Modification of Loop 1 Affects the Nucleotide Binding Properties of Myo1c, the Adaptation Motor in the Inner Ear

Myo1c is one of eight members of the mammalian myosin I family of actin-associated molecular motors. In stereocilia of the hair cells in the inner ear, Myo1c presumably serves as the adaptation motor, which regulates the opening and closing of transduction channels. Although there is conservation of sequence and structure among all myosins in the N-terminal motor domain, which contains the nucleotide- and actin-binding sites, some differences include the length and composition of surface loops, including loop 1, which lies near the nucleotide-binding domain. To investigate the role of loop 1, we expressed in insect cells mutants of a truncated form of Myo1c, Myo1c1IQ, as well as chimeras of Myo1c1IQ with the analogous loop from other myosins. We found that replacement of the charged residues in loop 1 with alanines or the whole loop with a series of alanines did not alter the ATPase activity, transient kinetics properties, or Ca2+ sensitivity of Myo1c1IQ. Substitution of loop 1 with that of the corresponding region from tonic smooth muscle myosin II (Myo1c1IQ-tonic) or replacement with a single glycine (Myo1c1IQ-G) accelerated the release of ADP from A.M 2?3-fold in Ca2+, whereas substitution with loop 1 from phasic muscle myosin II (Myo1c1IQ-phasic) accelerated the release of ADP 35-fold. Motility assays with chimeras containing a single ?-helix, or SAH, domain showed that Myo1cSAH-tonic translocated actin in vitro twice as fast as Myo1cSAH-WT and 3-fold faster than Myo1cSAH-G. The studies show that changes induced in Myo1c via modification of loop 1 showed no resemblance to the behavior of the loop donor myosins or to the changes previously observed with similar Myo1b chimeras

The Mechanism of Electro-Reduction of Chromate in Molten LiCl-KCl

When chromate ion is electro-reduced in molten LiCl- KCl in the presence of Mg (II), Zn (II) or Ni (II), the product is typically of composition LixMyCr04 , in which X + 2 Y = 5. Variations in composition accompany variations is experimental conditions, except in the case of Zn(II), for which X = 1 and Y = · 2. With Co (II), the product is either LixCoyCr04 or Co2Cr04 or a mixture of the two, depending upon the conditions. A mechanism involving a first two-electron reduction followed by a competition between further one-electron reduction and an internal chemical redox reaction accounts -satisfactorily for the variation of product with changes in experimental conditions

The Mechanism of Electro-Reduction of Chromate in Molten LiCl-KCl

When chromate ion is electro-reduced in molten LiCl- KCl in the presence of Mg (II), Zn (II) or Ni (II), the product is typically of composition LixMyCr04 , in which X + 2 Y = 5. Variations in composition accompany variations is experimental conditions, except in the case of Zn(II), for which X = 1 and Y = · 2. With Co (II), the product is either LixCoyCr04 or Co2Cr04 or a mixture of the two, depending upon the conditions. A mechanism involving a first two-electron reduction followed by a competition between further one-electron reduction and an internal chemical redox reaction accounts -satisfactorily for the variation of product with changes in experimental conditions

A practical approach to the production of ENC with high density bathymetric content

Over the last two years, the Australian Hydrographic Office (AHO) has published and maintained Electronic Navigational Charts (ENC) with greater scale and higher density bathymetric content than those derived from paper nautical charts. Land Information New Zealand (LINZ) is investigating the production of ENCs with high density bathymetric content which will likely replace the traditional berthing ENC. This article describes the approaches adopted by AHO and LINZ to produce such ENC using current IHO standards. The article describes also how AHO and LINZ engaged with stakeholders to meet the demands of large ships navigating in confined waters with small safety margins. ENCs with greater scale and high density-bathymetric content represent an opportunity for Hydrographic Offices to not only enhance safety of navigation under normal circumstances in confined waters, but also to potentially expand the range of weather and tidal conditions in which safe navigation may be conducted.En los dos últimos años, el Servicio Hidrográfico Australiano (AHO) ha publicado y mantenido Cartas Náuticas Electrónicas (ENCs) de mayor escala y con un contenido batimétrico de mayor densidad que las derivadas de las cartas náuticas de papel. Land Information New Zealand (LINZ) está investigando la producción de ENCs con un contenido batimétrico de alta densidad, que probablemente sustituirán a las tradicionales ENCs de las zonas de atraque. Este artículo describe los enfoques adoptados por el AHO y por LINZ para producir tales ENCs utilizando las normas actuales de la OHI. Este artículo también describe cómo el AHO y LINZ se comprometieron con las partes interesadas para satisfacer las demandas de los grandes buques que navegan en aguas confinadas con pequeños márgenes de seguridad. Las ENCs de mayor escala y de contenido batimétrico de alta densidad representan una oportunidad para que los Servicios Hidrográficos no sólo mejoren la seguridad de la navegación en circunstancias normales en aguas confinadas, sino que también amplíen potencialmente la variedad de condiciones meteorológicas y de mareas en las que se puede llevar a cabo una navegación segura.Ces deux dernières années, le Service hydrographique australien (AHO) a publié et tenu à jour des cartes électroniques de navigation (ENC) à plus grandes échelles et contenant des données bathymétriques à plus haute densité que celles issues des cartes marines papier. Le Land Information New Zealand (LINZ) étudie la production d’ENC contenant des données bathymétriques à haute densité, qui remplaceront sûrement les traditionnelles ENC d’accostage. Le présent article décrit l’approche adoptée par l’AHO et le LINZ pour produire ces ENC en utilisant les normes de l’OHI en vigueur. L’article décrit également la manière dont l’AHO et le LINZ se sont impliqués auprès des parties prenantes afin de répondre aux contraintes des navires de grande taille qui naviguent dans des eaux resserrées avec de faibles marges de sécurité. Des ENC contenant des données à plus grandes échelles et des données bathymétriques à haute densité représentent l’opportunité pour les services hydrographiques non seulement d’améliorer la sécurité de la navigation dans des eaux resserrées dans des circonstances normales, mais également d’étendre potentiellement l’éventail des conditions météorologiques et de marées dans lesquelles il est possible de naviguer en toute sécurité

Dynamic Pricing for Tenants in an Automated Slicing Marketplace

The paradigm shift from a one-size-fits-all architecture to a service-oriented network infrastructure promised by network slicing will demand novel technical solutions, as well as new business models. In particular, the role separation between infrastructure providers, i.e. the ones owning the network, and slice tenants, i.e. the ones providing specialized services tailored to their vertical segments, may encourage the definition of a shared platform (or marketplace) where the former can monetize their network infrastructure by leasing network resources at a market price, and the latter can rent on-demand the network resources needed to offer their services at the desired quality. This also enables the flexibility for the slice tenants to optimize the management of their slices by adapting their resource demand to fluctuations of their traffic or variations of the price in the market. In this paper, we extend the market mechanism scheme developed in previous works by including intra-slice radio admission control policies in the utility definition of the tenants in the slicing market game. Moreover, we characterize the mathematical properties of the game with respect to slice configuration, i.e. how diverse strategical behavior of the tenants affects the market operation, in terms of slice resource allocation and performance. Our analysis offers insights to the slice tenants on how they could reconfigure their techno-economic performance indicators in response to the dynamics of network and of the market, namely how to adapt their long-term (and/or real-time) strategies to the fluctuations of the traffic to enhance network performance and increase profits