Cancer Risks among Welders and Occasional Welders in a National Population-Based Cohort Study: Canadian Census Health and Environmental Cohort

MacLeod, Jill S.,Harris, M. Anne,Tjepkema, Michael,Peters, Paul A.,Demers, Paul A. Occupational Safety and Health Research Institute 2017 Safety and health at work Vol.8 No.3

Background: Welders are exposed to many known and suspected carcinogens. An excess lung cancer risk among welders is well established, but whether this is attributable to welding fumes is unclear. Excess risks of other cancers have been suggested, but not established. We investigated welding cancer risks in the population-based Canadian Census Health and Environmental Cohort. Methods: Among 1.1 million male workers, 12,845 welders were identified using Standard Occupational Classification codes and followed through retrospective linkage of 1991 Canadian Long Form Census and Canadian Cancer Registry (1992-2010) records. Hazard ratios (HRs) were calculated using Cox proportional hazards models based on estimated risks of lung cancer, mesothelioma, and nasal, brain, stomach, kidney, and bladder cancers, and ocular melanoma. Lung cancer histological subtypes and risks by industry group and for occasional welders were examined. Some analyses restricted comparisons to blue-collar workers to minimize effects of potential confounders. Results: Among welders, elevated risks were observed for lung cancer [HR: 1.16, 95% confidence interval (CI): 1.03-1.31], mesothelioma (HR: 1.78, 95% CI: 1.01-3.18), bladder cancer (HR: 1.40, 95% CI: 1.15-1.70), and kidney cancer (HR: 1.30, 95% CI: 1.01-1.67). When restricted to blue-collar workers, lung cancer and mesothelioma risks were attenuated, while bladder and kidney cancer risks increased. Conclusion: Excess risks of lung cancer and mesothelioma may be partly attributable to factors including smoking and asbestos. Welding-specific exposures may increase bladder and kidney cancer risks, and particular sources of exposure should be investigated. Studies that are able to disentangle welding effects from smoking and asbestos exposure are needed.

Cancer Risks among Welders and Occasional Welders in a National Population-Based Cohort Study: Canadian Census Health and Environmental Cohort

Jill S. MacLeod,M. Anne Harris,Michael Tjepkema,Paul A. Peters,Paul A. Demers 한국산업안전보건공단 산업안전보건연구원 2017 Safety and health at work Vol.8 No.3

Background: Welders are exposed to many known and suspected carcinogens. An excess lung cancer risk among welders is well established, but whether this is attributable to welding fumes is unclear. Excess risks of other cancers have been suggested, but not established. We investigated welding cancer risks in the population-based Canadian Census Health and Environmental Cohort. Methods: Among 1.1 million male workers, 12,845 welders were identified using Standard Occupational Classification codes and followed through retrospective linkage of 1991 Canadian Long Form Census and Canadian Cancer Registry (1992e2010) records. Hazard ratios (HRs) were calculated using Cox proportional hazards models based on estimated risks of lung cancer, mesothelioma, and nasal, brain, stomach, kidney, and bladder cancers, and ocular melanoma. Lung cancer histological subtypes and risks by industry group and for occasional welders were examined. Some analyses restricted comparisons to blue-collar workers to minimize effects of potential confounders. Results: Among welders, elevated risks were observed for lung cancer [HR: 1.16, 95% confidence interval (CI): 1.03e1.31], mesothelioma (HR: 1.78, 95% CI: 1.01e3.18), bladder cancer (HR: 1.40, 95% CI: 1.15e1.70), and kidney cancer (HR: 1.30, 95% CI: 1.01e1.67). When restricted to blue-collar workers, lung cancer and mesothelioma risks were attenuated, while bladder and kidney cancer risks increased. Conclusion: Excess risks of lung cancer and mesothelioma may be partly attributable to factors including smoking and asbestos. Welding-specific exposures may increase bladder and kidney cancer risks, and particular sources of exposure should be investigated. Studies that are able to disentangle welding effects from smoking and asbestos exposure are needed.

Creating works in the Co-Evolution Environment

알래스테어 맥러드(Alastair Macleod) 한국만화애니메이션학회 2008 한국만화애니메이션학회 학술대회자료집 Vol.2008 No.11

Blake Nose stable isotopic evidence against the mid-Cenomanian glaciation hypothesis

Ando, Atsushi,Huber, Brian T.,MacLeod, Kenneth G.,Ohta, Tomoko,Khim, Boo-Keun Geological Society of America 2009 Geology Vol.37 No.5

Ecology of Algal Mats from Hypersaline Ponds in the British Virgin Islands

Jarecki, Lianna,Sarah M. , Burton-MacLeod,Garbary, David J. The Korean Society of Phycology 2006 ALGAE Vol.21 No.2

Benthic sediment samples ranging from poorly aggregated sand to complex, stratified mats were collected from six hypersaline ponds from March and July 1995 in the British Virgin Islands. Assemblages were analyzed with respect to species composition and abundance within visibly distinct layers in each mat sample. In individual ponds there was no apparent association between changing depth and the development of the benthic mats. Some species were present in all samples (e.g. Oscillatoria sp.) while others were restricted to single sites (e.g. Johannesbaptistia pellucida). Primary species included Microcoleus chthonoplastes, Phormidium spp., Coccochloris stagnina, and purple sulfur bacteria. Quantitative analysis of community structure included cluster and principal component analysis. Samples from individual ponds were often clustered; however, this was subject to seasonal variation. Mats collected in March were generally thicker and contained more layers than those in July. Variation among sites was not explained by the measured variation in environmental factors such as average pond salinity, depth, and oxygen concentration (mg/L). This study provides a detailed analysis of mat communities in hypersaline ponds and compares them with similar mat communities from other areas.

The Effects of amino acid balance on heat production and nitrogen utilization in broiler chickens : measurement and modeling

Ji-Hyuk Kim,Murdo G. MacLeod 한국가금학회 2004 한국가금학회 정기총회 및 학술발표회 Vol.21 No.-

본 실험은 사료내 아미노산 균형과 라이신 함량이 성장기 브로일러의 에너지 대사 중 Heat production(HP)과 질소 대사에 어떤 영향을 미치는지 규명하기 위해 실시하였다. 실험1은 여러 단계의 조단백 함량과, 제1제한 아미노산으로써 일정농도의 라이신 함량으로 만들어진 사료로 테스트하였다. 실험2에서는 이와 반대로 일정한 조단백 함량과 각기 다른 수준의 라이신을 함유한 사료들을 사용하였다. Thermoregulatory demand에 따른 영향을 최소화하기 위해 실험3은 이전 실험들(20 ℃)보다 높은 온도인 30 ℃에서 시행되었다. 에너지 및 질소 대사 실험은 컴퓨터로 제어되는 multichamber calorimeter system을 사용하여 조사하였으며 사료의 단백질 및 라이신 조성에 따른 닭의 HP를 측정하였다. 또한 이를 통해 나온 결과들은 에너지 대사 컴퓨터 시뮬레이션 모델을 통한 예측치와 비교하였다.<br/> 다양한 단백질 함량과 일정한 라이신 함량의 사료를 통한 실험에서 단백질 함량이 증가함에 따라 질소 섭취에서는 75 %의 증가가 나타났다. 이것은 질소 배출에 있어서 150 %의 증가를 가져왔으나 이에 따른 HP에 유의적인 차이는 보이지 않았다. 다양한 라이신 함량과 일정한 단백질 함량의 사료를 사용한 실험2에서는 최저 라이신과 최고 라이신 처리구 간에 3배의 증체량의 차이를 보여주었다. HP에 있어서는 라이신 증가에 따라 유의적으로 증가하는 경향을 보였으나 체중 보정치에 있어서는 유의차가 사라졌다. 실험1과 실험2, 두 실험의 시뮬레이션을 통한 HP 계산치에 있어서도 처리구들 간에 차이를 보이지 않았다. 30 ℃에서 실시된 실험3에서는 실험2와 동일하게 라이신 함량증가에 따라 HP가 유의적으로 증가하였으나 그 경향은 이전 실험보다 크게 나타났다. 결과를 종합할 때, 총 HP의 발생은 사료의 단백질 함량보다는 제한 아미노산 농도와 더욱 관련이 깊으며, 아미노산 불균형에 따른 질소 배출로 인해 발생하는 energy cost가 차지하는 비율은 높지 않은 것으로 사료된다. 또한 질소 축적율에서 볼 때, 사료내 아미노산 균형이 체내 질소 이용효율과 밀접한 관련이 있음을 확인하였다. Three experiments were performed to test the assumption that imbalanced dietary amino acid mixtures must lead to increased heat production (HP). The first experiment was based on diets formulated to have a wide range of crude protein (CP) concentrations but a fixed concentration of lysine, formulated to be the first-limiting amino acid. In the second (converse) experiment, lysine concentration was varied over a wide range while CP content was kept constant. To prevent the masking of dietary effects by thermoregulatory demands, the third experiment was performed at 30 ℃ with the diets similar to the diets used in the second experiment. The detailed relationships among amino acid balance, nitrogen (N) metabolism and energy (E) metabolism were investigated in a computer-controlled chamber calorimetry system. The results of experiments were compared with the predictions of a computerised simulation model of E metabolism. In experiment 1, with constant lysine and varying CP, there was a 75 % increase in N intake as CP concentration increased. This led to a 150 % increase in N excretion, with no significant change in HP. Simulated HP agreed with the empirically determined results in not showing a trend with dietary CP. In experiment 2, with varying lysine but constant CP, there was a 3-fold difference in daily weight gain between the lowest and highest lysine diets. HP per bird increased significantly with dietary lysine concentration. There was still an effect when HP was adjusted for body weight differences, but it failed to maintain statistical significance. Simulated HP results agreed in showing little effect of varying lysine concentration and growth rate on HP. Based on the results of these two experiments, the third experiment was designed to test the response of birds to dietary lysine in high ambient temperature. In experiment 3 which performed at high ambient temperature(30 ℃), HP per bird increased significantly with dietary lysine content, whether or not adjusted for body-weight. The trend was greater than in the previous experiment (20 ℃).

TiO₂박막의 두께에 따른 실시간 스트레스 측정에 관한 연구

한성홍(Sung Hong Hahn),김석원(Sok Won Kim),H. Angus Macleod 한국광학회 1993 한국광학회지 Vol.4 No.3

실시간 (in-situ) 스트레스측정 간섭계를 사용하여 이온보조증착에 의해 TiO₂ 박막이 성장되는 동안에 박막내부의 스트레스를 측정하였다. 박막두께에 따른 스트레스의 변화는 이온빔에 의한 압축스트레스와 표면온도에 의해 결정되는 표면확산의 평형에 의해서 정성적으로 설명되어지며, 측정결과는 스트레스가 성장되는 박막에 전달되는 이온빔의 운동량에 따라 증가한다는 Windischmann의 모델과 일치하였다. An in-situ stress measurement interferometer is constructed and used to measure the intrinsic stress in TiO₂ thin films during their growth by ion-assisted deposition. It is found that the stress increases with the momentum transferred by the ion beam to the growing film and is fairly well agreed with Windischmann's model. The variation of the stress with thickness is qualitatively explained in terms of the balance between the compressive stress produced by the ion beam and the surface diffusion determined by the surface temperature.

Anismus, Physiology, Radiology: Is It Time for Some Pragmatism? A Comparative Study of Radiological and Anorectal Physiology Findings in Patients With Anismus

Umberto Pisano,Lesley Irvine,Justina Szczachor,Ahsin Jawad,Andrew MacLeod,Michael Lim 대한대장항문학회 2016 Annals of Coloproctolgy Vol.32 No.5

Purpose: Anismus is a functional disorder featuring obstructive symptoms and paradoxical contractions of the pelvic floor. This study aims to establish diagnosis agreement between physiology and radiology, associate anismus with morphological outlet obstruction, and explore the role of sphincteric pressure and rectal volumes in the radiological diagnosis of anismus. Methods: Consecutive patients were evaluated by using magnetic resonance imaging proctography/fluoroscopic defecography and anorectal physiology. Morphological radiological features were associated with physiology tests. A categorical analysis was performed using the chi-square test, and agreement was assessed via the kappa coefficient. A Mann-Whitney test was used to assess rectal volumes and sphincterial pressure distributions between groups of patients. A P-value of <0.05 was significant. Results: Forty-three patients (42 female patients) underwent anorectal physiology and radiology imaging. The median age was 54 years (interquartile range, 41.5–60 years). Anismus was seen radiologically and physiologically in 18 (41.8%) and 12 patients (27.9%), respectively. The agreement between modalities was 0.298 (P = 0.04). Using physiology as a reference, radiology had positive and negative predictive values of 44% and 84%, respectively. Rectoceles, cystoceles, enteroceles and pathological pelvic floor descent were not physiologically predictive of animus (P > 0.05). The sphincterial straining pressure was 71 mmHg in the anismus group versus 12 mmHg. Radiology was likely to identify anismus when the straining pressure exceeded 50% of the resting pressure (P = 0.08). Conclusion: Radiological techniques detect pelvic morphological abnormalities, but lead to overdiagnoses of anismus. No proctographic pathological feature predicts anismus reliably. A stronger pelvic floor paradoxical contraction is associated with a greater likelihood of detection by proctography.

Tandem Solar Cells from Solution-Processed CdTe and PbS Quantum Dots Using a ZnTe–ZnO Tunnel Junction

Crisp, Ryan W.,Pach, Gregory F.,Kurley, J. Matthew,France, Ryan M.,Reese, Matthew O.,Nanayakkara, Sanjini U.,MacLeod, Bradley A.,Talapin, Dmitri V.,Beard, Matthew C.,Luther, Joseph M. American Chemical Society 2017 Nano letters Vol.17 No.2

<P>We developed a monolithic CdTe–PbS tandem solar cell architecture in which both the CdTe and PbS absorber layers are solution-processed from nanocrystal inks. Due to their tunable nature, PbS quantum dots (QDs), with a controllable band gap between 0.4 and ∼1.6 eV, are a promising candidate for a bottom absorber layer in tandem photovoltaics. In the detailed balance limit, the ideal configuration of a CdTe (<I>E</I><SUB>g</SUB> = 1.5 eV)–PbS tandem structure assumes infinite thickness of the absorber layers and requires the PbS band gap to be 0.75 eV to theoretically achieve a power conversion efficiency (PCE) of 45%. However, modeling shows that by allowing the thickness of the CdTe layer to vary, a tandem with efficiency over 40% is achievable using bottom cell band gaps ranging from 0.68 and 1.16 eV. In a first step toward developing this technology, we explore CdTe–PbS tandem devices by developing a ZnTe–ZnO tunnel junction, which appropriately combines the two subcells in series. We examine the basic characteristics of the solar cells as a function of layer thickness and bottom-cell band gap and demonstrate open-circuit voltages in excess of 1.1 V with matched short circuit current density of 10 mA/cm<SUP>2</SUP> in prototype devices.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/nalefd/2017/nalefd.2017.17.issue-2/acs.nanolett.6b04423/production/images/medium/nl-2016-04423k_0006.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/nl6b04423'>ACS Electronic Supporting Info</A></P>