating than the event itself. A sensitive approach to recognizing the perpetrators of violence is needed.