483 research outputs found
A REASSESSMENT OF THE HYBRID APPROACH TO THE CONSTRUCTION OF REGIONAL INPUT-OUTPUT TABLES
This thesis lays the foundation for the creation of an economic database for the
counties of Devon and Cornwall in the form of a regional input-output table. The
thesis reconsiders the popular hybrid approach to the construction of such tables. In
particular, the nonsurvey-to-survey ordering of procedure is questioned. The thesis
attempts to restore a more logical preference-order which begins with first-best
(survey) estimation methods and extends to second-best (survey-based-nonsurvey)
methods. The third-best methods of estimation (pure nonsurvey i.e. location quotient)
are excluded from the process altogether. The thesis is largely concerned with the
development of the second-best method.
The second-best method is derived from an empirical analysis of the nature of
nonsurvey estimation error. The analysis is able to reject the Stevens et al. (1983)
hypothesis that differences in regional and national production functions are
insignificant. Nevertheless, the strategy of developing 'trade-only' nonsurvey
estimation methods is found to be valid since, whilst the error associated with regional
trade misspecification can be reduced within a broad method of estimation, the error
attributable to the misspecification of regional production functions remains largely
intractable to such an approach. Survey resources must therefore be devoted to the
specification of these functions.
The second-best methodology extends the Stevens et al. (1983) by deriving equations
that specify the RAS algorithm and local expenditure propensities for households
from empirical data for Scotland. These equations have general application within the
new hybrid methodology.
By restoring a more logical preference-order of approach to estimating hybrid regional
input-output tables, emphasis is placed on the analytical strength afforded by a good
data set, and not on the analytical 'strength' of magic-box mathematics. This should
encourage the regional input-output table to be implemented as an evolving local
economic database, which will improve the general quality of regional analysis and, in
the long-run, offer cost-savings in data collection and collation
Industrial applications of ASF+SDF
In recent years, a number of Dutch companies have used the algebraic specification formalism ASF+SDF. Bank MeesPierson has specified a language for describing interest rate products, their translation into COBOL, and their generation from interactive questionnaires. A consultancy company has specified a language to represent the company's object-oriented models, and the compilation of this language into Access. Bank ABN-AMRO has started investigating the use of algebraic specifications for renovating legacy COBOL systems. We discuss the implications of such projects for teaching algebraic specifications and software engineering, and the role students have been playing in these projects
In-Plane Vibration of Hammerhead Resonators for Chemical Sensing Applications
Thermally excited and piezoresistively detected in-plane cantilever resonators have been previously demonstrated for gas- and liquid-phase chemical and biosensing applications. In this work, the hammerhead resonator geometry, consisting of a cantilever beam supporting a wider semicircular “head”, vibrating in an in-plane vibration mode, is shown to be particularly effective for gas-phase sensing with estimated limits of detection in the sub-ppm range for volatile organic compounds. This paper discusses the hammerhead resonator design and the particular advantages of the hammerhead geometry, while also presenting mechanical characterization, optical characterization, and chemical sensing results. These data highlight the distinct advantages of the hammerhead geometry over other cantilever designs
After Mazibuko: exploring the responses of communities excluded from South Africa’s water experiment
Despite a constitutional right to water, challenges remain for access to sufficient water in South Africa. This article considers the degree to which current legal provisions perpetuate approaches, which are antithetical to genuinely eco-socio-sustainable water access. Water in South Africa has largely been re-cast as a commodity, exposed to market rules, proving problematic for many and giving rise to various responses, including litigation. In the seminal case of Mazibuko the Constitutional Court failed to provide robust protection to the right to water, providing impetus for the formation of “commons” strategies for water allocation. Indeed “commoning” is beginning to represent not only an emerging conceptual strand in urban resource allocation, but also a dynamic, contemporary, eco-sensitive, socio-cultural phenomenon, driving innovative, interactive and inclusive forms of planning and social engagement. Against the backdrop of unequal water access, commoning offers glimpses of an empowering and enfranchising subaltern paradigm
Diagnosis and Assessment of Depression and Suicidality Using the NIMH Diagnostic Interview Schedule for Children (DISC-2.3)
The Diagnostic Interview Schedule for Children (DISC-2.3) was studied in a sample of 265 adolescent inpatients to determine type and concurrent validity of depressive symptoms and depressive disorder diagnoses for different DISC-2.3 informants (parent, adolescent, both). The Children's Depression Rating Scale — Revised, Reynolds Adolescent Depression Scale (RADS), Suicide Ideation Questionnaire — Junior, Spectrum of Suicide Behavior Scale, and clinical consensus diagnoses were used to assess concurrent validity. Results indicated that (1) parents, compared to adolescents, reported a higher prevalence of all depressive symptoms with the exception of weight change; (2) DISC-2.3 depressive and suicidality symptoms were related positively to independent validating criteria for all informant conditions, suggesting good concurrent validity; (3) the DISC-2.3 both informant condition correctly identified the most depressive disorders; and (4) the parent, but not the adolescent, DISC-2.3 Informant condition contributed to the prediction of clinical consensus diagnoses of depression after taking into account RADS scores.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44585/1/10802_2004_Article_424863.pd
Attributing scientific and technical progress: the case of holography
Holography, the three-dimensional imaging technology, was portrayed widely as a paradigm
of progress during its decade of explosive expansion 1964–73, and during its subsequent
consolidation for commercial and artistic uses up to the mid 1980s. An unusually
seductive and prolific subject, holography successively spawned scientific insights, putative
applications and new constituencies of practitioners and consumers. Waves of forecasts,
associated with different sponsors and user communities, cast holography as a field on the
verge of success—but with the dimensions of success repeatedly refashioned. This retargeting
of the subject represented a degree of cynical marketeering, but was underpinned by
implicit confidence in philosophical positivism and faith in technological progressivism.
Each of its communities defined success in terms of expansion, and anticipated continual
progressive increase. This paper discusses the contrasting definitions of progress in holography,
and how they were fashioned in changing contexts. Focusing equally on reputed ‘failures’ of some aspects of the subject, it explores the varied attributes by which success and failure were linked with progress by different technical communities. This important case illuminates the peculiar post-World War II environment that melded the military, commercial and popular engagement with scientific and technological subjects, and the
competing criteria by which they assessed the products of science
Porphyromonas gingivalis oral infection exacerbates the development and severity of collagen-induced arthritis
Abstract
Introduction
Clinical studies suggest a direct influence of periodontal disease (PD) on serum inflammatory markers and disease assessment of patients with established rheumatoid arthritis (RA). However, the influence of PD on arthritis development remains unclear. This investigation was undertaken to determine the contribution of chronic PD to immune activation and development of joint inflammation using the collagen-induced arthritis (CIA) model.
Methods
DBA1/J mice orally infected with Porphyromonas gingivalis were administered with collagen II (CII) emulsified in complete Freund’s adjuvant (CFA) or incomplete Freund’s adjuvant (IFA) to induce arthritis. Arthritis development was assessed by visual scoring of paw swelling, caliper measurement of the paws, mRNA expression, paw micro-computed tomography (micro-CT) analysis, histology, and tartrate resistant acid phosphatase for osteoclast detection (TRAP)-positive immunohistochemistry. Serum and reactivated splenocytes were evaluated for cytokine expression.
Results
Mice induced for PD and/or arthritis developed periodontal disease, shown by decreased alveolar bone and alteration of mRNA expression in gingival tissues and submandibular lymph nodes compared to vehicle. P. gingivalis oral infection increased paw swelling and osteoclast numbers in mice immunized with CFA/CII. Arthritis incidence and severity were increased by P. gingivalis in mice that received IFA/CII immunizations. Increased synovitis, bone erosions, and osteoclast numbers in the paws were observed following IFA/CII immunizations in mice infected with P gingivalis. Furthermore, cytokine analysis showed a trend toward increased serum Th17/Th1 ratios when P. gingivalis infection was present in mice receiving either CFA/CII or IFA/CII immunizations. Significant cytokine increases induced by P. gingivalis oral infection were mostly associated to Th17-related cytokines of reactivated splenic cells, including IL-1β, IL-6, and IL-22 in the CFA/CII group and IL-1β, tumor necrosis factor-α, transforming growth factor-β, IL-6 and IL-23 in the IFA/CII group.
Conclusions
Chronic P. gingivalis oral infection prior to arthritis induction increases the immune system activation favoring Th17 cell responses, and ultimately accelerating arthritis development. These results suggest that chronic oral infection may influence RA development mainly through activation of Th17-related pathways.http://deepblue.lib.umich.edu/bitstream/2027.42/112639/1/13075_2013_Article_4062.pd
History of Galaxy Interactions and their Impact on Star Formation over the Last 7 Gyr from GEMS
We perform a comprehensive estimate of the frequency of galaxy mergers and
their impact on star formation over z~0.24--0.80 (lookback time T_b~3--7 Gyr)
using 3698 (M*>=1e9 Msun) galaxies with GEMS HST, COMBO-17, and Spitzer data.
Our results are: (1) Among 790 high mass (M*>=2.5e10 Msun) galaxies, the
visually-based merger fraction over z~0.24--0.80, ranges from 9%+-5% to 8%+-2%.
Lower limits on the major and minor merger fractions over this interval range
from 1.1% to 3.5%, and 3.6% to 7.5%, respectively. This is the first
approximate empirical estimate of the frequency of minor mergers at z<1. For a
visibility timescale of ~0.5 Gyr, it follows that over T_b~3--7 Gyr, ~68% of
high mass systems have undergone a merger of mass ratio >1/10, with ~16%, 45%,
and 7% of these corresponding respectively to major, minor, and ambiguous
`major or minor' mergers. The mean merger rate is a few x 1e-4 Gyr-1 Mpc-3. (2)
We compare the empirical merger fraction and rate for high mass galaxies to a
suite of Lambda CDM-based models: halo occupation distribution models,
semi-analytic models, and hydrodynamic SPH simulations. We find qualitative
agreement between observations and models such that the (major+minor) merger
fraction or rate from different models bracket the observations, and show a
factor of five dispersion. Near-future improvements can now start to rule out
certain merger scenarios. (3) Among ~3698 M*>=1e9 Msun galaxies, we find that
the mean SFR of visibly merging systems is only modestly enhanced compared to
non-interacting galaxies over z~0.24--0.80. Visibly merging systems only
account for less than 30% of the cosmic SFR density over T_b~3--7 Gyr. This
suggests that the behavior of the cosmic SFR density over the last 7 Gyr is
predominantly shaped by non-interacting galaxies.Comment: Accepted for Publication in the Astrophysical Journal. 17 pages of
text, 21 figures, 3 tables. Uses emulateapj5.st
Paschen-alpha Emission in the Gravitationally Lensed Galaxy SMM J163554.2+661225
We report the detection of the Paschen-alpha emission line in the z=2.515
galaxy SMM J163554.2+661225 using Spitzer spectroscopy. SMM J163554.2+661225 is
a sub-millimeter-selected infrared (IR)-luminous galaxy maintaining a high
star-formation rate (SFR), with no evidence of an AGN from optical or infrared
spectroscopy, nor X-ray emission. This galaxy is lensed gravitationally by the
cluster Abell 2218, making it accessible to Spitzer spectroscopy. Correcting
for nebular extinction derived from the H-alpha and Pa-alpha lines, the
dust-corrected luminosity is L(Pa-alpha) = (2.57+/-0.43) x 10^43 erg s^-1,
which corresponds to an ionization rate, Q = (1.6+/-0.3) x 10^55 photons s^-1.
The instantaneous SFR is 171+/-28 solar masses per year, assuming a
Salpeter-like initial mass function. The total IR luminosity derived using 70,
450, and 850 micron data is L(IR) = (5-10) x 10^11 solar luminosities,
corrected for gravitational lensing. This corresponds to a SFR=90-180 solar
masses per year, where the upper range is consistent with that derived from the
Paschen-alpha luminosity. While the L(8 micron) / L(Pa-alpha) ratio is
consistent with the extrapolated relation observed in local galaxies and
star-forming regions, the rest-frame 24 micron luminosity is significantly
lower with respect to local galaxies of comparable Paschen-alpha luminosity.
Thus, SMM J163554.2+661225 arguably lacks a warmer dust component (T ~ 70 K),
which is associated with deeply embedded star formation, and which contrasts
with local galaxies with comparable SFRs. Rather, the starburst is consistent
with star-forming local galaxies with intrinsic luminosities, L(IR) ~ 10^10
solar luminosities, but "scaled-up" by a factor of 10-100.Comment: Published in the Astrophysical Journal. 14 pages in emulateapj
format, 9 figures (many in color
CHD8 Regulates Neurodevelopmental Pathways Associated with Autism Spectrum Disorder in Neural Progenitors
Truncating mutations of chromodomain helicase DNA-binding protein 8 (CHD8), and of many other genes with diverse functions, are strong-effect risk factors for autism spectrum disorder (ASD), suggesting multiple mechanisms of pathogenesis. We explored the transcriptional networks that CHD8 regulates in neural progenitor cells (NPCs) by reducing its expression and then integrating transcriptome sequencing (RNA sequencing) with genome-wide CHD8 binding (ChIP sequencing). Suppressing CHD8 to levels comparable with the loss of a single allele caused altered expression of 1,756 genes, 64.9% of which were up-regulated. CHD8 showed widespread binding to chromatin, with 7,324 replicated sites that marked 5,658 genes. Integration of these data suggests that a limited array of direct regulatory effects of CHD8 produced a much larger network of secondary expression changes. Genes indirectly down-regulated (i.e., without CHD8-binding sites) reflect pathways involved in brain development, including synapse formation, neuron differentiation, cell adhesion, and axon guidance, whereas CHD8-bound genes are strongly associated with chromatin modification and transcriptional regulation. Genes associated with ASD were strongly enriched among indirectly down-regulated loci (P < 10[superscript −8]) and CHD8-bound genes (P = 0.0043), which align with previously identified coexpression modules during fetal development. We also find an intriguing enrichment of cancer-related gene sets among CHD8-bound genes (P < 10[superscript −10]). In vivo suppression of chd8 in zebrafish produced macrocephaly comparable to that of humans with inactivating mutations. These data indicate that heterozygous disruption of CHD8 precipitates a network of gene-expression changes involved in neurodevelopmental pathways in which many ASD-associated genes may converge on shared mechanisms of pathogenesis.Simons FoundationNancy Lurie Marks Family FoundationNational Institutes of Health (U.S.) (Grant MH095867)National Institutes of Health (U.S.) (Grant MH095088)National Institutes of Health (U.S.) (Grant GM061354)March of Dimes Birth Defects FoundationCharles H. Hood FoundationBrain & Behavior Research FoundationAutism Genetic Resource ExchangeAutism Speaks (Organization)Pitt–Hopkins Research Foundatio
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