350 research outputs found
On abstraction refinement for program analyses in Datalog
A central task for a program analysis concerns how to efficiently find a program abstraction that keeps only information relevant for proving properties of interest. We present a new approach for finding such abstractions for program analyses written in Datalog. Our approach is based on counterexample-guided abstraction refinement: when a Datalog analysis run fails using an abstraction, it seeks to generalize the cause of the failure to other abstractions, and pick a new abstraction that avoids a similar failure. Our solution uses a boolean satisfiability formulation that is general, complete, and optimal: it is independent of the Datalog solver, it generalizes the failure of an abstraction to as many other abstractions as possible, and it identifies the cheapest refined abstraction to try next. We show the performance of our approach on a pointer analysis and a typestate analysis, on eight real-world Java benchmark programs
Design and Development of Memristor Based Combinational Circuits.
Now a days the memristor based devices are gaining a lot of attention because of its nano device range and its non-volatile memory. The objective of our research work is to design an efficient, low power Combinational Circuits using memristor and to compare the performance of the memristor based combinational circuits with CMOS based combinational circuits using EDA tools. In this paper we are focusing on the design of full adder, full subtractor, and encoders /decoders using hybrid-CMOS memristor structure. Combining CMOS and memristor gives the promising solutions for area reduction on a chip
Effect of Polyethylene Glycol Induced Water Stress on Physiological and Biochemical Responses in Pigeonpea (Cajanus cajan L. Millsp.)
Water deficit induced by Polyethylene glycol (PEG) affect physiological and biochemical changes in pigeonpea. The plants were subjected to two progressive stresses: moderate (-0.51 MPa) and severe (-1.22 MPa) respectively. The water stress condition was created by irrigating 14 days old grown seedling pot with PEG nutrient solution and decreasing the osmotic potential -0.04 MPa regularly. Relative water content (RWC) content was significantly reduced under water stress condition. Increase in the free proline content during water stress condition suggests that proline is one of the common compatible osmolytes under water stress condition. The genotype exhibited lower accumulation of catalase (CAT) and increased activity of superoxide dismutase (SOD) and Peroxidase (POD) under stressed condition. The present data suggest a relation between proline content and water stress and a well developed antioxidant defense mechanism activated during water stress
Evaluation of cytotoxic profile of hydroalcoholic extract of fruit rinds of Garcinia pedunculata on human embryonic kidney and breast carcinoma cells
Background: The fruit rinds of Garcinia pedunculata has potential medicinal properties and used in many chronic ailments. It has been demonstrated that cytoprotective effects in various experimental research works. But its cytotoxic effect has not been evaluated. The present study was aimed to screen its relative cytotoxic effect on normal and cancer cell lines.Methods: In the present study, the cytotoxic effect of hydro alcoholic extract of Garcinia pedunculata was evaluated on normal human embryonic kidney (HEK-293) and M.D. Anderson metastatic breast cancer cell lines (MDA-MB 231) using 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay.Results: Higher dose level of hydro alcoholic extract of Garcinia pedunculata (HAGP) (500 μg/ml) has shown considerable increase (112.503) in the percentage viability of HEK-29 whereas; there is a remarkable decrease in the viable cell population (77.490) in MDA-MB 231.Conclusions: Based on the observed results we could conclude that HAGP has potential cytotoxic effect on the cancer cell line without altering the normal cell growth and proliferation. Thus it has potential to develop as a safer chemotherapeutic agent. Further detailed exploration is required to confirm its therapeutic efficacy in different cancer cell lines
Searching for Dark Matter with a Superconducting Qubit
Detection mechanisms for low mass bosonic dark matter candidates, such the
axion or hidden photon, leverage potential interactions with electromagnetic
fields, whereby the dark matter (of unknown mass) on rare occasion converts
into a single photon. Current dark matter searches operating at microwave
frequencies use a resonant cavity to coherently accumulate the field sourced by
the dark matter and a near standard quantum limited (SQL) linear amplifier to
read out the cavity signal. To further increase sensitivity to the dark matter
signal, sub-SQL detection techniques are required. Here we report the
development of a novel microwave photon counting technique and a new exclusion
limit on hidden photon dark matter. We operate a superconducting qubit to make
repeated quantum non-demolition measurements of cavity photons and apply a
hidden Markov model analysis to reduce the noise to 15.7 dB below the quantum
limit, with overall detector performance limited by a residual background of
real photons. With the present device, we perform a hidden photon search and
constrain the kinetic mixing angle to in a
band around 6.011 GHz (24.86 eV) with an integration time of 8.33 s. This
demonstrated noise reduction technique enables future dark matter searches to
be sped up by a factor of 1300. By coupling a qubit to an arbitrary quantum
sensor, more general sub-SQL metrology is possible with the techniques
presented in this work.Comment: 15 pages, 14 figures, 2 table. Dark matter exclusion analysis
modified to include experimental systematics. Discussion of background
calibration and detector compatibility with tunable cavity added to
conclusion. Future optimizations and integration into axion search sections
moved to Supplemental Material. References update
Oxidative and pro-inflammatory impact of regular and denicotinized cigarettes on blood brain barrier endothelial cells: is smoking reduced or nicotine-free products really safe?
Background: Both active and passive tobacco smoke (TS) potentially impair the vascular endothelial function in a causative and dose-dependent manner, largely related to the content of reactive oxygen species (ROS), nicotine, and pro-inflammatory activity. Together these factors can compromise the restrictive properties of the blood–brain barrier (BBB) and trigger the pathogenesis/progression of several neurological disorders including silent cerebral infarction, stroke, multiple sclerosis and Alzheimer’s disease. Based on these premises, we analyzed and assessed the toxic impact of smoke extract from a range of tobacco products (with varying levels of nicotine) on brain microvascular endothelial cell line (hCMEC/D3), a well characterized human BBB model.
Results: Initial profiling of TS showed a significant release of reactive oxygen (ROS) and reactive nitrogen species (RNS) in full flavor, nicotine-free (NF, “reduced-exposure” brand) and ultralow nicotine products. This release correlated with increased oxidative cell damage. In parallel, membrane expression of endothelial tight junction proteins ZO-1 and occludin were significantly down-regulated suggesting the impairment of barrier function. Expression of VE-cadherin and claudin-5 were also increased by the ultralow or nicotine free tobacco smoke extract. TS extract from these cigarettes also induced an inflammatory response in BBB ECs as demonstrated by increased IL-6 and MMP-2 levels and up-regulation of vascular adhesion molecules, such as VCAM-1 and PECAM-1.
Conclusions: In summary, our results indicate that NF and ultralow nicotine cigarettes are potentially more
harmful to the BBB endothelium than regular tobacco products. In addition, this study demonstrates that the
TS-induced toxicity at BBB ECs is strongly correlated to the TAR and NO levels in the cigarettes rather than the
nicotine conten
Universal Coronavirus Testing to Control the Pandemic: Ethical Issues and Dilemmas
Every country had to make several difficult decisions in the initial phase of the Coronavirus (COVID-19) pandemic to allocate resources for COVID testing. Decisions on who should be tested for COVID-19 testing are extremely vital for pandemic preparedness. In this article, we highlight the need for prioritization of testing resources including direct-to-consumer testing methods, ethical dilemmas involved in obligatory testing, and testing of refugees and immigrants
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