Implementing Integrated Water Resources Management in the Ebro River Basin: From Theory to Facts

JA-925

Differenzierung von Pangasius (Pangasius hypophthalmus) und Asiatischem Rotflossenwels (Hemibagrus wyckioides) durch Protein- und DNA-Analyse

In the last years farmed Pangasius (Tra-Pangasius, Pangasius hypophthalmus) from Vietnam has reached a considerable market share, whereas aquaculture of Asian Redtail Catfish (Hemibagrus wyckioides) is in its infancy. Recently it has been detected by food control authorities in Hamburg, that Pangasius fillets have been mislabelled and sold as fillets produced from Asian Redtail catfish. The necessity to improve the analytical methods for differentiation of Pangasius and Redtail Catfish prompted us to evaluate the suitability of isoelectric focusing (IEF) and DNA-analysis for identification of the two species. IEF of water soluble proteins was found to be a fast, reliable and economical method for differentiation of raw fillets of Pangasius and Redtail Catfish, as long as reference material is available. PCR-based DNA analysis was performed as follows: (i) amplification of a 464 bp segment of the cytochrome b gene; (ii) sequencing of the PCR product; (iii) comparison of the sequence with entries in GenBank using BLAST. The sequences of both species differed considerably, allowing the unequivocal differentiation between P. hypophthalmus and H. wyckioides. Kurzfassung Pangasius (Schlankwels, Tra-Pangasius, Pangasius hypophthalmus) hat sich innerhalb weniger Jahre zu einem bedeutenden Zuchtfisch entwickelt, während die Aquakultur des Asiatischen Rotflossenwelses (Hemibagrus wyckioides) in Vietnam noch in einem relativ kleinen Maßstab stattfindet. Kürzlich wurde von der Lebensmittelüberwachung in Hamburg nachgewiesen, dass im Handel erhältliche Filets mit der Deklaration „Rotflossenwels“ aus Pangasius hergestellt worden waren. Vor diesem Hintergrund wurden zwei Methoden auf ihre Eignung zur Differenzierung von Pangasius und Rotflossenwels geprüft. Es zeigte sich, dass sowohl die isoelektrische Fokussierung (IEF) wasserlöslicher Proteine als auch die PCR-basierte DNA-Analyse zur Unterscheidung beider Arten gut geeignet ist. Die IEF stellt eine schnelle und kostengünstige Untersuchungsmethode dar, die allerdings Referenzmaterial benötigt. Mit Hilfe der PCR (Polymerase-Kettenreaktion) wurde ein Abschnitt des Cytochrom b-Gens vervielfältigt und sequenziert. Die Sequenzen von P. hypophthalmus und H. wyckioides wiesen beträchtliche Unterschiede auf. Es wird diskutiert, wie sich durch Vergleich dieser Sequenzen mit Einträgen in Gendatenbanken unbekannte Proben beider Arten sicher zuordnen lassen.

基于分支设置的质量导引相位展开算法

二维相位展开方法是近年来较为活跃、引起关注的一个研究课题，它在许多测量应用中有着重要的作用。尽管掩膜阻断算法在多个领域都有成功应用实例，该算法存在着固有的缺陷。为了克服掩膜阻断算法的缺陷，综合分支阻断方法和质量导引方法的优点，提出一种基于分支设置的质量导引相位展开新算法。它先以一个初始质量图来引导分支的设置，然后把分支对应的相位质量设置为最低，从而产生一个新的质量图，最后按新质量图来引导相位展开，并使用几个包裹相位图来验证此方法的有效性。计算机模拟相位图和实际相位图的相位展开结果表明，在存在复杂轮廓不连续

Informatikaren oinarriak. C lengoaian ebatzitako problemak

I. Programazioko ariketa laburrak: - Enuntziatuak. - Soluzioen proposamenak. II. Ariketa luzeak: - Gailu elektronikoak. - Kontsumo ohiturak: edariak. - Irratsaioa. - Gasolindegia. - Denda. - Zentral elektrikoa. - Elca Comayor lapurra. - Medi igoerak. - Autopista. - Joko aretoa. - Farolak. - Herrien arteko distantziak. - Olinpiadak. - Ventas S.A. - Heriozko istripuak. - Euskadi Irratia. - San Sebastianak

Electric and magnetic losses and gains in determining the sign of refractive index

Within the framework of classic electromagnetic theories, we have studied the sign of refractive index of optical medias with the emphases on the roles of the electric and magnetic losses and gains. Starting from the Maxwell equations for an isotropic and homogeneous media, we have derived the general form of the complex refractive index and its relation with the complex electric permittivity and magnetic permeability, i.e. n = root epsilon mu, in which the intrinsic electric and magnetic losses and gains are included as the imaginary parts of the complex permittivity and permeability, respectively, as epsilon = epsilon(r) + i(epsilon i) and mu = mu(r) + i mu(i). The electric and magnetic losses are present in all passive materials, which correspond, respectively, to the positive imaginary permittivity and permeability epsilon(i) > 0 and mu(i) > 0. The electric and magnetic gains are present in materials where external pumping sources enable the light to be amplified instead of attenuated, which correspond, respectively, to the negative imaginary permittivity and permeability epsilon(i) < 0 and mu(i) < 0. We have analyzed and determined uniquely the sign of the refractive index, for all possible combinations of the four parameters epsilon(r), mu(r), epsilon(i), and mu(i), in light of the relativistic causality. A causal solution requires that the wave impedance be positive Re {Z} > 0. We illustrate the results for all cases in tables of the sign of refractive index. One of the most important messages from the sign tables is that, apart from the well-known case where simultaneously epsilon < 0 and mu < 0, there are other possibilities for the refractive index to be negative n < 0, for example, for epsilon(r) < 0, mu(r) > 0, epsilon(i) > 0, and mu(i) > 0, the refractive index is negative n < 0 provided mu(i)/epsilon(i) > mu(r)/vertical bar epsilon(r)vertical bar. (c) 2006 Elsevier B.V. All rights reserved.

Involvement of ANXA5 and ILKAP in Susceptibility to Malignant Melanoma

Single nucleotide-polymorphisms (SNPs) are a source of diversity among human population, which may be responsible for the different individual susceptibility to diseases and/or response to drugs, among other phenotypic traits. Several low penetrance susceptibility genes associated with malignant melanoma (MM) have been described, including genes related to pigmentation, DNA damage repair and oxidative stress pathways. In the present work, we conducted a candidate gene association study based on proteins and genes whose expression we had detected altered in melanoma cell lines as compared to normal melanocytes. The result was the selection of 88 loci and 384 SNPs, of which 314 fulfilled our quality criteria for a case-control association study. The SNP rs6854854 in ANXA5 was statistically significant after conservative Bonferroni correction when 464 melanoma patients and 400 controls were analyzed in a discovery Phase I. However, this finding could not be replicated in the validation phase, perhaps because the minor allele frequency of SNP rs6854854 varies depending on the geographical region considered. Additionally, a second SNP (rs6431588) located on ILKAP was found to be associated with melanoma after considering a combined set of 1,883 MM cases and 1,358 disease-free controls. The OR was 1.29 (95% CI 1.12-1.48; p-value= 4x10(-4)). Both SNPs, rs6854854 in ANXA5 and rs6431588 in ILKAP, show population structure, which, assuming that the Spanish population is not significantly structured, suggests a role of these loci on a specific genetic adaptation to different environmental conditions. Furthermore, the biological relevance of these genes in MM is supported by in vitro experiments, which show a decrease in the transcription levels of ANXA5 and ILKAP in melanoma cells compared to normal melanocytes.

Caracterização da resistência a quinolonas em Mycobacterium abscessus subsp. bolletii e outras micobactérias de crescimento rápido relacionadas

Em diversos estados do Brasil, foram relatadas epidemias de infecções causadas por micobactérias de crescimento rápido (MCR) desde o ano 2000. A maioria dos casos foi principalmente associada ao clone BRA100 de Mycobacterium massiliense, recentemente renomeada para Mycobacterium abscessus subsp. bolletii, isolado de pacientes submetidos a procedimentos invasivos nos quais os instrumentos médicos não foram adequadamente esterilizados e/ou desinfetados. Sendo as quinolonas uma opção no tratamento de infecções por MCR e sugerida para esquemas terapêuticos para esses surtos, foram avaliadas nesse trabalho as atividades in vitro de quatro gerações de quinolonas para cepas clinicas e de referência de MCR através da microdiluição em caldo. Também foram analisadas as sequências peptídicas das regiões determinantes da resistência a quinolonas (RDRQ) das subunidades A e B da DNA gyrase (GyrA e GyrB) após o seqüenciamento de DNA seguido pela tradução da sequência de aminoácidos. Cinquenta e quatro cepas de M. abscessus subsp bolletii, incluindo o clone BRA100, isoladas em diferentes estados do Brasil, e 19 cepas de referência de MCR foram caracterizadas. Todas as 54 cepas clínicas de M. abscessus subsp. bolletii foram resistentes a todas as gerações de quinolonas e mostraram o mesmo resíduo nas RDRQ, incluindo Ala-83 em GyrA, Arg-447 e Asp-464 em GyrB, descritos como sendo responsáveis por gerar um baixo nível de resistência a quinolonas em micobactérias. Porém, outras espécies de MCR apresentaram diferentes susceptibilidade e padrões de mutações contrários aos classicamente já definidos, sugerindo que outros mecanismos de resistência, diferentes de mutações em gyrA e gyrB também possam estar envolvidos na alta resistência a quinolonas.

Diet composition and prey selection of the introduced grouper species peacock hind (Cephalopholis argus) in Hawaii

The introduced grouper species peacock hind (Cephalopholis argus), was the dominant large-body piscivore on the Main Hawaiian Island (MHI) reefs assessed by underwater visual surveys in this study. However, published data on C. argus feeding ecology are scarce, and the role of this species in Hawaiian reef ecosystems is presently not well understood. Here we provide the first comprehensive assessment of the diet composition, prey electivity (dietary importance of prey taxa compared to their availability on reefs), and size selectivity (prey sizes in the diet compared to sizes on reefs) of this important predator in the MHI. Diet consisted 97.7% of fishes and was characterized by a wide taxonomic breadth. Surprisingly, feeding was not opportunistic, as indicated by a strongly divergent electivity for different prey fishes. In addition, whereas some families of large-body species were represented in the diet exclusively by recruit-size individuals (e.g., Aulostomidae), several families of smaller-body species were also represented by juveniles or adults (e.g., Chaetodontidae). Both the strength and mechanisms of the effects of C. argus predation are therefore likely to differ among prey families. This study provides the basis for a quantitative estimate of prey consumption by C. argus, which would further increase understanding of impacts of this species on native fishes in Hawaii.

Abundance of adult horseshoe crabs (Limulus polylphemus) in Delaware Bay estimated from a bay-wide mark-recapture study

Estimates of the abundance of American horseshoe crabs (Limulus polyphemus) are important to determine egg production and to manage populations for the energetic needs of shorebirds that feed on horseshoe crab eggs. In 2003, over 17,500 horseshoe crabs were tagged and released throughout Delaware Bay, and recaptured crabs came from spawning surveys that were conducted during peak spawning. We used two release cohorts to test for a temporary effect of tagging on spawning behavior and we adjusted the number of releases according to relocation rates from a telemetry study. The abundance estimate was 20 million horseshoe crabs (90 % confidence interval: 13−28 million), of which 6.25 million (90% CI: 4.0−8.8 million) were females. The combined harvest rate for Delaware, New Jersey, Virginia, and Maryland in 2003 was 4% (90% CI: 3−6%) of the abundance estimate. Over-wintering of adults in Delaware Bay could explain, in part, differences in estimates from ocean-trawl surveys. Based on fecundity of 88,000 eggs per female, egg production was 5.5×1011 (90% CI: 3.5×1011, 7.7×1011), but egg availability for shorebirds also depended on overlap between horseshoe crab and shorebird migrations, density-dependent bioturbation, and wave-mediated vertical transport.

Sexual differentiation and gonad development in striped mullet (Mugil cephalus L.) from South Carolina estuaries*

This study examined the sexual differentiation and reproductive dynamics of striped mullet (Mugil cephalus L.) in the estuaries of South Carolina. A total of 16,464 specimens were captured during the study and histological examination of sex and maturity was performed on a subsample of 3670 fish. Striped mullet were sexually undifferentiated for the first 12 months, began differentiation at 13 months, and were 90% fully differentiated by 15 to 19 months of age and 225 mm total length (TL). The defining morphological characteristics for differentiating males was the elongation of the protogonial germ tissue in a corradiating pattern towards the center of the lobe, the development of primary and secondary ducts, and the lack of any recognizable ovarian wall structure. The defining female characteristics were the formation of protogonial germ tissue into spherical germ cell nests, separation of a tissue layer from the outer epithelial layer of the lobe-forming ovarian walls, a tissue bud growing from the suspensory tissue that helped form the ovary wall, and the proliferation of oogonia and oocytes. Sexual maturation in male striped mullet first occurred at 1 year and 248 mm TL and 100% maturity occurred at age 2 and 300 mm TL. Female striped mullet first matured at 2 years and 291 mm total length and 100% maturity occurred at 400 mm TL and age 4. Because of the open ocean spawning behavior of striped mullet, all stages of maturity were observed in males and females except for functionally mature females with hydrated oocytes. The spawning season for striped mullet recruiting to South Carolina estuaries lasts from October to April; the majority of spawning activity, however, occurs from November to January. Ovarian atresia was observed to have four distinct phases. This study presents morpholog ical analysis of reproductive ontogeny in relation to size and age in South Carolina striped mullet. Because of the length of the undifferentiated gonad stage in juvenile striped mullet, previous studies have proposed the possibility of protandric hermaphrodism in this species. The results of our study indicate that striped mullet are gonochoristic but capable of exhibiting nonfunctional hermaphroditic characteristics in differentiated mature gonads.