25 research outputs found
Counting function fluctuations and extreme value threshold in multifractal patterns: the case study of an ideal noise
To understand the sample-to-sample fluctuations in disorder-generated
multifractal patterns we investigate analytically as well as numerically the
statistics of high values of the simplest model - the ideal periodic
Gaussian noise. By employing the thermodynamic formalism we predict the
characteristic scale and the precise scaling form of the distribution of number
of points above a given level. We demonstrate that the powerlaw forward tail of
the probability density, with exponent controlled by the level, results in an
important difference between the mean and the typical values of the counting
function. This can be further used to determine the typical threshold of
extreme values in the pattern which turns out to be given by
with . Such observation provides a
rather compelling explanation of the mechanism behind universality of .
Revealed mechanisms are conjectured to retain their qualitative validity for a
broad class of disorder-generated multifractal fields. In particular, we
predict that the typical value of the maximum of intensity is to be
given by , where is the
corresponding singularity spectrum vanishing at . For the
noise we also derive exact as well as well-controlled approximate
formulas for the mean and the variance of the counting function without
recourse to the thermodynamic formalism.Comment: 28 pages; 7 figures, published version with a few misprints
corrected, editing done and references adde
Microhydrogel-mediated synthesis of sintered hydroxyapatite granules
Synthesis of macroporous hydroxyapatite (HA) granules with a controlled microarchitecture has been demonstrated by following a polymer microhydrogel mediated synthesis process coupled with sintering. The process is basically based on in situ nucleation and growth of HA nanoparticles in polymer (polyvinyl alcohol) microhydrogels. A systematic variation of polymer concentration has manifested a controlled evolution of a hierarchical macroporous granular structure after sintering
Effects of some natural products from fungal and herbal sources on Giardia lamblia in vivo
Giardia lamblia (G. lamblia) is the most widely known protozoan parasite that causes human gastrointestinal infection worldwide. Some natural compounds exhibited pivotal effects against different infectious diseases. In this research, the antigiardial activity and cytotoxicity of fungal chitosan, nano-chitosan, Rhamnus cathartica (R. cathartica) and emodin were evaluated in Balb/c mice. Genotyping of G. lamblia was assessed by PCR-RFLP technique. Different concentrations of mentioned compounds were used to check their antigiardial and cytotoxicity effects on human intestinal epithelial cells (HT-29) after 24, 48 and 72 h. The G. lamblia strain used in the current work was genotyped and revealed as an AII assemblage. All the concentration showed acceptable activity against G. lamblia cysts and trophozoites in comparison to the negative and positive controls (furazolidone and metronidazole) in vitro (P < 0.05). Giardia lamblia cysts were susceptible after treatment in all experiments in vivo in comparison to negative control (P < 0.05). Approximately, in most of the concentration, nano-chitosan and emodin were more effective than chitosan and R. cathartica, respectively (P < 0.05). The effects of exposure times in antigiardial and cytotoxicity effects were not statistically significant (P > 0.05). The maximum mortality rate (100) was achieved at 100 and 50 μg kg -1 concentrations after 48 and 72 h of exposure time, respectively. Our results provide significant information about the new antigiardial agent and proposed the nano-chitosan and emodin for the development of new drugs against G. lamblia in the future. Copyright © Cambridge University Press 2019
Disparities in the Reporting and Treatment of Health Conditions in Children: An Analysis of the Medical Expenditure Panel Survey
OBJECTIVES: To determine whether racial and ethnic disparities in health care use differ for physical and behavioral health conditions. DATA SOURCES: Secondary analysis of the 1996–1997 Medical Expenditure Panel Survey. STUDY DESIGN: Retrospective cohort study of children aged 2–18 years old who were members of participating households. Children were categorized as Hispanic, black, or white. Differences in caregiver-reported behavioral and physical health conditions and services use were compared, and estimates were weighted to reflect the complex sampling scheme. PRINCIPAL FINDINGS: Of eligible children weighted to represent over 44 million in each year, 13–15 percent were Hispanic, 14 percent black, and 68–70 percent white. After adjusting for potential confounding, Hispanic and black children were less likely to report externalizing behavioral conditions than white children. Black but not Hispanic children were more likely than white children to report asthma. In addition, Hispanic and black children were less likely to report ambulatory visits, and black children were less likely to report receiving a prescription medication than white children. There were no differences in reported emergency room visits or hospitalizations. Interactions between race and various health conditions, health status, insurance, and income were not significant. CONCLUSIONS: In this nationally representative sample, we identified racial and ethnic disparities in the reporting of health conditions and the use of discretionary health services. Disparities differed between those with behavioral conditions and those with physical conditions. These disparities were not explained by traditional measures including the presence of health conditions, health status, insurance, and family income, and suggest that national surveys such as Medical Expenditure Panel Survey may benefit from the inclusion of additional explanatory measures
Transcranial direct current stimulation (tDCS) paired with massed practice training to promote adaptive plasticity and motor recovery in chronic incomplete tetraplegia: A pilot study
<p><b>Objective:</b> Our goal was to determine if pairing transcranial direct current stimulation (tDCS) with rehabilitation for two weeks could augment adaptive plasticity offered by these residual pathways to elicit longer-lasting improvements in motor function in incomplete spinal cord injury (iSCI).</p> <p><b>Design:</b> Longitudinal, randomized, controlled, double-blinded cohort study.</p> <p><b>Setting:</b> Cleveland Clinic Foundation, Cleveland, Ohio, USA.</p> <p><b>Participants:</b> Eight male subjects with chronic incomplete motor tetraplegia.</p> <p><b>Interventions:</b> Massed practice (MP) training with or without tDCS for 2 hrs, 5 times a week.</p> <p><b>Outcome Measures:</b> We assessed neurophysiologic and functional outcomes before, after and three months following intervention. Neurophysiologic measures were collected with transcranial magnetic stimulation (TMS). TMS measures included excitability, representational volume, area and distribution of a weaker and stronger muscle motor map. Functional assessments included a manual muscle test (MMT), upper extremity motor score (UEMS), action research arm test (ARAT) and nine hole peg test (NHPT).</p> <p><b>Results:</b> We observed that subjects receiving training paired with tDCS had more increased strength of weak proximal (15% vs 10%), wrist (22% vs 10%) and hand (39% vs. 16%) muscles immediately and three months after intervention compared to the sham group. Our observed changes in muscle strength were related to decreases in strong muscle map volume (r=0.851), reduced weak muscle excitability (r=0.808), a more focused weak muscle motor map (r=0.675) and movement of weak muscle motor map (r=0.935).</p> <p><b>Conclusion:</b> Overall, our results encourage the establishment of larger clinical trials to confirm the potential benefit of pairing tDCS with training to improve the effectiveness of rehabilitation interventions for individuals with SCI.</p> <p><b>Trial Registration:</b> NCT01539109</p