Adaptive planning in human search

How do people plan ahead when searching for rewards? We investigate planning in a foraging task in which participants search for rewards on an infinite two-dimensional grid. Our results show that their search is best-described by a model which searches at least 3 steps ahead. Furthermore, participants do not seem to update their beliefs during planning, but rather treat their initial beliefs as given, a strategy similar to a heuristic called root-sampling. This planning algorithm corresponds well with participants’ behavior in test problems with restricted movement and varying degrees of information, outperforming more complex models. These results enrich our understanding of adaptive planning in complex environments

Simple model for a quantum wire III. Transmission of finite samples with correlated disorder

The effect of a continuous model of correlations upon one-dimensional finite disordered quantum wires modeled by an array of delta-potentials, is analyzed. Although the model proposed is not able to include new truly extended states in the spectrum, the transport properties of a finite sample are noticeably improved due to the existence of states whose localization length is larger than the system size. This enhancement of transmission is maximized for relatively short chains.Comment: 6 pages, 18 figure

Molecular symmetry-constrained systematic search approach to structure solution of the coiled-coil SRGAP2 F-BARx domain.

This is the final version of the article. Available from International Union of Crystallography via the DOI in this record.SRGAP2 (Slit-Robo GTPase-activating protein 2) is a cytoplasmic protein found to be involved in neuronal branching, restriction of neuronal migration and restriction of the length and density of dendritic postsynaptic spines. The extended F-BAR (F-BARx) domain of SRGAP2 generates membrane protrusions when expressed in COS-7 cells, while most F-BARs induce the opposite effect: membrane invaginations. As a first step to understand this discrepancy, the F-BARx domain of SRGAP2 was isolated and crystallized after co-expression with the carboxy domains of the protein. Diffraction data were collected from two significantly non-isomorphous crystals in the same monoclinic C2 space group. A correct molecular-replacment solution was obtained by applying a molecular symmetry-constrained systematic search approach that took advantage of the conserved biological symmetry of the F-BAR domains. It is shown that similar approaches can solve other F-BAR structures that were previously determined by experimental phasing. Diffraction data were reprocessed with a high-resolution cutoff of 2.2 Å, chosen using less strict statistical criteria. This has improved the outcome of multi-crystal averaging and other density-modification procedures.This work was supported by funds from the ISF (Grant No. 1425/15 to YO) and BSF (Grant No. 2013310 to YO)

A Bio-Logical Theory of Animal Learning

This article provides the foundation for a new predictive theory of animal learning that is based upon a simple logical model. The knowledge of experimental subjects at a given time is described using logical equations. These logical equations are then used to predict a subject’s response when presented with a known or a previously unknown situation. This new theory suc- cessfully anticipates phenomena that existing theories predict, as well as phenomena that they cannot. It provides a theoretical account for phenomena that are beyond the domain of existing models, such as extinction and the detection of novelty, from which “external inhibition” can be explained. Examples of the methods applied to make predictions are given using previously published results. The present theory proposes a new way to envision the minimal functions of the nervous system, and provides possible new insights into the way that brains ultimately create and use knowledge about the world

Identification of e-young chronics through questionnaire

Background and Aims: Transforming the doctor-patient re lationship from analog to digital is no simple task and requires a great deal of courage and visionary leadership. The first step to do so is to identify the digital capabilities that the ultimate re cipient of every health system possesses: the patient. Methods: A scale questionnaire of 5 questions related to digital applications is carried out to patients under follow-up for type 1 diabetes mellitus, between 18?65 years old, who are prescribed the Abbott Freestyle Libre flash glucose monitoring device, which requires their connection to a mobile application (Libreview) by the user, for optimal use and communication of data with the healthcare professional electronically. Results: 62 patients were included.In the classification by predefined subgroups according to the questionnaire score, 35 patients (56.45%) were identified as having advanced training; 16 (25.81%) of basic training and 11 (17.74%) without digital training. 82.86% (29/35) of the patients predefined as highly qualified used the system adequately, compared to 43.75% (7/16) of those with low training and 0% (0/11) of patients without technological capabilities; p < 0.001. Conclusions: The coronavirus-19 pandemic has subjected our health services to a stress test like never before. In the current remote care scenario, we are presented with an opportunity (the great opportunity) to serve people immersed in the digital age. It would be bad news if after this pandemic, we returned to the starting box, the identification of those e-young and e-senior chronics patients is the first essential step to avoid it. Comunicaci?n-p?ster presentada en: ATTD Advanced Technologies & Treatments for Diabetes Conference Online del 2 al 5 june 2021

Psychiatric comorbidities in Asperger syndrome are related with polygenic overlap and differ from other Autism subtypes

There is great phenotypic heterogeneity within autism spectrum disorders (ASD), which has led to question their classification into a single diagnostic category. The study of the common genetic variation in ASD has suggested a greater contribution of other psychiatric conditions in Asperger syndrome (AS) than in the rest of the DSM-IV ASD subtypes (Non_AS). Here, using available genetic data from previously performed genome-wide association studies (GWAS), we aimed to study the genetic overlap between five of the most related disorders (schizophrenia (SCZ), major depression disorder (MDD), attention deficit hyperactivity disorder (ADHD), obsessive-compulsive disorders (OCD) and anxiety (ANX)), and AS, comparing it with the overlap in Non_AS subtypes. A Spanish cohort of autism trios (N = 371) was exome sequenced as part of the Autism Sequencing Consortium (ASC) and 241 trios were extensively characterized to be diagnosed with AS following DSM-IV and Gillberg's criteria (N = 39) or not (N = 202). Following exome imputation, polygenic risk scores (PRS) were calculated for ASD, SCZ, ADHD, MDD, ANX, and OCD (from available summary data from Psychiatric Genomic Consortium (PGC) repository) in the Spanish trios' cohort. By using polygenic transmission disequilibrium test (pTDT), we reported that risk for SCZ (Pscz = 0.008, corrected-PSCZ = 0.0409), ADHD (PADHD = 0.021, corrected-PADHD = 0.0301), and MDD (PMDD = 0.039, corrected-PMDD = 0.0501) is over-transmitted to children with AS but not to Non_AS. Indeed, agnostic clustering procedure with deviation values from pTDT tests suggested two differentiated clusters of subjects, one of which is significantly enriched in AS (P = 0.025). Subsequent analysis with S-Predixcan, a recently developed software to predict gene expression from genotype data, revealed a clear pattern of correlation between cortical gene expression in ADHD and AS (P < 0.001) and a similar strong correlation pattern between MDD and AS, but also extendable to another non-brain tissue such as lung (P < 0.001). Altogether, these results support the idea of AS being qualitatively distinct from Non_AS autism and consistently evidence the genetic overlap between AS and ADHD, MDD, or SCZ

The historical vanishing of the Blazhko effect of RR Lyr from GEOS and Kepler surveys

RR Lyr is one of the most studied variable stars. Its light curve has been regularly monitored since the discovery of the periodic variability in 1899. Analysis of all observed maxima allows us to identify two primary pulsation states defined as pulsation over a long (P0 longer than 0.56684 d) and a short (P0 shorter than 0.56682 d) primary pulsation period. These states alternate with intervals of 13-16 yr, and are well defined after 1943. The 40.8 d periodical modulations of the amplitude and the period (i.e. Blazhko effect) were noticed in 1916. We provide homogeneous determinations of the Blazhko period in the different primary pulsation states. The Blazhko period does not follow the variations of P0 and suddenly diminished from 40.8 d to around 39.0 d in 1975. The monitoring of these periodicities deserved and deserves a continuous and intensive observational effort. For this purpose we have built dedicated, transportable and autonomous small instruments, Very Tiny Telescopes (VTTs), to observe the times of maximum brightness of RR Lyr. As immediate results the VTTs recorded the last change of P0 state in mid-2009 and extended the time coverage of the Kepler observations, thus recording a maximum O-C amplitude of the Blazhko effect at the end of 2008, followed by the historically smallest O-C amplitude in late 2013. This decrease is still ongoing and VTT instruments are ready to monitor the expected increase in the next few years.Comment: 10 pages, 6 figures. Accepted for publication in MNRAS. Contents of appendix B may be requested to first autho

Temperature but not leptin prevents semi-starvation induced hyperactivity in rats: implications for anorexia nervosa treatment

The hypothesis linking hyperactivity with weight loss associated hypoleptinemia in anorexia nervosa gained momentum after a study showing that leptin suppressed semi-starvation induced hyperactivity in rats. Alternatively, ambient temperature is a key modulating factor of activity in semi-starved rats. The aim of the study is to compare the efficacy of leptin with increased ambient temperature in the prevention of hyperactivity in semi-starved rats. 74 Sprague-Dawley male rats were employed in two experiments with the difference residing in the length of baseline. After an extended (28 days), or shorter (14 days) baseline with free access to food and the running wheel, housed at 21 degrees C, animals were either ad-lib feed or food restricted (60% of food ingested during previous week) and infused with same amount of leptin at 21 degrees C, 25 degrees C, or vehicle at 21 degrees C, 25 degrees C and 32 degrees C for a week. Animals housed at 32 degrees C significantly reduced wheel running and weight loss during food restriction while animals given leptin did not yield no differences in activity or weight loss. Moreover, unlike animals housed at 32 degrees C, body temperature of leptin infused animals housed at 21 degrees C was significantly reduced during food restriction. Furthermore, leptin treated rats without a preceding stable pattern of activity displayed a severe dysregulation of circadian rhythm in activity and a collapse of body temperature. Housing temperature plays a more critical role than leptin in the regulation of semi-starvation induced hyperactivity in rats, which may be of relevance for the management of hyperactivity in anorexia nervosa

Probing the near infrared stellar population of Seyfert galaxies

We employ IRTF SpeX NIR (0.8-2.4 microns) spectra to investigate the stellar population (SP), active galactic nuclei (AGN) featureless continuum (FC) and hot dust properties in 9 Sy 1 and 15 Sy 2 galaxies. Both the starlight code and the hot dust as an additional base element were used for the first time in this spectral range. We found evidence of correlation among the equivalent widths (W) Si I 1.59 microns x Mg I 1.58 microns, equally for both kinds of activity. Part of the W{Na I 2.21 microns} and W {CO 2.3 microns} strengths may be related to galaxy inclination. Our synthesis shows significant differences between Sy 1 and Sy 2 galaxies: the hot dust component is required to fit the K-band spectra of ~90% of the Sy 1 galaxies, and only of ~25% of the Sy 2; about 50 % of the Sy 2 galaxies require a $FC$ component contribution >20%, while this fraction increases to 60% in the Sy 1; also, in about 50 % of the Sy2, the combined FC and young components contribute with more than 20%, while this occurs in 90% of the Sy1, suggesting recent star formation in the central region. The central few hundred parsecs of our galaxy sample contain a substantial fraction of intermediate-age SPs with a mean metallicity near solar. Our SP synthesis confirms that the 1.1 micron CN band can be used as a tracer of intermediate-age SPs. The simultaneous fitting of SP, FC and hot dust components increased in ~150% the number of AGNs with hot dust detected and the mass estimated. The NIR emerges as an excellent window to study the stellar population of Sy 1 galaxies, as opposed to the usually heavily attenuated optical range. Our approach opens a new way to investigate and quantify the individual contribution of the three most important NIR continuum components observed in AGNs.Comment: The paper contains 14 figures and 5 tables. Accepted for publication in MNRA

Kesterite thin films of Cu2ZnSnS4 obtained by spray pyrolysis

Thin films of Cu2ZnSnS4 CZTS were deposited using the spray pyrolysis method as relatively fast and vacuum free method. Obtained samples were analyzed using the X Ray Fluorescence, grazing incidence X Ray Diffraction and Raman Spectroscopy techniques. Analysis showed close to stoichiometry composition of the films with kesterite type structure but poor crystalline quality and possible existence of secondary phases. To improve the quality of the films, the as prepared layers were annealed in the presence of elemental Sn and S. Comparison of the results before and after annealing showed a strong improvement of the crystalline quality and a significant reduction of concentration of secondary phases of the films without significant change of composition. The measured optical band gap is equal to 1.52 and 1.55 eV in the as prepared and annealed films, respectively. The optical absorption coefficient is found to be gt; 10 4 cm