Dynamic virtual cluster cloud security using hybrid steganographic image authentication algorithm

Storing data in a third party cloud system causes serious problems on data confidentiality. Generally, encryption techniques provide data confidentiality but with limited functionality, which occurs due to unsupported actions of encryption operation in cloud storage space. Hence, developing a decentralized secure storage system with multiple support functions like encryption, encoding, and forwarding tends to get complicated, when the storage system spreads. This paper aims mainly on hiding image information using specialized steganographic image authentication (SSIA) algorithm in clustered cloud systems. The SSIA algorithm is applied to virtual elastic clusters in a public cloud platform. Here, the SSIA algorithm embeds the image information using blowfish algorithm and genetic operators. Initially, the blowfish symmetric block encryption is applied over the image and then the genetic operator is applied to re-encrypt the image information. The proposed algorithm provides an improved security than conventional blowfish algorithm in a clustered cloud system

Prevalence of Irreversible Airflow Obstruction among Chronic Asthmatics in Government Royapettah Hospital

BACKGROUND : Asthma is a chronic inflammatory airway disorder characterized by airway hyper responsiveness and reversible airflow obstruction. Subgroups of asthma patients develop airflow obstruction that is irreversible or only partially reversible and experience an accelerated rate of lung function decline. Airway remodelling has been associated with increased disease severity. Irreversible and partially reversible air flow obstruction(COPD pattern) in asthmatics have been associated with longer duration, reduced pulmonary function early in life, frequent exacerbations, smoking, continuing exposure to a sensitizing agent, and adult-onset asthma and lack of use of inhaled corticosteroids early in the course of the disease.The need to identify this pattern using pulmonary function test is always overlooked. This study looks at those patients with long duration asthma with a irreversible and a partially reversible airflow obstruction and analyses the risk factors that potentiate this phenotype in asthma patients and thereby gives clues towards prevention of lung function decline in asthmatics. OBJECTIVE : The objectives of this study are to determine the prevalence of irreversible air flow obstruction in chronic asthmatics using spirometry and to assess the risk factors contributing to the development of irreversible airflow obstruction in chronic asthmatics. MATERIALS AND METHODS : Patients who were aged more than 18years with asthma duration >10 years were included. The patients had their defined clinically by Diurnal variation of symptoms, predominantly nocturnal symptoms, seasonal aggravation of symptoms, presence of nasal polyps,Allergic tendencies to known allergens,positive family history, complete relief of the symptom in the past/present with nebulisation. Patients were thoroughly instructed on the use of spirometer and with the informed consent a FEV1, FVC and FEV1/FVC values were obtained using spirometer before and after salbutamol nebulisation. Steroid trail (40mg for 2 weeks) and the values were assessed after 2 weeks. Irreversible airflow obstruction was defined as a failure to increase the FEV1 by >12% or 200ml. The correlation of various factors like smoking, lack of steroid, duration of asthma and age at onset of asthma with the reversibility of airflow obstruction was assessed in the study group. RESULTS : Irreversible airflow obstruction was prevalent (50%)in the study population. Smoking, duration of asthma, severity of asthma were significantly associated with irreversible airflow obstruction (p.05). CONCLUSION : Although airflow obstruction in asthma is reversible, longer duration of asthma, smoking, severe type of asthma was found to be related to irreversible pattern of obstruction in asthmatics. Also asthma when irreversible mimicked clinically as COPD. Thus this study favours asthma as a predisposing/risk factor for COPD. The study also emphasis the importance of using spirometry in diagnosing and monitoring asthma. The recognition of this pattern among asthmatics help in planning the treatment as in outpatient visits and in Emergency rooms

Heptaphyrins: expanded porphyrins with seven heterocyclic rings

Expanded porphyrins containing seven pyrrole/heterocyclic rings linked in a cyclic fashion are termed heptaphyrins. The number of π-electrons in heptaphyrins depends on the number ofmeso carbon bridges used to link the heterocyclic rings, accordingly heptaphyrins with 28π-electrons and 30π-electrons are reported to date. Both condensation reactions of the appropriate precursors and acid-catalysed oxidative coupling reactions have been utilized to synthesise the heptaphyrins. The 30π heptaphyrins exhibit rich structural diversity where some of the heterocyclic rings in the macrocycle undergo a 180° ring flipping. An overview of the synthetic methods employed for the synthesis of heptaphyrins, their spectroscopic properties, structural behaviour and aromatic properties are highlighted in this paper

Core modified oxybenziporphyrins: new aromatic ligands for metalcarbon bond activation

Successful syntheses of two new aromatic core modified oxybenziporphyrins by a simple 3 + 1 methodology and the first aromatic core modified oxybenziporphyrin palladium complex are reported

Finite element model to simulate impact on a soft tissue simulant

A finite element model of an impact test on a soft tissue simulant, used as part of a shoulder surrogate, was developed in Ansys© LS-DYNA®. The surrogate consisted of a metal hemicylindrical core, with a diameter of 75 mm, covered with a 15 mm thick relaxed muscle simulant. The muscle simulant consisted of a 14 mm thick layer of silicone covered with 1 mm thick chamois leather to represent skin. The material properties of the silicone were obtained via quasi-static compression testing (curve fit with hyperelastic models) and compressive stress relaxation testing (curve fit with a Prony series). Outputs of the finite element models were compared against experimental data from impact tests on the shoulder surrogate at energies of 4.9, 9.8 and 14.7 J. The accuracy of the finite element models was assessed using four parameters: peak impact force, maximum deformation, impact duration and impulse. A 5-parameter Mooney-Rivlin material model combined with a 2-term Prony series was found to be suitable for modelling the soft tissue simulant of the shoulder surrogate. This model had under 10% overall mean deviation from the experimental values for the four assessment parameters across the three impact energies. Overall, the model provided a repeatable test method that can be adapted to help predict injuries to skin tissue and the performance/efficacy of personal protective equipment

Inverted porphyrins and expanded porphyrins: an overview

Porphyrins and metallopophyrins have attracted the attention of chemists for the past 100 years or more owing to their widespread involvement in biology. More recently, synthetic porphyrins and porphyrin-like macrocycles have attracted the attention of researchers due to their diverse applications as sensitizers for photodynamic therapy, MRI contrasting agents, and complexing agents for larger metal ions and also for their anion binding abilities. The number of π-electrons in the porphyrin ring can be increased either by increasing the numberof conjugated double bonds between the pyrrole rings or by increasing the number of heterocyclic rings. Thus, 22π sapphyrins, 26π rubyrins, 30π heptaphyrins, 34π octaphyrins and higher cyclic polypyrrole analogues containing 40π, 48π, 64π, 80π and 96π systems have recently been reported in the literature. These macrocycles show rich structural diversity where normal and different kinds of inverted structures have been identified. In this review, an attempt has been made to collect the literature of the inverted porphyrins and expanded porphyrins reported until December 2001. Since themeso aryl expanded porphyrins have tendency to form both inverted and non-inverted structures more emphasis has been given to meso aryl expanded porphyrins

Baldev Raj (1947-2018)

Baldev Raj (BR), a distinguished scientist and technologist of India passed away on 6 January 2018 at Pune while he was on official duty. BR was born on 9 April 1947 in Jammu. He lost his father at a very early age. In 1969, he graduated with a gold medal in the engineering discipline (metallurgy) from Ravishankar University, Raipur. In 1970, he joined the 14th batch of Bhabha Atomic Research Centre (BARC) Training School in Trombay. After successful completion of training, he joined BARC as a Scientific Officer. BR obtained his Ph D from the Indian Institute of Science (IISc), Bangalore in 1990 in the Faculty of Engineering, in a multidisciplinary area encompassing collaboration between the Department of Metallurgy and Aerospace Engineering