660 research outputs found

    Hydrocarbon generation in relation to thrusting in the sub Andean zone from 18 to 22°S, Bolivia

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    Formation of the Bolivian eastern cordillera started at the end of the Oligocene and continues to the present day with thrusting affecting the Sub Andean Zone since late Miocene. The "classical" source rock is the Devonian, but the Silurian interval has some potential. Their initial original potential is not high but they are thick (700 m, Los Monos Fm) and may be thicker still due to stacking in thrust duplexes. The three phases of sedimentation during the Tertiary each start with conglomeratic deposits and are discordant over the previous one. Seismic data allow us to correlate these steps with three periods of tectonic accretion : Late Miocene (Tariquia Fm), Pliocene (Guandacay Fm) and Plio-Quaternary (Emborozu Fm). Modelling demonstrates two phases of hydrocarbon generation. A first phase from Devonian to Carboniferous is due to the deepening of the Palaeozoic basin. The second phase of maturation is due to the Tertiary deposits in the foreland and under the piggyback basins. The central aera (Santa Cruz) has never been more deeply buried than during the Palaeozoic and has been a high during the Tertiary. (Résumé d'auteur

    Gas Blowing Ultrasonic Aluminium Degassing Assessment with the Reduced Pressure Test (RPT) Method

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    Entrapped gases, solidification shrinkage and non-metallic compound formation are main sources of porosity in aluminium alloy castings. Porosity is detrimental to the mechanical properties of these castings; therefore, its reduction is pursued. Rotary degassing is the method mostly employed in industry to remove dissolved gases from aluminium melts, reducing porosity formation during solidification of the cast part. Recently, ultrasonic degassing has emerged as a promising alternative thanks to a lower dross formation and higher energy efficiency. This work aims to evaluate the efficiency of the ultrasonic degasser and compare it to a conventional rotary degassing technique applied to an AlSi10Mg alloy. Degassing efficiency was evaluated employing the reduced pressure test (RPT), where samples solidified under reduced pressure conditions are analysed. Factors affecting RPT were considered and temperature parameters for the test were established. The influence of ultrasonic degassing process parameters, such as degassing treatment duration and purging gas flow rate were studied, as well as treated aluminium volume and oxide content. Finally, ultrasonic degassing process was contrasted to a conventional rotary degassing technique, comparing their efficiency.This work has been done within the AL-STRUC project supported by the ELKARTEK program of the Basque Government under Grant KK-2017/00020

    Hallazgos neurorradiológicos de la Acidosis Glutárica tipo I

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    Glutaric aciduria type I is a rare disorder of organic acid metabolism caused by deficiency of glutaryl-CoA dehydrogenase, a mitochondrial enzyme. Improper degeneration of amino acids: tryptophan, lysine, and hydroxylysine, results in increased levels of glutaric acid, which typically becomes clinically manifest as an acute dystonic crisis in young children. Accumulation of glutaric acid causes neurotoxicity in the basal ganglia and fronto-temporal cortex which can lead to progressive dystonia, hypotonia, permanently impaired speech and seizures. Because dietary and drug therapy may alter the natural history of the disease, early diagnosis of such patients is critical. We report the magnetic resonance (MR) imaging findings in a 16 year-old girl with this disorder who presented with a chronic dystonic syndrome and previously diagnosed of brain paralysis. MR imaging demonstrated bilateral involvement of the putamina and periventricular white matter, and bilateral temporal atrophy and widened Silvian fissure

    Piii‐37

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/109838/1/cptclpt2006257.pd

    Functional bold MRI: advantages of the 3 T vs. the 1.5 T

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    We quantitatively evaluate the benefits of a higher field strength for functional brain MRI (fMRI) based on the blood oxygenation level-dependent contrast. The 3-T fMRI shows a higher sensitivity for the motor and somatosensory stimulation and more specific localization in the grey substance. The 3-T fMRI detects additional areas of activation with the motor paradigm

    Revisiting the difference between instrumental and terminal values to predict (stimulating) prosocial behaviours: the transcendental‐change profile

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    Past research suggests that the connection between values and people's behaviour may not be as straightforward and robust as has been claimed. We propose that a more holistic and discriminative view that acknowledges the influence of a specific combination of values on specific kinds of behaviour is needed. In the current project, we test two hypotheses regarding the transcendental-change profile (TCP). First, that TCP is characterized by a combination of the readiness to engage in those challenges (instrumental) that can make the world a better place (terminal). Second, the centrality of the TCP facilitates performance of those prosocial actions that are perceived as stimulating and global. The results of five studies support the reliability and validity of this conceptualization of TCP (Studies 1 and 2), and show that when the prosocial initiative is perceived as either global (Study 3) or stimulating (Studies 4 and 5), the TCP is the strongest predictor of the willingness and commitment to engage in such prosocial action.info:eu-repo/semantics/acceptedVersio

    MicroRNA-135a regulates NHE9 to inhibit proliferation and migration of glioblastoma cells

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    Abstract Background Glioblastoma multiformae (GBM) is the most aggressive type of malignant brain tumor with complex molecular profile. Overexpression of Na+/H+ Exchanger isoform 9 (NHE9) promotes tumor progression and correlates positively with insensitivity to radiochemotherapy and poor prognosis. However, molecular mechanisms responsible for increase in NHE9 levels beyond a critical threshold have not been identified. Methods Bioinformatics analysis, luciferase reporter assays, real-time PCR and western blotting were conducted to examine the expression profiles and identify microRNAs (miRNA) that target NHE9. Cell proliferation and migration assays were conducted in U87 glioblastoma cells to determine the consequence of miRNA mediated targeting of NHE9. Endosomal pH measurements, immunofluorescence microscopy and surface biotinylation experiments were conducted to characterize the mechanistic basis of regulation. Results We show that microRNA 135a (miR-135a) targets NHE9 to downregulate its expression in U87 cells. MiR-135a levels are significantly lower in glioblastoma cells compared to normal brain tissue. Downregulation of NHE9 expression by miR-135a affects proliferative and migratory capacity of U87 cells. Selectively increasing NHE9 expression in these cells restored their ability to proliferate and migrate. We demonstrate that miR-135a takes a two-pronged approach affecting epidermal growth factor receptors (EGFRs) to suppress tumor cell growth and migration. EGFR activity is a potent stimulator of oncogenic signaling. While miR-135a targets EGFR transcripts to decrease the total number of receptors made, by targeting NHE9 it routes the few EGFRs made away from the plasma membrane to dampen oncogenic signaling. NHE9 is localized to sorting endosomes in glioblastoma cells where it alkalinizes the endosome lumen by leaking protons. Downregulation of NHE9 expression by miR-135a acidifies sorting endosomes limiting EGFR trafficking to the glioblastoma cell membrane. Conclusions We propose downregulation of miR-135a as a potential mechanism underlying the high NHE9 expression observed in subset of glioblastomas. Future studies should explore miR-135a as a potential therapeutic for glioblastomas with NHE9 overexpression.https://deepblue.lib.umich.edu/bitstream/2027.42/140393/1/12964_2017_Article_209.pd

    Domainâ specific impairment in cognitive control among remitted youth with a history of major depression

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    AimImpairment in neuropsychological functioning is common in major depressive disorder (MDD), but it is not clear to what degree these deficits are related to risk (e.g. trait), scar, burden or state effects of MDD. The objective of this study was to use neuropsychological measures, with factor scores in verbal fluency, processing speed, attention, setâ shifting and cognitive control in a unique population of young, remitted, unmedicated, early course individuals with a history of MDD in hopes of identifying putative trait markers of MDD.MethodsYouth aged 18â 23 in remission from MDD (rMDD; n = 62) and healthy controls (HC; n = 43) were assessed with neuropsychological tests at two time points. These were from four domains of executive functioning, consistent with previous literature as impaired in MDD: verbal fluency and processing speed, conceptual reasoning and setâ shifting, processing speed with interference resolution, and cognitive control.ResultsrMDD youth performed comparably to HCs on verbal fluency and processing speed, processing speed with interference resolution, and conceptual reasoning and setâ shifting, reliably over time. Individuals with rMDD demonstrated relative decrements in cognitive control at Time 1, with greater stability than HC participants.ConclusionMDD may be characterized by regulatory difficulties that do not pertain specifically to active mood state or fluctuations in symptoms. Deficient cognitive control may represent a trait vulnerability or early course scar of MDD that may prove a viable target for secondary prevention or early remediation.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/138407/1/eip12253_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/138407/2/eip12253.pd

    A prion-like domain in ELF3 functions as a thermosensor in Arabidopsis.

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    Temperature controls plant growth and development, and climate change has already altered the phenology of wild plants and crops1. However, the mechanisms by which plants sense temperature are not well understood. The evening complex is a major signalling hub and a core component of the plant circadian clock2,3. The evening complex acts as a temperature-responsive transcriptional repressor, providing rhythmicity and temperature responsiveness to growth through unknown mechanisms2,4-6. The evening complex consists of EARLY FLOWERING 3 (ELF3)4,7, a large scaffold protein and key component of temperature sensing; ELF4, a small α-helical protein; and LUX ARRYTHMO (LUX), a DNA-binding protein required to recruit the evening complex to transcriptional targets. ELF3 contains a polyglutamine (polyQ) repeat8-10, embedded within a predicted prion domain (PrD). Here we find that the length of the polyQ repeat correlates with thermal responsiveness. We show that ELF3 proteins in plants from hotter climates, with no detectable PrD, are active at high temperatures, and lack thermal responsiveness. The temperature sensitivity of ELF3 is also modulated by the levels of ELF4, indicating that ELF4 can stabilize the function of ELF3. In both Arabidopsis and a heterologous system, ELF3 fused with green fluorescent protein forms speckles within minutes in response to higher temperatures, in a PrD-dependent manner. A purified fragment encompassing the ELF3 PrD reversibly forms liquid droplets in response to increasing temperatures in vitro, indicating that these properties reflect a direct biophysical response conferred by the PrD. The ability of temperature to rapidly shift ELF3 between active and inactive states via phase transition represents a previously unknown thermosensory mechanism
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