Mutual inhibition and capacity sharing during parallel preparation of serial eye movements

Many common activities, like reading, scanning scenes, or searching for an inconspicuous item in a cluttered environment, entail serial movements of the eyes that shift the gaze from one object to another. Previous studies have shown that the primate brain is capable of programming sequential saccadic eye movements in parallel. Given that the onset of saccades directed to a target are unpredictable in individual trials, what prevents a saccade during parallel programming from being executed in the direction of the second target before execution of another saccade in the direction of the first target remains unclear. Using a computational model, here we demonstrate that sequential saccades inhibit each other and share the brain's limited processing resources (capacity) so that the planning of a saccade in the direction of the first target always finishes first. In this framework, the latency of a saccade increases linearly with the fraction of capacity allocated to the other saccade in the sequence, and exponentially with the duration of capacity sharing. Our study establishes a link between the dual-task paradigm and the ramp-to-threshold model of response time to identify a physiologically viable mechanism that preserves the serial order of saccades without compromising the speed of performance.

Electroless Ni-W-P Coating and Its Nano-WS2 Composite: Preparation and Properties

The ternary alloy Ni-W-P and its WS2 nanocomposite coatings were successfully obtained on low-carbon steel using the electroless plating technique. The sodium tungstate (Na2WO4) concentration in the bath was varied to obtain Ni-W-P deposits containing various Ni and P contents. WS2 composite was obtained with a suitable concentration of Na2WO4 in Ni-P coating. These deposits were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray analysis (EDX) studies. The corrosion behavior was investigated by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) studies in 3.5 wt % NaCl solutions, and the corrosion rates of the coatings for Ni-P, Ni-W-P, and Ni-W-P-WS2 were found to be 2.571 x 10(-5), 8.219 x 10(-7), and 7.986 x 10(-7) g/h, respectively. An increase in the codeposition of alloying metal tungsten (W) enhanced the corrosion resistance and microhardness and changed the structure and morphology of the deposits. Incorporation of WS2 nanoparticles to Ni-W-P alloy coating reduced the coefficient of friction from 0.16 to 0.11 and also helped in improving the corrosion resistance of the coating further.

Green synthesis of biopolymer-silver nanoparticle nanocomposite: An optical sensor for ammonia detection

Biopolymer used for the production of nanoparticles (NPs) has attracted increasing attention. In the presence article we use aqueous solution of polysaccharide Cyamopsis tetragonaloba commonly known as guar gum (GG), from plants. GG acts as reductive preparation of silver nanoparticles which are found to be <10. nm in size. The uniformity of the NPs size was measured by the SEM and TEM, while a face centered cubic structure of crystalline silver nanoparticles was characterized using powder X-ray diffraction technique. Aqueous ammonia sensing study of polymer/silver nanoparticles nanocomposite (GG/AgNPs NC) was performed by optical method based on surface plasmon resonance (SPR). The performances of optical sensor were investigated which provide the excellent result. The response time of 2-3. s and the detection limit of ammonia solution, 1. ppm were found at room temperature. Thus, in future this room temperature optical ammonia sensor can be used for clinical and medical diagnosis for detecting low ammonia level in biological fluids, such as plasma, sweat, saliva, cerebrospinal liquid or biological samples in general for various biomedical applications in human. © 2012 Elsevier B.V.

Expression of VP1 protein of serotype A and O of foot-and-mouth disease virus in transgenic sunnhemp plants and its immunogenicity for guinea pigs

Recently, transgenic plants expressing immunogenic proteins of foot-and-mouth disease virus (FMDV) have been used as oral or parenteral vaccines against foot-and-mouth disease (FMD). They exhibit advantages like cost effectiveness, absence of processing, thermostability, and easy oral application. FMDV VP1 protein of single serotype has been mostly used as immunogen. Here we report the development of a bivalent vaccine with tandem-linked VP1 proteins of two serotypes, A and O, present in transgenic forage crop Crotalaria juncea. The expression of the bivalent protein in the transgenic plants was confirmed by Western blot analysis. Guinea pig reacted to orally or parenterally applied vaccine by humoral as well as cell-mediated immune responses including serum antibodies and stimulated lymphocytes, respectively. The vaccine protected the animals against a challenge with the virus of serotype A as well as O. This is the first report on the development of a bivalent FMD vaccine using a forage crop.

Preparation and characterization chemistry of nano-crystalline Ni-Cu-Zn ferrite

In submitted research; nanocrystalline powders having elements Ni0.5Cu0.25Zn0.25Fe2 xInxO4 with varied amounts of indium ( x = 0.0, 0.1, 0.2, 0.3 and 0.4) were grown-up by modified citrate to nitrate alchemy. The realism of single phase cubic spinel creation of the synthesized ferrite samples was studied by the DTA-TGA, XRD, SEM, EDX, FT-IR, VSM and dielectric measurements. SEM was applied to inspect the morphological variations and EDX was used to determine the compositional mass ratios. The studies on the dielectric constant (epsilon'), dielectric loss (epsilon `'), loss tangent (tan delta), ac conductivity (sigma(ac)), resistive and reactive parts of the impedance analysis (Z' and Z `') at room temperature were also carried out. The saturation magnetizations (Ms) were determined using the vibrating sample magnetometer (VSM). Ms. decreased with the increase In3+ doping content, as Fe3+ of 5(mu B) ions are replaced by In3+ of 5 mu(B) ions. (C) 2012 Elsevier B. V. All rights reserved.

Preparation of Freestanding Zn Nanocrystallites by Combined Milling at Cryogenic and Room Temperatures

The present investigation reports the preparation of freestanding nanocrystalline Zn by combined mechanical milling at cryogenic and room temperatures. The cryomilling is used as an effective means of rapid fracturing. The detailed scanning electron microscopy and transmission electron microscopy observations indicate that the minimum crystallite size is 6 +/- A 2 nm after 3 hours of cryomilling. The crystallite size increases to 30 +/- A 2 nm after 3 hours of room temperature milling of the cryomilled powder due to deformation-induced sintering. Detailed theoretical analysis allows us to obtain a diagram of size of the nanoparticles formed vs temperature to explain the experimental findings.

Interconnected, ultrafine osmium nanoclusters: preparation and surface enhanced Raman scattering activity

Interconnected Os nanochains consisting of ultrafine particles prepared using a simple procedure yield a coupled surface plasmon peak in the visible region and can be used as substrates for surface enhanced Raman scattering of various analytes.

Treatment efficacy of algae-based sewage treatment plants

Lagoons have been traditionally used in India for decentralized treatment of domestic sewage. These are cost effective as they depend mainly on natural processes without any external energy inputs. This study focuses on the treatment efficiency of algae-based sewage treatment plant (STP) of 67.65 million liters per day (MLD) capacity considering the characteristics of domestic wastewater (sewage) and functioning of the treatment plant, while attempting to understand the role of algae in the treatment. STP performance was assessed by diurnal as well as periodic investigations of key water quality parameters and algal biota. STP with a residence time of 14.3 days perform moderately, which is evident from the removal of total chemical oxygen demand (COD) (60 %), filterable COD (50 %), total biochemical oxygen demand (BOD) (82 %), and filterable BOD (70 %) as sewage travels from the inlet to the outlet. Furthermore, nitrogen content showed sharp variations with total Kjeldahl nitrogen (TKN) removal of 36 %; ammonium N (NH4-N) removal efficiency of 18 %, nitrate (NO3-N) removal efficiency of 22 %, and nitrite (NO2-N) removal efficiency of 57.8 %. The predominant algae are euglenoides (in facultative lagoons) and chlorophycean members (maturation ponds). The drastic decrease of particulates and suspended matter highlights heterotrophy of euglenoides in removing particulates.

Preparation of Self Assembled Sodium Oleate Monolayer on Mild Steel and Its Corrosion Inhibition Behavior in Saline water

A self assembled monolayer (SAM) of sodium oleate was generated on mild steel by the dip coating method. Formation of the SAM on mild steel was examined using Infrared Reflection Absorption Spectroscopy (IRRAS) and contact angle measurements. The chemical and anticorrosive properties of the SAM were analyzed using different techniques. IRRAS and water contact angle data revealed the crystallinity and chemical stability of the SAM modified mild steel. The electrochemical measurements showed that the mild steel with the sodium oleate derived SAM exhibited better corrosion resistance in saline water. The effect of temperature and pH on the SAM formation and its anti corrosion ability was explored.

Preparation of zinc oxide coatings by using newly designed metal-organic complexes of Zn: Effect of molecular structure of the precursor and surfactant over the crystallization, growth and luminescence

We report large scale deposition of tapered zinc oxide (ZnO) nanorods on Si(100) substrate by using newly designed metal-organic complex of zinc (Zn) as the precursor, and microwave irradiation assisted chemical synthesis as a process. The coatings are uniform and high density ZnO nanorods (similar to 1.5 mu m length) grow over the entire area (625 mm(2)) of the substrate within 1-5 min of microwave irradiation. ZnO coatings obtained by solution phase deposition yield strong UV emission. Variation of the molecular structure/molecular weight of the precursors and surfactants influence the crystallinity, morphology, and optical properties of ZnO coatings. The precursors in addition with the surfactant and the solvent are widely used to obtain desired coating on any substrate. The growth mechanism and the schematics of the growth process of ZnO coatings on Si(100) are discussed. (c) 2013 Elsevier B.V. All rights reserved.

On existence of periodic solutions for stable interval plants with odd, sector type nonlinearities

In several systems, the physical parameters of the system vary over time or operating points. A popular way of representing such plants with structured or parametric uncertainties is by means of interval polynomials. However, ensuring the stability of such systems is a robust control problem. Fortunately, Kharitonov's theorem enables the analysis of such interval plants and also provides tools for design of robust controllers in such cases. The present paper considers one such case, where the interval plant is connected with a timeinvariant, static, odd, sector type nonlinearity in its feedback path. This paper provides necessary conditions for the existence of self sustaining periodic oscillations in such interval plants, and indicates a possible design algorithm to avoid such periodic solutions or limit cycles. The describing function technique is used to approximate the nonlinearity and subsequently arrive at the results. Furthermore, the value set approach, along with Mikhailov conditions, are resorted to in providing graphical techniques for the derivation of the conditions and subsequent design algorithm of the controller.

Intelligent prediction of ground vibration in coal formations using ANN

The present paper details the prediction of blast induced ground vibration, using artificial neural network. The data was generated from five different coal mines. Twenty one different parameters involving rock mass parameters, explosive parameters and blast design parameters, were used to develop the one comprehensive ANN model for five different coal bearing formations. A total of 131 datasets was used to develop the ANN model and 44 datasets was used to test the model. The developed ANN model was compared with the USBM model. The prediction capability to predict blast induced ground vibration, of the comprehensive ANN model was found to be superior.

Preparation and electrochemical performance of porous hematite (alpha-Fe2O3) nanostructures as supercapacitor electrode material

Porous alpha-Fe2O3 nanostructures have been synthesized by sol-gel route. The effect of preparation temperature on the morphology, structure, and electrochemical stability upon cycling has been studied for supercapacitor application. The discharge capacitance of alpha-Fe2O3 prepared at 300 A degrees C is 193 F g(-1), when the electrodes are cycled in 0.5 M Na2SO3 at a specific current of 1 A g(-1). The capacitance retention after 1,000 cycles is about 92 % of the initial capacitance at a current density of 2 A g(-1). The high discharge capacitance as well as stability of alpha-Fe2O3 electrodes is attributed to large surface area and porosity of the material. There is a decrease in specific capacitance (SC) on increasing the preparation temperature. As iron oxides are inexpensive, the synthetic route adopted for alpha-Fe2O3 in the present study is convenient and the SC is high with good cycling stability, the porous alpha-Fe2O3 is a potential material for supercapacitors.

Context dependency of rewards and services in an Indian ant-plant interaction: southern sites favour the mutualism between plants and ants

Protection-based ant-plant mutualisms may vary in strength due to differences in ant rewards, abundance of protective ants and herbivory pressure. We investigated geographical and temporal variation in host plant traits and herbivory pressure at five sites spanning the distribution range of the myrmecophyte Humboldtia brunonis (Fabaceae) in the Indian Western Ghats. Southern siteshad, onaverage, 2.4 times greater abundance of domatia-bearing individuals, 1.6 times greater extrafloral nectary numbers per leaf, 1.2 times larger extrafloral nectary sizes, 2.2 times greater extrafloral nectar (EFN) volumes and a two-fold increase in total amino acid and total sugar concentrations in EFN compared with northern sites. Astrong protection-based mutualismwith ants occurred at only one southern site where herbivory was highest, suggesting that investments in attracting ants correlate with anti-herbivore benefits gained from the presence of protective ants. Our results confirm a temporally stable north-south gradient in myrmecophytic traits in this ant-plant as several of these traits were re-sampled after a 5-y interval. However, the chemical composition of EFN varied at both spatial and short-term temporal scales suggesting that only repeated measurements of rewards such as EFN can reveal the real spectrum of trait variation in an ant-plant mutualistic system.