Quantum entanglement and Hawking temperature

The thermodynamic entropy of an isolated system is given by its von Neumann entropy. Over the last few years, there is an intense activity to understand thermodynamic entropy from the principles of quantum mechanics. More specifically, is there a relation between the (von Neumann) entropy of entanglement between a system and some (separate) environment is related to the thermodynamic entropy? It is difficult to obtain the relation for many body systems, hence, most of the work in the literature has focused on small number systems. In this work, we consider black-holes --- that are simple yet macroscopic systems --- and show that a direct connection could not be made between the entropy of entanglement and the Hawking temperature. In this work, within the adiabatic approximation, we explicitly show that the Hawking temperature is indeed given by the rate of change of the entropy of entanglement across a black hole's horizon with regard to the system energy. This is yet another numerical evidence to understand the key features of black hole thermodynamics from the viewpoint of quantum information theory.Comment: 10 pages, 5 figures (To appear in Eur. Phys. J. C

KNOWLEDGE AND AWARENESS REGARDING ANTIBIOTIC PROPHYLAXIS FOR INFECTIVE ENDOCARDITIS AMONG UNDERGRADUATE DENTAL STUDENTS

ABSTRACTObjective: To evaluate the knowledge and awareness regarding antibiotic prophylaxis for infective endocarditis (IE) among undergraduate dentalstudents.Methods: A validated questionnaire of 16 questions, regarding the basic knowledge and awareness about antibiotic prophylaxis for the preventionof IE, was distributed among 100 students randomly belonging to final year and internship (5 year trainee) of the undergraduate dental program inSaveetha Dental College and Hospital, Saveetha University, Chennai. The data extracted were tabulated, statistically analyzed, and results obtained.Results were calculated on the basis of frequency and percentages using SPSS Version 20.0.thResults: About 73% of the students were aware of IE prophylaxis, and 40% of dental students were exposed to treating patients susceptible to IE.56% of participants answered that amoxicillin is the first line of antibiotic for IE prophylaxis and 59% replied 2 g PO 1 hr before the appointment isthe recommended regimen. 36% said that erythromycin is no longer recommended by American Heart Association for IE prophylaxis. However, onlyone-third of the participants knew about the cardiac conditions and dental procedures that require antibiotic prophylaxis for the prevention of IE.Furthermore, only 16% knew about the recommended dosage of clindamycin.Conclusion: This study revealed a reasonable knowledge and awareness about IE prophylaxis among undergraduate dental students but wasinadequate. Hence, this study emphasizes the need for improved education in the teaching curriculum for dental students regarding IE prophylaxis.A standard protocol regarding the training as well as preventive measures for IE should be formulated for the dental students and the knowledgeacquired must be transferred into practice.Keywords: Infective endocarditis, Prophylaxis, Antibiotics, Dental students, Knowledge

A Hierarchical Framework for the Classification of Multispectral Imagery

AbstractOut of the abundant digital image data available, multispectral imagery is one which gives us information about the earth we live in. To gain knowledge from multispectral imagery, it is essential to classify the data present in the image based on spectral information. Classification plays a significant role in understanding the remotely sensed data obtained from the satellites. This paper brings out a new classification scheme based on a hierarchical framework. The hierarchical model proposed in this paper helps to understand the imagery at different levels of abstractness and concreteness to serve different applications like town planning, facility management and so on. The model depicts classification of the multispectral imagery on three abstract levels. The algorithm proposed outputs classification at different levels with an average accuracy of 72.6% in level 1 and 78.3% in level 2. The time sensitivity analysis of the algorithm shows that it outperforms the traditional SVM classifier. A detailed analysis of the algorithm proposed is detailed in this paper with respect to the parameters influencing the classification accuracy

On the polar decomposition of right linear operators in quaternionic Hilbert spaces

In this article we prove the existence of the polar decomposition for densely defined closed right linear operators in quaternionic Hilbert spaces: If $T$ is a densely defined closed right linear operator in a quaternionic Hilbert space $H$, then there exists a partial isometry $U_{0}$ such that $T = U_{0}|T|$. In fact $U_{0}$ is unique if $N(U_{0}) = N(T)$. In particular, if $H$ is separable and $U$ is a partial isometry with $T = U|T|$, then we prove that $U = U_{0}$ if and only if either $N(T) = \{0\}$ or $R(T)^{\bot} = \{0\}$.Comment: 17 page

The red rain phenomenon of Kerala and its possible extraterrestrial origin

A red rain phenomenon occurred in Kerala, India starting from 25th July 2001, in which the rainwater appeared coloured in various localized places that are spread over a few hundred kilometers in Kerala. Maximum cases were reported during the first 10 days and isolated cases were found to occur for about 2 months. The striking red colouration of the rainwater was found to be due to the suspension of microscopic red particles having the appearance of biological cells. These particles have no similarity with usual desert dust. An estimated minimum quantity of 50,000 kg of red particles has fallen from the sky through red rain. An analysis of this strange phenomenon further shows that the conventional atmospheric transport processes like dust storms etc. cannot explain this phenomenon. The electron microscopic study of the red particles shows fine cell structure indicating their biological cell like nature. EDAX analysis shows that the major elements present in these cell like particles are carbon and oxygen. Strangely, a test for DNA using Ethidium Bromide dye fluorescence technique indicates absence of DNA in these cells. In the context of a suspected link between a meteor airburst event and the red rain, the possibility for the extraterrestrial origin of these particles from cometary fragments is discussed.Comment: 18 pages, 15 figures, accepted for publication in Astrophysics and Space Scienc