Far-infrared study of K giants in the solar neighborhood: Connection between Li enrichment and mass-loss

We searched for a correlation between the two anomalous properties of K giants: Li enhancement and IR excess from an unbiased survey of a large sample of RGB stars. A sample of 2000 low-mass K giants with accurate astrometry from the Hipparcos catalog was chosen for which Li abundances have been determined from low-resolution spectra. Far-infrared data were collected from the $WISE$ and $IRAS$ catalogs. To probe the correlation between the two anomalies, we supplemented 15 Li-rich K giants discovered from this sample with 25 known Li-rich K giants from other studies. Dust shell evolutionary models and spectral energy distributions were constructed using the code DUSTY to estimate different dust shell properties, such as dust evolutionary time scales, dust temperatures, and mass-loss rates. Among 2000 K giants, we found about two dozen K giants with detectable far-IR excess, and surprisingly, none of them are Li-rich. Similarly, the 15 new Li-rich K giants that were identified from the same sample show no evidence of IR excess. Of the total 40 Li-rich K giants, only 7 show IR excess. Important is that K giants with Li enhancement and/or IR excess begin to appear only at the bump on the RGB. Results show that K giants with IR excess are very rare, similar to K giants with Li enhancement. This may be due to the rapid differential evolution of dust shell and Li depletion compared to RGB evolutionary time scales. We also infer from the results that during the bump evolution, giants probably undergo some internal changes, which are perhaps the cause of mass-loss and Li-enhancement events. However, the available observational results do not ascertain that these properties are correlated. That a few Li-rich giants have IR excess seems to be pure coincidence.Comment: Accepted for Publication in Astronomy & Astrophysics, 6 figures, 5 tables, 19 page

New Experimental Limit on the Electric Dipole Moment of the Electron in a Paramagnetic Insulator

We report results of an experimental search for the intrinsic Electric Dipole Moment (EDM) of the electron using a solid-state technique. The experiment employs a paramagnetic, insulating gadolinium gallium garnet (GGG) that has a large magnetic response at low temperatures. The presence of the eEDM would lead to a small but non-zero magnetization as the GGG sample is subject to a strong electric field. We search for the resulting Stark-induced magnetization with a sensitive magnetometer. Recent progress on the suppression of several sources of background allows the experiment to run free of spurious signals at the level of the statistical uncertainties. We report our first limit on the eEDM of $(-5.57 \pm 7.98 \pm 0.12)\times$10$^{-25}$e$\cdot$cm with 5 days of data averaging.Comment: 9 pages, 9 figures, Revtex 4.

Performance Degradation in Pre-rake Frequency-division Duplex/ Direct Sequence-code Division Multiple Access Systems

The transmitter-based pre-rake diversity combining technique reduces the complexity, size and cost of the mobile unit (MU), while achieving the same inter symbol interference (ISI) mitigation effects of rake receiver for direct sequence-code division multiple access (DS-CDMA) systems. The technique is based on preprocessing of transmitted signal relying on knowledge of the channel state information (CSI) before transmission. In most of the previous works, this a priori information is either assumed or estimated for the uplink and the same is applied to the downlink in time division duplex (TDD) systems due to channel reciprocity. In this paper, a method for channel prediction to evaluate the pre-rake system using binary phaseshift keying (BPSK) modulation in frequency-division duplex (FDD) through analytical and computer simulations for DS-CDMA downlink has been proposed. The performance of the system was also evaluated under ideal and predicted channel conditions using different spreading codes. The findings will have widespread applications in defence communication equipment.Defence Science Journal, 2010, 60(3), pp.282-289, DOI:http://dx.doi.org/10.14429/dsj.60.35

Validation of Molecular Markers Genetically Linked to S-Cytoplasm and Restoration-of-fertility (Rf) Loci in Hot Pepper (Capsicum annuum L.)

Existence of CGMS system in hot pepper is due to the rearrangements in the mitochondrial genome and is largely used in economized and pure F 1 hybrid seed production around the world. The orf456, a new ORF present at flanking region of the coxII gene at the 3’ end, was distinguished male sterile cytoplasm in hot peppers along with atp6-2gene. In the current study, eighteen pepper genotypes (nine each of A and corresponding B lines) of varied origin were used to validate with two male sterile cytoplasm (S-cytoplasm) specific sequence characterised amplified region (SCAR) markers viz., atp6-2 (875 bp) and orf456 (456 bp) and one restoration-of-fertility (Rf) locus specific marker, CRF (550 bp). The results clearly showed that the presence of CMS-S-cytoplasm and absence of restoration-of-fertility (Rf) gene in the pepper genotypes studied and is comparable with the phenotypic data. In view of the outcomes it has been reasoned that the accessible S and Rf markers available in the public domain are reproducible and can be promptly utilized for marker assisted selection (MAS) in hot pepper crop improvement program

Studies on Bacillus thuringiensis proteases involved in the production of insecticidal toxins from protoxins

Two mutants of Btk HD1 were isolated, one having elevated protease activity (Btk-e, hyper producing) and the other with a deficiency (Btk-q). These mutants were characterized by X-ray film spot assay, gelatin ymography, azocasein analysis, western blot analysis, plasmid profiles, PCR, and Southern blot analysis. Btkq mutant displayed 2-3 fold higher activity against Helieoverpa armigera, Spodoptera litura and Chilo partellus, whereas Btk-e mutant displayed no significant enhancement in activity, but slightly lower activity against C. partellus. Protease deficient mutant Btk-q did not reveal the presence of any 66 kDa toxin band as observed with the wild type strain Btk HD1. It showed only 132 kda protoxin. The protoxins isolated from Btk HDI..

A modified sensitive palladium-copper oxide and multiwalled carbon nanotubes electrochemical sensor for detection of ametridione pesticide

Glassy carbon electrode modified sensitive Pd-CuO/MWCNTs electrochemical nanosensor was used for detection of ametridione pesticide in water samples. The morphology characteristics of Pd-CuO/MWCNTs are examined by scanning electron microscopy and EDX. The ametridione pesticide under voltammetric investigation involves irreversible, 4e? electron reduction based on the protonation of the two carbonyl groups (>C=O). The voltammetric method was applied for the detection of ametridione in BR buffer solution at pH 5.0 as a supporting electrolyte. The detection limit, limit of quantification and concentration ranges of the proposed method were 0.0796 ?g?mL?1 (signal/noise=3), 0.5560 ?g?mL?1 and 0.1 to 10.0 ?g?mL?1, respectively. The electrochemical sensor was successfully applied for the detection of ametridione in tap, agricultural run-off and river water samples showing >98% mean recoveries.   &nbsp

Evaluation of Solanum species and eggplant cultivated varieties for bacterial wilt resistance

Bacterial wilt caused by Ralstonia solanacearum is one of the major diseases in Solanum species including cultivated Eggplant (Solanum melongena L.). Bacterial wilt (BW) disease management in eggplant is difficult due to high survival rate of pathogen in soil and chemical application is not eco-friendly. The best way to avoid bacterial wilt in eggplant is using disease-resistant varieties. However, only a limited number of bacterial wilt resistant varieties are available and, there is a necessity to identify and/or develop new resistant varieties. In the current study, wild Solanum species, and eggplant cultivated varieties were evaluated against Ralstonia solanacearum, and disease incidence was recorded. The cultivated varieties IIHR-108, Pusa Purple Long and Rampur Local were identified as susceptible, whereas, IIHR-7 and CARI-1 were identified as resistant to bacterial wilt. These resistant wild and cultivated varieties can be used as a root-stock in bacterialwilt disease resistant breeding programmes

Experimental Evidence of Time Delay Induced Death in Coupled Limit Cycle Oscillators

Experimental observations of time delay induced amplitude death in a pair of coupled nonlinear electronic circuits that are individually capable of exhibiting limit cycle oscillations are described. In particular, the existence of multiply connected death islands in the parameter space of the coupling strength and the time delay parameter for coupled identical oscillators is established. The existence of such regions was predicted earlier on theoretical grounds in [Phys. Rev. Lett. 80, 5109 (1998); Physica 129D, 15 (1999)]. The experiments also reveal the occurrence of multiple frequency states, frequency suppression of oscillations with increased time delay and the onset of both in-phase and anti-phase collective oscillations.Comment: 4 aps formatted RevTeX pages; 6 figures; to appear in Phys. Rev. Let

Parameterized Inapproximability of Target Set Selection and Generalizations

In this paper, we consider the Target Set Selection problem: given a graph and a threshold value $thr(v)$ for any vertex $v$ of the graph, find a minimum size vertex-subset to "activate" s.t. all the vertices of the graph are activated at the end of the propagation process. A vertex $v$ is activated during the propagation process if at least $thr(v)$ of its neighbors are activated. This problem models several practical issues like faults in distributed networks or word-to-mouth recommendations in social networks. We show that for any functions $f$ and $\rho$ this problem cannot be approximated within a factor of $\rho(k)$ in $f(k) \cdot n^{O(1)}$ time, unless FPT = W[P], even for restricted thresholds (namely constant and majority thresholds). We also study the cardinality constraint maximization and minimization versions of the problem for which we prove similar hardness results