A LC-MS/MS confirmatory method for determination of chloramphenicol in real samples screened by competitive immunoassay

A new liquid chromatography-tandem mass spectrometric (LC-MS/MS) method was developed to confirm chloramphenicol (CAP) residues in foods of animal origin and in urine samples, which were earlier found positive under the screening analysis, performed by competitive enzyme-linked immunoassay (ELISA) technique. The developed LC-MS/MS method was applied to four non-compliant samples from 2008 to 2012; giving concentrations of CAP residues from 1.18 to 3.68 μg kg−1. All samples, qualified positive by ELISA, were confirmed with the LC-MS/MS technique and found to be non-compliant. The effectiveness of the confirmatory method was proven by participating in a successful proficiency test in year 2010. Both LC-MS/MS and ELISA methods were validated according to the European Union 2002/657/EC decision. The decision limit of the confirmatory method was determined as 0.02 μg kg−1 for CAP in each validated matrix, while the detection capability of the screening test was 0.15 μg kg−1

Joint replenishment meets scheduling

In this paper we consider a combination of the joint replenishment problem (JRP) and single machine scheduling with release dates. There is a single machine and one or more item types. Each job has a release date, a positive processing time, and it requires a subset of items. A job can be started at time $t$ only if all the required item types were replenished between the release date of the job and time point $t$. The ordering of item types for distinct jobs can be combined. The objective is to minimize the total ordering cost plus a scheduling criterion, such as total weighted completion time or maximum flow time, where the cost of ordering a subset of items simultaneously is the sum of a joint ordering cost, and an additional item ordering cost for each item type in the subset. We provide several complexity results for the offline problem, and competitive analysis for online variants with min-sum and min-max criteria, respectively

Lower bounds for several online variants of bin packing

We consider several previously studied online variants of bin packing and prove new and improved lower bounds on the asymptotic competitive ratios for them. For that, we use a method of fully adaptive constructions. In particular, we improve the lower bound for the asymptotic competitive ratio of online square packing significantly, raising it from roughly 1.68 to above 1.75.Comment: WAOA 201

What next for unions in Central and Eastern Europe? Invisibility, departure and the transformation of industrial relations

This article examines union revitalization in Central and Eastern Europe, focusing on two countries: Hungary and Latvia. Trade unions have not only had to cope with a declining membership base, but have also had to respond to austerity programmes and government cuts in public sector employment. We argue that the inability of unions to provide a strong voice for alternative policies to the current neoliberal orthodoxy has been driven by a declining membership base, but also by weakened social dialogue mechanisms, limited industrial representation and an ageing membership profile, exacerbated by net outward migration in recent years. However, we find that unions in Latvia and Hungary have responded differently to these issues

Longest Fragment First Algorithms for Data Compression

On-line text-compression algorithms are considered, where compression is done by substituting substrings of the text according to some fixed dictionary (code book). Due to the long running time of optimal com- pression algorithms, several on-line heuristics have been introduced in the literature. In this paper we analyse two modified version of an old algo- rithm introduced by Shuegraf and Heaps [8]. We will investigate the worst case behaviour of this Longest Fragment First (LFF) algorithm for several types of special dictionaries