Wages in the first job after apprenticeship : movers versus stayers

"In this article the wage effects of occupational mobility in those who have completed a course of vocational training at a company are studied on the basis of the IAB employment sample. About 70% of this group remains in the company where they did their training, 30% move another company. There is hardly any difference in the average wages of those who remain in the company which trained them and of the changers, although the wages of the latter group are considerably more widely distributed. The results of the analyses show that the wage effect of a change varies between the different branches of industry. It is not possible to derive clear statements from the empirical findings as to whether changing company after completion of training is linked with a positive or negative wage effect." (Author's abstract, IAB-Doku) ((en))betriebliche Berufsausbildung, Ausbildungsabsolventen, Lohnhöhe, zwischenbetriebliche Mobilität - Auswirkungen, IAB-Beschäftigtenstichprobe

Sponges of the family Esperiopsidae (Demospongiae, Poecilosclerida) from Northwest Africa, with the descriptions of four new species

Sponges belonging to the genera Amphilectus Vosmaer, Esperiopsis Carter and Ulosa de Laubenfels of the family Esperiopsidae were collected during 1986 and 1988 expeditions of the Netherlands Centre for Biodiversity Naturalis (at that time the National Museum of Natural History at Leiden and the Zoological Museum of Amsterdam) in waters off the coasts of Mauritania and the Cape Verde Islands. Four new species, Amphilectus utriculus sp. nov., Amphilectus strepsichelifer sp. nov., Esperiopsis cimensis sp. nov., Ulosa capblancensis sp. nov., and two already known species, Amphilectus cf. fucorum (Esper) and Ulosa stuposa (Esper) are described and discussed

Affinities of the family Sollasellidae (Porifera, Demospongiae). II. Molecular evidence

This is the second part of a revision and re-classification of the demosponge family Sollasellidae, and an example of a successful use of combined morphological and molecular data. Sollasella had been a poorly known, long forgotten taxon, placed incertae sedis in the order Hadromerida in the last major revision of the demosponges. It has recently been suggested to belong to Raspailiidae in the order Poecilosclerida due to striking morphological similarities. The present analysis verified this re-classification using molecular markers. Comparing 28S rDNA fragments of Sollasella cervicornis, a newly described species S. moretonensis and a representative set of raspailiid and hadromerid samples. In our analyses Sollasella clearly clusters inside the Raspailiidae clade, and distantly from hadromerid taxa. Supporting morphological hypothesis of Van Soest et al. (2006), that Sollasella is a raspailiid sponge

Isolation and structure identification of new alkaloids from the sponge Rhabdastrella rowi

Chemical investigation on marine sponge Rhabdastrella rowi collected from Bali, Indonesia has been performed. This study was aimed to isolate and to identify structures of the sponge secondary metabolites as well as to test their cytotoxicity activity on mouse lymphoma cell line L5178Y.Isolation procedure was performed by using different chromatography techniques. NMR spectroscopy and mass spectrometry methods were used to identify the compounds chemical structures. Cytotoxicity of the isolates was tested on mouse lymphoma cell line L5178Y by using the microculture tetrazolium (MTT) assay.This study yielded two new alkaloids, quinolin-4-ol (1) and quninazolin-4-amine (2) which were found as minor constituents of Rhabdastrella rowi. Both compounds were observed as inactive against mouse lymphoma cell line L5178Y.Key words: Rhabdastrella rowi, sponge, alkaloid

Protein kinase inhibitors from Indonesian Sponge Axynissa sp.

A research about inhibitory activity on various cancer related protein kinases of several marine sponges collected in Indonesia was performed. This study aims were to isolate and to identify structures of biologically active sponge metabolites.A combination of a chemically-and biologically driven approach for drug discovery was employed. Sponge extracts were tested by protein kinase inhibitory assay by in vitro method in parallel to the usage of TLC, and HPLC coupled to UV spectrophotometry and mass spectrometry to isolate the chemically most interesting substances. Structure identification of active compounds was performed by using NMR spectroscopy and massspectrometry methods.This study showed that only Axynissa sp. fractions were found active in protein kinase inhibitory assay. Two bisabolene type sesquiterpenoids, (+)- curcuphenol (1) and (+)-curcudiol (2) were identified as active compounds from the sponge. Compound 1 showed SRC protein kinase inhibition with an IC50value of 7.8 μg/mL while 2 inhibited FAK with an IC50 value of 9.2 μg/mL.Key words: protein kinase inhibitor, Axynissa sp

Chemical investigation on Indonesian marine sponge Mycale phyllophila

Chemical investigation on marine sponge Mycale phyllophila collected from Bali, Indonesia has been performed. This study was aimed to isolate and to identify structures of the sponge secondary metabolites as well as to test their cytotoxic activity on mouse lymphoma cell line L5178Y.The sponge extract was fractionated by liquid-liquid partition followed with a vacuum liquid chromatography method. Structure elucidation was performed on the basis of extensive spectroscopic analysis involving one and two dimensional NMR spectroscopy as well as mass spectrometry. Cytotoxicity was tested on mouse lymphoma cell line L5178Y by using the microculture tetrazolium (MTT) assay. This study found a mixture of 5-pentadecyl-1H-pyrrole-2-carbaldehyde and (6’E)-5-(6’pentadecenyl)-1H-pyrrole-2-carbaldehyde as major constituents of the sponge extract. Those compounds were expected to be the active constituent to show growth inhibition of mouse lymphoma cell line (L5178Y) in vitro.Key words : Mycale phyllophila, cytotoxic agent, NMR spectroscopy

Soft sponges with tricky tree: On the phylogeny of dictyoceratid sponges

Keratose (horny) sponges constitute a very difficult group of Porifera in terms of taxonomy due to their paucity of diagnostic morphological features. (Most) keratose sponges possess no mineral skeletal elements, but an arrangement of organic (spongin) fibers, with little taxonomic or phylogenetic information. Molecular phylogenetics have targeted this evolutionary and biochemically important lineage numerous times, but the conservative nature of popular markers combined with ambiguous identification of the sponge material has so far prevented any robust phylogeny. In the following study, we provide a phylogenetic hypothesis of the keratose order Dictyoceratida based on nuclear markers of higher resolution potential (ITS and 28S C‐region), and particularly aim for the inclusion of type specimens as reference material. Our results are compared with previously published data of CO1, 18S, and 28S (D3‐D5) data, and indicate the paraphyly of the largest dictyoceratid family, the Thorectidae, due to a sister group relationship of its subfamily Phyllospongiinae with Family Spongiidae. Irciniidae can be recovered as monophyletic. Results on genus level and implications on phylogenetic signals of the most frequently described morphological characters are discussed

Intrinsic and extrinsic factors influencing large African herbivore movements

This document is the Accepted Manuscript version of the following article: Jan A. Venter, Herbert H. T. Prins, Alla Mashanova, Willem F. de Boer, and Rob Slotow, 'Intrinsic and extrinsic factors influencing large African herbivore movements', Ecological Informatics, Vol. 30: 257-262, November 2015, doi: https://doi.org/10.1016/j.ecoinf.2015.05.006. This manuscript version is made available under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives License (http://creativecommons.org/licenses/by-nc-nd/4.0/), which permits non-commercial re-use, distribution, and reproduction in any medium, provided the original work is properly cited, and is not altered, transformed, or built upon in any way.Understanding environmental as well as anthropogenic factors that influence large herbivore ecological patterns and processes should underpin their conservation and management. We assessed the influence of intrinsic, extrinsic environmental and extrinsic anthropogenic factors on movement behaviour of eight African large herbivore species. A cumulative odds ordinal logistic regression was used to determine the effect of season, feeding niche, number of vegetation types, home range size, and fences on the number of exponential distributions observed. When animals faced the trade-off between forage quality and quantity during the dry season, they moved further between forage areas and water sources in order to get to better forage, which added to the number of movement scales observed. Elephants had a lower number of movement scales, compared to all the other feeding types, which could be attributed to them being able to switch between browse and graze. The number of movement scales increased in more heterogeneous areas. Animals with larger home ranges, which are also larger species, and animals more restricted by fences, had fewer movement scales. In order for managers to effectively manage protected areas and associated biodiversity they need take cognisance of the different scales animals operate under, and the different factors that may be important for different species.Peer reviewe

Nothing in (sponge) biology makes sense - except when based on holotypes

Sponge species are infamously difficult to identify for non-experts due to their high morphological plasticity and the paucity of informative morphological characters. The use of molecular techniques certainly helps with species identification, but unfortunately it requires prior reference sequences. Holotypes constitute the best reference material for species identification, however their usage in molecular systematics and taxonomy is scarce and frequently not even attempted, mostly due to their antiquity and preservation history. Here we provide case studies in which we demonstrate the importance of using holo-type material to answer phylogenetic and taxonomic questions. We also demonstrate the possibility of sequencing DNA fragments out of century-old holotypes. Furthermore we propose the deposition of DNA sequences in conjunction with new species descriptions