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Showing papers by "University of Georgia published in 2008"


Journal ArticleDOI
21 Feb 2008-Nature
TL;DR: It is concluded that global resources to counter disease emergence are poorly allocated, with the majority of the scientific and surveillance effort focused on countries from where the next important EID is least likely to originate.
Abstract: Emerging infectious diseases (EIDs) are a significant burden on global economies and public health. Their emergence is thought to be driven largely by socio-economic, environmental and ecological factors, but no comparative study has explicitly analysed these linkages to understand global temporal and spatial patterns of EIDs. Here we analyse a database of 335 EID 'events' (origins of EIDs) between 1940 and 2004, and demonstrate non-random global patterns. EID events have risen significantly over time after controlling for reporting bias, with their peak incidence (in the 1980s) concomitant with the HIV pandemic. EID events are dominated by zoonoses (60.3% of EIDs): the majority of these (71.8%) originate in wildlife (for example, severe acute respiratory virus, Ebola virus), and are increasing significantly over time. We find that 54.3% of EID events are caused by bacteria or rickettsia, reflecting a large number of drug-resistant microbes in our database. Our results confirm that EID origins are significantly correlated with socio-economic, environmental and ecological factors, and provide a basis for identifying regions where new EIDs are most likely to originate (emerging disease 'hotspots'). They also reveal a substantial risk of wildlife zoonotic and vector-borne EIDs originating at lower latitudes where reporting effort is low. We conclude that global resources to counter disease emergence are poorly allocated, with the majority of the scientific and surveillance effort focused on countries from where the next important EID is least likely to originate.

5,992 citations


Journal ArticleDOI
13 Mar 2008-Nature
TL;DR: A map at single-base-pair resolution of methylated cytosines for Arabidopsis is generated by combining bisulphite treatment of genomic DNA with ultra-high-throughput sequencing using the Illumina 1G Genome Analyser and Solexa sequencing technology.
Abstract: Cytosine DNA methylation is important in regulating gene expression and in silencing transposons and other repetitive sequences. Recent genomic studies in Arabidopsis thaliana have revealed that many endogenous genes are methylated either within their promoters or within their transcribed regions, and that gene methylation is highly correlated with transcription levels. However, plants have different types of methylation controlled by different genetic pathways, and detailed information on the methylation status of each cytosine in any given genome is lacking. To this end, we generated a map at single-base-pair resolution of methylated cytosines for Arabidopsis, by combining bisulphite treatment of genomic DNA with ultra-high-throughput sequencing using the Illumina 1G Genome Analyser and Solexa sequencing technology. This approach, termed BS-Seq, unlike previous microarray-based methods, allows one to sensitively measure cytosine methylation on a genome-wide scale within specific sequence contexts. Here we describe methylation on previously inaccessible components of the genome and analyse the DNA methylation sequence composition and distribution. We also describe the effect of various DNA methylation mutants on genome-wide methylation patterns, and demonstrate that our newly developed library construction and computational methods can be applied to large genomes such as that of mouse.

2,108 citations


Journal ArticleDOI
28 Nov 2008-Science
TL;DR: High-contrast observations with the Keck and Gemini telescopes have revealed three planets orbiting the star HR 8799, with projected separations of 24, 38, and 68 astronomical units.
Abstract: Direct imaging of exoplanetary systems is a powerful technique that can reveal Jupiter-like planets in wide orbits, can enable detailed characterization of planetary atmospheres, and is a key step toward imaging Earth-like planets. Imaging detections are challenging because of the combined effect of small angular separation and large luminosity contrast between a planet and its host star. High-contrast observations with the Keck and Gemini telescopes have revealed three planets orbiting the star HR 8799, with projected separations of 24, 38, and 68 astronomical units. Multi-epoch data show counter clockwise orbital motion for all three imaged planets. The low luminosity of the companions and the estimated age of the system imply planetary masses between 5 and 13 times that of Jupiter. This system resembles a scaled-up version of the outer portion of our solar system.

1,966 citations


Journal ArticleDOI
TL;DR: New developments in understanding pectin structure, function, and biosynthesis indicate that these polysaccharides have roles in both primary and secondary cell walls.

1,810 citations


Journal ArticleDOI
TL;DR: It is demonstrated that deriving dihedral parameters by fitting to QM data for internal rotational energy curves for representative small molecules generally leads to correct rotamer populations in molecular dynamics simulations, and that this approach removes the need for phase corrections in the dihedral terms.
Abstract: A new derivation of the GLYCAM06 force field, which removes its previous specificity for carbohydrates, and its dependency on the AMBER force field and parameters, is presented. All pertinent force field terms have been explicitly specified and so no default or generic parameters are employed. The new GLYCAM is no longer limited to any particular class of biomolecules, but is extendible to all molecular classes in the spirit of a small-molecule force field. The torsion terms in the present work were all derived from quantum mechanical data from a collection of minimal molecular fragments and related small molecules. For carbohydrates, there is now a single parameter set applicable to both alpha- and beta-anomers and to all monosaccharide ring sizes and conformations. We demonstrate that deriving dihedral parameters by fitting to QM data for internal rotational energy curves for representative small molecules generally leads to correct rotamer populations in molecular dynamics simulations, and that this approach removes the need for phase corrections in the dihedral terms. However, we note that there are cases where this approach is inadequate. Reported here are the basic components of the new force field as well as an illustration of its extension to carbohydrates. In addition to reproducing the gas-phase properties of an array of small test molecules, condensed-phase simulations employing GLYCAM06 are shown to reproduce rotamer populations for key small molecules and representative biopolymer building blocks in explicit water, as well as crystalline lattice properties, such as unit cell dimensions, and vibrational frequencies.

1,751 citations


Journal ArticleDOI
04 Jan 2008-Science
TL;DR: This comparison reveals genomic changes concomitant with the evolutionary movement to land, including a general increase in gene family complexity; loss of genes associated with aquatic environments; acquisition of genes for tolerating terrestrial stresses; and the development of the auxin and abscisic acid signaling pathways for coordinating multicellular growth and dehydration response.
Abstract: We report the draft genome sequence of the model moss Physcomitrella patens and compare its features with those of flowering plants, from which it is separated by more than 400 million years, and unicellular aquatic algae. This comparison reveals genomic changes concomitant with the evolutionary movement to land, including a general increase in gene family complexity; loss of genes associated with aquatic environments (e.g., flagellar arms); acquisition of genes for tolerating terrestrial stresses (e.g., variation in temperature and water availability); and the development of the auxin and abscisic acid signaling pathways for coordinating multicellular growth and dehydration response. The Physcomitrella genome provides a resource for phylogenetic inferences about gene function and for experimental analysis of plant processes through this plant's unique facility for reverse genetics.

1,749 citations


Journal ArticleDOI
TL;DR: Soil pH was the best predictor of bacterial community composition across this landscape while fungal community composition was most closely associated with changes in soil nutrient status, suggesting specific changes in edaphic properties, not necessarily land-use type itself, may best predict shifts in microbialcommunity composition across a given landscape.
Abstract: Land-use change can have significant impacts on soil conditions and microbial communities are likely to respond to these changes. However, such responses are poorly characterized as few studies have examined how specific changes in edaphic characteristics do, or do not, influence the composition of soil bacterial and fungal communities across land-use types. Soil samples were collected from four replicated ( n = 3) land-use types (hardwood and pine forests, cultivated and livestock pasture lands) in the southeastern US to assess the effects of land-use change on microbial community structure and distribution. We used quantitative PCR to estimate bacterial–fungal ratios and clone libraries targeting small-subunit rRNA genes to independently characterize the bacterial and fungal communities. Although some soil properties (soil texture and nutrient status) did significantly differ across land-use types, other edaphic factors (e.g., pH) did not vary consistently with land-use. Bacterial–fungal ratios were not significantly different across the land-uses and distinct land-use types did not necessarily harbor distinct soil fungal or bacterial communities. Rather, the composition of bacterial and fungal communities was most strongly correlated with specific soil properties. Soil pH was the best predictor of bacterial community composition across this landscape while fungal community composition was most closely associated with changes in soil nutrient status. Together these results suggest that specific changes in edaphic properties, not necessarily land-use type itself, may best predict shifts in microbial community composition across a given landscape. In addition, our results demonstrate the utility of using sequence-based approaches to concurrently analyze bacterial and fungal communities as such analyses provide detailed phylogenetic information on individual communities and permit the robust assessment of the biogeographical patterns exhibited by soil microbial communities.

1,420 citations


Journal ArticleDOI
TL;DR: In this paper, the authors examined the corporate board structure, trends, and determinants, and found that board structure across firms is consistent with the costs and benefits of the board's monitoring and advising roles.

1,275 citations


Journal ArticleDOI
TL;DR: It is concluded that the enumeration of white blood cells from blood smears can provide a reliable assessment of stress in all vertebrate taxa because of the universal and consistent nature of the haematological response to stress.
Abstract: Summary 1. A growing number of ecologists are turning to the enumeration of white blood cells from blood smears (leukocyte profiles) to assess stress in animals. There has been some inconsistency and controversy in the ecological literature, however, regarding their interpretation. The inconsistencies may stem partly from a lack of information regarding how stress affects leukocytes in different taxa, and partly from a failure on the part of researchers in one discipline to consult potentially informative literature from another. 2. Here, we seek to address both issues by reviewing the literature on the leukocyte response to stress, spanning the taxa of mammals (including humans), birds, amphibians, reptiles and fish. 3. We show that much of the early literature points to a close link between leukocyte profiles and glucocorticoid levels. Specifically, these hormones act to increase the number and percentage of neutrophils (heterophils in birds and reptiles), while decreasing the number and percentage of lymphocytes. This phenomenon is seen in all five vertebrate taxa in response to either natural stressors or exogenous administration of stress hormones. For the ecologist, therefore, high ratios of heterophils or neutrophils to lymphocytes (‘H : L’ or ‘N : L’ ratios) in blood samples reliably indicate high glucocorticoid levels. Furthermore, this close relationship between stress hormones and N : L or H : L ratios needs to be highlighted more prominently in haematological assessments of stress, as it aids the interpretation of results. 4. As with hormone assays, there are challenges to overcome in the use of leukocytes profiles to assess levels of stress; however, there are also advantages to this approach, and we outline each. Given the universal and consistent nature of the haematological response to stress, plus the overwhelming evidence from the veterinary, biomedical and ecological literature reviewed here, we conclude that this method can provide a reliable assessment of stress in all vertebrate taxa.

1,219 citations


Journal ArticleDOI
13 Mar 2008-Nature
TL;DR: It is demonstrated that excess nitrate in streams elicits a disproportionate increase in the fraction of nitrate that is exported to receiving waters and reduces the relative role of small versus large streams as nitrate sinks.
Abstract: About a quarter of the nitrogen added to the biosphere is exported from rivers to the ocean or inland basins, indicating substantial sinks for nitrogen must exist in the landscape. Data from nitrogen stable isotope tracer experiments across 72 streams suggests that the total uptake of nitrate is related to ecosystem photosynthesis, and that denitrification is related to ecosystem respiration. A stream network model demonstrates that excess nitrate in streams elicits a disproportionate increase in the fraction of nitrate that is exported to receiving waters and reduces the relative role of small versus large streams as nitrate sinks. Anthropogenic addition of bioavailable nitrogen to the biosphere is increasing1,2 and terrestrial ecosystems are becoming increasingly nitrogen-saturated3, causing more bioavailable nitrogen to enter groundwater and surface waters4,5,6. Large-scale nitrogen budgets show that an average of about 20–25 per cent of the nitrogen added to the biosphere is exported from rivers to the ocean or inland basins7,8, indicating that substantial sinks for nitrogen must exist in the landscape9. Streams and rivers may themselves be important sinks for bioavailable nitrogen owing to their hydrological connections with terrestrial systems, high rates of biological activity, and streambed sediment environments that favour microbial denitrification6,10,11. Here we present data from nitrogen stable isotope tracer experiments across 72 streams and 8 regions representing several biomes. We show that total biotic uptake and denitrification of nitrate increase with stream nitrate concentration, but that the efficiency of biotic uptake and denitrification declines as concentration increases, reducing the proportion of in-stream nitrate that is removed from transport. Our data suggest that the total uptake of nitrate is related to ecosystem photosynthesis and that denitrification is related to ecosystem respiration. In addition, we use a stream network model to demonstrate that excess nitrate in streams elicits a disproportionate increase in the fraction of nitrate that is exported to receiving waters and reduces the relative role of small versus large streams as nitrate sinks.

1,193 citations


Journal ArticleDOI
TL;DR: The ecology of methanogens highlights their complex interactions with other anaerobes and the physical and chemical factors controlling their function.
Abstract: Although of limited metabolic diversity, methanogenic archaea or methanogens possess great phylogenetic and ecological diversity. Only three types of methanogenic pathways are known: CO(2)-reduction, methyl-group reduction, and the aceticlastic reaction. Cultured methanogens are grouped into five orders based upon their phylogeny and phenotypic properties. In addition, uncultured methanogens that may represent new orders are present in many environments. The ecology of methanogens highlights their complex interactions with other anaerobes and the physical and chemical factors controlling their function.

Journal ArticleDOI
TL;DR: Here, the minimum information about a genome sequence (MIGS) specification is introduced with the intent of promoting participation in its development and discussing the resources that will be required to develop improved mechanisms of metadata capture and exchange.
Abstract: With the quantity of genomic data increasing at an exponential rate, it is imperative that these data be captured electronically, in a standard format. Standardization activities must proceed within the auspices of open-access and international working bodies. To tackle the issues surrounding the development of better descriptions of genomic investigations, we have formed the Genomic Standards Consortium (GSC). Here, we introduce the minimum information about a genome sequence (MIGS) specification with the intent of promoting participation in its development and discussing the resources that will be required to develop improved mechanisms of metadata capture and exchange. As part of its wider goals, the GSC also supports improving the 'transparency' of the information contained in existing genomic databases.

Journal ArticleDOI
24 Apr 2008-Nature
TL;DR: Papaya offers numerous advantages as a system for fruit-tree functional genomics, and this draft genome sequence provides the foundation for revealing the basis of Carica’s distinguishing morpho-physiological, medicinal and nutritional properties.
Abstract: Papaya, a fruit crop cultivated in tropical and subtropical regions, is known for its nutritional benefits and medicinal applications. Here we report a 3x draft genome sequence of 'SunUp' papaya, the first commercial virus-resistant transgenic fruit tree to be sequenced. The papaya genome is three times the size of the Arabidopsis genome, but contains fewer genes, including significantly fewer disease-resistance gene analogues. Comparison of the five sequenced genomes suggests a minimal angiosperm gene set of 13,311. A lack of recent genome duplication, atypical of other angiosperm genomes sequenced so far, may account for the smaller papaya gene number in most functional groups. Nonetheless, striking amplifications in gene number within particular functional groups suggest roles in the evolution of tree-like habit, deposition and remobilization of starch reserves, attraction of seed dispersal agents, and adaptation to tropical daylengths. Transgenesis at three locations is closely associated with chloroplast insertions into the nuclear genome, and with topoisomerase I recognition sites. Papaya offers numerous advantages as a system for fruit-tree functional genomics, and this draft genome sequence provides the foundation for revealing the basis of Carica's distinguishing morpho-physiological, medicinal and nutritional properties.

Journal ArticleDOI
TL;DR: An expanded meta-analysis on the relationship between age and job performance that includes 10 dimensions of job performance shows that although age was largely unrelated to core task performance, creativity, and performance in training programs, it demonstrated stronger relationships with the other 7 performance dimensions.
Abstract: Previous reviews of the literature on the relationship between age and job performance have largely focused on core task performance but have paid much less attention to other job behaviors that also contribute to productivity. The current study provides an expanded meta-analysis on the relationship between age and job performance that includes 10 dimensions of job performance: core task performance, creativity, performance in training programs, organizational citizenship behaviors, safety performance, general counterproductive work behaviors, workplace aggression, on-the-job substance use, tardiness, and absenteeism. Results show that although age was largely unrelated to core task performance, creativity, and performance in training programs, it demonstrated stronger relationships with the other 7 performance dimensions. Results also highlight that the relationships of age with core task performance and with counterproductive work behaviors are curvilinear in nature and that several sample characteristics and data collection characteristics moderate age-performance relationships. The article concludes with a discussion of key research design issues that may further knowledge about the age-performance relationship in the future.

Journal ArticleDOI
TL;DR: This article examined how narcissism is manifested on a social networking Web site (i.e., Facebook) and found that narcissism predicted higher levels of social activity in the online community and more self-promoting content in several aspects of the social networking web pages.
Abstract: The present research examined how narcissism is manifested on a social networking Web site (i.e., Facebook.com). Narcissistic personality self-reports were collected from social networking Web page owners. Then their Web pages were coded for both objective and subjective content features. Finally, strangers viewed the Web pages and rated their impression of the owner on agentic traits, communal traits, and narcissism. Narcissism predicted (a) higher levels of social activity in the online community and (b) more selfpromoting content in several aspects of the social networking Web pages. Strangers who viewed the Web pages judged more narcissistic Web page owners to be more narcissistic. Finally, mediational analyses revealed several Web page content features that were influential in raters’ narcissistic impressions of the owners, including quantity of social interaction, main photo selfpromotion, and main photo attractiveness. Implications of the expression of narcissism in social networking communities are discussed.

Journal ArticleDOI
TL;DR: In this paper, a case study grounded in a social constructivist framework was conducted to understand teachers as professionals, where data were collected from multiple sources and analysed using three approaches: (a) constant comparative method, (b) enumerative approach, and (c) in-depth analysis of explicit content knowledge.
Abstract: The purpose of this study was to rethink the conceptualization of pedagogical content knowledge based on our descriptive research findings and to show how this new conceptualization helps us to understand teachers as professionals. This study was a multiple case study grounded in a social constructivist framework. Data were collected from multiple sources and analysed using three approaches: (a) constant comparative method, (b) enumerative approach, and (c) in-depth analysis of explicit PCK. The results indicated that (a) PCK was developed through reflection-in-action and reflection-on-action within given instructional contexts, (b) teacher efficacy emerged as an affective affiliate of PCK, (c) students had an important impact on PCK development, (d) students’ misconceptions played a significant role in shaping PCK, and (e) PCK was idiosyncratic in some aspects of its enactment. Discussion centres on how these five aspects are related to teacher professionalism.

Journal ArticleDOI
TL;DR: msatcommander is a platform‐independent program designed to search for microsatellite arrays, design primers, and tag primers using an automated routine, using single‐sequence or concatenated, fasta‐formatted files.
Abstract: msatcommander is a platform-independent program designed to search for microsatellite arrays, design primers, and tag primers using an automated routine. msatcommander accepts as input DNA sequence data in single-sequence or concatenated, fasta-formatted files. Search data and locus-specific primers are written to comma-separated value files for subsequent use in spreadsheet or database programs. Binary versions of the graphical interface for msatcommander are available for Apple OS X and Windows XP. Users of other operating systems may run the graphical interface version using the available source code, provided their environment supports at least Python 2.4, Biopython 1.43, and wxPython 2.8. msatcommander is available from http://code.google.com/p/msatcommander/.

Journal ArticleDOI
03 Apr 2008-Nature
TL;DR: The magnitude of the microbial metabolic capabilities encoded by the viromes was extensive, suggesting that they serve as a repository for storing and sharing genes among their microbial hosts and influence global evolutionary and metabolic processes.
Abstract: Microbial activities shape the biogeochemistry of the planet and macroorganism health. Determining the metabolic processes performed by microbes is important both for understanding and for manipulating ecosystems (for example, disruption of key processes that lead to disease, conservation of environmental services, and so on). Describing microbial function is hampered by the inability to culture most microbes and by high levels of genomic plasticity. Metagenomic approaches analyse microbial communities to determine the metabolic processes that are important for growth and survival in any given environment. Here we conduct a metagenomic comparison of almost 15 million sequences from 45 distinct microbiomes and, for the first time, 42 distinct viromes and show that there are strongly discriminatory metabolic profiles across environments. Most of the functional diversity was maintained in all of the communities, but the relative occurrence of metabolisms varied, and the differences between metagenomes predicted the biogeochemical conditions of each environment. The magnitude of the microbial metabolic capabilities encoded by the viromes was extensive, suggesting that they serve as a repository for storing and sharing genes among their microbial hosts and influence global evolutionary and metabolic processes.

Journal ArticleDOI
TL;DR: A cross-temporal meta-analysis found that narcissism levels have risen over the generations in 85 samples of American college students who completed the 40-item forced-choice Narcissistic Personality Inventory between 1979 and 2006, complementing previous studies finding increases in other individualistic traits.
Abstract: A cross-temporal meta-analysis found that narcissism levels have risen over the generations in 85 samples of American college students who completed the 40-item forced-choice Narcissistic Personality Inventory (NPI) between 1979 and 2006 (total n=16,475) Mean narcissism scores were significantly correlated with year of data collection when weighted by sample size (beta=53, p<001) Since 1982, NPI scores have increased 033 standard deviation Thus, almost two-thirds of recent college students are above the mean 1979-1985 narcissism score, a 30% increase The results complement previous studies finding increases in other individualistic traits such as assertiveness, agency, self-esteem, and extraversion

Journal ArticleDOI
TL;DR: Azides, which are extremely rare in biological systems, are emerging as attractive chemical handles for bioconjugation and have been employed for the tagging of a variety of biomolecules, activity-based protein profiling, and the chemical synthesis of microarrays and small molecule libraries.
Abstract: Azides, which are extremely rare in biological systems, are emerging as attractive chemical handles for bioconjugation.[1–5] In particular, the CuI catalyzed 1,3-dipolar cyclization of azides with terminal alkynes to give stable triazoles[6, 7] has been employed for the tagging of a variety of biomolecules,[8–12] activity-based protein profiling,[13] and the chemical synthesis of microarrays and small molecule libraries.[14]

Journal ArticleDOI
TL;DR: It is argued for an increased role for C. elegans in complementing other model systems in toxicological research, including genome-wide screening for molecular targets of toxicity and rapid toxicity assessment for new chemicals.

Journal ArticleDOI
TL;DR: It is demonstrated that a transcriptional network consisting of S ND1 and its downstream targets is involved in regulating secondary wall biosynthesis in fibers and that NST1, NST2, VND6, and VND7 are functional homologs of SND1 that regulate the same downstream targets in different cell types.
Abstract: SECONDARY WALL-ASSOCIATED NAC DOMAIN PROTEIN1 (SND1) is a master transcriptional switch activating the developmental program of secondary wall biosynthesis. Here, we demonstrate that a battery of SND1-regulated transcription factors is required for normal secondary wall biosynthesis in Arabidopsis thaliana. The expression of 11 SND1-regulated transcription factors, namely, SND2, SND3, MYB103, MYB85, MYB52, MYB54, MYB69, MYB42, MYB43, MYB20, and KNAT7 (a Knotted1-like homeodomain protein), was developmentally associated with cells undergoing secondary wall thickening. Of these, dominant repression of SND2, SND3, MYB103, MYB85, MYB52, MYB54, and KNAT7 significantly reduced secondary wall thickening in fiber cells. Overexpression of SND2, SND3, and MYB103 increased secondary wall thickening in fibers, and overexpression of MYB85 led to ectopic deposition of lignin in epidermal and cortical cells in stems. Furthermore, SND2, SND3, MYB103, MYB85, MYB52, and MYB54 were able to induce secondary wall biosynthetic genes. Direct target analysis using the estrogen-inducible system revealed that MYB46, SND3, MYB103, and KNAT7 were direct targets of SND1 and also of its close homologs, NST1, NST2, and vessel-specific VND6 and VND7. Together, these results demonstrate that a transcriptional network consisting of SND1 and its downstream targets is involved in regulating secondary wall biosynthesis in fibers and that NST1, NST2, VND6, and VND7 are functional homologs of SND1 that regulate the same downstream targets in different cell types.

Journal ArticleDOI
TL;DR: The users of this book can be teachers of measurement, research, and statistics courses as mentioned in this paper, and also they can be valuable to researchers and consumers of research as a reference. The book is written by as mentioned in this paper.
Abstract: The users of this book can be teachers of measurement, research, and statistics courses. Also, this book can be valuable to researchers and consumers of research as a reference. The book is written...

Journal ArticleDOI
TL;DR: It is demonstrated that mentoring is associated with a wide range of favorable behavioral, attitudinal, health-related, relational, motivational, and career outcomes, although the effect size is generally small.

Journal ArticleDOI
TL;DR: Exercise may prove to be a simple, yet important, method of enhancing those aspects of children’s mental functioning central to cognitive development.
Abstract: Studies that examine the effects of exercise on children’s intelligence, cognition, or academic achievement were reviewed and results were discussed in light of (a) contemporary cognitive theory development directed toward exercise, (b) recent research demonstrating the salutary effects of exercise on adults’ cognitive functioning, and (c) studies conducted with animals that have linked physical activity to changes in neurological development and behavior. Similar to adults, exercise facilitates children’s executive function (i.e., processes required to select, organize, and properly initiate goal-directed actions). Exercise may prove to be a simple, yet important, method of enhancing those aspects of children’s mental functioning central to cognitive development.

Posted Content
TL;DR: The authors found that top executives exhibit unique individual-specific and economically significant disclosure styles, and that managers' unique fixed effects are associated with observable characteristics of their own personal backgrounds, such as career tracks, managers born before World War II, and MBAs.
Abstract: Prior research in finance and accounting generally posits a limited role for idiosyncratic manager-specific attributes in explaining accounting and disclosure choices. In contrast, upper echelons theory, originating in the strategic management literature, suggests that differences among individuals can affect corporate outcomes. Extant research in voluntary disclosure follows the traditional financial economics perspective, yet even the most comprehensive empirical models leave most of the cross-sectional variation in disclosure unexplained. This prompts us to investigate whether these models are missing a major component: Do idiosyncratic differences among individual managers play a significant incremental role in voluntary corporate financial disclosure? We build a data set that tracks managers over time, which allows us to isolate manager-specific fixed effects after controlling for firm effects. We find that top executives do exhibit unique individual-specific and economically significant disclosure styles. That is, our evidence suggests that individual managers significantly influence attributes of their firms' voluntary disclosures, even after controlling for techno-economic determinants of disclosure identified in prior research, and firm- and time-specific effects. The collective magnitude of these manager-specific fixed effects is large: Manager-specific effects explain roughly as much or more of the variation in disclosure as the known techno-economic determinants combined. We then investigate whether managers' unique fixed effects are associated with observable characteristics of their own personal backgrounds. We find that managers promoted from finance, accounting, and legal career tracks, managers born before World War II, and managers holding MBAs tend to exhibit more conservative disclosure styles. These associations between our estimates of managers' fixed effects and distinctive (permanent) characteristics of their own personal backgrounds provide evidence confirming that our estimated manager fixed effects capture systematic long-lived differences in managers' unique disclosure styles. Our results suggest that individual-specific effects play an important - yet heretofore largely unexplored - role in voluntary financial disclosure. Further investigation of the role unique individual characteristics play in explaining corporate financial reporting is potentially a fruitful direction for future research.

Journal ArticleDOI
TL;DR: The results suggest that individual attributes, while important, are conditioned by the local work environment, and that when individuals face dissonance, they will conform to the local norms, rather than adhering to the norms from their prior experience.
Abstract: This study explores the process of organizational change by examining localized social learning in organizational subunits. Specifically, we examine participation in university technology transfer, a new organizational initiative, by tracking 1,780 faculty members, examining their backgrounds and work environments, and following their engagement with academic entrepreneurship. We find that individual adoption of the new initiative may be either substantive or symbolic. Our results suggest that individual attributes, while important, are conditioned by the local work environment. In terms of personal attributes, individuals are more likely to participate if they trained at institutions that had accepted the new initiative and been active in technology transfer. In addition, we find that the longer the time that had elapsed since graduate training, the less likely the individual was to actively embrace the new commercialization norm. Considering the localized social environment, we find that when the chair of the department is active in technology transfer, other members of the department are also likely to participate, if only for symbolic reasons. We also find that technology transfer behavior is calibrated by the experience of those in the relevant cohort. If an individual can observe others with whom they identify engaging in the new initiative, then they are more likely to follow with substantive compliance. Finally, when individuals face dissonance, a situation where their individual training norms are not congruent with the localized social norms in their work environment, they will conform to the local norms, rather than adhering to the norms from their prior experience.

Journal ArticleDOI
TL;DR: The history of the areas of multiple criteria decision making (MCDM) and multiattribute utility theory (MAUT) are extended and topics the authors believe to be important for the future of these fields are discussed.
Abstract: This paper is an update of a paper that five of us published in 1992. The areas of multiple criteria decision making (MCDM) and multiattribute utility theory (MAUT) continue to be active areas of management science research and application. This paper extends the history of these areas and discusses topics we believe to be important for the future of these fields.

Journal ArticleDOI
03 Jul 2008-Nature
TL;DR: The identification in mouse of a previously unknown cardiac myocyte lineage that derives from the proepicardial organ is reported, which provides a theoretical framework for applying these progenitors to effect cardiac repair and regeneration.
Abstract: Understanding the origins and roles of cardiac progenitor cells is important for elucidating the pathogenesis of congenital and acquired heart diseases. Moreover, manipulation of cardiac myocyte progenitors has potential for cell-based repair strategies for various myocardial disorders. Here we report the identification in mouse of a previously unknown cardiac myocyte lineage that derives from the proepicardial organ. These progenitor cells, which express the T-box transcription factor Tbx18, migrate onto the outer cardiac surface to form the epicardium, and then make a substantial contribution to myocytes in the ventricular septum and the atrial and ventricular walls. Tbx18-expressing cardiac progenitors also give rise to cardiac fibroblasts and coronary smooth muscle cells. The pluripotency of Tbx18 proepicardial cells provides a theoretical framework for applying these progenitors to effect cardiac repair and regeneration.

Journal ArticleDOI
TL;DR: Using a > 15 year soil warming experiment in a mid-latitude forest, it is shown that the apparent 'acclimation' of soil respiration at the ecosystem scale results from combined effects of reductions in soil carbon pools and microbial biomass, and thermal adaptation of microbial respiration.
Abstract: In the short-term heterotrophic soil respiration is strongly and positively related to temperature. In the long-term, its response to temperature is uncertain. One reason for this is because in field experiments increases in respiration due to warming are relatively short-lived. The explanations proposed for this ephemeral response include depletion of fast-cycling, soil carbon pools and thermal adaptation of microbial respiration. Using a > 15 year soil warming experiment in a mid-latitude forest, we show that the apparent 'acclimation' of soil respiration at the ecosystem scale results from combined effects of reductions in soil carbon pools and microbial biomass, and thermal adaptation of microbial respiration. Mass-specific respiration rates were lower when seasonal temperatures were higher, suggesting that rate reductions under experimental warming likely occurred through temperature-induced changes in the microbial community. Our results imply that stimulatory effects of global temperature rise on soil respiration rates may be lower than currently predicted.