Channel adaptive real-time medium access control protocols for industrial wireless networks

Wireless technology is increasingly finding its way into industrial communication because of the tremendous advantages it is capable of offering. However, the high bit error rate characteristics of wireless channel due to conditions, such as attenuation, noise, channel fading and interference seriously impact the timeliness and reliability guarantee that need to be provided for real-time traffic. Existing wireless protocols either do not adapt well to erroneous channel conditions or do not provide real-time guarantees. The goal of our work is to design and evaluate novel real-time MAC (Medium Access Control) protocols for combined scheduling of periodic and aperiodic messages taking into account the time-varying channel condition.;Our first contribution is the design of a combined scheduling algorithm that exploits both spatial and temporal diversity of the wireless channel through exchange of slots among nodes, to effectively mitigate bursty channel error conditions. Simulation results show that the proposed algorithm achieves significant improvements in message success ratio compared to baseline protocols under a wide range of traffic and channel conditions.;The second contribution assumes a two-level hierarchical network in which nodes are grouped into clusters and the communication occurs within each cluster and across clusters. The goal is to maximize the schedulability of intra- and inter-cluster periodic and aperiodic messages with deadline guarantees. In this context, we propose an Adaptive protocol that maximizes the channel utilization by enabling parallel transmissions in a collision-free manner, in conjunction with the use of the slot-exchange technique to actively combat the erroneous channel conditions. Through simulation studies, we show that the proposed Adaptive protocol achieves significant improvement in packet loss performance compared to the baseline protocols that exploit complete parallelism and full exchange, for a wide range of channel conditions.;The future work includes: (i) Formulation of the MAC scheduling problem to a n-level hierarchical network and developing novel scheduling algorithms (ii) Extending the scheduling problem to account for node mobility and developing mobility-aware MAC protocols

Catalytic Philanthropy In India

Catalytic Philanthropy is still in its infancy in India. Despite this, there are a surprising number of exemplary cases where Indian philanthropists are creating large-scale social change far beyond the resources invested. This report highlights these practices as well as the key issues that need to be addressed to accelerate its evolution

A Dangerous Twist of the 'T' Wave: A Case of Wellens' Syndrome

Wellens’ syndrome is a condition in which electrocardiographic (ECG) changes indicate critical proximal left anterior descending artery narrowing occurring during the chest pain-free period. Due to the severity of the obstruction, if such cases are managed by early invasive revascularisation therapy, a major threat in the form of a massive myocardial infarction or sudden death may be averted. We present the case of a patient with previous chest pain, whose ECG showing subtle ischemic changes was initially overlooked. A repeat ECG taken during the painless period showed a biphasic T wave, suggestive of Wellen’s’ syndrome. This was confirmed by an immediate coronary angiogram

Tea Polyphenols Chemistry for Pharmaceutical Applications

Tea is one of the most ancient popular beverages and extensively used dietary supplement in the western world. Tea leaves are rich in polyphenols and also well known for its antioxidant properties. In addition, green tea extract contains several polyphenols with antioxidant compounds. The predominant effective antioxidant components are epigallocatechin 3-gallate and epicatechin 3-gallate (monomers). Tea polyphenols have an additional role to induce aroma and taste in beverages. Furthermore, tea polyphenols have multiple applications in food industry and biomedical applications. This chapter will summarise the origin of tea leaves and its beneficial account on antioxidant, food industry (meat products, plant products and fish products) and therapeutic applications against many diseases such as lowering of blood pressure, diabetes, Parkinson’s disease and anticancer properties. Mainly tea polyphenols have potential to inhibit the cancer proliferation of skin, prostate, lung and breast cancer

Recurrent Pseudomonal Pneumonia

Community-acquired pneumonia due to Pseudomonas aeruginosa typically occurs in patients with pre-existing lung disease and immunocompromised individuals. We report the case of a previously healthy young adult who presented with recurrent episodes of pneumonia due to Pseudomonas aeruginosa complicated by pleural effusion. Careful and extensive evaluation ultimately revealed the unusual reason behind the patient’s illnes

Acute fatty liver of pregnancy: an update on mechanisms

Acute fatty liver of pregnancy (AFLP), characterized by hepatic microvesicular steatosis, is a sudden catastrophic illness occurring almost exclusively in the third trimester of pregnancy. Defective fatty acid oxidation in the fetus has been shown to be associated with this disease. Since the placenta has the same genetic makeup as the fetus and as AFLP patients generally recover following delivery, we hypothesized that the placenta might be involved in pathogenesis of this disease. In an animal model of hepatic microvesicular steatosis (using sodium valproate), we found that microvesicular steatosis results in mitochondrial structural alterations and oxidative stress in subcellular organelles of the liver. In placentas from patients with AFLP, we observed placental mitochondrial dysfunction and oxidative stress in subcellular organelles. In addition, defective placental fatty acid oxidation results in accumulation of toxic mediators such as arachidonic acid. Escape of these mediators into the maternal circulation might affect the maternal liver resulting in microvesicular steatosis

Utilization of waste tea leaves as bio-surfactant in CdS quantum dots synthesis and their cytotoxicity effect in breast cancer cells

Green technology for nanoparticles synthesis is considered to be of great significance in biomedical applications. Recently, low dimensional semiconductor cadmium sulfide (CdS) quantum dots (QDs) have raised great attention due to their optical properties and wide usage in biomedical studies. In our present work, we demonstrate a simple green synthesis route for CdS QDs production using waste matured tea leaves (mother leaf) as bio-surfactant that are a waste product of the tea leaf industry and not suitable for drinking. The structural and morphological analysis showed waste tea leaf derived CdS QDs range from 2.5 to 4 nm in particle size with a cubic crystalline structure. Interestingly, these CdS QDs exhibit strong florescence emission with maximum around 670 nm. We explored the cytotoxic effect of waste tea leaf mediated CdS QDs (MT-CdS QDs) in breast cancer cell lines and compared their viability with standard drug - cisplatin. Our experimental studies strongly suggest that MT-CdS QDs exhibits cytotoxic effect on breast cancer cells and their performance was compared with standard drug cisplatin. To further understand the role of MT-CdS QDs towards cytotoxicity, the fluorescence microscopy and flow cytometry analysis were carried out. The flow cytometry results reveal that MT-CdS QDs induces cell death as it arrests the cell cycle at S phase as well as G2/M phase. Further the apoptosis mechanism was confirmed with the expression of anti-apoptotic and apoptotic proteins. These studies explored that waste tea leaves have dual advantage – both in controlling the particle size of CdS QDs as well as facilitates their cytotoxicity effect in breast cancer cell death. Therefore, it is anticipated that the utilization of MT-CdS QDs produced from waste tea leaves as bi-functional drug and delivery vehicle in cancer treatment will be a promising approach. Also, this is a simple and circular economic route for producing biocompatible QDs at low-cost, which could simultaneously benefit tea and biomedical industries

Studies on Distribution of Biosurfactant Producing Bacteria in Contaminated and Undisturbed Soils of Kanchipuram

Abstract: Ever increasing environmental concern about chemical surfactants triggers attention to microbial derived surface-active compounds, essentially due to their low toxicity and biodegradable nature. At present, biosurfactants are predominantly used in remediation of pollutants, in the enhanced transport of metabolites in bacteria, in enhanced oil recovery, as cosmetic additives, in biological control. However, little is known about the distribution and prevalence of biosurfactant-producing bacteria in the environment. The primary objective of this study was to determine how common culturable surfactant producing bacteria are present in contaminated and undisturbed soil samples in and around Kanchipuram (12°50'23"N 79°42'0"E), Tamilnadu, India. A series of each 5 contaminated and undisturbed soils were collected and plated on R2A agar. Totally, 155 morphologically different bacterial isolates were obtained and qualitatively screened for biosurfactant production in mineral salts medium containing 2% glucose. Out of 155 isolates, eight isolates were positive for biosurfactant production, representing most of the soils tested. Quantitative estimation of surface activity identified two potent biosurfactant producing strains Bacillus sp.BS3 and Pseudomonas sp. Maximum surface activity was observed to be 26.58 x 10 -3 nm -1 and 20.60 x 10 -3 nm -1 respectively for Bacillus sp.BS3 and Pseudomonas sp. BS5. The present study is a preliminary demonstration that the Indian soils are rich in biosurfactant producing bacteria, which can be exploited for industrial production of biosurfactants

Single-agent arsenic trioxide in the treatment of newly diagnosed acute promyelocytic leukemia: durable remissions with minimal toxicity

Arsenic trioxide, as a single agent, has proven efficacy in inducing molecular remission in patients with acute promyelocytic leukemia (APL). There is limited long-term outcome data with single-agent As2O3 in the management of newly diagnosed cases of APL. Between January 1998 to December 2004, 72 newly diagnosed cases of APL were treated with a regimen of single-agent As2O3 at our center. Complete hematologic remission was achieved in 86.1%. At a median follow-up of 25 months (range: 8-92 months), the 3-year Kaplan-Meier estimate of EFS, DFS, and OS was 74.87% ± 5.6%, 87.21% ± 4.93%, and 86.11% ± 4.08%, respectively. Patients presenting with a white blood cell (WBC) count lower than 5 × 109/L and a platelet count higher than 20 × 109/L at diagnosis (n = 22 [30.6%]) have an excellent prognosis with this regimen (EFS, OS, and DFS of 100%). The toxicity profile, in the majority, was mild and reversible. After remission induction, this regimen was administered on an outpatient basis. Single-agent As2O3, as used in this series, in the management of newly diagnosed cases of APL, is associated with responses comparable with conventional chemotherapy regimens. Additionally, this regimen has minimal toxicity and can be administered on an outpatient basis after remission induction

Liver Injury in Acute Fatty Liver of Pregnancy: Possible Link to Placental Mitochondrial Dysfunction and Oxidative Stress

Acute fatty liver of pregnancy (AFLP) is a rare disorder which is fatal if not recognized and treated early. Delivery of the feto-placental unit results in dramatic improvement in maternal liver function, suggesting a role for the placenta. However, the mechanisms by which defects in the fetus or placenta lead to maternal liver damage are not well understood and form the focus of this study. Placenta and serum were obtained at delivery from patients with AFLP, and placental mitochondria and peroxisomes were isolated. Placental mitochondrial function, oxidative stress, and fatty acid composition as well asserumantioxidants, oxidativeandnitrosative stress markers,andfatty acid analysis were carried out. Hepatocytes in culture were used to evaluate cell death, mitochondrial function, and lipid accumulation on exposure to fatty acids. Oxidative stress was evident in placental mitochondria and peroxisomes of patients with AFLP, accompanied by compromised mitochondrial function. Increased levels of arachidonic acid were also seen inAFLPplacenta when compared to control. Patients with AFLP also had a significant increase in oxidative and nitrosative stress markers in serum, along with decreased antioxidant levels and elevated levels of arachidonic acid. These levels of arachidonic acid were capable of inducing oxidative stress in hepatocyte mitochondria accompanied by induction of apoptosis. Exposure to arachidonic acid also resulted in increased lipid deposition in hepatocytes. Conclusion: Oxidative stress in placental mitochondria and peroxisomes is accompanied by accumulation of toxic mediators such as arachidonic acid, which may play a causative role in maternal liver damage seen in AFLP