Dopamine restores reward prediction errors in old age.

Senescence affects the ability to utilize information about the likelihood of rewards for optimal decision-making. Using functional magnetic resonance imaging in humans, we found that healthy older adults had an abnormal signature of expected value, resulting in an incomplete reward prediction error (RPE) signal in the nucleus accumbens, a brain region that receives rich input projections from substantia nigra/ventral tegmental area (SN/VTA) dopaminergic neurons. Structural connectivity between SN/VTA and striatum, measured by diffusion tensor imaging, was tightly coupled to inter-individual differences in the expression of this expected reward value signal. The dopamine precursor levodopa (L-DOPA) increased the task-based learning rate and task performance in some older adults to the level of young adults. This drug effect was linked to restoration of a canonical neural RPE. Our results identify a neurochemical signature underlying abnormal reward processing in older adults and indicate that this can be modulated by L-DOPA

Calçots i calçotades : compte amb els gossos!

Tot i les innegables particularitats de cultiu i gastronòmiques que fan dels calçots un àpat de temporada molt valorat, saludable, distintiu i estimat entre els catalans, no s'hauria d'oblidar que continuen sent cebes. I és que encara hi ha força persones que desconeixen que cebes, alls i altres representants de la família de les liliàcies, que nosaltres mengem habitualment sense problemes, poden resultar tòxics i fins i tot letals per molts animals domèstics, entre els que es troben els gossos i els gats. En les populars calçotades, on moltes vegades estem acompanyats dels nostres gossos, els propietaris haurien de vigilar de no deixar a l'abast dels animals els calçots o restes d'ells, ja que el seu gust dolcenc pot resultar atractiu per alguns individus afamats o curiosos.A pesar de las innegables particularidades de cultivo y gastronómicas que hacen de los calçots (cebolletas tiernas) una comida de temporada muy valorada, saludable, distintiva y querida entre los catalanes, no se tendría que olvidar que continúan siendo cebollas. Y es que todavía hay bastantes personas que desconocen que cebollas, ajos y otros representantes de la familia de las liliácias, que nosotros comemos habitualmente sin problemas, pueden resultar tóxicos e incluso letales para muchos animales domésticos, entre los que se encuentran los perros y los gatos. En las populares calçotadas, donde muchas veces estamos acompañados de nuestros perros, los propietarios tendrían que vigilar de no dejar al alcance de los animales los calçots o restos de ellos, ya que su sabor dulzón puede resultar atractivo para algunos individuos hambrientos o curiosos

Las visitas etnográficas a los hogares de los estudiantes como estrategia para crear lazos de confianza entre docentes y familias

L’aproximació dels Fons de coneixement es basa en la premissa segons la qual totes les famílies, més enllà de la seva condició i peculiaritat lingüística, religiosa, econòmica, ètnica, disposen de sabers i habilitats acumulats a partir de les seves particulars pràctiques i experiències vitals tals com les experiències professionals. El repte pedagògic consisteix en incorporar aquests recursos al currículum escolar i les pràctiques formals d’ensenyança- aprenentatge. En aquest sentit, els docents visiten algunes de les llars dels seus estudiants amb l’objectiu d’aprendre de les seves experiències i dissenyar activitats educatives escolars a partir de la incorporació d’alguns dels recursos intel·lectuals i culturals prèviament identificats. En aquest article il·lustrem aquesta tesis a partir de la descripció d’una experiència implementada en un centre d’educació pública de Banyoles (Catalunya, España). Específicament, es descriuen cinc visites realitzades per part dels docents a algunes llars d’alguns dels seus estudiants. Es discuteixen els beneficis d’aquestes visites en la potencial millora de les relacions entre docents (escola) i famílie

Structural integrity of the substantia nigra and subthalamic nucleus predicts flexibility of instrumental learning in older-age individuals

Flexible instrumental learning is required to harness the appropriate behaviors to obtain rewards and to avoid punishments. The precise contribution of dopaminergic midbrain regions (substantia nigra/ventral tegmental area [SN/VTA]) to this form of behavioral adaptation remains unclear. Normal aging is associated with a variable loss of dopamine neurons in the SN/VTA. We therefore tested the relationship between flexible instrumental learning and midbrain structural integrity. We compared task performance on a probabilistic monetary go/no-go task, involving trial and error learning of: "go to win," "no-go to win," "go to avoid losing," and "no-go to avoid losing" in 42 healthy older adults to previous behavioral data from 47 younger adults. Quantitative structural magnetization transfer images were obtained to index regional structural integrity. On average, both some younger and some older participants demonstrated a behavioral asymmetry whereby they were better at learning to act for reward ("go to win" > "no-go to win"), but better at learning not to act to avoid punishment ("no-go to avoid losing" > "go to avoid losing"). Older, but not younger, participants with greater structural integrity of the SN/VTA and the adjacent subthalamic nucleus could overcome this asymmetry. We show that interindividual variability among healthy older adults of the structural integrity within the SN/VTA and subthalamic nucleus relates to effective acquisition of competing instrumental responses

Effectiveness of a multiple intervention strategy for the control of the tiger mosquito (Aedes albopictus) in Spain

This study was undertaken to evaluate the effectiveness of four complementary and combined strategies to minimize the presence of the invasive mosquito Aedes albopictus, firmly established in Sant Cugat del Vallès, Catalonia, Spain. A quasi-experimental design including six neighbourhoods was performed in 2008-2009. The abundance of mosquitoes was monitored through ovitraps. The multiple intervention strategy consisted of four actions: source reduction; larvicide treatments (Bacillus thuringiensis israelensis and diflubenzuron); adulticide treatments (alfacipermetrin); and cleaning up uncontrolled landfills. The results showed the number of eggs significantly reduced in the areas with intervention. In 2008, the accumulate median of eggs was 175 and 272 in the intervention and control areas, respectively. In 2009, these medians were 884 and 1668 eggs. In total, 3104 households were visited and 683 people were interviewed. During inspections inside the houses, the cooperation of citizens in 2009 was 16% higher than that in 2008 (95% CI 13-19%). These findings suggest that the strategy was effective in reducing the number of eggs. Citizen cooperation, an essential factor for success, was observed through a high level of collaboration by the home owners, who allowed entry into their private dwellings. This study could be a model for controlling the populations of Ae. albopictus in the Mediterranean region. © 2011 Royal Society of Tropical Medicine and Hygiene.Peer Reviewe

Intoxicación por paraquat : revisión

En este trabajo se revisan las características de la intoxicación por paraquat, y se presentan 15 casos clínicos altamente sugestivos de dicha intoxicación. El paraquat es un compuesto bipiridilo ampliamente usado en agricultura. Debido a que la intoxicación tiene efectos progresivos e irreversibles, es importante conocer la posibilidad de acceso al tóxico, pero ello muchas veces no es posible. Dado que el diagnóstico muchas veces es difícil para el clínico, la observación de un distress respiratorio severo, que empeora progresivamente en ausencia de signos radiológicos significativos, justifica un diagnóstico presuntivo de intoxicación por paraquat.In this work, we review the characteristics of paraquat poisoning and compare it with 15 clinical cases highly suggestive of this poisoning. Paraquat is a bipyridzlium compound, widely used as a contact herbicide in agriculture. Because the poisoning has progressive and irreversible effects, it's important to know a definitive history of acces to paraquat, but it 's difficult. Because the problem of diagnosis remains difficult for the practitioner; a clinical features of progressively worsening respiratory distress, in absence of radiógraphic demonstration of adequate cause of dyspnoea, justify a pressumptive diagnosis of paraquat poisoning

Increased mutation and gene conversion within human segmental duplications

Single-nucleotide variants (SNVs) in segmental duplications (SDs) have not been systematically assessed because of the limitations of mapping short-read sequencing data1,2. Here we constructed 1:1 unambiguous alignments spanning high-identity SDs across 102 human haplotypes and compared the pattern of SNVs between unique and duplicated regions3,4. We find that human SNVs are elevated 60% in SDs compared to unique regions and estimate that at least 23% of this increase is due to interlocus gene conversion (IGC) with up to 4.3 megabase pairs of SD sequence converted on average per human haplotype. We develop a genome-wide map of IGC donors and acceptors, including 498 acceptor and 454 donor hotspots affecting the exons of about 800 protein-coding genes. These include 171 genes that have ‘relocated’ on average 1.61 megabase pairs in a subset of human haplotypes. Using a coalescent framework, we show that SD regions are slightly evolutionarily older when compared to unique sequences, probably owing to IGC. SNVs in SDs, however, show a distinct mutational spectrum: a 27.1% increase in transversions that convert cytosine to guanine or the reverse across all triplet contexts and a 7.6% reduction in the frequency of CpG-associated mutations when compared to unique DNA. We reason that these distinct mutational properties help to maintain an overall higher GC content of SD DNA compared to that of unique DNA, probably driven by GC-biased conversion between paralogous sequences5,6.We thank T. Brown for help in editing this manuscript, P. Green for valuable suggestions, and R. Seroussi and his staff for their generous donation of time and resources. This work was supported in part by grants from the US National Institutes of Health (NIH 5R01HG002385, 5U01HG010971 and 1U01HG010973 to E.E.E.; K99HG011041 to P.H.; and F31AI150163 to W.S.D.). W.S.D. was supported in part by a Fellowship in Understanding Dynamic and Multi-scale Systems from the James S. McDonnell Foundation. E.E.E. is an investigator of the Howard Hughes Medical Institute (HHMI). This article is subject to HHMI’s Open Access to Publications policy. HHMI laboratory heads have previously granted a nonexclusive CC BY 4.0 licence to the public and a sublicensable licence to HHMI in their research articles. Pursuant to those licences, the author-accepted manuscript of this article can be made freely available under a CC BY 4.0 licence immediately on publication.Peer Reviewed"Article signat per 19 autors/es: Mitchell R. Vollger, Philip C. Dishuck, William T. Harvey, William S. DeWitt, Xavi Guitart, Michael E. Goldberg, Allison N. Rozanski, Julian Lucas, Mobin Asri, Human Pangenome Reference Consortium, Katherine M. Munson, Alexandra P. Lewis, Kendra Hoekzema, Glennis A. Logsdon, David Porubsky, Benedict Paten, Kelley Harris, PingHsun Hsieh & Evan E. Eichler"Postprint (published version

Alto contenido de metales en el molusco Pinna nobilis en el Archipiélago Balear (Mediterráneo occidental) y una revisión de las concentraciones en bivalvos marinos (Pinnidae)

Summary: Concentrations of metals (Cd, Cu, Hg, Pb and Zn) in the marine bivalve Pinna nobilis at several coastal locations of Majorca and the Cabrera Islands (Mediterranean Sea) were investigated. The elevated concentrations of metals found in the soft tissues of P. nobilis indicate high bioaccumulation factors. All concentrations and the calculated metal pollution index showed significant differences between sites, with particularly high concentrations in the Cabrera Archipelago, a marine protected area (MPA). The datasets were evaluated with the limited information published in the literature for Pinnidae species worldwide. In benthic P. nobilis, concentrations of Cd, Cu and Zn are more than 30 times higher and Hg and Pb concentrations are 4 and 7 times higher, respectively, than concentrations in other bivalve species, such as Mytilus galloprovincialis (Mytilidae). These observations from species inhabiting nearby ecological habitats of the coastal environment (Pinnidae vs. Mytilidae) are also discussed in the context of current marine monitoring strategies and assessmentsResumen: Se investigaron las concentraciones de metales (Cd, Cu, Hg, Pb y Zn) en el bivalvo marino Pinna nobilis en diferentes localidades costeras de las Islas de Mallorca y Cabrera (Mar Mediterráneo). Las elevadas concentraciones de metales que se encontraron en los tejidos blandos de P. nobilis revelaron una elevada bioacumulación. Las concentraciones de metales estudiadas, así como el índice de contaminación por metales (ICM) mostraron diferencias significativas entre los sitios, con concentraciones particularmente altas en el archipiélago de Cabrera, un área marina protegida (AMP). Se realizó una revisión bibliográfica de la escasa información publicada sobre las especies de la familia Pinnidae a nivel mundial. En comparación con otras especies de bivalvos, como Mytilus galloprovincialis (Mytilidae), la especie bentónica P. nobilis presentó concentraciones más de 30 veces superiores para Cd, Cu y Zn; y hasta 4 y 7 veces para Hg y Pb, respectivamente. La información recabada sobre estas especies que habitan en ecosistemas costeros (Pinnidae vs. Mytilidae) es discutida en el contexto de las actuales estrategias marinas de seguimiento y evaluaciónVersión del editor1,006

Assesing heavy metals in the marine bivalve Pinna nobilis in the Balearic Islands (western Mediterranean)

Heavy metals (Cd, Cu, Hg, Pb and Zn) concentration were determined in the marine bivalve Pinna nobilis along the Balearic Islands, comparing a protected area with two sites with strong anthropogenic influence. Analyses of Cabrera and Mallorca indicated that heavy metal concentration were generally higher in the most of samples, specially in Santa Maria bay (Cabrera, MPA), and Magaluf (Mallorca, with strong anthropogenic influence). Pinna nobilis appears to efficiently bioaccumulate heavy metals exhibiting large differences in a range of anthropic scenarios. The results on P. nobilis metal accumulation show that the concentrations decrease according to order: Zn > Cu >Pb> Cd > H