Modeling faking good on personality items: An item-level analysis.

Research has consistently demonstrated that personality inventories can be faked; however, there is disagreement about what effect faking has on the measurement properties of tests. This research examines the effects of experimentally induced faking on item-level measurement using polytomous item response theory. Military recruits were instructed to complete a personality inventory under 1 of 3 conditions: answer honestly, fake good, or fake good with coaching. A graded response model (F. Samejima, 1969) was fit to items from 3 personality scales. Although there was a large difference in latent personality trait scores because faking, there were few differences in the functioning of items across conditions. Results of confirmatory factor analyses suggest that faking leads to an increase in common variance that was unrelated to substantive construct variance. Implications for modeling and detection faking are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of seabird vectors on the fate, partitioning, and signatures of contaminants in a High Arctic ecosystem

Seabirds bioaccumulate contaminants from prey, transport them to their nesting sites, and deposit them in their excreta and carcasses, thereby focusing marine-derived contaminants into remote, terrestrial receptor sites. In the case of organochlorine chemicals transported by northern fulmars (Fulmarus glacialis) to a High Arctic seabird colony on Devon Island, Nunavut, Canada (76°13'N, 89°14'W), this contaminant pathway dominates all others. In freshwater ponds below the nesting cliffs, concentrations of organochlorine contaminants characteristic of fulmar input were 2- to 45-fold higher in sediments and water (depending on seabird input to the particular pond) than in ponds remote from the colony. Air-water fugacity quotients for the ponds decreased with seabird input, indicating that fulmar contaminant input shifts air-water partitioning to increasingly favor volatilization to air. Although contaminant evasion from water was favored, direct evidence of it was not detected in air samples. For PCBs, congener profiles of pond sediments or water became more similar to seabird sources as seabird input increased, and less similar to air profiles. Based on measurements of contaminants in fulmars and other local environmental media, this study presents the first application of fugacities and multivariate source apportionment statistics to resolve seabird biological vectors.     

Bioinformatics and its role in the study of the evolution and probiotic potential of lactic acid bacteria

Food Science and Biotechnology - Due to their numerous well-established applications in the food industry, there have been many studies regarding the adaptation and evolution of lactic acid...     

Phosphorous limitation in an arctic river biofilm—A whole ecosystem experiment

A fourth-order arctic river was experimentally enriched with phosphate (7.7 ± 7.0 μ g 1⁻¹) to determine the effect of such a loading (equivalent to a community of 10,000 people) upon the trophically important biofilm. The effect upon a light-grown biofilm (an autotrophic/heterotrophic assemblage) and a dark-grown biofilm (predominantly heterotrophic assemblage) was determined after 28 days of colonization. Seven attributes of the biofilms were monitored, 2 autotrophic indices, chlorophyll , [¹⁴C]HCO₃ incorporation into lipids and 5 heterotrophic indices; [¹⁴C]acetate incorporation into lipids, metabolic heat output, turn-over times of microbially labile glucose and glutamate and mineralization of microbially recalcitrant ring-labelled [¹⁴C]hydroxybenzoic acid. The findings showed that the addition of phosphorus resulted in a substantial stimulation of both autotrophic and heterotrophic processes suggesting that arctic rivers of this type would be liable to cultural eutrophication.     

Killer whales (Orcinus orca) face protracted health risks associated with lifetime exposure to PCBs

Polychlorinated biphenyl (PCB) concentrations declined rapidly in environmental compartments and most biota following implementation of regulations in the 1970s. However, the metabolic recalcitrance of PCBs may delay responses to such declines in large, long-lived species, such as the endangered and highly PCB-contaminated resident killer whales (Orcinus orca) of the Northeastern Pacific Ocean. To investigate the influence of life history on PCB-related health risks, we developed models to estimate PCB concentrations in killer whales during the period from 1930 forward to 2030, both within a lifetime (approximately 50 years) and across generations, and then evaluated these in the context of health effects thresholds established for marine mammals. Modeled PCB concentrations in killer whales responded slowly to changes in loadings to the environment as evidenced by slower accumulation and lower magnitude increases in PCB concentrations relative to prey, and a delayed decline that was particularly evident in adult males. Since PCBs attained peak levels well above the effects threshold (17 mg/kg lipid) in approximately 1969, estimated concentrations in both the northern and the more contaminated southern resident populations have declined gradually. Projections suggest that the northern resident population could largely fall below the threshold concentration by 2030 while the endangered southern residents may not do so until at least 2063. Long-lived aquatic mammals are therefore not protected from PCBs by current dietary residue guidelines.     

都市先锋

100年来,像底特律这样的城市已成为闻名世界的生产之都.美国人从未想过他们的工业丰碑会以我们正在见证的规模面临衰退、人口减少或者废弃. 今天,底特律给了我们机会修改我们对繁荣城市的看法.潜力在于工业城市向新兴都市形态的转型,该都市形态严重依赖农业生产以及副产品和服务网络以在城市中形成—个繁荣、多元的小经济体.最终,此类生产的目的不仅仅是自给自足,也是可持续的健康经济和居住环境的发展.     

The impact of initial surgical management on outcome in young patients with differentiated thyroid cancer

BACKGROUND/PURPOSE: It is generally believed that differentiated thyroid cancer (DTC) in young patients has an excellent prognosis. This calls into question the need for more extensive surgical ablation of the thyroid gland with attendant risks of surgical complications. The purpose of this report was to investigate both the incidence of surgical morbidity and the impact of surgery on locoregional recurrence of disease. METHODS: The authors reviewed the clinical course of patients under 22 years of age treated for DTC within Department of Defense hospitals since 1950. Data were available for determination of surgical morbidity in 126 and for outcome in 105. RESULTS: The incidence of postoperative hypocalcemia was 17% and of recurrent laryngeal nerve injury 3%. Factors predictive of morbidity were (1) more extensive thyroid surgery (P = .023), and (2) the presence of gross tumor invasion (P = .022). The incidence of neck recurrence was analyzed among a cohort of 90 patients. A total of 19 (21%) patients had a local recurrence. The median time to recurrence was 24 months. The factor predictive of recurrence was the presence of gross invasion (P = .0001). A strong trend toward locoregional recurrence was found among patients with metastatic disease to more than five cervical nodes (P < .08). The primary operations on the thyroid and regional nodes were not significant predictors of neck recurrence. Among these 19 patients there have been no deaths, but 25% had persistent disease at a mean follow-up of 12.6 years. CONCLUSIONS: The incidence of surgical morbidity does increase with more extensive surgery. Outcome is predicted primarily by the initial extent of disease.     

Further consideration of the use of narrow trait scales.

This study examined whether inclusion of narrow personality trait scales improved prediction of job performance enough to overcome increased capitalization on chance characteristics of the sample. Data were obtained from 262 midlevel managers who had completed a personality inventory and had been assessed using multisource performance ratings. Three methods of combining trait scores organized under the 5-factor model were compared in order to better understand the contribution of variance specific to the narrow traits in the prediction of performance: common factor scores, unit-weighted composite scores, and regression-weighted composites. Results showed that on average the sets of facet scores explained an additional 9% of the variance in performance beyond summated composites and 10% beyond the factor scores (4% and 5% after correction for shrinkage). Contrary to the idea that broadband predictors would fare better with broad criterion constructs, the increment was similar whether the criterion was a single dimension of performance or overall job performance. Recommendations include reporting results from multiple levels of the personality hierarchy, and suggestions are made for situations where sample size limits the number of predictors advisably entered into a regression equation. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Concentrations and fluxes of salmon-derived polychlorinated biphenyls (PCBs) in lake sediments

Fourteen sediment cores were collected from 10 lakes spanning a large gradient of sockeye salmon returns (0-40 000 spawners km(-2)) in Alaska and British Columbia in 1995-98 and 2002/03. The cores were analyzed for 210Pb to determine sedimentation rates and focusing factors. Polychlorinated biphenyl (PCBs) concentrations in the surface sediments (0-2 cm) were highly correlated with the number of sockeye salmon returns to each nursery lake. For 2002/03, the correlation between PCB concentration and number of salmon spawners was best with no correction factors applied, but decreased considerably when corrected for sedimentation rates, and was improved again by correcting for sediment focusing. Although sigmaPCB concentrations were similar in 1995-98 and 2002/03, the congener patterns varied. Because salmon are the dominant source of PCBs for most of these lakes, variation in sediment congener pattern likely derives from variation in congener patterns carried by the salmon. Overall, total PCB input by salmon has remained relatively constant since 1995. Unlike temperate Great Lakes contaminant studies, the North American west-coast lakes dominated by salmon bio-transport showed no sign of recent decrease in PCBs.