On computing serial dependency relations

In a database system where the data is a collection of shared objects there can be concurrent access to the data by several transactions. Traditional concurrency-controls use a notion of conflict between pairs of operations (of which the transactions are composed) to ensure correctness. Herlihy has proposed the notion of a serial dependency relation over the set of operations to capture this idea of conflict. Since the smaller the conflict relation the more the concurrency, it is of interest to construct minimal serial dependency relations. In this paper, we give necessary and sufficient conditions for a pair of operations to be related by a minimal serial dependency relation. However, we go on to show that, in general, the problem of constructing a minimal relation is undecidable. We also show that some approaches advocated for constructing serial dependency relations are not feasible in general. We then provide a sufficiency condition for cases where the minimal relations are computable

New Techniques in Scene Understanding and Parallel Image Processing.

There has been tremendous research interest in the areas of computer and robotic vision. Scene understanding and parallel image processing are important paradigms in computer vision. New techniques are presented to solve some of the problems in these paradigms. Automatic interpretation of features in a natural scene is the focus of the first part of the dissertation. The proposed interpretation technique consists of a context dependent feature labeling algorithm using non linear probabilistic relaxation, and an expert system. Traditionally, the output of the labeling is analyzed, and then recognized by a high level interpreter. In this new approach, the knowledge about the scene is utilized to resolve the inconsistencies introduced by the labeling algorithm. A feature labeling system based on this hybrid technique is designed and developed. The labeling system plays a vital role in the development of an automatic image interpretation system for oceanographic satellite images. An extensive study on the existing interpretation techniques has been made in the related areas such as remote sensing, medical diagnosis, astronomy, and oceanography and has shown that our hybrid approach is unique and powerful. The second part of the dissertation presents the results in the area of parallel image processing. A new approach for parallelizing vision tasks in the low and intermediate levels is introduced. The technique utilizes schemes to embed the inherent data or computational structure, used to solve the problem, into parallel architectures such as hypercubes. The important characteristic of the technique is that the adjacent pixels in the image are mapped to nodes that are at a constant distance in the hypercube. Using the technique, parallel algorithms for neighbor-finding and digital distances are developed. A parallel hypercube sorting algorithm is obtained as an illustration of the technique. The research in developing these embedding algorithms has paved the way for efficient reconfiguration algorithms for hypercube architectures

Potential of native weed species as nutrient contributors of coconut garden in an Entisol

Potential of native weed species as nutrient contributors of coconut garden in an Entiso

Microsurgical Treatment of Sporadic and von Hippel-Lindau Disease Associated Spinal Hemangioblastomas: A Single-Institution Experience

Study DesignRetrospective cohort study.PurposeTo examine the clinical profile and surgical complications in patients with spinal hemangioblastomas and to evaluate the long-term outcome in them.Overview of LiteratureAlthough considered to be histologically benign, hemangioblastomas may cause significant neurological deficits. The proportion of spinal hemangioblastomas associated with von Hippel–Lindau (VHL) disease has been estimated be 13%–59%. Preoperative neurological function correlates with postoperative neurological status. Studies have shown no difference in outcomes between sporadic and VHL-associated spinal hemangioblastomas.MethodsThis retrospective study included 14 consecutive patients treated for spinal hemangioblastomas at our institute between January 2000 and June 2013. The mean follow-up period was 5 years. Magnetic resonance imaging of the complete neuraxis was performed in all cases, and preoperative embolization was performed in two cases.ResultsIn total, 14 patients underwent 18 surgeries, of which 15 were for spinal hemangioblastomas. Of all the patients, 86% had motor weakness and 79% presented with sensory disturbances. Preoperative McCormick functional grades were grade I in 7 (50%), grade II in 3 (21%), and grade III in 4 (29%) patients; 50% patients were diagnosed with VHL disease. All patients underwent complete resection of the tumor. Eight patients experienced deterioration in their neurological status in the immediate postoperative period; among them, five had gradual improvement. At 5-year follow-up, 11 (78.57%) patients showed good functional outcomes.ConclusionsMicrosurgical excision of spinal hemangioblastomas can cause postoperative morbidity, mainly in the form of neurological deterioration. Almost half of our patients had deterioration in the McCormick grade in the immediate postoperative period. However, a complete microsurgical excision can result in good long-term functional outcomes, as most of the immediate postoperative neurological deterioration in our patients was reversible. There was no difference in the long-term functional outcomes between sporadic and VHL-associated spinal hemangioblastomas

EpCAM aptamer mediated cancer cell specific delivery of EpCAM siRNA using polymeric nanocomplex

BACKGROUND: Epithelial cell adhesion molecule (EpCAM) is overexpressed in solid tumors and regarded as a putative cancer stem cell marker. Here, we report that employing EpCAM aptamer (EpApt) and EpCAM siRNA (SiEp) dual approach, for the targeted delivery of siRNA to EpCAM positive cancer cells, efficiently inhibits cancer cell proliferation. RESULTS: Targeted delivery of siRNA using polyethyleneimine is one of the efficient methods for gene delivery, and thus, we developed a novel aptamer-PEI-siRNA nanocomplex for EpCAM targeting. PEI nanocomplex synthesized with EpCAM aptamer (EpApt) and EpCAM siRNA (SiEp) showed 198 nm diameter sized particles by dynamic light scattering, spherical shaped particles, of 151 ± 11 nm size by TEM. The surface charge of the nanoparticles was -30.0 mV using zeta potential measurements. Gel retardation assay confirmed the PEI-EpApt-SiEp nanoparticles formation. The difference in size observed by DLS and TEM could be due to coating of aptamer and siRNA on PEI nanocore. Flow cytometry analysis revealed that PEI-EpApt-SiEp has superior binding to cancer cells compared to EpApt or scramble aptamer (ScrApt) or PEI-ScrApt-SiEp. PEI-EpApt-SiEp downregulated EpCAM and inhibited selectively the cell proliferation of MCF-7 and WERI-Rb1 cells. CONCLUSIONS: The PEI nanocomplex fabricated with EpApt and siEp was able to target EpCAM tumor cells, deliver the siRNA and silence the target gene. This nanocomplex exhibited decreased cell proliferation than the scrambled aptamer loaded nanocomplex in the EpCAM expressing cancer cells and may have potential for EpCAM targeting in vivo

Flecainide challenge test: Predictors of unmasking of type 1 Brugada ECG pattern among those with non-type 1 Brugada ECG pattern

AbstractBackgroundMany subjects in community have non-type 1 Brugada pattern ECG with atypical symptoms, relevance of which is not clear. Provocative tests to unmask type 1 Brugada pattern in these patients would help in diagnosing Brugada Syndrome. However sensitivity and specificity of provocating drugs are variable.MethodsWe studied 29 patients referred to our institute with clinical presentation suggestive but not diagnostic of Brugada or with non-Type 1 Brugada pattern ECG. Flecainide Challenge Test (FCT) was done in these patients (IV Flecainide test in 4 patients and Oral Flecainide in 25 patients). Resting 12-lead ECG with standard precordial leads and ECG with precordial leads placed 1 Intercostal space above were performed after flecainide administration every 5 min for first 30 min and every 30 min thereafter until ECG became normal or upto 6 h. The positivity was defined as inducible Type 1 Brugada pattern in atleast 2 right sided leads.ResultMedian age was 35(range = 5–65) years. In 16 (55%) patients the Type 1 Brugada pattern was unmasked. There were no episodes of major AV block, atrial or ventricular tachyarrhythmia. Three groups were considered for analysis: Group 1(n = 9) – FCT Positive among patients with non-type 1 Brugada ECG pattern, Group 2(n = 4) – FCT Negative among the patients with non-type 1 Brugada ECG pattern, and Group 3(n = 7) – FCT Positive among patients with no spontaneous Brugada ECG pattern. Binary logistic regression analysis found that family h/o SCD was predictive of FCT positivity in Group 1 (Odd’s ratio 21, 95% Confidence interval 1.04 to 698.83, p = 0.004).ConclusionOral flecainide is useful and safe for unmasking of Type I Brugada pattern. In our study, among the many variables studied, family history of sudden cardiac death was the only predictor of flecainide test positivity among those with non-Type 1 Brugada pattern

Assessing the carcinogenic potential of low-dose exposures to chemical mixtures in the environment: the challenge ahead.

Lifestyle factors are responsible for a considerable portion of cancer incidence worldwide, but credible estimates from the World Health Organization and the International Agency for Research on Cancer (IARC) suggest that the fraction of cancers attributable to toxic environmental exposures is between 7% and 19%. To explore the hypothesis that low-dose exposures to mixtures of chemicals in the environment may be combining to contribute to environmental carcinogenesis, we reviewed 11 hallmark phenotypes of cancer, multiple priority target sites for disruption in each area and prototypical chemical disruptors for all targets, this included dose-response characterizations, evidence of low-dose effects and cross-hallmark effects for all targets and chemicals. In total, 85 examples of chemicals were reviewed for actions on key pathways/mechanisms related to carcinogenesis. Only 15% (13/85) were found to have evidence of a dose-response threshold, whereas 59% (50/85) exerted low-dose effects. No dose-response information was found for the remaining 26% (22/85). Our analysis suggests that the cumulative effects of individual (non-carcinogenic) chemicals acting on different pathways, and a variety of related systems, organs, tissues and cells could plausibly conspire to produce carcinogenic synergies. Additional basic research on carcinogenesis and research focused on low-dose effects of chemical mixtures needs to be rigorously pursued before the merits of this hypothesis can be further advanced. However, the structure of the World Health Organization International Programme on Chemical Safety 'Mode of Action' framework should be revisited as it has inherent weaknesses that are not fully aligned with our current understanding of cancer biology

One-year clinical outcome of patients with nonvalvular atrial fibrillation: Insights from KERALA-AF registry.

BackgroundWe report patient characteristics, treatment pattern and one-year clinical outcome of nonvalvular atrial fibrillation (NVAF) from Kerala, India. This cohort forms part of Kerala Atrial Fibrillation (KERALA-AF) registry which is an ongoing large prospective study.MethodsKERALA-AF registry collected data of adults with previously or newly diagnosed atrial fibrillation (AF) during April 2016 to April 2017. A total of 3421 patients were recruited from 53 hospitals across Kerala state. We analysed one-year follow-up outcome of 2507 patients with NVAF.ResultsMean age at recruitment was 67.2 years (range 18-98) and 54.8% were males. Main co-morbidities were hypertension (61.2%), hyperlipidaemia (46.2%) and diabetes mellitus (37.2%). Major co-existing diseases were chronic kidney disease (42.1%), coronary artery disease (41.6%), and chronic heart failure (26.4%). Mean CHA2DS2-VASc score was 3.18 (SD ± 1.7) and HAS-BLED score, 1.84 (SD ± 1.3). At baseline, use of oral anticoagulants (OAC) was 38.6% and antiplatelets 32.7%. On one-month follow-up use of OAC increased to 65.8% and antiplatelets to 48.3%. One-year all-cause mortality was 16.48 and hospitalization 20.65 per 100 person years. The main causes of death were cardiovascular (75.0%), stroke (13.1%) and others (11.9%). The major causes of hospitalizations were acute coronary syndrome (35.0%), followed by arrhythmia (29.5%) and heart failure (8.4%).ConclusionsDespite high risk profile of patients in this registry, use of OAC was suboptimal, whereas antiplatelets were used in nearly half of patients. A relatively high rate of annual mortality and hospitalization was observed in patients with NVAF in Kerala AF Registry

Micropropagation and conservation of selected endangered anticancer medicinal plants from the Western Ghats of India

Globally, cancer is a constant battle which severely affects the human population. The major limitations of the anticancer drugs are the deleterious side effects on the quality of life. Plants play a vital role in curing many diseases with minimal or no side effects. Phytocompounds derived from various medicinal plants serve as the best source of drugs to treat cancer. The global demand for phytomedicines is mostly reached by the medicinal herbs from the tropical nations of the world even though many plant species are threatened with extinction. India is one of the mega diverse countries of the world due to its ecological habitats, latitudinal variation, and diverse climatic range. Western Ghats of India is one of the most important depositories of endemic herbs. It is found along the stretch of south western part of India and constitutes rain forest with more than 4000 diverse medicinal plant species. In recent times, many of these therapeutically valued herbs have become endangered and are being included under the red-listed plant category in this region. Due to a sharp rise in the demand for plant-based products, this rich collection is diminishing at an alarming rate that eventually triggered dangerous to biodiversity. Thus, conservation of the endangered medicinal plants has become a matter of importance. The conservation by using only in situ approaches may not be sufficient enough to safeguard such a huge bio-resource of endangered medicinal plants. Hence, the use of biotechnological methods would be vital to complement the ex vitro protection programs and help to reestablish endangered plant species. In this backdrop, the key tools of biotechnology that could assist plant conservation were developed in terms of in vitro regeneration, seed banking, DNA storage, pollen storage, germplasm storage, gene bank (field gene banking), tissue bank, and cryopreservation. In this chapter, an attempt has been made to critically review major endangered medicinal plants that possess anticancer compounds and their conservation aspects by integrating various biotechnological tool