Contribution of morpho-physiological attributes in determining the yield of mungbean

Field experiments were conducted in 2006 and 2007 under subtropical conditions to investigate the variations in growth and reproductive characters, and yield attributes for selection of important source and sinks characters using correlation and path coefficient analyses in 45 mungbean genotypes. Large genetic variability existed in source characters viz., leaf area index (LAI) (1.22 to 3.80) and sink characters viz., number of racemes plant-1 (6.30 to 22.9), flowers plant-1 (18.1 to 51.9) and pods plant-1 (9.6 to 22.1). Genotypic correlation study revealed that among the traits investigated, LAI was the most important source that determined total dry mass (TDM) yield, and reproductive characters like number of racemes, flowers and pods plant-1 were the most important sinks that determined seed yield. Contrarily, reproductive efficiency (RE, % pod set to opened flowers) did not show significant relationship with pod number and seed yield, indicating that selection of high yield based on RE may be misleading. Path coefficient analysis further revealed that number of flowers, pods and 100-seed weight constituted central important sinks which exerted direct positive influence on seed yield. The results indicated that pod yield could be increased by increased raceme and flower production, while seed yield could be increased by increasing pod production. High yielding genotypes, in general, possessed higher earlier mentioned source (LAI) and sink (flower and pod number) characters which resulted in higher seed yield in mungbean. This information could be exploited in the future plant breeding programmes.Key words: Source-sink, correlation, path analysis, mungbean

The effects of gold nanoparticles size and concentration on viscosity, flow activation energy, dielectric and optical properties

This study was carried out to investigate viscosity in relation with the temperature, flow activation energy and dielectric properties for 10, 20 and 50 nm gold nanoparticles size (GNPs) in addition to absorption and fluorescence spectra at different concentrations (0.2 × 10-3 to 1 × 10-2%) in an attempt to cover and understand the toxicity and potential role of their therapeutic and diagnostic use in medical applications. 10, 20 and 50 nm GNPs dissolved in aqueous solution were purchased (Product MKN-Au, Canada) and used in this study. Mechanical parameters were measured using Brookfield LVDV-III Programmable rheometer with temperature bath controlled by a computer. 0.5 ml of each GNP size in aqueous solution was poured in the sample chamber of the rheometer. The spindle was immersed and rotated in these gold nanofluids in the speed range from 50 to 250 rpm in steps of 20 min. Viscosity of GNPs was measured at temperature of 37°C and at a gradually increase of temperature to 42ºC. UV–Visible characterization of GNPs at different concentrations from 0.2 × 10-3 to 1 × 10-2 % was performed using UV-1601 PC, UV-Visible spectrophotometer. The absorbance measurements were made over the wavelength range of 250 to 700 nm using 1 cm path length quartz cuvettes. Fluorescence characterization of GNPs was performed over the wavelength range of 250 to 700 nm using FluoroMax-2 JOBIAN YVON-SPEX. The measured viscosities for all GNP sizes decreased with increasing the temperatures from 37 to 42°C. The GNPs with larger size (50 nm) exhibited higher viscosity values compared with 10 and 20 nm GNPs. The flow activation energies (kJ/mol) for 10, 20 and 50 nm GNPs were 332.55, 415.4 and 182.2 kJ/mol, respectively. The optical properties such as absorption maxima and the absorption intensity are particle size-dependent. The fluorescence emission band for GNPs with an excitation wavelength of 308 nm and photoluminescence (PL) band centre appeared at 408 nm. With the increase of GNPs concentration at a fixed GNP size of 20 nm, the intensity of emission band positioned increased, and the trend was consistent with the changes of the corresponding surface plasmon resonance (SPR) of GNPs. The presented dielectric data indicates that GNPs have strong dielectric dispersion corresponding to the alpha relaxation region in the frequency range of 20 Hz to 100 kHz which was identified as anomalous frequency dispersion. At a constant GNP size, the absorbance was found to be proportional to the concentration of gold. This is due to the increase in the number of GNPs as well as the increase in the SPR of GNPs. An intense absorption peak was observed at wavelength of 517 nm which is generally attributed to the surface plasmon excitation of the small spherical GNPs. The incident light at 308 nm will lead to excitation of the surface plasmon coherent electronic motion as well as the d electrons. This study suggests that the relaxation of these electronic motions followed by the recombination of the sp electrons with holes in the d band leads to the fluorescence emission. These results indicate that the intensity of fluorescence emission band of GNPs was dependent on the concentration of GNPs. A rapid decrease in the dielectric constant may be attributed to the tendency of dipoles in GNPs to orient themselves in the direction of the applied field in the low-frequency range. However, in the high-frequency range, the dipoles will hardly be able to orient themselves in the direction of the applied field and hence the value of the dielectric constant is nearly constant.Key words: Gold nanoparticles, viscosity, size, temperature, dielectric, absorption, fluorescence

Isolated tricuspid valve infective endocarditis - A report of 6 cases

Six cases of isolated tricuspid valve endocarditis in young women are described. Preceding genital sepsis was a predisposing factor in 4 patients. Cardiac signs are unusual at presentation, rendering the diagnosis difficult. Pleuropulmonary manifestations are the predominant findings, while overt signs of tricuspid insufficiency and right heart failure occur late in the disease. Staphylococcus aureus is the pathogen most commonly found and requires energetic treatment for a minimum of 4 weeks. The value of echocardiography in establishing an early diagnosis is stressed. Persistent sepsis constitutes a major indication for surgery.S Afr Med J 1990; 78: 34-3

Characterization of kinetic and kinematic parameters for wearable robotics

The design process of a wearable robotic device for human assistance requires the characterization of both kinetic and kinematic parameters (KKP) of the human joints. The first step in this process is to extract the KKP from different gait analyses studies. This work is based on the human lower limb considering the following activities of daily living (ADL): walking over ground, stairs ascending/descending, ramp ascending/descending and chair standing up. The usage of different gait analyses in the characterization process, causes the data to have great variations from one study to another. Therefore, the data is graphically represented using Matlab® and Excel® to facilitate its assessment. Finally, the characterization of the KKP performed was proved to be useful in assessing the data reliability by directly comparing all the studies between each other; providing guidelines for the selection of actuator capacities depending on the end application; and highlighting optimization opportunities such as the implementation of agonist-antagonist actuators for particular human joints

De novo large rare copy-number variations contribute to conotruncal heart disease in Chinese patients

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Graphene plasmonics

Two rich and vibrant fields of investigation, graphene physics and plasmonics, strongly overlap. Not only does graphene possess intrinsic plasmons that are tunable and adjustable, but a combination of graphene with noble-metal nanostructures promises a variety of exciting applications for conventional plasmonics. The versatility of graphene means that graphene-based plasmonics may enable the manufacture of novel optical devices working in different frequency ranges, from terahertz to the visible, with extremely high speed, low driving voltage, low power consumption and compact sizes. Here we review the field emerging at the intersection of graphene physics and plasmonics.Comment: Review article; 12 pages, 6 figures, 99 references (final version available only at publisher's web site

Responses of marine benthic microalgae to elevated CO<inf>2</inf>

Increasing anthropogenic CO2 emissions to the atmosphere are causing a rise in pCO2 concentrations in the ocean surface and lowering pH. To predict the effects of these changes, we need to improve our understanding of the responses of marine primary producers since these drive biogeochemical cycles and profoundly affect the structure and function of benthic habitats. The effects of increasing CO2 levels on the colonisation of artificial substrata by microalgal assemblages (periphyton) were examined across a CO2 gradient off the volcanic island of Vulcano (NE Sicily). We show that periphyton communities altered significantly as CO2 concentrations increased. CO2 enrichment caused significant increases in chlorophyll a concentrations and in diatom abundance although we did not detect any changes in cyanobacteria. SEM analysis revealed major shifts in diatom assemblage composition as CO2 levels increased. The responses of benthic microalgae to rising anthropogenic CO2 emissions are likely to have significant ecological ramifications for coastal systems. © 2011 Springer-Verlag

Constraints on Nucleon Decay via "Invisible" Modes from the Sudbury Neutrino Observatory

Data from the Sudbury Neutrino Observatory have been used to constrain the lifetime for nucleon decay to ``invisible'' modes, such as n -> 3 nu. The analysis was based on a search for gamma-rays from the de-excitation of the residual nucleus that would result from the disappearance of either a proton or neutron from O16. A limit of tau_inv > 2 x 10^{29} years is obtained at 90% confidence for either neutron or proton decay modes. This is about an order of magnitude more stringent than previous constraints on invisible proton decay modes and 400 times more stringent than similar neutron modes.Comment: Update includes missing efficiency factor (limits change by factor of 2) Submitted to Physical Review Letter

Surgery and postoperative radiotherapy a valid treatment for advanced oropharyngeal carcinoma

Since 1992 we have prospectively included all head and neck cancer patients in our health region in a departmental based register. Our hospital takes care of all head and neck cancer patients in our health region consisting of approximately 1 million people. In 1997, we evaluated the results of the treatment of oropharyngeal cancer in the 1992–1997 period. On the basis of this evaluation, we changed our treatment policy for tonsillar and base of tongue carcinoma. We first changed the treatment for the lesions with worst prognosis, i.e., those with T3–T4 carcinomas, from radiotherapy only, to radical surgery and postoperative radiotherapy. We have since that time increasingly also operated the smaller oropharyngeal carcinomas. The 2 years’ overall survival and disease-specific survival for all patients diagnosed in the 1992–1997 period was 56 and 63%, respectively. The results from a similar group of patients in the 6 years’ period from 2000 to 2005, after the change in treatment, have increased to 83 and 88%. When we looked at the subgroup of patients in the 2000–2005 period treated with surgery and postoperative radiotherapy, 45 out of 69 patients (65%) presenting with an oropharyngeal cancer were fit for operation. With radical surgery and postoperative radiation therapy, the 2 years overall survival is now 91%. The 2-year disease-specific survival is 96% and the locoregional control is 98%. This is a marked improvement as compared to radiotherapy alone and definitely competitive with modern radiochemotherapy