Valence, instrumentality, expectancy, and ability as determinants of faking, and the effects of faking on criterion-related validity

We investigated individual differences in faking in simulated high-stakes personality assessments through the lens of expectancy (VIE) theory, using a novel experimental paradigm. Three hundred ninety-eight participants (MTurk) completed a “low-stakes” HEXACO personality assessment for research purposes. Three months later, we invited all 398 participants to compete for an opportunity to complete a genuine, well-paid, one-off MTurk job, and 201 accepted. After viewing the selection criteria, which described high levels of perfectionism as critical for selection, these participants completed the HEXACO personality assessment as part of their applications (“high-stakes”). All 201 participants were then informed their applications were successful and were invited to complete the performance task, with 189 accepting the offer. The task, which involved checking text data for inconsistencies, captured two objective performance criteria. We observed faking on measures of diligence and perfectionism. We found that perceived job desirability (valence) was the strongest (positive) determinant of individual differences in faking, along with perceived instrumentality and expectancy. Honesty-humility was also associated with faking however, unexpectedly, the association was positive. When all predictors were combined, only perceived job desirability remained a significant motivational determinant of faking, with cognitive ability also being a positive predictor. We found no evidence that cognitive ability moderated the relations of motivation and faking. To investigate the role of faking on predictive validity, we split the sample into those who had faked to a statistically large extent, and those who had not. We found that the validity of high-stakes assessments was higher amongst the group that had faked

Hydrologic indicators of hot spots and hot moments of mercury methylation potential along river corridors

The authors acknowledge financial support from the National Science Foundation: EAR-1226741 (to M.B.S.) and EAR-1225630 (to J.D.B.), and from the REG Trust (to M.B.S.).The biogeochemical cycling of metals and other contaminants in river-floodplain corridors is controlled by microbial activity responding to dynamic redox conditions. Riverine flooding thus has the potential to affect speciation of redox-sensitive metals such as mercury (Hg). Therefore, inundation history over a period of decades potentially holds information on past production of bioavailable Hg. We investigate this within a Northern California river system with a legacy of landscape-scale 19th century hydraulic gold mining. We combine hydraulic modeling, Hg measurements in sediment and biota, and first-order calculations of mercury transformation to assess the potential role of river floodplains in producing monomethylmercury (MMHg), a neurotoxin which accumulates in local and migratory food webs. We identify frequently inundated floodplain areas, as well as floodplain areas inundated for long periods. We quantify the probability of MMHg production potential (MPP) associated with hydrology in each sector of the river system as a function of the spatial patterns of overbank inundation and drainage, which affect long-term redox history of contaminated sediments. Our findings identify river floodplains as periodic, temporary, yet potentially important, loci of biogeochemical transformation in which contaminants may undergo change during limited periods of the hydrologic record. We suggest that inundation is an important driver of MPP in river corridors and that the entire flow history must be analyzed retrospectively in terms of inundation magnitude and frequency in order to accurately assess biogeochemical risks, rather than merely highlighting the largest floods or low-flow periods. MMHg bioaccumulation within the aquatic food web in this system may pose a major risk to humans and waterfowl that eat migratory salmonids, which are being encouraged to come up these rivers to spawn. There is a long-term pattern of MPP under the current flow regime that is likely to be accentuated by increasingly common large floods with extended duration.PostprintPeer reviewe

Isotopic evidence for mercury photoreduction and retention on particles in surface waters of Central California, USA

Cache Creek (Coast Range, California) and the Yuba River (Sierra Nevada Foothills, California) are two river systems affected by extensive mercury (Hg) contamination due to legacy sources of Hg related to mining. Stable Hg isotope techniques have proven useful for elucidating the complex cycling of Hg within aquatic ecosystems, and we applied these techniques to improve understanding of Hg and methylmercury (MeHg) transformations in these watersheds. Total mercury (THg) concentrations and Hg stable isotope ratios were measured in filtered surface waters and suspended particulate matter collected from 14 sites within the Cache Cr. and Yuba R. watersheds. Filtered surface waters from both watersheds exhibited values of ∆199Hg (0.37‰ to 0.71‰), consistently elevated above those observed in sediments (∆199Hg average = 0.07‰). Associated suspended particulates from these surface water samples displayed a much greater range of values for ∆199Hg (−0.61‰ to 0.70‰), although suspended particulates from the Yuba R. exhibited mostly negative ∆199Hg values (−0.61‰ to 0.10‰). The relationship between ∆199Hg and ∆201Hg in the filtered surface waters and associated suspended particulates was calculated using a bivariate York regression, yielding a slope of 1.57 ± 0.49 (±2SE) for the Yuba R. and 1.40 ± 0.27 (±2SE) for Cache Cr., both within error of the previously reported experimentally-derived slopes for MeHg- and inorganic Hg(II)-photoreduction. This provides isotopic evidence that Hg photoreduction is occurring within these surface waters to a significant degree, and suspended particulate phases are retaining the reduced product of Hg photoreduction, particularly within the Yuba R. The isotopic compositions of filtered surface waters are consistent with the isotopic signatures recorded in biota at low trophic positions within these watersheds, suggesting that the reservoir of Hg incorporated within the biota of these systems is similar to the filter-passing Hg fraction in surface waters

Evaluation of the model of music education of future teachers of primary education

Cilj je istraživanja evaluacija postojećega modela glazbenoga obrazovanja budućih učitelja i svojstava nastave glazbe na učiteljskim studijima u Hrvatskoj. Istraživanje je provedeno anketiranjem studenata učiteljskog studija na Učiteljskom fakultetu u Osijeku (N=307), Učiteljskom fakultetu u Zagrebu (N=344) i Odjelu za izobrazbu učitelja i odgojitelja Sveučilišta u Zadru (N=121) te među nastavnicima glazbe (N=12) na učiteljskim studijima u Hrvatskoj. Postojeći model glazbenoga obrazovanja budućih učitelja evaluiran je jednim stupnjem iznad prosječne ocjene, a između ocjena studenata i nastavnika nema značajne razlike. Utvrđena je značajna razlika u evaluaciji modela kod studenata s različitih fakulteta. Evaluacija materijalnih uvjeta pokazala je kako je opremljenost učionica za nastavu glazbe dobra osim u nedovoljnoj opremljenosti glazbenim instrumentima koje bi studenti mogli upotrebljavati tijekom nastavnoga procesa. U radu se predlažu moguća rješenja proizašla iz ovog istraživanja koja bi mogla dovesti kvalitativnih promjena u glazbenom obrazovanju budućih učitelja.The aim of this research is to evaluate the existing model of music education for future teachers as well as the characteristics of music teaching at various teaching study programmes in Croatia. A survey has been conducted among students at the Faculty of Education in Osijek (N = 307), the Faculty of Teacher Education in Zagreb (N = 344), the Department for Education of Teachers and Pre-school Teachers of the University of Zadar (N = 121), and among music teachers (N = 12) at teacher study programmes in Croatia. The existing model of music education for future teachers has been evaluated as better than average, both by students and teachers alike. A significant difference in model evaluation has been established among students from different faculties. The evaluation of material conditions has shown that music classrooms are well-equipped, except when it comes to musical instruments that could be used by students in lessons. The paper proposes possible solutions, resulting from the research, which could lead to qualitative changes in music education of future teachers

23 High Redshift Supernovae from the IfA Deep Survey: Doubling the SN Sample at z>0.7

We present photometric and spectroscopic observations of 23 high redshift supernovae spanning a range of z=0.34-1.03, 9 of which are unambiguously classified as Type Ia. These supernovae were discovered during the IfA Deep Survey, which began in September 2001 and observed a total of 2.5 square degrees to a depth of approximately m=25-26 in RIZ over 9-17 visits, typically every 1-3 weeks for nearly 5 months, with additional observations continuing until April 2002. We give a brief description of the survey motivations, observational strategy, and reduction process. This sample of 23 high-redshift supernovae includes 15 at z>0.7, doubling the published number of objects at these redshifts, and indicates that the evidence for acceleration of the universe is not due to a systematic effect proportional to redshift. In combination with the recent compilation of Tonry et al. (2003), we calculate cosmological parameter density contours which are consistent with the flat universe indicated by the CMB (Spergel et al. 2003). Adopting the constraint that Omega_total = 1.0, we obtain best-fit values of (Omega_m, Omega_Lambda)=(0.33, 0.67) using 22 SNe from this survey augmented by the literature compilation. We show that using the empty-beam model for gravitational lensing does not eliminate the need for Omega_Lambda > 0. Experience from this survey indicates great potential for similar large-scale surveys while also revealing the limitations of performing surveys for z>1 SNe from the ground.Comment: 67 pages, 12 figures, 12 tables, accepted for publication in the Astrophysical Journa

Diverse sediment microbiota shape methane emission temperature sensitivity in Arctic lakes

Northern post-glacial lakes are significant, increasing sources of atmospheric carbon through ebullition (bubbling) of microbially-produced methane (CH4) from sediments. Ebullitive CH4 flux correlates strongly with temperature, reflecting that solar radiation drives emissions. However, here we show that the slope of the temperature-CH4 flux relationship differs spatially across two post-glacial lakes in Sweden. We compared these CH4 emission patterns with sediment microbial (metagenomic and amplicon), isotopic, and geochemical data. The temperature-associated increase in CH4 emissions was greater in lake middles—where methanogens were more abundant—than edges, and sediment communities were distinct between edges and middles. Microbial abundances, including those of CH4-cycling microorganisms and syntrophs, were predictive of porewater CH4 concentrations. Results suggest that deeper lake regions, which currently emit less CH4 than shallower edges, could add substantially to CH4 emissions in a warmer Arctic and that CH4 emission predictions may be improved by accounting for spatial variations in sediment microbiota

Methylmercury degradation and exposure pathways in streams and wetlands impacted by historical mining

The authors acknowledge financial support from the National Science Foundation: EAR-1226741 (to M.B.S.) and EAR-1225630 (to J.D.B.).Monomethyl mercury (MMHg) and total mercury (THg) concentrations and Hg stable isotope ratios (δ202Hg and Δ199Hg) were measured in sediment and aquatic organisms from Cache Creek (California Coast Range) and Yolo Bypass (Sacramento Valley). Cache Creek sediment had a large range in THg (87 to 3870 ng/g) and δ202Hg (− 1.69 to − 0.20‰) reflecting the heterogeneity of Hg mining sources in sediment. The δ202Hg of Yolo Bypass wetland sediment suggests a mixture of high and low THg sediment sources. Relationships between %MMHg (the percent ratio of MMHg to THg) and Hg isotope values (δ202Hg and Δ199Hg) in fish and macroinvertebrates were used to identify and estimate the isotopic composition of MMHg. Deviation from linear relationships was found between %MMHg and Hg isotope values, which is indicative of the bioaccumulation of isotopically distinct pools of MMHg. The isotopic composition of pre-photodegraded MMHg (i.e., subtracting fractionation from photochemical reactions) was estimated and contrasting relationships were observed between the estimated δ202Hg of pre-photodegraded MMHg and sediment IHg. Cache Creek had mass dependent fractionation (MDF; δ202Hg) of at least − 0.4‰ whereas Yolo Bypass had MDF of + 0.2 to + 0.5‰. This result supports the hypothesis that Hg isotope fractionation between IHg and MMHg observed in rivers (− MDF) is unique compared to + MDF observed in non-flowing water environments such as wetlands, lakes, and the coastal ocean.PostprintPeer reviewe