• 생태와환경
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• 제43권1호
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• pp.24-34
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• 2010

This study was carried out to analyze some influences on ecological health conditions, threaten by various stressors such as physical, chemical and biological parameters. We collected samples in 2008 from three zones of upstream, midstream and downstream, Gap Stream. We applied multi-metric fish assessment index (MFAI), based on biotic integrity model to the three zones along with habitat evaluations based on Qualitative Habitat Evaluation Index (QHEI). We also examined fish fauna and compositions, and analyzed relations with MFAI values, QHEI values, and various guild types. Chemical parameters such as oragnic matter (BOD, COD), nutrients (TP, $NH_3$-N), coli-form number (as MPN), and suspended solids (SS) were analyzed to identify the relationship among multiple stressor effects. Using the sentinel species of Zacco platypus, the population structures and condition factors were analyzed along with DNA damages related with genotoxicant effects by comet assay. This study using all these parameters showed that stream condition was degraded along the longitudinal gradient from upstream to downstream, and the downstream, especially, was impacted by nutrient enrichment and toxicant exposure from the point source, wastewater treatment plant. Overall results indicated that our approaches applying various parameters may be used as a cause-effect technique in the stream health assessments and also used as a pre-warning tool for diagnosis of ecological degradation.

• Safety and Health at Work
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• 제6권4호
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• pp.329-337
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• 2015

Background: The aim of this study is to examine the prevalence of musculoskeletal complaints in Swiss operating room (OR) nurses, and to investigate how work-family conflict, work interruptions, and influence at work are related to lumbar and cervical back pain. Methods: Participants in this correlational questionnaire study included 116 OR nurses from eight different hospitals in Switzerland. Results: We found that 66% of the OR staff suffered from musculoskeletal problems. The most prevalent musculoskeletal complaints were lumbar (52.7%) and cervical pain (38.4%). Furthermore, 20.5% reported pain in the mid spine region, 20.5% in the knees and legs, and 9.8% in the hands and feet. Multiple linear regression analyses showed that work-family conflict (p < 0.05) and interruptions (p < 0.05) significantly predicted lumbar and cervical pain in OR nurses, while influence at work (p < 0.05) only predicted lumbar pain. Conclusion: These results suggest that reducing the work-family conflict and interruptions at work, as well as offering opportunities to influence one's workplace, help to promote OR nurses' health.

• The Journal of Asian Finance, Economics and Business
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• 제10권2호
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• pp.1-14
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• 2023

The purpose of this study is to discover the possible solutions for the problem faced by academicians during online learning by means of employing qualitative and quantitative approaches. Using a qualitative approach, selected academicians were interviewed, and their feedback was transcribed and used to develop the survey instrument. The quantitative research design was later used to determine the most plausible solutions for the problem that could be obtained and implemented by distributing the questionnaire to academicians at a public university. Multiple regression analysis results indicate that work-life conflict and lack of support are the main contributors to academicians' mental and emotional health issues. The study's major findings help higher education institutions craft appropriate strategies to enhance the effectiveness of online teaching and learning by providing the necessary support to the academicians. The study's findings suggest that academicians should separate work and family requirements to concentrate on their job. Furthermore, the immediate supervisor must be considerate in determining the number of tasks, the deadlines, and the assistance required to complete the task. Lastly, academicians must equip themselves with emotional intelligence to cope with stressors.

• Animal Bioscience
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• 제36권3호
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• pp.385-403
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• 2023

Male fertility is affected by multiple endogenous stressors, including reactive oxygen species (ROS), which greatly deteriorate the fertility. However, physiological levels of ROS are required by sperm for the proper accomplishment of different cellular functions including proliferation, maturation, capacitation, acrosomal reaction, and fertilization. Excessive ROS production creates an imbalance between ROS production and neutralization resulting in oxidative stress (OS). OS causes male infertility by impairing sperm functions including reduced motility, deoxyribonucleic acid damage, morphological defects, and enhanced apoptosis. Several in-vivo and in-vitro studies have reported improvement in quality-related parameters of sperm following the use of different natural and synthetic antioxidants. In this review, we focus on the causes of OS, ROS production sources, mechanisms responsible for sperm damage, and the role of antioxidants in preserving sperm fertility.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2022년도 학술발표회
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• pp.85-85
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• 2022

The world's most extensive and active deltas, Louisiana's wetlands, are deteriorating rapidly due to multiple stressors such as the discharge of the Mississippi River, sea-level rise, and coastal retreat, the substantial but spatially and temporally variable impacts. However, the ecological and anthropogenic histories, the mode of environmental changes on a multi-millennial timescale have not been thoroughly documented. This study, a palynology-based multiproxy analysis, investigates hydrological, geological, geochemical, and anthropogenic impacts on southern Louisiana wetlands and a variety of external forcing agents influencing ecological succession. Sediment cores extracted from a small pond on a mangrove-dominate island near Port Fourchon, Louisiana, USA yielded a 4,000-year record. The site has been transformed from freshwater to saline water environments, to a mangrove dominant island over the late Holocene. The multivariate principal component analysis identified the relative strength of external drivers responsible for each ecological shift. The Mississippi River delta cycle (lobe switching) was the dominant driver of ecosystem changes during the late Holocene, while relative sea-level rise, tropical cyclones, climate, and anthropogenic effects have been the main drivers late in the site's history.

• Journal of Ecology and Environment
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• 제38권3호
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• pp.307-318
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• 2015

The objectives of this study were to identify multi-level stressors from blood biomarkers to community-level bioindicators and diagnose the stream ecosystem health in polluted streams. Blood chemistry such as total protein ($T_{Pro}$), blood urea nitrogen ($B_{UN}$), total cholesterol ($T_{Cho}$) and $A_{lb}$umin ($A_{lb}$) were analyzed from sentinel fish tissues; the functions of kidney, gill and liver were significantly decreased in the impacted zone ($I_z$), compared to the control zone ($C_z$). Histopathological analysis showed that fish liver tissues were normal in the $C_z$. Fish liver tissues in the $I_z$, however, showed large cell necrosis and degeneration and also had moderate lobular inflammation and inflammatory cell infiltration of lymphocytic histocytes. Species biotic index (SBI) at species level and stream health assessment (SHA) at community level indicated that chemical impacts were evident in the $I_z$ (ecological health; poor - very poor), and this was matched with the blood tissue analysis and histopathological analysis. The impairments of the streams were supported by water chemistry analysis (nitrogen, phosphorus). Tolerance guild analysis and trophic guild analysis of fish were showed significant differences (P < 0.01) between $C_z$ and $I_z$. Overall, multiple parameter analysis from biomarker level (blood tissues) to bioindicator level (community health) showed significantly greater impacts in the $I_z$ than $C_z$. This approach may be effective as a monitoring tool in identifying the multilateral and forthcoming problems related to chemical pollution and habitat degradation of stream ecosystems.

• Journal of Preventive Medicine and Public Health
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• 제42권4호
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• pp.231-236
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• 2009

Objectives : This study was conducted to determine the appropriate sampling time of the salivary stress markers, chromogranin A (CgA) and cortisol as objective indices of job stress assessment in adult females. Methods : The subjects were 20${\sim}$39-year-old women (13 office workers, 11 sales-service workers, and 11 college students) who were eligible for the study and free of acute and chronic medical conditions. Salivary CgA and cortisol levels were determined by enzyme-linked immunosorbent assay (ELISA). Saliva samples were collected (2 $m{\ell}$ each) at 7:00, 8:00, 10:30, 12:00, 17:30, and 22:30 on a typical day. Salivary CgA and cortisol levels, according to sampling time, were compared among the three groups using general linear model. The full version of the Korean Occupational Stress Scale (KOSS), which includes socioeconomic characteristics, health behavior, workrelated characteristics, and BMI, was used to access the subjects' job stress. Multiple regression analysis of the job stressors identified by the KOSS was performed on salivary CgA and cortisol levels. Results : The salivary CgA level peaked at 7:00 (time of awakening), then decreased and were maintained at a low level throughout the day, and increased slightly at 17:30. The salivary cortisol level increased steeply within the 1st hour after awakening, followed by a gradual decrease by 12:00, and was then maintained at a low level throughout the day. The salivary cortisol levels of subjects who worked ${\leq}$5 days per week and graduated from the university were significantly lower at 8:00 (p=0.006). The salivary cortisol levels of non-smokers were significantly lower at 7:00 p=0.040) and 8:00 (p=0.003) compared to smokers. There were no significant differences in salivary CgA and cortisol levels at 10:30 and 12:00 in general characteristics. The regression coefficients on salivary CgA level were significant with interpersonal conflict at 17:30 and job insecurity at 22:30. Regression coefficients on salivary cortisol level were significant with organizational system and total job stressors at 17:30. Conclusions : We suggest that the appropriate sampling times for the salivary stress markers, CgA and cortisol, are at 7:00 (time of awakening), 8:00 (1 hour after awakening), 17:30 (early evening), and 22:30 (before sleep).

• 한국산학기술학회논문지
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• 제20권3호
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• pp.203-215
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• 2019

본 연구는 전국 보건기관 이용률과 보건기관 이용에 영향을 미치는 요인 중 개인특성과 지역특성변수를 규명하는데 목적이 있다. 자료는 개인특성변수 선정을 위해 2016 지역사회건강조사자료를 이용하였고, 지역특성변수는 국가통계포털과 한국환경공단의 대기환경 연보 자료를 이용하였다. 자료 분석은 독립표본 t-test, 분산분석, 다중로지스틱회귀분석을 이용하였고 보건기관 이용률에 대한 개인특성변수와 지역특성변수를 함께 분석하기 위해 다수준회귀분석을 이용하였다. 연구결과, 전체 보건기관 이용률은 25.54%이고 군, 시, 대도시 순으로 나타났다. 다수준회귀분석 결과, 고령지역, 여자, 높은 연령, 낮은 교육수준과 낮은 소득수준, 걷기 실천자, 영양표시 독해자, 우울감 경험자, 고혈압 진단을 받은 자, 건강검진을 받은 자, 필수 의료서비스 미충족자, 배우자가 있는 자, 기초생활수급권자에서 보건소 이용률이 증가하였다. 반면, 스트레스 인지자, 인구 천명당 보건의료인 수가 전국 평균이상이고 보건복지예산 비중과 재정자주도, 그리고 실업율이 평균 이상으로 높은 지역에서 보건소 이용이 감소하는 것으로 나타났다. 이상의 결과에서 중앙정부와 지자체는 지역보건의료정책 수립시 지역주민의 건강행태와 정신심리적 변수 등 개인특성 뿐 아니라 지역특성 변수들을 포괄적으로 분석하고 동시에 고려하는 것이 필요함을 시사한다.

• 생태와환경
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• 제41권4호
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• pp.441-448
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• 2008

The purpose of this study was to analyze chemical water quality, fish trophic guilds, tolerance indicators, and fish community conditions in the Gap Stream and to compare the stream conditions between the unimpacted site and impacted site. This study was conducted in the physically stable season (May 2008) to minimize physical impacts such as flow and hydrological disturbance, and applied the study in the Gap Stream with two sites of unimpacted upstream site (Unim-S), mainly surrounded by forested area and impacted site (Im-S), influenced by the wastewater disposal plants and industrial complex in the urban region. Chemical data analysis showed that the degree of organic matter pollution, based on BOD, and COD, was $2{\sim}3$ fold greater in the Im-S than the Unim-S, and that TP, as eutrophication indicators, was 4.7 fold greater in the Im-S. Also, $NH_3-N$ was in 8.2 fold greater in the Im-S ($6.25\;mg\;L^{-1}$) than the Unim-S ($0.76\;mg\;L^{-1}$), indicating a massive influence of wastewater from the disposal plant. Similar results were found in other chemical parameters. Thus, chemical impacts in the Im-S were evident, compared to the unimpacted site. Evaluations of tolerant indicator species indicated that sensitive species were dominant in the Unim-S (23.9%) and tolerant species were dominant (97.8%) in the Im-S. Condition factor (CF) was averaged 0.95 ($0.68{\sim}1.18$) in the Unim-S and 1.08 ($0.93{\sim}1.22$) in the Im-S. Fish community in the Unim-S and Im-S was categorized as Zacco-community and Hemibarbus-community, respectively, and the community diversity index (H') was significantly (p<0.05) higher in the Unim-S (0.810) than the Im-S (0.466). Overall, our results suggest that the comparison approach of various chemical and ecological indicators provide important information in identifying multiple stressors in the stream ecosystems.

• Fisheries and Aquatic Sciences
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• 제23권6호
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• pp.15.1-15.14
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• 2020

Background: Large rivers are ecological treasures with high human value, but most have experienced decades of degradation from industrial and municipal sewage, row-crop agricultural practices, and hydrologic alteration. We reviewed published analyses of long-term fish diversity publications from three intensively managed large river ecosystems to demonstrate the conservation potential of large river ecosystems. Results: We show how the incorporation of recent advances in river concepts will allow a better understanding of river ecosystem functioning and conservation. Lastly, we focus on the Wabash River ecosystem based on high conservation value and provide a list of actions to maintain and support the ecosystem. In the Wabash River, there were originally 66 species of freshwater mussels, but now only 30 species with reproducing populations remain. Although there were multiple stressors over the last century, the largest change in Wabash River fish biodiversity was associated with rapid increases in municipal nutrient loading and invasive bigheaded carps. Conclusions: Like similarly neglected large river systems worldwide, the Wabash River has a surprising amount of ecological resilience and recovery. For instance, of the 151 native fish species found in the 1800s, only three species have experienced local extinctions, making the modern assemblage more intact than many comparable rivers in the Mississippi River basin. However, not all the changes are positive or support the idea of recovery. Primary production underpins the productivity of these ecosystems, and the Wabash River phytoplankton assemblages shifted from high-quality green algae in the 1970s to lower less nutritional blue-green algae as nutrient and invasive species have recently increased. Our recommendations for the Wabash River and other altered rivers include the restoration of natural hydrology for the mainstem and tributaries, nutrient reductions, mechanisms to restore historical hydrologic patterns, additional sediment controls, and improved local hydraulics.