266 research outputs found
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The four varieties of South Asian monsoon low-pressure systems and their modulation by tropical intraseasonal variability
South Asian monsoon low-pressure systems (LPSs) are synoptic-scale cyclonic vortices that produce substantial precipitation over the Indian subcontinent. In this study, a catalogue of four regional varieties of LPSs, which occur during June–September 1979–2018, is used for
4 examining the track statistics, thermal and moisture structure, and precipitation contribution of each variety. The modulation of LPS activity by tropical intraseasonal variability, which is commonly monitored by the Boreal Summer Intraseasonal Oscillation, Monsoon Intraseasonal Oscillation and Madden-Julian Oscillation indices, is investigated
Shape-induced force fields in optical trapping
Advances in optical tweezers, coupled with the proliferation of two-photon polymerization systems, mean that it is now becoming routine to fabricate and trap non-spherical particles. The shaping of both light beams and particles allows fine control over the flow of momentum from the optical to mechanical regimes. However, understanding and predicting the behaviour of such systems is highly complex in comparison with the traditional optically trapped microsphere. In this Article, we present a conceptually new and simple approach based on the nature of the optical force density. We illustrate the method through the design and fabrication of a shaped particle capable of acting as a passive force clamp, and we demonstrate its use as an optically trapped probe for imaging surface topography. Further applications of the design rules highlighted here may lead to new sensors for probing biomolecule mechanics, as well as to the development of optically actuated micromachines
Wilson Expansion of QCD Propagators at Three Loops: Operators of Dimension Two and Three
In this paper we construct the Wilson short distance operator product
expansion for the gluon, quark and ghost propagators in QCD, including
operators of dimension two and three, namely, A^2, m^2, m A^2, \ovl{\psi} \psi
and m^3. We compute analytically the coefficient functions of these operators
at three loops for all three propagators in the general covariant gauge. Our
results, taken in the Landau gauge, should help to improve the accuracy of
extracting the vacuum expectation values of these operators from lattice
simulation of the QCD propagators.Comment: 20 pages, no figure
The classical case of character release: Darwin's finches ( Geospiza ) on Isla Daphne Major, GalÁpagos
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75575/1/j.1095-8312.1984.tb01679.x.pd
Routine pattern discovery and anomaly detection in individual travel behavior
Discovering patterns and detecting anomalies in individual travel behavior is
a crucial problem in both research and practice. In this paper, we address this
problem by building a probabilistic framework to model individual
spatiotemporal travel behavior data (e.g., trip records and trajectory data).
We develop a two-dimensional latent Dirichlet allocation (LDA) model to
characterize the generative mechanism of spatiotemporal trip records of each
traveler. This model introduces two separate factor matrices for the spatial
dimension and the temporal dimension, respectively, and use a two-dimensional
core structure at the individual level to effectively model the joint
interactions and complex dependencies. This model can efficiently summarize
travel behavior patterns on both spatial and temporal dimensions from very
sparse trip sequences in an unsupervised way. In this way, complex travel
behavior can be modeled as a mixture of representative and interpretable
spatiotemporal patterns. By applying the trained model on future/unseen
spatiotemporal records of a traveler, we can detect her behavior anomalies by
scoring those observations using perplexity. We demonstrate the effectiveness
of the proposed modeling framework on a real-world license plate recognition
(LPR) data set. The results confirm the advantage of statistical learning
methods in modeling sparse individual travel behavior data. This type of
pattern discovery and anomaly detection applications can provide useful
insights for traffic monitoring, law enforcement, and individual travel
behavior profiling
Salivary changes and dental caries as potential oral markers of autoimmune salivary gland dysfunction in primary Sjögren's syndrome
BACKGROUND: the classification criteria for primary Sjögren's syndrome (pSS) include a number of oral components. In this study we evaluated if salivary flow and composition as well as dental caries are oral markers of disease severity in pSS. METHODS: in 20 patients fulfilling the American-European Consensus criteria for pSS and 20 age-matched healthy controls whole and parotid saliva flow rates and composition, measures of oral dryness, scores of decayed, missing and filled tooth surfaces (DMFS), periodontal indices, oral hygiene, and dietary habits were examined. RESULTS: in pSS, salivary flow rates, pH, and buffer capacities were lower, and DMFS, salivary sodium and chloride concentrations higher than in the healthy controls. DMFS also correlated inversely to salivary flow rates and positively to oral dryness. Apart from slightly increased gingival index, and more frequent dental visits in pSS, the periodontal condition, oral hygiene or sugar intake did not differ between these two groups. In pSS, findings were correlated to labial salivary gland focus score (FS) and presence of serum-autoantibodies to SSA/SSB (AB). The patients having both presence of AB and the highest FS (>2) also had the highest salivary sodium and chloride concentrations, the lowest salivary phosphate concentrations, lowest salivary flow rates, and highest DMFS compared to those with normal salivary concentrations of sodium and chloride at a given flow rate. CONCLUSION: the salivary changes observed in some pSS patients reflect impaired ductal salt reabsorption, but unaffected acinar transport mechanisms, despite low salivary secretion. Our results suggest that changes in salivary flow and composition as well as dental caries may serve as potential markers of the extent of autoimmune-mediated salivary gland dysfunction in pSS. The study also indicates that the ductal epithelium is functionally affected in some pSS patients, which calls for future pathophysiological studies on the mechanisms underlying this impaired salt reabsorption
Total smoking bans in psychiatric inpatient services: a survey of perceived benefits, barriers and support among staff
Background: The introduction of total smoking bans represents an important step in addressing the smoking and physical health of people with mental illness. Despite evidence indicating the importance of staff support in the successful implementation of smoking bans, limited research has examined levels of staff support prior to the implementation of a ban in psychiatric settings, or factors that are associated with such support. This study aimed to examine the views of psychiatric inpatient hospital staff regarding the perceived benefits of and barriers to implementation of a successful total smoking ban in mental health services. Secondly, to examine the level of support among clinical and non-clinical staff for a total smoking ban. Thirdly, to examine the association between the benefits and barriers perceived by clinicians and their support for a total smoking ban in their unit. Methods: Cross-sectional survey of both clinical and non-clinical staff in a large inpatient psychiatric hospital immediately prior to the implementation of a total smoking ban. Results: Of the 300 staff, 183 (61%) responded. Seventy-three (41%) of total respondents were clinical staff, and 110 (92%) were non-clinical staff. More than two-thirds of staff agreed that a smoking ban would improve their work environment and conditions, help staff to stop smoking and improve patients' physical health. The most prevalent clinician perceived barriers to a successful total smoking ban related to fear of patient aggression (89%) and patient non-compliance (72%). Two thirds (67%) of all staff indicated support for a total smoking ban in mental health facilities generally, and a majority (54%) of clinical staff expressed support for a ban within their unit. Clinical staff who believed a smoking ban would help patients to stop smoking were more likely to support a smoking ban in their unit. Conclusions: There is a clear need to more effectively communicate to staff the evidence that consistently applied smoking bans do not increase patient aggression. There is also a need to communicate the benefits of smoking bans in aiding the delivery of smoking cessation care, and the benefits of both smoking bans and such care in aiding patients to stop smoking
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