78 research outputs found
Analysis of Daily Streamflow Complexity by Kolmogorov Measures and Lyapunov Exponent
Analysis of daily streamflow variability in space and time is important for
water resources planning, development, and management. The natural variability
of streamflow is being complicated by anthropogenic influences and climate
change, which may introduce additional complexity into the phenomenological
records. To address this question for daily discharge data recorded during the
period 1989-2016 at twelve gauging stations on Brazos River in Texas (USA), we
use a set of novel quantitative tools: Kolmogorov complexity (KC) with its
derivative associated measures to assess complexity, and Lyapunov time (LT) to
assess predictability. We find that all daily discharge series exhibit long
memory with an increasing downflow tendency, while the randomness of the series
at individual sites cannot be definitively concluded. All Kolmogorov complexity
measures have relatively small values with the exception of the USGS (United
States Geological Survey) 08088610 station at Graford, Texas, which exhibits
the highest values of these complexity measures. This finding may be attributed
to the elevated effect of human activities at Graford, and proportionally
lesser effect at other stations. In addition, complexity tends to decrease
downflow, meaning that larger catchments are generally less influenced by
anthropogenic activity. The correction on randomness of Lyapunov time
(quantifying predictability) is found to be inversely proportional to the
Kolmogorov complexity, which strengthens our conclusion regarding the effect of
anthropogenic activities, considering that KC and LT are distinct measures,
based on rather different techniques
A 3 tesla magnetic resonance imaging volumetric analysis of the hippocampal formation: dependence on handedness and age
Background: The hippocampal formation (HF) is one of the most important parts of the brain in the magnetic resonance imaging (MRI) volumetric analysis in various domains, but not completely from all aspects, including the handedness. The aim of our study was to evaluate the possible differences in the volume of the right and left HF among the healthy right-handed and left-handed subjects, and to determine whether the volume differences are age related.
Materials and methods: The MRI of this prospective study was performed using T1 fast field echo (FFE) sequence. The 124 subsequent coronal slices (thickness 1.5 mm) were performed in each participant. The obtained HF volumes were normalised and statistically compared. Volunteers comprised 30 persons aged 22.0 years, 12 of whom were the left-handed, and 30 persons aged 75.2 years on average, 9 of whom were the left-handed.
Results: The right and left HF volumes averaged 2.986 cm3 and 2.858 cm3 in the right-handed, and 2.879 cm3 and 3.020 cm3 in the left-handed young volunteers, as well as 2.728 cm3 and 2.650 cm3 in the right-handed, and 2.617 cm3 and 2.780 cm3 in the left-handed elderly persons. The HF volume ratios in the young left-handed participants showed a significant left-greater-than-right asymmetry. A significant difference was also noticed within the right-to-left volume ratios of the right- and left-handed young and elderly participants. The latter reduction in the HF volume within the aged group can be interpreted as a slight atrophy of the HF.
Conclusions: There is a significant difference in the volumes of the left and right HF of the left-handed young participants. The age related HF volume differences were proven between the groups of the young and elderly volunteers. The obtained data should be included into the future MRI studies of the HF volumes in various clinical domains.
Fisher zeros of the Q-state Potts model in the complex temperature plane for nonzero external magnetic field
The microcanonical transfer matrix is used to study the distribution of the
Fisher zeros of the Potts models in the complex temperature plane with
nonzero external magnetic field . Unlike the Ising model for
which has only a non-physical critical point (the Fisher edge singularity), the
Potts models have physical critical points for as well as the
Fisher edge singularities for . For the cross-over of the Fisher
zeros of the -state Potts model into those of the ()-state Potts model
is discussed, and the critical line of the three-state Potts ferromagnet is
determined. For we investigate the edge singularity for finite lattices
and compare our results with high-field, low-temperature series expansion of
Enting. For we find that the specific heat, magnetization,
susceptibility, and the density of zeros diverge at the Fisher edge singularity
with exponents , , and which satisfy the scaling
law .Comment: 24 pages, 7 figures, RevTeX, submitted to Physical Review
Accessing parental perspectives to inform the development of parent training in autism in south-eastern Europe
Parent training has been shown to be an important means of supporting families living with autism ā but such services are not universally accessible. A multinational project funded by the European Commission has been developed in order to establish such parent training in three south-eastern European countries. To ensure that the training was relevant and appropriate, a survey was carried out in autumn 2015 to ascertain the attitudes of parents of children with autism in Croatia, Cyprus and the Former Yugoslav Republic of Macedonia regarding this issue, and to identify the areas of training that they felt most important. Two hundred and fifty-three surveys were distributed, and 148 were returned, a response rate of 58%. Respondents in the three counties were overwhelmingly positive about parent training, with almost 90% stating that they would like to attend such training. Weekend training sessions were preferred by the majority of respondents. There was wide variation between the three countries with regard to what content was felt important to be included, with parents in the FYR of Macedonia seeking information in the greatest number of areas. Five topics were prioritised by parents across all three countries. These were: ā¢ Strategies for enhancing my childās communication ā¢ Strategies on facilitating my childās interaction with other children ā¢ Sensory integration and development ā¢ General information on behavioural management strategies ā¢ Identifying and/or developing socialisation opportunitie
Analyses of spatial CHF/REWET behaviour of fuel rod bundle in pump-trip simulation experiment with three-dimensional multi-fluid porous media approach
The investigation of three-dimensional transient propagations of dry-out fronts within a nuclear fuel rod bundle is performed, based on experimental and numerical simulations. The spreading of critical heat flux (CHF) fronts across a bundle, caused by gradual decrease of coolant mass flow rate without power increase is predicted, and the locus of dry patches is shown. Obtained results show that a simultaneous occurrence of CHF and rewet multi-fronts in simulated reactor coolant flow transient are less pronounced than in power transients. Due to a possible building of a vapour zone, the CHF front spatial propagation has to be carefully analysed in transient conditions
Three-dimensional characteristics of post-CHF behaviour within a rod bundle for loss-of-flow simulation: Experimental and three-fluid porous media numerical analyses
The investigation of three-dimensional transient propagations of dry-out fronts within a nuclear fuel rod bundle is performed, based on experimental and numerical simulations. The spreading of Critical Heat Flux (CHF) fronts across a bundle, caused by sudden decrease of coolant mass flow rate followed by delayed gradual decrease of power generation is predicted, and the locus of dry patches is shown. Simultaneous occurrence of CHF and rewet multi-fronts in here-analysed flow transient has not been detected so obvious as in power transient, previously analysed. Due to a possible building of a vapour zone, the CHF front spatial propagation has to be carefully analysed in transient conditions
MIF in autoimmunity and novel therapeutic approaches
Macrophage migration inhibitory factor (MIF) is a multipotent cytokine implicated in the pathogenesis of numerous inflammatory and autoimmune disorders. Since anti-cytokine therapy is considered to be a promising therapeutic strategy, selective targeting of MIF with either anti-MIF antibody or specific chemical MIF inhibitors might offer new therapeutic avenues for these disorders. Considering the unique relationship between MIF and glucocorticoids, therapeutic antagonism of MIF could also represent an effective approach for steroid-sparing therapies in patients with refractory autoimmune diseases. (c) 2008 Elsevier B.V. All rights reserved.Serbian Ministry of Science [143029
Beta cell function: the role of macrophage migration inhibitory factor
During evolution, beta cells adapted to a sole aim: the production and stimulus-dependent secretion of insulin. This acquired specificity was accompanied by a loss of protection mechanisms predisposing beta cell to a high vulnerability. Among beta cell-damaging molecules, a new one has been identified recently: macrophage migration inhibitory factor (MIF). MIF was at first designated as a T-cell product that inhibits random movement of macrophages. Over the years, the number of functions attributed to this protein increased significantly, positioning MIF at the top of inflammatory cascade in the combat against infection and in immunoinflammatory and autoimmune diseases. This exceptionally versatile molecule regulates insulin secretion in physiological conditions, while in pathological states it alters beta cell function and induces their apoptosis or necrosis and affects beta cell neoplasia.Ministry of Education and Science, Republic of Serbia [173013
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