A first principles study of wurtzite-structure MnO

We present results of a density functional theory study of MnO in the wurtzite structure. Our motivation is provided by recent experiments reporting ferromagnetism in Mn-doped wurtzite structure ZnO. We find that wurtzite MnO a) is not strongly energetically disfavored as compared with the ground state rocksalt MnO, b) shows strong magnetostructural coupling and c) has a piezoelectric response that is larger than that of ZnO. These predictions augur well for the creation of ferromagnetic piezoelectric semiconductor based on Mn-doped ZnO

Clinicopathological profile of ovarian tumors in the age group 10-20 years

Background: Adolescence is the period of transition from childhood to adulthood. 1% neoplasm occurs in this age group below 17 years, of this, 3% are ovarian neoplasms. Aim was to study retrospectively the clinicopathological profile and outcome of ovarian tumors in the age group 10-20 years in Government Medical College, Kottayam, Kerala, India from January 2008 for six years.Methods: Fifty Patients who have undergone laparotomy in this institution during the period were taken for study. Data regarding age, mode of presentation, diagnostic methods, treatment and histopathology were recorded. Follow-up was also taken into consideration. Patients with polycystic ovary, corpus luteal cyst, follicular cyst and endometriotic cyst are excluded.Results: Majority of the patients fall between the age group 15-20 years. Major clinical presentation was pain (40%), followed by abdominal mass. Laparotomy was done for all cases except three where laparoscopy was done. Imprint cytology taken for 3 cases. Histopathology showed malignant tumors in 6 cases and benign tumors in 44 cases. Epithelial tumors outnumbered germ cell tumors.Conclusions: This study shows the predominance of epithelial neoplasms in the age group 10-20 years. Proportion of malignancy is 12%

Chikungunya Epidemic Mortality in India: Lessons from 17th Century Bills of Mortality Still Relevant

Chikungunya is a virus spread by the bite of the Aedes mosquito, which recently reemerged as a massive epidemic in the Indian Ocean islands and India. Chikungunya is generally considered self-limiting and has been reported as non-fatal but, since March 2005, one-third of the 770,000 people in the Indian Ocean Island of R�union (a French territory) have been affected by Chikungunya with 237 deaths. India reported 1.3 million cases of Chikungunya however the Government of India has not reported any deaths. However there is evidence that deaths due to Chikungunya did occur. The lack of official reports of deaths is mainly due to the poor recording of ‘Causes of Death’ in India. The London Bills of Mortality from the 17th provides a very good example of the importance of proper reporting of deaths especially during an epidemic period. This paper reflects on the London bills of mortality and modern day lessons to be drawn from it as well as the reasons behind the apparent lack of death reporting in 2006’s Chikungunya epidemic.

Effect of Nitric Acid Oxidation on Vapor Grown Carbon Fibers (VGCFs). Use of these Fibers in Epoxy Composites

Pyrograf IIITM,/sup\u3e fibers (PR-19-PS, Applied Sciences, Inc.) with 100-300 nm diameters and ~ 10-100 ìm lengths were used with a low viscosity aliphatic epoxy resin (Clearstream 9000, Clearstream Products, Inc.) to produce composites. The VGCFs were oxidized in 69-71 wt% nitric acid (115°C) for various times (10 min to 24 h) to modify the surface to enhance fiber/matrix adhesion. Remarkably, little fiber weight loss was detected even after 24 h of oxidation. Composites containing 19.2 volume percent (29.4 weight percent) VGCFs were prepared. Their flexural strengths and flexural moduli were obtained. The flexural strengths did not increase using oxidized VGCFs. Fiber surfaces were characterized using N2 BET, CO2 DR, XPS, SEM, TEM and base uptake measurements. Increasing the oxidation time produced only small initial increases in surface area up to a limit. Significant surface oxygen was present before oxidation and the amount increased initially, though not continuously, with nitric acid oxidation

Chikungunya Fever: A Killer Epidemic in Ahmedabad City, India

Background The Chikungunya virus is an alphavirus native to tropical Africa and Asia and is transmitted to humans by the bite of infected Aedes mosquitoes. The symptoms of Chikungunya include sudden onset of fever, severe arthralgia, and maculopapular rash. Thirty percent of the population on the French R�union Island was afflicted with Chikungunya in the past year. They reported 237 deaths. India on the other hand reported 1.39 million cases of Chikungunya but no deaths. Methods Mortality data from 2002-2006 was obtained from the Ahmedabad Municipal Corporation (AMC). Actual mortality rate of 2006 was compared to the mortality rate of 2002-05 and its statistical significance tests were carried out. Findings Mortality data obtained from the Ahmedabad Municipal Corporation (AMC) suggests that 3112 excess deaths occurred in August-November (epidemic period) compared to the average deaths in the same months during the previous four years. These differences in deaths were found to be highly statistically significant. A peak in excess mortality is seen in the month of September when 1489 additional deaths were recorded. Case fatality rates for Ahmedabad also turn out to be much higher than that of the Reunion Island. Interpretation The Chikungunya epidemic was raging when the excess deaths occurred. There were no other adverse events or other epidemics that took place could explain this excess mortality. Government authorities, WHO and other international public health agencies should take these findings of excess mortality seriously and investigate into this occurrence of excess deaths to understand this reemerging disease and prevent future epidemics and mortality.

Anti-Islanding Protection of Distributed Generation Based on Social Spider Optimization Technique

Anti-islanding protection is one of the most important requirements for the connection of Distributed Generators in power systems. This paper proposes a Social Spider Optimization (SSO) algorithm to detect unintentional islanding in power systems with distributed generation. The SSO algorithm is employed to differentiate frequency oscillations in synchronous generator those caused by non-islanding events. The SSO algorithm is based on the forging strategy of social spiders, which generated vibrations spread over the spider web to determine the positions of preys or any other disturbances. The vibrations from the spider are used to detect the occurrence of islanding in the synchronous generator. The SSO algorithm has superior performance when tested with IEEE 34 bus distribution system. The taken test system is evaluated for different scenarios and load distribution. The proposed SSO algorithm detects the islanding and prevents the system from undue tripping and outages. Furthermore, this technique may apply to prevent the system from islanding and maintains the future Indian Distributed Generation (DG) system reliability

Quantum phase properties of photon added and subtracted displaced Fock states

Quantum phase properties of photon added and subtracted displaced Fock states (and a set of quantum states which can be obtained as the limiting cases of these states) are investigated from a number of perspectives, and it is shown that the quantum phase properties are dependent on the quantum state engineering operations performed. Specifically, the analytic expressions for quantum phase distributions and angular $Q$ distribution as well as measures of quantum phase fluctuation and phase dispersion are obtained. The uniform phase distribution of the initial Fock states is observed to be transformed by the unitary operation (i.e., displacement operator) into non-Gaussian shape, except for the initial vacuum state. It is observed that the phase distribution is symmetric with respect to the phase of the displacement parameter and becomes progressively narrower as its amplitude increases. The non-unitary (photon addition/subtraction) operations make it even narrower in contrast to the Fock parameter, which leads to broadness. The photon subtraction is observed to be a more powerful quantum state engineering tool in comparison to the photon addition. Further, one of the quantum phase fluctuation parameters is found to reveal the existence of antibunching in both the engineered quantum states under consideration. Finally, the relevance of the engineered quantum states in the quantum phase estimation is also discussed, and photon added displaced Fock state is shown to be preferable for the task.Comment: Quantum phase properties of an engineered quantum state has been studied from various perspective