2,227 research outputs found

    Linking brain and behaviour in motor sequence learning tasks

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    Sequence learning is a fundamental brain function that allows for the acquisition of a wide range of skills. Unlearned movements become faster and more accurate with repetition, due to a process called prediction. Predictive behaviour observed in the eye and hand compensates for the inherent temporal delays in the sensorimotor system and allows for the generation of motor actions prior to visual guidance. We investigated predictive behaviour and the brain areas associated with this processing in (i) the oculomotor system (Eye Only (EO): saccade vs. pursuit) and (ii) during eye and hand coordination (EH). Participants were asked to track a continuous moving target in predictable or random sequence conditions. EO and EH experiments were divided into 1) EO behavioural and 2) EO fMRI findings, and 3) EH behavioural and 4) EH fMRI findings. Results provide new insights into how individuals predict when learning a sequence of target movements, which is not limited to short--‐term memory capacities and that forms a link between shorter and longer--‐term motor skill learning. Furthermore, brain imaging results revealed distinct levels of activation within and between brain areas for repeated and randomized sequences that reflect the distinct timing threshold and adaptation levels needed for the two oculomotor systems. EH results revealed similar predictive behaviour in the eye and the hand, but also demonstrated enhanced coupling between the two motor systems during sequence learning. EH brain imaging findings have provided novel insights into the brain areas involved in coordination, and those areas more associated with sequence learning. Results show evidence of common predictive networks used for the eye and hand during learning

    Phosphonopropionic acid coating as platform for the efficient grafting of (bio)molecules to hydroxyapatite nanoparticles

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    A new synthesis strategy intended to increase apatite available surface groups for the covalent functionalization with (bio)molecules was developed. To that purpose, hydroxyapatite nanoparticles (Ap) were synthesized and terminated with 3-phosphonopropionic acid (PPA) yielding Ap with surface bound propionic acid through P-C bonds (ApCOO– ). A thorough characterization of ApCOO– by IR spectroscopy, transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, thermal gravimetric analysis, and specific surface area determination (BET model), strongly support an efficient surface grafting of the organophosphonates and a hydroxyapatite core of similar morphology and phase composition to that of synthetic Ap. ApCOO– was able to adsorb bovine serum albumin (BSA) up to 0.20 mg m–2 and showed no cytotoxic effects towards Balb/C 3T3 cells. ApCOO– abundant carboxyl surface groups facilitated the particles grafting through stable amide bonds with basic fuchsin (Fu) and tyrosine (Ty) yielding well covered surfaces. Fu-bound hydroxyapatite powders showed ten times stronger fluorescence than free Fu in ethanol, thus expanding the potential uses of Ap as fluorescent sensors in the red region of the visible spectrum. On the other hand, Ty-bound hydroxyapatite powders showed negative surface charges and high stability of the coating in aqueous suspensions. In contrast, Ty-physically adsorbed hydroxyapatite powders rendered positively charged surfaces and an unstable coating.Fil: Dittler, Maria Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Rodriguez, Hernan Bernardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Cippollone, Mariano. YPF - Tecnología; ArgentinaFil: Grillo, Claudia Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Gonzalez, Monica Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; Argentin

    A near-infrared study of the multi-phase outflow in the type-2 quasar J1509+0434

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    Based on new near-infrared spectroscopic data from the instrument EMIR on the 10.4 m Gran Telescopio Canarias (GTC) we report the presence of an ionized and warm molecular outflow in the luminous type-2 quasar J150904.22+043441.8 (z = 0.1118). The ionized outflow is faster than its molecular counterpart, although the outflow sizes that we derive for them are consistent within the errors (1.34±0.18 kpc and 1.46±0.20 kpc respectively). We use these radii, the broad emission-line luminosities and in the case of the ionized outflow, the density calculated from the trans-auroral [OII] and [SII] lines, to derive mass outflow rates and kinetic coupling efficiencies. Whilst the ionized and warm molecular outflows represent a small fraction of the AGN power (≤0.033% and 0.0001% of Lbol respectively), the total molecular outflow, whose mass is estimated from an assumed warm-to-cold gas mass ratio of 6× 10−5, has a kinetic coupling efficiency of ∼1.7%Lbol. Despite the large uncertainty, this molecular outflow represents a significant fraction of Lbol and it could potentially have a significant impact on the host galaxy. In addition, the quasar spectrum reveals bright and patchy narrow Paα emission extending out to 4″ (8 kpc) South-East and North-West from the active nucleus.Includes Horizon 202

    Differences between CO- and calcium triplet-derived velocity dispersions in spiral galaxies: evidence for central star formation?

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    We examine the stellar velocity dispersions (sigma) of a sample of 48 galaxies, 35 of which are spirals, from the Palomar nearby galaxy survey. It is known that for ultra-luminous infrared galaxies (ULIRGs) and merger remnants thesigma derived from the near-infrared CO band-heads is smaller than that measured from optical lines, while no discrepancy between these measurements is found for early-type galaxies. No such studies are available for spiral galaxies - the subject of this paper. We used cross-dispersed spectroscopic data obtained with the Gemini Near-Infrared Spectrograph (GNIRS), with spectral coverage from 0.85 to 2.5um, to obtain sigma measurements from the 2.29 μ\mum CO band-heads (sigma_{CO}), and the 0.85 um calcium triplet (sigma_{CaT}). For the spiral galaxies in the sample, we found that sigma_{CO} is smaller than sigma_{CaT}, with a mean fractional difference of 14.3%. The best fit to the data is given by sigma_{opt} = (46.0+/-18.1) + (0.85+/-0.12)sigma_{CO}. This "sigma discrepancy" may be related to the presence of warm dust, as suggested by a slight correlation between the discrepancy and the infrared luminosity. This is consistent with studies that have found no sigma-discrepancy in dust-poor early-type galaxies, and a much larger discrepancy in dusty merger remnants and ULIRGs. That sigma_{CO}$ is lower than sigma_{opt} may also indicate the presence of a dynamically cold stellar population component. This would agree with the spatial correspondence between low sigma_{CO} and young/intermediate-age stellar populations that has been observed in spatially-resolved spectroscopy of a handful of galaxies.Comment: Published in MNRAS, 446, 282

    The cross-regulation between h1 and h2 histamine receptors modulates the behavior of h2 receptor blockers

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    Histamine modulates severalbiological processes, including allergy and gastric acid secretion, through H1and H2 receptors (H1R, H2R). H2R blockers are mainlyused to treat gastrointestinaldisorders, such as gastric acid secretion and there is much interest on theirrepositioning for other pathologies. Thus, deepunderstanding of theirmechanisms of action is needed. We have previously described that H1R and H2Ragonists induce the receptor?s co-internalization andcross-desensitization. We havealso reported that H2R blockers lead to desensitization and internalization ofH2 receptor.The aim of this work was tostudy the capacity of H2R blockers (cimetidine, ranitidine and famotidine) toinduce the H1R cross-desensitization and how thismechanism affects the behaviorof H2R blockers. In this way, we used promonocytic U937 cells (endogenouslyexpressing H1R and H2R), PMA-differentiated U937cells and HEK293 cellstransiently transfected with one or both receptors.Fil: Díaz Nebreda, Antonela. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Sahores, Ana. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Zappia, Carlos Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Farmacológicas. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Investigaciones Farmacológicas; ArgentinaFil: Rodriguez Gonzalez, Angela. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Burghi, Valeria. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Farmacológicas. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Investigaciones Farmacológicas; ArgentinaFil: Monczor, Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Farmacológicas. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Investigaciones Farmacológicas; ArgentinaFil: Davio, Carlos Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Farmacológicas. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Investigaciones Farmacológicas; ArgentinaFil: Fernandez, Natalia Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Farmacológicas. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Investigaciones Farmacológicas; ArgentinaFil: Shayo, Carina Claudia. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaLXIII Reunión Anual de la Sociedad Argentina de Investigación Clínica; LXVI Reunión Anual de la Sociedad Argentina de Inmunología y Reunión Anual de la Sociedad Argentina de Fisiología.Mar del PlataArgentinaSociedad Argentina de Investigación ClínicaSociedad Argentina de InmunologíaSociedad Argentina de Fisiologí

    O nutritionDay na América Latina

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    El nutritionDay es una iniciativa de la Sociedad Europea de Nutrición Clínica y Metabolismo (ESPEN) y la Universidad de Viena, que desde 2006 pretende luchar contra la desnutrición hospitalaria(1). A través de la recolección de información en un día, busca también mejorar el cuidado nutricional de los pacientes hospitalizados y generar conciencia sobre la importancia de la desnutrición asociada con la enfermedad

    Involvement of histamine H1 and H2 receptor inverse agonists in receptor's crossregulation

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    Histamine [2-(4-Imidazolyl)-ethylamine] modulates different biological processes, through histamine H1 and H2 receptors, and their respective blockers are widely used in treating allergic and gastric acid-related disorders. Histamine H1 and H2 receptor crossdesensitization and cointernalization induced by its agonists have been previously described. In this study, we show how this crosstalk determines the response to histamine H1 and H2 receptor inverse agonists and how histamine H1 and H2 receptor inverse agonists interfere with the other receptor's response to agonists. By desensitization assays we demonstrate that histamine H1 and H2 receptor inverse agonists induce a crossregulation between both receptors. In this sense, the histamine H1 receptor inverse agonists desensitize the cAMP response to amthamine, a histamine H2 receptor agonist. In turn, histamine H2 receptor inverse agonists interfere with histamine H1 receptor signaling. We also determine that the crossdesensitization induced by histamine H1 or H2 receptor agonists alters the histamine inverse agonists receptor response: activation of histamine H1 receptor affects cAMP response induced by histamine H2 receptor inverse agonists, whereas histamine H2 receptor agonist induces a negative regulation on the anti-inflammatory response of histamine H1 receptor inverse agonists. Binding studies revealed that histamine H1 and H2 receptors cointernalize after stimulus with histamine receptor inverse agonists. In addition, the inhibition of the internalization process prevents receptor crossregulation. Our study provides new insights in the mechanisms of action of histamine H1 and H2 receptors that explain the effect of histamine H1 and H2 receptor inverse agonists and opens up new venues for novel therapeutic applications.Fil: Díaz, Antonela Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Zappia, Carlos Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Farmacológicas. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Investigaciones Farmacológicas; ArgentinaFil: Rodriguez Gonzalez, Angela Paola. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Sahores, Ana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Farmacológicas. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Investigaciones Farmacológicas; ArgentinaFil: Sosa, Máximo Hernán. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Farmacológicas. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Investigaciones Farmacológicas; ArgentinaFil: Burghi, Valeria. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Farmacológicas. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Investigaciones Farmacológicas; ArgentinaFil: Monczor, Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Farmacológicas. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Investigaciones Farmacológicas; ArgentinaFil: Davio, Carlos Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Farmacológicas. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Investigaciones Farmacológicas; ArgentinaFil: Fernandez, Natalia Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Farmacológicas. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Investigaciones Farmacológicas; ArgentinaFil: Shayo, Carina Claudia. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; Argentin

    The Children’s Faecal Matter Structure Is Built by Their Parents

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    Introduction: Humans have gone through physical changes over the last 4 million years. The mouth, however, has not changed teeth quantity or quality. Eight incisors for fruits, vegetables and tubers; four little canines for little animals; eight premolars and twelve flat molars are used for crushing these foods, especially whole grains and legumes. The teeth crushing foods are the first step in the building of faecal matter. Foods are selected mostly according to cultural guidelines than to biological needs. The patterns of consumption are induced by the publicity of industrialized or processed foods. Material and Methods: This study design was observational, analytical, correlational, transversal and prospective. One thousand children (0 - 12 years old) were questioned in order to learn about the relationship between Weekly Eating Frequency (WEF) and Faecal Matter (FM) characteristics. The FM was classified as soft , normal or hard and the outcome was expressed as Dry Faecal Residue (DFR). The WEF and Weekly Bowel Movement Frequency (WBMF) were determined and tabulated according to times per week. Environmental factors, parents’ education level and children’s birth order were examined. Results: There was a strong association between DFR, WBMF and WEF. Environment and education level did not play a key role although birth order did matter. Conclusions: Fibre-free foods (dairies, meats, flours and sweeties or sodas) increased DFR. Foods containing fibre from vegetables decreased DFR, which in turn contributed to the WBMF. Lowest DFR was observed in children under Exclusive Breastfeeding (EB). Distant last-born children had higher DFR. Comments: Daily examples support these results and it is clear that children’s FM is built by their parents. We encourage parents to follow the “mouth nature” rather than the “advertisements nature”.Facultad de Ciencias Médicas (FCM
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