Tuning Magnetic Avalanches in Mn12-ac

Using micron-sized Hall sensor arrays to obtain time-resolved measurements of the local magnetization, we report a systematic study in the molecular magnet Mn$_{12}$-acetate of magnetic avalanches controllably triggered in different fixed external magnetic fields and for different values of the initial magnetization. The speeds of propagation of the spin-reversal fronts are in good overall agreement with the theory of magnetic deflagration of Garanin and Chudnovsky \cite{Garanin}.Comment: 8 pages, 7 figures; discussion expanded and revise

Impacts of projected maximum temperature extremes for C21 by an ensemble of regional climate models on cereal cropping systems in the Iberian Peninsula

Crops growing in the Iberian Peninsula may be subjected to damagingly high temperatures during the sensitive development periods of flowering and grain filling. Such episodes are considered important hazards and farmers may take insurance to offset their impact. Increases in value and frequency of maximum temperature have been observed in the Iberian Peninsula during the 20th century, and studies on climate change indicate the possibility of further increase by the end of the 21st century. Here, impacts of current and future high temperatures on cereal cropping systems of the Iberian Peninsula are evaluated, focusing on vulnerable development periods of winter and summer crops. Climate change scenarios obtained from an ensemble of ten Regional Climate Models (multimodel ensemble) combined with crop simulation models were used for this purpose and related uncertainty was estimated. Results reveal that higher extremes of maximum temperature represent a threat to summer-grown but not to winter-grown crops in the Iberian Peninsula. The study highlights the different vulnerability of crops in the two growing seasons and the need to account for changes in extreme temperatures in developing adaptations in cereal cropping systems. Finally, this work contributes to clarifying the causes of high-uncertainty impact projections from previous studies

Numerical study of VIV over a flexible riser

This study is based on the simulation of the fluid-structure interaction on risers. We aim to quantify the structural response of these long flexible pipes, used for the extraction of offshore petroleum when they are subjected to marine currents. Toe occurring phenomenon is known as VIV (Vortex induced VIbration). These problems are a relevant challenge for several offshore companies, which are associated with K-Epsilon in a Citeph project. Toe project's goal is to use the FSI simulation tool developed by K-Epsilon and initially used for the simulation offlexible membranes such as sails, to model these VIV phenomena. Toe problem of VIV in the case of a riser is a strongly coupled problem, meaning that the added mass is not negligible compared to the mass of the structure. This can be challenging for most fluid-structure interaction software. A strongly coupled algorithm is presented [6]. First, numerical results of fluid around cylinders are presented and compared to experimental results ([l], [10]) with several turbulence models, and time step sizes. Toen, Chaplin's benchmark is presented with experimental / numerical comparison [3]

Efficacy of Neurofeedback on the Increase of Mindfulness-Related Capacities in Healthy Individuals: a Controlled Trial

Electroencephalogram (EEG) studies of mindfulness have shown it can lead to increases in alpha power, which are similar to those obtained by alpha-based neurofeedback (NF) interventions. It has been hypothesized there may be relationships between mindfulness and NF in terms of the neural pathways through which they induce salutary outcomes. The aim of the study was to evaluate possible changes in mindfulness and cognitive functioning following an alpha-based NF intervention, and the role of alpha power as a mediator of improvements. A controlled, non-randomized, trial with 50 healthy participants was conducted with two experimental conditions: a six-session NF intervention and a waiting-list control group. Both groups were administered mindfulness questionnaires (Mindful Attention Awareness Scale (MAAS), Five Facet Mindfulness Questionnaire (FFMQ)) and cognitive measures (Paced Auditory Serial Addition Task (PASAT)), at pre- and post-test. The NF intervention focused on the up-regulation of upper alpha power. Differences among groups were estimated using ANCOVAs, and mediation assessment through path analyses. Compared to controls, the NF group showed enhanced task-related upper alpha power (effect size (ES) = 1.16, p < 0.001), mindfulness outcomes (MAAS: ES = 0.94, p = 0.004; FFMQ: ES = 1.38, p < 0.001), and a trend of cognitive functioning (PASAT time: ES = 0.59, p = 0.062). Upper alpha power had a mediating effect for cognitive functioning (PASAT errors: indirect effect = 0.81, 95% CI = 0.21–1.85), but not for mindfulness. These results demonstrate the effectiveness of NF for increasing mindfulness in healthy individuals with no previous experience in mindfulness or neurofeedback training, suggesting that NF may be an acceptable method of augmenting mindfulness-related capacities in the general population

Cholesterol 24S-Hydroxylase overexpression inhibits the liver X receptor (LXR) pathway by activating small guanosine triphosphate-binding proteins (sGTPases) in neuronal cells

The neuronal-specific cholesterol 24S-hydroxylase (CYP46A1) is important for brain cholesterol elimination. Cyp46a1 null mice exhibit severe deficiencies in learning and hippocampal long-term potentiation, suggested to be caused by a decrease in isoprenoid intermediates of the mevalonate pathway. Conversely, transgenic mice overexpressing CYP46A1 show an improved cognitive function. These results raised the question of whether CYP46A1 expression can modulate the activity of proteins that are crucial for neuronal function, namely of isoprenylated small guanosine triphosphate-binding proteins (sGTPases). Our results show that CYP46A1 overexpression in SH-SY5Y neuroblastoma cells and in primary cultures of rat cortical neurons leads to an increase in 3-hydroxy-3-methyl-glutaryl-CoA reductase activity and to an overall increase in membrane levels of RhoA, Rac1, Cdc42 and Rab8. This increase is accompanied by a specific increase in RhoA activation. Interestingly, treatment with lovastatin or a geranylgeranyltransferase-I inhibitor abolished the CYP46A1 effect. The CYP46A1-mediated increase in sGTPases membrane abundance was confirmed in vivo, in membrane fractions obtained from transgenic mice overexpressing this enzyme. Moreover, CYP46A1 overexpression leads to a decrease in the liver X receptor (LXR) transcriptional activity and in the mRNA levels of ATP-binding cassette transporter 1, sub-family A, member 1 and apolipoprotein E. This effect was abolished by inhibition of prenylation or by co-transfection of a RhoA dominant-negative mutant. Our results suggest a novel regulatory axis in neurons; under conditions of membrane cholesterol reduction by increased CYP46A1 expression, neurons increase isoprenoid synthesis and sGTPase prenylation. This leads to a reduction in LXR activity, and consequently to a decrease in the expression of LXR target genes

Art and communication technologies: the inclusive theater in San Carlos de Bariloche. A study based on audiovisual records UNRN and Cre-Arte

Fil: Fil. Gonzalez Minguez, María C. Universidad Nacional de Río Negro. Sede Andina; Argentina.Fil: Gonzalez Minguez, María C. Instituto de Formación Docente de Bariloche; Argentina.Fil: Gonzalez Minguez, María C. Centro cultural y educativo para personas con discapacidad (Cre-arte); Argentina.Fil: Scarnichia, Muriel E. Universidad Nacional de Río Negro. Centro de Producción de Contenidos Audiovisuales (CPCA); Argentina.Fil: Saccomano, Matías P. Universidad Nacional de Río Negro. Centro de Producción de Contenidos Audiovisuales (CPCA); Argentina.This paper is based on the incorporation of the use of digital audiovisual record and communication technologies as a tool for the study and analysis of the theatrical creative process. It recovers the creative experience of the cast of Inclusive Theater conformed by actors and actresses of Cre-Arte (educational and cultural center for people with disabilities) and students of Dramatic Art of the National University of Río Negro (UNRN) and the audiovisual development carried out by the Audiovisual Content Production Center (CPCA) of UNRN in Bariloche, Río Negro, Argentina, between 2014 and 2019.Este trabajo se basa en la incorporación del uso del registro audiovisual digital y las tecnologías de la comunicación como herramienta para el estudio y análisis del proceso creativo teatral. Recupera la experiencia creativa del elenco de Teatro Inclusivo conformado por actores y actrices de Cre-Arte (centro educativo y cultural para personas con discapacidad) y estudiantes de Arte Dramático de la Universidad Nacional de Río Negro (UNRN) y el desarrollo audiovisual realizado por el Centro de Producción de Contenidos Audiovisuales (CPCA) de UNRN en Bariloche, Río Negro, Argentina, entre los años 2014 y 2019

Insulin levels are decreased in the cerebrospinal fluid of women with prodomal Alzheimer's disease

Previous studies have failed to reach consensus on insulin levels in cerebrospinal fluid of Alzheimer's disease (AD) patients and on its relation to pathological features. We performed a new analysis in patients at different stages of AD, and investigated the relationship of insulin levels with biochemical disease markers and with cognitive score. We included 99 patients from our Memory Clinic (Karolinska University Hospital, Sweden), including: 27 patients with mild AD, 13 that progressed from mild cognitive impairment (MCI) to AD in two years time, 26 with MCI stable after two years, and 33 with subjective cognitive impairment. Insulin was significantly decreased in the cerebrospinal fluid of both women and men with mild AD. Insulin deficits were seen in women belonging to both MCI groups, suggesting that this occurs earlier than in men. Insulin was positively associated with amyloid-β 1-42 (Aβ1-42) levels and cognitive score. Furthermore, total-tau/(Aβ1-42*insulin) ratio showed strikingly better sensitivity and specificity than the total-tau/Aβ1-42 ratio for early AD diagnosis in women

Changes in food characteristics reveal indirect effects of lake browning on zooplankton performance

Browning caused by colored dissolved organic matter is predicted to have large effects on aquatic ecosystems. However, there is limited experimental evidence about direct and indirect effects of browning on zooplankton in complex field settings. We used a combination of an ecosystem‐scale enclosure experiment and laboratory incubations to test how prolonged browning affects physiological and life‐history traits of the water flea Daphnia longispina, a key species in lake food webs, and whether any such effects are reversible. Daphnids and water were collected from enclosures in a deep clear‐water lake, where the natural plankton community had been exposed for 10 weeks to browning or to control conditions in clear water. Daphnid abundance was much lower in the brown than in the clear enclosure. Surprisingly, however, daphnids continuously kept in brown enclosure water in the laboratory showed increased metabolic performance and survival, and also produced more offspring than daphnids kept in clear enclosure water. This outcome was related to more and higher‐quality seston in brown compared to clear water. Moreover, daphnids transferred from clear to brown water or vice versa adjusted their nucleic acid and protein contents, as indicators of physiological state, to similar levels as individuals previously exposed to the respective recipient environment, indicating immediate and reversible browning effects on metabolic performance. These results demonstrate the importance of conducting experiments in settings that capture both indirect effects (i.e., emerging from species interactions in communities) and direct effects on individuals for assessing impacts of browning and other environmental changes on lakes.BMBF, 033L041B, Verbundprojekt: NITROLIMIT - Stickstofflimitation in Binnengewässern - ist Stickstoffreduktion ökologisch sinnvoll und wirtschaftlich vertretbar? Teilprojekt: Verfügbarkeit von gelösten organischen N-Verbindungen, Produktion von Lachgas und StickstoffeinträgeEC/FP7/603378/EU/Managing Aquatic ecosystems and water Resources under multiple Stress/MAR