Rare Disease Video Portal

Rare Disease Video Portal (RD Video) is a portal web where contains videos from Youtube including all details from 12 channels of Youtube.

Tapinoma pygmaeum (Dufour, 1857) (Hymenoptera, Formicidae), not a rare species

Tapinoma pygmaeum is an ant known from seven localities. Five of them are in theprovince of Girona (Spain). The apparent rarity and skewed distribution of this species isprobably an artifact due to the confussion, in field samplings, with a similar speciesPlagiolepis pygmaea

The contributions of rare objects in correspondence analysis

Correspondence analysis, when used to visualize relationships in a table of counts(for example, abundance data in ecology), has been frequently criticized as being too sensitiveto objects (for example, species) that occur with very low frequency or in very few samples. Inthis statistical report we show that this criticism is generally unfounded. We demonstrate this inseveral data sets by calculating the actual contributions of rare objects to the results ofcorrespondence analysis and canonical correspondence analysis, both to the determination ofthe principal axes and to the chi-square distance. It is a fact that rare objects are oftenpositioned as outliers in correspondence analysis maps, which gives the impression that theyare highly influential, but their low weight offsets their distant positions and reduces their effecton the results. An alternative scaling of the correspondence analysis solution, the contributionbiplot, is proposed as a way of mapping the results in order to avoid the problem of outlying andlow contributing rare objects.

Niobium and rare earth minerals from the Virulundo carbonatite, Namibe, Angola

The Virulundo carbonatite in Angola, one of the biggest in the world, contains pyrochlore as an accessory mineral in all of the carbonatite units (calciocarbonatites, ferrocarbonatites, carbonatite breccias, trachytoids). The composition of the primary pyrochlore crystals is very close to fluornatrocalciopyrochlore in all these units. High-temperature hydrothermal processes caused the pseudomorphic replacement of the above crystals by a second generation of pyrochlore, characterized by lower F and Na contents. Low-temperature hydrothermal replacement of the above pyrochlores, associated with production of quartz-carbonates-fluorite veins, controled the development of a third generation of pyrochlore, characterized by high Sr contents. Finally, supergene processes produced the development of a secondary paragenesis in the carbonatite, consisting in late carbonates, goethite, hollandite and REE minerals (mainly synchysite-(Ce), britholite-(Ce), britholite-(La), cerite-(Ce)). Separation of Ce from the other REE was allowed by oxidizing conditions. Therefore, Ce4+ was also incorporated into a late generation of pyrochlore, which is also strongly enriched in Ba and strongly depleted in Ca and Na

Structural disorder in two-dimensional random magnets: Very thin films of rare earths and transition metals

The low-temperature isothermal magnetization curves, M(H), of SmCo4 and Fe3Tb thin films are studied according to the two-dimensional correlated spin-glass model of Chudnovsky. We have calculated the magnetization law in approach to saturation and shown that the M(H) data fit well the theory at high and low fields. In our fit procedure we have used three different correlation functions. The Gaussian decay correlation function fits well the experimental data for both samples.

Description of a rare isopod crustacean, Arcturella poorei sp. nov. (Isopoda: Valvifera: Arcturidae), from the Atlantic seaboard of Cadiz (Iberian Peninsula)

This paper describes a new species of arcturidean isopod, Arcturella poorei, from the Atlantic seaboard of Cadiz (Spain). A diagnosis and description of the species is presented, and a comparison with other species of the genus from the area.

Overfishing of small pelagic fishes increases trophic overlap between immature and mature striped dolphins in the Mediterranean Sea

The interactions among diet, ecology, physiology, and biochemistry affect N and C stable isotope signatures in animal tissues. Here, we examined if ecological segregation among animals in relation to sex and age existed by analyzing the signatures of delta15N and delta13C in the muscle of Western Mediterranean striped dolphins. Moreover, we used a Bayesian mixing model to study diet composition and investigated potential dietary changes over the last two decades in this population. For this, we compared isotope signatures in samples of stranded dolphins obtained during two epizootic events occurring in 1990 and 2007-2008. Mean delta13C values for females and males were not significantly different, but age-related variation indicated delta13C enrichment in both sexes, suggesting that females and males most likely fed in the same general areas, increasing their consumption of benthic prey with age. Enrichment of delta15N was only observed in females, suggesting a preference for larger or higher trophic level prey than males, which could reflect different nutritional requirements. delta13C values showed no temporal variation, although the mean delta15N signature decreased from 1990 to 2007-2008, which could indicate a dietary shift in the striped dolphin over the last two decades. The results of SIAR indicated that in 1990, hake and sardine together contributed to 60% on the diet of immature striped dolphins, and close to 90% for mature striped dolphins. Conversely, the diet of both groups in 2007-2008 was more diverse, as hake and sardine contributed to less than 40% of the entire diet. These results suggest a dietary change that was possibly related to changes in food availability, which is consistent with the depletion of sardine stocks by fishing.

Evolutionary analysis of genetic variants involved in rare diseases

Next-generation sequencing techniques such as exome sequencing can successfully detect all genetic variants in a human exome and it has been useful together with the implementation of variant filters to identify causing-disease mutations. Two filters aremainly used for the mutations identification: low allele frequency and the computational annotation of the genetic variant. Bioinformatic tools to predict the effect of a givenvariant may have errors due to the existing bias in databases and sometimes show a limited coincidence among them. Advances in functional and comparative genomics are needed in order to properly annotate these variants.The goal of this study is to: first, functionally annotate Common Variable Immunodeficiency disease (CVID) variants with the available bioinformatic methods in order to assess the reliability of these strategies. Sencondly, as the development of new methods to reduce the number of candidate genetic variants is an active and necessary field of research, we are exploring the utility of gene function information at organism level as a filter for rare disease genes identification. Recently, it has been proposed that only 10-15% of human genes are essential and therefore we would expect that severe rare diseases are mostly caused by mutations on them. Our goal is to determine whether or not these rare and severe diseases are caused by deleterious mutations in these essential genes. If this hypothesis were true, taking into account essential genes as a filter would be an interesting parameter to identify causingdisease mutations.

Niobium and rare earth minerals from the Virulundo carbonatite, Namibe, Angola

The Virulundo carbonatite in Angola, one of the biggest in the world, contains pyrochlore as an accessory mineral in all of the carbonatite units (calciocarbonatites, ferrocarbonatites, carbonatite breccias, trachytoids). The composition of the primary pyrochlore crystals is very close to fluornatrocalciopyrochlore in all these units. High-temperature hydrothermal processes caused the pseudomorphic replacement of the above crystals by a second generation of pyrochlore, characterized by lower F and Na contents. Low-temperature hydrothermal replacement of the above pyrochlores, associated with production of quartz-carbonates-fluorite veins, controled the development of a third generation of pyrochlore, characterized by high Sr contents. Finally, supergene processes produced the development of a secondary paragenesis in the carbonatite, consisting in late carbonates, goethite, hollandite and REE minerals (mainly synchysite-(Ce), britholite-(Ce), britholite-(La), cerite-(Ce)). Separation of Ce from the other REE was allowed by oxidizing conditions. Therefore, Ce4+ was also incorporated into a late generation of pyrochlore, which is also strongly enriched in Ba and strongly depleted in Ca and Na

[Notes breus (fauna)] Noves introduccions i poblament actual de peixos a l’estany de Banyoles = New introductions and present population of fishes in Lake Banyoles

Nota breu de fauna sobre les noves introduccions i el poblament actual de peixos a l’estany de Banyoles

Small but powerful: Top predator local extinction affects ecosystem structure and function in an intermittent stream.

Top predator loss is a major global problem, with a current trend in biodiversity loss towards high trophic levels that modifies most ecosystems worldwide. Most research in this area is focused on large-bodied predators, despite the high extinction risk of small-bodied freshwater fish that often act as apex consumers. Consequently, it remains unknown if intermittent streams are affected by the consequences of top-predators' extirpations. The aim of our research was to determine how this global problem affects intermittent streams and, in particular, if the loss of a small-bodied top predator (1) leads to a 'mesopredator release', affects primary consumers and changes whole community structures, and (2) triggers a cascade effect modifying the ecosystem function. To address these questions, we studied the topdown effects of a small endangered fish species, Barbus meridionalis (the Mediterranean barbel), conducting an enclosure/exclosure mesocosm experiment in an intermittent stream where B. meridionalis became locally extinct following a wildfire.We found that top predator absence led to 'mesopredator release', and also to 'prey release' despite intraguild predation, which contrasts with traditional food web theory. In addition, B. meridionalis extirpation changed whole macroinvertebrate community composition and increased total macroinvertebrate density. Regarding ecosystem function, periphyton primary production decreased in apex consumer absence. In this study, the apex consumer was functionally irreplaceable; its local extinction led to the loss of an important functional role that resulted in major changes to the ecosystem's structure and function. This study evidences that intermittent streams can be affected by the consequences of apex consumers' extinctions, and that the loss of small-bodied top predators can lead to large ecosystem changes. We recommend the reintroduction of small-bodied apex consumers to systems where they have been extirpated, to restore ecosystem structure and function.

Experimental assessment of the effects of a Neotropical nocturnal piscivore on juvenile native and invasive fishes

We experimentally examined the predator-prey relationships between juvenile spotted sorubim Pseudoplastystoma corruscans and young-of-the-year invasive and native fish species of the Paraná River basin, Brazil. Three invasive (peacock bass Cichla piquiti, Nile tilapia Oreochromis niloticus, and channel catfish Ictalurus punctatus) and two native (yellowtail tetra Astyanax altiparanae and streaked prochilod Prochilodus lineatus) fish species were offered as prey to P. corruscans in 300 L aquaria with three habitat complexity treatments (0%, 50% and 100% structure-covered). Prey survival was variable through time and among species (C. piquiti < O. niloticus < A. altiparanae < P. lineatus < I. punctatus), depending largely on species-specific prey behavior but also on prey size and morphological defenses. Habitat complexity did not directly affect P. corruscans piscivory but some prey species changed their microhabitat use and shoaling behavior among habitat treatments in predator’s presence. Pseudoplatystoma corruscans preyed preferentially on smaller individuals of those invasive species with weak morphological defensive features that persisted in a non-shoaling behavior. Overall, our results contrast with those in a companion experiment using a diurnal predator, suggesting that nocturnal piscivores preferentially prey on different (rather diurnal) fish species and are less affected by habitat complexity. Our findings suggest that recovering the native populations of P. corruscans might help controling some fish species introduced to the Paraná River basin, particularly C. piquiti and O. niloticus, whose parental care is expected to be weak or null at night