381 research outputs found
Assessment of human errors in driving accidents; Analysis of the causes based on aberrant behaviors
Introduction: Today, mortalities and injuries due to traffic accidents have been confirmed as a global phenomenon. Meanwhile, mistakes and high risk behaviors by drivers, is the most important intervening factor in traffic accidents. This study is to analyze the causes of traffic accidents according to drivers' aberrant behaviors. Methods: This cross-sectional study was conducted on 540 taxi drivers using Manchester Driving Behaviour Questinnaire in 0-5 Likert scale. After being gathered, the data were analyzed by SPSS 11.5 using Pearson Correlation and Logistic Regression. Findings: The mean score of aberrant driving behaviors was obtained 2.06 (± 0.47) and lapse obtained the highest score and driving mistakes did the lowest. As age advanced, the rate of aberrant behaviours declined (P = 0.006). Commitment of mistakes and offences was more prevalent in ages under 30 years compared to other age ranges and lapse in the individuals over 50 years was more prevalent compared to other items. The results of logistic regression indicated that all variables of DBQ are important in predicting Iranian drivers' aberrant behaviors (P < 0.001), but intentional offences had the highest correlation. There was an inverse correlation between driving history and intentional offences and mistakes (P < 0.001). Conclusion: According to the results, it could be said that intentional offences and lapse in driving behaviors are more predictive of self-reported accidents compared to other variables. The drivers in low ages are more willing to practice aberrant behaviors due to lack of adequate skill and experience and having intrinsic excitements. By contrast, as age advances, intentional offenses declines and the rate of lapses ascends. It seems that through provision of regular, periodic training for the drivers by occupation and creating awareness, aberrant behaviors and, by extension, traffic accidents could be effectively decreased
Comparison of albuterol sulphate and base dry powder particulate deposition using the Calu-3 lung epithelial model
To effectively predict the fate of formulated inhalation compounds delivered to the lung, a model of the airway epithelium should reflect drug permeability and transport characteristics in vivo. Most cell-based system established for this purpose, study drug transport using wet models and thus do not necessarily represent in vivo conditions. Recently, air-interface models have been established that increase the relevance of in vitro transport studies to the in vivo state. The aim of our study was to elucidate the dissolution and diffusion process of deposited dry drug particulates (albuterol) after aerosolization onto the epithelial surface and compare these to conventional in vitro `glass models. Two forms of albuterol were investigated (albuterol base and albuterol sulphate), to evaluate the effects of lipophilicity and aqueous solubility on the mechanism of transport
The Effect of Cosmological Background Dynamics on the Spherical Collapse in MOND
The effect of background dynamics of the universe on formation of large scale
structures in the framework of Modified Newtonian Dynamics (MOND) is
investigated. A spherical collapse model is used for modeling the formation of
the structures. This study is done in two extreme cases: ({\it i}) assuming a
universe with a low-density baryonic matter without any cold dark matter and
dark energy; ({\it ii}) a dark energy dominated universe with baryonic matter,
without cold dark matter. We show that for the case ({\it ii}) the structures
virialize at lower redshifts with larger radii compared to the low-density
background universe. The dark energy slow downs the collapse of the structures.
We show that our results are compatible with recent simulations of the
structure formation in MOND.Comment: 16 pages, 4 Figures, accepted by New Astronom
Observational Constraints on the Modified Gravity Model (MOG) Proposed by Moffat: Using the Magellanic System
A simple model for the dynamics of the Magellanic Stream (MS), in the
framework of modified gravity models is investigated. We assume that the galaxy
is made up of baryonic matter out of context of dark matter scenario. The model
we used here is named Modified Gravity (MOG) proposed by Moffat (2005). In
order to examine the compatibility of the overall properties of the MS under
the MOG theory, the observational radial velocity profile of the MS is compared
with the numerical results using the fit method. In order to obtain
the best model parameters, a maximum likelihood analysis is performed. We also
compare the results of this model with the Cold Dark Matter (CDM) halo model
and the other alternative gravity model that proposed by Bekenstein (2004), so
called TeVeS. We show that by selecting the appropriate values for the free
parameters, the MOG theory seems to be plausible to explain the dynamics of the
MS as well as the CDM and the TeVeS models.Comment: 14 pages, 3 Figures, accepted in Int. J. Theor. Phy
Galactic kinematics with modified Newtonian dynamics
We look for observational signatures that could discriminate between
Newtonian and modified Newtonian (MOND) dynamics in the Milky Way, in view of
the advent of large astrometric and spectroscopic surveys. Indeed, a typical
signature of MOND is an apparent disk of "phantom" dark matter, which is
uniquely correlated with the visible disk-density distribution. Due to this
phantom dark disk, Newtonian models with a spherical halo have different
signatures from MOND models close to the Galactic plane. The models can thus be
differentiated by measuring dynamically (within Newtonian dynamics) the disk
surface density at the solar radius, the radial mass gradient within the disk,
or the velocity ellipsoid tilt angle above the Galactic plane. Using the most
realistic possible baryonic mass model for the Milky Way, we predict that, if
MOND applies, the local surface density measured by a Newtonist will be
approximately 78 Msun/pc2 within 1.1 kpc of the Galactic plane, the dynamically
measured disk scale-length will be enhanced by a factor of 1.25 with respect to
the visible disk scale-length, and the local vertical tilt of the velocity
ellipsoid at 1 kpc above the plane will be approximately 6 degrees. None of
these tests can be conclusive for the present-day accuracy of Milky Way data,
but they will be of prime interest with the advent of large surveys such as
GAIA.Comment: 5 page
Mono- and Cocultures of Bronchial and Alveolar Epithelial Cells Respond Differently to Proinflammatory Stimuli and Their Modulation by Salbutamol and Budesonide
© 2015 American Chemical Society. The aim of this study was to investigate the changes in transport and effectiveness of salbutamol sulfate (SAL) and budesonide (BD) following stimulation with transforming growth factor-β (TGF-β) in mono- and coculture models of bronchial and alveolar epithelium. Primary bronchial and alveolar epithelial cells, grown at air interface on filters, either as monocultures or in coculture with airway smooth muscle cells or alveolar macrophages, respectively, were stimulated with TGF-β. The biological response was modulated by depositing aerosolized SAL and BD on bronchial and alveolar models, respectively. Barrier integrity, permeability to fluorescein-Na, transport of the deposited drug, and the pharmacological response to SAL (cAMP and IL-8 levels) or BD (IL-6 and -8 levels) were measured. While stimulation with TGF-β did not have any significant effect on the transepithelial electrical resistance and permeability to fluorescein-Na in mono- and coculture models, transport of SAL and BD were affected in cultures from some of the patients (6 out of 12 for bronchial and 2 out of 4 for alveolar cells). The bronchial coculture showed a better responsiveness to SAL in terms of cAMP release than the monoculture. In contrast, the difference between alveolar mono- and cocultures to TGF-β mediated interleukin release and its modulation by BD was less pronounced. Our data point to intrinsic differences in the transport of, and responsiveness to, SAL and BD when epithelial cell cultures originate from different patients. Moreover, if the biological responses (e.g., IL-8, cAMP) involve communication between different cell types, coculture models are more relevant to measure such effects than monocultures
Gravitational anomalies signaling the breakdown of classical gravity
Recent observations for three types of astrophysical systems severely
challenge the GR plus dark matter scenario, showing a phenomenology which is
what modified gravity theories predict. Stellar kinematics in the outskirts of
globular clusters show the appearance of MOND type dynamics on crossing the
threshold. Analysis shows a ``Tully-Fisher'' relation in these systems,
a scaling of dispersion velocities with the fourth root of their masses.
Secondly, an anomaly has been found at the unexpected scales of wide binaries
in the solar neighbourhood. Binary orbital velocities cease to fall along
Keplerian expectations, and settle at a constant value, exactly on crossing the
threshold. Finally, the inferred infall velocity of the bullet cluster
is inconsistent with the standard cosmological scenario, where much smaller
limit encounter velocities appear. This stems from the escape velocity limit
present in standard gravity; the ``bullet'' should not hit the ``target'' at
more than the escape velocity of the joint system, as it very clearly did.
These results are consistent with extended gravity, but would require rather
contrived explanations under GR, each. Thus, observations now put us in a
situation where modifications to gravity at low acceleration scales cease to be
a matter of choice, to now become inevitable.Comment: 10 pages, 5 figures, Astrophysics and Space Science Proceedings 38,
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Fixed points of Suzuki type generalized multivalued mappings in fuzzy metric spaces with applications
The aim of this paper is to introduce a class of multivalued mappings satisfying a
Suzuki type generalized contractive condition in the framework of fuzzy metric
spaces and to present fixed point results for such mappings. Some examples are
presented to support the results proved herein. As an application, a common fixed
point result for a hybrid pair of single and multivalued mappings is obtained. We
show the existence and uniqueness of a common bounded solution of functional
equations arising in dynamic programming. Our results generalize and extend various
results in the existing literature.http://link.springer.com/journal/11784hb201
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