2,679 research outputs found
Qualitative Factors as Determinants of Continued Success:An Examination of eBusiness Entrepreneurial Firms Using the NewVenture Template
In this study, we analyze eBusiness entrepreneurs nominated by the Ernst & Young Entrepreneur of the Year Award program to ascertain whether qualitative factors are correlated with success. We find qualitative factors are incrementally informative above and beyond the information provided by quantitative factors. More specifically, firms that are able to maintain their innovative strategies by improving upon the product (or service) they offer and are able to meet the long-term needs of the customer are more likely to experience increased sales growth and have greater access to capital which results in a successful harvest strategy
Estimating carbon stock change in agroforestry and family forestry practices
Paper presented at the 11th North American Agroforesty Conference, which was held May 31-June 3, 2009 in Columbia, Missouri.In Gold, M.A. and M.M. Hall, eds. Agroforestry Comes of Age: Putting Science into Practice. Proceedings, 11th North American Agroforestry Conference, Columbia, Mo., May 31-June 3, 2009.The Carbon Management Evaluation Tool for Voluntary Reporting (COMET-VR) is an online tool that estimates short-term carbon stock (CS) changes under different farm or forest land management systems, including temperate agroforestry practices. It was developed by the USDA Natural Resources Conservation Service in conjunction with Colorado State University. The intended audience includes private farm and forest landowners, NRCS field staff, and technical service providers. Through the online interface, users identify their location, parcel size, surface soil texture, crop rotation history and tillage intensity. The user can choose either of two methods to estimate CS change for their agroforestry practice: 1) for new or future plantings, by using standard prescriptions common to their geographic region, or 2) for a more accurate estimate of an existing planting, by using a summary of live-tree stand inventory data collected from their parcel. Above and below-ground individual tree biomass is calculated using diameter-based allometric equations generalized for tree genera groups. For existing agroforestry plantings, growth estimates are based on empirical models developed from forest inventory data specific to species and region. For new or future plantings, growth estimates were derived for standard agroforestry prescriptions using the Forest Vegetation Simulator. COMET-VR uses the Century soil carbon model to estimate CS change in soil. The output of the tool is a report estimating CS changes over the forthcoming 10 years in the above and below-ground portions of live trees and in the soil. Although specifically designed to meet the requirements of the US Dept. of Energy voluntary greenhouse gas reporting program, COMET-VR may also be applicable to other private and public sector carbon offset programs.Miles L. Merwin (1), Mark Easter (2), Lyn R. Townsend (1), Roel C. Vining (1) and Greg L. Johnson (1) ; 1. USDA Natural Resources Conservation Service, 1201 NE Lloyd Blvd., Portland, OR 97232. 2. Natural Resource Ecology Laboratory, Colorado State University, Ft. Collins, CO.Includes bibliographical references
Publication trends in Family Medicine graduates: A cross-sectional review
Purpose: The ACGME emphasizes the importance of research throughout residency as it establishes the basis of evidence-based medicine. As future physicians practicing evidence-based medicine, it is crucial that physicians in training are able to both interpret and produce quality research. Currently, the long-term impact of active research participation is unknown in this population. In this study, we aim to (1) explore research activity as measured by peer-reviewed publications among family medicine residency graduates and (2) determine if an association exists between publication rates before, during, or after family medicine residency.Methods: We utilized a cross-sectional study design analyzing research output by family medicine residency graduates in relation to future publications and academic involvement from a random sample of 50 family medicine programs. Data were extracted for each graduate and analyzed using STATA 15.1 and Microsoft Excel. The public protocol can be found here: https://osf.io/pwa6d/.Results: We identified 654 residency programs of which we randomly sampled 50. Among the 50 programs, 8 were included, totaling 101 graduates from family medicine residencies for analysis. Of the 101 analyzed residents, 76 (75.2%) produced zero publications. Of the analyzed residents, 30 (29.7%) pursued a fellowship, with most in sports medicine (5/101 [5.0%]). The mean number of publications for all analyzed residents was 0.8, with most publishing after completion of residency.Conclusion: While a majority of family medicine graduate's publications were post-residency, the average number of publications was lowest during residency training. Increased research opportunity and activity during residency may increase the proportion of family medicine graduates pursuing fellowships and careers in academia, as well as increase resident comfort with both interpretation and utilization of evidence-based interventions in clinical practice
Mutations in gfpt1 and skiv2l2 Cause Distinct Stage-Specific Defects in Larval Melanocyte Regeneration in Zebrafish
The establishment of a single cell type regeneration paradigm in the zebrafish provides an opportunity to investigate the genetic mechanisms specific to regeneration processes. We previously demonstrated that regeneration melanocytes arise from cell division of the otherwise quiescent melanocyte precursors following larval melanocyte ablation with a small molecule, MoTP. The ease of ablating melanocytes by MoTP allows us to conduct a forward genetic screen for mechanisms specific to regeneration from such precursors or stem cells. Here, we reported the identification of two mutants, earthaj23e1 and juliej24e1 from a melanocyte ablation screen. Both mutants develop normal larval melanocytes, but upon melanocyte ablation, each mutation results in a distinct stage-specific defect in melanocyte regeneration. Positional cloning reveals that the earthaj23e1 mutation is a nonsense mutation in gfpt1 (glutamine:fructose-6-phosphate aminotransferase 1), the rate-limiting enzyme in glucosamine-6-phosphate biosynthesis. Our analyses reveal that a mutation in gfpt1 specifically affects melanocyte differentiation (marked by melanin production) at a late stage during regeneration and that gfpt1 acts cell autonomously in melanocytes to promote ontogenetic melanocyte darkening. We identified that the juliej24e1 mutation is a splice-site mutation in skiv2l2 (superkiller viralicidic activity 2-like 2), a predicted DEAD-box RNA helicase. Our in situ analysis reveals that the mutation in skiv2l2 causes defects in cell proliferation, suggesting that skiv2l2 plays a role in regulating melanoblast proliferation during early stages of melanocyte regeneration. This finding is consistent with previously described role for cell division during larval melanocyte regeneration. The analyses of these mutants reveal their stage-specific roles in melanocyte regeneration. Interestingly, these mutants identify regeneration-specific functions not only in early stages of the regeneration process, but also in late stages of differentiation of the regenerating melanocyte. We suggest that mechanisms of regeneration identified in this mutant screen may reveal fundamental differences between the mechanisms that establish differentiated cells during embryogenesis, and those involved in larval or adult growth
Senescent mouse cells fail to overtly regulate the HIRA histone chaperone and do not form robust Senescence Associated Heterochromatin Foci
<p>Abstract</p> <p>Background</p> <p>Cellular senescence is a permanent growth arrest that occurs in response to cellular stressors, such as telomere shortening or activation of oncogenes. Although the process of senescence growth arrest is somewhat conserved between mouse and human cells, there are some critical differences in the molecular pathways of senescence between these two species. Recent studies in human fibroblasts have defined a cell signaling pathway that is initiated by repression of a specific Wnt ligand, Wnt2. This, in turn, activates a histone chaperone HIRA, and culminates in formation of specialized punctate domains of facultative heterochromatin, called Senescence-Associated Heterochromatin Foci (SAHF), that are enriched in the histone variant, macroH2A. SAHF are thought to repress expression of proliferation-promoting genes, thereby contributing to senescence-associated proliferation arrest. We asked whether this Wnt2-HIRA-SAHF pathway is conserved in mouse fibroblasts.</p> <p>Results</p> <p>We show that mouse embryo fibroblasts (MEFs) and mouse skin fibroblasts, do not form robust punctate SAHF in response to an activated Ras oncogene or shortened telomeres. However, senescent MEFs do exhibit elevated levels of macroH2A staining throughout the nucleus as a whole. Consistent with their failure to fully activate the SAHF assembly pathway, the Wnt2-HIRA signaling axis is not overtly regulated between proliferating and senescent mouse cells.</p> <p>Conclusions</p> <p>In addition to the previously defined differences between mouse and human cells in the mechanisms and phenotypes associated with senescence, we conclude that senescent mouse and human fibroblasts also differ at the level of chromatin and the signaling pathways used to regulate chromatin. These differences between human and mouse senescence may contribute to the increased propensity of mouse fibroblasts (and perhaps other mouse cell types) to become immortalized and transformed, compared to human cells.</p
The Impact of HD Cooling on the Formation of the First Stars
We use numerical simulations to investigate the importance of HD formation
and cooling on the first generation of metal-free stars in a LCDM cosmology. We
have implemented and tested non-equilibrium HD chemistry in an adaptive mesh
refinement simulation code and applied it to two situations. (1) It is first
applied to the formation of 10^5 - 10^6 Msun halos which form in the absence of
any ionizing source. We show, in agreement with previous work, that HD cooling
is of only marginal importance for most halos; however, we find that for the
lowest mass halos, HD cooling can equal or surpass the H2 cooling rate. This
leads to a population of stars formed in halos with effective HD cooling that
are less massive by a factor of ~6 compared to halos dominated by H2 cooling.
(2) In the second part of the paper, we ionize the halos in order to explore
the impact of HD cooling in the presence of an ample population of free
electrons. This leads to cooler temperatures (due to the electron- catalyzed
production of H2) and somewhat lower resulting proto-stellar mass. Adding HD
chemistry lowers the temperature further, to the level of the CMB. We find that
HD cooling dominates over H2 cooling in the density range 10^2 cm^-3 to 10^6
cm^-3, but above this density, the temperature rises and H2 cooling dominates
again. Because of this, the accretion rate on to the protostar is almost the
same as in the H2 case (at least for accreted masses below 50-100 Msun),
therefore we argue that HD cooling in ionized halos will probably not result in
a population of significantly lower mass stars.Comment: 13 pages, 11 figures, with referee suggestions; ApJ accepte
The N2K Consortium. I. A Hot Saturn Planet Orbiting HD 88133
The N2K ("next 2000") consortium is carrying out a distributed observing campaign with the Keck, Magellan, and Subaru telescopes, as well as the automatic photometric telescopes of Fairborn Observatory, in order to search for short-period gas giant planets around metal-rich stars. We have established a reservoir of more than 14,000 main-sequence and subgiant stars closer than 110 pc, brighter than V = 10.5, and with 0.4 0.1 dex for this survey. We outline the strategy and report the detection of a planet orbiting the metal-rich G5 IV star HD 88133 with a period of 3.41 days, semivelocity amplitude K = 35.7 m s^(-1), and M sin i = 0.29M_J. Photometric observations reveal that HD 88133 is constant on the 3.415 day radial velocity period to a limit of 0.0005 mag. Despite a transit probability of 19.5%, our photometry rules out the shallow transits predicted by the large stellar radius
Buffering against maladaptive perfectionism in bipolar disorder:The role of self-compassion
Background Maladaptive perfectionism is a transdiagnostic risk and maintaining factor for a range of mental health conditions, including bipolar disorder (BD). Self-compassion represents a potential protective factor against maladaptive perfectionism, however no studies to date have examined the relationship of these constructs in BD. The aim of the present study was to examine associations between maladaptive perfectionism, self-compassion and symptoms among individuals with BD. Methods Baseline data were collected from 302 participants with a DSM-IV diagnosis of BD participating in an international randomised controlled trial. Participants completed measures of maladaptive perfectionism, self-compassion, symptom severity and emotion regulation difficulties. Clinician-administered measures of depression and mania severity were additionally collected. Correlation and mediation analyses were conducted. Results Maladaptive perfectionism was positively associated with depression, anxiety and emotion regulation difficulties. Lower levels of self-compassion correlated with greater self-reported depression, anxiety and emotion regulation difficulties. Self-compassion partially mediated relationships between maladaptive perfectionism, depression, anxiety and emotion regulation difficulties. Limitations The cross-sectional design limits conclusions about causal relationships between study variables. Results may not be generalizable to other BD populations. The role of maladaptive perfectionism and self-compassion in elevated mood states of BD remains unclear. Conclusion Self-compassion represents one mechanism through which maladaptive perfectionism influences symptoms of depression, anxiety and emotion regulation difficulties in BD. Self-compassion represents a modifiable treatment target; individuals with BD exhibiting maladaptive perfectionistic tendencies may benefit from interventions fostering self-compassion
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