Estimation of System Parameters in Discrete Dynamical Systems from Time Series

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

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

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

Role of Imaging in Identifying Various Renal Lesions in Children Less Than 5 Years Presenting with First Febrile Urinary Tract Infections

Febrile Urinary Tract Infections (UTI) is one of the common causes of infections in children. Unrecognized and untreated UTIs may lead to renal scarring of the growing kidneys with subsequent renal failure. Objectives: To compare the effectiveness of USG to detect vesicoureteric reflex confirmed by micturating cystourethrogram (MCU) and renal parenchymal abnormalities confirmed by dimercaptosuccinic acid scan (DMSA) between 1 month to 59 months of age. Methods: A prospective observational study was done at a tertiary care centre to study the imaging correlation in children with the first episode of febrile UTI. Ultrasonography Kidney-Urinary-Bladder (USG-KUB), MCU, and DMSA were done according to the Indian Academy of Paediatrics protocol after getting informed consent from parents. Results:  USG showed a perfect concordance with MCU in detecting VUR (100% sensitivity and specificity) and had a high sensitivity (94.1%) and specificity (100%) in detecting renal parenchymal abnormalities when compared to DMSA in less than 1 year old. It also showed a sensitivity of 85.4% and specificity of 100% in detecting renal parenchymal abnormalities when compared to DMSA in children aged 1-5 years. Conclusion: Overall, the results of this research article indicate that USG shows promising diagnostic accuracy as a non-invasive imaging modality in detecting VUR and renal parenchymal abnormalities across different age groups presenting with febrile UTI.To study the effectiveness of USG in detecting vesicoureteric reflex confirmed by micturating cystourethrogram and renal parenchymal abnormalities confirmed by dimercaptosuccinic acid scan (DMSA) in children with first episode febrile UTI. Short title: Role of imaging in children with first episode febrile UTI

Perceptions and Prospects: Technology-Enabled Teacher Education in the Digital Age

The integration of technology into education has led to significant transformations in teacher education programs. This study examines the perceptions of learners regarding technology-enabled teacher education programs. It explores the experiences and viewpoints of a diverse group of teacher education students, ranging from pre-service teachers to experienced educators pursuing advanced qualifications. The study reveals that learners generally perceive technology-enabled teacher education programs positively, highlighting advantages such as increased accessibility, flexibility, engagement, and personalization. However, they also acknowledge challenges related to technical issues and the digital divide. These findings emphasize the importance of ongoing research and development in technology integration within teacher education to better prepare educators for the digital age classroom

Tissue-specific role and associated downstream signaling pathways of adiponectin

According to the World Health Organization, metabolic syndrome (MetS) can be defined as a pathological condition characterized by abdominal obesity, insulin resistance, hypertension, and hyperlipidemia. The incidence of MetS keeps rising, as at least 35% of the USA population suffers from MetS. One of the worst comorbidities of metabolic syndrome are cardiovascular diseases that significantly amplifies the mortality associated with this syndrome. There is an urgent need to understand the pathophysiology of MetS to find novel diagnosis, treatment and management to mitigate the MetS and associated complications. Altered circulatory adiponectin levels have been implicated in MetS. Adiponectin has numerous biologic functions including antioxidative, anti-nitrative, anti-inflammatory, and cardioprotective effects. Being a pleiotropic hormone of multiple tissues, tissue-specific key signaling pathways of adiponectin will help finding specific target/s to blunt the pathophysiology of metabolic syndrome and associated disorders. The purpose of this review is to elucidate tissue-specific signaling pathways of adiponectin and possibly identify potential therapeutic targets for MetS as well as to evaluate the potential of adiponectin as a biomarker/therapeutic option in MetS

Desynchronized wave patterns in synchronized chaotic regions of coupled map lattices

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

A review on conventional and laser assisted machining of Aluminium based metal matrix composites

Aluminum based Metal Matrix Composites (Al-MMC) have been found in different industrial applications due its excellent properties compared to conventional materials. Machining of these composites is difficult due to the hard particle reinforcements. The wider usage of these composites is limited due high machining cost and excessive tool wear with conventional machining. Because of increasing demands in industries, any improvement of conventional machining process or any other deployment of additional technique is directly related to higher productivity. Laser Assisted Machining has become an effective alternative to the conventional machining of these difficult- to- cut materials. This paper provides an overview of conventional machining of MMCs and the potential of LAM. An attempt is made to give a better understanding of the operating conditions such as machining parameters and Laser parameters. Finally, the summary of the review is discussed and the scope for future research is presented

Diabetic Aldehyde Dehydrogenase 2 Mutant (ALDH2*2) Mice Are More Susceptible to Cardiac Ischemic-Reperfusion Injury Due to 4-Hydroxy-2-Nonenal Induced Coronary Endothelial Cell Damage

Background: Aldehyde dehydrogenase-2 (ALDH2), a mitochondrial enzyme, detoxifies reactive aldehydes such as 4-hydroxy-2-nonenal (4HNE). A highly prevalent E487K mutation in ALDH2 (ALDH2*2) in East Asian people with intrinsic low ALDH2 activity is implicated in diabetic complications. 4HNE-induced cardiomyocyte dysfunction was studied in diabetic cardiac damage; however, coronary endothelial cell (CEC) injury in myocardial ischemia-reperfusion injury (IRI) in diabetic mice has not been studied. Therefore, we hypothesize that the lack of ALDH2 activity exacerbates 4HNE-induced CEC dysfunction which leads to cardiac damage in ALDH2*2 mutant diabetic mice subjected to myocardial IRI. Methods and Results: Three weeks after diabetes mellitus (DM) induction, hearts were subjected to IRI either in vivo via left anterior descending artery occlusion and release or ex vivo IRI by using the Langendorff system. The cardiac performance was assessed by conscious echocardiography in mice or by inserting a balloon catheter in the left ventricle in the ex vivo model. Just 3 weeks of DM led to an increase in cardiac 4HNE protein adducts and, cardiac dysfunction, and a decrease in the number of CECs along with reduced myocardial ALDH2 activity in ALDH2*2 mutant diabetic mice compared with their wild-type counterparts. Systemic pretreatment with Alda-1 (10 mg/kg per day), an activator of both ALDH2 and ALDH2*2, led to a reduction in myocardial infarct size and dysfunction, and coronary perfusion pressure upon cardiac IRI by increasing CEC population and coronary arteriole opening. Conclusions: Low ALDH2 activity exacerbates 4HNE-mediated CEC injury and thereby cardiac dysfunction in diabetic mouse hearts subjected to IRI, which can be reversed by ALDH2 activation

Antiviral Plant Extracts

Herbal therapy has been an important part of health and wellness for hundreds of years. The renewed interest in medicinal plants has focused on herbal cures among indigenous populations around the world. Recent surveys have indicated that worldwide people now make more visits to healthcare professionals who specialize in alternative medicine than to doctors who practice conventional medicine. It is hoped that extracts from herbs will add new medicinal plants to the world’s pharmacopoeia before they are lost forever that too particularly against viral infection. Based on the ethnobotanical data and the information collected from Siddha/Ayurvedic practitioners of India, extracts obtained from Boerhavia diffusa, Eclipta alba and Phyllanthus amarus will be having great potential in curing various viral infections

Determining mercury and selenium in vitro bioaccessibility in country foods collected from Nunavik, Québec

Country food is a cornerstone of cultural, social, and spiritual life for Inuit communities (Gombay, 2005; Van Oostdam et al., 2005). Country foods refer to marine mammals, fish, plants, berries, seabirds and wild game that have been hunted and gathered from the local area (Van Oostdam et al., 2005). These country foods are a significant route of exposure to many environmental contaminants, including mercury (Hg) (Donaldson et al., 2010; Van Oostdam et al., 2005). Mercury can be very detrimental to human health through adverse cardiovascular, endocrine and neurotoxic effects, especially in vulnerable populations such as the elderly or pregnant women (Clarkson and Magos, 2006; Zahir et al., 2005). Despite being a major route for Hg exposure, country foods are very nutritious and contain high levels of numerous vitamins and minerals including the essential micronutrient – selenium (Se), which can potentially mitigate Hg toxicity (Kuhnlein and Receveur, 2007, 1996). An in vitro gastrointestinal model was used to estimate the in vitro bioaccessibility (IVBA) of Hg and Se in certain country foods. We used an in vitro gastrointestinal model to determine the Hg and Se in vitro bioaccessibility for country foods collected from Nunavik, Quebec that have been digested separately and in combination (i.e. single digest and co-digest, respectively). These country food samples were collected 2008-2013 through the community-based sampling programs overseen by the Nunavik Research Centre of the Makivik Corporation. The purpose of this thesis was to determine: (1) Do the Inuit country foods that have high levels of Hg also have high levels of Se? (2) Does the bioaccessibility of Hg and Se vary from one country food to another? (3) Can the co-consumption of specific food combinations affect the solubilization of Hg within the GI tract? For the single digest country foods, we evaluated Hg and Se in vitro bioaccessibility (IVBA) using a two-stage in vitro gastro-intestinal (GI) model for a variety of country foods harvested in Nunavik, Québec. By assessing the IVBA (i.e. the metal fraction of that would is soluble in the gut lumen), we can approximate metal bioavailability (i.e. the metal fraction o that would cross the gut-blood barrier and reach systemic circulation). The results showed a large variation in Hg (1.4 - 90%) and Se (29 - 108%) bioaccessibility for the country foods studied. The samples with the highest Hg concentration (ringed seal liver) also had the lowest Hg percent bioaccessibility. Generally, Se:Hg molar ratios for the majority of country foods increased and they were greater than one after accounting for metal bioaccessibility (i.e. Se bioaccessibility > Hg bioaccessibility). The main exceptions to this trend included the muscle and liver of ringed seals, which showed similar Se:Hg ratios before and after accounting for metal bioaccessibility. Some foods were also co-digested (or co-consumed) meaning they were digested together in the GI model. For the co-digested country foods, we evaluated the Hg and Se in vitro bioaccessibility (IVBA) using a two-stage in vitro gastrointestinal (GI) model for selected country foods. We compared country foods with high levels of total and IVBA Hg (i.e. ringed seal liver, beluga nikku, raw beluga meat, walrus, lake trout, eider duck egg white) and pair them with country foods that may have a mitigating effect on Hg IVBA (i.e. crowberries, blueberries, seaweed, sculpin eggs and tomato paste). Overall, our results show that there are no additive or subadditive results for IVBA Hg when foods were digested together. In the future, this research may aid in the ongoing contaminant exposure assessments in Nunavik and assist in the development of culturally relevant strategies promoting country food use while decreasing Hg body burden