A sequential mechanism for clathrin cage disassembly by 70-kDa heat-shock cognate protein (Hsc70) and auxilin

An essential stage in endocytic coated vesicle recycling is the dissociation of clathrin from the vesicle coat by the molecular chaperone, 70-kDa heat-shock cognate protein (Hsc70), and the J-domain-containing protein, auxilin, in an ATP-dependent process. We present a detailed mechanistic analysis of clathrin disassembly catalyzed by Hsc70 and auxilin, using loss of perpendicular light scattering to monitor the process. We report that a single auxilin per clathrin triskelion is required for maximal rate of disassembly, that ATP is hydrolyzed at the same rate that disassembly occurs, and that three ATP molecules are hydrolyzed per clathrin triskelion released. Stopped-flow measurements revealed a lag phase in which the scattering intensity increased owing to association of Hsc70 with clathrin cages followed by serial rounds of ATP hydrolysis prior to triskelion removal. Global fit of stopped-flow data to several physically plausible mechanisms showed the best fit to a model in which sequential hydrolysis of three separate ATP molecules is required for the eventual release of a triskelion from the clathrin-auxilin cage.

Hsc70-induced changes in clathrin-auxilin cage structure suggest a role for clathrin light chains in cage disassembly

The molecular chaperone, Hsc70, together with its cofactor, auxilin, facilitates the ATP-dependent removal of clathrin during clathrin-mediated endocytosis in cells. We have used cryo-electron microscopy to determine the 3D structure of a complex of clathrin, auxilin401-910 and Hsc70 at pH 6 in the presence of ATP, frozen within 20 seconds of adding Hsc70 in order to visualize events that follow the binding of Hsc70 to clathrin and auxilin before clathrin disassembly. In this map,we observe density beneath the vertex of the cage that we attribute to bound Hsc70. This density emerges asymmetrically from the clathrin vertex, suggesting preferential binding by Hsc70 for one of the three possible sites at the vertex. Statistical comparison with a map of whole auxilin and clathrin previously published by us reveals the location of statistically significant differences which implicate involvement of clathrin light chains in structural rearrangements which occur after Hsc70 is recruited. Clathrin disassembly assays using light scattering suggest that loss of clathrin light chains reduces the efficiency with which auxilin facilitates this reaction. These data support a regulatory role for clathrin light chains in clathrin disassembly in addition to their established role in regulating clathrin assembly. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Rib-cage-movement measurements as a potential new trigger signal in non-invasive mechanical ventilation

Non-invasive ventilation performed through an oronasal mask is a standard in clinical and homecare mechanical ventilation. Besides all its advantages, inevitable leaks through the mask cause errors in the feedback information provided by the airflow sensor and, hence, patient-ventilator asynchrony with multiple negative consequences. Here we investigate a new way to provide a trigger to the ventilator. The method is based on the measurement of rib cage movement at the onset of inspiration and during breathing by fibre-optic sensors. In a series of simultaneous measurements by a long-period fibre grating sensor and pneumotachograph we provide the statistical evidence of the 200 ms lag of the pneumo with respect the fibre-optic signal. The lag is registered consistently across three independent delay metrics. Further, we discuss exceptions from this trend and identify the needed improvements to the proposed fibre-sensing scheme.

Bullet proof cage surrounds Angela Davis as she performs in "Night with Angela Davis" at Madison Square Garden

General note: Title and date provided by Bettye Lane.

Bullet proof cage surrounds Angela Davis as she performs in "Night with Angela Davis" at Madison Square Garden

General note: Title and date provided by Bettye Lane.

A Decentralized Iron Cage: Do Chinese Local Officials Comply with the Central Government?

This paper contributes to the literature in nancial aid and authoritarian institutions.

For a long time, scholars are debating whether nancial aid is able to facilitate

development and governance. Though abundant evidence is provided, the answer is

still inconclusive. On the other hand, scholars investigating China argue that the

leadership uses various institutions to ensure local ocials' compliance. In this paper,

we nd that the nancial aid does not bring a positive impact and the central

government in China does not have enough monitoring capacity to force local o-

cials to comply. We study a redevelopment program established by Chinese central

government after the 2008 Wenchuan earthquake. By adopting a geographic regression

discontinuity combining with a dierence-in-dierences design, we show that

the redevelopment program does not signicantly develop the disaster area. On the

contrary, the evidence implies that the economy in the disaster area is worse after

receiving the aid. The results imply that local ocials do not follow the central government's

regulations and misuse the aid money for other purposes. In the future, we

expect to further investigate through which mechanism do local ocials undermine

the existing institutions.

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Nitriding in cathodic cage of stainless steel AISI 316: influence of sample position

R.R.M. de Sousa et al. Nitriding in cathodic cage of stainless steel AISI 316: Influence of sample position. Vacuum, [s.l.], n.83, 2009. Disponivel em: . Acesso em: 04 out.2010.

The Type of Behavior and the Role of Relationship Length in Mate Choice for Prosociality Among Physically Attractive Individuals

Two further key aspects of prosociality as a sexual signal are explored here. Firstly, the context in which it is used (in particular relationship length), and, second, also the different types of prosocial behaviors that exist in social interactions. Therefore, this commentary can show why prosocial behaviors are biased towards physically attractive individuals, as they can gain valuable information from them.

Nitriding in cathodic cage of stainless steel AISI 316: influence of sample position

R.R.M. de Sousa et al. Nitriding in cathodic cage of stainless steel AISI 316: Influence of sample position. Vacuum, [s.l.], n.83, 2009. Disponivel em: . Acesso em: 04 out.2010.

Melhoria da qualidade de jerked beef pela substituição de nitrito de sódio por extratos naturais de própolis e erva mate como agente antioxidante

Jerked beef, an industrial meat product obtained from beef with the addition of sodium chloride and curing salts and subjected to a maturing and drying process is a typical Brazilian product which has been gradually discovered by the consumer. The replacement of synthetic antioxidants by natural substances with antioxidant potential due to possible side effects discovered by lab tests, consumer health, is being implemented by the meat industry. This study aimed to evaluate the lipid oxidation of jerked beef throughout the storage period by replacing the sodium nitrite by natural extracts of propolis and Yerba Mate. For jerked beef processing brisket was used as raw material processed in 6 different formulations: formulation 1 (control - in nature), formulation 2 (sodium nitrite - NO), formulation 3 (Yerba Mate - EM), formulation 4 (propolis extract - PRO), formulation 5 (sodium nitrite + Yerba Mate - MS + NO), formulation 6 (propolis extract + sodium nitrite - PRO + NO). The raw material was subjected to wet salting, dry salting (tombos), drying at 25°C, packaging and storage in BOD 25°C. Samples of each formulation were taken every 7 days for analysis of lipid oxidation by the TBARS method. In all formulations, were carried out analysis of chemical composition at time zero and sixty days of storage. The water activity analysis and color (L *, a *, b *) was monitored at time zero, thirty and sixty days of storage. The Salmonella spp count, Coliform bacteria, Termotolerant coliforms and coagulase positive staphylococci were taken at time zero and sixty days. The activity of natural antioxidants evaluated shows the decline of lipid oxidation up to 2.5 times compared with the product in natura and presented values with no significant differences between treatments NO and EM, confirming the potential in minimize lipid oxidation of Jerked beef throughout the 60 days of storage. The results also showed that yerba mate has a higher antioxidant capacity compared to the propolis except the PRO + NO formulation. When associated with yerba mate with sodium nitrate, TBARS values become close to values obtained only for the control samples with the addition of sodium nitrite. The proximal composition of the formulations remained within the standards required in the IN nº22/2000 for jerked beef. Samples that differ significantly at 5% are directly related to the established type of formulation. The count of microorganisms was within the standards of the DRC nº12/2001 required for matured meat products. The intensity of the red (a*) decreased with storage time and increase the intensity of yellow (b*) indicates a darkening of the product despite L* also have been increased. These results suggest that yerba mate is a good alternative to meat industry in reducing healing addition salts when associated with another antioxidant.

Cage culture of Nile Tilapia

Nile tilapia (oreochromis niloticus) a fish introduced into Lake Victoria to boost the fishery industry after the Nile perch lates niloticus fed on the native tilapiine oreochromis esculentus and Oreochromis viabillis to almost extinction has been proposed to be cultured in the Lake Victoria. The fact sheet explains the culture of Nile tilapia in cages in Lake Victoria, Uganda.

Metodolog?a para el proceso de ense?anza aprendizaje en ni?os de 13-15 a?os en la comuna 16 de la ciudad de Cali, enfocada en la formaci?n y preparaci?n de la disciplina deportiva del ult?mate frisbee

Al ser un deporte relativamente nuevo, tiene 60 a?os de historia, no se cuenta con la suficiente bibliograf?a para su ense?anza, y mucho menos en las categor?as juveniles, es por eso que se quiere brindar un documento que, a partir de la experiencia en el campo y tomando modelos pedag?gicos de diferentes ?reas que no s?lo incluyen la educaci?n f?sica, con el cual los profesores de educaci?n f?sica y deporte puedan iniciar procesos formativos en menores de 16 a?os. Para llevar a cabo lo anterior, se pretende abordar temas que van m?s all? del entrenamiento deportivo juvenil, con el fin de brindar herramientas que permitan consolidar un grupo de trabajo cooperativo que abarque, desde la convocatoria de los ni?os, el trato y la participaci?n de los padres de familia, la organizaci?n de las sesiones de entrenamiento, hasta la conducci?n de procesos de autorregulaci?n, que incluyen el dialogo y el respeto como herramientas para la soluci?n de conflictos dentro y fuera del entrenamiento. Por lo tanto el presente trabajo de investigaci?n se estructur? en tres cap?tulos fundamentales que son: Capitulo uno hace referencia al planteamiento dial?ctico y epistemol?gico de la investigaci?n en donde se puede apreciar una correcta relaci?n entre el problema y los objetivos. En el cap?tulo dos encontramos una gran variedad de estudios internacionales y nacionales que nos permiten definir las tendencias m?s importantes del ult?mate y a partir de all? se realiza un an?lisis de c?mo han evolucionado en los ?ltimos tiempos el proceso de ense?anza- aprendizaje. Y en el tercer cap?tulo presentamos fase a fase el dise?o y elaboraci?n de la metodolog?a que proponemos para guiar el proceso de ense?anza ? aprendizaje en la muestra objeto de estudio, para finalmente realizar un an?lisis y discusi?n de resultados.