156 research outputs found

    Multiple Merkle Hash Trees to Detect and Localize Errors

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    Data security and integrity is an important aspect in outsourced databases. Outsourced databases are under the control of data publishers different from data owner and hence the concern to the data security grows. Data publisher communicates with data clients by answering the data queries. The outsourced data should be free from modifications and when queried should give a correct (data authentication) and complete (data integrity) result set. There are numerous techniques proposed in the past to ensure the integrity and authenticity of outsourced databases. However, none of the previous works are able to localize the errors occurring in the query result set. Previous research enables client know if the result set is manipulated but it impossible to predict the exact area or tuple region where the modification occurred. In this paper, we propose a technique based on Merkle hash trees that will identify modified records in the outsourced database thus localizing the region of malicious modifications by incurring minimum cost and computation overheads to querier. The experimental results shows that our model is effective in ensuring the integrity of outsourced databases

    The TANAMI Program

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    TANAMI (Tracking Active Galactic Nuclei with Austral Milliarcsecond Interferometry) is a monitoring program to study the parsec-scale structures and dynamics of relativistic jets in active galactic nuclei (AGN) of the Southern Hemisphere with the Long Baseline Array and associated telescopes. Extragalactic jets south of -30 degrees declination are observed at 8.4 GHz and 22 GHz every two months at milliarcsecond resolution. The initial TANAMI sample is a hybrid radio and gamma-ray selected sample since the combination of VLBI and gamma-ray observations is crucial to understand the broadband emission characteristics of AGN.Comment: Confernce Proceedings for "X-ray Astronomy 2009" (Bologna), 3 pages, 3 figures, needs cls-fil

    The Antarctic Submillimeter Telescope and Remote Observatory (AST/RO)

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    AST/RO, a 1.7 m diameter telescope for astronomy and aeronomy studies at wavelengths between 200 and 2000 microns, was installed at the South Pole during the 1994-1995 Austral summer. The telescope operates continuously through the Austral winter, and is being used primarily for spectroscopic studies of neutral atomic carbon and carbon monoxide in the interstellar medium of the Milky Way and the Magellanic Clouds. The South Pole environment is unique among observatory sites for unusually low wind speeds, low absolute humidity, and the consistent clarity of the submillimeter sky. Four heterodyne receivers, an array receiver, three acousto-optical spectrometers, and an array spectrometer are installed. A Fabry-Perot spectrometer using a bolometric array and a Terahertz receiver are in development. Telescope pointing, focus, and calibration methods as well as the unique working environment and logistical requirements of the South Pole are described.Comment: 57 pages, 15 figures. Submitted to PAS

    Evaluating the colour stability of esthetic resin composite: A study of Neospectra ST under different staining conditions

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    Background: There is a burgeoning interest in the colour permanence of aesthetic restorations, although only a handful of studies have been documented thus far. Aim: To investigate the impact of various common staining solutions on nanohybrid composite resin.. Materials and methods: Forty disk-shaped specimens (10 X 2 mm) were fabricated with Neo SpectraST composite material. The specimens were divided into four groups with 10 specimens (n=10) in each, based on the staining solutions, Group I: Turmeric, Group II: Coffee, Group III: Coke, and Group IV: Distilled water. Baseline measurements were taken using an ultraviolet spectrophotometer. Each sample group was immersed in their respective staining solutions, and the colour changes were recorded after 1, 7, and 14 days of immersion using the same spectrophotometer. The absorption values were recorded within the 300 to 800 nm range at baseline and after the immersion. The data was collected and subjected to statistical analysis. Results: Neo spectra ST composite showed the maximum staining capacity with the turmeric group compared to other staining solutions. One-way ANOVA showed significant differences (p=0.000) among the staining solutions at different time intervals. Repeated measures ANOVA displayed significant differences within the staining solutions (Turmeric: p=0.005; Coffee: p=0.001; and Coke: p=0.001) at different time intervals. Conclusion: The nanohybrid composite resin showed a significant colour change to turmeric compared to other staining solutions

    Protective Effects of Lemna minor Linn. On Hepatic and Cognitive Impairments in Acetaminophen Induced Hepatic Encephalopathy in Rats

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    Aim: Lemna minor Linn., an aquatic plant, is a promising novel therapeutic agent that has been traditionally used in ethnobotanical practices as an ecofriendly supplement for the management of various ailments. This study involves the evaluation of ethanolic extract of Lemna minor Linn. against Paracetamol-induced Hepatic Encephalopathy using in vitro and in vivo Models. Methods: The acute oral toxicity study of the ethanolic extract of Lemna minor (EELM) was conducted following the OECD-425 guidelines over a 14-day period. A total of nine animals were used for this toxicity assessment. The EELM was tested in Paracetamol(PCM)-induced bioactivation animal model at two different dosages 200 and  in comparison with silymarin as a standard compound. The In vivo experimental study was conducted using Sprague Dawley rats which was divided into 5 groups each group containing 6 animals so the total no of animals used in the study was 30 animals. The treatment groups included: normal control (  ), 100mg/kg silymarin (standard) and the EELM of two different doses of 200  and , p.o were administered to rats 10 hr before paracetamol (  ) treatment. Rats were orally administered their respective doses every day for total 30days. Paracetamol-induced oxidative liver damage disrupted normal levels of liver enzymes, total protein, and bilirubin, while also depleting antioxidant reserves. This oxidative stress was strongly associated with paracetamol toxicity, leading to a marked depletion of glutathione (GSH) and impairing both memory and cognitive function in the animals. Behavioral parameters are performed to evaluate the effect of drugs on cognitive behaviour of animals. Morris water maze test was performed to study how animals learn and remembers the spatial information relying on distal cues to locate the hidden platform in an opaque water. Additionally, elevated plus maze was performed to measures the anxious behaviour of rats, the criterion was tested based on the conflict between rats innate instincts to explore new environment and avoid open, well-lit areas. The potential protective effects of EELM was evaluated by measuring serum enzyme levels and antioxidants status in the liver and brain, further histopathological analysis was performed respectively. Results: The acute toxicity study did not report any mortality or toxicity signs in animals. PCM toxicity led to a statistically increase in the liver and body weight, along with brain water content. The PCM-intoxicated group exhibited a marked reduction in the level of superoxide dismutase (SOD) and glutathione (GSH) in the brain and liver, as well as an increase in lipid peroxidation and serum biomarkers (AST, ALT, ALP, and total bilirubin). EELM significantly (  ) reduced liver injury by inhibiting ALT, AST and ALP levels in serum. SOD, GSH and MDA liver content were significantly (  ) elevated by EELM, compared to PCM treated rats. Comparing the treatment and induced group, the treated group successfully recovered the activity of antioxidant levels and also been acknowledged for restored liver functioning by alleviating oxidative stress and also GSH level in brain was significantly  increased by EELM and preserved the histology of brain, which was chronically produced over a period of 30 days. Conclusion: The findings of this investigation indicate the traditional use of Lemna minor in hepatoprotection and neuroprotection by regulating oxidative stress and mitigating reactive oxygen species (ROS). The insights gained from this research contribute to the development of novel therapeutic agents and paves the way for further studies on Lemna minor to enhance health outcomes, particularly in the management of neurodegenerative diseases

    Unveiling Potent Anti-Asthmatic Effect of Curcumin in Combination with Salmeterol in Swiss Albino Mice

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    Background: Asthma is a long-term inflammatory respiratory condition marked by alterations in the airways and an increase in inflammatory cell infiltration. It has been observed that Curcumin possesses immune-modulating, anti-inflammatory, and relaxing properties for smooth muscle in the airways. Salmeterol is believed to ease the smooth muscles of the airways. Objective: Swiss Albino mice were used in the research to examine the combination anti-asthmatic effects of Curcumin and Salmeterol in asthma produced by ova albumin and milk induced eosinophilia and leucocytosis. Methods: The mice received pre-treatment with Curcumin (10 mg/kg, 20 mg/kg intraperitoneally) as well as Salmeterol (5 mg/kg) after being stimulated with an Ovalbumin (OVA) challenge and milk. After the induction period, various hematological, biochemical, molecular (ELISA), and histological analyses were performed. Results: The findings demonstrated that the combined treatment decreased the animal’s overall leukocyte and eosinophil numbers in a manner that was dose-dependent. Additionally, the therapy reduced albumin and overall protein amount in serum, BALF and lung tissues, facilitated changes in haematological parameters, and reduced the rise of Th2 cytokines (IL-4, TNF-α, IL-13) levels that is induced by OVA in lungs and BALF, total IgE level in serum. The combined action of Curcumin and Salmeterol reduced OVA-induced inflammatory influx and ultrastructural abnormalities, according to histopathological evaluation. Conclusion: The findings of this investigation demonstrate that curcumin and salmeterol together possess anti-asthmatic effects through suppressing Th2 triggered immune response and possessing an anti-inflammatory effect and anti-allergic effect. Thus combination of treatments might be a novel technique for managing asthma

    A review of hyperandrogenism state in polycystic ovarian syndrome

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    Polycystic ovary syndrome is one of the most prevalent endocrinopathy in premenopausal women. The pathophysiology of PCOS is not clear, however disturbance in the hypothalamic-pituitary-ovarian axis and abnormal steroidogenesis along with genetic and environmental factors act as main contributors to this disorder. The steroidogenic pathway is affected by the overexpression of the CYP11A, CYP17, and CYP19 genes in PCOS, which results in a hyperandrogenic condition. The initial effect of too much androgen in PCOS is impaired folliculogenesis. The most frequent clinical manifestations of hyperandrogenism in women with PCOS include hirsutism, acne, and androgenic alopecia. Women with PCOS may have an excess of androgen during foetal life due to the elevated expression of P450c17a during the whole pregnancy. PCOS is believed to be formed in utero by the influence of androgen excess on gene expression in adolescence and adulthood, which offers more solid evidence that real PCOS can be induced by prenatal androgenization. A prenatal androgen excess-induced epigenetic phenomena is suggested by the current theory of PCOS's developmental genesis. It is currently believed that the many tiny follicles seen in polycystic ovaries and the considerable irregularity in the very early stages of folliculogenesis are associated to the formation of anovulation in PCOS

    Reduced resource optimization in male alcoholics: N400 in a lexical decision paradigm.

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    Event Related Potential (ERP) studies have highlighted some measures, notably P3 amplitude, that are associated with both state and trait deficits in alcoholism, while studies examining N400 amplitude in alcoholism are few. The present study aims to examine differences in the N400 component, an electrophysiological correlate of semantic priming, in event-related potentials from a lexical decision task in 87 alcohol dependent subjects and 57 community controls. Each subject was presented with 300 stimuli sequentially in a quasi-randomized design, where 150 stimuli were words and 150 were non-words. The subjects made a lexical decision indicating the word/non-word status with a button press. Among the words, 50 words (primed) were always preceded by their antonyms (prime, n=50), whereas the remaining 50 words were unrelated. N400 amplitude and latency measures were compiled from ERPs to the primed and unprimed words. Corresponding reaction time (RT) and response characteristics were also analyzed.Control subjects revealed a significant attenuation of the N400 response to the primed word when compared to the unprimed word. Significantly less attenuation was observed in alcohol dependent subjects. No significant group differences were seen for latency and behavioral measures. All subjects had slower RT for unprimed words compared to primed words; however significantly less RT savings between the unprimed and primed condition was noted for alcoholics. These results suggest a reduced flexibility in the cognitive networks and a lack of resource optimization in alcoholics. The reduced attenuation of N400 during the primed condition in the alcohol dependent subjects may reflect an inability to engage similar neuronal substrates associated with semantic relatedness as seen in the controls. As diminished N400 attenuation during priming is observed in both alcoholics and high risk subjects, it may be a marker of risk and a good endophenotype for alcoholism.AMSUNY DownstateHenri Begleiter Neurodynamics LaboratoryN/

    TANAMI: Tracking Active Galactic Nuclei with Austral Milliarcsecond Interferometry. III. First-epoch S band images

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    With the emergence of very high energy astronomy (VHE; E>100 GeV), new open questions were presented to astronomers studying the multi-wavelength emission from blazars. Answers to these open questions, such as the Doppler crisis, and finding the location of the high-energy activity have eluded us thus far. Recently, quasi-simultaneous multi-wavelength monitoring programs have shown considerable success in investigating blazar activity. After the launch of the Fermi Gamma-ray Space Telescope in 2008, such quasi-simultaneous observations across the electromagnetic spectrum became possible. In addition, with very long baseline interferometry (VLBI) observations we can resolve the central parsec region of active galactic nuclei (AGN) and compare morphological changes to the gamma-ray activity to study high-energy emitting blazars. To achieve our goals, we need sensitive, long-term VLBI monitoring of a complete sample of VHE detected AGN. We performed VLBI observations of TeV-detected AGN and high likelihood neutrino associations as of December of 2021 with the Long Baseline Array (LBA) and other southern hemisphere radio telescopes at 2.3 GHz. In this paper we present first light TANAMI S-band images, focusing on the TeV-detected sub-sample of the full TANAMI sample. Apart from these very high energy-detected sources, we also show images of the two flux density calibrators and two additional sources included in the observations. We study the redshift, 0.1-100 GeV photon flux and S-band core brightness temperature distributions of the TeV-detected objects, and find that flat spectrum radio quasars and low synchrotron peaked sources on average show higher brightness temperatures than high-synchrotron-peaked BL Lacs. Sources with bright GeV gamma-ray emission also show higher brightness temperature values than gamma-low sources
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