Wheaton College - Massachusetts

rises but lose mass and become sensitive to orbital changes. Equatorial dust accumulation engenders supraglacial oligotrophic meltwater ecosystems, favorable for cyanobacteria and certain eukaryotes. Meltwater flushing through cracks enables organic burial and submarine deposition of airborne volcanic ash. The subglacial ocean is turbulent and well mixed, in response to geothermal heating and heat loss through the ice cover, increasing with latitude. Terminal carbonate deposits, unique to Cryogenian glaciations, are products of intense weathering and ocean stratification. Whole-ocean warming and collapsing peripheral bulges allow marine coastal flooding to continue long after ice-sheet disappearance. The evolutionary legacy of Snowball Earth is perceptible in fossils and living organisms.

It is the goal of this paper to discuss the more salient recent advances in the understanding of the controls of net CH3Hg formation in natural systems. The discussion highlights the gaps in knowledge and the areas where progress in understanding has occurred. In particular, this chapter focuses on recent developments in Hg bioavailability and uptake by methylating bacteria, on the competing roles of sulfate and sulfide in the control of methylation, and in pathways for demethylation. The role of sulfide in influencing methylation is discussed in detail. In addition, the impact of other environmental variables such as pH, dissolved organic carbon and temperature on mercury methylation are discussed. Lastly, we provide a synthesis of the variability in the methylation response to Hg inputs across ecosystems. We suggest that although methylation is a function of Hg concentration, the range of methylation rates across ecosystems is larger than the range in Hg deposition rates. Overall, we conclude that factors in addition to the amount Hg deposition play a large role in controlling CH3Hg production and bioaccumulation in aquatic ecosystems.

The Psychology of Religion The Biological Foundations of Religion Behavioral and Comparative Theories of Religion Religion in the Laboratory The Correlation Study of Religion The Perspective of Sigmund Freud Object-Relations Theory and Religion Erik H. Erikson: Religion in the Human Life Cycle C G Jung and the Analytical Tradition William James and His Legacy The German Descriptive Tradition The American Humanistic Synthesis Epilogue Glossary References Source Notes Author Index Subject Index.

In this article, we summarize the work of the NASA Outer Planets Assessment Group (OPAG) Roadmaps to Ocean Worlds (ROW) group. The aim of this group is to assemble the scientific framework that will guide the exploration of ocean worlds, and to identify and prioritize science objectives for ocean worlds over the next several decades. The overarching goal of an Ocean Worlds exploration program as defined by ROW is to "identify ocean worlds, characterize their oceans, evaluate their habitability, search for life, and ultimately understand any life we find." The ROW team supports the creation of an exploration program that studies the full spectrum of ocean worlds, that is, not just the exploration of known ocean worlds such as Europa but candidate ocean worlds such as Triton as well. The ROW team finds that the confirmed ocean worlds Enceladus, Titan, and Europa are the highest priority bodies to target in the near term to address ROW goals. Triton is the highest priority candidate ocean world to target in the near term. A major finding of this study is that, to map out a coherent Ocean Worlds Program, significant input is required from studies here on Earth; rigorous Research and Analysis studies are called for to enable some future ocean worlds missions to be thoughtfully planned and undertaken. A second finding is that progress needs to be made in the area of collaborations between Earth ocean scientists and extraterrestrial ocean scientists.

Abstract Founded in the mid‐1950s, the field of system dynamics has intellectual roots reaching much further into the past. The Archives section of the Review seeks to publish material from that past which can contribute to current theory and practice. The section welcomes previously unpublished but deserving system dynamics work, classics from past system dynamics literature that should receive renewed attention, and previously published articles from other disciplines of particular significance to current system dynamicists. Contributions emphasizing the philosophy and theory of model building, validation, implementation, education, and generic structures are particularly encouraged. Submissions may range in length from notes to main articles but may be edited. Send suggested material, together with a brief introduction placing it in historical and current contexts, to John D. Sterman, System Dynamics Group, M.I.T. E40‐294, Cambridge, MA 02139, U.S.A.

Abstract Most of the empirical studies that analyze the impact of corruption on investment have three common features: they employ country‐level data on investment, corruption is measured at the country level, and data for countries from several regions are pooled together. This paper uses firm‐level data on investment and measures corruption at the firm and country level, and allows the effect of corruption to vary by region. Our dependent variable is firms' investment growth and we employ six measures of corruption from four different sources—two firm‐level measures and four country‐level measures. We find that the effect of corruption on investments varies significantly across regions: corruption has a negative and significant effect on investment growth for firms in Transition countries but has no significant impact for firms in Latin America and Sub‐Saharan Africa. Furthermore, for Transition countries, corruption is the most important determinant of investment.

Using two different natural archiving media from remote locations, we have reconstructed the atmospheric deposition of mercury (Hg) over the last 800–1000 years in both hemispheres. This effort was designed (1) to quantify the historical variation and distributional patterns of atmospheric Hg fluxes in the midlatitudes of North America at Nova Scotia (N.S.) and at a comparable midlatitude region in the Southern Hemisphere at New Zealand (N.S.), (2) to identify and quantify the influence of anthropogenic and natural Hg contributions to atmospheric Hg fluxes, (3) to further investigate the suitability and comparability of our two selected media (lake sediments and ombrotrophic peat) for Hg depositional reconstructions, and (4) to assess the relative importance of wet and dry deposition to the study areas. Significant findings from the study include the following: (1) The lake sediments examined appear to faithfully record the contemporary flux of Hg from the atmosphere (e.g., 1997: N.S. Lakes: approximately 8 ± 3 μg m −2 yr −1 ; N.S. Rain: 8 μg m −2 yr −1 ). The upper 10 cm (approximately 10 yr) of ombrotrophic peat cores from Nova Scotia were dated using a biological chronometer ( Polytrichum ) and were also consistent with the flux data provided by current direct sampling of precipitation. These observations place limits on the contribution of dry deposition (40 ± 50% of wet flux). Unfortunately, the peat samples could not be dated below 10 cm. This was due to the apparent diagenetic mobility of the geochronological tracer ( 210 Pb). (2) There is no evidence of a significant enhancement in the atmospheric Hg flux as a result of preindustrial (<1900 c.e. (Common Era)) activities such as the extensive Au and Ag mining in the Americas. (3) A factor of 3 and 5x increase in the deposition of Hg to the lake sediment archives was observed since the advent of the industrial revolution in New Zealand and Nova Scotia respectively, suggesting a worldwide increase in the atmospheric deposition of Hg. Furthermore, this increase is synchronous with increases in the release of CO 2 from combustion of fossil fuels on a global scale. The magnitude of increase since industrialization appears larger in Nova Scotia than in New Zealand. This may be due to enhanced deposition of Hg as a result of either regional emission of Hg or enhanced regional oxidation of Hg°.

The structures of roller‐quenched SiO 2 ‐Al 2 O 3 glasses containing 10 to 50 wt% Al 2 O 3 were investigated by TEM and high‐resolution 27 Al and 29 Si magic angle sample spinning nuclear magnetic resonance (MASS‐NMR) spectroscopy. The chemical shifts observed in the NMR spectra of these phase‐separated (on the TEM scale) glasses provide evidence, for the existence of all three (4‐, 5‐, and 6‐jold) Al‐coordination units in these glasses and for the presence of A1 in both the Si‐rich and Si‐poor phases.

This paper employs data from the 1998 and 2003 Survey of Small Business Finances to analyze whether, after controlling for observable factors that influence loan decisions, there is a significant difference in the loan approval rate and the interest rate charged on approved loans for businesses owned by minority or white females and firms owned by white males.

Besides the American economy, immigration has dominated the national domestic agenda during this hotly contested 2008 election year. National controversies arose in 2006 and 2007, when Farmers Bran...

BACKGROUND: A variety of studies have demonstrated gains in cognitive ability following cognitive training interventions. However, other studies have not shown such gains, and questions remain regarding the efficacy of specific cognitive training interventions. Cognitive training research often involves programs made up of just one or a few exercises, targeting limited and specific cognitive endpoints. In addition, cognitive training studies typically involve small samples that may be insufficient for reliable measurement of change. Other studies have utilized training periods that were too short to generate reliable gains in cognitive performance. METHODS: The present study evaluated an online cognitive training program comprised of 49 exercises targeting a variety of cognitive capacities. The cognitive training program was compared to an active control condition in which participants completed crossword puzzles. All participants were recruited, trained, and tested online (N = 4,715 fully evaluable participants). Participants in both groups were instructed to complete one approximately 15-minute session at least 5 days per week for 10 weeks. RESULTS: Participants randomly assigned to the treatment group improved significantly more on the primary outcome measure, an aggregate measure of neuropsychological performance, than did the active control group (Cohen's d effect size = 0.255; 95% confidence interval = [0.198, 0.312]). Treatment participants showed greater improvements than controls on speed of processing, short-term memory, working memory, problem solving, and fluid reasoning assessments. Participants in the treatment group also showed greater improvements on self-reported measures of cognitive functioning, particularly on those items related to concentration compared to the control group (Cohen's d = 0.249; 95% confidence interval = [0.191, 0.306]). CONCLUSION: Taken together, these results indicate that a varied training program composed of a number of tasks targeted to different cognitive functions can show transfer to a wide range of untrained measures of cognitive performance. TRIAL REGISTRATION: ClinicalTrials.gov NCT-02367898.

This study examined the association of appointment nonadherence to markers of disease severity using one year of demographic and health information on 995 individuals with HIV in primary care at an urban community health centre. At the latest visit, 106 of 946 valid cases (11.2%) had a CD4 less than or equal to 200, and 454 of 936 valid cases (48.5%) had detectable plasma HIV RNA (greater than 50 copies/ml). Using logistic regression, appointment nonadherence (number of missed appointments) was a significant predictor (p < .03) of having an AIDS-defining CD4 count over and above the effects of number of kept appointments (p < .0001), and whether or not the patient was taking HAART (p < .002). Appointment nonadherence was also a significant predictor (p < .05) of having a detectable viral load over and above the effects of number of kept appointments (p < .003), HAART (p < .0001) and age (p < .004). Looking only at individuals with a detectable viral load at the earliest visit, the only significant unique predictor of improvement to an undetectable viral load at the latest visit was being on HAART (p < .05). Looking at those only with an undetectable viral load at the earliest visit, the only predictor of declining to a detectable viral load was number of kept appointments (p < 003), and being on HAART (p < .05).

(1961). Children's Discovery of the Conservation of Mass, Weight, and Volume: Piaget Replication Study II. The Journal of Genetic Psychology: Vol. 98, No. 2, pp. 219-227.

Geothermal activity is common at the foot of the Higher Himalaya near the Main Central Thrust (MCT), Nepal Himalaya. We have sampled hot springs along a 150 km stretch of the Himalayan front and find that they carry large fluxes of CO 2 derived from metamorphic reactions. Hot spring fluids are saturated with CO 2 , have [DIC] from 1.3 to &gt;100 mmol kg −1 and have δ 13 C DIC values from −13‰ to +13‰ (PDB) . Analysis of CO 2 released by decrepitation of fluid inclusions from syn‐ and postdeformational quartz veins indicate that crustal fluids had δ 13 C from −15‰ to +2‰ (PDB) , consistent with production of CO 2 from both thermal decomposition of organic matter and decarbonation at depth. Modeling of the hot spring fluid compositions indicates that they are strongly degassed. Combining our degassing calculations with estimates of the fraction of hydrothermal alkalinity in local rivers shows that the metamorphic degassing flux of CO 2 in the 32,000 km 2 Narayani basin of the central Himalaya is &gt;1.3 × 10 10 mol a −1 , exceeding the calculated consumption of CO 2 by chemical weathering for the Narayani River basin by a factor of four. Our study implies that the net impact of Himalayan orogenesis on the carbonate‐silicate geochemical cycle is not large‐scale drawdown of CO 2 because the weathering sink is substantially offset or even exceeded by the metamorphic source.

Sulfate-reducing bacteria (SRB) in anoxic waters and sediments are the major producers of methylmercury in aquatic systems. Although a considerable amount of work has addressed the environmental factors that control methylmercury formation and the conditions that control bioavailability of inorganic mercury to SRB, little work has been undertaken analyzing the biochemical mechanism of methylmercury production. The acetyl-coenzyme A (CoA) pathway has been implicated as being key to mercury methylation in one SRB strain, Desulfovibrio desulfuricans LS, but this result has not been extended to other SRB species. To probe whether the acetyl-CoA pathway is the controlling biochemical process for methylmercury production in SRB, five incomplete-oxidizing SRB strains and two Desulfobacter strains that do not use the acetyl-CoA pathway for major carbon metabolism were assayed for methylmercury formation and acetyl-CoA pathway enzyme activities. Three of the SRB strains were also incubated with chloroform to inhibit the acetyl-CoA pathway. So far, all species that have been found to have acetyl-CoA activity are complete oxidizers that require the acetyl-CoA pathway for basic metabolism, as well as methylate mercury. Chloroform inhibits Hg methylation in these species either by blocking the methylating enzyme or by indirect effects on metabolism and growth. However, we have identified four incomplete-oxidizing strains that clearly do not utilize the acetyl-CoA pathway either for metabolism or mercury methylation (as confirmed by the absence of chloroform inhibition). Hg methylation is thus independent of the acetyl-CoA pathway and may not require vitamin B(12) in some and perhaps many incomplete-oxidizing SRB strains.

In an earlier book of theirs called Amazing Conversions (1997), Bob Altemeyer and the late, lamented Bruce Hunsberger reported findings from interviews of university students whose questionnaire re...

The relationship between increasing sexual equality and the level of violence against wives has been the subject of some debate. A negative relationship has been posited by those who point out that as economic, educational, and legal opportunities and rights for women improve, fewer women remain trapped in violent marriages. Others have suggested that violence may increase as these social changes create additional strain and frustration for males attempting to retain their dominant position. This controversy is the focus of the present study. Using American states as the unit of analysis, the relationship between the societal status of women (in economic, educational, political, and legal spheres) and the rate of wife-beating is empirically examined. A status of Women Index is developed on the basis of U.S. Census and other data. State violence rates are based on data from a representative sample of 2143 American adults. The central finding of the study is that there appears to be a curvilinear relationship between women’s status and wife-beating. In states whre women’s status is lowest, wives are most likely to be assaulted by their husbands. Violence deceases as sexual equality increases—to a point. In those states where the status of women is highest, the level of violence against wives is also quite high. It is suggested that limited options to violent marriage may keep battered wives in abusive relationships in low-status states. In states where women’s status is relatively high, increased conflict and violence may be the consequence of rapid social changes which may be threatening to husbands. The study focuses on short-run consequences of increasing sexual equality. It does not address the impact of institutionalized sexual equality because even the highest status states are far from fully egalitarian.

Fluvial features on Titan have been identified in synthetic aperture radar (SAR) data taken during spacecraft flybys by the Cassini Titan Radar Mapper (RADAR) and in Descent Imager/Spectral Radiometer (DISR) images taken during descent of the Huygens probe to the surface. Interpretations using terrestrial analogs and process mechanics extend our perspective on fluvial geomorphology to another world and offer insight into their formative processes. At the landscape scale, the varied morphologies of Titan’s fluvial networks imply a variety of mechanical controls, including structural influence, on channelized flows. At the reach scale, the various morphologies of individual fluvial features, implying a broad range of fluvial processes, suggest that (paleo-)flows did not occupy the entire observed width of the features. DISR images provide a spatially limited view of uplands dissected by valley networks, also likely formed by overland flows, which are not visible in lower-resolution SAR data. This high-resolution snapshot suggests that some fluvial features observed in SAR data may be river valleys rather than channels, and that uplands elsewhere on Titan may also have fine-scale fluvial dissection that is not resolved in SAR data. Radar-bright terrain with crenulated bright and dark bands is hypothesized here to be a signature of fine-scale fluvial dissection. Fluvial deposition is inferred to occur in braided channels, in (paleo)lake basins, and on SAR-dark plains, and DISR images at the surface indicate the presence of fluvial sediment. Flow sufficient to move sediment is inferred from observations and modeling of atmospheric processes, which support the inference from surface morphology of precipitation-fed fluvial processes. With material properties appropriate for Titan, terrestrial hydraulic equations are applicable to flow on Titan for fully turbulent flow and rough boundaries. For low-Reynolds-number flow over smooth boundaries, however, knowledge of fluid kinematic viscosity is necessary. Sediment movement and bed form development should occur at lower bed shear stress on Titan than on Earth. Scaling bedrock erosion, however, is hampered by uncertainties regarding Titan material properties. Overall, observations of Titan point to a world pervasively influenced by fluvial processes, for which appropriate terrestrial analogs and formulations may provide insight.

Despite the hypothesized link betWeen arousal and behavior in persons With autism, there is a lack of idiographic research that directly assesses arousal responses to novel stimuli or social situations in this population. The current study used heart rate as a measure of sympathetic activity to compare arousal responses to the presentation of potentially stressful situations in five persons With autism and five age- and sex-matched typically developing individuals. Findings revealed that the group With autism shoWed significant responses to stressors only 22% of the time compared to the typically developing group, Which shoWed significant responses 60% of the time. Interpretation of these results and methodological considerations for future research on arousal in persons With autism are discussed.

This chapter contains sections titled: Introduction Computational Economies and the Grid An Example Study: G-commerce Simulations and Results Discussion Conclusions Acknowledgments References