6,293 research outputs found
Meteoroid sensor material development Final report, 20 Sep. 1968 - 20 Sep. 1969
Dielectrics evaluated for use in micrometeoroid sensor capacitor
Risk factors for chest infection in acute stroke: a prospective cohort study
<p><b>Background and Purpose:</b> Pneumonia is a major cause of morbidity and mortality after stroke. We aimed to determine key characteristics that would allow prediction of those patients who are at highest risk for poststroke pneumonia.</p>
<p><b>Methods:</b> We studied a series of consecutive patients with acute stroke who were admitted to hospital. Detailed evaluation included the modified National Institutes of Health Stroke Scale; the Abbreviated Mental Test; and measures of swallow, respiratory, and oral health status. Pneumonia was diagnosed by set criteria. Patients were followed up at 3 months after stroke.</p>
<p><b>Results:</b> We studied 412 patients, 391 (94.9%) with ischemic stroke and 21 (5.1%) with hemorrhagic stroke; 78 (18.9%) met the study criteria for pneumonia. Subjects who developed pneumonia were older (mean±SD age, 75.9±11.4 vs 64.9±13.9 years), had higher modified National Institutes of Health Stroke Scale scores, a history of chronic obstructive pulmonary disease, lower Abbreviated Mental Test scores, and a higher oral cavity score, and a greater proportion tested positive for bacterial cultures from oral swabs. In binary logistic-regression analysis, independent predictors (P<0.05) of pneumonia were age >65 years, dysarthria or no speech due to aphasia, a modified Rankin Scale score ≥4, an Abbreviated Mental Test score <8, and failure on the water swallow test. The presence of 2 or more of these risk factors carried 90.9% sensitivity and 75.6% specificity for the development of pneumonia.</p>
<p><b>Conclusions:</b> Pneumonia after stroke is associated with older age, dysarthria/no speech due to aphasia, severity of poststroke disability, cognitive impairment, and an abnormal water swallow test result. Simple assessment of these variables could be used to identify patients at high risk of developing pneumonia after stroke.</p>
On the Unicity of Smartphone Applications
Prior works have shown that the list of apps installed by a user reveal a lot
about user interests and behavior. These works rely on the semantics of the
installed apps and show that various user traits could be learnt automatically
using off-the-shelf machine-learning techniques. In this work, we focus on the
re-identifiability issue and thoroughly study the unicity of smartphone apps on
a dataset containing 54,893 Android users collected over a period of 7 months.
Our study finds that any 4 apps installed by a user are enough (more than 95%
times) for the re-identification of the user in our dataset. As the complete
list of installed apps is unique for 99% of the users in our dataset, it can be
easily used to track/profile the users by a service such as Twitter that has
access to the whole list of installed apps of users. As our analyzed dataset is
small as compared to the total population of Android users, we also study how
unicity would vary with larger datasets. This work emphasizes the need of
better privacy guards against collection, use and release of the list of
installed apps.Comment: 10 pages, 9 Figures, Appeared at ACM CCS Workshop on Privacy in
Electronic Society (WPES) 201
The Impact of Large-scale Employee Share Ownership Plans on Labour Productivity: The Case of Eircom
Large-scale Employee Share Ownership Plans (ESOPs) have been a distinctive characteristic of Irish public enterprise reform, with shareholdings of 14.9 per cent being allocated to employees as part of firm restructuring and privatisation programmes. This paper presents a case study analysis of a large-scale ESOP in Eircom, Ireland’s former national telecommunications operator. We identify changes in labour productivity during the eight years before and after the establishment of the company’s ESOP and use a framework based on Pierce et al. (2001, 1991) to explore the role played by the ESOP. The ESOP was found to play a key role in enabling firm-level reform through concession bargaining and changes in employee relations, and thereby indirectly affecting labour productivity. However, despite the substantial shareholding and influence of the ESOP, we find it has failed to create a sense of psychological ownership among employees, and thereby further impact on productivit
On the Complexity of -Closeness Anonymization and Related Problems
An important issue in releasing individual data is to protect the sensitive
information from being leaked and maliciously utilized. Famous privacy
preserving principles that aim to ensure both data privacy and data integrity,
such as -anonymity and -diversity, have been extensively studied both
theoretically and empirically. Nonetheless, these widely-adopted principles are
still insufficient to prevent attribute disclosure if the attacker has partial
knowledge about the overall sensitive data distribution. The -closeness
principle has been proposed to fix this, which also has the benefit of
supporting numerical sensitive attributes. However, in contrast to
-anonymity and -diversity, the theoretical aspect of -closeness has
not been well investigated.
We initiate the first systematic theoretical study on the -closeness
principle under the commonly-used attribute suppression model. We prove that
for every constant such that , it is NP-hard to find an optimal
-closeness generalization of a given table. The proof consists of several
reductions each of which works for different values of , which together
cover the full range. To complement this negative result, we also provide exact
and fixed-parameter algorithms. Finally, we answer some open questions
regarding the complexity of -anonymity and -diversity left in the
literature.Comment: An extended abstract to appear in DASFAA 201
Impact of alloy disorder on the band structure of compressively strained GaBiAs
The incorporation of bismuth (Bi) in GaAs results in a large reduction of the
band gap energy (E) accompanied with a large increase in the spin-orbit
splitting energy (), leading to the condition that
which is anticipated to reduce so-called CHSH Auger
recombination losses whereby the energy and momentum of a recombining
electron-hole pair is given to a second hole which is excited into the
spin-orbit band. We theoretically investigate the electronic structure of
experimentally grown GaBiAs samples on (100) GaAs substrates by
directly comparing our data with room temperature photo-modulated reflectance
(PR) measurements. Our atomistic theoretical calculations, in agreement with
the PR measurements, confirm that E is equal to for
9. We then theoretically probe the inhomogeneous
broadening of the interband transition energies as a function of the alloy
disorder. The broadening associated with spin-split-off transitions arises from
conventional alloy effects, while the behaviour of the heavy-hole transitions
can be well described using a valence band-anticrossing model. We show that for
the samples containing 8.5% and 10.4% Bi the difficulty in identifying a clear
light-hole-related transition energy from the measured PR data is due to the
significant broadening of the host matrix light-hole states as a result of the
presence of a large number of Bi resonant states in the same energy range and
disorder in the alloy. We further provide quantitative estimates of the impact
of supercell size and the assumed random distribution of Bi atoms on the
interband transition energies in GaBiAs. Our calculations support
a type-I band alignment at the GaBiAs/GaAs interface, consistent
with recent experimental findings
Dear Ireland When You\u27re Free
https://digitalcommons.library.umaine.edu/mmb-vp/4587/thumbnail.jp
Variation in the flowering time orthologs BrFLC and BrSOC1 in a natural population of Brassica rapa.
Understanding the genetic basis of natural phenotypic variation is of great importance, particularly since selection can act on this variation to cause evolution. We examined expression and allelic variation in candidate flowering time loci in Brassica rapa plants derived from a natural population and showing a broad range in the timing of first flowering. The loci of interest were orthologs of the Arabidopsis genes FLC and SOC1 (BrFLC and BrSOC1, respectively), which in Arabidopsis play a central role in the flowering time regulatory network, with FLC repressing and SOC1 promoting flowering. In B. rapa, there are four copies of FLC and three of SOC1. Plants were grown in controlled conditions in the lab. Comparisons were made between plants that flowered the earliest and latest, with the difference in average flowering time between these groups ∼30 days. As expected, we found that total expression of BrSOC1 paralogs was significantly greater in early than in late flowering plants. Paralog-specific primers showed that expression was greater in early flowering plants in the BrSOC1 paralogs Br004928, Br00393 and Br009324, although the difference was not significant in Br009324. Thus expression of at least 2 of the 3 BrSOC1 orthologs is consistent with their predicted role in flowering time in this natural population. Sequences of the promoter regions of the BrSOC1 orthologs were variable, but there was no association between allelic variation at these loci and flowering time variation. For the BrFLC orthologs, expression varied over time, but did not differ between the early and late flowering plants. The coding regions, promoter regions and introns of these genes were generally invariant. Thus the BrFLC orthologs do not appear to influence flowering time in this population. Overall, the results suggest that even for a trait like flowering time that is controlled by a very well described genetic regulatory network, understanding the underlying genetic basis of natural variation in such a quantitative trait is challenging
GOLF DRIVE LAUNCH ANGLES AND VELOCITY: 3D ANALYSIS VERSUS A COMMERCIAL LAUNCH MONITOR
The purpose of this study was to compare initial ball direction and velocity for a golf drive collected using a commercially available launch monitor and 3D data, collected using a retro-reflective motion analysis system. Six golfers (handicap: 2-20) completed 10 drives each, with data simultaneously recorded by both a 12 camera Vicon MX system (400Hz) and a Vector Pro launch monitor. Both systems produced outputs for launch angle, side angle and ball velocity. The launch monitor data were compared against the ‘benchmark’ 3D results and showed a high correlation (0.93 – 0.96). Mean errors (launch angle 0.5º, side angle 1.1º, ball velocity 1.1m/s) were also relatively small. The results of the study suggest that if a high speed 3D system is not available or practical, a launch monitor such as the one tested, should provide accurate measurements of golf ball launch data
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