215 research outputs found
FishBase: the on-line answer to ichthyological issues
FishBase was initiated by Daniel Pauly and Rainer Froese as an electronic fact sheets database for the economically most important fish species. From 1987 onwards FishBase was developed at the WorldFish Center (former ICLARM), and subsequently financed by the European Commission between 1989 and 2000. Since 2001, FishBase is supported by a consortium, including the WorldFish Center (Malaysia), FAO (Italy), The Royal Museum for Central Africa (Belgium), the Natural History Museums of Paris (France) and Stockholm (Sweden), the Universities of Kiel (Germany), British Columbia (Canada) and Thessaloniki (Greece), and the Chinese Academy of Fishery Sciences (China). At present FishBase is the largest on-line encyclopaedia on fishes, with about 20 - 25 million hits per month.Information on more than 30,000 fish species is available through the FishBase portal (www.fishbase.org) or one of its 6 mirror-sites, including data on the taxonomic position, distribution, morphology and ecology, as well as numerous aspects of aquaculture and fisheries biology. Information is based on scientific publications or provided by experts. Many deep links are provided to other relevant websites such as those of the IUCN (conservation) and GenBank (genetics). The Royal Museum for Central Africa is responsible for the validation and updating of the information on all African fresh- and brackish water fishes and developed in 2007 a portal for the African inland fishes (www.fishbaseforafrica.org).FishBase contains a lot of applications for fish and fisheries scientists, such as tools for fish identification, biogeographical modelling, construction and analysis of trophic pyramids, analysis of fishery and aquaculture statistics, diagnosis of fish diseases, etc. Some of these have already proved their importance to support concepts like ‘fishing down food webs’ (Pauly et al., 1998)
First record of the round goby, <i>Neogobius melanostomus</i> (Actinopterygii: Perciformes: Gobiidae) in Belgium
Almost six years after the first finding of the round goby Neogobius melanostomus (Gobiidae) in the Netherlands, several specimens of this invasive Ponto-Caspian benthic fish were also recorded in the Belgian part of the River Scheldt and in the Albert Canal. This is the first record of the round goby in Belgium
Effets de la couverture des cages flottantes et de la période de distribution de l\'aliment sur la survie et la croissance des alevins du poisson-chat africain Heterobranchus longifilis Valenciennes 1840 en élevage intensif
L\'influence du recouvrement des cages flottantes par des bâches plastiques noires non transparentes et de la période (jour ou nuit) de distribution de l\'aliment sur la survie et la croissance du poisson-chat africain Heterobranchus longifilis a été évaluée. L\'expérience a consisté à observer le jour et la nuit des alevins nourris en quatre repas, dans deux types de cages flottantes : cages couvertes et cages non couvertes. Quelle que soit la période de distribution de l\'aliment, les meilleurs taux de survie ont été observés dans les cages couvertes (73,0 ± 2,6 % le jour et 75,0 ± 1,7 % la nuit contre 64,0 ± 3,5 % le jour et 67,0 ± 2,0 % la nuit). Les poids moyens finaux des poissons enregistrés dans ces cages sont de 16,9 ± 1,9 g le jour et 17,8 ± 1,9 g la nuit. Ces poids sont comparables à ceux observés dans les cages non couvertes avec distribution nocturne de l\'aliment (16,8 ± 1,1 g). Ces résultats montrent qu\'en cages couvertes, la période de distribution de l\'aliment n\'a aucune influence sur la croissance des poissons.The effects of covering the breeding floating cages with a black plastic canvas and the feeding period (day or night) on the survival and growth of the african cat-fish Heterobranchus longifilis have been investigated. Juvenile individuals of this species fed four times during daytime and nighttime were reared in two types of floating cages : covered with black plastic canvas and without any canvas. Whatever the feeding period, the best survival rates were recorded in covered cages (73,0 ± 2,6 % for daytime and 75,0 ± 1,7 % for nighttime, against 64,0 ± 3,5 % for daytime and 67,0 ± 2,0 % for nighttime). In these cages, final mean weights of fishes recorded were 16,9 ± 1,9 g for daytime and 17,8 ± 1,9 g for nighttime. These data were similar to those recorded in non covered floating cage with nighttime feeding. Results suggest that there is no effect of the feeding period on the growth of H. longifilis reared in cages with canvas. Keywords: Heterobranchus longifilis, alevinage, cage flottante, éclairement, horaires de nourrissage./Heterobranchus longifilis, fry rearing, floating cage, light, feeding time.Sciences & Nature Vol. 4 (1) 2007: pp. 85-9
Unravelling the evolution of Africa's drainage basins through a widespread freshwater fish, the African sharptooth catfish Clarias gariepinus
Aim The formation history of Africa's current river basins remains largely unknown. In order to date changes in landscape and climate, we studied the biogeography of the African freshwater fish with the largest natural distribution. We also validated biogeographical units. Location Continental Africa. Taxon Clarias gariepinus sl. Methods We investigated mitochondrial cytb sequences of 443 individuals from 97 localities, using a haplotype network and a genetic landscape analysis. We inferred a dated phylogeny using maximum likelihood and Bayesian inference approaches and reconstructed ancestral areas with S-DEC and S-DIVA models. Microsatellite genotyping complemented the mitochondrial approach in the Congo basin, where the latter revealed complex patterns. Results Limited differentiation is found in northern and south-western Africa, and sharp genetic differentiation in the continent's east and centre. Populations with affinities to neighbouring basins occur at the edges of the Congo province. High diversity exists in the south of the Congo basin. The Zambezi province is partitioned into eastern, central and western sectors. In the east, specimens were related to those from the Congo. In the west, they were similar to Southern representatives. Phylogenetic inference placed the origin of C. gariepinus in the East Coast, with intraspecific diversification starting around the Great Lakes. These events occurred ca. 4.8-1.65 and 2.3-0.8 MYA respectively. Main conclusions Clades of C. gariepinus sl. show a clear geographical signature. The origin of C. gariepinus in the East Coast and diversification around the Great Lakes coincided with the periods of increased aridity. Low genetic differentiation in northern and southern Africa may result from connectivity during recent periods of higher rainfall. In contrast to other widespread African freshwater fish, colonization rather than extinction seemed to mediate distribution patterns. This can be explained by a high ecological tolerance. We highlight the species' suitability to study landscape and climate evolution at various scales.Peer reviewe
Six new dactylogyrid species (Platyhelminthes, Monogenea) from the gills of cichlids (Teleostei, Cichliformes) from the Lower Congo Basin
The Lower Congo Basin is characterized by a mangrove-lined estuary at its mouth and, further upstream, by many hydrogeographical barriers such as rapids and narrow gorges. Five localities in the mangroves and four from (upstream) left bank tributaries or pools were sampled. On the gills of Coptodon tholloni, Coptodon rendalli, Hemichromis elongatus, Hemichromis stellifer and Tylochromis praecox, 17 species of parasites (Dactylogyridae & Gyrodactylidae, Monogenea) were found, eight of which are new to science. Six of these are herein described: Cichlidogyrus bixlerzavalai n. sp. and Cichlidogyrus omari n. sp. from T praecox, Cichlidogyrus calycinus n. sp. and Cichlidogyrus polyenso n. sp. from H. elongatus, Cichlidogyrus kmentovae n. sp. from H. stellifer and Onchob-della ximenae n. sp. from both species of Hemichromis. On Cichlidogyrus reversati a ridge on the accessory piece was discovered that connects to the basal bulb of the penis. We report a putative spillback effect of the native parasites Cichlidogyrus berradae, Cichlidogyrus cubitus and Cichlidogyrus flexicolpos from C. tholloni to the introduced C. rendalli. From our results, we note that the parasite fauna of Lower Congo has a higher affinity with the fauna of West African and nearby freshwater ecoregions than it has with fauna of other regions of the Congo Basin and Central Africa.Peer reviewe
On the equivalence of the Langevin and auxiliary field quantization methods for absorbing dielectrics
Recently two methods have been developed for the quantization of the
electromagnetic field in general dispersing and absorbing linear dielectrics.
The first is based upon the introduction of a quantum Langevin current in
Maxwell's equations [T. Gruner and D.-G. Welsch, Phys. Rev. A 53, 1818 (1996);
Ho Trung Dung, L. Kn\"{o}ll, and D.-G. Welsch, Phys. Rev. A 57, 3931 (1998); S.
Scheel, L. Kn\"{o}ll, and D.-G. Welsch, Phys. Rev. A 58, 700 (1998)], whereas
the second makes use of a set of auxiliary fields, followed by a canonical
quantization procedure [A. Tip, Phys. Rev. A 57, 4818 (1998)]. We show that
both approaches are equivalent.Comment: 7 pages, RevTeX, no figure
Spiritual well-being and associated factors in Dutch patients with advanced cancer
CONTEXT: Palliative care aims to support patients' spiritual needs with the intention of promoting their spiritual well-being (SWB), an important dimension of quality of life. SWB is one of the less-studied dimensions of QoL, particularly in a secular country such as the Netherlands. OBJECTIVES: In this study we aimed to get a better understanding of SWB in Dutch patients with advanced cancer. We therefore examined its prominence and associated factors. METHODS: We used the baseline data of a cohort study on experienced quality of care and quality of life (eQuiPe study), which included 1,103 patients with advanced cancer. In addition to sociodemographic and religious/spiritual characteristics, study measures comprised the SWB subscales Meaning, Peace, and Faith of the revised FACIT-Sp-12, spiritual problems and needs (PNPCsv), quality of life (EORTC-QLQ-C30) and satisfaction with healthcare professionals' interpersonal skills (INPATSAT-32). RESULTS: On average, patients experienced quite a bit of Meaning (8.9, SD 2.3), a little bit to somewhat Peace (6.8, SD 2.7), and very low levels of Faith (2.9, SD 3.7). Two-thirds (71%) of patients reported one or more spiritual problems, for which the majority (54%) wanted to receive attention. In the final multivariable models, only a few factors were associated with SWB, such as greater spiritual needs with lower levels of Meaning and Peace. CONCLUSION: Dutch patients with advanced cancer experience medium to low levels of Meaning, Peace, and Faith. More attention for their SWB is warranted
Characterization and Evaluation of the Artemis Camera for Fluorescence-Guided Cancer Surgery
Purpose: Near-infrared (NIR) fluorescence imaging can provide the surgeon with real-time visualization of, e.g., tumor margins and lymph nodes. We describe and evaluate the Artemis, a novel, handheld NIR fluorescence camera.Procedures: We evaluated minimal detectable cell numbers (FaDu-luc2, 7D12-IRDye 800CW), preclinical intraoperative detection of sentinel lymph nodes (SLN) using indocyanine green (ICG), and of orthotopic tongue tumors using 7D12-800CW. Results were compared with the Pearl imager. Clinically, three patients with liver metastases were imaged using ICG.Results: Minimum detectable cell counts for Artemis and Pearl were 2 × 105 and 4 × 104 cells, respectively. In vivo, seven SLNs were detected in four mice with both cameras. Orthotopic OSC-19-luc2-cGFP tongue tumors were clearly identifiable, and a minimum FaDu-luc2 tumor size of 1 mm3 could be identified. Six human malignant lesions were identified during three liver surgery procedures.Conclusions: Based on this study, the Artemis system has demonstrated its utility in fluorescence-guided cancer surgery
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