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Differential effects of air conditioning type on residential endotoxin levels in a semi‐arid climate 下载免费PDF全文
J. D. Johnston B. A. Kruman M. C. Nelson R. M. Merrill R. J. Graul T. G. Hoybjerg S. C. Tuttle S. J. Myers R. B. Cook K. S. Weber 《Indoor air》2017,27(5):946-954
Residential endotoxin exposure is associated with protective and pathogenic health outcomes. Evaporative coolers, an energy‐efficient type of air conditioner used in dry climates, are a potential source of indoor endotoxins; however, this association is largely unstudied. We collected settled dust biannually from four locations in homes with evaporative coolers (n=18) and central air conditioners (n=22) in Utah County, Utah (USA), during winter (Jan‐Apr) and summer (Aug‐Sept), 2014. Dust samples (n=281) were analyzed by the Limulus amebocyte lysate test. Housing factors were measured by survey, and indoor temperature and relative humidity measures were collected during both seasons. Endotoxin concentrations (EU/mg) were significantly higher in homes with evaporative coolers from mattress and bedroom floor samples during both seasons. Endotoxin surface loads (EU/m2) were significantly higher in homes with evaporative coolers from mattress and bedroom floor samples during both seasons and in upholstered furniture during winter. For the nine significant season‐by‐location comparisons, EU/mg and EU/m2 were approximately three to six times greater in homes using evaporative coolers. A plausible explanation for these findings is that evaporative coolers serve as a reservoir and distribution system for Gram‐negative bacteria or their cell wall components in homes. 相似文献
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Visualization Approaches for Evaluating Ridge Regression Estimators in Mixture and Mixture‐Process Experiments 下载免费PDF全文
Dae‐Heung Jang Christine M. Anderson‐Cook 《Quality and Reliability Engineering International》2015,31(8):1483-1494
When the component proportions in mixture experiments are restricted by lower and upper bounds, the input space of a designed experiment space can become an irregular region that can induce multicollinearity problems when estimating the component proportion parameters. Thus, ridge regression provides a beneficial means of stabilizing the coefficient estimates in the fitted model. Previous research has focused on using prediction variance as a metric for determining an appropriate value of the ridge constant, k. We use visualization techniques to illustrate and evaluate ridge regression estimators and the robustness of estimation with respect to the variance and the bias. The addition of bias allows better balancing between the stability of the estimators and minimally changing the estimates. We illustrate the graphical methods with mixture and mixture‐process examples from the literature. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
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Low Dietary c9t11-Conjugated Linoleic Acid Intake from Dairy Fat or Supplements Reduces Inflammation in Collagen-Induced Arthritis 总被引:1,自引:0,他引:1 下载免费PDF全文
Shane M. Huebner Jake M. Olson James P. Campbell Jeffrey W. Bishop Peter M. Crump Mark E. Cook 《Lipids》2016,51(7):807-819
Dietary cis‐9,trans‐11 (c9t11) conjugated linoleic acid (CLA) fed at 0.5 % w/w was previously shown to attenuate inflammation in the murine collagen‐induced (CA) arthritis model, and growing evidence implicates c9t11‐CLA as a major anti‐inflammatory component of dairy fat. To understand c9t11‐CLA's contribution to dairy fat's anti‐inflammatory action, the minimum amount of dietary c9t11‐CLA needed to reduce inflammation must be determined. This study had two objectives: (1) determine the minimum dietary anti‐inflammatory c9t11‐CLA intake level in the CA model, and (2) compare this to anti‐inflammatory effects of dairy fat (non‐enriched, naturally c9t11‐CLA‐enriched, or c9t11‐CLA‐supplemented). Mice received the following dietary fat treatments (w/w) post arthritis onset: corn oil (6 % CO), 0.125, 0.25, 0.375, and 0.5 % c9t11‐CLA, control butter (6 % CB), c9t11‐enriched butter (6 % EB), or c9t11‐CLA‐supplemented butter (6 % SB, containing 0.2 % c9t11‐CLA). Paw arthritic severity and pad swelling were scored and measured, respectively, over an 84‐day study period. All c9t11‐CLA and butter diets decreased the arthritic score (25–51 %, P < 0.01) and paw swelling (8–11 %, P < 0.01). Throughout the study, plasma tumor necrosis factor (TNFα) was elevated in CO‐fed arthritic mice compared to non‐arthritic (NA) mice but was reduced in 0.5 % c9t11‐CLA‐ and EB‐fed mice. Interleukin‐1β and IL‐6 were increased in arthritic CO‐fed mice compared to NA mice but were reduced in 0.5 % c9t11‐CLA‐ and EB‐fed mice through day 42. In conclusion, 0.125 % c9t11‐CLA reduced clinical arthritis as effectively as higher doses, and decreased arthritis in CB‐fed mice suggested that the minimal anti‐inflammatory levels of c9t11‐CLA might be below 0.125 %. 相似文献
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Wax Ester Rich Oil From The Marine Crustacean,Calanus finmarchicus,is a Bioavailable Source of EPA and DHA for Human Consumption 下载免费PDF全文
Chad M. Cook Terje S. Larsen Linda D. Derrig Kathleen M. Kelly Kurt S. Tande 《Lipids》2016,51(10):1137-1144
Oil from the marine copepod, Calanus finmarchicus, which contains >86 % of fatty acids present as wax esters, is a novel source of n‐3 fatty acids for human consumption. In a randomized, two‐period crossover study, 18 healthy adults consumed 8 capsules providing 4 g of Calanus® Oil supplying a total of 260 mg EPA and 156 mg DHA primarily as wax esters, or 1 capsule of Lovaza® providing 465 mg EPA and 375 mg DHA as ethyl esters, each with an EPA‐ and DHA‐free breakfast. Plasma EPA and DHA were measured over a 72 h period (t = 1, 2, 4, 6, 8, 10, 12, 24, 48, and 72 h). The positive incremental area under the curve over the 72 h test period (iAUC0‐72 h) for both EPA and DHA was significantly different from zero (p < 0.0001) in both test conditions, with similar findings for the iAUC0–24 h and iAUC0–48 h, indicating the fatty acids were absorbed. There was no difference in the plasma iAUC0–72 h for EPA + DHA, or DHA individually, in response to Calanus Oil vs the ethyl ester condition; however, the iAUC0–48 h and iAUC0–72 h for plasma EPA in response to Calanus Oil were both significantly increased relative to the ethyl ester condition (iAUC0–48 h: 381 ± 31 vs 259 ± 39 μg*h/mL, p = 0.026; iAUC0‐72 h: 514 ± 47 vs 313 ± 49 μg*h/mL, p = 0.009). These data demonstrate a novel wax ester rich marine oil is a suitable alternative source of EPA and DHA for human consumption. 相似文献