4,573 research outputs found
Наклеп при накатке отверстий
Tolerancing has long been identified as a crucial part in the development of optical systems. It aims at finding the best balance between quality and cost as tolerances closely tie together manufacturing expenses and performance. Tolerance effects have been included into the optimization function (merit function) by some lens designers to find insensitive designs1-5 and frequently compensators are employed to further improve the performance of assembled lenses. Compensators are limited to a small number of system parameters, but selective assembly of components can extend the number of parameters available for compensation. It can be employed to reduce tolerance effects of disturbed parameters by finding the best matches out of a set of components. In this work we discuss how desensitization and selective assembly can be combined to loosen tolerances and increase as-built performance. The investigations concentrate on tolerance insensitive design forms under the presence of selective assembly compensators. In contrast to desensitizing a given lens or introducing new design means we focus on introducing new assembly strategies into the design procedure and investigate how using selective assembly as a compensator while desensitizing the remaining design parameters can lead to even less sensitive designs
Mobilization of Pollutant-Degrading Bacteria by Eukaryotic Zoospores
This study was supported by the Spanish Ministry of Science and Innovation (CGL2010-22068-C02-01 and CGL2013- 44554-R), the Andalusian Government (RNM 2337), and the CSIC JAE Program (RS). PvW has funding support from the BBSRC and NERC. Thanks are also given to Sara Hosseini of the Uppsala BioCenter, SLU, Uppsala, Sweden for a useful discussion on oomycete zoospores.Peer reviewedPostprin
Comparison of seismic reflection data to a synthetic seismogram in a volcanic apron at Site 953
The volcanic apron of Gran Canaria at Site 953 is characterized by numerous, closely spaced reflectors, allowing a highresolution
stratigraphic correlation. The calibration of the presite survey seismic data (during the Meteor Cruise 24) with regard
to the lithology and stratigraphy found at the drill site was achieved by computing a synthetic seismogram serving as the link
between seismic and borehole data. Because logging data were available for only 53% of the hole, velocity and density measurements
taken from the recovered cores were used in the missing intervals to obtain a complete synthetic seismogram. Most
reflectors in the upper ~900 m of the sequence (lithologic Units I–V) turned out to be thin volcaniclastic layers intercalated to
the nonvolcanic background sediments. Their thicknesses are generally <2 m, and the reflections from their tops and bases
overlap, forming a single reflection. The limit of the seismic detection of such interbeds is on the order of several decimeters
and thus requires special care for the processing of the velocity and density data to avoid destruction of the signal from these
thin layers
Seismic structure of the volcanic apron north of Gran Canaria
High-resolution reflection seismic profiles through the volcanic apron north of Gran Canaria collected during Meteor
Cruise 24 were interpreted in the light of results from Leg 157 (Sites 953 and 954). The shape of the submarine island flanks of
Gran Canaria and the two adjacent islands of Fuerteventura to the east and Tenerife to the west were reconstructed by interpretating
seismic profiles that penetrated the sediments covering the deeper portions of the volcanic pedestals. The ~4750-m-deep
flank of Fuerteventura is the oldest submarine island flank, influencing the subsequent shield-building of Gran Canaria to the
east, whose 16- to 15-Ma shield is ponded against Fuerteventura, forming a topographic barrier between the islands. The associated
reduction of the current cross section has caused strong bottom currents, indicated by erosional features and contourites.
To the north, the flank of Gran Canaria extends 60 km seaward to a depth of ~4500 m. The shield of the Anaga massif on northeast
Tenerife onlaps the flank of Gran Canaria to the east. Seismic correlation of the feathered edge of the Anaga shield (~50
km off Tenerife at a depth of 4000 m) to the bio- and magnetostratigraphy at Site 953 results in an age of ~6 Ma.
The surrounding sedimentary basin is characterized by chaotic and discontinuous reflection patterns of the slope facies,
turning into well-stratified basin facies ~30–40 km off the coast. The westward decrease of reflectivity in the northern apron is
interpreted to be caused by the submarine ridge off Galdar at the western limit of the north coast of Gran Canaria, through
which mass flows from Gran Canaria entering the sea in the north were diverted to the northeastern part of the apron. The volcanic
activity correlates with the sedimentation rates in the apron. The lowest rate corresponds to the volcanic hiatus on Gran
Canaria (9–5 Ma) with 3–4 cm/k.y., and the highest rate (up to 12 cm/k.y.) was found during the voluminous Miocene volcanism
on the island. A number of large mass-wasting events could be identified, interbedded with the pelagic background sedimentation.
The basaltic breccia drilled at Site 954 (lithologic Unit IV) is interpreted to represent the deposits associated with a
slope failure at the northern flank of Gran Canaria at 12 Ma. The seismic mapping reveals >60 km3 of debris advanced at least
70 km into the apron. The volume fits well with the dimensions of an amphitheater at the northern flank of Gran Canaria. The
Quaternary volcanism on La Isleta at northeast Gran Canaria extends further seaward, where the seismic data show young lava
flows. Other submarine volcanism occurred in the channel between Gran Canaria and Fuerteventura
Syndecan-4 knockout leads to reduced extracellular transglutaminase-2 and protects against tubulointerstitial fibrosis
Transglutaminase type 2 (TG2) is an extracellular matrix crosslinking enzyme with a pivotal role in kidney fibrosis. The interaction of TG2 with the heparan sulfate proteoglycan syndecan-4 (Sdc4) regulates the cell surface trafficking, localization, and activity of TG2 in vitro but remains unstudied in vivo. We tested the hypothesis that Sdc4 is required for cell surface targeting of TG2 and the development of kidney fibrosis in CKD. Wild-type and Sdc4-null mice were subjected to unilateral ureteric obstruction and aristolochic acid nephropathy (AAN) as experimental models of kidney fibrosis. Analysis of renal scarring by Masson trichrome staining, kidney hydroxyproline levels, and collagen immunofluorescence demonstrated progressive fibrosis associated with increases in extracellular TG2 and TG activity in the tubulointerstitium in both models. Knockout of Sdc-4 reduced these effects and prevented AAN-induced increases in total and active TGF-b1. In wild-type mice subjected to AAN, extracellular TG2 colocalized with Sdc4 in the tubular interstitium and basement membrane, where TG2 also colocalized with heparan sulfate chains. Heparitinase I, which selectively cleaves heparan sulfate, completely abolished extracellular TG2 in normal and diseased kidney sections. In conclusion, the lack of Sdc4 heparan sulfate chains in the kidneys of Sdc4-null mice abrogates injury-induced externalization of TG2, thereby preventing profibrotic crosslinking of extracellular matrix and recruitment of large latent TGF-b1. This finding suggests that targeting the TG2- Sdc4 interaction may provide a specific interventional strategy for the treatment of CKD
Proteomic analysis of the Mycocentrospora acerina-carrot interaction during storage
During post harvest storage, a large proportion of carrots (more than 50%) may have to be discarded due to the development of liquorice rot caused by Mycocentrospora acerina. This fungus is soil borne and brought into the store in to soil adhering to the root. Liquorice rot development is mainly related to physiological or structural resistance of carrot, therefore the control of this storage disease is based on cultural practices and storage conditions.
It is believed that carrots at the beginning of storage can resist disease developments due to chemical defence mechanisms involving some proteins, peptides and secondary metabolites. The hypothesis is that proteome changes during storage of carrots are related to the susceptibility to M. acerina. During root-pathogen interactions, several genes have been reported to provide resistance against pathogens but only few proteins have been identified using proteomic approaches. Little is known about proteins involved during M. acerina - carrot interaction.
The carrots used in this study are grown under two different agricultural practices (one conventional, one organic) in order to investigate the effect of the cropping system on the susceptibility to liquorice rot.
We developed a bioassay for infection studies of M. acerina on conventional and organic carrots in order to determine the important time points of the infection process. Then the proteome is investigated at these different time points. The protocol for extraction of proteins has been improved so that it can be used to obtain an optimal recovery of proteins from both plant and pathogen on their own as well as from infected carrot roots. Proteomes of carrot and of M. acerina are characterized by two dimensional gel electrophoreses and the proteins whose synthesis varies significantly in the course of pathogen infection are identified by mass spectrometry (MALDI TOF-TOF)
Introduction
Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich.This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.With this volume, the European Association of Urban Historians (EAUH) introduces itself for the first time to American readers and includes some of the results of its Fifth International Conference, which took place in August/ September 2000 in Berlin. The EAUH was founded in 1989 by English, Dutch, Belgian, and French historians. The focus of its activities is the International Conference on Urban History. It takes place every two years in a significant European city. After Amsterdam 1992, Strasbourg, Budapest, Venice, and Berlin each hosted the conference consecutively. It has become one of the biggest and most important forums for international academic exchange in the field of historic urban research
Gulerodens farefulde vej fra marken til forbrugeren
Kølelagring af Lammefjords-gulerødder muligør, at der kan leveres danskproducerede gulerødder i perioden fra november til april. Sidst på lagringssæsonen kan mere ed 50% af rødderne dog være kassable på grund af lagersygdomme.
I marken angribes rødderne af forskellige jordboende svampe, der allerede ved høst kan resultere i kassable rødder. I lagerperioden kan tilsyneladende raske gulerøder dog også udvikle sygdomme forårsaget af de mikrosvampe der forkommer naturligt på rødderne. Sår på rodoverfladen fremmer angreb under lagring og desuden reduceres gulerøddernes modstandsdygtighed overfor sygdomme i takt med røddernes aldring.
I artiklen beskrives de mest betydende sygdomsfremkaldende organismer (patogener), faktorer der er af betydning for udvikling af lagersygdomme samt muligheder for forbedret lagerkvalitet ved hjælp af biologiske forebyggelsesmetoder
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