Evidence of the anomalous charge state 57Fe4+ in the nuclear decay of 57Co3+

The first observation of the elusive Fe4+ charge state coming from the nuclear decay of 57Co3+ has been found in the Mössbauer emission spectra of 57Co:La2Li0.5Co0.5O4. A Ti-doped sample was prepared in order to show that the Fe4+ fraction can be conveniently monitored. Both results were predicted on the basis of the electronic energy-band scheme of these oxides.

Schmidtea mediterranea phylogeography: an old species surviving on a few mediterranean islands?

Schmidtea mediterranea (Platyhelminthes, Tricladida, Continenticola) is found in scattered localities on a few islands and in coastal areas of the western Mediterranean. Although S. mediterranea is the object of many regeneration studies, little is known about its evolutionary history. Its present distribution has been proposed to stem from the fragmentation and migration of the Corsica-Sardinia microplate during the formation of the western Mediterranean basin, which implies an ancient origin for the species. To test this hypothesis, we obtained a large number of samples from across its distribution area. Using known and new molecular markers and, for the first time in planarians, a molecular clock, we analysed the genetic variability and demographic parameters within the species and between its sexual and asexual populations to estimate when they diverged. Results: A total of 2 kb from three markers (COI, CYB and a nuclear intron N13) was amplified from ~200 specimens. Molecular data clustered the studied populations into three groups that correspond to the west, central and southeastern geographical locations of the current distribution of S. mediterranea. Mitochondrial genes show low haplotype and nucleotide diversity within populations but demonstrate higher values when all individuals are considered. The nuclear marker shows higher values of genetic diversity than the mitochondrial genes at the population level, but asexual populations present lower variability than the sexual ones. Neutrality tests are significant for some populations. Phylogenetic and dating analyses show the three groups to be monophyletic, with the west group being the basal group. The time when the diversification of the species occurred is between ~20 and ~4 mya, although the asexual nature of the western populations could have affected the dating analyses. Conclusions: S. mediterranea is an old species that is sparsely distributed in a harsh habitat, which is probably the consequence of the migration of the Corsica-Sardinia block. This species probably adapted to temperate climates in the middle of a changing Mediterranean climate that eventually became dry and hot. These data also suggest that in the mainland localities of Europe and Africa, sexual individuals of S. mediterranea are being replaced by asexual individuals that are either conspecific or are from other species that are better adapted to the Mediterranean climate.

Comment on: Deuterium nuclear fusion at room temperature: A pertinent inequality on barrier penetration

In a recent letter, Rosen claims to justify ...

Migration Flows and Quality of Life in a Metropolitan Area: the Case of Barcelona-Spain

The phenomenon of human migration is certainly not new and it has been studied from a variety of perspectives. Yet, the attention on human migration and its determinant has not been fading over time as confirmed by recent contributions (see for instance Cushing and Poot 2004 and Rebhun and Raveh 2006). In this paper we combine the recent theoretical contributions by Douglas (1997) and Wall (2001) with the methodological advancements of Guimarães et al. (2000, 2003) to model inter-municipal migration flows in the Barcelona area. In order to do that, we employ two different types of count models, i.e. the Poisson and negative binomial and compare the estimations obtained. Our results show that, even after controlling for the traditional migration factors, QoL (measured with a Composite Index which includes numerous aspects and also using a list of individual variables) is an important determinant of short distance migration movements in the Barcelona area.

Nuclear magnetic resonance

This article reviews the principles and methods of nuclear magnetic resonance spectroscopy, and gives examples of applications carried out at ourFacility, which illustrate the capabilities of the technique.

Migration Determinants at a Local Level

This paper is about determinants of migration at a local level. We use data from Catalan municipalities in order to understand what explains migration patterns trying to identify whether they are main explained by amenities or economic characteristics. We distinguish three typologies of migration in terms of distance travelled: short-distance, short-medium-distance and medium-distance and we hypothesize whether migration determinants vary across these groups. Our results show that, effectively, there are some noticeable differences, suggest that spatial issues must be taken into account and provide some insights for future research. Keywords: population dynamics, spatial econometrics. JEL codes: C21, R0, R23

Polychlorinated trityl radicals for dynamic nuclear polarization: the role of chlorine nuclei

Polychlorinated trityl radicals bearing carboxylate substituents are water soluble persistent radicals that can be used for dynamic nuclear polarization. In contrast to other trityl radicals, the polarization mechanism differs from the classical solid effect. DFT calculations performed to rationalize this behaviour support the hypothesis that polarization is transferred from the unpaired electron to chlorine nuclei and from these to carbon by spin diffusion. The marked differences observed between neutral and anionic forms of the radical will be discussed.

A nuclear defect in the 4p16 region predisposes to multiple mitochondrial DNA deletions in families with Wolfram syndrome.

Wolfram syndrome is a progressive neurodegenerative disorder transmitted in an autosomal recessive mode. We report two Wolfram syndrome families harboring multiple deletions of mitochondrial DNA. The deletions reached percentages as high as 85-90% in affected tissues such as the central nervous system of one patient, while in other tissues from the same patient and from other members of the family, the percentages of deleted mitochondrial DNA genomes were only 1-10%. Recently, a Wolfram syndrome gene has been linked to markers on 4p16. In both families linkage between the disease locus and 4p16 markers gave a maximum multipoint lod score of 3.79 at theta = 0 (Pi<0.03) with respect to D4S431. In these families, the syndrome was caused by mutations in this nucleus-encoded gene which deleteriously interacts with the mitochondrial genome. This is the first evidence of the implication of both genomes in a recessive disease.

A nuclear defect in the 4p16 region predisposes to multiple mitochondrial DNA deletions in families with Wolfram syndrome.

Wolfram syndrome is a progressive neurodegenerative disorder transmitted in an autosomal recessive mode. We report two Wolfram syndrome families harboring multiple deletions of mitochondrial DNA. The deletions reached percentages as high as 85-90% in affected tissues such as the central nervous system of one patient, while in other tissues from the same patient and from other members of the family, the percentages of deleted mitochondrial DNA genomes were only 1-10%. Recently, a Wolfram syndrome gene has been linked to markers on 4p16. In both families linkage between the disease locus and 4p16 markers gave a maximum multipoint lod score of 3.79 at theta = 0 (Pi<0.03) with respect to D4S431. In these families, the syndrome was caused by mutations in this nucleus-encoded gene which deleteriously interacts with the mitochondrial genome. This is the first evidence of the implication of both genomes in a recessive disease.

Dessalinització nuclear : estudi preliminar per l'aplicació a Catalunya

Aquest document pretén donar a conèixer el concepte de dessalinització nuclear, determinar els avantatges i inconvenients a nivell ambiental, així com els costos econòmics i energètics que poden suposar. Podem definir dessalinització nuclear com una planta de dessalinització d’aigua marina que és alimentada pel seu complet funcionament per un reactor nuclear. La planta utilitza tant l’energia elèctrica que es produeix com l’energia calorífica retinguda en l’aigua que surt del reactor. S’ha estructurat el treball en tres parts. La primera és una anàlisi de quin és l’ús que se’n fa a nivell mundial de la tecnologia de dessalinització. S’ofereixen dades de la producció mundial d’aigua dolça a partir d’aquesta tecnologia, en quins països se’n fa més ús i perquè. També es defineixen els tipus de plantes de dessalinització que es poden construir. El segon apartat és un anàlisi històric i d’actualitat de la dessalinització nuclear mundial. S’analitza el perquè del desenvolupament d’aquesta tecnologia i s’estudien les necessitats hídriques que es podran tenir en un futur. Es planteja si aquesta tecnologia pot satisfer-les. S’estudien les onze plantes de dessalinització nuclear que han funcionat. El tercer apartat és un estudi de la possible transformació de les dues plantes dessalinitzadores catalanes en dessalinitzadores nuclears. Es fa un anàlisi de costos energètics i de producció, sense tenir en compte els d’instal·lació. També s’investiga els possibles impactes per contaminació radiològica que podria generar l’aigua produïda amb aquesta tecnologia.

Mitochondrial fusion is increased by the nuclear coactivator PGC-1beta

Background There is no evidence to date on whether transcriptional regulators are able to shift the balance between mitochondrial fusion and fission events through selective control of gene expression. Methodology/Principal Findings Here, we demonstrate that reduced mitochondrial size observed in knock-out mice for the transcriptional regulator PGC-1β is associated with a selective reduction in Mitofusin 2 (Mfn2) expression, a mitochondrial fusion protein. This decrease in Mfn2 is specific since expression of the remaining components of mitochondrial fusion and fission machinery were not affected. Furthermore, PGC-1β increases mitochondrial fusion and elongates mitochondrial tubules. This PGC-1β-induced elongation specifically requires Mfn2 as this process is absent in Mfn2-ablated cells. Finally, we show that PGC-1β increases Mfn2 promoter activity and transcription by coactivating the nuclear receptor Estrogen Related Receptor α (ERRα). Conclusions/Significance Taken together, our data reveal a novel mechanism by which mammalian cells control mitochondrial fusion. In addition, we describe a novel role of PGC-1β in mitochondrial physiology, namely the control of mitochondrial fusion mainly through Mfn2.

The Catalan migration to New York. A view from La Llumanera de Nova York (1874-1881)

The first issue of La Llumanera de Nova York came out in November 1874 and was not published until 1881. The challenge was certainly complicated: editing a newspaper in Catalan in New York, with the aim of influencing a group of potential readers who were distributed in the United States and, at the same time, become a medium that would bring the ideas of a new era, both from a political and cultural point of view

A global view of cross-border migration

This paper evaluates the global welfare impact of observed levels of migration using a quantitativemulti-sector model of the world economy calibrated to aggregate and firm-level data.Our framework features cross-country labor productivity differences, international trade, remittances,and a heterogeneous workforce. We compare welfare under the observed levels ofmigration to a no-migration counterfactual. In the long run, natives in countries that receiveda lot of migration -such as Canada or Australia- are better o due to greater product varietyavailable in consumption and as intermediate inputs. In the short run the impact of migrationon average welfare in these countries is close to zero, while the skilled and unskilled nativestend to experience welfare changes of opposite signs. The remaining natives in countries withlarge emigration flows -such as Jamaica or El Salvador- are also better off due to migration,but for a different reason: remittances. The welfare impact of observed levels of migration issubstantial, at about 5 to 10% for the main receiving countries and about 10% in countries withlarge incoming remittances. Our results are robust to accounting for imperfect transferabilityof skills, selection into migration, and imperfect substitution between natives and immigrants.

Coregulator Control of Androgen Receptor Action by a Novel Nuclear Receptor-Binding Motif

The androgen receptor (AR) is a ligand-activated transcription factor that is essential for prostate cancer development. It is activated by androgens through its ligand-binding domain (LBD), which consists predominantly of 11 α-helices. Upon ligand binding, the last helix is reorganized to an agonist conformation termed activator function-2 (AF-2) for coactivator binding. Several coactivators bind to the AF-2 pocket through conserved LXXLL or FXXLF sequences to enhance the activity of the receptor. Recently, a small compound-binding surface adjacent to AF-2 has been identified as an allosteric modulator of the AF-2 activity and is termed binding function-3 (BF-3). However, the role of BF-3 in vivo is currently unknown, and little is understood about what proteins can bind to it. Here we demonstrate that a duplicated GARRPR motif at the N terminus of the cochaperone Bag-1L functions through the BF-3 pocket. These findings are supported by the fact that a selective BF-3 inhibitor or mutations within the BF-3 pocket abolish the interaction between the GARRPR motif(s) and the BF-3. Conversely, amino acid exchanges in the two GARRPR motifs of Bag-1L can impair the interaction between Bag-1L and AR without altering the ability of Bag-1L to bind to chromatin. Furthermore, the mutant Bag-1L increases androgen-dependent activation of a subset of AR targets in a genome-wide transcriptome analysis, demonstrating a repressive function of the GARRPR/BF-3 interaction. We have therefore identified GARRPR as a novel BF-3 regulatory sequence important for fine-tuning the activity of the AR.