803 research outputs found
An Identity-Based Approach to Social Enterprise
Social enterprise has gained widespread acclaim as a tool for addressing social and environmental problems. Yet because social enterprises integrate social welfare and commercial logics, they face the challenge of pursuing frequently conflicting goals. Studies have begun to address how established social enterprises can manage these tensions, but we know little about how, why, and with what consequences social entrepreneurs mix competing logics as they create new organizations. To address this gap, we develop a theoretical model based in identity theory that helps to explain (1) how commercial and social welfare logics become relevant to entrepreneurship, (2) how different types of entrepreneurs perceive the tension between these logics, and (3) what implications this has for how entrepreneurs recognize and develop social enterprise opportunities. Our approach responds to calls from organizational and entrepreneurship scholars to extend existing frameworks of opportunity recognition and development to better account for social enterprise creation
Converging Winds: Logic Hybridization in the Colorado Wind Energy Field
This study explores the hybridization of field-level logics, a process that integrates previously incompatible logics within an organizational field. Through an inductive study of the wind energy field in Colorado, we find that logic hybridization resulted when social movement organizations, incumbent firms, and policy makers variously responded to incompatibility between economizing and ecologizing logics. Compromise and framing efforts catalyzed social movements to alter the balance of power in the field, which transformed the relationship between field logics. Hybrid organizations then emerged to establish, legitimize, and embed a new set of inter-linked frames, practices, and arrangements that integrated previously incompatible logics. Incumbent firms and policy makers further formalized and embedded the new hybridized logic in the field. Our findings suggest that the hybridization of field level logics is a complex process in which organizational actions and field-level conditions recursively influence each other over time
Values-Based Rivalry: A Theoretical Framework of Rivalry Between Activists and Firms
In this article we develop a theoretical framework to explain values-based rivalry between activists and firms by integrating and advancing key insights from competitive dynamics and social activist research. The first part of our framework conceptualizes the unique tensions, actions, and responses that characterize values-based rivalry and distinguish it from rivalry between firms. The second part of our framework conceptualizes the role of managersâ perceptions in shaping their firmsâ likelihood of responding to activistsâ actions during values-based rivalry. Overall, our conceptualization primarily expands competitive dynamics research to account for rivalry between dissimilar actors and, in doing so, broadens social activist research to account for such rivalry
The evolution of founder identity as an authenticity work process
Research has shown founders' identities have a significant impact on their ventures. Yet, the process through which founder identity evolves and takes shape remains relatively unexplained. This paper explores the evolution of founder identity through a qualitative study of first-time sustainable entrepreneurs, and their stakeholders, over a three years period. Our analysis revealed the importance of personal identity, the aspect of the self that defines a person as a unique individual based largely on values and beliefs. We found that first-time founders sought to align their personal identity with their evolving founder identity over time. Based on these findings we theorize a process model of founder authenticity work, defined as the activities founders engage in to feel and seem authentic while engaged in entrepreneurial action. This study thus details the significance of personal identity as a guidepost for founder identity evolution, complementing extant founder identity studies focused on role and social identities. In addition, our analysis enriches the current conceptualization of authenticity in entrepreneurship research by linking it to validation of personal identity and highlighting its negotiated nature in the evolution of authentic founder identities
CD56negCD16+ NK cells are activated mature NK cells with impaired effector function during HIV-1 infection
BACKGROUND: A subset of CD3(neg)CD56(neg)CD16âș Natural Killer (NK) cells is highly expanded during chronic HIV-1 infection. The role of this subset in HIV-1 pathogenesis remains unclear. The lack of NK cell lineage-specific markers has complicated the study of minor NK cell subpopulations.
RESULTS: Using CD7 as an additional NK cell marker, we found that CD3(neg)CD56(neg)CD16âș cells are a heterogeneous population comprised of CD7âș NK cells and CD7(neg) non-classical myeloid cells. CD7âșCD56(neg)CD16âș NK cells are significantly expanded in HIV-1 infection. CD7âșCD56(neg)CD16âș NK cells are mature and express KIRs, the C-type lectin-like receptors NKG2A and NKG2C, and natural cytotoxicity receptors similar to CD7âșCD56âșCD16âș NK cells. CD7âșCD56(neg) NK cells in healthy donors produced minimal IFNÎł following K562 target cell or IL-12 plus IL-18 stimulation; however, they degranulated in response to K562 stimulation similar to CD7âșCD56âș NK cells. HIV-1 infection resulted in reduced IFNÎł secretion following K562 or cytokine stimulation by both NK cell subsets compared to healthy donors. Decreased granzyme B and perforin expression and increased expression of CD107a in the absence of stimulation, particularly in HIV-1-infected subjects, suggest that CD7âșCD56(neg)CD16âș NK cells may have recently engaged target cells. Furthermore, CD7âșCD56(neg)CD16âș NK cells have significantly increased expression of CD95, a marker of NK cell activation.
CONCLUSIONS: Taken together, CD7âșCD56(neg)CD16âș NK cells are activated, mature NK cells that may have recently engaged target cells
Photometric redshifts from reconstructed QSO templates
From SDSS commissioning photometric and spectroscopic data, we investigate
the utility of photometric redshift techniques to the task of estimating QSO
redshifts. We consider empirical methods (e.g. nearest-neighbor searches and
polynomial fitting), standard spectral template fitting and hybrid approaches
(i.e. training spectral templates from spectroscopic and photometric
observations of QSOs). We find that in all cases, due to the presence of strong
emission-lines within the QSO spectra, the nearest-neighbor and template
fitting methods are superior to the polynomial fitting approach. Applying a
novel reconstruction technique, we can, from the SDSS multicolor photometry,
reconstruct a statistical representation of the underlying SEDs of the SDSS
QSOs. Although, the reconstructed templates are based on only broadband
photometry the common emission lines present within the QSO spectra can be
recovered in the resulting spectral energy distributions. The technique should
be useful in searching for spectral differences among QSOs at a given redshift,
in searching for spectral evolution of QSOs, in comparing photometric redshifts
for objects beyond the SDSS spectroscopic sample with those in the well
calibrated photometric redshifts for objects brighter than 20th magnitude and
in searching for systematic and time variable effects in the SDSS broad band
photometric and spectral photometric calibrations.Comment: 21 pages, 9 figures, LaTeX AASTeX, submitted to A
Black Hole Data via a Kerr-Schild Approach
We present a new approach for setting initial Cauchy data for multiple black
hole spacetimes. The method is based upon adopting an initially Kerr-Schild
form of the metric. In the case of non-spinning holes, the constraint equations
take a simple hierarchical form which is amenable to direct numerical
integration. The feasibility of this approach is demonstrated by solving
analytically the problem of initial data in a perturbed Schwarzschild geometry.Comment: 13 pages, RevTeX forma
High-Redshift Quasars Found in Sloan Digital Sky Survey Commissioning Data IV: Luminosity Function from the Fall Equatorial Stripe Sampl
This is the fourth paper in a series aimed at finding high-redshift quasars
from five-color imaging data taken along the Celestial Equator by the SDSS.
during its commissioning phase. In this paper, we use the color-selected sample
of 39 luminous high-redshift quasars presented in Paper III to derive the
evolution of the quasar luminosity function over the range of 3.6<z<5.0, and
-27.5<M_1450<-25.5 (Omega=1, H_0=50 km s^-1 Mpc^-1). We use the selection
function derived in Paper III to correct for sample incompleteness. The
luminosity function is estimated using three different methods: (1) the 1/V_a
estimator; (2) a maximum likelihood solution, assuming that the density of
quasars depends exponentially on redshift and as a power law in luminosity and
(3) Lynden-Bell's non-parametric C^- estimator. All three methods give
consistent results. The luminous quasar density decreases by a factor of ~ 6
from z=3.5 to z=5.0, consistent with the decline seen from several previous
optical surveys at z<4.5. The luminosity function follows psi(L) ~ L^{-2.5} for
z~4 at the bright end, significantly flatter than the bright end luminosity
function psi(L) \propto L^{-3.5} found in previous studies for z<3, suggesting
that the shape of the quasar luminosity function evolves with redshift as well,
and that the quasar evolution from z=2 to 5 cannot be described as pure
luminosity evolution. Possible selection biases and the effect of dust
extinction on the redshift evolution of the quasar density are also discussed.Comment: AJ accepted, with minor change
The Angular Clustering of Galaxy Pairs
We identify close pairs of galaxies from 278 deg^2 of Sloan Digital Sky
Survey commissioning imaging data. The pairs are drawn from a sample of 330,041
galaxies with 18 < r^* < 20. We determine the angular correlation function of
galaxy pairs, and find it to be stronger than the correlation function of
single galaxies by a factor of 2.9 +/- 0.4. The two correlation functions have
the same logarithmic slope of 0.77. We invert Limber's equation to estimate the
three-dimensional correlation functions; we find clustering lengths of r_0= 4.2
+/- 0.4 h^{-1} Mpc for galaxies and 7.8 +/- 0.7 h^{-1} Mpc for galaxy pairs.
These results agree well with the global richness dependence of the correlation
functions of galaxy systems.Comment: 12 pages. ApJ, in pres
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