Two New Species of Monstrillopsis Sars (Crustacea: Copepoda: Monstrilloida) from the White Sea and Norway, with Comments on M. dubia Scott

A new species of monstrilloid copepod, Monstrillopsis ferrarii n. sp., based on four adult female specimens collected in the White Sea, northern Russia, is described and illustrated. The new species is most closely related to M. dubia Scott from Scotland and the Mediterranean and M. dubia (sensu Sars, 1921) from Norwegian fjords. The latter is considered to represent a distinct species, described herein as M. dubioides n. sp. It differs from M. dubia in characters related to antennule length compared to body length, but mainly to the shape and relative size of the genital double somite and other urosomal somites. Records of M. dubia in Norway and off Lisbon are referable to M. dubioides n. sp. On the other hand, M. ferrarii n. sp. differs from M. dubia, M. dubioides, and the other species of the genus by a combination of characters, including 1) two rounded protuberances in the cephalic area, flanking the ocelli; 2) a wide zone of transverse cuticular striations encircling the cephalic area; 3) very long exopodal setae on the fifth legs, with no distal elongation of the exopodal lobe beyond the setal bases; 4) a relatively long genital double somite with the margins of the anterior half produced laterally; and 5) the nearly equal sizes of the anal somite and the preceding somite. It is considered that M. dubia and related forms represent a species complex with subtle morphological differences and a wide distribution. This is the first record of a species of Monstrillopsis in Russia and the sixth species of this order to be recorded in polar environments.On décrit et illustre une nouvelle espèce de copépode de la famille des monstrillidés, Monstrillopsis ferrarii n. sp., établie d'après quatre spécimens femelles adultes prélevés dans la mer Blanche (Russie septentrionale). Cette nouvelle espèce est très proche de M. dubia Scott qui vit au large de l'Écosse et en Méditerranée, et de M. dubia (sensu Sars, 1921) présente dans les fjords norvégiens. On considère que cette dernière représente une espèce distincte, décrite ici sous le nom de M. dubioides n. sp. Elle se différencie de M. dubia par certains éléments liés à la longueur de l'antennule par rapport à la longueur corporelle, mais surtout par la forme et la taille relative du double somite génital et d'autres segments de l'urosomite. Les observations de M. dubia en Norvège et au large de Lisbonne portent en fait sur M. dubioides n. sp. D'un autre côté, M. ferrarii n. sp. se différencie de M. dubia, M. dubioides et des autres espèces appartenant à ce genre par une combinaison de caractéristiques qui comprennent: 1) deux protubérances arrondies dans la zone céphalique, situées de part et d'autre des ocelles; 2) une large zone de stries cuticulaires transversales entourant la partie céphalique; 3) de très longues soies exopoditiques sur la cinquième paire de pattes, sans élongation distale du lobe de l'exopodite au-delà de la partie basilaire des soies; 4) un double somite génital relativement long dont les bords de la moitié antérieure se développent latéralement; et 5) une taille presque similaire du somite anal et du somite qui le précède. On considère que M. dubia et les formes apparentées représentent une espèce complexe qui témoigne de différences morphologiques subtiles et d'une large distribution. Il s'agit là de la première observation de Monstrillopsis en Russie et de la sixième espèce de cet ordre à être observée dans un environnement polaire

Confinement and Chiral Symmetry Breaking via Domain-Like Structures in the QCD Vacuum

A qualitative mechanism for the emergence of domain structured background gluon fields due to singularities in gauge field configurations is considered, and a model displaying a type of mean field approximation to the QCD partition function based on this mechanism is formulated. Estimation of the vacuum parameters (gluon condensate, topological susceptibility, string constant and quark condensate) indicates that domain-like structures lead to an area law for the Wilson loop, nonzero topological susceptibility and spontaneous breakdown of chiral symmetry. Gluon and ghost propagators in the presence of domains are calculated explicitly and their analytical properties are discussed. The Fourier transforms of the propagators are entire functions and thus describe confined dynamical fields.Comment: RevTeX, 48 pages (32 pages + Appendices A-E), new references added [1,2,4,5] and minor formulae corrected for typographical error

Is the meiofauna a good indicator for climate change and anthropogenic impacts?

Our planet is changing, and one of the most pressing challenges facing the scientific community revolves around understanding how ecological communities respond to global changes. From coastal to deep-sea ecosystems, ecologists are exploring new areas of research to find model organisms that help predict the future of life on our planet. Among the different categories of organisms, meiofauna offer several advantages for the study of marine benthic ecosystems. This paper reviews the advances in the study of meiofauna with regard to climate change and anthropogenic impacts. Four taxonomic groups are valuable for predicting global changes: foraminifers (especially calcareous forms), nematodes, copepods and ostracods. Environmental variables are fundamental in the interpretation of meiofaunal patterns and multistressor experiments are more informative than single stressor ones, revealing complex ecological and biological interactions. Global change has a general negative effect on meiofauna, with important consequences on benthic food webs. However, some meiofaunal species can be favoured by the extreme conditions induced by global change, as they can exhibit remarkable physiological adaptations. This review highlights the need to incorporate studies on taxonomy, genetics and function of meiofaunal taxa into global change impact research

BEAM EXTACTION SYSTEM FROM DC60 CYCLOTRON

The results of numerical simulation of the heavy ions<br />beam extraction system (A/Z=6&divide;12, W=0.35&divide;1.77<br />MeV/amu) from the DC60 cyclotron are presented. The<br />parameters of the extraction system elements<br />(electrostatic deflector and focusing magnetic channel)<br />and diagnostic elements are chosen. The experimental<br />extraction efficiency of 14N2+ and 84Kr12+ beams<br />is equal to 60&divide;65% with intensity 1.5&divide;2.5 &mu;A.IMP;Chinese Academy of Science

Meiofauna of the Koster-area, results from a workshop at the Sven Lovén Centre for Marine Sciences (Tjärnö, Sweden)

During a two-week workshop held at the Sven Lovén Centre for Marine Sciences on Tjärnö, an island on the Swedish west-coast, meiofauna was studied in a large variety of habitats using a wide range of sampling techniques. Almost 100 samples coming from littoral beaches, rock pools and different types of sublittoral sand- and mudflats yielded a total of 430 species, a conservative estimate. The main focus was on acoels, proseriate and rhabdocoel flatworms, rotifers, nematodes, gastrotrichs, copepods and some smaller taxa, like nemertodermatids, gnathostomulids, cycliophorans, dorvilleid polychaetes, priapulids, kinorhynchs, tardigrades and some other flatworms. As this is a preliminary report, some species still have to be positively identified and/or described, as 157 species were new for the Swedish fauna and 27 are possibly new to science. Each taxon is discussed separately and accompanied by a detailed species list