Hydrodynamic simulations of galaxy formation in a cosmological context

The formation of galaxies and their subsequent evolution through cosmic time is governed by a variety of complex physical processes such as gas cooling, star formation, feedback and merger events. In this thesis we use hydrodynamical simulations to study the effect of these processes on galaxy properties. We first investigate the change in galaxy morphology as they undergo mergers. We look at a wide variety of merger events from interaction between small dark matter subhaloes and galactic discs, to major mergers. In the second part of the thesis we turn our attention to the role of stellar feedback in regulating star formation. A model for short range photoheating of gas by radiation from massive stars is tested by simulating a representative volume of the Universe and comparing the statistical properties of simulated galaxies with the observed ones. Finally, we introduce a new, computationally efficient model to calculate the gas cooling rate in the presence of local radiation fields. The model uses simple assumptions for absorption of ultra-violet photons and an optically thin approximation to propagate local radiation fields throughout the entire simulation volume. Using this new method we show that local radiation has a significant effect in regulating the star formation rate of L* galaxies. It reduces gas accretion onto the disc, thereby, producing realistic galaxies without resorting to extreme feedback mechanisms

PSOFuzz: Fuzzing Processors with Particle Swarm Optimization

Hardware security vulnerabilities in computing systems compromise the security defenses of not only the hardware but also the software running on it. Recent research has shown that hardware fuzzing is a promising technique to efficiently detect such vulnerabilities in large-scale designs such as modern processors. However, the current fuzzing techniques do not adjust their strategies dynamically toward faster and higher design space exploration, resulting in slow vulnerability detection, evident through their low design coverage. To address this problem, we propose PSOFuzz, which uses particle swarm optimization (PSO) to schedule the mutation operators and to generate initial input programs dynamically with the objective of detecting vulnerabilities quickly. Unlike traditional PSO, which finds a single optimal solution, we use a modified PSO that dynamically computes the optimal solution for selecting mutation operators required to explore new design regions in hardware. We also address the challenge of inefficient initial seed generation by employing PSO-based seed generation. Including these optimizations, our final formulation outperforms fuzzers without PSO. Experiments show that PSOFuzz achieves up to 15.25$\times$ speedup for vulnerability detection and up to 2.22$\times$ speedup for coverage compared to the state-of-the-art simulation-based hardware fuzzer.Comment: To be published in the proceedings of the ICCAD, 202

Selective Serotonin-Norepinephrine Reuptake Inhibitors-Induced Takotsubo Cardiomyopathy

CONTEXT: Takotsubo translates to octopus pot in Japanese. Takotsubo cardiomyopathy (TTC) is characterized by a transient regional systolic dysfunction of the left ventricle. Catecholamine excess is the one most studied and favored theories explaining the pathophysiology of TTC. CASE REPORT: We present the case of a 52-year-old Hispanic female admitted for venlafaxine-induced TTC with a review literature on all the cases of Serotonin-norepinephrine reuptake inhibitors (SNRI)-associated TTC published so far. CONCLUSION: SNRI inhibit the reuptake of catecholamines into the presynaptic neuron, resulting in a net gain in the concentration of epinephrine and serotonin in the neuronal synapses and causing iatrogenic catecholamine excess, ultimately leading to TTC

Total phenolic and flavonoid content, antioxidant effects and antidiarrheal activity of balacaturbhadrika churna – an Ayurvedic preparation

485-492Balacaturbhadrika churna (BC) is an important pediatric preparation in Ayurveda. It is used to treat various diseases of gastro-intestinal tract particularly diarrhea in children. Free radicals cause oxidative damage in the intestine and are correlated with its diseases. In the current study, total phenolic and flavonoid contents of BC extracts were determined and their antioxidant evaluation in various in vitro models was carried out. Procedures mentioned in The Ayurvedic Formulary of India were followed to prepare in-house BC; alcoholic (BCAL) and aqueous (BCAQ) extracts were prepared and tested by standard procedures. BCAL was tested for antidiarrheal activity in castor oil induced model. The ethanolic extract showed better antioxidant activity in many of the models as compared to aqueous extract. The present study showed substantial amounts of flavonoids and phenolics in churna extracts. BCAL showed significant antidiarrheal activity against the tested model. The potential antioxidant and antidiarrheal activities displayed by Balacaturbhadrika churna extracts could be attributed to these contents

Total phenolic and flavonoid content, antioxidant effects and antidiarrheal activity of balacaturbhadrika churna – an Ayurvedic preparation

Balacaturbhadrika churna (BC) is an important pediatric preparation in Ayurveda. It is used to treat various diseases of gastro-intestinal tract particularly diarrhea in children. Free radicals cause oxidative damage in the intestine and are correlated with its diseases. In the current study, total phenolic and flavonoid contents of BC extracts were determined and their antioxidant evaluation in various in vitro models was carried out. Procedures mentioned in The Ayurvedic Formulary of India were followed to prepare in-house BC; alcoholic (BCAL) and aqueous (BCAQ) extracts were prepared and tested by standard procedures. BCAL was tested for antidiarrheal activity in castor oil induced model. The ethanolic extract showed better antioxidant activity in many of the models as compared to aqueous extract. The present study showed substantial amounts of flavonoids and phenolics in churna extracts. BCAL showed significant antidiarrheal activity against the tested model. The potential antioxidant and antidiarrheal activities displayed by Balacaturbhadrika churna extracts could be attributed to these contents

Delayed Spontaneous Recanalization of Chronic Total Occlusion of Left Anterior Descending Artery after Attempted but Failed Revascularization During Percutaneous Coronary Intervention

Chronic total occlusion (CTO) of coronary artery remains the Achilles heel of the interventional cardiologist and is present in a significant proportion of referrals for coronary artery bypass graft surgery (CABG); however, with the development and standardization of modern CTO recanalization techniques, it has been able to achieve excellent success while coping with lesions of increasing complexity. Nevertheless, failure to recanalize despite the development of new techniques still remains one of the challenges in the field of interventional cardiology. Spontaneous recanalization has been described in nonocclusive coronary artery dissections in detail; none has addressed the possibility of spontaneous recanalization after failed percutaneous coronary intervention (PCI). We report a case of spontaneous but delayed recanalization of CTO of left anterior descending artery 3 years after attempted but failed revascularization during PCI

Bronchiectasis in India:results from the European Multicentre Bronchiectasis Audit and Research Collaboration (EMBARC) and Respiratory Research Network of India Registry

BACKGROUND: Bronchiectasis is a common but neglected chronic lung disease. Most epidemiological data are limited to cohorts from Europe and the USA, with few data from low-income and middle-income countries. We therefore aimed to describe the characteristics, severity of disease, microbiology, and treatment of patients with bronchiectasis in India. METHODS: The Indian bronchiectasis registry is a multicentre, prospective, observational cohort study. Adult patients ( 6518 years) with CT-confirmed bronchiectasis were enrolled from 31 centres across India. Patients with bronchiectasis due to cystic fibrosis or traction bronchiectasis associated with another respiratory disorder were excluded. Data were collected at baseline (recruitment) with follow-up visits taking place once per year. Comprehensive clinical data were collected through the European Multicentre Bronchiectasis Audit and Research Collaboration registry platform. Underlying aetiology of bronchiectasis, as well as treatment and risk factors for bronchiectasis were analysed in the Indian bronchiectasis registry. Comparisons of demographics were made with published European and US registries, and quality of care was benchmarked against the 2017 European Respiratory Society guidelines. FINDINGS: From June 1, 2015, to Sept 1, 2017, 2195 patients were enrolled. Marked differences were observed between India, Europe, and the USA. Patients in India were younger (median age 56 years [IQR 41-66] vs the European and US registries; p<0\ub70001]) and more likely to be men (1249 [56\ub79%] of 2195). Previous tuberculosis (780 [35\ub75%] of 2195) was the most frequent underlying cause of bronchiectasis and Pseudomonas aeruginosa was the most common organism in sputum culture (301 [13\ub77%]) in India. Risk factors for exacerbations included being of the male sex (adjusted incidence rate ratio 1\ub717, 95% CI 1\ub703-1\ub732; p=0\ub7015), P aeruginosa infection (1\ub729, 1\ub710-1\ub750; p=0\ub7001), a history of pulmonary tuberculosis (1\ub720, 1\ub707-1\ub734; p=0\ub7002), modified Medical Research Council Dyspnoea score (1\ub732, 1\ub725-1\ub739; p<0\ub70001), daily sputum production (1\ub716, 1\ub703-1\ub730; p=0\ub7013), and radiological severity of disease (1\ub703, 1\ub701-1\ub704; p<0\ub70001). Low adherence to guideline-recommended care was observed; only 388 patients were tested for allergic bronchopulmonary aspergillosis and 82 patients had been tested for immunoglobulins. INTERPRETATION: Patients with bronchiectasis in India have more severe disease and have distinct characteristics from those reported in other countries. This study provides a benchmark to improve quality of care for patients with bronchiectasis in India. FUNDING: EU/European Federation of Pharmaceutical Industries and Associations Innovative Medicines Initiative inhaled Antibiotics in Bronchiectasis and Cystic Fibrosis Consortium, European Respiratory Society, and the British Lung Foundation

Embolized prostatic brachytherapy seeds mimicking acute chest pain syndromes

A 59-year-old male with a history of nonobstructive coronary artery disease, diabetes mellitus, hypertension, and prostate cancer presented to the hospital with 1-day history of pleuritic chest pain. Initial workup for acute coronary event was unremarkable. Chest X-ray revealed multiple small radial densities which were linear and hyperdense, consistent with embolization of metallic seeds to the pulmonary circulation. The patient was noted to have had radioactive metallic seeds implanted for prostate cancer 6 months ago. Diagnosis of pulmonary embolization of prostatic seeds is challenging as they frequently present with chest pain mimicking acute coronary syndromes