A Hyperstable Miniprotein: Additive Effects of D- and L-Ala Substitutions

The effects of alanine substitutions in each helical segment of the structure, and Gly to D-Ala mutations at sites where glycines have positive phi angles in the Trp-cage miniprotein are reported. The effects of the stabilizing mutation were additive, yielding a 20-residue construct (Tm = 83^o^C). Gly to L-Ala substitutions were uniformly destabilizing ([DELTA][DELTA]G~F~ > 11 kJ/mol): the preference for a D-Ala can be as large as 16 kJ/mol. Glycine to D-Ala mutations are validated as a strategy for the design of hyperstable miniprotein scaffolds suitable for stereospecific pharmacophore display

Vibriocidal antibodies induced by Yersinia enterocolitica serotype IX

Yersinia enterocolitica serotype IX has been found to stimulate the production of vibriocidal antibody against Vibrio cholerae, particularly in Inaba serotype, in experimental rabbits and infected man to a significant degree. This activity could be absorbed by both Inaba and Yersinia antigens from anti-yersinia sera, but Yersinia antigen could not absorb vibriocidal activity from the anti-cholera sera, indicating a unilateral relation. Vibrio agglutinating antibody, particularly against Ogawa, in anti-yersinia rabbit or human sera was found to be less liable to non-specific stimulation. V. cholerae, while removing vibriocidal antibody, could not absorb the Yersinia agglutinin from anti-yersinia sera, suggesting that there is a different determinant for these two types of antibody activities. The non-specific production of vibriocidal antibody by Y. enterocolitica type IX indicates the need for caution in the interpretation of the results of vibriocidal tests where such organisms are prevalen

Universal Properties of Linear Magnetoresistance in Strongly Disordered Semiconductors

Linear magnetoresistance occurs in semiconductors as a consequence of strong electrical disorder and is characterized by nonsaturating magnetoresistance that is proportional to the applied magnetic field. By investigating a disordered MnAs-GaAs composite material, it is found that the magnitude of the linear magnetoresistance (LMR) is numerically equal to the carrier mobility over a wide range and is independent of carrier density. This behavior is complementary to the Hall effect that is independent of the mobility and dependent on the carrier density. Moreover, the LMR appears to be insensitive to the details of the disorder and points to a universal explanation of classical LMR that can be applied to other material systems.Comment: Accepted by Phys. Rev. B (2010

Variation in spike initiation in some Piper longum germplasms of North East India

The risk of adverse reactions in herbal remedies is less and has become popular to be used traditionally for treating various diseases. The species associated with genus Piper are important medicinal plants used for preparation of herbal medicines. The present investigation was carried out in the Experimental farm, Department of Horticulture, Assam Agricultural University, Jorhat-13 during 2013-14 and 2014-15 to investigate the flowering variation of some Piper longum germplasms of North East  India. A total of 16 Piper longum germplasms including ‘Viswam’ as check variety were evaluated and experimental data revealed significant difference in spike initiation time among the germplasms with shortest spike initiation period (245.30 days) that recorded in germplasm PLJ-19 while the check var. recorded 287.40 days. Significant and shortest period for spike initiation to maturity was recorded in germplasm PLJ-19 (61.04days) followed by PLJ-01 (61.00days), PLJ-11 (61.38days) and check var. (70.03days).The number of flowering spike per plant ranges in between 58.53-113.73. The highest number of flowering spike per plant 113.73 was observed in germplasm PLJ-19 followed by PLJ-01 (109.40), PLJ-11 (104.11), PLJ-16 (100.33) and were found to be superior over check var.  (92.07). The present findings has a significant contribution in determination and identification of germplasm having shorter spike formation period with higher number of flowering spike as the variation in piperine content depends on both the characters also

Effect of Fluid Suction on an Oscillatory MHD Channel Flow with Heat Transfer

Magnetohydrodynamics (MHD) is generally concerned with the study of the magnetic properties (behaviour) of electrically conducting fluids (plasmas, liquid metals etc.) moving in an electromagnetic field. The importance of the concept of MHD in various fields such as astrophysics, bio-medical research, missile technology and geophysics motivates the modelling and investigation of MHD flow and transport problems. The role of fluid suction is paramount in laminar flow control and has wide applications in fields such as aeronautical engineering, automobile engineering and rocket science. This fact inspires the study of the effects of fluid suction in flow and transport models. Time dependent flows are widely encountered in engineering applications such as turbines and in physiological studies such as flow of bio-fluid (blood etc.). In the present paper, an attempt has been made to investigate analytically the problem of a time dependent channel flow with heat transfer, where the channel is bounded by two infinite parallel porous walls. The pressure gradient is assumed to be oscillatory in nature. A magnetic field of uniform strength is assumed to be applied normal to the walls. After necessary idealization of the momentum and energy equations, the governing equations of our problem are solved by adopting the regular perturbation technique. The effects of magnetic field, suction velocity, viscous dissipation, Reynolds number, Prandtl number etc. on the flow and heat transfer are studied and demonstrated graphically. It is seen that magnetic field, fluid suction, viscous dissipation, Reynolds number, Prandtl number have a significant effect on the flow and heat transfer characteristic. For instance, the imposition of the magnetic field enhances the rates of heat transfer at the walls and the fluid suction decreases the temperature and aids in laminar flow control

Outage Probability Analysis of Dual Hop Relay Networks in Presence of Interference

Cooperative relaying improves the performance of wireless networks by forming a network of multiple independent virtual sources transmitting the same information as the source node. However, interference induced in the network reduces the performance of cooperative communications. In this work the statistical properties, the cumulative distribution function (CDF) and the probability density function (PDF) for a basic dual hop cooperative relay network with an arbitrary number of interferers over Rayleigh fading channels are derived. Two system models are considered: in the first system model, the interferers are only at the relay node; and in the second system model, interferers are both at the relay and the destination. This work is further extended to Nakagami-m faded interfering channels. Simulation results are presented on outage probability performance to verify the theoretical analysis

Supercritical-Carbon Dioxide-Assisted Cyclic Deposition of Metal Oxide and Metal Thin Films

Thin films of aluminum oxide and palladium were deposited on silicon at low temperatures (70-120 °C) by a cyclic adsorption/reaction processes using supercritical CO2 solvent. Precursors included Al(hfac)3, Al(acac)3, and Pd(hfac)2, and aqueous H2O2, tert-butyl peracetate, and H2 were used as the oxidants or reductants. For the precursors studied, growth proceeds through a multilayer precursor adsorption in each deposition cycle, and film thickness increased linearly with the number of growth cycles

Experimental demonstration of single-mode large mode area multi-trench fiber for UV-VIS light transmission

Step-index optical fibers are widely used waveguides for light transmission. However, non-linear effects are always a severe challenge for optical fibers with increasing power level. This challenge is more severe at shorter wavelengths, where core size has to be much smaller in order to maintain a single mode operation. For an example, for 0.005 core refractive index with respect to cladding, a 10µm core diameter can ensure single mode operation at 1550nm. On other hand, core diameter has to be ~4µm and ~2µm at lambda=632nm and 300nm respectively for single mode operation. At these shorter wavelengths, photonic crystal fiber (PCF) and hollow core photonic bandgap fiber (HC-PBGF) have been proposed to address non-linear effects by offering large core diameter and air-core respectively [1-2]. However, such fibers are relatively difficult to fabricate. Moreover, presence of air-holes causes considerable difficulties in cleaving and splicing.Recently, we proposed an all-solid fiber design known as multi-trench fiber (MTF) as shown in Fig. 1(a) [3]. In this paper, we demonstrated their mode area scaling capability for UV-VIS wavelengths. Numerical simulations show the potential of achieving an effective single mode for 10µm and 20µm core diameter MTF by ensuring high loss to the higher order modes (HOMs) at ~300nm and ~632nm respectively. Fig. 1(b) shows numerically computed bending loss of a 20µm core MTF with trench thickness (t)=1.34µm, refractive index difference between core and cladding (Delta.n)=0.005, and resonant ring thickness (d)=6µm at 632nm. It is important to note that MTF ensures similar level of loss (as shown in Fig. 1(b)) to the HOMs even in an unbent case thanks to the resonant coupling between modes of core and resonant ring, which ensures suitability for beam delivery applications. Fig. 1(c) shows the RIP and microscope image of a 20µm core MTF fabricated by MCVD process in conjunction with rod-in-tube technique. Fig. 1(d) shows the measured bending loss of fiber. The loss remains lower than 0.2dB/m and 0.5dB/m at ~30cm and ~15cm bend radius respectively at ~632nm. This loss can even be reduced down with further refinement in fabrication process. We investigated the output profile of a 2m long MTF using the experimental set-up shown in Fig. 1(e) with respect to the multi-mode input beam as shown in Fig. 1(g). Fig. 1(f) shows the output for different offset launching, while fiber is coiled at ~20cm bend radius. On the other hand, Fig. 1(h) shows the output at different coil radii for optimum launching. In this paper, for the first time, to the best of our knowledge, an effective-single-mode behaviour of an all-solid and cylindrical symmetrical fiber of a large core (~20µm) fiber at ~632nm has been demonstrated. All-solid design and cylindrical symmetry ensure suitability for mass-scale production and easy cleaving and splicing. Further, with these advantages, a large core (~10µm) MTF at ~300nm as confirmed by our simulations can also be achieved and details will be presented at conference

Evaluation of petroleum based horticulture oil for the management of the tea red spider mite, Oligonychus coffeae Neitner (Acarina: Tetranychidae)

The Servo agro spray oil (petroleum based horticulture oil) was evaluated in the laboratory against tea red spider mite, Oligonychus coffeae to determine its effect on adult mortality, viability of eggs, oviposition deterrence and repellent properties. The same was also evaluated in the field to determine its effect on mite population. Direct spray method was used in the laboratory at concentrations of 0.5, 1.0, and 1.5%. Mortality of O. coffeae was both concentration and time dependent. Deposition of eggs by adult mites on treated leaf surfaces decreased significantly and the viability of eggs was also significantly reduced. In addition, different concentrations of the Servo agro spray also exhibited repellent properties against adult mites. In the field Servo agro spray oil significantly reduced the mite population and its bio-efficacy was comparable to that of the synthetic pesticide (propargite 57 EC). No phytotoxic effect was observed when tea bushes were sprayed with different doses of Servo agro spray. Tea samples were taint free. Quality (appearance of liquor, flavour, taint and taste) of made tea was not adversely affected by treatments with Servo agro spray oil. Therefore Servo agro spray oil may be a potential agent to be used in the sustainable management of tea red spider mite