993 research outputs found
Real-Time Hand Shape Classification
The problem of hand shape classification is challenging since a hand is
characterized by a large number of degrees of freedom. Numerous shape
descriptors have been proposed and applied over the years to estimate and
classify hand poses in reasonable time. In this paper we discuss our parallel
framework for real-time hand shape classification applicable in real-time
applications. We show how the number of gallery images influences the
classification accuracy and execution time of the parallel algorithm. We
present the speedup and efficiency analyses that prove the efficacy of the
parallel implementation. Noteworthy, different methods can be used at each step
of our parallel framework. Here, we combine the shape contexts with the
appearance-based techniques to enhance the robustness of the algorithm and to
increase the classification score. An extensive experimental study proves the
superiority of the proposed approach over existing state-of-the-art methods.Comment: 11 page
Dynamic phase transition properties and hysteretic behavior of a ferrimagnetic core-shell nanoparticle in the presence of a time dependent magnetic field
We have presented dynamic phase transition features and stationary-state
behavior of a ferrimagnetic small nanoparticle system with a core-shell
structure. By means of detailed Monte Carlo simulations, a complete picture of
the phase diagrams and magnetization profiles have been presented and the
conditions for the occurrence of a compensation point in the system
have been investigated. According to N\'{e}el nomenclature, the magnetization
curves of the particle have been found to obey P-type, N-type and Q-type
classification schemes under certain conditions. Much effort has been devoted
to investigation of hysteretic response of the particle and we observed the
existence of triple hysteresis loop behavior which originates from the
existence of a weak ferromagnetic core coupling , as well as a
strong antiferromagnetic interface exchange interaction . Most
of the calculations have been performed for a particle in the presence of
oscillating fields of very high frequencies and high amplitudes in comparison
with exchange interactions which resembles a magnetic system under the
influence of ultrafast switching fields. Particular attention has also been
paid on the influence of the particle size on the thermal and magnetic
properties, as well as magnetic features such as coercivity, remanence and
compensation temperature of the particle. We have found that in the presence of
ultrafast switching fields, the particle may exhibit a dynamic phase transition
from paramagnetic to a dynamically ordered phase with increasing ferromagnetic
shell thickness.Comment: 12 pages, 12 figure
Locomotor differences in Mongolian gerbils with the effects of midazolam administration in the form of eye drops
Background: Midazolam is a sedative-hypnotic agent with amnestic and anticonvulsant properties that can be administrated to mammals through various routes, such as intravenous, intramuscular, oral, intrathecal, rectal, and buccal. Midazolam administration in the form of eye drops through the conjunctiva is not reported in the literature. Aim:This study aims to demonstrate the possible central nervous system effects of midazolam administration as eyes drops in Mongolian gerbils. Materials and Methods: Fourteen gerbils were randomly assigned to one of two equal sized groups. The active arm received 2 ml of 10 mg midazolam as eye drops in both eyes. Control group received a total of 2 ml of physiological saline(0.9% NaCl). We subjected the gerbils to an adapted “Open Field” to determine the possible effects on central nervous system of midazolam. Gerbils were allowed to move freely in the open field. Before and after the drug administration, locomotor activities of each gerbil have been recorded. Frequency of loss of righting reflex was quantified. Results: Conjunctival Midazolam administration resulted with the transient loss of righting reflex (p=0.017) and suppressed exploration motion (p=0.018) in the open field test compared to control subjects. Conclusions: In the present study, administration of conjunctival midazolam as an eye drop may affect gerbil’s locomotor activities and open field behaviors. We argue that, using a sedative and anticonvulsive drug such as midazolam via conjunctival route may be useful in some clinical situations. Therefore, it could be beneficial to develop a new conjunctival formulation of midazolam. Also, there is a need for trials in humans with pharmacokinetic studies.Keywords: Righting reflex; Conjunctival Midazolam; Gerbillinae; Midazolam; Eye drop; New administration routeAfrican Health sciences Vol 14 No. 1 March 201
Podwyższony poziom greliny w stanie przedrzucawkowym: czy grelina jest przyjacielem czy wrogiem?
Objectives: To investigate maternal serum ghrelin levels in pregnancies complicated by preeclampsia and to explore the relationship between ghrelin level and disease severity.
Materials and methods: This case-control study included 40 healthy pregnant women, 42 women with mild preeclampsia, and 40 women with severe preeclampsia. The groups were matched in terms of maternal and gestational age and body mass index. Serum ghrelin levels were measured via enzyme immunoassay.
Results: Serum ghrelin levels were significantly higher in women with mild and severe preeclampsia than in healthy controls (p < 0.001). Although serum ghrelin levels were somewhat higher in the severe compared to the mild preeclampsia group, the difference was not statistically significant (p > 0.05). In the control group, no significant correlation was observed between ghrelin level and any other parameter, but in the preeclampsia group, serum ghrelin levels were negatively correlated with uterine artery Doppler index values and both systolic and diastolic blood pressure (all p-values < 0.05). Multivariate stepwise linear regression analysis revealed that systolic blood pressure (β = 0.493, p = 0.023) was independently associated with serum ghrelin level.
Conclusion: Elevated blood ghrelin levels were correlated with disease severity in pregnancies complicated by preeclampsia.Cel pracy: Ocena poziomu greliny w surowicy kobiet w ciąży powikłanej stanem przedrzucawkowym i określenie związku między poziomem greliny a ciężkością choroby.
Materiał i metoda: Do badania włączono 40 zdrowych kobiet w ciąży, 42 z łagodnym stanem przedrzucawkowym i 40 z ciężkim stanem przedrzucawkowym. Grupy były dobrane pod względem wieku ciążowego, wieku matek i wskaźnika masy ciała. Poziom greliny w surowicy był mierzony metodą immunoenzymatyczną.
Wyniki: Poziom greliny w surowicy był istotnie wyższy u kobiet z łagodnym i ciężkim stanem przedrzucawkowym niż w grupie kontrolnej (p < 0,001). Chociaż poziom greliny w surowicy był wyższy w grupie z ciężkim stanem przedrzucawkowym niż w grupie z łagodnym stanem przedrzucawkowym, to ta różnica nie była istotna statystycznie (p > 0,05). W grupie kontrolnej nie obserwowano żadnych istotnych związków pomiędzy poziomem greliny a jakimkolwiek innym parametrem, ale w grupie ze stanem przedrzucawkowym poziom greliny w surowicy był ujemnie skorelowany z indeksami przepływów Dopplera w tętnicy macicznej oraz ciśnieniem krwi skurczowym i rozkurczowym (all p-values < 0,05). Wieloczynnikowa analiza regresji liniowej wykazała, że skurczowe ciśnienie krwi było niezależnym czynnikiem związanym z poziomem greliny w surowicy (β = 0,493, p = 0,023).
Wnioski: Podwyższony poziom greliny we krwi był związany z ciężkością choroby w ciążach powikłanych stanem przedrzucawkowym
Isolation and identification of high lactic acid producer bacteria from forage and their silages grown in different ecologies
A survey of localization in wireless sensor network
Localization is one of the key techniques in wireless sensor network. The location estimation methods can be classified into target/source localization and node self-localization. In target localization, we mainly introduce the energy-based method. Then we investigate the node self-localization methods. Since the widespread adoption of the wireless sensor network, the localization methods are different in various applications. And there are several challenges in some special scenarios. In this paper, we present a comprehensive survey of these challenges: localization in non-line-of-sight, node selection criteria for localization in energy-constrained network, scheduling the sensor node to optimize the tradeoff between localization performance and energy consumption, cooperative node localization, and localization algorithm in heterogeneous network. Finally, we introduce the evaluation criteria for localization in wireless sensor network
Pruning Edge Research with Latency Shears
Edge computing has gained attention from both academia and industry by pursuing two significant challenges: 1) moving latency critical services closer to the users, 2) saving network bandwidth by aggregating large flows before sending them to the cloud. While the rationale appeared sound at its inception almost a decade ago, several current trends are impacting it. Clouds have spread geographically reducing end-user latency, mobile phones? computing capabilities are improving, and network bandwidth at the core keeps increasing. In this paper, we scrutinize edge computing, examining its outlook and future in the context of these trends. We perform extensive client-to-cloud measurements using RIPE Atlas, and show that latency reduction as motivation for edge is not as persuasive as once believed; for most applications the cloud is already 'close enough' for majority of the world's population. This implies that edge computing may only be applicable for certain application niches, as opposed to a general-purpose solution.Peer reviewe
Enterprise 2.0: Research challenges and opportunities
© Springer International Publishing Switzerland 2015. Blending Web 2.0 technologies with enterprise information systems is setting up the stage for a new generation of information systems that will help enterprises open up new communication channels with their stakeholders. Contrary to traditional enterprises with top-down command flow and bottom-up feedback flow, the same flows in Enterprise 2.0 cross all levels and in all directions bringing people together in the development of creative and innovative ideas. The power of Web 2.0 technologies stems from their ability to capture real-world phenomena such as collaboration, competition, and partnership that can be converted into useful and structured information sources from which enterprises can draw information about markets’ trends, consumers’ habits, suppliers’ strategies, etc. This paper discusses the research efforts that our international research group has put into the topic of Enterprise 2.0 (aka Social Enterprise). In particular, our research group advocates that existing practices for managing enterprise information systems need to be re-visited in a way that permits to capture social relations that arise inside and outside the enterprise, to establish guidelines and techniques to assist IT practitioners integrate social relations into their design, development, and maintenance efforts of these information systems, and last but not least to identify and tackle challenges that prevent capturing social relations
Evaluation of rate law approximations in bottom-up kinetic models of metabolism.
BackgroundThe mechanistic description of enzyme kinetics in a dynamic model of metabolism requires specifying the numerical values of a large number of kinetic parameters. The parameterization challenge is often addressed through the use of simplifying approximations to form reaction rate laws with reduced numbers of parameters. Whether such simplified models can reproduce dynamic characteristics of the full system is an important question.ResultsIn this work, we compared the local transient response properties of dynamic models constructed using rate laws with varying levels of approximation. These approximate rate laws were: 1) a Michaelis-Menten rate law with measured enzyme parameters, 2) a Michaelis-Menten rate law with approximated parameters, using the convenience kinetics convention, 3) a thermodynamic rate law resulting from a metabolite saturation assumption, and 4) a pure chemical reaction mass action rate law that removes the role of the enzyme from the reaction kinetics. We utilized in vivo data for the human red blood cell to compare the effect of rate law choices against the backdrop of physiological flux and concentration differences. We found that the Michaelis-Menten rate law with measured enzyme parameters yields an excellent approximation of the full system dynamics, while other assumptions cause greater discrepancies in system dynamic behavior. However, iteratively replacing mechanistic rate laws with approximations resulted in a model that retains a high correlation with the true model behavior. Investigating this consistency, we determined that the order of magnitude differences among fluxes and concentrations in the network were greatly influential on the network dynamics. We further identified reaction features such as thermodynamic reversibility, high substrate concentration, and lack of allosteric regulation, which make certain reactions more suitable for rate law approximations.ConclusionsOverall, our work generally supports the use of approximate rate laws when building large scale kinetic models, due to the key role that physiologically meaningful flux and concentration ranges play in determining network dynamics. However, we also showed that detailed mechanistic models show a clear benefit in prediction accuracy when data is available. The work here should help to provide guidance to future kinetic modeling efforts on the choice of rate law and parameterization approaches
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