Observation of R-Band Variability of L Dwarfs

We report, for the first time, photometric variability of L dwarfs in $R$ band. Out of three L1 dwarfs (2MASS 1300+19, 2MASS 1439+19, and 2MASS 1658+70) observed, we have detected R band variability in 2MASS 1300+19 and 2MASS 1439+19. The objects exhibit variability of amplitude ranging from 0.01 mag to 0.02 mag. Object 2MASS 1658+70, turns out to be non-variable in both $R$ and $I$ band. However, more observations are needed to infer its variability. No periodic behaviour in the variability is found from the two L1 dwarfs that are variable. All the three L1 dwarfs have either negligible or no $H_{\alpha}$ activity. In the absence of any direct evidence for the presence of sufficiently strong magnetic field, the detection of polarization at the optical favors the presence of dust in the atmosphere of L dwarfs. We suggest that the observed $R$ band photometric variability is most likely due to atmospheric dust activity.Comment: 13 pages (latex, aastex style) including 3 eps figures. Accepted for publication in The Astrophysical Journal Letter

Night sky at the Indian Astronomical Observatory during 2000-2008

We present an analysis of the optical night sky brightness and extinction coefficient measurements in UBVRI at the Indian Astronomical Observatory (IAO), Hanle, during the period 2003-2008. They are obtained from an analysis of CCD images acquired at the 2 m Himalayan Chandra Telescope at IAO. Night sky brightness was estimated using 210 HFOSC images obtained on 47 nights and covering the declining phase of solar activity cycle-23. The zenith corrected values of the moonless night sky brightness in mag/square arcsecs are 22.14(U), 22.42(B), 21.28(V), 20.54(R) and 18.86(I) band. This shows that IAO is a dark site for optical observations. No clear dependency of sky brightness with solar activity is found. Extinction values at IAO are derived from an analysis of 1325 images over 58 nights. They are found to be 0.36 in U-band, 0.21 in B-band, 0.12 in V-band, 0.09 in R-band and 0.05 in I-band. On average, extinction during the summer months is slightly larger than that during the winter months. No clear evidence for a correlation between extinction in all bands and the average night time wind speed is found. Also presented here is the low resolution moonless optical night sky spectrum for IAO covering the wavelength range 3000-9300 \AA. Hanle region thus has the required characteristics of a good astronomical site in terms of night sky brightness and extinction, and could be a natural candidate site for any future large aperture Indian optical-infrared telescope(s).Comment: 18 pages, 7 figures, uses basi.cls, accepted for publication in Bulletin of the Astronomical Society of Indi

Multifunctional Antenna with Reconfigurable Ultra-Wide Band Characteristics

In this paper a multifunctional antenna is presented which offers an ultra-wideband (UWB) operation, an UWB operation with two switchable notches and reconfigurable dual-band operation for WiMAX and WLAN applications, respectively. Total seven functions/states could be achieved from a single antenna using an electronic switching. The antenna uses dual slots on the ground plane to provide a wide bandwidth, ranging from 3.1 GHz to 10.6 GHz. U-Shaped slot and C-Shaped printed strip in the ground are used to generate two notches at 3.6 GHz(WiMAX) and 5.2 GHz (WLAN/ WiFi) bands, respectively. Moreover, four parasitic strips are added in the feed side to make antenna functional at either3.6 GHz or 5.2 GHz or both. Total Five PIN diodes are required to obtain seven operations from the proposed antenna. Seven structures are fabricated and measured to verify the seven states and results are found in good agreement with estimated results obtained from the simulation

Importance of Primary Health Care in the Society

Primary health care (PHC) is the frontline care of the health care system that is comprehensive and coordinated. PHC provides multidisciplinary, patient-centered care with a focus on both the treatment and prevention of various conditions. It is the first point of contact to keep people well and improve their quality of life. A strong, accessible PHC system reduces pressure on hospitals by supporting people to manage their health issues in the society. The ultimate goal of primary health care is better health for all. WHO has identified key elements to achieving that goal: reducing exclusion and social disparities in health, organizing health services around people\u27s needs and expectations. The present paper is related to status and role of primary health care in India

Surface modification of silicate, borosilicate and phosphate bioactive glasses to improve/control protein adsorption: PART I

Bioactive glasses (BGs) are promising for bone tissue regeneration. BG composition can be tailored, according to the application of interest, and/or functionalized with organic molecules/biomolecules to improve their performances. However, despite the wide knowledge concerning BGs, their interaction with proteins, fundamental for controlling the fate of the implant, has not been deeply investigated yet. Controlling or predicting protein adsorption requires a full understanding of the materials surface physico-chemical properties. In this work, four different BGs (S53P4, B25, SCNB, PhGlass) were surface-modified by four different treatments: 72 h-soaking in TRIS, 72 h soaking in simulated body fluid, APTES grafting and quaternized APTES grafting. The surfaces were then characterized both untreated and after each treatment by contact angle, zeta potential analysis, X-ray photoelectron spectroscopy, Fourier Transform InfraRed–Attenuated Total Reflectance spectroscopy and Scanning Electron Microscopy and Energy Dispersive Spectroscopy. Inductively Coupled Plasma – Optical Emission Spectrometry was then performed to investigate the ion leaching. The aim of this study (Part I) is the physico-chemical characterization of BGs as a function of the implemented treatments, aiming to better understand how the superficial properties are successively affecting protein adsorption. Protein adsorption on untreated and treated BGs will be discussed in a following manuscript (Part II)

Chemical Stabilisation of Sand Part IX: Orthophthalate type Unsaturated Polyester Resin for Inducing Fast setting Behaviour and High Strength

Polymer concrete composites have been made from orthophthalate-type unsaturated polyester resin, methyl ethyl ketone peroxide as initiator, cobalt naphthenate as accelerator and desert sand as filler. Composites preferred using resin (10-25 per cent), initiator (4 per cent) and accelerator (2 per cent) with representative desert sand samples of different particle sizes (0.2-0.02 mm, 2-0.2 mm and 4-2 mm) as filler recorded unconfined compression strength ranging from 4 to 442 kg/cm/sup 2/ after curing at 50 degree centigrade in an oven for 0.5-24 h. Using coarse and fine sand samples with 10 and 15 per cent resin systems the maximum strength of 391 and 326 kg/cm/sup 2/ respectively was attained after 2 h of curing at 50 degree centigrade. The fast setting resin system with strength in this range is quite adequate for the construction of chemically stabilised surfaces, which withstand trafficability of vehicles, operation of helicopters and aircraft's requiring a maximum strength up to 275 kg/cm/sup 2/. These composites may prove useful for rapid repair of roads, helipads and runways damaged during operational activities. A mathematical model has been developed for predicting resin percentage needed for obtaining composite material of requisite strength. The observed and model predicted values have been found to show close agreement

NUTRACEUTICALS AND HERBALS AS ADJUVANTS IN THE CHEMOTHERAPY OF CANCER? A REVIEW

Cancer is the third leading cause of death worldwide. The current cancer treatments such as chemotherapy and radiotherapy resulting in the development of unintended adverse effects that reduce the quality of life and economic burden in oncology patients. Nutraceuticals along with food value have natural bioactive components that have reassuring therapeutic properties in several diseases. Herbs of significant interest have been proven to prevent and treat various types of cancer and also reduce the side effects of chemotherapy and radiotherapy. The efficacy of nutraceuticals and herbs such as chemopreventive and chemotherapy is highlighted. We conclude that further studies are required to countersign the targeted approaches and efficacy of herbs and nutraceuticals in cancer patients as adjuvant therapy

Modeling the Interdependences between Voltage Fluctuation and BTI Aging

With technology scaling, the susceptibility of circuits to different reliability degradations is steadily increasing. Aging in transistors due to bias temperature instability (BTI) and voltage fluctuation in the power delivery network of circuits due to IR-drops are the most prominent. In this paper, we are reporting for the first time that there are interdependences between voltage fluctuation and BTI aging that are nonnegligible. Modeling and investigating the joint impact of voltage fluctuation and BTI aging on the delay of circuits, while remaining compatible with the existing standard design flow, is indispensable in order to answer the vital question, “what is an efficient (i.e., small, yet sufficient) timing guardband to sustain the reliability of circuit for the projected lifetime?” This is, concisely, the key goal of this paper. Achieving that would not be possible without employing a physics-based BTI model that precisely describes the underlying generation and recovery mechanisms of defects under arbitrary stress waveforms. For this purpose, our model is validated against varied semiconductor measurements covering a wide range of voltage, temperature, frequency, and duty cycle conditions. To bring reliability awareness to existing EDA tool flows, we create standard cell libraries that contain the delay information of cells under the joint impact of aging and IR-drop. Our libraries can be directly deployed within the standard design flow because they are compatible with existing commercial tools (e.g., Synopsys and Cadence). Hence, designers can leverage the mature algorithms of these tools to accurately estimate the required timing guardbands for any circuit despite its complexity. Our investigation demonstrates that considering aging and IR-drop effects independently, as done in the state of the art, leads to employing insufficient and thus unreliable guardbands because of the nonnegligible (on average 15% and up to 25%) underestimations. Importantly, considering interdependences between aging and IR-drop does not only allow correct guardband estimations, but it also results in employing more efficient guardbands

Effect of dual-purpose summer legumes and zinc fertilization on system productivity, economics and nutrient use-efficiencies of rice (Oryza sativa) – wheat (Triticum aestivum) cropping system

A field experiment was conducted during 2007-09 at the research farm of IARI, New Delhi, India; to study the effects of dual-purpose summer legumes and zinc fertilization in aromatic hybrid rice (Oryza sativa L.)– wheat (Triticum aestivum L.) cropping system. The higher system productivity, N and Zn uptake, nutrient-use efficiencies, net return and B:C ratio were recorded in cowpea [Vigna unguiculata (L.) Walp.] or mungbean (Vigna radiata L.) residue incorporated plots. The N balance was negative (-) in all treatments but it was least negative (-) in cowpea among summer treatments followed by mungbean. The highest N and Zn uptake, system productivity in terms of grain yield, i.e. 12.32 and 12.71 tonnes/ha was observed with application of 2.0% ZEU (ZnSO4.7H2O). Among the Zn fertilization treatments the lowest negative (-) balance of N was recorded with control (only N), i.e. -36.92 kg/ha in 2007-08 however in 2008-09 it was recorded with coating material coated urea, i.e. -39.54 kg N/ha over rest of the Zn treatments. The application of 5.0 kg Zn/ha (ZnO) gave the highest (2 696 and 2 601 g/ha during 2007-08 and 2008-09, respectively) positive Zn balance under rice-wheat cropping system. Partial factor productivity, agronomic efficiency, apparent recovery and physiological efficiency of applied N and Zn in rice-wheat cropping system were increased with Zn-enriched urea. The agronomic efficiency of N with 2.0% ZEU (ZnSO4.7H2O) increased by 49.7% and the N recovery efficiency in grain increased up to 57.6% over normal practice of prilled urea application. With the application of 2.0% ZEU (ZnSO4.7H2O) the agronomic efficiency of Zn increased in the range of 54 to 160% while Zn apparent recovery (%) in grain increased from 70 to 318% over 2.0% ZEU (ZnO) and 5.0 kg Zn/ha (ZnO), respectively. The dual-purpose summer legume incorporation in rice-wheat system gave higher net returns by 29 to 34% in 2007-08 and 42 to 45% during 2008-09 over summer fallow with B:C ratio up to 3.01. The application of 2.0% ZEU (ZnSO4.7H2O) gave the highest B:C ratio of 3.02 and increased net returns of aromatic-hybrid rice-wheat system by 11.6 to 12.2% over prilled urea application