187 research outputs found

    Secure Digital Signal Transmission by Multistep Parameter Modulation and Alternative Driving of Transmitter Variables

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    The idea of secure communication of digital signals via chaos synchronization has been plagued by the possibility of attractor reconstruction by eavesdroppers as pointed out by Perez and Cerdeira. In this Letter, we wish to present a very simple mechanism by which this problem can be overcome, wherein the signal is transmitted via a multistep parameter modulation combined with alternative driving of different transmitter variables, which makes the attractor reconstruction impossible. The method is illustrated by means of the Lorenz system and Chua's circuit as examples.Comment: 15 pages, RevTeX, 6 eps figures, To appear in Int. J. Bifurcation and Chaos (July 2001

    Estimation of System Parameters in Discrete Dynamical Systems from Time Series

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    We propose a simple method to estimate the parameters involved in discrete dynamical systems from time series. The method is based on the concept of controlling chaos by constant feedback. The major advantages of the method are that it needs a minimal number of time series data and is applicable to dynamical systems of any dimension. The method also works extremely well even in the presence of noise in the time series. The method is specifically illustrated by means of logistic and Henon maps.Comment: 4 page

    Estimation of System Parameters and Predicting the Flow Function from Time Series of Continuous Dynamical Systems

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    We introduce a simple method to estimate the system parameters in continuous dynamical systems from the time series. In this method, we construct a modified system by introducing some constants (controlling constants) into the given (original) system. Then the system parameters and the controlling constants are determined by solving a set of nonlinear simultaneous algebraic equations obtained from the relation connecting original and modified systems. Finally, the method is extended to find the form of the evolution equation of the system itself. The major advantage of the method is that it needs only a minimal number of time series data and is applicable to dynamical systems of any dimension. The method also works extremely well even in the presence of noise in the time series. This method is illustrated for the case of Lorenz system.Comment: 12 pages, 4 figure

    Desynchronized wave patterns in synchronized chaotic regions of coupled map lattices

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    We analyze the size limits of coupled map lattices with diffusive coupling at the crossover of low-dimensional to high-dimensional chaos. We investigate the existence of standing-wave-type periodic patterns, within the low-dimensional limit, in addition to the stable synchronous chaotic states depending upon the initial conditions. Further, we bring out a controlling mechanism to explain the emergence of standing-wave patterns in the coupled map lattices. Finally, we give an analytic expression in terms of the unstable periodic orbits of the isolated map to represent the standing-wave patterns

    The role of Remote Sensing and GIS for spatial prediction of vector-borne diseases transmission: A systematic review

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    There have been several attemps made to the appreciation of remote sensing and GIS for the study of vectors,biodiversity, vector presence, vector abundance and the vector-borne diseases with respect to space and time.This study was made for reviewing and appraising the potential use of remote sensing and GIS applications forspatial prediction of vector-borne diseases transmission. The nature of the presence and the abundance of vectorsand vector-borne diseases, disease infection and the disease transmission are not ubiquitous and are confined withgeographical, environmental and climatic factors, and are localized. The presence of vectors and vector-bornediseases is most complex in nature, however, it is confined and fueled by the geographical, climatic andenvironmental factors including man-made factors. The usefulness of the present day availability of the informationderived from the satellite data including vegetation indices of canopy cover and its density, soil types, soil moisture,soil texture, soil depth, etc. is integrating the information in the expert GIS engine for the spatial analysis of othergeoclimatic and geoenvironmental variables. The present study gives the detailed information on the classicalstudies of the past and present, and the future role of remote sensing and GIS for the vector-borne diseasescontrol. The ecological modeling directly gives us the relevant information to understand the spatial variation ofthe vector biodiversity, vector presence, vector abundance and the vector-borne diseases in association withgeoclimatic and the environmental variables. The probability map of the geographical distribution and seasonalvariations of horizontal and vertical distribution of vector abundance and its association with vector-borne diseasescan be obtained with low cost remote sensing and GIS tool with reliable data and speed

    Amniotic membrane as a scaffold in wound healing and diabetic foot ulcer: an experimental technique and recommendations

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    Background: Human amniotic membrane has been used clinically in a variety of applications for over the past 100 years and produced a significant amount of data in multiple areas of medicine. Its clinical usage ranges from wound coverage for burn victims to healing of the conjunctiva after pterygium repair. The amniotic membrane natural properties provide an easy to use, safe option for various medical applications. There is need to develop a method for storage of amniotic membrane which can retain the biological properties and as well have long shelf life too.Methods: The experimental technique was standardized for cryopreservation of amniotic membrane. For this, amniotic membrane was obtained from mothers who had delivered through caesarean section with their consent.Results: The standardized protocol for cryopreservation of amniotic membrane was found to be safe and preserved amniotic membrane is expected to have long shelf life.  Conclusions: The advantages associated with amniotic membrane such as easily available, inexpensive, non-immunogenic and antimicrobial, anti-inflammatory properties make it a suitable graft to be used in wound healing and diabetic foot ulcers

    Comparative secretome analysis of Colletotrichum falcatum identifies a cerato-platanin protein (EPL1) as a potential pathogen-associated molecular pattern (PAMP) inducing systemic resistance in sugarcane

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    Colletotrichum falcatum, an intriguing hemibiotrophic fungal pathogen causes the devastating red rot disease of sugarcane. Repeated in vitro subculturing of C. falcatum under dark condition alters morphology and reduces virulence of the culture. Hitherto, no information is available on this phenomenon at molecular level. In this study, the in vitro secretome of C. falcatum cultured under light and dark conditions was analyzed using 2-DE coupled with MALDI TOF/TOF MS. Comparative analysis identified nine differentially abundant proteins. Among them, seven proteins were less abundant in the dark-cultured C. falcatum, wherein only two protein species of a cerato-platanin protein called EPL1 (eliciting plant response-like protein) were found to be highly abundant. Transcriptional expression of candidate high abundant proteins were profiled during host-pathogen interaction using qRT-PCR. Comprehensively, this comparative secretome analysis identified five putative effectors, two pathogenicity-related proteins and one pathogen-associated molecular pattern (PAMP) of C. falcatum. Functional characterization of three distinct domains of the PAMP (EPL1) showed that the major cerato-platanin domain (EPL1 Δ N1–92) is exclusively essential for inducing defense and hypersensitive response (HR) in sugarcane and tobacco, respectively. Further, priming with EPL1 Δ N1–92 protein induced systemic resistance and significantly suppressed the red rot disease severity in sugarcane. Biological significance Being the first secretomic investigation of C. falcatum, this study has identified five potential effectors, two pathogenicity-related proteins and a PAMP. Although many reports have highlighted the influence of light on pathogenicity, this study has established a direct link between light and expression of effectors, for the first time. This study has presented the influence of a novel N-terminal domain of EPL1 in physical and biological properties and established the functional role of major cerato-platanin domain of EPL1 as a potential elicitor inducing systemic resistance in sugarcane. Comprehensively, the study has identified proteins that putatively contribute to virulence of C. falcatum and for the first time, demonstrated the potential role of EPL1 in inducing PAMP-triggered immunity (PTI) in sugarcane

    Epidemiology of Untreated Psychoses in 3 Diverse Settings in the Global South

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    Importance: Less than 10% of research on psychotic disorders has been conducted in settings in the Global South, which refers broadly to the regions of Latin America, Asia, Africa, and Oceania. There is a lack of basic epidemiological data on the distribution of and risks for psychoses that can inform the development of services in many parts of the world. / Objective: To compare demographic and clinical profiles of cohorts of cases and rates of untreated psychoses (proxy for incidence) across and within 3 economically and socially diverse settings in the Global South. Two hypotheses were tested: (1) demographic and clinical profiles of cases with an untreated psychotic disorder vary across setting and (2) rates of untreated psychotic disorders vary across and within setting by clinical and demographic group. / Design, Setting, and Participants: The International Research Program on Psychotic Disorders in Diverse Settings (INTREPID II) comprises incidence, case-control, and cohort studies of untreated psychoses in catchment areas in 3 countries in the Global South: Kancheepuram District, India; Ibadan, Nigeria; and northern Trinidad. Participants were individuals with an untreated psychotic disorder. This incidence study was conducted from May 1, 2018, to July 31, 2020. In each setting, comprehensive systems were implemented to identify and assess all individuals with an untreated psychosis during a 2-year period. Data were analyzed from January 1 to May 1, 2022. / Main Outcomes and Measures: The presence of an untreated psychotic disorder, assessed using the Schedules for Clinical Assessment in Neuropsychiatry, which incorporate the Present State Examination. / Results: Identified were a total of 1038 cases, including 64 through leakage studies (Kancheepuram: 268; median [IQR] age, 42 [33-50] years; 154 women [57.5%]; 114 men [42.5%]; Ibadan: 196; median [IQR] age, 34 [26-41] years; 93 women [47.4%]; 103 men [52.6%]; Trinidad: 574; median [IQR] age, 30 [23-40] years; 235 women [40.9%]; 339 men [59.1%]). Marked variations were found across and within settings in the sex, age, and clinical profiles of cases (eg, lower percentage of men, older age at onset, longer duration of psychosis, and lower percentage of affective psychosis in Kancheepuram compared with Ibadan and Trinidad) and in rates of untreated psychosis. Age- and sex-standardized rates of untreated psychoses were approximately 3 times higher in Trinidad (59.1/100 000 person-years; 95% CI, 54.2-64.0) compared with Kancheepuram (20.7/100 000 person-years; 95% CI, 18.2-23.2) and Ibadan (14.4/100 000 person-years; 95% CI, 12.3-16.5). In Trinidad, rates were approximately 2 times higher in the African Trinidadian population (85.4/100 000 person-years; 95% CI, 76.0-94.9) compared with the Indian Trinidadian (43.9/100 000 person-years; 95% CI, 35.7-52.2) and mixed populations (50.7/100 000 person-years; 95% CI, 42.0-59.5). / Conclusions and Relevance: This analysis adds to research that suggests that core aspects of psychosis vary by historic, economic, and social context, with far-reaching implications for understanding and treatment of psychoses globally

    Protein kinase Cθ is required for cardiomyocyte survival and cardiac remodeling

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    Protein kinase Cs (PKCs) constitute a family of serine/threonine kinases, which has distinguished and specific roles in regulating cardiac responses, including those associated with heart failure. We found that the PKCθ isoform is expressed at considerable levels in the cardiac muscle in mouse, and that it is rapidly activated after pressure overload. To investigate the role of PKCθ in cardiac remodeling, we used PKCθ−/− mice. In vivo analyses of PKCθ−/− hearts showed that the lack of PKCθ expression leads to left ventricular dilation and reduced function. Histological analyses showed a reduction in the number of cardiomyocytes, combined with hypertrophy of the remaining cardiomyocytes, cardiac fibrosis, myofibroblast hyper-proliferation and matrix deposition. We also observed p38 and JunK activation, known to promote cell death in response to stress, combined with upregulation of the fetal pattern of gene expression, considered to be a feature of the hemodynamically or metabolically stressed heart. In keeping with these observations, cultured PKCθ−/− cardiomyocytes were less viable than wild-type cardiomyocytes, and, unlike wild-type cardiomyocytes, underwent programmed cell death upon stimulation with α1-adrenergic agonists and hypoxia. Taken together, these results show that PKCθ maintains the correct structure and function of the heart by preventing cardiomyocyte cell death in response to work demand and to neuro-hormonal signals, to which heart cells are continuously exposed
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