Designing and implementing an assay for the detection of rare and divergent NRPS and PKS clones in European, Antarctic and Cuban soils

The ever increasing microbial resistome means there is an urgent need for new antibiotics. Metagenomics is an underexploited tool in the field of drug discovery. In this study we aimed to produce a new updated assay for the discovery of biosynthetic gene clusters encoding bioactive secondary metabolites. PCR assays targeting the polyketide synthases (PKS) and non-ribosomal peptide synthetases (NRPS) were developed. A range of European soils were tested for their biosynthetic potential using clone libraries developed from metagenomic DNA. Results revealed a surprising number of NRPS and PKS clones with similarity to rare Actinomycetes. Many of the clones tested were phylogenetically divergent suggesting they were fragments from novel NRPS and PKS gene clusters. Soils did not appear to cluster by location but did represent NRPS and PKS clones of diverse taxonomic origin. Fosmid libraries were constructed from Cuban and Antarctic soil samples; 17 fosmids were positive for NRPS domains suggesting a hit rate of less than 1 in 10 genomes. NRPS hits had low similarities to both rare Actinobacteria and Proteobacteria; they also clustered with known antibiotic producers suggesting they may encode for pathways producing novel bioactive compounds. In conclusion we designed an assay capable of detecting divergent NRPS and PKS gene clusters from the rare biosphere; when tested on soil samples results suggest the majority of NRPS and PKS pathways and hence bioactive metabolites are yet to be discovere

Long-term trends in the longevity of scientific elites: evidence from the British and the Russian academies of science.

National science academies represent intellectual elites and vanguard groups in the achievement of longevity. We estimated life expectancy (LE) at age 50 of members of the British Royal Society (RS) for the years 1670-2007 and of members of the Russian Academy of Sciences (RAS) for the years 1750-2006. The longevity of academicians was higher than that of their corresponding national populations, with the gap widening from the 1950s. Since the 1980s, LE in the RS has been higher than the maximum LE among all high-income countries. In each period, LE in the RS was greater than in the RAS, although since the 1950s it has risen in parallel in the two academies. This steep increase shared by academicians in Britain and Russia suggests that general populations have the potential for a substantial increase in survival to high ages

Baltic cod recruitment – the impact of climate variability on key processes

Large-scale climatic conditions prevailing over the central Baltic Sea resulted in declining salinity and oxygen concentrations in spawning areas of the eastern Baltic cod stock. These changes in hydrography reduced the reproductive success and, combined with high fishing pressure, caused a decline of the stock to the lowest level on record in the early 1990s. The present study aims at disentangling the interactions between reproductive effort and hydrographic forcing leading to variable recruitment. Based on identified key processes, stock dynamics is explained using updated environmental and life stage-specific abundance and production time-series. Declining salinities and oxygen concentrations caused high egg mortalities and indirectly increased egg predation by clupeid fish. Low recruitment, despite enhanced hydrographic conditions for egg survival in the mid-1990s, was due to food limitation for larvae, caused by the decline in the abundance of the copepod Pseudocalanus sp. The case of the eastern Baltic cod stock exemplifies the multitude effects climatic variability may have on a fish stock and underscores the importance of knowledge of these processes for understanding stock dynamics

Parental effects on early life history traits of haddock Melanogrammus aeglefinus

Gametes from five male and three female haddock ( Melanogrammus aeglefinus ) were crossed to produce 15 half-sibling families that were used to evaluate potential parental contributions to early life history variability. Larval morphology at 0 and 5 days post-hatch (dph) and time to starvation in the absence of food were examined. Maternal influences on larval standard length and yolk area were significant at 0 and 5 dph. Paternal effects on larval standard length were significant at 0 and 5 dph, whereas paternal effects on yolk area were only significant at 5 dph. Larval eye diameter was influenced by maternity at day 0 post-hatch and by both maternity and paternity at 5 dph. Myotome height of larvae was subject to maternal and paternal influences at 0 and 5 dph. Growth rate was significantly influenced by both paternity and maternity. Yolk utilization efficiency was significantly influenced by parental interaction, while the time taken for larvae to die in the absence of food was affected only by maternity. Results of this study not only confirm the importance of female contributions to larval development but also indicate a paternal influence on the development and the early life history success of marine fish

Overview of the CLEF 2005 Interactive Track.

The CLEF Interactive Track (iCLEF) is devoted to the comparative study of user-inclusive cross-language search strategies. In 2005, we have studied two cross-language search tasks: retrieval of answers and retrieval of annotated images. In both tasks, no further translation or post-processing is needed after performing the tasks to fulfill the information need. In the interactive Question Answering task, users are asked to find the answer to a number of questions in a foreign-language document collection, and write the answers in their own native language. In the interactive image retrieval task, a picture is shown to the user, and then the user is asked to find the picture in the collection. This paper summarizes the task design, experimental methodology, and the results obtained by the research groups participating in the track

Mortality in Belarus, Lithuania, and Russia: divergence in recent trends and possible explanations

Before the collapse of the Soviet Union, Belarus, Lithuania, and Russia were quite comparable in terms of their socioeconomic development. Despite some differences in overall mortality levels, the three former Soviet republics were also very close to each other in terms of directions of mortality trends and age- and cause-specific mortality patterns. After 1991, all the three countries experienced substantial political and social transformations, and the challenges associated with the transition from a socialist to a market economy system. The sudden changes brought numerous problems, such as rapid growth in unemployment, falling standards of living, and growing social and income inequalities. These factors contributed to the significant deterioration of the health situation in all the countries, but the size and the nature of the mortality crisis was different in Belarus than it was in Lithuania and Russia. The marked similarities in socioeconomic and mortality trends in the countries up to 1991 contrast with their notable divergence during the subsequent years. The nature and success of market reforms seems to be the most plausible explanation for these differences. Russia and Lithuania have chosen more radical forms of economic and political transformations, which have led to massive privatization campaigns. The reforms were more sustainable and systematic in Lithuania than in Russia. By contrast, Belarus has chosen a gradual and slow transition path. Recent mortality trends in Belarus are explored in detail here, and are contrasted with those observed in Lithuania and Russia. Including a cause-of-death analysis sheds more light on the plausible determinants of the variations in mortality levels between the countries.Avant la chute de l’Union Soviétique, la Biélorussie, la Lituanie et la Russie étaient tout à fait comparables en termes de développement socio-économique. En dépit de quelques différences de taux de mortalité générale, les ex-Républiques Soviétiques étaient également très proches en termes de tendances et de variations de la mortalité par cause et par âge. Après 1991, les 3 pays ont connu des bouleversements politiques et sociaux, et ont dû faire face aux défis associés au passage d’une économie socialiste à l’économie de marché. Ces changements soudains ont provoqué de nombreux problèmes, tels qu’une montée rapide du chômage, la baisse du niveau de vie et le développement d’inégalités sociales et de revenu. L’ensemble de ces facteurs a contribué à une détérioration significative de la situation sanitaire dans tous les pays, mais la crise de mortalité en Biélorussie était différente de celles de la Lituanie et de la Russie, à la fois en termes d’étendue et de nature. Les grandes similitudes des tendances socio-économiques et de mortalité dans ces pays jusqu’en 1991 contrastent avec leur divergence notable au cours des années qui ont suivi. La nature et le succès des réformes liées au passage à l’économie de marché est l’explication la plus plausible de ces différences. La Russie et la Lituanie ont choisi des formes plus radicales de transformation économique et politique, qui ont mené à des campagnes de privatisation massives. Les réformes étaient plus durables et systématiques en Lituanie qu’en Russie. La Biélorussie, en revanche, a choisi la voie d’une transformation graduelle et lente. Les tendances récentes de la mortalité en Biélorussie sont examinées en détail dans cette étude, et comparées à celles observées en Lituanie et en Russie. Une analyse des causes de décès éclaire sur les déterminants plausibles des variations de niveau de mortalité entre ces pays

Marginal Eyespots on Butterfly Wings Deflect Bird Attacks Under Low Light Intensities with UV Wavelengths

Predators preferentially attack vital body parts to avoid prey escape. Consequently, prey adaptations that make predators attack less crucial body parts are expected to evolve. Marginal eyespots on butterfly wings have long been thought to have this deflective, but hitherto undemonstrated function.Here we report that a butterfly, Lopinga achine, with broad-spectrum reflective white scales in its marginal eyespot pupils deceives a generalist avian predator, the blue tit, to attack the marginal eyespots, but only under particular conditions-in our experiments, low light intensities with a prominent UV component. Under high light intensity conditions with a similar UV component, and at low light intensities without UV, blue tits directed attacks towards the butterfly head.In nature, birds typically forage intensively at early dawn, when the light environment shifts to shorter wavelengths, and the contrast between the eyespot pupils and the background increases. Among butterflies, deflecting attacks is likely to be particularly important at dawn when low ambient temperatures make escape by flight impossible, and when insectivorous birds typically initiate another day's search for food. Our finding that the deflective function of eyespots is highly dependent on the ambient light environment helps explain why previous attempts have provided little support for the deflective role of marginal eyespots, and we hypothesize that the mechanism that we have discovered in our experiments in a laboratory setting may function also in nature when birds forage on resting butterflies under low light intensities

The Pharmacological Effect Of Bothrops Neuwiedii Pauloensis (jararaca-pintada) Snake Venom On Avian Neuromuscular Transmission.

The neuromuscular effects of Bothrops neuwiedii pauloensis (jararaca-pintada) venom were studied on isolated chick biventer cervicis nerve-muscle preparations. Venom concentrations of 5-50 micro g/ml produced an initial inhibition and a secondary increase of indirectly evoked twitches followed by a progressive concentration-dependent and irreversible neuromuscular blockade. At venom concentrations of 1-20 micro g/ml, the responses to 13.4 mM KCl were inhibited whereas those to 110 micro M acetylcholine alone and cumulative concentrations of 1 micro M to 10 mM were unaffected. At venom concentrations higher than 50 micro g/ml, there was pronounced muscle contracture with inhibition of the responses to acetylcholine, KCl and direct stimulation. At 20-24 degrees C, the venom (50 g/ml) produced only partial neuromuscular blockade (30.7 +/- 8.0%, N = 3) after 120 min and the initial inhibition and the secondary increase of the twitch responses caused by the venom were prolonged and pronounced and the response to KCl was unchanged. These results indicate that B.n. pauloensis venom is neurotoxic, acting primarily at presynaptic sites, and that enzyme activity may be involved in this pharmacological action.36617-2