81 research outputs found

    Cadmium accumulation and interactions with zinc, copper, and manganese, analysed by ICP-MS in a long-term Caco-2 TC7 cell model

    Get PDF
    The influence of long-term exposure to cadmium (Cd) on essential minerals was investigated using a Caco-2 TC7 cells and a multi-analytical tool: microwave digestion and inductively coupled plasma mass spectrometry. Intracellular levels, effects on cadmium accumulation, distribution, and reference concentration ranges of the following elements were determined: Na, Mg, Ca, Cr, Fe, Mn, Co, Ni, Cu, Zn, Mo, and Cd. Results showed that Caco-2 TC7 cells incubated long-term with cadmium concentrations ranging from 0 to 10 lmol Cd/l for 5 weeks exhibited a significant increase in cadmium accumulation. Furthermore, this accumulation was more marked in cells exposed long-term to cadmium compared with controls, and that this exposure resulted in a significant accumulation of copper and zinc but not of the other elements measured. Interactions of Cd with three elements: zinc, copper, and manganese were particularly studied. Exposed to 30 lmol/l of the element, manganese showed the highest inhibition and copper the lowest on cadmium intracellular accumulation but Zn, Cu, and Mn behave differently in terms of their mutual competition with Cd. Indeed, increasing cadmium in the culture medium resulted in a gradual and significant increase in the accumulation of zinc. There was a significant decrease in manganese from 5 lmol Cd/l exposure, and no variation was observed with copper. Abbreviation: AAS – Atomic absorption spectrometry; CRM– Certified reference material; PBS – Phosphate buffered saline without calcium and magnesium; DMEM – Dubelcco’s modified Eagle’s medium

    DynACof, a model fro growth, yield, carbon, water, energy balances and ecosystem services of Coffea in agroforestry

    Full text link
    Agroforestry systems (AFS) are complex to model mainly due to the high spatial variability induced by the shade trees. Recently, the microclimate and lighf heterogeneity issue in AFS has been addressed using the 30 ecophysiological process-based model MAESPA (Charbonnier et al., 2013; Vezy et al., 2018). MAESPA surpassed the classical sun/shade dichotomy in AFS (Charbonnier et al., 2014) and provided continuous maps of e.g. available light, light-use~ fficiency and canopy temperature within Coffea Agroforestry Systems (GAS). A step further was to design a crop model for Coffea grown under agroforestry that would benefit from this continuum to estimate ecosystem services on the long term and under climate change scenarios. We designed DynA_Cof, a new process-based growth and yield model to compute plot-scale net and gross primary productivity, carbon allocation, growth, yield, energy, and water balance of GAS according to shade tree species and management, while accounting for fine-scale spatial effects using MAESPA metamodels (Figure 1). DynA_Cof satisfactorily simulated the daily plot-scale gross primary productivity (RMSE= 1.69 gc m-2 d-1 on 1562 days) and the energy and water balances (RMSE: AET = 0.63 mm d-1 , H= 1.27 MJ m-2 d-1, Rn= 1.98 MJ m-2 d-1) compared to measurements from an eddy-flux tower in Aquiares (Costa Rica) and also the NPP for above and below-ground organs, coffee bean yield and shade tree wood production compared to a comprehensive database from this site

    Detection and Attribution of Temperature Changes in the Mountainous Western United States

    Get PDF
    Large changes in the hydrology of the western United States have been observed since the mid-twentieth century. These include a reduction in the amount of precipitation arriving as snow, a decline in snowpack at low and midelevations, and a shift toward earlier arrival of both snowmelt and the centroid (center of mass) of streamflows. To project future water supply reliability, it is crucial to obtain a better understanding of the underlying cause or causes for these changes. A regional warming is often posited as the cause of these changes without formal testing of different competitive explanations for the warming. In this study, a rigorous detection and attribution analysis is performed to determine the causes of the late winter/early spring changes in hydrologically relevant temperature variables over mountain ranges of the western United States. Natural internal climate variability, as estimated from two long control climate model simulations, is insufficient to explain the rapid increase in daily minimum and maximum temperatures, the sharp decline in frost days, and the rise in degree-days above 0°C (a simple proxy for temperature-driven snowmelt). These observed changes are also inconsistent with the model-predicted responses to variability in solar irradiance and volcanic activity. The observations are consistent with climate simulations that include the combined effects of anthropogenic greenhouse gases and aerosols. It is found that, for each temperature variable considered, an anthropogenic signal is identifiable in observational fields. The results are robust to uncertainties in model-estimated fingerprints and natural variability noise, to the choice of statistical downscaling method, and to various processing options in the detection and attribution method.California Energy Commission///Estados UnidosU.S. Department of Energy/[DE-AC52-07NA27344]//Estados UnidosUniversidad de Costa Rica//UCR/Costa RicaUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigaciones Geofísicas (CIGEFI

    Attribution of Declining Western U.S. Snowpack to Human Effects

    Get PDF
    Observations show snowpack has declined across much of the western United States over the period 1950–99. This reduction has important social and economic implications, as water retained in the snowpack from winter storms forms an important part of the hydrological cycle and water supply in the region. A formal model-based detection and attribution (D–A) study of these reductions is performed. The detection variable is the ratio of 1 April snow water equivalent (SWE) to water-year-to-date precipitation (P), chosen to reduce the effect of P variability on the results. Estimates of natural internal climate variability are obtained from 1600 years of two control simulations performed with fully coupled ocean–atmosphere climate models. Estimates of the SWE/P response to anthropogenic greenhouse gases, ozone, and some aerosols are taken from multiple-member ensembles of perturbation experiments run with two models. The D–A shows the observations and anthropogenically forced models have greater SWE/P reductions than can be explained by natural internal climate variability alone. Model-estimated effects of changes in solar and volcanic forcing likewise do not explain the SWE/P reductions. The mean model estimate is that about half of the SWE/P reductions observed in the west from 1950 to 1999 are the result of climate changes forced by anthropogenic greenhouse gases, ozone, and aerosols.Lawrence Livermore National Laboratory///Estados UnidosScripps Institution of Oceanography//SIO/Estados UnidosMinistry of Education, Culture, Sports, Science and Technology///JapónCalifornia Energy Commission///Estados UnidosProgram of Climate Model Diagnosis and Intercomparison/[DOE-W-7405-ENG-48]/PCMDI/Estados UnidosUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigaciones Geofísicas (CIGEFI

    Low-frequency and rare exome chip variants associate with fasting glucose and type 2 diabetes susceptibility

    Get PDF
    Fasting glucose and insulin are intermediate traits for type 2 diabetes. Here we explore the role of coding variation on these traits by analysis of variants on the HumanExome BeadChip in 60,564 non-diabetic individuals and in 16,491 T2D cases and 81,877 controls. We identify a novel association of a low-frequency nonsynonymous SNV in GLP1R (A316T; rs10305492; MAF=1.4%) with lower FG (β=−0.09±0.01 mmol l−1, P=3.4 × 10−12), T2D risk (OR[95%CI]=0.86[0.76–0.96], P=0.010), early insulin secretion (β=−0.07±0.035 pmolinsulin mmolglucose−1, P=0.048), but higher 2-h glucose (β=0.16±0.05 mmol l−1, P=4.3 × 10−4). We identify a gene-based association with FG at G6PC2 (pSKAT=6.8 × 10−6) driven by four rare protein-coding SNVs (H177Y, Y207S, R283X and S324P). We identify rs651007 (MAF=20%) in the first intron of ABO at the putative promoter of an antisense lncRNA, associating with higher FG (β=0.02±0.004 mmol l−1, P=1.3 × 10−8). Our approach identifies novel coding variant associations and extends the allelic spectrum of variation underlying diabetes-related quantitative traits and T2D susceptibility. Both rare and common variants contribute to the aetiology of complex traits such as type 2 diabetes (T2D). Here, the authors examine the effect of coding variation on glycaemic traits and T2D, and identify low-frequency variation in GLP1R significantly associated with these traits

    A database of freshwater fish species of the Amazon Basin

    Get PDF
    The Amazon Basin is an unquestionable biodiversity hotspot, containing the highest freshwater biodiversity on earth and facing off a recent increase in anthropogenic threats. The current knowledge on the spatial distribution of the freshwater fish species is greatly deficient in this basin, preventing a comprehensive understanding of this hyper-diverse ecosystem as a whole. Filling this gap was the priority of a transnational collaborative project, i.e. the AmazonFish project - https://www.amazon-fish.com/. Relying on the outputs of this project, we provide the most complete fish species distribution records covering the whole Amazon drainage. The database, including 2,406 validated freshwater native fish species, 232,936 georeferenced records, results from an extensive survey of species distribution including 590 different sources (e.g. published articles, grey literature, online biodiversity databases and scientific collections from museums and universities worldwide) and field expeditions conducted during the project. This database, delivered at both georeferenced localities (21,500 localities) and sub-drainages grains (144 units), represents a highly valuable source of information for further studies on freshwater fish biodiversity, biogeography and conservation

    Speech rhythm in language interaction : benefit of a musical rhythmic training in deaf children

    No full text
    La musique et la parole possèdent toutes deux un degré d’organisation temporelle i.e. de régularité dans le temps. Les stimuli de nature rythmique ont la particularité de pouvoir être anticipés par le cerveau et des études en linguistique et neurosciences ont montré que plus le cerveau est capable d’anticiper les évènements auditifs, meilleure est la qualité du traitement des stimuli. Les enfants sourds, bien que bénéficiant d’un input auditif de plus en plus précis grâce aux implants cochléaires et d’une prise en charge précoce, n’atteignent pas des niveaux de langage homogènes et souffrent de difficultés de perception en milieux bruyants ou lors de conversations. La situation conversationnelle présente un contexte complexe, nécessitant l’activation de la voie audio-motrice pour anticiper et s’adapter aux variations de la parole de son interlocuteur notamment au niveau temporel. Dans ce travail de thèse, nous avons cherché à analyser, grâce à des mesures électrophysiologiques et comportementales, si un entrainement rythmique actif de 30 minutes, pouvait avoir un effet sur les capacités de perception et d’accommodation temporelles de l’enfant sourd dans une tâche de dénomination en alternance avec un partenaire virtuel. Nous avons également testé les capacités rythmiques de ces enfants à différents niveaux de complexités. Les résultats montrent que les enfants sourds souffrent de difficultés à structurer les événements acoustiques selon différent niveaux de hiérarchie mais qu’un entrainement rythmique de 30 minutes versus une stimulation auditive, permet d’améliorer leurs compétences de perception et de production temporelles de la parole dans une situation d’interaction.Music and speech both possess a certain degree of temporal organization i.e. a certain degree of regularity across time. Studies in linguistics and neuroscience have shown that the brain can extract regularities and use them to anticipate the forthcoming stimuli. It is furthermore established that the better the brain is able to anticipate auditory events, the better the quality of stimulus processing. Deaf children benefit from more and more precise auditory inputs due to advances in cochlear implants development, together with early rehabilitation interventions. However, a great majority of them do not achieve consistent language levels and have strong difficulties in noisy environments or conversations. The conversational situation presents a complex context, requiring the activation of the audio-motor path to anticipate and adapt to the variations of the speech of its interlocutor notably at the temporal level. In this thesis work, we have investigated the temporal perception and accommodation capacities of deaf children in a naming task alternating with a virtual partner, at both behavioral and electrophysiological levels. We have also tested whether an active rhythmic training lasting 30 minutes, could enhance these conversational abilities. Then, we have investigated the rhythmic abilities of these children at different levels complexities. The results show that deaf children suffer from difficulties in structuring acoustic events according to different levels of hierarchy but that a rhythmic training of 30 minutes versus an auditory stimulation, makes it possible to improve their skills of temporal perception and production of speech in a situation of interaction

    Eufonía : didáctica de la música

    No full text
    Resumen basado en el de la publicaciónSe analiza como la práctica musical afecta a los procesos perceptivos y cognitivos necesario para el tratamiento del lenguaje. Música y lenguaje comparten características similares y redes neuronales. Esto dota a los músicos de una facilitación en el tratamiento del lenguaje que va desde el conocimiento más rápido y preciso de sonidos hasta el aprendizaje de una lengua extranjera.Biblioteca de Educación del Ministerio de Educación y Formación Profesional; Calle San Agustín, 5 - 3 Planta; 28014 Madrid; Tel. +34917748000; [email protected]

    The effect of speech degradation on the ability to track and predict turn structure in conversation

    No full text
    Conversation represents a considerable amount of the daily language usage and plays an important role in language acquisition. In conversation, listeners simultaneously process their interlocutor’s turn and prepare their own next turn. As such the turn-taking dynamics heavily relies on prediction. In other words, listeners avail prior knowledge to constrain both speech perception and production. Here we explored the relation between prediction and comprehension while watching two interlocutors having a conversation. We capitalize on gaze switch as a proxy of predictive behaviour to class dialogue turns as more or less well predicted and explore how this affects dialogue comprehension. Moreover, we study the extent to which speech degradation, by increasing the global uncertainty of the context, affects the relation between predictions, brain correlates of prediction errors (N400) and global comprehension. Results show that 1) listeners direct gaze to the current speaker, in particular in challenging conditions, 2) gaze behaviour possibly affects the semantic processing of the upcoming turn (N400), 3) participants with a more efficient gaze predictive behaviour better solve semantic uncertainties at the turn onset, in particular in the most challenging listening condition. Our findings contribute to a better understanding of the relation between predictions, neural predictions errors and speech comprehension under challenging conditions

    Speak on time! Effects of a musical rhythmic training on children with hearing loss

    No full text
    International audienceThis study investigates temporal adaptation in speech interaction in children with normal hearing and in children with cochlear implants (CIs) and/or hearing aids (HAs). We also address the ques-tion of whether musical rhythmic training can improve these skills in children with hearing loss (HL). Children named pictures presented on the screen in alternation with a virtual partner. Alterna-tion rate (fast or slow) and the temporal predictability (match vs mismatch of stress occurrences) were manipulated. One group of children with normal hearing (NH) and one with HL were tested. The latter group was tested twice: once after 30 minutes of speech therapy and once after 30 minutes of musical rhythmic training. Both groups of children (NH and with HL) can adjust their speech production to the rate of alternation of the virtual partner. Moreover, while children with normal hearing benefit from the temporal regularity of stress occurrences, children with HL become sensitive to this manipulation only after rhythmic training. Rhythmic training may help children with HL to structure the temporal flow of their verbal interactions
    corecore