774 research outputs found
Incorporating sustainable forestry into standards for professional forestry education
In 1991, the National Association of Professional Forestry Schools and Colleges (NAPFSC) and the Society of American Foresters (SAF) co-hosted a three-day Forest Resources Education Symposium, entitled Forest Resources Management in the 21st Century: Will Forestry Education Meet the Challenge? The objectives of the national symposium were to present major forces shaping the country\u27s management of forest resources, and then to discuss the adequacy of educational criteria in preparing tomorrow\u27s resource managers to excel under an expanding array of consumer and employer demands. As an outcome, the discussants developed a summary of specific challenges and solutions within five issue areas: The Future of Forestry, Future Educational Needs, Defining Appropriate Curricula, Student Characteristics, and Faculty Characteristics. Many existing problems were identified as a result of that process, as well as potentially useful strategies for corrective action
Epstein-Barr virus IL-10 gene expression by a recombinant murine gammaherpesvirus in vivo enhances acute pathogenicity but does not affect latency or reactivation.
BackgroundMany viral genes affect cytokine function within infected hosts, with interleukin 10 (IL-10) as a commonly targeted mediator. Epstein-Barr virus (EBV) encodes an IL-10 homologue (vIL-10) expressed during productive (lytic) infection and induces expression of cellular IL-10 (cIL-10) during latency. This study explored the role of vIL-10 in a murine gammaherpesvirus (MHV) model of viral infection.MethodsThe EBV vIL-10 gene was inserted into MHV-76, a strain which lacks the ability to induce cIL-10, by recombination in transfected mouse cells. Mice were infected intranasally with the recombinant, vIL-10-containing MHV-76 or control virus strains and assayed at various days post infection for lung virus titer, spleen cell number, percentage of latently infected spleen cells and ability to reactivate virus from spleen cells.ResultsRecombinant murine gammaherpesvirus expressing EBV vIL-10 rose to significantly higher titers in lungs and promoted an increase in spleen cell number in infected mice in comparison to MHV strains lacking the vIL-10 gene. However, vIL-10 expression did not alter the quantity of latent virus in the spleen or its ability to reactivate.ConclusionsIn this mouse model of gammaherpesvirus infection, EBV vIL-10 appears to influence acute-phase pathogenicity. Given that EBV and MHV wild-type strains contain other genes that induce cIL-10 expression in latency (e.g. LMP-1 and M2, respectively), vIL-10 may have evolved to serve the specific role in acute infection of enlarging the permissive host cell population, perhaps to facilitate initial survival and dissemination of viral-infected cells
VerdictDB: Universalizing Approximate Query Processing
Despite 25 years of research in academia, approximate query processing (AQP)
has had little industrial adoption. One of the major causes of this slow
adoption is the reluctance of traditional vendors to make radical changes to
their legacy codebases, and the preoccupation of newer vendors (e.g.,
SQL-on-Hadoop products) with implementing standard features. Additionally, the
few AQP engines that are available are each tied to a specific platform and
require users to completely abandon their existing databases---an unrealistic
expectation given the infancy of the AQP technology. Therefore, we argue that a
universal solution is needed: a database-agnostic approximation engine that
will widen the reach of this emerging technology across various platforms.
Our proposal, called VerdictDB, uses a middleware architecture that requires
no changes to the backend database, and thus, can work with all off-the-shelf
engines. Operating at the driver-level, VerdictDB intercepts analytical queries
issued to the database and rewrites them into another query that, if executed
by any standard relational engine, will yield sufficient information for
computing an approximate answer. VerdictDB uses the returned result set to
compute an approximate answer and error estimates, which are then passed on to
the user or application. However, lack of access to the query execution layer
introduces significant challenges in terms of generality, correctness, and
efficiency. This paper shows how VerdictDB overcomes these challenges and
delivers up to 171 speedup (18.45 on average) for a variety of
existing engines, such as Impala, Spark SQL, and Amazon Redshift, while
incurring less than 2.6% relative error. VerdictDB is open-sourced under Apache
License.Comment: Extended technical report of the paper that appeared in Proceedings
of the 2018 International Conference on Management of Data, pp. 1461-1476.
ACM, 201
In Defense of the Epistemic Imperative
Sample (2015) argues that scientists ought not to believe that their theories are true because they cannot fulfill the epistemic obligation to take the diachronic perspective on their theories. I reply that Sample’s argument imposes an inordinately heavy epistemic obligation on scientists, and that it spells doom not only for scientific theories but also for observational beliefs and philosophical ideas that Samples endorses. I also delineate what I take to be a reasonable epistemic obligation for scientists. In sum, philosophers ought to impose on scientists only an epistemic standard that they are willing to impose on themselves
A high resolution atlas of the galactic plane at 12 microns and 25 microns
High resolution images of the 12 micron and 25 micron IRAS survey data from each HCON crossing the Galactic Plane are being created for those regions that the original IRAS processing labeled as confused. This encompasses the area within 100 deg longitude of the Galactic Center and within 3 deg to 10 deg of the Plane. The procedures used to create the images preserve the spatial resolution inherent in the IRAS instrument. The images are separated into diffuse and point source components and candidate sources are extracted from the point source image after non-linear spatial sharpening. Fluxes are estimated by convolving the candidate sources with the point response function and cross-correlating with the original point source image. A source is considered real if it is seen on at least two HCON's with a rather generous flux match but a stringent position criterion. A number of fields spanning a range of source densities from low to high have been examined. Initial analysis indicates that the imaging and extraction works quite well up to a source density of about 100 sources per square degree or down to roughly 0.8 Janskys
Jamming and Fluctuations in Granular Drag
We investigate the dynamic evolution of jamming in granular media through
fluctuations in the granular drag force. The successive collapse and formation
of jammed states give a stick-slip nature to the fluctuations which is
independent of the contact surface between the grains and the dragged object --
thus implying that the stress-induced collapse is nucleated in the bulk of the
granular sample. We also find that while the fluctuations are periodic at small
depths, they become "stepped" at large depths, a transition which we interpret
as a consequence of the long-range nature of the force chains.Comment: 7 pages, 4 figures, RevTe
Isospin breaking in the vector current of the nucleon
Extraction of the nucleon's strange form factors from experimental data
requires a quantitative understanding of the unavoidable contamination from
isospin violation. A number of authors have addressed this issue during the
past decade, and their work is reviewed here. The predictions from early models
are largely consistent with recent results that rely as much as possible on
input from QCD symmetries and related experimental data. The resulting bounds
on isospin violation are sufficiently precise to be of value to on-going
experimental and theoretical studies of the nucleon's strange form factors.Comment: 5 pages, 3 figures. Presented at the International Workshop "From
Parity Violation to Hadronic Structure and more...", Milos, Greece, 16-20 May
2006. Version 2 is only to update Refs. [21] and [25
A mathematical description of nerve fiber bundle trajectories and their variability in the human retina
AbstractWe developed a mathematical model wherein retinal nerve fiber trajectories can be described and the corresponding inter-subject variability analyzed. The model was based on traced nerve fiber bundle trajectories extracted from 55 fundus photographs of 55 human subjects. The model resembled the typical retinal nerve fiber layer course within 20° eccentricity. Depending on the location of the visual field test point, the standard deviation of the calculated corresponding angular location at the optic nerve head circumference ranged from less than 1° to 18°, with an average of 8.8°
Essential health information available for India in the public domain on the internet
<p>Abstract</p> <p>Background</p> <p>Health information and statistics are important for planning, monitoring and improvement of the health of populations. However, the availability of health information in developing countries is often inadequate. This paper reviews the essential health information available readily in the public domain on the internet for India in order to broadly assess its adequacy and inform further development.</p> <p>Methods</p> <p>The essential sources of health-related information for India were reviewed. An extensive search of relevant websites and the PubMed literature database was conducted to identify the sources. For each essential source the periodicity of the data collection, the information it generates, the geographical level at which information is reported, and its availability in the public domain on the internet were assessed.</p> <p>Results</p> <p>The available information related to non-communicable diseases and injuries was poor. This is a significant gap as India is undergoing an epidemiological transition with these diseases/conditions accounting for a major proportion of disease burden. Information on infrastructure and human resources was primarily available for the public health sector, with almost none for the private sector which provides a large proportion of the health services in India. Majority of the information was available at the state level with almost negligible at the district level, which is a limitation for the practical implementation of health programmes at the district level under the proposed decentralisation of health services in India.</p> <p>Conclusion</p> <p>This broad review of the essential health information readily available in the public domain on the internet for India highlights that the significant gaps related to non-communicable diseases and injuries, private health sector and district level information need to be addressed to further develop an effective health information system in India.</p
Radiative Muon Capture on Hydrogen and the Induced Pseudoscalar Coupling
The first measurement of the elementary process is reported. A photon pair spectrometer was used to measure
the partial branching ratio ( for photons of k >
60 MeV. The value of the weak pseudoscalar coupling constant determined from
the partial branching ratio is , where the first error is the quadrature sum of statistical
and systematic uncertainties and the second error is due to the uncertainty in
, the decay rate of the ortho to para molecule. This
value of g_p is 1.5 times the prediction of PCAC and pion-pole dominance.Comment: 13 pages, RevTeX type, 3 figures (encapsulated postscript), submitted
to Phys. Rev. Let
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