Synchronization and an application of a novel fractional order King Cobra chaotic system.

In this paper, we design a new three dimensional King Cobra face shaped fractional order chaotic system. The multi-scale synchronization scheme of two fractional order chaotic systems is described. The necessary conditions for the multi-scale synchronization of two identical fractional order King Cobra chaotic systems are derived through feedback control. A new cryptosystem is proposed for an image encryption and decryption by using synchronized fractional order King Cobra chaotic systems with the supports of multiple cryptographic assumptions. The security of the proposed cryptosystem is analyzed by the well known algebraic attacks. Numerical simulations are given to show the effectiveness of the proposed theoretical results.

Comment on "Generalized projective synchronization in time-delayed systems: nonlinear observer approach" [Chaos 19, 013102 (2009); 20, 029902 (2010)].

In Chaos 19, 013102 (2009), the author proposed generalized projective synchronization for time delay systems using nonlinear observer and obtained sufficient condition to ensure projective synchronization for modulated time varying delay. There are concerns with the obtained conditions as the result was applicable only to trivial case of time varying delay τ[over dot](1)(t)=dτ(1)(t)/dt<1. In this paper, we note the drawbacks of the proposed sufficient condition. The new improved sufficient condition for ensuring the projective synchronization of time varying delayed systems is presented. The proposed new criteria have been verified by adopting the Ikeda system.

Toxic epidermal necrolysis: retrospective analysis of 21 consecutive cases managed at a tertiary centre.

BACKGROUND: Toxic epidermal necrolysis (TEN) is a rare, severe blistering disease. Outcome data in British patients is limited to case reports or small series. AIMS: To characterize the aetiology, clinical features, complications and outcome in TEN, and to evaluate the effect of treatments including intravenous immunoglobulin (IVIg). METHODS: This was a retrospective study of 21 consecutive patients with histologically confirmed TEN presenting between 1995 and 2007 to a tertiary referral unit for TEN in a university hospital in the UK. RESULTS: The mean age of the patients was 53.5 years. The mean surface area of denuded skin was 44% (range 30-90%). An adverse drug reaction was implicated in all patients, with mean time of TEN onset being 17 days (range 2-41 days) after initial drug exposure. The SCORTEN index was calculated in 19 patients (median SCORTEN 3, range 2-5). The SCORTEN predicted 7.3 deaths in this cohort, and 7 deaths were seen in the group of patients for whom SCORTEN was calculated. The overall mortality was 8/21 (38%). Ten patients received corticosteroids before transfer to our centre. In the steroid-treated group 4/10 patients (40%) died, and 4/11 patients (36%) who were not treated with steroids also died. Between 1995 and 2000, patients were treated with cyclophosphamide 1.5 mg/kg/day (n=2; both died) and subsequently with ciclosporin 2.5-4 mg/kg/day (n=3; 2 deaths). From 2000, patients were treated with IVIg 0.4-1 g/kg/day (n=14; 3 deaths); the SCORTEN-predicted mortality in this group was 5 deaths. Complications included sepsis (n=18), and organisms included Enterococcus, Acinetobacter, Staphylococcus aureus and methicillin-resistant S. aureus strains). Other complications included anaemia (n=17), lymphopenia (n=11) and neutrophilia (n=9). The presence of neutropenia (n=6; 4 deaths), renal impairment (n=5; 4 deaths) and disseminated intravascular coagulation (n=4; all died) were strong risk factors for mortality. Of 12 patients with ocular involvement, 6 (50%) developed symblepharon and/or visual impairment. CONCLUSIONS: This study confirmed the validity of SCORTEN in our series. In the subgroup treated with IVIg, there were three deaths, compared with the SCORTEN predicted mortality of five deaths. Corticosteroids did not seem to be beneficial.

Lichen planus in children: review of 26 cases.

Lichen Planus (LP) is a common, very itchy papulosquamous disorder. Most reports of LP in children have come from the Indian subcontinent, suggesting that children of South Asian origin are more susceptible to developing LP. We conducted a retrospective, open, observational study of children with LP over a 10-year period, comparing the proportion of ethnicity in this group with the background ethnicity using UK census data from 2001. Of 26 children included in the study, 21 (80.8%) were from the Indian subcontinent, whereas the majority of the child population of Birmingham (0-17 years) was white (58%), with only 28% of the population being South Asian. Statistical analysis showed that the over-representation of South Asians in our series is significant (P < 0.001, 95% CI 56-91%). To our knowledge, this is the largest study on LP in children outside the Indian subcontinent.

Controllability of fractional higher order stochastic integrodifferential systems with fractional Brownian motion.

This paper presents a new set of sufficient conditions for controllability of fractional higher order stochastic integrodifferential systems with fractional Brownian motion (fBm) in finite dimensional space using fractional calculus, fixed point technique and stochastic analysis approach. In particular, we discuss the complete controllability for nonlinear fractional stochastic integrodifferential systems under the proved result of the corresponding linear fractional system is controllable. Finally, an example is presented to illustrate the efficiency of the obtained theoretical results.

Sliding mode control for generalized robust synchronization of mismatched fractional order dynamical systems and its application to secure transmission of voice messages.

This paper proposes a generalized robust synchronization method for different dimensional fractional order dynamical systems with mismatched fractional derivatives in the presence of function uncertainty and external disturbance by a designing sliding mode controller. Based on the proposed theory of generalized robust synchronization criterion, a novel audio cryptosystem is proposed for sending or sharing voice messages secretly via insecure channel. Numerical examples are given to verify the potency of the proposed theories.

Dynamical Analysis of the Hindmarsh-Rose Neuron With Time Delays.

This brief is mainly concerned with a series of dynamical analyses of the Hindmarsh-Rose (HR) neuron with state-dependent time delays. The dynamical analyses focus on stability, Hopf bifurcation, as well as chaos and chaos control. Through the stability and bifurcation analysis, we determine that increasing the external current causes the excitable HR neuron to exhibit periodic or chaotic bursting/spiking behaviors and emit subcritical Hopf bifurcation. Furthermore, by choosing a fixed external current and varying the time delay, the stability of the HR neuron is affected. We analyze the chaotic behaviors of the HR neuron under a fixed external current through time series, bifurcation diagram, Lyapunov exponents, and Lyapunov dimension. We also analyze the synchronization of the chaotic time-delayed HR neuron through nonlinear control. Based on an appropriate Lyapunov-Krasovskii functional with triple integral terms, a nonlinear feedback control scheme is designed to achieve synchronization between the uncontrolled and controlled models. The proposed synchronization criteria are derived in terms of linear matrix inequalities to achieve the global asymptotical stability of the considered error model under the designed control scheme. Finally, numerical simulations pertaining to stability, Hopf bifurcation, periodic, chaotic, and synchronized models are provided to demonstrate the effectiveness of the derived theoretical results.

Delay decomposition approach to [Formula: see text] filtering analysis of genetic oscillator networks with time-varying delays.

In this paper, the [Formula: see text] filtering problem is treated for N coupled genetic oscillator networks with time-varying delays and extrinsic molecular noises. Each individual genetic oscillator is a complex dynamical network that represents the genetic oscillations in terms of complicated biological functions with inner or outer couplings denote the biochemical interactions of mRNAs, proteins and other small molecules. Throughout the paper, first, by constructing appropriate delay decomposition dependent Lyapunov-Krasovskii functional combined with reciprocal convex approach, improved delay-dependent sufficient conditions are obtained to ensure the asymptotic stability of the filtering error system with a prescribed [Formula: see text] performance. Second, based on the above analysis, the existence of the designed [Formula: see text] filters are established in terms of linear matrix inequalities with Kronecker product. Finally, numerical examples including a coupled Goodwin oscillator model are inferred to illustrate the effectiveness and less conservatism of the proposed techniques.

Synchronization of Markovian jumping inertial neural networks and its applications in image encryption.

This study is mainly concerned with the problem on synchronization criteria for Markovian jumping time delayed bidirectional associative memory neural networks and their applications in secure image communications. Based on the variable transformation method, the addressed second order differential equations are transformed into first order differential equations. Then, by constructing a suitable Lyapunov-Krasovskii functional and based on integral inequalities, the criteria which ensure the synchronization between the uncontrolled system and controlled system are established through designed feedback controllers and linear matrix inequalities. Further, the proposed results proved that the error system is globally asymptotically stable in the mean square. Moreover, numerical illustrations are provided to validate the effectiveness of the derived analytical results. Finally, the application of addressed system is explored via image encryption/decryption process.

A new thresholding technique based on fuzzy set as an application to leukocyte nucleus segmentation.

BACKGROUND AND OBJECTIVES: The main aim of this paper is to segment leukocytes in blood smear images using interval-valued intuitionistic fuzzy sets (IVIFSs). Generally, uncertainties occur in terms of vagueness through brightness levels of image. Processing of such uncertain images can be efficiently handled by using fuzzy sets, particularly IVIFSs. METHODS: Logarithmic membership function is utilized for computing membership values corresponding to intensities of the pixel. Non-membership function of IVIFS is constructed by using Yager generating function. By varying parameters, 256 IVIFSs are generated. An IVIFS is selected from 256 IVIFSs having maximizing ultrafuzziness along with varying threshold. Threshold is determined by finding an IVIFS with maximum similarity between ideal segmented and segmented results obtained from the proposed method. RESULTS: Quantitatively, the segmented images are evaluated using precision-recall, receiver operator characteristic curves, Jaccard coefficient and measure for structural similarity index along with the time taken for segmenting nucleus, and their results are compared with results of existing methods. Performance measures reveal that the proposed method seems to segment leukocytes better than other comparable methods. CONCLUSIONS: Segmentation of leukocytes using the proposed method helps the analyst in differentiating various types of leukocytes and in the determination of leukocyte count, and the counting is essential in finding out diseases related to reduction or surplus quantity of these cells.

Pediatric brain tumors: An analysis of 5 years of data from a tertiary cancer care center, India.

BACKGROUND: Pediatric brain tumors are the most common solid tumors in children and a leading cause of mortality and morbidity in children worldwide. Even though there are enough data about the epidemiology of pediatric brain tumors in western population, there are only a few reports from developing countries like India. AIMS: To study the epidemiological patterns of brain tumors in children, to study the patterns of care, and to assess the treatment response. MATERIALS AND METHODS: A retrospective epidemiological approach is used. The records of children <18 years registered in our department from August 2006 to July 2011 diagnosed as primary brain tumors are selected. Data regarding age, sex, site of the tumor, clinical features, histology, treatment plan, and treatment response are collected. The World Health Organization classification of neoplasms was adopted. RESULTS: Of 250 cases, females (57%) slightly outnumbered males. The present study revealed that astrocytoma (52%) is the most common brain tumor in childhood. Surgery was the main modality of treatment. Chemotherapy was given to 16% of patients. Even though radiation therapy was offered to 74% of patients, only 42% completed radiotherapy. There was subjective clinical improvement in 68% of patient population after treatment. CONCLUSIONS: This is the second study from Tamil Nadu that deals with epidemiology of brain tumors. Multimodality management including surgery, chemotherapy, and radiation therapy remains the cornerstone in the management of pediatric brain tumors.

Admissibility analysis for discrete-time singular systems with randomly occurring uncertainties via delay-divisioning approach.

This paper deals with the problem of admissibility analysis for discrete-time singular system with time-delays. The uncertainties occurring in the system parameters are assumed to be random. By constructing Lyapunov functional, sufficient delay-dependent stochastic admissibility conditions are established via delay divisioning approach in terms of linear matrix inequalities (LMIs), which can be easily checked by utilizing the numerically efficient Matlab LMI toolbox. Numerical examples and their simulation results are given to illustrate the effectiveness of the obtained theoretical results.

Mean square delay dependent-probability-distribution stability analysis of neutral type stochastic neural networks.

The aim of this manuscript is to investigate the mean square delay dependent-probability-distribution stability analysis of neutral type stochastic neural networks with time-delays. The time-delays are assumed to be interval time-varying and randomly occurring. Based on the new Lyapunov-Krasovskii functional and stochastic analysis approach, a novel sufficient condition is obtained in the form of linear matrix inequality such that the delayed stochastic neural networks are globally robustly asymptotically stable in the mean-square sense for all admissible uncertainties. Finally, the derived theoretical results are validated through numerical examples in which maximum allowable upper bounds are calculated for different lower bounds of time-delay.

An analysis of medulloblastoma: 10 year experience of a referral institution in South India.

BACKGROUND: Medulloblastoma is an embryonal tumor with aggressive behavior and is more commonly seen in children than adults. The aim of this study was to determine the epidemiological patterns of medulloblastoma in a tertiary care center in Southern India. MATERIALS AND METHODS: It is a retrospective study, in which the records of all the clinically diagnosed medulloblastoma cases in the last 10 years (2002-2012) were analyzed. RESULTS: A total of 58 cases were found, with the mean age at diagnosis being 10 years. There was a slight predilection for the male sex (58.62%). The first presenting symptom was mostly related to raise intracranial pressure and the mean duration of symptoms was 200 days. Nearly, 89.6% of patients were in Stage 0 and had a central tumor location. Multimodality treatment included surgery followed by craniospinal irradiation up to 36 gray followed by posterior fossa boost up to 54 gray. Median radiation therapy duration was 6.5 weeks and concurrent single agent vincristine was the most common chemotherapy used. Most of the patients showed only a partial response to treatment, mainly because of large tumors at presentation, which could be attributed to the lack of awareness, delayed medical attention and poor follow-up. CONCLUSION: Early diagnosis and treatment is the key to management of medulloblastoma, which still needs to be achieved. Bulky tumors have a poor outcome, efforts should be aimed at complete surgery and giving risk stratification based treatment. Resources need to be allocated to make more conformal methods of radiotherapy available, which will decrease the growth abnormalities and cognitive impairments.

The estimation of dermal collagen in osteoporotic patients by a histomorphometric method.

Sections of skin biopsies from the dorsum of the hand of patients with symptomatic osteoporosis were compared with those of carefully selected age-sex matched controls. The amount of dermal collagen in the osteoporotic individuals estimated by a histomorphometric method was found to be significantly less and severe degrees of collagen loss could be readily identified by microscopic examination. Distinct morphological abnormalities of the collagen fibres could also be observed in most patients with osteoporosis. This loss of dermal collagen is suggested to be the main factor responsible for the decrease in skin fold thickness and the frequently striking transparency of skin observed in association with osteoporosis.

Nerve root canals of the lumbar spine.

The nerve root canal is an essential part of the spinal canal. Though it is an appendage of the spinal canal, the nerve root canal, like the inguinal canal, has its own anatomical boundaries and relationships. A knowledge of its anatomy is necessary in the understanding and treatment of low back pain.

Healing of non-vascularised diaphyseal bone transplants. An experimental study.

Four different experiments were performed to study the healing of a large, non-vascularised, diaphyseal, bone segment in adult cats. In the first experiment, a 4 cm segment of tibia with its periosteum was excised and replaced in its bed. The other experiments were similar, except that in the second, the periosteum of the segment was removed, in the third its medullary canal was blocked with a Silastic rod, and in the last group the segment was isolated from its muscle bed by a Silastic sheet. The reparative processes were quantified by estimating the resorption index, the cortical new bone formation index, the callus encasement index, and the osteocyte count. Bone resorption and apposition occurred in the segment even when the periosteum was absent or the medullary canal was blocked, with osseous union at both ends by eight to 12 weeks, provided the segment was not isolated from its muscle bed. Thus, the muscle bed played a significant role in these reparative processes.

Moiré topography in scoliosis. Its accuracy in detecting the site and size of the curve.

Moiré topography was added to school scoliosis screening in Singapore in 1982. The results from 1342 topographs, assessed in isolation, were used to study the accuracy of the method in predicting the radiographic location and magnitude of scoliotic curves. Accuracy in identifying the site of the curve was 68% in the thoracic spine, 54% in the thoracolumbar spine, and 15% in the lumbar region. There were 12.7% false-positive results and 4.3% false negatives. Of patients with a deviation of one moiré fringe, 76.5% had a curve of 15 degrees or less; of those with a deviation of four moiré fringes, 69% had a curve greater than 26 degrees. The prediction of the Cobb angle was less accurate when there was a deviation of two or three fringes. It is suggested that moiré topography as a screening device should be reserved for use in the second tier of screening, since the forward-bending test is an effective and cheap method for the first tier of a mass school-screening programme.

A repair operation for recurrent dislocation of peroneal tendons.

A lesion similar to that described by Bankart in recurrent dislocation of the shoulder was seen in seven patients with recurrent dislocation of the peroneal tendons. Detachment of the periosteum had resulted in the formation of a false pouch on the surface of the lower end of the fibula; into this pouch the peroneal tendons could easily dislocate. Reattachment of the periosteum to drill holes in the fibula prevented dislocation, and this anatomical method of repair is described. This lesion is one of the causes of recurrent dislocation of the peroneal tendons.