Renormalized entropy for one dimensional discrete maps: periodic and quasi-periodic route to chaos and their robustness

We apply renormalized entropy as a complexity measure to the logistic and sine-circle maps. In the case of logistic map, renormalized entropy decreases (increases) until the accumulation point (after the accumulation point up to the most chaotic state) as a sign of increasing (decreasing) degree of order in all the investigated periodic windows, namely, period-2, 3, and 5, thereby proving the robustness of this complexity measure. This observed change in the renormalized entropy is adequate, since the bifurcations are exhibited before the accumulation point, after which the band-merging, in opposition to the bifurcations, is exhibited. In addition to the precise detection of the accumulation points in all these windows, it is shown that the renormalized entropy can detect the self-similar windows in the chaotic regime by exhibiting abrupt changes in its values. Regarding the sine-circle map, we observe that the renormalized entropy detects also the quasi-periodic regimes by showing oscillatory behavior particularly in these regimes. Moreover, the oscillatory regime of the renormalized entropy corresponds to a larger interval of the nonlinearity parameter of the sine-circle map as the value of the frequency ratio parameter reaches the critical value, at which the winding ratio attains the golden mean.Comment: 14 pages, 7 figure

Metal nanoring and tube formation on carbon nanotubes

The structural and electronic properties of aluminum covered single wall carbon nanotubes (SWNT) are studied from first-principles for a large number of coverage. Aluminum-aluminum interaction that is stronger than aluminum-tube interaction, prevents uniform metal coverage, and hence gives rise to the clustering. However, a stable aluminum ring and aluminum nanotube with well defined patterns can also form around the semiconducting SWNT and lead to metallization. The persistent current in the Al nanoring is discussed to show that a high magnetic field can be induced at the center of SWNT.Comment: Submitted to Physical Review

Inhomogeneous DNA: conducting exons and insulating introns

Parts of DNA sequences known as exons and introns play very different role in coding and storage of genetic information. Here we show that their conducting properties are also very different. Taking into account long-range correlations among four basic nucleotides that form double-stranded DNA sequence, we calculate electron localization length for exon and intron regions. Analyzing different DNA molecules, we obtain that the exons have narrow bands of extended states, unlike the introns where all the states are well localized. The band of extended states is due to a specific form of the binary correlation function of the sequence of basic DNA nucleotides.Comment: 14 pages, 6 figure

Histopathological effects of maternal hair dye use on the cornea

The aim of this study is to investigate and compare the histopathological effects of hair dye additives, 2- amino-5-nitrophenol (2A5NP) and 2-nitro-p-phenylendiamin (2NPPD) on cornea of neonates from pregnant rats that have been administered these additives subcutaneously. The study included 90 neonates of 26 nulligravida wistar-albino rats among which ten were given 100 mg/kg/day 2A5NP (Group I), ten rats received 150 mg/kg/day 2NPPD (Group II) and control rats received saline (Group III) injections subcutaneously between 7th and 15th gestational days. No sign of toxicity was observed during the treatment and there was no gross abnormality in both the study and control groups. Histopathologicalchanges of cornea were seen in 22 of 30 newborn rats in Group I (73.4%), in 23 of 30 rats in Group II (76.7%) and only 5 of 30 rats in the control saline injected Group III (16.7%). Histopathological effect of the two additives were statistically significant when compared to the control group (Chi-square:27.63, p = 0.0001), but there was no difference between the effects of 2A5NP and 2NPPD additives on cornea (Chisquare: 0.089, p = 0.766). The present experimental study on rats confirmed the histopathological effect of 2A5NP and 2NPPD on cornea beyond doubt. In the light of which, we can speculate that maternal exposure of hair dyes during pregnancy has some teratogenic effects on newborn rat cornea

Design of a Polarization-Independent Dual-Band Electromagnetically Induced Transparency-Like Metamaterial

In this study, the classical analog of single and dual-band electromagnetically induced transparency is demonstrated with a four-fold symmetric metamaterial consisting of a Minkowski fractal ring resonator surrounded by a square ring resonator. The proposed metamaterials show high transmission ratios at the polarization independent resonances, as confirmed by the applied two different numerical methods. Delay-bandwidth products are found to be 0.34 and 0.61 at the resonances of the dual-band metamaterial. The peak frequencies and transmission ratios maintain also for oblique angle of incidences. These features of the proposed metamaterials are promising for single and multi-band filtering applications as well as for slow light and sensing devices

Systematic study of adsorption of single atoms on a carbon nanotube

We studied the adsorption of single atoms on a semiconducting and metallic single-wall carbon nanotube from first principles for a large number of foreign atoms. The stable adsorption sites, binding energy, and the resulting electronic properties are analyzed. The character of the bonding and associated physical properties exhibit dramatic variations depending on the type of the adsorbed atom. While the atoms of good conducting metals, such as Cu and Au, form very weak bonding, atoms such as Ti, Sc, Nb, and Ta are adsorbed with relatively high binding energy. Most of the adsorbed transition-metal atoms excluding Ni, Pd, and Pt have a magnetic ground state with a significant magnetic moment. Our results suggest that carbon nanotubes can be functionalized in different ways by their coverage with different atoms, showing interesting applications such as one-dimensional nanomagnets or nanoconductors and conducting connects, etc

Feasibility study of a plastic helical coil heat exchanger for a domestic water storage tank

The main goal of this study is to investigate whether it is possible to use a polymeric helical coil heat exchanger as an alternative to conventional metallic helical coil. More specifically this work focuses on a helical coil design for a domestic water storage tank application. Corrosion and fouling resistance, scarcity of the materials, low weight and cost are the driving forces to consider designing polymeric heat exchangers rather than metallic heat exchangers. However, simply replacing the metallic material by the polymer material and applying the traditional design methods used for metallic heat exchangers do not lead to an acceptable design. If one wants to design a good polymer heat exchanger, heat transfer and structural problems have to be solved first. In addition, the pressure drop limitation should not be neglected. In order to reach this goal, a model is developed to predict the optimal design of a helical coil heat exchanger immersed in the water storage tank for a certain water mass flow rate and temperature. This design compensates for the low thermal conductivity and strength of the polymer.Papers presented to the 12th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Costa de Sol, Spain on 11-13 July 2016

The International Workshop on Osteoarthritis Imaging Knee MRI Segmentation Challenge: A Multi-Institute Evaluation and Analysis Framework on a Standardized Dataset

Purpose: To organize a knee MRI segmentation challenge for characterizing the semantic and clinical efficacy of automatic segmentation methods relevant for monitoring osteoarthritis progression. Methods: A dataset partition consisting of 3D knee MRI from 88 subjects at two timepoints with ground-truth articular (femoral, tibial, patellar) cartilage and meniscus segmentations was standardized. Challenge submissions and a majority-vote ensemble were evaluated using Dice score, average symmetric surface distance, volumetric overlap error, and coefficient of variation on a hold-out test set. Similarities in network segmentations were evaluated using pairwise Dice correlations. Articular cartilage thickness was computed per-scan and longitudinally. Correlation between thickness error and segmentation metrics was measured using Pearson's coefficient. Two empirical upper bounds for ensemble performance were computed using combinations of model outputs that consolidated true positives and true negatives. Results: Six teams (T1-T6) submitted entries for the challenge. No significant differences were observed across all segmentation metrics for all tissues (p=1.0) among the four top-performing networks (T2, T3, T4, T6). Dice correlations between network pairs were high (>0.85). Per-scan thickness errors were negligible among T1-T4 (p=0.99) and longitudinal changes showed minimal bias (<0.03mm). Low correlations (<0.41) were observed between segmentation metrics and thickness error. The majority-vote ensemble was comparable to top performing networks (p=1.0). Empirical upper bound performances were similar for both combinations (p=1.0). Conclusion: Diverse networks learned to segment the knee similarly where high segmentation accuracy did not correlate to cartilage thickness accuracy. Voting ensembles did not outperform individual networks but may help regularize individual models.Comment: Submitted to Radiology: Artificial Intelligence; Fixed typo

Two Males with SRY-Positive 46,XX Testicular Disorder of Sex Development

The 46,XX testicular disorder of sex development (46,XX testicular DSD) is a rare phenotype associated with disorder of the sex chromosomes. We describe the clinical, molecular, and cytogenetic findings of a 16-and a 30-year-old male patient with sex-determining region Y (SRY)-positive 46,XX testicular DSD. Chromosomal analysis revealed 46,XX karyotype. Fluorescence in situ hybridization (FISH) showed the SRY region translocated to the short arm of the X chromosome. The presence of the SRY gene was also confirmed by polymerase chain reaction (PCR). The X chromosome inactivation (XCI) assay showed that both patients have a random pattern of X chromosome inactivation. This report compares the symptoms and features of the SRY-positive 46,XX testicular DSD patients. © 2013 Informa Healthcare USA, Inc