NGF Enhances CGRP Release Evoked by Capsaicin from Rat Trigeminal Neurons: Differential Inhibition by SNAP-25-Cleaving Proteases

Nerve growth factor (NGF) is known to intensify pain in various ways, so perturbing pertinent effects without negating its essential influences on neuronal functions could help the search for much-needed analgesics. Towards this goal, cultured neurons from neonatal rat trigeminal ganglia—a locus for craniofacial sensory nerves—were used to examine how NGF affects the Ca²⁺-dependent release of a pain mediator, calcitonin gene-related peptide (CGRP), that is triggered by activating a key signal transducer, transient receptor potential vanilloid 1 (TRPV1) with capsaicin (CAP). Measurements utilised neurons fed with or deprived of NGF for 2 days. Acute re-introduction of NGF induced Ca²⁺-dependent CGRP exocytosis that was inhibited by botulinum neurotoxin type A (BoNT/A) or a chimera of/E and/A (/EA), which truncated SNAP-25 (synaptosomal-associated protein with Mr = 25 k) at distinct sites. NGF additionally caused a Ca²⁺-independent enhancement of the neuropeptide release evoked by low concentrations (<100 nM) of CAP, but only marginally increased the peak response to ≥100 nM. Notably, BoNT/A inhibited CGRP exocytosis evoked by low but not high CAP concentrations, whereas/EA effectively reduced responses up to 1 µM CAP and inhibited to a greater extent its enhancement by NGF. In addition to establishing that sensitisation of sensory neurons to CAP by NGF is dependent on SNARE-mediated membrane fusion, insights were gleaned into the differential ability of two regions in the C-terminus of SNAP-25 (181–197 and 198–206) to support CAP-evoked Ca²⁺-dependent exocytosis at different intensities of stimulation.     

Modeling Evaporation-Seepage Losses for Reservoir Water Balance in Semi-arid Regions

In the water balance of reservoir system, evaporation plays a crucial role particularly so for the reservoir systems of smaller size located in the semi-arid or arid regions. Such regions are most often characterized by significant seepage losses from reservoirs, besides evaporation losses. Usually, in the optimization of a reservoir system, it is a common practice to assume evaporation loss either as some constant value or as negligible. Such assumptions, however, may affect the results of reservoir optimization. This is demonstrated in this study by a case study in the optimal scheduling of Pilavakkal reservoir system in Vaipar basin of Tamilnadu, India. For modeling reservoir losses, many models are available, of which, Penman combination model is most commonly used. In this study, an alternative approach based on Genetic Programming (GP) is proposed. The results of GP and Penman model for both evaporation loss estimation and reservoir scheduling are compared. It is found that while GP and Penman combination model performs equally well for estimating evaporation losses, GP is also able to model seepage losses (or other losses from reservoir) to a much better degree. It is also shown the reservoir scheduling does get influenced based on how the reservoir losses are modeled in the reservoir water balance equation.     

Whirl flutter analysis of a horizontal-axis wind turbine with a two-bladed teetering rotor

An investigation to explore the possibility of whirl flutter and to find the effect of pitch-flap coupling (δ₃) on teetering motion of the DOE/NASA Mod-2 wind turbine is presented. The equations of motion are derived for an idealized five-degree-of-freedom mathematical model of a horizontal-axis wind turbine with a two-bladed teetering rotor. The model accounts for the out-of-plane bending motion of each blade, the teetering motion of the rotor, and both the pitching and yawing motions of the rotor support. Results show that the Mod-2 design is free from whirl flutter. Selected results are presented indicating the effect of variations in rotor support damping, rotor support stiffnes, and δ₃ on pitching, yawing, teetering, and blade bending motions.     

Design and implementation of low-energy turbo decoders

Turbo codes have been chosen in the third generation cellular standard for high-throughput data communication. These codes achieve remarkably low bit error rates at the expense of high-computational complexity. Thus for hand held communication devices, designing energy efficient Turbo decoders is of great importance. In this paper, we present a suite of MAP-based Turbo decoding algorithms with energy-quality tradeoffs for additive white Gaussian noise (AWGN) and fading channels. We derive these algorithms by applying approximation techniques such as pruning the trellis, reducing the number of states, scaling the extrinsic information, applying sliding window, and early termination on the MAP-based algorithm. We show that a combination of these techniques can result in energy savings of 53.2%(50.0%) on a general purpose processor and energy savings of 80.66%(80.81%) on a hardware implementation for AWGN (fading) channels if a drop of 0.35 dB in SNR can be tolerated, at a bit error rate (BER) of 10/sup -5/. We also propose an adaptive Turbo decoding technique that is suitable for low power operation in noisy environments.     

NON-RANDOM DISTRIBUTION OF ADSORBATES ON CATALYTIC SURFACES: THE ROLE OF INTERACTIONS BETWEEN ADSORBATES

It has been repeatedly stressed in the literature that the commonly invoked assumption of a random distribution of adsorbates on the catalyst surface is suspect under certain operating conditions. Nonrandom distribution of the adsorbates can occur as a result of interaction between adsorbates and/or their inadequate mobility. We have studied the effect of adsorbate interactions on the rates and stability of catalytic reactions, and the salient features are outlined with several examples. An analysis of the thermodynamic data concerning the oxidation of SO₂ on platinum is presented within the framework of the proposed model.     

Diffusion and reaction of multicomponent gas mixtures in isothermal porous catalysts

Exact (numerical) and approximate semi-analytical solution procedures are developed to investigate the problem of multicomponent diffusion accompanied by multiple reactions in porous catalyst pellets. Examples are presented to illustrate the application of the proposed procedures and to compare exact and approximate solutions. In certain circumstances it is found that reactants can diffuse in the direction in which their concentration increases.     

In Vivo Molding of Airway Stents

Like ready-to-wear clothing, medical devices come in a fixed set of sizes. While this may accommodate a large fraction of the patient population, others must either experience suboptimal results due to poor sizing or must do without the device. Although techniques have been proposed to fabricate patient-specific devices in advance of a procedure, this process is expensive and time consuming. An alternative solution that provides every patient with a tailored fit is to create devices that can be customized to the patient's anatomy as they are delivered. This paper reports an in vivo molding process in which a soft flexible photocurable stent is delivered into the trachea or bronchi over a ultraviolet (UV)-transparent balloon. The balloon is expanded such that the stent conforms to the varying cross-sectional shape of the airways. UV light is then delivered through the balloon curing the stent into its expanded conformal shape. The potential of this method is demonstrated using phantom, ex vivo, and in vivo experiments. This approach can produce stents providing equivalent airway support to those made from standard materials while providing a customized fit.     

An evaluation of Māori values in multiscalar environmental policies governing Kaipara Harbour in New Zealand

Indigenous knowledge and values are increasingly found in watershed management to engage important stakeholders in the development of modern resource management practices and policies. This paper explores the integration of Māori values in water and land policies governing Kaipara Harbour in New Zealand as a case study for this approach. Multijurisdictional documents were analysed for the inclusion of nine well-established Māori values that have applications to land, water and natural resource management. The results of this study identified the most and least commonly mentioned values in policy documents, and a scalar trend in which integration of Māori values increased as the geographic scale and jurisdiction of the respective governing policies decreased.     

A Model of Gas-Phase Transport During the Initial Stages of Sintering of Silicon Carbide

Carbon, which is often used as an additive to silicon carbide powder, is thought to facilitate densification during sintering by aiding the removal of the native SiO₂ layer, which is present on the starting SiC powder. The mechanism is the reduction of SiO₂ to SiC with the formation of primarily CO gas, which diffuses out from the porous compact at a temperature below the normal sintering temperature. It has been found beneficial to hold the compact at an intermediate temperature to allow time for the CO and other gases to diffuse out before the pores close. We investigate this process using a computational model based on codiffusion of multiple gas species, which enables prediction of the gas and condensed phase compositions as a function of time and position in the specimen. The results are used to determine the optimum holding time for complete SiO₂ removal as a function of key parameters, such as specimen thickness, particle size, temperature, etc., as well as the necessary amount of C additive. The results of the modeling are consistent with the experimentally observed spatial variation of density and composition in SiC compacts.