5,618 research outputs found
LSA project technology development update
The state of low cost solar array technology is discussed. The goal of achieving $500/kW by 1986 is also discussed
Building Morphological Chains for Agglutinative Languages
In this paper, we build morphological chains for agglutinative languages by
using a log-linear model for the morphological segmentation task. The model is
based on the unsupervised morphological segmentation system called
MorphoChains. We extend MorphoChains log linear model by expanding the
candidate space recursively to cover more split points for agglutinative
languages such as Turkish, whereas in the original model candidates are
generated by considering only binary segmentation of each word. The results
show that we improve the state-of-art Turkish scores by 12% having a F-measure
of 72% and we improve the English scores by 3% having a F-measure of 74%.
Eventually, the system outperforms both MorphoChains and other well-known
unsupervised morphological segmentation systems. The results indicate that
candidate generation plays an important role in such an unsupervised log-linear
model that is learned using contrastive estimation with negative samples.Comment: 10 pages, accepted and presented at the CICLing 2017 (18th
International Conference on Intelligent Text Processing and Computational
Linguistics
Magnetic Field Structure around Low-Mass Class 0 Protostars: B335, L1527 and IC348-SMM2
We report new 350 micron polarization observations of the thermal dust
emission from the cores surrounding the low-mass, Class 0 YSOs L1527,
IC348-SMM2 and B335. We have inferred magnetic field directions from these
observations, and have used them together with results in the literature to
determine whether magnetically regulated core-collapse and star-formation
models are consistent with the observations. These models predict a pseudo-disk
with its symmetry axis aligned with the core magnetic field. The models also
predict a magnetic field pinch structure on a scale less than or comparable to
the infall radii for these sources. In addition, if the core magnetic field
aligns (or nearly aligns) the core rotation axis with the magnetic field before
core collapse, then the models predict the alignment (or near alignment) of the
overall pinch field structure with the bipolar outflows in these sources. We
show that if one includes the distorting effects of bipolar outflows on
magnetic fields, then in general the observational results for L1527 and
IC348-SMM2 are consistent with these magnetically regulated models. We can say
the same for B335 only if we assume the distorting effects of the bipolar
outflow on the magnetic fields within the B335 core are much greater than for
L1527 and IC348-SMM2. We show that the energy densities of the outflows in all
three sources are large enough to distort the magnetic fields predicted by
magnetically regulated models.Comment: Accepted for publication in The Astrophysical Journa
Ovalbumin sensitization and challenge increases the number of lung cells possessing a mesenchymal stromal cell phenotype
Abstract Background Recent studies have indicated the presence of multipotent mesenchymal stromal cells (MSCs) in human lung diseases. Excess airway smooth muscle, myofibroblasts and activated fibroblasts have each been noted in asthma, suggesting that mesenchymal progenitor cells play a role in asthma pathogenesis. We therefore sought to determine whether MSCs are present in the lungs of ovalbumin (OVA)-sensitized and challenged mice, a model of allergic airways disease. Methods Balb/c mice were sensitized and challenged with PBS or OVA over a 25 day period. Flow cytometry as well as colony forming and differentiation potential were used to analyze the emergence of MSCs along with gene expression studies using immunochemical analyses, quantitative polymerase chain reaction (qPCR), and gene expression beadchips. Results A CD45-negative subset of cells expressed Stro-1, Sca-1, CD73 and CD105. Selection for these markers and negative selection against CD45 yielded a population of cells capable of adipogenic, osteogenic and chondrogenic differentiation. Lungs from OVA-treated mice demonstrated a greater average colony forming unit-fibroblast (CFU-F) than control mice. Sorted cells differed from unsorted lung adherent cells, exhibiting a pattern of gene expression nearly identical to bone marrow-derived sorted cells. Finally, cells isolated from the bronchoalveolar lavage of a human asthma patient showed identical patterns of cell surface markers and differentiation potential. Conclusions In summary, allergen sensitization and challenge is accompanied by an increase of MSCs resident in the lungs that may regulate inflammatory and fibrotic responses.http://deepblue.lib.umich.edu/bitstream/2027.42/78265/1/1465-9921-11-127.xmlhttp://deepblue.lib.umich.edu/bitstream/2027.42/78265/2/1465-9921-11-127.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/78265/3/1465-9921-11-127-S1.DOCPeer Reviewe
Detection of a dense clump in a filament interacting with W51e2
In the framework of the Herschel/PRISMAS Guaranteed Time Key Program, the
line of sight to the distant ultracompact HII region W51e2 has been observed
using several selected molecular species. Most of the detected absorption
features are not associated with the background high-mass star-forming region
and probe the diffuse matter along the line of sight. We present here the
detection of an additional narrow absorption feature at ~70 km/s in the
observed spectra of HDO, NH3 and C3. The 70 km/s feature is not uniquely
identifiable with the dynamic components (the main cloud and the large-scale
foreground filament) so-far identified toward this region. The narrow
absorption feature is similar to the one found toward low-mass protostars,
which is characteristic of the presence of a cold external envelope. The
far-infrared spectroscopic data were combined with existing ground-based
observations of 12CO, 13CO, CCH, CN, and C3H2 to characterize the 70 km/s
component. Using a non-LTE analysis of multiple transitions of NH3 and CN, we
estimated the density (n(H2) (1-5)x10^5 cm^-3) and temperature (10-30 K) for
this narrow feature. We used a gas-grain warm-up based chemical model with
physical parameters derived from the NH3 data to explain the observed
abundances of the different chemical species. We propose that the 70 km/s
narrow feature arises in a dense and cold clump that probably is undergoing
collapse to form a low-mass protostar, formed on the trailing side of the
high-velocity filament, which is thought to be interacting with the W51 main
cloud. While the fortuitous coincidence of the dense clump along the line of
sight with the continuum-bright W51e2 compact HII region has contributed to its
non-detection in the continuum images, this same attribute makes it an
appropriate source for absorption studies and in particular for ice studies of
star-forming regions.Comment: Accepted for publication in A&
Adjustment with aphasia after stroke: study protocol for a pilot feasibility randomised controlled trial for SUpporting wellbeing through PEeR Befriending (SUPERB)
Background: Despite the high prevalence of mood problems after stroke, evidence on effective interventions particularly for those with aphasia is limited. There is a pressing need to systematically evaluate interventions aiming to improve wellbeing for people with stroke and aphasia. This study aims to evaluate the feasibility of a peer-befriending intervention.
Methods/design: SUPERB is a single blind, parallel group feasibility trial of peer befriending for people with aphasia post-stroke and low levels of psychological distress. The trial includes a nested qualitative study and pilot economic evaluation and it compares usual care (n = 30) with usual care + peer befriending (n = 30). Feasibility outcomes include proportion screened who meet criteria, proportion who consent, rate of consent, number of missing/incomplete data on outcome measures, attrition rate at follow-up, potential value of conducting main trial using value of information analysis (economic evaluation), description of usual care, and treatment fidelity of peer befriending. Assessments and outcome measures (mood, wellbeing, communication, and social participation) for participants and significant others will be administered at baseline, with outcome measures re-administered at 4 and 10 months post-randomisation. Peer befrienders will complete outcome measures before training and after they have completed two cycles of befriending. The qualitative study will use semi-structured interviews of purposively sampled participants (n = 20) and significant others (n = 10) from both arms of the trial, and all peer befrienders to explore the acceptability of procedures and experiences of care. The pilot economic evaluation will utilise the European Quality of life measure (EQ-5D-5 L) and a stroke-adapted version of the Client Service Receipt Inventory (CSRI).
Discussion: This study will provide information on feasibility outcomes and an initial indication of whether peer befriending is a suitable intervention to explore further in a definitive phase III randomised controlled trial.
Trial registration: ClinicalTrials.gov identifier NCT02947776, registered 28th October 2016
Using novel palaeolimnological techniques to define conservation objectives for Hatch Mere: Report for Cheshire Wildlife Trust
This is the final report to Natural England on the project ‘Using novel palaeolimnological techniques to define lake conservation objectives for Hatch Mere’. The aim is to use existing and recently developed palaeoecological techniques to define reference conditions and assess the condition of Hatch Mere Special Scientific Interest (SSSIs) in the Cheshire meres, and thereby assist in the setting of conservation objectives and management goals. Two sediment cores (one open water and one marginal), approximately 1 m in length, were collected from Hatch Mere in August 2011. The cores were sampled at 1 cm intervals throughout and approximately ten samples from each site were analysed for diatoms, Cladocera, macrofossils, geochemistry (XRF) and pigments. The cores were dated using radiometric techniques in order to place the fossil remains within a known time frame. An existing diatom-total phosphorus (TP) transfer function was applied to the diatom data to reconstruct the nutrient history of the mere. The dating results suggest that the open water core (HAT3) extends back to ~1800 AD and the marginal core extends back beyond ~17o00 AD. The palaeoecological data indicate that the site has been a moderately enriched lake for the whole of the period represented by the cores with diatom-inferred TP concentrations of ~30 μg L-1 in the lower part of the record. However, there were marked changes across a range of indicators from the early 1800s indicative of enrichment, which has continued through the twentieth century. The key changes were the expansion of the eutrophic diatom species Cyclostephanos dubius and hence an increase in diatom-inferred TP to ~84 μg L-1, a steady increase in pigment concentrations from all algal groups, and shifts in the zooplankton community indicative of increased pelagic productivity. Eutrophication has resulted in marked changes in the aquatic plant community from a structurally diverse flora with abundant Charophytes, nymphaeids and taxa with a mix of seasonalities to the current state with no submerged flora and only Nuphar lutea. The most notable changes in the macrofossil record have occurred from the mid-1800s and are, therefore, coincident with the main phase of enrichment. The dominance of the upper sediments by planktonic zooplankton and abundant Daphnia ephippia towards the top of the core, lends further weight to a plankton dominated system. This study provides information on the plant and animal communities that were present in the lake prior to the major eutrophication phase and this significantly alters the generic target previously set for the lake and will be valuable for setting targets for future management of the site
Shocked molecular gas towards the SNR G359.1-0.5 and the Snake
We have found a bar of shocked molecular hydrogen (H2) towards the OH(1720
MHz) maser located at the projected intersection of supernova remnant (SNR)
G359.1-0.5 and the nonthermal radio filament, known as the Snake. The H2 bar is
well aligned with the SNR shell and almost perpendicular to the Snake. The
OH(1720 MHz) maser is located inside the sharp western edge of the H2 emission,
which is consistent with the scenario in which the SNR drives a shock into a
molecular cloud at that location. The spectral-line profiles of 12CO, HCO+ and
CS towards the maser show broad-line absorption, which is absent in the 13CO
spectra and most probably originates from the pre-shock gas. A density gradient
is present across the region and is consistent with the passage of the SNR
shock while the H2 filament is located at the boundary between the pre--shocked
and post-shock regions.Comment: 8 pages, 12 figures, accepted by the MNRAS, typos fixe
- …