Search results for "LAB"
showing 10 items of 7932 documents
Do laboratory exposures represent field exposures? Effects of sediments contaminated by wood industry on yolk-sac fry of rainbow trout (Oncorhynchus …
2015
Purpose. Risk assessment of contaminated sediments is routinely based on laboratory exposures. The purpose of this work was to study if sediments contaminated by the chemical wood industry cause developmental defects in fish fry and how well a laboratory exposure correlates with a field exposure. Materials and methods. Newly hatched yolk-sac fry of rainbow trout (Oncorhynchus mykiss) were exposed in the laboratory and in situ. In the laboratory, the fish were placed in contact with either clean or contaminated sediment in aquaria. In the field, half of the fish were placed in contact with the lake sediment and the other half were similarly caged 2 m above it, to discern the effects of the s…
GekkoFS - A Temporary Distributed File System for HPC Applications
2018
We present GekkoFS, a temporary, highly-scalable burst buffer file system which has been specifically optimized for new access patterns of data-intensive High-Performance Computing (HPC) applications. The file system provides relaxed POSIX semantics, only offering features which are actually required by most (not all) applications. It is able to provide scalable I/O performance and reaches millions of metadata operations already for a small number of nodes, significantly outperforming the capabilities of general-purpose parallel file systems. The work has been funded by the German Research Foundation (DFG) through the ADA-FS project as part of the Priority Programme 1648. It is also support…
DelveFS - An Event-Driven Semantic File System for Object Stores
2020
Data-driven applications are becoming increasingly important in numerous industrial and scientific fields, growing the need for scalable data storage, such as object storage. Yet, many data-driven applications cannot use object interfaces directly and often have to rely on third-party file system connectors that support only a basic representation of objects as files in a flat namespace. With sometimes millions of objects per bucket, this simple organization is insufficient for users and applications who are usually only interested in a small subset of objects. These huge buckets are not only lacking basic semantic properties and structure, but they are also challenging to manage from a tec…
Challenges and Solutions for Tracing Storage Systems
2018
IBM Spectrum Scale’s parallel file system General Parallel File System (GPFS) has a 20-year development history with over 100 contributing developers. Its ability to support strict POSIX semantics across more than 10K clients leads to a complex design with intricate interactions between the cluster nodes. Tracing has proven to be a vital tool to understand the behavior and the anomalies of such a complex software product. However, the necessary trace information is often buried in hundreds of gigabytes of by-product trace records. Further, the overhead of tracing can significantly impact running applications and file system performance, limiting the use of tracing in a production system. In…
MERCURY: A Transparent Guided I/O Framework for High Performance I/O Stacks
2017
The performance gap between processors and I/O represents a serious scalability limitation for applications running on computing clusters. Parallel file systems often provide mechanisms that allow programmers to disclose their I/O pattern knowledge to the lower layers of the I/O stack through a hints API. This information can be used by the file system to boost the application performance. Unfortunately, programmers rarely make use of these features, missing the opportunity to exploit the full potential of the storage system. In this paper we propose MERCURY, a transparent guided I/O framework able to optimize file I/O patterns in scientific applications, allowing users to control the I/O b…
Tratamiento digital de señales. Problemas y ejercicios resueltos
2003
El documento es un libro de problemas y ejercicios de Tratamiento Digital de Señales. Este libro publicado por Prentice-Hall en 2003, se ofrece actualmente como recurso de acceso abierto tras su descatalogación. En él se ofrecen ejemplos de problemas y ejercicios resueltos de Tratamiento Digital de Señales, a los que previamente se introduce la base teórica suficiente como para seguir el desarrollo del texto. El contenido es el siguiente: Señales y sistemas en tiempo discreto; Análisis frecuencial de señales y sistemas; Transformada z; Realización de sistemas en tiempo discreto; Efectos de longitud de palabra finita; Diseño de filtros digitales; Sistemas adaptativos. That document is a book…
Financing Unemployment Benefits: Dismissal versus Employment Taxes
2006
This paper investigates the effects of using dismissal taxes to finance unemployment benefits. We compare dismissal and employment taxes in a model with search frictions. Employment taxes give rise to externalities because firms do not take into account the effects their dismissal decisions have on others. By introducing dismissal taxes to finance unemployment insurance, these externalities can partly be internalized. Taking into account the budget of the unemployment insurance, employment taxes can be reduced by more than necessary to offset the adverse effect of dismissal taxes on the firm value. The introduction of dismissal taxes leads to higher job creation and lower unemployment, in c…
Uzņēmuma SIA Volburg finanšu analīze
2016
Uzņēmuma finanšu analīze ir uzņēmuma finanšu rādītāju salīdzinājums par periodiem, kuru galvenā funkcija ir sniegt savlaicīgu informāciju uzņēmuma vadībai par to, kādi ir finanšu rādītāji un kādas ir to tendences. Nekvalitatīvas vai novēlotas finanšu analīzes veikšana uzņēmumā, var radīt finanšu rādītāju nekorektu atspoguļojumu, kas attiecīgi rada finansiālus zaudējumus uzņēmumam. Finanšu analīzes nozīme ir tāda, ka ar tās palīdzību tiek savlaicīgi noteikti saimnieciskās darbības kritiskie finanšu rādītāji un tiek identificētas vadlīnijas starp savstarpēji ietekmējošiem faktoriem. Šo vadlīniju identificēšana, palīdz uzņēmuma vadībai veikt nepieciešamās korektīvās rīcības kritisko rādītāju u…
Glucocorticoid receptor (DlGR1) is expressed in pre-larval and larval stages of the teleost fish Dicentrarchus labrax.
2008
Glucocorticoid hormone receptors (GR), members of the nuclear hormone receptor superfamily, are ligand-dependent transcription factors expressed in various tissues by binding to specific DNA sequences. Since glucocorticoids have a role in maintaining the homeostatic status in fish, we previously cloned and sequenced a GR (DlGR1) of adult Dicentrarchus labrax; we also showed mRNA expression (in situ hybridization) and tissue immunohistochemical localization of DlGR1 in several organs. This work has now been extended to the examination of the expression, tissue distribution, and cytolocalization of DlGR1 in larval developmental stages by similar methods to those used for the adult organs. The…
By-products of farmed European sea bass (Dicentrarchus labrax L.) as a potential source of n-3 PUFA
2013
Total by-products (TBP) obtained by filleting farmed and wild European sea bass (Dicentrarchus labrax) were analyzed to evaluate if, on the basis of the percentage yield, total lipid content and fatty acid composition, they can be considered a resource of n-3 polyunsaturated fatty acids (PUFA). Results show that TBP from intensively farmed fish (IFF) contain higher total lipid content and have a higher level of n-3 PUFA rich in eicosapentaenoic (EPA) and docosaexaenoic acid (DHA), compared to extensively farmed fish (EFF) and to wild fish (WF) (P < 0.05). This difference may suggest a way of promotion of TBP from IFF sea bass through the n-3 PUFA recovery by extraction.