996 research outputs found
A French/English dialogue in architecture and interior decoration from the mid-eighteenth century until the years between the Great Wars.
SIGLEAvailable from British Library Document Supply Centre-DSC:DXN012963 / BLDSC - British Library Document Supply CentreGBUnited Kingdo
Primary Care: A Service-Learning Environment for Occupational Therapy Students
This research provides evidence on occupational therapy (OT) students in primary care (PC). OT demonstrates the skills and knowledge to address chronic medical conditions in PC with entry-level education. Limited evidence of occupational therapists in PC demonstrates a need to examine OT services in this setting. In this emerging area of practice and ever-changing reimbursement models, additional evidence is needed to define the value and continuation of OT services in PC. A mixed-methods study aimed to answer the primary research question: How are OT students used in the PC setting in fieldwork or capstone experiences? A two-phase process was involved. A survey and interview enabled an in-depth exploration of how OT students are used in PC during fieldwork, experiential, and capstone experiences. The benefits identified were: providing holistic care because occupational therapists address social detriments and improvement of patient satisfaction with simple interventions. The top barriers were: limited number of occupational therapists and reimbursement for services. Common methods of student use in PC include: provide interventions, evaluate and screen for OT services, and report patient and provider satisfaction outcomes. Identification of these benefits, barriers, and methods of OT and OTA student use in PC can further advocate for the need of OT in PC while meeting ACOTE standards in education
Vertical Resolved Dust Mass Concentration and Backscatter Coefficient Retrieval of Asian Dust Plume Using Quartz Raman Channel in Lidar Measurements
In this work, we present a method for estimating vertical resolved mass concentration of dust immersed in Asian dust plume using Raman scattering of quartz (silicon dioxide, silica). During the Asian dust period of March 15, 16, and 21 in 2010, Raman lidar measurements detected the presence of quartz, and successfully showed the vertical profiles of the quartz backscatter coefficient. Since the Raman backscatter coefficient was connected with the Raman backscatter differential cross section and the number density of quartz molecules, the mass concentration of quartz in the atmosphere can be estimated from the quartz backscatter coefficient. The weight percentage from 40 to 70 % for quartz in the Asian dust was estimated from references. The vertical resolved mass concentration of dust was estimated by quartz mass concentration and weight percentage. We also present a retrieval method to obtain dust backscatter coefficient from the mixed Asian dust and pollutant layer. OPAC (Optical Properties of Aerosol and Clouds) simulations were conducted to calculate dust backscatter coefficient. The retrieved dust mass concentration was used as an input parameter for the OPAC calculations. These approaches in the study will be useful for characterizing the quartz dominated in the atmospheric aerosols and estimating vertical resolved mass concentration of dust. It will be especially applicable for optically distinguishing the dust and non-dust aerosols in studies on the mixing state of Asian dust plume. Additionally, the presented method combined with satellite observations is enable qualitative and quantitative monitoring for Asian dust
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Infrequent new particle formation over the remote boreal forest of Siberia
Aerosol particle number size distributions (PNSD) were investigated to verify, if extremely low-volatility organic vapors (ELVOC) from natural sources alone could induce new particle formation and growth events over the remote boreal forest region of Siberia, hundreds of kilometers away from significant anthropogenic sources. We re-evaluated observations determined at a height of 300 m of the remote observatory ZOTTO (Zotino Tall Tower Observatory, http://www.zottoproject.org). We found that new particle formation events occurred only on 11 days in a 3-year period, suggesting that homogeneous nucleation with a subsequent condensational growth could not be the major process, maintaining the particle number concentration in the planetary boundary layer of the remote boreal forest area of Siberia. © 2018 Elsevier Lt
The Partial Visibility Representation Extension Problem
For a graph , a function is called a \emph{bar visibility
representation} of when for each vertex , is a
horizontal line segment (\emph{bar}) and iff there is an
unobstructed, vertical, -wide line of sight between and
. Graphs admitting such representations are well understood (via
simple characterizations) and recognizable in linear time. For a directed graph
, a bar visibility representation of , additionally, puts the bar
strictly below the bar for each directed edge of
. We study a generalization of the recognition problem where a function
defined on a subset of is given and the question is whether
there is a bar visibility representation of with for every . We show that for undirected graphs this problem
together with closely related problems are \NP-complete, but for certain cases
involving directed graphs it is solvable in polynomial time.Comment: Appears in the Proceedings of the 24th International Symposium on
Graph Drawing and Network Visualization (GD 2016
Characterization of primary biogenic aerosol particles in urban, rural, and high-alpine air by DNA sequence and restriction fragment analysis of ribosomal RNA genes
This study explores the applicability of DNA analyses for the characterization of primary biogenic aerosol (PBA) particles in the atmosphere. Samples of fine particulate matter (PM<sub>2.5</sub>) and total suspended particulates (TSP) have been collected on different types of filter materials at urban, rural, and high-alpine locations along an altitude transect in the south of Germany (Munich, Hohenpeissenberg, Mt. Zugspitze). <br><br> From filter segments loaded with about one milligram of air particulate matter, DNA could be extracted and DNA sequences could be determined for bacteria, fungi, plants and animals. Sequence analyses were used to determine the identity of biological organisms, and terminal restriction fragment length polymorphism analyses (T-RFLP) were applied to estimate diversities and relative abundances of bacteria. Investigations of blank and background samples showed that filter materials have to be decontaminated prior to use, and that the sampling and handling procedures have to be carefully controlled to avoid artifacts in the analyses. <br><br> Mass fractions of DNA in PM<sub>2.5</sub> were found to be around 0.05% in urban, rural, and high-alpine aerosols. The average concentration of DNA determined for urban air was on the order of ~7 ng m<sup>&minus;3</sup>, indicating that human adults may inhale about one microgram of DNA per day (corresponding to ~10<sup>8</sup> haploid bacterial genomes or ~10<sup>5</sup> haploid human genomes, respectively). <br><br> Most of the bacterial sequences found in PM<sub>2.5</sub> were from <i>Proteobacteria</i> (42) and some from <i>Actinobacteria</i> (10) and <i>Firmicutes</i> (1). The fungal sequences were characteristic for <i>Ascomycota</i> (3) and <i>Basidiomycota</i> (1), which are known to actively discharge spores into the atmosphere. The plant sequences could be attributed to green plants (2) and moss spores (2), while animal DNA was found only for one unicellular eukaryote (protist). <br><br> Over 80% of the 53 bacterial sequences could be matched to one of the 19 T-RF peaks found in the PM<sub>2.5</sub> samples, but only 40% of the T-RF peaks did correspond to one of the detected bacterial sequences. The results demonstrate that the T-RFLP analysis covered more of the bacterial diversity than the sequence analysis. Shannon-Weaver indices calculated from both sequence and T-RFLP data indicate that the bacterial diversity in the rural samples was higher than in the urban and alpine samples. Two of the bacterial sequences (<i>Gammaproteobacteria</i>) and five of the T-RF peaks were found at all sampling locations
Comparison of different Aethalometer correction schemes and a reference multi-wavelength absorption technique for ambient aerosol data
Deriving absorption coefficients from Aethalometer attenuation data requires different corrections to compensate for artifacts related to filter-loading effects, scattering by filter fibers, and scattering by aerosol particles. In this study, two different correction schemes were applied to seven-wavelength Aethalometer data, using multi-angle absorption photometer (MAAP) data as a reference absorption measurement at 637 nm. The compensation algorithms were compared to five-wavelength offline absorption measurements obtained with a multi-wavelength absorbance analyzer (MWAA), which serves as a multiple-wavelength reference measurement. The online measurements took place in the Amazon rainforest, from the wet-to-dry transition season to the dry season (June\u2013September 2014). The mean absorption coefficient (at 637 nm) during this period was 1.8 +/-2.1Mm-1, with a maximum of 15.9Mm-1. Under
these conditions, the filter-loading compensation was negligible. One of the correction schemes was found to artificially
increase the short-wavelength absorption coefficients. It was found that accounting for the aerosol optical properties in the scattering compensation significantly affects the absorption \uc5ngstr\uf6m exponent (\ue5ABS/ retrievals. Proper Aethalometer data compensation schemes are crucial to retrieve the correct \ue5ABS, which is commonly implemented in brown carbon contribution calculations. Additionally, we found that the wavelength dependence of uncompensated Aethalometer attenuation data significantly correlates with the \ue5ABS retrieved from offline MWAA measurements
Seasonal variation of ozone deposition to a tropical rain forest in southwest Amazonia
International audienceWithin the project EUropean Studies on Trace gases and Atmospheric CHemistry as a contribution to Large-scale Biosphere-atmosphere experiment in Amazonia (LBA-EUSTACH), we performed tower-based eddy covariance measurements of O3 flux above an Amazonian primary rain forest at the end of the wet and dry season. Ozone deposition revealed distinct seasonal differences in the magnitude and diel variation. In the wet season, the rain forest was an effective O3 sink with a mean daytime (midday) maximum deposition velocity of 2.3 cm s?1, and a corresponding O3 flux of ?11 nmol m?2 s?1. At the end of the dry season, the ozone mixing ratio was about four times higher (up to maximum values of 80 ppb) than in the wet season, as a consequence of strong regional biomass burning activity. However, the typical maximum daytime deposition flux was very similar to the wet season. This results from a strong limitation of daytime O3 deposition due to reduced plant stomatal aperture as a response to large values of the specific humidity deficit. As a result, the average midday deposition velocity in the dry burning season was only 0.5 cm s?1. The large diel ozone variation caused large canopy storage effects that masked the true diel variation of ozone deposition mechanisms in the measured eddy covariance flux, and for which corrections had to be made. In general, stomatal aperture was sufficient to explain the largest part of daytime ozone deposition. However, during nighttime, chemical reaction with nitrogen monoxide (NO) was found to contribute substantially to the O3 sink in the rain forest canopy. Further contributions were from non-stomatal plant uptake and other processes that could not be clearly identified. Measurements, made simultaneously on a 22 years old cattle pasture enabled the spatially and temporally direct comparison of O3 dry deposition values from this site with typical vegetation cover of deforested land in southwest Amazonia to the results from the primary rain forest. The mean ozone deposition to the pasture was found to be systematically lower than that to the forest by 30% in the wet and 18% in the dry season
Spectral- and size-resolved mass absorption efficiency of mineral dust aerosols in the shortwave spectrum: a simulation chamber study
This paper presents new laboratory measurements
of the mass absorption efficiency (MAE) between 375 and
850 nm for 12 individual samples of mineral dust from different
source areas worldwide and in two size classes: PM10:6
(mass fraction of particles of aerodynamic diameter lower
than 10.6 \u3bcm) and PM2:5 (mass fraction of particles of aerodynamic
diameter lower than 2.5 \u3bcm). The experiments were
performed in the CESAM simulation chamber using mineral
dust generated from natural parent soils and included optical
and gravimetric analyses.
The results show that the MAE values are lower for
the PM10:6 mass fraction (range 37\u2013135x10-3 m2 g-1 at
375 nm) than for the PM2:5 (range 95\u2013711x10-3 m2 g-1 at
375 nm) and decrease with increasing wavelength as lambda-AAE,
where the \uc5ngstr\uf6m absorption exponent (AAE) averages
between 3.3 and 3.5, regardless of size. The size independence
of AAE suggests that, for a given size distribution, the oxide fraction, which could ease the application and the validation
of climate models that now start to include the representation
of the dust composition, as well as for remote
sensing of dust absorption in the UV\u2013vis spectral region
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