Showing papers by "San Francisco State University published in 2007"
TL;DR: These genome sequences augment the formidable genetic tools that have made Drosophila melanogaster a pre-eminent model for animal genetics, and will further catalyse fundamental research on mechanisms of development, cell biology, genetics, disease, neurobiology, behaviour, physiology and evolution.
Abstract: Comparative analysis of multiple genomes in a phylogenetic framework dramatically improves the precision and sensitivity of evolutionary inference, producing more robust results than single-genome analyses can provide. The genomes of 12 Drosophila species, ten of which are presented here for the first time (sechellia, simulans, yakuba, erecta, ananassae, persimilis, willistoni, mojavensis, virilis and grimshawi), illustrate how rates and patterns of sequence divergence across taxa can illuminate evolutionary processes on a genomic scale. These genome sequences augment the formidable genetic tools that have made Drosophila melanogaster a pre-eminent model for animal genetics, and will further catalyse fundamental research on mechanisms of development, cell biology, genetics, disease, neurobiology, behaviour, physiology and evolution. Despite remarkable similarities among these Drosophila species, we identified many putatively non-neutral changes in protein-coding genes, non-coding RNA genes, and cis-regulatory regions. These may prove to underlie differences in the ecology and behaviour of these diverse species.
2,057 citations
University of California, Berkeley1, Bryn Mawr College2, Food and Agriculture Organization3, San Francisco State University4, University of Rochester5, York University6, University of Reading7, University of Virginia8, University of Bayreuth9, University of Montana10, University of California, Davis11, University of Texas at Austin12, University of Göttingen13, University of California, Santa Barbara14
TL;DR: A conceptual model for exploring how one mobile-agent-based ecosystem service (MABES), pollination, is affected by land-use change, and then generalize the model to other MABES is developed.
Abstract: Many ecosystem services are delivered by organisms that depend on habitats that are segregated spatially or temporally from the location where services are provided. Management of mobile organisms contributing to ecosystem services requires consideration not only of the local scale where services are delivered, but also the distribution of resources at the landscape scale, and the foraging ranges and dispersal movements of the mobile agents. We develop a conceptual model for exploring how one such mobile-agent-based ecosystem service (MABES), pollination, is affected by land-use change, and then generalize the model to other MABES. The model includes interactions and feedbacks among policies affecting land use, market forces and the biology of the organisms involved. Animal-mediated pollination contributes to the production of goods of value to humans such as crops; it also bolsters reproduction of wild plants on which other services or service-providing organisms depend. About onethird of crop production depends on animal pollinators, while 60–90% of plant species require an animal pollinator. The sensitivity of mobile organisms to ecological factors that operate across spatial scales makes the services provided by a given community of mobile agents highly contextual. Services vary, depending on the spatial and temporal distribution of resources surrounding the site, and on biotic interactions occurring locally, such as competition among pollinators for resources, and among plants for pollinators. The value of the resulting goods or services may feed back via market-based forces to influence land-use policies, which in turn influence land management practices that alter local habitat conditions and landscape structure. Developing conceptual
1,277 citations
TL;DR: In this paper, the authors take note of advances in the entrepreneurial cognition research stream and bring increasing attention to the usefulness of entrepreneurship cognition research, and propose a central research question to further enable entrepreneurial cognition inquiry.
Abstract: In this article, we take note of advances in the entrepreneurial cognition research stream. In doing so, we bring increasing attention to the usefulness of entrepreneurial cognition research. First, we offer and develop a central research question to further enable entrepreneurial cognition inquiry. Second, we present the conceptual background and some representative approaches to entrepreneurial cognition research that form the context for this question. Third, we introduce the articles in this Special Issue as framed by the central question and approaches to entrepreneurial cognition research, and suggest how they further contribute to this developing stream. Finally, we offer our views concerning the challenges and opportunities that await the next generation of entrepreneurial cognition scholarship. We therefore invite (and seek to enable) the growing community of entrepreneurship researchers from across multiple disciplines to further develop the “thinking– doing” link in entrepreneurship research. It is our goal to offer colleagues an effective research staging point from which they may embark upon many additional research expeditions and investigations involving entrepreneurial cognition.
762 citations
TL;DR: In two studies, evidence for an anticipatory but not a consummatory pleasure deficit in schizophrenia is found and anticipatory pleasure was related to clinical ratings of anhedonia and functional outcome.
722 citations
TL;DR: Findings point to potential biological pathways, such that well-being can directly bolster immune functioning and buffer the impact of stress, which are not solely due to ill-being having a detrimental impact on health.
Abstract: This research synthesis integrates findings from 150 experimental, ambulatory and longitudinal studies that tested the impact of well-being on objective health outcomes. Results demonstrated that well-being positively impacts health outcomes (r=0.14). Well-being was found to be positively related to short-term health outcomes (r=0.15), long-term health outcomes (r=0.11), and disease or symptom control (r=0.13). Results from the experimental studies demonstrated that inductions of well-being lead to healthy functioning, and inductions of ill-being lead to compromised health at similar magnitudes. Thus, the effect of subjective well-being on health is not solely due to ill-being having a detrimental impact on health, but also to well-being having a salutary impact on health. Additionally, the impact of well-being on improving health was stronger for immune system response and pain tolerance, whereas well-being was not significantly related to increases in cardiovascular and physiological reactivity...
511 citations
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TL;DR: The authors hypothesize that Americans will experience greater family demand, which will have greater impact on work-family conflict, whereas the Chinese will experience higher work demand, and that family demand will have the greater impact in work family conflict.
Abstract: Given differences in values about work and family time, we hypothesize that Americans will experience greater family demand, which will have greater impact on work-family conflict, whereas the Chinese will experience greater work demand, which will have the greater impact on work-family conflict. The results of a survey of working men and women in the two countries generally supported the hypothesis; however, work demand did not differ significantly between the two countries and did not have a greater effect than family demand on work-family conflict in China.
428 citations
TL;DR: In this article, a dyadic perspective is proposed to examine how and why configurations of two firms' resources and capabilities affect the costs and benefits associated with each governance structure, and the likelihood of a pair of firms forming an alliance vs. engaging in an acquisition.
Abstract: For firms seeking to strategically combine their resources with those of other firms, two popular alternative governance structures emerge: alliance or acquisition. In this paper, we propose a dyadic perspective to examine how and why configurations of two firms' resources and capabilities affect the costs and benefits associated with each governance structure. More specifically, we posit that factors such as (1) the resource similarity and complementarity between a pair of firms, (2) the combined relational capabilities of a pair of firms, and (3) the partner-specific knowledge between a pair of firms will affect the likelihood of observing that pair of firms forming an alliance vs. engaging in an acquisition. We test and find support for our hypotheses using extensive longitudinal data from a sample of the largest firms in the United States from 1991 to 2000. Copyright © 2007 John Wiley & Sons, Ltd.
413 citations
TL;DR: In this paper, the authors reported precise Doppler measurements of GJ 317 (M3.5 V) that reveal the presence of a second Jupiter-mass planet with a minimum mass M_P sin i = 1.2 M_(Jup) in an eccentric, 692.9 day orbit.
Abstract: We report precise Doppler measurements of GJ 317 (M3.5 V) that reveal the presence of a planet with a minimum mass M_P sin i = 1.2 M_(Jup) in an eccentric, 692.9 day orbit. GJ 317 is only the third M dwarf with a Doppler-detected Jovian planet. The residuals to a single-Keplerian fit show evidence of a possible second orbital companion. The inclusion of a second Jupiter-mass planet (P ≈ 2700 days, M_P sin i = 0.83 M_(Jup)) decreases √X_v^2 from 2.02 to 1.23, and reduces the rms from 12.5 to 6.32 m s^(-1). A false-alarm test yields a 1.1% probability that the curvature in the residuals of the single-planet fit is due to random fluctuations, lending additional credibility to the two-planet model. However, our data only marginally constrain a two-planet fit, and further monitoring is necessary to fully characterize the properties of the second companion. To study the effect of stellar mass on giant planet occurrence, we measure the fraction of stars with planets in three mass bins comprised of our samples of M Dwarfs, solar-mass stars, and intermediate-mass subgiants. We find a positive correlation between stellar mass and the occurrence rate of Jovian planets within 2.5 AU. Low-mass K and M stars have a 1.8% ± 1.0% planet occurrence rate compared to 4.2% ± 0.7% for solar-mass stars and 8.9% ± 2.9% for the higher mass subgiants. This result indicates that the former F- and A-type stars with M_* ≥ 1.3 M_☉ in our sample are nearly 5 times more likely than the M dwarfs to harbor a giant planet. Our analysis shows that the correlation between Jovian planet occurrence and stellar mass exists even after correcting for the effects of stellar metallicity.
401 citations
TL;DR: It is argued that by embodying novel technologies in objects with specific functional, symbolic, and aesthetic properties, innovating firms also endow their products with cues that trigger a variety of cognitive and emotional responses that underlie initial perceptions of value.
Abstract: Innovation researchers recognize that the uncertainty with regard to the value-creating potential of product innovations increases with their technological novelty, and have argued that the usefulness and value of novel products are socially constructed. Despite this recognition, researchers have not explored how the outer form in which a technological innovation is embodied influences the processes through which the innovation's value is constructed and perceived. In this paper we argue that by embodying novel technologies in objects with specific functional, symbolic, and aesthetic properties, innovating firms also endow their products with cues that trigger a variety of cognitive and emotional responses. Drawing on psychological research we articulate how such cognitive and emotional responses underlie initial perceptions of value and theorize how innovating firms can influence them through product form design. Our framework explains how product form contributes to perceptions of value by modulating the actual technological novelty of a product innovation and facilitating how customers cope with it. Our theoretical framework makes an important contribution to innovation research and practice because it articulates how product form can be used strategically to achieve specific cognitive and emotional effects and enhance the initial customer perceptions of the value of an innovation.
386 citations
TL;DR: In this article, the authors derived detailed theoretical models for 1074 nearby stars from the Spectroscopic Properties of Cool Stars (SPOCS) catalog and derived the likelihood for each set of stellar model parameters separated by uniform time steps along the stellar evolutionary tracks.
Abstract: We derive detailed theoretical models for 1074 nearby stars from the SPOCS (Spectroscopic Properties of Cool Stars) Catalog. The California and Carnegie Planet Search has obtained high-quality (R 70,000-90,000, S/N 300-500) echelle spectra of over 1000 nearby stars taken with the Hamilton spectrograph at Lick Observatory, the HIRES spectrograph at Keck, and UCLES at the Anglo Australian Observatory. A uniform analysis of the high-resolution spectra has yielded precise stellar parameters (Teff, log g, v sin i, [M/H], and individual elemental abundances for Fe, Ni, Si, Na, and Ti), enabling systematic error analyses and accurate theoretical stellar modeling. We have created a large database of theoretical stellar evolution tracks using the Yale Stellar Evolution Code (YREC) to match the observed parameters of the SPOCS stars. Our very dense grids of evolutionary tracks eliminate the need for interpolation between stellar evolutionary tracks and allow precise determinations of physical stellar parameters (mass, age, radius, size and mass of the convective zone, surface gravity, etc.). Combining our stellar models with the observed stellar atmospheric parameters and uncertainties, we compute the likelihood for each set of stellar model parameters separated by uniform time steps along the stellar evolutionary tracks. The computed likelihoods are used for a Bayesian analysis to derive posterior probability distribution functions for the physical stellar parameters of interest. We provide a catalog of physical parameters for 1074 stars that are based on a uniform set of high-quality spectral observations, a uniform spectral reduction procedure, and a uniform set of stellar evolutionary models. We explore this catalog for various possible correlations between stellar and planetary properties, which may help constrain the formation and dynamical histories of other planetary systems.
364 citations
TL;DR: A new coding scheme is described to evaluate sexual content from a feminist perspective and captures depictions of boys/men and girls/women thinking, feeling, and behaving in relational and sexual encounters in ways that sustain power inequalities between men and women.
Abstract: Although it is widely recognized that sexual content pervades television, research rarely examines how television's sexual messages are gendered and occur in a relational context This study describes the development and implementation of a new coding scheme to evaluate sexual content from a feminist perspective Merging scripting theory (Simon and Gagnon, 1986) with the theory of compulsory heterosexuality (Rich, 1980), we explicate a heteronormative and dominant sexual script, the Heterosexual Script, and assessed its presence in the 25 primetime television programs viewed most frequently by adolescents Our codes captured depictions of boys/men and girls/women thinking, feeling, and behaving in relational and sexual encounters in ways that sustain power inequalities between men and women Male characters most frequently enacted the Heterosexual Script by actively and aggressively pursuing sex Less frequently but still at high rates were depictions of female characters willingly objectifying themselves
TL;DR: In this article, the authors reported precision Doppler measurements of three intermediate-mass subgiants obtained at Lick and Keck Observatories, and found a planet with a minimum mass M_P sin i = 2.5 M_J in a 351.5 day orbit around HD 192699, a planet of 2.0 M.M.
Abstract: We report precision Doppler measurements of three intermediate-mass subgiants obtained at Lick and Keck Observatories. All three stars show variability in their radial velocities consistent with planet-mass companions in Keplerian orbits. We find a planet with a minimum mass M_P sin i = 2.5 M_J in a 351.5 day orbit around HD 192699, a planet with a minimum mass of 2.0 M_J in a 341.1 day orbit around HD 210702, and a planet with a minimum mass of 0.61 M_J in a 297.3 day orbit around HD 175541. Mass estimates from stellar interior models indicate that all three stars were formerly A-type, main-sequence dwarfs with masses ranging from 1.65 to 1.85 M_☉. These three long-period planets would not have been detectable during their stars' main-sequence phases due to the large rotational velocities and stellar jitter exhibited by early-type dwarfs. There are now nine "retired" (evolved) A-type stars (M_* > 1.6 M_☉) with known planets. All nine planets orbit at distances ɑ ≥ 0.78 AU, which is significantly different from the semimajor axis distribution of planets around lower mass stars.
TL;DR: While strategy and organizational researchers increasingly recognize that observers' perceptions and beliefs about firms have a substantive effect on firms' access to resources and performance, the authors in this paper pointed out that the...
Abstract: While strategy and organizational researchers increasingly recognize that observers' perceptions and beliefs about firms have a substantive effect on firms' access to resources and performance, the...
College of Charleston1, Clemson University2, Boston University3, San Francisco State University4, Duke University5, University of Florida6, University of Rhode Island7, Woods Hole Oceanographic Institution8, St. Francis Xavier University9, Wilfrid Laurier University10, United States Environmental Protection Agency11, University of Miami12, University of New Orleans13, University of Waterloo14, Mount Desert Island Biological Laboratory15, College of William & Mary16, Louisiana State University17, University of Georgia18
TL;DR: It is suggested that a more complete genomics toolbox for F. heteroclitus and related species will permit researchers to exploit the power of this model organism to rapidly advance the understanding of fundamental biological and pathological mechanisms among vertebrates, as well as ecological strategies and evolutionary processes common to all living organisms.
TL;DR: In this article, the authors used small automated telescopes in Arizona and Hawaii to detect an object transiting one member of the double star system ADS 16402, which is a pair of G0 main-sequence stars with age about 3 Gyr at a distance of ~139 pc and projected separation of ~1550 AU.
Abstract: Using small automated telescopes in Arizona and Hawaii, the HATNet project has detected an object transiting one member of the double star system ADS 16402. This system is a pair of G0 main-sequence stars with age about 3 Gyr at a distance of ~139 pc and projected separation of ~1550 AU. The transit signal has a period of 4.46529 days and depth of 0.015 mag. From follow-up photometry and spectroscopy, we find that the object is a "hot Jupiter" planet with mass about 0.53M_J and radius ~1.36R_J traveling in an orbit with semimajor axis 0.055 AU and inclination about 85.9°, thus transiting the star at impact parameter 0.74 of the stellar radius. Based on a data set spanning 3 yr, ephemerides for the transit center are T_C = 2453984.397 + N_(tr) × 4.46529. The planet, designated HAT-P-1b, appears to be at least as large in radius, and smaller in mean density, than any previously known planet.
TL;DR: The surface modified iron nanoparticles (S-INP) were synthesized, characterized and tested for the remediation of arsenite (As(III)), a well known toxic groundwater contaminant of concern as discussed by the authors.
Abstract: The surface-modified iron nanoparticles (S-INP) were synthesized, characterized and tested for the remediation of arsenite (As(III)), a well known toxic groundwater contaminant of concern. The S-INP material was fully dispersed in the aqueous phase with a particle size distribution of 2–10 nm estimated from high-resolution transmission electron microscopy (HR-TEM). X-ray photoelectron spectroscopy (XPS) revealed that an Fe(III) oxide surface film was present on S-INP in addition to the bulk zero-valent Fe0 oxidation state. Transport of S-INP through porous media packed in 10 cm length column showed particle breakthroughs of 22.1, 47.4 and 60 pore volumes in glass beads, unbaked sand, and baked sand, respectively. Un-modified INP was immobile and aggregated on porous media surfaces in the column inlet area. Results using S-INP pretreated 10 cm sand-packed columns containing ∼2 g of S-INP showed that 100 % of As(III) was removed from influent solutions (flow rate 1.8 mL min−1) containing 0.2, 0.5 and 1.0 mg L−1 As(III) for 9, 7 and 4 days providing 23.3, 20.7 and 10.4 L of arsenic free water, respectively. In addition, it was found that 100% of As(III) in 0.5 mg/L solution (flow rate 1.8 mL min−1) was removed by S-INP pretreated 50 cm sand packed column containing 12 g of S-INP for more than 2.5 months providing 194.4 L of arsenic free water. Field emission scanning electron microscopy (FE-SEM) showed S-INP had transformed to elongated, rod-like shaped corrosion product particles after reaction with As(III) in the presence of sand. These results suggest that S-INP has great potential to be used as a mobile, injectable reactive material for in-situ sandy groundwater aquifer treatment of As(III).
TL;DR: It is argued that individual behaviors are the products of the interaction between culture, culture, social roles, and personality and that situational context moderates the relative contributions of the three sources in influencing behavior.
Abstract: In this article I propose a model that posits three major sources of influence on behavior-basic human nature (via universal psychological processes), culture (via social roles), and personality (via individual role identities) and argue that individual behaviors are the products of the interaction between the three. I discuss how culture emerges from the interaction of basic human nature and the ecological contexts in which groups exist, and how social roles are determined by culture-specific psychological meanings attributed to situational contexts. The model further suggests that situational context moderates the relative contributions of the three sources in influencing behavior. I provide examples of apparent contradictory findings in the study of emotion that can be explained by the model proposed.
TL;DR: In this paper, a study of welders working on a new span of the San Francisco-Oakland Bay Bridge without adequate protection was performed using a multidisciplinary method to identify the dose-effect relationship between adverse health effects and Mn in air or whole blood.
Abstract: Background: Although adverse neuropsychological and neurological health effects are well known among workers with high manganese (Mn) exposures in mining, ore-processing and ferroalloy production, the risks among welders with lower exposures are less well understood. Methods: Confined space welding in construction of a new span of the San Francisco-Oakland Bay Bridge without adequate protection was studied using a multidisciplinary method to identify the dose-effect relationship between adverse health effects and Mn in air or whole blood. Bridge welders (n = 43) with little or no personal protection equipment and exposed to a welding fume containing Mn, were administered neurological, neuropsychological, neurophysiological and pulmonary tests. Outcome variables were analysed in relation to whole blood Mn (MnB) and a Cumulative Exposure Index (CEI) based on Mn-air, duration and type of welding. Welders performed a mean of 16.5 months of welding on the bridge, were on average 43.8 years of age and had on average 12.6 years of education. Results: The mean time weighted average of Mn-air ranged from 0.11-0.46 mg/m(3) (55% > 0.20 mg/m(3)). MnB > 10 mu g/l was found in 43% of the workers, but the concentrations of Mn in urine, lead in blood and copper and iron in plasma were normal. Forced expiratory volume at 1s: forced vital capacity ratios (FEV1/FVC) were found to be abnormal in 33.3% of the welders after about 1.5 years of welding at the bridge. Mean scores of bradykinesia and Unified Parkinson Disease Rating Scale exceeded 4 and 6, respectively. Computer assisted tremor analysis system hand tremor and body sway tests, and University of Pennsylvania Smell Identification Test showed impairment in 38.5/61.5, 51.4 and 88% of the welders, respectively. Significant inverse dose-effect relationships with CEI and/or MnB were found for IQ (p <= 0.05), executive function (p <= 0.03), sustaining concentration and sequencing (p <= 0.04), verbal learning (p <= 0.01), working (p <= 0.04) and immediate memory (p <= 0.02), even when adjusted for demographics and years of welding before Bay Bridge. Symptoms reported by the welders while working were: tremors (41.9%); numbness (60.5%); excessive fatigue (65.1%); sleep disturbance (79.1%); sexual dysfunction (58.1%); toxic hallucinations (18.6%); depression (53.5%); and anxiety (39.5%). Dose-effect associations between CEI and sexual function (p < 0.05), fatigue (p < 0.05), depression (p < 0.01) and headache (p < 0.05) were statistically significant. Conclusions: Confined space welding was shown to be associated with neurological, neuropsychological and pulmonary adverse health effects. A careful enquiry of occupational histories is recommended for all welders presenting with neurological or pulmonary complaints, and a more stringent prevention strategy should be considered for Mn exposure due to inhalation of welding fume.
TL;DR: In this paper, a detailed analysis of spring blooms in three embayments of San Francisco Bay over 3 years shows a consistent sequence of events that result in bursts of chlorophyll.
Abstract: The substantial inventory of nitrate (NO3) in San Francisco Bay (SFB) is unavailable to the resident phytoplankton most of the year due to the presence of ammonium (NH4) at inhibitory concentrations that prevents NO3 uptake. Low annual primary productivity in this turbid estuary is generally attributed to the poor irradiance conditions. However, this may not be the only cause; spring phytoplankton blooms occur irregularly in north SFB only when NH4 concentrations are low, <4 mmol L � 1 and NO3 uptake by phytoplankton occurs. Field measurements and enclosure experiments confirm the NH4 inhibition process to be the cause of low NO3 utilization most of the year. Detailed analysis of spring blooms in three embayments of SFB over 3 years shows a consistent sequence of events that result in bursts of chlorophyll. The first requirement is improved irradiance conditions through stabilization of the water column by stratification or reduced tidal activity. Second, NH4 concentrations must be reduced to a critical range, 1 to 4 mmol L � 1 through dilution by precipitation and by phytoplankton uptake. This enables rapid uptake of NO3 and subsequent increase in chlorophyll. The resulting bloom is due to both the initial uptake of NH4 and the subsequent uptake of NO3. The NO3 uptake step is crucial since it is the larger nitrogen source and uptake occurs at higher rates than that for NH4 at the concentrations that occur in SFB. Existing models of light-limited, non-nutrient limited productivity in SFB require modification to include the NH4 inhibition effect. From measured NH4 uptake rates and initial concentrations, calculations can be made to predict the length of time that favorable irradiance conditions are required for the phytoplankton population to reduce ambient NH4 concentrations to non-inhibiting concentrations and allow bloom formation to begin. For Suisun Bay, the time required is so long that blooms are unlikely in any season. For San Pablo and Central Bays, these times are too long in summer but sufficiently short in spring to allow bloom development, depending on the ambient NH4 concentration prior to the productivity season. NH4 sources to SFB are primarily anthropogenic, from agricultural drainage and sewage treatment plants, and if not sufficiently diluted by runoff and precipitation can prevent development of the spring phytoplankton bloom. Attention should be paid to the form of N making up dissolved inorganic nitrogen (DIN) in nutrient-rich estuaries. 2007 Elsevier Ltd. All rights reserved.
TL;DR: This article argued that African-American and Latina/o youth respond to community and school conditions through civic engagement facilitated by community-based organizations, such as youth organizing, spoken word, volunteering, and participation in civic affairs.
Abstract: Research on African‐American and Latina/o youth has been dominated by studies that focus on ‘problem’ adolescent behavior. Typically, they explain youth crime, delinquency, and violence as individual pathological behavior or cultural adaptations stemming from social disorganization in their communities. This article argues for a more nuanced understanding of the relationship between youth‐serving organizations and youth agency in urban communities, which can avoid the pitfall of focusing on the most egregious activities among youth. Rather, it is argued that African‐American and Latina/o youth respond to community and school conditions through civic engagement facilitated by community‐based organizations. Urban youth collectively respond to community and school problems through youth organizing, spoken word, volunteering, and participation in civic affairs. Organizations in urban communities can provide youth with opportunities to develop critical civic praxis through engagement with ideas, social network...
TL;DR: In this paper, the authors used a laboratory flume to investigate experimentally how bedrock channel slope, width, roughness, alluvial cover, and incision rate collectively adjusted during the transient incision of an initially smooth channel with a varying bed load supply rate.
Abstract: [1] In transient landscapes, adjustments in river channel width, roughness, and alluvial cover, in addition to slope, provide potentially important but poorly understood mechanisms by which bedrock channels accommodate changes in external forcing. We used a laboratory flume to investigate experimentally how bedrock channel slope, width, roughness, alluvial cover, and incision rate collectively adjusted during the transient incision of an initially smooth channel with a varying bed load supply rate. When the channel was free of alluvial cover, incision was focused over a fraction of the bed width that varied strongly with both bed load supply and bed load transport capacity. Nondimensionalization yields a relationship for the width of active incision that explicitly incorporates bed load supply rate, sediment grain size, and bed shear stress, which suggests that in natural channels, width may respond dynamically to accommodate changes in bed load sediment supply. Because increases in sediment supply widened the band of active bed load sediment transport and thus the width over which incision took place, mass removal from the bed scaled with sediment supply when the bed was free of cover, consistent with incision being limited by the availability of erosive tools. However, bed roughness growth due to the spatial variation of incision during the experiment eventually inhibited bed load transport efficiency. This, in turn, led to deposition of alluvial cover and the suppression of incision on the bed at high sediment supply rates, consistent with incision being limited by the extent of alluvial cover deposited on the bed. The dynamics of roughness creation and alluvial cover deposition can therefore drive both negative and positive feedbacks on incision rate change following sediment supply perturbations. These experimental results offer several potentially field-testable hypotheses that together may help explain variability in the width, slope, and bed roughness of bedrock river channels in transient landscapes.
TL;DR: The estimates developed in this study are consistent with a hypothesis of high overall fungal species diversity and are in line with a calculated estimate of between 53,000 and 110,000 macrofungal species derived using plant/macrofungAL species ratio data.
Abstract: Data on macrofungal diversity and distribution patterns were compiled for major geographical regions of the world. Macrofungi are defined here to include ascomycetes and basidiomycetes with large, easily observed spore-bearing structures that form above or below ground. Each coauthor either provided data on a particular taxonomic group of macrofungi or information on the macrofungi of a specific geographic area. We then employed a meta-analysis to investigate species overlaps between areas, levels of endemism, centers of diversity, and estimated percent of species known for each taxonomic group for each geographic area and for the combined macrofungal data set. Thus, the study provides both a meta-analysis of current data and a gap assessment to help identify research needs. In all, 21,679 names of macrofungi were compiled. The percentage of unique names for each region ranged from 37% for temperate Asia to 72% for Australasia. Approximately 35,000 macrofungal species were estimated to be “unknown” by the contributing authors. This would give an estimated total of 56,679 macrofungi. Our compiled species list does not include data from most of S.E. Europe, Africa, western Asia, or tropical eastern Asia. Even so, combining our list of names with the estimates from contributing authors is in line with our calculated estimate of between 53,000 and 110,000 macrofungal species derived using plant/macrofungal species ratio data. The estimates developed in this study are consistent with a hypothesis of high overall fungal species diversity.
TL;DR: In this paper, the authors combine spectroscopic and photometric data for subgiant stars of ω Cen to extract results that neither data set could have provided on its own.
Abstract: We combine spectroscopic and photometric data for subgiant stars of ω Cen to extract results that neither data set could have provided on its own. GIRAFFE@VLT spectra of 80 stars at R = 6400 give metallicities for all of them and abundances of C, N, Ca, Ti, and Ba for a subset of them. The photometric data, which have unusually high accuracy, come from a ~10 × 10 arcmin2 mosaic of HST ACS images centered on the cluster center and on multicolor images of a ~34 × 33 arcmin2 field, taken with the WFI@ESO2.2m camera. Stars with [Fe/H] < -1.25 have a large magnitude spread on the flat part of the SGB. We interpret this as empirical evidence for an age spread, and from theoretical isochrones we derive a relative age for each star. Within the SGB region we identify four distinct stellar groups: (1) an old, metal-poor group ([Fe/H] ~ -1.7); (2) an old, metal-rich group ([Fe/H] ~ -1.1); (3) a young (up to 4-5 Gyr younger than the old component) metal-poor group ([Fe/H] ~ -1.7); (4) a young, intermediate-metallicity ([Fe/H] ~ -1.4) group, on average 1-2 Gyr younger than the old metal-poor population, and with an age spread that we cannot properly quantify with the present sample. In addition, many SGB stars are spread between the intermediate-metallicity and metal-rich branches. We tentatively propose connections between the SGB stars and both the multiple main-sequence and the red giant branches. Finally, we discuss the implications of the multiple stellar populations on the formation and evolution of ω Cen. The spread in age within each population establishes that the original system must have had a composite nature.
TL;DR: In this paper, the authors reported the discovery of a massive (M_p = 9.04 ± 0.50 M_J) planet transiting the bright F8 star HD 147506, with an orbital period of 5.63341 ±0.00013 days and an eccentricity of e = 0.520 ± 0.010.
Abstract: We report the discovery of a massive (M_p = 9.04 ± 0.50 M_J) planet transiting the bright (V = 8.7) F8 star HD 147506, with an orbital period of 5.63341 ± 0.00013 days and an eccentricity of e = 0.520 ± 0.010. From the transit light curve we determine that the radius of the planet is R_p = 0.982^(+0.038)_(-0.105) R_J. HD 147506b (also coined HAT-P-2b) has a mass about 9 times the average mass of previously known transiting exoplanets and a density of ρp ≈ 12 g cm^(-3), greater than that of rocky planets like the Earth. Its mass and radius are marginally consistent with theories of structure of massive giant planets composed of pure H and He, and accounting for them may require a large (≳100 M_⊕) core. The high eccentricity causes a ninefold variation of insolation of the planet between peri- and apastron. Using follow-up photometry, we find that the center of transit is T_(mid) = 2,454,212.8559 ± 0.0007 (HJD) and the transit duration is 0.177 ± 0.002 days.
TL;DR: The QPCR study showed the dominance of H. hauckii-Richelia symbioses in the Amazon plume waters, implying that these associations had an ecological advantage over the other diazotrophic communities along gradients of salinity and nutrients in the WTNA.
Abstract: The vertical and horizontal distributions of seven diazotrophic populations in the western tropical north Atlantic (WTNA) Ocean were examined using a nifH DNA quantitative polymerase chain reaction (QPCR) approach. The nifH phylotype abundances were highest near the surface and decreased with depth, with the exception of the cyanobacterial symbiont Calothrix, which was not detected at any station. Richelia associated with the diatoms Rhizosolenia clevei and Hemiaulus hauckii were distributed within the freshwater lens of the Amazon plume. Abundances of H. hauckii-Richelia nifH genes dominated all depths in 6 of 10 vertical profiles and 10 of 20 surface samples. In addition, estimates of Richelia associated with H. hauckii increased northwest (8– 12uN, 56–54uW) from the river mouth, where significantly ( p , 0.001) higher abundances (.105 copies L–1) were found in mesohaline waters (31–34.9). nifH copy abundance for surface populations of the H. hauckii-Richelia symbioses were positively correlated (r2 5 0.59) with salinity. Three unicellular cyanobacterial groups and Trichodesmium had similar horizontal distributions, where the highest nifH copy estimates were at stations with salinity $35 and northeast (6–10u N5 0uW) of the freshwater lens. The abundance of Trichodesmium spp. and unicellular Group B nifH gene copies co-varied (r2 5 0.60). The QPCR study showed the dominance of H. hauckii-Richelia symbioses in the Amazon plume waters, implying that these associations had an ecological advantage over the other diazotrophs. Outside of the plume nutrients were below detection, abundances of freeliving unicellular cyanobacterial phylotypes, including a novel group designated Group C, were abundant (.105 copies L21) and comparable to the abundances of Trichodesmium spp. Thus, there appeared to be a cascade of diazotrophic communities along gradients of salinity and nutrients in the WTNA.
TL;DR: Improved methods revealed that more than 77% of this heterochromatin sequence, including introns and intergenic regions, is composed of fragmented and nested transposable elements and other repeated DNAs.
Abstract: The repetitive DNA that constitutes most of the heterochromatic regions of metazoan genomes has hindered the comprehensive analysis of gene content and other functions. We have generated a detailed computational and manual annotation of 24 megabases of heterochromatic sequence in the Release 5 Drosophila melanogaster genome sequence. The heterochromatin contains a minimum of 230 to 254 protein-coding genes, which are conserved in other Drosophilids and more diverged species, as well as 32 pseudogenes and 13 noncoding RNAs. Improved methods revealed that more than 77% of this heterochromatin sequence, including introns and intergenic regions, is composed of fragmented and nested transposable elements and other repeated DNAs. Drosophila heterochromatin contains “islands” of highly conserved genes embedded in these “oceans” of complex repeats, which may require special expression and splicing mechanisms.
TL;DR: Higher levels of mental distress in effeminate men seemed to primarily result from more experiences of homophobia, suggesting the need for more attention to gender in research as well as counseling of sexual minority men.
Abstract: This study explored whether gender nonconformity in gay and bisexual men is related to mental distress and if so, whether this relationship is mediated by negative experiences that are likely associated with gender nonconformity, including abuse and harassment. To study this question, data were analyzed from face-to face interviews with 912 self-identified gay and bisexual Latino men in three major U.S. cities collected by Diaz and colleagues (2001). Gay and bisexual Latino men who considered themselves to be effeminate had higher levels of mental distress and more frequently reported various negative experiences, compared with gay and bisexual Latino men who did not identify as effeminate. Higher levels of mental distress in effeminate men seemed to primarily result from more experiences of homophobia. Findings suggest the need for more attention to gender in research as well as counseling of sexual minority men.
TL;DR: In this paper, the authors consider theories of teaching in urban contexts by examining effective practices in urban classrooms and outline an original framework of five indicators of effective teaching in cities and use examples from practice to illustrate those indicators and their relationship to increased achievement.
Abstract: Drawing from three years of research in the classrooms of four highly effective elementary and secondary teachers in South Los Angeles, this article considers theories of teaching in urban contexts by examining effective practices in urban classrooms. It outlines an original framework of five indicators of effective teaching in urban schools and uses examples from practice to illustrate those indicators and their relationship to increased achievement. Finally, it discusses possibilities for better preparation and development of teachers in these areas of their practice.
TL;DR: This paper analyzes various approaches to defining andness and orness, and uses a generalized conjunction/disjunction (GCD) to build compound preference logic functions and logic models for system evaluation.
Abstract: In this paper, we investigate mathematical models that are suitable for modeling decisions in the area of system evaluation, comparison, and selection. Our interest is focused on soft computing models that can be directly related to observable properties of human reasoning, and have a record of use in system evaluation practice. We analyze various approaches to defining andness and orness, and use a generalized conjunction/disjunction (GCD) to build compound preference logic functions and logic models for system evaluation. We also present applications of the continuous preference logic in decision models based on the LSP method.
TL;DR: This article explored the process by which formal management systems foster the creation of shared organization values, addressing the basic question: Can workplace values be "managed?" Drawing upon interviews conducted at a Department of Defense installation with civilian employees and managers over a 5-year period, they use comparative case analysis to explore differences in the relationships between installation practices and social values across high-performing and low-performing work units.
Abstract: This article explores the process by which formal management systems foster the creation of shared organization values, addressing the basic question: Can workplace values be "managed?" Drawing upon interviews conducted at a Department of Defense installation with civilian employees and managers over a 5-year period, we use comparative case analysis to explore differences in the relationships between installation practices and social values across high-performing and low-performing work units. Our findings suggest that strategic values are motivating to employees to the extent that they reflect employees' internal affective, normative, and task-oriented values, a zone of existing values. Although values management is a social process that results from routine interactions, formal management systems provide opportunities to enhance the social interactions that are motivating to employees. Middle managers play key roles in using formal management systems to integrate the organization's strategic practices with values that derive from employees' societal, cultural, and religious experiences.