132 research outputs found
A Soft Budget Constraint Explanation for the Venture Capital Cycle
We explore why venture capital funds limit the amount of capital they raise and do not reinvest the proceeds. This structure is puzzling because it leads to a succession of several funds financing each new venture which multiplies the well known agency problems. We argue that an inside investor cannot provide a hard budget constraint while a less well informed outsider can. Therefore, the venture capitalist delegates the continuation decision to the outsider by ex ante restricting the amount of capital he has under management. The soft budget constraint problem becomes the more important the higher the entrepreneur’s private benefits are and the higher the probability of failure of a project is
A kinematically distinct core and minor-axis rotation : the MUSE perspective on M87
Date of Acceptance: 22/08/2014We present evidence for the presence of a low-amplitude kinematically distinct component in the giant early-type galaxy M87, via data sets obtained with the SAURON and MUSE integral-field spectroscopic units. The MUSE velocity field reveals a strong twist of ∼140° within the central 30 arcsec connecting outwards such a kinematically distinct core to a prolate-like rotation around the large-scale photometric major axis of the galaxy. The existence of these kinematic features within the apparently round central regions of M87 implies a non-axisymmetric and complex shape for this galaxy, which could be further constrained using the presented kinematics. The associated orbital structure should be interpreted together with other tracers of the gravitational potential probed at larger scales (e.g. globular clusters, ultra-compact dwarfs, planetary nebulae): it would offer an insight in the assembly history of one of the brightest galaxies in the Virgo cluster. These data also demonstrate the potential of the MUSE spectrograph to uncover low-amplitude spectral signaturesPeer reviewedFinal Accepted Versio
Spectral Energy Distribution Fitting of Hetdex Pilot Survey Ly-alpha Emitters in Cosmos and Goods-N
We use broadband photometry extending from the rest-frame UV to the near-IR to fit the individual spectral energy distributions of 63 bright (L(Ly-alpha) greater than 10(exp 43) erg s(exp 1) Ly-alpha emitting galaxies (LAEs) in the redshift range 1.9 less than z less than 3.6. We find that these LAEs are quite heterogeneous, with stellar masses that span over three orders of magnitude, from 7.5 greater than logM/solar mass less than 10.5. Moreover, although most LAEs have small amounts of extinction, some high-mass objects have stellar reddenings as large as E(B V ) is approximately 0.4. Interestingly, in dusty objects the optical depths for Ly-alpha and the UV continuum are always similar, indicating that Ly photons are not undergoing many scatters before escaping their galaxy. In contrast, the ratio of optical depths in low-reddening systems can vary widely, illustrating the diverse nature of the systems. Finally, we show that in the star-formation-rate-log-mass diagram, our LAEs fall above the "main-sequence" defined by z is approximately 3 continuum selected star-forming galaxies. In this respect, they are similar to submillimeter-selected galaxies, although most LAEs have much lower mass
Recommended from our members
A qualitative study of the activities performed by people involved in clinical decision support: recommended practices for success
Objective: To describe the activities performed by people involved in clinical decision support (CDS) at leading sites. Materials and methods We conducted ethnographic observations at seven diverse sites with a history of excellence in CDS using the Rapid Assessment Process and analyzed the data using a series of card sorts, informed by Linstone's Multiple Perspectives Model. Results: We identified 18 activities and grouped them into four areas. Area 1: Fostering relationships across the organization, with activities (a) training and support, (b) visibility/presence on the floor, (c) liaising between people, (d) administration and leadership, (e) project management, (f) cheerleading/buy-in/sponsorship, (g) preparing for CDS implementation. Area 2: Assembling the system with activities (a) providing technical support, (b) CDS content development, (c) purchasing products from vendors (d) knowledge management, (e) system integration. Area 3: Using CDS to achieve the organization's goals with activities (a) reporting, (b) requirements-gathering/specifications, (c) monitoring CDS, (d) linking CDS to goals, (e) managing data. Area 4: Participation in external policy and standards activities (this area consists of only a single activity). We also identified a set of recommendations associated with these 18 activities. Discussion All 18 activities we identified were performed at all sites, although the way they were organized into roles differed substantially. We consider these activities critical to the success of a CDS program. Conclusions: A series of activities are performed by sites strong in CDS, and sites adopting CDS should ensure they incorporate these activities into their efforts
Optical and IR Photometry of Globular Clusters in NGC1399: Evidence for Color-Metallicity Nonlinearity
We combine new Wide Field Camera~3 IR Channel (WFC3/IR) F160W (H) imaging
data for NGC1399, the central galaxy in the Fornax cluster, with archival F475W
(g), F606W (V), F814W (I), and F850LP (z) optical data from the Advanced Camera
for Surveys (ACS). The purely optical g-I, V-I, and g-z colors of NGC1399's
rich globular cluster (GC) system exhibit clear bimodality, at least for
magnitudes . The optical-IR I-H color distribution appears
unimodal, and this impression is confirmed by mixture modeling analysis. The
V-H colors show marginal evidence for bimodality, consistent with bimodality in
V-I and unimodality in I-H. If bimodality is imposed for I-H with a double
Gaussian model, the preferred blue/red split differs from that for optical
colors; these "differing bimodalities" mean that the optical and optical-IR
colors cannot both be linearly proportional to metallicity. Consistent with the
differing color distributions, the dependence of I-H on g-I for the matched GC
sample is significantly nonlinear, with an inflection point near the trough in
the g-I color distribution; the result is similar for the I-H dependence on g-z
colors taken from the ACS Fornax Cluster Survey. These g-z colors have been
calibrated empirically against metallicity; applying this calibration yields a
continuous, skewed, but single-peaked metallicity distribution. Taken together,
these results indicate that nonlinear color-metallicity relations play an
important role in shaping the observed bimodal distributions of optical colors
in extragalactic GC systems.Comment: 15 pages, 12 figures, accepted for publication in the Astrophysical
Journa
Lessons Learned from Implementing Service-Oriented Clinical Decision Support at Four Sites: A Qualitative Study
Objective
To identify challenges, lessons learned and best practices for service-oriented clinical decision support, based on the results of the Clinical Decision Support Consortium, a multi-site study which developed, implemented and evaluated clinical decision support services in a diverse range of electronic health records.
Methods
Ethnographic investigation using the rapid assessment process, a procedure for agile qualitative data collection and analysis, including clinical observation, system demonstrations and analysis and 91 interviews.
Results
We identified challenges and lessons learned in eight dimensions: (1) hardware and software computing infrastructure, (2) clinical content, (3) human-computer interface, (4) people, (5) workflow and communication, (6) internal organizational policies, procedures, environment and culture, (7) external rules, regulations, and pressures and (8) system measurement and monitoring. Key challenges included performance issues (particularly related to data retrieval), differences in terminologies used across sites, workflow variability and the need for a legal framework.
Discussion
Based on the challenges and lessons learned, we identified eight best practices for developers and implementers of service-oriented clinical decision support: (1) optimize performance, or make asynchronous calls, (2) be liberal in what you accept (particularly for terminology), (3) foster clinical transparency, (4) develop a legal framework, (5) support a flexible front-end, (6) dedicate human resources, (7) support peer-to-peer communication, (8) improve standards.
Conclusion
The Clinical Decision Support Consortium successfully developed a clinical decision support service and implemented it in four different electronic health records and four diverse clinical sites; however, the process was arduous. The lessons identified by the Consortium may be useful for other developers and implementers of clinical decision support services
- …